JP3019035B2 - Liquid crystal display device and driving method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal display device.

[Summary of the Invention] The present invention relates to a liquid crystal display device in which a voltage waveform deformation such as a rounding or a spike in a scanning voltage waveform applied to a scanning electrode and a signal voltage waveform applied to a signal electrode occurs. It is generated based on the rules included in the graphics and character patterns to be displayed, which causes a difference in the effective voltage applied to each display pixel, and has been proposed with a focus on unevenness in display contrast. The effective voltage applied to each display dot is compensated by changing at least one of the scanning voltage waveform and the signal voltage waveform based on the rules included in the graphic or character pattern displayed by the liquid crystal display device (hereinafter, correction). This also eliminates uneven display contrast.

[0003]

2. Description of the Related Art When a simple matrix type liquid crystal display device is driven, a driving method generally called a voltage averaging method is conventionally employed.

The above-mentioned conventional driving method will be described with reference to FIGS. FIG. 54 shows the configuration and display contents of the liquid crystal panel. The liquid crystal panel 1 includes a liquid crystal layer and a pair of substrates 2 and 3 sandwiching the liquid crystal layer. One of the substrates 2 has scanning electrodes Y1 to Y6 formed in the lateral direction, and the other substrate 3 has signal electrodes X1 to X6 formed thereon. Intersections between the scanning electrodes Y1 to Y6 and the signal electrodes X1 to X6 serve as display dots.

In FIG. 54, hatched display dots indicate a lighting state, and other display dots indicate a non-lighting state. The liquid crystal panel in the illustrated example has a 6 × 6 dot configuration, but this is for the sake of simplicity.
The actual number of dots on a liquid crystal panel is usually much higher.

A selection voltage or a non-selection voltage is sequentially applied to each of the scan electrodes Y1 to Y6, and a period required for sequentially applying the selection voltage or the non-selection voltage to all the scan electrodes Y1 to Y6 is one. It is called a frame.

When a selection voltage or a non-selection voltage is sequentially applied to the scanning electrodes Y1 to Y6, a lighting voltage or a non-lighting voltage is simultaneously applied to the signal electrodes X1 to X6. In other words, when lighting a display dot at the intersection of a certain scanning electrode and a certain signal electrode, when that scanning electrode is selected, a lighting voltage is applied to that signal electrode,
When not lighting, a non-lighting voltage is applied. Examples of actual driving waveforms (applied voltage waveforms) are shown in FIGS.

FIG. 55 (A) shows a signal voltage waveform applied to the signal electrode X5 in FIG. 54, and FIG. 55 (B) shows a scanning electrode Y3.
(C) is a voltage waveform applied to the display dot (lighting state) at the intersection of the signal electrode X5 and the scanning electrode Y3.

FIG. 56A shows a signal voltage waveform applied to the signal electrode X5, FIG. 56B shows a scan voltage waveform applied to the scan electrode Y4, and FIG. 56C shows a signal voltage waveform between the signal electrode X5 and the scan electrode Y4. It is a voltage waveform applied to the display dot (non-lighting state) at the intersection.

In FIGS. 55 and 56, F1 and F2
Is a frame period.

In the frame period F1, the selection voltage = V0,
Non-selection voltage = V4, lighting voltage = V5, non-lighting voltage = V
3, in the frame period F2, the selection voltage = V5, the non-selection voltage = V1, the lighting voltage = V0, the non-lighting voltage = V2,
It is.

V0-V1 = V1-V2 = V, V3
−V4 = V4−V5 = V, V0−V5 = N · V (N
Is a constant). Thus, the frame period F
1, AC drive is performed by changing the polarity at F2.

As can be seen from the comparison between FIG. 55 and FIG. 56, whether the display dot is turned on or off is determined when the selection voltage is applied to the scanning electrode where the display dot exists. It depends on whether a lighting voltage or a non-lighting voltage is applied to the signal electrode. Such a driving method is a conventional driving method called a voltage averaging method.

However, when driven by the above-described conventional voltage averaging method, actually, a clear rectangular wave is not always applied to the display dots as shown in FIGS. The first reason is that a display dot has an electric capacity determined by its area, the thickness of a liquid crystal layer, the dielectric constant of a liquid crystal material, and the like. The second reason is that both the scanning electrode and the signal electrode are generally made of a transparent conductive film having a sheet resistance of about several tens of ohms, and naturally have a constant electric resistance.

[0015] For this reason, if the driving circuit is temporarily switched to the state shown in FIG.
Even if a clean rectangular wave as shown in FIG. 6 is applied, the waveform actually applied to the display dots becomes a more or less distorted waveform. As a result, there is a problem that a difference occurs in the effective voltage of the waveform applied to each display dot, resulting in uneven contrast.

This problem has been known in the past, and as a countermeasure, for example, a method of inverting the polarity of the voltage applied to the liquid crystal panel a plurality of times during one frame (hereinafter, referred to as a line inversion driving method) is special. Japanese Patent Application Laid-Open Nos. 62-31825, 60-19195, 60-19196, and the like.

[0017]

However, the improvement effect obtained by the above-described line inversion driving method is very limited because it has only a certain effect on display unevenness in a first mode described later, and uneven display contrast. Was not completely eliminated.

The present inventors have conducted intensive studies on the unevenness of contrast in the above-mentioned conventional liquid crystal display device, and have found the following.

That is, first, the distortion of the voltage waveform applied to the display dots is generated based on the regularity included in the pattern of characters and figures displayed by the liquid crystal display device. That is, the change of the effective voltage based on the distortion of the voltage waveform applied to the display dot causes the contrast unevenness.

Based on this finding, the present inventors quantitatively extract the rules contained in the pattern displayed by the liquid crystal display device and correct the applied voltage waveform in accordance with the amount of extraction, whereby the contrast unevenness is reduced. I thought the outbreak could be prevented.
Based on such a concept, the problem is what regularity of the pattern causes what kind of distortion of the applied voltage waveform and further causes uneven contrast. At present, the present inventors have found that there are the following four modes for uneven contrast. Hereinafter, each mode will be described.

First Mode (hereinafter referred to as alternate threading) This mode will be described with reference to FIGS. 54, 57, 58, and 59. For convenience of explanation, it is assumed that the scanning electrodes Y1 to Y6 are driven so as to be sequentially selected from the first scanning electrode Y1 to the sixth scanning electrode Y6 and then return to the first scanning electrode Y1. Further, it is assumed that the liquid crystal panel performs a so-called positive display that becomes darker when the effective voltage applied to the display dots increases. This condition is the same hereinafter.

When the display as shown in FIG. 54 is performed, the liquid crystal display device actually has an uneven display contrast as shown in FIG. 57. At this time, the signal voltage waveforms (X1 to X4) at the display dots of the signal electrodes X1 to X4 are displayed.
X4 has the same waveform) as shown in FIG.
5 (B) shows a scanning voltage waveform at the display dot portion of FIG. 5, and FIG. 6 (C) shows a voltage waveform applied to the display dot formed by the intersection of the signal electrodes X1 to X4 and the scanning electrode Y3. Strictly speaking, the voltage waveforms applied to these four display dots are slightly different, but this difference is ignored here for the time being.
Here, as shown in FIG. 58B, a spike-like voltage distortion occurs in the non-selection voltage level of the scanning voltage waveform. The direction and magnitude of generation of the spike-like voltage have the following relationship with the display pattern.

In general, when the selection shifts from the nth scan electrode to the (n + 1) th scan electrode, the number of signal electrodes to which the lighting voltage is continuously applied is a, the number of signal electrodes to which the non-lighting voltage is continuously applied is b, and the lighting voltage is Let c be the number of signal electrodes added by switching from non-lighting voltage to non-lighting voltage, and d be the number of signal electrodes added by switching from non-lighting voltage to lighting voltage.

The number of lit dots on the n-th scanning electrode is N _ON , the number of non-lit dots is N _OFF , the number of lit dots on the (n + 1) th scanning electrode is M _ON , and the number of non-lit dots is M _OFF.
And Then, N _ON = a + c, N _OFF = b + d, M _ON
= A + d, M _OFF = b + c, N _ON + N _OFF = M _ON + M
_OFF = K (K is a constant and the total number of display dots on each scanning electrode). Here the value I and _{I = c~d = N ON ~M ON} . In conclusion, when the numerical value I is negative, the direction in which the spike-like voltage is generated is on the lighting voltage side, and when the numerical value I is positive, on the non-lighting voltage side. Then, the magnitude of the spike increases as the absolute value of the numerical value I increases.

In other words, when the number d of the signal electrodes at which the applied voltage switches from the non-lighting voltage to the lighting voltage is greater than the number c of the signal electrodes at which the applied voltage switches from the lighting voltage to the non-lighting voltage, the scanning voltage waveform Then, a spike-like voltage is generated on the lighting voltage side. Conversely, when the sign of the difference 1 between c and d changes, a spike-like voltage is generated on the non-lighting voltage side. In addition, the value of the spike voltage corresponds to the absolute value of I.

For this reason, when the change in the signal voltage waveform and the direction of the spike-like voltage on the non-selection voltage of the scanning voltage waveform are in the same phase as shown in FIGS. The voltage waveform of FIG. The longer the period of the same phase, the smaller the effective value and the thinner the display.

Next, the case where the change in the signal voltage waveform and the direction of the spike on the scanning voltage waveform are in opposite phases will be described.

FIG. 59A shows the signal electrode X in FIG.
FIG. 59 (B) is a scanning voltage waveform at the display dot portion of the scanning electrode Y3, and FIG.
(C) shows the voltage waveform applied to the display dot at the intersection of the signal electrode X5 and the scanning electrode Y3.

As shown in FIGS. 59A and 59B, when the change in the signal voltage waveform and the direction of the spike-like voltage on the non-selection voltage of the scanning voltage waveform are in opposite phases, A spike-like voltage is generated in the voltage waveform applied to the display dot, and the effective value increases. The longer the period during which the phase is reversed, the larger the effective value becomes, and as a result, the display becomes darker. For this reason, FIG.
The display dots on the 7 signal electrodes X1 to X4 become lighter, and the display dots on the signal electrode X5 become darker regardless of the lighting state or the non-lighting state. The density of the display dot on the signal electrode X6 is intermediate between the two.

FIG. 60 shows another pattern displayed on the same liquid crystal panel as in FIG. 54 described above. FIG. 61 shows contrast unevenness generated when this pattern is displayed. The reason why the unevenness as shown in FIG.

The display dot is a capacitor in an equivalent circuit. In addition, the value of the capacitance of the capacitor is different between the lighting state and the non-lighting state, and the value is larger in the lighting state. This phenomenon is caused by the fact that the liquid crystal material has dielectric anisotropy and that the orientation changes between the lit state and the non-lit state. Therefore, the capacitance of all the dots on the scanning electrode Y2 with many lighting dots is:
The capacity is larger than the capacity of all the dots on the scanning electrode Y4 with few lighting dots. Since the wiring resistances of the scanning electrodes are all the same, the rounding of the voltage waveform of the scanning electrode Y2 is larger. This situation is shown in FIGS. 62 and 63.

FIG. 62A shows the signal electrode X1 in FIG.
The signal voltage waveform at the upper display dot portion, FIG. 62B is the scan voltage waveform at the display dot portion on the scan electrode Y2, and FIG.
(C) shows a voltage waveform applied to the dot at the intersection of the signal electrode X1 and the scanning electrode Y2.

FIG. 63A shows a signal voltage waveform at a display dot portion on the signal electrode X1 in FIG. 60, and FIG.
Represents a scanning voltage waveform at a display dot portion on the scanning electrode Y4,
FIG. 9C shows a voltage waveform applied to a dot at the intersection of the signal electrode X1 and the scanning electrode Y4.

As can be seen from a comparison between FIG. 62 (B) and FIG. 63 (B), the scanning electrode Y2 having more lit dots is the same as that shown in FIG.
The shift from the non-selection voltage to the selection voltage is only dimmed in the shaded portion. Therefore, when comparing FIG. 62 (c) and FIG. 63 (C), the voltage effective value of the waveform applied to the dot on the scanning electrode Y2 is reduced only in the shaded portion in FIG. 62 (C).
Therefore, the display dots on the scanning electrode Y2 having many lighting dots in FIG. 61 become thin. As described above, when the number of lighting dots on each scanning electrode is represented by Z, the display becomes thinner as the numerical value Z becomes larger.

Third Mode (hereinafter referred to as warp milling) FIG. 65 shows display unevenness when the contents (pattern) shown in FIG. 64 are displayed. FIG. 66A shows a signal voltage waveform at the display dot portion on the signal electrode X6 at this time, and FIG. 66B shows a scan voltage waveform at the display dot portion on the scan electrode Y2.
FIG. 3C shows a voltage waveform applied to a display dot formed by an intersection between the signal electrode X6 and the scanning electrode Y2. Similarly, FIGS. 67A to 67C show the voltage waveforms on the signal electrode X5 and the scanning electrode Y2 and the voltage waveforms applied to the display dots at the intersections.

FIG. 69 shows display unevenness when the pattern shown in FIG. 68 is displayed. The signal voltage waveform at the display dot portion on the signal electrode X6 at this time is shown in FIG.
0 (A) shows the scanning voltage waveform at the display dot portion on the scanning electrode Y2, and FIG. 2 (B) shows the voltage waveform applied to the display dot formed by the intersection of the signal electrode X6 and the scanning electrode Y2. )Pointing out toungue. Similarly, FIGS. 71 (A) to 71 (C) show respective voltage waveforms on the signal electrode X5 and the scanning electrode Y2 and voltage waveforms applied to the display dots at the intersections.

Here, the non-selection voltage level of the scanning voltage waveform when displaying the contents of FIG. 64 having many lighting dots changes to the lighting voltage side as shown in FIG. 66 (B). Conversely, the non-selection voltage level of the scanning voltage waveform when displaying the contents of FIG. 68 with few lighting dots fluctuates to the non-lighting voltage side as shown in FIG. This variation is caused by the fact that when there are many lighting dots, each of the scanning electrodes Y1 to Y6 is connected to a signal electrode to which a lighting voltage is applied via a display dot capacitor, and a signal electrode to which a non-lighting voltage is applied. This is caused by a small number of connections to the server.

Although the reason why such a phenomenon occurs is not exactly known, it is considered that it probably occurs when the output impedance of the power supply circuit is not sufficient for the load of the liquid crystal panel. The following describes what rules cause such a voltage shift.

When the number of illuminated dots is T and the number of non-illuminated dots is L among all the display dots on the liquid crystal panel shown in FIGS. 64 and 68, a numerical value T 'obtained by T' = TL is obtained.
Is positive, the non-selection voltage level fluctuates toward the lighting voltage side. Conversely, when negative, the non-selection voltage level fluctuates to the non-lighting voltage side. And the magnitude of the fluctuation is
It increases as the absolute value of the numerical value T 'increases.

That is, when a display with a large number of lighting dots as shown in FIG. 64 is performed, the difference between the non-lighting voltage and the non-selection voltage increases, and the difference between the lighting voltage and the non-selection voltage decreases. Therefore, as shown in FIG. 65, the voltage waveform applied to the display dots on the signal electrode X5 having no lighting dots, ie, FIG. 67, is compared with the voltage waveform applied to the display dots on the signal electrode X6 including the lighting dots, ie, FIG. FIG. 67
The effective voltage applied to the display dots on the signal electrode X5 is higher only in the hatched portion (C), and the display dots on the signal electrode X5 are darker.

Similarly, when a display with a small number of lighting dots as shown in FIG. 68 is performed, the difference between the lighting voltage and the non-selection voltage increases, and the difference between the non-lighting voltage and the non-selection voltage decreases. Therefore, comparing the voltage waveform applied to the display dot on the signal electrode X6 including the lighting dot, that is, FIG. 70 with the voltage waveform applied to the display dot on the signal electrode X5 having no lighting dot, that is, FIG. The effective voltage applied to the display dots on the signal electrode X6 is higher only in the hatched portions, and the display dots on the signal electrode X6 are darker.

Fourth Mode (hereinafter referred to as “Polarity Reversal Stringing”) The display unevenness when the content shown in FIG. 72 is displayed is shown in FIG.
3 is shown. At this time, the signal voltage waveform at the display dot portion on the signal electrode X6 is shown in FIG. 74 (A), and the scanning voltage waveform at the display dot portion on the scan electrode Y2 is shown in FIG. 74 (B). The voltage waveform applied to the display dot formed by the intersection of the scanning electrode Y2 is shown in FIG. FIG. 75 shows a voltage waveform applied to a display dot formed by an intersection of the signal electrode X5 and the scanning electrode Y2.

FIG. 77 shows display unevenness when the contents shown in FIG. 76 are displayed. FIG. 78A shows the signal voltage waveform at the display dot portion of the signal electrode X6 at this time.
FIG. 7B shows a scanning voltage waveform at a display dot portion on the scanning electrode Y2, and FIG. 7C shows a voltage waveform applied to a display dot formed by an intersection of the signal electrode X6 and the scanning electrode Y2. FIG. 79 shows a voltage waveform applied to a display dot formed by the intersection of the signal electrode X5 and the scanning electrode Y2.

Here, attention is paid to before and after the switching of the frame period, that is, before and after switching from F1 to F2 in FIGS. 74 and 78 (this switching of the frame period is hereinafter referred to as polarity reversal). As shown in FIG. 72, the voltage applied to the signal electrodes is the lighting voltage before the polarity inversion and the number of signal electrodes that remain the lighting voltage after the polarity inversion (FIG. 7).
In FIG. 72, the sixth signal electrode X6 only has the non-lighting voltage before the polarity inversion and the number of signal electrodes at the non-lighting voltage after the polarity inversion (in FIG. 72, five signal electrodes X1 to X5).
If the number is smaller than the above, rounding occurs as shown in FIG.

Conversely, as shown in FIG. 76, the number of signal electrodes that switch from the lighting voltage to the lighting voltage before and after the polarity inversion (in FIG. 76, the signal electrodes X1, X2, X3, X4, X6
Are the number of signal electrodes that switch from the non-lighting voltage to the non-lighting voltage before and after the polarity inversion (in FIG. 76, the signal electrode X
5), a spike-like voltage shown in FIG. 78B is generated at the time of polarity inversion.

For this reason, when the display shown in FIG. 72 is performed, at the time of polarity reversal, the scan voltage waveform becomes rounded as shown in FIG. 74 (B).

At this time, as shown in FIG. 74 (C), before and after the polarity inversion, the voltage waveform applied to the display dot on the signal electrode X6 which changes from the lighting voltage to the lighting voltage includes the waveform shown in FIG.
As shown in (2), a spike-like voltage is generated, the effective voltage increases, and the display becomes dark. The signal electrodes X1 to X change from the non-lighting voltage to the non-lighting voltage before and after the polarity inversion.
As shown in FIG. 75, the voltage waveform applied to the display dot on No. 5 becomes dull, the effective voltage becomes small, and the display becomes thin.

Conversely, when the display is as shown in FIG. 76, a spike-like voltage is generated in the scanning voltage waveform shown in FIG.

At this time, as shown in FIG. 78 (B), the voltage applied to the display dots on the signal electrodes X1, X2, X3, X4 and X6 changes the signal voltage waveform from the lighting voltage to the lighting voltage before and after the polarity inversion. The waveform is rounded as shown in FIG. 78 (C), the effective voltage becomes small, and the display becomes thin. The signal electrode X changes from the non-lighting voltage to the non-lighting voltage
As shown in FIG. 79, a spike-like voltage is generated in the voltage waveform applied to the display dot on No. 5, the effective voltage increases, and the display becomes dark.

The above is generalized as follows. That is, at the time of polarity reversal, the number of signal electrodes that switch from the lighting voltage to the lighting voltage is a, the number of signal electrodes that switch from the non-lighting voltage to the non-lighting voltage is b, and the number of signal electrodes that switch from the lighting voltage to the non-lighting voltage Is c, and the number of signal electrodes that switch from the non-lighting voltage to the lighting voltage is d. Also, the number of lit dots on the scanning electrode (scanning electrode Y6 in FIGS. 72 and 76) selected immediately before the polarity inversion is set to N _ON , and the number of non-lit dots is set to N _OFF, and the selection is made immediately after the polarity inversion. The number of lit dots on the scanning electrode (scanning electrode Y1 in FIGS. 72 and 76) is M _ON , and the number of non-lit dots is M _OFF .

At this time, N _ON = a + c, N _OFF = b + d M _ON = a + d, M _OFF = b + c N _ON + N _OFF = M _ON + M _OFF = K (K is a constant, and the number of display dots on each scanning electrode is Show)
Is represented. Therefore, if the numerical value F such that F = ab = N _ON −M _OFF = N _ON + M _ON −K is negative, a rounding occurs at the time of non-selection change on the scan electrode at the time of polarity inversion. On the other hand, when it is positive, a spike-like voltage is generated on the lighting voltage side. Then, the magnitude increases as the absolute value of the numerical value F increases. This leads to display unevenness as described above.

The four modes of the mechanism for causing the display to have uneven contrast due to the deformation of the voltage waveform have been described above. Elucidation of such a mechanism is not yet complete. Therefore, there is a possibility that a new mechanism will be discovered in the future. In any case, the display contrast unevenness occurs according to the regularity of the display content.

According to the present invention, a liquid crystal display device having a uniform appearance without contrast unevenness can be obtained by quantitatively extracting the regularity of the above display contents and performing a correction corresponding to the extracted amount. It was done.

[0054]

According to a liquid crystal display device of the present invention, a scanning electrode group is formed on one substrate, a signal electrode group is formed on the other substrate, and a liquid crystal layer is formed between the pair of substrates. In a liquid crystal display device sandwiched therebetween, first voltage applying means for applying a scanning voltage waveform to the scanning electrode group, second voltage applying means for applying a signal voltage waveform to the signal electrode group, and the signal voltage When the effective voltage applied to the liquid crystal layer shifts due to a change in the voltage level of the waveform, there is provided a means for applying a rectangular voltage pulse to the signal electrode for compensating the shift. A method for driving a liquid crystal display device according to the present invention is directed to a liquid crystal display in which a scan electrode group is formed on one substrate, a signal electrode group is formed on the other substrate, and a liquid crystal layer is sandwiched between the pair of substrates. In the method of driving a device, a scan voltage waveform is applied to the scan electrode group, a signal voltage waveform is applied to the signal electrode group, and an effective voltage applied to the liquid crystal layer with a change in the voltage level of the signal voltage waveform. If the displacement is incorrect,
A voltage pulse having a shape is applied to the signal electrode.

[0055]

According to the above arrangement, the change in the effective voltage caused by the deformation of the scanning voltage waveform and the signal voltage waveform generated in the liquid crystal panel by the pattern of the figure or the character displayed by the liquid crystal display device is determined by the scanning voltage waveform and / or the signal voltage. By changing at least one of the waveforms, it is possible to correct the shift of the effective voltage applied to each display dot and prevent the above-mentioned uneven display contrast.

[0056]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to an embodiment shown in the drawings in accordance with the above four modes.

Embodiment 1 (FIGS. 1 to 8) First, an embodiment for the display unevenness due to the alternate stringing will be described.

As described above, the degree of display unevenness due to alternate stringing is determined by the number M _ON of the lit dots on the selected scanning electrode and the number N _ON of the lit dots on the next selected scanning electrode. (I = N _ON -M _ON ). Therefore, during the operation of the liquid crystal display device, the waveform correction corresponding to the value of the numerical value I may be performed while calculating the numerical value I.

FIG. 1 shows one embodiment of a specific liquid crystal display device for performing such correction.

In FIG. 1, reference numeral 101 denotes a liquid crystal unit, which is composed of a liquid crystal panel and a driving circuit. Reference numeral 102 denotes a series of control signals for controlling the operation of the liquid crystal display device, which includes a latch signal LP, a frame signal FR, and a data-in signal DI.
An N, X driver shift clock signal XSCL and others. 103 is a data signal, 104 is a waveform correction signal generation circuit (hereinafter simply referred to as a correction circuit), and 105 is a power supply circuit.

The correction circuit 104 calculates the numerical value I, and outputs the sign signal 1 for transmitting the sign of the numerical value I.
08 and an intensity signal 10 conveying the magnitude of the absolute value of the numerical value I.
9 is transmitted to the power supply circuit 105 as a correction signal. The intensity signal 109 is active for a length of time corresponding to the absolute value of the numerical value I.

The power supply circuit 105 is provided with the above-described code signal 1
08: A scan electrode driving power supply (hereinafter referred to as Y power supply) 10 supplied to the liquid crystal unit 101 in accordance with the intensity signal 109.
6, a signal electrode driving power supply (hereinafter referred to as X power supply) 10
7, and the voltage of the Y power supply 106 is corrected.

The basic operation of this embodiment shown in FIG. 1 is as follows.

That is, first, the correction circuit 104 takes in the data signal 103 when a certain scanning electrode is selected, and counts the number M _ON of the lighting dots on the next selected scanning electrode. Next, the difference from the number N _ON of the lighting dots on the currently selected scanning electrode, that is, the numerical value I is calculated. And
When the selection is changed, the sign and the absolute value of the result are output as a sign signal 108 and an intensity signal 109, respectively.
At the same time, _MON is captured and stored as the number N _ON of the lit dots on the selected scanning electrode. Then, the power supply circuit 105 performs necessary correction on the voltage of the Y power supply 106 according to the sign signal 108 and the intensity signal 109.

By such an operation, it is possible to prevent display unevenness caused by alternate stringing occurring on the liquid crystal panel. In the present embodiment, as a correction method, for a spike-like noise generated in a drive waveform applied to a liquid crystal panel, a constant voltage is applied in a direction corresponding to the spike-like noise for a time corresponding to the intensity of the spike-like noise. Things. The sign signal 108 determines the direction of the constant voltage, and the intensity signal 109 determines the application time.

The specific configuration and operation of each component of this embodiment will be described below. 2 to 5 show details of the components of FIG.

FIG. 2 shows an example of a specific configuration of the liquid crystal unit 101.

In the figure, reference numeral 201 denotes a liquid crystal panel, one of a pair of substrates 202 and 203 sandwiching a liquid crystal layer.
Scan electrodes Y1 to Y6 arranged horizontally are formed on the upper side, and signal electrodes X1 to X6 arranged vertically on the other substrate 203 are formed. The scanning electrodes Y1 to Y6 and the signal electrode X1
X6 intersect to form a display dot 204. Although the liquid crystal panel has a 6 × 6 dot configuration,
This is for the sake of simplicity of description, and is not limited to this.

Reference numeral 205 denotes a scan electrode driving circuit, which comprises a shift register circuit 206 and a level shifter circuit 207.
The output of the level shifter circuit 207 is
To the scanning electrodes Y1 to Y6.

Reference numeral 208 denotes a signal electrode drive circuit, which comprises a shift register circuit 209, a latch circuit 210, and a level shifter circuit 211. The output of the level shifter circuit 208 is guided to each signal electrode X1 to X6 of the liquid crystal panel 201.

FIG. 3 shows each signal DI of the control signal 102.
6 is a timing chart of N, LP, FR, XSCL and a data signal 103.

The above signals DIN and LP are supplied to the shift register circuit 206 of the scan electrode driving circuit 205 in FIG.
Each works as data and a shift clock. Signal LP
Signal DIN is shifted by the falling edge of the shift register circuit 2
06 and transferred. Here, the signal DIN
Makes "H" active and is normally output once at intervals of the number of scanning electrodes Y1 to Y6 of the liquid crystal panel 201 or more than the number of signals LP.
The data of "H" is passed, and otherwise, it becomes "L." The selection voltage is supplied to the scan electrodes Y1 to Y6 when active by the level shifter circuit 207 according to the contents of the shift register circuit 206, and the non- When active, a non-selection voltage is supplied to the scan electrodes Y1 to Y6, and the selection voltage and the non-selection voltage are supplied from the Y power source 106.

The data signal 103 and the signals XSCL and LP function as data and a shift clock of the shift register circuit 209 of the signal electrode driving circuit 208 and a latch clock of the latch circuit 210, respectively. In FIG. 3, the data signal 103 makes “H” active and indicates lighting. The data signal 103 functions as a signal for determining whether to turn on or off the display dot 204 on the next scanning electrode while a certain scanning electrode of the liquid crystal panel 201 is selected. Then, as a signal corresponding to a display dot on the next selected scanning electrode during a period in which a certain scanning electrode is selected, the shift register circuit 20 is output at the falling edge of the signal XSCL.
9 When the data signal 103 is taken in according to the signal XSCL, the falling edge of the signal LP causes
The contents of the shift register circuit 209 are taken into the latch circuit 210. Next, in accordance with the content thus taken, the shift register circuit 211 supplies the lighting voltage to the signal electrodes X1 to X6 when active and supplies the non-lighting voltage to the signal electrodes X1 to X6 when inactive. . The lighting voltage and the non-lighting voltage are supplied by the X power supply 107.

Further, the above-mentioned signal FR (frame signal)
Is connected to drive circuits 205 and 208 for AC driving the liquid crystal panel 201. The signal FR switches in synchronization with the fall of the signal LP, and switches the selection of the driving voltage potential. That is, the driving voltage is 2
It has a set of three selected / non-selected / lighting / non-lighting voltages and is switched by the frame signal FR.

The structure of the liquid crystal unit 101 and the method of driving the liquid crystal unit 101 are merely examples for explaining the present invention, and do not limit the structure of the liquid crystal unit 101.

FIG. 4 is a block diagram showing an example of a specific configuration of the correction circuit 104 in FIG. In the figure, 401 is a counting circuit, 402 is a first counting and holding circuit,
403 is a second count holding circuit, 404 is a numerical operation circuit,
405 is a pulse width control circuit.

The counting circuit 401 corresponds to the liquid crystal panel 20 shown in FIG.
While the first n-th scanning electrode is selected, the number of lighting dots in the display dots on the (n + 1) -th scanning electrode is counted.
The counting circuit 401 outputs the signal XSCL from the fall of the signal LP of the control signal 102 to the fall of the next signal LP.
The number of lit dots on the (n + 1) th scanning electrode is counted by adding only when the data signal 103 is active at the falling edge of. Then, at the falling of the signal LP, the count value is output to the first count holding circuit 402 and the count circuit 4
The count value of 01 is reset to 0, counting is started again, and this is sequentially repeated. The count may be 1 in some cases.
It is not necessary to perform strictly down to the dot unit. For example, if the number of the signal electrodes X1 to X6 is about 640, the counting error is ±
16 dots may be used.

Next, the first count holding circuit 402 sequentially takes in the count value immediately before the count value of the counting circuit 401 becomes 0 at the falling of the signal LP, and the second count holding circuit 4
03 is a falling edge of the signal LP,
2 sequentially takes in the count value from the first count holding circuit 402 immediately before taking in the next count value from the count circuit 401. Therefore, when the first count holding circuit 402 captures the number M _ON of the display dots on the (n + 1) th scanning electrode, the second count holding circuit 403 sets the lighting dot of the display dot on the nth scanning electrode. In the state where the number N _ON is taken in, the numerical values M _ON and N _ON are respectively calculated by the numerical operation circuit 404.
Output to

Next, the numerical operation circuit 404 outputs the numerical value M from the first and second count holding circuits 402 and 403.
The difference between _ON and N _ON, i.e. to calculate the I = N _ON -M _ON, and outputs to output the sign of the value I as the code signal 108 of the, the absolute value of the value I to the pulse width control circuit 405 .

The pulse width control circuit 405 outputs an active signal for a length of time corresponding to the absolute value of the numerical value I input from the numerical operation circuit 404 to the intensity signal 109.
And outputs it in synchronization with the fall of the signal LP of the control signal 102. However, when the signal FR changes, the signal LP changes.
No output at falling edge of.

[0081] The width W of the intensity signal 109 with respect to the absolute value of the numerical I, have become increasing function expressed by ^{_{W = Σa K × I K +}} Σb K × I 1 / K. a _K and b _K are constants, K
Are 0, 1, 2, 3, ... The width W is a numerical value I
May be different depending on whether it is positive or negative. In this embodiment, W = a ₁ × I regardless of whether the numerical value I is positive or negative. The operation and function of the correction circuit 104 have been described above.
Specific circuit configurations 01 to 405 are omitted because they can be easily realized appropriately based on the above description.

FIG. 5 shows the voltage power supply circuit 1 shown in FIG.
5 shows an example of a specific configuration.

In the figure, 501 to 509 are resistors,
The voltage V0 and the voltage V5 are connected in series in this order.
Is supplied. Assuming that the resistance values of the resistors 501 to 509 are R1 to R9, respectively, R1 = R9, R2 = R8, R3 = R7, R4 = R6, and R1 + R2 = R3 + R4 = R9 + R8 = R7 + R6 = R5 / (N-4) ( N is a constant). Therefore, the voltages at the ends of the resistors 501 to 509 are sequentially changed to V0, V1U, V1 as shown in FIG.
N, V1L, V2, V3, V4U, V4N, N4L, V
Assuming that 5, the following relationship holds.

V0−V1N = V1N−V2 = V4N−V5 = V3−V4N = (V2−V3) / (N−4) K1 = (V1U−V1N) / (V0−V1N) = (V4N−V4L) / (V4N-V5) K2 = (V1N-V1L) / (V0-V1N) = (V4U-V4N) / (V4N-V5) Here, K1 and K2 are such that 0.1 ≦ K2 and K1 ≦ 1. Are set to the resistance values of the resistors 501 to 509.

Reference numeral 510 denotes the divided voltage V1U, V1N, V1L, V2, V3, V generated by each of the resistors 501 to 509.
This is a voltage stabilizing circuit for stabilizing 4U.V4N.V4L, and outputs the same voltage as the input voltage as a low impedance. In this embodiment, the voltage stabilizing circuit 510 is constituted by a voltage follower circuit using an operational amplifier circuit.

Switches 511 and 512 are switched by the code signal 108 and the intensity signal 109 from the correction circuit 104. That is, when the intensity signal 109 is active and the sign signal 108 indicates positive, the switches 511 and 512 are switched to the voltages V1U and V4L, respectively. Conversely, when the intensity signal 109 is active and the sign signal 108 is Indicates that the switches 511 and 51
2 is switched between the voltage V1L and the voltage V4U. When the intensity signal 109 is inactive, the switches 511 and 512 are switched to the voltage VIN and the voltage V4N, respectively. Then, the voltages of the switches 5
11, 512 as output voltages V1, V4,
The voltages V1 and V4 and the voltages V0 and V5 correspond to FIG.
Is output as the Y power source 106 at Also, the voltage V0
V2, V3, and V5 are output as the X power supply 107 in FIG.

Therefore, the Y power supply 106 is connected to the voltage V0 ·
The X power supply 107 has the voltages V1, V2, V3, and V5 shown in FIG. 5, and the liquid crystal unit 10 has a set of two voltages shown below.
1 is output.

That is, as one set of voltages, the Y power source 1
The voltage V0 of the X power supply 106 is a selection voltage, the voltage V4 of the X power supply 106 is a non-selection voltage, the voltage V5 of the X power supply 107 is a lighting voltage, the voltage V3 of the X power supply 107 is a non-lighting voltage. The voltage V5 of the Y power supply 106 is a selection voltage, the voltage V1 of the Y power supply 106 is a non-selection voltage, the voltage V0 of the X power supply 107 is a lighting voltage, and the voltage V2 of the X power supply 107 is a non-lighting voltage. Is done.

The two sets of voltages are applied to the scan electrode driving circuit 2
05 and the signal electrode driving circuit 208, the control signal 102
Are synchronously and alternately switched by the signal FR.

With the above configuration, when the selection of the scan electrodes Y1 to Y6 of the liquid crystal panel 201 is switched from the nth to the (n + 1) th, if the numerical value I is positive, the Y power supply 1
06 are the voltages V1 and V4 in FIG. 5 for a length of time corresponding to the magnitude of the absolute value of the numerical value I, respectively.
1U · V4L is output to the liquid crystal unit 101. When the numerical value I is negative, the voltage V1L / voltage V4U is similarly set as the voltage V1 / voltage V4 for a length of time corresponding to the magnitude of the absolute value of the numerical value I. Is output to the liquid crystal unit 101.

When the intensity signal becomes inactive,
The voltage V1N and the voltage V4N are output as the voltage V1 and the voltage V4, respectively, including when the numerical value I is 0.

The above operation will be specifically described with reference to an example in which the pattern shown in FIG. 6 is displayed.

FIG. 7 shows an example of the applied voltage waveform at that time. FIG. 7A shows the voltage waveform applied to the signal electrode X4 forming the display dot 601 shown in FIG. 6, and FIG. FIG. 4C shows a voltage waveform applied to the scanning electrode Y3 forming the display dot 601. FIG. 5C shows a voltage waveform applied to the display dot 601.

7A and 7B indicate the voltages V0, V2, V3, and V5 of the X power supply 107 and the voltages V0, V1, V4, and V5 of the Y power supply 106, respectively.

FIG. 8 is an enlarged view of a portion surrounded by a circle 701 in FIG. In FIG. 8, reference numeral 801 denotes a spike-like noise voltage to be generated in the scanning electrode;
02 is a changing non-selection voltage generated by the Y power supply 106;
Indicates a voltage synthesized by the voltage 801 and the voltage 802.

Here, when displaying the pattern of FIG. 6,
When the selection shifts from the nth scanning electrode to the (n + 1) th scanning electrode, the number of _ON dots N _ON and n +
The difference I lighting dot number M _ON on the first scan electrodes is as follows.

When the selection shifts from the first scanning electrode Y1 to the second scanning electrode Y2, I = -2. When the selection shifts from the second scanning electrode Y2 to the third scanning electrode Y3, I = 23rd. When the selection shifts from the scan electrode Y3 to the fourth scan electrode Y4, I = −44 When the selection shifts from the fourth scan electrode Y4 to the fifth scan electrode Y5, I = 45 When the selection shifts to the sixth scanning electrode Y6, I = -6. When the selection shifts from the sixth scanning electrode Y6 to the first scanning electrode Y1, I = 6.

As a result, the order from the first to the second, the second to the third, the third to the fourth,...
Of the noise voltage 801 becomes larger. However, the time during which the non-selection voltage 802 changes in the direction opposite to the direction in which the noise voltage 801 is generated also becomes longer at the same time as T1 to T3, so that the synthesized voltage 803 is corrected. Therefore, the voltage applied to the display dot 601 in FIG. 7C is corrected, and the uneven display of every other stringing is significantly reduced.

As described above, when the selection shifts from the n-th scanning electrode to the (n + 1) -th scanning electrode of the liquid crystal panel 201, the difference I between the n-th scanning electrode and the (n + 1) -th scanning electrode in the number of lighting dots on the n-th scanning electrode is obtained. Y power supply 1 for the length of time corresponding to
By changing the non-selection voltage of 06, it is possible to remarkably reduce the unevenness in the display of every other stringing.

As described above, in the present embodiment, the correction is performed by increasing or decreasing the time for changing the voltage of the non-selection voltage. This is hereinafter referred to as time axis correction of the non-selection voltage.

Embodiment 2 (FIGS. 9 to 13) Next, another embodiment for non-uniform display caused by alternate stringing will be described.

As described above, in the first embodiment, the unevenness of the display of every other stringing is reduced by time axis correction of the non-selection voltage. However, the non-selection voltage is changed by a voltage width corresponding to the difference I for a certain period of time. However, a similar effect can be obtained.

FIG. 9 shows an example of a specific device configuration for performing such correction.

In the figure, 904 is a correction circuit, and 905 is a power supply circuit. The other configuration is the same as that of the first embodiment, and the same reference numerals are given and the description will not be repeated.

The correction circuit 904 calculates the numerical value I as in the first embodiment. Then, the sign of the numerical value I is changed to a sign signal 1
08 and the absolute value of the numerical value I are transmitted to the power supply circuit 905 as an intensity signal 909. The power supply circuit 905 changes the non-selection voltage of the Y power supply 906 to be applied to the liquid crystal unit 101 in a direction corresponding to the sign signal 108 and for a fixed time by a voltage width corresponding to the intensity signal 909.

By such an operation, the liquid crystal panel 20
The non-selection voltage is changed by a voltage width corresponding to the intensity of the generated spike noise for a certain period of time in the direction to cancel the spike noise generated on one electrode, and the display unevenness due to stringing every other line It is to prevent. It is the code signal 108 that determines the above changing direction,
The voltage width is determined by the intensity signal 909.

The detailed configuration and operation of each component of this embodiment will be described below.

FIG. 10 shows the configuration of the correction circuit 904 described above.

In the figure, 401 is a counting circuit, 402 is a first counting and holding circuit, 403 is a second counting and holding circuit,
Numeral 04 denotes a numerical operation circuit, each of the circuits 401 to 401 in FIG.
It is the same as 404 and performs the same operation. That is, the counting circuit 401 counts the number of lighting dots from the data signal 103,
First count holding circuit 402 and second count holding circuit 403
Hold the numbers M _ON and N _ON of the lighting dots on the (n + 1) -th and n-th scanning electrodes 202, respectively, whereby the numerical operation circuit 404 calculates the numerical value I. And control signal 1
02 in synchronism with the signal LP of No. 02,
And an intensity signal 909 indicating the absolute value of the numerical value I.

FIG. 11 shows the structure of the power supply circuit 905.

In the figure, reference numerals 1101 to 1105 denote resistors connected in series, and a voltage V0 and a voltage V5
Is applied.

Assuming that the resistance values of the above-described low-resistance devices 1101 to 1105 are r0, r1, r2, r3, and r4, respectively, r0 = r1 = r3 = r4, and (N-4) Xr0 = r2.

Further, each of the resistors 1101-1105
Assuming that the divided voltages applied to the ends of V1 are V0, V1N, V2, V3, V4N, and V5, respectively, as shown in FIG. ) / (N−4). Each of the divided voltages is stabilized and output by the voltage stabilizing circuit 510 as in the example of FIG.

Reference numerals 1107 and 1108 denote voltage generating circuits for generating voltages according to the sign signal 108 and the intensity signal 909, and in this example, are constituted by D / A converters.

The voltage generation circuit 1107 outputs the code signal 10
When 8 indicates positive, a voltage V1C whose voltage value is shifted toward the voltage V0 by a voltage width corresponding to the magnitude of the absolute value of the numerical value I indicated by the intensity signal 909 with respect to the voltage V1N is generated,
Similarly, the voltage generation circuit 1108 generates a voltage V4C whose voltage value is shifted toward the voltage V5 by a voltage width corresponding to the absolute value of the numerical value I indicated by the intensity signal 909 with respect to the voltage V4N.

Conversely, when the sign signal 108 indicates a negative value,
Each of the voltage generating circuits 1107 and 1108 has a voltage V
A voltage V1 whose voltage value is shifted to the second side and the voltage V3 side by a voltage width corresponding to the magnitude of the absolute value of the numerical value I indicated by the intensity signal 909.
Generates CV4C.

At this time, the magnitude of the voltage width according to the magnitude of the absolute value of the numerical value I indicated by the intensity signal 909 may be different between the positive and negative values of the numerical value I indicated by the sign signal 108. .

Reference numeral 1109 denotes a pulse width generating circuit for generating a signal which is an active state for a fixed time, and outputs the signal in synchronization with the signal LP of the control signal 102. However, it is not output when the signal FR of the control signal 102 switches.

Reference numeral 1110 denotes a switch for switching between the voltages V1N and V1C, and reference numeral 1111 denotes a switch for switching between the voltages V4N and V1C.
4C, which are switched by signals output from the pulse width generation circuit 1109. That is, each of the switches 1110 and 111
When the signal output from the pulse width generation circuit 1109 is active, the voltage V1C and the voltage V4C are selected for a certain period of time according to the pulse width. It is switched to V1N and voltage V4N, and output as voltage V1 and voltage V4, respectively. Therefore, the directions and magnitudes of the voltages V1 and V4 output from the switches 1110 and 1111 change according to the numerical value I for a certain period of time.

The power supply circuit 905 supplies the voltage V1
And V4 and voltages V0 and V5 are output as Y power supply 906, and voltages V0, V2, V3, and V5 are output as X power supply 107.

The Y power source 906 and the X power source 107 are output to the liquid crystal unit 101 as a set of the following two voltages as in the first embodiment.

That is, as one set of voltages, the Y power source 9
06 is a selection voltage, the voltage V4 of the Y power supply 906 is a non-selection voltage, the voltage V5 of the X power supply 107 is a lighting voltage, and the voltage V3 of the X power supply 107 is a non-lighting voltage. The voltage V5 of the power supply 906 is a selection voltage, the voltage V1 of the Y power supply 906 is a non-selection voltage, and the voltage V of the X power supply 107 is
0 is set as the lighting voltage, and the voltage V2 of the X power supply 107 is set as the non-lighting voltage, and is output to the liquid crystal unit 101, respectively.

The configuration and function of the present embodiment are as described above, and the direction and magnitude of the non-selection voltage change by the numerical value I for a certain period of time.

The above operation will be described with reference to an example in which the pattern shown in FIG. 6 is displayed.

FIG. 12 shows an example of the applied voltage waveform at that time. FIG. 12A shows the signal voltage waveform applied to the signal electrode X4 forming the display dot 601 in FIG. 6, and FIG.
FIG. 4C shows a voltage waveform applied to the scanning electrode Y3 forming the display dot 601. FIG. 5C shows a voltage waveform applied to the display dot 601.

The voltages indicated by broken lines in FIGS. 12A and 12B are the voltages V0, V2, V3, V5 of the X power
The voltages V0, V1, V4, and V5 of the power supply 906 are shown.

FIG. 13 is an enlarged view of a portion surrounded by a circle 1201 in FIG. In FIG. 13, 1301
Denotes a spike-like noise voltage to be generated in the scan electrode, 1302 denotes a changing non-selection voltage generated by the Y power supply 906, and E1 to E3 denote the changing voltage width. Further, reference numeral 1303 in FIG.
Shows the voltage synthesized by

Here, when the display shown in FIG. 6 is performed, n
As described above, the difference I between the number of lit dots on the nth scan electrode and the number of lit dots on the n + 1th scan electrode when the selection shifts from the nth scan electrode to the (n + 1) th scan electrode is as follows. When moving from 1st to 2nd, 1 = -2 When moving from 2nd to 3rd, I = 2 When moving from 3rd to 4th, I = -4 When moving from 4th to 5th, I = 4 From the fifth to the sixth, I = -6. From the sixth to the first, I = 6.

As a result, as shown in FIG. 13, the noise voltage 1301 in FIG. 13 increases as the first to second, second to third, third to fourth...
However, since the width of the non-selection voltage 1302 that changes for a certain time in the opposite direction to the direction in which the noise voltage 1301 is generated also increases simultaneously with E1 to E3, the synthesized voltage 1303 is corrected. Therefore, the voltage applied to the display dots 601 in FIG. 12C is corrected, and the display unevenness of every other stringing is significantly reduced.

As described above, when the selection shifts from the n-th scanning electrode of the liquid crystal panel 201 to the (n + 1) -th scanning electrode, the lighting dots on the n-th scanning electrode and the (n + 1) -th scanning electrode of the liquid crystal panel 201 are changed. By changing the non-selection voltage of the Y power supply 906 by a voltage corresponding to the numerical value I of the number for a certain period of time, it is possible to remarkably reduce the unevenness of the display of every other string as in the first embodiment.

As described above, in this embodiment, the non-selection voltage is corrected by changing the non-selection voltage by a voltage width corresponding to the numerical value I for a certain period of time. This is hereinafter referred to as voltage axis correction of the non-selection voltage. .

Embodiment 3 (FIGS. 14 and 15) Next, still another embodiment for non-uniform display of every other string will be described.

In each of the first and second embodiments, the non-selection voltage is corrected by either the time or the voltage according to the numerical value I. However, the correction is performed by both the time and the voltage according to the numerical value I. The same effect can be obtained by the above.

FIG. 14 shows an example of a specific device configuration for performing such correction.

In the figure, the configuration other than the power supply circuit 1405 and the Y power supply 1406 formed by the power supply circuit 1405 are exactly the same as the configuration of FIG. 9, and the operation is the same.

FIG. 15 shows a specific configuration of the power supply circuit 1405. The configuration other than the pulse width control circuit 1509 is exactly the same as the configuration of FIG. 11, and the operation is the same.

The pulse width control circuit 1509 outputs an active signal for a length of time corresponding to the value of the intensity signal 909 in synchronization with the fall of the signal LP of the control signal 102. However, it is not output when the signal FR of the control signal 102 switches. The signal from the pulse width control circuit 1509 controls the switches 1110 and 1111 and switches the switches 1110 and 1111 for a time corresponding to the numerical value I.

With the above configuration, the non-selection voltage of the Y power supply 1406 changes with the time according to the numerical value I and the voltage width according to the numerical value I, and corrects the noise voltage generated in the liquid crystal panel 201. This makes it possible to remarkably reduce display unevenness caused by alternate stringing as in the first and second embodiments.

As described above, in the present embodiment, the non-selection voltage is corrected by both the time and the voltage in accordance with the numerical value I, and this is hereinafter referred to as the time-voltage biaxial correction of the non-selection voltage.

Fourth Embodiment (FIGS. 16 to 20) The first to third embodiments correct the spike noise generated on the scanning electrodes of the liquid crystal panel 201 by adding a square wave voltage to the non-selection voltage. Was done. However, the noise that actually occurs is in a spike shape (in the case of Masa Us, the liquid crystal panel 201).
(A waveform represented by an exponential function by a differentiation circuit formed by the resistance of the scanning electrode and signal electrode and the capacitor of the liquid crystal layer). Therefore, in order to perform the correction more accurately, if the correction is performed by adding a voltage waveform having a peak value corresponding to the numerical value I and a form close to the generated noise to the non-selection voltage, it is even more preferable. Display unevenness due to stringing can be improved.

FIG. 16 shows an example of a specific configuration for performing such correction. In the figure, a power supply circuit 1605,
Except for the Y power supply 1606 output from the power supply circuit 1605, the configuration is the same as that of FIG.

FIG. 17 shows a concrete configuration of the power supply circuit 1605. In the drawing, reference numerals 1701 to 1703 denote resistors connected in series in order, and their resistance values are denoted by r1 and r1, respectively.
If r2 and r3, then r1 / 2 = r2 / 2 = r3 / (N-4).

Voltages V0 and V5 (voltage V0> voltage V5) are supplied to both ends of the resistors 1701 to 1703, and the voltages at the ends of the resistors 1701 to 1703 are sequentially changed as shown in FIG. , V0, V2, V3, and V5, (V0-V2) / 2 = (V3-V5) / 2 = (V2-V3) / (N-4).

The voltages V2 and V3 are the same as those of the voltage stabilizing circuit 510 shown in FIG.
704.

Here, the voltages V1N and V4N are defined as follows.

V1N = (V0−V2) / 2 + V2 V4N = (V3−V5) / 2 + V5 That is, the voltage V1N is the midpoint between the voltage V0 and the voltage V2,
Voltage V4N is the midpoint between voltage V3 and voltage V5.

In FIG. 17, reference numerals 1705 and 1706 denote function waveform generating circuits, respectively, and
, And a function waveform voltage whose direction and peak value change according to the intensity signal 109 are generated.

The function waveform circuit 1705 is obtained by: E = α × exp (−β × T) where α and β are constants, and T is a voltage of an exponential function waveform (FIG. 18) expressed by time, A correction voltage V1 to which V1N is added is output.

Similarly, the function waveform generating circuit 1706 converts the voltage of the exponential function waveform (shown in FIG. 18) expressed by E = −α × exp (−β × T) into the above V
A correction voltage V4 to which 4N has been added is output.

Here, the sign of α corresponds to the sign shown by the sign signal 108, and the direction of the voltage generated thereby changes. The absolute value of α changes according to the intensity signal 909, and the peak value changes accordingly.

That is, the sign signal 108 is positive and the intensity signal 9
As the value of 09 increases, the function waveform generation circuit 17
05 is the waveform 1801, 1802, 1803 in FIG.
Take ... When the sign signal 108 is negative, the waveforms 1806, 1807, 1808,... Shown in FIG.

Conversely, the function waveform generating circuit 1706 is
As the sign signal 108 of FIG. 6 is positive and the value of the intensity signal 909 increases, the waveforms 1806, 1807, and 1 of FIG.
808 ... 1 when the sign signal 108 is negative.
8 waveforms 1801, 1802, 1803,...

The function waveform generating circuit 1705.1
706 outputs the above-mentioned correction voltages V1 and V4 in synchronization with the signal LP of the control signal 102. However, there is no synchronization when the signal FR of the control signal 102 switches, and the respective function waveform generation circuits 1705 and 1706 output the voltage V
It outputs 1N · voltage V4N.

Note that the above function waveform generating circuit 1705
E = α (β−T) When β ≧ T E = 0 When β <T where α · β is a constant, and T is time. 19) is added to V1N to output a voltage V1.
06 is a triangular waveform voltage approximating an exponential function waveform represented by E = -α (β-T) β ≧ T and E = 0 β <T (FIG. 1).
9) may be output as the voltage V4 obtained by adding the voltage V4N.

Here, the sign of α corresponds to the sign shown by the sign signal 108 in the same manner as described above, and the direction of the voltage generated thereby changes. Also, the absolute value of α changes according to the intensity signal 909 as described above, and the peak value changes accordingly.

That is, the function waveform generating circuits 1705 and 170
6, the sign signal 108 is positive, and as the value of the intensity signal 909 increases, the waveform 1901.
1902, 1903 ... and waveforms 1906/1907/1
908 ... Conversely, when the sign signal 108 is negative, the waveforms 1906, 1907, and 1908 of FIG.
, And waveforms 1901, 1902, 1903,.

Next, each of the above function waveform generating circuits 1705
FIG. 20 shows a specific configuration example of 1706.

In the figure, reference numeral 2001 denotes a reference voltage, which is a voltage V1N in the case of the function waveform generating circuit 1705,
In the case of the function waveform generation circuit 1706, the voltage is V4N. Reference numeral 2002 denotes a variable resistor, which is composed of a plurality of resistors and switches whose resistance values increase in an exponential function of r, 2r, 4r... Then, by switching the switch, the resistance value can be changed.

A circuit 2003 changes the resistance value of the variable resistor 2002 according to the intensity signal 909. As the intensity signal 909 increases, the variable resistor 200 changes.
2 is increased. Reference numeral 2004 denotes a capacitor, which forms a differentiating circuit together with the variable resistor 2002.

Reference numeral 2005 denotes a first switching voltage source having a voltage higher than the reference voltage 2001. Instead of providing the voltage source 2005, the function waveform generating circuit 1705 uses the voltage V0 and the function waveform generating circuit 17
06, the voltage V3 may be used.

Reference numeral 2006 denotes a second switching voltage source having a voltage lower than the reference voltage 2001 described above. Also in this case, the voltage V2 may be used in the function waveform generation circuit 1705, and the voltage V5 may be used in the function waveform generation circuit 1706.

Reference numeral 2007 denotes a switch, which is switched by a switch control circuit 2008. The switch control circuit 2008 synchronizes with the signal LP of the control signal 102 (except when the signal FR of the control signal 102 is switched) to switch the first switching voltage from the state connected to the opposite electrode of the capacitor 2004. Source 2005, or second
To the switching voltage source 2006 according to the state of the sign signal 108.

That is, in the case of the function waveform generation circuit 1705,
When the sign signal 108 indicates positive, the switch 2007
To the first switching voltage source 2005, and the sign signal 10
When 8 indicates negative, the switch 2007 is switched to the second switching voltage source 2006.

Similarly, in the case of the function waveform generating circuit 1706, when the sign signal 108 indicates positive, the switch 20
07 is switched to the second switching voltage source 2006, and when the sign signal 108 indicates negative, the switch 2007 is switched to the first switching voltage source 2005.

Before the signal LP of the next control signal 102 is input to the switch control circuit 2008, the switch 2
007 is switched to the counter electrode of the capacitor 2004.

Reference numeral 2009 denotes a voltage follower circuit formed by an operational amplifier circuit, which outputs a voltage waveform applied to the input terminal indicated by a + mark with reduced impedance. 2010 is an output voltage from the voltage follower circuit 2009, which is output as a voltage V1 in the case of the function waveform generation circuit 1705 and as a voltage V4 in the case of the function waveform generation circuit 1706.

With the above configuration, the capacitor 2004 and the variable resistor 20 are synchronized with the signal LP of the control signal 102.
Since the first switching voltage source 2005 or the second switching voltage source 2006 is connected to the differentiating circuit 02, an exponential function voltage waveform is generated at the input terminal of the voltage follower circuit 2009.

The magnitude of this voltage waveform is
4 and the resistance value of the variable resistor 2002, the resistance value of the variable resistor 2002 increases as the intensity signal 909 increases, and the voltage waveform also increases. The direction in which the voltage is generated is determined by the sign signal 108. Further, the voltage follower circuit 2009 outputs the voltage waveform of the exponential function generated at the input terminal portion with the impedance lowered as described above.

The function waveform generating circuit 1705.
The voltages V1 and V4 generated by the voltage generator 1706 and the voltages V0 and V
5 together with the liquid crystal unit 10
1 and the voltages V0, V2, V3, V5
Is output to the liquid crystal unit 101 as an X power supply 107. At this time, an exponential function waveform having a different direction and magnitude or an exponential function waveform having a magnitude different from that of the non-selection voltage is obtained by the sign signal 108 and the intensity signal 909 obtained by the numerical value I. The voltage of the trigonometric function voltage waveform is applied in a superimposed manner.

Since the present embodiment is configured as described above, when the selection shifts from the nth scanning electrode to the (n + 1) th scanning electrode of the liquid crystal panel 201, the n
An exponential function voltage waveform having a magnitude corresponding to the difference I between the number of lighting dots on the n-th scan electrode and the n + 1-th scan electrode or a trigonometric function voltage waveform similar thereto is superimposed on the non-selection voltage of the Y power supply. This superimposed voltage waveform is applied to the liquid crystal panel 2
The direction and direction of the spike-like noise to be generated in the non-selection voltage on each scan electrode 01 are opposite to those of the spike-like noise and have substantially the same size and shape. As a result, the spike-like noise is almost completely canceled, and the voltage applied to each display dot 204 is corrected, so that the display unevenness of every other stringing can be remarkably improved.

As described above, in the present embodiment, the non-selection voltage is corrected by the function waveform having the direction and magnitude corresponding to the numerical value 1, and this is hereinafter referred to as the function waveform correction of the non-selection voltage.

Embodiment 5 (FIGS. 21 to 23) In Embodiments 1 to 4, the non-selection voltage corresponding to the numerical value I is corrected. However, the same effect can be obtained by changing the lighting voltage and the non-lighting voltage in accordance with the numerical value I, and unevenness due to stringing every other line can be improved.

Here, FIG. 21 shows a specific configuration example in which the lighting voltage and the non-lighting voltage are subjected to time axis correction according to the numerical value I.

In the figure, the configuration other than the power supply circuit 2105 and the configuration other than the Y power supply 2106 and the X power supply 2107 output from the power supply circuit 2105 is the same as the configuration shown in FIG. 1, and the operation is the same.

The above power supply circuit 2105 has a
8 and an intensity signal 109 are input to output an X power supply 2107 whose lighting voltage and non-lighting voltage change, and a Y power supply 2106 of a selection voltage and a non-selection voltage with no voltage change.

FIG. 22 shows a specific configuration of the power supply circuit 2105.

In the figure, reference numerals 2201 to 2213 denote resistors connected in series, and a voltage V0U.multidot.
The voltage V5L is supplied.

As shown in FIG. 22, the voltages at the ends of the resistors 2201 to 2213 are V0U, V0N,
V0L, V1, V2U, V2N, V2L, V3U, V3
Assuming that N, V3L, V4, V5U, V5N, and V5L, V0N-V1 = V1-V2N = V3N-V4 = V4-V5N = (V2N-V3N) / (N-4) and (V0N-V0L) / ( (V0N-V1) = (V2N-V2L) / (V1-V2N) = (V3U-V3N) / (V3N-V4) = (V5U-V5N) / (V4-V5N) Further, (V0U-V1N) / (V0N). −V1) = (V2U−V2N) / (V1−V2N) = (V3N−V3L) / (V3N−V4) = (V5N−V5L) / (V4−V5N) The resistance value is set.

The voltages V0N to V5N generated by the resistors 2201 to 2213 are stabilized by voltage stabilizing circuits 510 similar to those shown in FIG.

Reference numerals 2214 to 2217 denote switches which are switched by the sign signal 108 and the intensity signal 109.

That is, when the sign signal 108 is positive while the intensity signal 109 is active, each switch 22
14 to 2217 are connected to the following voltages.

The switch 2214 has a voltage V0U switch 2215, a voltage V2U switch 2216, a voltage V3L switch 2217 has a voltage V5L. When the sign signal 108 indicates a negative value, the switch 2214 has a voltage V0L switch 2215 has a voltage V0L. The V2L switch 2216 is connected to the voltage V3U, and the switch 2217 is connected to the voltage V5U.

When the intensity signal 109 is inactive, regardless of the state of the sign signal 108, the switch 2214 includes the voltage V0N switch 2215, the voltage V2N switch 2216, the voltage V3N switch 2217, and the voltage V5N Connected to

Here, assuming that the voltages output from the switches 2114 to 2117 are V0, V2, V3, and V5, the power supply circuit 2105 outputs the voltages V0, V2, V3,
V5 is output as the X power supply 2107 and the voltage V0
The combination of N, V1, V4, and V5N is output as a Y power supply 2106.

The Y power source 2106 and the X power source 210
7 is supplied to the liquid crystal unit 101 as a set of the following two voltages.

That is, as one set, the voltage V0N of the Y power supply 2106 is a selection voltage, the voltage V4 of the Y power supply 2106 is a non-selection voltage, the voltage V5 of the X power supply 2107 is a lighting voltage, and the voltage V3 of the X power supply 2107 is a non-lighting voltage. In the other set, the voltage V5N of the Y power supply 2106 is a selection voltage. The voltage V1 of the Y power supply 2106 is a non-selection voltage. The voltage V0 of the X power supply 2107 is a lighting voltage. The voltage V2 of the X power supply 2107 is a non-lighting voltage. Supply. The mechanism for obtaining one of the two sets is the same as that in the first embodiment.

The configuration of the present embodiment is as described above. When the difference I between the numbers of lit dots on the scan electrodes before and after the selection of the scan electrodes Y1 to Y6 of the liquid crystal panel 201 is positive,
The X power source 2107 is set as voltages V0, V2, V3, and V5.
The voltages V0U, V2U, V3L, and V5L are supplied to the liquid crystal unit 101 for a length of time according to the absolute value of the difference I.

Conversely, when the difference I is negative, the X power supply 2107 sets the voltages V0, V2, V3, and V5 to the voltages V0L and V2L for a time corresponding to the absolute value of the difference I.
-Supply V3U / V5U to the liquid crystal unit 101.

The above operation will be described with reference to the case of displaying the pattern shown in FIG. 6 as an example. 23A shows a voltage waveform on the signal electrode X4 forming the display dot 601 in FIG. 6 at that time, and FIG. 23B shows a voltage waveform on the scanning electrode Y3 forming the display dot 601. C) is a display dot 601
1 shows an example of a voltage waveform applied to the oscilloscope.

As the difference I between the lit dots on the scanning electrodes before and after the selection of the scanning electrodes of the liquid crystal panel 201 shifts, the spike noise superimposed on the non-selection voltage of the voltage waveform in FIG. Become. However, the lighting voltage and the non-lighting voltage shown in FIG. 3A fluctuate in the direction in which the spike noise is superimposed, and the fluctuating time depends on the difference I as shown in FIG.・ T2 and T3 become longer. Therefore, the effective voltage shown in FIG. 9C is corrected, and the display unevenness due to alternate stringing is significantly reduced.

As described above, according to this embodiment, the same effect as that of the above embodiment can be obtained by changing the lighting voltage and the non-lighting voltage for a time corresponding to the numerical value I. This is called time-base correction of the lighting voltage and the non-lighting voltage.

Embodiment 6 As another embodiment, a similar effect can be obtained by performing the above-described voltage axis correction, time voltage dual axis correction, or function waveform correction on the lighting voltage and the non-lighting voltage. Further, the same correction as described above may be performed on the non-selection voltage, the lighting voltage or the non-lighting voltage, or the three. It should be noted that a specific configuration example for this can be easily realized based on each of the above-described embodiments, and will not be described.

As described above, according to the first to sixth embodiments, the non-selection voltage or the non-selection voltage or the number of lighting dots on the scanning electrodes before and after the selection of the scanning electrodes Y1 to Y6 is switched. By changing the lighting voltage and the non-lighting voltage, display unevenness due to alternate stringing can be significantly reduced.

The first to sixth embodiments do not limit the correction method, and any method may be used as long as the difference in the effective voltage applied to the display dots caused by the difference I can be eliminated.

Embodiment 7 (FIGS. 24 to 31) Next, an embodiment for the uneven display caused by the weft threading will be described. As described above, the degree of display unevenness due to weft threading is determined by the number Z of lighting dots on the selected scanning electrode. Therefore, during the operation of the liquid crystal display device, the waveform correction may be performed while counting the numerical value Z.

FIG. 24 shows an example of a specific configuration for performing such correction.

In the figure, reference numeral 2404 denotes a correction circuit (correction signal generation circuit), which counts the number Z of lighting dots on the scanning electrode to be selected next, and becomes active for a time corresponding to the value Z. The signal 2409 is the signal L of the control signal 102.
Output in synchronization with P. Reference numeral 2405 denotes a power supply circuit, which receives the above intensity signal 2409 and generates a Y power supply 2406 and an X power supply 107 whose selection voltage changes. At this time, the voltage width in which the selection voltage changes is constant, and the changing time changes in response to the intensity signal 2409. That is, the selection voltage changes for a time corresponding to the numerical value Z.

Accordingly, the numerical value Z counted by the correction circuit 2404
The required correction is applied to the selection voltage only for a time corresponding to.

Hereinafter, the detailed configuration of each of the above components will be described. FIG. 25 shows a specific configuration of the correction circuit 2404.

In the figure, reference numeral 2501 denotes a counting circuit;
Reference numeral 02 denotes a count holding circuit, which operates in the same manner as the counting circuit 401 and the first count holding circuit 402 in FIG. That is, the numerical number M _ON of the lighting dot on the scanning electrode to be selected next counting circuit 2501 is counted in FIG 25 Z
Is output to the count holding circuit 2502.

Reference numeral 2503 denotes a pulse width control circuit which outputs an intensity signal 2409 which becomes active only for a length of time corresponding to the numerical value Z inputted from the count holding circuit 2502,
2 is output in synchronization with the fall of the signal LP.

The width W during which the intensity signal 2409 is active is represented by the following formula: W = Σa _K Z ^{1 / K} + Σb _K Z ^{1 / K} a _K · b _K is a constant and K = 1・ 2 ・ 3 ... In this embodiment, a _{W = a 0 + a 1 Z} + a 2 Z 2 + b 2 Z 1/2.

Since the above correction circuit 2404 has the above configuration, when the selection is changed, an intensity signal 2409 having a length corresponding to the number of lighting dots on the next selected scanning electrode is output.

Next, the configuration of the power supply circuit 2405 is shown in FIG. In the figure, reference numerals 2601 to 2607 denote resistors connected in series, and a voltage V0U and a voltage V5L are provided at both ends.
Is supplied.

Here, the voltages generated at the ends of each of the resistors 2601 to 2607 are sequentially changed to V0U, V0N, V1, V2, V3, V4, V5N, V5 as shown in FIG.
Assuming 5L, V0N-V1 = V-V2 = V3-V4 = V4-V5N = (V2-V3) / (N-4) N is a constant, and (V0U-V0N) / (V1-V2) = (V5N −V5L) / (V4−V5N) so that the respective resistors 2601 to 260
7 is set.

The voltages V0N to V5N generated by the resistors 2601 to 2607 are stabilized by a voltage stabilizing circuit 510 similar to that shown in FIG.

Reference numerals 2608 and 2609 denote switches, which are switched by an intensity signal 2409.

That is, when the intensity signal 2409 is active, the switches 2608 and 2609 are connected to the voltage V0U and the voltage V5L, respectively. Conversely, when the intensity signal 2509 is inactive, the switches 2608 and 2609 respectively connect to the voltages V0N and V5N.

The voltages output from the switches 2608 and 2609 are referred to as voltages V0 and V5, respectively, and the voltages V0 and V5 and the voltages V1 and V4 are
06 is output. Also, the voltages V0N, V2, V3, V
5N is output as the X power supply 107.

Since the power supply circuit 2405 has the above configuration, while the power signal 2409 is active, the intensity signal 2409 output from the correction circuit 2404
The voltage V0 and the voltage V5 of the selection voltage of the Y power
0U, voltage V5L, and when inactive, voltage V0N
-Output voltage V5N.

Also, the above-mentioned Y power source 2406 and X power source 107
, The selection voltage, the emergency selection voltage, the lighting voltage, and the non-lighting voltage supplied to the liquid crystal unit 101 are provided as two sets as in the case of the above-described embodiment, and the selection voltage of the Y power supply 2406 changes according to the numerical value Z. .

The structure and function of this embodiment are as described above.
When the selection is shifted to the first scanning electrode, the time corresponding to the number Z of the lighting dots on the (n + 1) th scanning electrode is a time corresponding to the number of lighting dots.
The voltage V0N of the Y power supply 2406 is referred to as a voltage V0N.
-Output voltage V0U and voltage V5L instead of voltage V5N.

The above operation will be described by taking as an example a case where the liquid crystal panel 201 displays the pattern shown in FIG.

FIG. 28A shows the signal electrode X1 forming the display dot 2701 when displaying the pattern of FIG.
The upper voltage waveform, the same figure (B) shows the voltage waveform on the scanning electrode Y4 forming the display dot 2701, and the same figure (C) shows the display dot 2
701 shows the voltage waveform applied to 701.

FIG. 29A shows the signal electrode X1 forming the display dot 2701 when displaying the pattern of FIG.
The upper voltage waveform, the same figure (B) shows the voltage waveform on the scanning electrode Y4 forming the display dot 2701, and the same figure (C) shows the display dot 2
701 shows the voltage waveform applied to 701.

FIG. 28A shows a voltage waveform on the signal electrode X1 forming the display dot 2702 in FIG.
(B) shows a voltage waveform on the scanning electrode Y2 forming the display dot 2702, and (C) shows a voltage waveform applied to the display dot 2702.

Here, FIGS. 28 (A) and (B) and FIG. 29 (A)
The voltages indicated by broken lines in (B) are voltages supplied by the Y power supply 2406 and the X power supply 107.

FIG. 30 is an enlarged view of a portion surrounded by a circle 2801 in FIG. 28 (B). In FIG. 30, reference numeral 3001 denotes a non-selection voltage to be generated at the second scan electrode Y2 in FIG. Blur waveform when moving to the selection voltage, 3002
Represents the waveform of the changing selection voltage generated by the Y power supply 2406;
Numeral 03 indicates a voltage waveform on the second scan electrode 202 in FIG. 27 obtained by synthesizing the waveforms 3001 and 3002.

Similarly, FIG. 31 is a view showing a case where a circle 290 is shown in FIG.
2 is an enlarged view of a portion surrounded by 1 in FIG.
7, a transition waveform from a non-selection voltage to be generated on the fourth scan electrode Y4 to a selection voltage, a change waveform 3102 generated by the Y power supply 2406, 310
Reference numeral 3 denotes a voltage waveform on the fourth scan electrode Y4 in FIG. 27 obtained by synthesizing the waveforms 3101 and 3102.

Here, the number Z of the lit dots of each scanning electrode 202 when the display shown in FIG. 27 is performed is as follows: the first scanning electrode Y1, Z = 0, the second scanning electrode Y2, Z = 5. The third scan electrode Y3, Z = 0, the fourth scan electrode Y4, Z = 1, the fifth scan electrode Y5, Z = 0, and the sixth scan electrode Y6, Z = 0.

For this reason, when the fifth scan electrode Y5 is selected, the waveform 3001 in FIG. 30 and the waveform 3101 in FIG. 31 are better when the second scan electrode Y2 is selected.
As can be seen from the comparison, a large rounding is about to occur when shifting from the non-selection voltage to the selection voltage. However, FIG.
The waveform 3002 of the selection voltage has been changing for a longer time in the direction of rising from the non-selection voltage to the selection voltage earlier than the waveform 3102 of the selection voltage in FIG.

As a result, the waveform 30 shown in FIGS.
Correction is performed according to the size of the rounding of 01 · 3101. Thereby, as shown in FIGS. 28 (C) and 29 (C), there is no difference between the effective voltages applied to the display dots 2701 and 2702 in FIG. 27, and the unevenness of the display of the weft stringing is remarkably improved. .

By correcting the selection voltage on the time axis according to the number of lighting dots Z on the scanning electrode selected as described above, the display unevenness of the weft threading can be remarkably improved.

Embodiment 8 As another embodiment, the selection voltage is corrected by the voltage axis correction according to the number Z of the lighting dots on the scanning electrode selected in FIG.
Similar effects can be obtained by performing the time-voltage dual axis correction and the function waveform correction.

Embodiment 9 As still another embodiment, the lighting voltage and the non-lighting voltage are time-axis corrected, voltage-axis corrected, time-voltage double-axis corrected, and the function waveform is changed according to the number Z of the lighted dots on the selected scanning electrode. Similar effects can be obtained by performing the correction.

Embodiment 10 (FIGS. 32 to 36) Next, an embodiment for the above-described uneven display of warp stringing will be described. As described above, the degree of uneven display of warp stringing is determined by the difference T 'between the number T of all lit dots and the number L of non-lit dots on the liquid crystal panel.

Here, the sum of the number of lit dots T and the number of non-lit dots L is the total number of display dots G of the liquid crystal panel. Therefore, T ′ = TL = T− (G−T) = 2 × TG (G is a constant) Therefore, when the liquid crystal display device is operated, the correction corresponding to the numerical value T is performed while counting the numerical value T. Should be performed.

FIG. 32 shows a specific configuration example for performing such correction.

In the figure, reference numeral 3204 denotes a correction circuit which counts the number T of lighting dots on the liquid crystal panel 201 and outputs the number T as an intensity signal 3209. Reference numeral 3205 denotes a power supply circuit to which the above intensity signal 3209 is input, and shifts the potential value of the non-lighting voltage of the Y power supply 3206 according to this value. Such an operation prevents uneven display due to vertical stringing.

The specific configuration of each of the above components will be described below. FIG. 33 shows a specific configuration of the correction circuit 3204.

In the figure, reference numeral 3301 denotes a counting circuit which counts the number T of all lighting dots of the liquid crystal panel 201. The counting circuit 3301 adds from the signal DIN of the control signal 102 to the next signal DIN when the signal XSCL falls, and only when the data signal 103 is active.
Is output to the count holding circuit 3302, the count value is set to 0, and counting is started again. Thus, the number T of lighting dots on the liquid crystal panel 201 is counted. It is not always necessary to accurately count up to one dot, and an error of about 5% of the number of all display dots 204 of the liquid crystal panel 201 does not cause any problem.

The counting and holding circuit 3302 is a circuit for holding the count value T output from the counting circuit 3301 and outputs the numerical value T as an intensity signal 3209.

The configuration of the correction circuit 3204 is as described above.
As an intensity signal 3209.

FIG. 34 shows a specific configuration of the power supply circuit 3205.

In the figure, reference numerals 3401 to 3403 denote resistors connected in series in series.
Is supplied.

The voltages at the ends of the resistors 3401 to 3403 are respectively represented by V0, V2, and V, as shown in FIG.
3, V5, the resistance value of each resistor is set such that (V0−V2) / 2 = (V3−V5) / 2 = (V2−V3) / (N−4).

A voltage stabilizing circuit 510 similar to that shown in FIG. 5 is provided to stabilize the voltages V2 and V3.

Here, the voltages V1N and V4N are defined as follows.

V1N = (V0 + V2) / 2 V4N = (V5 + V3) / 2 That is, the voltages V1N and V4N are the voltage at the midpoint of the voltages V0 and V2, respectively, and the voltage at the midpoint of the voltages V3 and V5. .

Reference numerals 3405 and 3406 denote voltage generating circuits for outputting a voltage that changes according to the intensity signal 3209.
/ A converter.

Here, it is defined that P = T−γ × G.

G is the number of all the display dots 204 on the liquid crystal panel 201, and γ is a number close to 、.
/ 2.

The voltage generation circuit 3405 outputs the intensity signal 3
When the numerical value T indicated by 209 is large (when T> γ × G), when the numerical value T is small (when T <γ × G), the voltage V0 depends on the absolute value of the numerical value P. A voltage having a voltage value shifted from the voltage V1N by the voltage is output.

Similarly, when the value T indicated by the intensity signal 3209 is large, the voltage generation circuit 3406 shifts the voltage V3 to the voltage V3 side.
When it is smaller, a voltage having a voltage value shifted from the voltage V4N by a voltage corresponding to the absolute value of the numerical value P is output to the voltage V5 side.

Then, the above-mentioned voltage generating circuit 3405.3
The voltages output from the 406 are denoted by V1 · V4, and the voltages V1 · V4 and the voltages V0 · V5
06, and the voltages V0, V2, V3, and V5 are output from the power supply circuit 3205 as the X power supply 3207.

The Y power source 3206 and the X power source 3207
In the same manner as described above, the voltage V1 and the voltage V4, which are non-selection voltages of the Y power source 3206, are supplied to the liquid crystal panel 201 as a set of two voltages, and the potential values thereof are changed according to the numerical value T as described above. Is done.

The present embodiment is configured as described above. When the number of all the lit dots on the liquid crystal panel 201 is small, the non-selection voltage of the Y power supply 3206 is biased toward the lit voltage side, and conversely, the number of lit dots is large. Sometimes, the voltage is biased toward the non-lighting voltage side.

The above operation will be described in more detail by taking as an example the case of displaying the pattern shown in FIG.

The display contents shown in FIG. 35 are for the case where the number of lighting dots is small, and the display dots 3501 at this time are displayed.
FIG. 36 (A) shows the voltage waveform on the signal electrode X6 forming
FIG. 7B shows a voltage waveform on the scanning electrode Y3 forming the display dot 3501, and FIG. 7C shows a voltage waveform applied to the display dot 3501.

In FIG. 36B, reference numeral 3601 denotes a non-selection voltage applied to the scanning electrode, a voltage which tends to shift to the non-lighting voltage side, and 3602 denotes a non-selection voltage output from the Y power supply 3206 in FIG. The voltage shown, 3603 is the above voltage 3
The voltage on the scan electrode obtained by the combination of 601 and 3602 is shown.

The display contents shown in FIG.
01 is small in number of lighting dots (T <γ × G)
Therefore, the non-selection voltage on the scan electrode is the voltage 3601 in FIG.
As described above. However, FIG.
The non-selection voltage output from the Y power supply 3206 is offset toward the lighting voltage side like the voltage 3602 in FIG. 36 because the number of lighting dots on the liquid crystal panel 201 is small.
As a result, the voltage 3603 is corrected to a voltage between the lighting voltage and the non-lighting voltage, and the difference between the effective voltages applied to the display dots of the liquid crystal panel 201 as shown in FIG.

Conversely, when the number of lit dots on the liquid crystal panel 201 is large (T> γ × G), the non-selection voltage on the scanning electrode tends to shift to the lit voltage side. However, Y power 3
The non-selection voltage output from 206 is offset in the non-lighting voltage side because the number of lighting dots on the liquid crystal panel 201 is large, and is similarly corrected.

As described above, by changing the non-selection voltage according to the number T of lighting dots on the liquid crystal panel 201,
The display unevenness due to vertical stringing can be remarkably improved. Embodiment 11 The same effect can be obtained by changing the lighting voltage and the non-lighting voltage according to the number T of lighting dots on the liquid crystal panel 201. That is, by changing the lighting voltage and the non-lighting voltage in the same direction and in the same direction as the voltage at which the non-selection voltage on the scanning electrode shifts according to the number T of lighting dots on the liquid crystal panel 201, display unevenness due to vertical stringing is significantly reduced. Can be improved.

The above-described embodiment does not limit the correction method, and any method may be used as long as the difference in the effective voltage caused by the number of lighting dots T on the liquid crystal panel 201 can be corrected.

Embodiment 12 (FIGS. 37 to 44) Next, an embodiment for the above-described uneven display of the polarity reversal stringing will be described. As described above, the degree of display unevenness of the polarity reversal stringing is on each scan electrode from the sum of the numbers of lit dots on the selected scan electrode and the next selected scan electrode when the polarity is reversed. It is determined by the value F obtained by subtracting the number of display dots. Therefore, when the liquid crystal display device is operated, the correction corresponding to this numerical value may be performed while counting the numerical value F.

FIG. 37 shows a specific configuration for performing such a correction.

In the figure, the configuration other than the correction circuit 3704 and the code signal 3708 and the intensity signal 3709 output from the correction circuit is the same as the configuration of FIG. 1 in the first embodiment, and has the same function. Are denoted by the same reference numerals and the description thereof will not be repeated.

The correction circuit 3704 controls the control signal 102
And the data signal 103, a value F is calculated by subtracting the number of display dots on each scanning electrode from the sum of the number of lighting dots on the selected scanning electrode and the next selected scanning electrode. , The sign of the numerical value F is output as a sign signal 3708, and the intensity signal 3709, which is active for a time corresponding to the absolute value of the numerical value F, is synchronized with the signal LP when the signal FR of the control signal 102 is switched. And output.
Thus, the power supply circuit 105 uses the sign signal 3708 and the intensity signal 3709 to generate the Y power 10
The non-selection voltage of No. 6 is changed, and thereby the correction is performed.

The detailed structure of the correction circuit 3704 is shown in FIG.
FIG.

In the figure, reference numeral 401 denotes a counting circuit;
Denotes a first count holding circuit, and 403 denotes a second count holding circuit, and their configurations are the same as those in FIG. 4 and the operation is the same.

Reference numeral 3804 denotes a numerical operation circuit for performing the following operation.

F = − (N _ON + M _ON −Q) Q is a number close to the number of the signal electrodes X1 to X6, and in this embodiment, the number of the signal electrodes X1 to X6.

The sign of numerical value F obtained by this operation is output as code signal 3708, and the absolute value of numerical value F is output to pulse width control circuit 3805.

The pulse width control circuit 3805 outputs an intensity signal 3709 which is active for a length of time corresponding to the absolute value of the numerical value F output from the numerical operation circuit 3804 when the signal FR of the control signal 102 changes. And output in synchronization with the signal LP. The relationship between the time width during which the intensity signal 3709 is active and the absolute value of the numerical value F is the same as that of the pulse width control circuit 405 in FIG.

The configuration of the correction circuit 3704 is as described above. The code signal 3708 and the intensity signal 3709 output from the correction circuit 3704 are the same as the code signal 108 and the intensity signal 109 of the first embodiment shown in FIG. Work.

In the above configuration, when the polarity is inverted when the selection is shifted to the (n) th to (n + 1) th scanning electrodes,
When the sum of the number of lighting dots on the n-th scanning electrode and the number of lighting dots on the (n + 1) -th scanning electrode is larger than the number of signal electrodes X1 to X6, the scanning electrode Y1 has a length corresponding to the difference. The non-selection voltage applied to .about.Y6 changes to the non-lighting voltage side. Conversely, when the sum of the number of illuminated dots on the n-th scan electrode and the number of illuminated dots on the (n + 1) -th scan electrode is smaller than the number of signal electrodes X1 to X6, non-display is performed for a time corresponding to the difference. The selection voltage changes to the lighting voltage side.

The above operation is performed by the liquid crystal panel 201 shown in FIG.
And a case where the pattern shown in FIG. 42 is displayed will be specifically described.

FIG. 40A shows a voltage waveform on the signal electrode X6 forming the display dot 3901 when the display of FIG. 39 is performed, and FIG. 40B shows a voltage waveform on the scanning electrode Y4 forming the display dot 3901. The waveform is shown, and FIG.
3 shows a voltage waveform applied to the power supply.

FIG. 41 is the same as FIG.
01 is an enlarged view of the portion surrounded by 01.
Reference numeral 1 denotes a voltage waveform of a spike-like noise to be generated on the scan electrode, and 4102 denotes a Y power supply 1 supplied to the scan electrode.
The voltage waveform of the non-selection voltage 07, 4103, is the voltage waveform on the scan electrode synthesized by the above voltage waveforms 4101 and 4102.

FIG. 43 (A) shows the voltage waveform on the signal electrode X6 forming the display dot 4201 when the display of FIG. 42 is performed, and FIG. 43 (B) shows the voltage waveform on the scanning electrode Y4 forming the display dot 4201. Voltage waveform, FIG. 4 (C) shows display dot 4
2 shows a voltage waveform applied to 201.

FIG. 44 is the same as FIG.
FIG. 440 is an enlarged view of a portion surrounded by 01.
Reference numeral 1 denotes a voltage waveform of a spike-like noise to be generated on the scan electrode, and reference numeral 4402 denotes a Y power supply 1 supplied to the scan electrode.
A voltage waveform 4403 of the non-selection voltage that changes is a voltage waveform 4403 on the scanning electrode synthesized with the voltage waveforms 4401 and 4402 described above. Note that FIG. 41 and FIG. 44 are enlarged at the same magnification.

Here, the numerical value F in the case of FIG.
2 The numerical value F in the case of FIG. 42 is F = -4.

Also, comparing FIG. 41 and FIG. 44, the voltage waveform 4401 is about to generate a motorcycle-like noise that is larger than the voltage waveform 4101.

However, voltage waveform 4402 is the same as voltage waveform 41
The non-selection voltage changes in a direction to suppress the noise to be generated for a longer time according to the numerical value F as compared with 02. As a result, the non-selection voltage on the scanning electrode is corrected, so that there is no difference between the effective voltages applied to the display dots as shown in FIG. 40 (C) and FIG. 43 (C). As described above, by correcting the non-selection voltage on the time axis according to the numerical value F, the display unevenness at the time of polarity inversion can be remarkably improved.

Embodiment 13 As another embodiment, the same effect can be obtained by performing the above-described voltage axis correction, time voltage axis correction, and function waveform correction on the non-selected voltage according to the numerical value F. .

Embodiment 14 As still another embodiment, the same applies if the lighting voltage and the non-lighting voltage are subjected to time axis correction, voltage axis correction, time voltage axis correction, and function waveform correction in accordance with the numerical value F. The effect is obtained.

The above-described embodiment does not limit the correction method. When the polarity is inverted, the effective voltage applied to the display dots due to the deformation of the non-selection voltage on the scan electrodes Y1 to Y6 generated according to the numerical value F is changed. Any method can be used as long as the difference can be corrected.

The above is the embodiment for the display unevenness in each of the threading modes. In the above embodiment, the numerical values defining the characterization of the display content pattern for the display unevenness in each of the threading modes are as described above. It is not limited to the numerical value I, the numerical value Z, the numerical value T, and the numerical value F.

For example, although it has been described that the mechanism of generating uneven display due to the weft stringing depends on the number M _ON of the lit dots on the selected scanning electrode, that is, the numerical value Z, more specifically, when a certain scanning electrode is selected. pattern of scan electrodes and the result of analyzing the charging and discharging of the signal electrode, the numerical _{Z 'Z' = M ON +} δ × (M ON -N ON) δ expressed by the following equation of the display content for the unevenness of the display by a constant By defining and correcting the characterization of, the unevenness of display due to weft stringing can be further reduced.

Note that the above equation Z '= M _ON + δ × (M _ON −
N _ON ) is derived from Z ′ = M _ON + δ × (dc). Here, c is the number of signal electrodes that switch from the lighting voltage to the non-lighting voltage when the selection shifts, and d is the number of signal electrodes that switch from the non-lighting voltage to the lighting voltage.

[0281] Then, the meaning of the above figures Z ', when the voltage on the scanning electrodes moves the selection voltage from the non-selective voltage, the numerical M _ON first term i.e. M _ON is defining a weft pulling mode Prevents the voltage on the scan electrode from shifting to the selection voltage, that is, increases the rounding. Here, since the direction of the voltage change of the signal electrode that switches from the non-lighting voltage to the lighting voltage is opposite to the voltage change on the scan electrode, the voltage on the scan electrode is also prevented from shifting to the selection voltage. On the other hand, the signal electrode that switches from the lighting voltage to the non-lighting voltage has the same direction of the voltage change as the voltage change of the scanning electrode, and therefore, has a function of helping the voltage on the scanning electrode to shift to the selection voltage to some extent. I do. For this reason, the voltage on the scanning electrode becomes the selected voltage by the term (d−c) of the difference (d−c) between the number d of the signal electrodes that change from the non-lighting voltage to the lighting voltage and the number c of the signal electrodes that change from the lighting voltage to the non-lighting voltage. This causes dullness during the transition.

Embodiment 15 (FIGS. 45 to 50) FIG. 45 shows the configuration of an embodiment for correcting display unevenness based on the above numerical value Z '.

In the figure, the configuration other than the correction circuit 4504, the intensity signal 4509 output from the correction circuit, and the Y power supply 4506 output from the power supply circuit 2405 is the same as that of FIG. Do the same thing.

The above correction circuit 4504 controls the control signal 10
2 and the data signal 103 to calculate a numerical value Z ', and an intensity signal 450 which becomes active for a time corresponding to the numerical value Z'.
9 is output in synchronization with the signal LP of the control signal 102. The power signal 2405 is generated by the intensity signal 4509.
Changes the selection voltage of the Y power supply, thereby performing the correction.

FIG. 46 shows a specific configuration of the correction circuit 4504.

In the figure, reference numeral 401 denotes a counting circuit;
Is a first count holding circuit, 403 is a second count holding circuit,
Reference numeral 405 denotes a pulse width control circuit, which is the same as that of FIG. 4 and performs the same operation. Reference numeral 4604 denotes a numerical operation circuit which performs the following operation.

FIG. 24 shows an example of a specific configuration for performing such correction.

In the figure, reference numeral 2404 denotes a correction circuit (correction signal generation circuit) which counts the number Z of lighting dots on the scanning electrode to be selected next, and becomes active for a time corresponding to the value Z. The signal 2409 is the signal L of the control signal 102.
Output in synchronization with P. Reference numeral 2405 denotes a power supply circuit, which receives the above intensity signal 2409 and generates a Y power supply 2406 and an X power supply 107 whose selection voltage changes. At this time, the voltage width in which the selection voltage changes is constant, and the changing time changes in response to the intensity signal 2409. That is, the selection voltage changes for a time corresponding to the numerical value Z.

Accordingly, the numerical value Z counted by the correction circuit 2404
The necessary correction is added to the selection voltage for the length of time corresponding to
Reference numeral 05 denotes a pulse width control circuit, which is the same as that of FIG. 4 and performs the same operation. Reference numeral 4604 denotes a numerical operation circuit which performs the following operation.

Z ′ = M _ON + δ × (M _ON −N _ON ) The numerical value Z ′ obtained as a result of this operation is output to the pulse width control circuit 405.

The pulse width control circuit 405 is an intensity signal 4509 which becomes active for a time corresponding to a value obtained by adding a constant s to the numerical value Z 'inputted from the arithmetic circuit 4604.
Is output. The above-mentioned constant value s is a number obtained by multiplying the number of the signal electrodes X1 to X6 of the liquid crystal panel 201 by δ and added so that Z ′ does not become negative.

Since the configuration of the present embodiment is as described above, the selection voltage changes for a time corresponding to the value Z 'when the n-th scanning electrode is selected.

The above operation is performed by the liquid crystal panel 201 shown in FIG.
A specific example will be described with reference to the case of displaying the pattern shown in FIG.

FIG. 48 shows the state of display unevenness when the display of FIG. 47 is displayed by performing the embodiment for display unevenness due to weft threading. In FIG. 48, reference numeral 4801 denotes remaining display unevenness (hereinafter, referred to as fine weft threading) even when the embodiment for the display unevenness due to the weft threading is performed. The fine weft stringing occurs on the scanning electrode at the boundary of the display as shown in the figure. Here, the numerical value Z 'when the display of FIG. 47 is performed is as follows.

For the first scan electrode Y1, Z '= 0 for the second scan electrode Y2, Z' = 0 for the third scan electrode Y3, Z '= 4 + 4 × δ, for the fourth scan electrode Y4, Z' = 45. In the fifth scan electrode Y5, Z '= 46. In the sixth scan electrode Y6, Z' = 0-4.times..delta .. The non-selection voltage of the voltage waveforms on the third and fourth scan electrodes Y3 and Y4 at this time is selected. FIGS. 49 and 50 show enlarged portions of the operation.

In FIG. 49, reference numeral 4901 denotes a voltage waveform that causes the voltage of the scan electrode to be blunted, 4902 denotes a voltage waveform in which the selection voltage to be supplied changes, and 4903 denotes the voltage waveform 4
9 shows a voltage waveform on a scan electrode synthesized by 901 and 4902.

Similarly, in FIG. 50, reference numeral 5001 denotes a voltage waveform in which the voltage of the scanning electrode is about to be reduced, 5002 denotes a voltage waveform in which the selection voltage to be supplied changes, and 5003 denotes a scan synthesized by the above voltage waveforms 5001 and 5002. 3 shows a voltage waveform on an electrode.

In FIG. 47, the first scanning electrodes Y1 to Y2
When the selection is shifted to the second scanning electrode Y2, the difference between the number Z (= 4) of the lighting dots on the second scanning electrode Y2 and the number of the lighting dots on the first scanning electrode Y1 and the second scanning electrode Y2. In response to (= 4), the voltage waveform becomes like the voltage waveform 4901 in FIG. Similarly, in FIG. 47, when the selection shifts from the third scanning electrode Y3 to the fourth scanning electrode Y4, the number Z (= 4) of lighting dots on the third scanning electrode Y3 and the second scanning electrodes Y2 and 3 The voltage waveform 5001 shown in FIG. 50 tends to be changed according to the difference (= 0) in the number of lit dots on the scan electrode Y3.

At this time, the rounding of the voltage waveform 4901 in FIG. 49 is larger than that of the voltage waveform 5001 in FIG. 50 by the difference in the number of lighting dots. However, the voltage in the voltage waveform 4902 in FIG. 49 is changed in such a direction that the scan electrode is quickly raised for a longer time than the voltage waveform 5002 in FIG. 50 by the difference in the number of the lighting dots. Thereby, voltage waveform 4903 in FIG. 49 and voltage waveform 5003 in FIG. 50 are corrected. This can improve display unevenness due to fine weft stringing.

As described above, the charge / discharge of the charge between the scan electrode and the signal electrode generated by the pattern displayed by the liquid crystal panel 201 is analyzed, and the difference between the effective voltages applied to the display dots generated by the analysis is determined by the scan electrode. The display unevenness can be improved by changing and correcting the voltages applied to Y1 to Y6 and the signal electrodes X1 to X6. Further, the charge / discharge of the charge between the adjacent signal electrodes X1 to X6 via the scan electrodes Y1 to Y6 or the charge / discharge of the charge between the adjacent scan electrodes Y1 to Y6 via the signal electrodes X1 to X6 is analyzed. Display unevenness can be further improved by correcting the difference between the effective voltages applied to the display dots caused by this by changing the voltages applied to the scan electrodes Y1 to Y6 and the signal electrodes X1 to X6.

The same effect can be obtained by counting non-lighted dots instead of lighted dots.

Further, by weighting when counting the number of lighting dots according to the position where the lighting dots are displayed, the display unevenness can be further reduced.

Further, the above-mentioned embodiments for the above-mentioned display unevenness can be used in combination.

Embodiment 16 (FIGS. 51 to 53) Hereinafter, by combining the above-described embodiments for each display unevenness as described above, every other stringing, weft threading,
An embodiment for correcting display unevenness due to warp stringing and polarity reversal stringing will be described.

FIG. 51 shows the structure of this embodiment. In this embodiment, the time axis correction of the non-selection voltage is performed on the numerical value I for every other stringing.

As for the weft stringing, the time axis of the selected voltage is corrected for the numerical value Z.

Regarding the warp stringing, the non-selection voltage is changed with respect to the numerical value T.

For the polarity inversion stringing, the time axis of the non-selection voltage is corrected for the numerical value F.

In FIG. 51, 5104 is a correction circuit, 5105 is a power supply circuit, 5106 and 5107 are Y and X power supplies made by the power supply circuit 5105, 5108 is a sign signal, 5109 is a first intensity signal, and 5109 is a second intensity signal. 5111 is a third intensity signal.

The correction circuit 5104 calculates the numerical value I, outputs the sign (positive or negative) of the numerical value I as a sign signal 5108, and outputs a signal that becomes active for a time corresponding to the absolute value of the numerical value I. Is output as a first intensity signal 5109 in synchronization with the signal LP of the control signal 102. However, this does not apply when the signal FR changes. Then, when the signal FR changes, the correction circuit 5104 calculates the numerical value F, outputs the sign of the numerical value F as the above-mentioned code signal 5108, and outputs the sign of the numerical value F for a time corresponding to the absolute value of the numerical value F. The active signal is output as the intensity signal 5109 in synchronization with the signal LP of the control signal 102.

The correcting circuit 5104 simultaneously outputs the value T
And outputs the result as a second intensity signal 5110.

Further, the correction circuit 5104 calculates a numerical value Z, and sets a signal which is recommended for a time corresponding to the numerical value as a third intensity signal 5111 in synchronization with the signal LP of the control signal 102. Output.

The power supply circuit 5105 is connected to the first to third power supply circuits.
Of the Y power supply 5106 and the X power supply 5107 are changed by the intensity signals 5109 to 5111 and the sign signal 5108. This change reduces display unevenness.

Next, each of the above components will be described in detail.
FIG. 52 shows a specific configuration of the correction circuit.

In the figure, reference numeral 401 denotes a counting circuit;
Is a first count holding circuit, 403 is a second count holding circuit,
Numeral operation circuits 404 have the same configuration and the same operation as those in FIG. 4, that is, the counting circuit 401 counts the number of lighting dots, and the first count holding circuit 402 calculates the numerical value M _ON . The second count holding circuit 403 holds the value N
Hold _ON . Then, by the numerical operation circuit 404,
Calculate the numerical value I.

Numeral 3804 denotes a numerical operation circuit which is the same as that of FIG.
And numeric M _ON to hold 02, the second counter holding circuit 403
The numerical value F is calculated from the numerical value N _ON held by. Reference numeral 5206 denotes a switching circuit which includes a numerical operation circuit 404 and a numerical operation circuit 380.
4 is a circuit for taking one of the sign and the absolute value of the numerical value output from the circuit 4. This switching takes the numerical value I of the numerical operation circuit 404 when the signal FR of the control signal 102 does not change, and takes the numerical value F of the numerical operation circuit 3804 when it changes.

The switching circuit 5206 outputs the sign of the numerical value I or F as a sign signal 5108 and sends the value of the numerical value I or F to the pulse width control circuit 405. The pulse width control circuit 405 corresponds to FIG.
And outputs an active signal as a first intensity signal 5109 for a time corresponding to the absolute value of the numerical value I or F sent from the switching circuit 5206.
Therefore, the sign signal 5108 and the first intensity signal 5109
Indicates a correction amount for alternate stringing and polarity reversal stringing.

Next, in FIG. 52, reference numeral 3301 denotes a counting circuit, 3302 denotes a counting and holding circuit, which has the same configuration and operation as those of the same reference numerals in FIG.
The result is output as a second intensity signal 5110. For this reason, the second intensity signal 5110 indicates the correction amount for the warp stringing.

Reference numeral 2503 denotes a pulse width control circuit as shown in FIG.
In the same way as the first signal, the active signal is output as the third intensity signal 5111 for a length of time corresponding to the numerical value M _ON shown in the first count holding circuit 402, in other words, for the length corresponding to the numerical value Z.
Therefore, the third intensity signal 5111 indicates the correction amount for the weft stringing.

Since the correction circuit 5104 has the above configuration, the correction amount for each display unevenness is output as a correction signal.

FIG. 53 shows a specific configuration of the power supply circuit 5105.

In the figure, reference numerals 5301 to 5308 denote resistors, which are sequentially connected in series, and have a voltage V0U and a voltage V5L applied to both ends.

The voltages at the ends of the resistors 5301 to 5308 are sequentially changed to V0U, V0N, and V1 as shown in FIG.
Assuming that N, V2, V3, V4N, V5N, and V5L, V0N-V1N = V1N-V2 = V3-V4N = V4N-V5N = (V2-V3) / (N-4) N is a constant, and (V0U-V0N). ) / (V0N−V1N) = (V5N−V5L) / (V4N−V5N) The resistance values of the resistors 5301 to 5308 are set.

The voltages V0N to V5N are stabilized by the stabilizing circuit 510.

Reference numerals 3405 and 3406 denote the same voltage generating circuits as those shown in FIG.
Changes the output voltage.

Reference numerals 5309 to 5312 denote reference voltages. The absolute values of the reference voltages 5309 and 5312 have the same value, and have the opposite signs with respect to the voltages V1N and V4N, respectively. The voltage at this time is defined as V1U · V4L.

Similarly, the absolute values of the voltages of the reference voltages 5310 and 5311 take the same value, and the voltages V1N.V4
It has the opposite sign based on N. The voltage at this time is V1L
・ It is V4U.

Reference numerals 511 and 512 denote the same switches as those shown in FIG.
09.

That is, the switch 511 outputs the voltage V1U.V1
The switch 512 takes one of the voltages V4U, V4N, and V4L.

Here, the voltages output from the switches 511 and 512 are referred to as voltages V1 and V4, respectively.

Reference numerals 2608 and 2609 denote the same switches as those in FIG. 26, and are switched by the third intensity signal 5111. That is, the switch 2608 operates at the voltage V0U.
• Take one of VON and switch 2609 is the voltage V
Take any of 5U V5N.

Here, the voltages output from the switches 2608 and 2609 are referred to as voltages V0 and V5.

Reference numeral 5106 denotes a Y power source, and the third intensity signal 51
11, the selection voltage changes, and the non-selection voltage changes with the sign signal 5108, the first intensity signal 5109, and the second intensity signal 5110. Reference numeral 5107 denotes an X power supply.

Since the present embodiment has the above configuration,
The above-described correction is performed by changing the selection voltage and the non-selection voltage of the Y power supply according to the correction signal including the above-mentioned code signal and the first to third intensity signals.

Here, the correction for the single-place stringing is only the non-selection voltage when the signal FR of the control signal 102 does not change, and the correction for the polarity inversion stringing is only the non-selection voltage when the signal FR changes. It is. The correction for the weft stringing is only the selection voltage. The warp changes the voltages V1N and V4N constituting the non-selection voltage. As described above, the corrections are almost independent of each other and can be easily combined.

Seventeenth Embodiment In the sixteenth embodiment, the time axis correction is performed on the numerical values I, Z, and F. However, a similar effect can be obtained by combining other correction methods described above.

Embodiment 18 In Embodiment 16, when a certain degree of stringing is small, it is possible to omit correction for the degree of stringing and to simplify the circuit configuration. For example, when the display unevenness due to the warp is negligible and can be ignored, the counting circuit 3301 and the count holding circuit 3302 in FIG. 52 are omitted to eliminate the second intensity signal 5110, and
The configuration can be simplified by replacing the voltage generation circuits 3405 and 3406 in FIG.

The present invention can be applied to a display device in which a voltage applied to a signal electrode is switched between a lighting voltage and a non-lighting voltage during a period in which a certain scanning electrode is selected to perform gradation display. Yes, the same effects as above can be obtained.

[0339]

As described above, according to the present invention,
By changing at least one of the scanning voltage waveform and the signal voltage waveform based on the rules contained in the graphic or character pattern displayed by the liquid crystal display device, the conventional display unevenness can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a device configuration of a first embodiment of the liquid crystal display device of the present invention.

FIG. 2 is a diagram illustrating a configuration of a liquid crystal unit.

FIG. 3 is a timing chart of a control signal and a data signal.

FIG. 4 is a block diagram showing a configuration of a correction circuit (waveform correction signal generation circuit).

FIG. 5 illustrates a structure of a power supply circuit.

FIG. 6 is a perspective view of a liquid crystal panel showing an example of display contents.

7 (A), (B), and (C) are waveform diagrams of voltages applied to the liquid crystal panel when the display of FIG. 6 is performed.

FIG. 8 is an enlarged view of a case where a circle is shown in FIG.

FIG. 9 is a block diagram illustrating a device configuration according to a second embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of the correction circuit.

FIG. 11 illustrates a structure of a power supply circuit.

12 (A), (B) and (C) are waveform diagrams of voltages applied to the liquid crystal panel when the display of FIG. 6 is performed.

FIG. 13 is an enlarged view of a part circled in FIG. 12 (B).

FIG. 14 is a block diagram showing an apparatus configuration according to a third embodiment of the present invention.

FIG. 15 illustrates a configuration of the power supply circuit.

FIG. 16 is a block diagram illustrating a device configuration according to a fourth embodiment of the present invention.

FIG. 17 is a diagram illustrating a configuration of the power supply circuit.

FIG. 18 is an exponential function waveform diagram.

FIG. 19 is a triangular voltage waveform diagram.

FIG. 20 is a diagram showing a configuration of a function waveform generation circuit.

FIG. 21 is a block diagram showing a device configuration according to a fifth embodiment of the present invention.

FIG. 22 is a diagram showing a configuration of the power supply circuit.

23 (A), (B) and (C) are waveform diagrams of voltages applied to the liquid crystal panel when the display of FIG. 6 is performed.

FIG. 24 is a block diagram showing a device configuration of a seventh embodiment of the present invention.

FIG. 25 is a block diagram showing a configuration of the correction circuit.

FIG 26 illustrates a structure of a power supply circuit.

FIG. 27 is a perspective view of a liquid crystal panel showing another display content.

28 (A), (B) and (C) are waveform diagrams of voltages applied to the liquid crystal panel when the display of FIG. 27 is performed.

29 (A), (B) and (C) are waveform diagrams of voltages applied to the liquid crystal panel when the display of FIG. 27 is performed.

FIG. 30 is an enlarged view of a portion circled in FIG. 28 (B).

FIG. 31 is an enlarged view of a part circled in FIG. 29 (B).

FIG. 32 is a block diagram showing a device configuration of a tenth embodiment of the present invention.

FIG. 33 is a block diagram showing a configuration of the correction circuit.

FIG. 34 illustrates a structure of a power supply circuit.

FIG. 35 is a perspective view of a liquid crystal panel showing another display content.

36 (A), (B) and (C) are waveform diagrams of voltages applied to the liquid crystal panel when the display of FIG. 35 is performed.

FIG. 37 is a block diagram showing a device configuration according to a twelfth embodiment of the present invention.

FIG. 38 is a block diagram showing a configuration of the correction circuit.

FIG. 39 is a perspective view of a liquid crystal panel showing another display content.

40 (A), (B) and (C) are waveform diagrams of voltages applied to the liquid crystal panel when the display of FIG. 39 is performed.

FIG. 41 is an enlarged view of a part circled in FIG. 40 (B).

FIG. 42 is a perspective view of a liquid crystal panel showing another display content.

43 (A), (B), and (C) are waveform diagrams of voltages applied to the liquid crystal panel when the display of FIG. 42 is performed.

FIG. 44 is an enlarged view of a part circled in FIG. 43 (B).

FIG. 45 is a block diagram showing a device configuration of a fourteenth embodiment of the present invention.

FIG. 46 is a block diagram showing a configuration of the correction circuit.

FIG. 47 is a perspective view of a liquid crystal panel showing another display content.

FIG. 48 is a view showing display unevenness when the display of FIG. 47 is performed.

FIG. 49 is a view showing a voltage waveform when a scan electrode shifts from a non-selection voltage to a selection voltage.

FIG. 50 is a view showing a voltage waveform when a scanning electrode shifts from a non-selection voltage to a selection voltage.

FIG. 51 is a block diagram showing a device configuration of a sixteenth embodiment of the present invention.

FIG. 52 is a block diagram showing a configuration of the correction circuit.

FIG. 53 illustrates a structure of a power supply circuit.

FIG. 54 is a perspective view of a liquid crystal panel showing display contents.

FIGS. 55 (A), (B) and (C) are waveform diagrams of ideally applied voltages to the liquid crystal panel when the display of FIG. 54 is performed.

56 (A), (B) and (C) are waveform diagrams of ideal applied voltages to the liquid crystal panel when the display of FIG. 54 is performed.

FIG. 57 is a perspective view of a liquid crystal panel showing display unevenness when the display of FIG. 54 is performed.

58 (A), (B) and (C) are voltage waveform diagrams actually applied to the liquid crystal panel when the display of FIG. 54 is performed.

59 (A), (B) and (C) are voltage waveform diagrams actually applied to the liquid crystal panel when the display of FIG. 54 is performed.

FIG. 60 is a perspective view of a liquid crystal panel showing another display content.

FIG. 61 is a diagram showing display unevenness when the display of FIG. 60 is performed.

62 (A), (B) and (C) are voltage waveform diagrams actually applied to the liquid crystal panel when the display of FIG. 60 is performed.

63 (A), (B) and (C) are diagrams showing voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 60 is performed.

FIG. 64 is a perspective view of a liquid crystal panel showing another display content.

FIG. 65 is the same view showing display unevenness when the display of FIG. 64 is performed.

FIGS. 66 (A), (B), and (C) are diagrams showing voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 64 is performed.

67 (A), (B) and (C) are diagrams showing voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 64 is performed.

FIG. 68 is a perspective view of a liquid crystal panel showing another display content.

69 is a diagram showing the display unevenness when the display of FIG. 68 is performed.

70 (A), (B) and (C) are diagrams showing voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 68 is performed.

71 (A), (B) and (C) are diagrams of voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 68 is performed.

FIG. 72 is a perspective view of a liquid crystal panel showing another display content.

73 is a view showing the same display unevenness when the display of FIG. 72 is performed.

74 (A), (B) and (C) are diagrams showing voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 72 is performed.

75 (A), (B) and (C) are diagrams showing voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 72 is performed.

FIG. 76 is a perspective view of a liquid crystal panel showing another display content.

FIG. 77 is a view showing the same display unevenness when the display of FIG. 76 is performed.

78 (A), (B) and (C) are diagrams showing voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 76 is performed.

79 (A), (B) and (C) are diagrams showing voltage waveforms actually applied to the liquid crystal panel when the display of FIG. 76 is performed.

[Explanation of symbols]

101 is a liquid crystal unit 102 is a control signal 103 is a data signal 104, 904, 2404, 3204, 3704, 45
04 · 5104 is a correction circuit 105 · 905 · 1405 · 1605 · 2105 · 24
05, 3205, and 5105 are power supply circuits.

Continued on the front page (31) Priority claim number Japanese Patent Application No. 63-27924 (32) Priority date February 9, 1988 (1988.2.9) (33) Priority claim country Japan (JP) (58) Field surveyed (Int.Cl. ⁷ , DB name) G09G 3/36 G02F 1/133 G09G 3/20

Claims (2)

(57) [Claims] 1. A scanning electrode group is formed on one substrate,
In a liquid crystal display device in which a signal electrode group is formed on the other substrate and a liquid crystal layer is sandwiched between the pair of substrates, a first voltage application unit that applies a scanning voltage waveform to the scanning electrode group; A second voltage applying means for applying a signal voltage waveform to the signal electrode group; and a rectangular shape for compensating for a shift when an effective voltage applied to the liquid crystal layer is shifted due to a change in the voltage level of the signal voltage waveform. the liquid crystal display device of the voltage pulse, to characterized in that it has, and means for applying to said signal electrodes. 2. A scanning electrode group is formed on one substrate,
A signal electrode group is formed on the other substrate, and a driving method of a liquid crystal display device in which a liquid crystal layer is sandwiched between the pair of substrates, wherein a scanning voltage waveform is applied to the scanning electrode group; When an effective voltage applied to the liquid crystal layer shifts with a change in the voltage level of the signal voltage waveform, a rectangular voltage pulse for compensating the shift is applied to the signal electrode . A method for driving a liquid crystal display device characterized by the above.