Background technology
Characteristics such as volume is little because of having for LCD, light weight, thin thickness, power consumption are low, do not glimmer, radiation is few have been widely used in electronic equipments such as TV, notebook computer, mobile phone, personal digital assistant.
LCD generally includes a display panels and and the module backlight of planar light is provided for this display panels.This display panels generally includes public electrode, pixel electrode and a plurality of liquid crystal molecule that driven by this public electrode and this pixel electrode and reverse.When the change in voltage that is applied between this public electrode and the pixel electrode, the windup-degree of this liquid crystal molecule is different, thereby the light percent of pass of this display panels is different, and the cooperation colored filter can be realized the demonstration of different pictures.
Yet; When temperature reduces, influenced by the liquid crystal molecule self-characteristic, its response speed is slack-off; The curve of voltage and light percent of pass squints between the public electrode of this display panels and the pixel electrode; Liquid crystal molecule often can't be torqued into specified angle, and then phenomenons such as this LCD generation display frame disorder, image residue and contrast reduction, and display effect is relatively poor.
Summary of the invention
Be to solve prior art LCD relatively poor problem of display effect when temperature reduces, display effect LCD preferably when being necessary to provide a kind of temperature reduction.
Be to solve prior art LCD relatively poor problem of display effect when temperature reduces, the display effect driving method of LCD preferably when being necessary to provide a kind of temperature reduction.
A kind of LCD; It comprises a common electric voltage circuit, a data drive circuit, a gamma-correction circuit and a display panels; This common electric voltage circuit is used for exporting a public voltage signal to this display panels; This data drive circuit is used for exporting a plurality of gray scale voltage signals to this display panels, and this gamma-correction circuit comprises a plurality of gamma correction look-up tables, wherein; When temperature reduces; This common electric voltage circuit increases the amplitude of this public voltage signal, and this gamma-correction circuit selects corresponding gamma correction look-up table that view data is carried out gamma correction according to the corresponding gamma value of this public voltage signal amplitude, and the view data of this data drive circuit after according to gamma correction produces these a plurality of gray scale voltage signals.
A kind of LCD; It comprises a common electric voltage circuit, a data drive circuit, a gamma-correction circuit and a display panels; This display panels comprises a public electrode and a plurality of pixel electrode, and this common electric voltage circuit is used for exporting a public voltage signal to this public electrode, and this data drive circuit is used for exporting a plurality of gray scale voltage signals to this pixel electrode; This gamma-correction circuit comprises a plurality of gamma correction look-up tables; Wherein, when temperature variation, the magnitude of this this public voltage signal of common electric voltage circuit control; And this gamma-correction circuit selects corresponding gamma correction look-up table that view data is carried out gamma correction according to the corresponding gamma value of this public voltage signal amplitude, and the view data of this data drive circuit after according to gamma correction produces these a plurality of gray scale voltage signals.
A kind of driving method of LCD, this LCD comprises a display panels, this driving method comprises the steps: to apply a public voltage signal that increases with temperature reduction amplitude and arrives this display panels; With according to should public voltage signal corresponding gamma value select corresponding gamma correction look-up table that view data is carried out gamma correction, and produce a plurality of gray scale voltages and apply these a plurality of gray scale voltage signals to this display panels according to the view data behind the gamma correction.
A kind of driving method of LCD, this LCD comprise a public electrode and a plurality of pixel electrode, and this driving method comprises the steps: to apply the temperature variant public voltage signal of an amplitude to this public electrode; With according to should public voltage signal corresponding gamma value select corresponding gamma correction look-up table that view data is carried out gamma correction, and produce a plurality of gray scale voltages and apply these a plurality of gray scale voltage signals to these a plurality of pixel electrodes according to the view data behind the gamma correction.
Compared with prior art; In the Liquid Crystal Display And Method For Driving of the present invention; When ambient temperature reduced, the public voltage signal that applies the amplitude increase was to this display panels, and the voltage that drives liquid crystal molecules is reversed increases; Liquid crystal molecule is torqued into specified angle easily, so when effectively improving temperature and reducing disorderly, the image residue of display frame to show phenomenon with contrast reduction etc.
Embodiment
Seeing also Fig. 1, is the circuit block diagram of LCD one preferred embodiments of the present invention.This LCD 1 comprises a display panels 10, common electric voltage circuit 20, a data drive circuit 30, a controller 40, a gamma-correction circuit 50 and a temperature sensing circuit 60.
This temperature sensing circuit 60 is electrically connected this controller 40; Be used for sensing ambient temperature and the temperature signal of correspondence outputed to this controller 40, it comprises a temperature sensing circuit 601, an A/D conversion circuit 603 and a scrambler 605 that is electrically connected in regular turn.
This controller 40 is electrically connected this common electric voltage circuit 20 and this gamma-correction circuit 50; It receives outside view data and this temperature signal; And according to this temperature signal outputting common voltage control signal to this common electric voltage circuit 20, also output image data selects signal to arrive this gamma-correction circuit 50 with gamma simultaneously.This controller 40 comprises a look-up table 401, a plurality of temperature signals of storage and a plurality of common electric voltage amplitudes corresponding with this temperature signal and the gamma value corresponding with this common electric voltage amplitude in this look-up table 401.
This common electric voltage circuit 20 is electrically connected this display panels 10, and it is exported corresponding public voltage signal and be applied to this display panels 10 according to this common electric voltage control signal.
This gamma-correction circuit 50 is electrically connected this data drive circuit 30, and it selects signal that this view data is carried out gamma correction according to this gamma, and the view data after will proofreading and correct outputs to this data drive circuit 30.This gamma-correction circuit 50 comprises the corresponding gamma correction look-up table 501 of a plurality of different gamma values.
This data drive circuit 30 is electrically connected this display panels 10, and it produces a plurality of gray scale voltage signals according to corrected image data, and should be applied to this display panels 10 by a plurality of gray scale voltage signals.
This display panels 10 comprises many sweep traces that are parallel to each other 101; Many be parallel to each other and with these sweep trace 101 vertically insulated crossing data lines 103; A plurality of on-off elements 105 that are positioned at this sweep trace 101 and the data line 103 crossing a plurality of minimum rectangular area that constitute; A plurality of pixel electrodes 107 that are connected with this on-off element 105; One and these a plurality of pixel electrodes 107 public electrode 109 and the liquid crystal molecule 111 between this pixel electrode 107 and public electrode 109 that are oppositely arranged.
The principle of work of this LCD 1 is following:
These temperature sensing circuit 601 sensing ambient temperatures, and will represent the simulating signal of ambient temperature to output to this A/D conversion circuit 603.This A/D conversion circuit 603 is a digital signal with this analog signal conversion.This scrambler 605 produces this encoding digital signals, compression the temperature signal of representing ambient temperature and this temperature signal is outputed to this controller 40.
This controller 40 receives the view data of the representative display frame of this temperature signal and external circuit output.At first; This controller 40 is inquired about in this look-up table 401 and is obtained corresponding common electric voltage amplitude of this temperature signal and the gamma value corresponding with this common electric voltage amplitude; And, produce the common electric voltage control signal of representing this common electric voltage amplitude and the gamma of representing this gamma value and select signal further according to this common electric voltage amplitude and gamma value.Then, this controller 40 outputs to this common electric voltage circuit 20 with this common electric voltage control signal, selects signal and this view data to output to this gamma-correction circuit 50 this gamma simultaneously.
This common electric voltage circuit 20 receives this common electric voltage control signal, arrives this display panels 10 according to this common electric voltage control signal outputting common voltage signal.Wherein, this public voltage signal is a continuous square-wave signal, and when ambient temperature reduced, this common electric voltage circuit 20 increased according to the amplitude of this common electric voltage control signal with this public voltage signal; When ambient temperature raise, this common electric voltage circuit 20 reduced according to the amplitude of this common electric voltage control signal with this public voltage signal.
Seeing also Fig. 2, is the oscillogram of this public voltage signal of correspondence under the different temperatures.Wherein, the common electric voltage waveform when on behalf of ambient temperature, waveform A be t1, the amplitude of its public voltage signal is V
Com1On behalf of ambient temperature, waveform B drop to t2, and (during t2<t1), the amplitude of its public voltage signal is V
Com2Wherein, V
Com2>V
Com1
This gamma-correction circuit 50 receives this gamma and selects signal and this view data; Select signal to select corresponding gamma correction look-up table 501 according to this gamma earlier; Carry out gamma correction according to 501 pairs of these view data of this gamma correction look-up table again, the view data after will proofreading and correct then outputs to this data drive circuit 30.
This data drive circuit 30 receives corrected image data, and it produces a plurality of gray scale voltage signals according to this view data.When this public voltage signal was provided to this display panels 10, this data drive circuit 30 should be applied to this display panels 10 by a plurality of gray scale voltage signals.
This display panels 10 receives this public voltage signal and a plurality of gray scale voltage signal.Wherein, this public voltage signal is provided to this public electrode 109; When this sweep trace 101 is scanned successively; These a plurality of gray scale voltage signals are applied to this a plurality of pixel electrodes 107 through these many data lines 103 with a plurality of on-off elements 105 respectively; This liquid crystal molecule 101 is reversed by the driven between this public electrode 109 and this pixel electrode 107, and then this display panels 10 realizes that picture shows.
Compared with prior art; The common electric voltage circuit 20 of LCD 1 of the present invention is when ambient temperature reduces; The public voltage signal that applies the amplitude increase is to this display panels 10; Make the voltage between this public electrode 109 and the pixel electrode 107 increase, liquid crystal molecule 111 is torqued into specified angle easily; When ambient temperature raises; Apply public voltage signal that amplitude reduces to this display panels 10; The windup-degree of liquid crystal molecule 111 also relatively accurately, and then when effectively improving temperature and reducing disorderly, the image residue of display frame to show phenomenon with contrast reduction etc.
In addition; This LCD 1 also selects corresponding 501 pairs of these view data of gamma lookup table to carry out gamma correction according to the corresponding gamma value of this common electric voltage amplitude; Thereby common electric voltage amplitude and problem that the color quality that cause descend not corresponding with gamma value can not take place, and the display effect of this LCD 1 is better.