CN101290756B - Gamma voltage generating device, liquid crystal display device and method for controlling gamma voltage - Google Patents
Gamma voltage generating device, liquid crystal display device and method for controlling gamma voltage Download PDFInfo
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Abstract
A gamma voltage generator is used in a liquid display device and comprises a voltage division circuit coupled between a first voltage and a second voltage and used to generate a gamma voltage, wherein the voltage division circuit comprises a zero order gamma voltage output end of the gamma voltage used to output liquid crystal pixel unit zero order gray scale as well as a voltage division element connected in series inside the voltage division circuit; and both end parts of the voltage division element are respectively connected with the zero order gamma voltage output end through a switching element. The invention also provides a method and a liquid crystal display device for controlling the gamma voltage. The gamma voltage generator not only can increase liquid crystal response time, but also ensures that liquid crystal has better image display effect.
Description
Technical field
The present invention relates to the liquid crystal technology field, particularly the method for a kind of generation device of gamma voltage, liquid crystal indicator and control gamma voltage.
Background technology
The GTG performance of LCD is what to be managed by the source electrode driver of display interior.So-called " GTG " is meant the rank of brightness, and each point of being seen on liquid crystal display equipment screen is a pixel, and it is made up of three sub-pixels of red, green, blue (RGB), and the different gray scales that each sub-pixel demonstrates are exactly " GTG ".Realize the variation of picture color, just must make the control of different shading values respectively, to mix different colors to three sub-pixels of RGB.For example, the 6bit panel, wherein " 6bit " just represents that each sub-pixel can show the brightness of 6 a powers different stage of 2, is referred to as 64 GTGs.If so each sub-pixel R, G, B control with 6 bit binary data respectively, each pixel just can access 64 * 64 * 64 grades of gray scales, can show 262,144 kinds of colors.And the 8bit panel can show 28 powers, equals 256 luminance levels, just is referred to as 256 GTGs, and then the maximum color number of each pixel energy performance is 256 * 256 * 256=16777216 kind color.GTG is overstepping the bounds of propriety bright, and panel picture displayed color is just abundant more, and picture is also just true to nature more.
GTG is to control turning to of liquid crystal molecule by the source electrode driver of LCD by the voltage difference on the control layer glass to realize, and voltage difference is the signal controlling exported on the source electrode driver by LCD.At present the method for the realization GTG of main flow has two kinds, be respectively width modulation (Pulse Width Modulation, PWM) and Frame-rate Control (Frame Rate Control, FRC).Width modulation is to be divided into several timeslices in the time at single pass.Frame-rate Control is that each timeslice has become a subframe, shows 64 grades of gray scales, will use 64 subframes so.At first will distinguish the notion of subframe (subframe), frame frequency is meant the number of times of the full frame data of second interscan, and in order to realize FRC, a frame is divided into some subframes.Because the visual effect of human eye feels that the brightness that is adding up of all subframes.
Because human eye can't disappear along with the disappearance of object brightness immediately to brightness sensation, but after a period of time, just disappear, utilized the such physiological property of visual persistence of human eye, adopt suitable Frame-rate Control, add the color between the consecutive frame is carried out certain control, people are when watching LCD screen like this, and what see is color between this consecutive frame.
Therefore, 6 (6bit) source electrode drivers are totally 64 GTGs, simulate 8bit totally 256 GTGs by FRC (Frame-rate Control method) in the mode of emulation, can improve picture color GTG and performance.
Fig. 1 is the block diagram of generation device, source electrode driver, display panels and the gate drivers annexation of existing gamma voltage.As shown in Figure 1, voltage is adjusted in source electrode driver (or being called data driver) 14 inputs that the generation device 16 of gamma voltage is used for to liquid crystal indicator, the GTG of described source electrode driver 14 control display panels 12, gate drivers 10 is connected with described display panels 12, is used for the pixel of gating display panels.
Fig. 2 is the circuit diagram of the generation device of gamma voltage shown in Figure 1, zone of positive pressure that Fig. 3 produces for the circuit of Fig. 2 and negative pressuren zone are (because the signal of the control liquid crystal panel of source electrode driver output is an alternating signal, thereby, need the different gamma voltage of positive-negative polarity.) oscillogram of gamma voltage.As shown in Figure 2, the resistance string of the generation device 16 of gamma voltage directly is connected with the resistance string of source electrode driver 14 on the pcb board A side; As shown in Figure 3, the zone of positive pressure and the negative pressuren zone L0 gamma voltage of generation device 16 outputs of gamma voltage are respectively V00P and V00N, the output waveform figure of corresponding source electrode driver as shown in Figure 4, TP is the control output signal sequential chart of source electrode driver, CLK is a gate driving clock signal sequential chart, KW is the output waveform figure of square wave signal generator, and L0+ and L0-represent the voltage oscillogram of the source electrode driver output of positive gamma voltage and negative gamma voltage respectively, and VCOM is a public electrode voltages.
But the interference meeting was more serious when the interference, particularly aanalogvoltage that these grey menu of coming by FRC produce some pictures because of complicated digital-to-analog conversion meeting differed bigger.Now, usually apply big black voltage in dark attitude and improve liquid crystal by the response time of non-zero GTG to the zero level gray scale variation, as illustrated in Figures 5 and 6, when voltage during from 0V to 1.4V, the brightness transmitance is basic identical, cause and to make thus that greater than 1.4V the gamma pressure reduction of the gray level L1 that L0 (complete black) is adjacent with it is very big by the voltage VL0-L1 from full grey black rank L0 (or being called the zero level GTG) to next GTG L1 (or being called the one-level GTG), cause the FRC serious interference.If but the gamma voltage that just reduces L0 reduces the pressure reduction of the gray level L1 that L0 is adjacent, then can cause the liquid crystal response time slack-off.
Summary of the invention
The invention provides a kind of method of generation device, liquid crystal indicator and control gamma voltage of gamma voltage, in order to improve liquid crystal response speed and to reduce picture and disturb.
According to an aspect of the present invention, the invention provides a kind of generation device of gamma voltage, be used for liquid crystal indicator, it comprises and is coupled to bleeder circuit between first voltage and second voltage, that be used to produce gamma voltage, described bleeder circuit comprises the zero level gamma voltage output terminal of gamma voltage when being used to export liquid crystal pixel cells zero level GTG, is series at the sectional pressure element in the described bleeder circuit; Described on-off element is a single-way switch, comprises first on-off element that is connected with an end of described sectional pressure element and the second switch element that is connected with another end of described sectional pressure element; Described first on-off element and second switch element are coupled to square wave signal generator; Wherein, described square wave signal generator is used to produce square-wave signal and controls described first on-off element and second switch element; The gate driving clock signal of the rising edge of described square-wave signal and the thin film transistor (TFT) of described liquid crystal indicator and the control output signal of source electrode driver are synchronous, and the duration of the high level of described square-wave signal is by the response characteristic decision of liquid crystal; When described square-wave signal is high level, trigger the described first on-off element closure, and control described second switch element and disconnect, make described zero level gamma voltage output terminal export the first zero level gamma voltage, when described square-wave signal is low level, control described zero level gamma voltage output terminal and export the second zero level gamma voltage, wherein the second zero level gamma voltage is less than the first zero level gamma voltage.
According to a further aspect in the invention, the present invention also provides a kind of liquid crystal indicator with generation device of above-mentioned gamma voltage.
In accordance with a further aspect of the present invention, the invention provides a kind of method of controlling gamma voltage, it is applied to have in the liquid crystal indicator of source electrode driver, described liquid crystal indicator has the pixel cell of a non-zero order GTG at least, described method comprises to described source electrode driver imports the first zero level gamma voltage, so that described source electrode driver applies tertiary voltage to the pixel cell of non-zero order GTG; Behind the elapsed-time standards Trt, to the second zero level gamma voltage of described source electrode driver input less than the first zero level gamma voltage, so that described source electrode driver applies the 4th voltage less than tertiary voltage to described pixel cell, wherein, described time T rt is the response time of described pixel cell when tertiary voltage.
Compared with prior art, one of them of technique scheme has the following advantages at least:
By in the generation device of gamma voltage with bleeder circuit, the series connection sectional pressure element, and two ends of described sectional pressure element are connected with described zero level gamma voltage output terminal by on-off element respectively, make described zero level gamma voltage output terminal can select two ends of one the described sectional pressure element of connection by on-off element, thereby can export the voltage of two ends of described sectional pressure element respectively, be that zero level gamma voltage output terminal can be exported two different magnitudes of voltage, when the needs high voltage improves the liquid crystal pixel cells response speed, can pass through on-off element, make described zero level gamma voltage output terminal be connected with the end of described sectional pressure element high voltage, and when the needs low voltage reduces interference, can make described zero level gamma voltage output terminal be connected by described on-off element once more with the end of described sectional pressure element low voltage, thereby can either improve response speed, can reduce picture again and disturb.
Description of drawings
Fig. 1 is the block diagram of generation device, source electrode driver, display panels and the gate drivers annexation of existing gamma voltage;
Fig. 2 is the circuit diagram of the generation device of gamma voltage shown in Figure 1;
Fig. 3 is the zone of positive pressure that produces of the device of Fig. 2 and the oscillogram of negative pressuren zone gamma voltage;
Fig. 4 puts on the voltage oscillogram of source electrode driver output behind the source electrode driver for the gamma voltage of Fig. 1;
Fig. 5 is a kind of symmetrical voltage-transmittance family curve of liquid crystal material;
Fig. 6 is the partial enlarged drawing of Fig. 5;
Fig. 7 is the synoptic diagram of generation device of the gamma voltage of the embodiment of the invention;
Fig. 8 is the oscillogram of the zone of positive pressure and the negative pressuren zone gamma voltage of embodiments of the invention;
Fig. 9 to Figure 13 inputs to the oscillogram of source electrode driver output behind the source electrode driver for the gamma voltage of the generation device of gamma voltage of the present invention.
Embodiment
Below in conjunction with accompanying drawing the specific embodiment of the present invention is described in detail.
A lot of details have been set forth in the following description so that fully understand the present invention.But the present invention can implement much to be different from alternate manner described here, and those skilled in the art can do similar popularization under the situation of intension of the present invention, so the present invention is not subjected to the restriction of following public concrete enforcement.
Voltage is adjusted in source electrode driver (or being called data driver) input that the generation device of gamma voltage is used for to liquid crystal indicator, so that the view data of input pixel cell is done an adjustment, make adjusted data can drive liquid crystal pixel cells and present different GTGs.
Yet, because the liquid crystal molecule in the liquid crystal pixel cells has certain response time, (or be called full grey black rank by the non-zero order GTG to the zero level GTG at pixel cell, the i.e. full GTG of correspondence when light tight of this pixel cell) when refreshing, need apply big voltage, this makes that the zero level GTG gamma voltage difference corresponding with follow-up one-level GTG is bigger, and the liquid crystal indicator picture displayed that bigger gamma voltage missionary society causes pixel cell to be formed produces interference, image quality reduction.And reduction non-zero order GTG puts on the voltage of liquid crystal pixel cells when the zero level GTG is changed, though the gamma voltage in the time of can reducing the conversion of zero level GTG and follow-up one-level GTG is poor, reduce and disturb, but but make liquid crystal pixel cells slack-off by the response time of non-zero order GTG when the zero level GTG is changed.
The invention provides a kind of generation device of gamma voltage, can either when the zero level GTG is changed, improve the response time of liquid crystal, can reduce the interference of zero level GTG when follow-up one-level GTG is changed again at the non-zero order GTG.The generation device of gamma voltage provided by the invention, comprise and be coupled to first voltage and second voltage (wherein, herein and this instructions " first " and " second " and " the 3rd " and " the 4th " mentioned in describing below just to difference, be not order of representation) between the bleeder circuit that is used to produce gamma voltage, described bleeder circuit has a plurality of output terminals, be used to export different gamma voltage corresponding to the different GTGs of liquid crystal pixel cells, wherein, comprise a zero level gamma voltage output terminal at least.This zero level gamma voltage output terminal is used for the gamma voltage when liquid crystal pixel cells provides the zero level GTG.In addition, described gamma voltage generating device also comprises the sectional pressure element that is series in the described bleeder circuit, and two ends of described sectional pressure element are connected with described zero level gamma voltage output terminal by on-off element respectively.
That is to say, described zero level gamma voltage output terminal can be selected two ends of one the described sectional pressure element of connection by on-off element, thereby can export the voltage of two ends of described sectional pressure element respectively, be that zero level gamma voltage output terminal can be exported two different magnitudes of voltage, when the needs high voltage improves the liquid crystal pixel cells response speed, can pass through on-off element, make described zero level gamma voltage output terminal be connected with the end of described sectional pressure element high voltage, and when the needs low voltage reduces interference, can make described zero level gamma voltage output terminal be connected by described on-off element once more with the end of described sectional pressure element low voltage.Thereby the generation device by gamma voltage of the present invention can either improve response speed, can reduce picture again and disturb.
Wherein, described bleeder circuit is coupled between first voltage and second voltage, the voltage difference dividing potential drop that is used for first voltage and second voltage is a plurality of voltages, these a plurality of voltages are used for providing liquid crystal pixel cells needed gamma voltage to source electrode driver by the different node outputs of described bleeder circuit.
Be that the situation of a plurality of divider resistances of being cascaded is described in detail the generation device of gamma voltage of the present invention as embodiment with described bleeder circuit below; need to prove; below the embodiment that only describes for a more clear understanding of the present invention of many details introduce, it should not constitute the restriction to the protection domain of claim of the present invention.Should recognize that the present invention's technical scheme required for protection is not limited to the description of following embodiment, it can also be realized by being different from the alternate manner that describes below.
In the present embodiment, bleeder circuit comprises first circuit 16a that produces positive gamma voltage and the second circuit 16b that connects with the described first circuit 16a, produce negative gamma voltage, please refer to Fig. 7.Described first circuit 16a and second circuit 16b are formed by a plurality of divider resistances of connecting.Wherein, two of sectional pressure elements are series at respectively among described first circuit 16a and the second circuit 16b, and described first circuit 16a and second circuit 16b are cascaded.The described first circuit 16a is used for the opposite gamma voltage of polarization with second circuit 16b, because the first circuit 16a is identical with the structure of second circuit 16b, thereby, be that example describes only in the following description with the first circuit 16a, description wherein also goes for second circuit 16b.
Please refer to Fig. 7, the described first circuit 16a comprises a plurality of divider resistance R1, R2, R3, R4...... that are cascaded, described divider resistance is cascaded, one end connects direct supply V33 (i.e. first voltage), the other end and described second circuit 16b are cascaded (being that resistance among the described first circuit 16a and the resistance among the described second circuit 16b are cascaded), the other end ground connection of described second circuit 16b (i.e. second voltage).
Please continue with reference to figure 7, the node between per two divider resistances is exported described gamma voltage.For example, node output gamma voltage V00P between divider resistance R1 and the R2, node output gamma voltage V01P between divider resistance R2 and the R3, the other gamma voltage V10P of node output between divider resistance R3 and the R4, ... enumerate no longer one by one here, in a word, divider resistance is cascaded, and exports gamma voltage at the node of divider resistance series connection as required.
Since the dividing potential drop effect of divider resistance, the voltage difference of exporting between the different nodes, and the voltage of output can be respectively as zero level gamma voltage, one-level gamma voltage ....
Certainly, the described first circuit 16a can also comprise other dividing potential drop components and parts, perhaps is made up of other components and parts; In addition, as long as can be as required, the circuit that the voltage of direct current is decomposed into a plurality of different voltages can be the first circuit 16a of the present invention, gives unnecessary details no longer in detail here.
The number of the magnitude of voltage of the gamma voltage of each grade of the number of wherein said divider resistance and the concrete needs of the resistance value of each divider resistance basis and the gamma voltage of needs is relevant, those skilled in the art can set the number of divider resistance and the resistance of each divider resistance according to actual needs, are not described in detail here.
In the described first circuit 16a, also be in series with sectional pressure element R6.Wherein, the sectional pressure element R6 described in the present embodiment is a divider resistance.Described sectional pressure element R6 is series between the divider resistance R1 and R2 of the first circuit 16a.Two ends of described sectional pressure element R6 are connected by the output terminal of on-off element with the zero level gamma voltage of this first circuit 16a, for example, the first on-off element SW1 and second switch element SW2 are connected to zero level gamma voltage output terminal, be used to export zero level gamma voltage V00P, and described first on-off element SW1 and second switch element SW2 are connected to two ends of described sectional pressure element R6 respectively.
Wherein, described first on-off element SW1 and second switch element SW2 have out at least and close two states, by controlling the on off state of described first on-off element SW1 and second switch element SW2, described zero level gamma voltage output terminal can optionally be selected one and be connected with one of them end of described sectional pressure element R6, thereby the voltage of one of them end of exportable this sectional pressure element R6 is as the zero level gamma voltage.For example, when the first on-off element SW1 closure, when second switch element SW2 disconnected, zero level gamma voltage output terminal was communicated with the upper end of described sectional pressure element R6, exports the voltage of this sectional pressure element R6 upper end; When second switch element SW2 closure, when the first on-off element SW1 disconnects, the voltage of zero level gamma voltage output terminal output sectional pressure element R6 bottom.As required, control the on off state of the first on-off element SW1 and second switch element SW2, optionally the output terminal with the zero level gamma voltage is communicated with the different ends of sectional pressure element R6, exports different zero level gamma voltages.
Wherein, described first on-off element SW1 and second switch element SW2 can be the single-way switch of square-wave signal control, for example, when square-wave signal is high level, described first on-off element SW1 and second switch element SW2 closure, when square-wave signal was low level, described first on-off element SW1 and second switch element SW2 disconnected; Perhaps, when square-wave signal was high level, described first on-off element SW1 and second switch element SW2 disconnected, when square-wave signal is low level, and described first on-off element SW1 and second switch element SW2 closure.When being applied to present embodiment based on the first on-off element SW1 of above-mentioned principle and second switch element SW2, one square wave signal generator can be connected in the described first on-off element SW1, this square wave signal generator is connected in second switch element SW2 after by a phase inverter C, closed or disconnect to control described first on-off element SW1 and second switch element SW2.
With when square-wave signal is high level, described first on-off element SW1 and second switch element SW2 closure, when square-wave signal is low level, described first on-off element SW1 and second switch element SW2 are broken as example, synoptic diagram as shown in Figure 7, described square wave signal generator Signal KW produces square-wave signal, and this square-wave signal directly is coupled to the first on-off element SW1 on the one hand, is coupled to second switch element SW2 by phase inverter C on the other hand.When the high level of square-wave signal is controlled first on-off element SW1 closure, it is low level that described square-wave signal passes through behind the phase inverter, can control described second switch element SW2 simultaneously disconnects, thereby can make zero level gamma voltage output terminal be connected in the upper end of described sectional pressure element R6, the exportable higher gamma voltage V00P1 of described zero level gamma voltage output terminal.
Otherwise, when the square-wave signal low level comes can make described zero level gamma voltage output terminal be connected in the bottom of described sectional pressure element R6 temporarily.The exportable lower gamma voltage V00P2 of zero level gamma voltage output terminal; Wherein, described V00P1 is greater than described V00P2, and the difference V1 of V00P1 and V00P2 determines according to the resistance value of described R6.
That is to say that can control the magnitude of voltage of zero level gamma voltage output terminal according to square-wave signal, this magnitude of voltage is coupled to source electrode driver, by the GTG conversion of source electrode driver may command liquid crystal pixel cells.In addition, the rising edge of described square-wave signal can be synchronous with the control output signal TP of the gate driving clock signal clk of thin film transistor (TFT) (TFT) and source electrode driver, and the duration T kw of the high level of described square-wave signal is by the response characteristic decision of liquid crystal.
In addition, the described first on-off element SW1 can also be controlled by two different square wave signal generators respectively simultaneously with second switch element SW2, the square-wave signal position that two square wave signal generators wherein send differs 180 °, the square-wave signal constant phase difference that described square wave signal generator sends, closed or the disconnection of may command first on-off element SW1 and second switch element SW2, thereby control zero level gamma voltage output terminal is selected one and is communicated with described sectional pressure element R6, makes the exportable different zero level gamma voltage of described zero level gamma voltage output terminal.Here be not described in detail, those skilled in the art can make corresponding change according to the instruction of the above embodiments.
In addition, described first on-off element SW1 and second switch element SW2 can be different, for example, and closure when the first on-off element SW1 is high level, and second switch element SW2 closure when being low level.Based on this, can adopt a square wave signal generator to be coupled to described first on-off element SW1 and second switch element SW2 simultaneously, perhaps adopt two mutually identical square wave signal generators in position to be respectively coupled to described first and second on-off elements, thereby control zero level gamma voltage output terminal is selected one and is communicated with described sectional pressure element R6, makes the exportable different zero level gamma voltage of described zero level gamma voltage output terminal.The square-wave signal that also can adopt output two mutually opposite square wave signal generators of position each other adds a phase inverter and connects described first on-off element SW1 and second switch element SW2.Here be not described in detail, those skilled in the art can make corresponding change according to the instruction of the above embodiments.
In addition, described first on-off element SW1 and second switch element SW2 can also be single-way switch or other switches of other type, described first on-off element SW1 and second switch element SW2 also can control with other mode, and those skilled in the art can utilize other on-off element to reach above-mentioned purpose according to the instruction of the foregoing description.Generally speaking; so long as utilize switching characteristic; make zero level gamma voltage output terminal selectively select device or parts or an element that is connected with two ends of sectional pressure element R6, the device that is applied to be used in the bleeder circuit to produce different gamma voltages all should be included within the protection domain of claim of the present invention.
In addition, described on-off element can be the two-way switch of single-pole double-throw (SPDT), by controlling this two-way switch, makes described zero level gamma voltage output terminal select one of them end of the described sectional pressure element of a connection, is not described in detail here.
In addition, described bleeder circuit also comprises the electric capacity that is used for voltage stabilizing that couples with each gamma voltage output terminal, is not described in detail here.
In addition, need to prove, also can only in the first circuit 16a or second circuit 16b, be connected with sectional pressure element, be not described in detail here.
Use the gray scale variation of described gamma voltage generating device may command liquid crystal pixel cells, for example, when the N frame, certain pixel cell is the non-zero order GTG, when the N+1 frame, need change to the zero level GTG.When the N+1 frame changes, gate driving clock signal clk control TFT opens, simultaneously, the square-wave signal Signal KW synchronous with this gate driving rising edge clock signal rises to high level simultaneously, trigger the described first on-off element SW1 closure, and control described second switch element SW2 and disconnect, make the voltage of described zero level gamma voltage output terminal output rise to V00P1 (i.e. the first zero level gamma voltage), please refer to sequential chart shown in Figure 8, wherein, described KW is the square-wave signal that square wave signal generator sends, V00P is the voltage oscillogram of the first circuit 16a (promptly producing the circuit of positive gamma voltage) zero level gamma voltage output terminal, V00N is the voltage oscillogram of the zero level gamma voltage output terminal of second circuit 16b (promptly producing the circuit of negative gamma voltage), and VCOM is the voltage oscillogram of the public electrode of liquid crystal indicator.As shown in Figure 8, when the KW signal was high level, V00P rose to higher gamma voltage V00P1 by lower gamma voltage V00P2, and when the KW signal was low level, V00P got back to original gamma voltage V00P2 (i.e. the second zero level gamma voltage) again.
Please refer to sequential chart shown in Figure 9, wherein, TP is the control output signal sequential chart of source electrode driver, CLK is a gate driving clock signal sequential chart, KW is the output waveform figure of square wave signal generator, L0+ and L0-represent the voltage oscillogram of the source electrode driver output of positive gamma voltage and negative gamma voltage respectively, and VCOM is a public electrode voltages.
When liquid crystal pixel cells by non-zero order GTG N frame when the N+1 frame of zero level GTG changes, TP Controlling Source driver output high level, CLK makes the TFT conducting by the control grid, source signal is applied to described pixel cell, the high level of KW output simultaneously, make the on-off element SW1 closure of winning, second switch element SW2 disconnects, the gamma voltage V00P1 that the output of zero level gamma voltage output terminal is higher, after the gate drivers response, (this decline is the characteristic decision by gate drivers after experiencing an of short duration decline, it mainly acts on is for power saving), rise to higher voltage (being tertiary voltage), to improve the speed of response of liquid crystal molecule, the liquid crystal molecule direction of controlling faster in the liquid crystal pixel cells changes, through behind the response time Trt, the first on-off element SW1 disconnects, second switch element SW2 closure, zero level gamma voltage output end voltage becomes V00P2, required voltage when source electrode driver output voltage slowly drops to the zero level GTG (the 4th voltage), wherein, its decline scope is V1 (equaling the voltage difference of V00P1 and V00P2).Voltage difference when reducing the zero level GTG with follow-up one-level gray scale variation by above-mentioned decline process, thus the image quality of raising liquid crystal pixel cells demonstration disturbed when reducing the zero level GTG to follow-up one-level gray scale variation.That is to say, adopt the structure of embodiments of the invention, neither can influence the response time of liquid crystal, have picture display effect preferably again.
Wherein, at the non-zero order GTG in the variation of zero level GTG, the mode of the decline V1 of the output of described source electrode driver can have multiple, both can be decline slowly shown in Figure 10, can be again transition shown in Figure 11, can also be branch two-stage transition shown in Figure 12, can certainly be shown in Figure 13 linear gradual, in a word, the decline mode of the voltage of source electrode controller output can be a lot, it can be realized by the time of opening and disconnecting of the first on-off element SW1 and second switch element SW2, repeat no more here.
In addition, the generation device of the described gamma voltage of the above embodiments can be applied in the liquid crystal indicator, and this liquid crystal indicator can also be applied to repeat no more here in the electronic equipment.
The present invention also provides a kind of method of controlling gamma voltage, is applied to have in the liquid crystal indicator of source electrode driver, and wherein, it is the non-zero order GTG that described liquid crystal indicator has a pixel cell at least; Comprise:
Import the first zero level gamma voltage to described source electrode driver, so that described source electrode driver applies tertiary voltage to the pixel cell of non-zero order GTG;
Behind the elapsed-time standards Trt, to the second zero level gamma voltage of described source electrode driver input, so that described source electrode driver applies the 4th voltage less than tertiary voltage to described pixel cell less than the first zero level gamma voltage; Wherein, described time T rt is the response time of described pixel cell when tertiary voltage.
Though the present invention with preferred embodiment openly as above; but it is not to be used for limiting the present invention; any those skilled in the art without departing from the spirit and scope of the present invention; can make possible change and modification, so protection scope of the present invention should be as the criterion with the scope that claim of the present invention was defined.
Claims (13)
1. the generation device of a gamma voltage, be used for liquid crystal indicator, it comprises and is coupled to bleeder circuit between first voltage and second voltage, that be used to produce gamma voltage that described bleeder circuit comprises the zero level gamma voltage output terminal of gamma voltage when being used to export liquid crystal pixel cells zero level GTG;
Be series at the sectional pressure element in the described bleeder circuit, two ends of described sectional pressure element are connected with described zero level gamma voltage output terminal by on-off element respectively;
Described on-off element is a single-way switch, comprises first on-off element that is connected with an end of described sectional pressure element and the second switch element that is connected with another end of described sectional pressure element;
Described first on-off element and second switch element are coupled to square wave signal generator; It is characterized in that:
Described square wave signal generator is used to produce square-wave signal and controls described first on-off element and second switch element;
The gate driving clock signal of the rising edge of described square-wave signal and the thin film transistor (TFT) of described liquid crystal indicator and the control output signal of source electrode driver are synchronous, and the duration of the high level of described square-wave signal is by the response characteristic decision of liquid crystal;
When described square-wave signal is high level, trigger the described first on-off element closure, and control described second switch element and disconnect, make described zero level gamma voltage output terminal export the first zero level gamma voltage, when described square-wave signal is low level, control described zero level gamma voltage output terminal and export the second zero level gamma voltage, wherein the second zero level gamma voltage is less than the first zero level gamma voltage.
2. the generation device of gamma voltage as claimed in claim 1 is characterized in that: described bleeder circuit comprises first circuit that produces positive gamma voltage and the second circuit of connecting with described first circuit, produce negative gamma voltage.
3. the generation device of gamma voltage as claimed in claim 2, it is characterized in that: described sectional pressure element is series in described first circuit or the second circuit; Or described sectional pressure element is two, is series at respectively in described first circuit and the second circuit.
4. as the generation device of claim 1 or 2 or 3 described gamma voltages, it is characterized in that: described sectional pressure element is a divider resistance.
5. as the generation device of claim 1 or 2 or 3 described gamma voltages, it is characterized in that: described first on-off element and second switch element closure when square-wave signal is high level disconnects during for low level at square-wave signal; Or when described square-wave signal is low level closure, disconnect during at square-wave signal for high level.
6. the generation device of gamma voltage as claimed in claim 5 is characterized in that: also comprise phase inverter;
Described square wave signal generator is coupled to described first on-off element, and by being coupled to described second switch element behind the phase inverter.
7. the generation device of gamma voltage as claimed in claim 5, it is characterized in that: square wave signal generator comprises first party wave generator and second party wave generator, and described first party wave generator is mutually opposite with the square-wave signal position that the second party wave generator sends; Described first party wave generator is coupled to described first on-off element, and described second party wave generator is coupled to described second switch element.
8. as the generation device of claim 1 or 2 or 3 described gamma voltages, it is characterized in that: described first on-off element closure when square-wave signal is high level disconnects during for low level at square-wave signal; Described second switch element closure when square-wave signal is low level disconnects during for high level at square-wave signal.
9. the generation device of gamma voltage as claimed in claim 8, it is characterized in that: square wave signal generator comprises first party wave generator and second party wave generator;
Described first party wave generator is mutually identical with the square-wave signal position that the second party wave generator sends, and described first party wave generator is coupled to described first on-off element; The second party wave generator is coupled to described second switch element;
Or described first party wave generator is mutually opposite with the square-wave signal position that the second party wave generator sends, and described first party wave generator is coupled to described first on-off element; The second party wave generator is coupled to described second switch element after by phase inverter.
10. as the generation device of claim 1 or 2 or 3 described gamma voltages, it is characterized in that: described bleeder circuit comprises a plurality of divider resistances of series connection, and the node between per two divider resistances is exported described gamma voltage.
11. the generation device as claim 1 or 2 or 3 described gamma voltages is characterized in that, also comprises the electric capacity that couples with each gamma voltage output terminal.
12. a liquid crystal indicator is characterized in that comprising the generation device of the described gamma voltage of the arbitrary claim of claim 1 to 11.
13. a method of controlling gamma voltage is applied to have in the liquid crystal indicator of source electrode driver, wherein, described liquid crystal indicator has the pixel cell of a non-zero order GTG at least; It is characterized in that, comprising:
Import the first zero level gamma voltage to described source electrode driver, so that described source electrode driver applies tertiary voltage to the pixel cell of non-zero order GTG;
Behind the elapsed-time standards Trt, to the second zero level gamma voltage of described source electrode driver input, so that described source electrode driver applies the 4th voltage less than tertiary voltage to described pixel cell less than the first zero level gamma voltage;
Wherein, described time T rt is the response time of described pixel cell when tertiary voltage.
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| CN107529233A (en) * | 2017-08-14 | 2017-12-29 | 电子科技大学 | A kind of heating and temperature measurement circuit based on RTD |
| CN111477192B (en) * | 2020-05-25 | 2022-04-15 | 京东方科技集团股份有限公司 | Adjusting method, adjusting module and display device |
| CN112669786A (en) | 2021-01-11 | 2021-04-16 | 北京京东方技术开发有限公司 | Gamma circuit, driving method thereof and display panel |
| CN113409732B (en) * | 2021-06-30 | 2022-08-02 | 惠州华星光电显示有限公司 | Drive circuit and drive method of drive circuit |
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| CN1728227A (en) * | 2004-07-27 | 2006-02-01 | 精工爱普生株式会社 | Grayscale voltage generation circuit, driver circuit, and electro-optical device |
| CN1858835A (en) * | 2005-05-02 | 2006-11-08 | 三星Sdi株式会社 | Gamma reference voltage generating circuit and flat panel display having the same |
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| CN1728227A (en) * | 2004-07-27 | 2006-02-01 | 精工爱普生株式会社 | Grayscale voltage generation circuit, driver circuit, and electro-optical device |
| CN1858835A (en) * | 2005-05-02 | 2006-11-08 | 三星Sdi株式会社 | Gamma reference voltage generating circuit and flat panel display having the same |
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Address after: 215301 No. 1, Longteng Road, Kunshan, Jiangsu Patentee after: InfoVision Optoelectronics(Kunshan)Co.,Ltd. Address before: 215301 No. 1, Longteng Road, Kunshan, Jiangsu Patentee before: INFOVISION OPTOELECTRONICS (KUNSHAN) Co.,Ltd. |