JP4905011B2 - Liquid crystal device and electronic device - Google Patents

Description

  The present invention relates to a liquid crystal device and an electronic apparatus.

  As one form of the liquid crystal device, there is known a method of controlling the alignment of liquid crystal by applying an electric field in the substrate surface direction to the liquid crystal layer (hereinafter referred to as a horizontal electric field method), and applying an electric field to the liquid crystal. There are known what is called an IPS (In-Plane Switching) system, an FFS (Fringe-Field Switching) system, etc., depending on the form of the electrodes.

These horizontal electric field type liquid crystal devices generally control transmission and blocking of light by applying a voltage between a pixel electrode and a counter electrode and aligning the liquid crystal in the direction of the generated electric field. However, since the source line (image signal line) is formed adjacent to the pixel electrode, a horizontal electric field is generated between the source line and the pixel electrode, and the alignment state of the liquid crystal is disturbed by the horizontal electric field. . This phenomenon is called edge reversal and causes problems such as a decrease in viewing angle and a decrease in contrast of the liquid crystal device. As a method for preventing such edge reversal, for example, it is conceivable to suppress the generation of a lateral electric field by widening the distance between the source line and the pixel electrode, but a new problem such as a decrease in aperture ratio occurs. . In addition, there is a technique for preventing edge reverse by providing a protective film or a dielectric film on a source line and forming an electric field shielding layer thereon (see, for example, Patent Documents 1 and 2).
JP-A-5-127195 JP 2004-198846 A

  However, the technique disclosed in the above patent document has a low practicality because the manufacturing process for forming the electric field shielding layer becomes complicated. Therefore, it is desired to provide a liquid crystal device that can obtain a higher aperture ratio.

  The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a liquid crystal device and an electronic apparatus that can obtain a higher aperture ratio.

The liquid crystal device according to the present invention is a liquid crystal device including a first substrate and a second substrate that are arranged to face each other with a liquid crystal layer interposed therebetween . The liquid crystal device is first in the first direction on the liquid crystal layer side of the first substrate. First and second data line pairs each consisting of two data lines that are spaced apart and extend in a second direction that intersects the first direction, and first and second that extend in the first direction A first pixel electrode comprising: a scanning line; a first conductive portion extending in the second direction; and a plurality of first branch electrodes branched from the first conductive portion and extending in the first direction; A second pixel comprising: a second conducting portion extending in the second direction; and a plurality of second branch electrodes branched from the second conducting portion and extending in a direction opposite to the first direction. An electrode and a common electrode provided through an insulating layer between the first and second pixel electrodes, and the first electrode The liquid crystal layer is driven by an electric field generated between the second pixel electrode and the common electrode, and the first and second pixel electrodes are connected to the first and second data line pairs and the first and second scans. In a region surrounded by the line, the second pixel electrode is positioned on the first direction side with respect to the first pixel electrode, and ends of the plurality of first branch electrodes and the plurality of second electrodes. The ends of the branch electrodes are arranged so as to be spaced apart from each other by a second distance, the first distance is a, and the data of the first and second data line pairs and the closer of the first and second data line pairs. When the distance between the pair of lines is b and the second distance is c, the following equation (a + c) / 2 <b holds.

The liquid crystal device is preferably operated by line inversion driving .

Alternatively, the liquid crystal device may be operated by dot inversion driving .

In the liquid crystal device, the data line pair is preferably covered with a dielectric film having a dielectric constant higher than that of the liquid crystal layer .

The electronic device may obtain Bei the liquid crystal device.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings. The liquid crystal device of the present invention is a horizontal electric field type liquid crystal device typified by an IPS (In Plane Switching) method, an FFS (Fringe Field Switching) method, etc., and a first electrode provided on the liquid crystal layer side of the first substrate. An electric field generated between the liquid crystal layer and the second electrode is applied to the parallel alignment liquid crystal layer to control the alignment state of the liquid crystal layer to display an image.

  The liquid crystal device according to the present embodiment is a liquid crystal device that employs the FFS (Fringe Field Switching) method among the above-described lateral electric field methods. The liquid crystal device according to the present embodiment is a color liquid crystal device having a color filter on a substrate, and includes three sub-pixels that emit light of R (red), G (green), and B (blue). One pixel is constituted. Therefore, a display area which is a minimum unit constituting display is referred to as a “sub-pixel area”, and a display area including a set of (R, G, B) sub-pixels is referred to as a “pixel area”.

  FIG. 1 is a plan configuration diagram of a liquid crystal device, and FIG. 2 is a circuit configuration diagram of a sub-pixel region constituting the liquid crystal device of the present embodiment. 3 is a partial cross-sectional configuration diagram taken along the line AA ′ in FIG. 1, and FIG. 4 is a diagram showing an optical axis arrangement in FIG. In each drawing, each layer and each member are displayed in different scales so that each layer and each member can be recognized on the drawing.

  As shown in FIG. 1, the liquid crystal device 100 is provided with a data line pair 7 in which two data lines 6a are arranged at a predetermined interval a, and a scanning line 3a orthogonal to (intersect) the data line pair 7. It has been. A pixel electrode (first electrode) 9 having a substantially comb-like shape (rake shape) in a plan view is formed in the region surrounded by the data line pair 7 and the scanning line 3a (hereinafter also referred to as a partition region). Two pixel electrodes 9 are arranged along the extending direction of 3a, and the pixel electrodes 9 (a plurality of strip electrodes 9c, between the plurality of strip electrodes 9c, and a passage portion are arranged in a plane opposed to the pixel electrodes 9). A common electrode (second electrode) 19 is provided so as to cover 9a).

  That is, the liquid crystal device 100 of the present embodiment has a configuration in which two sub-pixel regions are included in a partition region surrounded by the data line pair 7 and the scanning line 3a. In addition, columnar spacers (not shown) for holding the TFT array substrate 10 and the counter substrate 20 at a predetermined interval are provided at the corners (or the gaps between the partition regions) of the partition regions. ) Is provided. A light shielding film (black matrix) (not shown) is provided so as to cover the gap between the data line pair 7, the scanning line 3 a, and the pixel electrodes 9 arranged to face each other. It is partitioned and display is possible for each sub-pixel.

  Specifically, the pixel electrode 9 connects a plurality of strip electrodes (branch electrodes) 9c extending in the X-axis direction and one end of the strip electrodes 9c (in this embodiment, on the data line 6a side). The conductive portions 9a extending in the Y-axis direction (the extending direction of the data lines 6a) are electrically connected between the strip electrodes 9c. In addition, a contact portion 9b in which the pixel contact hole 45 is provided is provided on the −Y side of the conduction portion 9a. That is, the pixel electrode 9 has a comb-teeth shape that opens the other end portion of the strip electrode 9c (referred to as an open end in the following description). Each pixel electrode 9 is arranged in a partition area surrounded by the data line pair 7 and the scanning line 3a so that the open end sides are opposed to each other. Although details will be described later, the interval between the pixel electrode 9 and the data line 6a adjacent to the pixel electrode 9 is set so as not to cause a problem such as a decrease in viewing angle and a decrease in contrast due to edge reverse. It has become.

  The common electrode 19 is a flat solid conductive film made of a transparent conductive material such as ITO (indium tin oxide). In addition to the transparent electrode made of a transparent conductive material as in this embodiment, for example, the common electrode adopts a configuration partially including a reflective electrode made of a light-reflective metal material. It can also be applied to a transflective liquid crystal device. In this case, while the transparent electrode constitutes a common electrode that generates an electric field between the transparent electrode and the pixel electrode, the reflective electrode functions as a reflective layer, and the visibility of the reflective display can be improved.

  As shown in FIG. 1, in the liquid crystal device 100 according to the present embodiment, two pixel electrodes 9 are arranged in the partition region surrounded by the data lines 6a and the scanning lines 3a along the extending direction of the scanning lines 3a. The pixel electrode 9 and the data line 6a (data line pair 7) are arranged so as to satisfy the relationship described later. With this configuration, edge reversal is prevented and a higher aperture ratio can be obtained as compared with a conventional liquid crystal device.

  Here, the structure of a conventional liquid crystal device will be described in order to explain the special effects of the liquid crystal device 100 according to the present embodiment. In the conventional liquid crystal device, as shown in FIG. 9, one pixel electrode is disposed in a region surrounded by scanning lines and data lines. Moreover, about the structure similar to the liquid crystal device 100 of this embodiment, the same code | symbol is attached | subjected and demonstrated about the same member.

  In general, in the liquid crystal device, when the pixel electrode 9 and the data line 6a approach each other, a potential difference between the data line 6a and the pixel electrode 9 causes a different electric field from the lateral electric field generated perpendicularly to the extending direction of the comb teeth (branch electrode). A transverse electric field is generated. Such a horizontal electric field disturbs the alignment state of the liquid crystal (edge reverse). When such edge reversal occurs, the viewing angle of the liquid crystal device is lowered and the contrast is lowered. Therefore, in the conventional liquid crystal device, it is necessary to increase the distance between the pixel electrode 9 and the data line 6a until the influence of the edge reverse is reduced.

As shown in FIG. 9, in the conventional liquid crystal device, the distance between the data line 6a and the pixel electrode is b, the width of the pixel electrode 9 is d, and the width of the data line 6a is e.
The width of the effective pixel area of the conventional liquid crystal device can be defined by (2b + d + e). Further, since the pixel width corresponds to the width of the pixel electrode 9, the pixel width can be defined by d. Since the liquid crystal layer is aligned in a region corresponding to the pixel width d and pixel display is performed, the ratio of the width of the effective pixel region to the pixel width, that is, the aperture ratio A1 of the liquid crystal device is expressed as d / (2b + d + e). Can be specified.

  In the liquid crystal device 100 according to the present embodiment, the comb-like pixel electrodes 9 are arranged in the partition region so that the open end sides are opposed to each other. As shown in FIG. 1, in the liquid crystal device 100 of the present embodiment, the interval between the two data lines 6 a forming the data line pair 7 is a, the pixel electrode 9 and the data close to the pixel electrode 9 are arranged. The distance from the line 6a is defined as b, and the distance between the pixel electrodes arranged in the partition region surrounded by the data line pair 7 and the scanning line 3a is defined as c.

  The width e of the data line 6a and the width d of the pixel electrode 9 are equal to those of the conventional liquid crystal device (see FIG. 9). Here, when the aperture ratio of the liquid crystal device 100 is defined, as described above, two sub-pixel regions are included in the partition region surrounded by the data lines 6a and the scanning lines 3a.

  In the liquid crystal device 100, the width of the effective pixel area including the two sub-pixel areas can be defined as (a + 2b + c + 2d + 2e). Since the partition area (effective pixel area) includes two sub-pixel areas, the pixel width corresponds to the width of the two pixel electrodes 9, and the pixel width can be defined by 2d. In the liquid crystal device 100, pixel display is performed by aligning the liquid crystal layer in a region corresponding to the pixel width 2b. Therefore, the ratio of the width of the effective pixel area to the pixel width, that is, the aperture ratio A2 of the liquid crystal device 100 can be defined by 2d / (a + 2b + c + 2d + 2e).

  The liquid crystal device 100 of the present embodiment is provided with the pixel electrode 9 and the data line 6a so as to satisfy the following formula (1).

  (A + c) / 2 <b (1)

  The above formula (1) is an inequality that satisfies the condition that the difference (A2−A1) between the aperture ratio A2 of the liquid crystal device 100 and the aperture ratio A1 of the conventional liquid crystal device is positive (> 0). That is, the liquid crystal device 100 according to the present embodiment has a higher aperture ratio than the conventional one.

  Incidentally, it is necessary to set the interval c between the pixel electrodes 9 arranged in the partition region to be sufficiently large. This is because, since different voltages are generally applied between adjacent pixel electrodes, the liquid crystal alignment is disturbed by a potential difference generated between adjacent pixel electrodes. Therefore, in general, the interval c between the pixel electrodes 9 is preferably set equal to the interval b between the pixel electrode 9 and the data line 6a (b = c).

  In the present liquid crystal device 100, the pixel electrodes 9 having a comb-like shape in plan view are arranged so that the open end sides are opposed to each other, so that the conductive portion 9a side (the side opposite to the open end) that connects the strip electrodes 9c is opposed. Compared with the arrangement, the capacitance formed between the opposing pixel electrodes 9 is reduced. Accordingly, the interval between the pixel electrodes arranged opposite to each other can be reduced, that is, the interval c can be further reduced, and therefore the relationship c <b is satisfied.

  Further, it is preferable that the distance a between the data lines 6a forming the data line pair 7 is a <b. In this case, an electric field may be generated when the data lines 6a having a potential difference approach, but the data line pair 7 is an area that does not contribute to display, and thus is covered with a light-shielding film (black matrix). Absent. Therefore, the relationship of a <b can be satisfied.

  Thus, according to the liquid crystal device 100 according to the present embodiment, the above relational expressions (c <b, a <b) are satisfied. When the left side and the right side of these relational expressions are added together, a + c <b + b is satisfied, and the above formula (1); (a + c) / 2 <b is satisfied.

  Therefore, the liquid crystal device 100 in which the pixel electrode 9 and the data line 6a are provided on the TFT array substrate 10 in a state satisfying the above-described expression (1) is higher than the conventional one while suppressing the influence of edge reverse. Aperture ratio can be realized.

  In the present embodiment, the liquid crystal device 100 is operated by line inversion driving. According to this configuration, since the pixel electrodes 9 arranged opposite to each other have the same polarity when the liquid crystal device 100 is driven, generation of an electric field between the pixel electrodes 9 is suppressed. Therefore, the pixel electrodes 9 can be formed closer to each other, the distance c can be further reduced, and the aperture ratio of the liquid crystal device 100 can be further improved.

  The liquid crystal device 100 may be operated by dot inversion driving. In this case, although the aperture ratio is slightly reduced as compared with the line inversion driving, the pixel electrodes 9 arranged opposite to each other have different polarities when the liquid crystal device 100 is driven. Therefore, the data lines 6a forming the data line pair 7 are used. Are charged with different polarities on the surface of the insulating layer (gate insulating film 11, first interlayer insulating film 12). Therefore, the mutual polarities cancel each other, and as a result, charging of the insulating layer covering the data line pair 7 is suppressed, and burn-in of the liquid crystal layer provided on the insulating layer can be prevented. The driving method of the liquid crystal device 100 can be appropriately selected according to the user's request.

  Each data line 6a constituting the data line pair 7 is connected to a pixel electrode 9 arranged in the partition region, and supplies an image signal line. In the partition region, a common line 3b connected to the common electrode 19 is formed so as to extend in parallel with the scanning line 3a. The common line 3b is electrically connected to each common electrode 19 provided for each partition region (sub-pixel region). A TFT 30 is provided in the vicinity of the intersection of the data line 6a and the scanning line 3a. The TFT 30 includes a semiconductor layer 35 made of amorphous silicon partially formed in a planar region of the scanning line 3a, and a source electrode 6b and a drain electrode 32 formed to partially overlap the semiconductor layer 35 in a planar manner. . The scanning line 3 a functions as a gate electrode of the TFT 30 at a position overlapping the semiconductor layer 35 in plan view.

  The source electrode 6b of the TFT 30 is formed in a substantially L shape in plan view that branches from the data line 6a and extends on the semiconductor layer 35, and the drain electrode 32 has a substantially rectangular shape in plan view at a position extending to the −Y side. The capacitor electrode 31 is electrically connected. On the capacitance electrode 31, the contact portion 9 b of the pixel electrode 9 is disposed so as to overlap with the end portion on the −Y side in a plane.

  Next, an equivalent circuit of sub-pixel areas formed in a matrix that forms the image display area of the liquid crystal device 100 will be described. In each subpixel region, as shown in FIG. 2, a pixel electrode 9 and a TFT 30 that is electrically connected to the pixel electrode 9 and performs switching control are formed, and extends from the data line driving circuit 101. The data line 6 a is electrically connected to the source of the TFT 30. The data line driving circuit 101 supplies the image signals S1, S2,..., Sn to each pixel via the data line 6a. The image signals S1 to Sn may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a.

  Further, the scanning line 3a extending from the scanning line driving circuit 102 is electrically connected to the gate of the TFT 30, and the scanning signal G1 is supplied from the scanning line driving circuit 102 to the scanning line 3a in a pulse manner at a predetermined timing. , G2,..., Gm are applied to the gate of the TFT 30 in the order of lines in this order. The pixel electrode 9 is electrically connected to the drain of the TFT 30. The TFT 30 serving as a switching element is turned on for a certain period by the input of scanning signals G1, G2,..., Gm, so that the image signals S1, S2,. Writing is performed on the pixel electrode 9. Note that the liquid crystal device 100 of the present embodiment performs line inversion driving as described above.

  Image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 are held for a certain period between the pixel electrode 9 and the common electrode opposed via the liquid crystal.

  In the cross-sectional structure shown in FIG. 3, the liquid crystal device 100 has a liquid crystal layer 50 sandwiched between a TFT array substrate (first substrate) 10 and a counter substrate (second substrate) 20 that are arranged to face each other. The liquid crystal layer 50 is sealed between the substrates 10 and 20 by a sealing material (not shown) provided along the edge of the region where the TFT array substrate 10 and the counter substrate 20 face each other. ing. A backlight 90 including a light guide plate 91 and a reflection plate 92 is provided on the back side (the lower side in the figure) of the TFT array substrate 10.

  The TFT array substrate 10 has a substrate body 10A made of glass, quartz, plastic, or the like as a base, and a scanning line 3a and a common line 3b are formed on the inner surface side (liquid crystal layer 50 side) of the substrate body 10A. A gate insulating film 11 is formed so as to cover the scanning line 3a and the common line 3b.

  An amorphous silicon semiconductor layer 35 is formed on the gate insulating film 11, and a source electrode 6 b and a drain electrode 32 are formed so as to partially run over the semiconductor layer 35. The semiconductor layer 35 is disposed to face the scanning line 3 a via the gate insulating film 11, and the scanning line 3 a constitutes the gate electrode of the TFT 30 in the facing region.

  A first interlayer insulating film 12 is formed so as to cover the semiconductor layer 35, the source electrode 6b, and the drain electrode 32, and a common electrode 19 made of a transparent conductive material such as ITO is covered so as to cover the first interlayer insulating film 12. Is formed.

  Therefore, in the liquid crystal device 100 of the present embodiment, a planar region in which the planar region including the pixel electrode 9 and the planar region where the common electrode 19 is formed overlaps among the sub-pixel regions illustrated in FIG. This is a pixel display region in which display is performed by modulating the light incident from the backlight 90 and transmitted through the liquid crystal layer 50.

  A second interlayer insulating film 13 made of silicon oxide or the like is formed so as to cover the common electrode 19. A pixel electrode 9 made of a transparent conductive material such as ITO is formed on the surface of the second interlayer insulating film 13 on the liquid crystal layer side. An alignment film 18 made of polyimide, silicon oxide or the like is formed so as to cover the pixel electrode 9 and the second interlayer insulating film 13.

  A pixel contact hole 45 penetrating the first interlayer insulating film 12 and the second interlayer insulating film 13 and reaching the drain electrode 32 is formed, and a contact portion 9b of the pixel electrode 9 is partially embedded in the pixel contact hole 45. As a result, the pixel electrode 9 and the drain electrode 32 are electrically connected. An opening is provided in the common electrode 19 corresponding to the formation region of the pixel contact hole 45, and the pixel electrode 9 and the drain electrode 32 are electrically connected through the opening, and the common electrode 19 is also connected. The pixel electrode 9 is not short-circuited.

  On the other hand, the counter substrate 20 includes a translucent substrate body 20A such as glass, quartz, or plastic. A color filter 22 is provided on the inner surface side (the liquid crystal layer 50 side) of the substrate body 10 </ b> A, and an alignment film 28 such as polyimide is laminated on the color filter 22. Note that a planarizing film made of a transparent resin material or the like may be further laminated on the color filter 22, whereby the surface of the counter substrate 20 can be planarized and the thickness of the liquid crystal layer 50 can be made uniform. It is possible to prevent the drive voltage from becoming nonuniform in the pixel region and lowering the contrast.

  In this embodiment, the relative dielectric constant ε = 6 and the film thickness t = 0.1 μm of the second interlayer insulating film 13 that separates the common electrode 19 that is the first electrode and the pixel electrode 9 that is the second electrode. It is. As the liquid crystal constituting the liquid crystal layer 50, those having positive anisotropy with relative dielectric constants of ε⊥ = 4.0 and ε // = 15.3, respectively, were used.

  Further, polarizing plates 14 and 24 are disposed on the outer surface sides of the substrate bodies 10A and 20A, respectively. One or a plurality of retardation plates (optical compensation plates) can be provided between the polarizing plate 14 and the substrate body 10A and between the polarizing plate 24 and the substrate body 20A.

Next, an arrangement example of each optical axis in the liquid crystal device 100 of the present embodiment will be described with reference to FIG.
The transmission axis 153 of the polarizing plate 14 on the TFT array substrate 10 side and the transmission axis 155 of the polarizing plate 24 on the counter substrate 20 side are arranged to be orthogonal to each other, and the transmission axis 153 is parallel to the X axis. The transmission axis 155 is arranged in a direction parallel to the Y axis. Further, the alignment films 18 and 28 are initially provided with an alignment in the same direction (for example, by rubbing treatment) in plan view, and the direction is an initial alignment direction 151 shown in FIG.

  By the way, the liquid crystal molecules cannot be rotated even if a lateral electric field is applied to the liquid crystal molecules in the initial alignment state from the vertical direction. In the present embodiment, as described above, the strip electrode 9c extends in a direction intersecting the X axis (rubbing direction 151) in FIG. Therefore, the transverse electric field EFt acting in the direction perpendicular to the extending direction of the strip electrode 9c is not orthogonal to the rubbing direction 151, and therefore the liquid crystal molecules can be reliably rotated in the transverse electric field direction.

  Note that the initial alignment direction 151 is limited to the direction shown in FIG. 4 as long as the initial alignment direction 151 intersects the main direction of the lateral electric field EFt generated between the pixel electrode 9 and the common electrode 19 (a direction that does not coincide). is not.

  Note that when a potential difference is generated between the pixel electrodes 9 arranged opposite to each other, a leakage electric field is generated in the X-axis direction shown in FIG. 1 between the end portions of the strip electrodes 9c. Since this leakage electric field coincides with the rubbing direction (the initial alignment direction of the liquid crystal) 151 described above, the alignment of the liquid crystal molecules is not disturbed, and problems such as a decrease in contrast due to light leakage can be prevented.

  In the liquid crystal device 100 having the above-described configuration, the pixel electrode 9 and the data line 6a are provided on the TFT array substrate 10 so as to satisfy the above-described formula (1), and thus are surrounded by the scanning line 3a and the data line 6a. The aperture ratio is further improved as compared with the configuration of a conventional liquid crystal device in which one pixel electrode is disposed in the partitioned area. Further, the interval b between the data line 6a and the pixel electrode 9 is set so as not to be affected by edge reverse, and also in this embodiment, there are problems such as a decrease in viewing angle and a decrease in contrast due to edge reverse. Is prevented.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The liquid crystal device according to the present embodiment is a liquid crystal device that employs an IPS (In Plane Switching) method in a horizontal electric field method. FIG. 5 is a plan configuration diagram of the liquid crystal device of the liquid crystal device 200 of the present embodiment, and FIG. 6 is a partial cross-sectional configuration diagram along line AA ′ in FIG. 5. In addition, about the structural member similar to the liquid crystal device 100 which concerns on the said 1st Embodiment, the same code | symbol is attached | subjected and detailed description shall be abbreviate | omitted.

  As shown in FIG. 5, the liquid crystal device 200 is provided with a data line pair 7 in which two data lines 6 a are arranged at a predetermined interval, and a scanning line 3 a intersecting the data line pair 7. Two pixel electrodes (first electrodes) 9 having a substantially comb-like shape (rake shape) in a plan view are arranged in a region surrounded by the data line pair 7 and the scanning line 3a along the extending direction of the scanning line 3a. Has been.

  In the present embodiment, unlike the liquid crystal device 100 of the above embodiment, a common electrode (second electrode) 19 is formed along the outer periphery of the TFT array substrate 10 and branches from the conductive portion (not shown). And a plurality of strip-shaped electrodes 19c. Each band-like electrode 19c is provided so as to sew between the band-like electrodes 9c of the pixel electrode 9 having a comb shape in a plan view.

  In addition, as shown in FIG. 5, the interval between the two data lines forming the data line pair 7 is a, and the interval between the pixel electrode 9 and the data line 6a adjacent to the pixel electrode 9 is b. When the interval between the pixel electrodes 9 arranged in the partition region surrounded by the data line pair 7 and the scanning line 3a is c, the liquid crystal device 100 according to this embodiment satisfies the above formula (1). Thus, the pixel electrode 9 and the data line 3a are formed on the TFT array substrate 10.

  Further, similarly to the above-described embodiment, since the open end sides of the pixel electrodes 9 having a comb-like shape in plan view are arranged to face each other, the capacitance formed between the opposed pixel electrodes 9 is reduced, and the spacing is reduced. c is narrower (c <b). Thus, the above formula (1) is surely satisfied and the aperture ratio of the liquid crystal device 200 is improved.

  Note that the liquid crystal device 200 of this embodiment is also preferably driven by line inversion to improve the aperture ratio, and is preferably driven by dot inversion to prevent burn-in of the liquid crystal layer.

(Cross-section structure)
Next, a cross-sectional configuration of the liquid crystal device 200 will be described with reference to FIG. As shown in FIG. 6, the liquid crystal device 200 has a configuration in which a liquid crystal layer 50 is sandwiched between the TFT array substrate 10 and the counter substrate 20, similarly to the liquid crystal device 100.

  In the present embodiment, unlike the above embodiment, a common electrode 19 is formed on the gate insulating film 11. A first interlayer insulating film 12 made of a transparent insulating material such as silicon oxide is formed so as to cover the TFT 30 and the common electrode 19, and a first layer made of a transparent insulating material such as silicon oxide is formed on the first interlayer insulating film 12. A two-layer insulating film 13 is formed.

  On the second interlayer insulating film 13, the pixel electrode 9 made of a transparent conductive material such as ITO is formed. A contact hole 45 that penetrates through the second interlayer insulating film 13 and reaches the capacitor electrode 31 is formed, and the contact portion 9 b of the pixel electrode 9 is partially embedded in the contact hole 45. Thereby, the pixel electrode 9 and the capacitor electrode 31 are electrically connected. An alignment film 18 such as polyimide is formed to cover the pixel electrode 9 and the common electrode 19.

  The counter substrate 20 side has the same configuration as that of the above embodiment, and thus the description thereof is omitted. A liquid crystal layer 50 is sandwiched between the TFT array substrate 10 and the counter substrate 20. The liquid crystal layer 50 is sealed between the substrates 10 and 20 by a sealing material (not shown) provided along an edge of a region where the TFT array substrate 10 and the counter substrate 20 face each other.

  A polarizing plate 14 is laminated on the outer surface side of the TFT array substrate 10 (opposite the liquid crystal layer 50), and a polarizing plate 24 is also disposed on the outer surface side of the counter substrate 20. A backlight 90 is provided on the back side (the bottom side in the figure) of the TFT array substrate 10.

Since the arrangement example of each optical axis in the liquid crystal device 200 of the present embodiment is the same as that of the above embodiment, the details are omitted.
The operation of the above-described liquid crystal device 200 will be described. When a non-selection voltage is applied, the liquid crystal molecules constituting the liquid crystal layer are aligned horizontally with the substrate along the rubbing direction 151. When a selection voltage is applied between the pixel electrode 9 and the common electrode 19, a horizontal electric field EFt acts in a direction perpendicular to the extending direction of the strip electrodes 9c and 19c, and liquid crystal molecules are aligned along the horizontal electric field direction. Reorientate. Since the rubbing direction 151 of the alignment film is set to a direction that intersects the lateral electric field direction at an angle other than perpendicular, all liquid crystal molecules can be rotated in the same direction. Therefore, the liquid crystal device 200 can perform good brightness display.

  Also in the liquid crystal device 200 according to the present embodiment, the pixel electrode 9 and the data line 6a are provided on the TFT array substrate 10 so as to satisfy the above formula (1), as in the above-described embodiment. Compared to the IPS liquid crystal device, the aperture ratio is further improved. In addition, problems such as a decrease in viewing angle and a decrease in contrast due to edge reverse are prevented.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In the present embodiment, in the liquid crystal device 100 described in the first embodiment, the data line pair 7 is covered with a dielectric film having a dielectric constant higher than that of the liquid crystal layer 50. FIG. 7 is a plan structural view of the liquid crystal device 300 according to the present embodiment. In addition, about the structure similar to the liquid crystal device 100 which concerns on the said 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

As shown in FIG. 7, a dielectric film M made of acrylic resin or the like is provided so as to cover the data line pair 7. With this configuration, the dielectric film M absorbs the electric field generated between the data line 6 a and the pixel electrode 9, and suppresses the occurrence of edge reverse due to the electric field generated between the data line 6 a and the pixel electrode 9. By doing so, an aperture ratio can be raised more.
The dielectric film M may be provided in the IPS liquid crystal device 200 described above. Accordingly, an IPS liquid crystal device with a high aperture ratio can be provided.

(Electronics)
FIG. 8 is a perspective view showing an example of an electronic apparatus according to the present invention. A cellular phone (electronic device) 1300 shown in this figure includes the liquid crystal device of the present invention as a small-sized display portion 1301, and includes a plurality of operation buttons 1302, an earpiece 1303, and a mouthpiece 1304. . The liquid crystal device of each of the above embodiments is not limited to the mobile phone, but is an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type or a monitor direct view type video tape recorder, a car navigation device, a pager, and an electronic notebook. , Calculators, word processors, workstations, videophones, POS terminals, devices equipped with touch panels, etc. Further, the liquid crystal device of the present invention may be used as a light modulation means (liquid crystal light valve) of a projector. In any electronic device, a highly reliable display portion with a high aperture ratio can be realized.

It is a plane lineblock diagram of the liquid crystal device concerning a 1st embodiment. It is a circuit block diagram of the sub pixel area | region of a liquid crystal device. It is side part sectional drawing of a liquid crystal device. FIG. 3 is a layout diagram of optical axes of a liquid crystal device. It is a plane block diagram of the liquid crystal device which concerns on 2nd Embodiment. It is side part sectional drawing of the liquid crystal device which concerns on 2nd Embodiment. It is a plane block diagram of the liquid crystal device which concerns on 3rd Embodiment. It is a schematic structure perspective view of the mobile telephone which shows an example of an electronic device. It is a plane block diagram which shows the structure of the conventional liquid crystal device.

Explanation of symbols

3a ... scanning line, 6a ... data line, 7 ... data line pair, 10 ... TFT array substrate (first substrate), 20 ... counter substrate (second substrate), 9 ... pixel electrode (first electrode), 9c ... band shape Electrode (branch electrode), 19 ... Common electrode (second electrode), 50 ... Liquid crystal layer, 100, 200, 300 ... Liquid crystal device, 1300 ... Mobile phone (electronic device), M ... Dielectric film

Claims (5)

In a liquid crystal device including a first substrate and a second substrate disposed to face each other with a liquid crystal layer interposed therebetween,
  On the liquid crystal layer side of the first substrate,
  A first and second data line pair each comprising two data lines extending in a second direction that is spaced apart from each other in the first direction and intersects the first direction;
  First and second scan lines extending in the first direction;
  A first pixel electrode comprising: a first conduction part extending in the second direction; and a plurality of first branch electrodes branched from the first conduction part and extending in the first direction;
  A second pixel electrode comprising: a second conductive portion extending in the second direction; and a plurality of second branch electrodes branched from the second conductive portion and extending in a direction opposite to the first direction. When,
  A common electrode provided through an insulating layer between the first and second pixel electrodes;
  Have
  The liquid crystal layer is driven by an electric field generated between the first and second pixel electrodes and the common electrode,
  The first and second pixel electrodes may be connected to the first pixel electrode in a region surrounded by the first and second data line pairs and the first and second scan lines. Are positioned on the first direction side, and the ends of the plurality of first branch electrodes and the ends of the plurality of second branch electrodes are spaced apart from each other by a second distance,
  The first interval is a, the interval between each of the first and second conducting portions and the closest data line pair of the first and second data line pairs is b, and the second interval is c. When the following formula,
  (A + c) / 2 <b
  Is a liquid crystal device. The liquid crystal device according to claim 1, wherein the liquid crystal device is operated by line inversion driving. The liquid crystal device according to claim 1, wherein the liquid crystal device is operated by dot inversion driving. The liquid crystal device according to claim 1, wherein the first and second data line pairs are covered with a dielectric film having a dielectric constant higher than that of the liquid crystal layer. The electronic device provided with the liquid crystal device as described in any one of Claims 1-4.

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