JP2007310281A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of preventing lateral crosstalk and a lateral stripe from being generated even when using four or more colors. <P>SOLUTION: In the same columns, positive/negative polarities are inverted at intervals of two scanning lines to constitute columns wherein a pixel electrode and a right adjacent pixel electrode have different or same positive/negative polarities for every scanning line, i.e., columns of R, G, and B and a column of W wherein a pixel electrode and a right adjacent pixel electrode have different positive/negative polarities. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device capable of preventing the occurrence of horizontal crosstalk and horizontal stripes even when there are four or more colors.

Some conventional liquid crystal display devices perform so-called 2H2V inversion driving. In this liquid crystal display device, the positive / negative polarity of the potential of the pixel electrode with respect to the potential of the counter electrode is inverted every two scanning lines in the same column comprising the pixel electrodes to which the potential of the same signal line is set. In every column, whether the positive / negative polarity is different or the same between the pixel electrode in the column and the adjacent pixel electrode across the signal line of the adjacent column with respect to the pixel electrode is set for each scanning line. Thus, crosstalk and flicker can be prevented (see FIG. 15 and Patent Document 1).
JP 2003-215540 A

  Such a 2H2V inversion drive is performed by four-color liquid crystal composed of a red (R) column, a green (G) column, a blue (B) column, and a white (W) column as shown in FIG. When the display device is used, as shown in FIG. 17, the positive and negative polarities of the pixel electrodes are equal in the same color pixel group in the same row.

  For this reason, when monochromatic display is performed, the potential of the storage capacitor line in the row greatly fluctuates at the beginning of writing to the row. Since the writing is completed before the potential returns, the potential of the pixel electrode changes this time when it returns.

  When an intermediate color pattern is drawn on a monochrome background, the potential fluctuation amount of the storage capacitor line is different between the line that intersects the pattern and the line that does not intersect, so that the potential fluctuation amount of the pixel is different. appear.

  Further, in the conventional liquid crystal display device, when 2H2V inversion driving is performed, light and darkness of checkered pixels as shown in FIG. 18 appears. When 2H2V inversion driving is performed with a four-color liquid crystal display device, the light and darkness of checkered pixels as shown in FIG. 19 appears. Therefore, when monochromatic display is performed by 2H2V inversion driving in a four-color liquid crystal display device, horizontal stripes as shown in FIG. 20 appear.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display device capable of preventing occurrence of horizontal crosstalk and horizontal stripes even when there are four or more colors. .

  In order to solve the above problems, the liquid crystal display device of the present invention inverts the positive / negative polarity of the potential of the pixel electrode with respect to the potential of the counter electrode every two scanning lines, so that the pixel electrode and the pixel electrode in the column are reversed. A column in which positive / negative polarity is different or the same between adjacent pixel electrodes across the signal line of the adjacent column for each scanning line, a pixel electrode in the column, and the pixel electrode adjacent to the pixel electrode Columns having different positive and negative polarities between adjacent pixel electrodes across the column signal lines are formed.

  According to the liquid crystal display device of the present invention, if only the former column is configured, in a four-color liquid crystal display device or the like, the positive and negative polarities of the pixel electrodes are equal in the same color pixel group in the same row, and the horizontal In the case where crosstalk occurs, the latter column is configured so that the positive and negative polarities of the pixel electrodes are not equal in a pixel group of the same color in the same row in a four-color liquid crystal display device, etc. Occurrence of lateral crosstalk during display can be prevented.

  In the liquid crystal display device of the present invention, two pixels having the same positive and negative polarity and adjacent pixel electrodes in the same column are divided into light and dark. In a four-color liquid crystal display device or the like, the same color pixels in the same row Since both bright and dark pixels exist in the group, it is possible to prevent the occurrence of horizontal streaks during monochrome display.

  In the liquid crystal display device of the present invention, a difference occurs in the amount of potential fluctuation due to the coupling capacitance Cpv between adjacent pixel electrodes in the same column in two pixels divided into light and dark, and in the latter column, the pixel electrodes in the column Difference between the pixel electrode and the adjacent pixel electrode across the signal line of the adjacent column does not occur, so that the coupling capacitance Cpv can be reduced to reduce the brightness.

  However, in the former column, a difference occurs in the potential fluctuation amount due to the coupling capacitance Cpn, and the difference is larger than the difference due to the coupling capacitance Cpv and is opposite in sign. Therefore, in the former column and the latter column, If the coupling capacitance Cpv is made equal, the contrast in the former column becomes conspicuous.

  Therefore, in the former column, the coupling capacitance Cpv is made larger than the coupling capacitance Cpv in the latter column. As a result, the difference due to the coupling capacitance Cpv increases, and the difference due to the coupling capacitance Cpn acts to cancel out. As a result, in two pixels that are divided into light and dark in the former row, the total difference in potential fluctuation amount becomes small, and light and dark are reduced. Therefore, by making the coupling capacitance Cpv in the former column larger than the coupling capacitance Cpv in the latter column, light and darkness can be reduced in both columns.

  According to the liquid crystal display device of the present invention, by configuring the columns having different positive and negative polarities between the pixel electrode in the column and the pixel electrode adjacent to the pixel electrode with the signal line of the adjacent column interposed therebetween, In a four-color liquid crystal display device or the like, the positive and negative polarities of the pixel electrodes are not equal in a pixel group of the same color in the same row, and it is possible to prevent the occurrence of horizontal crosstalk in the case of monochromatic display.

  In a four-color liquid crystal display device or the like, both bright and dark pixels exist in the same color pixel group in the same row, so that it is possible to prevent the occurrence of horizontal stripes during single color display.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of a liquid crystal display device 1 according to the first embodiment. Here, the liquid crystal display device 1 is an active matrix liquid crystal display device using a polycrystalline silicon thin film transistor as a pixel transistor. Hereinafter, the thin film transistor is referred to as a TFT.

  The liquid crystal display device 1 includes an array substrate 100, a counter substrate 200 disposed opposite to the upper surface of the array substrate 100 at a predetermined interval, and an alignment film sandwiched between the array substrate 100 and the counter substrate 200. And a liquid crystal layer (not shown) disposed therebetween. The array substrate 100 and the counter substrate 200 are bonded to each other with a sealant 400.

  The array substrate 100 includes a plurality of gate lines (scanning lines) Y extending in parallel along the row direction (horizontal scanning direction) and a plurality of gate lines extending in parallel along the column direction (vertical scanning direction). A pixel thin film transistor, that is, a pixel TFT 110 as a switching element provided at each intersection of the signal line X, each gate line Y, and each signal line X, and a plurality of pixel electrodes 120 provided corresponding to each pixel TFT 110. And.

  The pixel TFT 110 is a polycrystalline silicon TFT having a polycrystalline silicon film as a semiconductor layer. The gate electrode of the pixel TFT 110 is connected to the gate line Y, and the source electrode is connected to the signal line X. The drain electrode of the pixel TFT 110 is connected to the pixel electrode 120 via an electrode 160 formed in the same layer as the signal line X. The electrode 160 forms an auxiliary capacitance element 130 a between the electrode 160 and the auxiliary capacitance line 140 formed in the same layer as the gate line Y. A liquid crystal capacitor element 130 b is formed between the pixel electrode 120 and the counter electrode 210 formed on the counter substrate 200.

  The gate line drive circuit 150 that supplies a drive signal to the gate line Y is integrally formed on the array substrate 100 by the same manufacturing process as the pixel TFT 110.

  The pixel electrode polarity control means of the present invention has the same configuration of TCP 500-1, 500-2, etc., in which a signal line driving IC 511 and the like are mounted on a flexible wiring board and electrically connected to an external connection terminal of the array substrate 100. 500-4 (hereinafter referred to as “TCP500-N” when any one of the TCPs 500 is shown) and a signal line switching circuit 170 formed on the array substrate 100 by the same manufacturing process as the pixel TFT 110. Is done. The TCP 500 -N is arranged in such a manner that one side is electrically connected to one side of the array substrate 100 and the opposite side is connected to a PCB substrate 600 as an external circuit board.

  FIG. 2 is a diagram showing the arrangement of each signal line and pixel electrode and the circuit of the signal line switching circuit 170. As shown in FIG. 2, each signal line to which reference numerals X1, X2,... Are assigned is formed to the left of the pixel electrode to which the potential of the signal line is set.

  In addition, pixels in the column indicated by R, G, and B in FIG. 2 include red, green, and blue colored layers between the pixel electrode 120 and a wiring layer that includes the signal lines X and the scanning lines Y, respectively. On the other hand, the pixels in the column indicated by W include a transparent layer between the wiring layer and the pixel electrode 120.

  The signal line switching circuit 170 is wired with TFT control lines TFTCON1 and TFTCON2 from the signal line driving IC 511.

  The signal line switching circuit 170 includes a TFT 171 and a TFT 172 for the analog video signal converted from the digital signal by the signal line driving IC 511, that is, the video signal IN1 for the signal lines X1 and X2.

  The source signal of the TFT 171 is supplied with the video signal IN1, the drain electrode is connected to the signal line X1, and the gate electrode is connected to the TFT control line TFTCON2.

  The video signal IN1 is supplied to the source electrode of the TFT 172, the drain electrode is connected to the signal line X2, and the gate electrode is connected to the TFT control line TFTCON1.

  Similarly, the signal line switching circuit 170 includes a TFT 173 connected to the TFT control line TFTCON2 and a TFT 174 connected to the TFT control line TFTCON1 for the video signal IN2 for the signal lines X3 and X4.

  Similarly, the signal line switching circuit 170 includes a TFT 175 connected to the TFT control line TFTCON1 and a TFT 176 connected to the TFT control line TFTCON2 for the video signal IN3 for the signal lines X5 and X6.

  Similarly, the signal line switching circuit 170 includes a TFT 177 connected to the TFT control line TFTCON1 and a TFT 178 connected to the TFT control line TFTCON2 for the video signal IN4 for the signal lines X7 and X8.

  Similarly, the signal line switching circuit 170 includes a TFT 179 connected to the TFT control line TFTCON2 and a TFT 1710 connected to the TFT control line TFTCON1 for the video signal IN5 for the signal lines X9 and X10.

  Similarly, the signal line switching circuit 170 includes other TFTs for video signals for other signal lines.

  In FIG. 2, a reference numeral is attached to the right side of the pixel electrode 120, and for example, the pixel electrode 120 attached with the reference numeral 1 is referred to as the pixel electrode 1.

  In FIG. 2, in a certain frame (n frame), a + sign is attached to a pixel electrode set to a positive potential, a − sign is attached to a pixel electrode set to a negative potential, and the first half of the horizontal scanning period. The pixel electrode to which the potential is set is marked with a circle.

(Operation of the first embodiment)
Next, the operation of the liquid crystal display device 1 according to the first embodiment will be described.

  3 and 4 are timing charts of the first embodiment, and FIG. 5 is a distribution diagram of the positive / negative polarity of the potential of the pixel electrode with respect to the potential of the counter electrode.

  As shown in FIG. 5, in the first embodiment, the positive / negative polarity is inverted every two scanning lines in the same column. In the first embodiment, the pixel electrode in the column and the pixel electrode on the right side (that is, the pixel electrode adjacent to the pixel electrode in the column with the signal line in the adjacent column interposed therebetween, the same applies hereinafter). The positive / negative polarity is different between the column in which the positive / negative polarity is different or the same for each scanning line, that is, the R, G, B column, and the pixel electrode in the column and the pixel electrode on the right side A column, that is, a column of W is formed.

  First, in a certain frame (n frame), as shown in FIGS. 3 and 4, the TFT control line TFTCON1 is set to a high voltage in the first half of the horizontal scanning period H1 in which the potentials of the pixel electrodes 1, 2,. The TFT control line TFTCON2 is set to a low voltage.

  As a result, the TFTs 171, 173, 176, 178, 179,... Are turned on, and the TFTs 172, 174, 175, 177,.

  Thus, the signal lines X1, X3, X6, X8, X9,... Connected to these turned-on TFTs, and the pixel TFTs connected to these signal lines and having the gate lines driven during the horizontal scanning period H1. , Video signals IN1, IN2, IN3, IN4, IN5,... Are written to the pixel electrodes 1, 3, 6, 8, 9,... Connected to these pixel TFTs.

  At this time, the video signals IN1, IN4,... Are positive video signals with respect to the counter electrode, and the video signals IN2, IN3, IN5,.

  As a result, the pixel electrodes 1, 8,... Are set to a positive potential, the pixel electrodes 3, 6, 9,... Are set to a negative potential, and the potential is maintained until the writing timing in the subsequent frame (n + 1 frame). Will be held.

  Subsequently, in the second half of the horizontal scanning period H1, the TFT control line TFTCON1 is set to a low voltage, and the TFT control line TFTCON2 is set to a high voltage.

  As a result, the TFTs 171, 173, 176, 178, 179,... Are turned off, and the TFTs 172, 174, 175, 177,.

  As a result, the signal lines X2, X4, X5, X7,... Connected to these turned-on TFTs and the pixel TFTs connected to these signal lines and whose gate lines are driven in the horizontal scanning period H1 are passed through. Thus, video signals IN1, IN2, IN3, IN4,... Are written to the pixel electrodes 2, 4, 5, 7,.

  The video signals IN1, IN3,... At this time are video signals having a positive polarity with respect to the counter electrode, and the video signals IN2, IN4,.

  Thereby, the pixel electrodes 2, 5,... Are set to a positive potential, the pixel electrodes 4, 7,... Are set to a negative potential, and the potential is held until the write timing in the n + 1 frame. It will be.

  Subsequently, in the first half of the horizontal scanning period H2 in which the potentials of the pixel electrodes 1, 2,... In FIG. 2 are set, the TFT control line TFTCON1 is continuously set to a low voltage and the TFT control line TFTCON2 is set to a high voltage.

  As a result, the TFTs 171, 173, 176, 178, 179... Are turned off and the TFTs 172, 174, 175, 177.

  As a result, the signal lines X2, X4, X5, X7,... Connected to these turned-on TFTs and the pixel TFTs connected to these signal lines and whose gate lines are driven in the horizontal scanning period H2 are connected. Then, the video signals IN1, IN2, IN3, IN4,... Are written to the pixel electrodes 12, 14, 15, 17,.

  At this time, the video signals IN1, IN3,... Are video signals having a negative polarity with respect to the counter electrode, and the video signals IN2, IN4,.

  As a result, as shown in FIG. 4, the pixel electrodes 12, 15,... Are set to a negative potential, and the pixel electrodes 14, 17,. Will be held.

  Subsequently, in the second half of the horizontal scanning period H2, the TFT control line TFTCON1 is set to a high voltage, and the TFT control line TFTCON2 is set to a low voltage.

  As a result, the TFTs 171, 173, 176, 178, 179,... Are turned on, and the TFTs 172, 174, 175, 177,.

  Thereby, each of the signal lines X1, X3, X6, X8, X9,... Connected to these turned-on TFTs, and the pixel TFTs connected to these signal lines and whose gate lines are driven in this horizontal scanning period H2. , Video signals IN1, IN2, IN3, IN4, IN5,... Are written to the pixel electrodes 11, 13, 16, 18, 19,... Connected to these pixel TFTs.

  At this time, the video signals IN1, IN4,... Are positive video signals with respect to the counter electrode, and the video signals IN2, IN3, IN5,.

  As a result, the pixel electrodes 11, 18,... Are set to a positive potential, the pixel electrodes 13, 16, 19,... Are set to a negative potential, and the potential is held until the write timing in the n + 1 frame. It becomes.

  The same processing is performed in the subsequent horizontal scanning periods H3,... To obtain a polarity distribution as shown in FIG.

  In each subsequent frame, the positive / negative polarity of all the pixel electrodes is reversed from that of the previous frame.

  In the first embodiment, by obtaining the polarity distribution shown in FIG. 5, the positive and negative polarities of the pixel electrodes are not equal in the pixel group of that color in the same row even if the single color display is performed as shown in FIG. 6. . Therefore, occurrence of lateral crosstalk can be prevented.

  Next, potential fluctuations of adjacent pixel electrodes having the same positive / negative polarity in the same column of W will be described by taking the pixel electrode 8 and the pixel electrode 18 as an example.

  When the potential of the pixel electrode 18 is set, the potential of the pixel electrode 8 is subjected to a potential fluctuation + dVv in the positive direction due to a coupling capacitance between both pixel electrodes (hereinafter, the same is referred to as a coupling capacitance Cpv). On the other hand, when the potential of the pixel electrode 28 is set, the potential of the pixel electrode 18 receives a negative potential fluctuation −dVv by the coupling capacitor Cpv. Therefore, the difference obtained by subtracting the potential fluctuation amount of the pixel electrode 8 due to the coupling capacitance Cpv from the potential fluctuation amount of the pixel electrode 18 due to the coupling capacitance Cpv is −2 dVv.

  Further, the potential of the pixel electrode 8 is set in the positive direction by the coupling capacitance between the pixel electrode 8 and the signal line X9 (hereinafter, the same is referred to as the coupling capacitance Cpn) when the potential of the pixel electrode 29 is set. It receives potential fluctuation + dVn. On the other hand, the potential of the pixel electrode 18 is also subjected to a potential fluctuation + dVn in the positive direction by the coupling capacitor Cpn when the potential of the pixel electrode 29 or the like is set. Therefore, the difference obtained by subtracting the potential fluctuation amount of the pixel electrode 8 due to the coupling capacitance Cpn from the potential fluctuation amount of the pixel electrode 18 due to the coupling capacitance Cpn is 0 (zero).

  Further, the potential of the pixel electrode 8 is negative in the negative direction due to the coupling capacitance between the pixel electrode 8 and the signal line X8 (hereinafter, the same is referred to as the coupling capacitance Cps) when the potential of the pixel electrode 28 or the like is set. Receiving potential fluctuation -dVs. On the other hand, the potential of the pixel electrode 18 is also subjected to negative potential fluctuation −dVs by the coupling capacitor Cps when the potential of the pixel electrode 28 or the like is set. Therefore, the difference obtained by subtracting the potential fluctuation amount of the pixel electrode 8 due to the coupling capacitance Cps from the potential fluctuation amount of the pixel electrode 18 due to the coupling capacitance Cps is 0 (zero).

  Therefore, in total, the difference obtained by subtracting the potential fluctuation amount of the pixel electrode 8 from the potential fluctuation amount of the pixel electrode 18 (hereinafter, the same is referred to as the difference dVw) is −2 dVv. The pixel and the pixel having the pixel electrode 18 are divided into light and dark.

  In this way, two pixels having pixel electrodes having the same positive and negative polarity and adjacent to each other in the same column of W are separated into light and dark.

  Next, potential variations of pixel electrodes having the same positive and negative polarity and adjacent to each other in the same row of any of RGB will be described using the pixel electrode 1 and the pixel electrode 11 as an example.

  When the potential of the pixel electrode 11 is set, the potential of the pixel electrode 1 is subjected to a potential fluctuation + dVv in the positive direction by the coupling capacitor Cpv. On the other hand, when the potential of the pixel electrode 21 is set, the potential of the pixel electrode 11 receives a potential fluctuation −dVv in the negative direction by the coupling capacitor Cpv. Therefore, the difference obtained by subtracting the potential fluctuation amount of the pixel electrode 1 due to the coupling capacitance Cpv from the potential fluctuation amount of the pixel electrode 11 due to the coupling capacitance Cpv is −2 dVv.

  Further, the potential of the pixel electrode 1 is subjected to negative potential fluctuation −dVn by the coupling capacitor Cpn when the potential of the pixel electrode 22 or the like is set. On the other hand, the potential of the pixel electrode 11 is subjected to a positive potential fluctuation + dVn by the coupling capacitor Cpn when the potential of the pixel electrode 32 or the like is set. Therefore, the difference obtained by subtracting the potential fluctuation amount of the pixel electrode 11 due to the coupling capacitance Cpn from the potential fluctuation amount of the pixel electrode 11 due to the coupling capacitance Cpn is +2 dVn.

  Further, the potential of the pixel electrode 1 is subjected to a negative potential fluctuation −dVs by the coupling capacitor Cps when the potential of the pixel electrode 21 or the like is set. On the other hand, the potential of the pixel electrode 11 is also subjected to negative potential fluctuation −dVs by the coupling capacitor Cps when the potential of the pixel electrode 21 or the like is set. Therefore, the difference obtained by subtracting the potential fluctuation amount of the pixel electrode 1 due to the coupling capacitance Cps from the potential fluctuation amount of the pixel electrode 11 due to the coupling capacitance Cps is 0 (zero).

  Therefore, in total, the difference obtained by subtracting the potential fluctuation amount of the pixel electrode 1 from the potential fluctuation amount of the pixel electrode 11 (hereinafter, the same is referred to as the difference dVrgb) is +2 dVn−2 dVv. Based on this difference, the pixel having the pixel electrode 1 and the pixel having the pixel electrode 11 are separated into light and dark.

  In this way, two pixels having pixel electrodes having the same positive and negative polarity and adjacent to each other in the same row of any of RGB are divided into light and dark.

  That is, the two pixels having the same positive and negative polarity and adjacent pixel electrodes in the same column are divided into light and dark, and the light and dark of the pixel as shown in FIG. 7 appears.

  However, in the first embodiment, even if a single color is displayed as shown in FIG. 8, since both bright and dark pixels exist in the pixel group of the color in the same row, the occurrence of horizontal stripes is prevented. Can do.

[Second Embodiment]
Next, a liquid crystal display device according to a second embodiment of the present invention will be described. The liquid crystal display device according to the second embodiment has a configuration for reducing the contrast shown in FIG. 7 with respect to the liquid crystal display device according to the first embodiment. Since it is the same as the embodiment, here, the configuration and the operation and effect thereof will be described.

  In the first embodiment, the above-described difference dVrgb> 0. That is, the difference due to the coupling capacitance Cpn is larger than the difference due to the coupling capacitance Cpv and is opposite in sign, and this is assumed below.

  FIG. 9 is a plan view of the pixel electrode in the W column and the periphery thereof in the second embodiment. FIG. 10 is a cross-sectional view taken along the line ABC of FIG.

  As shown in FIGS. 9 and 10, the auxiliary capacitance lines 140 and 140 ′ are arranged in parallel with the gate line Y. The pixel electrode 120 is disposed so as to be surrounded by two parallel signal lines X and X ′ and two auxiliary capacitance lines 140 and 140 ′ orthogonal thereto. The pixel electrode 120 is connected to one signal line X of two adjacent signal lines via the pixel TFT 110.

  The electrode 160 connected to the pixel electrode 120 is disposed so as not to overlap the pixel electrode 120 ′ located on the pixel electrode 120.

  Thereby, since the coupling capacitance Cpv is reduced, dVv is reduced, and the difference dVw = −2 dVv can be reduced. As a result, brightness and darkness can be reduced.

  FIG. 11 is a plan view of pixel electrodes in the respective RGB columns and the periphery thereof in the second embodiment. 12 is a cross-sectional view taken along the line ABC in FIG. 13 is a cross-sectional view taken along line D-E in FIG.

  As shown in FIGS. 11 and 12, auxiliary capacitance lines 140 and 140 ′ are arranged in parallel with the gate line Y. The pixel electrode 120 is disposed so as to be surrounded by two parallel signal lines X and X ′ and two auxiliary capacitance lines 140 and 140 ′ orthogonal thereto. The pixel electrode 120 is connected to one signal line X of two adjacent signal lines via the pixel TFT 110.

  As described above, a difference in potential fluctuation amount due to the coupling capacitance Cpn occurs in each RGB column, and the difference is larger than the difference due to the coupling capacitance Cpv and is opposite in sign. If the coupling capacitance Cpv is made equal for the W column, the contrast in the RGB columns becomes conspicuous.

  Therefore, in each of the RGB columns, the coupling capacitance Cpv is larger than the coupling capacitance Cpv of the W column.

  For example, as shown in FIGS. 11 and 13, the electrode 160 connected to the pixel electrode 120 extends toward the pixel electrode 120 ′ located above the pixel electrode 120, and a part of the electrode 160 is connected to the pixel electrode 120 ′. overlapping.

  Thereby, since the coupling capacitance Cpv is increased, dVv is increased, and the difference dVrgb can be decreased. As a result, brightness and darkness can be reduced.

  Also, as shown in FIGS. 10 and 12, a shield electrode 180 having electrostatic shielding properties is disposed between the pixel electrode 120 and each of the signal lines X and X ′. The shield electrode 180 is formed by extending a part of the auxiliary capacitance line 140 along the signal lines X and X ′. A shield electrode 180 'is similarly formed for the auxiliary capacitance line 140'.

  As a result, the coupling capacitance Cpn is reduced, so that dVn is reduced and the difference dVrgb can be reduced. As a result, brightness and darkness can be reduced.

  Therefore, by making the coupling capacitance Cpv in each of the RGB columns larger than the coupling capacitance Cpv in the W column, it is possible to reduce the brightness in both columns.

[Third Embodiment]
In the first and second embodiments, each signal line is formed on the left side of the pixel electrode to which the potential of the signal line is set. Therefore, the polarity distribution as shown in FIG. In the embodiment, each signal line is formed on the left side of the pixel electrode to which the potential of the signal line is set. Therefore, by setting the polarity distribution as shown in FIG. 14, it is possible to prevent the occurrence of lateral crosstalk by the same action.

  Also in the third embodiment, by making the coupling capacitance Cpv in each of the RGB columns larger than the coupling capacitance Cpv in the W column, it is possible to reduce light and darkness in both columns. it can.

  In the above description, the four-color liquid crystal display device has been described. Even in the case of a five-color or more liquid crystal display device, the same effect can be obtained by providing a column corresponding to the W column corresponding to the RGB column. An effect is obtained.

1 is a schematic configuration diagram of a liquid crystal display device 1 according to a first embodiment. FIG. 5 is a diagram showing the arrangement of signal lines and pixel electrodes and a circuit of a signal line switching circuit 170. It is a timing chart of a 1st embodiment. It is a timing chart of a 1st embodiment. It is a distribution map of the positive / negative polarity of a pixel electrode. It is a distribution map of the positive / negative polarity in the case of a monochrome display. It is a figure which shows the lightness and darkness of the pixel in 1st Embodiment. It is a figure which shows the lightness and darkness of the pixel at the time of monochromatic display. It is a top view of the pixel electrode of W row | line | column in 2nd Embodiment, and its periphery. FIG. 10 is a cross-sectional view taken along the line A-B-C in FIG. 9. It is a top view of the pixel electrode of RGB each row | line in 2nd Embodiment, and its periphery. FIG. 12 is a cross-sectional view taken along the line A-B-C in FIG. 11. FIG. 12 is a sectional view taken along line D-E in FIG. 11. It is a distribution map of the positive / negative polarity in 3rd Embodiment. It is a distribution map of positive / negative polarity when 2H2V inversion driving is performed. FIG. 6 is a distribution diagram of positive and negative polarities when 2H2V inversion driving is performed in a four-color liquid crystal display device. FIG. 6 is a distribution diagram of positive and negative polarities when a monochrome display is performed by performing 2H2V inversion driving in a four-color liquid crystal display device. It is a figure which shows the lightness and darkness of a pixel when 2H2V inversion drive is performed. It is a figure which shows the lightness and darkness of a pixel when 2H2V inversion drive is performed with the liquid crystal display device of 4 colors. It is a figure which shows the lightness and darkness of a pixel at the time of performing a 2H2V inversion drive with a 4 color liquid crystal display device, and carrying out a monochrome display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device 100 ... Array substrate 110 ... Pixel TFT
DESCRIPTION OF SYMBOLS 120 ... Pixel electrode 130a ... Auxiliary capacitance element 130b ... Liquid crystal capacitance element 140 ... Auxiliary capacitance line 150 ... Gate line drive circuit 160 ... Electrode 170 ... Signal line switching circuit 180 ... Shield electrode 200 ... Counter substrate 210 ... Counter electrode Cpn, Cps, Cpv ... Coupling capacitance X ... Signal line Y ... Gate line (scanning line)

Claims (7)

A plurality of signal lines and a plurality of scanning lines intersect with each other, and pixel thin film transistors that are turned on by driving the scanning lines at the intersections and potentials of the signal lines at the intersections are set by the turned-on pixel thin film transistors. An array substrate including a pixel electrode;
A counter substrate provided with a counter electrode facing each pixel electrode through a liquid crystal layer;
In the same column comprising each pixel electrode to which the potential of the same signal line is set, the positive / negative polarity of the potential of the pixel electrode with respect to the potential of the counter electrode is inverted every two scanning lines, and the pixels in the column A column in which positive / negative polarity is different or the same between the electrode and the adjacent pixel electrode across the signal line of the adjacent column with respect to the pixel electrode for each scanning line, and a pixel electrode in the column And a pixel electrode polarity control unit that constitutes a column having positive and negative polarities different from each other with respect to the pixel electrode across a signal line in the adjacent column. The pixel electrode polarity control means includes:
In a column having a first color layer, a second color layer, or a third color layer between the pixel electrode in the column and the wiring layer on which each signal line and each scan line is formed, Whether the positive / negative polarity is different or the same between the pixel electrode and the adjacent pixel electrode across the signal line of the adjacent column with respect to the pixel electrode, for each scanning line,
In a column having a fourth color layer between the pixel electrode in the column and the wiring layer in which each signal line and each scanning line is formed, the pixel electrode and the signal line in the column adjacent to the pixel electrode The liquid crystal display device according to claim 1, wherein the positive and negative polarities differ between pixel electrodes adjacent to each other.   3. The liquid crystal display device according to claim 2, wherein the first color, the second color, and the third color are composed of red, green, and blue, and the fourth color is white. A signal line for each column is formed on the left side of the column,
The pixel electrode polarity control means includes:
A column in which the positive and negative polarities between the pixel electrode in the column and the pixel electrode on the right side thereof are the same or different for each scanning line, the pixel electrode in the column and the pixel electrode on the right side thereof 4. The liquid crystal display device according to claim 1, wherein the liquid crystal display device comprises columns having different positive and negative polarities. A signal line for each column is formed to the right of the column,
The pixel electrode polarity control means includes:
A column in which positive / negative polarity is different or the same between the pixel electrode in the column and the pixel electrode on the left side thereof for each scanning line, a pixel electrode in the column and a pixel electrode on the left side of the pixel electrode 4. The liquid crystal display device according to claim 1, wherein the liquid crystal display device comprises columns having different positive and negative polarities.   A coupling capacitance between pixel electrodes in a column in which positive / negative polarity is different or the same for each scanning line is defined as a coupling capacitance between pixel electrodes in a column having different positive / negative polarity between adjacent pixel electrodes. 6. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is larger than a ring capacity. An electrode connected to one of the two pixel electrodes and the other pixel electrode overlap each other in a column in which the positive and negative polarities are different or the same for each scanning line. The electrode connected to one of the two pixel electrodes that causes coupling capacitance between the pixel electrodes in a column having different positive and negative polarities between adjacent pixel electrodes and the other pixel electrode are not overlapped. The liquid crystal display device according to claim 6.

Images