CN101383130A

CN101383130A - Lcd

Info

Publication number: CN101383130A
Application number: CNA2007101215335A
Authority: CN
Inventors: 籍欣
Original assignee: Beijing BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2007-09-07
Filing date: 2007-09-07
Publication date: 2009-03-11
Anticipated expiration: 2027-09-07
Also published as: CN101383130B

Abstract

The invention relates to an LCD (Liquid Crystal Display) which comprises a display panel with a plurality of public electrode sections, a control box generating a first enabling signal and a control signal, an enabling signal converter receiving the first enabling signal, and a plurality of voltage adjusting circuits correspondingly receiving a plurality of second enabling signals output by the enabling signal converter; the voltage adjusting circuits adjust output public electrode voltages according to the received corresponding second enabling signals and the control signal output by the control box, and the public electrode voltages output by the voltage adjusting circuits are correspondingly exerted on the public electrode sections of the display panel and are provided for the work of the display panel. Through public electrode adjusting circuits, the invention can realize the blocking adjustment of the public electrode voltages so as to optimize flash adjustment and improve the picture display quality.

Description

LCD

Technical field

The present invention relates to a kind of LCD, especially a kind of LCD that can realize optimize flash adjustment.

Background technology

As shown in Figure 1, have public electrode (common electrode), pixel electrode (pixel electrode) and the liquid crystal layer between public electrode and pixel electrode on the general liquid crystal panel, cover layer of transparent conducting film ITO on the electrode, by applying public electrode voltages to public electrode and apply pixel voltage, promptly can utilize the voltage difference between public electrode and the pixel electrode and change the light transmittance of liquid crystal layer to pixel electrode.

Fig. 2 is thin film transistor (TFT) (TFT) structural representation, and Clc is that liquid crystal capacitance, Cs are memory capacitance.The light transmittance of liquid crystal layer be with public electrode and pixel electrode between the voltage extent relevant, and the polarity of voltage difference is irrelevant therewith.The value of supposing liquid crystal display common electrode voltage VCOM is 5 volts, LCD is under a reversing mode, if the pixel voltage of a certain pixel is 0 volt and its neighbor as if need be identical with its brightness, then the pixel voltage of this neighbor is 10 volts, but when the public electrode voltages of these two pixels is inequality, its voltage difference is just no longer identical, causes the brightness difference, also is the liquid crystal scintillation.Therefore, the flicker of LCD is to stem from the skew of public electrode voltages and the luminance nonuniformity that causes pixel.

The original liquid crystal panel that dispatches from the factory must strictly be adjusted this parameter to avoid the pixel luminance nonuniformity.A kind of method of reduction LCD flicker of prior art is by adjusting a variable resistor to reach the flicker level that reduces whole front panel, as shown in Figure 3, the base substrate of liquid crystal display can be thought low resistance earthing, add a common single channel mechanical potentiometer and regulate public electrode voltages VCOM value, VDD applies voltage.

The public electrode voltages regulating circuit mainly contains two kinds in the liquid crystal display circuit at present: digital VCOM and simulation VCOM, the public electrode that both are all TFT links together, regulate public electrode voltages (VCOM) value by the numeral or the mimic channel that are integrated on the printed circuit board (pcb) then, thereby make flicker minimum, wherein, numeral VCOM circuit is by specific integrated circuit (IC) supplied with digital signal being changed the VCOM value of IC output, is to change the VCOM value by manual adjustments variable resistor (VR) value and simulate the VCOM circuit.

The panel designs of Thin Film Transistor-LCD (TFT-LCD) is to go up at thin film transistor (TFT) (TFT) to cover layer of transparent conducting film ITO, because ITO has certain resistance value, so just must cause having pressure reduction between the public electrode voltages of each TFT, and because prior art is that VCOM regulating circuit (digital VCOM or simulation VCOM) is integrated on the PCB, driving integrated chip (SD-IC) by limited tie point and source again links to each other, the public electrode that is to say all TFT links together, therefore regulating VCOM can only be integrally-regulated to it, and because the influence of the resistance of ITO makes that the public electrode voltages of each pixel is also inconsistent, integrally-regulatedly can not eliminate this species diversity, thereby can not realize optimize flash adjustment, reduce the display frame quality.

Summary of the invention

The purpose of this invention is to provide a kind of LCD,, realize optimize flash adjustment, improve the picture display quality in order to solve the problem that prior art can not realize optimize flash adjustment.

The present invention provides following technical scheme by some embodiment:

A kind of LCD is characterized in that comprising:

One display panel has a plurality of public electrode subregions;

One control enclosure, first enable signal and the control signal that are used to regulate the public electrode voltages that is applied on the described public electrode according to described display panel demonstration situation output, whether described first enable signal is used to indicate public electrode voltages to need to regulate, and described control signal is used to indicate public electrode voltages to increase or reduces;

Whether one enable signal converter receives described first enable signal, exports a plurality of second enable signals, be used to indicate its pairing voltage regulator circuit to need to regulate, and regulate its pairing voltage regulator circuit successively;

A plurality of voltage regulator circuits receive described second enable signal and control signal, and according to this output public electrode voltages of described voltage regulator circuit are regulated, the described public electrode subregion of the corresponding electric connection of described voltage regulator circuit output.

Embodiments of the invention are public electrode voltages to be divided into several portions (being driven the number decision of integrated chip by the source) regulate respectively, make each source drive the public electrode voltages unanimity of integrated chip output, eliminate the pressure reduction influence that the ITO resistance causes, therefore realize the optimization of flash adjustment, improved the display quality of picture.

Further specify technical scheme of the present invention below in conjunction with the drawings and specific embodiments.

Description of drawings

Fig. 1 is the liquid crystal panel structure synoptic diagram;

Fig. 2 is the TFT structural representation;

Fig. 3 adjusts synoptic diagram for existing public electrode voltages;

Fig. 4 is the embodiment of the invention one structural representation;

Fig. 5 is voltage regulator circuit one an embodiment synoptic diagram of the present invention;

Fig. 6 is second enable signal, the one waveform sequential chart among the present invention;

Fig. 7 is enable signal converter and voltage regulator circuit one embodiment synoptic diagram;

Fig. 8 is first enable signal among Fig. 7 embodiment, controllable pulse signal, second enable signal, one ripple

The shape synoptic diagram;

Fig. 9 is enable signal converter and another embodiment synoptic diagram of voltage regulator circuit.

Embodiment

Referring to Fig. 4, be the embodiment of the invention one structured flowchart.A kind of LCD comprises that one has display panel, a control enclosure, an enable signal converter and a plurality of voltage regulator circuit of a plurality of public electrode subregions, the corresponding public electrode subregion that connects display panel of the public electrode voltages of voltage regulator circuit output drives display panel with this;

Because the influence of the resistance of ITO makes each subregion have pressure reduction, there is scintillation thus, so just need to regulate the public electrode voltages of each voltage regulator circuit output, the feasible public electrode voltages unanimity that is added in each subregion, eliminate scintillation with this, control enclosure is by the demonstration situation of eye-observation display panel, judge whether to regulate and how to regulate, output is used to indicate public electrode voltages whether to need first enable signal CE that regulates and the control signal CTL that is used to indicate public electrode voltages to increase or reduce;

The enable signal converter receives the first enable signal CE, export the second enable signal CE1, CE2......CE6, whether CE1 is used to indicate first voltage regulator circuit to need to regulate the same CE1 of remaining second enable signal principle of work as second enable signal of first voltage regulator circuit;

Voltage regulator circuit receives the second enable signal CE1, CE2......CE6 and control signal CTL, and regulate public electrode voltages VCOM1, the VCOM2......VCOM6 of its output in view of the above, and be applied on each subregion of public electrode of display panel, make that the public electrode voltages that is applied on each public electrode subregion is identical.

Referring to Fig. 5, be voltage regulator circuit one embodiment synoptic diagram of the present invention.Voltage regulator circuit (VCOM Circuit) is integrated in the source and drives integrated chip (SD-IC) inside, the number of SD-IC is by the size decision of display panel, 6 SD-IC (being suitable for 19 cun liquid crystal display) have been shown in the present embodiment, because each source drives the electrical characteristics unanimity of integrated chip, therefore, guaranteed to be applied to the consistance on the display panel, adopted integrated method can save the space simultaneously by the public electrode voltages of voltage regulator circuit output.The output signal of voltage regulator circuit is respectively VCOM1, VCOM2......VCOM6, input signal is second enable signal (CE1, CE2......CE6) and control signal CTL, CTL is produced by control enclosure, be used to indicate VCOM to increase or reduce, second enable signal (CE1, CE2......CE6) is generated by the first enable signal CE, be used for regulating successively its pairing voltage regulator circuit, reset signal RESET is exported by control enclosure, as the another input signal of voltage regulator circuit, can readjust VCOM1, VCOM2......VCOM6.

Fig. 6 shows the second enable signal CE1, the sequential oscillogram of CE2......CE6, VALID shows second enable signal effective time (during high level), i.e. time of regulating of the voltage regulator circuit of the second enable signal correspondence, illustrate: at the VALID of CE1 in the time, show that it is gating that first film source drives integrated chip, can carry out the adjustment of its public electrode voltages VCOM1 according to the control signal CTL that comes from control enclosure, at this moment, other the second enable signal (CE2, CE3, CE4, CE5, CE6) be low level, can not regulate VCOM2, VCOM3, VCOM4, VCOM5, VCOM6, the time span of the VALID of CE1 can be manual, promptly can determine its length, adjust up to it according to the effect of the display frame of regulating; After VCOM1 regulates, next regulate VCOM2, CE1's drops to low level by high level at this moment, promptly can not regulate VCOM1 again, CE2 becomes high level by low level, remaining CE3, CE4, CE5, CE6 are still low level, promptly can only regulate VCOM2, the same VCOM1 of the adjustment process of VCOM2 this moment; After this flow process of public electrode voltages VCOM3, VCOM4, VCOM5, VCOM6 and principle are with above-mentioned.That is to say that voltage regulator circuit is the work of regulating successively, all regulates up to all public electrode voltages VCOM1, VCOM2......VCOM6, promptly all public electrode voltages VCOM1, VCOM2......VCOM6 can be adjusted to identical value.Because public electrode voltages is that piecemeal is regulated, can overcome the pressure reduction influence that unvanquishable ITO produces when integrally-regulated, realize optimize flash adjustment, improve the picture display quality.

Referring to Fig. 7, be enable signal converter and voltage regulator circuit one embodiment synoptic diagram.This enable signal converter comprises the shift register corresponding with voltage regulator circuit (Shift Register), and shift register and the voltage regulator circuit source that all is integrated in drives in the integrated chip (S D-IC); First shift register receives the first enable signal CE of control enclosure output, and it is carried out shifting processing, output is as the second enable signal CE1 of first voltage regulator circuit input, CE1 is used to indicate whether that the public electrode voltages VCOM1 to first voltage regulator circuit output regulates, and input signal as thereafter second shift register, the rest may be inferred, up to generating the second all enable signals, and finishes the adjusting of each public electrode voltages; All shift registers all connect same controllable pulse CP, CP is a may command pulse signal, can control the CP signal pulse by the manual operation button, make it consistent with the adjusting time of correspondent voltage regulating circuit, can control for second enable signal effective time according to the difference of regulating the time like this, satisfy the needs that each voltage regulator circuit is regulated asynchronism(-nization);

Fig. 8 shows the waveform synoptic diagram of CE in the present embodiment, CP and CE1, CE2......CE6.Therefore, by second enable signal that present embodiment generates, can realize the blocking adjustment of public electrode voltages.

Referring to Fig. 9, be enable signal converter and another embodiment synoptic diagram of voltage regulator circuit.An integrated selector switch in the control enclosure in the present embodiment, selector output end connects the SD-IC1......S D-IC6 that is integrated with voltage regulator circuit, with a last Embodiment C E1, CE2.......CE6 generates by shift register, present embodiment is to select to generate by selector switch, selector switch can be a single pole multiple throw, control enclosure produces the first enable signal CE, (need regulate which VCOM) gating and corresponding S D-IC of VCOM according to circumstances, promptly in the time will regulating VCOM1, switch is thrown on the contact that links to each other with first S D-IC, CE is delivered to first voltage regulator circuit, can regulate VCOM1, according to the adjusting time, manual adjustments CE effective time is because other S D-IC and CE disconnection, so public electrode voltages that can not regulate other this moment, after VCOM1 regulates, then regulate VCOM2, after this regulate VCOM2, flow process and the principle of VCOM3......VCOM6 are the same.Therefore, can realize the blocking adjustment of public electrode voltages equally by present embodiment.

It should be noted that at last: above embodiment only in order to technical scheme of the present invention to be described, is not intended to limit; Although with reference to previous embodiment the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of various embodiments of the present invention technical scheme.

Claims

1, a kind of LCD is characterized in that comprising:

One display panel has a plurality of public electrode subregions;

A plurality of voltage regulator circuits receive described second enable signal and control signal, and according to this public electrode voltages of described voltage regulator circuit output are regulated, and described a plurality of voltage regulator circuits and described a plurality of public electrode subregion connect one to one.

2, LCD according to claim 1 is characterized in that:

Described a plurality of voltage regulator circuit correspondence is integrated in multiple source and drives in the integrated chip.

3, LCD according to claim 1, it is characterized in that: described enable signal converter comprises a plurality of shift registers corresponding with described voltage regulator circuit, each described shift register carries out shifting processing to the output signal of its previous shift register, and export to its corresponding voltage regulator circuit, as second enable signal of its corresponding voltage regulator circuit, first described shift register receives described first enable signal.

4, LCD according to claim 1, it is characterized in that: described enable signal converter comprises a selector switch, described selector switch receives described first enable signal, and exports this first enable signal to each voltage regulator circuit successively as second enable signal of each voltage regulator circuit correspondence.

5, LCD according to claim 4 is characterized in that: described selector switch is a single pole multiple throw.

6, according to the described arbitrary LCD of claim 1-5, it is characterized in that: described control enclosure is also exported and is used to indicate voltage regulator circuit to readjust the reset signal of public electrode voltages.