CN101034528A - Display device - Google Patents

Abstract

An organic EL device driven by thin-film transistors is disclosed, wherein for suppressing the deterioration with time of thin-film transistors, at least one of the thin-film transistors, or a second thin-film transistor is formed of a p-channel type thin-film transistor. The p-channel type thin-film transistor is preferably formed in the same step of process as the thin-film transistors in built-in drive circuits.

Description

Display device

Technical field

The present invention relates to active matrix type display, this device adopts by drive current and flows through and luminous EL (electroluminescence) element or LED light-emitting components such as (light emitting diodes) and the thin film transistor (TFT) (hereinafter referred to as TFT) of controlling the luminous work of this light-emitting component at light-emitting films such as organic semiconductor films.The Driving technique that relates to each element that in such display device, constitutes in more detail.

Background technology

A kind of active matrix type display with current-control type light-emitting components such as EL element or LED elements is arranged.Because the light-emitting component that this class display device is used is all own luminous, and is different with liquid crystal indicator, do not need back-lighting, also little to the dependence of angle of visibility in addition, this is the advantage of this class display device.

As an example of this class display device, Figure 31 is the block scheme with the active matrix type display of electric charge injection type organic film EL element.In the display device 1A shown in this figure, on transparency carrier, constitute: multi-strip scanning line gate, this sweep trace gate is prolonged many data line sig that the crossing direction prolongation setting of direction is set, many the public supply lines coms arranged side by side with these data lines sig, the pixel 7 corresponding with the joining of data line sig and sweep trace gate.

On each pixel 7, constitute: the 1TFT 20 that sweep signal is supplied with grid (the 1st grid) through sweep trace gate, the picture intelligence that preservation is supplied with by data line sig through this 1TFT 20 keep electric capacity cap, keep the 2TFT 30 of picture intelligence supply grid (the 2nd grid) of electric capacity cap preservation by this, at the light-emitting component 40 (representing) that when 30 couples of public supply lines com of 2TFT are electrically connected, flows drive current as resistance by public supply lines com.

In the display device 1A of above-mentioned formation, in the past, as to get the N channel-type be example, then from the point of view of simplified manufacturing technique, and 1TFT 20 and 2TFT 30, its equivalent electrical circuit is such shown in figure 32, and all the TFT as N channel-type or P channel-type constitutes.Therefore be example as getting the N channel-type, as Figure 33 (A), (B) shown in, the sweep signal Sgate that is supplied with by sweep trace gate is in noble potential, in a single day keeping the picture intelligence data that writes noble potential on the electric capacity cap by data line sig when 1TFT 20 is in conducting state, then 2TFT 30 keeps conducting states.Its result flows through to the drive current of opposite electrode OP direction along direction shown in the arrow E in rapid succession from pixel electrode 41 on light-emitting component 40, and light-emitting component 40 is not stopped paying out light (illuminating state) in succession.In contrast, the sweep signal Sgate that is supplied with by sweep trace gate is in noble potential, when 1TFT 20 is in conducting state, if by data line sig keep electric capacity cap write than the current potential of public supply lines com and opposite electrode OP current potential between certain current potential picture intelligence data of electronegative potential also, then 2TFT30 disconnects, and light-emitting component 40 extinguishes (extinguishing state).

In this display device 1A, the semiconductor film, dielectric film, electrode etc. that constitute each element are by being made of the film of piling up on substrate, and consider the thermotolerance etc. of substrate, and this film adopts low temperature process to form more.Thereby, result from film and substrate body physical property difference etc., cause defective waits film quality low more, therefore, with regard to TFT etc., insulation breakdown and through the time problem such as aging easily come to the surface.

Even is common in what is called at the liquid crystal indicator of making optical modulation element with liquid crystal on the film this point, but because AC driving optical modulation element in this case, thus liquid crystal not only, and TFT through the time agingly also can both suppress.In contrast, in display device 1A with the current-control type light-emitting component, from the direct drive this point of having to, TFT also than liquid crystal indicator easier cause through the time aging.In order to address this is that, fully improve even in the display device 1A that uses the current-control type light-emitting component, can't say the product of on the structure of TFT and technology, being improved.

In addition, because under the situation of making optical modulation element with liquid crystal by this optical modulation element of Control of Voltage, only to the instantaneous electric current that flows through of each element, so consumption of electric power is low.In contrast, in the display device 1A of current-control type light-emitting component, must continue to flow through light-emitting component with drive current for lighting continuously, thus the consumption of electric power height, be easy to generate insulation breakdown and through the time aging.

At liquid crystal indicator, can be with a TFT AC driving of each pixel liquid crystal, and in the display device 1A of current-control type light-emitting component each pixel with two TFT, 20,30 direct drive light-emitting elements 40, so driving voltage increases, so-called above-mentioned insulation breakdown and to expend electric power Da Zhu problem more remarkable.For example, shown in Figure 33 (A), because the gate voltage Vg sw of 1TFT 20 is equivalent at the current potential of the noble potential that is equivalent to sweep signal Sgate and keeps potential difference (PD) between the current potential (keeping the grid potential of current potential or the 2TFT 30 of capacitor C ap) of potential electrode st when selecting pixel, keep the current potential of potential electrode st and the light-emitting component high brightness is lighted so improve, when improving the gate voltage Vg cur of 2TFT 30, because the gate voltage step-down of 1TFT, so be necessary to increase the amplitude of sweep signal Sgate, the driving voltage of device displaying result 1A has uprised.2TFT ends in turn because the current potential that light-emitting component 40 makes picture intelligence data when extinguishing is than certain current potential between the current potential of the current potential of public supply lines com and opposite electrode op is low among this external aforesaid display device 1A, so the big problem of so-called picture intelligence data amplitude is also arranged.Therefore in this display device 1A, compare, must consider especially to expend the withstand voltage of electric power and TFT, and this consideration is abundant inadequately among the existing display device 1A with liquid crystal indicator.

Summary of the invention

Therefore problem of the present invention provides display device, this display device can be with the type of drive of the conductivity type of the TFT that has considered the luminous action of light-emitting component that Control current is driving, thus take into account lower voltage because of driving voltage reduce expend electric power, insulation breakdown, through the time aging and improve display quality.

For solving above-mentioned problem, the invention relevant with claim 1 is: the multi-strip scanning line is arranged on substrate, with many crossing data lines of sweep trace, many public supply lines and the rectangular pixel that forms by aforementioned data line and aforementioned sweep trace, respectively have on this pixel: the 1TFT that supplies with the 1st grid by aforementioned sweep trace sweep signal, preserve the electric capacity of keeping of the picture intelligence supplied with by aforementioned data by 1TFT, supply with the 2TFT of the 2nd grid by this earlier figures picture signals of keeping the electric capacity preservation, and the image electrode that is formed by each aforementioned pixel flows through drive current by aforementioned pixel electrode and light-emitting film when being electrically connected to aforementioned public supply lines by 2TFT and makes the luminous light-emitting component of aforementioned light-emitting film between opposed opposite electrode, and it is characterized by: the current potential of setting aforementioned public supply lines under the situation that aforementioned 2TFT is a N type channel-type is lower than aforementioned opposite electrode.

In display device of the present invention, because the gate voltage during the 2TFT conducting is equivalent to the poor of the current potential of public supply lines and side's current potential in the pixel electrode current potential and grid potential (current potential of picture intelligence), so make the relative height of the current potential optimization of the opposite electrode of the current potential of public supply lines and light-emitting component corresponding to the conductivity type of 2TFT, the gate voltage that constitutes 2TFT makes it be equivalent to current potential poor that public supply lines current potential and current potential keep electrode.For example, suppose that 2TFT is the N channel-type, the opposite electrode current potential of light-emitting component reduces public supply lines current potential relatively.Because should public supply lines current potential, different with the pixel electrode current potential, can be set in enough low value, so can obtain big conducting electric current, can carry out high brightness and show at 2TFT.In addition, suppose to obtain on the 2TFT high gate voltage during for illuminating state in pixel, then because can reduce the current potential of picture intelligence, the place can reduce picture intelligence amplitude, reduce the driving voltage in the display device.Therefore its advantage is for to expend on each element that is made of film the electric power worrying proof voltage problem unlikely too obvious except reducing.

In the present invention, the corresponding outer pixel of lighting state is cand be compared to the low or equipotential of current potential of aforementioned opposite electrode most under the situation that above-mentioned 2TFT is the N channel-type by the current potential of the picture intelligence of aforementioned data line supply.Under situation about so constituting, keep the 2TFT conducting state, also can reduce the amplitude of picture intelligence and the driving voltage in the reduction display device.

In the present invention, the current potential of the 2TFT picture intelligence that to be state is extinguished in the corresponding position under the situation of N channel-type pixel supplied with by the aforementioned data line cans be compared to the current potential height or the equipotential (claim 5) of aforementioned public supply lines most.That is: pixel is got not add when extinguishing state and is made 2TFT in turn by such big gate voltage (picture intelligence).In conjunction with the nonlinear electrical properties of light-emitting component, can realize extinguishing state.Therefore can reduce the amplitude of picture intelligence, the driving voltage in the display device is descended, can impel the high frequencyization of picture intelligence in addition.

In the present invention with above-mentioned each constitute on the contrary, aforementioned 2TFT is under the situation of P channel-type, the relativeness of each current potential conversely.That is: under the situation that aforementioned 2TFT is the P channel-type, it is characterized by aforementioned public supply lines and be set in the current potential also higher, (claim 2) than aforementioned opposite electrode.The pixel of corresponding position illuminating state is cand be compared to the current potential height or the equipotential (claim 4) of aforementioned opposite electrode most by the current potential of the picture intelligence of aforementioned data line supply in this case.In addition, the pixel of state is extinguished in the corresponding position, and the current potential of the picture intelligence of being supplied with by the aforementioned data line cans be compared to the low or equipotential (claim 6) of current potential of aforementioned public supply lines most.

In the present invention, the most handy opposite admittance type TFT of aforementioned 1TFT and aforementioned 2TFT constitutes (claim 7).That is: if 1TFT is the N channel-type, then the 2nd TFT is the P channel-type; Suppose that 1TFT is the P channel-type, then 2TFT is preferably the N channel-type.The aftermentioned that further details are relevant with claim 8, if adopt this formation, the direction of resistance decreasing changes the current potential of the picture intelligence of illumination when then needing only to the 1TFT conducting in the driving voltage range ability of display device, just can impel the high speed of display action.In addition because at this moment for the current potential that makes the picture intelligence that pixel lights during towards the conducting of 2TFT the resistance decreasing direction change, so can impel brightness to rise.Therefore, can realize taking into account driving voltage lower voltage and raising display quality.

In other embodiments of the invention (claim 8), that is: multi-strip scanning line, many data lines that intersect with this sweep trace, many public supply lines and form rectangular pixel by aforementioned data line and aforementioned sweep trace arranged on substrate; Respectively have on this pixel: the 1TFT that supplies with the 1st grid by aforementioned sweep trace sweep signal; Preserve the electric capacity of keeping of the picture intelligence supplied with by the aforementioned data line by this 1TFT; Supply with the 2TFT of the 2nd grid by this earlier figures picture signals of keeping the electric capacity preservation; And the light-emitting component that light-emitting film is arranged, the drive current that flows through between by aforementioned pixel electrode and aforementioned opposite electrode when aforementioned public supply lines being electrically connected by aforementioned 2TFT at the pixel electrode that is formed by aforementioned each pixel with to the aforementioned pixel electrode of interlayer between the opposed opposite electrode of this pixel electrode makes this light-emitting film luminous, and it is characterized by: aforementioned 1TFT and 2TFT are made of the TFT of contrary conducting type.

In the present invention, for example suppose that 1TFT is the N type, wish that then 2TFT is the P type, because 1TFT and 2TFT are contrary conducting type, so in order to improve the write capability of 1TFT, improve the strobe pulse height of sweep signal, in order to reduce the admittance resistance of 2TFT, improve luminosity, must reduce the current potential of picture intelligence.The such sweep signal and the optimization of picture intelligence be to the gate voltage of 1TFT, writes and keep electric capacity along with having the picture intelligence that makes the level that light-emitting component lights during pixel selection, works for the conducting electric current augment direction skew towards this TFT.Therefore, successfully write picture intelligence by 1TFT keeping electric capacity by data line.Here, when selecting pixel the gate voltage of 1TFT be equivalent at the current potential that is equivalent to the sweep signal noble potential and when lighting current potential keep the current potential of electrode (for lighting the picture intelligence current potential of usefulness, keep the grid potential of the current potential or the 2TFT of electric capacity) poor, the current potential of keeping potential electrode when the grid voltage of 2TFT is equivalent to light and the current potential of public supply lines poor, when the current potential of keeping electrode with current potential was at this moment made benchmark, being equivalent to the current potential of sweep signal noble potential and the current potential of public supply lines was same polarity.Therefore, if change the current potential (for lighting the picture intelligence current potential of usefulness) that current potential when lighting is kept electrode, then the gate voltage of the gate voltage of 1TFT and 2TFT both carry out moving of same degree to equidirectional.Therefore in the driving voltage range ability of display device,, then can impel the display action high speed if the resistance decreasing direction moves when making to the picture intelligence current potential of lighting usefulness towards the 1TFT conducting.In addition, because at this moment move, rise so can seek brightness for the direction of the resistance decreasing of current potential when making the 2TFT conducting of the picture intelligence of lighting usefulness.Therefore, can reach the lower voltage of taking into account driving voltage and the raising of display quality.

In the present invention, the polarity when added gate voltage is with this 2TFT conducting state on extinguishing the aforementioned 2TFT of state pixel is identical, and preferably is in the value (claim 9) of the threshold voltage that is no more than this 2TFT.That is: be in not add when extinguishing state in pixel and make 2TFT fully by the gate voltage (picture intelligence) of the sort of degree.Therefore can reduce the amplitude of picture intelligence, the high frequencyization of realization picture intelligence.

Under situation about constituting as mentioned above, if aforementioned 1TFT is that N channel-type, aforementioned 2TFT are the P channel-type, then the current potential of sweep signal current potential and aforementioned public supply lines is identical when aforementioned 1TFT conducting state, and the sweep signal current potential when the pixel of extinguishing state added gate electrode potential on aforementioned 2TFT is preferably than aforementioned 1TFT conducting state is deducted the also low current potential (claim 10) of current potential of the threshold voltage of this 1TFT.In contrast, if aforementioned 1TFT is that P channel-type, aforementioned 2FFT are the N channel-type, sweep signal current potential during then aforementioned 1TFT conducting state is identical with the current potential of aforementioned public supply lines, and the sweep signal current potential when the pixel of extinguishing state added grid potential on aforementioned 2TFT is preferably than aforementioned 1TFT conducting state adds the also high current potential (claim 11) of threshold voltage of this 1TFT.If the sweep signal current potential as mentioned above during the 1TFT conducting state equates with the current potential of public supply lines, then the level number owing to each drive signal reduces, so can reduce the signal input part number that connects to display device, so can reduce and expend electric power because can reduce the power supply number simultaneously.

In the present invention, preferably supply with trigger-gate delay on the electrode of the electrode contraposition that is electrically connected with the 2nd grid of aforementioned 2TFT in aforementioned two electrodes of keeping electric capacity, be partial to reciprocal pulse (claim 12) with this strobe pulse current potential than aforementioned sweep signal.If as above-mentioned formation, then because can replenish and to write picture intelligence,, make that institute's addition image signal potential moves to the high brightness direction on the 2TFT grid so the amplitude of picture intelligence is increased to keeping electric capacity.

At other embodiment of the present invention, many data lines, many public supply lines, aforementioned data line and aforementioned sweep traces of the multi-strip scanning line is arranged, intersecting on substrate with this sweep trace form rectangular pixel; Respectively have on this pixel: supply with 1TFT on the 1st grid by aforementioned sweep trace sweep signal; Preserve the electric capacity of keeping of the picture intelligence supplied with by the aforementioned data line by this 1TFT; Keep earlier figures picture signals that electric capacity preserves by this and supply with 2TFT on the 2nd grid; And the light-emitting component that light-emitting film is arranged, the drive current that flows through between by aforementioned pixel electrode and aforementioned opposite electrode when aforementioned public supply lines being electrically connected by aforementioned 2TFT at the pixel electrode that is formed by aforementioned each pixel with to the aforementioned pixel electrode of the interlayer of this pixel electrode opposite electrode makes this light-emitting film luminous, it is characterized by: on the aforementioned electrode of keeping electrode contraposition one side that is electrically connected with the 2nd grid of aforementioned 2TFT in two electrodes of electric capacity, supply with trigger-gate delay, be partial to reciprocal pulse (claim 13) with this strobe pulse current potential than sweep signal.

If adopt above-mentioned formation,,, the current potential of institute's addition image signal on the grid of 2TFT is moved to high brightnessization so can not make the amplitude increase of picture intelligence then because can replenish to the writing of the picture intelligence of keeping electric capacity.

Also can application examples such as organic semiconductor film (claim 14) in above-mentioned arbitrary invention as light-emitting film.

In each invention of the present invention, 2TFT is flow through abnormal current in saturation region operation at light-emitting component by it, can prevent from other pixel is produced crosstalk (crossview) because of voltage descends.(claim 15).

In addition by preventing that in its linear zone work this threshold voltage dispersion (deviation) is to showing the influence (claim 16) of work.

Description of drawings

Fig. 1 is that the expression of demonstration ground is suitable for display device planimetric map of the present invention.

Fig. 2 is the block scheme that expression is suitable for display device basic comprising of the present invention.

Fig. 3 is the planimetric map that amplifies the pixel of expression display device shown in Figure 2.

Fig. 4 is the sectional view along A-A ' line of Fig. 3.

Fig. 5 is the sectional view along B-B ' line of Fig. 3.

Fig. 6 (A) is the sectional view along C-C ' line of Fig. 3, and Fig. 6 (B) is the key diagram of the effect when constituting shown in the key diagram 6 (A).

Fig. 7 (A), (B) are respectively the sectional views of the light-emitting component used in display device shown in Figure 2.

Fig. 8 (A), (B) have the light-emitting component sectional view that is different from light emitting element structure shown in Figure 7.

Fig. 9 is the figure of the I-E characteristic of light-emitting component shown in presentation graphs 7 (A), Fig. 8 (B).

Figure 10 is the figure of the I-E characteristic of the light-emitting component shown in presentation graphs 7 (B), Fig. 8 (A).

Figure 11 is the figure of the I-E characteristic of expression N channel-type TFT.

Figure 12 is the figure of the I-E characteristic of expression P channel-type TFT.

Figure 13 is the process profile that expression is suitable for the manufacture method of display device of the present invention.

Figure 14 (A), (B) represent pixel planes figure and the sectional view to the different formations of pixel of display device shown in Figure 6 with Fig. 3 respectively.

Figure 15 is the equivalent circuit diagram that the display device pixel of the expression embodiment of the invention 1 constitutes.

Figure 16 (A), (B) represent the oscillogram of the potential change of the key diagram of status of electrically connecting of each element of being made of pixel shown in Figure 15 and expression drive signal etc. respectively.

Figure 17 is the equivalent circuit diagram that the pixel of display device of the modified example of the expression embodiment of the invention 1 constitutes.

Figure 18 (A), (B) represent the oscillogram of the potential change of the key diagram of status of electrically connecting of each element of being made of pixel shown in Figure 17 and expression drive signal etc. respectively.

Figure 19 is the equivalent circuit diagram that the pixel of the display device of expression embodiments of the invention 2 constitutes.

Figure 20 (A), (B) represent the oscillogram of the potential change of the key diagram of status of electrically connecting of each element of being made of pixel shown in Figure 19 and expression drive signal etc. respectively.

Figure 21 is the equivalent circuit diagram that the pixel of the display device of expression embodiments of the invention 2 constitutes.

Figure 22 (A), (B) represent the oscillogram of the potential change of the key diagram of status of electrically connecting of each element of being made of pixel shown in Figure 21 and expression drive signal etc. respectively.

Figure 23 is the equivalent circuit diagram that the pixel of the display device of the expression embodiment of the invention 3 constitutes.

Figure 24 (A), (B) are expressed as the signal waveforms that drives pixel shown in Figure 23 respectively and represent the key diagram that these signals are corresponding with equivalent electrical circuit.

Figure 25 is the signal waveforms for the pixel of the display device that drives the embodiment of the invention 2.

Figure 26 is the equivalent circuit diagram that the display device pixel of the expression embodiment of the invention 3 constitutes.

Figure 27 (A), (B) are expressed as the signal waveforms that drives pixel shown in Figure 26 respectively and represent these signals and the key diagram of equivalent electrical circuit correspondence.

Figure 28 (A), (B) represent respectively the embodiment of the invention 4 the display device pixel equivalent circuit diagram and for driving its signal waveforms.

Figure 29 is the scanning one side drive circuit calcspar for producing signal shown in Figure 28.

Figure 30 is the oscillogram by each signal of scan-side driving circuit output shown in Figure 29.

Figure 31 is the block scheme of display device.

Figure 32 is the equivalent circuit diagram that existing pixel constitutes in the expression display device shown in Figure 31.

Figure 33 (A), (B) are expressed as the signal waveforms that drives pixel shown in Figure 32 respectively and represent these signals and the key diagram of equivalent electrical circuit correspondence.

Figure 34 (A), (B) represent to form with the gate line of adjacency the formation calcspar and the gate voltage signal waveform thereof of electric capacity respectively.

1 display device

2 display parts

3 data side driving circuits

4 scan-side driving circuits

5 testing circuits

6 install with pad

7 pixels

10 transparency carriers

20 1TFT

The grid of 21 1TFT

30 2TFT

The grid of 31 2TFT

40 light-emitting components

41 pixel electrodes

42 hole injection layers

43 organic semiconductor films

50 gate insulating films

Bank memory bank layer

Cap keeps electric capacity

Cline electric capacity line

The public supply lines of com

The gate sweep trace

The op opposite electrode

The sig data line

St keeps potential electrode

Embodiment

With reference to the description of drawings embodiments of the invention.Before these external explanation various embodiments of the present invention, the common formation of each embodiment is described earlier.There is common funtion part to take of the repetition of same label with regard to each embodiment here to avoid illustrating.

(one-piece construction of active-matrix substrate)

Fig. 1 is the block scheme of all layouts of demonstration ground expression display device.Fig. 2 is the equivalent circuit diagram of the active matrix that is made of it.

As shown in Figure 1, in the display device 1 of present embodiment, get at the middle body of the transparency carrier 10 of its matrix and to make display part 2.In the outer peripheral portion of transparency carrier 10, constitute data side driving circuit 3 and testing circuit 5 respectively, constitute scan-side driving circuit 4 sweep trace gate output scanning signal at left and right sides towards drawing to data line sig output image signal towards the upper and lower sides of drawing.These driving circuits 3,4 constitute complementary type TFT by N type TFT and P type TFT, and these complementary types TFT constitutes shift-register circuit, level phase shifter circuit, analog switching circuit etc.On transparency carrier 10 at the terminal group installed module that is formed for input image signal and various current potential, pulse signal from data side driving circuit 3 outside outer regions.

Same with the active-matrix substrate of liquid crystal indicator on display device 1, on transparency carrier 10, constitute multi-strip scanning line gate, this sweep trace gate is prolonged the crossing direction prolongation that direction is set many data line sig are set, as shown in Figure 2, intersect by these data lines sig and sweep trace gate and constitute a large amount of rectangular pixels 7.

Constitute 1TFT20 on each pixel of these pixels 7, sweep signal is supplied with the grid 21 (the 1st grid) of 1TFT by sweep trace gate.One side of the source-drain area of this TFT 20 is electrically connected with data line sig, and another source-drain area is kept electrode st with current potential and is electrically connected, that is: to the parallel configuration of sweep trace gate electric capacity line cline, this electric capacity line cline and current potential are kept to form between the electrode st and kept electric capacity cap.Therefore by scanning line selection, if 1TFT 20 is in conducting state, then by data line sig through 1TFT 20, picture intelligence writes keeps electric capacity cap.

Keep the grid 31 (the 2nd grid) that electrode st is electrically connected 2TFT 30 at current potential, a side of the source-drain area of 2TFT 30 is electrically connected public supply lines com, and the opposing party's source-drain area is electrically connected to side's electrode (pixel electrode described later) of light-emitting component 40.Public supply lines com keeps constant potential.The electric current of public supply lines com flows through light-emitting component 40 through 2TFT 30 and makes light-emitting component 40 luminous when 2TFT 30 is in conducting state.

In the display device 1 of above-mentioned formation, because of flowing through current path, drive current constitutes by light-emitting component 40,2TFT 30 and public supply lines com, so 2TFT 30 is in cut-off state, there is not electric current to flow through.Just, at present embodiment 1, if selected by sweep circuit, when 1TFT 20 was in conducting state, then picture intelligence write through 1TFT 20 from data line sig and keeps electric capacity cap.Therefore, even 1TFT 20 is in cut-off state, the grid of 2TFT30 also keeps the current potential suitable with picture intelligence by keeping electric capacity cap, so 2TFT 30 keeps conducting state.Therefore, drive current continues to flow through at light-emitting component 40, and this pixel keeps illuminating state.This state is maintained to new pictorial data and writes and keep electric capacity cap, till 2TFT 30 ends.

In display device to public supply lines com, pixel 7 and data line sig have various configurations, but at present embodiment, in public supply lines com both sides, and dispose a plurality of pixels 7 of the light-emitting component of supplying with drive current between this public supply lines, to these pixels 7,2 data lines sig by with the opposed side of public supply lines com.Promptly, with data line sig, connected pixel group, 1 public supply lines com, connected pixel group, and the data line sig that picture element signal is supplied with this pixel group is provided with direction as 1 unit with its prolongation along sweep trace gate and repeats, with the pixels 7 supply drive currents of 1 public supply lines to 2 row parts.Therefore at present embodiment, folder is being that center line disposes 1TFT 20 symmetrically with this public supply lines com between two pixels 7 of public supply lines com ground configuration, 2TFT 30 and light-emitting component 40 are realized the electrical connection between these elements and each wiring layer easily.

As mentioned above at present embodiment, because drive the pixel of 2 row parts with 1 public supply lines com, so compare with the situation that on per 1 row pixel group, forms public distribution wire com, public supply lines com number can save 1/2, need not the gap of guaranteeing between public supply lines com that same interlayer forms and the data line sig simultaneously.Therefore, on transparency carrier 10, be used in the regional stenosis of distribution, so can improve display performances such as brightness, contrast.Have again,,, the pixel group of every row is supplied with picture intelligence so data line sig is in per 2 states arranged side by side owing to adopt the formation of the pixel that on the above 1 public supply lines com, connects 2 row parts.

(formation of pixel)

To Fig. 6 in detail each pixel 7 of the display device 1 of structure as mentioned above is described in detail with reference to Fig. 3.

Fig. 3 is the planimetric map that amplifies 3 pixels in a plurality of pixels 7 that form in the display device 1 of expression present embodiment, Fig. 4, Fig. 5, and Fig. 6 be respectively A-A ' line sectional view, B-B ' line sectional view and the C-C ' line sectional view of Fig. 3.

At first, at the island silicon fiml 20 that on each pixel 7, has formed 1TFT20 of transparency carrier 10, form gate insulating film 50 as shown in Figure 4 on its surface in the position that is equivalent to Fig. 3 A-A ' line.Surface at gate insulating film 50 forms grid 21 (part of sweep trace gate), and this grid 21 is formed source- drain area 22,23 in coupling ground automatically.Face side at gate insulating film 50 forms the 1st interlayer dielectric 51, and by the contact hole 61,62 that forms on this interlayer dielectric, data line sig and current potential are kept electrode st and electrically contacted with source- drain area 22,23 respectively.

Sweep trace gate and grid 21 same interlayers (between gate insulating film 50 and the 1st interlayer dielectric 51) form electric capacity line cline, it is overlapping that the prolongation of keeping electrode st by the 1st interlayer dielectric 51 current potentials is provided with 1 pair of this electric capacity line of part st cline, so that arranged side by side with sweep trace on each pixel 7.Therefore, the prolongation of keeping electrode st of electric capacity line cline and current potential is provided with part st1 and constitutes with what the 1st interlayer dielectric 51 was made the dielectric film and keep electric capacity cap.Have again, keep at current potential and form the 2nd interlayer dielectric 52 on the face side of electrode st and data line sig.

As shown in Figure 5, the data line sig of corresponding each pixel 7 in surface of the 1st interlayer dielectric 51 that forms on transparency carrier 10 and the 2nd interlayer dielectric 50 forms two states arranged side by side on the position suitable with Fig. 3 B-B ' line.

On the position suitable, shown in Fig. 6 (A), formed the island silicon fiml 300 that is used to form 2TFT 30, formed gate insulating film 50 on silicon fiml surface with Fig. 3 C-C ' line, so as on transparency carrier 10 across two pixels 7 of folder with public supply lines com.On each pixel 7, forming grid 31 respectively on the surface of gate insulating film 50, this grid 31 is being mated ground voluntarily form source-drain area 32,33, so that folder is with public supply lines com.Form the 1st interlayer dielectric 51 on the face side of gate insulating film 50, by the contact hole 63 that forms on this interlayer dielectric, repeater electrode 35 is electrically connected with source-drain area 62.Public supply line com constitutes the part electrical connection of public source-drain area 33 on two pixels 7 of silicon fiml 30 central authorities by 64 pairs of the contact holes of the 1st interlayer dielectric 51 on the one hand.On the surface of these public supply lines com and repeater electrode 35, form the 2nd interlayer dielectric 52.Surface at the 2nd interlayer dielectric 52 forms the pixel electrode 41 that is made of the ITO film.This pixel electrode 41 is electrically connected with repeater electrode 35 by the contact hole 65 that forms on the 2nd interlayer dielectric 52, is electrically connected with the source-drain area 32 of 2TFT 30 by this repeater electrode 35.

(characteristic of light-emitting component)

Even because under the situation of using any structure, all be suitable for the present invention, so its typical case of following explanation as light-emitting component 40.

At first, the pixel electrode 41 that is made of aforementioned ITO film constitutes side's electrode (positive electrode) of light-emitting component 40 shown in Fig. 7 (A).At the surperficial lamination of this pixel electrode 41 hole injection layer 42 and as the organic semiconductor film 43 of light-emitting film, then form the opposite electrode OP (negative pole) that constitutes by metal films such as aluminium that contains lithium or calcium on the surface of organic semiconductor film 43.This opposite electrode OP should constitute the common electrode that forms by on the face of whole transparency carrier 10 or bar shaped face, remains on certain potentials.In contrast, flowing through under the situation of drive current also just like the pixel electrode 41 (negative pole) that constitutes by the ITO film successively to upper layer side from lower floor shown in Fig. 7 (B) with light-emitting component 40 reverse directions shown in Fig. 7 (A), has the thin like that aluminium electrode 45 that contains lithium of light transmission, organic semiconductor layer 43, hole injection layer 42, ITO film 46, opposite electrode OP (positive pole) lamination that is made of metal films such as aluminium that contains lithium or calcium constitutes the situation of light-emitting component 40.If constitute as mentioned above, even then in light-emitting component 40 shown in Fig. 7 (A), (B), flow through under the reversed polarity drive current situation respectively, because the structure of hole injection layer 42 and organic semiconductor layer 43 direct-connected electrode layers is identical, so the characteristics of luminescence is identical.Light-emitting component 40 shown in these Fig. 7 (A), (B) all has the pixel electrode 41 that is made of the ITO film at lower layer side (substrate-side), and light sees through pixel electrode 41 and transparency carrier 10 from transparency carrier 10 inboard ejaculations shown in arrow hv.

In contrast, if constitute light-emitting component 40 shown in Fig. 8 (A), (B), then light sees through opposite electrode OP shown in arrow hv, injects to the face side of transparency carrier 10.That is: the surperficial lamination organic semiconductor film 43 and the hole injection layer 42 of the pixel electrode 14 (negative pole) that is made of the metal films such as aluminium that contain lithium as Fig. 8 (A) be shown in have then formed the opposite electrode OP (positive pole) that is made of the ITO film on the surface of hole injection layer 42.This opposite electrode OP also is pole plate on whole or the common electrode that forms strip, remains on certain current potential.In contrast, when flowing through drive current with the light-emitting component reverse direction shown in Fig. 8 (A), shown in Fig. 8 (B), also have by lower layer side to upper layer side, in the following order lamination, the pixel electrode 41 (positive pole) that constitutes by the metal films such as aluminium that contain lithium, ITO rete 46, hole injection layer 42, organic semiconductor film 43, have the like that thin aluminium electrode 45 that contains lithium of light transmission, the opposite electrode OP (negative pole) that is made of the ITO film constitutes the situation of light-emitting component 40.

When formation had the light-emitting component 40 of any structure, if hole injection layer 42 and organic semiconductor film 43 are formed by the inboard of ink-jet method at base layer bank as described later, even then upper-lower position is opposite, manufacturing process was also uncomplicated.In addition, even append aluminium electrode 45 that contains lithium and ITO rete 46 thin as having light transmission, the aluminium electrode 45 that contains lithium becomes also also accessible to showing with the structure of pixel electrode 41 same area laminations, and ITO rete 46 also becomes with opposite electrode OP also also accessible to showing at the structure of the same area lamination.Therefore containing the aluminium electrode 45 of lithium and pixel electrode 41, to form image respectively good, but good with the unified formation of same mask pattern.Similarly, it is good that ITO rete 46 and opposite electrode OP form pattern respectively, but good with the unified formation of same mask pattern.Certainly aluminium electrode 45 and 46 medial areas at base layer bank of ITO rete of containing lithium form good.

Form opposite electrode OP with the ITO film, it is good to form pixel electrode 41 with metal film.Under any circumstance light should penetrate from transparent ITO film.

The light-emitting component 40 of Gou Chenging is given opposite electrode OP and pixel electrode 41 making alives respectively as positive pole and negative pole as mentioned above, as Fig. 9 (Fig. 7 (A), the I-E characteristic of the light-emitting component 40 shown in Fig. 8 (B)), Figure 10 (Fig. 7 (B), the I-E characteristic of the light-emitting component 40 shown in Fig. 8 (A)) shown in the difference, surpass the regional conducting of threshold value at institute's making alive (transverse axis/opposite electrode OP is to the current potential of pixel electrode 41), that is: be in low resistance state, the electric current (drive current) that flows through organic semiconductor film 43 sharply increases.Its result, light-emitting component 40 is luminous as electroluminescent cell or LED element, and the ejaculation light of light-emitting component 40 reflects on opposite electrode OP, by transparent pixel electrode OP pixel capacitors 41 and transparency carrier 10 is penetrated.In contrast, institute's making alive (current potential of transverse axis/opposite electrode 41) is lower than the zone of threshold value, ends, and is in high resistance state that is:, does not have electric current (drive current) to flow through organic semiconductor film 43, and light-emitting component 40 extinguishes.Having at Fig. 9, respectively near+2V, is threshold voltage near the-2V in the example shown in Figure 10 again.

There is luminescence efficiency slightly lowly to be inclined to here, the hole injection layer 42 of omission is also arranged.The situation that electron injecting layer is set on the position of the position opposite side that organic semiconductor layer 43 is formed hole injection layer 42 without hole injection layer 42 is also arranged in addition.In addition, the situation that also has hole injection layer 42 and electron injecting layer both to be provided with.

(characteristic of TFT)

As the luminous TFT (1TFT20 and the 2TFT 30 of Fig. 2) that controls the light-emitting component 40 that constitutes as mentioned above, Figure 11 and Figure 12 (drain voltage of two figure is all got 4V, 8V provides as an example) provide the current-voltage characteristic of N channel-type and P channel-type TFT.As what seen by these figure, TFT is carried out conducting, is ended action by the gate voltage that is added on the grid.That is: gate voltage one exceeded threshold voltage, TFT is in conducting state (low resistance state), and leakage current increases.In contrast, gate voltage-be lower than threshold voltage, TFT is in cut-off state (high resistance state), and leakage current reduces.

(manufacture method of display device)

Manufacture method for the display device 1 that constitutes as mentioned above, since identical substantially up to the manufacturing process that makes 1TFT20 and 2TFT 30 on transparency carrier 10 with the operation of the active-matrix substrate of making liquid crystal indicator 1, so with reference to Figure 13 its summary is described simply.

Figure 13 is given in the process profile of the process of each component part that forms display device 1 under the temperature conditions below 600 ℃ with demonstrating.

That is: as required transparency carrier 10 usefulness TEOS (tetraethoxysilane) and oxygen etc. being made unstrpped gas shown in Figure 13 (A) relies on plasma CVD method to form the substrate protective film (not shown) that the silicon oxide film by about 2000～5000  of thickness constitutes.Secondly the temperature of setting substrate is about 350 ℃, and relying on plasma CVD method to form by thickness on the surface of substrate protective film is the semiconductor film 100 that the amorphous silicon film of about 300～700  constitutes.Secondly the semiconductor film 100 that is made of amorphous silicon film is carried out crystallization step such as laser annealing or solid phase flop-in method, make semiconductor film 100 crystallizations turn to polysilicon.In the laser annealing method, for example use the excimer laser instrument, the long size of its harness shape line beam of 400mm, its output intensity for example is 200mJ/cm ²Line beam is scanned, so that line beam is being equivalent to its part of lacking dimensional directions laser intensity peak value 90% at each region overlapping.

Secondly, shown in Figure 13 (B), semiconductor film is handled the formation pattern, as island semiconductor film 200,300, unstrpped gas is made with TEOS (tetraethoxysilane) and oxygen etc. in its surface rely on plasma CVD method to form the gate insulating film 50 that silicon oxide film or silicon nitride film by about 600～1500  of thickness constitute.

Secondly as Figure 13 (C) shown in, form the conducting film that constitutes by metal films such as aluminium, tantalum, molybdenum, titanium, tungsten with sputtering method after, form pattern, formation is as the gate electrode 21,31 of the part of sweep trace gate.Also form electric capacity line cline in this operation.Have, 310 is that the prolongation of grid 31 is provided with part among the figure again.

Under this state, inject impurity such as high concentration phosphorus ion or boron ion, on silicon thin film 200,300, gate electrode 21,31 is formed source- drain area 22,23,32,33 in coupling ground automatically.The part of not mixing impurity constitutes channel region 27,37.At present embodiment, as described later, because the situation of making the different TFT of conductivity type on same substrate is arranged, so in this case, in the doping impurity operation, with mask topped TFT against conductivity type form zone on one side, carry out impurity on one side and mix.

Secondly shown in Figure 13 (D), forming the 1st interlayer dielectric 51 back formation contact holes 61,62,63,64,69, form data line sig, electric capacity line cline and the current potential that the overlapping prolongation that has on the part 310 is provided with part st1 is set and keep electrode st, public supply lines com and repeater electrode 35 in the prolongation of gate electrode 31.Its result, current potential is kept electrode st by contact hole 69 and prolong and part 310 to be set to be electrically connected with grid 31.So form 1TFT20 and 2TFT 30.In addition, the prolongation of keeping electrode st by electric capacity line cline and current potential is provided with part st1 and forms and keep electric capacity cap.

Secondly as Figure 13 (E) shown in, form the 2nd interlayer dielectric 52, on this interlayer dielectric at the part formation contact hole 65 suitable with repeater electrode 35.Then after the surface of whole the 2nd interlayer dielectric 52 forms conducting film, form pattern, form the pixel electrode 41 that the source-drain area 32 with 2TFT 30 electrically contacts by contact hole 65.

Secondly shown in Figure 13 (F), after the face side of the 2nd interlayer dielectric 52 forms the black resist layer, stay this resist layer, form memory bank layer bank so that surround the zone of the organic semiconductor film 43 and the hole injection layer 42 that should form light-emitting component 40.Here, no matter be that each pixel independently forms box-like situation separately or forms two kinds of situations of the situation of strip along data line sig, the also only its corresponding shape of organic semiconductor film 43 forms memory bank layer bank, can be suitable for the manufacture method of present embodiment.

Secondly, the medial area of memory bank layer bank sprays the fluent material (precursor) that is used to constitute organic semiconductor film 43 by ink gun IJ, forms organic semiconductor film 43 at memory bank layer bank medial area.Equally, the medial area of memory bank layer bank is used to constitute the fluent material (precursor) of hole injection layer 42 by ink gun IJ ejection, forms hole injection layer 42 at the medial area of memory bank layer bank.The structure that light-emitting component 40 is described as reference Fig. 7 (A), (B) and Fig. 8 (A), (B) is arranged again, the order of also with good grounds its structure change formation organic semiconductor film 43 and hole injection layer 42.

, be hydrophobicity here because memory bank layer bank is made of resist layer.In contrast, because the precursor hydrophilic solvent of organic semiconductor film 43 and hole injection layer 42, the applying area of organic semiconductor film 43 is accurately limited by memory bank layer bank, can not expose on pixel adjacent.In addition, in case enough highlands form memory bank layer bank, even then without also forming organic semiconductor film 43 and hole injection layer 42 under the situation of ink-jet method with coating processes such as spin rubbing methods in presumptive area.

Work efficiency when present embodiment relies on ink-jet method to form organic semiconductor film 43 and hole injection layer 42 in order to improve, as shown in Figure 3, even being set in the prolongation along sweep trace gate, the spacing of arbitrary pixel 7 of direction adjacency also equates with the formation district center spacing of aforementioned organic semiconductor film 43.Therefore shown in arrow Q, just its advantage has been gone by the material of ink gun IJ ejection organic semiconductor film 43 on equally spaced position for the prolongation along sweep trace gate is provided with direction.In addition, owing to can equidistantly move,, and improve the injection precision of ink gun IJ easily so ink-jet IJ travel mechanism is simple.

Afterwards, shown in Figure 13 (G), on the face side of transparency carrier 10, form opposite electrode OP.Here opposite electrode OP forms whole or be strip, when opposite electrode is strip and forms, after the whole surface of transparency carrier 10 forms conducting film it is formed strip pattern.

On data side driving circuit 3 shown in Figure 1 or scan-side driving circuit 4, also form TFT, but these TFT quoted on aforementioned pixel 7 operation that forms TFT all or part of carry out.Therefore the TFT that constitutes driving circuit is also forming with the same interlayer of the TFT of pixel 7.

At present embodiment, because being black, memory bank layer bank constitute by the insulativity resist, remaining untouched remains, as the insulation course utilization that is used to reduce black matrix" (black-matrix black matrix) and stray capacitance.

Promptly as shown in Figure 1, even the neighboring area of transparency carrier 10 is also formed aforementioned memory bank floor bank (stamping oblique line forming the district).Therefore, because data side driving circuit 3 and scan-side driving circuit 4 are all topped by memory bank layer bank, so even opposite electrode OP is in overlap condition to the formation district of these driving circuits, between the wiring layer of driving circuit and opposite electrode OP, also get involved memory bank layer bank.The stray capacitance on the driving circuit 3,4 be can prevent thus,, low consumption electrification or display action high speed impelled so can reduce the load of data side driving circuit 3.

This external present embodiment such as Fig. 3 to formation memory bank layer bank shown in Figure 5 so that overlap on the data line sig.Therefore, memory bank layer bank gets involved between data line sig and the opposite electrode op, so can prevent stray capacitance on data line sig.Its result can reduce the load of driving circuit, so can impel low consumption electrification or display action high speed.

Then,, shown in Fig. 4 and Fig. 6 (A), also can form memory bank layer bank at pixel electrode 41 and repeater electrode 35 overlay regions as Fig. 3 at present embodiment.That is: shown in Fig. 6 (B), do not form under the situation of memory bank layer bank at pixel electrode 51 and repeater electrode 35 overlay regions, for example between pixel electrode and opposite electrode OP, flow through drive current, make organic semiconductor film 43 luminous, because this light is clipped between repeater electrode 35 and the opposite electrode OP, can not penetrate, so to showing not contribution.This drive current that does not have the part of contribution to flow through to demonstration is seen from the angle that shows and is called idle current.Yet the part that should flow through this idle current at present embodiment forms memory bank layer bank, has prevented that at this drive current from flowing through, so can prevent from public supply lines com, to flow through futile useless electric current.Therefore public power supply live width can corresponding stenosis.

In addition, the in a single day residual as previously mentioned memory bank bank that constitutes by the black resist, then memory bank bank has the function as black matrix", can improve display qualities such as brightness, contrast.Promptly on the display device 1 of present embodiment since opposite electrode OP in the whole face side of transparency carrier 10 or in wide scope, be strip and form, so reduced contrast because of the reflected light of opposite electrode OP.Yet at present embodiment, because the formation district of regulation organic semiconductor film 43 constitutes the memory bank floor bank that suppresses the stray capacitance function by the black resist on one side on one side, so the memory bank layer also has the function as black matrix, hidden the invalid reflected light that comes from opposite electrode OP, so the high advantage of so-called contrast is arranged.In addition because can utilize memory bank layer bank to mate regulation luminous zone, ground voluntarily, thus not memory bank layer bank as black matrix with and be unwanted with the adjustment allowance that other metal level etc. is done the black matrix time spent and become the luminous zone of problem.

(other structure of active-matrix substrate)

The invention is not restricted to above-mentioned formation, can be suitable for various active-matrix substrates.For example, with reference to Figure 31 explanation like that, on transparency carrier 1 with 1 data lines sig, 1 public supply lines com, 1 row pixel 7 also can be suitable for the present invention as 1 unit for the display device 1A that the prolongation to sweep trace gate is provided with the formation that direction repeats.

In addition to keep electric capacity cap without the electric capacity line public supply lines com and current potential keep constitute between the electrode st good.In this case, shown in Figure 14 (A), (B), keep the prolongation of the gate electrode 31 that electrode st and gate electrode 31 be electrically connected lower floor's one side that part 310 is expanded to public supply lines com always is set being used for current potential, constitute so that the 1st interlayer dielectric 51 between part 310 and the public supply lines com to be set in this prolongation and keep electric capacity cap as the dielectric film.

And with regard to keeping electric capacity cap, omitted diagram, but that the polysilicon film that is used to constitute TFT constitutes is also passable, and, be not limited to electric capacity line or public supply lines, also can and the sweep trace of prime between constitute.

(embodiment 1)

Figure 15 is the equivalent circuit diagram that the display device pixel of expression present embodiment constitutes.Figure 16 (A), (B) are illustrated in the key diagram of status of electrically connecting of each element that constitutes on each pixel and the oscillogram that expression drive signal equipotential changes.

Shown in Figure 15, Figure 16 (A), (B), at present embodiment, 1TFT 20 is N channel-types.Therefore, when the sweep signal Sgate that is supplied with by sweep trace is in noble potential, 1TFT 20 is in conducting state, picture intelligence data is write through 1TFT 20 from data line sig and to keep electric capacity cap, during the sweep signal Sgate that is supplied with by sweep trace gate is in electronegative potential by keeping the picture intelligence data drive controlling 2TFT 30 that electric capacity cap preserves.

At present embodiment, 2TFT 30 also is the N channel-type.Therefore, what by data line sig the picture intelligence date of hot side is write the pixel that should light keeps electric capacity cap, and what the picture intelligence date of low potential side write the pixel that should extinguish keeps electric capacity cap.

Here, the gate voltage Vgcur of 2TFT 30 is equivalent to the poor of current potential that side's current potential low in the current potential of the current potential of public supply lines com and pixel 30 and current potential keep electrode st.Yet at present embodiment, reduce the current potential of the opposite electrode OP of the relative light-emitting component 40 of public supply lines com, when making 2TFT 30 be in conducting state, as shown by arrow F, its formation wishes that electric current flows through from public supply lines com one side of light-emitting component 40 1 directions.Therefore, the gate voltage Vg cur of 2TFT30 is equivalent to the poor of the current potential of public supply lines com and current potential that current potential is kept electrode st.Current potential about the pixel electrode 30 of the current potential between the current potential of the current potential of this public supply lines com and current potential that is equivalent to public supply lines com and opposite electrode op is different, can be set in enough low value.So at present embodiment, owing to can get sufficiently high value to the gate voltage Vgcur of 2TFT 30, thus the conducting electric current of 2TFT 30 is big, so can carry out the demonstration under the high brightness.In addition, during making the pixel illuminating state, if the gate voltage Vgcur as 2TFT 30 obtains high value, then to keep the current potential of electrode st be the current potential of the hot side of picture intelligence date because can correspondingly reduce at this moment current potential, so can reduce the amplitude of picture intelligence data and reduce driving voltage on the display device 1.

In addition, the conducting electric current of 2TFT 30 is not limited to gate voltage Vgcur, also depends on drain voltage, but does not change above-mentioned conclusion.

In addition, at present embodiment, the conducting electric current of 2TFT 30 is stipulated by the difference of the current potential that current potential and the current potential of public supply lines com are kept electrode st, because be not subjected to directly influencing of opposite electrode op current potential, so reducing the current potential of the picture intelligence data hot side of the bright state of capture vegetarian refreshments arrives than the also low current potential of opposed electrode op current potential, reduce the amplitude of picture intelligence, impel the electronegative potentialization of the driving voltage in the display device 1.In addition, the current potential of the hot side of the picture intelligence data of the bright state of reduction capture vegetarian refreshments arrives and opposite electrode op equipotential, and the amplitude that reduces picture intelligence is good.

Then, relatively become high slightly current potential side for the current potential of the picture intelligence data that should be the pixel supply of extinguishing state and the current potential of public supply lines com by data line sig at present embodiment.Because 2TFT 30 is N channel-types, institute thinks ends it fully, and the gate voltage Vgcur that should get 2TFT 30 is negative (than the low current potential of public supply lines com).Perhaps set the current potential height of picture intelligence data low potential side, so that the absolute value of the gate voltage Vgcur of 2TFT 30 should be in than the low slightly current potential of threshold voltage absolute value that is equivalent to 2TFT 30.At this moment, the polarity of the gate voltage that is in 2TFT 30 on the pixel 7 of extinguishing state during with 2TFT 30 conducting states is identical, and is set in below the threshold voltage of 2TFT30.At this moment, even setting as mentioned above under the high situation of picture intelligence data low potential side current potential, because 2TFT 30 is in high resistance state, the conducting electric current is minimum, so light-emitting component 40 also extinguishes.Get equipotential from data line sig for the current potential of the picture intelligence data of the pixel supply that should extinguish in addition, also can reduce the amplitude of picture intelligence data with public supply line com.

If to the low potential side potential setting of above-mentioned picture intelligence data at the noble potential that does not surmount 2TFT 30 threshold level, then because can reduce the amplitude of picture intelligence data, so can reduce the driving voltage of picture intelligence data.But as previously mentioned, because the hot side current potential of the picture intelligence data of the bright state of reduction capture vegetarian refreshments is up to the current potential lower than the current potential of opposed electrode OP, the current potential of picture intelligence data returns in the range of being stipulated by opposite electrode OP and public supply lines.Therefore, can reduce the driving voltage in the display device 1, and the electric power that expends that reduces display device 1.In addition, aforesaid formation is also unlikely to cause that image quality is low, remarkable action and the frequency that can move reduce, and its advantage is that the driving voltage of display device 1 is low, so the proof voltage problem of the worrying element that is made of film can not display.

(variation of embodiment 1)

Figure 17 is the equivalent circuit diagram that the pixel of the display device 1 of expression present embodiment constitutes.Figure 18 (A), (B) are the oscillograms that is illustrated respectively in the potential change of the key diagram of status of electrically connecting of each element that constitutes on each pixel and expression drive signal etc.Opposite with the 1st embodiment at present embodiment, 1TFT 20 and 2TFT 30 are made of P channel-type TFT.But at present embodiment is each element of drive controlling under the technological thought identical with embodiment 1, and the polarity of the drive signal of embodiment 1 explanation is turned around, because other each point is had identical formation, only makes simple explanation to constituting.

As Figure 17, shown in Figure 18 (A), (B), at present embodiment, because 1TFT 20 is P channel-types, so when the sweep signal Sgate that is supplied with by sweep trace gate was in electronegative potential, 1TFT 20 was in conducting state.

At present embodiment, 2TFT 30 also is the P channel shape.Therefore, from data line sig the picture intelligence data of low potential side is write the pixel that should get illuminating state and keep electric capacity cap, the picture intelligence data of hot side is write to get the pixel of extinguishing state and keep electric capacity cap.

Here, the gate voltage Vgcur of 2TFT 30 is equivalent in the current potential of the current potential of public supply lines com and pixel electrode 30 high side's current potential and current potential and keeps the poor of electrode st current potential.Yet at present embodiment, improve the current potential of the opposite electrode op current potential of the relative light-emitting component 40 of public supply lines com, as shown by arrow E, electric current flows through to light-emitting component 40 sides from public supply lines com direction when making 2TFT 30 be in conducting state.Therefore, the gate voltage Vgcur of 2TFT 30 is equivalent to the poor of the current potential of public supply line com and current potential that current potential is kept electrode st.Current potential to the pixel electrode of the current potential between the current potential of the current potential of this public supply lines com and current potential that is equivalent to public supply lines com and opposite electrode OP is different, can be set in sufficiently high value.Therefore, at present embodiment, because the gate voltage Vgcur of 2TFT 30 can get sufficiently high value, the conducting electric current of 2TFT 30 is big, so can show under high brightness.In addition, capture is plain be illuminating state during, if can get the high value, then keep the current potential of electrode st because of correspondingly removing to improve at this moment current potential as the gate voltage Vgcur of 2TFT 30, that is: the current potential of the low potential side of picture intelligence data is so can reduce the amplitude of picture intelligence data.

In addition, at present embodiment, because the conducting electric current of 2TFT 30 directly is not subjected to the influence of the current potential of opposite electrode OP, so the capture element reduces the amplitude of picture intelligence data for the current potential of the low potential side of the picture intelligence data of illuminating state rises to the current potential higher slightly than the current potential of opposed electrode OP always.In addition, the capture element rises to the current potential that equates with opposite electrode OP for the current potential of the low potential side of the picture intelligence data of illuminating state always, and the amplitude that reduces picture intelligence data is good.

Also have,, will drop to the current potential lower slightly for the current potential that should get the picture intelligence data that the pixel of extinguishing state supplies with always by data line sig than the current potential of public supply lines com at present embodiment.That is: the hot side current potential of setting picture intelligence data is low, so that the absolute value of the gate voltage Vgcur of 2TFT 30 becomes the low slightly current potential of level than the absolute value of the threshold voltage that is equivalent to this TFT.Therefore the conducting electric current of 2TFT 30 is minimum, and light-emitting component 40 extinguishes.Be set to and public supply lines com equipotential for the current potential of the picture intelligence data of the pixel supply that should get the state that extinguishes by data line sig in addition, also can reduce the amplitude of picture intelligence data.

The potential setting of the low potential side of picture intelligence data gets high as mentioned above, and the capture element is that the potential setting of hot side of the picture intelligence data of illuminating state must be low, so the current potential of picture intelligence data is got back in the level by opposite electrode OP and public supply lines com regulation.Therefore, can reduce the driving voltage in the display device 1, the consume electric power etc. that can reduce display device 1 has effect same with embodiment 1.

(embodiment 2)

Figure 19 is the equivalent electrical circuit that the pixel of expression present embodiment display device 1 constitutes.Figure 20 (A), (B) are illustrated respectively in the key diagram of status of electrically connecting of each element that constitutes on each pixel and the oscillogram that expression drive signal equipotential changes.

As Figure 19, shown in Figure 20 (A), (B), at present embodiment, 1TFT 20 is made of N channel-type TFT, and 2TFT is made of P channel-type TFT.Because 2TFT 30 is P channel-types, so writing the pixel that should get illuminating state by data line sig, the picture intelligence data of low potential side keeps electric capacity cap, the picture intelligence data of hot side writes and should get the pixel of extinguishing state and keep electric capacity cap.The gate voltage Vgcur of 2TFT 30 is equivalent to side's current potential high in the current potential of the current potential of public supply lines com and pixel electrode and current potential is kept the poor of electrode st current potential.

The opposite electrode OP current potential height of the current potential of public supply lines com than light-emitting component 40 is set at present embodiment, and the gate voltage of 2TFT makes its current potential that is equivalent to public supply lines com and current potential keep current potential poor of electrode st.Because relatively can so the conducting electric current of 2TFT 30 is big, can under high brightness, show to the potential setting of this public supply lines com in sufficiently high value with image electrode 41.In addition, because can correspondingly improve the current potential that at this moment current potential is kept electrode st, that is: the current potential of the low potential side of picture intelligence data is so can reduce the amplitude of picture intelligence data.In addition, because the conducting electric current of 2TFT 30 directly is not subjected to the influence of opposite electrode OP current potential, so rising to than the high current potential of the current potential of opposed electrode OP or with it always, the current potential of the low potential side of the plain picture intelligence data for illuminating state of capture equates the amplitude of reduction picture intelligence data.Then make the current potential of supplying with the picture intelligence data that should get the pixel of extinguishing state by data line sig lower slightly or equate the amplitude of reduction picture intelligence data with it than the current potential of public supply lines com at embodiment.Because making the current potential of picture intelligence data thus gets back in the range of being stipulated by opposite electrode OP and public supply lines com, and then the driving voltage of reduction display device 1, so can reduce the consume electric power of display device 1 etc., reach embodiment 1 or the identical effect of its distortion.

Present embodiment because 1TFT 20 is N channel-types is and the contrary conductivity types of 2TFT 30, so the current potential (sweep signal Sgate) of sweep trace gata is a noble potential when selecting pixel.At this moment the gate voltage Vgsw of 1TFT 20 is equivalent to the current potential and the current potential of the noble potential of sweep signal Sgate and keeps the poor of electrode st (keeping the gate electrode potential of electric capacity st current potential, 2TFT 30) current potential.Here because 2TFT 30 is P channel-types, so the picture intelligence data that is used for a bright pixel 7 at low potential side, the current potential that current potential is kept electrode st during the selection of pixel 7 reduces.Therefore the gate voltage guide Vgsw galvanization augment direction of 1TFT 20 moves.

On the one hand the gate voltage Vgcur of 2TFT 30 is equivalent to public supply lines com and current potential and keeps potential difference (PD) between the electrode st, inner potential is kept the tendency that electrode st has current potential to reduce when the pixel of selecting 7 is in illuminating state because during selecting, so the gate voltage guide Vgcur galvanization augment direction of 2TFT 30 moves.

As mentioned above, at present embodiment, because 1TFT 20 and 2TFT 30 are contrary conductivity types, so in order to improve the write capability of 1TFT 20, improve the strobe pulse height of sweep signal Sgate, for improving the brightness of light-emitting component 40, should reduce the conducting resistance of 2TFT 30, thereby reduce picture intelligence data.Keep electric capacity along with the picture intelligence of the level that light-emitting component 40 is lighted writes in during the selection of pixel 7, it is effective that the optimization of the strobe pulse height of aforesaid sweep signal Sgate and picture intelligence data is moved to augment direction the conducting electric current of this TFT of gate voltage of 1TFT 20.Therefore picture intelligence writes through 1TFT 20 from data line sig and keeps electric capacity cap.Select the gate voltage Vgsw of the 1TFT 20 during the pixel 7 to be equivalent to the current potential suitable and current potential here and keep the poor of the current potential of electrode st (keeping the current potential of the gate electrode of the current potential of electric capacity cap or 2TFT 30) with the noble potential of sweep signal Sgate, the gate voltage Vgcur of 2TFT 30 is equivalent to current potential and the current potential of public supply lines com and keeps the poor of electrode st current potential, when the current potential of keeping electrode st with current potential was made benchmark, being equivalent to the current potential of noble potential of sweep signal Sgate and the current potential of public supply lines com was same polarity.Therefore, if change the current potential that current potential is kept electrode st, then the gate voltage Vgsw of 1TFT 20 and the gate voltage Vgcur both sides of 2TFT 30 correspondingly move with same section at equidirectional.Thus in the scope of the driving voltage range of display device 1, if the resistance decreasing direction of current potential when 1TFT 20 conductings of its picture intelligence data that is used to light changed, then can impel the display action high speed, the direction of while because of current potential resistance decreasing when 2TFT 30 conductings of the picture intelligence data that at this moment is used to light changes, so can impel brightness to rise.Therefore, can realize taking into account the raising of driving voltage lower voltage and display quality.

(variation of embodiment 2)

Figure 21 is the equivalent electrical circuit that the pixel of the display device 1 of expression present embodiment constitutes.Figure 22 (A), (B) are respectively the oscillograms that is illustrated in the potential change of the key diagram of status of electrically connecting of each element that constitutes on each pixel and expression drive signal etc.Have at present embodiment on the contrary with embodiment 2 again, 1TFT 20 is as the P channel-type, and the TFT of 2TFT 30 usefulness N channel-types constitutes.But present embodiment with embodiment 2 same technological thoughts under each element of drive controlling, only the polarity with the drive signal of embodiment 2 explanation is opposite, so its formation of simple declaration only.

As Figure 21, shown in Figure 22 (A), (B), at present embodiment similarly to Example 1, because 2TFT 30 is N channel-types, so what the picture intelligence data of hot side write the pixel that should be illuminating state from data line sig keeps electric capacity cap, the picture intelligence data of low potential side write should be the pixel of extinguishing state keep electric capacity cap.Here, the gate voltage Vgcur of 2TFT is equivalent in the current potential of public supply lines com and pixel electrode 30 current potentials low side's current potential and current potential and keeps the poor of electrode st current potential.At present embodiment because the current potential of public supply lines com is lower than the current potential of the opposite electrode op of light-emitting component, so the gate voltage Vgcur of 2TFT 30 is equivalent to the poor of the current potential of public supply lines com and current potential that current potential is kept electrode st.Because the electrical potential energy of this public supply lines com is got enough low current potential,, can under high brightness, show so the conducting electric current of 2TFT 30 is big.Perhaps at the brightness height, make at this moment current potential keep the current potential of electrode st, that is: the current potential of the hot side of picture signal data rises, and can reduce the amplitude of picture intelligence data.In addition, because the conducting electric current of 2TFT 30 directly is not subjected to the influence from opposite electrode OP current potential, so being used to make pixel is that the hot side current potential of the picture intelligence data of illuminating state drops to current potential or the equipotential lower than the current potential of opposed electrode OP, reduces the amplitude of picture intelligence data always.And, get current potential or the equipotential higher slightly for the current potential of the picture intelligence data that should get the pixel supply of extinguishing state than the current potential of public supply lines com by data line sig at present embodiment, reduce the amplitude of picture intelligence data.Thus, the current potential of picture intelligence data is got back in the range of being stipulated by opposite electrode op and public supply lines com, the driving voltage in the display device 1 descends, so degradation is also descended in the power consumption of display device 1, with embodiment 1 and distortion thereof same effect is arranged.

At present embodiment, 1TFT 20 is P channel-types, with 2TFT 30 are contrary conductivity types, so the current potential (sweep signal Sgate) of the sweep trace gate when selecting pixel is an electronegative potential.In contrast, because 2TFT 30 is N channel-types, be in hot side so be used for the picture intelligence data of a bright pixel 7.

As mentioned above, at present embodiment, because 1TFT 20 and 2TFT 30 are contrary conductivity types, so in order to improve the write capability of 1TFT 20, reduce the current potential of the strobe pulse of sweep signal Sgate, in order to improve the brightness of light-emitting component 40, reduce the current potential of picture intelligence data, so that reduce the conducting resistance of 2TFT 30.During the selection of pixel 7, the picture intelligence data of the level that light-emitting component 40 lights is write keep electric capacity cap, the optimization of the strobe pulse height of aforesaid sweep signal Sgate and picture intelligence data has been moved effect to the gate voltage of 1TFT to the conducting electric current augment direction of this TFT.Therefore, when the current potential of keeping electrode st with current potential is made benchmark, owing to be equivalent to the current potential of sweep signal Sgate electronegative potential and the current potential of public supply lines com is a same polarity, if so change the current potential that current potential is kept electrode st, then correspondingly the gate voltage Vgcur both sides of the gate voltage Vgsw of 1TFT 20 and 2TFT 30 only to equidirectional mobile same section.Thus in the driving voltage range ability of display device 1, if the current potential that is used in the picture intelligence data that lights during towards 1TFT 20 conductings the direction of resistance decreasing change, then can impel the display action high speed.Because the direction of the resistance decreasing of the current potential that at this moment is used in the picture intelligence data that lights during towards 2TFT 30 conductings changes, so can impel brightness to rise.Therefore, similarly to Example 2, can realize taking into account the lower voltage of driving voltage and the rising of display quality.

With Figure 25 illustrate the foregoing description 2 and the distortion in the optimal drive method.

At embodiment 2, the 1TFT are N channel-types, and 2TFT is the P channel-type.As shown in figure 25, during light-emitting component 40 extinguishes, improve the current potential height of the current potential of picture intelligence data than public supply lines com, the 2TFT 30 of P channel-type is ended, and at present embodiment, as shown in figure 25, even under the situation that light-emitting component 40 extinguishes, 2TFT 30 is ended fully.That is: at present embodiment, because 2TFT 30 is P channel-types, for it is ended fully, should to get gate voltage Vgcur be 0V (idiostatic with public supply lines com) or get positive potential (than the high current potential of public supply lines com), and at present embodiment, potential setting when picture signal data extinguishes must be low, so that the gate voltage Vgcur of 2TFT 30 is in the high slightly current potential of level than the threshold voltage vt hp (cur) that is equivalent to this TFT.Therefore, the polarity that is in when added gate voltage is with 2TFT 30 conducting states on the 2TFT 30 on the pixel 7 of extinguishing state is identical, and is in the value of the threshold voltage that surpasses 2TFT 30.The threshold voltage (Vthp (cur)) of for example establishing 2TFT 30 is during for-4V, then gets-3V extinguishing the gate voltage that state is added on the 2TFT 30.

As mentioned above, 1TFT is the N type, when 2TFT is the P type, if it is lower than existing to set the current potential that extinguishes side of picture intelligence data, then because can reduce the amplitude of picture intelligence data, so can impel low pressureization and the high frequencyization of picture intelligence data.In addition, even under the low situation of the current potential that extinguishes side of setting aforesaid picture intelligence data, because of the 2TFT 30 at the P channel-type is in than the high slightly current potential of level that is equivalent to threshold voltage vt hp (cur), so the electric current that flows through when extinguishing is minimum.In addition, if the voltage that is added on the light-emitting component 40 is low, then only flow into minimum drive current.Therefore light-emitting component 40 is extinguished, do not have problems in fact.

In addition, at present embodiment, if the unnecessary current potential that surmounts public supply lines com of current potential during the extinguishing of picture intelligence data, the current potential that then can set public supply lines com is higher.Therefore at present embodiment, the sweep signal Sgate current potential of the current potential that makes public supply lines com during with 1TFT 20 conductings equates.Therefore, it is good that the signal level of using as the noble potential of sweep signal Sgate on the scan-side driving circuit is supplied with public supply lines com in the same old way, so display device 1 at present embodiment, the level number of the drive signal of using is few good, can reduce the wiring terminal number that is used for to display device 1 input drive signal.In addition, owing to can reduce the power supply number, can impel power circuit low consumption electrification and save the space.

In this case, because 1TFT 20 is N channel-types, 2TFT 30 is P channel-types, so that be added in the also low current potential of current potential of difference that current potential that the current potential of the gate electrode on the 2TFT 30 of the pixel 7 of extinguishing state becomes the sweep signal gate than from 1TFT 20 conducting states the time deducts the threshold potential Vthn (sw) of this 1TFT20.That is: make pixel 7 when extinguishing state picture intelligence data (current potential is kept the current potential of electrode st) and the absolute value of the potential difference (PD) Voff between the public supply lines com be shown below,

Vthn (sw)＜| Voff| sets also greatlyyer than the threshold voltage vt hn (sw) of 1TFT 20, can prevent to break down in the write activity of the 1TFT 20 when selecting pixel 7.

1TFT 20 in the variation of embodiment 2 is P channel-types, 2TFT 30 is under the situation of N channel-type, with reference to Figure 26 and Figure 27 (A), (B) as described later, the relative height of each signal that transposing illustrates in the present embodiment makes on 1TFT 20 and the 2TFT 30 alive polarity turn around.Even in this case, as shown in this embodiment,, then can impel lower voltage and the high frequencyization of picture intelligence data if 2TFT 30 not exclusively ends when light-emitting component is extinguished.In addition, the current potential of the sweep signal Sgate of the current potential by making public supply lines com during with 2TFT 20 conducting states equates, can reduce the power supply number.In this situation, the current potential that becomes the sweep signal gate than in 1TFT 20 conducting states the time in added gate electrode potential on the 2TFT 30 of the pixel 7 of extinguishing state adds the also high current potential of threshold voltage vt hn (sw) of this 1TFT 20, so that the write activity of the 1TFT 20 when selecting pixel 7 does not produce obstacle.

(embodiment 3)

At present embodiment, same as providing among Figure 23 shown in its equivalent electrical circuit with enforcement 2, all be to get 1TFT 20 to be the N channel-type in each pixel 7,2TFT 30 is the example that the P channel-type constitutes.In addition, even are P channel-types because of 2TFT 30, so the current potential of public supply lines com is than the current potential height of the opposite electrode OP of light-emitting component 40 in the display device 1 of present embodiment.Therefore, when 2TFT 30 is in conducting state, as shown by arrow E, flow through electric current to light-emitting component 40 1 sides from public supply lines com.Because similarly to Example 2, so its common ground is omitted explanation, only record and narrate its difference.Be provided with at embodiment 2 and keep electric capacity, to keep electric capacity cap this point different but there is no at present embodiment.By such formation, can be increased in the potential change that output terminal is kept electrode st.

At 1TFT 20 are P channel-types, 2TFT 30 is under the situation of N channel-type, with reference to Figure 26 and Figure 27 (A), (B) as described later, the explanation of transposing present embodiment the relative height of each signal, the polarity of voltage that is added on 1TFT 20 and the 2TFT 30 is turned around.Even in order to improve the write capability of 1TFT 20, reduce the current potential of the strobe pulse of sweep signal,, improve luminosity and increase the current potential of picture signal for reducing the conducting resistance of 2TFT 30 in this situation.

(variation of embodiment 3)

At the foregoing description 3, illustrate that at arbitrary pixel 7, the 1TFT 20 all be the N channel-type, 2TFT 30 is situations of P channel-type, provides shown in the equivalent electrical circuit as Figure 26, and 2TFT 20 is the P channel-type, and 2TFT 30 constitutes good as the N channel-type.At example shown in this figure, the current potential that reduces public supply lines com is lower than the current potential of the opposite electrode OP of light-emitting component 40, when 2TFT 30 was conducting state, electric current flowed to public supply lines com one side from opposite electrode OP one side of light-emitting component 40 as shown by arrow F.

When composing images 7 as mentioned above, shown in Figure 27 (A), (B), the polarity of each drive signal of the waveform shown in Figure 24 (A) is turned around.

At embodiment 3, at 1TFT 20 are N channel-types, when 2TFT 30 is the P channel-type, the current potential that reduces public supply lines com is lower than the current potential of the opposite electrode OP of light-emitting component 40, when 2TFT 30 is in conducting state, also there is the situation of this formation to wish that promptly electric current flows to public supply lines com one side from opposite electrode OP one side of light-emitting component 40.Even in the situation of above-mentioned formation, also can obtain to make 1TFT 20 and 2TFT 30 to be effect against conductivity type.In contrast, at 1TFT 20 are P channel-types, 2TFT 30 improves the current potential of public supply lines com to the opposite electrode OP current potential of light-emitting component 40 when being the N channel-type, when 2TFT 30 was in conducting state, the situation that electric current the mobile formation of light-emitting component 40 sides from public supply lines com direction also can obtain to make 1TFT 20 and 2TFT 30 to be the effect against conductivity type.

(embodiment 4)

At the foregoing description 1,2, in 3, as the explanation of reference Figure 28 (A), (B), in keeping two electrodes of electric capacity cap, with the trigger-gate delay of supplying with on the opposite side electrode of the electrode of the grid that is electrically connected to 2TFT 30 by sweep signal gate, good with the formation that this strobe pulse current potential is partial to reciprocal pulse.

Example here, shown in Figure 28 (A), in keeping two electrodes of electric capacity cap, constitute by prolonging the electric capacity line cline that is provided with, so that arranged side by side with sweep trace gate with the electrode of the opposite side of keeping the electrode that electrode st is electrically connected by current potential on the grid of 2TFT 30.

Shown in Figure 28 (B), the current potential stg that comprises pulse signal Pstg supplies with on this electric capacity line cline, and this pulse signal Psrg is partial in the other direction by the strobe pulse Pgate delay of sweep signal Sgate and with this strobe pulse Pgate current potential.

After strobe pulse Pgate is in nonselection mode, utilize the capacitive coupling of keeping electric capacity cap, this pulse signal Pstg moves the current potential of picture intelligence data.Be in the signal that the current potential that keeps picture intelligence data on the electric capacity cap adds pulse signal Pstg current potential appropriate section of keeping that extinguishes state in pixel 7 thus.Because 1TFT 20 conducting resistance are big, the signal that will fully write the hot side of picture intelligence data in the limited time is difficult.In this example, can not light under the situation that can not fully write.But write picture intelligence data by utilizing present embodiment can replenish to keeping electric capacity cap.Therefore need not enlarge the maximum range of the current potential of drive signal.

So, when pulse signal Pstg is added electric capacity line cline, as shown in figure 29, draw electric capacity line cline from scan-side driving circuit 4, simultaneously on scan-side driving circuit 4 at each grid, the output signal of shift register 40 is outputed to sweep trace gate by NA ND gate circuit and phase inverter as sweep signal Sgate, the opposing party, the output signal of shift register 40 is postponed on one side by NAND gate circuit and 2 grades of phase inverters, to Vccy, it is good to output to electric capacity line cline from the Vdd level shift for the potential level that makes on one side hot side as shown in figure 30.

In the foregoing description and each variation thereof, during additional maintenance electric capacity, explanation be the light-emitting component that is provided with electric capacity line cline type.But, present embodiment is not limited to be provided with the formation of this electric capacity line cline, by constituting good in abutting connection with the gate line of keeping electric capacity one side's electrode.Figure 34 (A), (B) provide circuit block diagram and the gate line grid voltage waveform to the direction of scanning respectively to an example of formation like this.As mentioned above, by with the gate line of adjacency formation, the effect that electric capacity line cline needn't specially be set this pixel is arranged as side's electrode of keeping electric capacity.

(other embodiment)

2TFT the various embodiments described above do not put down in writing the work of the I-E characteristic of 2TFT 30 in each zone, if in its saturation region operation, then can utilize the weak steady current characteristic of TFT to prevent to flow through abnormal current in light-emitting component 40.For example when generation pin hole gaps such as the organic semiconductor film that constitutes light-emitting component 40,, can between the electrode of light-emitting component 40, not form dead short even in this situation also limits defective light-emitting component, flow through electric current.

In contrast, if make 2TFT30 in its range of linearity work, the fluctuation that can prevent its threshold voltage is to showing the influence of work.

For the structure of TFT, be not limited to the one pole type, ambipolar also passable, with regard to its manufacture method, also be not limited to low temperature process.

(utilizability of invention)

As described above, in the display unit of claim 1 to 7 of the present invention, because 2TFT Gate voltage during conducting is equivalent to the high side of current potential in the current potential of public supply lines and pixel electrode The current potential of current potential and gate electrode (current potential of picture intelligence) poor, thus with the conduction of 2TFT The current potential of the current potential of the public supply lines of type respective settings and the opposite electrode of light-emitting component relative high Low, the gate voltage of 2TFT makes its current potential that is equivalent to public supply lines and current potential keep electrode Current potential poor. For example, if 2TFT is the N channel-type, reduce public supply lines to luminous unit The current potential of the opposite electrode current potential of part. Because to the current potential of this public supply lines and the electricity of pixel electrode The position is different, can be set in enough low value, thus can obtain big conductance current at 2TFT, Can under high brightness, show. In addition, if when pixel is lighted, get as 2TFT To high gate voltage, then because can correspondingly reduce the current potential of picture intelligence at this moment, so energy Reduce the amplitude of picture intelligence, reduce the driving voltage in the display unit. Therefore, its advantage is, Can reduce power consumption, not manifest for worrying withstand voltage the asking of each element that is consisted of by film simultaneously Topic.

The described display unit of this external claim 7 to 11 of the present invention is because 1TFT With 2TFT be contrary conductivity type, so be used for pixel selection sweep signal pulse and be used for point The current potential of the picture intelligence of bright light-emitting component has opposite relation. Thereby, the current potential dimension when lighting The current potential (lighting the current potential of the picture intelligence of usefulness) of holding electrode is during as benchmark, owing to be equivalent to sweep Retouching the current potential of high potential of signal and the current potential of public supply lines is same polarity, so if change point Current potential when bright is kept the current potential (lighting the current potential of the picture intelligence of usefulness) of electrode, then 1TFT Gate voltage and two voltages of the gate voltage of 2TFT to equidirectional correspondingly only mobile identical Amount. Therefore, use picture intelligence if in the range ability of the driving voltage of display unit, make to light Current potential during to the 1TFT conducting resistance decreasing direction move, then can impel the high speed of demonstration work Change, simultaneously because at this moment light the current potential of the picture intelligence of usefulness should be to the 2TFT conducting time resistance become Little direction moves, so can impel brightness to rise. Therefore can realize taking into account the low electricity of driving voltage The raising of pressureization and display quality.

And, in claim 11 of the present invention or 12 described display unit, because keeping In two electrodes of electric capacity, with the other side of the electrode of the 2nd gate electrode that is electrically connected 2TFT Electrode is supplied with pulse, and this pulse is by the trigger-gate delay of sweep signal, and deflection and this selection arteries and veins The opposite direction of current potential of punching, so, can the compensation image picture signals to keeping writing of electric capacity. Therefore, Do not increase the amplitude of picture intelligence, just can make the picture intelligence electricity on the gate electrode that is added in 2TFT Move to the high brightness direction position.

Claims (5)

1. display device has: sweep trace, and data line, supply lines, pixel, described display device are characterised in that to have on the described pixel: by described sweep trace, supply with the 1st transistor of sweep signal; By described the 1st transistor, keep picture signal by described data line supply, have the electric capacity of keeping of the 1st electrode and the 2nd electrode; The 2nd transistor that has connected gate electrode in described the 2nd electricity level; And the light-emitting component that possesses light-emitting film, when the pixel electrode that described light-emitting film forms on by described pixel is electrically connected to described supply lines by described the 2nd transistor, undertaken luminous by the drive current that between pixel electrode that forms on the described pixel and opposite electrode, flows through;

Described sweep signal offers described the 1st electrode with the regulation current potential under nonselection mode, utilize the described electric capacity combination of keeping electric capacity, can move the current potential of described the 2nd transistorized described gate electrode.

2. display device has: sweep trace, and data line, supply lines, pixel, described display device are characterised in that to have on the described pixel: by described sweep trace, supply with the 1st transistor of sweep signal; By described the 1st transistor, keep picture signal by described data line supply, have the electric capacity of keeping of the 1st electrode and the 2nd electrode; The 2nd transistor that has connected gate electrode in described the 2nd electricity level; And the light-emitting component that possesses light-emitting film, when the pixel electrode that described light-emitting film forms on by described pixel is electrically connected to described supply lines by described the 2nd transistor, undertaken luminous by the drive current that between described pixel electrode and opposite electrode, flows through;

Described pixel is supplied to the pulse than the trigger-gate delay of described sweep signal and current potential and this strobe pulse reverse direction deflection.

3. according to claim 1 or 2 any described display device, it is characterized by: described light-emitting film is an organic semiconductor film.

4. according to claim 1 or 2 any described display device, it is characterized by: described the 2nd transistor is worked in the zone of saturation.

5. according to claim 1 or 2 any described display device, it is characterized by: described the 2nd transistor is in linear regional work.

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