JP2008203674A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain satisfactory display quality of a liquid crystal display wherein a pixel electrode and a common electrode are layered via an insulating film. <P>SOLUTION: Each pixel includes: the pixel electrode and the common electrode which are layered via the insulating film provided on one of a pair of substrates interposing a liquid crystal layer; and an alignment layer disposed on the liquid crystal layer side of both the electrodes. The liquid crystal layer side electrode of the pixel electrode and the common electrode has a slit part nearly parallel to a rubbing direction of the alignment layer. A pixel electrode region consisting of the pixel electrode and the slit part has a transmittance characteristic A depending on voltage between the pixel electrode and the common electrode. A region between pixel electrodes arranged in a direction crossing the rubbing direction and adjacent to each other has transmittance characteristics B to D depending on voltage between the pixel electrodes adjacent to each other. The distance between the pixel electrodes adjacent to each other is such a distance that at least a part of transmittance characteristics of the region between the pixel electrodes adjacent to each other is equal to or lower than the transmittance characteristic of the pixel electrode region. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a configuration in which a pixel electrode and a common electrode are stacked via an insulating film.

  In an FFS (Fringe Field Switching) type liquid crystal display device, both a pixel electrode for controlling the alignment of liquid crystal and a common electrode are provided on the same substrate, and these two electrodes are laminated via an insulating film. . Among the electrodes, the upper electrode, that is, the electrode on the liquid crystal layer side is provided with a slit. When the rubbing process is performed substantially parallel to the longitudinal direction (long side direction) of the slit and the voltage between the electrodes is an off voltage, the liquid crystal molecules are aligned substantially parallel to the longitudinal direction of the slit (initial alignment state). When a voltage higher than the off voltage is applied between the electrodes, an electric field is generated between the electrodes through a slit. This electric field is generated in a direction perpendicular to the long side of the slit, and the liquid crystal molecules rotate in a plane parallel to the substrate along the electric field direction. The amount of transmitted light is controlled by controlling the rotation angle of the liquid crystal molecules.

JP-A-11-202356 JP 2003-57670 A

  When the pixel electrode is an upper electrode, in addition to the electric field passing through the slit, an electric field extending between adjacent pixel electrodes can be generated. In the region where the electric field between adjacent pixel electrodes intersects the rubbing direction, the liquid crystal molecules deviate from the initial alignment state, so that the transmittance of the region becomes high and light leakage occurs.

  FIG. 6 is a diagram for explaining the state of light leakage. FIG. 6 is a diagram in which transmittance is simulated for a cross section that crosses the slit portion 663 of the pixel electrode and the branch portion 662 that is arranged across the slit portion 663, that is, a cross section that crosses the rubbing direction. Note that the pixel electrode is stacked with the common electrode 640 through an insulating film (not shown). FIG. 6 illustrates a region 540 between adjacent pixel electrodes and two pixel electrode regions 530 arranged with the region 540 interposed therebetween, and illustrates a case where the gradation level of the pixel electrode region 530 is approximately 20%.

  As can be seen from FIG. 6, the transmittance in the inter-pixel electrode region 540 may be higher than the transmittance in the pixel electrode region 530. In this case, there is a problem in that the luminance between the adjacent pixel electrode regions 540 is higher than that of the pixel electrode region 530 and the display quality is deteriorated.

  Generally, the shorter the distance between adjacent pixel electrodes, the stronger the electric field between adjacent pixel electrodes. For this reason, as the definition becomes higher, light leakage in the adjacent pixel electrode region 540 is more likely to occur.

  In addition, the liquid crystal molecules in the region 540 between adjacent pixel electrodes are affected by the potential fluctuation of the pixel electrodes on both sides, and therefore the alignment state is unstable. For this reason, light leakage in the adjacent pixel electrode region 540 flickers like flicker and tends to be emphasized. Also in this respect, there is a problem that display quality is deteriorated.

  Here, as a measure for preventing the light leakage, it is conceivable that the inter-adjacent pixel electrode region 540 is shielded by a light shielding film. However, in order to suppress the flicker, it is necessary to shield light including light emitted in an oblique direction from the adjacent pixel electrode region 540. For this reason, the light shielding film is enlarged. In general, the FFS structure has a feature that an aperture ratio is higher than a structure in which a storage capacitor is provided separately because a storage capacitor is formed by a stacked structure of a pixel electrode and a common electrode. The enlargement of the light shielding film may reduce the features of FFS.

  In general, partial seizure is likely to occur at a location where the potential difference is large and in the vicinity thereof. For this reason, for example, when a large potential difference is applied to the adjacent pixel electrode region 540 by line inversion driving or high definition, image sticking is likely to occur in the region 540, and there is a problem that display quality is deteriorated.

  An object of the present invention is to provide a liquid crystal display device having a configuration in which a pixel electrode and a common electrode are stacked with an insulating film interposed therebetween and capable of obtaining good display quality.

  The liquid crystal display device according to the present invention is a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates, a pixel electrode and a common electrode stacked via an insulating film provided on one of the pair of substrates, A plurality of pixels each including an alignment film disposed closer to the liquid crystal layer than the pixel electrode and the common electrode, and the electrode on the liquid crystal layer side of the pixel electrode and the common electrode is the alignment The pixel electrode region having a slit portion substantially parallel to the rubbing direction of the film and having the pixel electrode and the slit portion has a transmittance characteristic depending on a voltage between the pixel electrode and the common electrode. The region between the adjacent pixel electrodes arranged in a direction crossing the rubbing direction has a transmittance characteristic depending on the voltage between the adjacent pixel electrodes, and the distance between the adjacent pixel electrodes is The adjoining Wherein the transmission characteristics of the region between that pixel electrode is transmittance characteristic and the distance to be equal to or less than the pixel electrode region at least in part. According to the above configuration, light leakage or the like in a region between adjacent pixel electrodes is suppressed. Therefore, good display quality can be obtained.

  In addition, it is preferable that potentials having opposite polarities based on the common electrode are applied to the adjacent pixel electrodes. Generally, when potentials having opposite polarities are applied to adjacent pixel electrodes, the voltage between the adjacent pixel electrodes is higher than when potentials having the same polarity are applied. However, according to the above configuration, good display quality can be obtained.

  The liquid crystal display device according to the present invention is a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates, a pixel electrode and a common electrode stacked via an insulating film provided on one of the pair of substrates, A plurality of pixels each including an alignment film disposed closer to the liquid crystal layer than the pixel electrode and the common electrode, and the electrode on the liquid crystal layer side of the pixel electrode and the common electrode is the alignment A slit portion that is substantially parallel to the rubbing direction of the film, and the distance between the adjacent pixel electrodes is at least 60% or less of the voltage, and the electric field strength between the adjacent pixel electrodes is The distance is equal to or less than the electric field strength of the pixel electrode region formed by the slit portion. According to the above configuration, light leakage or the like in a region between adjacent pixel electrodes is suppressed. Therefore, good display quality can be obtained.

  1 and 2 are a cross-sectional view and a plan view of a part of the display area of the liquid crystal display device 10 according to the embodiment of the present invention. 1 corresponds to a cross-sectional view taken along line 1-1 in FIG. FIG. 2 illustrates pixels 20 arranged in a matrix of 2 rows and 3 columns, and only two pixels 20 are illustrated by thick broken lines in order to avoid complication of the drawing. In FIG. 2, some of the elements shown in FIG. 1 are omitted.

  The liquid crystal display device 10 includes two support substrates 110 and 210 disposed to face each other, and a liquid crystal layer 300 sandwiched between the two support substrates 110 and 210. The support substrates 110 and 210 can be composed of a light-transmitting substrate such as a glass plate. The thickness of the liquid crystal layer 300 corresponds to the cell gap, and is 2 to 4 μm, for example.

  The liquid crystal display device 10 includes a wiring 120, an insulating film 130, a common electrode 140, an insulating film 150, a pixel electrode 160, and an alignment film 170 on the liquid crystal layer 300 side of the support substrate 110.

  The wiring 120 is, for example, a gate line, a display signal line, or the like, and FIG. 1 illustrates a case where the wiring 120 is disposed on the support substrate 110. The insulating film 130 is disposed so as to cover the wiring 120, and FIG. 1 illustrates the case where the insulating film 130 is disposed on the support substrate 110.

  The common electrode 140 is disposed on the insulating film 130. The common electrode 140 can be composed of a light-transmitting conductive film such as ITO (Indium Tin Oxide). A common potential is supplied to each pixel 20 by the common electrode 140. Here, the case where the common electrode 140 is formed of a conductive film disposed over all the pixels 20 is illustrated, but for example, the common electrode 140 is divided for each pixel 20 and the plurality of divided electrodes are connected by wiring. May be. Further, for example, all the pixels 20 can be divided into a plurality of groups, and the common electrode 140 can be divided and arranged for each group.

  The pixel electrode 160 is stacked on the common electrode 140 with the insulating film 150 interposed therebetween. The pixel electrode 160 can be composed of a light-transmitting conductive film such as ITO. The pixel electrode 160 is provided in each pixel 20. The pixel electrode 160 is connected to a display signal line through a switching element (not shown), for example, a transistor. As a result, a potential corresponding to the display of the pixel 20 is supplied to the pixel electrode 160 from the display signal line via the switching element.

  The pixel electrode 160 includes one trunk portion (or back portion) 161 and a plurality of branch portions (or tooth portions) 162. The branch parts 162 are arranged with the slit part (or groove part) 163 interposed therebetween, and constitute a line-and-space pattern together with the slit part 163. In addition, the number of the branch parts 162 and the slit parts 163 is not restricted to the illustration of illustration. The plurality of branch portions 162 are connected by a trunk portion 161 at one end. That is, the pixel electrode 160 has a comb-tooth shape. In addition, the width of the branch part 162 is 2.5-3.5 micrometers, for example, and the space | interval between the branch parts 162, ie, the width | variety of the slit part 163, is 4.0-5.0 micrometers, for example. Note that the corner (corner portion) of the contour line of the pixel electrode 160 may be square or rounded.

  Here, the case where the branch part 162 and the slit part 163 extend in the illustrated horizontal direction in FIG. 2 (in other words, the horizontal direction in the figure) is illustrated, and this form is referred to as a “lateral slit type”. Further, here, the pixel electrodes 160 arranged in the illustrated vertical direction (in other words, in the vertical direction in the drawing) are alternately arranged in the direction of the open end of the comb-shaped shape, in other words, the position of the stem 161 of the comb-shaped shape. The case where it is done is illustrated.

  The common electrode 140 faces not only the slit portion 163 of the pixel electrode 160 but also the trunk portion 161 and the branch portion 162, and both electrodes 140 and 160 constitute a storage capacitor via the insulating film 150.

  The alignment film 170 is laminated so as to cover the pixel electrode 160. The surface of the alignment film 170 in contact with the liquid crystal layer 300 is rubbed substantially in parallel with the longitudinal directions of the branch portions 162 and the slit portions 163, for example, in a direction inclined about 5 ° to 10 ° with respect to the longitudinal direction. FIG. 2 schematically shows an example of the rubbing direction R by arrows.

  The liquid crystal display device 10 includes a polarizing plate (not shown) on the opposite side of the support substrate 110 from the liquid crystal layer 300.

  The liquid crystal display device 10 includes a light shielding film 220 and a color filter 230 on the liquid crystal layer 300 side of the support substrate 210. The light shielding film 220 can be made of, for example, a resin. An opening is formed in the light shielding film 220 so as to face the pixel electrode 160 for each pixel 20. A color filter 230 having a hue corresponding to the display color of the pixel 20 is disposed in each opening. FIG. 1 illustrates a case where the light shielding film 220 and the color filter 230 are disposed on the support substrate 210.

  The liquid crystal display device 10 includes an overcoat layer (not shown) and an alignment film 240 that are sequentially stacked so as to cover the color filter 230. The surface of the alignment film 240 that contacts the liquid crystal layer 300 is rubbed in a predetermined direction. The liquid crystal display device 10 includes a polarizing plate (not shown) on the opposite side of the support substrate 210 from the liquid crystal layer 300.

  When the voltage between the common electrode 140 and the pixel electrode 160 is an off voltage, the liquid crystal molecules near the electrodes 140 and 160 are aligned in the rubbing direction R (initial alignment state). When a voltage higher than the off voltage is applied between the electrodes 140 and 160, an electric field E3 is generated between the electrodes 140 and 160 through the slit portion 163. The liquid crystal molecules rotate in a plane parallel to the support substrate 110. That is, the liquid crystal (molecule) is driven. The amount of transmitted light is controlled by controlling the rotation angle of the liquid crystal molecules. The common electrode 140 and the pixel electrode 160 form an electrode pair in each pixel 20, and the electric field E <b> 3 is generated in each pixel 20.

  For example, depending on the relationship between the rubbing direction of the two alignment films 170 and 240 and the polarization axis direction of the two polarizing plates, the liquid crystal display device 10 is normally black type and normally white type. It can be designed with either type. Here, the case where the liquid crystal display device 10 is a normally black type is illustrated.

  Although the case where the pixels 20 are arranged in a matrix is illustrated above (see FIG. 2), the pixels 20 may be arranged in other arrangements such as a delta arrangement. Here, the case where the boundary of the pixel 20 is a position that bisects the region 40 between the adjacent pixel electrodes 160 is illustrated (see FIGS. 1 and 2). For example, the pixel electrode 160 and the slit portion 163 are separated. It is also possible to define a region 30 (see FIGS. 1 and 2) consisting of

  The region 40 between the adjacent pixel electrodes 160 is referred to as an “inter-pixel electrode region 40”, and the region 30 is referred to as a “pixel electrode region 30”. In FIG. 2, only one pixel electrode region 30 is illustrated with a thick broken line in order to avoid complication of the drawing.

  FIG. 3 illustrates a voltage-transmittance characteristic diagram (VT characteristic diagram) for explaining the characteristics of the liquid crystal display device 10. In the characteristic diagram, the horizontal axis represents voltage, and the left vertical axis represents transmittance. The transmittance is shown in arbitrary units. Characteristic lines A to D described below can be obtained by simulation, for example.

  A characteristic line A indicates a transmittance characteristic in the pixel electrode region 30. Note that the transmittance characteristic of the pixel electrode region 30 corresponds to the transmittance characteristic of the pixel 20. Regarding the characteristic line A, the horizontal axis indicates the voltage between the pixel electrode 160 and the common electrode 140 arranged in the pixel electrode region 30. In the exemplary characteristic line A, the transmittance of the pixel electrode region 30 is substantially 0 (zero) when the voltage is in the range of 0 V to about 1.3 V, and the transmittance is within the range of about 1.3 V to about 4.0 V. As the voltage increases, it increases from 0 to about 0.75, and saturates at about 07.5 when the voltage is in the range of about 4.0V to about 4.5V. At this time, the slope of the tangent line of the characteristic line A, in other words, the rate of change in transmittance increases with an increase in voltage in the range of about 1.3 V to about 2.0 V, and the voltage increases from about 2.0 V to about 2.0 V. It is almost constant in the range of about 3.3V, and decreases with increasing voltage in the range of about 3.3V to about 4.0V. Note that the transmittance when the maximum transmittance (0.75) of the pixel electrode region 30 is normalized as 100% is shown as the gradation level on the right horizontal axis of the VT characteristic diagram.

  Characteristic lines B to D indicate transmittance characteristics in the region 40 between the pixel electrodes 160 arranged in a direction intersecting the rubbing direction R (here, a direction substantially orthogonal to the vertical direction in FIG. 2) and adjacent to each other. Yes. When the width of the region 40, that is, the distance between adjacent pixel electrodes 160 across the region 40 is d (see FIGS. 1 and 2), each characteristic line B is d = 4 μm, 7 μm, and 10 μm. , C, D. Regarding the characteristic lines B to D, the horizontal axis indicates the voltage between the adjacent pixel electrodes 160.

  In the exemplary characteristic line B, the transmittance of the inter-adjacent pixel electrode region 40 is substantially 0 (zero) when the voltage is in the range of 0V to about 1.0V, and the voltage is within the range of about 1.0V to about 2.2V. Increases from 0 to about 0.85, peaks at about 2.2V, and decreases from about 0.85 to about 0.2 when the voltage is in the range of about 2.2V to about 4.5V. At this time, the slope of the tangent line of the characteristic line B, in other words, the change rate of the transmittance increases when the voltage is in the range of about 1.0 V to about 1.5 V, and the voltage is about 1.5 V to about 2.0 V. The voltage range is substantially constant, the voltage is decreased in the range of about 2.0V to about 2.2V, the voltage is approximately constant in the range of about 2.2V to about 3.2V, and the voltage is about 3.2V to It decreases in the range of about 4.5V.

  In the exemplary characteristic line C, the transmittance of the inter-adjacent pixel electrode region 40 is substantially 0 (zero) when the voltage is in the range of 0V to about 1.8V, and the voltage is within the range of about 1.8V to about 3.5V. Increases from 0 to about 0.92, peaks at about 3.5V, and decreases from about 0.92 to about 0.8 when the voltage is in the range of about 3.5V to about 4.5V. At this time, the slope of the tangent line of the characteristic line C, in other words, the change rate of the transmittance increases when the voltage is in the range of about 1.8V to about 2.5V, and the voltage is about 2.5V to about 3.0V. The range is substantially constant, the voltage decreases in the range of about 3.0V to about 3.5V, and increases in the range of about 3.5V to about 4.5V.

  In the exemplary characteristic line D, the transmittance of the inter-adjacent pixel electrode region 40 is substantially 0 (zero) in the voltage range of 0V to about 2.4V, and the voltage is in the range of about 2.4V to about 4.5V. Increases from 0 to about 0.55. At this time, the slope of the tangent line of the characteristic line D, in other words, the change rate of the transmittance increases when the voltage is in the range of about 2.4V to about 3.5V, and the voltage is about 3.5V to about 4.5V. The range is almost constant.

  When the characteristic lines B to D are compared, the inclination of the portion where the transmittance increases in the characteristic lines B to D tends to decrease (become gentle) as the distance d between the adjacent pixel electrodes 160 increases. I understand that there is.

  Here, in the characteristic lines B and C, the transmittance decreases with the above peak as a boundary. This is considered to be due to the following reason. That is, when the potential difference between the adjacent pixel electrodes 160 is large, the component in the direction perpendicular to the support substrate 110 becomes strong in the electric field E4 (see FIG. 1) between the electrodes 160. It is considered that the transmittance is lowered because the liquid crystal molecules are inclined with respect to the support substrate 110 due to the vertical component. In the case of the characteristic line D, since the distance d between the adjacent pixel electrodes 160 is long, it is considered that the vertical component of the electric field E4 is weak within the above voltage range.

  According to the VT characteristic diagram of FIG. 3, the characteristic line D is located below the characteristic line A in the entire range within the liquid crystal driving voltage range (here, the range of 0 V to about 4.5 V). Yes. That is, the transmittance of the region 40 between adjacent pixel electrodes is lower than the transmittance of the pixel electrode region 30 in the entire liquid crystal driving voltage range. For this reason, when the area | region 40 between adjacent pixel electrodes has the transmittance | permeability characteristic of the characteristic line D, the light leakage in the said area | region 40 can be suppressed. Further, since the luminance of light leakage is lower than the luminance of the pixel electrode region 30, it is difficult to recognize even if the light leakage flickers. Therefore, when d = 10 μm, good display quality can be obtained. At this time, unlike the configuration in which light leakage or the like is shielded by extending the light shielding film, the aperture ratio is not reduced.

  Here, in view of the above-described aspect of controlling the alignment of liquid crystal molecules, in the case of the relationship between the characteristic lines A and D, the intensity of the electric field E4 formed in the region 40 by the adjacent pixel electrode 160 is the pixel electrode in the pixel electrode region 30. It is lower than the intensity of the electric field E3 formed between 160 and the common electrode 140. For this reason, the image sticking in the area | region 40 between adjacent pixel electrodes can be suppressed. Therefore, the influence of the image sticking on the display in the pixel electrode region 30 can be suppressed, and a good display quality can be obtained.

  The characteristic line C is positioned below the characteristic line A in a part of the liquid crystal driving voltage range (here, the voltage is in the range of 0 V to about 2.8 V). That is, the transmittance and electric field E4 of the adjacent pixel electrode region 40 are lower than the transmittance and electric field E3 of the pixel electrode region 30 in the partial range. For this reason, in the said partial range, the light leak etc. in the area | region 40 between adjacent pixel electrodes can be suppressed. Here, light leakage or the like in the region 40 between adjacent pixel electrodes is easily recognized when the gradation level of the pixel electrode region 30 is about 60% or less, for example. In view of this point, good display quality can be obtained even when d = 7 μm.

  On the other hand, the characteristic line B is located below the characteristic line A in a part of the liquid crystal driving voltage range (here, the voltage is in a range of about 3 V to about 4.5 V). Greatly exceeds the characteristic line A in the range of about 60% or less. For this reason, when d = 4 μm, it seems difficult to suppress light leakage or the like in the region 40 between adjacent pixel electrodes.

  From the above consideration, the following can be understood. That is, at least a part of the VT characteristic of the inter-adjacent pixel electrode region 40 is equal to or less than the VT characteristic of the pixel electrode region 30, thereby causing light leakage in the inter-pixel electrode region 40. Can be suppressed. At this time, it is preferable that at least a part of the pixel includes a range where the gradation level of the pixel electrode region 30 is about 0% or more and 60% or less. Alternatively, in the voltage range corresponding to the gradation range including at least the range where the gradation level of the pixel electrode region 30 is about 0% or more and 60% or less, the intensity of the electric field E4 in the region 40 between adjacent pixel electrodes is higher than that of the pixel electrode region 30. By being equal to or less than the intensity of the electric field E3, it is possible to suppress recognition of the light leakage and the like. That is, the distance d between the adjacent pixel electrodes 160 is a distance at which the electric field strength of the inter-adjacent pixel electrode region 40 is equal to or less than the electric field strength of the pixel electrode region 30 when the voltage is at least 60% or less. Therefore, it is possible to suppress the light leakage and the like.

  The above-described conditions regarding the VT characteristic or the electric field strength can be satisfied by controlling the distance d between the adjacent pixel electrodes 160. In the case of the VT characteristic illustrated in FIG. 3, the above condition can be satisfied by setting the distance d to 7 μm or more, more preferably 8 μm or more.

  Here, for example, potentials having opposite polarities may be applied to adjacent pixel electrodes 160 based on the potential of the common electrode 140 by line inversion driving or dot inversion driving. In this case, the voltage between the adjacent pixel electrodes 160 is higher than that when a potential having the same polarity is applied. However, even in this case, by setting the distance d between the pixel electrodes 160 arranged in the direction intersecting the rubbing direction R and adjacent to each other so as to satisfy the above condition, it is possible to suppress light leakage and the like. Display quality can be obtained.

  In the region 40 between the pixel electrodes 160 arranged substantially parallel to the rubbing direction R and adjacent to each other, the electric field E4 between the pixel electrodes 160 is formed substantially parallel to the rubbing direction R. For this reason, the amount of change in transmittance in the region 40 is small, and it is considered that the influence on the display is small.

  The case where the pixel electrode 160 is a horizontal slit type has been illustrated above. On the other hand, the branch part 162 and the slit part 163 can be extended in the vertical direction. This form is referred to as a “longitudinal slit type”. Even in the vertical slit type, the alignment film covering the pixel electrode 160 is rubbed substantially parallel to the longitudinal direction of the branch portion 162 and the slit portion 163. It is also possible to extend the branch part 162 and the slit part 163 in a direction inclined with respect to the vertical direction or the horizontal direction. In addition, when the inclination angle is small, for example, when it is 10 ° or less, it can be substantially regarded as the vertical slit type or the horizontal slit type.

  In the above description, the pixel electrodes 160 arranged in the vertical direction are illustrated as being alternately arranged in the direction of the open ends of the comb teeth. However, it is also possible to arrange the open ends toward the same side. is there. It is also possible to apply the pixel electrode 160B shown in the plan view of FIG. The pixel electrode 160 </ b> B has a shape in which the open end of the branch portion 162 is connected to the other trunk portion 161 in the pixel electrode 160. In this case, each slit portion 163 does not reach the outer edge of the pixel electrode 160B, but the pixel electrode 160B also includes a line-and-space pattern of the branch portion 162 and the slit portion 163.

  Further, the case where the pixel electrode 160 is disposed on the liquid crystal layer 300 side with respect to the common electrode 140, that is, the case where the pixel electrode 160 is the upper electrode is illustrated above. On the other hand, the common electrode 140 can be the upper electrode as in the liquid crystal display device 10B shown in the cross-sectional view of FIG. In this case, although the slit portion 143 is provided in the common electrode 140, an electric field E4 may be generated between the adjacent pixel electrodes 160 through the slit portion 143. However, by setting the distance d in the same manner as described above, good display quality can be obtained even in the liquid crystal display device 10B.

1 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention. 1 is a plan view of a liquid crystal display device according to an embodiment of the present invention. FIG. 10 is a VT characteristic diagram illustrating a liquid crystal display device according to an embodiment of the present invention. It is a top view explaining the other example of the pixel electrode which concerns on embodiment of this invention. It is sectional drawing explaining the other example of the liquid crystal display device which concerns on embodiment of this invention. It is a figure explaining the light leakage between the pixel electrodes in the conventional liquid crystal display device.

Explanation of symbols

  10, 10B liquid crystal display device, 20 pixels, 30 pixel electrode area, 40 adjacent pixel electrode area, 110, 210 substrate, 140 common electrode, 150 insulating film, 160, 160B pixel electrode, 163, 143 slit, 170 alignment film , 300 liquid crystal layer, A to D characteristic lines, E3, E4 electric field, R rubbing direction, d distance.

Claims (3)

In a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates,
A pixel electrode and a common electrode laminated via an insulating film provided on one of the pair of substrates, and an alignment film disposed on the liquid crystal layer side of the pixel electrode and the common electrode, respectively. With multiple pixels,
Of the pixel electrode and the common electrode, the electrode on the liquid crystal layer side has a slit portion substantially parallel to the rubbing direction of the alignment film,
A pixel electrode region composed of the pixel electrode and the slit portion has a transmittance characteristic that depends on a voltage between the pixel electrode and the common electrode,
A region between the pixel electrodes arranged adjacent to each other in a direction crossing the rubbing direction has a transmittance characteristic that depends on a voltage between the adjacent pixel electrodes,
The distance between the adjacent pixel electrodes is a distance in which a transmittance characteristic of a region between the adjacent pixel electrodes is at least partially equal to or less than a transmittance characteristic of the pixel electrode region. Display device. The liquid crystal display device according to claim 1,
A liquid crystal display device, wherein potentials having opposite polarities with respect to the common electrode are applied to the adjacent pixel electrodes. In a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates,
A pixel electrode and a common electrode laminated via an insulating film provided on one of the pair of substrates, and an alignment film disposed on the liquid crystal layer side of the pixel electrode and the common electrode, respectively. With multiple pixels,
Of the pixel electrode and the common electrode, the electrode on the liquid crystal layer side has a slit portion substantially parallel to the rubbing direction of the alignment film,
The distance between the adjacent pixel electrodes is equal to or higher than the electric field strength of the pixel electrode region formed by the pixel electrode and the slit portion, in a voltage range of at least 60% or less. A liquid crystal display device characterized in that the distance is as follows.

Images