CN102763157B

CN102763157B - Display inspection method

Info

Publication number: CN102763157B
Application number: CN201180009554.2A
Authority: CN
Inventors: 上坂望; 石地弘树; 横山洋介
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2010-02-17
Filing date: 2011-02-15
Publication date: 2015-01-14
Anticipated expiration: 2031-02-15
Also published as: JPWO2011102347A1; WO2011102347A1; JP5512788B2; CN102763157A

Abstract

Disclosed is a display inspection method that can easily confirm whether or not a voltage (Vcom) is at an optimal value without using a special configuration. While performing inversion driving-during which the polarity of an image signal is inverted every vertical scanning period-of a pixel electrode wherein a liquid crystal layer is disposed between opposing electrodes, the electric potential of the abovementioned image signal within each vertical scanning period is maintained. At this point, at least two display regions-an area (A) that displays on the basis of a first video signal of which the center voltage is caused to match the center voltage of the voltage (Vcom), and an area (B) that displays on the basis of a second video signal of which the center voltage has been caused to be different from the center voltage of the voltage (Vcom) despite the electric potential difference of adjacent vertical scanning period pairs being the same as that of the abovementioned first video signal-are displayed simultaneously on a single screen.

Description

Display inspection method

Technical field

The present invention relates to the display inspection method in the liquid crystal indicator exchanging type of drive.

Background technology

In liquid crystal indicator, when long-time applying DC voltage, the persistence of vision being called as " ghost " can be caused.Therefore, the interchange by making the polarity of the voltage being applied to pixel electrode reverse relative to counter-electrode voltage Vcom drives and prevents ghost.

Such as, have employed in the liquid crystal indicator by every frame inversion driving mode making the reversal of poles of vision signal 1 image duration, the value of counter-electrode voltage Vcom (hreinafter referred to as voltage Vcom) sets in the mode each pixel not being produced to DC composition.More particularly, voltage Vcom is set as optimum value by the mode equaling the minus polarity signal of vision signal and the potential difference (PD) V (-) of voltage Vcom with the potential difference (PD) V (+) of the positive signal of vision signal and voltage Vcom.

But when voltage Vcom off-target value, above-mentioned potential difference (PD) V (+) is just not equal to potential difference (PD) V (-), and therefore DC composition is applied to liquid crystal layer.When this DC composition is positive pole and negative pole time cause voltage difference on liquid crystal layer, therefore show as the difference of light transmission.The difference of this light transmission is identified as the light on and off in the integral multiple cycle with frame time by the ocular vision of people, namely glimmer.This flicker can make display quality worsen certainly, and the display therefore need the generation of inspection flicker, carrying out revising when voltage Vcom off-target value checks operation.

That discloses below Patent Document 1 discloses following method: make the display pattern of display as the pixel of the voltage being applied in the arbitrary homopolarity in positive pole or negative pole is white display in each frame, according to based on the state shown by this display pattern, check the current potential of comparative electrode.

More particularly, as shown in (a) of Fig. 15, when not applying drive singal the normal white mode that brightness is higher liquid crystal indicator in, in the current frame, alternately show the pixel column of black pixel column and white intermediate grey scales (i.e. grey).To the display voltage of the larger negative polarity of the pixel applying value shown in bullet, on the other hand, the display voltage of the positive polarity of white middle gray stage can be shown to the pixel applying shown in white round dot.

Then, as shown in (b) of Figure 15, in the next frame after 1/60 second, according to reversal of poles mode, the polarity being applied to the display voltage of each pixel can be reversed.Therefore, apply the display voltage of positive polarity to the pixel shown in bullet, on the other hand, the display voltage of the negative polarity of white middle gray stage can be shown to the pixel applying shown in white round dot.Such reversal of poles is also repeatedly performed in ensuing frame.

Following record is had: due to the white pixel column of the visual identity mode in frame entirety with identical polar display pattern can be formed with the mankind like this in 1 frame in patent documentation 1, therefore when creating flicker, can this flicker of visual identity exactly.

In addition, that discloses below Patent Document 2 discloses the voltage Vcom changing liquid crystal indicator, while the flicker value using color analyzer to measure carrys out the method and apparatus of the voltage Vcom of automatically computing the best.

prior art document

patent documentation

Patent documentation 1: Japanese Laid-Open Patent Publication " JP 2002-258232 (on September 11st, 2002 is open) "

Patent documentation 2: Japanese Laid-Open Patent Publication " JP 2006-215500 (on August 17th, 2006 is open) "

Summary of the invention

the problem that invention will solve

But, in the technology disclosed in patent documentation 1 and 2, have do not use special form just can not confirm that whether voltage Vcom is the problem of optimum value simply.

Figure 16 illustrates and is set as to by voltage Vcom the general flow that the process of optimum value is relevant.First, in step (being abbreviated as S) 1, confirm display frame, while determine voltage Vcom in the mode not producing flicker.As this display frame, such as following confirmation screen is applicable: as shown in figure 17, show the confirmation screen I of the rest image of the black and grey horizontal stripe alternately configured by every 1 row, or as shown in figure 18, show the confirmation screen II of the rest image of the gradual change image changed with 10 stages from black to white from the left end of display frame to right-hand member and the black horizontal stripe alternately configured by every 1 row.

Then, in S2, the storer to the driver driving comparative electrode is written in the value of the voltage Vcom determined in S1.

Thereafter, in S3, reaffirm whether the setting value of the voltage Vcom being written to above-mentioned storer is best.Specifically, when above-mentioned driver has Read (reading) function, this Read function is used to confirm to be written to the setting value of storer, while confirm whether above-mentioned confirmation screen I or confirmation screen II produces flicker.When above-mentioned driver does not have Read function, observe confirmation screen I or confirmation screen II and be confirmed whether to produce flicker.

But, in above-mentioned flicker confirmation method, even employ the display pattern described in patent documentation 1, the degree that the state be also very difficult to by seeing 1 picture judges to glimmer, judges to glimmer as minimal level.Its reason is, whether flicker is minimal level, can judge with the epidemic situation comparison of the different pictures after the value of change voltage Vcom.

In addition, even if by the different pictures after the value that alternately show change voltage Vcom, can judge that the flicker of which picture is less, some in the value of also not necessarily these 2 voltage Vcom is optimum value.Therefore, can only be undertaken by the value constantly changing voltage Vcom making repeated attempts and obtain the optimum value of voltage Vcom.

In addition, in the method and apparatus disclosed in patent documentation 2, can automatically machine voltage Vcom, but there is the problem needing to carry out the special formation of this computing.

In view of the above-mentioned problems, the object of the invention is to, provide do not use special form just can confirm that whether Vcom is the display inspection method of optimum value simply.

for the scheme of dealing with problems

The feature of display inspection method of the present invention is, in order to solve the above problems,

(1) while the pixel electrode being configured with liquid crystal layer between to comparative electrode carries out making the reversion of the reversal of poles of vision signal drive by every 1 vertical scanning period, when keeping the current potential of above-mentioned vision signal in every 1 vertical scanning period,

(2) counter-electrode voltage being applied to above-mentioned comparative electrode is made to be fixed voltage, or making by the center voltage (Va) of the above-mentioned counter-electrode voltage when reversal of poles of every 1 vertical scanning period by counter-electrode voltage is fixed voltage

(3) on 1 picture, show the 1st viewing area and the 2nd viewing area, at least 2, viewing area simultaneously, the display based on the 1st vision signal is carried out in above-mentioned 1st viewing area, the center voltage (A) of above-mentioned 1st vision signal is consistent with the above-mentioned fixed voltage of above-mentioned counter-electrode voltage, the display based on the 2nd vision signal is carried out in above-mentioned 2nd viewing area, above-mentioned 2nd vision signal is identical in adjacent vertical scanning period potential difference (PD) each other with above-mentioned 1st vision signal in adjacent vertical scanning period potential difference (PD) each other, on the other hand, the center voltage (B) of above-mentioned 2nd vision signal is different from the above-mentioned fixed voltage of above-mentioned counter-electrode voltage.

According to above-mentioned formation, carrying out showing as follows in the 1st viewing area based on the display of the 1st vision signal: the amplitude of the positive and negative arbitrary polarity being benchmark with the above-mentioned fixed voltage of counter-electrode voltage (being called the 1st polarity) becomes and equals, with the state of the amplitude of the 1st opposite polarity polarity (being called the 2nd polarity), to keep the current potential of vision signal in every 1 vertical scanning period.

If the counter-electrode voltage of the 1st viewing area is optimum value, then, in each vertical scanning period, can not produce the difference of the light transmission in pixel, therefore in each vertical scanning period, each pixel continues display same grey level, does not consequently produce flicker.

But the adjustment of counter-electrode voltage uses testing fixture and operated by people, the device mistake (misoperation) when therefore sometimes artificial mistake (optimum value confirms mistake) and write causes counter-electrode voltage off-target value.In this case, in the 1st viewing area, flicker is produced.

Therefore, in the present invention, 2nd viewing area and the 1st viewing area are shown simultaneously in 1 picture, the display based on the 2nd vision signal is carried out in above-mentioned 2nd viewing area, above-mentioned 2nd vision signal is identical in adjacent vertical scanning period potential difference (PD) each other with above-mentioned 1st vision signal in adjacent vertical scanning period potential difference (PD) each other, on the other hand, the center voltage of above-mentioned 2nd vision signal is different from the above-mentioned fixed voltage of above-mentioned counter-electrode voltage.

Such as, if make the amplitude of above-mentioned 1st polarity of the 1st vision signal become large Δ V, the amplitude of above-mentioned 2nd polarity is diminished Δ V, just can generate the center voltage of the 1st vision signal to the 1st polarity lateral deviation from the 2nd vision signal after Δ V.In addition, on the contrary, if make the amplitude of above-mentioned 1st polarity of the 1st vision signal diminish Δ V, make the amplitude of above-mentioned 2nd polarity become large Δ V, just can generate the center voltage of the 1st vision signal to the 2nd polarity lateral deviation from the 2nd vision signal after Δ V.

In addition, counter-electrode voltage is jointly supplied to any pixel in 1 picture entirety.

So, in the present invention, generate the 2nd vision signal making the center voltage of vision signal different from the above-mentioned fixed voltage of counter-electrode voltage, thus in the 1st viewing area and the 2nd viewing area, the state after the above-mentioned fixed voltage changing counter-electrode voltage in analog can be formed, 2 display states are compared on 1 picture simultaneously.

Consequently, just can judge which side flicker in the 1st viewing area and the 2nd viewing area is less, can easily judge whether can using the counter-electrode voltage of the 1st viewing area as optimum value at a glance.Particularly, in the 1st vision signal of the 1st viewing area, the above-mentioned fixed voltage that its center voltage is set to regard as with above-mentioned counter-electrode voltage is consistent, therefore whether this setting is really optimum condition, can by seeing that each display state of the 1st viewing area and the 2nd viewing area judges immediately simultaneously.

And, as mentioned above, only change the amplitude of vision signal, therefore do not need special formation, just can confirm whether counter-electrode voltage is optimum value simply.

In addition, the combination of the formation described in claim that the combination of certain formation described in claim paid close attention to and formation described in other claim is not limited only to and is quoted by the claim of this concern, as long as object of the present invention can be reached, it also can be the combination with the formation described in the claim do not quoted by the claim of this concern.

invention effect

As described above, in display inspection method of the present invention, while carry out making the reversion of the reversal of poles of vision signal drive by every 1 vertical scanning period to the pixel electrode being configured with liquid crystal layer between comparative electrode, while keep the current potential of above-mentioned vision signal in every 1 vertical scanning period, when carrying out such display, the counter-electrode voltage being applied to above-mentioned comparative electrode is made to be fixed voltage, or make to make the center voltage when reversal of poles of counter-electrode voltage be fixed voltage by every 1 vertical scanning period, 1 picture shows the 1st viewing area and the 2nd viewing area, at least 2, viewing area simultaneously, the display based on the 1st vision signal is carried out in above-mentioned 1st viewing area, the center voltage of above-mentioned 1st vision signal is consistent with the above-mentioned fixed voltage of above-mentioned counter-electrode voltage, the display based on the 2nd vision signal is carried out in above-mentioned 2nd viewing area, above-mentioned 2nd vision signal is identical in adjacent vertical scanning period potential difference (PD) each other with above-mentioned 1st vision signal in adjacent vertical scanning period potential difference (PD) each other, on the other hand, the center voltage of above-mentioned 2nd vision signal is different from the above-mentioned fixed voltage of above-mentioned counter-electrode voltage.

Therefore, it is possible to just judge which side flicker in the 1st viewing area and the 2nd viewing area is less at a glance, can easily judge whether to regard the counter-electrode voltage of the 1st viewing area as optimum value.And, only change the amplitude of vision signal, therefore do not need special formation, just obtain and can confirm that whether counter-electrode voltage is the effect of optimum value simply.

Accompanying drawing explanation

Fig. 1 is the oscillogram of the waveform that the source electrode of each pixel that 3 viewing areas be supplied in 1 picture are shown exports, a () illustrates the situation that center voltage that source electrode exports is consistent with the center voltage of voltage Vcom, (b) (c) illustrates the situation of the center voltage of the center voltage offset voltage Vcom that source electrode exports.

Fig. 2 is the oscillogram of the waveform that vision signal (source electrode output) and the voltage Vcom being applied to source bus line is shown.

Fig. 3 is the front view of display state that the display frame carried out when display that whether display frame produce flicker checks is shown.

The oscillogram of the waveform that source electrode when Fig. 4 is n field (the n frame) that the pixel capable relative to m is conceptually shown exports.

The oscillogram of the waveform that source electrode when Fig. 5 is (n+1) field that the same pixel capable relative to m is conceptually shown exports.

Fig. 6 is the front view of the display state of region A ~ C when n field is shown.

Fig. 7 is the front view of the display state of region A ~ C when (n+1) field is shown.

Fig. 8 is the key diagram of the setting way of the input data signal in each region of the tolerance deviation of the optimum setting value that to illustrate flicker be minimum voltage Vcom when managing as ± 1bit (bit).

Fig. 9 is the key diagram of tolerance deviation as the setting way of the input data signal in each region when ± 2bit management of the optimum setting value that to illustrate flicker be minimum voltage Vcom.

Figure 10 illustrates that the display whether producing flicker in display frame checks that the flicker of region A is the front view of minimum display state in operation.

Figure 11 illustrates that the display whether producing flicker in display frame checks that the flicker of region B is the front view of minimum display state in operation.

Figure 12 illustrates that the display whether producing flicker in display frame checks that the flicker of region C is the front view of minimum display state in operation.

Figure 13 is the block diagram of the configuration example that liquid crystal indicator of the present invention is shown.

Figure 14 is the key diagram of the definition that flicker rate is shown.

Figure 15 is the key diagram of the display pattern illustrated in existing display inspection.

Figure 16 illustrates and process flow diagram voltage Vcom being set as the general processing sequence that the process of optimum value is relevant.

Figure 17 is the key diagram of the example that the general display frame shown when checking is shown.

Figure 18 is the key diagram of other example that the general display frame shown when checking is shown.

Embodiment

Below, embodiments of the present invention are explained.

(formation of the liquid crystal indicator relevant to counter-electrode voltage)

Figure 13 is the block diagram of the formation that liquid crystal indicator 1 is shown, the equivalent circuit of 1 pixel 3 shown in display part (liquid crystal panel) 2.At this, be described the formation relevant to counter-electrode voltage Vcom (hreinafter referred to as voltage Vcom), other formation is aftermentioned.

Pixel 3 is arranged accordingly with the point of crossing of grid bus GL and source bus line SL.Pixel 3, except possessing TFT4, liquid crystal capacitance CL and auxiliary capacitor Cs, usually also comprises and is formed at the stray capacitances such as electric capacity Cgd between pixel electrode 5 and grid bus GL.

The grid of TFT4 is connected with grid bus GL, and the source electrode of TFT4 is connected with source bus line SL, and the drain electrode of TFT4 is connected with pixel electrode 5.

Liquid crystal capacitance CL is formed owing to configuring liquid crystal layer between pixel electrode 5 and the comparative electrode 6 being applied in voltage Vcom.In addition, auxiliary capacitor Cs is due at pixel electrode 5 or configure dielectric film between the electrode be connected with pixel electrode 5 and the auxiliary capacitance bus being applied in voltage Vcs and formed.In addition, voltage Vcs such as can equal voltage Vcom, also can be other value.

Voltage Vcom is that the setting etc. by changing the register forming comparative electrode driver 7 manually adjusts, and generates the voltage Vcom corresponding with setting value, applies to comparative electrode 6.

(reversion drives and flicker)

Fig. 2 is the oscillogram of the waveform that vision signal (source electrode output) and the voltage Vcom being applied to source bus line SL is shown.The polarity of vision signal is reversed by every 1 image duration (1 vertical scanning period) according to frame inversion driving mode.

In addition, the polarity of voltage Vcom is reversed with the opposite polarity mode of vision signal to become according to common inversion driving mode.Thus, compared with voltage Vcom being remained the situation of fixed value, the amplitude of vision signal can be made to diminish.But, the situation that the present invention is also applicable to not adopt common inversion driving mode and voltage Vcom is remained fixed value.

(a) of Fig. 2 illustrate vision signal consistent with the center voltage of the median of the voltage of negative polarity and the center voltage (fixed voltage described in claim) of voltage Vcom as the voltage of positive polarity after optimum condition.That is, even if the potential difference (PD) frame of vision signal and voltage Vcom changes also is fixing.

In addition, (b) of Fig. 2 illustrates the state that the center voltage of voltage Vcom is larger than the center voltage of vision signal, and (c) of Fig. 2 illustrates the state that the center voltage of voltage Vcom is less than the center voltage of vision signal.

In arbitrary situation in (b) (c) of Fig. 2, the potential difference (PD) of vision signal and voltage Vcom all increases and decreases repeatedly with the frame period, therefore produces the flicker of the light transmission increase and decrease of pixel.

In addition, voltage Vcom is applied to all pixels being formed display part 2 with identical value.Therefore, when carrying out voltage Vcom and whether being set as that the display of optimum value checks, be see that the display frame entirety of display part 2 checks whether to produce flicker in the past.

In this way, when the setting value changing voltage Vcom checks the generation situation of flicker, can not see that the display frame before changing voltage Vcom compares simultaneously, therefore be difficult to judge whether the generation of glimmering is minimum.

(display drive method in display inspection of the present invention)

Therefore, in display inspection method of the present invention, can under the state being jointly applied with identical voltage Vcom to all pixels forming display part 2, partly form the viewing area (region A, B, C shown in Fig. 3) after the setting changing voltage Vcom in analog, by voltage Vcom before changing after display state confirm in 1 picture simultaneously, compare.

Fig. 3 illustrates the front view in the display state of carrying out display frame 2a when whether display frame 2a produces the display inspection of flicker.Elementary video in display frame 2a is by the rest image of the black and grey horizontal stripe alternately configured by every 1 row.

First, the vision signal (the 1st vision signal) of this elementary video of display is described.Fig. 1 is the oscillogram that the waveform that the source electrode of each pixel being supplied to region A ~ C (suitable by this order and the 1st viewing area, the 2nd viewing area, the 3rd viewing area) exports is shown.(a) of Fig. 1 illustrates the waveform of above-mentioned 1st vision signal of the source bus line SL being applied to region A.In the 1st vision signal, the voltage of the positive polarity corresponding with the gray level X of ash is maintained in 1 image duration i.e. 1 vertical scanning period, after the display carrying out not having gray level to change and rest image display, in the next frame, be reversed to the voltage of negative polarity according to frame inversion driving mode.In addition, also proceed after voltage reversal not free on the display of gray level change.Be counted as consistent with the center voltage of above-mentioned voltage Vcom as the voltage of positive polarity with the initial setting of the center voltage A (center voltage) of the median of the voltage of negative polarity.

At the background area D (background area) of the display frame 2a shown in Fig. 3 with in shown region A, carry out the display based on above-mentioned 1st vision signal as a part of region wherein.

(b) of Fig. 1 is depicted as the waveform of the source bus line SL applying to region B and the 2nd vision signal after correcting above-mentioned 1st vision signal.2nd vision signal keeps the voltage of positive polarity of the 1st vision signal and the difference of the voltage of negative polarity same as before regularly, and center voltage B adds+α relative to center voltage A.That is, the 2nd vision signal has the DC composition of+α relative to the center voltage of voltage Vcom.

In the region B in a part of region as display frame 2a, carry out the display based on above-mentioned 2nd vision signal.Thereby, it is possible to confirm the display state of region A and the display state of region B simultaneously, compare the generation state of flicker, therefore whether the DC setting of voltage Vcom in region a suitably can by easily differentiating with comparing of region B.

(c) of Fig. 1 illustrates with the offset method of center voltage to be the waveform of the 3rd vision signal after the mode contrary with the 2nd vision signal corrects the 1st vision signal.3rd vision signal keeps the voltage of positive polarity of the 1st vision signal and the difference of the voltage of negative polarity same as before regularly, and center voltage C decreases-α relative to center voltage A.That is, the 3rd vision signal has the DC composition of-α relative to the center voltage of voltage Vcom.

Source bus line SL to the region C in a part of region as display frame 2a applies above-mentioned 3rd vision signal, in the C of region, therefore carry out the display based on the 3rd vision signal.Thus, except the display state of region A and region B, the display state of region C can also be confirmed simultaneously, compare the generation state of flicker.Particularly, in region B and region C, contrary to the polarity of the DC composition that the 1st vision signal corrects, if therefore can confirm that the flicker of region A is less than the flicker of region B, C by the flicker of comparing in 3 kinds of displays, the flicker just can making region A is minimum reliable judgement.

In addition, can control specifically to exercise to certain in certain specific field the liquid crystal indicator that source electrode output is positive polarity or the source electrode driver for the specification of negative polarity if possess, just can when the flicker of region A be not minimum, voltage Vcom be optimum value, easily judge this DC of voltage Vcom is set to+and-which side change.

In addition, each region in the A ~ C of region to be shown by the mode of carrying out surrounding based on the background area D of the display of above-mentioned 1st vision signal, therefore, it is possible to confirm the deviation of the flicker in 1 picture.

This is because, by making the gray level display identical with region A in background area D, can confirm produce the part of flicker and do not produce the part of flicker in large-area background area D.

In addition, the deviation of the flicker in 1 picture is mixed into caused reason etc. is caused by the stray capacitance deviation of the thin film transistor (TFT) in picture etc., the deviation of element thickness, the impurity (encapsulant periphery) of picture periphery.

In addition, above-mentioned comparative electrode driver 7, according to specification, have the setting value of voltage Vcom to write type that the type of 1 time and this setting value can write more than 2 times.If the flicker being confirmed region A by the comparison of above-mentioned zone A ~ C is not minimum, just can be able to write in the comparative electrode driver 7 of the type of more than 2 times in this setting value, rewrite this setting value, repeatedly carry out display and check operation, search the optimum value of voltage Vcom.

(details of the 2nd vision signal and the 3rd vision signal)

Below, the voltage sets of the 2nd vision signal and the 3rd vision signal is described in further detail.

The voltage (positive polarity source electrode exports) of the positive polarity (positive) of the vision signal be output and the voltage (negative polarity source electrode exports) of negative polarity (negative) is determined accordingly with each gray level of input data signal on the basis becoming vision signal.That is, if gray level is different, then source electrode exports also different.

The oscillogram of the waveform that source electrode when Fig. 4 is n field (the n frame) that the pixel capable relative to m is conceptually shown exports, the oscillogram of the waveform that source electrode when Fig. 5 is (n+1) field that the same pixel capable relative to m is conceptually shown exports.

In addition, Fig. 6 and Fig. 7 is the front view with the display state of region A ~ C during (n+1) field when n field is shown respectively.

As shown in Figure 4 and Figure 5, in the present embodiment, 3 kinds of gray level X that the output of use source electrode is mutually different, the combination of Y, Z form the display of above-mentioned zone A ~ C.

The positive polarity source electrode of gray level X, Y, Z is exported (V) as Xp, Yp, Zp, negative polarity source electrode exports (V) respectively as Xn, Yn, Zn.

Gray level Y is the gray level that positive polarity source electrode exports that Yp is (Xp+ α) V, negative polarity source electrode output Yn is (Xn-α) V.

Gray level Z is the gray level that positive polarity source electrode exports that Zp is (Xp-α) V, negative polarity source electrode output Zn is (Xn+ α) V.

In display frame 2a when carrying out display and checking, as shown in Figure 6 and Figure 7, the rest image of the horizontal stripe shown as any gray level (if the input data signal of 8 bits, being then 128 gray levels etc.) beyond black and black alternately configured by every 1 row is easy to confirm the image of flicker like this.In addition, also can as the confirmation screen II be described with reference to Figure 17, to show from the left end of display frame to right-hand member from black to white with the gradual change image that 10 stages change.

In addition, frame rate is slower, is more easy to confirm flicker, but preferably confirms flicker using the frame rate of 60Hz or 50Hz as actual drive condition.

As shown in Figure 6 and Figure 7, in region a, making above-mentioned any gray level be X gray level when n field, is also X gray level when (n+1) field, source electrode is exported be that positive polarity source electrode exports Xp when n field, be that negative polarity source electrode exports Xn when (n+1) field.That is, the waveform of (the 1st vision signal) is exported relative to the source electrode of the pixel of region A for the waveform Wa shown in Fig. 4 and Fig. 5.

To this, in the B of region, making above-mentioned any gray level be Y gray level when n field, is Z gray level when (n+1) field, source electrode is exported and is that positive polarity source electrode exports Yp when n field, is that negative polarity source electrode exports Zn when (n+1) field.That is, the waveform of (the 2nd vision signal) is exported relative to the source electrode of the pixel of region B for the waveform Wb shown in Fig. 4 and Fig. 5.

On the other hand, in the C of region, making above-mentioned any gray level be Z gray level when n field, is Y gray level when (n+1) field, source electrode is exported and is that positive polarity source electrode exports Zp when n field, is that negative polarity source electrode exports Yn when (n+1) field.That is, the waveform of (the 3rd vision signal) is exported relative to the source electrode of the pixel of region C for the waveform Wc shown in Fig. 4 and Fig. 5.

In addition, the above-mentioned gray level setting in region B and region C can also be exchanged.

Thus, adjacent field (vertical scanning period) potential difference (PD) each other (source electrode amplitude) becomes identical shown in 3 waveforms Wa, Wb, Wc formula 1 ~ formula 3 all described as follows.

Region A:Xp-Xn=Vpp formula 1

Region B:Yp-Zn=((Xp+ α)-(Xn+ α))=Xp-Xn=Vpp formula 2

Region C:Zp-Yn=((Xp-α)-(Xn-α))=Xp-Xn=Vpp formula 3

In addition, when the center voltage A making the source electrode of region A export is Va, the center voltage of region B is just Va+ α, and the center voltage of region C is just Va-α, relative to the region A of input usually, and can by the center voltage of region B and region C skew+α or-α.

So, correction is carried out to generate above-mentioned 2nd vision signal and the 3rd vision signal respectively by the data of the input gray grade being supplied to the source electrode driver SD (Figure 13) exporting above-mentioned 1st vision signal.

In addition, above-mentioned 2nd vision signal and the 3rd vision signal generate respectively by correcting the data of the above-mentioned input gray grade corresponding with the positive polarity voltage of above-mentioned 1st vision signal and the data of the above-mentioned input gray grade corresponding with the reverse voltage of above-mentioned 1st vision signal.Further, the data of mode to above-mentioned input gray grade offset to identical polar side by identical correcting value (α) with the positive polarity voltage of above-mentioned 1st vision signal and reverse voltage correct.Thus, the side-play amount of each center voltage of above-mentioned 2nd vision signal and the 3rd vision signal also becomes and equals above-mentioned correcting value (α), therefore, it is possible to change the display after the DC setting of voltage Vcom simply in analog.

In addition, according to the specification of source electrode driver, have and can not control specifically to exercise source electrode output for positive polarity or the source electrode driver for negative polarity to certain in certain specific field.In this case, the polarity be difficult to the source electrode of region B (or region C) exports intentionally controls to positive side (or minus side).

In addition, even be provided with the Liquid Crystal Module of the source electrode driver that can control this polarity, if want to control to be positive polarity to the output of the specific enforcement of certain in certain specific field source electrode or to be negative polarity, then, when also needing the signal inputted to source electrode driver in generation, take into full account polarity.

To this, in the present case, in adjacent field, be gray level Y → gray level Z and in the C of region, make input gray grade be gray level Z → gray level Y as made input gray grade in the B of region, the input gray grade of exchanging region B and region C is easy.Therefore, even if the polarity that the source electrode of region B and region C exports intentionally is not controlled to positive side (or minus side), also can judge if the flicker of region A is minimum by means of only the input gray grade of exchanging region B and region C, as best.And, by means of only the input gray grade of exchanging region B and region C, independently the center voltage of region B can be offset to the side in+α or-α with the specification of source electrode driver, by the center voltage of region C to the opposing party's skew in+α or-α.

(the gray level setting of input data signal)

Then, the gray level setting of the input data signal of the display for realizing above-mentioned zone A ~ C is described with reference to Fig. 8 and Fig. 9.

Fig. 8 is the key diagram of tolerance deviation as the setting way of the input data signal in each region when ± 1bit management of the optimum setting value that to illustrate flicker be minimum voltage Vcom, and it is the tolerance deviation that is the optimum setting value of minimum voltage Vcom using flicker as the key diagram of the setting way of the input data signal in each region when ± 2bit management that Fig. 9 illustrates.

The DC adjustment of voltage Vcom is adjusted by the serial setting of driver mostly, therefore in the present embodiment, utilizes the bit of the regulating object as serial setting to be described.

As shown in Figure 8 and Figure 9, after the optimum setting value of voltage Vcom is written to comparative electrode driver 7, for region A, in n field and (n+1) field, to source electrode driver SD (Figure 13) input with by data that gray level intermediate grey scales such as () such as 128 gray levels determined is corresponding.

Then, when as shown in Figure 8 using tolerance deviation as ± 1bit management, such as the one party in region B or region C, depart from using-the α corresponding to the amount of-3bit of the amount adjusted as the DC of voltage Vcom (α is the increase and decrease amount of the center voltage that above-mentioned source electrode exports) mode resulting from one party in center voltage B or center voltage C that source electrode exports, determine the gray level of input data signal.

In addition, for the opposing party in region B or region C, make the polarity of input data signal contrary, depart from using+the α corresponding to the amount of+3bit of the amount adjusted as the DC of voltage Vcom the mode resulting from center voltage B that source electrode exports or center voltage C, determine the gray level of input data signal.

In addition, the prerequisite that the gray level of input data signal determines as described above be, using can not the source electrode driver of polarity of control inputs data-signal.

Above-mentioned as a result, if the DC setting being written to the voltage Vcom of comparative electrode driver 7 is correct, then the flicker of region A is minimum.

On the other hand, when the correct DC setting of the voltage Vcom being written to comparative electrode driver 7 is illustrated in figure 8 the above negative direction of-2bit, then the flicker of the one party in region B or region C is minimum.

In addition, when the correct DC setting of the voltage Vcom being written to comparative electrode driver 7 is illustrated in figure 8 the above positive dirction of+2bit, then the flicker of the opposing party in region B or region C is minimum.

In addition, when as shown in Figure 9 using tolerance deviation as ± 2bit management, such as the one party in region B or region C, in the mode departing from the side resulted from center voltage B or center voltage C that source electrode the exports of-α corresponding to the amount of-5bit of the amount adjusted as the DC of voltage Vcom, determine the gray level of input data signal.

And, for the opposing party in region B or region C, make the polarity of input data signal contrary, depart from using+the α corresponding to the amount of+5bit of the amount adjusted as the DC of voltage Vcom the mode resulting from center voltage B that source electrode exports or center voltage C, determine the gray level of input data signal.

Thus, when the correct DC setting of the voltage Vcom being written to comparative electrode driver 7 is illustrated in figure 9 the above negative direction of-3bit, the flicker of the one party then in region B or region C is minimum, when positive dirction above for+3bit, then the flicker of the opposing party in region B or region C is minimum.

(display checks operation)

Based on above setting, show in the A ~ C of region, check the generation state of flicker.Figure 10 illustrates to check that the flicker of region A in operation is the front view of minimum display state in the display whether producing flicker, Figure 11 illustrates that the flicker of region B is the front view of minimum display state, and Figure 12 illustrates that the flicker of region C is the front view of minimum display state.

Such as, Figure 10 represents that the DC of the voltage Vcom being written to comparative electrode driver 7 sets correct result, and namely the flicker of region A has become minimum state.

In addition, Figure 11 represent departing from of-α corresponding to the amount of such as-3bit or with the corresponding+α of the amount of+3bit depart from the result resulting from the center voltage B that source electrode exports, namely the flicker of region B has become minimum state.

In addition, Figure 12 represent departing from of-α corresponding to the amount of such as-3bit or with the corresponding+α of the amount of+3bit depart from the result resulting from the center voltage C that source electrode exports, namely the flicker of region C has become minimum state.

As shown in Figure 10 ~ 12, in 1 display frame 2a, usual input viewing area after display makes the center voltage of voltage Vcom consistent with the center voltage that source electrode exports (regarding as) and the viewing area after intentionally center voltage being offset, whether the DC setting value being therefore written to the voltage Vcom of comparative electrode driver 7 is best, easily can confirm according to outward appearance.

And, the center voltage exported by source electrode offsets to mutually opposite polarity side in region B and region C, therefore as shown in Figure 10, if can confirm that the flicker of region A is less than the flicker of region B, C, the flicker just can making region A is minimum reliable judgement.

And then, each region in the A ~ C of region is shown in the mode of being surrounded by background area D, in the D of above-mentioned background region, carries out the display exported based on the source electrode identical with region A.Thereby, it is possible to confirm the deviation of the flicker in 1 picture.

In addition, also according to the side-play amount resulting from voltage Vcom by comprising the impact of at least 1 factor that temperature variation, timeliness change and illumination hits of prediction, the source electrode different with the center voltage of voltage Vcom from making center voltage can be generated and export corresponding input data signal.Based on such input data signal, show in region B or region C, can judge that whether flicker that this region produces is beyond permissible level thus.

Thereby, it is possible to before in fact above-mentioned various factors causes voltage Vcom to offset, detect the unacceptable product producing and glimmer beyond the exception of permissible level.

In addition, to the flicker produced whether beyond the judgement of permissible level, have the flicker rate employing determinator to measure or the limit sample that sets with the mode of the maximal value becoming permissible level with flicker rate the method such as to compare.

So-called flicker rate, refers to as shown in figure 14, is represented by the ratio of the fluctuation amplitude A C of the brightness of display frame and the mean value DC of brightness, i.e. (AC/DC) × 100 with percent.

(formation of liquid crystal indicator and supplementing of action)

Finally, get back to Figure 13, first talk about other formation and action of liquid crystal indicator 1.

As shown in figure 13, liquid crystal indicator 1, except possessing above-mentioned display part 2, also possesses source electrode driver SD, gate drivers GD and display control circuit 8.Source electrode driver SD drives source bus line SL, and gate drivers GD driving grid bus GL, display control circuit 8 controls source electrode driver SD and gate drivers GD.In addition, the holding capacitor wiring driving circuit driving holding capacitor distribution (Cs distribution) also can be set as required.

Display control circuit 8 receives from the signal source (such as tuner) of outside the digital video signal Dv, the horizontal-drive signal HSY corresponding with this digital video signal Dv and vertical synchronizing signal VSY and the control signal Dc for controlling display action that represent the image that should show.

In addition, display control circuit 8 is based on these each signal Dv, HSY, VSY, Dc of receiving, generation data initial pulse signal SSP, data clock signal SCK, the data image signal DA (signal corresponding with digital video signal Dv) representing the image that should show, grid initial pulse signal GSP, gate clock signal GCK and gate drivers export control signal (sweep signal output control signal) GOE and are shown in the signal of display part as the image for making this digital video signal Dv represent, are exported by these signals.

More particularly, after above-mentioned digital video signal Dv being carried out in internal storage timing adjustment etc. as required, export from display control circuit 8 as data image signal DA.Generate above-mentioned data clock signal SCK as the signal comprising the pulse corresponding with each pixel of the image that this data image signal DA represents.In addition, above-mentioned data initial pulse signal SSP is generated as the signal being only in high level (H level) based on above-mentioned horizontal-drive signal HSY by every 1 horizontal scan period in specified time limit.And, generate above-mentioned grid initial pulse signal GSP as the signal being only in H level based on above-mentioned vertical synchronizing signal VSY by every 1 image duration (1 vertical scanning period) in specified time limit.Based on above-mentioned horizontal-drive signal HSY, generate above-mentioned gate clock signal GCK.Based on above-mentioned horizontal-drive signal HSY and above-mentioned control signal Dc, generate above-mentioned gate drivers and export control signal GOE.

As mentioned above, in the signal being created on display control circuit 8, polarity inversion signal POL, the data initial pulse signal S SP and data clock signal SCK of the polarity of control figure picture signal DA are imported into source electrode driver SD.On the other hand, grid initial pulse signal GSP, gate clock signal GCK and gate drivers export control signal GOE and are imported into gate drivers GD.

Source electrode driver SD is based on data image signal DA, data clock signal SCK, data initial pulse signal SSP and polarity inversion signal POL, the simulation current potential (data-signal) suitable with the pixel value in each scan signal line of the image represented by data image signal DA generates successively by every 1 horizontal scan period, and these data-signals are outputted to source bus line SL.

Gate drivers GD exports control signal GOE based on grid initial pulse signal GSP, gate clock signal GCK and gate drivers, generate gate-on pulses signal, these signals are outputted to grid bus GL, thus, optionally driving grid bus GL.

As mentioned above, by source electrode driver SD and gate drivers GD, the grid bus GL of display part 2 and source bus line SL is driven, thus via the TFT4 be connected with selected grid bus GL, from source bus line SL, data-signal is written to pixel electrode 5.Liquid crystal layer thus to each pixel 3 applies voltage, controls the transmissivity of the light from backlight thus, the image that display digital video signal Dv represents.

Below, above-mentioned display inspection method of the present invention is supplemented.

The feature of display inspection method of the present invention is, also on above-mentioned 1 picture, show the 3rd viewing area simultaneously, the display based on the 3rd vision signal is carried out in above-mentioned 3rd viewing area, and the center voltage of above-mentioned 3rd vision signal is in from the opposite polarity side of above-mentioned center voltage of above-mentioned 2nd vision signal relative to the above-mentioned fixed voltage of above-mentioned counter-electrode voltage and different.

Thereby, it is possible to confirm on 1 picture using the above-mentioned fixed voltage of the counter-electrode voltage of the 1st viewing area as benchmark simultaneously, 3 states after the above-mentioned fixed voltage of counter-electrode voltage is offset in analog to the polarity side of positive and negative both sides.Consequently, if can confirm that the flicker of the 1st viewing area is less than the flicker of the 2nd viewing area and the 3rd viewing area, the flicker just can making the 1st viewing area is minimum reliable judgement.

In addition, can control specifically to exercise to certain in certain specific field the liquid crystal indicator that source electrode output is positive polarity or the source electrode driver for the specification of negative polarity if possess, just when the flicker of the 1st viewing area be not minimum, counter-electrode voltage is not optimum value, can easily judge this increase or this minimizing counter-electrode voltage.

The feature of display inspection method of the present invention is, is also shown in the mode of being surrounded by the background area on above-mentioned 1 picture in each region in above-mentioned viewing area, carries out the display based on above-mentioned 1st vision signal in above-mentioned background region.

As mentioned above, make the display state of the background area in the region beyond as multiple viewing areas such as the 1st ~ 3rd viewing areas identical with the display state of the 1st viewing area, the deviation of the flicker in 1 picture can be confirmed thus.

This is because, by making the gray level display identical with the 1st viewing area in background area, can confirm produce the part of flicker and do not produce the part of flicker in large-area background area.

The feature of display inspection method of the present invention is, the 2nd vision signal obtained based on making center voltage different from the above-mentioned fixed voltage of above-mentioned counter-electrode voltage according to the side-play amount resulting from above-mentioned counter-electrode voltage by comprising the impact of at least 1 factor that temperature variation, timeliness change and illumination hits of prediction or the 3rd vision signal, show in the 2nd viewing area or the 3rd viewing area, judge that whether the flicker produced in the 2nd viewing area or the 3rd viewing area is beyond permissible level.

Thereby, it is possible to before in fact various factors causes voltage Vcom to offset, detect the unacceptable product producing and glimmer beyond the exception of permissible level.

In addition, to resulting from the flicker of the 2nd viewing area whether beyond the judgement of permissible level, have the flicker rate employing determinator to measure or the limit sample that sets with the mode of the maximal value becoming permissible level with flicker rate the method such as to compare.

The invention is not restricted to above-mentioned each embodiment, various change can be carried out in the scope shown in claim, appropriately combined disclosed technical scheme and the embodiment that obtains also is contained in technical scope of the present invention respectively in various embodiments.

industrial utilizability

The present invention can be used in the display inspection method exchanged in the liquid crystal indicator of type of drive.

description of reference numerals

Claims

1. show an inspection method, it is characterized in that,

While the pixel electrode being configured with liquid crystal layer between to comparative electrode carries out making the reversion of the reversal of poles of vision signal drive by every 1 vertical scanning period, when keeping the current potential of above-mentioned vision signal in every 1 vertical scanning period,

Make the counter-electrode voltage being applied to above-mentioned comparative electrode be fixed voltage, or to make by the center voltage (Va) of the above-mentioned counter-electrode voltage when reversal of poles of every 1 vertical scanning period by counter-electrode voltage be fixed voltage,

1 picture shows the 1st viewing area and the 2nd viewing area, at least 2, viewing area simultaneously, the display based on the 1st vision signal is carried out in above-mentioned 1st viewing area, the center voltage (A) of above-mentioned 1st vision signal is consistent with the above-mentioned fixed voltage of above-mentioned counter-electrode voltage, the display based on the 2nd vision signal is carried out in above-mentioned 2nd viewing area, above-mentioned 2nd vision signal is identical in adjacent vertical scanning period potential difference (PD) each other with above-mentioned 1st vision signal in adjacent vertical scanning period potential difference (PD) each other, on the other hand, the center voltage (B) of above-mentioned 2nd vision signal is different from the above-mentioned fixed voltage of above-mentioned counter-electrode voltage.

2. display inspection method according to claim 1, is characterized in that,

Above-mentioned 1 picture shows the 3rd viewing area simultaneously, the display based on the 3rd vision signal is carried out in above-mentioned 3rd viewing area, and the center voltage of above-mentioned 3rd vision signal is in from the opposite polarity side of above-mentioned center voltage of above-mentioned 2nd vision signal relative to the above-mentioned fixed voltage of above-mentioned counter-electrode voltage and different.

3. display inspection method according to claim 1 and 2, is characterized in that,

Each region in above-mentioned viewing area is shown in the mode of being surrounded by the background area on above-mentioned 1 picture,

The display based on above-mentioned 1st vision signal is carried out in above-mentioned background region.

4. display inspection method according to claim 2, is characterized in that,

The 2nd vision signal obtained based on making center voltage different from the above-mentioned fixed voltage of above-mentioned counter-electrode voltage according to the side-play amount resulting from above-mentioned counter-electrode voltage by comprising the impact of at least 1 factor that temperature variation, timeliness change and illumination hits of prediction or the 3rd vision signal, show in the 2nd viewing area or the 3rd viewing area

Judge that whether the flicker produced in the 2nd viewing area or the 3rd viewing area is beyond permissible level.

5. display inspection method according to claim 1, is characterized in that,

Above-mentioned 2nd vision signal is generated by carrying out correction to the data of the input gray grade being supplied to the source electrode driver exporting above-mentioned 1st vision signal.

6. display inspection method according to claim 5, is characterized in that,

Above-mentioned 2nd vision signal is generated by carrying out correction respectively to the data of the above-mentioned input gray grade corresponding with the positive polarity voltage of above-mentioned 1st vision signal and the data of the above-mentioned input gray grade corresponding with the reverse voltage of above-mentioned 1st vision signal.

7. display inspection method according to claim 2, is characterized in that,

Above-mentioned 3rd vision signal is generated by carrying out correction to the data of the input gray grade being supplied to the source electrode driver exporting above-mentioned 1st vision signal.

8. display inspection method according to claim 7, is characterized in that,

Above-mentioned 3rd vision signal is generated by carrying out correction respectively to the data of the above-mentioned input gray grade corresponding with the positive polarity voltage of above-mentioned 1st vision signal and the data of the above-mentioned input gray grade corresponding with the reverse voltage of above-mentioned 1st vision signal.