JP2008281982A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with a reflection region and a transmission region, the liquid crystal display device capable of correcting a gradation difference between both regions on an identical substrate attributable to cell gaps. <P>SOLUTION: By setting a capacity of a storage capacitor Cst in the transmission region At smaller than that of a storage capacitor Csr in the reflection region Ar (Cst<Csr), in the case that a signal voltage is written in a pixel electrode via a signal line SL in a time period in which a switching element Tr is kept in the turned-on state with capacitively coupled driving, and subsequently a compensation voltage is applied to storage capacitor lines CsrL, CstL in a time period in which the switching element Tr is kept in the turned-off state, variations in change amounts ΔVt, ΔVr of pixel electrode potentials Vpix attributable to cell gaps different in the transmission region At and the reflection region Ar are made equal to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device including a reflective region for performing reflective display and a transmissive region for performing transmissive display.

Liquid crystal display devices with both reflective areas for reflective display and transmissive areas for transmissive display can be used widely in information terminals such as mobile phones because they can ensure good visibility in bright and dark places. (For example, refer to Patent Document 1 and Patent Document 2). In this liquid crystal display device, a so-called multi-gap method is generally used in which the cell gap in the reflection region (the thickness of the liquid crystal layer) is made smaller than the cell gap in the transmission region in order to equalize the distance of light passing through the liquid crystal layer. Yes (see Patent Document 3).
JP 2002-303863 A JP 2003-216116 A JP 2005-189570 A

  However, the conventional liquid crystal display device has different applied voltage-transmittance characteristics because the cell gap is different between the reflective region and the transmissive region. As a result, there is a problem that even when the same voltage is applied, the gradation is not the same. In order to correct the gradation difference between the reflective display and the transmissive display, the gradation setting of the output of the DAC circuit may be changed. However, when a single IC or the like is used, there is a problem that a substrate for mounting a plurality of resistors for changing the gradation setting is newly required.

  In Patent Document 3, in order to correct the gradation difference, the capacity of the storage capacitor in the transmissive region is made larger than the capacity of the storage capacitor in the reflective region. However, since the liquid crystal capacitances in the transmission region and the reflection region are treated as being equal in the equation for calculating the variation amount of the pixel potential, in the above configuration, the applied voltage-transmittance characteristics cannot be made the same.

  The present invention has been made in view of the above, and in a liquid crystal display device having a reflective region and a transmissive region, it is an object to correct a gradation difference between both regions due to a difference in cell gap on the same substrate. And

  A liquid crystal display device according to a first aspect of the present invention includes a plurality of signal lines and a plurality of scanning lines that are arranged to cross each other, and a switching element that is disposed at each intersection of the plurality of signal lines and the plurality of scanning lines. A plurality of storage capacitor lines wired for each scanning line; a first region in which a pixel electrode capable of reflective display is connected to the switching element; and a second region in which a pixel electrode capable of transmissive display is connected to the switching element; In the first region, one end is connected to the switching element and the other end is connected to the storage capacitor line. In the second region, one end is connected to the switching element and the other end is connected to the storage capacitor line. And a second storage capacitor having a capacity smaller than that of the first storage capacitor.

  In the present invention, the capacitance of the second storage capacitor in the second region capable of transmissive display is made smaller than the capacity of the first storage capacitor in the first region capable of reflective display, so that the switching element can be driven by capacitive coupling driving. After the signal voltage is written to the pixel electrode through the signal line during the ON period, when the compensation voltage is applied to the storage capacitor line during the period when the switching element is OFF, the cell gap differs between the first region and the second region. It is possible to suppress variation in the variation amount of the pixel electrode potential due to the above.

  A liquid crystal display device according to a second aspect of the present invention includes a plurality of signal lines and a plurality of scanning lines that are arranged to cross each other, and a switching element disposed at each intersection of the plurality of signal lines and the plurality of scanning lines. A plurality of storage capacitor lines wired for each scanning line; a first region in which a pixel electrode capable of reflective display is connected to the switching element; and a second region in which a pixel electrode capable of transmissive display is connected to the switching element; A storage capacitor having one end connected to the switching element and the other end connected to the storage capacitor line, a first drive circuit that performs capacitive coupling drive by applying a compensation voltage to the storage capacitor line in the first region, and a second And a second drive circuit that performs capacitive coupling drive by applying a compensation voltage having a smaller amount of fluctuation than the fluctuation amount of the compensation voltage applied by the first drive circuit to the storage capacitor line in the region.

  In the present invention, the variation amount of the compensation voltage applied to the storage capacitor in the second region capable of transmissive display is made smaller than the variation amount of the compensation voltage applied to the storage capacitor in the first region capable of reflective display. As a result, it is possible to suppress variation in the variation amount of the pixel electrode potential caused by different cell gaps in the first region and the second region.

  In addition, the pixel electrode in the first region in the liquid crystal display device is a transflective pixel electrode capable of not only reflective display but also transmissive display.

  Further, the pixel electrode in the second region in the liquid crystal display device is a transflective pixel electrode capable of not only transmissive display but also reflective display.

  In the liquid crystal display device, capacitive coupling driving is performed in which a signal voltage is applied to the signal line while the switching element is on, and then the potential of the storage capacitor line is varied during the period when the switching element is off. It is characterized by performing.

  According to the liquid crystal display device of the present invention, it is possible to correct the gradation difference between the two regions due to the difference in cell gap on the same substrate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[First Embodiment]
As shown in the block diagram of FIG. 1, in the liquid crystal display device, a plurality of signal lines SL and a plurality of scanning lines GL are wired so as to cross each other in the display area A on the array substrate. A switching element Tr is disposed at each intersection of the plurality of signal lines SL and the plurality of scanning lines GL. A plurality of storage capacitor lines CL are wired for each scanning line GL. The display area A has a reflective area Ar (first area) and a transmissive area At (second area).

  In the reflective region Ar, a pixel electrode (not shown) that can be reflected and displayed on the switching element Tr and a storage capacitor Csr are connected to perform reflective display using external light. In the transmissive region At, a pixel electrode (not shown) that can be transmissively displayed on the switching element Tr and a storage capacitor Cst are connected, and transmissive display is performed using the light of the backlight. The capacity of the storage capacitor Csr in the reflective area Ar is larger than the capacity of the storage capacity Cst in the transmissive area At. Here, in order to equalize the distance of light passing through the liquid crystal layer, the cell gap of the reflective region Ar is made smaller than the cell gap of the transmissive region At (multi-gap method).

  Further, the present liquid crystal display device includes a signal line driving circuit 11 connected to the signal line SL, a scanning line driving circuit 12 connected to the scanning line GL, and a storage capacitor line driving circuit 13 connected to the storage capacitor line CL. And a controller 15 connected to each circuit described above is provided on the array substrate. The signal line driver circuit 11 applies a signal voltage to the signal line SL. The scanning line driving circuit 12 applies a control signal to the scanning line GL. The storage capacitor line drive circuit 13 applies a compensation voltage to the storage capacitor line CL. In order to realize a high-resolution liquid crystal display device, it is desirable to use a p-Si TFT for the drive circuit.

  When this liquid crystal display device is applied to, for example, a mobile phone display device, a reflective display is displayed in a region where the remaining battery level, clock, radio wave status, etc. are displayed, and a transparent display is displayed in a main region for displaying a photograph or the like. . This makes it easier to see the clock display even when waiting (when the backlight is turned off), improving the display image quality during normal times (when the backlight is lit).

  Next, the configuration of the pixel will be described with reference to FIG. The circuit diagram of FIG. 2 shows a configuration of pixels arranged near the boundary between the reflective area Ar and the transmissive area At. The signal line SL and the scanning line GL are wired substantially orthogonally, and the storage capacitor line CL is wired substantially parallel to the scanning line GL.

  In the reflection region Ar, the storage capacitor Csr (first storage capacitor) has one end connected to the switching element Tr and the other end connected to the storage capacitor line CL. As the switching element Tr, a thin film transistor (TFT) formed of polycrystalline silicon is used. Specifically, the gate terminal of the TFT is connected to the scanning line GL, the drain terminal is connected to the signal line SL, and the source terminal is connected in parallel to the storage capacitor Csr and the pixel electrode. Although not shown here, the counter electrode is disposed on the counter substrate so as to face the pixel electrode with the liquid crystal layer interposed therebetween, and a liquid crystal capacitor Clcr is formed for each pixel. The pixel electrode is formed by patterning the conductive light reflecting film into a predetermined shape.

  In the transmissive region At, the storage capacitor Cst (second storage capacitor) has one end connected to the switching element Tr and the other end connected to the storage capacitor line CL. Here, the capacity of the storage capacitor Cst is smaller than the capacity of the storage capacitor Csr. Specifically, the gate terminal of the TFT used as the switching element Tr is again connected to the scanning line GL, the drain terminal is connected to the signal line SL, and the source terminal is connected in parallel to the storage capacitor Cst and the pixel electrode. The A light-transmissive conductive member such as indium tin oxide (ITO) is used for the pixel electrode. Again, the counter electrode is disposed opposite the pixel electrode to form the liquid crystal capacitance Clct. Since the cell gap in the reflective region Ar is smaller than the cell gap in the transmissive region At, the liquid crystal capacitance Clcr is larger than the liquid crystal capacitance Clct.

  FIG. 3 is a voltage waveform diagram showing the relationship among the signal line potential Vs, the scanning line potential Vg, the counter electrode potential Vcom, and the storage capacitor potential Vcs. Here, it is assumed that a high level signal voltage VsH and a low level signal voltage VsL are applied to the signal line SL from the signal line driving circuit 11. A high level control signal VgH and a low level control signal VgL are applied to the scanning line GL from the scanning line driving circuit 12. A constant voltage is applied to the counter electrode. A high level compensation voltage VcsH and a low level compensation voltage VcsL are applied to the storage capacitor line CL from the storage capacitor line driving circuit 13. ΔVcs indicates a change in potential of the storage capacitor line.

  In the nth frame, the signal line potential Vs is VsH, the storage capacitor potential Vcs is VcsL, and the scanning line potential Vg is VgL. In the (n + 1) th frame, the switching element Tr is turned on when the scanning line potential Vg changes from VgL to VgH. In a period in which the switching element Tr is on, a signal voltage is applied to the signal line SL, and the signal voltage is written to the pixel electrode. Thereafter, when the scanning line potential Vg changes from VgH to VgL, the switching element Tr is turned off. During the period when the switching element Tr is off, the compensation voltage is applied to the storage capacitor line CL, and the storage capacitor potential Vcs changes from VcsL to VcsH. Thereafter, the signal line potential Vs changes from VsH to VsL.

  In the (n + 2) th frame, the switching element Tr is turned on when the scanning line potential Vg changes from VgL to VgH. In a period in which the switching element Tr is on, a signal voltage is applied to the signal line SL, and the signal voltage is written to the pixel electrode. Thereafter, when the scanning line potential Vg changes from VgH to VgL, the switching element Tr is turned off. During the period when the switching element Tr is off, a compensation voltage is applied to the storage capacitor line CL, and the storage capacitor potential Vcs changes from VcsH to VcsL. Thereafter, the signal line potential Vs changes from VsL to VsH. The potential change as described above is repeated for each frame.

  As described above, in this embodiment, due to capacitive coupling driving, a signal voltage is applied to the signal line SL to write the signal voltage to the pixel electrode during the period when the switching element Tr is on, and then the switching element Tr is turned off. During this period, a compensation voltage is applied to the storage capacitor line CL. In capacitive coupling drive, the pixel electrode potential Vpix is changed by changing the potential of the storage capacitor line CL connected to the storage capacitors Csr and Cst, and the liquid crystal application voltage ΔVsig is determined.

  Next, the pixel electrode potential Vpix will be described with reference to the voltage waveform diagram of FIG. In the (n + 1) th frame, when the scanning line potential Vg changes from VgL to VgH, the pixel electrode potential Vpix rises to VsH. Even after the scanning line potential Vg returns from VgH to VgL, the pixel electrode potential Vpix maintains a value of approximately VsH. When the storage capacitor potential Vcs changes from VcsL to VcsH, the pixel electrode potential Vpix becomes (VsH + ΔV). Thereafter, even when the signal line potential Vs changes from VsH to VsL, the pixel electrode potential Vpix maintains a value of approximately (VsH + ΔV).

  In the (n + 2) th frame, when the scanning line potential Vg changes from VgL to VgH, the pixel electrode potential Vpix drops to VsL. Even after the scanning line potential Vg returns from VgH to VgL, the pixel electrode potential Vpix maintains a value of approximately VsL. When the storage capacitor potential Vcs changes from VcsH to VcsL, the pixel electrode potential Vpix becomes (VsL−ΔV). Thereafter, even if the signal line potential Vs changes from VsL to VsH, the pixel electrode potential Vpix maintains a value of approximately (VsL−ΔV).

  Next, the change amount ΔV of the pixel electrode potential Vpix will be described in more detail. Here, the change amount ΔV of the pixel electrode potential Vpix due to the change ΔVcs of the potential of the storage capacitor can be expressed by the following equation (1).

ΔV = ΔVcs × (Cs / (Cs + Clc + parasitic capacitance)) (1)
Cs: storage capacity, Clc: liquid crystal capacity From the equation (1), the fluctuation amount ΔVr of the pixel electrode potential in the reflection region Ar is expressed as follows when the fluctuation amount of the storage capacitor potential is ΔVcs, the storage capacity is Csr, and the liquid crystal capacity is Clcr. (2).

ΔVr = ΔVcs × (Csr / (Csr + Clcr + parasitic capacitance)) (2)
Similarly, from the equation (1), the variation amount ΔVt of the pixel electrode potential in the transmissive region At is expressed by the following equation (3) where the variation amount of the storage capacitance potential is ΔVcs, the storage capacitance is Cst, and the liquid crystal capacitance is Clct. .

ΔVt = ΔVcs × (Cst / (Cst + Clct + parasitic capacitance)) (3)
Here, in the present liquid crystal display device, the cell gap of the reflection region Ar is made smaller than that of the transmission region At in order to equalize the distance that light passes through the liquid crystal layer. The following relational expression is established between the liquid crystal capacitance Clcr in the reflection region and the liquid crystal capacitance Clct in the transmission region.

Clcr> Clct (4)
In the present embodiment, the capacitance of the liquid crystal capacitor Clcr is 0.14 pF and the capacitance of the liquid crystal capacitor Clct is 0.10 pF. Therefore, the capacitance of the storage capacitor Csr in the reflective region is 0.33 pF, and the storage capacitor Cst in the transmissive region is The capacity is set to 0.25 pF so that the capacity of the storage capacitor Cst is smaller than the capacity of the storage capacitor Csr. Further, the variation amount ΔVcs of the storage capacitor potential is set to 4.2 V so that the liquid crystal applied voltage ΔVsig becomes 3.0V.

Thereby, the variation amount ΔVr of the pixel electrode potential in the reflection region Ar and the variation amount ΔVt of the pixel electrode potential in the transmission region At can be made closer to each other from the expressions (2) and (3). That is, by adjusting the storage capacitor Csr in the reflection region and the storage capacitor Cst in the transmission region, the variation amount ΔVr of the pixel electrode potential in the reflection region Ar and the variation amount ΔVt of the pixel electrode potential in the transmission region At are made equal (ΔVr = ΔVt). Therefore,
ΔVcs × (Csr / (Csr + Clcr + parasitic capacitance))
= ΔVcs × (Cst / (Cst + Clct + parasitic capacitance))
Therefore, by adjusting the storage capacitors Csr and Cst of the reflective area Ar and the transmissive area At so that Csr> Cst, the variation amount ΔVt of the pixel electrode potential Vpix caused by the different cell gaps in the transmissive area At and the reflective area Ar. Since ΔVr can be made equal, it is possible to correct the gradation difference between the two regions due to the difference in cell gap on the same substrate.

  As described above, according to the present embodiment, the capacitance of the storage capacitor Cst in the transmissive region At is made smaller than the capacitance of the storage capacitor Csr in the reflection region Ar (Csr> Cst), and the switching element Tr is thereby driven by capacitive coupling driving. After the signal voltage is written to the pixel electrode through the signal line SL during the ON period, and when the compensation voltage is applied to the storage capacitor line CL during the OFF period of the switching element Tr, the transmission region At and the reflection region The variations ΔVt and ΔVr of the pixel electrode potential Vpix caused by different cell gaps in Ar can be made equal. Therefore, it is possible to correct the gradation difference between the two regions due to the difference in cell gap on the same substrate.

[Comparative example]
Next, in order to clarify the effect of the present embodiment, a liquid crystal display device of a comparative example will be described. In the liquid crystal display device of the comparative example, when the storage capacities in the reflective region and the transmissive region are equal (Csr = Cst) in the equations (2) and (3), the following relationship is obtained from the relationship (4) to (Clcr> Clct): The formula holds.

(Csr / (Csr + Clcr + parasitic capacitance)) <(Cst / (Cst + Clct + parasitic capacitance))
Therefore, the following relational expression is established between the variation amount ΔVr of the pixel electrode potential in the reflection region Ar and the variation amount ΔVt of the pixel electrode potential in the transmission region At.

ΔVr <ΔVt
FIG. 5 is a graph showing voltage-transmittance characteristics in the liquid crystal display device of the comparative example. The voltage-transmittance characteristic of the reflective display is shifted in a gentler direction than the voltage-transmittance characteristic of the transmissive display. This indicates that there is a difference in gradation in the display of both regions as a result of the difference ΔVt and ΔVr in the pixel electrode potential Vpix between the transmissive region At and the reflective region Ar.

  FIG. 6 is a graph showing voltage-transmittance characteristics in the present liquid crystal display device. The voltage-transmittance characteristics of the reflective display and the voltage-transmittance characteristics of the transmissive display are substantially equal. This indicates that the variations ΔVt and ΔVr of the pixel electrode potential Vpix caused by different cell gaps in the transmissive region At and the reflective region Ar are substantially equal, and the gradation difference between the two regions is corrected on the same substrate. Yes.

[Second Embodiment]
Next, a second embodiment will be described. FIG. 7 is a block diagram illustrating a configuration of the liquid crystal display device in this embodiment. The liquid crystal display device shown in FIG. 7 is the same as the liquid crystal display device shown in FIG. 1 in that the storage capacitors Cs arranged in the reflective region Ar and the transmissive region At have the same capacity, and the storage capacitor drive shown in FIG. The circuit 13 is different in that it is divided into a first storage capacitor drive circuit 16 that drives the storage capacitor line CsrL in the reflective region Ar and a second storage capacitor drive circuit 17 that drives the storage capacitor line CstL in the transmissive region At. Yes.

  Since the cell gap between the reflective region Ar and the transmissive region At is different, the liquid crystal capacitance Clc in the formula (1) is different between the reflective region Ar and the transmissive region At. Therefore, when the capacitance of the storage capacitor Cs is the same, the pixel electrode potential Vpix. The amount of change ΔV differs. However, from equation (1), even when the storage capacitor Cs is the same, the potential change ΔVcs of the storage capacitor Cs is driven to be different between the reflective region Ar and the transmissive region At, so that the reflective region Ar and the transmissive region At are driven. It is possible to make the change amount ΔV of the pixel electrode potential Vpix close to each other.

  Therefore, the first storage capacitor drive circuit 16 and the second storage capacitor drive circuit 17 store the storage capacitance potential fluctuation amount ΔVcst in the transmission region At so as to be smaller than the storage capacitance potential fluctuation amount ΔVcsr in the reflection region Ar. The capacitor lines CsrL and CstL are driven separately. Even in this case, the voltage-transmittance characteristics can be made substantially the same.

  In this embodiment, the storage capacitor Cs is set to 0.25 pF, the storage capacitor potential fluctuation amount ΔVcsr in the reflective region Ar is 4.7 V, and the storage capacitor potential fluctuation amount ΔVcst in the transmission region At is 4.2 V. In addition, the storage capacitor lines CsrL and CstL were driven.

  Therefore, according to the present embodiment, the variation amount ΔVcst of the compensation voltage applied to the storage capacitance line CstL in the transmission region At is made smaller than the variation amount ΔVcsr of the compensation voltage applied to the storage capacitance line CsrL in the reflection region Ar. Accordingly, it is possible to suppress variation in the variation amount ΔV of the pixel electrode potential caused by different cell gaps in the reflective region Ar and the transmissive region At.

[Third Embodiment]
Next, a third embodiment will be described. The configuration of the liquid crystal display device according to this embodiment is the same as the basic configuration described in the first embodiment. The difference from the first embodiment is that the pixel electrode in the first region is a transflective pixel electrode capable of not only reflective display but also transmissive display.

  Here, if the liquid crystal capacitance of the first region (semi-transmissive region) is Clch, the relationship with the liquid crystal capacitance Clct of the second region (transmissive region) is Clch> Clct. Therefore, assuming that the storage capacity of the first region is Csh and the fluctuation amount of the storage capacity potential is ΔVcsh, the same effects as in the first and second embodiments can be obtained by setting Csh> Cst or ΔVcsh> ΔVcst. Can do.

[Fourth Embodiment]
Next, a fourth embodiment will be described. The configuration of the liquid crystal display device according to this embodiment is the same as the basic configuration described in the first embodiment. The difference from the first embodiment is that the pixel electrode in the second region is a transflective pixel electrode capable of not only transmissive display but also reflective display.

  Here, assuming that the liquid crystal capacitance in the second region (semi-transmissive region) is Clch, the relationship with the liquid crystal capacitance Clcr in the first region (reflection region) is Clcr> Clch. Therefore, assuming that the storage capacity of the second region is Csh and the fluctuation amount of the storage capacity potential is ΔVcsh, the same effects as in the first and second embodiments can be obtained by setting Csr> Csh or ΔVcsr> ΔVcsh. be able to.

1 is a circuit block diagram illustrating an overall configuration of a liquid crystal display device according to a first embodiment. It is a circuit diagram which shows the structure of the pixel of the said liquid crystal display device. FIG. 4 is a voltage waveform diagram showing the relationship among a signal line potential, a scanning line potential, a counter electrode potential, and a storage capacitor potential. It is the voltage waveform figure which added the voltage waveform of the pixel electrode to the said voltage waveform figure. It is a graph which shows the voltage-transmittance characteristic in the liquid crystal display device of a comparative example. It is a graph which shows the voltage-transmittance characteristic in the liquid crystal display device which concerns on 1st Embodiment. It is a circuit block diagram which shows the whole structure of the liquid crystal display device which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Signal line drive circuit 12 ... Scan line drive circuit 13 ... 1st storage capacity line drive circuit 14 ... 2nd storage capacity line drive circuit 15 ... Controller A ... Display area Ar ... Reflection area At ... Transmission area SL ... Signal line GL ... Scanning line Tr ... Switching element (TFT)
Cs: Storage capacity Csr: Storage capacity (reflection area)
Cst: Storage capacity (transmission area)
Clct: Liquid crystal capacitance in transmission region Clcr: Liquid crystal capacitance in reflection region CL ... Storage capacitance line CsrL: Storage capacitance line (reflection region)
CstL: Storage capacitor line (transmission area)
Vs ... Signal line potential Vg ... Scanning line potential Vcom ... Counter electrode potential Vcs ... Storage capacitance potential Vpix ... Pixel electrode potential

Claims (5)

A plurality of signal lines and a plurality of scanning lines wired crossing each other;
Switching elements disposed at intersections of the plurality of signal lines and the plurality of scanning lines;
A plurality of storage capacitor lines wired for each of the scanning lines;
A first region in which a pixel electrode capable of reflective display is connected to the switching element;
A second region in which a pixel electrode capable of transmissive display is connected to the switching element;
A first storage capacitor having one end connected to the switching element and the other end connected to the storage capacitor line in the first region;
A second storage capacitor having one end connected to the switching element and the other end connected to the storage capacitor line in the second region, and having a capacity smaller than the first storage capacitor;
A liquid crystal display device comprising: A plurality of signal lines and a plurality of scanning lines wired crossing each other;
Switching elements disposed at intersections of the plurality of signal lines and the plurality of scanning lines;
A plurality of storage capacitor lines wired for each of the scanning lines;
A first region in which a pixel electrode capable of reflective display is connected to the switching element;
A second region in which a pixel electrode capable of transmissive display is connected to the switching element;
A storage capacitor having one end connected to the switching element and the other end connected to the storage capacitor line;
A first drive circuit for performing capacitive coupling drive by applying a compensation voltage to the storage capacitor line in the first region;
A second drive circuit that performs capacitive coupling drive by applying a compensation voltage having a variation amount smaller than a variation amount of the compensation voltage applied by the first drive circuit to the storage capacitor line in the second region;
A liquid crystal display device comprising:   3. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a transflective pixel electrode capable of the reflective display and the transmissive display in the first region.   3. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a transflective pixel electrode capable of the transmissive display and the reflective display in the second region. Applying a signal voltage to the signal line during a period when the switching element is on,
2. The liquid crystal display device according to claim 1, wherein capacitive coupling driving is performed to change a potential of the storage capacitor line during a period in which the switching element is off.

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