JP2008185872A - Optical compensation plate, liquid crystal apparatus and electronic equipment equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical compensation plate which is excellent in light resistance and heat resistance and is suitable for miniaturization. <P>SOLUTION: The optical compensation plate (200) comprises a first crystal plate (201) and a second crystal plate (202) each of which has one surface arranged facing each other and contains a positive uniaxial crystal. A first optical axis (L1), which is an optical axis of the positive uniaxial crystal in the first crystal plate, obliquely leans toward one surface of the first crystal plate. A second optical axis (L2), which is the optical axis of the positive uniaxial crystal in the second crystal plate, intersects the first optical axis (L1) when seen from a normal line direction of one surface of the first crystal plate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical compensator used for a liquid crystal device such as a liquid crystal light valve, for example, and a liquid crystal device and an electronic apparatus including the same.

  This type of optical compensator is made of, for example, an organic film, has a refractive index that exhibits elliptical anisotropy, and the maximum refractive index direction of the elliptical refractive index is in a state of intersecting the plate surface. There is a laminate in which an inclined phase difference plate and a phase difference plate in which a difference in phase difference in a direction perpendicular to the plate surface is within 50% of the inclined phase difference plate are laminated (see Patent Document 1).

  When this type of optical compensator is used in, for example, a light valve of a liquid crystal projector that is an example of an electronic device, the optical compensator is exposed to extremely strong projection light. Heat resistance is important. For this reason, for example, Patent Document 2 describes a technique in which an optically anisotropic element composed of an inorganic dielectric multilayer film is disposed inclining according to the alignment direction of liquid crystal molecules. Patent Documents 3 and 4 describe a retardation plate composed of two quartz plates having different thicknesses. In Patent Document 5, a phase difference plate is formed by laminating a plurality of crystal phase difference plates in which two crystal plates having an optical axis in a plane are overlapped so that the optical axes of the crystal plates are orthogonal to each other. Is described.

Japanese Patent Laid-Open No. 7-181325 JP 2006-11298 A JP 2004-117447 A JP 2004-246286 A JP 2003-302523 A

  However, the optical compensator described in Patent Document 1 has poor light resistance and heat resistance, and is inappropriate as an optical compensator used for a liquid crystal projector. In addition, there is a technical problem that it is difficult to compensate for VA (Vertical Alignment) type liquid crystal in an optical compensator in which organic films are laminated.

  In addition, when the optically anisotropic element is inclined and arranged as in the technique described in Patent Document 2, it is necessary to secure a space for arranging the optically anisotropic element. For this reason, there is a technical problem that it is difficult to reduce the size of the optical engine and the degree of freedom in layout is hindered.

  In addition, since the optically anisotropic element is tilted according to the alignment direction of the liquid crystal molecules, the mechanism for tilting the optically anisotropic element may be complicated depending on the alignment direction, or may be added in the assembly process. There is a technical problem that adjustment may be necessary.

  In the phase difference plate using the difference in thickness of the crystal plate as described in Patent Documents 3 to 5, when the thickness of the phase difference plate is increased and used as an optical compensator, it is described in Patent Document 2. It must be placed tilted as in the technology. Also in this case, there is a technical problem that it is difficult to reduce the size of the optical engine and the degree of freedom in layout is hindered.

  The present invention has been made in view of the above-mentioned problems, for example, and provides an optical compensator excellent in light resistance and heat resistance and suitable for downsizing, and a liquid crystal device and a projector including the same. Is an issue.

  In order to solve the above problems, an optical compensator of the present invention includes first and second crystal plates that are disposed so that one surface thereof is opposed to each other and each includes a positive uniaxial crystal. The first optical axis, which is the optical axis of the positive uniaxial crystal in the first crystal plate, is inclined with respect to the one surface of the one crystal plate, and the one surface of the first crystal plate is inclined. As viewed from the normal direction, the second optical axis, which is the optical axis of the positive uniaxial crystal in the second crystal plate, intersects the first optical axis.

  According to the optical compensation plate of the present invention, for example, the first and second crystal plates including positive uniaxial crystals that are quartz are arranged so that one surfaces thereof are opposed to each other. Typically, the first and second crystal plates are bonded together with, for example, an adhesive resin. Here, “one surface” according to the present invention means one main surface in a flat crystal plate having two main surfaces. The first and second crystal plates may be integrally accommodated in the case, and the first and second crystal plates may have no birefringence, for example, isotropic glass or the like as a support substrate. May be arranged.

  The thicknesses of the first and second crystal plates are both tens of μm, and are calculated by, for example, a predetermined arithmetic expression based on the retardation (Δn · d) in the liquid crystal in the liquid crystal device including the optical compensation plate. Or it is calculated | required by simulation. The thicknesses of the first and second crystal plates are preferably the same. However, the difference between the thicknesses of the first and second crystal plates may be within a few μm in consideration of errors in the forming process such as polishing.

  The first optical axis that is the optical axis of the positive uniaxial crystal in the first crystal plate is inclined with respect to the one surface of the first crystal plate. On the other hand, the second optical axis, which is the optical axis of the positive uniaxial crystal in the second crystal plate, may be inclined obliquely or parallel to the one surface of the second crystal plate.

  When only the first optical axis is inclined with respect to one surface of the first crystal plate, the angle at which the first optical axis is inclined with respect to one surface of the first crystal plate includes the optical compensation plate. Specifically, the major axis direction of the assumed refractive index ellipsoid in the crystal plate and the liquid crystal are adjusted so as to be a predetermined angle (for example, 4 degrees to 5 degrees) that compensates for the birefringence caused by the liquid crystal in the liquid crystal device. Preferably, the pretilt axis direction (that is, the major axis direction of the liquid crystal molecules at the position in contact with the alignment film when the liquid crystal device is not driven) intersects with each other, preferably perpendicularly.

  When the optical axes of both the first and second optical axes are inclined with respect to one surface, the difference between the angles at which the first and second optical axes are inclined with respect to the one surface is predetermined. An angle at which each of the first and second optical axes is inclined with respect to one surface is set so as to be an angle.

  When viewed from the normal direction of one surface, the second optical axis intersects the first optical axis at an angle of, for example, 80 degrees or more and 90 degrees or less. The angle formed by the first optical axis and the second optical axis is set according to the alignment state of the liquid crystal in the liquid crystal device including the optical compensation plate. Desirably, the first and second optical axes are set to be orthogonal when viewed from the axial direction of the pretilt of the liquid crystal.

  According to the research of the present inventor, generally, birefringence caused by liquid crystal can be effectively compensated by a C plate inclined by a predetermined angle. On the other hand, in an optical compensator that generates an inclined C plate by laminating two organic films, the inclination of the C plate is 10 degrees or more, and the pretilt is small, for example, 4 degrees to 5 degrees. It has been found that it is not suitable for liquid crystal compensation.

  However, in the present invention, the first and second optical axes in the first and second crystal plates that are disposed so that one surface faces each other have a predetermined relationship. Accordingly, an inclined negative C plate can be generated, and the negative C plate generated by changing the difference in the angle at which each of the first and second optical axes is inclined with respect to one surface. You can change the slope of Therefore, it can be suitable for compensation of a VA type liquid crystal with a small pretilt.

  Further, it is not necessary to incline the optical compensation plate, and the thickness of the crystal plate is as thin as several tens of μm, so that it is possible to reduce the size of a liquid crystal device or the like including the optical compensation plate. In addition, when quartz is used as the positive uniaxial crystal, for example, it is cheaper than the case where the optical compensation plate is formed of sapphire or the like, and the processing of the crystal plate constituting the optical compensation plate is easy. . Therefore, cost can be reduced.

  Not only the VA type liquid crystal but also the TN (Twisted Nematic) type liquid crystal, the OCB (Optically Compensated Birefringence) type liquid crystal, etc. can be effectively obtained by appropriately setting the relationship between the first and second optical axes. Compensation can be performed.

  As a result, according to the optical compensator of the present invention, it is excellent in light resistance and heat resistance and can be suitable for downsizing.

  In one aspect of the optical compensation plate of the present invention, the second optical axis is inclined obliquely with respect to the one surface of the second crystal plate.

  According to this aspect, when the difference between the angles formed by the first and second optical axes with respect to one surface is set to, for example, 40 degrees to 60 degrees, only one of the first and second optical axes is Compared to the case where the crystal plate is formed so as to be inclined with respect to one surface, the crystal plate can be efficiently cut out from the crystal material, and the cost can be reduced.

  In another aspect of the optical compensation plate of the present invention, the second optical axis is parallel to the one surface of the second crystal plate.

  According to this aspect, it is possible to reduce, for example, shaving margin when forming the crystal plate, and it is possible to reduce the cost.

  In another aspect of the optical compensation plate of the present invention, an angle formed by the first optical axis with respect to the one surface of the first crystal plate, and the second optical axis on the one surface of the second crystal plate. The difference between the first optical axis and the second optical axis intersects the first optical axis and the second optical axis when viewed from the normal direction of the one surface of the first and second crystal plates. The angle formed is between 80 degrees and 90 degrees.

  According to this aspect, it is possible to effectively compensate for the birefringence caused by the VA liquid crystal.

  In another aspect of the optical compensation plate of the present invention, the one surface of the first or second crystal plate is a surface formed by polishing.

  According to this aspect, a crystal plate having a predetermined thickness can be formed relatively easily.

  For a crystal plate whose optical axis is inclined with respect to one surface, for example, the crystal is cut at a predetermined angle with respect to the optical axis of the crystal, and polished so as to have a predetermined thickness. May be formed. The surface opposite to the one surface is preferably polished so as to be parallel to the one surface, but the angle at which each of the first and second optical axes is inclined with respect to the one surface is small ( For example, it may not be polished.

  In another aspect of the optical compensation plate of the present invention, the first and second crystal plates are bonded together with an adhesive that transmits light.

  According to this aspect, it is possible to make the relationship between the first and second optical axes relatively easy to be a predetermined relationship, and it is possible to reduce the cost due to the failure to arrange the first and second crystal plates. Become.

  In another aspect of the optical compensation plate of the present invention, the optical compensation plate further includes a support substrate for fixing the first and second crystal plates in a state of being opposed to each other.

  According to this aspect, for example, since the first and second crystal plates are fixed on a support substrate such as a quartz substrate so as to face each other, the physical strength of the optical compensation plate can be improved, and the optical compensation can be performed. The board can be easily handled.

  In another aspect of the optical compensator of the present invention, the optical compensator further includes a fixing member that fixes the first and second crystal plates in an opposed state.

  According to this aspect, for example, the first and second crystal plates are fixed in a state of being opposed to each other by a screw or a U-shaped fixing member, so that the physical strength of the optical compensation plate can be improved, The optical compensator can be easily handled. In addition, you may accommodate in the case etc. in the state in which the 1st and 2nd crystal plate was laminated | stacked.

  In another aspect of the optical compensation plate of the present invention, the first and second crystal plates are opposed to each other through a medium that transmits light.

  According to this aspect, for example, the isotropic glass is used as a support substrate, and the first and second crystal plates are disposed or attached to both sides of the support substrate, so that the physical strength of the optical compensation plate is improved. And the optical compensator can be easily handled.

  The “medium” has a property of transmitting light and is optional as long as there is no birefringence, and it is desirable not to form an interface with the crystal plate. For example, air, isotropic glass, adhesive, Resin etc. may be sufficient.

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

  According to the electronic apparatus according to the present invention, since the optical compensator according to the present invention described above is provided, the optical characteristics such as light resistance and heat resistance are excellent. In addition, the thickness of the liquid crystal device included in the electronic device can be reduced, which is suitable for downsizing. As a result, a projection display device, a television, a mobile phone, an electronic notebook, a word processor, a viewfinder type or a monitor direct view type video tape recorder, a workstation, a video phone, Various electronic devices such as a POS terminal and a touch panel can be realized.

  In order to solve the above problems, a liquid crystal device of the present invention includes a liquid crystal panel having a liquid crystal layer, and an optical compensator arranged to face the liquid crystal panel, and the optical compensators have one surface each other. The first and second crystal plates are disposed opposite to each other and each include a positive uniaxial crystal, and the positive electrode in the first crystal plate is opposed to the one surface of the first crystal plate. The first optical axis that is the optical axis of the uniaxial crystal is inclined obliquely, and the positive uniaxial crystal in the second crystal plate is seen from the normal direction of the one surface of the first crystal plate. The second optical axis that is the optical axis of the crosses the first optical axis.

  According to the liquid crystal device according to the present invention, similarly to the optical compensator according to the present invention described above, it is excellent in optical characteristics such as light resistance and heat resistance and can be suitable for miniaturization.

  Note that the liquid crystal device of the present invention can also adopt various aspects similar to the various aspects of the optical compensation plate of the present invention described above.

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

  Hereinafter, embodiments of the liquid crystal device according to the present invention will be described with reference to FIGS.

(Liquid crystal device)
First, the liquid crystal device according to the present embodiment will be described with reference to FIGS. 1 and 2. The liquid crystal device according to the present embodiment is a liquid crystal device used for a light valve of a projection display device such as a liquid crystal projector. FIG. 1 is a plan view of a TFT (Thin Film Transistor) array substrate together with the components formed thereon, as viewed from the counter substrate side, and FIG. 2 is a cross-sectional view taken along the line HH ′ of FIG. It is. In each of the drawings referred to below, the scale of each layer and each member is different in order to make each layer and each member recognizable on the drawing.

  1 and 2, in the liquid crystal device 100 of the present embodiment, the TFT array substrate 10 and the counter substrate 20 are arranged to face each other. An optical compensation plate 200 is disposed on the opposite side of the TFT array substrate 10 from the side facing the counter substrate 20. The TFT array substrate 10 is made of a transparent substrate such as a quartz substrate, a glass substrate, or a silicon substrate, and the counter substrate 20 is made of a transparent substrate such as a quartz substrate or a glass substrate, 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 surrounded by an image display region 10a corresponding to a region where a plurality of pixels are provided. They are bonded to each other by a sealing material 52 provided in the sealing area located.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or an ultraviolet / heat combination type curable resin for bonding the two substrates, and is applied to the TFT array substrate 10 in the manufacturing process, and then irradiated with ultraviolet rays. And cured by heating or the like. In the sealing material 52, a gap material such as glass fiber or glass beads for dispersing the distance (ie, gap) between the TFT array substrate 10 and the counter substrate 20 to a predetermined value is dispersed. Note that the gap material may be arranged in the image display region 10a or a peripheral region located around the image display region 10a in addition to or instead of the material mixed in the seal material 52.

  In FIG. 1, a light-shielding frame light-shielding film 53 that defines the frame area of the image display region 10a is provided on the counter substrate 20 side in parallel with the inside of the seal region 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.

  A data line driving circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10 in a region located outside the sealing region in which the sealing material 52 is disposed in the peripheral region. The sampling circuit 7 is provided so as to be covered with the frame light shielding film 53 on the inner side of the seal region along the one side. The scanning line driving circuit 104 is provided so as to be covered with the frame light-shielding film 53 inside the seal region along two sides adjacent to the one side.

  On the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with the vertical conduction material 107 are arranged in regions facing the four corner portions of the counter substrate 20. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20. Further, a lead wiring 90 for electrically connecting the external circuit connection terminal 102 to the data line driving circuit 101, the scanning line driving circuit 104, the vertical conduction terminal 106, and the like is formed.

  In FIG. 2, on the TFT array substrate 10, a layered structure is formed in which pixel switching TFTs as drive elements, wiring lines such as scanning lines and data lines are formed. Although the detailed structure of this laminated structure is not shown in FIG. 2, pixel electrodes 9a made of a transparent material such as ITO are formed in an island shape in a predetermined pattern for each pixel on the laminated structure. Has been.

  The pixel electrode 9a is formed in the image display region 10a on the TFT array substrate 10 so as to face a counter electrode 21 described later. On the surface of the TFT array substrate 10 facing the liquid crystal layer 50, that is, on the pixel electrode 9a, an alignment film 16 is formed so as to cover the pixel electrode 9a.

  A light shielding film 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. For example, the light shielding film 23 is formed in a lattice shape when viewed in plan on the facing surface of the facing substrate 20. In the counter substrate 20, a non-opening area is defined by the light shielding film 23, and an area partitioned by the light shielding film 23 is an opening area through which light emitted from the backlight is transmitted. The light shielding film 23 may be formed in a stripe shape, and the non-opening region may be defined by the light shielding film 23 and various components such as data lines provided on the TFT array substrate 10 side.

  On the light shielding film 23, a counter electrode 21 made of a transparent material such as ITO is formed so as to face the plurality of pixel electrodes 9a. In order to perform color display in the image display region 10a on the light shielding film 23, a color filter (not shown in FIG. 2) may be formed in a region including a part of the opening region and the non-opening region. An alignment film 22 is formed on the counter electrode 21 on the counter surface of the counter substrate 20.

  The liquid crystal layer 50 includes liquid crystal molecules having negative dielectric anisotropy. Therefore, the liquid crystal device 100 is a liquid crystal device in which the alignment of liquid crystal molecules is controlled in the vertical alignment (VA) mode. The liquid crystal device according to the present invention is not limited to a liquid crystal device having liquid crystal molecules having a negative dielectric anisotropy, and includes, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed. It may be a liquid crystal device that takes a predetermined alignment state between the pair of alignment films 16 and 22.

  In addition to the data line driving circuit 101, the scanning line driving circuit 104, and the like, the image signal on the image signal line is sampled and supplied to the data line on the TFT array substrate 10 shown in FIGS. Sampling circuit 7, precharge circuit for supplying a precharge signal of a predetermined voltage level to a plurality of data lines in advance of an image signal, for inspecting quality, defects, etc. of the liquid crystal device during manufacture or at the time of shipment An inspection circuit or the like may be formed.

(Optical compensation plate)
Next, the optical compensator according to the present embodiment will be described with reference to FIGS. FIG. 3 is a perspective view of the optical compensation plate according to this embodiment.

  In FIG. 3, the optical compensation plate 200 includes crystal plates 201 and 202 that are arranged so that one surface faces each other. Here, the “crystal plates 201 and 202” according to the present embodiment are examples of the “first and second crystal plates” according to the present invention, respectively. The crystal plates 201 and 202 are arranged so that the slow axes 212 and 222 in the crystal plates 201 and 202 intersect at, for example, 80 degrees or more and 90 degrees or less. Typically, the crystal plates 201 and 202 are bonded to each other by an adhesive resin or the like.

  Here, the crystal plates 201 and 202 will be described with reference to FIG. FIG. 4 is a conceptual diagram showing a method for forming a crystal plate constituting the optical compensation plate according to this embodiment. In FIG. 4, for convenience of explanation, the angle θ is shown to be larger than the actual angle.

  In FIG. 4A, for example, a positive uniaxial crystal 2a, which is a crystal, is cut along a cutting line p along the optical axis L and polished so as to have a predetermined thickness. As shown, a crystal plate 201 is formed. As the polishing, for example, various polishing techniques such as CMP (Chemical Mechanical Polishing) by tilting the crystal plate can be applied.

  The optical axis L1 as an example of the “first optical axis” according to the present invention in the crystal plate 201 is parallel to the surface of the crystal plate 201 facing the crystal plate 202. Therefore, the assumed refractive index ellipsoid 211 in the crystal plate 201 is also parallel to the surface of the crystal plate 201 facing the crystal plate 202. The thickness d1 of the crystal plate 201 is, for example, 25 μm, and is set based on the retardation (Δn · d) in the liquid crystal layer 50 in the liquid crystal device including the optical compensation plate 200.

  In FIG. 4C, the positive uniaxial crystal 2b is cut along cutting lines q1 and q2 inclined by an angle θ with respect to the optical axis L, and polished so as to have a predetermined thickness. A crystal plate 201 as shown in FIG. The angle θ is, for example, 4 degrees to 5 degrees according to the alignment state of the liquid crystal layer 50 in the liquid crystal device including the optical compensation plate 200, specifically, depending on the pretilt that the alignment films 16 and 22 give to the liquid crystal molecules. Is set to

  The optical axis L2 as an example of the “second optical axis” according to the present invention in the crystal plate 202 is inclined by an angle θ with respect to the surface of the crystal plate 202 facing the crystal plate 201. Therefore, the assumed refractive index ellipsoid 221 in the crystal plate 202 is also inclined by the angle θ with respect to the surface of the crystal plate 202 facing the crystal plate 201. The thickness d2 of the crystal plate 202 is, for example, 25 μm, and is preferably the same as the thickness d1 of the crystal plate 201.

  Next, the relationship between the optical axes L1 and L2 will be described with reference to FIG. FIG. 5 is a conceptual diagram showing the relationship between the optical axes L1 and L2 according to this embodiment. FIG. 5A is a view of the optical axes L1 and L2 as viewed from the normal direction (ie, the z-axis direction in FIG. 3) of the surfaces of the crystal plates 201 and 202 facing each other. b) shows the difference between the angle formed by the optical axis L1 with respect to the surface of the crystal plate 201 facing the crystal plate 202 and the angle formed by the optical axis L2 with respect to the surface of the crystal plate 202 facing the crystal plate 201. FIG. In FIG. 5, for convenience of explanation, the angle θ is shown to be larger than the actual angle.

  In FIG. 5A, the optical axes L1 and L2 intersect with each other at an angle φ. The angle φ is, for example, not less than 80 degrees and not more than 90 degrees, and is set according to the alignment state of the liquid crystal layer 50 in the liquid crystal device including the optical compensation plate 200. The angle φ is desirably set so that the optical axes L1 and L2 are orthogonal to each other when viewed from the axial direction of the pretilt of the liquid crystal. In FIG. 5B, an angle formed by the optical axis L1 with respect to the surface of the crystal plate 201 facing the crystal plate 202, and an angle formed by the optical axis L2 with respect to the surface of the crystal plate 202 facing the crystal plate 201. Is the angle θ.

  Next, the phase difference of light generated by the optical compensation plate 200 configured as described above will be described with reference to FIG. 6A and 6B are a conceptual diagram illustrating a method for measuring the phase difference of light generated by the optical compensation plate 200 according to the present embodiment, and FIG. 6B is an example of a measurement result. Here, in the optical compensation plate 200 used for the measurement, the crystal plates 201 and 202 are made of crystal, and the thickness of each of the crystal plates 201 and 202 is 25 μm.

  As shown in FIG. 6A, when light is incident on the optical compensation plate 200 from a direction inclined by an angle α with respect to the z axis on the zx plane, and a phase difference generated in the light after transmission is measured. As shown by the solid line a in FIG. Further, when light is incident on the optical compensation plate 200 from a direction inclined by an angle β with respect to the z-axis on the yz plane and a phase difference generated in the light after transmission is measured, a broken line in FIG. It was like b.

  The relationship between the angle and the phase difference as shown in FIG. 6B is similar to the characteristics of the inclined negative C plate. Therefore, by laminating crystal plates 201 and 202 including positive uniaxial crystals so that one surface faces each other such that the relationship between the optical axes L1 and L2 becomes a predetermined relationship, C plate can be obtained.

  The optical compensation plate 200 is not limited to be disposed on the light emission side of the liquid crystal device 100, and may be disposed on the light incident side of the liquid crystal device 100. When the liquid crystal device 100 includes a plurality of optical compensation plates 200, the optical compensation plate 200 may not be disposed on each of the light incident side and the light emission side of the liquid crystal device 100. You may arrange | position only to one side among a light-incidence side and a light-projection side.

  Note that when the optical compensation plate 200 is mounted on a liquid crystal device or the like, the crystal plates 201 and 202 are not limited to being mounted on the liquid crystal device or the like by bonding the crystal plates 201 and 202 with an adhesive such as an adhesive resin. That is, as shown in FIG. 7 (a), a crystal plate 201 and 202 fixed to the support substrate 301 with the crystal plates 201 and 202 facing each other may be mounted, or as shown in FIG. 7 (b), the crystal plate You may mount what was fixed by the fixing member 302 in the state which opposes 201 and 202. FIG. Alternatively, as shown in FIG. 7C, the crystal plates 201 and 202 may be mounted on both sides of the frame 303, respectively. That is, the crystal plates 201 and 202 facing each other with the air layer 304 therebetween may be mounted. As a result, the physical strength of the optical compensation plate 200 can be improved, so that the optical compensation plate 200 can be easily handled.

  As a result, according to the liquid crystal device according to the present embodiment, since the optical compensation plate 200 having the crystal plates 201 and 202 arranged to face each other is provided, light resistance and heat resistance can be improved. . In addition, it is not necessary to incline the optical compensator 200, and the crystal plates 201 and 202 are thin, which can be suitable for downsizing. Furthermore, the time for arranging the optical compensation plate 200 can be shortened.

(Modification of optical compensator)
Next, a modification of the optical compensator according to the present embodiment will be described with reference to FIG. FIG. 8 is a conceptual diagram showing a method of forming a crystal plate constituting the optical compensator according to the present embodiment having the same purpose as FIG. In FIG. 8, for convenience of explanation, the angles ψ1 and ψ2 are shown to be larger than actual.

  8A, the positive uniaxial crystal 2c is cut along cutting lines r1 and r2 inclined by an angle ψ1 with respect to the optical axis L, and polished so as to have a predetermined thickness. A crystal plate 203 as shown in FIG.

  The optical axis L3 as an example of the “first optical axis” according to the present invention in the crystal plate 203 is inclined by an angle ψ1 with respect to the surface of the crystal plate 203 facing the crystal plate 204. Therefore, the assumed refractive index ellipsoid 231 in the crystal plate 203 is also inclined by the angle ψ 1 with respect to the surface of the crystal plate 203 facing the crystal plate 204. The thickness d3 of the crystal plate 203 is, for example, 25 μm, and is set based on the retardation (Δn · d) in the liquid crystal layer 50 in the liquid crystal device including the optical compensation plate 200.

  In FIG. 8C, the positive uniaxial crystal 2d is cut along cutting lines s1 and s2 that are inclined with respect to the optical axis L by an angle ψ2, and polished so as to have a predetermined thickness. A crystal plate 204 as shown in FIG.

  The optical axis L4 as an example of the “second optical axis” according to the present invention in the crystal plate 204 is inclined by an angle ψ2 with respect to the surface of the crystal plate 204 facing the crystal plate 203. Therefore, the assumed refractive index ellipsoid 241 in the crystal plate 204 is also inclined by the angle ψ2 with respect to the surface of the crystal plate 204 facing the crystal plate 203. The thickness d4 of the crystal plate 202 is, for example, 25 μm, and is preferably the same as the thickness d3 of the crystal plate 201.

  The difference between the angle ψ 1 and the angle ψ 2 is set according to the alignment state of the liquid crystal layer 50 in the liquid crystal device including the optical compensation plate 200.

(Electronics)
Next, a case where the above-described liquid crystal device is applied to a projector which is an example of an electronic device will be described with reference to FIG. The liquid crystal device described above is used as a light valve of a projector. FIG. 9 is a plan view showing a configuration example of the projector. As shown in FIG. 9, 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 have the same configuration as that of the above-described liquid crystal device, and are driven by R, G, and B primary color signals supplied from the image signal processing circuit, respectively. The light modulated by these liquid crystal panels enters the dichroic prism 1112 from three directions. In this dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Accordingly, 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 images by the liquid crystal panels 1110R and 1110B need to be horizontally reversed with respect to the display images by the liquid crystal panel 1110G.

  Since light corresponding to the primary colors 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. 9, a mobile personal computer, a mobile phone, 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 with touch panels, and the like. Needless to say, the present invention can be applied to these various electronic devices.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. The compensation plate, and the liquid crystal device and electronic apparatus including the same are also included in the technical scope of the present invention.

It is the top view which looked at the liquid crystal device concerning a 1st embodiment from the counter substrate side with each component. It is the HH 'sectional view taken on the line of FIG. It is a perspective view of the optical compensator concerning this embodiment. It is a conceptual diagram which shows the formation method of the crystal plate which comprises the optical compensation board which concerns on this embodiment. It is a conceptual diagram which shows the relationship of the optical axis which concerns on this embodiment. (A) The conceptual diagram which shows the measurement method of the phase difference of the light which arises with the optical compensator which concerns on this embodiment, (b) It is an example of a measurement result. It is sectional drawing which shows an example of the structure at the time of mounting the optical compensation board which concerns on this embodiment in a liquid crystal device etc. It is a conceptual diagram which shows the formation method of the crystal plate which comprises the modification of the optical compensation board which concerns on this embodiment. It is a top view which shows the structural example of a projector.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 7 ... Sampling circuit, 9a ... Pixel electrode, 10 ... TFT array substrate, 10a ... Image display area, 20 ... Counter substrate, 21 ... Counter electrode, 23 ... Light shielding film, 16, 22 ... Alignment film, 50 ... Liquid crystal layer, 52 DESCRIPTION OF SYMBOLS ... Sealing material 53 ... Frame light shielding film, 90 ... Lead wiring, 100 ... Liquid crystal device, 101 ... Data line drive circuit, 102 ... External circuit connection terminal, 104 ... Scanning line drive circuit, 106 ... Vertical conduction terminal, 107 ... Vertical conduction material, 200 ... optical compensation plate, 201, 202 ... crystal plate

Claims (11)

A first crystal plate and a second crystal plate, each of which is disposed so that one surface thereof is opposed to each other and each includes a positive uniaxial crystal;
A first optical axis that is an optical axis of the positive uniaxial crystal in the first crystal plate is inclined with respect to the one surface of the first crystal plate;
When viewed from the normal direction of the one surface of the first crystal plate, a second optical axis that is an optical axis of the positive uniaxial crystal in the second crystal plate intersects the first optical axis. An optical compensator characterized by comprising:   The optical compensator according to claim 1, wherein the second optical axis is inclined with respect to the one surface of the second crystal plate.   The optical compensation plate according to claim 1, wherein the second optical axis is parallel to the one surface of the second crystal plate. The difference between the angle formed by the first optical axis with respect to the one surface of the first crystal plate and the angle formed by the second optical axis with respect to the one surface of the second crystal plate is less than 10 degrees. And
The angle formed by the intersection of the first optical axis and the second optical axis when viewed from the normal direction of the one surface of the first and second crystal plates is not less than 80 degrees and not more than 90 degrees. The optical compensator according to claim 1, wherein the optical compensator is characterized in that   5. The optical compensation plate according to claim 1, wherein the one surface of the first or second crystal plate is a polished surface. 6.   6. The optical compensation plate according to claim 1, wherein the first and second crystal plates are bonded together with an adhesive that transmits light.   The optical compensation plate according to any one of claims 1 to 5, further comprising a support substrate that fixes the first and second crystal plates in a state of being opposed to each other.   The optical compensation plate according to claim 1, further comprising a fixing member that fixes the first and second crystal plates in a state of being opposed to each other.   The optical compensation plate according to any one of claims 1 to 8, wherein the first and second crystal plates are opposed to each other through a medium that transmits light.   An electronic apparatus comprising the optical compensation plate according to claim 1. A liquid crystal panel having a liquid crystal layer;
An optical compensator disposed to face the liquid crystal panel,
The optical compensator is
And having first and second crystal plates that are arranged so that one surface faces each other and each includes positive uniaxial crystals,
A first optical axis that is an optical axis of the positive uniaxial crystal in the first crystal plate is inclined with respect to the one surface of the first crystal plate;
When viewed from the normal direction of the one surface of the first crystal plate, a second optical axis that is an optical axis of the positive uniaxial crystal in the second crystal plate intersects the first optical axis. A liquid crystal device characterized by comprising:

Images