CN101373583B - Device and method for generating gamma reference voltage and apparatus for generating grayscale voltage - Google Patents
Device and method for generating gamma reference voltage and apparatus for generating grayscale voltage Download PDFInfo
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- CN101373583B CN101373583B CN2007101417765A CN200710141776A CN101373583B CN 101373583 B CN101373583 B CN 101373583B CN 2007101417765 A CN2007101417765 A CN 2007101417765A CN 200710141776 A CN200710141776 A CN 200710141776A CN 101373583 B CN101373583 B CN 101373583B
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Abstract
The invention relates to a gamma reference voltage generation device as well as a method thereof and a grayscale voltage generation device. The grayscale voltage generation device comprises a selection unit and a grayscale voltage generator. The selection unit is used for receiving M first gamma reference voltages and selecting and outputting N second gamma reference voltages from the first gamma reference voltage, wherein M and N are positive integers, and M is larger than N. The grayscale voltage generator is coupled with the selection unit for generating a plurality of grayscale voltages according to the second gamma reference voltage. Accordingly, gamma curves can be adjusted adaptively to improving the display quality.
Description
Technical field
The present invention relates to a kind of voltage generating technique of display, and particularly relate to a kind of grayscale voltage generating technique and gamma reference voltage generating technique.
Background technology
At improving rapidly of multimedia society, be indebted to the tremendous progress of semiconductor subassembly or man-machine display device mostly.With regard to display, cathode-ray tube (CRT) (Cathode Ray Tube is called for short CRT) because of having excellent display quality and its economy, is monopolized monitor market in recent years always.Yet still there are a lot of problems in cathode-ray tube (CRT), problem such as for example bulky and radiant quantity height.Therefore, the LCD (LCD) with high image quality, high spatial utilization ratio, low consumpting power, advantageous characteristic such as radiationless becomes the main flow in market gradually.Do further explanation with next type of drive at LCD.
Fig. 1 is the synoptic diagram of known LCD.Fig. 2 A and Fig. 2 B are a kind of gamma reference voltage source of Fig. 1 and the circuit diagram of source electrode driver.Please merge with reference to figure 1, Fig. 2 A and Fig. 2 B, conventional liquid crystal 100 can utilize gamma reference voltage source 110 (Gamma Reference VoltageSource) that gamma reference voltage V is provided
GMA_1～V
GMA_NGive source electrode driver (Source Driver) 120.Gamma reference voltage source 110 is coupled to system voltage AVDD, and a plurality of resistance 112 are serially connected, and produces different gamma reference voltage V by the dividing potential drop mode
GMA_1～V
GMA_NGive the grayscale voltage generator 122 of source electrode driver 120.In addition, the gamma reference voltage source 110 of Fig. 2 A also can replace with the gamma reference voltage source 114 of Fig. 2 B.Gamma reference voltage source 114 can produce different gamma reference voltage V by the resistance difference of each resistance 116
GMA_1～V
GMA_N
Hold above-mentionedly, and please continue with reference to figure 1 and Fig. 2 A.Grayscale voltage generator 122 is again according to V
GMA_1～V
GMA_NGamma reference voltage, use producing different gradation data corresponding gray scale voltage V
G1～V
GnThen, source electrode driver 120 passes through source drive line S respectively with gate drivers (Gate Driver) 130
1～S
iWith gate driving line G
1～G
jCan drive each pixel cell 142 of display panel (DisplayPanel) 140 in regular turn.
Fig. 3 is the gray scale input data of Fig. 1 and the corresponding curve map of gamma output voltage, please merge with reference to figure 2 and Fig. 3, and the gray scale input data that the digital analog converter of source electrode driver 120 (not illustrating) utilization is received produce corresponding gamma output voltage.When gray scale input data are G
LnThe time, digital analog converter (not illustrating) can produce the gamma output voltage V
nBy that analogy, when the data input voltage be G
LmThe time, digital analog converter (not illustrating) then can produce the gamma output voltage V
m, V wherein
n～V
mThe corresponding V of difference
G1～V
GnOne of them.Gray scale input data are so-called gamma curve 150 with the corresponding curve of gamma output voltage, use making LCD 100 can present correct brightness.
Yet gamma curve 150 has just been set when LCD 100 is dispatched from the factory and has been finished.That is to say, along with the environment that uses not simultaneously, known LCD 100 also can't be adjusted gamma curve 150 thereupon.
In view of this, U.S. Patent application US20070085792A1 then proposes the outer group voltage source of adding of a kind of utilization in the gamma reference voltage source, and using each gamma reference voltage that series resistor produced that makes in the gamma reference voltage source can translation.This practice not only needs to set up voltage source, expends cost.In addition, only can make the translation in the lump of each gamma reference voltage, therefore can't change the gamma curve shape, its adjustment mode is very limited.
In addition, U.S. Patent application US20070085792A1 proposes a kind of selection control that utilizes same group of voltage source is coupled to wherein groups of organizing series resistors more, because the resistance ratio of many group series resistors is all inequality, therefore can produce different gamma curve.Yet this practice must dispose many group series resistors, not only needs to expend sizable cost, and can cause circuit area significantly to increase.In addition, one group of series resistor only can produce a kind of gamma curve.In other words, when display only disposes three groups of series resistors, then only can switch in three kinds of gamma curve, its adjustment mode is equally quite limited.
Summary of the invention
The invention provides a kind of grayscale voltage generation device, make the digital gray scale data can correctly correspond to its grayscale voltage.
The invention provides a kind of gamma reference voltage generation device and method thereof, use and elasticity to adjust gamma curve, and then promote display quality.
The present invention proposes a kind of grayscale voltage generation device, is used for display device, and this display device can show a plurality of gray scales.The grayscale voltage generation device comprises selected cell and grayscale voltage generator.Selected cell selects and is output as N second gamma reference voltage in order to receive M first gamma reference voltage from M first gamma reference voltage, wherein M, N are positive integer, and M is greater than N.Grayscale voltage generator couples selected cell, in order to foundation N second gamma reference voltage, produces a plurality of grayscale voltages.Wherein, display device utilizes above-mentioned grayscale voltage to show above-mentioned gray scale.
In one embodiment of this invention, selected cell comprises N change-over switch, be defined as in regular turn the 1st change-over switch, the 2nd change-over switch ... the N change-over switch.Each change-over switch comprises P input end, at least one control end and at least one output terminal.P input end be numbered in regular turn the 1st input end, the 2nd input end ... the P input end, the control end of above-mentioned change-over switch receives switching signal, an input end exports output terminal to make above-mentioned change-over switch select wherein respectively according to switching signal, and wherein i, P are positive integer, and i is less than N.
In one embodiment of this invention, the grayscale voltage generation device also comprises the divider resistance unit, couples voltage source.The divider resistance unit has a plurality of dividing points, in order to the first above-mentioned gamma reference voltage to be provided respectively.In another embodiment, the divider resistance unit comprises the series resistor unit, couples voltage source, uses first gamma reference voltage that provides above-mentioned.In another embodiment, the divider resistance unit comprises a plurality of series resistors unit, with and the mode that connects couple voltage source, use first gamma reference voltage that provides above-mentioned respectively, wherein each first gamma reference voltage differs from one another.
From another viewpoint, the invention provides a kind of gamma reference voltage generation device, be coupled to source electrode driver.The gamma reference voltage generation device comprises gamma reference voltage source, selected cell.The gamma reference voltage source is in order to provide M first gamma reference voltage.Selected cell is coupled to the gamma reference voltage source, and in order to N second gamma reference voltage of selection and output is to source electrode driver from M first gamma reference voltage, wherein M, N are positive integer, and M is greater than N.
From another viewpoint, the invention provides a kind of gamma reference voltage generation device and comprise divider resistance unit and selected cell.The divider resistance unit couples voltage source.The divider resistance unit has first dividing point and second dividing point, and first gamma reference voltage and second gamma reference voltage are provided respectively.Selected cell comprises first change-over switch.This first change-over switch couples first dividing point and second dividing point, receives first gamma reference voltage and second gamma reference voltage, and selects an output according to switching signal from each gamma reference voltage that is received of first change-over switch.
In one embodiment of this invention, the divider resistance unit also has one the 3rd dividing point, in order to the 3rd gamma reference voltage to be provided.In another embodiment, first switch unit couples the 3rd dividing point, receives the 3rd gamma reference voltage.In another embodiment, selected cell also comprises second change-over switch, couple second dividing point and the 3rd dividing point, receive second gamma reference voltage and the 3rd gamma reference voltage, and from each gamma reference voltage that second change-over switch is received, select an output according to switching signal.
In one embodiment of this invention, when first change-over switch was exported first gamma reference voltage, second change-over switch was then exported second gamma reference voltage.When first change-over switch was exported second gamma reference voltage, second change-over switch was then exported the 3rd gamma reference voltage.
In one embodiment of this invention, the divider resistance unit also has the 4th dividing point, in order to the 4th gamma reference voltage to be provided.In another embodiment, selected cell also comprises the 3rd change-over switch.The 3rd change-over switch couples the 3rd dividing point and the 4th dividing point, receives the 3rd gamma reference voltage and the 4th gamma reference voltage, and selects an output according to switching signal from each gamma reference voltage that the 3rd change-over switch is received.
In one embodiment of this invention, first switch unit couples the 3rd dividing point, receives the 3rd gamma reference voltage.In another embodiment, selected cell also comprises the 4th change-over switch.The 4th change-over switch couples second dividing point, the 3rd dividing point and the 4th dividing point, receive second gamma reference voltage, the 3rd gamma reference voltage and the 4th gamma reference voltage, and from each gamma reference voltage that is received of the 4th change-over switch, select an output according to switching signal.In another embodiment, when first change-over switch was exported first gamma reference voltage, the 4th change-over switch was then exported second gamma reference voltage.When first change-over switch was exported second gamma reference voltage, the 4th change-over switch was then exported the 3rd gamma reference voltage.When first change-over switch was exported the 3rd gamma reference voltage, the 4th change-over switch was then exported the 4th gamma reference voltage.
From a viewpoint again, the invention provides a kind of gamma reference voltage production method, comprise receiving M gamma reference voltage that wherein M is a positive integer.When receiving first switching signal, then from M gamma reference voltage, select N gamma reference voltage as first gamma curve, and with N gamma reference voltage output.In addition, when receiving second switching signal, then from M gamma reference voltage, select N gamma reference voltage as second gamma curve, and with N gamma reference voltage output, wherein N is a positive integer, and M is greater than N, and first gamma curve is different from second gamma curve.
The present invention selects from M gamma reference voltage and N gamma reference voltage of output by receiving M gamma reference voltage again, and wherein M, N are positive integer, and M is greater than N.Along with the mode difference of selecting N gamma reference voltage, gamma curve also can change thereupon.Therefore can adjust gamma curve adaptively, use the lifting image quality.
For above-mentioned feature and advantage of the present invention can be become apparent, several embodiment cited below particularly, and be described with reference to the accompanying drawings as follows.
Description of drawings
Fig. 1 is the synoptic diagram of known LCD.
Fig. 2 A and Fig. 2 B are a kind of gamma reference voltage source of Fig. 1 and the circuit diagram of source electrode driver.
Fig. 3 is the gray scale input data of Fig. 1 and the corresponding curve map of gamma output voltage.
Fig. 4 is the synoptic diagram according to a kind of LCD of the first embodiment of the present invention.
Fig. 5 A is according to a kind of gamma reference voltage of the first embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.
Fig. 5 B is the principle schematic according to three kinds of series resistor unit of the first embodiment of the present invention.
Fig. 5 C is the synoptic diagram according to three kinds of gamma curve of the first embodiment of the present invention.
Fig. 6 A is according to a kind of gamma reference voltage of the second embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.
Fig. 6 B is according to a kind of gamma reference voltage of the third embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.
Fig. 6 C is according to a kind of gamma reference voltage of the fourth embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.
Fig. 7 A～7C is according to a kind of gamma reference voltage of the fifth embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.
The reference numeral explanation
100,101: LCD
110,114,311～315: the gamma reference voltage source
112,116,512,612: resistance
120: source electrode driver
122,520: grayscale voltage generator
130: gate drivers
140: display panel
142: pixel cell
410: selected cell
411～418: change-over switch
510: series resistor unit or title divider resistance unit
610,710: the series resistor unit
S
1～S
i: the source drive line
G
1～G
j: the gate driving line
SW: switching signal
A～E: end points
L
1, L
1+, L
1-: gamma curve
P
1～P
17: dividing point
V
G1～V
Gn: grayscale voltage
AVDD: system voltage
V
GMA_1～V
GMA_N, V
GMA_1 '～V
GMA_M ', V
GMA_i '± Δ V
C ', V
GMA_j '± Δ V
C ', V
GMA_i '± Δ V
D ', V
GMA_j '± Δ V
D ', V
GMA_i '± Δ V
E ', V
GMA_j '± Δ V
E ': gamma reference voltage
Embodiment
Owing to also can't at random adjust gamma curve in the prior art, and its hardware cost is quite high.In view of this, embodiments of the invention utilize selected cell to receive M gamma reference voltage, select from M gamma reference voltage and N gamma reference voltage of output again, and wherein M, N are positive integer, and M can adjust gamma curve thus adaptively greater than N.With next be that example is done further explanation with the LCD.
For instance, Fig. 4 is the synoptic diagram according to a kind of LCD of the first embodiment of the present invention.Please refer to Fig. 4, in the present embodiment, LCD 101 has comprised gamma reference voltage source 110, selected cell 410, source electrode driver 120, gate drivers 130 and display panel 140.Wherein gate drivers 130 is similar with display panel 140 and prior art, it should be noted that gamma reference voltage source 110, selected cell 410 and source electrode driver 120.Gamma reference voltage source 110 provides M gamma reference voltage V
GMA_1 '～V
GMA_M '410 of selected cells can be from M gamma reference voltage V wherein
GMA_1 '～V
GMA_M 'The middle selection and N gamma reference voltage V of output
GMA_1～V
GMA_NFor convenience of description, in the present embodiment, M, N are that example describes with 17,8 respectively, but the present invention is not as limit.M, N can be any positive integer in other embodiments, and M is greater than N.Do further explanation at gamma reference voltage source 110, selected cell 410 with source electrode driver 120 with next.
Fig. 5 A is according to a kind of gamma reference voltage of the first embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.Please refer to Fig. 5 A, gamma voltage generating device has comprised gamma reference voltage source 110 and selected cell 410.From another angle, the grayscale voltage generation device has comprised selected cell 410 and grayscale voltage generator 520 again, and wherein grayscale voltage generator 520 is for example configurable in source electrode driver 120.A for example available divider resistance unit 510, gamma reference voltage source 110 is implemented.In the present embodiment, divider resistance unit 510 is to provide gamma reference voltage V with 18 resistance 512 respectively with serial arrangement
GMA_1 '～V
GMA_17 'Give dividing point P
1～P
17, gamma reference voltage V wherein
GMA_1 '～V
GMA_17 'Descending in regular turn arrangement.
Fig. 5 B is the principle schematic according to three kinds of series resistor unit of the first embodiment of the present invention.Please refer to Fig. 5 B.Divider resistance unit in the foregoing description (or claim series resistor unit) is though 510 implement with 18 resistance, 512 polyphones, but in other embodiments, those skilled in the art can be according to the voltage divider principle of Fig. 5 B, resistance with varying number is realized divider resistance unit 510, uses the dividing potential drop that varying number is provided.For instance, the voltage of supposing terminal A, B is respectively V
GMA_i ', V
GMA_j 'When divider resistance unit 510 was implemented with two resistance serial connections, the voltage of end points C then was V
GMA_i '± Δ V
C 'Or V
GMA_j '± Δ V
C 'By that analogy, when divider resistance unit 510 was implemented with three resistance serial connections, the voltage of end points D then was V
GMA_i '± Δ V
D 'Or V
GMA_j '± Δ V
D ', the voltage of end points E then is V
GMA_i '± Δ V
E 'Or V
GMA_j '± Δ V
E '
Refer again to Fig. 5 A, selected cell 410 for example has change-over switch 411～418.Change-over switch 411～418 has 3 input ends, a control end and an output terminal respectively in the present embodiment.In more detail, change-over switch 411 can be from gamma reference voltage V according to switching signal SW
GMA_1 '～V
GMA_3 'One of them also exports middle selection as V
GMA_1In like manner, change-over switch 412 can be from gamma reference voltage V
GMA_3 '～V
GMA_5 'One of them also exports middle selection as V
GMA_2Change-over switch 413～418 by that analogy, then repeat no more at this.Grayscale voltage generator 520 then can be according to gamma reference voltage V
GMA_1～V
GMA_8And generation grayscale voltage, for example V
G1～V
G64, it is corresponding grey scale data G respectively
L1～G
L64101 of LCD are to utilize grayscale voltage V
G1～V
G64With display gray scale data G
L1～G
L64
Fig. 5 C is the synoptic diagram according to three kinds of gamma curve of the first embodiment of the present invention.Please merge with reference to figure 4, Fig. 5 A and Fig. 5 C.Switching signal SW can be used to control its switch 411～418 selected input ends.In the present embodiment, switching signal SW can synchronous control its switch 411～418 select the input end of same numbering as output terminal.Suppose that when original state change-over switch 411 can be selected gamma reference voltage V
GMA_2 ', change-over switch 412 can be selected gamma reference voltage V
GMA_4 ', 413 of change-over switches can be selected gamma reference voltage V
GMA_6 ', change-over switch 414～418 selected each gamma reference voltage do not repeat them here by that analogy, and this moment, gamma curve was L1.
When LCD 101 because of environmental factor or other factors, when making the picture deepening that display panel 140 presented, can change-over switch 411 be switched to gamma reference voltage V by switching signal SW
GMA_1 ', change-over switch 412 can switch to character used in proper names and in rendering some foreign names agate gamma reference voltage V simultaneously
GMA_3 ', change-over switch 413 then can switch to gamma reference voltage V
GMA_5 ', 414～418 of change-over switches switch to each gamma reference voltage by that analogy, do not repeat them here, and this moment, gamma curve then can be changed into L
1+.Thus, the picture recovery that display panel 140 is presented is normal.
On the other hand, when LCD 101 because of environmental factor or other factors, when the picture that makes display panel 140 be presented brightens, also can change-over switch 411 be switched to gamma reference voltage V by switching signal SW
GMA_3 ', change-over switch 412 can switch to gamma reference voltage V simultaneously
GMA_5 ', change-over switch 413 then can switch to gamma reference voltage V
GMA_7 ', each gamma reference voltage of being switched of change-over switch 414～418 does not repeat them here by that analogy, and this moment, gamma curve then can be changed into L
1-.Thus, the picture recovery that display panel 140 is presented is normal.Therefore whether present embodiment can bright partially or dark partially according to the picture that display panel 140 is presented, and utilizes switching signal SW that picture is adjusted into normal condition.
Yet though switching signal SW is with synchro control change-over switch 411～418 in the present embodiment, the input end that makes its selection have identical numbering is an example, in other embodiments.Also can utilize a plurality of switching signals to control each change-over switch respectively.For instance, utilize switching signal SW1～SW8 control its switch 411～418 selected input ends respectively.Thus, gamma curve then can have 3
8Plant and change.
Moreover, though change-over switch 411～418 is that example describes to have 3 input ends respectively in the present embodiment, in other embodiments, Ben Lin and technician also can change 411～418 quantity with input end of change-over switch.For instance, change-over switch 411～418 has 5 input ends respectively, and gamma curve then can have 5 thus
8Plant and change.In addition, each change-over switch also can have the input end of varying number certainly.For instance, change-over switch 411～418 has 2～9 input ends respectively, and thus, gamma curve then can have 2 * 3 * ... * 9 kinds of variations.
In addition, also visual its demand of those skilled in the art changes the quantity of switch unit.For instance, when the quantity of change-over switch becomes 64 and it has 3 input ends respectively, and can control each change-over switch by switching signal respectively.Gamma curve then can have 3 thus
64Plant and change.
Moreover it is fixed value that those skilled in the art also can provide the part gamma voltage, only makes the changeable selection of gamma voltage of part.For instance, the change-over switch among Fig. 5 A 411 and 412 can be omitted, with gamma reference voltage V
GMA_2 'As V
GMA_1, with gamma reference voltage V
GMA_4 'As V
GMA_2In addition, system voltage AVDD and gamma reference voltage V
GMA_2 'Between two resistance 512 can merge into a resistance, gamma reference voltage V
GMA_2 'With gamma reference voltage V
GMA_4 'Between two resistance 512 also can merge into a resistance.Thus, those skilled in the art then can only adjust at the part section of gamma curve, but also can reduce hardware cost, have for example saved two resistance and two change-over switches.For the advantage that makes embodiments of the invention is more obvious, embodiments of the invention and known technology are done one relatively with next.
In the known technology, U.S. Patent application US20070085792A1 adjusts gamma curve by the system voltage of setting up many groups, not only make gamma voltage produce skew easily but also need set up the system voltages of organizing more also need spend more costs, and only can make the translation in the lump of each gamma reference voltage.U.S. Patent application US20070085792A1 utilizes selection control that same group system voltage is coupled to wherein groups of organizing series resistors more in addition, not only must configuration organize series resistors more, and need expend sizable cost, and can cause circuit area significantly to increase.
Accept above-mentionedly, with in comparison known, present embodiment need not change under the situation of system voltage AVDD, and only utilizes a series resistor unit and a selected cell to adjust gamma curve adaptively, makes gamma curve that quite multiple variation can be arranged.Because system voltage AVDD is a fixed value in the present embodiment, the situation that does not therefore have variation takes place.In addition, what deserves to be mentioned is that the change-over switch in the selected cell can utilize transistor to implement, its cost is not only cheap but also circuit area is also quite little, so present embodiment not only can significantly be saved hardware cost but also can have more and flexibly adjusts gamma curve.
What deserves to be mentioned is, though gamma reference voltage generation device and method thereof and grayscale voltage generation device have been depicted a possible kenel in the foregoing description, but those skilled in the art should know, each manufacturer is all different for the design of gamma reference voltage generation device and method and grayscale voltage generation device, and therefore application of the present invention is when being not restricted to the possible kenel of this kind.In other words, so long as receive M gamma reference voltage, select from M gamma reference voltage and export N gamma reference voltage, wherein M, N are positive integer, and M uses the adjustment gamma curve greater than N, have been to have met spiritual place of the present invention just.Below again for several embodiment so that those skilled in the art can further understand spirit of the present invention, and implement the present invention.
Fig. 6 A is according to a kind of gamma reference voltage of the second embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.Please merge with reference to figure 5A and Fig. 6 A, the source electrode driver 120 of Fig. 6 A and selected cell 410 and Fig. 5 category-A seemingly do not repeat them here.It should be noted that, switch unit 411～418 has first input end and second input end respectively in the present embodiment, and first input end of second input end of change-over switch 411 and change-over switch 412 is coupled to same gamma reference voltage, second input end of change-over switch 412 and first input end of change-over switch 413 are coupled to same gamma reference voltage, by that analogy ...In addition, series resistor unit 610 has only used 10 resistance 612 in the present embodiment.Suppose that when original state change-over switch 411 can be selected gamma reference voltage V
GMA_1 ', change-over switch 412 can be selected gamma reference voltage V
GMA_2 ', 413 of change-over switches can be selected gamma reference voltage V
GMA_3 ', change-over switch 414～418 selected each gamma reference voltage by that analogy.
When LCD 101 because of environmental factor or other factors, when the picture that makes display panel 140 be presented brightens, can change-over switch 411 be switched to gamma reference voltage V by switching signal SW
GMA_2 ', change-over switch 412 can switch to gamma reference voltage V simultaneously
GMA_3 ', change-over switch 413 then can switch to gamma reference voltage V
GMA_4 ', 414～418 of change-over switches switch to each gamma reference voltage by that analogy, do not repeat them here.Thus, the picture recovery that display panel 140 is presented is normal.In addition, present embodiment not only can be kept the shape of gamma curve originally, simplifies the circuit that couples of change-over switch 412, also can reduce the quantity of resistance 612.
From another angle, Fig. 6 B is according to a kind of gamma reference voltage of the third embodiment of the present invention and the synoptic diagram of grayscale voltage generation device again.Please merge with reference to figure 6A and Fig. 6 B, the source electrode driver 120 of Fig. 6 B, selected cell 410 and gamma reference voltage source 311 and Fig. 6 category-A seemingly do not repeat them here.It should be noted that hypothesis is when original state in the present embodiment, change-over switch 411 can be selected gamma reference voltage V
GMA_2 ', change-over switch 412 can be selected gamma reference voltage V
GMA_3 ', 413 of change-over switches can be selected gamma reference voltage V
GMA_4 ', change-over switch 414～418 selected each gamma reference voltage by that analogy.
When LCD 101 because of environmental factor or other factors, when making the picture deepening that display panel 140 presented, can change-over switch 411 be switched to gamma reference voltage V by switching signal SW
GMA_1 ', change-over switch 412 can switch to gamma reference voltage V simultaneously
GMA_2 ', change-over switch 413 then can switch to gamma reference voltage V
GMA_3 ', 414～418 of change-over switches switch to each gamma reference voltage by that analogy, do not repeat them here.Thus, not only the picture recovery that display panel 140 is presented is normal, also can realize the effect similar with the foregoing description.
Those skilled in the art can change the Organization Chart of gamma reference voltage and grayscale voltage generation device according to spirit of the present invention, and for example Fig. 6 C is according to a kind of gamma reference voltage of the fourth embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.In the present embodiment, label person same as the previously described embodiments can be with reference to the embodiment of the foregoing description.It should be noted that gamma reference voltage source 312, in the present embodiment selected cell 410 is integrated in the source electrode driver 120, and gamma reference voltage source 312 middle part sub-resistances 612 are changed into be disposed in the source electrode driver 120.So the practice also can realize the effect similar with the foregoing description.
In addition, those skilled in the art can change the Organization Chart of grayscale voltage generation device according to spirit of the present invention, and for example Fig. 7 A～7C is according to a kind of gamma reference voltage of the fifth embodiment of the present invention and the synoptic diagram of grayscale voltage generation device.In the present embodiment, label person same as the previously described embodiments can be with reference to the embodiment of the foregoing description.Gamma reference voltage source 313～315 that it should be noted that Fig. 7 A～7C is connected in parallel with multi-form a plurality of series resistors unit 710 respectively, and different gamma reference voltages is provided respectively.In more detail, each series resistor unit 710 is to utilize the resistance string of varying number to be connected together or be connected together with the resistance string of different resistances to use the gamma reference voltage that provides different.So the practice also can realize the effect similar with the foregoing description.
Though only be example in the foregoing description with the LCD, but in other embodiments, also spirit of the present invention can be applied to dissimilar displays, for example the display of Organic Light Emitting Diode (being called for short OLED) or Thin Film Transistor-LCD (being called for short TFTLCD).
In sum, the present invention receives M gamma reference voltage, selects from M gamma reference voltage and N gamma reference voltage of output again, and wherein M, N are positive integer, and M can adjust gamma curve thus adaptively greater than N.All embodiment of the present invention in addition have following advantage at least:
Utilize a switching signal to control change-over switches all in the selected cell simultaneously, can simplify the complexity of control, use the rapid adjustment gamma curve.
Utilize a plurality of switching signals to control change-over switch in the selected cell respectively, can have more and flexibly adjust gamma curve.
Utilize a plurality of change-over switches, use and select different gamma reference voltages, and the part gamma reference voltage is fixed, can flexibly adjust the part section of gamma curve.
The gamma reference voltage source utilizes one group of series resistor unit that a plurality of gamma reference voltages that differ from one another can be provided, and saves circuit area and cost significantly.
Under the situation that system voltage is fixed, utilize selected cell to switch the purpose that different gamma reference voltages can realize adjusting gamma curve, cause the situation of variation to take place and do not have because of changing system voltage.
Can promote the possibility of the variation of gamma curve by the input end quantity that increases change-over switch.
By increasing the resistance quantity of series resistor unit, can provide the how different selective unit of gamma reference voltage to select output, therefore also can promote the possibility of the variation of gamma curve.
Can promote the possibility of the variation of gamma curve by the quantity that increases change-over switch.
Though the present invention discloses as above with several embodiment; right its is not in order to qualification the present invention, those skilled in the art, under the premise without departing from the spirit and scope of the present invention; when can doing a little change and modification, so protection scope of the present invention should be as the criterion with claim of the present invention.
Claims (12)
1. a grayscale voltage generation device is used for a display device, and this display device can show a plurality of gray scales, and this grayscale voltage generation device comprises:
One selected cell in order to receive M first gamma reference voltage, is selected from described first gamma reference voltage and N second gamma reference voltage of output, and wherein M, N are positive integer, and M is greater than N; And
One grayscale voltage generator couples this selected cell, in order to according to described second gamma reference voltage, produces a plurality of grayscale voltages, and wherein, this display device utilizes described grayscale voltage to show described gray scale;
Wherein this selected cell comprises N change-over switch, be defined as the 1st change-over switch in regular turn, the 2nd change-over switch, ... the N change-over switch, each change-over switch comprises P input end, one control end and an output terminal, described input end is numbered the 1st input end in regular turn, the 2nd input end, ... the P input end, described input end receives the one of described M first gamma reference voltage respectively, this control end of described change-over switch receives one and switches signal, an input end exports this output terminal to make described change-over switch select wherein respectively according to this switching signal, and wherein P is a positive integer.
2. grayscale voltage generation device as claimed in claim 1, this grayscale voltage generation device wherein also comprises:
One divider resistance unit couples a voltage source, and this divider resistance unit has a plurality of dividing points, in order to described first gamma reference voltage to be provided respectively.
3. grayscale voltage generation device as claimed in claim 2, this divider resistance unit wherein comprises:
One series resistor unit couples this voltage source, and using provides described first gamma reference voltage.
4. grayscale voltage generation device as claimed in claim 2, this divider resistance unit wherein comprises:
A plurality of series resistors unit, with and the mode that connects couple this voltage source, use described first gamma reference voltage be provided respectively, wherein respectively this first gamma reference voltage differs from one another.
5. a gamma reference voltage generation device is coupled to the one source pole driver, and this gamma reference voltage generation device comprises:
One gamma reference voltage source is in order to provide M first gamma reference voltage; And
One selected cell is coupled to this gamma reference voltage source, in order to from described first gamma reference voltage, select and N second gamma reference voltage of output to this source electrode driver, wherein M, N are positive integer, and M is greater than N;
Wherein this selected cell comprises N change-over switch, be defined as the 1st change-over switch in regular turn, the 2nd change-over switch, ... the N change-over switch, each change-over switch comprises P input end, a control end and an output terminal, described input end is numbered the 1st input end in regular turn, the 2nd input end, ... the P input end, described input end receives the one of described M first gamma reference voltage respectively, this control end of described change-over switch receives one and switches signal, an input end exports this output terminal to make described change-over switch select wherein respectively according to this switching signal, and P is a positive integer.
6. grayscale voltage generation device as claimed in claim 5, this gamma reference voltage generation device wherein also comprises:
One divider resistance unit couples a voltage source, and this divider resistance unit has a plurality of dividing points, in order to described first gamma reference voltage to be provided respectively.
7. gamma reference voltage generation device as claimed in claim 6, this divider resistance unit wherein comprises:
One series resistor unit couples this voltage source, and using provides described first gamma reference voltage.
8. gamma reference voltage generation device as claimed in claim 6, this divider resistance unit wherein comprises:
A plurality of series resistors unit, with and the mode that connects couple this voltage source, use described first gamma reference voltage be provided respectively, wherein respectively this first gamma reference voltage differs from one another.
9. gamma reference voltage generation device comprises:
One divider resistance unit couples a voltage source, and this divider resistance unit has M dividing point, and M first gamma reference voltage is provided respectively; And
One selected cell comprises:
N change-over switch, each change-over switch comprises P input end, control end and an output terminal, described input end be numbered in regular turn the 1st input end, the 2nd input end ... the P input end couples the one of M dividing point respectively, switch signal according to one and make described change-over switch select an output respectively from the described gamma reference voltage that is received, wherein P is a positive integer.
10. gamma reference voltage generation device as claimed in claim 9, this divider resistance unit wherein comprises:
One series resistor unit couples this voltage source, and using provides described gamma reference voltage.
11. gamma reference voltage generation device as claimed in claim 9, this divider resistance unit wherein comprises:
A plurality of series resistors unit, with and the mode that connects couple this voltage source, using provides respectively this gamma reference voltage respectively, wherein respectively this gamma reference voltage differs from one another.
12. a gamma reference voltage production method comprises:
Receive M gamma reference voltage, wherein M is a positive integer;
When receiving one first switching signal, then P gamma reference voltage from M gamma reference voltage selected the one of one as N gamma reference voltage respectively, uses N gamma reference voltage of output as one first gamma curve, and wherein P is a positive integer; And
When receiving one second switching signal, then P gamma reference voltage from M gamma reference voltage selected the one of one as N gamma reference voltage respectively, use N gamma reference voltage of output as one second gamma curve, wherein N is a positive integer, and M is greater than N, and this first gamma curve is different from this second gamma curve.
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| CN2007101417765A CN101373583B (en) | 2007-08-21 | 2007-08-21 | Device and method for generating gamma reference voltage and apparatus for generating grayscale voltage |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2007101417765A CN101373583B (en) | 2007-08-21 | 2007-08-21 | Device and method for generating gamma reference voltage and apparatus for generating grayscale voltage |
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| CN101373583A CN101373583A (en) | 2009-02-25 |
| CN101373583B true CN101373583B (en) | 2010-08-25 |
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| CN102682715B (en) * | 2012-04-26 | 2014-07-09 | 京东方科技集团股份有限公司 | Gray scale voltage generating circuit and method, source driver IC and liquid crystal display (LCD) device |
| CN103021365B (en) * | 2012-12-14 | 2015-01-21 | 京东方科技集团股份有限公司 | Device and method for adjusting gamma curve and liquid crystal display device |
| CN103295506B (en) | 2013-05-31 | 2016-03-16 | 京东方科技集团股份有限公司 | Gamma curve method of adjustment and gamma curve adjusting gear |
| CN104123919B (en) * | 2013-07-19 | 2017-10-13 | 深超光电（深圳）有限公司 | Liquid crystal display device and display device |
| KR102081128B1 (en) * | 2013-12-13 | 2020-02-25 | 엘지디스플레이 주식회사 | Driving circuit |
| TWI517120B (en) * | 2014-04-24 | 2016-01-11 | 瑞鼎科技股份有限公司 | Source driving circuit and resistor renormalization method |
| CN104409048B (en) * | 2014-12-19 | 2018-01-02 | 二十一世纪（北京）微电子技术有限公司 | Source electrode drive circuit, grayscale voltage generation circuit and display device |
| US9772756B2 (en) * | 2015-06-01 | 2017-09-26 | Novatek Microelectronics Corp. | Display driver and method for adjusting color temperature of image |
| CN110379396B (en) * | 2019-06-17 | 2022-03-25 | 北京集创北方科技股份有限公司 | Gamma voltage generation method, generation circuit, source electrode driving circuit, driving chip and display device |
| CN110473492B (en) * | 2019-08-28 | 2021-01-26 | 上海灵信视觉技术股份有限公司 | Dynamic nonlinear display adjustment method, system and device for LED full-color display screen |
| CN114627801B (en) * | 2022-02-17 | 2023-09-26 | Tcl华星光电技术有限公司 | Pixel circuit and display panel |
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| CN1759434A (en) * | 2003-02-03 | 2006-04-12 | 夏普株式会社 | Liquid crystal display |
| JP2006285255A (en) * | 2005-03-30 | 2006-10-19 | Samsung Electronics Co Ltd | Liquid crystal display |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1759434A (en) * | 2003-02-03 | 2006-04-12 | 夏普株式会社 | Liquid crystal display |
| JP2006285255A (en) * | 2005-03-30 | 2006-10-19 | Samsung Electronics Co Ltd | Liquid crystal display |
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