JP2010191037A - Electrooptical device and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively suppress the generation of a domain area while securing a sufficient aperture ratio in an image display area in an electrooptical device such as a liquid crystal device. <P>SOLUTION: The electrooptical device includes: a pair of substrates (10, 20); an electrooptical substance (50) held between the pair of substrates; and a pixel electrode (9) disposed on one substrate for each pixel and having a first edge part formed along a first direction within a substrate surface and a second edge part and a third edge part formed along a second direction within the substrate surface and arranged corresponding to both ends of the first edge part. The first direction and the second direction are specified so that the first edge part and the second edge part are in a direction where the domain area is easily generated by a lateral electric field formed along the substrate in comparison with the third edge part. At least one of the second and third edge parts has a notch part (3) formed so that a distance (a1) between the second and third edge parts in one area (1) close to the first edge out of the pixel electrode is shorter than a distance (a2) in the other area (2) excluding the one area. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of an electro-optical device such as a liquid crystal device and an electronic apparatus including the electro-optical device such as a mobile phone.

  In a liquid crystal device that is an example of this type of electro-optical device, for example, a driving voltage corresponding to a display image is applied between a pixel electrode and a counter electrode provided on each of a pair of substrates that hold liquid crystal. Image alignment is performed by controlling the alignment state of the liquid crystal molecules sandwiched between the electrodes. The pixel electrode is formed in an island shape for each pixel, and different drive voltages are applied to each of the pixel electrodes. Therefore, a horizontal electric field (that is, an electric field parallel to the substrate surface or an oblique electric field including a component parallel to the substrate surface) is generated between the adjacent pixel electrodes according to the potential difference, which causes alignment defects in the liquid crystal molecules. It becomes. As described above, if there is a region where alignment failure occurs (that is, a domain region), it causes various problems such as a decrease in contrast of a display image.

  On the other hand, Patent Document 1 discloses a technique for suppressing the occurrence of a transverse electric field and reducing the alignment state of liquid crystal molecules by cutting off corners of pixel electrodes obliquely.

JP 2007-199451 A

  However, according to the background art described above, although there is a possibility that the alignment defects of the liquid crystal molecules can be alleviated, the lateral electric field still remains. Therefore, a device for suppressing generation of a further lateral electric field is required in order to enable a higher quality image display with a small domain area. Further, when the corner portion of the pixel electrode is cut off, the area of the pixel electrode is greatly reduced. Since the area of the opening region through which the display light is transmitted in the pixel is increased or decreased according to the area of the pixel electrode, the area of the opening region is reduced when the area of the pixel electrode is reduced. That is, if the corner of the pixel electrode is cut off, the aperture ratio in the image display area is lowered, and the image quality of the display image is lowered.

  The present invention has been made in view of the above problems, for example, and an electro-optical device capable of effectively suppressing the occurrence of a domain region while sufficiently ensuring an aperture ratio in an image display region, a manufacturing method thereof, and It is an object to provide an electronic apparatus including such an electro-optical device.

  In order to solve the above-described problem, an electro-optical device according to an aspect of the invention includes a pair of substrates, an electro-optical material sandwiched between the pair of substrates, and a pixel disposed on one of the pair of substrates. The first edge portion formed along the first direction in the one substrate surface and the first direction in the one substrate surface when viewed in plan on the one substrate. A pixel electrode having a second edge and a third edge formed along the intersecting second direction and arranged to correspond to both ends of the first edge, and the first direction and the The second direction is defined such that the first edge is a direction in which a domain region is more likely to be generated by a lateral electric field along the one substrate than the second edge and the third edge. At least one of the second edge and the third edge is a pixel electrode. The distance between the second edge and the third edge in one area close to the first edge is formed to be smaller than in the other area of the pixel electrode other than the one area. Having a cutout.

  The electro-optical device of the present invention has a structure in which an electro-optical material is sandwiched between a pair of substrates (typically, an element substrate and a counter substrate). For example, on the element substrate, electronic elements such as scanning lines, data lines, and pixel switching transistors are stacked as necessary while being insulated from each other via an insulating film, thereby forming pixel electrodes. A circuit for driving is configured, an image electrode is disposed on the upper layer side, and a counter electrode is provided on the counter substrate so as to face the pixel electrode formed on the element substrate. Then, by applying a driving voltage corresponding to the display image between the pixel electrode and the counter electrode, the alignment state of the electro-optical material such as liquid crystal sandwiched between the substrates is controlled. That is, the alignment state is controlled by a vertical electric field. In this way, it is possible to display an image in a pixel area or a pixel array area (or also referred to as an “image display area”) in which a plurality of pixel electrodes are arranged.

  The electro-optic material is, for example, a liquid crystal layer including TN (Twisted Nematic) liquid crystal molecules.

  The pixel electrode in the present invention has a first edge, a second edge, and a third edge. The first edge portion of the pixel electrode including the second edge portion and the third edge portion when viewed in plan on one substrate, the domain region is typically between adjacent pixel electrodes. This is an edge portion that is relatively easily generated by a transverse electric field. In this type of electro-optical device, a domain region is easily formed in a specific portion of the edge of the pixel electrode depending on the type of electro-optical material, the alignment state when no driving voltage is applied, and the like. In the present invention, the edge where the domain region is relatively likely to occur is the first edge, and the direction in which the first edge extends is the first direction.

  Although there may be cases where the domain region is generated in the second edge portion and the third edge portion due to the transverse electric field, the domain region may be generated to be larger or smaller. However, the present invention aims to reduce the relatively strongly generated domain region. Yes. That is, even if the domain region is slightly generated by the transverse electric field in the second edge portion and the third edge portion, or if there is little or no domain region, the special case described in detail below of the present invention. A remarkable effect is exhibited, and the present invention is correspondingly effective in any case.

  Both the second edge and the third edge are formed along a second direction that intersects the first direction, and are arranged so as to correspond to both ends of the first edge. That is, the pixel electrode can take any shape as long as it includes the first edge, the second edge, and the third edge when viewed on one substrate. For example, the pixel electrode has a rectangular shape, a pentagonal shape, or the like. It has a polygonal shape that includes it. As a specific example, each pixel divided by a data line and a scanning line extending in the first direction and the second direction may be formed in a square or a rectangle.

  In the present invention, in particular, the pixel electrode has a distance between the second edge and the third edge in a region where at least one of the second edge and the third edge is close to the first edge of the pixel electrode. However, the pixel electrode has a cutout portion formed so as to be smaller than those in other regions except for one region. According to the research of the present inventor, it has been found that the formation of the notches in this way can effectively suppress the lateral electric field generated between adjacent pixel electrodes. The reason is not completely elucidated, but since the magnitude of the lateral electric field depends on the distance between adjacent pixel electrodes having different potentials, the domain region is easily formed at the first edge. It is considered that by providing a notch portion in a near area so as to ensure a large distance between adjacent pixel electrodes, it is possible to suppress a lateral electric field that causes a domain area.

  Moreover, what is necessary is just to provide such a notch part in at least one among a 2nd edge part and a 3rd edge part. From the viewpoint of effectively suppressing the formation of the domain region, the notch is preferably formed on both the second edge and the third edge, but the second edge and the third edge. Even if it is formed only on one of them, the advantages of the present invention, which is good if the formation of the domain region is suppressed, can be enjoyed.

  As described above, according to the electro-optical device of the present invention, the formation of the domain region can be effectively suppressed by forming the notch in the pixel electrode, and high-quality image display is possible. An electro-optical device can be realized.

  In one aspect of the electro-optical device according to the aspect of the invention, the cutout portion has a length along the second direction larger than a length along the first direction.

  According to the inventor of the present application, the length along the second direction is along the first direction compared to the case where the length along the second direction of the notch is smaller than the length along the first direction. It has been found that the generation of domains in the electro-optic material can be remarkably effectively suppressed when the length is larger than the length.

  Further, by forming the shape of the notch in this way, a wide opening area in the image display area can be secured. As a result, it is possible to realize an electro-optical device that can prevent light leakage from occurring in the image display area and can display a bright, clear and high-quality image.

  In another aspect of the electro-optical device according to the aspect of the invention, the cutout portion includes a fourth edge portion extending in a third direction intersecting the first and second directions in the one region.

  According to this aspect, the notch includes a portion that is obliquely cut out so as to take corners of the pixel electrode at both ends of the first edge where the domain region is formed. As in the above-described aspect, the distance between the second edge and the third edge in one area close to the first edge of the pixel electrode is the other area except for one area of the pixel electrode. If the formation of the domain region cannot be sufficiently suppressed only by forming it to be smaller than that in the case, the domain region can be formed more effectively by including a notched portion as in this embodiment. Can be suppressed.

  In order to solve the above problems, an electronic apparatus according to the present invention includes the above-described electro-optical device according to the present invention (including various aspects thereof).

  According to the electronic apparatus of the present invention, since it includes the electro-optical device of the present invention described above, a projection display device, a television, a mobile phone, an electronic notebook, a word processor, capable of performing high-quality image display, Various electronic devices such as a viewfinder type or a monitor direct-view type video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized. In addition, as an electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper, an electron emission device (Field Emission Display and Conduction Electron-Emitter Display), and a display device using these electrophoretic device and electron emission device Is also possible.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

It is a top view which shows the whole structure of the liquid crystal device which concerns on this embodiment. It is HH 'sectional drawing of FIG. It is a circuit diagram which shows the electrical structure of the liquid crystal device which concerns on this embodiment. It is a schematic diagram which shows transparently the positional relationship of wiring etc. in the image display area of the liquid crystal device concerning this embodiment. FIG. 5 is a plan view schematically illustrating a detailed shape of a pixel electrode extracted from FIG. 4. It is a schematic diagram which shows the planar shape of another pixel electrode used for verifying the influence of the planar shape of a pixel electrode with respect to a domain area | region. 7 is a table showing a result of measuring a V1 margin of a liquid crystal device adopting the planar shape of the pixel electrode shown in FIG. It is an example of an electronic apparatus to which the electro-optical device of the present embodiment is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a driving circuit built-in type TFT active matrix driving type liquid crystal device, which is an example of the electro-optical device of the present invention, is taken as an example.

<Liquid crystal device>
First, the overall configuration of the liquid crystal device according to the present embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a schematic plan view showing a configuration of a liquid crystal device when the TFT array substrate 10 is viewed from the counter substrate 20 side together with each component formed thereon, and FIG. 2 is a plan view of FIG. It is HH 'sectional drawing.

  1 and 2, the liquid crystal device according to the present embodiment includes a TFT array substrate 10 and a counter substrate 20 that are arranged to face each other. The TFT array substrate 10 is, for example, a transparent substrate such as a quartz substrate or a glass substrate, or a silicon substrate. The counter substrate 20 is also a substrate made of the same material as the TFT array substrate 10, for example. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are sealed around the image display region 10a where the electro-optical operation is performed. They are bonded to each other by a sealing material 52 provided in the region.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. Further, for example, in the sealing material 52, a gap material 56 such as a glass fiber or a glass bead for dispersing the distance (inter-substrate gap) between the TFT array substrate 10 and the counter substrate 20 to a predetermined value is dispersed.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display area 10a is provided on the counter substrate 20 side in parallel with the inside of the seal area where the sealing material 52 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  On the TFT array substrate 10, a data line driving circuit 101, a sampling circuit 7, a scanning line driving circuit 104, and an external circuit connection terminal 102 are formed in the peripheral area 10b located around the image display area 10a.

  In the peripheral region 10 b on the TFT array substrate 10, the data line driving circuit 101 and a plurality of external circuit connection terminals 102 are provided along one side of the TFT array substrate 10 on the outer peripheral side from the seal region.

  Further, a region located inside the seal region in the peripheral region 10b on the TFT array substrate 10 is covered with the frame light shielding film 53 along one side of the image display region 10a along one side of the TFT array substrate 10. Thus, the sampling circuit 7 is arranged.

  The scanning line driving circuit 104 is provided along two sides adjacent to one side of the TFT array substrate 10 so as to be covered with the frame light shielding film 53. Further, in order to electrically connect the two scanning line driving circuits 104 provided on both sides of the image display region 10a in this way, the TFT array substrate 10 is covered with the frame light shielding film 53 along the remaining side. A plurality of wirings 105 are provided.

  Further, in the peripheral region 10 b on the TFT array substrate 10, vertical conduction terminals 106 are arranged in regions facing the four corners of the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are vertically connected. A conductive material is provided corresponding to the vertical conductive terminal 106 and electrically connected to the terminal 106.

  In FIG. 2, on the TFT array substrate 10, a laminated structure is formed in which wirings such as TFTs for pixel switching, scanning lines, and data lines are formed. In the image display area 10a, pixel electrodes 9 are provided in a matrix form on the upper layer of wiring such as pixel switching TFTs, scanning lines, and data lines. The pixel electrode 9 is formed as a transparent electrode made of an ITO film. An alignment film 16 is formed on the pixel electrode 9.

  On the other hand, a light shielding film 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. The light shielding film 23 is formed of, for example, a light shielding metal film or the like, and is patterned, for example, in a lattice shape in the image display region 10a on the counter substrate 20. On the light shielding film 23 (below the light shielding film 23 in FIG. 2), the counter electrode 21 made of an ITO film is formed, for example, in a solid shape so as to face the plurality of pixel electrodes 9, and further on the counter electrode 21 (FIG. 2, below the counter electrode 21), an alignment film 22 is formed.

  The liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films. A liquid crystal storage capacitor is formed between the pixel electrode 9 and the counter electrode 21 by applying a voltage to each of the liquid crystal devices during driving.

  Although not shown here, on the TFT array substrate 10, in addition to the data line driving circuit 101 and the scanning line driving circuit 104, a plurality of data lines are precharged at a predetermined voltage level prior to the image signal. A precharge circuit to be supplied, an inspection circuit for inspecting the quality, defects, etc. of the liquid crystal device during manufacture or at the time of shipment may be formed.

  Next, the electrical configuration of the image display area of the liquid crystal device according to the present embodiment will be described with reference to FIG. FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix forming the image display area of the liquid crystal device according to this embodiment.

In FIG. 3, a pixel electrode 9 and a pixel switching TFT 30 are formed in each of a plurality of pixels formed in a matrix that forms the image display region 10a. The TFT 30 is electrically connected to the pixel electrode 9, and performs switching control of the pixel electrode 9 when the liquid crystal device according to the present embodiment operates. The data line 6 to which the image signal is supplied is electrically connected to the source region of the TFT 30. Image signals S1, S2,..., Sn to be written to the data lines 6 may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6. Good.

  The scanning line 11 is electrically connected to the gate of the TFT 30, and the liquid crystal device according to the present embodiment applies the scanning signals G1, G2,..., Gm to the scanning line 11 in a pulsed manner at a predetermined timing. It is configured to apply in a line sequential order. The pixel electrode 9 is electrically connected to the drain of the TFT 30, and the image signal S1, S2,..., Sn supplied from the data line 6 is obtained by closing the switch of the TFT 30 serving as a switching element for a certain period. It is written at a predetermined timing. A predetermined level of image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 is constant between the counter electrode 21 (see FIG. 2) formed on the counter substrate 20 (see FIG. 2). Hold for a period.

  The liquid crystal constituting the liquid crystal layer 50 (see FIG. 2) modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The transmittance for light is increased, and light having a contrast corresponding to an image signal is emitted from the liquid crystal device as a whole.

  In order to prevent the image signal held here from leaking, a storage capacitor 70 is added electrically in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the counter electrode 21 (see FIG. 2). ing. One electrode of the storage capacitor 70 is connected to a fixed potential line 300 so as to have a predetermined potential.

  Next, in the liquid crystal device according to the present embodiment, the positional relationship of electrodes and wirings arranged for performing an electro-optical operation in the image display region 10a will be described with reference to FIG. FIG. 4 is a schematic diagram transparently showing the positional relationship between electrodes and wirings arranged for performing an electro-optical operation in the image display region 10a of the liquid crystal device according to the present embodiment. In FIG. 4, in order to make each layer and each member recognizable on the drawing, the scale is different for each layer and each member.

  On the image display area 10 a of the TFT array substrate 10, the scanning lines 11 and the data lines 6 are arranged along the X direction and the Y direction, respectively, and the TFT 30 (that is, the intersection of the data lines 6 and the scanning lines 11). The semiconductor layer 30a and the gate electrode 30b) are formed.

  The scanning line 11 is made of a light-shielding conductive material, for example, W (tungsten), Ti (titanium), TiN (titanium nitride) or the like, and is wider than the semiconductor layer a so as to include the semiconductor layer 30a of the TFT 30. Is formed. Since the scanning line 11 is arranged on the lower layer side than the semiconductor layer 30a, the scanning line 11 is formed wider than the semiconductor layer 30a of the TFT 30 in this way, thereby reflecting the back surface of the TFT array substrate 10 or a double-plate type. The channel region 30b of the TFT 30 can be almost or completely shielded from return light such as light emitted from another liquid crystal device by a projector or the like and penetrating through the composite optical system. As a result, the light leakage current in the TFT 30 is reduced during the operation of the liquid crystal device, the contrast ratio can be improved, and high-quality image display can be performed.

  The TFT 30 includes a semiconductor layer 30a and a gate electrode 30b. The semiconductor layer 30a is formed including a source region 30a1, a channel region 30a2, and a drain region 30a3. Here, an LDD (Lightly Doped Drain) region may be formed at the interface between the channel region 30a2 and the source region 30a1 or between the channel region 30a2 and the drain region 30a3.

  The gate electrode 30b is made of, for example, conductive polysilicon, and is electrically connected to the scanning line 11 through a contact hole 34 opened in the gate insulating film. Thus, the TFT 30 is controlled to be turned on / off by applying a scanning signal to the gate electrode 30b.

  An image signal is supplied to the data line 6 and is electrically connected to the source region 30 a 1 through the contact hole 31. On the other hand, the drain region 30 a 3 is electrically connected to the relay layer 7 through the contact hole 32. Further, the relay layer 7 is connected to the pixel electrode 9 through the contact hole 33. That is, the relay layer 7 applies a driving voltage corresponding to the image signal output from the drain region 30a3 of the TFT 30 to the pixel electrode by relay-connecting the drain region 30a3 and the pixel electrode 9.

  Here, the planar structure of the pixel electrode 9 will be described with reference to FIG. FIG. 5 is a plan view schematically showing the detailed shape of the pixel electrode 9 extracted from FIG. In FIG. 5, the scales of the layers and members are different from each other in order to make the layers and members recognizable on the drawing.

  The pixel electrode 9 is a first edge portion 9a extending in the X direction corresponding to the “first direction” in the present invention when viewed in plan on the TFT array substrate 10, and the “second edge” in the present invention. It has the 2nd edge part 9b and the 3rd edge part 9c which extend along the Y direction corresponding to "direction".

  Of the edge portions of the pixel electrode 9, the first edge portion 9 a is a portion where a domain region is more likely to be formed or formed than other edge portions. The liquid crystal device according to the present embodiment employs 1H inversion driving (that is, driving in which a driving voltage having the same polarity is applied to pixel electrodes arranged on one scanning line and the polarity is inverted for each scanning line). Therefore, a lateral electric field is likely to be generated between the pixel electrodes 9 adjacent in the Y direction. In the present embodiment, the generation of the domain region in the first edge portion 9a can be suppressed by devising the shape of the pixel electrode 9 as described below.

  The inversion driving method according to the present embodiment is not limited to 1H inversion driving, and 1S inversion driving (that is, a driving voltage having the same polarity is applied to pixel electrodes arranged on one data line, and data is In addition, various methods such as dot inversion driving, field inversion driving, double speed inversion driving, and area scanning inversion driving may be adopted. As long as there is an edge where a domain region is relatively likely to occur due to a lateral electric field, this embodiment functions more or less effectively by treating the edge as the first edge.

  The pixel electrode 9 in the present embodiment is formed in a substantially square shape when viewed in plan on the TFT array substrate 10. And the 2nd edge 9b and the 3rd edge 9c which are the edges formed along the Y direction are the 2nd edge 9b and the 3rd edge 9c in one field 1 near the 1st edge 9a. The distance a <b> 1 is formed so as to have the first cutout portion 3 formed to be smaller than the distance a <b> 2 in the other region 2 excluding one region 1 in the pixel electrode 9. The first notch 3 is an example of the “notch” in the present invention. As will be described in detail later, according to the inventor's research, the formation of such a first cutout 3 can effectively suppress a lateral electric field generated between adjacent pixel electrodes 9. However, it has been found from the evaluation result by simulation, theoretical calculation or theoretical experiment, or the evaluation result by experiment using a real object.

  Although the mechanism of suppression of the lateral electric field by the first notch 3 is not necessarily completely elucidated, the magnitude of the lateral electric field depends on the distance between adjacent pixel electrodes 9 having different potentials. In one region 1 close to the first edge 9a1 where the domain region is likely to be formed, by securing a large distance b between the adjacent pixel electrodes 9, it is possible to weaken the lateral electric field that causes the domain region to be generated. This is thought to be possible.

  As shown in the evaluation results in the specific examples described later, when the length c along the Y direction of the first notch 3 is formed to be about ½ of the length c of the third edge 9a3, the most Generation | occurrence | production of a domain area | region can be suppressed effectively. Even when the length c along the Y direction is not about ½ of the length c of the third edge portion 9a3, the lateral electric field is suppressed by forming the first cutout portion 3. You can enjoy the effect.

  In the present embodiment, the first notch 3 is provided on both the second edge 9b and the third edge 9c, but may be provided on at least one of the second edge 9b and the third edge 9c. Good. From the viewpoint of more effectively suppressing the formation of the domain region, it is preferable to form the first notch 3 at both the second edge 9b and the third edge 9c. Even if it is formed on only one of the three edge portions 9c, it is possible to enjoy the advantages of the present invention that should suppress the formation of the domain region.

  Furthermore, in this embodiment, in order to suppress the formation of the domain region more effectively, the second notch 4 is formed at both ends of the first edge 9a (that is, the lower left side and the lower right side of the pixel electrode 9 in FIG. 5). Is provided. The second cutout portion 4 is formed obliquely so as to face the corners located at both ends of the first edge portion 9a of the pixel electrode 9 formed in a substantially square shape as a whole. By forming the second cutout portion 4 in this way, as described above, the first cutout portion 3 is replaced with the second edge portion 9b and the third edge portion 3 in the region 1 of the pixel electrode 9 close to the first edge portion 9a. If the formation of the domain region cannot be sufficiently suppressed only by forming the distance a1 between the edge portions 9c to be smaller than the distance a2 in the other region 2, the second notch portion 4 is formed. Thus, the formation of the domain region can be more effectively suppressed.

  Here, with reference to FIG. 6 and FIG. 7, evaluation results in various specific examples in which the degree of formation of the domain region of the pixel electrode 9 having various shapes is verified with respect to the liquid crystal device will be shown. FIG. 6 is a plan view schematically showing the shape of the pixel electrode 9 used for verification. FIG. 7 shows the measured voltage effective value (hereinafter referred to as V1 margin as appropriate) at which the domain region disappears when the effective voltage applied to the pixel is increased for the liquid crystal device adopting the shape shown in FIG. It is a table | surface which shows the result. A larger value of the V1 margin indicates that the formation of the domain region is suppressed, and conversely, a smaller value indicates that the domain region is more easily formed. That is, the larger the value of the V1 margin, the more effectively the formation of the domain region is suppressed. In the determination in FIG. 7, the case where the V1 margin is less than 5.0V is “impossible”, the case where the V1 margin is 5.0V or more and less than 5.2V is “possible”, and the V1 margin is 5.2V or more and 5.5V. The determination is made with “good” when the value is less than “V” and “excellent” when the V1 margin is 5.5 V or more.

  First, the shape of the pixel electrode 9 shown in FIG. 6A is such that the distance a1 between the second edge portion 9b and the third edge portion 9c in one region 1 near the first edge portion 9a is The first notch 3 is formed to be smaller than the distance a2 in the other region 2 excluding the one region 1, and the length c in the Y direction of the first notch 3 is The second edge portion 9b is formed to have a length that is about ½ of the entire length d (that is, d / 2). As a result, as shown in FIG. 7, the result that the V1 margin is 5.5 V or more can be obtained, and it is specifically shown that the formation of the domain region is very effectively suppressed (that is, the determination) Is “excellent”).

  The shape of the pixel electrode 9 shown in FIG. 6B is such that the distance a1 between the second edge portion 9b and the third edge portion 9c in one region 1 near the first edge portion 9a is one of the pixel electrodes 9. The first notch 3 is formed to be smaller than the distance a2 in the other region 2 excluding the region 1, and the length c in the Y direction of the first notch 3 is the second The edge portion 9b is formed to be longer than half the length d of the entire edge portion 9b (that is, d / 2). As a result, as shown in FIG. 7, a result of 5.3 V to 5.5 V can be obtained, and it is specifically shown that the formation of the domain region is effectively suppressed (that is, the determination is “ Good ”). In this case, although the size of the V1 margin is reduced as compared with the shape of the pixel electrode 9 shown in FIG. 6A, the formation of the domain region can be effectively suppressed to some extent.

  The shape of the pixel electrode 9 shown in FIG. 6C is such that the distance a1 between the second edge portion 9b and the third edge portion 9c in one region 1 near the first edge portion 9a is one of the pixel electrodes 9. The first notch 3 is formed to be smaller than the distance a2 in the other region 2 excluding the region 1, and the length c in the Y direction of the first notch 3 is the second The edge portion 9b is formed to be smaller than a length ½ of the entire length d (that is, d / 2). As a result, as shown in FIG. 7, the result that the V1 margin is 5.0 V can be obtained, and it is specifically shown that the formation of the domain region is suppressed to some extent (that is, the determination is “OK”). Is). In this case, as in the case shown in FIG. 6B, although the size of the V1 margin is reduced as compared with the case of the shape of the pixel electrode 9 shown in FIG. In addition, the formation of the domain region can be suppressed.

  From the results described above, in order to effectively suppress the formation of the domain region, it is preferable to form the pixel electrode 9 so that the length c in the Y direction of the first notch 3 is about d / 2. I understand that. In other words, even if the length c in the Y direction of the first notch 3 is formed larger than or smaller than d / 2, the formation of the domain region can be effectively suppressed. I understand that I can do it.

  Next, the shape of the pixel electrode 9 shown in FIG. 6D is such that the distance a1 between the second edge portion 9b and the third edge portion 9c in one region 1 close to the first edge portion 9a is the pixel electrode 9. In contrast to the distance a2 in the other region 2 except for one region 1, the first notch 3 is formed to be smaller than the above-described shape. As a result, as shown in FIG. 7, the size of the V1 margin is less than 5.0 V, which specifically indicates that it is difficult to suppress the formation of the domain region (that is, the determination is “ Not possible).

  The shape of the pixel electrode 9 shown in FIG. 6E is formed in a typical square shape without providing the first notch 3 and the second notch 4. As a result, as shown in FIG. 7, the size of the V margin is less than 5.0 V, which specifically indicates that it is difficult to suppress the formation of the domain region (that is, the determination is “ Not possible).

  Thus, from the verification results shown in FIG. 6 and FIG. 7, in order to effectively suppress the formation of the domain region, the first notch 3 is the second edge in one region 1 close to the first edge 9a. It has been found that it is preferable to form the distance a1 between the portion 9b and the third edge portion 9c to be smaller than the distance a2 in the other region 2 of the pixel electrode 9 excluding one region 1. In particular, if the length c in the Y direction of the first notch 3 is set to about half of the entire length of the second edge 9b (that is, d / 2), the formation of the domain region can be suppressed extremely well. It has been found that it can be done.

As described above, according to the electro-optical device of the present invention, the formation of the domain region can be effectively suppressed by forming the notch in the pixel electrode, and high-quality image display is possible. An electro-optical device can be realized.
<Electronic equipment>
Next, the case where the liquid crystal device which is the above-described electro-optical device is applied to various electronic devices will be described.

  FIG. 8 is a plan view showing a configuration example of the projector. Hereinafter, a projector using the liquid crystal device as a light valve will be described.

  As shown in FIG. 8, a projector 1100 includes a lamp unit 1102 made of a white light source such as a halogen lamp. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

  The configurations of the liquid crystal panels 1110R, 1110B, and 1110G are the same as those of the liquid crystal device described above, and are driven by R, G, and B primary color signals supplied from the image signal processing circuit. The light modulated by these liquid crystal panels enters the dichroic prism 1112 from three directions. In the dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Therefore, as a result of the synthesis of the images of the respective colors, a color image is projected onto the screen or the like via the projection lens 1114.

  Here, paying attention to the display images by the liquid crystal panels 1110R, 1110B, and 1110G, the display image by the liquid crystal panel 1110G needs to be horizontally reversed with respect to the display images by the liquid crystal panels 1110R and 1110B.

  In addition, since light corresponding to each primary color of R, G, and B is incident on the liquid crystal panels 1110R, 1110B, and 1110G by the dichroic mirror 1108, it is not necessary to provide a color filter.

  In addition to the electronic device described with reference to FIG. 8, a mobile personal computer, a mobile phone, a liquid crystal television, a viewfinder type, a monitor direct-view type video tape recorder, a car navigation device, a pager, an electronic device Examples include a notebook, a calculator, a word processor, a workstation, a videophone, a POS terminal, and a device equipped with a touch panel. Needless to say, the present invention can be applied to these various electronic devices.

  In addition to the liquid crystal devices described in the above embodiments, the present invention includes a reflective liquid crystal device (LCOS), a plasma display (PDP), a field emission display (FED, SED), an organic EL display, and a digital micromirror device. (DMD), electrophoresis apparatus and the like are also applicable.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and an electro-optical device with such a change, In addition, an electronic apparatus including the electro-optical device is also included in the technical scope of the present invention.

  1 1 area, 2 other area, 3 first notch, 4 second notch, 6 data line, 7 relay layer, 9 pixel electrode, 9a1 first edge, 9a2 second edge, 9a3 third edge Part, 10 TFT array substrate, 10a image display area, 11 scanning lines, 30 TFT, 50 liquid crystal

Claims (4)

A pair of substrates;
An electro-optic material sandwiched between the pair of substrates;
A first edge which is arranged for each pixel on one of the pair of substrates and is formed along a first direction in the plane of the one substrate when viewed in plan on the one substrate. And a second edge and a third edge formed along the second direction intersecting the first direction in the one substrate surface and arranged to correspond to both ends of the first edge. A pixel electrode having a portion,
The first direction and the second direction are directions in which the first edge portion is more likely to generate a domain region due to a lateral electric field along the one substrate than the second edge portion and the third edge portion. Is defined as
At least one of the second edge and the third edge has a distance between the second edge and the third edge in one region of the pixel electrode close to the first edge. An electro-optical device having a cutout portion formed so as to be smaller than those in other regions except the one region.   The electro-optical device according to claim 1, wherein the notch has a length along the second direction that is greater than a length along the first direction.   3. The electricity according to claim 1, wherein the notch includes a fourth edge portion extending along a third direction intersecting the first and second directions in the one region. Optical device.   An electronic apparatus comprising the electro-optical device according to claim 1.

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