CN100565638C - The driving method of self-luminous display device, display control unit and current output type drive circuit thereof - Google Patents

The driving method of self-luminous display device, display control unit and current output type drive circuit thereof Download PDF

Info

Publication number
CN100565638C
CN100565638C CNB2004800352448A CN200480035244A CN100565638C CN 100565638 C CN100565638 C CN 100565638C CN B2004800352448 A CNB2004800352448 A CN B2004800352448A CN 200480035244 A CN200480035244 A CN 200480035244A CN 100565638 C CN100565638 C CN 100565638C
Authority
CN
China
Prior art keywords
current
gray scale
voltage
electric current
output
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CNB2004800352448A
Other languages
Chinese (zh)
Other versions
CN1886772A (en
Inventor
柘植仁志
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Japan Display Central Inc
Japan Display Inc
Original Assignee
Toshiba Matsushita Display Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Matsushita Display Technology Co Ltd filed Critical Toshiba Matsushita Display Technology Co Ltd
Publication of CN1886772A publication Critical patent/CN1886772A/en
Application granted granted Critical
Publication of CN100565638C publication Critical patent/CN100565638C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Control Of El Displays (AREA)

Abstract

In common self-luminous display device, there is the disadvantage that shows with the gray scale that is lower than the regulation gray scale when low gray scale shows that transferring to high gray scale shows sometimes.The driving method of self-luminous display device of the present invention comprises following steps: during the 1st, described each image element circuit is applied the step of the gray scale electric current that meets display gray scale; Follow-up during the 1st the 2nd during, self-emission device is applied demonstration electric current based on the gray scale electric current, the step of the described display gray scale that conforms to demonstration; And during the 3rd before during the 1st, the 1st condition according to the rules applies the step of pre-charge current to self-emission device.

Description

The driving method of self-luminous display device, display control unit and current output type drive circuit thereof
Technical field
The present invention relates to realize using the driving method of the self-luminous display device of the driving method of the display device of organic illuminating element such as organic electric-field light-emitting element for example, the display control unit of self-luminous display device, current output type drive circuit of self-luminous display device etc.This organic illuminating element is used for utilizing the magnitude of current to carry out display device driving that use, that carry out electric current output that gray scale shows with semiconductor circuit etc.
Background technology
Because organic illuminating element is self-emission device, thereby do not need the back-lighting that needs in the liquid crystal indicator, have advantages such as field angle is big, be hopeful as display device of future generation.
Fig. 4 illustrates the component structure cut-open view of general organic illuminating element.Organic layer 42 constituted by negative electrode 41 and anode 43 be clipped in the middle.If connect direct supply 44, then positive hole and electronics are injected into organic layer 42 from anode 43 and negative electrode 41 respectively.The electric field that power supply 44 forms makes the positive hole of injection and electronics move to opposed electrode in organic layer 42.Moving midway, electronics and positive hole recombination in organic layer 42 produce exciton.In the process of the energy deactivation of exciton, may observe is luminous.Luminous look, the energy that has because of exciton is different, is essentially the light of the wavelength of the corresponding energy of value with the band gap that has with organic layer 42.
For the light that will produce in the organic layer is fetched into the outside, at least one side of electrode uses in the visible region material transparent.For the ease of organic layer is injected electronics, negative electrode adopts the low material of work function.For example aluminium, magnesium, calcium etc.For permanance, further reduce work function, adopt their alloy, these materials of aluminium lithium alloy sometimes.
It is convenient to inject according to positive hole, and an anode adopts the big material of ionization potential energy.Because negative electrode does not have the transparency, the transparent material of the most employings of the electrode here.Indium oxide lead), gold, indium zinc oxide (IZO) etc. therefore, adopt ITO (Indium Tin Oxide: usually.
In recent years, use in the organic illuminating element of low molecular material,, sometimes organic layer 42 is constituted multilayer in order to improve luminescence efficiency.Therefore, each layer can share that charge carrier injects, charge carrier is to the lighting function of the light that moves, has desired wavelength of luminous zone, by respectively each layer being adopted the good material of efficient, can be made into the organic illuminating element with greater efficiency.
The organic illuminating element of Xing Chenging is shown in Fig. 5 (a) like this, and brightness is directly proportional to electric current; Shown in Fig. 5 (b), luminance against voltage is a nonlinear relationship.Therefore, when carrying out gray-scale Control, it is preferable to utilize current value to control.
Under the situation of active array type, these two kinds of voltage driving mode and current drives modes are arranged.
Voltage driving mode working voltage output type source electrode driver becomes electric current in pixel inside with voltage transformation, and with the current supply organic illuminating element after the conversion.
In this method, owing to utilize the transistor of each pixel setting to carry out voltage current transformation, output current produces deviation with this characteristics of transistor deviation, has the problem that uneven luminance takes place.
The current drives mode is used the current-output type source electrode driver, only has in the inner function that keeps the current value of one scan phase output of pixel, and organic illuminating element is supplied with the current value identical with source electrode driver.
Fig. 6 illustrates the example of current drives mode.The mode of Fig. 6 is used the current duplicator mode at image element circuit.
Circuit when Fig. 7 illustrates pixel 67 work of Fig. 6.
Shown in Fig. 7 (a), when selecting pixel, gate drivers 35 output signals make the signal line 61a of the row of this pixel allow switch form conducting state, and to make 61b be nonconducting state.Fig. 7 (a) illustrates the situation of image element circuit at this moment.At this moment, the electric current as circulation in the source signal line 60 of the electric current that is input to source electrode driver 36 circulates on the path shown in the dotted line 71.Therefore, the transistor 62 circulations electric current identical with the electric current that flows through source signal line 60.So the current potential of node 72 is the current potential that meets the current-voltage characteristic of transistor 62.
Then, when becoming nonselection mode, form the circuit shown in Fig. 7 (b) by signal line 61.Electric current flows to light-emitting component 63 by the path with 73 dotted lines of representing from EL power lead 64.This electric current depends on the current-voltage characteristic of the current potential and the transistor 62 of node 72.
Fig. 7 (a) and (b) in, the current potential of node 72 is constant.Therefore, Fig. 7 (a) and (b) in, the drain current of same transistor 62 circulations is identical.In view of the above, the identical electric current of current value that circulates in circulation numerical value and the source signal line 60 in the organic illuminating element 63.Even there is deviation in the current-voltage characteristic of transistor 62, on principle, do not influence the value of electric current 71 and 73 yet, can realize not being subjected to the even demonstration of transistor characteristic deviation effects.
Therefore, in order to obtain even demonstration, need to use the current drives mode, thereby source electrode driver 36 must be the driver IC (IC) of current-output type.
Figure 10 illustrates the example of the output stage of the current driver IC that exports the current value that meets gray scale.To display gray scale data 54, digital-analog conversion portion 106 carries out analog current output from 104.Gray scale that the ingredient of A/D conversion portion comprises a plurality of (being at least the figure place of gradation data 54) shows with current source 103 and switch 108 and stipulates that each gray scale shows the common gate polar curve 107 with the current value of current source 103 circulations.
Among Figure 10, to 3 inputs, 105 output analog currents.Be connected to electric current output 104 by the current source of being selected by switch 108 whether quantity to be met a weighting 103, can export the electric current that meets gray scale, for example during data 1, current source 103 is exported 1 share electric current, then exports the electric current of 7 shares during data 7.Meet 106 of driver output number by this being formed quantity in parallel, can realize the current-output type driver.For the temperature characterisitic of compensation transistor 103, by the voltage of minute adapted mirror transistor 102 decision common gate polar curves 107.Transistor 102 and current source group 103 constitute current mirror, determine the electric current of each gray scale according to the value of reference current 89.Utilize this composition, output current changes according to gray scale, and is determined the electric current of each gray scale by reference current.
Figure 21 to Figure 23 illustrates the example as the display device of an example of the electronic equipment of the present invention that uses organic illuminating element.Figure 21 illustrates the stereographic map of televisor, and (Figure 21 (a) and composition frame chart thereof (Figure 21 (b)), Figure 22 illustrate digital camera or digital recording video camera, Figure 23 illustrates portable information terminal.The organic illuminating element response speed is fast, thereby becomes the many suitable display boards (for example with reference to the patent disclosure 2001-147659 of Japan communique) of these display device of chance of show events image.
In the current driver shown in Figure 10, number in parallel is the identical transistor 103 of the scale of (number of greyscale levels-1), make with the number of exporting related transistor 103 to the input data variation, thereby carry out electric current output.Therefore, gray scale and output current form the relation of direct ratio.During with this electric current former state output,, can see whole turning white (low gray scale side is turned white) according to human vision property.In the drive unit of regular display, the output that adapts to each gray scale carried out gamma correction after, make its output.Under the situation of LCD, owing to be driven, need meet the magnitude of voltage (under voltage condition, can not addition shows according to the gray scale share as electric current, thereby each gray scale needs voltage) of each gray scale.Therefore, be adjusted into the magnitude of voltage that forms the voltage output that meets gamma correction in each grayscale voltage level, and exported, so even if 6 driver has also been made gamma correction, can abundant display gray scale.
On the other hand, in the current driver,,,, but require than 6 thin gray scales outputs in order to make the class interval of hanging down gray scale portion thin owing to do not make gamma correction even if be 6 equally.Take out with frame when deleting (FRC) and implementing this, bottom line also needs the frame between 4 frames to take out to delete, and the organic illuminating element response speed is fast sometimes, produces flicker.Therefore, need carry out thin gray scale performance, for example need to make 8 without FRC ground.
This problem be current driver that gray scale is directly proportional with output current and input current be directly proportional with brightness the combination of current-output type display element the time distinctive problem.
In order not make gamma correction based on FRC, can consider to constitute the output that makes current driver and be increased to 8 from 6, and before the source electrode driver input, carry out the gamma processing, 8 signals after gamma is handled are input to source electrode driver.
As with the output of current driver from 6 methods that extend to 8, the method for preparing 255 transistors 103 is arranged, but the method compares with method (63 transistors 103) in the past, the transistor 103 that needs are 4 times, the area of source electrode driver is also along with increase.The ratio that output stage transistor accounts for the entire chip area is about 7 one-tenth, thereby compares when only being 6, is about 3 times scale.Aspect cost, also influence big.
Summary of the invention
Therefore, the present invention considers above-mentioned problem, even its purpose is to provide the output figure place that increases current driver also the increase of circuit scale can be suppressed to less, current output type of semiconductor circuit, demonstration with drive unit, display device, current output method.
The 1st the present invention is a kind of driving method of self-luminous display device, and this display device has each image element circuit that is arranged in rectangular self-emission device and corresponding setting with each described self-emission device, and driving method comprises following steps:
During the 1st, described each image element circuit is applied the step of the gray scale electric current that meets display gray scale;
Follow-up during the described the 1st the 2nd during, described self-emission device is applied the step of the described display gray scale that conforms to demonstration based on the demonstration electric current of described gray scale electric current; And
During before during the described the 1st the 3rd, the 1st condition according to the rules applies the step of pre-charge current to described self-emission device.
The 2nd the present invention is the driving method of the 1st self-luminous display device of the present invention, wherein, can change during the described the 3rd corresponding to the display gray scale of authorizing the demonstration electric current that applies on the described self-emission device.
The 3rd the present invention is the driving method of the 1st self-luminous display device of the present invention, wherein, the pairing current value of display gray scale of the demonstration carried out of the described self-emission device in the next line of the pairing current value of display gray scale of the demonstration that the described self-emission device in the same regulation row that lists of described matrix is carried out and described regulation row compares;
As the 1st condition of described regulation, when the difference of these current values showed described next line under more than or equal to the situation of setting, the described self-emission device to described next line during the described the 3rd applied pre-charge current.
The 4th the present invention is the driving method of the 3rd self-luminous display device of the present invention, wherein, can change with the size of described difference during the described the 3rd.
The 5th the present invention is the driving method of the 1st or the 3rd self-luminous display device of the present invention, wherein, the pairing current value of display gray scale of the demonstration carried out of the described self-emission device in the next line of the pairing current value of display gray scale of the demonstration that the described self-emission device in the same regulation row that lists of described matrix is carried out and described regulation row compares;
As the 1st condition of described regulation, when the difference of these current values shows the described self-emission device of described next line under less than the situation of setting, do not apply described pre-charge current.
The 6th the present invention is the driving method of the 1st self-luminous display device of the present invention, wherein, as the 1st condition of described regulation, when under the situation of display gray scale for the current value corresponding of the demonstration that described self-emission device carries out, carrying out this demonstration, do not apply described pre-charge current with black demonstration.
The 7th the present invention is the driving method of the 1st self-luminous display device of the present invention, and wherein, the value of described pre-charge current is the current value that is equivalent to carry out white demonstration.
The 8th the present invention is the driving method of the 1st self-luminous display device of the present invention, wherein, from group during the corresponding with a plurality of pulse lengths of preparing driving circuit in advance the 3rd respectively, selects during the described the 3rd.
The 9th the present invention is the driving method of the 1st self-luminous display device of the present invention, and wherein, during the described the 4th before also being included in during the described the 3rd, the 2nd condition according to the rules applies the step of the voltage of regulation to described self-emission device.
The 10th the present invention is the driving method of the 9th self-luminous display device of the present invention, wherein, the pairing current value of display gray scale of the demonstration carried out of the described self-emission device in the next line of the pairing current value of display gray scale of the demonstration that the described self-emission device in the same regulation row that lists of described matrix is carried out and described regulation row compares;
As the 2nd condition of described regulation, when the difference of these current values shows described next line under more than or equal to the situation of setting, during the described the 4th, the described self-emission device of described next line is applied the voltage of described regulation.
The 11st the present invention is the driving method of the 9th self-luminous display device of the present invention, wherein, the 2nd condition as described regulation, when under the situation of display gray scale for the current value corresponding of the demonstration that described self-emission device carries out, carrying out this demonstration, during the described the 4th, described self-emission device is applied the voltage of described regulation with black demonstration.
The 12nd the present invention is the driving method of the 9th self-luminous display device of the present invention, the voltage that the current value that applies when wherein, the voltage of described regulation is the demonstration that equals to carry out at last with described self-emission device is suitable or be equivalent to hangs down the voltage of gray scale color when showing.
The 13rd the present invention is the driving method of the 12nd self-luminous display device of the present invention, and wherein, described the 1st voltage is the voltage that is equivalent to deceive when showing.
The 14th the present invention is a kind of display control unit of self-luminous display device, wherein, this self-luminous display device has each image element circuit that is arranged in rectangular self-emission device and corresponding setting with each described self-emission device, and during the 1st, described each image element circuit is applied the gray scale electric current that meets display gray scale, follow-up during the described the 1st the 2nd during, described self-emission device is applied demonstration electric current based on described gray scale electric current, the described display gray scale that conforms to demonstration;
During before described display control unit is included in during the described the 1st the 3rd, the 1st condition according to the rules applies the pre-charge current applying unit of pre-charge current to described self-emission device.
The 15th the present invention is the display control unit of the 14th self-luminous display device of the present invention, wherein, can change during the described the 3rd corresponding to the display gray scale of authorizing the demonstration electric current that applies on the described self-emission device.
The 16th the present invention is the display control unit of the 14th self-luminous display device of the present invention, wherein, the pairing current value of display gray scale of the demonstration carried out of the described self-emission device in the next line of the pairing current value of display gray scale of the demonstration that the described self-emission device in the same regulation row that lists of described matrix is carried out and described regulation row compares;
As the 1st condition of described regulation, when the difference of these current values was carried out the demonstration of described next line under more than or equal to the situation of setting, the described self-emission device to described next line during the described the 3rd applied pre-charge current.
The 17th the present invention is the display control unit of the 16th self-luminous display device of the present invention, wherein, can change with the size of described difference during the described the 3rd.
The 18th the present invention is the display control unit of the 14th or the 16th self-luminous display device of the present invention, wherein, the pairing current value of display gray scale of the demonstration carried out of the described self-emission device in the next line of the pairing current value of display gray scale of the demonstration that the described self-emission device in the same regulation row that lists of described matrix is carried out and described regulation row compares;
As the 1st condition of described regulation, when the difference of these current values shows the described self-emission device of described next line under less than the situation of setting, do not apply described pre-charge current.
The 19th the present invention is the display control unit of the 14th self-luminous display device of the present invention, wherein, the 1st condition as described regulation, when under the situation of display gray scale for the current value corresponding of the demonstration that described self-emission device carries out, carrying out this demonstration, do not apply described pre-charge current with black demonstration.
The 20th the present invention is the display control unit of the 14th self-luminous display device of the present invention, and wherein, the value of described pre-charge current is the current value that is equivalent to carry out white demonstration.
The 21st the present invention is a kind of current output type drive circuit of self-luminous display device, wherein, this self-luminous display device has and is arranged in rectangular self-emission device, and each image element circuit of corresponding setting with each described self-emission device, during the 1st, described each image element circuit is applied the gray scale electric current that meets display gray scale, follow-up during the described the 1st the 2nd during, described self-emission device is applied the described display gray scale that the demonstration electric current based on described gray scale electric current conforms to demonstration, and during the 3rd before during the described the 1st, the 1st condition according to the rules applies pre-charge current to described self-emission device, described current output type drive circuit comprise generation time length simultaneously different a plurality of described the 3rd during the 3rd period generating unit.
The 22nd the present invention is the current output type drive circuit of the 21st self-luminous display device of the present invention, and wherein, the pulse length when applying described pre-charge current produces during the described a plurality of the 3rd.
The 23rd the present invention is the current output type drive circuit of the 21st self-luminous display device of the present invention, wherein, and as the current-output type source electrode drive circuit.
The 24th the present invention is a kind of self-luminous display device, wherein comprises
Be arranged in rectangular self-emission device;
Each image element circuit of corresponding setting with each described self-emission device; And
Drive the driving circuit of described self-emission device and described image element circuit,
As described driving circuit, has the current output type drive circuit described in one or more the 21st the present invention at least.
The 25th the present invention is a kind of self-luminous display device, wherein comprises
Be arranged in rectangular self-emission device;
Each image element circuit of corresponding setting with described self-emission device;
The display control unit of the 14th self-luminous display device of the present invention; And
The current output type drive circuit of the 21st self-luminous display device of the present invention,
Described display control unit is carried out the relevant action that applies described pre-charge current.
The 26th the present invention is the 24th or the 25th self-luminous display device of the present invention, and wherein, described self-emission device is an organic EL.
The 27th the present invention is a kind of electronic equipment, wherein, the 26th self-luminous display device of the present invention is set as display unit.
The 28th the present invention is the 27th electronic equipment of the present invention as televisor.
The 29th the present invention is a kind of program, wherein, the driving method that is used to make computing machine carry out the 1st self-luminous display device of the present invention, during the 1st, described each image element circuit is applied the step of the gray scale electric current that meets display gray scale; Follow-up during the described the 1st the 2nd during, described self-emission device is applied the step of the described display gray scale that conforms to demonstration based on the demonstration electric current of described gray scale electric current; And during the 3rd before during the described the 1st, the 1st condition according to the rules applies the step of pre-charge current to described self-emission device.
A kind of recording medium of the 30th the present invention can be handled by computing machine, wherein, writes down the 29th program of the present invention.
Adopt current output type of semiconductor circuit of the present invention, demonstration with drive unit, display device, current output method,, also the increase of circuit scale can be suppressed to less even then increase the output figure place of current driver.
Description of drawings
Fig. 1 is the figure that the waveform input signal of current output type of semiconductor circuit of the present invention is shown.
Fig. 2 is a block diagram of making the driver IC when selecting from the outside whether the vision signal of each 1 share is carried out precharge.
Fig. 3 is the figure that the display board that uses multiple source driver IC is shown.
Fig. 4 is the figure that the structure of organic illuminating element is shown.
Fig. 5 (a) is the figure that the current-voltage-light characteristic of organic illuminating element is shown, and (b) is the figure that the current-voltage-light characteristic of organic illuminating element is shown.
Fig. 6 is the figure that the circuit of the active matrix type display that uses the image element circuit that current duplicator forms is shown.
Fig. 7 (a) is the figure that the running of current duplicator circuit is shown, and (b) is the figure that the running of current duplicator circuit is shown.
Fig. 8 is the figure that constant-current source circuit is shown.
Fig. 9 illustrates precharge pulse, precharge judgement signal and the graph of a relation that applies judging part output.
Figure 10 is the figure that electric current is outputed to the circuit of respectively exporting usefulness that existing current-output type driver is shown.
Figure 11 is that the gray scale that Figure 10 is shown shows with the transistor scale of current source 103 and the graph of a relation of output current deviation.
Figure 12 (a) is the figure that the equivalent electrical circuit when pixel stream TongYuan utmost point signal wire electric current in the image element circuit that current duplicator forms is shown, and (b) is the figure that the equivalent electrical circuit when pixel stream TongYuan utmost point signal wire electric current in the image element circuit that current duplicator forms is shown.
Figure 13 illustrates the electric current output of 1 lead-out terminal and the graph of a relation of pre-charge voltage applying unit and change-over switch.
Figure 14 (a) illustrates the transistorized raceway groove scale of each crystal nest of tubes of formation and the graph of a relation of deviation, (b) is that the transistorized raceway groove scale of each crystal nest of tubes of formation and the graph of a relation of deviation are shown.
Figure 15 is the pre-charge voltage implementation period and graph of a relation based on the period of output of the electric current of gradation data that illustrates in 1 horizontal scanning period.
Figure 16 is the circuit composition diagram that the input part of source electrode driver that can differential input is shown.
Figure 17 (a) is the graph of a relation that gradation data and precharge judgement signal are shown, and (b) is the graph of a relation that gradation data and precharge judgement signal are shown, and (c) is the graph of a relation that gradation data and precharge judgement signal are shown.
Figure 18 illustrates the figure that input serial electric current is distributed to the circuit of each signal.
Figure 19 is the deviation of output current between terminals of adjacent and the graph of a relation of gray scale that the source electrode driver that uses the output stage shown in Figure 25 and Figure 14 (a) is shown.
Figure 20 is the figure that the image element circuit of the use current duplicator when adopting the n transistor npn npn is shown.
Figure 21 illustrates the situation that is used for televisor to the display device of using embodiment of the present invention.
Figure 22 illustrates the situation that is used for digital camera to the display device of using embodiment of the present invention.
Figure 23 illustrates the situation that is used for portable information terminal to the display device of using embodiment of the present invention.
Figure 24 illustrates the figure of notion of the electric current efferent of the semiconductor circuit that uses embodiment of the present invention.
Figure 25 illustrates the figure that constitutes the situation of current source in the composition of Figure 24 with transistor.
Figure 26 illustrates the gray scale of input signal of Figure 24 or electric current efferent shown in Figure 25 to the graph of a relation of output current.
Figure 27 illustrates with the transistor of certain scale to form 1 of low side in output 8 bit data, and remaining high-end 7 are had than the big transistor of the transistor drain magnitude of current of 1 of low side and carry out the figure of the electric current output stage that gray scale shows according to transistorized number.
Figure 28 illustrates the figure that imports at a high speed the sequential chart when transmitting data under the situation that data reduce source electrode driver input signal cable number by each look serially.
Figure 29 illustrates the figure that imports at a high speed the sequential chart when transmitting order under the situation that data reduce source electrode driver input signal cable number by each look serially.
Figure 30 is the transmission figure in proper order that Figure 28 and Figure 29 of 1 horizontal scanning period are shown.
Figure 31 is the figure of wiring that the EL power lead of Fig. 6 or Figure 44 is shown.
Figure 32 be illustrate utilize transistor channel width to 8 digital videos inputs adjust 2 of low sides with high-end 6 between the size of current relation, and in everybody, make electric current according in the composition of the output stage of transistor number variation to further adding the composition diagram of current source with most significant end position corresponding current sources.
Figure 33 is the figure that the difference between current of gray scale 127 and gray scale 128 is shown.
Figure 34 illustrates the logical value skew tolerable limit of output current value of the transistor 241 in the driver that 256 gray scales of Figure 25 show and the graph of a relation of display gray scale.
Figure 35 illustrates the circuit composition diagram that detects the gray scale upset in the source electrode driver of the output stage with Figure 39 and carry out timing.
Figure 36 is the figure that the gray scale difference of gray scale 3 and gray scale 4 is shown.
Figure 37 is the figure that the gray scale difference of gray scale 131 and gray scale 132 is shown.
Figure 38 illustrates the composition diagram of making the output stage that can export electric current that adapts to gray scale and the either party in the voltage that adapts to gray scale selectively or in chronological order it being exported when in 1 horizontal scanning period.
Figure 39 illustrates the figure that the band most significant end digit current source electric current that uses when improving signal wire improves the electric current output stage of function.
Figure 40 be the voltage of a plurality of precharge power supplys 24 is shown and also can export selectively a plurality of voltages which and carry out electric current output or only carry out the precharge pulse in the source electrode driver of electric current output, the graph of a relation that signal and source signal line are judged in precharge.
Figure 41 is the figure that the process flow diagram that judges whether to export pre-charge voltage among the present invention is shown.
Figure 42 is the figure that the precharge judgement signal generator of realizing that precharge mode of the present invention is used is shown.
Figure 43 is the composition diagram that the source electrode driver of the function of passing through to change the level elimination gray scale upset that improves signal when an example has the upset of generation gray scale is shown.
Figure 44 is the figure that the display device of the pixel composition that uses the current mirror form is shown.
Figure 45 illustrates the example that zone 452 can not get the display pattern of regulation brightness.
Figure 46 is the figure that the example of the pattern that the brightness about zone 462 upside 1～5 row uprises is shown.
Figure 47 be illustrate gray scale 0 to gray scale 4, gray scale 0 to the source signal line current of gray scale 255 and the variation diagram of voltage.
Figure 48 be illustrate gray scale 255 to gray scale 4, gray scale 255 to the source signal line current of gray scale 0 and the variation diagram of voltage.
Figure 49 illustrates the graph of a relation that source signal line current and voltage under the situation that gray scale 0 to gray scale 4 changes maximum current circulation phase when big are set.
Figure 50 is the figure that the flow process of whether doing the precharge judgement of voltage and current is shown.
Figure 51 illustrates the vision signal gray scale and the graph of a relation that is written to the data of storer 522.
Figure 52 be illustrate carry out with 1 row before the block diagram of circuit of comparison of data.
Figure 53 be illustrate utilize with 1 row before data relatively change the block diagram of circuit of the disposal route of pre-charge electricity.
Figure 54 illustrates the value of order A and the graph of a relation of not making the condition of pre-charge electricity.
Figure 55 illustrates the block diagram of whether making the circuit that pre-charge electricity and voltage precharge uses when judging the 1st line data.
Figure 56 illustrates the block diagram that judges whether to carry out the circuit of pre-charge electricity according to the data before 1 row.
Figure 57 illustrates according to the gray scale of vision signal to judge it is the block diagram which carries out pre-charge electricity during or do not carry out the circuit of pre-charge electricity.
Figure 58 illustrates to utilize hangover to tackle measure to set whether carry out the block diagram that pre-charge electricity, pre-charge electricity carry out the circuit of phase.
Figure 59 illustrates to make can utilize input command to be modified to the pre-charge electricity phase of pre-charge electricity cycle selected cell decision not carry out the order of precharge circuit and the graph of a relation of the electric judgment standard of pre-charge.
Figure 60 is the block diagram that the circuit that carries out voltage precharge judgement is shown.
Figure 61 is the graph of a relation that the value of the order L among Figure 60 is shown and whether makes the precharge judgment standard of voltage.
Figure 62 illustrates to judge whether to carry out to the pre-charge electricity and the voltage precharge of incoming video signal and determine the figure of the precharge judgement signal generator of pre-charge electricity phase.
Figure 63 is the graph of a relation that precharge running and precharge judgement signal are shown.
Figure 64 illustrates the circuit composition diagram that enrolls the display device of using source electrode driver of the present invention and control IC.
Figure 65 is the block diagram with pre-charge electric work energy and source electrode driver of the function of output gate drivers control signal.
Figure 66 is the graph of a relation that gate line 651 and gate drivers 652 are shown.
Figure 67 illustrates the block diagram of judging the circuit of signal parallel series output data according to video signal generating precharge.
Figure 68 is the figure that the sequential chart of storer 522, data conversion portion 521 is shown.
Figure 69 illustrates the figure that produces the circuit block diagram that pre-charge electric pulse and voltage precharge pulse use.
Figure 70 is the figure of the block diagram of the driver IC when being illustrated in output stage use current duplicator.
Figure 71 is the figure that the circuit example that realizes digital-analog conversion portion is shown.
Figure 72 is the figure that the gray scale reference current wiring lines when connecting a plurality of driver IC is shown.
Figure 73 is the figure that the circuit of electric current holding unit is shown.
Figure 74 is the figure that the situation of the drain current that utilizes signal line 741 to change node 742 and driving transistors 731 is shown.
Figure 75 is the figure of drain current-grid voltage characteristic that driving transistors is shown.
Figure 76 is " bust " drain current difference of causing when the transistor that mobility is different being shown being used for driving transistors of each output.
Figure 77 illustrates in the current duplicator circuit figure that inserts the electric current holding unit of 1 transistor when reducing " bust ".
Figure 78 is the figure that the circuit of gray scale reference current generating unit is shown.
Figure 79 is the figure that the waveform of 2 signal lines among Figure 77 is shown.
Figure 80 is the figure that the circuit of gray scale reference current generating unit is shown.
Figure 81 is the figure that the reference current generating unit is shown.
Figure 82 is the figure that the circuit of the digital-analog conversion portion that comprises enabling signal is shown.
Figure 83 is the graph of a relation of timing pip, chip start signal, selection signal and gray scale current signal that 1 horizontal scanning period is shown.
Figure 84 is the figure that the different transistorized I-E characteristic of W/L is shown.
Figure 85 illustrates the figure that uses little amplitude to transmit vision signal and precharge mark at a high speed and have the composition example of the display board when setting electronic potentiometer and setting the source electrode driver of 1 order of the bit that precharge phase uses.
Figure 86 is the figure that the transfer mode example when transmitting precharge mark and vision signal at a high speed by same signal wire is shown.
Figure 87 is the figure that the sequential chart of order wire is shown.
Figure 88 is the circuit composition diagram that the pre-charge voltage transformation component that produces the pre-charge voltage that adapts to gray scale is shown.
Figure 89 is the internal frame diagram of the source electrode driver used among Figure 85.
Figure 90 illustrates the relation of the current/voltage corresponding with gradation data output and judges the figure of the transmission example of signal with the precharge of gradation data synchronous driving.
Figure 91 illustrates the figure that the signal wire input reference current settings identical with video signal cable and precharge is applied each the transfer mode example of phase during setting signal.
Figure 92 is illustrated in the graph of a relation that the interior data of 1 horizontal scanning period transmit phase and blanking interval.
Figure 93 is the inner composition diagram of source electrode driver that illustrates when making video signal cable and reference current and precharge phase setting signal line shared.
Figure 94 is the figure of the wiring between the driver IC that illustrates when using the source electrode driver with the output of gate drivers control line.
Figure 95 is the figure that the data transferring method in the embodiment of the present invention is shown.
Figure 96 is that the data that illustrate in 1 horizontal scanning period transmit routine figure.
Figure 97 is the figure that each the signal wire waveform after source electrode driver inside makes gradation data, precharge inversion signal, gate drivers control line and video signal cable separates is shown.
Figure 98 illustrates the inner composition diagram of the source electrode driver with gate drivers control line output function.
Figure 99 is the figure that the pre-charge voltage generating unit of Figure 98 is shown.
Figure 100 is the figure that the pre-charge voltage selection of Figure 98 is shown and applies judging part.
Figure 101 is the input/output relation figure that the decoding part 1001 among Figure 100 is shown.
Figure 102 is the source signal line current when image element circuit that uses Fig. 6 is shown and the graph of a relation of source signal line voltage.
Figure 103 is illustrated in the electric current output stage and also is provided with the figure that utilizes the current source that pre-charge electric wire supplying electric current uses except that the current source that adapts to gray scale is set.
Figure 104 illustrates the changing condition figure of source signal line current when 10nA changes to 0nA.
Figure 105 illustrates the changing condition figure of source signal line current when 0nA changes to 10nA.
Figure 106 is the variation diagram that illustrates on the current-voltage characteristic of source signal line among Figure 104 and Figure 105.
Figure 107 is the source signal line current changing condition figure that illustrates when carrying out the pre-charge electricity.
Figure 108 is that the source electrode driver when being illustrated in 10 times of top output rated current of horizontal scanning period electric current is exported variation diagram in time.
Figure 109 is the composition diagram that the source electrode driver of the electric current output usefulness that realizes that Figure 108 is such is shown.
Figure 110 illustrates the reference current generating unit of the source electrode driver corresponding with polychrome output and the composition diagram of electric current output stage.
Figure 111 illustrates the figure that (precharge reference current generating unit, pre-charge current output stage) formed in the pre-charge current output corresponding with polychrome output.
Figure 112 illustrates the composition diagram that pre-charge current and pre-charge voltage can be outputed to the source electrode driver of source signal line.
Figure 113 is the inside composition diagram that the pre-charge current voltage output stage of Figure 112 is shown.
Figure 114 is the graph of a relation that the state of the input of judgement signal interpretation portion 1131 of Figure 113 and switch 1132 to 1135 is shown.
Figure 115 is the figure that the process flow diagram of the precharge mark 862 that output imports in source electrode driver is shown.
Figure 116 illustrates precharge mark generating unit and to the figure of the sending part of source electrode driver.
Figure 117 illustrates the go forward side by side composition diagram of source electrode driver of line precharge of 1 cycle can selecting in voltage precharge and a plurality of different cycles.
Figure 118 is the figure that the circuit of the electric current efferent 1171 with the function of carrying out the pre-charge electricity is shown.
Figure 119 is the graph of a relation that the input/output signal of pulse choice portion 1175 is shown.
Figure 120 illustrates according to Figure 119 to make the precharge pulse 1174,451 in pulse choice portion when running and the time variation diagram that line 984 and output are judged in precharge.
Figure 121 is the figure that the input signal format of the driver IC that constitutes Figure 117 is shown.
Figure 122 is the figure that the circuit of the electric current efferent 1171 with the function of carrying out the pre-charge electricity is shown.
Figure 123 is the graph of a relation that the pre-charge current period of output of display gray scale and needs is shown.
Figure 124 is the electric current variation diagram that illustrates when using the pre-charge electricity.
Figure 125 is the changing condition figure of the source signal line current when interim output pre-charge voltage of each horizontal scanning and pre-charge current are shown.
Figure 126 is the source signal line current changing condition figure that illustrates when under the indeclinable situation of the interim source signal line current of a plurality of horizontal scannings pre-charge voltage not being set and applying phase 1251 and pre-charge current period of output 1252.
Figure 127 is the figure that the display mode example of situation that has the identical electric current of the continuous output of source signal line and the situation that this electric current changes is shown.
Figure 128 is the variation diagram that the source signal line current when use is of the present invention among Figure 127 is shown.
Figure 129 is the figure that the determination methods that only generation pre-charge voltage or pre-charge current period of output are used when the source signal line current changes is shown.
Figure 130 illustrates the drain current of driving transistors 62 and the concerning Yin Wendu of grid voltage and the figure of situation about changing.
Figure 131 is illustrated in that source electrode driver is outside to use resistive element and temperature compensating element and with Yin Wendu and different voltage is input to the composition diagram of pre-charge voltage generating unit.
Figure 132 illustrates Yin Wendu and pre-charge voltage when pre-charge voltage is changed changes the figure of example.
Figure 133 is that the drain current of the transistor 62 when Figure 132 being shown exporting pre-charge voltage like that is with respect to temperature variation.
Figure 134 is the figure that when being illustrated in the outer setting temperature compensating element image element circuit is applied the circuit block diagram of pre-charge voltage.
Figure 135 is that order control that the data of utilizing the temperature probe unit and origin self-controller be shown produces with the value of the electronic potentiometer figure according to the circuit block diagram of temperature change pre-charge voltage.
Figure 136 is that electronic potentiometer output voltage during circuit that Figure 135 is shown is formed is to the graph of a relation of temperature.
Figure 137 is that the leakage current of the transistor 62 when illustrating by the electronic potentiometer of Figure 136 the relation control pre-charge voltage of temperature is based on variation of temperature figure.
Figure 138 is the circuit composition diagram that illustrates when forming pre-charge voltage in the array that forms image element circuit and this array and producing with transistor.
Figure 139 illustrates the grid voltage of transistor 1381 and 62 and the graph of a relation of drain current.
Figure 140 illustrates pre-charge voltage of the present invention to produce the figure that uses the transistor arrangement scheme.
Figure 141 illustrates the pre-charge voltage of selecting to form in the array to produce with 1 in the circuit and be linked into the figure of the circuit of source electrode driver input terminal.
Figure 142 illustrates to distribute and the circuit composition diagram when disposing the pre-charge voltage generating unit that forms in a plurality of arrays.
Figure 143 be illustrate transistor 62 and 1381 when high temperature grid voltage and the figure of drain current characteristics.
Figure 144 is the figure that the situation that the electric current that circulates in the EL element that the early effect of driving transistors 62 causes increases is shown.
No matter how Figure 145 illustrates to measure in the display device of using organic illuminating element to flow through the total current of EL element and make this current value the display board figure of the adjustment circuit of constant usefulness.
Figure 146 is the figure that the adjustment circuit of Figure 145 is illustrated method of adjustment.
Figure 147 is the figure of the example when illustrating with vernier capacitor adjustment pre-charge voltage.
Figure 148 is the circuit composition diagram when illustrating that result with the temperature probe unit is input to controller and according to this result the signal controlling of source electrode driver and gate drivers being changed.
Figure 149 illustrates gate drivers 61b in the composition of Figure 148 at the figure of the waveform of 1 image duration.
Figure 150 is the figure of the waveform when utilize output enabling signal control grid signal wire 2 non-being shown lighting the phase.
Figure 151 is the graph of a relation that gray scale and brightness are shown.
Figure 152 illustrates the vision signal gray scale when applying gamma correction and the graph of a relation of source electrode driver output gray level.
Figure 153 illustrates to judge whether to carry out the circuit composition diagram that precharge is used after incoming video signal applied gamma correction.
Figure 154 is the figure that the precharge judgement signal generator in the embodiment of the present invention is shown.
Figure 155 is the figure of the display gray scale of each pixel in certain frame when whole screen display gray scale 1 is shown.
Figure 156 illustrates according to the output gray level number of source electrode driver applying the block diagram that signal behind the gamma correction carries out the circuit of greyscale transformation.
Figure 157 illustrates the figure that display gray scale with source electrode driver is each pixel display gray scale in benchmark certain frame when making the 1st row display gray scale the 0.25, the 2nd to the 4th row display gray scale 3.
Figure 158 is whether each pixel illustrates precharge judgement in the display mode of Figure 157 figure.
Figure 159 illustrates the figure that display gray scale with source electrode driver is each pixel display gray scale in benchmark certain frame when making the 1st row display gray scale the 0.25, the 2nd to the 4th row display gray scale 3.
Figure 160 is that display gray scale with source electrode driver is shown is each pixel display gray scale, the value of carry signal and the figure of precharge judged result in benchmark certain frame when making the 1st row display gray scale the 0.25, the 2nd to the 4th row display gray scale 3.
Figure 161 illustrates the figure that vision signal is applied the circuit block legend of gamma correction, precharge processing.
Figure 162 illustrates the figure that vision signal is applied the circuit block legend of gamma correction, precharge processing.
Figure 163 is the figure that the data corresponding with each pixel of the data that are input to precharge judgement signal generator are shown.
Figure 164 illustrates the figure that display gray scale with source electrode driver is each pixel display gray scale in benchmark certain frame when making the 1st row display gray scale the 0, the 2nd to the 4th row display gray scale 2.75.
Figure 165 is the figure that the data corresponding with each pixel of the data that are input to precharge judgement signal generator are shown.
Figure 166 be illustrate with 1 row before data exist the N gray scale difference or bigger carry out when poor under the precharge situation with 1 row before the relevant row and 1 of data when having the N-1 gray scale difference go the figure of precharge judged result of preceding carry signal value.
Figure 167 be illustrate with 1 row before data exist the N gray scale difference or bigger carry out when poor under the precharge situation with 1 row before the relevant row and 1 of data when having the N gray scale difference go the figure of precharge judged result of preceding carry signal value.
Figure 168 illustrates the figure that vision signal is applied the circuit block legend of gamma correction, precharge processing.
Figure 169 illustrates to make the circuit composition diagram that each illuminant colour can make the pulse generating unit of different usefulness of pre-charge electricity phase.
Figure 170 is the figure that the internal circuit of the synthetic portion of pulse is shown.
Figure 171 is the changing condition figure that the interim voltage precharge pulse of certain horizontal scanning, difference between current correction pulse, pre-charge electric pulse are shown.
Figure 172 illustrates to make the circuit composition diagram that each illuminant colour can make different time spent pulse generating units of pre-charge electricity phase.
Figure 173 is the figure that the source electrode driver output stage that can make pre-charge electricity phase and pre-charge current value both variations is shown.
Figure 174 illustrates the graph of a relation that line and precharge running are judged in precharge.
Figure 175 illustrates output current value of the present invention variation diagram in time.
Figure 176 is the circuit composition diagram that the pre-charge voltage generating unit of the change in voltage that the temperature of transistor characteristic that can utilize electronic potentiometer to adjust pre-charge voltage and compensation pixel causes is shown.
Figure 177 is the figure that the source electrode driver output stage that can make pre-charge electricity phase and pre-charge current value both variations is shown.
Figure 178 illustrates to use data enable signal at vertical blanking interval gray scale 0 to be inserted into vision signal and to judge the circuit composition diagram that signal generator output specified signal is used in precharge.
Figure 179 is the figure that the running of the black data insertion section among Figure 178 is shown.
Figure 180 is the figure that the running of the precharge judgement signal change portion among Figure 178 is shown.
Figure 181 illustrates the interim figure that exports the situation of difference source signal line potential change because of source electrode driver of vertical blanking.
Figure 182 is the end horizontal scanning period that the is illustrated in vertical blanking interval source signal line potential change condition diagram when carrying out voltage precharge and gray scale 0 output control.
Figure 183 illustrates the 1st row is carried out the pre-charge source signal line changing condition figure in when electricity.
Figure 184 illustrates the 1st row is carried out the pre-charge source signal line changing condition figure in when electricity.
Figure 185 is the figure that the running of output enabling signal of the present invention is shown.
Figure 186 illustrates to have the figure that output starts the output-stage circuit example of function, voltage pre-charging functions, pre-charge electric work energy.
Figure 187 is the figure that the pixel selection phase situation different with the interim voltage precharge pulse of vertical blanking is shown.
Figure 188 is the figure that the situation of the interim voltage precharge pulse of vertical blanking, precharge mark and source signal line voltage is shown.
Figure 189 illustrates order to transmit the graph of a relation that phase and timing pip, command register upgrade timing.
Figure 190 illustrates the inner composition diagram of source electrode driver of the present invention.
Label declaration
The 11st, video data, the 12nd, data line, the 13rd, address, the 14th, the data after distributing, the 15th, clock, the 16th, starting impulse, the 241st, transistor.
Embodiment
In the current output type of semiconductor circuit of the present invention, 2 bit positions that append in the low distolateral interpolation of in the past 6 bit positions.Therefore, prepare to have the gray scale of using in output 6 outputs in the past to show 1/4th current source, and add 3 this current sources, thereby carry out the output of 256 gray scales with the current value of current source 103.Figure 24 is the concept map that the electric current output stage of carrying out 8 outputs is shown.
The number of transistors that increase because of 8 are changed are 3, compare composition little when high order end adds so can realize the increase of circuit scale.
Show the adjustment of the current value in (the highest gray scale shows) in vain, can adjust the value of " I ", because the reference current 89 of the composition of control chart 8 can make the value of this " I " change, so by realizing this adjustment according to using input control data 88.
Figure 25 is the example that illustrates when realizing the composition of Figure 24 with transistor.The transistor 252 of high-end 6 bit positions as 1 example corresponding to the 1st unit transistor of the present invention, the transistor 251 of low side 2 bit positions as 1 example corresponding to the 2nd unit transistor of the present invention.Crystal nest of tubes 241a, 241b as 1 example corresponding to the 1st current source group of the present invention, crystal nest of tubes 242a, 242b, 242c, 242d, 242e, 242f as 1 example corresponding to the 2nd current source group of the present invention.To incoming video signal data D[7:0], at D[0] and D[1] between, D[2] to D[7] between, be connected to the weighting of every of the transistorized number performance of output by change, and by the weighting between transistor channel width 2 of low sides of decision and high-end 4.In the transistor 251 and 252, it is about 4 times of 251 sides that 252 sides are designed to channel width.But channel width is not accurate consistent than with the output current ratio, thereby can determine transistorized channel width ratio according to simulating between 3.3 times to 4 times or TEG transistor measured data, thereby constitutes the high output stage of gray scale.
Output current depends on the quantity of the current source transistor that connects everybody, and in the mode of the magnitude of current of 1 transistor circulation of accumulation number share output current is changed.Under the situation of 8 outputs of Figure 24 and Figure 25, gray scale and output current characteristic such as Figure 26 (because the relation of drawing only illustrates low side 64 gray scales).By the electric current shown in high-end 6 transistor 252 outputs 262 zones, by the electric current shown in transistor 251 outputs 261 zones of 2 of low sides.262 electric current changes because of the difference current value of transistor number, thus class interval width difference can be 1% or littler.The major part of output current is 262 part, even thereby the electric current of 261 parts produce some deviations and also do not influence the gray scale linearity.Again, though 261 class interval width bigger or little than setting because the different part of class interval width only appears 1 time in 4 gray scales, consider the ratio of 262 and 261 pairs of output currents, then also no problem in the practicality.In the little low gray area of 262 current ratio, be difficult to discern luminance difference on the human eye characteristic, class interval width difference more not remarkable, thereby no problem.
Output bias between the terminals of adjacent of the transistor 252 of high-end 6 bit positions, owing to use the driver identical with 6 bit drivers, deviation has confirmed not produce the vertical line that the output current deviation causes in 2.5%.
On the other hand, for the transistor of 2 bit positions that increase newly, channel width only is 1/4, and transistorized channel area is little, thereby deviation strengthens, and surpasses 2.5% (the output current deviation between terminals of adjacent and the square root of transistor area are inversely proportional to).
Figure 19 illustrates the relation of current deviation between gray scale in the composition of output stage of Figure 25 and terminals of adjacent.When only reducing the scale of transistor 251 of low side 2 bit positions, form the gray scale shown in solid line 191 and the dotted line 192 and the relation of deviation, gray scale 3 and time exist deviation to surpass 2.5% problem.Figure 14 (b) illustrates the deviation when only making channel width position 1/4 and the relation of gray scale.In the gray scale 1 to 3, deviation surpasses 2.5%, so do not allow.
Therefore, among the present invention, have only the value of gray scale 1 to 3 contributive 3 transistors 251 being kept transistor channel width/transistor channel length, output current is changed, strengthen channel width and channel length, channel area is strengthened, thereby deviation is reduced.Figure 14 (a) illustrates example.At this moment, channel length, channel width are 2 times, and channel area is 4 times, thereby in whole gray scale, deviation is in 2.5%.
This example is set forth theoretic numerical value, and the channel width of real crystal nest of tubes 241a and crystal nest of tubes 241b is worth greater than this.Owing to make toward big direction, develop toward the direction that the output current deviation is had surplus, can at first calculate and design by theoretical value, change according to measured data more at last.
The area that this method is brought totally then increase about 1.04 times whole, thereby increment rate is little, and can be formed demonstration that can't see deviation with respect to 1.05 times of 7 one-tenth overall increases.The pass of gray scale and deviation is the relation of solid line 191 shown in Figure 19 and 193 expressions, and all gray scale realizes deviation 2.5%.
And owing to form the crystal nest of tubes of crystal nest of tubes 241 and crystal nest of tubes 242 with different scale, according to the skew of simulation with measured value, the electric current output of crystal nest of tubes 241 becomes big with respect to the electric current output of crystal nest of tubes 242 or diminishes.
Form for a short time even establish the electric current output of crystal nest of tubes 241, also and the non-negotiable negative current, the gray scale upset does not take place, so no problem with respect to the electric current output of crystal nest of tubes 242.
On the other hand, the electric current of crystal nest of tubes 241 output is during greater than the electric current output of crystal nest of tubes 242, between the gray scale that the transistor output of crystal nest of tubes 241 the is helped gray scale adjacent with helpless gray scale gray scale may take place and overturn.For example between gray scale 3 and 4, the gray scale 127 and 128.
As shown in figure 36, the luminance difference of existence 33% between the gray scale 3 and 4.Output bias is 2.5%, as shown in figure 14, even thereby hypothesis produce deviation in the little direction of gray scale difference, also have 30% poor.Therefore, compare with the analogue value, the electric current of real crystal nest of tubes 241 is exported big by 30%, and is also no problem.
As shown in figure 33, the gray scale difference of formation 0.79% between gray scale 127 and 128.By gray scale 124 parts and the gray scale 128 in identical transistor 242 output gray levels 127 of scale, so identical with deviation between the adjacent gray scale, deviation also is 0.5%.Therefore, might the gray scale difference minimum be 0.29%.Even the transistorized electrorheological of crystal nest of tubes 241 is big, is suppressed to 0.29% generally and gets final product.If the transistor current maximum of crystal nest of tubes 241 changes 12.3% only, just there is not the gray scale upset.
When surpassing gray scale 128, in the time of for example between the gray scale 131 and 132, as shown in figure 37, gray scale difference is 0.75%, but all has the electric current output of crystal nest of tubes 242f, and that different is crystal nest of tubes 242a, crystal nest of tubes 241a and these 3 groups of crystal nest of tubes 241b.242f compares with the crystal nest of tubes, and the electric current of crystal nest of tubes 242a is 1/32nd, and the current value that transistorized deviation causes changes when comparing 128 gray scales or its time gray scale little.At this moment may reduce 0.08%, even thereby transistor have deviation, luminance difference also is 0.67%.Since with 127 and 128 between compare, it is big that luminance difference becomes, and the ratio that occupies the electric current output of crystal nest of tubes 241 diminishes, at least with 127 and 128 between compare, it is greatly also no problem that the transistor current of crystal nest of tubes 241 becomes.
The scope of gray scale upset and the relation of display gray scale do not take place greater than the analogue value (theoretical value) in the transistor current amount that Figure 34 illustrates crystal nest of tubes 241 yet.
According to Figure 34, do not allow that the scope of deviation theory value is being 12.3% to the maximum under this situation between 127 and 128 gray scales.At least theoretical value and actual value do not depart from 12%, then can realize output current and gray scale upset does not take place.
In 8 bit drivers of the composition of Figure 24 and Figure 35,, can not have gray scale yet and show turningly even hypothesis changes the transistor scale of 2 of low sides (241 outputs of crystal nest of tubes) and high-end 6 (242 outputs of crystal nest of tubes).
The upset of the easiest generation gray scale be between gray scale 127 and the gray scale 128, thereby Figure 32 illustrates and enrolls when the gray scale upset takes place between these two gray scales, utilizes the circuit composition of 1 output of the electric current output stage 23 of repairing the circuit of eliminating the gray scale upset.
Compare with the composition of Figure 25, it is characterized in that the electric current that adds more than or equal to 128 gray scales increases with transistor 322 and switching part 321.
The terminal 323 of switching part 321 has 3, and connecting electric current respectively increases with transistor 322, earthing potential, current source 242.
Switching part 321 connects 323a and 323b usually, and 323c is a not-connected status.Therefore, electric current increases with transistor 322 does not influence electric current output.During with the upset of no gray scale for this reason state dispatch from the factory.
On the other hand, take place when the electric current of crystal nest of tubes 241 is big under the situation of gray scale upset, the electric current more than or equal to 128 gray scales is increased, prevent the gray scale upset, thereby utilize the connection of change switching parts 321 such as laser, terminal 323a is connected with 323c.
Thus, the electric current increase more than or equal to 128 gray scales can prevent the gray scale upset.
Electric current increases about 10% the electric current that electric current with transistor 323 is the electric current of output transistor group 241a.The electric current of crystal nest of tubes 241 surpasses at 12.3% o'clock, overturns between 127 and 128 gray scales, thereby in order to save this point, is taken as about 10%.The electric current of crystal nest of tubes 241 departed from 22% o'clock, can not prevent the gray scale upset between 127 and 128 gray scales, but at this moment the gray scale upset had taken place between 63 and 64 gray scales.This circuit can not take place in the correction between 63 and 64 gray scales, so needn't consider 22% skew.
Therefore, among the present invention, constitute the gray scale upset between the gray scale of the just the easiest generation gray scale upset of only rescue, thus electric current increase electric current with transistor 322 can be crystal nest of tubes 241a electric current about 10%.
With respect to the electric current of 128 gray scales, the output current that electric current increases with transistor 322 is 1/1280, is overall 0.08%, so the influence of adjacent deviation of this 322 couple can be ignored.About 1/4 scale with crystal nest of tubes 241a or crystal nest of tubes 241a is made also out of question.
By switching part 321 being set, realize the little driver IC of gray scale upset possibility in each output.Therefore, can utilize Laser Processing etc., make not good enough product become good merchantable brand, can expect that yield rate improves.
Yet Laser Processing is carried out in each output, processes spended time and causes the number of working processes to increase, and causes cost to increase, and the effect that possible yield rate improves is remarkable more, and cost is high more.
Therefore, as shown in figure 39, consider to constitute and to carry out electric current by switch unit 391 and increase, control switch units 391 by improving signal 392 with being connected of transistor 322 and current source 242f, thereby according to the external command input, thereby can be easily with improving the electric current that signal 392 can improve the 128th gray scale.
Can each output set to improve signal 612 and get final product, but at this moment need to keep the latch of value of the raising signal 612 of each signal wire.If the shared shift register that is used to distribute vision signal can utilize 392 pairs of each latch distributing signals of 1 signal input.Yet, because the latch of signalization line share exists circuit scale to become big problem.The figure place that latchs the data that portion 22 should keep increases by 1 in each source electrode line.Under the big also passable situation of circuit scale, or use fine processing and occupy under the little situation of the area of the overall portion that latchs, can determine that also each output control does not improve signal to improve, but when the gray scale upset takes place, produce the analogue value and the complete inconsistent situation of measured value, so should need judge whether electric current to increase jointly by whole basically terminals with transistor 322.
Therefore, improve signal wire 392 and be in 1 source electrode driver all 1 shared signal line, utilize the control of this signal wire, decision whether whole output increase by 128 gray scales and on the electric current of gray scale.
The sort signal line places and for example is generally low level, makes switching part 391 be nonconducting state, switch to high level but will improve signal wire 392 with Laser Processing, thereby all output is controlled in batches, then can implement at short notice to repair.Form Figure 43 431 shown in circuit, then can realize.
Moreover, can be when the inner formation of source electrode driver IC36 ROM351, can utilize external control signal that the value of ROM351 is write, and be written to the IC that the gray scale upset takes place and in ROM351, will improve signal wire 392 and be taken as high level, IC that gray scale overturns does not take place will be improved signal wire 392 be taken as low level in ROM351.
For example Figure 35 is such, make when checking and to be input to ROM351 from the signal of PC etc. 352, the current value that utilizes output current measuring unit 353 detects whether the gray scale upset takes place in PC etc. 352, and when the gray scale upset takes place, high level signal is written to ROM351.When the gray scale upset does not take place, low level signal is written to ROM351.Thus.Can judge whether to proofread and correct gray scale upset automatically, manually stay out of and can save not good enough product, thus energy high speed and IC is provided at an easy rate.
In the explanation above, source electrode driver is taken as 8, is illustrated, also can not realize the present invention but be not 8.Except that 2 of low sides and high-end 6 combination, as shown in figure 27, also can realize with 1 of low side and high-end 7 combination again.By form low side N position with certain transistor scale, form high-end M position with another transistor scale, can realize the current driver of N+M (〉=3) position output.At this moment, preferably the transistor of low side N position export high-end M position transistorized electric current output 1/2 NElectric current.Yet, if also consider can the high-end M of representing gradation position transistorized electric current output situation about getting final product greater than transistorized this output of low side N position.
The relation of N and M is good with N≤M.Along with N becomes big, the transistorized electric current output ratio corresponding with the N position strengthens, thereby the influence of the current value deviation theory value corresponding with the N position is big.For example during 8 bit drivers, under the situation of N=2, M=6, the tolerable skew reaches 12.3%, but under the situation of N=3, M=5 and N=4, M=4, can only allow 5.26% and 2.46% respectively.Become at 2.46% o'clock, identical with adjacent extent of deviation, this degree is the minimum value of the deviation of energy control theory value and measured value.
Therefore, in 8 bit drivers, N=4 is a maximal value.
In the N+M bit driver, the influence of general low side transistor (N bit position) deviation theory value is little, thereby needs N≤M.Even N≤M in order to make the gray scale between adjacent gray scale good, is good with N≤4.
Input applies 8 signals of gamma correction, when utilizing source electrode driver IC36 to show, also can realize applying demonstration behind the gamma correction without FRC.Therefore, the demonstration of low gray scale side is easier to carry out (influence of the flicker that no FRC causes), can realize the display device that display quality is high.
Driver IC 36 is that Figure 21 is to the requisite driver of display device shown in Figure 23.
So far, the example the when transistor that pixel 67 usefulness are shown is the p transistor npn npn, but use the n transistor npn npn can realize too.
Figure 20 is the circuit of 1 pixel share when forming current mirror type pixel composition with the n transistor npn npn.The direction upset that electric current flows brings supply voltage to change.Therefore, flowing through the electric current of source signal line 205 need be from source electrode driver 36 toward pixels 67 flow.The current mirror that consists of the p transistor npn npn of output stage is formed, and makes electric current be discharged to the outside.The direction of reference current needs upset too.
Like this, the transistor that uses in the pixel can use p, n both.
In recent years, in the portable information terminal, multicolor gets along with, and 60,000 5 thousand looks and 220,000 looks become main flow.The input signal of driver IC needs 16 or 18 under the situation of rgb interface.Therefore, input signal cable quantity only needs 16 to 18 to transmit data.In addition, for the running signal of shift register and the setting of various detecting devices etc., also need signal wire.
Therefore, wiring quantity becomes many, for example shown in Figure 3, and for display board 33, controller IC 31 to the wiring between the source electrode driver IC36 becomes many.Therefore, exist flexible plate 32 to become big or problem that the cost of the multilayer bottom plate that uses etc. improves.
Fig. 2 illustrates the composition of current-output type source electrode driver IC36 of the present invention.Increase and decrease with output quantity by only making the shift register 21 that each output needs and latching the quantity that portion 22, electric current output stage 23, pre-charge voltage apply judging part 56, electric current output/pre-charge current selection portion 25, can realize making the increase and decrease of output quantity, thereby can tackle arbitrarily and export quantity (still, when output quantity increases, chip-scale is greatly undue and do not have versatility, thereby practical upward maximum quantity is about 600).
Utilize signal wire 12 and 13, import the vision signal of driver IC 36 of the present invention from control IC28.By dispenser 27 this signal is divided into vision signal and various setting signal, only vision signal is input to shift register portion 21.Latch portion 22 by shift register portion 21 and 2, it is assigned to each lead-out terminal.Vision signal after distributing is input to electric current output stage 23.Electric current output stage 23 is exported current value up to specification according to the reference current of vision signal and 26 generations of reference current generating unit.Signal data is judged in precharge in the portion of latching, be input to pre-charge voltage and apply judging part 56.On the other hand, pre-charge voltage applies judging part 56 utilization and latchs the precharge that portion 22 latchs and judge signal and precharge pulse, produces the signal that voltage that whether control supply with precharge power supply 24 outputs to the switch of output 53.Thus, by electric current output/pre-charge voltage selection portion 25, curtage is outputed to the outside of driver IC 36.This electric current output/pre-charge voltage selection portion 25 applies the output signal of judging part 56 according to pre-charge voltage, and the voltage that the electric current of gray scale outputs to the outside of driver IC 36 or provides precharge power supply 24 to supply with will be provided in selection.
The voltage of precharge power supply 24 outputs is that display board shows black required magnitude of voltage.The method that applies this pre-charge voltage is to export the driver IC 36 distinctive compositions that carry out gray scale demonstration usefulness according to electric current in the active matrix type display.
For example, consider certain pixel to be write the situation of rated current value from the source signal line in the active matrix type display of the described pixel composition of Fig. 6.When not carrying out precharge, when promptly not having pre-charge circuit, the circuit that the output stage of extraction source electrode driver 36 obtains to the related circuit of the current path of pixel is shown in Figure 12 (a).
The electric current I that meets gray scale in the driver IC 36 in the mode of current source 122 as introducing current flowing.This electric current is input to pixel 67 inside by source signal line 60.The electric current of input flows through driving transistors 62.That is, in the pixel 67 of selection, pass through driving transistors 62, source signal line 60, circulating current I on source electrode driver IC36 from EL power lead 64.
When thereby vision signal changed the current value variation that makes current source 122, the electric current that flows through driving transistors 62 and source signal line 60 also changed.At this moment, the voltage of source signal line changes according to the I-E characteristic of driving transistors 62.The current-voltage characteristic of driving transistors 62 is under the situation of Figure 12 (b), and the current value of for example establishing current source 122 circulations changes to I1 from I2, and then the voltage of source signal line changes to V1 from V2.Electric current according to current source 122 produces this change in voltage.
There is stray capacitance 121 in source signal line 60.In order to make source signal line voltage change to V1, need to discharge the electric charge of this stray capacitance from V2.This discharges the time Δ T that needs and forms Δ Q (electric charge of stray capacitance)=I (electric current that the source signal linear flow is logical) * Δ T=C (parasitic capacitance value) * Δ V.Wherein, establish Δ V (the white signal wire amplitude that shows when black the demonstration) and be 5V, C=10pF, I=10nA then needs Δ T=50 millisecond.1 horizontal scanning period (75 is delicate) when this time is longer than with the frame frequency driving QCIF+ scale (pixel count 176 * 220) of 60Hz, thereby hypothesis is deceived demonstration in the pixel of white display pixel downside, then the variation of source signal line current is written to electric current switching transistor 66a, the 66b conducting that pixel is used midway, thereby mean that it is luminous that pixel is pressed the intermediate luminance of white and black owing to store middle gray in the pixel.
Gray scale is low more, and the I value is more little, thereby is difficult to discharge the electric charge of stray capacitance 121, and low gray scale shows, changes to the preceding signal of regulation brightness and is written to the remarkable more appearance of inner this problem of pixel.Extreme, during black the demonstration, the electric current of current source 122 is 0, and circulating current can not discharge the electric charge of stray capacitance 121.
Therefore, the composition that decision is taked has than the low voltage source of current source 122 impedances, is applied to as required on the source signal line 60.This voltage source is equivalent to the precharge power supply 24,25th of Fig. 2, finishes the mechanism 25 that applies usefulness.
Figure 13 illustrates the summary circuit to a source signal line 60.Be applied to source signal line 60 by the voltage that precharge electric capacity 24 is supplied with, the electric charge of stray capacitance 121 is discharged and recharged.The voltage that precharge power supply 24 is supplied with can be made the voltage corresponding with each gray scale electric current can be provided according to the characteristic of Figure 12 (b), but voltage generation circuit need adapt to the digital-analog conversion portion of data 54, thereby circuit scale becomes big.In the small display panel (9 inches or littler), the capacitance of stray capacitance 121 is that 10pF～15pF and pixel quantity are few, so obtain the vertical scanning phase longer, the voltage that precharge power supply 24 produces in the practicality only produces and is difficult to write into the corresponding voltage of the grey black degree of current value, we can say effect expense (chip area) than aspect abundant (in the large-scale high definition display board, shown in Figure 38 as what illustrate later, also the driver IC of digital-analog conversion portion is used in consideration).
In the small display panel, the voltage that precharge power supply 24 produces can be 1, as long as judge whether output voltage and gauge tap 131 according to data.That is to say, have 1 signal wire (precharge judgement signal) that before carrying out the electric current output corresponding, judges whether to apply voltage source 24 with certain vision signal.
The voltage that Fig. 9 illustrates the circuit composition of Figure 13 applies the judgement running.Utilize precharge to judge that signal judges whether to apply voltage.Establish " H " level in this example and apply voltage, " L " level does not have the voltage of applying.
Become the time of the output voltage that equals precharge power supply 24 by grid voltage with the driving transistors 62 of time constant decision image element circuit 67 inside of the product representation of the wiring capacitance of source signal line 60 and cloth line resistance.This time is depended on the buffer scale and the display board scale of precharge power supply 24 output terminals, can change about 1 microsecond～5 microseconds.
When utilizing voltage to carry out the gray scale demonstration, because the I-E characteristic deviation of driving transistors 62, promptly enable each pixel is supplied with identical voltage, the electric current of circulation is also different in the EL pixel 63, produce uneven luminance, thereby, in 1 microsecond～5 microseconds, behind the formation assigned voltage, carry out electric current output in order to proofread and correct the deviation of driving transistors 62.
Reach the voltage output of this purpose and the switching of electric current output with precharge pulse.Only when precharge pulse and precharge judge that signal 55 is " H " simultaneously, the voltage of output precharge power supply 24, carry out electric current output under other situation, thereby carry out electric current output when not needing to apply voltage, also after applying voltage, can utilize electric current to carry out offset correction in the time of need applying voltage.
Switch 131 to control precharge power supply 24 carries out above-mentioned running, but based on the running of the switch 132 of electric current output control part 133 as shown in figure 15, needs conducting at electric current period of output 152, but can conducting at the voltage period of output, also can block.
If blocking-up, from the output of source electrode driver former state output precharge power supply 24, thereby no problem.On the other hand, even conducting, the voltage of electric current output place 104 of digital-analog conversion portion 106 is also by load decision, if thereby make the output of precharge power supply, the voltage of the source signal line 60 just voltage with precharge power supply 24 is identical.So switch 132 is which state all can.
Therefore, can there be switch 132 and electric current output control part 133 yet.But, in fact in the output of precharge power supply 24, use operational amplifier, then gray scale is shown with current source 103 input currents from operational amplifier, need to improve the electric current fan-out capability of operational amplifier.Therefore, often constitute when can not improve the ability of operational amplifier, switch 132 is set, carry out the running opposite, replenish the deficiency of operational amplifier electric current fan-out capability with switch 131.
Operational amplifier design decision when having or not switch 132 entirely with design of Driver.Make under the little situation of operational amplifier, switch 132 is set, and supply with operational amplifier or precharge power supply 24 from the outside of source electrode driver 36; Use under the situation of the power supply that fully has the electric current fan-out capability,, constitute sometimes and remove switch 132 and electric current output control part 133 in order to reduce the circuit scale of source electrode driver.
Because the magnitude of voltage of precharge power supply 24 output is the corresponding voltage (black voltage hereinafter referred to as) of electric current when spending with grey black only, when for example establishing the gradation data 54 continuous interim demonstration limes of a plurality of horizontal scannings and spend, the source signal line repeats to deceive, in vain, black, white state.When not carrying out precharge, then white state produces continuously.That is, by carrying out precharge, signal wire changes greatly on the contrary, and according to the electric current of white demonstration, might produce the write current deficiency, not exclusively bleaches.
Therefore, can make and use precharge to judge signal, not carry out precharge in the bigger gray scale of electric current energising, only near the rated current the grey black degree does not allow labile gray scale to accept the help of precharge power supply 24.For example, only make and to have pre-charge voltage when (deceiving) in gray scale 0 and connect the phase, disconnect pre-charge voltage when showing other gray scale, the most effective like this.Brightness when making minimum gray scale reduces, and improves contrast, can show the image than U.S..
For example shown in Figure 17 (a),, can only when gray scale 0, carry out precharge by being to set up precharge at 0 o'clock to judge signal 55 only at gradation data 54.
If at gradation data 54 is to set up precharge at 0,1 o'clock to judge signal 55, then can carry out precharge (Figure 17 (b)) at 0,1 o'clock in gray scale.
In the source signal line unconverted pattern of whole image for black demonstration, only the top of 1 frame applies pre-charge voltage, even then the back only also is enough to make the regulation gray scale fully to be made progress for black current.
That is, when same black demonstration, also logical according to the interim source signal linear flow of preceding horizontal scanning current value makes the asynchronism(-nization) of only arriving the rated current value with electrorheologicalization, and variable quantity is big more, changes spended time more.For example carry out the black demonstration after the white demonstration, spended time, but deceive when showing after black the demonstration, signal wire only changes the deviation part of driving transistors 62, thereby the time that needs in changing weak point.
Therefore, can import a kind of composition, synchronously import the signal (signal 55 is judged in precharge) that judges whether to apply pre-charge voltage, can select to have or not precharge in any gray scale or same gray scale by every look and gradation data 54.
To gradation data 54, add precharge and judge signal 55.Thereupon, latching portion 22 also needs to latch precharge and judges signal, thereby has the portion that latchs of vision signal figure place+1.
Figure 17 (c) when gray scale 0 is shown and also the gray scale in preceding cycle connected precharge situation (carrying out precharge during gray scale 0) at non-0 o'clock even but consecutive hours gray scale 0 is not carried out precharge yet.
Different with said method, the advantage that this method has is: even same gray scale also can select to carry out or do not carry out precharge according to the state of the source signal line before 1 horizontal scanning period.
Supply with this precharge from control IC28 and judge signal.Shown in Figure 17 (a) to (c), can utilize the command operation of control IC28, make precharge judge that the pattern of signal 55 changes and output.
Can be according to the capacity of source signal line and the length of 1 horizontal scanning period, from the outside of source electrode driver IC36 precharge setting is changed flexibly, have the advantage that versatility increases.
Explanation produces the method that signal 55 is judged in precharge at control IC22.Whether incoming video signal is done precharge judgement, its result is judged that as precharge signal 55 outputs to source electrode driver from control IC22.
Whether change to the angle of rated current value from the current change quantity that influences the source signal line and the logical current value of source signal linear flow,, carry out the differentiation of display gray scale of differentiation, this row of the state before 1 row whether doing precharge judgement.
For example, under the state of source signal line is white, black, black situation, when being black from leucismus, variable quantity is big, spended time, but from deceiving when spreading all over multirow like that and showing same grayscale, with show same grayscale capable corresponding during, the variation of source signal line current is the share of compensate only, so variable quantity is little.
Utilize this point,, when only the gray difference of the data before 1 row and these data is big, carry out voltage output according to pre-charge voltage with reference to the data before 1 row.In the last example, carry out precharge when deceiving, do not carry out precharge when deceiving from black changing to from changing in vain.Can extend from the required transformation period of the offset correction of deceiving and not carry out precharge share, can further improve the precision of correction.In view of the above, distinguish and do not do precharge when the gradation data that is preferably in gray scale and this row before 1 row is identical.
Moreover the voltage of using do precharge only is the voltage corresponding with black state, thus during the state before brightness ratio 1 row of relevant row big, can be only in accordance with regulations electric current carry out the gray scale demonstration, and do not form black state.Do not do precharge when therefore, the gray scale of the gray scale of distinguishing best relevant row before than 1 row is high.
When relevant pixel was middle gray or higher gray scale, the magnitude of current was big, changed to rated current easily, thereby no matter the pixel before 1 row does not need precharge.But but the magnitude of current is little, the display board scale is big etc. is difficult under the situation such as variation in exploring degree height, middle gray, when the pixel before 1 row is middle gray or lower gray scale, can carry out precharge.
The variation of current value is from changing to black state in vain generally than changing to white state difficulty from deceiving.As indicated above, here must be according to the electric current that adapts to the display gray scale that shows now, the state from the state variation of the source signal line before 1 row to the source signal line of hope, the low gray scale portion that current value is more little, difficult more variation.And when variable quantity was big, before variation was finished, horizontal scanning period finished.Therefore, change spended time, variable quantity is big and the situation of relevant gray scale for low gray scale under, the brightness of relevant pixel was less than or equal under the situation of middle gray when promptly the gray scale of the preceding pixel of 1 row was greater than or equal to middle gray, it is effective to carry out precharge.
Before 1 row is middle gray or lower gray scale, and the little part of variable quantity also can show the regulation gray scale when then middle gray was less than or equal in the brightness of relevant pixel.
Therefore, the brightness of relevant pixel is not carried out precharge during greater than certain gray scale, when being equal to or less than certain gray scale, then utilize the preceding gray scale of 1 row, and, greater than the data before 1 row time, do not carry out precharge according to the data before 1 row, carry out precharge during less than the data before 1 row.Do not carry out precharge when identical with the data before 1 row, and no matter the gray scale of relevant row.
In addition, about there not being the 1st data of going of the preceding data of 1 row, the data in importantly going the 1st are written to the state before the pixel, the i.e. state of the source signal line that vertical blanking is interim.
Which generally exist the unselected vertical blanking interval in provisional capital in 1 frame.At this moment, switching transistor makes the source signal line break away from all pixels, the no current path.When constituting the electric current output stage of source electrode driver IC as shown in Figure 13, vertical blanking is interim, and 104 of current output terminals connect the source signal line, will introduce electric current from the source signal line even gray scale shows with current source 103, also no current path, thereby not introducing.
So gray scale shows will introduce electric current by force with current source 103, the transistor drain voltage that constitutes current source 103 is reduced.The current potential of source signal line also descends simultaneously.
Vertical blanking interval finishes, and in the time of be to the pixel supplying electric current of the 1st row, source signal line current potential descends big, compares during with white demonstration usually, and source signal line current potential is low.(here, the current potential of source signal line is minimum when white the demonstration, and is the highest during black the demonstration; When being taken as the pixel composition of Fig. 6).Therefore, make the potential change of source signal line to the value that meets gray scale (required vary within wide limits) than other row difficulty.
Source signal line current potential descends under the big situation, compares during with white demonstrations, and current potential is lower, even capablely carry out white demonstration the 1st, when changing also spended time, shows with the brightness that is higher than regulation brightness.For the row that scans immediately after the vertical blanking interval end, preferably export pre-charge voltage, no matter display gray scale.
Therefore, among the present invention, utilize vertical synchronizing signal, judge as the pairing precharge of the data of the next line that is equivalent to vertical blanking interval and mandatoryly in the signal carry out precharge signal, solve the problem of the 1st row and the luminance difference of other row.
In addition, as the current potential that makes the source signal line method little and that relax that descends, can be at vertical blanking interval to the black video data of gradation data 54 inputs, and make switch 108 be nonconducting state, descend thereby suppress source signal line current potential.Also can electric current export 104 and the source signal line between switch is set, and to make this switch at vertical blanking interval be nonconducting state.But this switch double as current/voltage selection portion 385 is taken as 3 values with the state of switch, forms to cut off electric current output, voltage output, source signal line, then can reduce the composing quantity of switch.
About the regulation gray scale be difficult to write into phenomenon, especially black phenomenon for the middle gray demonstration, influence display image mean flow rate, light rate.When the rate of lighting was high, the overall brightness height showed even form middle gray, can not distinguish a small amount of black display pixel.Otherwise when the rate of lighting was low, the brightness of most of pixel was set lowly, and under the situation that this brightness can not normally show, the brightness of whole image changes in fact, thereby forms the demonstration that departs from former video, and is big to the display quality influence.
Therefore, can set the demonstration that the little height of display quality influence is lighted rate and not do precharge, so that the even demonstration of current drives obtains preferentially, and black display brightness improves significant low lighting in the rate demonstration and carries out precharge.
Can calculate the rate of lighting of display board by whole brightness data additions with 1 image duration.The value of the rate of lighting that obtains according to the method is not carried out precharge when the rate of lighting is high, then carry out precharge according to the judged result in past when the rate of lighting is low, thereby can verily show the brightness of the pixel that low gray scale shows.
Figure 41 illustrates the process flow diagram of pre-charge method shown in the enforcement above.
According to vision signal and pressure precharging signal, when forcing precharging signal effective, no matter the output pre-charge voltage is vision signal.When a plurality of voltage is arranged, the voltage of output is changed with vision signal.Here, if only making when corresponding vision signal is gone in input and the 1st forces precharging signal effective, then the data of the 1st row are carried out precharge, no matter vision signal, thus can avoid the low electric current that causes of the interim source signal line drop of vertical blanking to be difficult to change to the phenomenon of setting.
When forcing precharging signal invalid, then judge the gray scale (412) of incoming video signal.
In small display panel and the low exploring degree display board, the high gray area of Duoing than low gray scale portion can only make electric current change to the rated current value in specified period (1 horizontal scanning period).Therefore, in 412, judge, in the gray scale that can not write rated current, do not carry out precharge, only carry out precharge in the gray scale that can not become rated current with electric current.
Then, under the situation of precharge regulation gray scale of needs or lower gray scale, proceed to 413 (here, for the regulation gray scales, since different because of display board, preferably can utilize external command to set the gray scale of regulation).Do not do precharge according to the vision signal state judgement before 1 row.Current video signal data gray scale is higher than under the preceding data conditions of 1 row, utilizes precharge to form when deceiving, and signal wire changes greatly on the contrary, so do not do precharge.Equally, when identical, do not carry out precharge before gray scale and 1 row yet.
So far in the judgement, all be judged as when carrying out precharge, then with reference to lighting rate, under the high situation of the rate of lighting, no matter judged result is not carried out precharge.Under the low situation of the rate of lighting, carry out precharge according to judgement.
In this explanation, pass through 411 to 414 Overall Steps successively, judge whether to do precharge, but also can pass through Overall Steps.
In addition, the output of precharge power supply 24 has when a plurality of, has a plurality of switches 131, and the output number that can consider to apply judging part also is voltage output number+1 of precharge power supply 24.Because output has voltage output number+1, precharge to judge that signal 55 neither 1, needs N position (2 N〉=voltage output number+1, N is a natural number).The figure place that latchs portion 22 also can be by being adapted to its variation.Figure 40 illustrates 2 precharge and judges example under the signal.The magnitude of voltage of precharge power supply 24 has under 3 the situation, judge that two of signals are 0 o'clock only output current if make precharge, be the cycle that had output the 1st voltage at 1 o'clock entirely, only 55a had the 2nd voltage output cycle at 1 o'clock, only 55b had the 3rd voltage output cycle at 1 o'clock, then, can apply suitable pre-charge voltage by judging signal 55 according to gray-scale Control precharge.
Figure 42 illustrates the circuit block diagram of realizing pre-charge method of the present invention.Whether output makes precharge judgement signal 417, as the judged result of each several part to vision signal 410.Utilize with the identical in fact timing of vision signal 410 on the signal 417 determining source driver sides of judging exported whether carry out precharge.May not need string-and transformation component 427, with Fig. 2 36 in the source electrode driver IC combination that constitutes when being realized, the parts that need to cooperate the input interface of source electrode driver 36 to use.
Vision signal 410 is input to precharge judging part 421 and storage unit 422.
As Figure 41 411 shown in, no matter vision signal 410, when precharging signal 416 is forced in input, carry out precharge owing to form, can insert pressure precharge in the mode of sheltering judged result in whole final stages of precharge determination component.Therefore, among Figure 42, constitute precharge mark generating unit 408 in final stage.If precharge judges that signal 417 carries out precharge with " H " level, the then only running with regard to realizing wishing with logic and this assembly of formation.
Data before 1 row are not carried out precharge during less than current data, so at first data before 1 row and relevant data of going are compared.As this circuit relatively, storage unit 422 and the preceding data comparing section 400 of 1 row are arranged.Storage part 422 has the capacity that the data of share are counted in the output that can keep source electrode driver 36, by vision signal being kept the time of 1 horizontal scanning period, keeps the preceding data of 1 row.By the vision signal 410 and the output of this storage unit 422 are compared, the preceding and relevant data of going of 1 row are compared, and comparative result is input to next precharge judging part.With representing to do or do not do precharge 1 output comparative result.
In addition, under the situation of only using the writeable high gradation data of electric current, owing to carry out precharge, and reference video signal 410, differentiation is greater than or equal to or applies the gray scale that gray scale judges that signal 429 is set less than precharge, and whether output carries out precharge signal.
And then, judge according to the rate of lighting.Light rate judging part 409 according to the rate of the lighting data of calculating 420 with light rate setting signal 418, surpass light 418 decisions of rate setting signal light rate the time, precharge signal is carried out in output.
Import 1 row preceding data comparing section, precharge judging part and light the output of rate judging part and the precharge mark generating unit 408 of forcing precharging signal 416, when carrying out precharge according to pressure precharging signal 416, no matter other signal, precharge signal 417 is carried out in output.Under other situation, only data comparing section, precharge judging part and the rate judging part of lighting are output as when all carrying out precharge before 1 row, export to make precharge mode.
Thus, the precharge mark 417 corresponding with vision signal 410 meets the result's who judges according to the flow process of Figure 41 output.
Need to go here and there-and transformation component 427, so that cooperate the input interface of the source electrode driver 36 of Fig. 3; When parallel transfer vision signal of all kinds and precharge output 417 (every look all has), do not need this transformation component (former state outputs to source electrode driver).
The composition of Fig. 2 illustrates the example that constitutes control IC with another chip, but also can be the one-piece type chip that constitutes with same chip.At this moment, the composition of built-in Figure 41 and Figure 42 in the source electrode driver 36.
Preferably can be with the output voltage values of control such as electronic potentiometer precharge power supply 24.This is because be the precharge power supply that benchmark decision circulation rated current is used with the voltage of EL power lead 64.Among Figure 12, source signal line 60 is wanted circulating current I2, and then according to the relation (Figure 12 (b)) of the drain current-drain-gate voltage of transistor 62, the current potential of source signal line 60 (voltage of EL power lead 64) is-V2.
On the other hand, in the display board shown in Figure 31, EL power lead 64 is supplied with each pixel with wiring 313,314.When all pixel is white the demonstration, at 313 circulation maximum currents; Deceive when showing in 313 circulation minimum currents.At this moment, because 313 cloth line resistance, point 315 is different with the current potential on the point 316.Otherwise during black the demonstration, current potential is equal in fact on 315 and 316.That is, when showing in vain and during black the demonstration, the current potential of EL power lead 64 is different because of the voltage drop of power lead 313.That is to say that even circulate identical electric current I 2, because the voltage drop amount difference of EL power lead 313, the voltage of source signal line 60 is variant.Therefore, 313 voltage drop amount changes the magnitude of voltage of precharge power supply 24, and then the electric current of source signal line changes, thereby the problem that exists brightness to change.
The voltage difference of EL power lead 64 then needs to make the voltage difference that applies on the source signal line 60.Also can make with the rate of the lighting data change voltage in 1 frame.When the rate of lighting was high, the electric current of EL power lead 313 circulations was big, and voltage drop is big, thereby the control electronic potentiometer, and the magnitude of voltage of precharge power supply 24 is reduced.Otherwise when the rate of lighting was low, the voltage drop of EL power lead 313 was little, thereby by utilizing electronic potentiometer to strengthen the magnitude of voltage of precharge power supply 24, can eliminate the uneven luminance that the cloth line resistance of EL power lead 313 causes.
On the other hand, in the large-scale display board, be difficult to write electric current to such an extent that reach setting, thus especially need be on low gray scale in fact each gray scale have magnitude of voltage, write with improvement.Increase the method for precharge in order further to increase magnitude of voltage, to have, but also need the switch 131 of voltage number with power supply 24.Particularly, each source signal line needs the switch of power supply number, thereby takies large tracts of land.
To power supply several 2 N-1, need the precharge of N position to judge signal 55; Because N position signal, the judging part 39 that applies of each source signal line needs control 2 N-1 decoding part that switch is used so the circuit scale of this decoding part increases along with the increasing of N, exists chip area to become big problem.
Like this, owing in each source electrode line numerical data (gradation data) is transformed into simulated data (pre-charge voltage), each source electrode line needs digital-analog conversion portion, causes output voltage several to increase more, and circuit scale is big more.
Therefore, as shown in figure 38, make and only have 1 digital-analog conversion portion 381 in the semiconductor circuit, after only the next data conversion of serial transfer becomes aanalogvoltage, distribute to each source signal line.Therefore, the output 382 of digital-analog conversion portion is input to dispenser and maintaining part 383, will distributes to each source signal line based on the aanalogvoltage of gradation data.
On the other hand, identical with Fig. 2, output meets the method for electric current of gray scale also at shift register with latch portion 384 gradation data 386 is distributed to each source electrode line, and is met the electric current of gray scale by electric current output stage 23 outputs that each source electrode line has.
Before current/voltage selection portion 385 is configured in output to the source signal line, as the part that determines output current whether or voltage.Utilize precharge to judge that signal 380, pre-charge voltage apply judging part 56 and precharge pulse 52 switch current voltage selection portions 385, decision is an output current behind output current or the output voltage.Pre-charge voltage applies judging part 56 and determines whether setting voltage output is carried out the phase, and precharge pulse 52 is when carrying out voltage output, and the output of decision voltage is carried out the phase.
Therefore, digital-analog conversion portion 381 has the analog output stage number that meets grey, the then exportable voltage that meets gray scale, can at first utilize voltage to make the source signal line current change to setting in cycle (being equivalent to horizontal scanning period) of selecting certain row, the current value skew that utilizes the transistor variation of each pixel of electric current output calibration to cause then.
Utilize electric current to make it change to the rated current value, especially in most times that need cost to be longer than or to equal horizontal scanning period of low gray scale portion, but utilize voltage to make the method for its variation finish variation with 1 microsecond in fact, and slightly carry out current correction, have and make electric current change to the advantage of rated current in the horizontal scanning period easily so apply behind the voltage method of circulating current.
For example, with in the semiconductor circuit, only with electric current just can change to rated current value on high-end 128 gray scales in the driving that can do the gray scale demonstration, then output voltage can be used low side 128 gray scale parts.Therefore, digital-analog conversion portion 381 can be 7 bit resolutions, can export 128 kinds of voltages and get final product.When gradation data 386 was in high-end 128 gray scales 1, signal 380 was judged in input precharge, and voltage output is not carried out.Thus, current/voltage selection portion 385 inevitable only output currents.Because the output signal of digital-analog conversion portion 381 does not output to the outside that drives with semiconductor circuit, any value all can.As the simplest method, can ignore input gray level data 386 high-end 1, the corresponding voltage of value of output and 7 of low sides.
Gradation data 386 is under the situation between 0 to 127 gray scale, utilizes precharge to judge signal 380 Control current voltage selection portions 385, and setting will output to the cycle that drives with the semiconductor circuit outside from the aanalogvoltage of digital-analog conversion portion 381.
Thus, can form the circuit that the resolution that makes digital-analog conversion portion reduces.Again, generally under the situation that the pixel of the current mirror of the current duplicator of the p transistor npn npn that uses Fig. 6 or Fig. 4 is formed, voltage is the highest during black the demonstration, and voltage reduces along with forming white the demonstration for the voltage of source signal line.Compare with black change in voltage amplitude to white scope, black change in voltage amplitude to the scope of middle gray is little.Therefore, only be taken as and when 0 to 121 gray scale, under the situation of the composition of output voltage, can reduce the timing range of output voltage.
Again, among the source electrode driver IC36 of the present invention, apply output current behind the voltage, proofread and correct the running of driving transistors deviation, the voltage of output applies and forms in fact that the target current value gets final product, and does not require precision.In view of the above, what the output bias value of the voltage of digital-analog conversion portion 381 output can be than LCD panel is big, so can reduce the circuit scale of this share.General owing to use the scale difference (source electrode line stray capacitance difference) different with the pixel count of direction of scanning (horizontal scanning period differences) of the display board of source electrode driver, the easy degree difference that electric current changes.When using the driver IC of this composition, from the outside input of source electrode driver IC precharge pulse 52, then as shown in Figure 2, become the external signal input because signal 380 and gradation data 386 are judged in precharge, thereby have and only utilize electric current or utilize voltage and current that both can set the advantage of carrying out gray scale gray-scale displayed scope arbitrarily according to display board.The setting of the control IC control tonal range that available Fig. 2 externally forms like that.When utilizing the order input that the running of control IC is changed, can utilize the order input to adjust again.Beyond the outside of source electrode driver IC constitutes the situation of control IC, also can on same chip, be integrally formed source electrode driver IC and control IC as shown in Figure 2, make liquid crystal with seeing on the part of source electrode driver.At this moment, can make the order input that can utilize incorporate IC and adjust tonal range.
According to foregoing invention, low gray scale portion is because the electric current that the source signal linear flow leads to is little, electric current can not change to setting in (horizontal scanning period) at the appointed time, so the brightness that utilizes the pre-charge voltage input to solve the pixel of the next line that carries out white demonstration is higher than the problem of setting.
Fig. 8 is the figure that reference current generating circuit is shown.In the composition of output stage shown in Figure 10, reference current is stipulated the current value (reference current 89) of each gray scale.
In Fig. 8, by the resistance value of the current potential and the resistive element 81 of node 80, decision reference current 89.
And, can the current potential of node 80 be changed according to control data 88 by voltage adjustment part 85.
Show the transistor scale of using current source 103 according to the gray scale of carrying out electric current output usefulness, produce the output current deviation of each terminal.Figure 11 illustrates the relation of transistor scale (channel area) and output current deviation.Consider the reference current deviation, need make in the chip, the deviation between the terminals of adjacent of chip chamber is in 2.5%, thereby the output current deviation among Figure 11 (current deviation in the output stage) is good smaller or equal to 2.5%, and 103 transistor scale is good more than or equal to 160 microns squares.
Use in the display board of organic illuminating element, only put circulating current in the bright pixel, non-some bright pixel be circulating current not.Therefore, whole image shows electric current maximum when white, and whole image shows circulation minimum current when black.
Need make the capacity of maximum current circulation to the power circuit of display board supplying electric current.Yet the situation that the picture of formation circulation maximum current shows is few.For the maximum current that few chance only takes place the high capacity power circuit is set, waste is big.And, in order to reduce power consumption, need reduce maximum current as far as possible.
Therefore, as the method that reduces to increase electric current, be overall 6 one-tenths or more for a long time at white display pixel, make the brightness reduction about 2%～3% of whole pixels.Like this, then maximum current reduces 2%～3%, and the power during peak value reduces.
In order to realize this method, make the value of the reference current 89 that the reference current generating unit 26 of the electric current of each gray scale of decision produces change about 2%～3%, just can realize.
Therefore, according to the value of display mode change control data 88, make the change in voltage of node 80, thereby change reference current 89.
Like this, in order to change the value of control data according to display mode, the control that needs to differentiate display mode and change control data according to the differentiation result.Therefore, utilize control IC28 to carry out this differentiation usually.
Therefore, from control IC28 be input to source electrode driver IC36 signal wire quantity except that video signal cable, also have the quantity of the control data line of electronic potentiometer.So the input and output terminal of two IC increases, be under the situation of 18 (6 of all kinds) be controlled to be 6, video signal cable of electronic potentiometer, need 24 terminals.
And because built-in precharge power supply 24, the register of the output voltage of precharge power supply 24 is set in existence.By the threshold voltage decision pre-charge voltage of the TFT characteristic of display board and organic illuminating element, thereby need each different display board to set different magnitudes of voltage, and need at least from external setting-up 1 time.In order to set 1 time external input terminals is set, efficient is poor.
Reduce input/output signal line quantitative aspects, dwindle chip area, simplify the outside and connect up back and forth effectively.
Therefore, among the present invention, data line and address wire are connected between control IC and the source electrode driver IC, high speed serialization transmits vision signal and various setting signal, thereby reduces the signal wire number.Also serial transfer 3 primary color red are turquoise for vision signal.
Fig. 1 illustrates the sequential chart of data line and address wire.Behind the input driving pulse 16, transmit the pixel data of 1 row share from data line 12.Then, transmit the data of control usefulness.Electronic potentiometer setting value etc. for example.What the data that circulate for judgment data line 12 are, with the data sync transfer address 13 of data line 12.In this example, the data of address wire 13 be 0 o'clock be red data, 1 o'clock is green data, 2 o'clock is blue data.Value more than or equal to 4 is an order data.
For the data of distributing serial transfer, Figure 18 illustrates the block diagram of dispenser 27.Constitute dispenser by 2 grades of registers or latch cicuit in the vision signal, then constitute this one in other order data with 1 grade.
Only import the data that need by the 1st grade of register or latch cicuit 182, and vision signal 11 is adjusted the timing of 3 chrominance signals, the carry pulse of next shift register portion 21 can be extended.Thus, take out video data 11 shown in Figure 1.Utilize shift register 21 to give each output with this data allocations.
Figure 28 to Figure 30 illustrates the 2nd example that reduces the signal wire number.
This example is the method that each look has signal wire and serial transfer data of all kinds.Transmit the vision signal corresponding successively, and utilize blanking interval to transmit command signal with each point.Figure 30 illustrates the relation of the interim transmission of 1 horizontal scanning.Carry out the identification that vision signal transmits phase 301 and order transmission phase 302 by data command mark 282.Each data command mark 282 is put on 1 data (this example is used 1 in the red data) at top of the data 281 of 1 pixel share and judged that if high level, these data are judged as video data, low level then is judged as order.Whether this data command mark 282 can be in any part of 1 pixel share 281, can at first differentiate the data of input and order but be in top, thereby handle easily.
In this example, the data 281 of 1 pixel share comprise 6 secondary data and transmit, and transmit 11 signals that signal 55,8 digital video signals are judged in 3 precharge by 2 signal line with 6 times of speed.Figure 28 illustrates details.At first, transmission precharge sends vision signal group 284 after judging the group 283 of signal 55.Be not subjected to this sequence limit.Form in order to make red data, green data, blue data be identical circuit, signal 55, vision signal group 284 are judged in the transmission precharge of the data of 1 share of best empty starting end.Because the serial transfer vision signal, by string-and transformation component, be transformed into parallel after, be input to shift register.Output after the red data serial conversion of 286 expressions regularly.
The cycle of 285 expressions can be used as the blanking data and transmits.In this example, formation will be input to source electrode driver with 3 grades of signal wires that serial transfer is sent here, after serial converted is made in source electrode driver inside, carry out the signal of gate drivers is supplied with, thereby (use in the display device of organic illuminating element at the signal of 3 grades of signal wires of cycle 285 input, rated current is circulated in determined pixel, and EL that the pixel selection of usefulness uses with the electric current of gate drivers and continuous flow pixel storage lights with gate drivers, each driver needs clock respectively, starting impulse, direction of scanning control, output starts terminal, then need 8 signal line altogether, when sending signal wire with 13 grades of signal wire in 2 intervals of 6 intervals and 285, available 1 pixel is regularly carried out the Waveform Control of gate drivers.Can do thinner control.In order to realize this point, except that the interval that the serial transfer of signal line is used, also need 285 interval).
Figure 29 illustrates the example that the data when sending order transmit.Often the figure place of each order is just enough about 6, thereby gathers whole RGB data in this example, is taken as 6 signal, and the data of 5 shares after the input data command identification signal 282, as order.Even blanking interval also needs the gate drivers running, thereby import the signal that gate drivers is used, no matter the value of mark 282 in the interval of gate line and 285.
In the regularly identical signal with data command mark 282, the interval of the signal of using except that the input gate drivers, the idle data that also has 3 shares.This part can be taken on the short order of figure place length, but needs to set 5 or when more ordering, as command address.Have among Figure 29 be less than or equal 10 be that example is expressed as 292 1 order of the bit address to carry out the source electrode driver that order accepts.The command register that change is upgraded according to 282,292 value.Owing to transmit 1 secondary data, can not need to go here and there-and transformation component, internal register input (the electronic potentiometer input of decision precharge power supply 24 etc.) directly upgraded.
By utilizing Figure 28 to input interface multiplex vision signal shown in Figure 30 and precharge judgement signal, and carry out order input in the non-video signal transmission phase, be 10 at command number, command bit length is that making in the past, 93 incoming line reduces to 6 signal line under 6 the situation.
Energy is setting signal line number and transfer rate arbitrarily, and the signal wire number can be set minimum for and be 1 of all kinds, is the required signal figure place of each pixel of all kinds to the maximum partly.When the signal wire number reduced, clock frequency raise, and the outside is difficult wiring back and forth, thereby preferably is taken as the signal wire number of data transfer rate smaller or equal to 100MHz in the practicality.Among the present invention,, be taken as the only frequency partly of clock, carry out the data input at two ends because EMI (electromagnetic interference (EMI)) is reduced.
Moreover, as input signal, even the signal of non-CMOS level also can utilize differential transmission to send.When making differential transmission, general signal wire amplitude reduces, thereby has the effect that EMI reduces.
For clock and the data line that reduces to transmit at a high speed, as the input mode of Figure 16, the RSDS mode that available difference according to 2 input signal cables (161 and 162) is taken out clock signal 164 sends.165 and 166 is that electric current is sent the resistive element that signal transformation becomes magnitude of voltage to use.Determine the value of this resistive element according to the standard of transmitter side.By this input terminal being enrolled whole signal wires of Figure 28, load mode is taken as differential transmission, realize the little driver of EMI.
Thus, can realize the source electrode driver IC36 that the input signal cable number is few.
Figure 70 illustrate utilize Figure 73 736 shown in the summary of the driver IC of current duplicator when form forming the electric current output stage form.
In the current duplicator circuit, make input current flow to driving transistors 731, and determine the voltage of node 742 according to the magnitude of current of circulation by switch 734 and 735.In order to keep this voltage, 732 pairs of electric charges of memory capacitance are set store, from the face sustaining voltage.Behind the storage input voltage, make switch 734 and 735 be nonconducting state, thus the storage input current.During output current, be conducting state, make the electric current that adapts to memory capacitance 732 charge stored amounts flow out to 731 by making 733 transistor.Utilize the drain current-grid voltage characteristic storage input current of this driving transistors 731, having can no matter how the transistor characteristic deviation that output causes all exports the advantage of the electric current identical with input current.
And the current duplicator circuit also has memory function because input current temporarily is stored in memory capacitance 732 laggard line outputs.Therefore, the current duplicator circuit is had the input data allocations to making the regularly function of the consistent portion that latchs of data output behind each lead-out terminal, so in the composition of Figure 70, can not use the portion of latching, and the vision signal that serial transfer comes is distributed to each output.
The current duplicator circuit after digital-analog conversion portion 706 becomes to meet the analog current (being gray scale current signal 730) of gray scale with video signal conversion, utilizes the output signal of transistor 21 to be assigned to each output owing to can keep analog current in advance.The electric current holding unit of using at the electric current that keeps distributing 702 forms the current duplicator circuit.
As indicated above the carrying out like that of current duplicator circuit temporarily keeps back output to adapt to the running of the electric current of input current input current, thereby can not output current during the storage input current, and carry out electric current when output, can not input gray level current signal 730.
There is the problem that changes to the rated current spended time in the image element circuit in electric current output to display board, the long-time continuous output current so best level was tried one's best in sweep time.Therefore, the best normal output current of source electrode driver IC.
Therefore, the also normal continuous output current of output stage for the current duplicator circuit is formed is formed in same lead-out terminal 2 current duplicator circuit is set, and when 1 storage gray scale current signal 730, another outputs to the driver IC outside with electric current.
Figure 73 illustrates the circuit of output stage.2 holding circuit 736a and 736b constitute current duplicator.Selecting signal 738 is which that be used for determining making 2 holding circuits is the signal of output and which storage gray scale current signal 730.Select signal 738 each horizontal scanning period to change, make each horizontal scanning period change holding circuit 736, thereby can carry out the electric current output of adaptive video signal.By making, can determine the holding circuit that is used to export according to selecting signal 738 to change the state of the electric current output of holding circuit 736 with transistor 733.
When 2 holding circuits 736 are not exported, all be taken as low level realization electric current by the anti-phase output 739 that will select signal 738 and selection signal and export continuously.738 and 739 may not insert into anti-phasely, but 2 inequality signals are high level.As other method, can make 738 and 739 always for anti-phase, and enabling signal is set separately, the result of the logic product of input 738 and 739 in the signal of gauge tap 733, thus carry out same running.
Finish each output distribution gray scale current signal 730 by shift register 21 and electric current holding unit 72.Then, the circuit that produces gray scale current signal 730 is described.In order to become gray scale current signal as the video signal conversion of logical signal as simulating signal, digital-analog conversion portion 706 is set, and the electric current of output adaptive video signal.Figure 71 illustrates the circuit example of digital-analog conversion portion 706.
It is formed from the every corresponding electric current of outside input with vision signal, and electric current (gray scale reference current 1～gray scale reference current 8) with respect to correspondence, utilize grey scale signal 711 gauge tap 712 in the mode that current value conforms to, thereby output meets the gray scale current signal 730 of grey scale signal 711.Make from specified signal 1 (711a) successively under specified signal 8 (711h) and the corresponding situation in least significant end position to most significant end position, set current value, make 2 times of gray scale reference current 1 (700c) to be gray scale reference current 2, in the broadest sense, make 2 times of gray scale reference current n to be gray scale reference current n+1 (n is more than or equal to 1 and less than the integer of figure place) here, and import.
Thus, switch 712 is become conducting state gray scale reference current 700 and as gray scale current signal 730 output.
Then, the method that bears gray scale reference current 700 and be input to digital-analog conversion portion 706 is described.
Shown in Figure 78, produce gray scale reference current 700 by gray scale reference current generating unit 704.Be taken as great reference current 781 according to the electric current that will set each gray scale, utilize output such as current mirror composition to meet the gray scale reference current 700 of the position of vision signal.Here, during 8 outputs, there are 8 outputs in gray scale reference current 700.Need the accurately electric current of the current value of current value * 2=gray scale reference current n+1 of output formation gray scale reference current n, thereby, output current is changed preferably by changing the quantity of the transistor 782 of implementing current mirror.Under the situation of the method, the gray scale height, but have the big shortcoming of circuit area.On the other hand, the transistor 782 that produces each gray scale reference current 700 is taken as in each cycle successively electric current is each 1, and by changing channel width, gray scale reference current 1 to 8 is changed, but electric current is not accurately consistent with channel width, thereby needs to utilize simulation that channel width is changed with operation.Therefore, compare with the transistorized method of arranging the number share, gray scale may reduce.So, shown in Figure 78, the gray scale reference current is divided into groups in low gray scale portion and high gray scale portion, and by changing channel width between low gray scale portion and the high gray scale portion, current value is changed, and changing transistorized number between the low gray scale portion and between the high gray scale portion, thus the change electric current.
Among Figure 78, to hang down gray scale portion and be taken as 2 of low sides, high gray scale portion is taken as high-end 6, with comparing with the transistor of the dotted line shown in 784, about 1/4 channel width is (more than or equal to-10% to less than+50%, because of operation fluctuates) form the transistor of the dotted line shown in 783, thus can realize keeping gray scale and the little gray scale reference current generating unit 704 of circuit scale.
Owing to is 1, in the time of improving gray scale, shown in Figure 80, can utilize number of transistors to make electric current change (because circuit area with respect to totally smaller or equal to 10%) for the driver IC circuit.
Shown in Figure 81, can realize reference current 781 by utilizing resistance, operational amplifier etc. to constitute constant current source.Also can utilize control data 88 to change the current value of reference current 781.The control of this reference current 781 plays a part to suppress power, prevent to burn, improve contrast.
Above-mentioned such gray scale reference current 700 that forms can be input to digital-analog conversion portion 706, but directly connect, then when connecting multiple source driver IC36, be difficult to whole switches and supply with gray scale reference current 700 by error smaller or equal to 1%.
Each chip is provided with reference current generating unit 703 and gray scale reference current generating unit 704, the mean-squared departure of the deviation in the current mirror of the deviation of reference current generating unit 703 of Figure 81 and Figure 78 or Figure 80 then takes place in the gray scale reference current 700, thereby according to chip, the current value of possible certain gray scale is variant, each chip generation uneven luminance.Reduce the deviation aspect that the minute surface ratio deviation of current mirror causes, can realize by strengthening 782,801 transistor scale, but will make deviation smaller or equal to 1%, then need be more than or equal to the scale of 10000 square microns.
Eliminate deviation under the small-scale and each chip is supplied with gray scale reference current 700, its method is: to 1 display part, use 1 gray scale reference current generation 704 generation gray scale reference currents 700 from 1 reference current generating unit 703, distribute to each chip.Fig. 7 exports this notion.
Supply with the whole chips that comprise 36a by the gray scale reference current 704 that source electrode driver 36a is produced, supply with agonic electric current in each chip.Here, need not simultaneously to 2 or more source electrode driver IC36 supply gray scale reference current 700.Different with voltage, under the situation of electric current, connect a plurality of drivers, then shunt, thus the gray scale reference current value difference of 1 driver IC circulation.Therefore, consider to constitute the switch 712 that utilization has digital-analog conversion portion 706, make not input gray level reference current 700 simultaneously of a plurality of driver ICs 36, and produce when meeting the gray scale current signal 730 of vision signal at some IC, the switch 712 among other IC all is a nonconducting state.
Output signal during to electric current holding unit 702 supplying electric currents makes 1 in the output of shift register 21 is imported.At this moment need gray scale current signal 730.That is, input driving pulse 16 and the cycle before the next stage IC36 output pulse of 701 pairs of cascades of carry output are the cycles that needs gray scale current signal 730.
Therefore, beyond the cycle that shift register 21 is exported, the switch 712 of digital-analog conversion portion 706 is ignored grey scale signal 711, always is nonconducting state.In order to realize this point, chip start signal generating unit 707 is set, when shift register operates beyond, make that switch 712 is total to be nonconducting state.Chip start signal generating unit 707 only allow input driving pulse 16 go forward side by side advance before the position output 701 during export pulse, video signal conversion is become analog current.Accurately, during the interior Output Shift Register output 719 of same chip during this period.Driving pulse 16 might change because of relation and the shift register composition 21 of input data with driving pulse 16 with the relation of shift register output 719 with relation, the carry output 701 of shift register output 719, so adjust during this period according to driving pulse 16 and carry output 701, with output enabling signal 821.Figure 82 illustrates the circuit diagram of the digital-analog conversion portion 706 corresponding with enabling signal.Chip start signal 821 behind the input driving pulse 16 to carry out carry output 710 during be high level state, gray scale reference current 700 is output into gray scale current signal 730 according to grey scale signal 711.During other then chip start signal 821 be low level signal, thereby switch 712 is nonconducting state, not supplying electric current always.
Figure 83 illustrate interim certain driver IC of 1 horizontal scanning (chip 1) chip start signal 821, select the sequential chart of signal 738, gray scale current signal 738, grey scale signal 711.
Select signal 738 according to timing pip 29, each horizontal scanning period changes, and decision make gray scale current signal 738 store into to 1 output have 2 holding circuit 736 which, whether another export the electric current of storage.In cycle 831a,, and make gray scale electric current 730 store holding circuit B (736b) into from holding circuit A (736a) output current.
Export storage successively one by one, and which output is stored by shift register 719 decisions to gray scale electric current 730.And, owing to be taken as the wiring that a plurality of driver ICs is distributed reference current,, only during shift register work, utilize chip start signal 821 to make 706 runnings of digital-analog conversion portion, with circulation gray scale electric current 738 in order to prevent shunting.The chip start signal 821 of chip 1 only in as chip 1 shift register work during cycle 832a become high level signal.During cycle 832b (shift register beyond the chip 1 carries out work), chip start signal 821 is a low level, and gray scale current signal 738 does not circulate.Therefore, can do branch's wiring to a plurality of driver ICs.Compare with distribution,, can accurately supply with identical electric current owing to distribute with time division way based on current mirror etc.
Current duplicator being set and each is exported the method for distributing the gray scale electric current in each output can be regardless of the characteristic deviation of driving transistors 731, the identical electric current of electric current of output and storage, thereby be not easy to take place output bias.Yet, owing to be called the phenomenon of " bust ", output current possible deviation.
In the holding circuit of Figure 73, when making the signal of signal line 741 be high level, storage gray scale electric current.For example establish the electric current of storage lime degree, then shown in Figure 74, in the driving transistors 731, drain current is lime degree electric current (being Iw here).At this moment, according to the I-E characteristic (Figure 75) of driving transistors 731, the voltage of node 742 is Vw (cycle 747).
Cycle 747 finishes, and finish holding circuit 736 storaging currents, thereby signal line 741 is varied to low level.At this moment, the voltage drop of signal line 741 utilizes capacitive coupling to make the voltage of node 742 also reduce VG by the grid capacitance of transistor 735a.Therefore, the drain current of driving transistors 731 also reduces IG from Iw.
Because be somebody's turn to do " bust ", output current may change according to terminal.For example establish exist have Figure 76 765,766 shown in the driving transistors 731 of I-E characteristic.The voltage of node 742 (being the grid voltage of driving transistors 731) is when changing VG owing to bust, the drain current of driving transistors 765 is Iw1, the drain current of driving transistors 766 is Iw2, and this electric current flows to the outside by output signal line 737, makes output current produce deviation.The difference of Iw2 and Iw1 more than or equal to 1% o'clock, influences display quality in the mode of uneven luminance with respect to their average current.
If the grid capacitance of transistor 735 is Cgs, the electric capacity of memory capacitance 732 is Cs, and the amplitude of signal line 741 is Vga, at the voltage variety VG that then uses VG=Vga * Cgs/ (Cgs+Cs) expression node 742.
In order to reduce VG, reduce Cgs or Vga, perhaps strengthen Cs.The method that strengthens Cs makes chip-scale become big, thereby has any problem on the reality.Vga has the amplitude of analog power voltage share basically.When reducing this voltage, the voltage amplitude of lead-out terminal reduces, thereby the exportable dynamic range of electric current reduces.When only making signal line 741 reduce high level voltage, need the power supply of these signal line 741 usefulness, thereby number of power sources increases.Number of power sources increases brings power circuit to increase, thereby is difficult to realize this method.
Therefore, among the present invention, consider to reduce the grid current Cgs of transistor 735.Only reduce under the situation of scale of transistor 735, the drain current during blocking-up increases, and the electric charge that memory capacitance 732 keeps moves by transistor 735, thereby produces the problem that the potential change of node 742 causes rated current not circulate.
Consideration is divided into 2 or more with transistor 735, and reduces the wherein transistor of the most close memory capacitance 732.Figure 77 illustrates the circuit of the electric current holding unit 702 when being divided into 2.
If with transistor 735 be divided into 2 and by 775 and 772 these 2 constitute.Compare 772 raceway groove small scale with transistor 775.And the signal wire that connects grid separately separates, and utilizes the control of grid enabling signal 711, makes transistor 772 to 775 early form nonconducting state.Figure 79 illustrates sequential chart.
Making a plurality of transistorized advantages is: make 2 transistorized signal line waveform differences, transistor 772 near memory capacitance 732 at first is a nonconducting state, 775 is nonconducting state then, thereby " bust; depend on grid capacitance Cgl, memory capacitance Cs, the grid amplitude Vgate of transistor 772; because Cgs＞Cgl can make VG itself reduce.And, in order to keep the electric charge of memory capacitance 732, make signal line 741 change to low level, so as 772 become nonconducting state fully after, 755 is nonconducting state.755 drain current reduces, thereby is designed to the value increasing of transistorized channel width/channel length.2 transistors of connecting have the little advantage of drain current, again since between transistor 755 and memory capacitance 732 with nonconducting state insertion transistor 772, thereby the advantage that has that signal that 775a does not take place causes to " bust " of node 742.
Like this, be divided into a plurality of with being connected the grid of driving transistors 731 and the transistor between the drain electrode, make the transistor of the most close memory capacitance 732 in the mode that reduces the raceway groove scale, and make it more early for nonconducting state than other transistor, thereby eliminate the problem that electric charge leaks, can realize that the bust amount reduces.
Moreover about the channel width/channel length (hereinafter being called W/L) of driving transistors 731, preferably the value of W/L reduces.
Figure 84 illustrates I-E characteristic.The value of W/L is more little, and slope is more little, and the reducing of the magnitude of current of gray scale current signal 730 storage back " bust " when causing the grid voltage of driving transistors 731 to reduce VG, and curve 841 is bigger than curve 842.Therefore, reduce in order to suppress the drain current that " bust " cause, the W/L that preferably makes driving transistors is smaller or equal to 0.5.At this moment with respect to setting electric current I w, the reduction amount is smaller or equal to 1%.Because the influence that the chip area that the minimum manufactured size of channel width, extension channel length cause increases need make lower limit more than or equal to 0.002.
In sum, by forming the output stage of using the current duplicator circuit, realize the little driver IC of output bias.
In the source electrode driver of large-screen display board, need transmit vision signal at a high speed, thereby signal wire frequency height, cause the problem that has the radiated electromagnetic wave noise.Again, in the display board of televisor etc., the signal wire figure place of input increases, thereby has problems such as signal wire is many.
Therefore, decision transmits vision signal with little amplitude signal.Source electrode driver 852, gate drivers 851, controller 854 that at this moment Figure 85 illustrates are connected with power supply module 853.What wherein carry out the small-signal transmission is the high clock of signal frequency 858, synchronizing signal 857, video signal cable 856.
Figure 86 illustrates the load mode of video signal cable 856.Form the transmission phase (data transmit the phase 965) and the blanking interval 866 of the data that output to pixel in 1 horizontal scanning period 864.May not there be blanking interval.
Source signal line number (being divided into signal wire number/chromatic number (being generally 3 looks) during colored display board) dividing data by display board transmits the phase 865.Cycle after dividing is taken as the cycle 862.In this cycle 862, transmit whether decision is inserted the data of all kinds 861 of RGB and met gray scale at the top of level phase 1 the precharge mark 862 that applies voltage by video signal cable 856.Available any means transmits video signal data 861 and precharge mark 862, comprises according to the situation of the constraint that transmits signal rate, the signal wire number whole numerical digits of parallel transfer together to the situation of serial transfer by turn.
Again, large-scale with in the current driver, the source signal line stray capacitance that causes greatly because of the display board scale increases, pixel increases the horizontal scanning period that causes and shortens electric current in 1 horizontal scanning period can not to change to the problem of setting remarkable.Therefore, must be before utilizing electric current to show the regulation gray scale, temporarily utilize voltage to make the source signal line states change near the regulation gray scale after, utilize electric current to make it change to rated current.
Figure 89 illustrates the composition example of source electrode driver.The source electrode driver here illustrates the source electrode driver 852 of Figure 85.Vision signal is made little amplitude signal with clock and synchronizing signal and is transmitted, thereby vision signal is input to the differential input sink of using do level translation in the source electrode driver side 893.Video signal conversion is become the gradation data 386 of CMOS or TTL level.Gradation data 386 is input to shift register and latchs portion 384 and pre-charge voltage transformation component 884.By shift register with latch portion 384 gradation data 386 is distributed to each output, the gradation data that distributes is transformed into the magnitude of current that meets gray scale by electric current output stage 23.Thus, can meet the electric current output of gray scale.On the other hand, gradation data is input to pre-charge voltage transformation component 884 simultaneously.Pre-charge voltage transformation component 884 utilizes the circuit shown in Figure 88 to form, and 885 outputs meet the voltage of gradation data according to signal.Can make the change in voltage of output according to the value of the transformation matrix and the resistive element 833 of precharge level transformation component 882.
Electric current writes interim pixel and the equivalent electrical circuit between the source electrode driver is the circuit shown in Figure 12 (a).At this moment, the electric current when establishing white the demonstration is I3, and the electric current during black the demonstration is I1, and then the mobility scale of pre-charge voltage output is the scope of the V3 to V1 of Figure 12 (b).The value of V3 and V1 changes according to the raceway groove scale of the driving transistors 62 of pixel, and for example channel width is more little, and the difference of V3 and V1 is big more.Among the present invention, from the outside add configuration Figure 88 883 shown in 2 resistive elements, and can set resistance value arbitrarily so that can export because of the different magnitude of voltage of display board (pixel transistor composition), thereby the voltage of the various display boards of can opposing is exported.In the red, green, blue, the electric current-light characteristic difference of general organic illuminating element, thereby the value difference of I1 of all kinds, I3, result make V1 of all kinds, V3 also different.Therefore, the pre-charge voltage transformation component shown in Figure 88 884 needs the source electrode driver of 3 circuit.External resistor value difference of all kinds.Figure 85 and Figure 89 describe 1 circuit, but 3 circuit of physical presence RGB.
Utilize dispenser and maintaining part 383 to make the above-mentioned voltage distribution of exporting according to gray scale like that arrive each output.Thus, each output is distributed electric current that meets gray scale and the voltage that meets gray scale.By the either party in current/voltage selection portion 385 selection output currents and the voltage.
Apply judging part 56 decision by pre-charge voltage and select in electric currents and the voltage which side.Pre-charge voltage applies judging part 56 to be judged according to precharge pulse 451 and precharge startup 895, only carries out applying voltage under the situation of precharge signal at input precharge pulse 451 and precharge startup 895 outputs.
Thus, shown in the output 901 of Figure 90, if the voltage corresponding with gradation data Dn (n is a natural number) be VDn, with the corresponding electric current of these data be IDn, then precharge judges that signal 383 is for high level and when carrying out precharge, in 1 horizontal scanning period behind the output VDn, output IDn (VDn apply phase depend on the pulse width of precharge pulse 451).Otherwise, when low level, do not export VDn, during 1 horizontal scanning period, only export IDn (Figure 47 illustrates the roughly sequential chart of electric current output or voltage output).By utilizing precharge to judge signal 383, after being difficult to change to the low gray scale portion of the electric current corresponding, utilizing voltage that the source signal line states is roughly changed, utilize electric current to make the source signal line change to the rated current value with the regulation gray-scale value.On the other hand, in the 2nd row and subsequent row when high gray scale portion and the same gray scale of the continuous demonstration of multirow, because the source signal line can change to the rated current value and multirow consecutive hours source signal line states needn't change easily in the high gray scale portion, do not need to utilize change in voltage to the regulation gray-scale value, judge that signal 383 carries out precharge control (when utilizing voltage to change under this state so can not utilize precharge, may produce the uneven luminance that the characteristic deviation of the driving transistors 62 of image element circuit causes, thereby be good) not apply voltage.Precharge judges that signal has like this according to the source signal line states decision and whether carries out precharge advantage.Therefore, even each many 1 of the every look of data volume that needs to transmit on the video signal cable 856 also transmits.
Utilize order wire 847 that precharge pulse 451 is input to source electrode driver to precharge phase, thus can be according to the pulse width of precharge phase setting value change precharge pulse 451.Thus,, carry out voltage output, and make the electric current period of output that forms regulation brightness long as far as possible, thereby be convenient to the uneven luminance of the characteristic deviation of the driving transistors 62 that correction voltage produces in setting in the shortest time that precharge needs according to screen size.Owing to reduce the signal wire number of order wire 847, shown in Figure 87, constitute and utilize serial transfer that 1 bit data is sent to source electrode driver.The order that source electrode driver needs is set 872 except that precharge phase, only reference current setting 871 and the driver output enabling signal of using for the change reference current value.These signals are not frequently rewritten, and get final product even frequently carry out rewriting 1 time in 1 horizontal scanning period yet.In the address of Figure 87, be 15 all, the clock 871 that shift register is used in the source electrode driver can be more abundant than the time that changes in 1 horizontal scanning period, so can not be subjected to the influence ground of electromagnetic wave noise to transmit signal.Therefore the signal wire number can be 1.Again, the differentiation of the data of circulation is set by for example making reference potential with 8 shares of next clock of leaving timing pip 849 from high-end position to the order of low side position in the order wire 847, secondly set for precharge phase, for the output enabling signal, then do not need command determination line (address setting) at last.Thus, can set source electrode driver with few signal wire number.And the reference current generating unit 891 that constitutes input reference current settings signal can be utilized electronic potentiometer change reference current, and changes the electronic potentiometer value according to setting signal, thereby changes reference current (Fig. 8 illustrates and forms example).
When constituting vision signal with even bit of all kinds (10 for example of all kinds, 30 altogether), to each 1 precharge mark 862 of interpolation of all kinds, thereby all the figure place summation must be odd bits (during this example being 33).When carrying out the low-amplitude signal transmission, wiring transmits with twisted pair substantially.Under situation about transmitting on 33 the signal wire, need 66 lines when transfer rate is identical with driver.Here, wiring quantity is many, thereby conventional transfer rate is brought up to respect to the driver clock is that certain multiple ground transmits, and makes the corresponding minimizing of wiring number.For example under the situation with 2 times of speed transmission, when transmitting each 17 in 1 transmission, can transmit 34.Wherein, by by 33 input data, data are carried out 2 times of speed transmit.Yet, compare with 34 of actual transfer capabilities, be equivalent to transmit 1 clear data.Equally, when transmitting with even multiples, must transmit 1 clear data in the data of odd bits, obviously the signal wire utilization factor is low.That is, even increase by 1 bit data, also not shadow to transfer rate (multiple of clock), signal wire number.
Therefore, among the present invention, decision is added data/Command Flags 911 in each vision signal of RGB and precharge mark, thereby the value that can make this data/Command Flags 911 is at for example 1 o'clock, transmit vision signal and precharge mark, carried out the various registers of source electrode driver at 0 o'clock and set.Figure 91 (a) illustrates data and transmits, everybody composition when Figure 91 (b) illustrates various registers and sets, and Figure 92 illustrates the transmission timing that data transmit and various register is set.Utilize and transmit vision signal all of all kinds and the blanking interval behind the precharge mark in 1 horizontal scanning period, the various registers that utilize data/Command Flags 911 to carry out source electrode driver are set.Here, shown in Figure 91 (b), set reference current setting and pre-charge voltage and apply the phase.
Like this, just do not need the order wire 847 of Figure 85, can reduce the signal wire number.
Figure 93 illustrates the block diagram of source electrode driver.Order data is separated from video signal cable 856 with vision signal, thereby to add vision signal and order separated part 931 that little amplitude signal is transformed into the circuit of CMOS level usefulness are differences with the composition of Figure 89.
Precharge mark and video signal cable are synchronously transmitted and need carry out to transmit video signal cable and precharge mark or video signal cable, precharge mark and various register with same signal wire at a high speed according to little amplitude signal and setting among the source electrode driver IC that various registers set.Thus, wiring, various register that can reduce the precharge mark needs are set the quantity of the wiring of usefulness, and the electromagnetic wave noise can reduce to transmit at a high speed the time.
In the display board of small-sized purposes, arrangement of components is spatially restricted, need do one's utmost to reduce the signal wire number that is drawn out to the display board outside.Compare with large-scale display board, figure place showing is few, so the video signal cable transfer rate is low.Therefore, shown in Figure 94 and Figure 95, in the video signal cable 856, remove data (the RGB data of all kinds that the multiple connection gray scale shows usefulness, here be taken as R data, G data, B data) and this gray scale video data judged whether to carry out outside the precharge precharge mark 862, also send gate drivers control with data 951.Send the signal wire that both control of gate drivers A (851a) and gate drivers B (851b) needs.The signal that sends is the signal of shift register work clock, driving pulse, output enabling signal and the decision direction of displacement used.Export enabling signal and with the unit of several microseconds signal line states is changed sometimes, thereby not only transmit the phase 962 but also, transmit gate drivers control data 951 among Figure 96 at blanking interval 963 in data.Therefore, shown in Figure 95 (b), except that transfer source driver setting signal, also transmit gate drivers control data 951.Thus, except that power lead, available minimum 2 pairs of rope-lay conductors and 3 signal line constitute the signal wire of drawing from display board.
When the minimizing signal wire was counted, transfer rate improved, thereby was contained in the power consumption increase of the clock produce department of transmitter side controller 854.Usually, carrying out the little amplitude power when transmitting is the power that clock produce department consumes substantially.Therefore, require the equipment of low-powerization to increase the quantity of the rope-lay conductor that is used for video signal cable 856, reduce transfer rate, thereby make power consumption reduce (signal wire power consumption be clock produce department power consumption 1/10th to 1/20th).Serializable transmit successively Figure 96 964 shown in cycle in Figure 95 (a) of sending serial data or according to the part or all of serial data of quantity parallel transfer of video signal cable 856.
The data of separating the video signal cable 856 of doing little amplitude transmission like this with source electrode driver 852.Figure 98 illustrates the intraware of source electrode driver 852.It is characterized by: have the synchronous gradation data 386 of the source electrode driver clock that is used to export clock 853, video signal cable 856, generates with starting impulse 848 to clock 858 871, vision signal and the order separated part 931 that signal 383 and gate drivers control line 941 are judged in precharge.Shown in Figure 95, the gate drivers control signal must be being sent with vision signal and the corresponding mode of order, thereby energy be demodulated to the signal synchronous with source electrode driver clock 871 as Figure 97.Like this, just will not be drawn out to the display board outside by the signal line, can realize the display board that signal wire quantity is few.And, have by exporting synchronously the advantage that makes the timing of source electrode driver and gate drivers be convenient to aim at source electrode driver clock 871.Owing to do not need the control line of controller 854 to gate drivers 851, the lead-out terminal quantity of controller 854 is few, can make controller 851 with less packaging part again.
Compare with the composition of Figure 93, the composition of Figure 98 produces and exports the assembly difference of pre-charge voltage.Among Figure 93, produce the adaptive video voltage of signals, and it is distributed to each output with analog chip, but a plurality of voltage distribution of among Figure 98 voltage being set the pre-charge voltage generating unit 981 of line 986 decisions are given each output stage, and are selected and apply judging part 982 to judge a plurality of voltages of output or only carry out electric current output by pre-charge voltage.Therefore, do not need dispenser and maintaining part 383.Compare with large-scale display board, in the small display panel,, write the high-side current value easily because 1 horizontal scanning period is long and stray capacitance source electrode line is little.Therefore.This source electrode driver is a prerequisite only not apply voltage with the also writeable high gray scale of electric current portion, reduces the quantity that produces magnitude of voltage, seeks to reduce circuit scale.Be taken as 3 value output voltages in this example.The quantity of magnitude of voltage is changed to about 7 from 1.
The pre-charge voltage output intent of adaptive video signal data is described.Utilize the method for Figure 95 (a) to send vision signal and precharge mark in pairs from video signal cable 865.Under the situation of colored display board, send each 1 pair of RGB respectively.Owing to utilize identical method to carry out precharge, describe with red signal here.The R precharge mark 861a and the R data 861a that send in pairs are input to vision signal and order separated part 931.After this one is transformed into the CMOS level, forms precharge respectively and judge signal 383 and gradation data 386.The signal that pixel is one by one sent here successively is input to be distributed to the shift register of respectively exporting usefulness and latchs portion 384.After the distribution, gradation data 386 is input to electric current output stage 23, meets the electric current of gray scale from 104 outputs by gradation data line 985.On the other hand, precharge is judged signal 383 outputs to precharge and judges line 984.Shown in Figure 100, pre-charge voltage is selected and applies judging part 982 to utilize precharge to judge line 984 and precharge pulse 451 control decoding part 1001 and selection portions 1004, and in output gray level electric current 104 or the output pre-charge voltage 983 which judged.Here from 4 inputs, select 1 signal, thereby precharge judges that line 984 needs 2 width.In the broadest sense, establish precharge and judge that the figure place of line 984 is N (N is a natural number), then need the figure place of the value of 2N more than or equal to pre-charge voltage number+1.
As Figure 47 473 shown in, precharge pulse 451 is the signals that determine that the voltage period of output in 1 horizontal scanning period is used.Therefore, when judging line 984 any pre-charge voltage 983 of output, also only at the input phase of precharge pulse 451 output voltage by precharge.
Precharge pulse 451 is shown Figure 101 and line 984 and the relation of exporting 1005 are judged in precharge.In view of the above, be input to the signal that line 984 is judged in precharge, can set the cycle of the output pre-charge voltage corresponding with vision signal by slave controller control.
Produce pre-charge voltage by pre-charge voltage generating unit 981.Figure 99 illustrates internal circuit and forms example.Divide and produce each voltage (the general concatenation operation amplifier of 983 outputs) by resistance.By resistive element 992a and 992b decision Vp1.Vp3 is then because the current value difference that illuminant colour needs constitutes each look change voltage of energy.Can use any among resistive element 997 and the voltage selection portion 994 selection Vs1 to Vs4.Like this, have in the display device of image element circuit of Fig. 6, the I-E characteristic of the relation of source signal line current (in=EL element 63 circulation electric current) and the voltage of source signal line 60 and the driving transistors 62 of Figure 102 is consistent, thereby the current deviation of green different each gray scale that causes with the luminescence efficiency of EL element in the basket shows as source signal line voltage deviation.When consider needing precharge 0 gray scale to 2 gray scale, blue lower than green luminescence efficiency, thereby need many electric currents, even be similarly the 2nd gray scale, indigo plant is 1021 point, and green then is 1022 point.Therefore, magnitude of voltage is also different.Utilize voltage to set line 986 control voltage selection portions 994, for example 994c selects Vs4 (955c), and 994b selects Vs1 (995a), thereby the pre-charge voltage value is changed according to the look of Figure 102.Meet 997,998 resistance value of the characteristic of driving transistors 62 by decision, can produce high-end voltage.Voltage is set line 986 can be from its value of external setting-up, and as Figure 95 (b) shown in, after order phase input pre-charge voltage sets 953, by vision signal and order separated part 931 its and vision signal is separated, thus taking-up voltage setting line 986.Utilize this point, carry out different voltage of all kinds when setting, newly-increased external signal line number also can be realized.Only record and narrate 3 pre-charge voltages 983 among Figure 98, but this is the figure that monochromatic example is shown, under the situation of polychrome, each look has 3 pre-charge voltages, needs 9 altogether.Pre-charge voltage is selected and the voltage that applies judging part 982 is input as 3.This is because each output has determined to show look, so input 3 voltages corresponding with the look of output get final product.
When needing 8 or more magnitude of voltage, it is big that the decoding part 1001 of Figure 100 and the circuit scale of selection portion 1004 become, thereby the circuit of Figure 89 is formed preferable.
Making the composition of Figure 95, Figure 98 or the composition of Figure 91, Figure 93 can select which side to determine according to display board scale and pixel count.
Thus, can realize to do the source electrode driver IC of electric current and voltage output with few signal wire.
The problem of current driver IC specifically is to change slow because of source signal line stray capacitance that output current value in the low gray scale portion causes for a short time discharges and recharges insufficient electric current that is written to pixel.Change the time that needs with Δ t=C * Δ V/I (wherein C is a source electrode line electric capacity, and Δ V is the source electrode line voltage variety, and I is the logical electric current of source signal linear flow) expression electric current, thereby distinguish that specifically gray scale is low more, changing needs the time more.Distinguish that also black extremely white variation is than spended time in white extremely black, the black extremely white variation.
For example, if the source signal line current of circulation 10nA when showing in vain, the source signal line current of circulation 0nA during black the demonstration, the then white situation that changes to black source signal line current is the waveform shown in Figure 104, the black situation that changes to white source signal line current is the waveform shown in Figure 105.
In the display board of QCIF+176 * 220 pixels, scan with 60Hz under the situation of 1 frame, 1 horizontal scanning period is about 70 microseconds.From the variation that original state is carried out with 70 microseconds, reach 94% with respect to object variations like that wherein white extremely deceiving shown in Figure 104, and black in only changing 5% with respect to target like that in vain shown in Figure 105.
The difference that occurs reaching this degree in the variation between 10nA and the 0nA is because source signal line magnitude of voltage is non-linear to being changed to of source signal line current value.Figure 106 illustrates the relation of source signal line current and voltage.By the relation of current-voltage characteristic 1063 decision electric currents with the voltage of driving transistors 62, the voltage corresponding with curve 1063 is with the electric current formation source signal line magnitude of voltage of source signal line.Electric current changes among formula Δ t=C * Δ V/I of the time that needs, when deceiving to leucismus, and I=10nA; During in vain to black the variation, the electric current of source electrode driver is 0, but because driving transistors will be supplied with the electric current of 10nA, is similarly I=10nA in the original state.So, distinguish that Δ V must equate when Δ t was identical with 70 microseconds.During from the status source electrode potential rising Δ V of 10nA and when the status source electrode potential of 0nA reduces Δ V, according to the characteristic of curve 1063, current change quantity is different fully.On the direction that current potential raises, shown in 1061, be reduced to 6nA, and on the direction that current potential reduces, can only change to 0.5nA from 0nA from 10nA.As a result, forming the electric current shown in Figure 104 and Figure 105 changes.
Here be illustrated with the example that is changed between 10nA and the 0nA, but during gray scale makes up arbitrarily, equally also be that high gray scale is faster than the variation of the paramount gray scale of low gray scale to the variation of low gray scale.
Therefore, the present invention considers to accelerate the method for the variation usefulness of the slow paramount gray scale of low gray scale of pace of change.
In order to accelerate to change, reduce the source signal line capacitance or reduce voltage variety or the increasing electric current.The source signal line capacitance is determined by the display board scale, thereby can not change.Voltage variety is reduced, can only change the current-voltage characteristic of driving transistors, particularly, can only strengthen transistorized channel width or shorten channel length.When strengthening channel width, the transistor scale increases, and the small-sized high-resolution display board that the area of 1 pixel share is little not can do with.Shorten channel length, it is bigger that early effect then takes place, if write fashionable when luminous with EL the drain voltage of (cycle of Fig. 7 (a) and Fig. 7 (b)) driving transistors 62 different, produce early effect and cause the problem that drain current changes under each situation, so can not shorten channel length.Therefore, consider to strengthen the source signal line current.
Source electrode driver electric current output waveform of the present invention when Figure 108 illustrates a certain pixel write current I.It is characterized by: spread all over the cycle that 10 microseconds are provided with the electric current of 10 times of rated currents of circulation at horizontal scanning period top.By the 10 times of electric currents that circulate, for example shown in Figure 107, electric current change can as the past 1072 to 1071 change, the rated current that can make 70 microseconds writes.In the cycle that the setting of the top of 1 horizontal scanning period increases the logical electric current of source signal linear flow, accelerate thereby current value changes, and write rated current like this.
Making electric current is 10 times of ground of setting when exporting, and needs to calculate the value of 10 times of rated currents, and need the function that make 10 times of current flowing also be set in the source electrode driver side.Here the problem of Chan Shenging is to need computing circuit, maybe must make the current source of the electric current output stage of source electrode driver increase by 10 times, thereby circuit scale strengthens.According to the current value that shows each gray scale of look not simultaneously, each gray scale multiplying power is changed again.Therefore, handle complexity.
Therefore, among the present invention, because difficult variation during variation of the low paramount gray scale of gray scale, and gray scale 0 changes the slowest in the low gray scale, investigation changes to next gray scale in order to make gray scale 0, has great electric current to change in 1 horizontal cycle, and after the top cycle as 1 horizontal scanning period of the example during the present invention the 3rd of being formed in applies this current value (being Ip1 here), apply rated current, thereby in 1 horizontal scanning period, can change to the rated current value.When stipulating gray-scale value greater than Ip1, also circulation regulation gray scale electric current can both write the electric current of gray scale 0 to the regulation gray scale thereby spread all over whole gray area in 1 horizontal scanning period during circulating current Ip1.At this moment, the cycle of only inserting Ip1 when vision signal does not reach certain gray scale can be set, thereby not need multiplier.The current source of 1 output Ip1 also can only be set each output in output stage.Figure 103 illustrates notion.Except that gray scale shows with the current source, also the current source Ip1 (1033) that precharge is used is set in electric current output 104, then can realize.Use this electric current I p1, only in order to accelerate to change to the speed of regulation gray scale, so between terminals of adjacent deviation can be arranged.Therefore, compare, export identical electric current, also can realize to such an extent that the transistor total area is little with the transistor of the current source of using in the demonstration of formation gray scale.
In addition, this electric current I p1 does not rely on the luminescence efficiency of EL element 63 according to the current-voltage characteristic decision optimum value of source electrode line capacity, pixel transistor.Therefore, of all kindsly can all comprise common current value, needn't adjust individually by each look, can constitute with little circuit.
The composition of the source electrode driver IC of the current output type drive circuit that is equivalent to self-luminous display device of the present invention when the top that Figure 109 is illustrated in horizontal scanning period is provided with the function of output Ip1.Here, the electric current I p1 that exports on the horizontal scanning period top is called pre-charge current.It is characterized by: the precharge reference current generating unit 1092 that produces pre-charge current and use is set, the pre-charge current output stage of whether the source signal line being exported according to the 1st condition judgment of regulation of the present invention 1092 and the pulse generating unit 1097 of setting the pre-charge current phase.Precharge reference current generating unit 1092 and pre-charge current output stage 1094 constitute pre-charge current applying unit of the present invention, and they constitute the display control unit of self-luminous display device of the present invention together with the controller of Controlling Source driver IC (not shown among Figure 109).Pulse generating unit 1097 is equivalent to the 3rd period generating unit of the present invention.About the unshowned controller of Figure 109 portion, can be integrated with source electrode driver, also can be used as other controller and be used as another device.It is especially effective to the more small-sized display device of using 1～2 left and right sides source electrode driver to be integrated into 1 chip block.
Judge by precharge whether signal 383 decisions export pre-charge current.Because signal 383 and gradation data synchronized transmission are judged in precharge, can set each pixel whether the pre-charge current period of output is set, and can set wherein which of selection when a plurality of pre-charge current is set.For distribute to each output, by shift register and latch portion 384 with its together with gradation data 386 distribute to each output.Gradation data is input to the electric current output stage 23 that is located at each output as gradation data line 985.Electric current output stage 23 outputs to 1093 with the magnitude of current of the reference current value that gradation data line 985, adaptation reference current generating unit 892 produce.Figure 110 with gradation data line 985 be 3 example when polychrome being shown adapting to driver reference current generating unit 891 and the composition of electric current output stage 23.Utilize reference current to set line 934 and make 1101 signal wire potential change, thereby the current value of the constant-current circuit that operational amplifier 1103, resistance 1102 and transistor are formed changes.Thus, distinguish that the value that electric current is set line 934 with reference current changes.Change the quantity of the current source transistor 105 that connects output according to the value of gradation data line 985, thereby make gradation data line 985 change the electric current of output 1093.Organic EL is each illuminant colour luminescence efficiency difference generally, thereby need make the electric current difference of each each gray scale of illuminant colour.Among the present invention, make, adjust resistance 1102 easily, the current value of each gray scale is changed, obtain white equilibrium with resistance value by constituting resistance 1102 in IC outer member mode.On the other hand, the precharge of distributing to each output is judged that line 984 is input to the pre-charge current output stage.Pre-charge current output stage 1094 also from precharge reference current generating unit 1092 according to precharge pulse 1098 input signals.
Pulse width by pulse generating unit 1097 decision precharge pulses 1098.Pulse generating unit 1097 utilizes the pre-charge electricity phase to set value, timing pip and the clock value of line 1096, and usage counter circuit etc. are set the value of line 1096 and from timing pip output precharge pulse 1098 exported according to precharge phase.
The precharge reference current generating unit 1092 of decision pre-charge current value utilizes pre-charge current to set the input of line 1091, and pre-charge current is changed.
These 2 external setting-up values (the pre-charge electricity phase sets line 1096 and pre-charge current is set line 1091) in order to reduce the source electrode driver input signal cable, utilize the blanking interval of vision signal to send setting signal on video signal cable 856 in blanking interval.Therefore, set line 1091 by vision signal and order separated part 931 from 856 taking-up pre-charge electricity phases of video signal cable setting line 1096 and pre-charge current.
Figure 111 illustrates the circuit of pre-charge current output stage 1094 and precharge reference current generating unit 1092 and forms (examples of 2 broken colour 3 colour cells).
In the pre-charge current output stage 1094, utilize precharge to judge the judgement signal interpretation portion 1111 of line 984 and input precharge pulse 1098, be connected to output 104 with 1 in pre-charge current source transistor 1112 to 1114 or the gray scale electric current 1093, thereby select whether to export pre-charge current.
Thus, when precharge pulse 1098 is high level, can judge which or output gray level electric current that the value decision of line 984 is exported in the pre-charge current source do not have pre-charge current according to precharge.
Pre-charge current can be monodrome, but because the current value that needs is different because of display board scale (being capability value), when being extensive use of the IC driver, by adjusting electric current towards large-scale, small display panel ground with random scale, make it export a plurality of values, can improve versatility.
The pulse width of precharge pulse 1098 depends on display board scale and horizontal scanning period length, but preferably is longer than or equals 5 microseconds and smaller or equal to 50% of horizontal scanning period.When not writing the regulation gray scale in this scope, adapt to by making the pre-charge current increase.Can judge signals 383 according to gradation data 386 control precharge, the electric current that makes the output of electric current output stage applies and is provided with the value that electric current inserts the gradation data 386 of phase during less than pre-charge current.In order to reduce the input signal cable number and to tackle electromagnetic wave, the mode shown in available Figure 95 judges that to precharge signal 383 carries out the small-amplitude differential input.
Like this, even compare with the data before 1 row, the data of next line are under the situation of high gray scale, by the input pre-charge current, also write the electric current of hope.
During from high grey scale change to low gray scale, shown in Figure 104, write target current value in fact, thereby can keep intact, but for gray scale 0 (deceive), can accurately show and blackly can improve contrast, strengthen and to show the advantage of deceiving as the self-emission device feature.
Therefore, the grey scale change beyond 0 is during to 0 gray scale, applies in the top phase that is equivalent to the horizontal scanning period during the of the present invention the 4th and utilizes voltage to show black voltage, thereby realize black accurately.When the source signal line was applied the voltage corresponding with black current, some applies voltage because the current-voltage characteristic deviation of driving transistors 62, from pixel observation to black (glimmering) phenomenon of floating.In order to prevent this point, apply voltage and make and consider the current characteristics deviation, even apply the also voltage of circulating current (pre-charge voltage) not of the alive driving transistors 62 of permanent current, thereby can prevent the luminance deviation that the driving transistors deviation causes.Here, during with the described the 3rd, be set at 0 o'clock,, and during with described 3, set at non-0 o'clock, be set the top phase during the described the 3rd the top phase that is set in during the 4th during the described the 1st.
Figure 112 illustrates the composition that can apply the source electrode driver of pre-charge current or pre-charge voltage in horizontal scanning period.It is characterized by: contain pre-charge voltage generating unit 982, the voltage precharge pulse 451 of phase is carried out in given voltage precharge, so that can supply with pre-charge voltage.
When line precharge was compressed in electricity consumption, voltage applied the phase and is longer than or equals 0.8 microsecond and be shorter than or equal 3 microseconds, just can fully charge to the source signal line.Therefore, only apply the time shorter, so the different line voltage signal precharge pulse 451 of input and pre-charge electric pulse 1098 than pre-charge electricity.Can with pre-charge electricity is shared should the time, but at this moment because to meet circulation phase of electric current of gray scale short, the abundant deviation of the driving transistors that causes of correcting current, may be when black display voltage value changes the generation uneven luminance.Therefore, do one's utmost to shorten voltage and apply the phase, lengthening gray scale electric current period of output (various display boards can be adjusted pre-charge voltage according to the deviation of driving transistors 62 respectively, but in fact between the display board, characteristic deviation that might driving transistors 62 between in batches is big.At this point, adjust pre-charge voltage, then can be shared, but need to adjust operation, impracticable.Adjust function owing to utilize electric current to implement this, it is preferable that gray scale electric current period of output is grown.In the small display panel, because the source electrode line capacity is less and horizontal scanning period is long, even sharedly also can fully proofread and correct.So press preferential shared 2 precharge pulses of chip-scale).
1098 with 451 these 2 precharge pulse reference positions identical (horizontal scanning period top), pulse width difference only, thereby can utilize according to the counter of source electrode driver clock 871 and timing pip 849 establishments and work out.Set line 1096 by the pre-charge electricity phase respectively, the voltage precharge phase is set line 933 predetermined pulse width.Identical with the composition of Figure 109, in order to reduce the input/output signal line number of source electrode driver, utilize the blanking interval of video signal cable 856 to send.Owing in 12 pulse of 1 horizontal scanning period output, can in blanking interval, insert the signal of setting, rewrite 1 time in 1 horizontal scanning period even if the most normal rewriting is set also.
Though be the pre-charge voltage value that applies, should value produce by pre-charge voltage generating unit 981.The voltage that outputs to pre-charge current voltage output stage 112 is of all kinds when a plurality of this voltage is arranged, the available composition identical with Figure 99, but when the voltage corresponding with gray scale 0 only is monodrome in of all kinds, it forms the available electron potentiometer and operational amplifier constitutes 3 voltages respectively, and utilizes electronic potentiometer to adjust magnitude of voltage.Any composition all utilizes pre-charge voltage setting line 986 to carry out the magnitude of voltage adjustment.Identical with precharge pulse, also utilize the blanking interval of vision signal 856 to implement to set line.
In the 1st condition, the 2nd condition that pre-charge current voltage output stage 1121 is stipulated according to the present invention, which side in pre-charge voltage, pre-charge current, the gray scale electric current selection export.Figure 113 illustrates the circuit of pre-charge current voltage output stage 1121 and forms.In this example, because 2 pre-charges electricity current sources 1112 and 1113 and 1 precharge voltage line (amounting to 3) and gray scale electric current 1093 are selected, precharge judges that line 984 is 2.Judge that signal interpretation portion 1131 is according to judging that line 984 and precharge pulse 1098 and 451 decipher out which the signal in 4 of the judgement outputs.Figure 114 illustrates the state of switching part 1132,1133,1134,1135 and the relation of input signal.Judge by precharge whether line 984 decisions are carried out precharge, are electric current or voltage when carrying out precharge.And, when being designed to carry out precharge, only carry out precharge, At All Other Times output gray level electric current then at the curtage precharge phase.Thus, realize having the source electrode driver IC of curtage pre-charging functions.Among Figure 12 to Figure 14, providing the 1st condition, the 2nd condition of the present invention regulation, be that a kind of all kinds, the electric current number of pre-charge electricity are 2 kinds of all kinds and are illustrated by the precharge voltage number of voltage, but kind all can realize arbitrarily.
Figure 115 illustrates the generation process flow diagram of the precharge mark on the basis that becomes precharge judgement line.
Here, take into account the condition of line precharge.As the 2nd condition of the present invention's regulation, only when forming gray scale 0, carry out voltage precharge.And, when being gray scale 0 before 1 row,, needn't carry out voltage precharge, so do not carry out precharge because signal wire does not change in this 2 horizontal scanning period.Then, be the pre-charge electricity, but when being greater than or equal to certain gray scale, the data before 1 row are which type of data can both utilize the gray scale electric current fully to write, thereby do not need pre-charge.Output does not generally need pre-charge greater than pre-charge electricity with the gray scale of the gray scale electric current of the current value I p of current source.Record and narrate the process flow diagram of 3.5 type QVGA raceway grooves in the example of Figure 115.Under this situation, 32 gray scales or higher gray scale do not need pre-charge owing to can change to the regulation gray scale.What need the pre-charge electricity is 1 to 31 gray scale display line, and the data before 1 row are also carried out pre-charge during greater than display gray scale.During the data of the data of relevant row before or gray scale when identical, do not need pre-charge less than 1 row.When the data before 1 row were gray scale 0, majority applied pre-charge voltage, prevents the uneven luminance that voltage causes, thereby applies the voltage that is higher than the regulation gray scale.Therefore, the potential change amount of source signal line is big, is difficult to write the regulation gray scale.So, can be 0 o'clock in the data before 1 row, have the Ip0 of pre-charge current value greater than Ip, and at gray scale 0 this electric current of back output.
Owing to realize above-mentioned precharge, shown in Figure 115,, and transfer to and do not need precharge gray scale 32 or higher gray scale, form the precharge gray scale 0 of voltage, other gray scale at first at the investigation of the square frame shown in 1151 video signal data.Gray scale 32 or higher gray scale be not owing to need precharge, and the judgement according to 1157 makes the precharge mark value be 0 (using the situation of truth table of the judgement signal interpretation portion 1131 of Figure 114).
Under the situation of gray scale 0, utilize 1152 the preceding data of flow process reference 1 row.Do not need precharge during gray scale 0, thereby be divided into gray scale 0 and non-gray scale 0, gray scale 0 table is done precharge (1157), make to be labeled as 0, but not 0 of gray scale be judged as 1154 do voltage precharge, make precharge be labeled as 1.
Remaining is greater than or equal to gray scale 1 to the scope of being less than or equal to gray scale 31, when the video signal data before 1 row is big, does not need precharge, thereby does not do precharge (1157), is labeled as 0.During gray scale 0, need be with electric current I p0 as pre-charge current, thereby form 1155 pre-charge electricity (current source 1113).So mark value is 3.Under other situation, use conventional current precharge (current value I p), thereby form 1156 pre-charge electricity (current source 1112), precharge mark output 2 (suppose that here current source 1112 is current sources of Ip, current source 1113 is current sources of Ip0).
According to display board, the value of Ip is big sometimes, and bringing needs precharge grey to increase.At this moment 1151 transfer command can be set, make the condition of conditional transfer can utilize changes such as external command.Under the situations such as the quantity of pre-charge current source and voltage source increases, can work out suitable process flow diagram equally, and realize its circuit.
The precharge mark generating unit 1162 that realizes this process flow diagram is shown in Figure 116, usually the output of the memory of data 1164 before controller 854 inside are with stored video signal 1161 and 1 row is as input, and synchronously is input to small-amplitude differential signal transformation portion 1163 with vision signal 1161.In order to reduce the signal wire number and to tackle electromagnetic wave noise, be transformed into the small-amplitude differential signal in this one, and in blanking interval, insert the control signal of source electrode driver, and to source electrode driver outputting video signal line 851 and clock 858.When constituting controller and source electrode driver, can not need small-amplitude differential signal transformation portion 1163, this signal former state is input to shift register and latchs portion 384 with 1 IC.
Among Figure 109 and Figure 112, output gate drivers control line 941, but this signal is used to reduce controller output signal line quantity, when controller output signal line quantity is unrestricted, does not need this signal.
Distinguish that the pre-charge electricity magnitude of current that needs is carrying out same gray scale when showing, also because of the display gray scale difference before 1 row.For example under the situation of display gray scale 16, gray scale before 1 row is 0 o'clock, it is the pre-charge current that meets 16 gray scales (=also can be 0) that the pre-charge current that need meet 64 gray scales, and the gray scale before 1 row is need meet the pre-charge current of 26 gray scales at 1 o'clock, the gray scale before 1 row are 20.Therefore, during the decision pre-charge current, need to set best pre-charge current according to the data before 1 row and the value of relevant line data with reference to the data before 1 row.
Have data before 1 row are prepared the method for matrix table with the control pre-charge current with the relation of relevant line data and pre-charge current value, but grey for a long time, the scale of table is big, the big problem of circuit scale when having the IC design.
Do not constitute that to prepare matrix table be because to form what state big in the difference that transformation period occurs at source signal line top with the decision pre-charge current.With representing that with the source signal line potential difference (PD) of relevant row electric current changes the time of needs before source signal line capacity * 1 row.The electric current of source signal line and the relation of voltage are deferred to the characteristic of driving transistors 62 shown in Figure 106, thereby represent with nonlinear curve.Display gray scale is low more, and the potential difference (PD) of each gray scale is big more.Therefore, even gray scale difference is identical, change to rated current also the time greatly different.For example compare with 0 gray scale to 2 gray scale, the potential difference (PD) of 2 gray scale to 4 gray scales is 1/2, thus with the source signal line current be 2 extraordinarily together, then the write time is 1/4 (gray scale difference was all 2 o'clock).Not only need to detect gray scale difference, and need be according to gray scale difference and display gray scale decision precharge, the data before will going with reference to 1 at least and the data of relevant row.
There are proportional relation in gray scale difference and source potential difference, and it is poor with respect to the source potential of gray scale difference 1 then to determine uniquely, thereby determine the electric current share that each gray scale difference needs.Can utilize calculating any gray scale difference to be obtained the magnitude of current of needs according to this point, thereby can be according to the current value of gray scale difference result of calculation decision needs, if have the unit only can store the electric current that data and each gray scale difference need before 1 row, just can determine pre-charge current.
Yet, in the self-luminous display device of the present invention, gray scale difference and source potential difference do not form proportional relation, even the identical different situation of source potential difference that also produces of gray scale difference, thereby the pre-charge current value is at first calculated source signal line potential difference (PD) in view of the above with reference to the preceding data and relevant line data of 1 row.Need be according to source signal line potential difference (PD) decision precharge potential.Can not obtain the relation of data and relevant line data and source signal line potential difference (PD) before 1 row or need the very large calculating of circuit scale with calculating, thereby it is in fact impossible, in order to prepare table in advance, to distinguish the current value of needs according to data before 1 row and relevant line data, need in whole gray scale combinations, write down the pre-charge current value in advance
Under the situation of 256 gray scales, need store, at this moment be difficult to the actual fabrication circuit and (during actual fabrication, do not store the combination of the gray scale that does not need the pre-charge electricity, to reduce circuit scale to considerable whole 60,000 5 thousand kinds of combinations.Thus, can realize with the memory space about 10,000 kinds).
Therefore, the circuit scale of the circuit of the present invention in order further to reduce to judge pre-charge current, decision utilizes voltage to apply the voltage suitable with gray scale 0 at the top of horizontal scanning period.Can be to realize utilizing voltage to make the source signal line states change to gray scale 0 about 1 microsecond～3 microseconds.Since horizontal scanning period 10% when interior chien shih its change, needn't sacrifice in a large number and write the time that needs, just can make the source signal line change to the state of gray scale 0.
Apply time (be called voltage and preset the phase) of the suitable voltage of this and gray scale 0 by setting, can make the source signal line states always begin to change, needn't store the state (because being 0 always) before 1 row from the state of gray scale 0.Because only storage meets the pre-charge current of display gray scale, memory space greatly reduces, even how also to be just passable about 70 kinds.
Voltage presets after date, in order to change to rated current fast, the pre-charge current period of output is set, make electric current change near the regulation gray scale after, export the electric current of gray scale up to specification, thereby also can change fast even change slow-footed low gray area at electric current.
Making the pre-charge current that meets display gray scale is in the method for exporting after the optimum value, and each output needs the best of required current value kind to meet the current source of pre-charge current value.Except that gray scale shows with the current source 241, also dispose when pre-charge is electric uses current source, it is big that the circuit of source electrode driver becomes, and chip-scale increases.Because changing the time that needs, electric current changes the display board pre-charge electricity current value difference of possible different scales because of source signal line capacity again.The driver IC that forms circuit can not make pre-charge current change, thereby can be for example by will be less than and more than the current value of the current source number of needs as backup, the preference pattern that changes the current value that meets gray scale is tackled, but the problem that exists circuit scale further to strengthen.
Therefore, among the present invention, make pre-charge current apply the phase, and current value is with grey scale change, so that can be with the optimum current precharge that adapts to multiple display board scale from command operation of outside etc. with grey scale change.
Particularly, making pre-charge current is the corresponding electric current of electric current when showing with maximum gray scale, and the time that applies this pre-charge current is when changing, under the situation of time weak point, the variable quantity of pre-charge current is little, thus form the electric current of low gray scale degree, and under the situation of time length, because the variable quantity of pre-charge current is big, forms high gray scale electric current.
Figure 117 illustrates the source electrode driver of realizing this point and forms.Figure 118 illustrates the circuit bank precedent of the output pre-charge current and the electric current efferent 1171 of the electric current that meets gray scale.
Among Figure 118, gray scale shows whether decision is connected to output 104 with the switch unit 1183 of current source 241 according to 985 controls of gradation data line.This current source is designed to the position weighting variation of the magnitude of current with gradation data line 985.Particularly, form current source with transistor as shown in Figure 25, and according to number decision electric current weighting, then accurate output current.
By reducing the circuit scale of current source portion from same current source output pre-charge current.Therefore, it is in parallel with 113 with whether current source to be connected to the switch unit 114 of output 104, utilize pre-charge electric control line 181 to control switch units 1184, thereby common current source reduces circuit scale., be only because the pre-charge current value is that maximum current (showing electric current in vain) could be realized with just realizing 1 current source, 241 configuration switch units 1183 in parallel and 1184 like this.With the switch unit parallel connection, but the either party is a conducting state, then the electric current of the current source of output connection.Therefore, these 2 switches realize logics and circuit and in pre-charge electricity period of output pre-charge electric control line 1181 be high level, it when not exporting low level, utilize gradation data 985 output currents when then not exporting, whole precharge control lines 241 are exported during output, thereby can no matter how gradation data 985 all exports pre-charge current.By using lowest high-current value, electric current changes fast, can shorten pre-charge current period of output 1203 as far as possible, has the gray scale electric current period of output 1204 that accurately carries out gray scale demonstration usefulness is obtained long advantage.
By the switching part 1183,1184 that 2 parallel connections are set, the element that does not need logical operation to use, thereby can reduce circuit scale.
For according to gray-scale Control pre-charge current period of output, the high period that can make this pre-charge electric control line 1181 is according to grey scale change.Therefore, among the present invention, pulse choice portion 1175, a plurality of pre-charge electric pulse are set, according to 1 pulse among the value selection pre-charge electric pulse group 1171 of precharge judgement line 984, and each pre-charge electric pulse 1174 makes the different signal of high period for utilizing order to set in advance, thereby precharge phase is changed.
Figure 119 illustrates the input/output relation of this pulse choice portion 1175.The state of pre-charge electric control line 1181 and voltage precharge control line 1182 judges that according to precharge the value of line 984 changes.When the source signal line states does not change under showing the continuous situations such as row of same grayscale, do not need voltage and current precharge, thereby judge that in precharge line 984 is at 0 o'clock in this example, only adapt to the electric current output of gray scale.When gray scale 0, utilize voltage precharge display gray scale 0, thereby only do not need the pre-charge electricity, so precharge judges that line 984 is at 7 o'clock, only being provided with, pre-charge electric control line always is low level pattern.Under the situation of other judgment value, can strobe pulse in the different a plurality of pre-charge current pulses of width 1.
Thus, shown in Figure 120, decision judges that from precharge line 984, voltage precharge pulse 451, pre-charge electric pulse 1174 output to the signal of output 104.When deferring to the concerning of Figure 119, output has the pre-charge current period of output 1203 of the time that adapts to pre-charge electric pulse 1174d after the 1st horizontal scanning period carried out voltage precharge, and the end forms gray scale electric current period of output 1204.1 follow-up horizontal scanning is interim, only has gray scale electric current period of output 1204.By such arrangement, be designed to utilize precharge to judge that line 984 changes the pre-charge electricity phase of carrying out, the high period of each pre-charge electric pulse 1174 is changed according to the outside input, then can realize and to carry out the source electrode driver that optimum current charges and adapts to any display board scale, pixel count according to display board scale, horizontal scanning period.
Among the present invention, shown in Figure 117, utilize pulse generating unit 1121 to produce pre-charge electric pulse group 1174 and voltage precharge pulse 451.Set line 1096 with order separated part 931 from the outside with the pre-charge electricity phase by vision signal, the voltage precharge phase is set line 933 and is input to pulse generating unit 1122, thereby can realize precharge pulse with external command with any pulse width.
Again, use in the display device of organic illuminating element, each shows look luminescence efficiency difference, thereby respectively shows the current value difference of each gray scale in the look, so the problem that exists the pre-charge current value to change.In the best demonstration look of efficient, show that in vain current value is little, thereby may the insufficient regulation gray scale that changes to of electric current.Therefore, among the present invention, pre-charge electric pulse group 1174 has 1174g, 1174h, 1174i by each look, adjusts electric current and applies the phase, thereby address the above problem.Particularly, the best look of efficient makes the share that the whole increasing electric current of precharge pulse width reduces.
Electric current changing condition explanation with Figure 124 can (at this moment, be established driver output and carry out 8, the output of 256 gray scales, describe with the situation that grey scale change forms rated current by the length that makes precharge pulse 1174.Grey is considered to replace according to the figure place that reality is used, and then the driver of any digit also can illustrate equally).
If the pre-charge electric pulse phase is for example 1174a, after then electric current utilizes pre-charge current period of output 1242 to change fast, the output rated current, thereby slowly change, the electric current that forms the curve representation shown in Figure 124 (b) changes.
On the other hand, during with time long mode output current precharge, when for example exporting the pre-charge current of 1174c phase, change fast in 1243 phases, electric current slowly changes to gray scale 30 (curve 124 (c)) according to the rules then.
And, when often applying the pre-charge electric pulse, shown in Figure 124 (d), change like that.
Electric current change curve to Figure 124 (d) is distinguished: carry out the pre-charge electricity, and up near after forming near regulation gray-scale value, output regulation gray scale electric current, then electric current can the fastest variation.Gray scale is high more, and the pre-charge current period of output is long more, and along with forming low gray scale, this period of output shortens, thereby even the pre-charge current value does not change itself, also can only just change to the regulation gray scale in the phase that applies.
Figure 123 illustrates the pre-charge current phase of 3.5 type QVGA display boards needs and the relation of gray scale.Along with gray scale uprises, the pre-charge current phase needs lengthening.And, distinguish that 36 gray scales or higher gray scale do not need the pre-charge current phase.Therefore, make the electric current phase and the pre-charge electric pulse that need as Figure 123, have corresponding relation, and utilize external command that the high period of each pre-charge electric pulse is appointed as the cycle shown in Figure 123, thereby utilize the external command operation, also can accurately show the regulation gray scale to whole grey scale change by 1 pre-charge current source at next line.
Gray scale and pre-charge electric pulse corresponding is replaced as precharge judges the corresponding of line 984 and pre-charge electric pulse.By utilizing generation such as controller IC and providing the precharge corresponding with gradation data to judge signal, with the precharge pulse of display gray scale being selected wish, it is corresponding with the pre-charge electric pulse to obtain gray scale.
This gray scale and precharge pulse to change the time can utilize the control of control IC to make the pre-charge electric pulse to favourable aspect the grey scale change.
When the current value of each gray scale is big, even low gray scale is not made the pre-charge electricity and can be shown the regulation gray scale yet.For example compare, when each gray scale is 2 times of electric currents, can writes 18 gray scales or higher gray scale in theory, and not make pre-charge with the situation of Figure 123.At this moment, can rewrite relation, be tackled by the processing in the controller IC that changes the relation of controlling gray scale and precharge judgement line 984.
Therefore, prepare precharge dividually separately with grey scale signal like this and judge line, and utilize this precharge to judge line options pre-charge electric pulse, thereby, also can show with same source electrode driver when even the luminescence efficiency of organic illuminating element changes.
Judge that according to precharge the value of line 984 selects to have in 1 the method in the precharge pulse 1174 of a plurality of pulse widths, in order to need the signal of a plurality of pulse widths of regulation from the outside with whole pulse widths of a plurality of precharge pulses 1174 of order control.When driver IC 36 is directly imported all this signal, need many input pins, impracticable.Therefore, the present invention utilizes the blanking interval of vision signal, by the whole setting values of video signal cable 856 serial transfer in blanking interval, thereby can set the precharge pulse width, and not increase the external signal line number.
Figure 121 illustrates and utilizes video signal cable 856 to carry out the signal inputting method of order input usefulness.Shown in Figure 121 (a), the vision signal transmission phase is imported each show chromatic number and (is envisioned for RGB here according to 861.Be not limited to this 3 look, can be the data of the random colour that adapts to display device.3 for example dark green, yellow, pinkish red looks etc.) with as judging whether to carry out the precharge mark 862 of the signal that precharge uses, and make both correspondences to respectively applying 861.Send together and differentiate data/Command Flags 950 that vision signal is used.Being 1 when for example making data, is 0 during order, then passes through with reference to this position, and can discern the signal that sends is vision signal or order.
Then, send order at blanking interval.Making data/Command Flags 950 is 0, and can discern is order.With 1 transmission, can set complete order, then do not need like this, but among the present invention, order quantity is many, thereby some positions are used as the address, corresponding according to the value judgment data of address with which order.The example of Figure 121 is judged pre-charge electricity setting signal or other signal in the A1211 of address.Figure 121 (b) carries out the setting of the signal that the pre-charge electricity phase needs beyond setting, and sends pre-charge voltage value, voltage precharge phase, stipulates the reference current setting signal 912 of the electric current of each gray scale.Among Figure 121 (c),, set address B1212 again, and set much according to the pulse width of address B1212 decision pre-charge electric pulse because each look needs respectively pre-charge electricity period of output to be carried out 6 settings.
According to Figure 123, the pre-charge electric pulse pulse width be about 0.4 microsecond class interval, thereby, implement, and variable range is the 6.4z microsecond with 0.2 microsecond or 0.4 microsecond as the class interval width, then can adjust any display board.Can set 32 grades or 16 grades gets final product.1174a to 1174f needn't have identical pulse width, thereby should be able to set different values respectively, and share the task of each pulse, making 1174a is the pulse width minimum, 1174f is the pulse width maximum, then can configuration example as setting the pulse width of minimum 0.2 microsecond to maximum 8.4 microseconds, the setting range that makes 1174a is 0.2 microsecond to 6.6 microsecond (32 grades of adjustment), the scope of 1174f is 2.0 microsecond to 8.4 microseconds (32 grades of adjustment).Stagger a bit by setting each pulse width variable range for each pulse like this, can dwindle variable range, reduce to set the signal wire width of usefulness, can realize the device that circuit scale is little.
Like this, make and to utilize outside input command to set various values, can realize adapting to the electric current output source electrode driver IC36 fast of gray scale of the display device of any display board scale and exploring degree.
Electric current efferent 1171 of the present invention except that Figure 118 like that to 1 current source, 241 a plurality of switching parts in parallel, also with can be shown in Figure 122 connect gradation data lines 985 at current source 241 like that everybody with the control of the switching part 1221 of the OR-gate of pre-charge electric control line 1181 in the method used realized.The operation that switching part 1183 and 1184 forms for a short time can be made the circuit scale of Figure 118 reduce, but can not reduce the time, adding sometimes can be with the method for the OR circuit of logical signal rule establishment, and circuit scale is less.
Take any in these 2 kinds of circuit, can consider the operation rule, adopt the less side of circuit scale.
In this example, voltage precharge pulse 451 is no matter show look, import same pulse, but like this when voltage changes the source signal line states, utilize the driving force decision state variation speed of the operational amplifier of output, do not have each gray scale electric current etc. respectively to show the influence that look different signal causes, thereby in order to reduce circuit scale, making voltage precharge pulse 451 is 1.When circuit scale is no problem, can have 3 pulses, so that can of all kindsly specify respectively.
Have among the source electrode driver IC36 of output stage ingredient of Figure 118 or Figure 122, the output that can have pre-charge current period of output 1243 with the relation of gray scale shown in Figure 123 and precharge pulse, but when the relation of utilizing Figure 123 only determines pre-charge current period of output 1243 to gray scale, even under the situation of the unconverted same gray scale of the continuous output of for example source signal line, also carry out precharge.
Shown in Figure 125, the pre-charge voltage at horizontal scanning period top applied in the phase 1251, after signal wire changes to black show state, in pre-charge current period of output 1252, the state variation of source signal line is to the value near the rated current value, in the gray scale electric current period of output 1253 at end, change to the rated current value, thereby on the top of horizontal scanning period, the temporary transient formation of source signal line current deceived state, so the time compare with not carrying out pre-charge current output, signal line states changes and produces and writes inadequate possibility and improve on the contrary.
Therefore, the present invention is shown in Figure 126, when the same gray scale electric current of output is exported continuously, the capable pre-charge current period of output 1252 of not establishing of back, only establish gray scale electric current period of output 1253, reduce the source signal line states and change, write inadequate state and be difficult to produce thereby make.
Under the situation of the display mode shown in Figure 127 (1272 districts in this pattern, the brightness of 1274 districts are identical, and the brightness of 1273 districts is lower than 1272 districts, 1274 districts), at the 1st row that forms 1273 districts with form the 1st capable pre-charge that carries out in 1274 districts.The output current wave of the source signal line corresponding with row 1271 is as Figure 128.During district's 1272 correspondences, the output current no change, thereby only be gray scale electric current period of output in the horizontal scanning period 1281.
Transfer among the 1st horizontal scanning period 1281d after 1273, the source signal line current changes, thereby for electric current is changed fast, pre-charge voltage is set applies phase 1251d and pre-charge current period of output 1252d, when not exporting pre-charge current with the past (1282) mutually specific energy in the short time, export and district's 1373 corresponding electric currents.The demonstration consecutive hours in district 1273 is not provided with pre-charge current and pre-charge voltage period of output too, only carries out the output of gray scale electric current, thereby it is minimum that the source signal line current is changed.
In addition, when the source signal line carries out the output corresponding with the demonstration in district 1274, only carry out voltage and current precharge, and pre-charge current period of output 1252g is longer than 1252d at the 1st horizontal scanning period 1281g.According to the gray scale of Figure 123 and the relation of pre-charge electricity period of output, it is high more that this meets gray scale, and just electric current is big more, and the pre-charge current period of output is long more.When supposing district 1274 for gray scale 0, then pre-charge voltage applies the back formation gray scale electric current period of output 1253g of phase 1251g, does not have pre-charge current period of output 1251g (pre-charge current period of output 1251 exists with gray scale, thereby may not be defined as existence).By carrying out this precharge, compared without precharge, the situation (1283) that only output current value changed with the past with the output of gray scale electric current, can in the short time, make the electric current of source signal line change to the rated current value.
When so only the source signal line states changes, in order to carry out voltage precharge and pre-charge electricity or voltage precharge, in Figure 123 with the relation of gray scale, also need and 1 row before gray scale relatively, only the relation by Figure 123 is carried out precharge when vision signal changes.
Figure 129 illustrates and judges whether to carry out the flow process that precharge is used.According to vision signal 1291, detect current gray-scale value (1292).Here, gray scale is 0 o'clock, and is identical with Figure 123, also only carries out voltage precharge, and output adapts to the electric current (1293) of gray scale then.
Even gray scale 36 or higher gray scale are not carried out precharge, electric current also changes to the regulation gray scale, thereby only adapts to the electric current output (1296) of gray scale.
Gray scale is then handled (1294) according to the gray scale change before 1 row more than or equal to 1 to the scope smaller or equal to 35, and the gray scale identical with current gray level only adapts to the electric current output (1296) of gray scale.This is for when showing same grayscale continuously, makes wave form varies little as Figure 126.
On the other hand, in 1294 the processing, when gray scale before 1 row and current grey scale change, adapt to the pre-charge electricity of the time of gray scale after pre-charge voltage output, remaining time adapts to the electric current output (1295) of gray scale.This is equivalent to the running in the horizontal scanning period of 1281d and 1281g among Figure 128.
Precharge judges that the signal of line 984 is state 1294,1295 o'clock in the judged result that becomes 292 by figure, produces signal in the mode of the relation of the gray scale that forms Figure 123 and pre-charge current period of output, then carries out the output shown in Figure 126 among the source electrode driver IC.During formation state 1296, can be without the relation of Figure 123, and judge the value of line 984 by the requirement decision precharge of total output gray level electric current.
Thus, it is minimum that the source signal line is changed, and can electric current be changed fast at change point again, thus the also accurate border of viewing area in the such demonstration of Figure 127.
In the demonstration of gray scale 0, by the source signal line pre-charge voltage is applied to the grid level of the driving transistors 62 in the image element circuit, make its circulation and the corresponding electric current (smaller or equal to the electric current of 1.3nA) of black demonstration.Yet, at this moment in the driving transistors 62, voltage transformation is become electric current, thereby the drain current corresponding with input voltage changes because of temperature variation.For example such shown in Figure 130, make under the situation of driving transistors 62 (Figure 130 (b)) electric current smoothness when (Figure 130 (a)) was lower than temperature when temperature was high with low temperature polycrystalline silicon.Electric current during therefore black the demonstration increases, and existence produces black problem of floating, and (under the situation that the circuit of Fig. 6 is formed, the drain current of driving transistors 62 is the electric current that circulates in the EL element.Therefore, the electrorheological of this EL element circulation is big, makes that EL element is faint to be lighted, and produces black floating).
For example, (a) adjusted to pre-charge voltage under the situation of VBk2 when temperature was hanged down, the drain current of the transistor 62 of circulation Ibk.This electric current is the black degree (1.3nA) of floating of miss or littler.Temperature raises under this state, and the characteristic that makes transistor 62 is during by the curvilinear motion shown in Figure 130 (b), and circulating current ID is increased to electric current and perceives black degree of floating.In order also there not to be black floating under the condition of high temperature, need make grid voltage be elevated to VBk1.
The raceway groove scale design of pixel transistor is become wide 25 microns, in the time of long 15 microns, establish (a) and be-20 ℃, (b) be+50 ℃, then voltage Ebk2 (64 magnitudes of voltage) is-1V, and voltage VBk1 (64 magnitudes of voltage) is-3V.Voltage between the source electrode of pixel transistor 62 and the drain electrode is respectively the value of 1V, 3V.
The source electrode that needs with drain between voltage Yin Wendu and different, then can make the pre-charge voltage that is applied to transistor 62 according to temperature variation.When producing pre-charge voltage, utilize resistance to divide under the situation that produces reference voltage, shown in Figure 131,1 in the resistive element 1312 is installed in parallel thermistor equitemperature compensating element, 1131, and then the voltage of division points 1314 is according to temperature variation.If thermistor, resistance value raises with temperature and diminishes, thereby the resistive element 1312a that connects 64 mains side in 2 resistive elements 1312 goes up temperature compensating element 1311 in parallel.Adjust the value of each resistive element and the resistance value and the temperature coefficient of thermistor, then shown in Figure 123, can carry out the setting that pre-charge voltage raises and strengthens with temperature.
Figure 134 illustrates concrete circuit and forms.Image element circuit with source electrode driver 36 and 1 pixel share describes.The circuit of source electrode driver 36 is is only recorded and narrated and is carried out the precharge simulation efferent of voltage.The composition of entire circuit is for example such shown in Figure 117.When carrying out voltage precharge, by the voltage of 1187 pairs of electric current output lines of voltage precharge control line, 104 output pre-charge voltage generating units, 1313 generations.
The voltage of output is transmitted on the source signal line, and be applied to the node 72 of image element circuit 67 inside of signal line 61 selections.
When the pixel selection phase finished, switch 66a, 66b were nonconducting state, and 66c is a conducting state, and according to the relation of the grid voltage and the drain current of transistor 62, EL element 63 circulating currents.At this moment the grid voltage and the pass of drain current are Figure 130, thereby pre-charge voltage ignores temperature, and during the output steady state value, node 72 (being the grid voltage of transistor 62) is also constant, and according to the relation of Figure 130, the electric current of EL element circulation varies with temperature and changes.
Therefore, the present invention is in pre-charge voltage generating unit 1313, produce the voltage that carries out buffer memory with operational amplifier without electronic potentiometer 1341, and use resistive element 1312 and temperature compensating element 1311 to produce this voltage through external connection terminals, thereby pre-charge voltage (being the voltage of node 74) is varied with temperature, make the current constant of EL element 63 circulations, do not depend on temperature.
The dotted line 1311 of Figure 133 illustrates the drain current (electric currents of WL element 63 circulations) of the transistor 62 of pre-charge voltage when constant and the relation of temperature.
Current value when the solid line 1332 of Figure 133 illustrates the pre-charge voltage variation is to variation of temperature.Under 1332 situation, distinguish that the drain current of transistor 62 is constant, do not depend on temperature.By selected resistive element 1312 and temperature compensating element 1311, make this current value smaller or equal to 1.3nA, can realize not having black demonstration of floating.
In the composition of Figure 134, the serviceability temperature compensating element, changes according to the temperature characteristic compensation electric current, but when electronic potentiometer 1341 is arranged, also can make the value of electronic potentiometer 1341 according to temperature variation.
The generally control of carrying out electronic potentiometer 1341 with controller 1351, thereby can electronic potentiometer control be varied with temperature with order in the controller side.For this reason, the signal of input temp probe unit 1350 in the controller 1351.
In order to set electronic potentiometer, use electronic potentiometer control signal 1353 among this figure, slave controller 1351 carries out the control of source electrode driver 36, but the source electrode driver shown in Figure 117 is accepted the magnitude of voltage of pre-charge voltage generating unit 981 from video signal cable 856 by vision signal and order separated part 931.Method with Signal Separation is arranged after utilizing other signal wire slave controller to the source electrode driver serial transfer like this, thereby may not need electronic potentiometer control signal 1353.Can between source electrode driver and controller, be connected controllable signal wire with the independent mode of electronic potentiometer control usefulness or with the mode of other signal common.
During with electronic potentiometer 1341 control magnitudes of voltage,, magnitude of voltage is increased by the relation that temperature is directly proportional, and shown in the solid line of Figure 136, the output voltage of electronic potentiometer (being pre-charge voltage) change steppedly because input is a digital signal.
At this moment, all in the temperature range, the electric current of EL element 63 circulation is smaller or equal to 1.3nA, thereby can make the electronic potentiometer output voltage like that temperature variation one-tenth is not less than the magnitude of voltage of the dotted line 1362 of according temperature compensation component variation as the solid line 1361 that makes the electronic potentiometer value and change.
When arranging like this, as Figure 137 1371 shown in, the drain current of transistor 62 is with respect to the temperature flow galvanization.Thus, can ignore temperature, and the electric current that makes the EL element circulation was not compared according to 1331 of temperature variation with do not make pre-charge voltage in the past smaller or equal to 1.3nA, even the temperature height also can realize not having black demonstration of floating.
Figure 138 illustrates and does not use thermistor equitemperature compensating element, 1331 and make the method for pre-charge voltage value according to temperature variation.
Of the present invention being characterized as: on the face of the array identical, form pre-charge voltage and produce with circuit 1382 with the array 1383 that forms image element circuit 67, and operating characteristic transistor 1381 output voltages identical with driver transistor.
Pre-charge voltage produces with circuit 1382 formations and comprises transistor 1381 and electric capacity 1396, and compares with image element circuit 67, forms the identical circuit of pixel selection state.Distinguish the operational amplifier that the voltage of node 1387 is input to the pre-charge voltage generating unit 1313 of source electrode driver 36, make the not voltage during circulating current of pre-charge voltage generating unit 1313 output transistors 1382, thereby this pre-charge voltage can be exported and the corresponding voltage (without the output of electronic potentiometer 1341) of black show state in this array.Here, in order to form the state that 1381 electric current does not circulate, the input impedance that operational amplifier 1388 need be designed to operational amplifier 1388 is enough high.
Transistor 1381 and driving transistors 62 are in the same array surface, can make the pass of drain current and grid voltage tie up between 2 transistors very little.This is because the deviation of between-lot and the deviation between the thin layer are compared, and the deviation in the lamina plane is less.
In order further to reduce the black brightness (reducing electric current) that shows, the current potential of node 72 is raise.For the voltage of the node 72 that raises, can only strengthen the voltage that pre-charge voltage produces the node 1387 of using circuit 1382.For this reason, the method for the drain current that reduces transistor 1381 is arranged, but under this situation, can only improve the input impedance of operational amplifier 1388, be subjected to the influence of the characteristic deviation of operational amplifier 1388 easily.
Therefore, the present invention's decision is by strengthening the channel width of transistor 1381, even drain current identical (not changing the composition of source electrode driver) also makes the characteristic rising of the voltage of node 1387 according to transistor 1381.
At this moment, voltage (voltage of node 72) when only determining that by 2 transistors that form on the same array surface 1383 pre-charge voltage and driving transistors 62 are deceived demonstration, thereby the deviation in the inhibition array surface, then have any external circuit and can both realize that black demonstration is always constant.
When strengthening the channel width of transistor 1381 or shortening channel length, the relationship change of drain current and grid voltage can realize the curve 1391 and 1392 shown in Figure 139.
Form 2 transistors, be the relation of Figure 139, then because leakage current etc. and in transistor 1381 during circulating current Id1, the current potential of node 1387 becomes Vg1, and exports this Vg1 as pre-charge voltage.At this moment, also apply identical voltage Vg1 on the node 72 of image element circuit 67, make in the driving transistors 62 and circulate less than the electric current I d2 of Id1.Thus, in pixel, circulate, thereby can deceive the demonstration that display brightness further reduces less than the electric current I d2 of the Id1 that becomes leakage current.By characteristic relation (being transistorized channel width and length ratio) the decision Id1 of transistor 1381 and 62 and the relation of Id2, thereby, adopt the method for the channel width that strengthens transistor 1381 for black demonstration electric current is further reduced.Scale identical also can, but be preferably formed as channel width about 3 times.
When this existed in the transistor 62 by source signal line 60 circulations 0 electric current, also the circulate problem of the electric current about 3.5nA of EL element 63 in order to tackle this point, added extensive.Because the early effect of the transistor 62 that the relation of the drain current shown in Figure 144 and source electrode-drain voltage is such, source electrode-the drain voltage of the driving transistors of the source electrode-drain voltage during from source signal line 60 write currents 0 during with EL element 63 circulating currents is different fully, so even the electric current that exists Id1 to write also is increased to the problem of electric current I d3.Electric current I d3 equals 3.5nA, compares with black unchallenged 1.3nA or the littler electric current of showing in the subjective assessment, and about 3 times electric current that circulates, thereby in order to make electric current reduce 1/3, be 3 times by the channel width that makes transistor 1381 and tackle.Owing to smaller or equal to 1.3nA, can be, but, be taken as about 3 times because the transistorized area of the formation on the array increases more than or equal to 3 times.
Again, because in same array surface, the temperature dependency deviation is little, shown in Figure 143, if the characteristic during normal temperature is 1391,1392, then as 1431,1432, be offset during high temperature identically, the voltage that provides as pre-charge voltage only changes to Vg2 from Vg1, the drain current of driving transistors 62 is that Id2 is constant, can show.This point is represented energy compensation temperature characteristic and it is not adjusted.Therefore, even without temperature control unit, also can the compensation temperature characteristic by forming the precharge generation with transistor in array surface.
Figure 140 illustrates the example that pre-charge voltage produces the configuration position of using circuit 1382.Form image element circuit in the viewing area, thereby can not dispose.Therefore, make it be formed on the pixel periphery.The periphery of gate drivers 35 is had vacant position etc. under the situation, this place of can packing into.
In addition, all form 1382 the circuit of Figure 140, shown in Figure 141, can be input to pre-charge voltage generating unit 1313 by connecting 1 that change portion 1411 will be wherein.Prepare the wiring of this connection change portion from the outside, and can utilize Laser Processing etc. to change, even thereby hypothesis 1 transistor 1381a is not good enough in the array manufacturing process, utilize laser repairing, the change wiring, also can expect that then yield rate improves with the output of normal transistor, Figure 141 illustrates the wiring example of transistor 1381c when working properly.
Among Figure 142, further transistor 1381 all is connected to source electrode driver input terminal 1389.The current constant of circulation on the terminal 1389, thereby the electric current of each transistor 1381 circulations is about 1/4, can realize further showing black circuit.
As Figure 140, be configured in four jiaos, produce the black voltage that shows usefulness, thereby have the deviation that can absorb each transistor 1381 and output advantage near the voltage of mean value with the transistor of the various characteristics in the array surface.Because of 1 transistorized when unusually circulating big electric current, according to this characteristics of transistor decision voltage.The current value of circulation is identical on the terminal 1389, thereby can be according to the transistor characteristic decision voltage of circulation maximum current.So the best transistor of characteristic is also exported and can be made the black voltage that shows, thereby have and also can not have black showy advantage when the worst.
When there is defective in transistor 1381, the wiring that can only utilize laser cutting to be connected with this transistor, thereby can repair easily.
The wiring that comprises the node 1387 that connects change portion 1421 is owing to the impedance height, and antinoise is poor.In order to suppress the change that noise causes, the capacitance of electric capacity 1386 in the image element circuit.Different with display board, aperture efficiency can be zero, thereby can form enough big capacitor.Thus, can the equable voltage of service voltage.
When the array external circuit that comprises source electrode driver IC applies pre-charge voltage, the shiny black degree of each display board difference during smaller or equal to the pre-charge voltage of to a certain degree (0.1 bank/square metre).
As the method for adjusting pre-charge voltage, the example of Figure 145 and Figure 147 is proposed.The difference of these 2 figure is: when supplying with pre-charge voltage from the outside, with electronic potentiometer with the program mode (PM) change or with metallic ceramics vernier capacitor etc. with the hardware mode adjustment.
Feature of the present invention is: the electric current of the EL cathode power 1450 of whole negative electrodes of the EL element of usefulness galvanometer 1453 measurement connection EL display boards, and make pre-charge voltage with current value change.
Under the situation of EL element, brightness and electric current have the relation of direct ratio, as long as thereby distinguish formation smaller or equal to 0.1 bank/square metre the current value of brightness, only measure electric current and just can judge whether black level abundant.
Compare with measuring brightness, when measuring, do not need the darkroom, and have can be with the specific luminance advantage that honest and clean galvanometer adjusts of valuating by electric current.
Under the situation of Figure 145, adjust the voltage of precharge voltage line 1455 with electronic potentiometer 1456, thereby utilize the value of the input logic input current meter 1453 of 1452 pairs of electronic potentiometers 1456 of personal computer equal controller, and the value of electronic potentiometer control line 1459 is changed with this value automatically, then can adjust cathode current automatically.Can not have and manually get involved and adjust at low cost.
The situation of Figure 147 is to replace electronic potentiometer 1456 and storage unit 1457 to adjust the example of pre-charge voltage with resistive element 1472 and trimmer 1473.Among this figure,, go back serviceability temperature compensating element, 1471 simultaneously for the compensation temperature characteristic.At this moment, can simultaneously observe the value of galvanometer 1453, one side is adjusted trimmer 1473, with formation rated current value, thereby realizes black the demonstration.
Figure 146 adjusts the process flow diagram that best pre-charge voltage is used.One side is carried out voltage precharge, and one side is deceived demonstration (1461).At this moment, measure the current value (1461) of EL cathode power 1450.Known formation 0.1 bank/square metre current value, thereby judge whether this value (1463) of current value.
If not setting, the control electronic potentiometer makes pre-charge voltage change (1464).Measure the value after changing, judge whether setting once more.Repeat this operation, up to forming setting.
After forming setting, the signal value that then will supply with electronic potentiometer stores storage unit 1457 (1465) into.
When electronic potentiometer inside does not have storage unit, when dispatching from the factory as assembly after the voltage adjustment of the present invention, can not keep the value of electronic potentiometer.Therefore, storage unit is set separately, the value of electronic potentiometer is remained in the storage unit, and checking that the value of end back according to storage unit 1457 produces pre-charge voltage (1467).At first, before checking end, will be worth write storage unit 1457 from control modules such as personal computers.
Therefore, even cut off the electricity supply, also can supply with each display board and form the best black pre-charge voltage that shows.
According to foregoing invention, no matter display board,, can realize deceiving demonstration always the brightness during black the demonstration is constant, and does not have black brightness of floating by adjusting to.
In addition to the above methods, as the method that suppresses the black brightness that shows without voltage precharge, the break-make control of signal line 2 (61b) that can be by making Figure 148 changes, and shortens the time of organic EL 63 circulating currents, suppresses brightness.
Figure 149 illustrates the waveform of signal line 2 (61b).Figure 149 (a) is existing waveform, only forms non-lighting the phase 1493 in 1 horizontal scanning period that will be input to from the electric current of source signal line in the pixel in 1 frame.Circulating current in organic EL 63 At All Other Times, thereby organic EL is lighted.
Among the present invention, as Figure 149 (b), only constituting the part-time in 1 frame (for example 1/10), to make switch be conducting state, organic EL 63 circulating currents.Owing to make display gray scale constant, light emission period 1494 is that to make the electric current from the source signal line be 10 times for 1/10 part.The organic EL 63 10 times of electric currents that in 1/10 time, circulate, thus the brightness of each frame kept as beforely.
0。, only early effect 0 electric current because of driving transistors 62 only increases certain value, but this is with original identical.Current value.On the other hand, because the time of the circulating current of organic EL 63 is 1/10, brightness is reduced reach 1/10.
The length of lighting the phase 1494 is short more, it is non-that to light the phase 1495 long more, the alive time of organic EL 63 reliable stream shortens, but under the situations such as white demonstration, the momentary current of organic EL 63 circulations increases, the organic EL deterioration that may exist heating, electric current that momentary current causes to increase to cause etc., thus minimum be good with about 1/10 times.On the other hand, because during black demonstration that need be about 3.5nA, this electric current is reduced to 1.3nA, need be at least 1/3 times non-lighting the phase.
But the such pixel quantity of large-scale tv machine is many, and horizontal scanning period is short, and does not write under the situation of rated current, thereby uses when making the electric current of each gray scale increase the unit that writes with same unit, thinks the electric current maximum of these 10 times of current ratios.
Go back dual-purpose working voltage precharge etc. and realize that its method is under the situation of the black methods that show except that the present invention: the existing example of for example press Figure 149 (a) drives black when showing electric current, and it is reduced to about 2nA, then makes the phase of lighting 1494 be existing routine half.Have and form 2 times and then move to right 1 and wait advantages such as computing is convenient, thereby can think that the burden of logical circuit alleviates.Therefore, make up two or more methods of the present invention, then can make the phase of lighting is 1/2.
In addition, for the phase of lighting 1494 that makes this signal line 2 (61b) changes, the method for the starting impulse length of available control gate driver 35 etc. changes the phase of lighting 1494.By utilizing order to change the logic of controller 1482 inside, can realize this variation.
Can utilize controller 1482 that the phase of lighting 1494 is changed.Equally, the electric current of source electrode driver 36 also can be supported the reference current generating unit of Fig. 8, and utilizes the electronic potentiometer slave controller that reference current is changed.Reference current is 2 times, and then the electric current of each gray scale is 2 times.
For example utilizing the control of controller 1482 to make the reference current of source electrode driver 36 is 2 times, and changes the drive pulse length of gate drivers, and making the phase of lighting 1494 of signal line 2 (36b) is 1/2 times, and the brightness during then black the demonstration is 1/2 times.
Do not carry out the control of source electrode driver and gate drivers simultaneously, and it is identical to make it be driven into multiplying power, then can realizes lighting the phase 1482 arbitrarily, and the black brightness that shows is reduced.
Because the temperature characterisitic of the early effect of driving transistors 62, temperature is high more, and the brightness during black the demonstration is big more.Therefore, the signal that the present invention constitutes temperature probe unit 1481 gained is input to controller 1482, makes the phase of lighting 1482 according to temperature variation.Temperature is low more, and the phase of lighting is long more; Temperature is high more, and the phase of lighting is short more.Therefore temperature is low more, and the electric current of source electrode driver is more little, and electric current only increases when high temperature.
Electric current is increased, do not need then the organic EL big electric current that do not circulate, thereby can realize the display device that deterioration is little.
The multiplying power that can set is also discontinuous, can set the discrete value variation with the scan signal line number that adapts to display device for.Can be with the ratio increase and decrease of 1/ number of scanning lines.
It is 1/10 ~ 1/3 that black measure of floating when tackling black the demonstration is made the phase of lighting, and according to its ultimate value of display board node, non-ly sometimes accurately equals 1/10, and the value of N/ number of scanning lines gets final product (N be natural number and less than number of scanning lines) between including 1/10 ~ 1/3 in.
When except that the controlling and driving pulse width, going back the output enabling signal of dual-purpose gate drivers, can set time, non-lighting the phase 1495 arbitrarily.When using the method, two petiolareas 1494 and non-ly light the phase 1496 and alternately mix, thereby have the effect that suppresses flicker mutually.
Figure 149 (b) illustrates the waveform of the signal line 2 (61b) when using the output enabling signal.To the result of the signal line waveform of Figure 149 (a) in the output at end, applying the output enabling signal.By in 1 frame, light so comprehensively, be not easy to occur flicker.The reference current of source electrode driver 36 can be set for by slave controller and control electronic potentiometer, it is changed according to the non-ratio of lighting the phase 1495, thus the brightness of the gray scale beyond black for stipulating.
According to above-mentioned composition, may not use electronic potentiometer, also can realize not having black demonstration of floating.
Figure 45 is illustrated in the display mode that district 451 and district 452 carry out the demonstration of the demonstration of gray scale 0 and gray scale 4 respectively.At this moment, the row of establishing district 452 few (for example 1 row) then has the brightness in time zone 452 extremely to reduce.
This is because the electric current little (smaller or equal to 20nA) of gray scale 4, the electric charge that the stray capacitance of source signal line 60 stores is difficult to discharge and recharge, and the source signal line voltage variety of each gray scale is big in the low gray scale, so, produce the problem that brightness reduces in order to show the gray scale (between 0 to 4) in the process that changes to gray scale 4.
Cross over multirow existence district 452 o'clock, brightness increases gradually since the 1st row, show the regulation gray scale since the 3rd or the 4th row, thereby formation shows the state that slightly lacks.Only 1 when row, the line in whole district 452 can not get showing under the worst situation, and generation can not show with the black small characters of background and the problem of horizontal bar chart picture of being shown as.Otherwise, when the display gray scale in district 452 is high, even 1 row also accurately shows.
Figure 47 illustrates the source signal line current of each gray scale and the relation of voltage.Make from the time that district 451a changes to district's cost in 452 o'clock be Δ t4 when the display gray scale 4, be Δ t255 when display gray scale 255.Δt4＝C×ΔV4/I4，Δt255＝C×ΔV255/I255。I255 ≈ 64 * I4, but Δ V255 ≈ 3.5 * Δ V4.Therefore, Δ t4 compares with Δ t255, and changing needs about 18 times time.
This is because the increase of source signal line current and the non-proportional relation of increase of source signal line voltage.Gray scale is low more, and voltage is big more with respect to the variation of electric current.Shown in the efficient circuit of Figure 12 (a), the curve of the drain current of transistor 62 and the relation of grid voltage decision Figure 47.Therefore, form nonlinear relationship, the variation from identical display gray scale to bright gray scale, it is difficult more to change to low more gray scale.
When driving with the 60Hz frame frequency in the QVGA display board, confirm in the district 451 that under the gray scale of source signal line current smaller or equal to 40nA, in the gray scale of source signal line current smaller or equal to 300nA in district 452, the brightness in district 452 reduces.
The phenomenon that does not write the regulation electric charge in the electric capacity in the pixel 65 is used as " writing insufficient ".
In the display mode of Figure 46, district 461 shows 255 gray scales, and when district 462 wanted display gray scale 0 and gray scale 4, the following number formulary row that spreads all over district 461 produced the phenomenon that brightness increases.The 1st row brightness maximum in district 462, along with row down, brightness reduces gradually, the regulation brightness in viewing area, 3 row～5 row left and right sides 462.
As shown in figure 48,, write and distinguish 462 corresponding gray scales, must utilize the electric current that circulates on the source signal line charge charging stray capacitance in order to distinguish in 461 the footline behind the write current, because the magnitude of current is little, the length spended time.For example change under the situation of gray scale 4, must make its variation, must make its variation with electric current I0 when changing to gray scale 0 with electric current I4.Therefore, gray scale is low more, changes spended time more.Voltage variety also is to make low more grey scale change, and variable quantity is big more.Therefore, it is the strictest to change to 0 gray scale, along with gray scale increases, writes setting easily.
In the display board of the pixel count of QVGA, represent with 60Hz under the situation of 1 frame that the source signal line current of district in 462 is during smaller or equal to 40nA, 1 row～5 row brightness at top are greater than regulation brightness.
This phenomenon is called " hangover ".
" write insufficient ", " hangover " all produce because the source signal line current is little.Therefore, the present invention is provided with maximum gray scale electric current and temporarily circulates the phase, and the structure that electric current changes near the back of rated current circulation rated current in the source signal line is set, thereby makes the state of source signal line change to the regulation gray scale fast.
For example, in the example of Figure 47, when gray scale 0 changes to gray scale 4, as shown in figure 49, the lowest high-current value that during Δ t4p1 (491), circulates (being 255 gray scale electric currents here), the gray scale electric current (I4) of circulation regulation during remaining Δ t4p2 (492).Thus, if the voltage in 493 is Vip, then gray scale 0 becomes C * (V0-Vip)/I255+C * (Vip-V4)/I4 to the transformation period Δ t4p=Δ t4p1+ Δ t4p2 of gray scale 4, I255=(255/4) * I4 wherein, utilize Δ t4=C * (V0-V4)/I4, then become Δ t4=Δ t4+ ((251 * C)/(255 * I4)) * (Vip-V0) because V0＞Vip, form Δ t4p＜Δ t4.Therefore, the electric current transformation period of 0 grey scale change to the, 4 gray scales can shorten.
When tackling hangover, can not only increase electric current.Therefore, supply with respect to the voltage (V0) of grey black degree from source electrode driver, make the source signal line be gray scale 0 show state after, as Figure 49 just now, carry out the demonstration of gray scale 4.Potential difference (PD) before and after the variation of gray scale 0 to the variation of gray scale 4 and gray scale 255 to gray scale 4 only changes is different, and gray scale 255 is bigger to the potential difference (PD) of the variation of gray scale 4.The method of Figure 49 can be to change than simple gray scale 0 to the short time of the variation of gray scale 4, thereby gray scale 255 is also the easiest to the variation of gray scale 4 finishes following variation: utilize voltage to form gray scale 0 back (owing to make its variation with voltage, the transformation period weak point reaches 1 microsecond～2 microseconds), circulating current, near gray scale 4, the electric current with gray scale 4 shows the regulation gray scale then.
The maximum current that will circulate before being transformed into the rated current value like this is defined as pre-charge.
The running of carrying out the pre-charge electricity at first applies the voltage corresponding with gray scale 0, exports lowest high-current value then, and up near the regulation gray scale, rated current at last circulates.
When " writing insufficient ", also voltage available changes to gray scale 0 once.Do not form gray scale 0 and form the electric current transformation period that maximum current brings and foreshorten to rare 100 microseconds, even thereby increase voltage about 2 microseconds and apply phase and pre-charge electricity phase (depend on gray scale, but about 2 microseconds), also apply voltage.
Thus, both same pre-charge electricity runnings that can descend of " writing insufficient " and " hangover ", thereby it is simple to carry out the circuit of pre-charge electricity usefulness.
When not existing the voltage that forms gray scale 0 to apply the phase, though same display gray scale, if the gray scale difference before 1 row then needs to change the pre-charge electricity and applies the phase.Gray scale 3 is during to the variation of gray scale 9 and gray scale 6 during to the variation of gray scale 9, and the voltage variety difference is so change the asynchronism(-nization) that needs.Therefore, when supposing not exist 0 gray scale to form the phase, need change maximum gray scale period of output according to the gray scale before 1 row and the value of current gray level, so need gray scale difference computing etc., control is complicated.
When gray scale 0 being set forming voltage and once applying the phase, must begin to change from gray scale 0, can set the pre-charge electricity according to display gray scale and carry out the phase based on the grey scale change of pre-charge electricity.
By carrying out the pre-charge electricity like this, in the display mode of Figure 47, Figure 48, also can accurately show even show when hanging down gray scale.
When carrying out the pre-charge electricity, must specify optimum current precharge apply the phase, need about 10 kinds～20 kinds the pattern that applies whole 255 gray scales by the whole gray scales of demonstration.
Carry out the control that the pre-charge electricity applies the phase in the source electrode driver inside shown in Figure 65.Shown in Figure 120, for example prepare 7 pre-charge electric pulses 1174 and voltage source precharge pulse 451, and utilize pulse choice portion 1157 shown in Figure 118, Figure 119 and electric current efferent 1171 to realize.Pre-charge electricity is judged some in the line 984 decision pre-charge electric pulses or only for not doing the voltage precharge (the only voltage of output gray level 0 state) of pre-charge electricity, thereby the transmission that is directly proportional with vision signal.By selecting precharge to judge line to vision signal, for example establish and select pre-charge electric pulse 1174, after then utilizing the voltage precharge pulse at first to export the voltage corresponding with gray scale 0 from pre-charge voltage generating unit 981, at pre-charge electric pulse 1174b is the cycle circulation electric current corresponding with maximum gray scale of high level, when forming low level, output meets the electric current of gray scale.Because need select the optimum current precharge pulse according to the vision signal of 1 pixel share, pulse choice portion 1175 and electric current efferent 1171 need the output number of source electrode driver.
When preparing 6 kinds of pre-charge electricity and voltage precharge, consider 8 kinds of systems of selection, wherein comprise no precharge.Therefore, precharge judges that line needs 3 at least, and pulse generation portion 1175 need be from 3 decoding parts (for example according to the running of the truth table shown in Figure 119) that change to 7.
If all gray scale will be carried out the pre-charge electricity, then this pre-charge electric pulse 1174 needs 20～30, and the circuit scale of pulse choice portion 1175 increases.Because have 1175 of source electrode driver output number, the increase of circuit scale is big to the chip area influence.Again, send precharge in pairs with respect to vision signal and judge line 984, also increase so latch the figure place of portion.Therefore, when considering the cost of source electrode driver, the kind of carrying out the pre-charge electricity is preferably 6 kinds.
The kind of carrying out the pre-charge electricity is retrained by the source electrode driver scale, is defined as 6 kinds, thereby all gray scale is carried out the pre-charge electricity, and the low gray area that only needs carries out pre-charge.
Figure 50 illustrates the process flow diagram that judges whether to carry out pre-charge electricity usefulness.At first input judges whether gray scale 0 to vision signal.When being gray scale 0, do not need the pre-charge electricity, only need voltage precharge, thereby proceed to voltage precharge judging part, whether decision carries out voltage precharge.
When being not gray scale 0, then carry out comparing with 1 capable preceding gray scale.Here owing to need the grey of pre-charge electricity different under " hangover " and " writing insufficient " two states, whether do the judgement of pre-charge electricity according to problem separately.Here, before 1 row and current gray scale when consistent, can fully not show the regulation gray scale yet, thereby be judged as and do not make pre-charge even do not carry out the pre-charge electricity.Be judged as when gray scale is low before 1 row (the demonstration example of Figure 94), confirm in the district 451 under the gray scale of source signal line current smaller or equal to 40nA, in the district 451 under the gray scale of source signal line current smaller or equal to 300nA, the brightness in district 452 reduces, thereby can only carry out pre-charge when meeting this condition.When not meeting, district 542 shows with regulation brightness, so can not carry out pre-charge.
Gray scale is when higher (the demonstration example of Figure 46) before being judged as 1 row, under the situation of source signal line current smaller or equal to 40nA in district 462, top 1～5 row brightness is higher than regulation brightness, thereby only during smaller or equal to 40nA, carries out pre-charge in current source signal line current.
Thus, form the process flow diagram of Figure 50.
Figure 52 illustrates gray scale relatively 502 compositions preceding with 1 row.In order to compare the preceding gray scale of 1 row, need the line storage of 1 row share.By the information used of input 1 horizontal scanning period in the storer 522, the data of current data and storer 522 are compared, thereby can compare its scale.
Need 8 line storages and the comparer that compares 8 bit value sizes when importing 8 digital video signals.It is big that the circuit of line storage and comparer becomes.Therefore, among the present invention, if utilization according to Figure 50 current gray level and 1 row before gray scale all form greater than the current value of 40nA this point of needs pre-charge electricity not just, and according to the efficient of the organic illuminating element that uses, make under the situation of 8 signals in gray scale 15 or the higher gray scale electric current greater than 40nA.That is, the signal of gray scale 15 or higher gray scale does not need precharge in the ranks when 2 extend continuously.
Therefore, as shown in Figure 51,521 pairs of incoming video signals carry out data conversion in data conversion portion, and storer 522 write, then storer 522 is 4 and gets final product that (area of storer reduces by half, storer 522 takies the area of half approximately when constituting control IC, thereby can expect that the area of control IC reduces 20% at least).According to Figure 51, comparer 525 is 4 bit data relatively, and when the data of 15 gray scales or higher gray scale and 15 gray scales or higher data are compared, can be judged as both unanimities, do not make pre-charge.The either party can compare its scale, thereby take to tackle the measure of " hangover " and " writing insufficient " during less than gray scale 15.
Can make storer also keep the data of 1 row.When transmitting data with 6 times of speed as shown in Figure 28, clock is with 6 times of speed runnings.That is, transmit 1 data during the input 6 clocks.Figure 68 illustrates the relation of clock 685 and vision signal.Follow-up 2 numeral row and the row of the DATA of vision signal.DATA12 refers to the data of the 1st row, the 2nd row.Data conversion portion 521 has latch or trigger, can stored video signal.Data after the 5th clock is with conversion are written to storer.Make address stored and row number at once, can keep the data of same address in 1 image duration.Because in the data of the 5th clock updated stored 522, when between the 3rd clock to the 5 clocks, the output 686 of storer 522 and data conversion portion 521 being compared at least, can compare preceding the and current gray scale of 1 row., can compare when carrying out comparison the 1st row of the data of the 1st row and the 2nd row at cycle 681a.Equally, use the 2nd address of storer 522 to compare at cycle 681b, then can comparing data.
Thus, the share of storer with source electrode driver output number * 4 gets final product.
According to above-mentioned judgement, even for example change 1 gray scale, also change when hanging down gray scale, then carry out pre-charge.Because variable quantity is little, carries out or do not carry out pre-charge and show electricly and all can.Carry out pre-charge when electricity, corresponding voltage when applying the showing of 1 pre-charge voltage generating unit 981 with gray scale 0.This voltage supposes that the grid voltage of transistor 62 and the relation of drain current produce deviation owing to be added on the grid voltage of transistor 62, and then each pixel is more high or low than the voltage of optimum gradation 0.In order to make this magnitude of voltage change to the magnitude of voltage of gray scale up to specification, the use pre-charge, but because the current value of pre-charge electricity and source signal line capacity are in that to carry out in the precharge time deviation little, relatively there are difference in the magnitude of voltage and the optimum value of carrying out after the precharge, the result is low, and the gray area electric current reduces, thereby this deviation can not proofread and correct in the regulation gray scale current flowing phase, may produce irregular with the irregular corresponding demonstration of transistor 62.Therefore, among the present invention, consider to be formed in when changing 1 little gray scale difference and do not carry out the pre-charge electricity, thereby can realize showing irregular little demonstration.Wherein, when gray scale 0 changed to gray scale 1, under the situation of former gray scale 0, the brightness when being not limited to black the demonstration near 0, thereby utilized voltage precharge display gray scale 0, even can think and import identical voltage and carry out the pre-charge electricity, did not also influence demonstration.Again, voltage variety is big between gray scale 0 and the gray scale 1, only is difficult to change with electric current sometimes, even thereby preferably constitute 1 gray scale difference and also can implement pre-charge.Under the situations such as the current value of each gray scale is big, two gray scale differences are not made the pre-charge electricity sometimes, can show yet.At this moment, apply voltage in order to reduce shiny black degree, can to improve in the gray scale 0, or, can only carry out pre-charge 0 to 1,0 to 2 variation because the variable quantity of gray scale 0 to 1,0 to 2 is big.
Therefore, the present invention gets the circuit of Figure 53 and forms, and replacing Figure 55, decision is arranged under the condition such as 1 gray scale difference, 2 gray scale differences of order A appointment can be judged as the determining device 531 of not making the pre-charge electricity.Figure 54 records and narrates the content of order A.The value of order A is 0 o'clock, does not make pre-charge electricity (not using pre-charge) fully.Be taken as at 1 o'clock, under the situation of 1 gray scale difference, do not make pre-charge; , under the situation of 1 gray scale difference except 0 to 1 the variation, do not make pre-charge at 2 o'clock; , under situation, do not make pre-charge at 3 o'clock smaller or equal to 2 gray scales; , under the situation except 0 to 1,0 to 2 the variation, do not make pre-charge at 4 o'clock smaller or equal to 2 gray scale differences.And, according to the efficient of organic illuminating element and with the value of the order A of the variation correspondence of display board brightness (because the electric current during 255 gray scales changes, brightness is big more, easy more demonstration regulation gray scale), select optimum value, thereby can carry out the pre-charge of subsistence level limit.This relatively determining device 531 to be judged as the number of times of not making the pre-charge electricity many more, the pixel count that uses the pre-charge electricity to show in 1 picture is few more, thereby can realize applying the irregular indiscoverable demonstration of influence of demonstration that voltage causes.
To the 1st demonstration of going that can not compare with the state before 1 row, get the composition of Figure 55, to replace Figure 53.Dividing condition in the time of when the 1st behavior 0 gray scale and beyond 0 judges whether to carry out voltage precharge when gray scale 0, thereby the 1st row voltage precharge judging part 554 is imported.Here, utilize order B to judge whether to carry out voltage precharge.The precharge situation of voltage of not carrying out is set herein, so as can do not carry out voltage precharge also can show when black and the application of shiny black degree greatly also can (contrast little also can) time on the display device used etc., select not carry out precharge.
Under the situation beyond the 1st behavior gray scale 0, whether the 1st row pre-charge electricity judgement section judges carries out pre-charge.C can determine whether carry out precharge with order, and make can the brightness maximum, organic illuminating element efficient is low and the big electric current that circulates etc. under the situation, can not carry out pre-charge even gray scale is hanged down in the time of also fully showing the regulation gray scale.
The 1st row pre-charge electricity judging part 551 is judged as when carrying out the pre-charge electricity, then need select the pre-charge electricity to carry out the phase according to gray scale.Figure 57 illustrates according to gray scale and selects the pre-charge electricity to carry out the circuit block diagram of phase.The circuit block diagram of Figure 57 is according to vision signal and order D to the value of ordering I, judges pre-charge electricity 1 to 6 or does not carry out pre-charge.Source electrode driver 36 sides with the time set precedent of pre-charge electricity 1 to 6 as Figure 120, and carry out pre-charge in the high period of pre-charge electric pulse 1174.Which of 6 pulses in this pre-charge electric pulse 1174 selected in decision according to the truth table of Figure 119.Therefore, in order to make the pre-charge phase, can make precharge judge that the value of line 984 is with grey scale change with grey scale change.
According to vision signal and order dividing condition, each result to 571 to 577 shown in Figure 63 can judge signal 55 by the consideration output precharge identical with Figure 119 among Figure 57.Thus, source electrode driver 36 can be judged the value of signal 55 according to the precharge that sends in pairs with vision signal, and decision is carried out pre-charge electricity (also can similarly determine only to carry out voltage precharge or do not carry out this precharge) with great length.
Also the length of each pre-charge electric pulse is set in the source electrode driver side.Shown in Figure 65, by pulse generating unit 1122 each pulse length of decision.Pulse generating unit 1122 comprises counter 693, pulse generation unit 694, frequency dividing circuit 692 shown in Figure 69.The value of counter 693 counting gained is set line 1096 with the pre-charge phase of decision pre-charge phase compares, and output meet setting value during be the pre-charge electric pulse 1174 of high level.Carry out voltage precharge at top to source signal line output gray level, carry out pre-charge then, and output gray level electric current, thereby the high level of pre-charge electric pulse 1174 drives the phase after timing pip 848 outputs, therefore, it is clear 0 that counter 693 is pressed the input of timing pip 848, thereby be benchmark with timing pip 88, produces pulse.Voltage precharge phase setting line 933 and voltage precharge pulse 451 are also carried out with same composition.The composition that electric current efferent 1171 and voltage apply selection portion 1173 is the circuit shown in Figure 118, thereby pre-charge electric pulse 1174 and voltage precharge pulse 451 can form high level in same timing as Figure 120.In order to simplify pulse generation unit 694, be taken as the such waveform of Figure 120.Therefore, the high level length of pre-charge electric pulse 1174 equals the voltage precharge phase is set the result of the value addition gained of line 933 and pre-charge electricity phase setting line 1096.Pre-charge electric pulse 1174 has 6, thereby can set 6 kinds of pre-charge electricity phases and set line 1096.Constitute again owing to have frequency dividing circuit, even because of source electrode driver clocks such as pixel count variation 871 change, also can be tackled by the setting range unanimity that makes pulse width as far as possible, even and the pulse width that needs also can be tackled by divider ratio is changed because of sharply variations such as EL efficient raisings.Therefore, has the advantage of using identical source electrode driver with ignoring any pixel count, EL element luminescence efficiency.
Thus, utilization order D orders to 6 that order I and specifies 6 tonal ranges of carrying out the pre-charge electricity, and with the electric phase setting of the pre-charge of source electrode driver 36 length of 1096 electric phases of each pre-charge of decision of line, then can realize optimum current precharge.More than or equal to gray scale 1 to carrying out pre-charge electricity 1 with scope smaller or equal to the gray scale of order D appointment, extremely carry out pre-charge electricity 2 with scope in gray scale smaller or equal to the gray scale of order E appointment more than or equal to order D appointment, extremely carry out pre-charge electricity 3 with scope in gray scale smaller or equal to the gray scale of order F appointment more than or equal to order E appointment, extremely carry out pre-charge electricity 4 with scope in gray scale smaller or equal to the gray scale of order G appointment more than or equal to order F appointment, extremely carry out pre-charge electricity 5 with scope in gray scale smaller or equal to the gray scale of order H appointment more than or equal to order G appointment, extremely carry out pre-charge electricity 6 with scope in gray scale smaller or equal to the gray scale of order I appointment more than or equal to order H appointment, do not carry out the pre-charge electricity during greater than the gray scale of order I appointment, become 57.
Under the situation beyond the 1st row, shown in Figure 53,, also need to tackle the measure of " writing insufficient " and " hangover " even carry out the pre-charge electricity.These 2 measures are with respect to 504 to 506 the flow process of Figure 50.
Tackling and write when insufficient, be the gray scale greater than 40nA before 1 row, does not then need the pre-charge electricity, thereby at first shown in Figure 56,1 capable preceding data gray scale detection unit is set.Under situation, do not make pre-charge more than or equal to the setting gray scale of ordering J.Here, because the gray scale suitable with the electric current of 40nA is different in response to using, or is shown that look, organic material luminescence efficiency influence, for the purpose of prudent, carry out the order input.When these conditions were determined, input command not also can be by more than or equal to the regulation gray scale, judge less than the regulation gray scale.Less than regulation during gray scale, then need be with respect to the pre-charge electricity arbitration functions of 506 judgement.This function can shared Figure 57 above.The gray scale of order I is set to the gray scale of source signal line current formation greater than the electric current of 300nA, then satisfies Figure 50.
Then, when tackling " hangover ", can carry out 504 judgement, thus shown in Figure 58, identical with Figure 57, also utilize pre-charge electricity phase selected cell 578 to judge.Thus, " hangover " disappeared, but because the characteristic deviation of the transistor 62 of pixel internal circuit, according to pixel, applying sometimes to surpass needs ground to form the black voltage that shows when applying voltage precharge.At this moment, the pre-charge electricity should surpass when needing to have under the black situation about showing of ground formation less than regulation brightness (meaning has this possibility under the last situation, because certainly exist the electric current period of output of brightness up to specification, may not reduce) owing to bias free.Under the situation that " writes insufficient ", deceive, also take smooth variation, thereby be difficult to noticeable even establish to form; Under the situation of " hangover ", 461 is that gray scale 48,462 is during for gray scale 40 among Figure 46, only might produce the situation of 462 the most up display gray scale 20, between the gray scale 48 and 40 then the halation of times gray scale 48 cover, be difficult to noticeable, but compare with these 2 gray scales, when occurring hanging down gray scale, intersection produces dark horizontal line.
Influence picture quality when consider producing dark horizontal line and " hangover " more is difficult to prominent because of halation than " writing insufficient ", then can think and compare with tackling " writing insufficient " time when tackling " hangover ", utilize the necessity of the accurate generation of pre-charge electricity display gray scale little.
When experimentizing with 3.5 type scale QVGA display boards, produce " writing insufficient " in gray scale 0 to the scope of gray scale 7 before 1 row, current gray level then produces during to gray scale 74 in gray scale 1.Otherwise gray scale before 1 row is not depended in the generation of " hangover ", and current gray level then produces " hangover " during to gray scale 9 in gray scale 0.Distinguish with " writing insufficient " and compare that the grey that must make the pre-charge electricity when " hangover " is few.
Therefore, the present invention is input to pre-charge with the output of pre-charge electricity phase selected cell 578 again and is electrically interposed in judging unit 581, utilizes order K further to limit the scope of carrying out the pre-charge electricity.Order K have Figure 59 when such precharge insert the function that the output of judging unit 581 changes, the value of for example establishing order K is 6, then utilizes the running of Figure 59 to bring: according to gray scale, perhaps do not make the pre-charge electricity, perhaps carry out pre-charge electricity 1.Carry out the scope of pre-charge electricity 1 by order D decision, thereby when being less than or equal to the setting gray scale of order D, make pre-charge.Constituting hangover with 2 utmost points like this and eliminate setting 580, is in order to reduce command number.Have 2 values when order hangover usefulness and that write insufficient usefulness, 12 orders of needs, but mode of the present invention then gets final product with 7 orders, thereby have the advantage that can reduce command register quantity.Plan is used as the judgement of pre-charge electricity shared, unwanted part utilization order K deletion when only trailing.
Current gray level is 0 o'clock, and electric current is 0, thereby does not need the pre-charge electricity, and judges whether to apply the voltage precharge that equals that meets 0 gray scale.This judgement is taken as precharge judging part 503 in Figure 50, and forms the composition of Figure 60.Here, Data Detection portion 601 before 1 row is set, at continuous 2 row or more do not need during multirow display gray scale 0 before 1 row, the source signal line states to be changed, even thereby gray scale 0 also can not do voltage precharge.Control by only utilizing electric current.Can reduce the influence of the luminance deviation that the deviation of transistor 62 causes.Therefore, before 1 row Data Detection portion 601 only judge before 1 row data whether gray scale 0 (at this moment, data are vision signals 523 before the row of 1 after the data conversion before 1 row.Because conversion is carried out according to Figure 51, if judge whether 0 gray scale, the data after the available conversion are carried out).Data before can accepting output jointly and judge 1 row from the storer 522 of Figure 52.
Even under the also abundant little situation of gray scale 0, shiny black degree, or under the big also no problem situation of shiny black degree, can not do voltage precharge, thereby formation can judge whether to do voltage precharge.Utilize order L to control this judgement, and judge whether to do the voltage precharge shown in Figure 61 according to the value of order L.When shiny black degree was extremely reduced, employing must be done voltage precharge.Can prevent black the floating that leakage current causes.
Gathering above-mentioned precharge and judge, then is that Figure 62 is such.At first, judge that whether vision signal handle in the gray scale 0 (621), 0 and non-0 different.Whether 0 o'clock for doing voltage precharge.Judge whether to do voltage precharge (601) according to data before 1 row.But the 1st row is owing to incomparably than data, judge precharge (554) according to the gray scale of the 1st row.
During non-gray scale 0, judge whether to do the pre-charge electricity, and then when making the pre-charge electricity, judge and select in 6 kinds of precharge phases which.In order to tackle " hangover ", " writing insufficient ", to compare with gray scale before 1 row, current gray level is big or little, and it handles different.Incommensurable the 1st row and the 2nd row and different thereafter, the 1st row utilizes square frame 551,552 to compare.The 2nd row reaches thereafter to be judged with hangover elimination unit 580 when tackling " hangover ", tackles " writing insufficient " and then utilizes 561 and 578 to judge.Gray scale is identical and do not do under the situations such as precharge is preferable because of 1 gray scale difference etc., is judged as in 531 and does not make pre-charge.
3.5 in the type QVGA display board, make order A output 2, order B output 566, order C output 522, and order D appointment gray scale 1, order E specifies gray scale 2, and order F specifies gray scale 4, orders G to specify gray scale 10, and order H specifies gray scale 30, order I appointment gray scale 80.Order J specifies gray scale 11, and order K specifies 4, and order L specifies 1, thereby realizes being difficult to show that the low gray scale of regulation gray scale shows.
As the result of Figure 62, shown in Figure 67, add precharge accordingly with vision signal and judge signal (judging that by precharge signal generator 671 carries out the judgement of Figure 62).
May not need string-and transformation component 672, but when control IC is sent to source electrode driver with not conversion of signal ground, need 8 of vision signals to add that precharge judgement signal 55 is after 3 11 and because of existing 3 colouring components to become 33 transmission line.Connect the problem that signal wire causes wiring back and forth to be not easy and to exist the input and output pin increase to cause the packaging part scale to increase more, so preferably serial transfer is made in this wiring.When controlling IC and source electrode driver with the IC formation of same packaging part, the IC internal wiring is a problem, thereby needn't be transformed into serial.
When Fig. 1 and Figure 28 illustrate serial transfer also-string efferent 856 output waveform.On same signal wire, transmit precharge successively and judge the order of signal 55, vision signal, source electrode driver.Basically in the wiring between control IC and the source electrode driver IC, transmit this signal.
Figure 64 illustrates the display board of mode of the present invention and forms.Control IC28 is subjected to synchronizing signal 63 and vision signal 64 from the main equipment side joint, and it is transformed into the input signal format of source electrode driver 36, and vision signal and command signal are used as video signal cable 856 outputs.In addition, timing pip 849, the serial transfer of the timing of the clock of also the shift register work of source electrode driver 36 inside being used 858, direction of displacement control 890, driving pulse 848, the output of decision analog current are input to source electrode driver 36 with the gate line 651 that reduces the signal wire number.
Press the sequential chart shown in Figure 66 and transmit gate line 651.Gate drivers 35 has 2 circuit (switch 66a, 66b control is used and 66c control is used), thereby needs 8 signals such as starting impulse output enabling signal, clock, direction of displacement control respectively.Therefore, 6 times of speed transmit because 1 output only transmits 6 signals, 2 signals are included in the idle component 1 of green data 856b, 856c.Include 8 signals in, then output to 3 grades of driver control lines 652 together.Therefore, the signal wire of 3 grades of drivers is changed at least by the time interval of 1 output share.Might control 2 gate drivers to 1 source electrode driver, thereby source electrode driver about 36 is exported the gate drivers control line 658 of each 1 circuit share respectively.Figure 64 is during like that with 2 source electrode drivers, 36 control gate drivers 35, and source electrode driver 36 adjacent outputs do not need the output of gate drivers control line 652.Therefore, actual output enabling signal L and the R (653) that left and right sides gate drivers control line 652 is not exported is set.Thus, eliminate unnecessary output, suppress noise and output to the outside.
The power control line 641 of control on/off is exported.Deng biding one's time and non-demonstrations time formation stops reducing the function of standby power power circuit 646.It is because the on-off timing difference that power circuit is divided into display board power circuit 646a, actuator electrical source circuit 646b.This be since power supply when raising the output of gate drivers 35 non-constant, the transistor 66 non-original meanings ground of image element circuit 67 form conducting states sometimes.When for example switch 66c formed conducting state, the electric charge of memory capacitance 65 was 255 gray scale show states, and then this pixel forms illuminating state.Energized and experience 2 frames after, the gray scale electric current of regulation is written to pixel 67, and the output of gate drivers 35 is according to the starting impulse variation level of gate drivers, thereby EL element 63 circulation predetermined electric current, form the regulation gray scale.Energized and experience 2 frames during might produce and stipulate that the different gray scale of gray scale shows, thereby the glittering problem once of display board when having energized.Therefore, in order to address this problem, behind 1 frame, connect the power supply of EL power lead 64, thereby during the memory capacitance of the pixel 65 storages gray scale different with the regulation gray scale during with accurate oxide-semiconductor control transistors 66, EL power lead 64 is supplying electric current not, thereby EL element 63 is not luminous.Thus, avoid bright problem of display board wink.Therefore, power control line 641 needs 2.
In this composition, in order to reduce the signal wire number between control IC28 and the source electrode driver 36, best Fig. 1 or the such serial transfer data of Figure 28.Display brightness when the dotted line 1511 of Figure 151 illustrates use current-output type source electrode driver is to the relation of source electrode driver input gray level.Brightness forms proportional relation to gray scale.
On the other hand, need apply gamma correction according to the human eye characteristic, make the relation of gray scale and brightness form the relation shown in the curve 1512 after, export.
Owing to be difficult to make the gray scale of source electrode driver and the relationship change of light characteristic, for realize Figure 151 1512 shown in curve, in timing controller etc., make the relationship change of vision signal gray scale and source electrode driver gray scale in advance, form 1521 the such relation of relation to 1522 of Figure 152.
Output gray level by making source electrode driver like this is corresponding with the vision signal gray scale, can simultaneously carry out gamma correction, and one side realizes that gray scale shows.At this moment, for example the vision signal gray scale is under 2 the situation, source electrode driver gray scale output 0.5.Yet source electrode driver can not be exported 0.5 gray scale, thus use frame to take out to delete, shake, error-diffusion method etc., carry out the output suitable with analog form with 0.5 gray scale.For example make 1 display gray scale 1 in 2 times, 1 time remaining display gray scale 0 then can average the output suitable with 0.5 gray scale.Equally,, 4 display machines meetings are arranged, then can make 0,1 display gray scale 1 of 3 display gray scales if be vision signal gray scale 1.The vision signal gray scale is 5 to 7 o'clock, by the time gray scale 1 and gray scale 2 the rate of change of demonstration number of times realized.According to the viewpoint that prevents to glimmer, when appointment can not gray-scale displayed, preferably use near 2 gray scales that can not gray-scale displayed to show.
An example of the source electrode driver gray scale output of certain frame when Figure 155 illustrates for example whole screen display vision signal gray scale 1 (for illustrative ease, illustrates the monochromatic display board that shows among this figure.Under the situation of colored display board, the pattern by each look demonstration Figure 155 can realize).
When observing a certain display area, 1/4th pixel is that gray scale 1 shows, 3/4ths pixel is that gray scale 0 shows, further when interframe is observed same pixel, be to be gray scale 0 in time of gray scale 3/1sts, 4 in 1/4th time, thereby set up the little demonstration of flicker.Under the situation of colored display board, by making the pixel difference of each look display gray scale 1, the flicker that can reduce in the white demonstration reduces.
Figure 153 illustrates the circuit block diagram that the straight lines of 1522 expressions that realize Figure 152 are used.The vision signal 1536 of 1536 pairs of inputs of gamma-correction circuit is carried out conversion.At this moment,, carry out greyscale transformation, to suppress the brightness of low gray scale portion in order to meet human vision property.Low gray scale need use the class interval width thinner than vision signal gray scale to increase gray scale, thereby the vision signal behind the gamma correction 1539 is more than vision signal 1531 figure places.
If the figure place of the vision signal behind the gamma correction 1539 is identical with the video data figure place of source electrode driver 36, but former state input signal, but the time source electrode driver 36 figure place when increasing, it is many to latch the figure place that portion 22 latchs, the gray scale that respectively exporting to reduces adds the electric current output stage 54 of figure place share shows with current source 103, switch 108, thereby the circuit scale of source electrode driver 36 becomes big, the cost raising.
Therefore, the 1539 general figure places of the vision signal behind the gamma correction are more than the video data figure place of source electrode driver 36.When the figure place difference is big, must as Figure 152 explanation, uses frame to take out to delete etc. and carry out the gray-scale displayed number and increase.Organic illuminating elements etc. are because response speed is fast, carry out frame and take out when deleting the flicker that the gray scale difference of 2 gray scales using causes and have the trend of seeing arbitrarily.When flicker-freely showing, distinguish according to actual displayed that frame is taken out and delete the method needs and in 4 frames, finish with frame frequency 60Hz.
If the vision signal behind the gamma correction 1593 is M position (M be natural number and greater than N), the video data figure place of source electrode driver 36 is N position (N is a natural number), then needs the M bit map is become the data conversion portion 1537 of N position.
Therefore, among Figure 153, the vision signal behind the gamma correction 1539 is transformed into vision signal 1532 (N position) after the conversion by data conversion portion 1537.
As the method for carrying out conversion, shown in Figure 156, the high-end N position and the low side M-N that are divided in the input M position handle.Here, former state is supplied with high-end N position and is made its gray scale with source electrode driver corresponding, and the current value that each gray scale is needed is 2 (M-N)Doubly output then can accurately realize per 2 (M-N)The demonstration of gray scale.Yet, can not show its middle gray scale, appear as per 2 in fact (M-N)Cast out data.For it is proofreaied and correct, the low side M-N bit data of the gamma correction rear video signal 1539 of data is cast out in storage part 1564 storages, and uses that totalizer A1563 keeps, addition, in the amount of casting out (the addition aggregate values of low side M-N bit data) more than or equal to 2 (M-N)The time, the high-end N of gamma correction rear video signal position 1561 is added 1, the gray scale deficiency that causes with the compensation amount of casting out.Thus, can not import the display gray scale reduction that causes low side M-N position in the calibration source driver 36.
When paying close attention to same pixel, in 4 frames, do not finish correction, then produce flicker, thereby preferably low side M-N position is M-N≤2.When using the slow display material of response speed, may not can determine the higher limit of M-N according to display board smaller or equal to 2.M-N is more little, and the figure place of source electrode driver is many more, and cost is high more, does not carry out frame and takes out the picture quality of deleting with the part of dithering process but improve.There is the coordination of picture quality and cost, thereby can determines M-N as required.
In the following explanation, situation about using in the display board that uses organic illuminating element is described, thereby the value of M-N is taken as 2, describe.
Figure 152 1522 shown in the relation of vision signal gray scale (gamma handle after, M position) and source electrode driver gray scale (N position) in, the figure place of establishing source electrode driver is 8, the figure place after then gamma is handled can show 10 1024 gray scales.
With source electrode driver as benchmark, then show as apart from the data of gamma being handled the rear video signal and show 256 gray scales with minimum 0.25 gray level.
Example during Figure 155 during whole screen display gray scale 0.25.High-end 8 of gamma correction rear video signal always is 0, and 2 of low sides always are 1.Each display line of top that shows is according to the value of the value decision storage part 1564 of the random number generating unit 1569 that produces random number.This is because each display line of the value by making storage part 1564 in advance changes, and the stagger display gray scale of source electrode driver of every row increases by 1 timing when showing same gray scale, and flicker is not seen arbitrarily.Under this situation, 1562 is data of 2 shares, so the value that random number generating unit 1569 produces is in 0 to 3 any.
Among the 1st row 155a of Figure 155, random number generating unit 1569 is output as 0, thereby storage part 1564 is an original state.During from 1539 inputs data suitable with pixel 1553, signal wire 1561 outputs 0, signal wire 1562 outputs 1.The output 1533 of totalizer A1563 and 1565 is according to the result as 1562 and 1566 additions of each 2 input, and the result that low side is 2 outputs to 1565, and is output to 1565 because output becomes 1533,1,533 0,1 of output of the carry output after the carry.Store storage part 1564 into 1.
Therefore, totalizer B former state output data 1561, vision signal 1532 outputs 0 after the conversion.
Then, the input data (gray scale 0.25) corresponding with pixel 1554.High-end 8 bit data 1561 are 0.1562 is 1.The output of totalizer A1563 is because the data of storage part 1564 are 1,1533 output 0.1565 outputs 2.The output of totalizer B1568 as a result is identical with 1561, also exports 0.
Then, during input data (gray scale 0.25) corresponding with pixel 1555,1561 is 0,1562 to be 1.Totalizer A1563 is output as 1562,1566, thereby 1565 be 3,1533 to be 0, and totalizer B1568 is output as 0 as a result.
Then, during input data (gray scale 0.25) corresponding with pixel 1556,1561 is 0,1562 to be 1.The data of storage part 1564 are 3, thereby the output 1565 of totalizer A1563 is 0.1533 is 1.Therefore, totalizer B1568 is output as 1, thereby to pixel 1566 outputs 1.
When 1 row is gray scale 0.25 entirely, repeat this 4 kinds of states.
The data of storage part 1564 in the terminal column are not kept at the top of next line, and the value that random number generating unit 1569 is produced is input to storage part 1564, carries out the data input and output.Even random number generating unit 1569 may not produce random number, finding 2 (M-N)During the value of the storage part 1564 of the start-up time point of row, also can carry out 2 (M-N)Pass is according to output.
By such arrangement, can realize the source electrode driver gray scale of line 1522 expressions shown in Figure 152 and the relation of vision signal gray scale.
Will improve like this circuit of Figure 153 of gamma characteristic import the present invention, when the vision signal 1532 after the input conversion is judged in the signal generator in precharge, take place near the row of grey scale change, to produce the problem of flicker sometimes according to certain specific gray scale combination.
As for example gray scale of the source electrode driver shown in Figure 157, the 1st row shows 0.25 gray scale, the 2nd row and when showing 3 gray scales thereafter, and each pixel is in the output gray level pattern that determines driver in a certain frame as the circuit block diagram of Figure 156 to Figure 157.
In this pattern, there is not precharge when setting the preceding and relevant gray scale difference of going of 1 row for smaller or equal to 2 gray scales, more than or equal to 3 gray scales precharge is arranged then, then the gray scale of the 1st row is different because of row in the 2nd row, cause the 1st to the 3rd row to have 3 gray scale differences, so carry out the pre-charge electricity, but gray scale difference is 2 in the 4th row, does not carry out pre-charge.Figure 158 illustrates the situation whether each pixel record carries out precharge judged result.
Its result does not carry out that current value is difficult to change to the regulation gray scale in the row of pre-charge electricity, produces according to the data content before 1 row to write insufficiently, even the demonstration of gray scale 3, brightness is also little.Figure 159 1591 shown in pixel coverage in, brightness reduces.The 1st row is output as that brightness diminishes in 1 the row, thereby the row that 1 row brightness reduces occur in 4 row.Gray scale is low more, and it is long more to change to official hour, and is big more with the difference between current of regulation gray scale, so the luminance difference of regulation brightness is become big, dark part is remarkable.Each frame of part of dark part and regulation brightness changes, and moves successively, so see the flicker of mode movable about dark center line.
Even the 1st row shows identical gray scale with the 2nd provisional capital is normal,, also in 4 pixels, show 1 different gray scale at least owing to there is the data conversion portion 1537 of Figure 156.Produce flicker under this situation.Be thereby that 1 totalizer B1568 adds at 1 o'clock to signal at 1533 signal especially, writing of producing that flicker causes is insufficient.
In addition, as the pattern that produces flicker, also as the display mode of Figure 164, the demonstration before 1 row is always identical, but relevant going (be here the 2nd go) display gray scale 2.75, so or display gray scale 2, perhaps display gray scale 3, Yin Lie and difference.In the case, the row of display gray scale 2 do not carry out the pre-charge electricity, so write insufficiently, cause the brightness to be lower than gray scale 2 to show, the row of display gray scale 3 then owing to carry out the pre-charge electricity, show the gray scale 3 of regulation.Gray scale 2 is big with the luminance difference of the viewing area of gray scale 3, thereby sees flicker easily.
For from the signal of source electrode driver as vision signal output, during change, the skew of flicker and display gray scale takes place, cause display quality to reduce.
Therefore, among the present invention, precharge is set separately judges that signal generator 1538 carries out the signal that gray scale is judged, perhaps award the signal of judging usefulness again, thereby eliminate flicker.
Method as realizing this point illustrates 3 examples.
Figure 162 illustrates the circuit block diagram that the 1st method of realization is used.Output applies the vision signal 1532 behind the gamma correction to the video signal cable of input and judges whether to do precharge and precharge mark 380 that the precharge type is used.With the existing methods difference is to be input to precharge to judge that the signal of signal generator 1621 is not the output of data conversion portion 1537, adopts the high-end N bit data 1561 of gamma correction rear video signal.The running of data conversion portion 1537 is identical with Figure 156.
Thus, the data that are used to judge are not passed through totalizer B1568, thereby judge with the data of casting out input signal low side 2 bit data.Even for example show and go up the demonstration of carrying out Figure 164, judge that the signal that precharge is used also is the pattern shown in Figure 165, always gray scale difference is the no precharge demonstrations of 2,1 formation, does not glimmer.On the other hand, under the situation of the display mode of Figure 157,, form and always carry out the pre-charge electricity, do not produce flicker equally because signal is judged in the precharge shown in input Figure 163.
A certain its follow-up 1 row of being about to is when showing same gray scale respectively, and it is constant whether to carry out precharge judgement, does not depend on row, so prevent the flicker that has or not precharge difference to cause.
Figure 168 illustrates the 2nd method.
In this method, the conversion rear video signal 1532 that uses totalizer B1568 to produce according to the high-end N bit data 1561 of gamma correction rear video signal.This signal former state is input to precharge when judging signal generator 1621, glimmers, thereby signal generator 1621 is judged in the precharge that is input to that deducts in the subtracter 1681 after the part of totalizer B1568 addition gained.
Thus, the signal that the high-end N bit data of signal generator 1621 inputs and gamma correction rear video signal 1561 is identical is judged in precharge, thus identical with the 1st method, also can prevent the flicker that has or not precharge difference to cause.
Signal delay in data conversion portion 1537 circuit is big, synchronous in order to obtain precharge mark 380 with conversion rear video signal 1535, precharge judges that signal generator etc. needs regularly to adjust with under the situation of holding circuit among Figure 162, compare with totalizer 1681, when the circuit scale of holding circuit became big, the 2nd method was effective.
Figure 161 illustrates the circuit block diagram of the 3rd method, and Figure 154 illustrates the block diagram that signal generator 1538 is judged in the precharge of using among Figure 161.
In the inventive method, be with the difference of the 1st, the 2nd method: from data conversion portion 1537 output carry signals 1533, and use conversion rear video signal 1532 and carry signal 15332 both, judge the output of precharge mark 380.
Among Figure 159, have pixel 1591 that gray scale 3 accurately do not apply and the pixel 1592 that accurately applies, its reason is the situation that the data before 1 row exist gray scale 0 and gray scale 1, and this is when display gray scale 0.25, being gray scale 0 during no-carry signal 1533, is gray scale 1 when carry signal 1533 is arranged.Figure 160 (a) illustrates the display gray scale of each pixel and the example of display mode of the value of expression carry signal 1533 in bracket.
Here, even distinguish the demonstration of gray scale 3 do not carry out yet precharge pixel must appear at 1 row before the corresponding carry signal 1533 of pixel be 1 o'clock.Therefore, carrying out in the setting of pre-charge electricity during more than or equal to 3 gray scale differences, is 1 according to carry signal 1533, with 1 row before gray scale difference be to be judged as in 2 o'clock to carry out precharge, then whole pixels of display gray scale 3 are carried out the pre-charge electricity, thereby can prevent from not write the flicker that the regulation gray scale causes.
Generally more than or equal to the N gray scale difference time, carry out under the situation of precharge setting, shown in Figure 166, when the N-1 gray scale difference, with reference to carry signal 1533, carry signal 1533 before 1 row is 1, relevant capable carry signal is 0 o'clock, is regardless of the appointment more than or equal to the N gray scale, carries out pre-charge.Under other 3 kinds of situations, even without carry signal, with gray scale difference before 1 row also less than the N gray scale difference, thereby do not carry out precharge.
In addition, under the situation of N gray scale difference, shown in Figure 167, it is different because of the value of carry signal 1533 whether to carry out precharge judgement.For example during the subsequent rows display gray scale 2.25 of display gray scale 0,3/4ths row form 2 gray scale differences, and 1/4th row are because carry signal 1533 forms 3 gray scale differences.At this moment, only the pixel of 3 gray scale differences is carried out the pre-charge electricity, then gray scale 2 becomes big with the luminance difference of gray scale 3, thereby glimmers.Therefore, shown in Figure 167, carry signal 1533 is that 1 and 1 row advanced potential signal is 0 o'clock in current pixel, even if the N gray scale difference does not carry out precharge yet.Therefore, can prevent the flicker that has or not precharge to cause.
Under the situation more than or equal to the N+1 gray scale difference, there is gray scale difference, do not depend on to have or not carry signal, thereby ignore carry signal, carry out judging with in the past identical precharge more than or equal to the N gray scale difference.
In order to carry out this judgement, shown in Figure 161, signal generator 1538 is judged in precharge, except that input conversion rear video signal 1532, go back input carry signal 1533, judge whether to carry out precharge according to vision signal and carry signal.
At this moment, carry signal 1533 need compare with the data before 1 row, thereby relatively determining device 1541 also newly needs the line storage of 1 carry signal except that the line storage that needs vision signal.This point is different with invention embodiment in the past.
By the line storage of carry signal 1533 usefulness is set, can do the judgement of Figure 166 and Figure 167, can implement the present invention.
By using foregoing invention, in the gray scale display mode of Figure 160 (a), judge like that shown in Figure 160 (b) to have or not precharge, make same grayscale demonstration also can prevent the precharge Yin Lie of having or not and the different flicker that is caused as problem of the present invention.
Among the present invention,, be illustrated, but, use any element to implement so long as electric current such as light emitting diode, SED (surface field viewing area), FED and brightness form the display element of proportional relation with organic illuminating element as display element.
To shown in Figure 28, use the display device of display element of the present invention to be used for televisor, camcorders, portable phone as Figure 21, can realize gray scale display performance high product by adopting.
Use in the colour display device of organic illuminating element, form different because of the material of each illuminant colour with element with respect to the luminescence efficiency of red green blue tricolor organic illuminating element electric current.Green BELAND efficient is high about 2～5 times under the As-Is, thereby the current value that each gray scale needs differs about 2～5 times.
On the other hand, source signal line stray capacitance, horizontal scanning period are then of all kinds identical.Therefore, show that identical gray scale also differs about 2～5 times even change to each look of time of rated current value needs.
Therefore, adopt identical pre-charge electricity during the phase, use in the pixel of the low demonstration look of luminescence efficiency, the magnitude of current is big, thereby the voltage of the source signal line after the voltage precharge, electric current changes greatly, and demonstration is greater than the brightness of stipulating brightness; Use in the pixel of the high demonstration look of luminescence efficiency, the magnitude of current is little, thereby the source signal line voltage after the voltage precharge, electric current changes for a short time, shows deepening.Promptly produce and write inadequate phenomenon.
Therefore, among the present invention, consider to show that by constituting each look changes 6 grades of pre-charge electric pulse length, make and produce on the lead-out terminal that writes the high demonstration look of inadequate luminescence efficiency, strengthen precharge pulse length, the lengthening maximum current circulation phase, insufficient thereby elimination writes.
Figure 172 is the 1st method that realizes that the present invention uses.Can both independent Control current precharge pulse width setup in the red green blue tricolor, the pre-charge electric pulse group 1691 of output can of all kindsly export 6 respectively.Thus, of all kindsly can independently control the pre-charge current period of output shown in Figure 123.Luminescence efficiency according to current organic illuminating element considers, then with respect to the electric current of blue display pixel, the electric current of red display pixel is about 80%, and the electric current of green display pixel is about 50%.
Difference between current is ± 20%, even then pre-charge electricity condition is identical, the interim rated current value that also changes to of conventional current circulation, thereby can each look do not set the pulse width of pre-charge electric pulse respectively, but when as this example, having 50% difference between current, indigo plant is applied the optimum current precharge pulse, then greenly make the insufficient regulation gray scale that changes to of current value, brightness deepening.Therefore, when showing the white square pattern, the Bai Hangzhong that is scanned at first, only green brightness diminishes, thereby white the demonstration changes to magenta.So the band look is seen at the edge of chequer, display quality reduces.
Therefore, when each pulse all will be set 2 times for green corresponding pre-charge electronic pulse width,, also can realize stipulating the demonstration of gray scale even relate to green.
In addition, common voltage precharge pulse 451, with look irrelevant.This is to apply with the relation of drain current and the corresponding voltage of black demonstration because of the grid voltage according to driving transistors 62, this pulsion phase together, ignore the demonstration look, again because the driving force decision of the operational amplifier that uses according to source signal line capacity and pre-charge voltage generating unit changes to the time of assigned voltage, needn't each show that look sets.Can as Figure 172, only adjust pre-charge electric pulse group 1174 respectively by each look.
It is because of showing look different not carry out the gray scale that the pre-charge electricity also can write.Under the situation that is shown as gray scale 0 before 1 row, do not carry out the pre-charge electricity when blue and can write yet, but when red, need the pre-charge electricity, then do not carry out precharge more than or equal to 49 gray scales and can write yet less than the demonstration of 48 gray scales more than or equal to 36 gray scales; When green, need the pre-charge electricity, then do not carry out the pre-charge electricity more than or equal to 76 gray scales and also can write less than the demonstration of 75 gray scales.Therefore, the maximum gray scale that the gray scale of the long pulse of pre-charge electric pulse (among Figure 123 corresponding to 1174 pulse) is set is set the gray scale share of needs of all kinds for.By making the order I that can independently set of all kinds from the order D of the pre-charge electricity phase selected cell 578 that is input to Figure 57, can be accomplished.Pre-charge of the present invention is electrically interposed in the method, carry out depositing of the 1 preceding data of row with 4, when so data are more than or equal to gray scale 15 before 1 row, can not differentiate this gray scale, depend on order A setting value, but the value of for example ordering A is 1 o'clock, under the preceding situation of data of 1 row more than or equal to gray scale 14, display gray scale can not carry out pre-charge more than or equal to 13, yet green do not apply 70 gray scales occur in 1 the row before data be 0 o'clock, if before 1 row data greater than or greater than 14 gray scales, green also can write greater than or greater than the data of 14 gray scales, thereby show go up no problem.
Figure 169 is the 2nd method of the present invention.Figure 170 is the figure of internal circuit example that the synthetic portion 1694 of pulse of Figure 169 is shown, and Figure 171 is the figure of the pre-charge electric pulse waveform of output when an example being shown using the pulse generating unit 1122 of Figure 169.
Under the situation of the composition of Figure 172, the circuit scale of pulse generation unit 694 is compared when shared with of all kinds, is 3 times of its scale.
Therefore, among the present invention, the generating unit that makes 6 kinds of pre-charge electric pulses is same, and the corresponding output of the pixel of and the look little with the magnitude of current that is difficult to change is before or after the pre-charge electric pulse, according to showing that look sets the pulse period of output of certain hour.Among Figure 171, before the pre-charge electric pulse, be provided as difference between current and proofread and correct the insertion phase 1712 of inserting different pulse width of all kinds (also can be identical, shown in 1695c, also can not have pulse when electric current can fully change) with pulse 1695.
Thus, the horizontal scanning period setting at first is a voltage precharge phase 1711, secondly proofreaies and correct with pulse input phase 1712, the shared 6 grades of pulses of RGB for difference between current and includes the phase in, writes the phase (the gray scale electric current writes the phase) for rated current at last.
Form in order to simplify circuit, make 1711 identical with 1712 total length, thereby the position, top of pre-charge electric pulse 1691 can fix, can make the simplification of circuit composition.Voltage precharge pulse and difference between current are proofreaied and correct with the length summation of pulse in short-term, between voltage precharge pulse and difference between current are proofreaied and correct with pulse common gray scale electric current are set and write the phase, the adjustment timing.
Thus, the pulse of 1713 phases output ground as before can be realized the pulse of 1713 interim outputs at pulse generation unit B1693 according to counter and 1096,933 setting value.With compare in the past, only the pulse rising edge is regularly different, thereby the circuit scale of this part does not increase.
On the other hand, utilize counter 693 and corrected value setting signal 1697 output currents to proofread and correct with pulse 1695.Pulse is 3 profits, thereby compares with pulse generation unit B1693, can constitute with the circuit scale of half.
The actual pre-charge electricity phase of implementing is that difference between current is proofreaied and correct with pulse 1695 and the precharge summation with pulse 1696 (in selecting to suppress 1 to 6 1), thereby each demonstration is set gets difference between current and proofread and correct with pulse 1695 and the synthetic portion 1694 of pulse of precharge, with the pre-charge electric pulse 1691 of realizing that each shows the length that look different with the logic and the usefulness of pulse 1696.Among Figure 171, as an example, the waveform of pre-charge electric pulse 1 is shown.The pre-charge electricity can be set for electric current the most difficult variation green elongated the phase.Among Figure 170, constitute, but in order to reduce circuit scale, it is anti-phase that precharge is proofreaied and correct with the output of pulse 1695 with pulse 1696 and difference between current, and constitute with NAND circuit with logic and circuit.
Thus, the circuit scale summation of synthetic portion 1694 of pulse and pulse generation unit A1692 is less than 3 times of the circuit scale of pulse generation unit B1693, then, can form with the circuit littler and realize to set each illuminant colour circuit of different pre-charge electricity phases than the past according to the present invention.
When the gray scale electric current of pre-charge electricity after date of doing one's utmost to wish to extend writes the phase, do not make the driving phase 1713 be fixed value, can apply the length of phase 1711 according to voltage precharge and change the pre-charge enable position of electricity phase.After applying voltage precharge, formed for 1712 phases immediately.Each shows look, 1712 phase differences.Yet the pre-charge electricity phase 1713 is constant, does not depend on the demonstration look.Each shows when look changes enable position, needs each look to change the generation timing of pre-charge electric pulse, needs each look to produce precharge pulse as a result under this situation.Because all the time by the common precharge pulse that produces, ignore of all kindsly, effectively utilize the advantage that reduces circuit scale, 1712 phases need be steady state value.At this moment, available with breadth extreme that can setting command as 1712 phases or detect the order of current input and make 1712 the length and the difference between current of output maximum pulse proofread and correct the consistent method of length of usefulness pulse 1695.
Under the pixel selection phase shortens situation because display board maximizes or the pixel quantity of vertical direction increases,, when changing greatly, also be difficult to make current value fully to change to the regulation gray scale from the vision signal before 1 row even than the big gray scale of big current value middle gray.
Even pre-charge electric pulse group 1174 pulse width is maximum, when gray scale was maximum, the electric current of precharge phase was identical value with the electric current that meets gray scale, the precharge effect do not occur.
Therefore, the present invention constitutes the electric current makes the interim circulation of the pre-charge function greater than the electric current of maximum gray scale circulation is set, thereby can implement maximum gray scale demonstration the time, utilizes precharge to make electric current change to the rated current value fast.
Figure 173 illustrates the circuit of the electric current output stage of implementing this composition usefulness and forms, Figure 175 (a) illustrates precharge and judges that the value of line 984 is the control method of output current under the situation of 14 o'clock display gray scales 222, and Figure 175 (b) illustrates the straight changing condition of electric current of source signal line.
Except that gray scale shows the current source 241 of usefulness, current source 171 also is set, make greater than maximum current big current flowing, and judge the value of 1 (984b) of line according to the precharge of new interpolation, make current source 1731 outputs in the high period of pre-charge electric control line 1181.
Judge that with precharge 3 of line are selected the pre-charge electricity phase, select the pre-charge current value with 1.Whom at this moment, with 3 decision times of low side,, but carry out all can with high-end 1 decision magnitude of current.By utilizing the position partition functionality, can reduce precharge judgement line 984 is deciphered the circuit of usefulness.Compare with the circuit composition of finishing the precharge phase selection at 6 grades, now be increased to 12 grades according to the current value size, but the circuit that increases just can realize the switch of current source 1731 and current source 1731 break-makes and the control circuit of this switch (2 input logics amass circuit) by only adding, thereby can do one's utmost to suppress the increase of the logical circuit except the current source 1731, can realize that again high gray scale shows also effectively pre-charge.
Figure 174 illustrates precharge and judges the value of line and the relation of precharge running.Select the pre-charge electricity phase with 3 of low sides, select current value with high-end 1.
Thus, low gray scale is with the little lime degree electric current of current value, at 6 progressive line precharges; Middle gray～high gray scale then increases current value, adds the electric current of current source 1731, reconciles 6 grades cycle, carries out the pre-charge electricity, thereby even middle gray～high gray scale, the electric current pace of change is also fast, can write the regulation gray scale at whole gray areas.
Determine the current value size of current source 1731 according to the pixel count of display board scale and vertical direction, when thereby the length of 1 horizontal scanning period is big, according to the viewpoint that reduces the source driver chip scale, current source 1731 is 20%～50% with respect to the current value summation of current source 241; Horizontal scanning period in short-term, it is remarkable to write insufficient phenomenon, thereby the current value need carry out precharge the time strengthens, and is preferably formed as 50%～100% current source of current source 241.
In this example, the size of selecting current source with 1 has been described, and with the length of 3 selection precharge phases, but can both realize equally with any digit.
For example, when making the figure place of selecting the current source size be 3, can prepare 3 current sources 1174 (export the current value different accordingly), and get whether make the control line that each current source 1174 exports and the logic product of pre-charge electric control line 1181 with the figure place weighting.Figure 117 exports this point.
On the other hand, increase the type of precharge phase, need increase the inside ingredient of pulse choice portion 1175 and pre-charge electric pulse group 1174 umber of pulse.Paired pulses selection portion 1175 can constitute the many circuit of pass of the truth table of getting Figure 119.For example under 4 the situation, take to connect the many circuit of pass of the truth table of maximum 14 times electrographs 119.For example under 4 the situation, take to connect the method for maximum 14 times pre-charge electric pulses.
The circuit of Figure 176 makes pre-charge voltage according to temperature variation at source electrode driver outer setting temperature compensating element 1311.The voltage of resistance value that provides by electronic potentiometer 1341 and 1313 outputs of the resistance value sum of temperature compensating element 1311 decision pre-charge voltage generating unit.
Therefore, adjust the pre-charge voltage deviation of each display board,, magnitude of voltage changed by changing the resistance value of temperature compensating element 1311 by electronic potentiometer 1341, from and magnitude of voltage skew that temperature the same display board is caused.
Thus, do not debug whole potentiometer outside source electrode driver 36 does not need, can realize seeking to reduce cost.
In addition, when showing with 2 or more source electrode driver, make only some electronic potentiometer 1341 output voltages, the output of the electronic potentiometer 1341 of other chip separates with operational amplifier.By will the terminal different being connected to the outside input 1761 of whole source electrode drivers 36 with the power supply 64 of temperature compensating element 1311, can export pre-charge voltage by same voltage, do not depend on the quantity of source electrode driver.
In the display device of the organic illuminating element that employing shows with the current-output type source electrode driver, when having vertical blanking interval, because what pixel of vertical blanking interval is not selected, source electrode driver is output as quick condition.
For example Figure 10 constitutes the output stage of source electrode driver like that.Here, under gradation data 54 was data conditions beyond 0, at least 1 gray scale showed with current source 103 to carry out work from the mode of source signal line introducing electric current.
Here, when the output of source electrode driver was floated, gray scale shows will introduce electric current with current source 103, thereby carries out work in the mode that reduces drain potential.The result as Figure 181 (a) even shown in the pattern of whole screen display gray scale 5, the current potential of source signal line also as vertical blanking interim shown in 1811 like that the voltage when gray scale 5 shows descend.The example of 4 horizontal scanning period is shown, but after the blanking interval end, current potential is reduced to 1812.
In this state, write the electric current of gray scale 5, then the amount of change in voltage needs is big, and current value is little, so the time that variation needs is long.Therefore, shown in Figure 181 (a), do not change to the voltage of display gray scale 5, the current potential 1813 finishes the horizontal scanning period of the 1st row.In Fig. 6 and the active array type display board shown in Figure 44, that the state storage of horizontal scanning period end point (time point that the pixel selection phase finishes) is inner and shown in pixel.High brightness shows the 1st row when therefore, using than regulation gray scale (5 gray scale).
The 2nd capable follow-up state in the 1st row changes, thereby variable quantity can change to the regulation current potential, accurately display gray scale than the 1st capable lacking.
Produce the bright problem of the 1st row on the gray scale.
In addition, the little and display board of the electric current of each gray scale maximizes and horizontal scanning period shortens or the source signal line becomes under the situation such as big, because source signal line current potential is not easy to change, and the 2nd row and can not show regulation brightness thereafter sometimes.This under similar circumstances, can show that certainty 2nd reach thereafter can accurately show if make the 1st row as problem.
Therefore, the voltage pre-charging functions that the method that the present invention designs utilizes the interim source electrode driver of vertical blanking to have applies and the corresponding voltage of black demonstration, thereby prevents that source signal line current potential from sharply reducing.
As the 1st method, by controller gray scale 0 is sent to source electrode driver at vertical blanking interval.At this moment, be input to precharge and judge in the vision signal of signal generator 1621 and also insert gray scale 0 that then precharge judges that signal generator 1621 produces the precharge marks.At this moment, as the precharge setting of voltage, " must do voltage precharge " in shown in shown in setting Figure 61, then 1 horizontal scanning of vertical blanking interval is interim applies the voltage corresponding with deceiving demonstration 1 time, and forms the source signal change in voltage in the vertical blanking interval shown in Figure 181 (b).Thus, voltage precharge applies the voltage that forms the display gray scale 0 shown in 1814 in the phase (1818), changes as 1815 in gray scale 0 period of output 1819.Owing to be gray scale 0, source electrode driver switch inside 108 shows with current source 103 and the disconnection of source signal line gray scale, thereby thinks that the current potential of source signal line does not change in fact.But, consider that also the leakage of switch 108 causes potential change, thereby establish among Figure 181 (b) 1815 such potential change take place.Leakage current very little (smaller or equal to 1nA) is so variable quantity is little.Therefore, the current potential 1816 when the 1st row writes beginning reduces little, even low gray scale shows that the potential change amount is also little, thereby can not fully show the regulation gray scale.Because the 1st row can show accurately that the 2nd row reaches and must show thereafter.
Leakage current is little, and under the little situation of the source signal line potential change during gray scale 0 output, ignores the setting among Figure 16, and the 1st row also can fully write.At this moment, in vision signal, insert the method for gray scale 0, also can make the output that utilizes source electrode driver 36 and start 51 function, the gray scale demonstration of source signal line is separated with the source signal line with current source.Output startup 51 is related with whole outputs of source electrode driver 36, and when the startup function operated as Figure 186, electric current efferent 1171 disconnected with output 104.Thus, source signal line and source electrode driver disconnect, thereby can prevent that current potential from reducing.
Moreover, shown in Figure 178, the data enable signal 1781 that detects the blanking interval of incoming video signal is input to black data insertion section 1782 and precharge judgement signal generator 1621, carry out the judgement of Figure 79 and Figure 180, the voltage precharge of then ignoring when showing 0 gray scale is set, interim each horizontal scanning period of vertical blanking can be inserted voltage precharge phase 1818, can realize the potential change of the source signal line that Figure 181 (b) is such.Figure 180 judges that with the interim precharge of vertical blanking the output of signal generator is taken as 7, this is because the source electrode driver side is done the precharge judgement and output is taken as 7 as Figure 119, but setting value is not simultaneously, in the source electrode driver side, pre-charge electric control line always is " L " level, makes voltage precharge control line be the value identical with 451.
If source signal line current potential reduction before the write current in the 1st row after vertical blanking interval finishes can think that then the 1st row writes high-end gray scale.Therefore, be right after that the horizontal scanning that writes before the 1st row is interim implements to carry out voltage precharge and output gray level 0 at least.
Figure 182 illustrates the variation that writes the source signal line current potential when the preceding horizontal scanning of the 1st row is interim carries out voltage precharge.Before writing 2 preceding horizontal scanning period of 1 row, gray scale is output as arbitrarily, have or not precharge all can, even current potential is reduced to potential minimum, current potential also changes to 1821 level in the voltage precharge phase 1862, utilizes 0 gray scale period of output 1825 to make potential change terminate in minimum value then.Therefore, can make the source signal line current potential that writes before the 1st row is 1823, thereby the variable quantity in the low gray scale is little and can write.
Therefore, can implement in last 1 horizontal scanning period that vertical blanking interval finishes: must carry out voltage precharge and form gray scale 0 output.May not need during before this sweep time to implement.Can select the easy to handle method.When utilizing data enable signal 1781, be difficult to judge the end of vertical blanking interval, thereby whole vertical blanking is interim carries out identical running and be easier to implement.
When using source electrode driver of the present invention, shown in Figure 62, the data of the 1st row can utilize the 1st row detecting unit to implement precharge alone at the 1st row.Among Figure 55, utilize order C to select to implement the pre-charge electricity, and utilize order B to select to implement voltage precharge, then gray scale 0 must be implemented voltage precharge, fully to write black level voltage.
On the other hand, beyond the gray scale 0 then in the pre-charge electricity phase selected cell 578, to ordering in the I, can do the pre-charge electricity phase and adjust and fully write fashionable, not do the selection of pre-charge electricity according to gray scale at the order D shown in Figure 57.Thus, even low gray scale, also shown in Figure 183, at first force the voltage of transient change to display gray scale 0 at the voltage precharge phase, make source signal line voltage sharply change to the assigned voltage value in the pre-charge electricity phase then, according to the pixel transistor characteristic, write the voltage of regulation with the conventional current value at last.
The originally high gray scale of the gray scale that can fully write portion is many, so source signal line current potential is low.Therefore, in the blanking interval, even voltage is low, because variable quantity is little, and if high gray scale, the electric current that is used to change is big, so also can fully change to the regulation gray scale.On the other hand, when hanging down gray scale, utilize precharge operation, at first force to make change in voltage arrive black level, thereby no matter any the voltage of vertical blanking interval is, makes its variation all no problem with voltage precharge.Except that the 1st row, running does not thereafter have any variation, so can fully write.
Therefore, like that the 1st row is implemented the pre-charge electricity,, also can make the 1st row luminous with regulation brightness even specially do not do vertical blanking interval control by Figure 184.
Utilize above-mentioned running, can make the 1st row luminous, " thereby realize the high display device of display quality with regulation brightness.
Moreover it is interim to make vertical blanking, and source electrode driver always carries out the precharge voltage output of voltage, then eliminates source signal line current potential and changes toward white direction.
For this reason, shown in Figure 187 (a), need in vertical blanking interval, show that with conventional the interim voltage precharge pulse that makes changes.In conventional the demonstration, the voltage precharge pulse can be 1 microsecond～3 microseconds.On the other hand, vertical blanking is interim, needs the voltage precharge pulse always to be in high level (carrying out voltage precharge during high level).And when no-voltage precharge also can accurately show each gray scale, the demonstration phase can not apply voltage precharge, thereby can make precharge be labeled as 0, and perhaps total as Figure 187 (b) is low level.According to the present invention, it is characterized in that: the voltage precharge pulse of vertical blanking interval forms different states with the voltage precharge pulse that shows the phase.
Moreover, for the voltage when vertical blanking interval applies demonstration 0 gray scale to the source signal line.Therefore, shown in Figure 188, when using source electrode driver of the present invention, be controlled to and make precharge be labeled as 7, and this mark and precharge pulse are lumped together, with total output pre-charge voltage.
In order to differentiate vertical blanking interval and demonstration phase like this,, need each horizontal scanning period of energy to set the length of precharge pulse to change the width of precharge pulse.
Among the present invention, use the source electrode driver of as Figure 28, Figure 29, Figure 30, importing data and order, and can 1 horizontal scanning period change 1 subcommand.When input command transmits the timing pip 849 of phase 302, order is sent to the register of source electrode driver inside, keep its value.Because 1 timing pip of the interim input of 1 horizontal scanning changes pulse width in order to utilize this function at vertical blanking interval and demonstration phase, can be when the order input phase input command of Figure 29, the order of input voltage precharge pulse width setup.
Figure 190 illustrates the circuit block diagram of the source electrode driver that comprises command register 1902.Utilize the order data identification signal that the data of video signal cable 856 are divided into demonstration data, various setting data and gate drivers control signal by order and data separating unit 931.Demonstration is sent to internal drive after making the data conversion of serial transfer become parallel transfer with data and gate drivers control signal successively.On the other hand, (pulse width of electronic potentiometer setting, pre-charge electric pulse 1 to 6 and voltage precharge pulse that electronic potentiometer is set, the adjustment pre-charge voltage is used that the adjustment reference current is used is set to constitute various command, and the RGB luminescence efficiency is different and set electrorheological when big, as source electrode driver, reference current is adjusted, the pulse width of pre-charge electric pulse 1 to 6 preferably can the independent respectively control of RGB), especially precharge pulse width setup, usage counter 693 output pulses as shown in Figure 69, consistent up to setting value with count value; When change is set in the counter running, the logic instability, thereby inevitable in timing pip 848 input back changes, set so that finish the back change in the counter running.
Moreover source electrode driver of the present invention has the function of the signal of the gate drivers control usefulness that can export 2 systems.This is because in the current mirror type pixel composition of the pixel composition that the current duplicator of Fig. 6 is used and Figure 44,1 pixel needs 2 signal lines, in order respectively it to be scanned successively, 1 display device is equipped with 2 gate drivers, thereby needs 1 source electrode driver that 2 gate drivers are transmitted control signal.
Gate drivers output enabling signal 1901 is used for making signal not be issued to the outside cutting off unwanted output when source electrode driver is exported the gate drivers control signal.
When using 2 source electrode drivers, make the startup function effective, do not export unnecessary signal, thereby have low-powerization and suppress the advantage that array produces noise each 1 of control line away from the gate drivers side in each chip.
In the above-mentioned explanation, the driver that is taken as monochromatic output is illustrated, but also available in the polychrome output driver.The same circuits of preparing show chromatic number gets final product.When for example exporting this 3 look of red, green, blue, the circuit that 3 the identical circuit of can packing in same IC also are used as red usefulness, green usefulness, blue usefulness respectively uses.
In the above-mentioned explanation, transistor is taken as MOS transistor, is illustrated, but available too in MIS transistor and the bipolar transistor.
In addition, transistor is any materials such as silicon metal, low temperature polycrystalline silicon, high temperature polysilicon, amorphous silicon, arsenic gallium compound, also can use the present invention.
Program of the present invention can be used for making computing machine to carry out the action of all or part of step of the driving method of the invention described above self-luminous display device, and operates with collaborative computer.
The present invention can be a kind of medium, carry the program of all or part of action usefulness of the above-mentioned all or part of step that makes the driving method that computing machine carries out self-luminous display device of the present invention, can read by computing machine, and the described program that reads and collaborative computer are carried out above-mentioned action.
Moreover above-mentioned " part steps " of the present invention implication is the several steps in these a plurality of steps, perhaps 1 part action that step is interior.
Again, the present invention comprises minute book invention recording medium program, embodied on computer readable.
Again, a kind of mode of utilizing of program of the present invention can be: be recorded in the recording medium of embodied on computer readable and with collaborative computer and operate.
Program of the present invention another utilize mode can be: transmit in transmission medium, and after being read by computing machine, operate with collaborative computer.
As data structure of the present invention, comprise database, data layout, tables of data, list, data type etc. again.
As recording medium, comprise ROM etc. again; Comprise transport sector, light, electric wave, sound waves etc. such as internet as transmission medium.
Again, the invention described above computing machine is not limited to pure hardware such as CPU, can comprise firmware, OS, also can comprise peripherals.
Moreover illustrated as mentioned, composition available software mode of the present invention realizes that also the available hardware mode realizes.
Industrial practicality
Adopt the present invention, then can be in the demonstration of self-luminous type display unit, accelerate from slow low of pace of change Grey scale change is to high gray scale, as being useful such as showing with drive unit, display unit etc.

Claims (5)

1, a kind of driving method of self-luminous display device, this display device have each image element circuit that is arranged in rectangular self-emission device and corresponding setting with each described self-emission device, it is characterized in that, comprise following steps:
During the 1st, described each image element circuit is applied step corresponding to the gray scale electric current of display gray scale;
Follow-up during the described the 1st the 2nd during, described self-emission device is applied demonstration electric current based on described gray scale electric current, to show the step of corresponding described display gray scale;
During before during the described the 1st the 3rd, the 1st condition according to the rules applies the step of pre-charge current to described image element circuit; And
During before during the described the 3rd the 4th, described image element circuit is applied the step of the 1st voltage,
Length during the described the 3rd is difference with described gray scale electric current,
The 1st condition as described regulation, the pairing current value of display gray scale of the pairing current value of display gray scale of the demonstration that the described self-emission device in the same regulation row that lists of described matrix is carried out, the demonstration carried out with described self-emission device in the next line of described regulation row compares, when showing described next line under the difference of these current values situation more than or equal to the setting that is used to determine to apply pre-charge current, the described self-emission device to described next line during the described the 3rd applies described pre-charge current.
2, the driving method of the self-luminous display device described in claim 1 is characterized in that,
Described the 1st voltage is the voltage that is equivalent to deceive when showing.
3, the driving method of the self-luminous display device described in claim 1 is characterized in that,
Described the 1st voltage flows through described self-emission device when being adjusted to black the demonstration electric current formed smaller or equal to 0.1 bank/square metre the corresponding voltage of the electric current of brightness and be applied in.
4, the driving method of the self-luminous display device described in claim 1 is characterized in that,
From group during the corresponding with a plurality of pulse lengths of driving circuit, preparing in advance the 3rd respectively, select during the described the 3rd.
5, a kind of display control unit of self-luminous display device is characterized in that,
This self-luminous display device has each image element circuit that is arranged in rectangular self-emission device and corresponding setting with each described self-emission device, and during the 1st, described each image element circuit is applied gray scale electric current corresponding to display gray scale, follow-up during the described the 1st the 2nd during, described self-emission device is applied demonstration electric current based on described gray scale electric current, to show corresponding described display gray scale;
During before described display control unit is included in during the described the 1st the 3rd, the 1st condition according to the rules applies the pre-charge current applying unit of pre-charge current to described self-emission device,
During before during the described the 3rd the 4th, described image element circuit is applied the 1st voltage,
Length during the described the 3rd is difference with described gray scale electric current,
The 1st condition as described regulation, the pairing current value of display gray scale of the pairing current value of display gray scale of the demonstration that the described self-emission device in the same regulation row that lists of described matrix is carried out, the demonstration carried out with described self-emission device in the next line of described regulation row compares, when showing described next line under the difference of these current values situation more than or equal to the setting that is used to determine to apply pre-charge current, the described self-emission device to described next line during the described the 3rd applies described pre-charge current.
CNB2004800352448A 2003-12-02 2004-11-29 The driving method of self-luminous display device, display control unit and current output type drive circuit thereof Expired - Fee Related CN100565638C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP403547/2003 2003-12-02
JP2003403547 2003-12-02
JP321167/2004 2004-11-04

Publications (2)

Publication Number Publication Date
CN1886772A CN1886772A (en) 2006-12-27
CN100565638C true CN100565638C (en) 2009-12-02

Family

ID=37584103

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB2004800352448A Expired - Fee Related CN100565638C (en) 2003-12-02 2004-11-29 The driving method of self-luminous display device, display control unit and current output type drive circuit thereof

Country Status (1)

Country Link
CN (1) CN100565638C (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102593537B1 (en) * 2018-12-27 2023-10-26 삼성디스플레이 주식회사 Driving controller, display device having the same and driving method of display device
CN109801585B (en) * 2019-03-25 2022-07-29 京东方科技集团股份有限公司 Display panel driving circuit and driving method and display panel
JP7271348B2 (en) * 2019-07-09 2023-05-11 ラピスセミコンダクタ株式会社 Display driver and semiconductor device
CN110838276B (en) * 2019-11-08 2020-11-27 四川遂宁市利普芯微电子有限公司 Pre-charging method of LED display screen
CN112530369B (en) * 2020-12-25 2022-03-25 京东方科技集团股份有限公司 Display panel, display device and driving method

Also Published As

Publication number Publication date
CN1886772A (en) 2006-12-27

Similar Documents

Publication Publication Date Title
CN104700773B (en) Organic light-emitting display device and its driving method
CN100405436C (en) Electronic circuit, electrooptical equipment, driving method for electrooptical equipment and electronic device
CN101174382B (en) Organic light emitting diode display and driving method thereof
CN101465096B (en) Organic electroluminescent display device and method of driving the same
CN1975847B (en) Organic light emitting diode display device and driving method thereof
KR100934293B1 (en) Matrix type display device
US20070132674A1 (en) Driving method of self-luminous type display unit, display control device of self-luminous type display unit, current output type drive circuit of self-luminous type display unit
CN100555386C (en) Organic light emitting diode display and driving method thereof
CN108447446A (en) Pixel circuit, display panel and its driving method
CN103578422A (en) Display device and electronic apparatus, and driving method of display panel
CN110503917A (en) Pixel-driving circuit and display device with pixel-driving circuit
CN107452329A (en) Organic light emitting diode display and its driving method
CN109754754A (en) Drive the drive control circuit and display device of pixel-driving circuit
CN106920516A (en) Compensation method and device for OLED, display device
CN100543820C (en) Active matrix organic LED display and driving method thereof
CN103426398A (en) Organic light emitting diode display and its driving method
CN100565638C (en) The driving method of self-luminous display device, display control unit and current output type drive circuit thereof
US20230410723A1 (en) Display device and driving method thereof
CN115050317B (en) Data driving circuit, display module and method for outputting driving signal
CN115588410A (en) Display device
CN101221729B (en) Active matrix organic LED display
JP2005338494A (en) Active matrix type display device using organic light emitting element and driving method thereof, and semiconductor circuit
CN100507995C (en) Electroluminescent display panel and method for operating the same
CN101295463A (en) Electronic circuit, optoelectronic device, method for driving optoelectronic device, and electronic apparatus
JP2005181461A (en) Current output type semiconductor circuit

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
C56 Change in the name or address of the patentee

Owner name: JAPAN DISPLAY MIDDLE INC.

Free format text: FORMER NAME: TOSHIBA MOBILE DISPLAY CO., LTD.

Owner name: TOSHIBA MOBILE DISPLAY CO., LTD.

Free format text: FORMER NAME: TOSHIBA MATSUSHITA DISPLAY TECHNOLOGY LTD.

CP01 Change in the name or title of a patent holder

Address after: Saitama Prefecture, Japan

Patentee after: JAPAN DISPLAY Inc.

Address before: Saitama Prefecture, Japan

Patentee before: Toshiba Mobile Display Co.,Ltd.

CP03 Change of name, title or address

Address after: Saitama Prefecture, Japan

Patentee after: Toshiba Mobile Display Co.,Ltd.

Address before: Tokyo, Japan

Patentee before: TOSHIBA MATSUSHITA DISPLAY TECHNOLOGY Co.,Ltd.

CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20091202

Termination date: 20191129

CF01 Termination of patent right due to non-payment of annual fee