JP2009025541A - Projector and its optical compensation method, and liquid crystal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable display of high contrast in a projector. <P>SOLUTION: The projector includes a light source (12) emitting light, a liquid crystal panel (15c) where a liquid crystal is held between a pair of substrates and which modulates light, and a pair of polarizing plates (15b, 15d) disposed across the liquid crystal panel. An optical compensation element (15a) disposed between the pair of polarizing plates and having (i) a first plate like optical member (511) having one surface and the other surface opposed to the one surface and inclined to the one surface, (ii) a first optically anisotropic layer (513) formed on the other surface and having negative refractive index anisotropy and a first optical axis along the normal of the other surface as an optical axis and (iii) a second optically anisotropic layer (514) formed on the one surface and having positive or negative refractive index anisotropy and a second optical axis along the one surface as an optical axis is further provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technical field of a projector, an optical compensation method thereof, and a liquid crystal device.

  In recent years, liquid crystal projectors have been put into practical use as display devices that enable large screen display. In such a projector, a liquid crystal device that is driven in a “VA (Vertical Alignment) mode” in which a liquid crystal having a negative dielectric anisotropy is aligned perpendicularly to a substrate and is tilted by voltage application is provided as a light valve. Proposed. As a technique for improving the contrast of this type of liquid crystal projector, there has been proposed a technique in which a phase difference plate is inclined with respect to a liquid crystal light valve (see Patent Document 1).

JP 2006-11298 A

  However, according to the technique disclosed in Patent Document 1, the contrast is certainly improved as compared with the case where the retardation plate is not tilted. However, depending on the combination of the polarizing plate and the diffractive element provided in the liquid crystal projector, sufficient contrast may be obtained. There is a technical problem that it may not be obtained.

  First, in the polarizing plate, a TAC (triacetyl cellulose) film is used as a protective film. However, the protective film itself has a phase difference, and the retardation plate can compensate for the phase difference. Can not.

  In addition, when a diffractive element such as a microlens array is provided, the phase difference occurs in the light depending on the position where the light passes through the microlens, and the light is further diffused. Even if the angle is set, light that is not compensated is included, and the contrast is lowered.

  The present invention has been made in view of, for example, the above-described problems. For example, it is an object of the present invention to provide a projector capable of obtaining a high-contrast display, an optical compensation method thereof, and a liquid crystal device.

  In order to solve the above problems, a projector according to the present invention includes a light source that emits light, a liquid crystal sandwiched between a pair of substrates, and a liquid crystal panel that modulates the light, and the liquid crystal panel interposed therebetween. A first plate having a pair of polarizing plates, (i) one surface disposed between the pair of polarizing plates, and another surface facing the one surface and inclined with respect to the one surface An optical member; and (ii) a first optical anisotropy formed on the other surface and having a negative refractive index anisotropy and having a first optical axis along the normal line of the other surface as an optical axis. A layer, and (iii) a second optically anisotropic layer formed on the one surface and having a positive or negative refractive index anisotropy and having a second optical axis along the one surface as an optical axis. And an optical compensation element.

  According to the projector of the present invention, the light emitted from the light source is color-separated into red light, green light, and blue light by a color separation optical system such as a reflection mirror and a dichroic mirror. The liquid crystal panel is used as a light valve that modulates red light, green light, and blue light, for example. In the liquid crystal panel, for example, the alignment state of liquid crystal molecules of each pixel is regulated according to a data signal (or image signal), and an image corresponding to the data signal is displayed in the display area. An image displayed by each liquid crystal panel is synthesized by a color synthesis optical system such as a dichroic prism, and projected onto a projection surface such as a screen as a projection image via a projection lens.

  A liquid crystal panel has a liquid crystal sandwiched between a pair of substrates. The liquid crystal is typically a vertically aligned liquid crystal, that is, a VA liquid crystal. For example, an alignment film is provided on each of the pair of substrates, and the alignment film imparts a pretilt in which liquid crystal molecules constituting the liquid crystal rise in a predetermined direction by a predetermined angle. For example, when the liquid crystal is a VA liquid crystal, the liquid crystal molecules are aligned with a pretilt angle in a predetermined direction with respect to the normal of the substrate surface of the liquid crystal panel (that is, the substrate surfaces of the pair of substrates). The liquid crystal panel is disposed so as to be sandwiched between a pair of polarizing plates.

  In particular, the present invention includes an optical compensation element having a first plate-like optical member, a first optical anisotropic layer, and a second optical anisotropic layer.

  The optical compensation element is disposed between the pair of polarizing plates. More specifically, it is disposed between one polarizing plate and the liquid crystal panel of the pair of polarizing plates, or between the other polarizing plate and the liquid crystal panel of the pair of polarizing plates. In other words, it is provided between the pair of polarizing plates on the side where light is incident or the side where light is emitted in the liquid crystal panel.

  The first plate-like optical member is made of, for example, plate-like glass, and the other surface of the first plate-like optical member is formed so as to be inclined by a predetermined angle corresponding to the pretilt angle of the liquid crystal, for example. Typically, the first plate-like optical member is formed in a wedge shape having one surface that is not inclined and another surface that is formed to be inclined. Here, the “wedge shape” refers to a trapezoidal shape in a cross section cut perpendicularly to the one surface along a predetermined orientation on the one surface of the first plate-shaped optical member that is not inclined.

  The first optical anisotropic layer has negative refractive index anisotropy, and is made of, for example, a C plate. The first optical anisotropic layer is formed on the other surface of the first plate-like optical member, and the first optical axis which is the optical axis (that is, the optical axis) of the first optical anisotropic layer is the first optical axis. It is along the normal line of the other surface of 1 plate-shaped optical member. In other words, the first optical axis forms a predetermined angle corresponding to the normal of one surface of the first plate-like optical member and, for example, the pretilt angle of the liquid crystal.

  The second optical anisotropic layer has positive or negative refractive index anisotropy, and is made of, for example, an A plate or a biaxial plate. The second optically anisotropic layer is formed on one surface of the first plate-like optical member, and the second optical axis that is the optical axis of the second optically anisotropic layer is the same as that of the first plate-like optical member. Along one surface. In the state where the optical compensation element is disposed between the pair of polarizing plates, the second optical anisotropic layer is arranged so that the second optical axis is along the transmission axis of any one of the pair of polarizing plates. It is formed on one surface of the first plate-like optical member.

  The optical compensation element has, for example, a first optical axis along the major axis of liquid crystal molecules inclined by a pretilt angle, and one surface of the first plate-shaped optical member along the substrate surface of the liquid crystal panel. Be placed.

  Accordingly, during the operation of the projector, the phase difference of the light generated when the light emitted from the light source passes through a liquid crystal composed of liquid crystal molecules inclined by a pretilt angle, for example, a pair of polarizing plates, etc. Can be compensated for by the first and second optically anisotropic layers.

  That is, the first optical anisotropic layer and the liquid crystal are arranged by arranging the optical compensation element so that the first optical axis of the first optical anisotropic layer is along the long axis of the liquid crystal molecules inclined by the pretilt angle. The phase difference (in other words, birefringence effect) generated in the liquid crystal by the first optical anisotropic layer can be canceled (that is, compensated). Further, the optical compensation element is arranged so that the second optical axis of the second optically anisotropic layer is, for example, along the transmission axis of one of the pair of polarizing plates. A phase difference of light generated due to, for example, a pair of polarizing plates can be compensated by the anisotropic layer.

  By performing such compensation, it is possible to prevent the light that has passed through the liquid crystal panel from entering the output-side polarizing plate in a phase-shifted state. Therefore, for example, in the polarizing plate on the emission side, the possibility of leakage of light that should not be transmitted is reduced, and it is possible to prevent a decrease in contrast and a reduction in viewing angle.

  Further, particularly in the present invention, as described above, the first and second optically anisotropic layers are respectively formed on the other surface and one surface of the first plate-like optical member typically having a wedge shape. Thus, one optical compensation element is configured. Therefore, if the first and second optically anisotropic layers are formed on different (ie, separate) glass substrates, they are arranged in the projector as compared with the case where two optical compensation elements are configured. In other words, the first and second optical anisotropic layers can be easily arranged as one optical compensation element in the projector. it can.

  As described above, according to the projector of the present invention, the phase difference of light generated in the liquid crystal can be compensated by the first optical anisotropic layer included in the optical compensation element, and further, for example, due to the pair of polarizing plates. The phase difference of the light thus generated can be compensated by the second optical anisotropic layer included in the optical compensation element. Therefore, a high-contrast and high-quality display can be obtained.

  One aspect of the projector of the present invention further includes first optical adjustment means capable of rotating the optical compensation element about an axis centering on a normal line of the substrate surface of the liquid crystal panel.

  According to this aspect, the optical compensation element is rotated by the first optical adjustment means so that the phase difference of the light caused by the pair of polarizing plates is canceled by the second optical anisotropic layer of the optical compensation element. It is possible. Therefore, it is possible to more reliably prevent a decrease in contrast and a reduction in viewing angle.

  In another aspect of the projector of the present invention, each of the one surface and the other surface has a quadrilateral shape, and the other surface is viewed from the normal direction of the one surface, and It is formed so as to incline along a direction perpendicular to one side of one surface.

  According to this aspect, the other surface of the first plate-like optical member can be easily formed so as to be inclined with respect to the one surface. Therefore, the manufacturing cost can be reduced.

  In another aspect of the projector of the present invention, each of the one surface and the other surface has a quadrilateral shape, and the other surface is viewed from the normal direction of the one surface, and It forms so that it may incline along the direction which makes an acute angle with respect to one side of one surface.

  According to this aspect, the other surface of the first plate-shaped optical member is formed to be inclined along a direction that forms an angle of, for example, 45 degrees with respect to one side of the first plate-shaped optical member. Therefore, when the alignment direction of the liquid crystal panel (in other words, the direction in which the liquid crystal molecules are inclined by the pretilt angle) is a direction that forms an angle of, for example, 45 degrees with respect to one side of the liquid crystal panel, the first plate shape By arranging the optical member and the liquid crystal panel so that one side of one surface of the first plate-shaped optical member and one side of the liquid crystal panel are along each other, the first optical axis of the first optical anisotropic layer and the liquid crystal panel The clear viewing direction (that is, the direction along the major axis of the liquid crystal molecules tilted by the pretilt angle or the director direction, in other words, the pretilt direction) can be made almost or completely coincident with each other.

  In another aspect of the projector according to the aspect of the invention, the optical compensation element may further include a second plate-like optical member disposed so as to sandwich the first optical anisotropic layer with the first plate-like optical member. And the one surface of the second plate-shaped optical member facing the first optical anisotropic layer is inclined with respect to the other surface of the second plate-shaped optical member facing the one surface. Is formed.

  According to this aspect, the second plate-like optical member typically has the same shape as the first plate-like optical member. That is, the second plate-like optical member typically has a wedge shape. The first optical anisotropic layer is sandwiched between the first plate-like optical member and the second plate-like optical member. The first and second plate-like optical members are thinned in directions (that is, the direction in which the other surface of the first plate-like optical member is inclined and the direction in which one surface of the second plate-like optical member is inclined). Are arranged opposite to each other. In other words, in the first and second plate-like optical members, the one surface of the first plate-like optical member that is not inclined and the other surface of the second plate-like optical member that is not inclined are along each other (or substantially parallel to each other). Arranged).

  Therefore, it is possible to prevent the light emitted from the optical compensation element from being inclined with respect to the light incident on the optical compensation element. That is, the refraction of light caused by the first plate-like optical member and the refraction of light caused by the second plate-like optical member can cancel each other, and the light passes through the optical compensation element. The straightness of light in the can be improved.

  Further, since the light incident on the optical compensation element passes through the first plate-like optical member or the second plate-like optical member and then enters the first optical anisotropic layer, the first optical anisotropic layer Can be suppressed, in other words, the light resistance of the optical compensation element can be improved.

  In another aspect of the projector of the present invention, the projector further includes second optical adjustment means capable of tilting the optical compensation element with respect to the substrate surface of the liquid crystal panel.

  According to this aspect, the optical compensation element is tilted with respect to the substrate surface of the liquid crystal panel by the second optical adjustment means so that the first optical axis of the first optical compensation layer is surely matched with the clear viewing direction of the liquid crystal panel. Can be made. That is, the first optical axis can be finely adjusted so as to coincide with the clear viewing direction of the liquid crystal panel.

  In another aspect of the projector of the present invention, the first optical axis coincides with the clear viewing direction of the liquid crystal panel.

  According to this aspect, it is possible to satisfactorily compensate for the phase difference of light generated in the liquid crystal, and it is possible to more reliably prevent a decrease in contrast and a reduction in viewing angle. The term “coincidence” according to the present invention means that the first optical axis of the liquid crystal panel is in a range sufficient to compensate for the phase difference of light generated in the liquid crystal to the extent permitted by the product specifications. In other words, the first optical axis and the clear viewing direction of the liquid crystal panel are substantially different in addition to the case where the first optical axis and the clear viewing direction of the liquid crystal panel literally coincide with each other. It means to include the case where they match.

  In order to solve the above problems, an optical compensation method for a projector of the present invention includes a light source that emits light, a liquid crystal panel that sandwiches liquid crystal between a pair of substrates, and modulates the light, and sandwiches the liquid crystal panel. A pair of polarizing plates disposed; and (i) having one surface and another surface facing the one surface and inclined with respect to the one surface. A first plate-like optical member; and (ii) a first optical axis formed on the other surface, having negative refractive index anisotropy and having a first optical axis along the normal of the other surface as an optical axis. An optically anisotropic layer; and (iii) a second optical material formed on the one surface and having a positive or negative refractive index anisotropy and having a second optical axis along the one surface as an optical axis. An optical compensation method for a projector comprising an optical compensation element having an isotropic layer, wherein the light A tilt adjustment step of tilting the one surface of the compensation element with respect to the substrate surface of the liquid crystal panel; and a rotation adjustment step of rotating the optical compensation element about an axis in a normal direction of the substrate surface of the liquid crystal panel. .

  According to the projector optical compensation method of the present invention, the tilt adjustment step of tilting the optical compensation element causes the phase difference of the light generated in the liquid crystal (that is, the level of the light caused by the tilt of the liquid crystal molecules by the pretilt angle). (Phase difference) can be easily compensated. Furthermore, the rotation adjustment step of rotating the optical compensation element can easily compensate for the phase difference of light caused by, for example, a pair of polarizing plates. As a result, a high-contrast and high-quality display can be obtained.

  In order to solve the above problems, a liquid crystal device according to the present invention has a liquid crystal panel in which liquid crystal is sandwiched between a pair of substrates, a pair of polarizing plates disposed with the liquid crystal panel interposed therebetween, and a pair of polarizing plates. (I) a first plate-like optical member having one surface and another surface that is opposed to the one surface and is inclined with respect to the one surface; and (ii) the other surface A first optical anisotropic layer having a negative refractive index anisotropy and having a first optical axis along the normal of the other surface as an optical axis; and (iii) on the one surface And an optical compensation element having a second optical anisotropy layer having a positive or negative refractive index anisotropy and having a second optical axis along the one surface as an optical axis.

  According to the liquid crystal device of the present invention, the phase difference of the light generated in the liquid crystal can be compensated by the first optical anisotropic layer of the optical compensation element, and further, for example, the light generated due to the pair of polarizing plates The phase difference can be compensated by the second optical anisotropic layer included in the optical compensation element. Therefore, a high-contrast and high-quality display can be obtained.

  In another aspect of the liquid crystal device of the present invention, each of the one surface and the other surface has a quadrilateral shape, and the other surface is the first surface when viewed from the normal direction of the one surface. It is formed so as to incline along a direction perpendicular to one side of the surface.

  According to this aspect, the other surface of the first plate-like optical member can be easily formed so as to be inclined with respect to the one surface.

  In another aspect of the liquid crystal device of the present invention, each of the one surface and the other surface has a quadrilateral shape, and the other surface is viewed from the normal direction of the one surface. It forms so that it may incline along the direction which makes an acute angle with respect to one side of one surface.

  According to this aspect, for example, it is possible to prevent a decrease in contrast and a reduction in viewing angle without rotating the optical compensation element almost or not by the optical adjustment means.

  In another aspect of the liquid crystal device of the present invention, the optical compensation element includes a second plate-like optical member disposed so as to sandwich the first optical anisotropic layer with the first plate-like optical member. Further, the one surface of the second plate-shaped optical member facing the optically anisotropic layer is inclined with respect to the other surface of the second plate-shaped optical member facing the one surface. Is formed.

  According to this aspect, it is possible to prevent the light emitted from the optical compensation element from being inclined with respect to the light incident on the optical compensation element. Further, since the light incident on the optical compensation element passes through the first plate-like optical member or the second plate-like optical member and then enters the first optical anisotropic layer, the first optical anisotropic layer Can be prevented.

  In another aspect of the liquid crystal device of the present invention, the first optical axis coincides with the clear viewing direction of the liquid crystal panel.

  According to this aspect, it is possible to satisfactorily compensate for the phase difference of light generated in the liquid crystal, and it is possible to more reliably prevent a decrease in contrast and a reduction in viewing angle.

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

Embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
The projector according to this embodiment will be described with reference to FIGS.

  First, the overall configuration of the projector according to the present embodiment will be described with reference to FIG.

  FIG. 1 is a schematic configuration diagram of a projector according to the first embodiment. In the present embodiment, a three-plate projector provided with three liquid crystal light valves will be described. However, the number of liquid crystal light valves provided in the projector is not limited to three, and may be two or four or more. Good.

  In FIG. 1, a projector 10 is a front projection type projector that projects an image on a screen 11 provided in front. The projector 10 includes a light source 12, dichroic mirrors 13 and 14, liquid crystal light valves 15, 16 and 17 as examples of the “liquid crystal device” according to the invention, a projection optical system 18, a cross dichroic prism 19, and a relay. System 20.

  The light source 12 is composed of an ultrahigh pressure mercury lamp that supplies light including red light, green light, and blue light. The dichroic mirror 13 is configured to transmit the red light LR from the light source 12 and reflect the green light LG and the blue light LB. The dichroic mirror 14 is configured to transmit the blue light LB and reflect the green light LG among the green light LG and the blue light LB reflected by the dichroic mirror 13. As described above, the dichroic mirrors 13 and 14 constitute a color separation optical system that separates the light emitted from the light source 12 into the red light LR, the green light LG, and the blue light LB. Between the dichroic mirror 13 and the light source 12, an integrator 21 and a polarization conversion element 22 are sequentially arranged from the light source 12 side. The integrator 21 makes the illuminance distribution of the light emitted from the light source 12 uniform. The polarization conversion element 22 converts the light from the light source 12 into polarized light having a specific vibration direction such as s-polarized light.

  The liquid crystal light valve 15 is a transmissive liquid crystal device that modulates the red light LR transmitted through the dichroic mirror 13 and reflected by the reflection mirror 23 in accordance with an image signal. The liquid crystal light valve 15 includes a liquid crystal panel 15c, an optical compensation element 15a, and polarizing plates 15b and 15d.

  Here, the red light LR incident on the liquid crystal light valve 15 passes through the polarizing plate 15b and is converted into, for example, s-polarized light. The liquid crystal panel 15c converts the incident s-polarized light into p-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to the image signal. Furthermore, the polarizing plate 15d is a polarizing plate that blocks s-polarized light and transmits p-polarized light. Accordingly, the liquid crystal light valve 15 is configured to modulate the red light LR in accordance with the image signal and to emit the modulated red light LR toward the cross dichroic prism 19.

  The liquid crystal light valve 16 modulates the green light LG reflected by the dichroic mirror 14 after being reflected by the dichroic mirror 13 in accordance with the image signal, and emits the modulated green light LG toward the cross dichroic prism 19. This is a transmissive liquid crystal device. As with the liquid crystal light valve 15, the liquid crystal light valve 16 includes a liquid crystal panel 16c, an optical compensation element 16a, and polarizing plates 16b and 16d.

  The liquid crystal light valve 17 reflects the blue light LB reflected by the dichroic mirror 13, passes through the dichroic mirror 14 and then passes through the relay system 20 according to the image signal, and directs the modulated blue light LB to the cross dichroic prism 19. A transmissive liquid crystal device that emits light. Similarly to the liquid crystal light valves 15 and 16, the liquid crystal light valve 17 includes a liquid crystal panel 17c, an optical compensation element 17a, and polarizing plates 17b and 17d.

  The relay system 20 includes relay lenses 24a and 24b and reflection mirrors 25a and 25b. The relay lenses 24a and 24b are provided to prevent light loss due to the long optical path of the blue light LB. The relay lens 24a is disposed between the dichroic mirror 14 and the reflection mirror 25a. The relay lens 24b is disposed between the reflection mirrors 25a and 25b. The reflection mirror 25a is disposed so as to reflect the blue light LB transmitted through the dichroic mirror 14 and emitted from the relay lens 24a toward the relay lens 24b. The reflection mirror 25 b is disposed so as to reflect the blue light LB emitted from the relay lens 24 b toward the liquid crystal light valve 17.

  The cross dichroic prism 19 is a color synthesis optical system in which two dichroic films 19a and 19b are orthogonally arranged in an X shape. The dichroic film 19a reflects the blue light LB and transmits the green light LG. The dichroic film 19b reflects the red light LR and transmits the green light LG. Accordingly, the cross dichroic prism 19 is configured to combine the red light LR, the green light LG, and the blue light LB modulated by each of the liquid crystal light valves 15, 16, and 17 and emit the resultant light toward the projection optical system 18. Has been. The projection optical system 18 includes a projection lens (not shown), and is configured to project the light combined by the cross dichroic prism 19 onto the screen 11.

  The red and blue liquid crystal light valves 15 and 17 are provided with λ / 2 retardation plates, and light incident on the cross dichroic prism 19 from these liquid crystal light valves 15 and 17 is set as s-polarized light. As the configuration without the λ / 2 retardation plate, a configuration in which the light incident on the cross dichroic prism 19 from the liquid crystal light valve 16 is p-polarized light can be employed. By making the light incident on the cross dichroic prism 19 into different types of polarized light, an optimized color synthesis optical system can be configured in consideration of the reflection characteristics of the dichroic films 19a and 19b. In general, since the dichroic films 19a and 19b are excellent in the reflection characteristics of s-polarized light, as described above, the red light LR and the blue light LB reflected by the dichroic films 19a and 19b are s-polarized, and the dichroic films 19a and 19b are used. The transmitted green light LG may be p-polarized light.

  Next, the configuration of the liquid crystal panel included in the projector according to the present embodiment will be described with reference to FIG.

  2A is an overall configuration diagram of the liquid crystal panel, and FIG. 2B is a cross-sectional view taken along the line HH ′ of FIG. The liquid crystal light valves 15, 16 and 17 differ only in the wavelength range of light to be modulated, and the basic configuration is the same. Therefore, hereinafter, the liquid crystal panel 15c and the liquid crystal light valve 15 including the liquid crystal panel 15c will be described as an example.

  As shown in FIG. 2, the liquid crystal panel 15 c includes a counter substrate 31 and a TFT array substrate 32 that are arranged to face each other, and are bonded together via a seal material 33. A liquid crystal layer 34 is sealed in a region surrounded by the counter substrate 31, the TFT array substrate 32, and the sealing material 33. The liquid crystal layer 34 is made of a liquid crystal having negative dielectric anisotropy. The liquid crystal panel 15 c has a configuration in which liquid crystal molecules are vertically aligned with a predetermined inclination (pretilt angle) between the alignment films 43 and 98.

  The liquid crystal panel 15 c has a liquid crystal layer 34 sealed in a region partitioned by the TFT array substrate 32, the counter substrate 31 and the sealing material 33. In the liquid crystal panel 15c, a light shielding film 53 is formed inside the region where the sealing material 33 is formed so as to be part of the periphery. An inter-substrate conductive material 57 for providing electrical continuity between the TFT array substrate 32 and the counter substrate 31 is disposed at a corner on the outer peripheral side of the sealing material 33.

  A data line driving circuit 71, an external circuit mounting terminal 75, and two scanning line driving circuits 73 are formed in a region outside the formation region of the sealing material 33 in a plan view of the TFT array substrate 32. Further, a plurality of wirings 74 for connecting the scanning line driving circuits 73 provided on both sides of the image display region in which the plurality of pixel electrodes 42 are arranged are also formed in the region of the TFT array substrate 32. Yes. Instead of forming the data line driving circuit 71 and the scanning line driving circuit 73 on the TFT array substrate 32, for example, they are formed on the TAB (Tape Automated Bonding) substrate on which the driving LSI is mounted and the peripheral portion of the TFT array substrate 32. The terminal group may be electrically and mechanically connected via an anisotropic conductive film.

  As shown in FIG. 2B, the counter substrate 31 is a microlens substrate (condensing substrate) having a plurality of microlenses arranged in a plane. The counter substrate 31 is mainly composed of a substrate 92, a resin layer 93, and a cover glass 94.

  The substrate 92 and the cover glass 94 are transparent substrates made of glass or the like, and substrates made of quartz, borosilicate glass, soda lime glass (blue plate glass), crown glass (white plate glass), or the like can also be used. A plurality of recesses (microlenses) 95 are formed on the liquid crystal layer 34 side (the lower surface side in the drawing) of the substrate 92. The microlens 95 condenses the light incident on the substrate 92 from the side opposite to the liquid crystal layer 34 and emits it to the liquid crystal layer 34 side.

  The resin layer 93 is a layer made of a resin material filled on the microlens 95 of the substrate 92, and is formed using a resin material that can transmit light, such as an acrylic resin. The resin layer 93 is provided so as to cover one side of the substrate 92 and fill the concave interior of the microlens 95. The upper surface of the resin layer 93 is a flat surface, and a cover glass 94 is attached to the flat surface.

  A light shielding film 35, a common electrode 97, and an alignment film 98 are formed on the surface of the counter substrate 31 on the liquid crystal layer 34 side. The light shielding film 35 is formed on the cover glass 94 in a substantially lattice shape in plan view. The microlenses 95 are located between the light shielding films 35 and are respectively disposed in regions overlapping the pixel region of the liquid crystal panel 15c (region where the pixel electrode 42 is formed) in plan view. The alignment film 98 is a vertical alignment film that aligns liquid crystal molecules constituting the liquid crystal layer 34 substantially perpendicularly to the substrate surface. For example, a silicon oxide film formed with a columnar structure by oblique deposition, It consists of a polyimide film or the like that has been subjected to orientation treatment.

  The TFT array substrate 32 is mainly composed of a transparent substrate 41 made of glass or quartz, a pixel electrode 42 formed on the side surface of the liquid crystal layer 34 of the substrate 41, a TFT 44 for driving the pixel electrode, and an alignment film 43. Has been.

  As shown in FIG. 2A, the pixel electrode 42 is a conductive film having a substantially rectangular shape in plan view made of a transparent conductive material such as ITO, and is arranged on the substrate 41 in a matrix shape in plan view. It is formed in a region overlapping with the microlens 95.

  Although the TFT 44 is simplified in illustration, it is formed on the substrate 41 corresponding to each of the pixel electrodes 42, and is usually a region overlapping with the light shielding film 35 on the counter substrate 31 side in plan view (that is, non-display). Area or light shielding area).

  The alignment film 43 formed so as to cover the pixel electrode 42 is a vertical alignment film made of a silicon oxide film or the like formed by oblique deposition, like the previous alignment film 98.

  The alignment films 43 and 98 are formed such that the alignment directions of each other (the alignment direction of the columnar structures) are substantially parallel in plan view, and the liquid crystal molecules constituting the liquid crystal layer 34 are arranged in a predetermined manner with respect to the substrate surface. The liquid crystal molecules function so as to be aligned substantially vertically with an inclination and to make the inclination direction of the liquid crystal molecules uniform in the substrate surface direction.

  Note that a data line (not shown) and a scanning line (not shown) for connecting the pixel electrode 42 and the TFT 44 are formed in a region on the liquid crystal layer 34 side surface of the substrate 41 inside the region where the sealing material 33 is formed in plan view. ) Is formed. The data line and the scanning line are formed in a region overlapping the light shielding film 35 in plan view. A region bordered by the light shielding film 35, the TFT 44, the data line, and the scanning line is a pixel region of the liquid crystal panel 15c. A plurality of pixel areas are arranged in a matrix in plan view to form an image display area.

  Next, an optical compensation element provided in the projector according to the present embodiment will be described with reference to FIGS.

  FIG. 3 is an explanatory diagram showing the configuration of the liquid crystal light valve. FIG. 4 is a diagram showing the optical axis arrangement of each component of the liquid crystal light valve. FIG. 5 is a perspective view showing a specific configuration example of the projector according to the present embodiment. FIG. 6 is a perspective view showing the configuration of the optical compensation element according to this embodiment.

  As shown in FIG. 3, the liquid crystal light valve 15 includes the liquid crystal panel 15c described above with reference to FIG. 2, the polarizing plate 15b disposed outside the counter substrate 31 of the liquid crystal panel 15c, and the outside of the TFT array substrate 32. The optical compensation element 15a is disposed on the optical compensation element 15a, and the polarizing plate 15d is disposed outside the optical compensation element 15a.

  In the liquid crystal light valve 15 according to the present embodiment, the side where the polarizing plate 15b is disposed (the upper side in FIG. 3) is the light incident side, and the side where the polarizing plate 15d is disposed (the lower side in FIG. 3). ) Is the light exit side.

  In FIG. 3, the alignment films 43 and 98 facing each other with the liquid crystal layer 34 of the liquid crystal panel 15c interposed therebetween are formed, for example, by depositing silicon oxide from an oblique direction shifted by about 50 ° from the substrate normal direction. The film thickness is about 40 nm in all cases. The alignment directions 43a and 98a represented by the arrows attached to the alignment films 43 and 98 in FIG. 3 coincide with the direction in the substrate plane among the vapor deposition directions at the time of formation. The alignment direction 43a in the alignment film 43 and the alignment direction 98a in the alignment film 98 are parallel to each other.

  The liquid crystal molecules 51 constituting the liquid crystal layer 34 are aligned in a state inclined by about 2 ° to 10 ° from the substrate normal by the alignment regulating force of the alignment films 43 and 98, and the director (or long axis) of the liquid crystal molecules 51. Are aligned such that the direction (i.e., the pretilt direction P) is aligned with the alignment directions 43a and 98a when viewed from the normal direction of the substrate.

  Each of the polarizing plates 15b and 15d has a three-layer structure in which a polarizing element 151 made of dyed PVA (polyvinyl alcohol) is sandwiched between two protective films 152 made of TAC (triacetyl cellulose).

  As shown in FIGS. 4 and 5, the transmission axis 151b of the polarizing plate 15b and the transmission axis 151d of the polarizing plate 15d are arranged orthogonally. The directions of the transmission axes 151b and 151d are shifted by about 45 ° in plan view with respect to the alignment direction 43a of the alignment film 43 of the liquid crystal panel 15c.

  As shown in FIGS. 6A and 6B in addition to FIG. 3, the optical compensation element 15a includes a first plate-like optical member 511, a second plate-like optical member 512, and a first optically anisotropic material. The optical layer 513 and the second optical anisotropic layer 514 are provided.

  In FIG. 6A, the first plate-like optical member 511 is made of, for example, plate-like glass. The surface 511a of the first plate-like optical member 511 is inclined by an angle β with respect to the surface 511b of the first plate-like optical member 511 facing the surface 511a. The angle β is set according to the pretilt angle of the liquid crystal, for example, 2 ° to 10 °. That is, the first plate-like optical member 511 is formed in a wedge shape having a surface 511a formed so as to be inclined and a surface 511b not inclined. The cross section cut perpendicularly to the surface 511b along the azimuth 511c that forms an angle of about 90 ° with the side 511b1 of the non-inclined surface 511b of the first plate-like optical member 511 forms a trapezoid. In other words, the surface 511a is inclined along the azimuth 511c that forms an angle of about 90 ° with the side 511b1 of the non-inclined surface 511b.

  The side 511b1 is an example of “one side of one surface” according to the present invention.

  Similarly to the first plate-like optical member 511, the second plate-like optical member 512 is made of, for example, plate-like glass, and has the same shape as the first plate-like optical member 511. That is, the surface 512a of the second plate-like optical member 512 is inclined by an angle β with respect to the surface 512b of the second plate-like optical member 512 facing the surface 512a. That is, the second plate-like optical member 512 is formed in a wedge shape having a surface 512a formed so as to be inclined and a surface 512b not inclined. The cross section cut perpendicularly to the surface 512b along the direction forming an angle of about 90 ° with the side 512b1 of the non-inclined surface 512b of the second plate-like optical member 512 forms a trapezoid.

  The first plate-like optical member 511 and the second plate-like optical member 512 are formed so that the surface 511a of the first plate-like optical member 511 is inclined and the second plate-like optical member 512 is inclined. The surfaces 512a are arranged so as to be opposed to each other, and the thickness decreasing directions are opposite to each other.

  The first optical anisotropic layer 513 is composed of a negative uniaxial retardation plate (that is, a C plate) made of, for example, a film-like organic compound, and includes a first plate-like optical member 511 and a second plate-like optical member 512. It is sandwiched between. Therefore, the optical axis 513p of the first optical anisotropic layer 513 is along the normal direction 511an of the surface 511a of the first plate-like optical member 511. The first optical anisotropic layer 513 is attached to the surface 511a of the first plate-like optical member 511 and the surface 512a of the second plate-like optical member 512 by, for example, an adhesive. The first optically anisotropic layer 513 may be a C plate using a discotic liquid crystal, or an unstretched cellulose ester film (for example, unstretched triacetyl cellulose (TAC), unstretched cellulose). An optical film using an acetate propionate (CAP) or the like, a biaxially stretched norbornene resin, or the like may be used.

  In FIG. 3, an average refractive index ellipsoid 255a of the first optical anisotropic layer 513 is schematically shown on the side of the optical compensation element 15a. In this figure, nx and ny indicate the main refractive index in the surface direction of the first optical anisotropic layer 513 (that is, the direction along the surface 511a of the first plate-like optical member 511), and nz is the thickness. The main refractive index in the vertical direction (that is, the normal direction 511an of the surface 511a of the first plate-like optical member 511) is shown. In the present embodiment, the main refractive indexes nx, ny, and nz are configured to satisfy the relationship nx = ny> nz. That is, the refractive index nz in the thickness direction is smaller than the refractive index in the other direction, and the refractive index ellipsoid has a disk shape. The refractive index ellipsoid is oriented in parallel to the main surface of the first optical anisotropic layer 513 (that is, the surface along the surface 511a of the first plate-like optical member 511), and the first optically anisotropic layer is formed. The optical axis 513p (the minor axis direction of the refractive index ellipsoid) of the isotropic layer 513 is parallel to the normal direction of the main surface (that is, the normal direction 511an of the surface 511a of the first plate-like optical member 511). Yes.

  In FIG. 6A, the second optical anisotropic layer 514 is composed of, for example, a positive uniaxial retardation plate (that is, an A plate) made of a film-like organic compound. It is formed on the surface 511b. The optical axis 514d of the second optical anisotropic layer 514 is along the surface 511b of the first plate-like optical member 511, and further along the direction that forms an angle γ with the side 511b1.

  As shown in FIG. 5, the angle γ is set as an angle along which the optical axis 514d of the second optical anisotropic layer 514 is along the transmission axis 151b of the polarizing plate 15b in a state where the optical compensation element 15a is disposed in the projector. In this embodiment, it is about 45 °.

  Note that the angle γ is set as an angle where the optical axis 514d of the second optical anisotropic layer 514 is along the transmission axis 151d of the second polarizing plate 15d in a state where the optical compensation element 15a is disposed in the projector. Also good. In this case, the angle γ is about 135 °.

  The second optical anisotropic layer 514 is not limited to the A plate, and may be a biaxial plate.

  The A plate is an optical film in which the main refractive indexes nx, ny and nz satisfy the relationship of nx> ny = nz, and is produced using a rod-like liquid crystalline compound, a uniaxially stretched polymer (for example, polycarbonate) or the like. can do. The biaxial plate is an optical film in which the main refractive indices nx, ny and nz satisfy the relationship of nx> ny> nz, and stretched cellulose ester (for example, stretched cellulose acetate propionate (stretched CAP), triacetylcellulose ( For example, stretched TAC).

  As shown in FIG. 5, the optical compensation element 15a has an orientation 511c in which the surface 511a is inclined along the orientation direction 43a, and the optical axis 514d of the second optical anisotropic layer 514 is the transmission axis of the polarizing plate 15b. It is arrange | positioned along 151b. In the present embodiment, the alignment direction 43a of the liquid crystal panel 15c is a direction that forms an angle of 45 ° with respect to the horizontal direction in the projector (that is, one direction on the bottom surface of the projector). Therefore, the optical compensation element 15a has one side (more specifically, the side adjacent to the side 511b1 on the surface 511b described above with reference to FIG. 6) at an angle of 45 ° with respect to the horizontal direction of the projector. Are arranged as follows.

  4 and 5, the optical compensation element 15 a is configured to be rotatable around each of the rotation shafts 81 a and 82 a by the optical adjustment unit 80. The optical adjustment unit 80 is an example of the “first optical adjustment unit” and the “second optical adjustment unit” according to the present invention.

  The rotation axis 81a is an axis along a direction orthogonal to the alignment direction 43a (98a) in the liquid crystal panel 15c when viewed from the normal direction of the substrate surface of the liquid crystal panel 15c. The optical adjustment unit 80 rotates the optical compensation element 15a around the rotation axis 81a, so that the first optical anisotropic layer 513 (see FIG. 4 or 6) is inclined with respect to the substrate surface of the liquid crystal panel 15c. The tilt angle can be adjusted. More specifically, the optical adjustment unit 80 rotates the optical compensation element 15a about the rotation axis 81a by an angle θ1, thereby causing the first optical anisotropic layer 513 to have an angle with respect to the substrate surface of the liquid crystal panel 15c. It can be inclined by an angle (β + θ1) which is the sum of β and angle θ1.

  The rotation axis 82a is an axis along the normal direction of the liquid crystal panel 15c (in other words, the normal direction of the surface 511b of the first plate-like optical member 511). The optical adjustment unit 80 rotates the optical compensation element 15a about the rotation axis 82a by an angle θ2, thereby changing the angle between the optical axis 514d of the second optical anisotropic layer 514 and the transmission axis 151b of the polarizing plate 15b. It is possible to change or adjust only θ2.

  Next, the operation and effect of the projector according to the present embodiment will be described with reference to FIGS.

  In FIG. 3, the liquid crystal layer 34 sealed in the liquid crystal panel 15c exhibits optically positive uniaxiality, and the refractive index in the director direction of the liquid crystal molecules 51 is larger than the refractive index in the other direction. That is, the liquid crystal layer 34 has a rugby ball type refractive index ellipsoid as shown in FIG. 3 showing an average refractive index ellipsoid 250a. Here, the liquid crystal molecules 51 of the liquid crystal layer 34 are obliquely aligned along the pretilt direction P, cause a residual phase difference during black display, and differ in the elliptical shape when observed from the oblique direction. With a dependent phase difference. This phase difference causes light leakage in black display, and reduces the contrast ratio of the liquid crystal panel.

  However, in FIGS. 3 to 6, according to the projector according to the present embodiment, the optical compensation element 15 a is provided, so that the light emitted from the light source 12 during the operation of the projector causes the liquid crystal light valve 15 to emit light. A liquid crystal layer 34 composed of liquid crystal molecules 51 and polarizing plates 15b and 15d, which are oriented obliquely along the pretilt direction P (that is, inclined by a pretilt angle with respect to the normal direction of the substrate surface of the liquid crystal panel 15c), micro The phase difference of light generated by passing through the lens 95 or the like can be compensated by the first optical anisotropic layer 513 and the second optical anisotropic layer 514 included in the optical compensation element 15a.

  More specifically, in FIG. 3, the first optical anisotropic layer 513 included in the optical compensation element 15 a exhibits optically negative uniaxiality, and thus the optical axis of the first optical anisotropic layer 513. If 513p (that is, the optical axis in the z direction of the disk-shaped refractive index ellipsoid 255a) is arranged in parallel with the optical axis 251a of the refractive index ellipsoid 250a in the liquid crystal layer 34, the optical positive / negative is reversed. The birefringence effect in the liquid crystal panel 15c can be canceled out.

  Therefore, in the present embodiment, as described above with reference to FIG. 6, the first optical anisotropic layer 513 is formed on the inclined surface 511a of the first plate-like optical member 511 formed in a wedge shape, The first optical anisotropic layer 513 is parallel to the substrate surface of the liquid crystal panel 15c so that the optical axis 513p of the first optical anisotropic layer 513 substantially coincides with the pretilt direction P of the liquid crystal molecules 51 constituting the liquid crystal layer 34. It is arranged so as to be inclined at an angle β from the correct position. Thereby, the phase difference generated in the liquid crystal panel 15c can be compensated three-dimensionally. That is, the optical compensation element 15a is arranged so that the optical axis 513p of the first optical anisotropic layer 513 is along the pretilt direction P of the liquid crystal molecules 51 inclined by the pretilt angle, whereby the first optical anisotropy is obtained. The optical positive and negative of the layer 513 and the liquid crystal layer 34 are opposite to each other, and the phase difference generated in the liquid crystal by the first optical anisotropic layer 513 can be canceled.

  Further, the optical compensation element 15a is arranged so that the optical axis 514d of the second optical anisotropic layer 514 is along the transmission axis 151b of the polarizing plate 15b, so that the second optical anisotropic layer 514 causes the polarizing plate to be polarized. The phase difference of light generated due to 15b and 15d and the phase difference of light due to the influence of diffraction of the microlens 95 can be compensated.

  In addition, in FIG. 4 and FIG. 5, the optical adjustment unit 80 is particularly provided in the present embodiment. Therefore, the optical adjustment unit 80 rotates the optical compensation element 15 a around the rotation axis 82 a, thereby polarizing plate. The phase difference caused by 15b and 15d and the phase difference caused by the diffraction effect of the microlens 95 can be more reliably compensated. In particular, since the protective film 152 of the polarizing plate has an optical axis that varies in the plane, luminance unevenness may occur in the image display region due to the influence of the protective film 152, but only the contrast is caused by the second optical anisotropic layer 154. In addition, the luminance unevenness as described above can be suppressed.

  Note that the optical compensation element 15a may be tilted by rotating the optical compensation element 15a around the rotation shaft 81a by the optical adjustment unit 80. In this case, the alignment direction 43a in the liquid crystal panel 15c and the optical axis 513p of the first optical anisotropic layer 513 are held parallel to each other when viewed from the normal direction of the substrate of the liquid crystal panel 15c. Adjustment can be made so that 513p and the pretilt direction P coincide with each other, and an optimum display can be obtained very easily.

  In addition, particularly in the present embodiment, as described above with reference to FIG. 6, the first optical anisotropic layer 513 and the second optical anisotropic layer 514 have a wedge-shaped first plate-like optical member. One optical compensation element 15a is formed by being formed on the surfaces 511a and 511b of 511, respectively. Therefore, as compared with the case where the first optical anisotropic layer 513 and the second optical anisotropic layer 514 are formed on different (separate) glass substrates, respectively, as two optical compensation elements, the projector is compared. Less space is required for placement in the space (that is, space can be saved). Accordingly, the first optical anisotropic layer 513 and the second optical anisotropic layer 514 can be easily arranged as one optical compensation element 15a in the projector.

  By performing the above-described compensation by the optical compensation element 15a, it is possible to prevent the light having passed through the liquid crystal panel 15c from entering the output-side polarizing plate 15d in a state of being out of phase. Therefore, the possibility of leakage of light that should not be transmitted through the polarizing plate 15d on the emission side is reduced, and it is possible to prevent a decrease in contrast and a reduction in viewing angle.

  In FIG. 6, particularly in the present embodiment, the optical compensation element 15 a is disposed so as to sandwich the first optical anisotropic layer 513 between the first plate-like optical member 511 and the first plate-like optical member. Similar to 511, a second plate-like optical member 512 having a wedge shape is provided. Therefore, the light emitted from the optical compensation element 15a can be prevented from being inclined with respect to the light incident on the optical compensation element 15a. That is, the refraction of light caused by the first plate-like optical member 511 and the refraction of light caused by the second plate-like optical member 512 can cancel each other, and the light causes the optical compensation element 15a to cancel. It is possible to improve the straightness of light when passing through.

  Furthermore, since the light incident on the optical compensation element 15a passes through the second plate-like optical member 512 and then enters the first optical anisotropic layer 513, the first optical anisotropic layer 513 is deteriorated. In other words, the light resistance of the optical compensation element 15a can be improved. In the present embodiment, the light incident on the optical compensation element 15a passes through the second plate-like optical member 512 and the first plate-like optical member 511 and then enters the second optical anisotropic layer 514. Therefore, the deterioration of the second optical anisotropic layer 514 can be suppressed.

  The optical adjustment of the liquid crystal light valve 15 in the projector according to the present embodiment is performed by rotating the optical compensation element 15a about the rotation axis 81a by the optical adjustment unit 80, so that the first optical compensation layer with respect to the substrate surface of the liquid crystal panel 15c. This can be implemented by an inclination adjustment step for adjusting the inclination angle at which 513 is inclined, and a rotation adjustment step for rotating the optical compensation element 15a around the rotation axis 82a by the optical adjustment unit 80.

  4 and 5, in the tilt adjustment step, the tilt angle at which the first optical compensation layer 513 tilts is adjusted by rotating the optical compensation element 15a by an angle θ1 about an axis centering on the rotation shaft 81a. The optical axis 513p of the first optical anisotropic layer 513 and the pretilt direction P of the liquid crystal layer 34 are substantially matched. In addition, the magnitude | size of the inclination angle which the 1st optical compensation layer 513 inclines is the angle ((beta) + (theta) 1) mentioned above. As a result, the first optical anisotropy is located at a position where the phase difference of the liquid crystal layer 34 composed of the liquid crystal molecules 51 aligned with the pretilt angle with respect to the normal of the substrate surface of the liquid crystal panel 15c can be compensated three-dimensionally. The conductive layer 513 can be arranged more reliably.

  In the rotation adjustment step, the optical compensation element 15a is rotated by an angle θ2 about an axis centering on the rotation axis 82a to adjust the orientation of the optical axis 514d of the second optical compensation layer 514, whereby the polarizing plates 15b and 15d are adjusted. The optical compensation element 15a is arranged at a position where the phase difference of the light caused and the phase difference of the light caused by the influence of the diffraction of the microlens 95 can be compensated. That is, by changing the angle θ2, the positional relationship between the optical axis 514d of the second optical anisotropic layer 514 and the optical axes of the polarizing plates 15b and 15d and the liquid crystal panel 15c is changed, and the second optical anisotropic layer is changed. The position of 514 can be optimized.

  The rotation adjustment step described above is preferably performed while actually measuring the contrast (or the luminance of black display). In general, the optical axis in the plane direction of the protective film 152 of the polarizing plate is not set in a fixed direction, and the optical axis may vary within the plane even with the same polarizing plate. Therefore, it is difficult to set the angle θ2 for rotating the optical compensation element 15a about the rotation axis 82a to a constant angle, and the optical compensation element 15a has a position where the maximum contrast is actually obtained or a position where the black level is lowest. The optimal position may be set.

  Next, the function and effect of the present invention will be described in more detail with reference to FIG.

  FIG. 7 is a graph for explaining the effects of the present invention.

  The graph of FIG. 7 is a graph showing the change in contrast of the liquid crystal light valve with respect to the tilt angle of the first optical anisotropic layer 513. The tilt angle of the first optical anisotropic layer 513 is an angle at which the first optical anisotropy 513 is tilted with respect to the substrate surface of the liquid crystal panel 15c. In the present embodiment, as described above, the angle is (Β + θ1).

  In FIG. 7, as shown in data D1, when the pretilt angle of the liquid crystal molecules 51 (see FIG. 3) is within the range of 2 ° to 5 ° (that is, when the pretilt angle is small), the first optical difference is detected. If the inclination angle of the isotropic layer 513 is 6 °, the maximum contrast can be obtained. However, as shown in the data D2, when the pretilt angle of the liquid crystal molecules 51 is in the range of 6 ° to 9 ° (that is, when the pretilt angle is large), the tilt angle of the first optical anisotropic layer 513 is set. If the angle is not 10 °, the maximum contrast cannot be obtained. Therefore, if the first optical anisotropic layer 513 is simply formed as a flat phase plate, a sufficient space for tilting the first optical anisotropic layer 513 is not secured in the projector. The tilt angle of the first optical anisotropic layer 513 cannot be set to 10 °, and there is a possibility that the maximum contrast cannot be obtained.

  However, according to the optical compensation element 15a according to the present embodiment, as described above, the first optical anisotropic layer 513 in the optical compensation element 15a has an angle β with respect to the surface 511b (or the surface 512b) of the optical compensation element 15a. Therefore, the maximum contrast can be obtained even if the angle θ1 at which the optical compensation element 15a is tilted is small. That is, according to the optical compensation element 15a in which the angle β is set to 6 °, for example, when the pretilt angle as shown in the data D1 is in the range of 2 ° to 5 °, the angle θ1 is set to 0 °. The maximum contrast can be obtained, and when the pretilt angle as shown in the data D2 is in the range of 6 ° to 9 °, the maximum contrast can be obtained by setting the angle θ1 to 4 °. it can. In other words, the angle θ1 for obtaining the maximum contrast can be reduced by the angle β. That is, according to the optical compensation element 15a according to the present embodiment, the angle θ1 at which the optical compensation element 15a is inclined is compared with the case where the first optical anisotropic layer 513 is simply formed as a flat phase plate. The contrast can be increased while reducing or eliminating the size. Therefore, there is little or no space for tilting the optical compensation element 15a in the projector. For this reason, the projector can be miniaturized.

  Furthermore, since the angle θ1 for inclining the optical compensation element 15a with respect to the substrate surface of the liquid crystal panel 15c can be reduced, the heat dissipation of the liquid crystal panel 15c can be enhanced. That is, the cooling air flow for cooling the liquid crystal panel 15c disposed in the housing of the projector 10 (see FIG. 1) is disposed such that the optical compensation element 15a is inclined with respect to the substrate surface of the liquid crystal panel 15c. Can be reduced or prevented.

  In addition, it is possible to increase the pretilt angle, which is the angle that the liquid crystal molecules 51 make with the normal direction of the substrate surface of the liquid crystal panel 15c. Therefore, the response speed of the liquid crystal molecules 51 can be improved and the reverse tilt domain can be reduced.

In the present embodiment, the case where the optical compensation element 15a is arranged on the light emission side of the liquid crystal panel 15c has been described as the configuration of the liquid crystal light valve 15. May be arranged. In the present embodiment, the case where the second optical anisotropic layer 514 is disposed on the light emission side with respect to the first optical anisotropic layer 513 has been described. The first optical anisotropic layer 513 may be disposed on the light incident side.
Second Embodiment
Next, a projector according to a second embodiment will be described with reference to FIGS.

  First, the configuration of the optical compensation element provided in the projector according to the present embodiment will be described with reference to FIG.

  FIG. 8 is a perspective view showing the configuration of the optical compensation element according to the second embodiment, and FIG. 8A is an exploded perspective view of the optical compensation element according to the second embodiment, and FIG. These are the perspective views which show the whole optical compensation element concerning 2nd Embodiment. In FIG. 8, for convenience of explanation, the angle β is shown to be larger than the actual angle. In FIG. 8, the same components as those of the first embodiment shown in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The projector according to the present embodiment is different from the projector according to the first embodiment described above in that it includes an optical compensation element 15a2 instead of the optical compensation element 15a according to the first embodiment described above. The projector is configured in substantially the same manner as the projector according to the first embodiment described above.

  As shown in FIGS. 8A and 8B, the optically anisotropic element 15a2 includes a first plate-like optical member 521, a second plate-like optical member 522, and a first optically anisotropic layer 523. And a second optically anisotropic layer 524.

  The first plate-like optical member 521 is made of, for example, plate-like glass, and the surface 521a of the first plate-like optical member 521 has an angle with respect to the surface 521b of the first plate-like optical member 521 facing the surface 521a. It is inclined by β. That is, the first plate-like optical member 521 is formed in a wedge shape having a surface 521a formed so as to be inclined and a surface 521b not inclined.

  In the present embodiment, in particular, the cross section cut perpendicularly to the surface 521b along the azimuth 521c that forms an angle of about 45 ° with the side 521b1 of the non-inclined surface 521b of the first plate-like optical member 521 forms a trapezoid. In other words, the surface 521a is inclined along an azimuth 521c that forms an angle of about 45 ° with the side 521b1 of the non-inclined surface 521b.

  The side 521b1 is an example of “one side of one surface” according to the present invention.

  The second plate-like optical member 522 is made of, for example, plate-like glass, and has the same shape as the first plate-like optical member 521. That is, the surface 522a of the second plate-like optical member 522 is inclined by an angle β with respect to the surface 522b of the second plate-like optical member 522 facing the surface 522a. A cross section cut perpendicularly to the surface 522b along the direction of about 45 degrees with the side 522b1 of the non-inclined surface 522b of the second plate-shaped optical member 522 forms a trapezoid.

  The first plate-like optical member 521 and the second plate-like optical member 522 are formed so that the surface 521a of the first plate-like optical member 521 is inclined and the second plate-like optical member 522 is inclined. The surfaces 522a are opposed to each other, and the thickness decreasing directions are opposite to each other.

  The first optical anisotropic layer 523 is made of, for example, a negative uniaxial retardation plate (that is, a C plate) made of a film-like organic compound, and the first plate-like optical member 521 and the second plate-like optical member 522. It is sandwiched between. Therefore, the optical axis 523p of the optical anisotropic layer 523 is along the normal direction 521an of the surface 521a of the first plate-like optical member 521.

  The second optical anisotropic layer 524 is made of, for example, a positive uniaxial retardation plate (that is, an A plate) made of a film-like organic compound, and is formed on the surface 521b of the first plate-like optical member 521. . The optical axis 524d of the second optically anisotropic layer 524 is along the surface 511b of the first plate-like optical member 511, and is further in a direction perpendicular to the side 521b1 (that is, about 90 ° with respect to the side 521b1). Along the direction of the angle).

  As shown in FIG. 9, in the optical compensation element 15a2, the azimuth 521c where the surface 521a is inclined is along the alignment direction 43a, and the optical axis 524d of the second optical anisotropic layer 524 is the transmission axis of the polarizing plate 15b. It is arrange | positioned along 151b. With this arrangement, the optical axis 523p of the first optical anisotropic layer 523 and the clear viewing direction of the liquid crystal panel 15c can be substantially matched. Therefore, the phase difference generated in the liquid crystal panel 15c can be compensated three-dimensionally by the first optical anisotropic layer 523. Further, the second optically anisotropic layer 524 compensates for the phase difference of the light generated due to the polarizing plates 15b and 15d and the light phase difference due to the diffraction effect of the microlens 95. can do.

  In the present embodiment, the alignment direction 43a of the liquid crystal panel 15c is a direction that forms an angle of about 45 ° with respect to the horizontal direction in the projector.

  Particularly in this embodiment, as described above with reference to FIG. 8, the azimuth 521c, which is the azimuth in which the surface 521a of the first plate-like optical member 521 of the optical compensation element 15a2 is inclined, is an angle of about 45 ° with the side 521b1. I am doing. Therefore, by arranging the optical compensation element 15a2 so that the side 521b1 is along the horizontal direction in the projector, the azimuth 521c where the surface 521a is inclined is along the alignment direction 43a as described above, and the second optical The optical axis 524d of the anisotropic layer 524 can be arranged along the transmission axis 151b of the polarizing plate 15b. In other words, the azimuth 521c, which is the azimuth in which the surface 521a of the first plate-like optical member 521 of the optical compensation element 15a2 is inclined, forms an angle of about 45 ° with the side 521b1, and thus is described above with reference to FIG. The optical compensation element 15a in the first embodiment is arranged so that one side thereof forms an angle of about 45 ° with respect to the horizontal direction in the projector, and the optical compensation element 15a2 has one side in the horizontal direction in the projector. It can arrange | position along a direction. For this reason, the optical compensation element 15a2 can be easily and stably arranged in the projector. Alternatively, even if a mechanism for rotating the optical compensation element 15a2 is not provided, the optical compensation element 15a can be positioned in the projector simply by dropping the optical compensation element 15a into the projector.

  As described above, according to the projector according to the second embodiment, the phase difference of light generated in the liquid crystal can be compensated by the first optical anisotropic layer 523 included in the optical compensation element 15a2, and further, the polarizing plate The phase difference of light caused by 15b and 15d can be compensated by the second optical anisotropic layer 524 included in the optical compensation element 15a2. Therefore, a high-contrast and high-quality display can be obtained. Furthermore, the optical compensation element 15a2 can be easily and stably arranged in the projector.

1 is a schematic configuration diagram of a projector according to a first embodiment. It is the whole liquid crystal panel block diagram and HH 'sectional view. It is explanatory drawing which shows the structure of a liquid crystal light valve. It is a figure which shows the optical axis arrangement | positioning of each structural member of a liquid crystal light valve. FIG. 3 is a perspective view illustrating a specific configuration example of the projector according to the first embodiment. It is a perspective view which shows the structure of the optical compensation element which concerns on 1st Embodiment. It is a graph for demonstrating an effect. It is a perspective view which shows the structure of the optical compensation element which concerns on 2nd Embodiment. It is a perspective view which shows the specific structural example of the projector which concerns on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Projector, 11 ... Screen, 12 ... Light source, 15, 16, 17 ... Liquid crystal light valve, 15a ... Optical compensation element, 15b, 16b, 17b, 15d, 16d, 17d ... Polarizing plate, 15c, 16c, 17c ... Liquid crystal Panel, 31 ... Counter substrate, 32 ... TFT array substrate, 43a, 98a ... Alignment direction, 43, 98 ... Alignment film, 51 ... Liquid crystal molecule, 81a ... Rotation axis, 82a ... Rotation axis, LB ... Blue light, LG ... Green Light, LR: Red light, P ′: Optical axis, P: Pretilt direction, 15a, 15a2: Optical compensation elements, 511, 521: First plate-like optical member, 513, 523: First optical anisotropic layer, 512 522 ... 2nd plate-shaped optical member, 514, 524 ... 2nd optical anisotropic layer

Claims (13)

A light source that emits light;
A liquid crystal panel in which liquid crystal is sandwiched between a pair of substrates and modulates the light;
A pair of polarizing plates disposed across the liquid crystal panel;
A first plate-like optical member disposed between the pair of polarizing plates and having (i) one surface and another surface facing the one surface and inclined with respect to the one surface;
(Ii) a first optical anisotropic layer formed on the other surface and having a negative refractive index anisotropy and having a first optical axis along a normal line of the other surface as an optical axis; iii) An optical compensation having a second optical anisotropic layer formed on the one surface and having a positive or negative refractive index anisotropy and having a second optical axis along the first surface as an optical axis. A projector comprising: an element.   2. The projector according to claim 1, further comprising a first optical adjustment unit capable of rotating the optical compensation element about an axis centering on a normal line of a substrate surface of the liquid crystal panel. Each of the one surface and the other surface has a quadrilateral shape,
The said other surface is formed so that it may incline along the direction perpendicular | vertical with respect to the one side of said one surface seeing from the normal line direction of said one surface. The projector according to 1 or 2. Each of the one surface and the other surface has a quadrilateral shape,
The other surface is formed so as to incline along a direction that forms an acute angle with respect to one side of the one surface when viewed from the normal direction of the one surface. Item 3. The projector according to Item 1 or 2. The optical compensation element is:
A second plate-like optical member disposed so as to sandwich the first optical anisotropic layer with the first plate-like optical member;
One surface of the second plate-shaped optical member facing the first optical anisotropic layer is formed to be inclined with respect to the other surface of the second plate-shaped optical member facing the one surface. The projector according to any one of claims 1 to 4, wherein the projector is provided.   6. The projector according to claim 1, further comprising a second optical adjustment unit capable of inclining the optical compensation element with respect to a substrate surface of the liquid crystal panel.   The projector according to claim 1, wherein the first optical axis and a clear viewing direction of the liquid crystal panel coincide with each other. A light source that emits light, a liquid crystal panel that modulates the light by sandwiching a liquid crystal between a pair of substrates, a pair of polarizing plates that are disposed across the liquid crystal panel, and a pair that is disposed between the pair of polarizing plates (I) a first plate-like optical member having one surface and another surface that is opposed to the one surface and is inclined with respect to the one surface; and (ii) formed on the other surface. A first optical anisotropic layer having a negative optical anisotropy and having a first optical axis along a normal line of the other surface as an optical axis; and (iii) formed on the one surface. And an optical compensation element having a second optical anisotropy layer having a positive or negative refractive index anisotropy and having a second optical axis along the one surface as an optical axis. A method,
A tilt adjusting step of tilting the one surface of the optical compensation element with respect to a substrate surface of the liquid crystal panel;
And a rotation adjusting step of rotating the optical compensation element about an axis in a normal direction of the substrate surface of the liquid crystal panel. A liquid crystal panel in which liquid crystal is sandwiched between a pair of substrates;
A pair of polarizing plates disposed across the liquid crystal panel;
A first plate-like optical member disposed between the pair of polarizing plates and having (i) one surface and another surface facing the one surface and inclined with respect to the one surface; ii) a first optical anisotropic layer formed on the other surface and having a negative refractive index anisotropy and having a first optical axis along the normal of the other surface as an optical axis; And a second optically anisotropic layer formed on the one surface and having a positive or negative refractive index anisotropy and having a second optical axis along the first surface as an optical axis. And a liquid crystal device. Each of the one surface and the other surface has a quadrilateral shape,
The said other surface is formed so that it may incline along the direction perpendicular | vertical with respect to the one side of said one surface seeing from the normal line direction of said one surface. The liquid crystal device according to 1. Each of the one surface and the other surface has a quadrilateral shape,
The other surface is formed so as to incline along a direction that forms an acute angle with respect to one side of the one surface when viewed from the normal direction of the one surface. Item 10. A liquid crystal device according to item 9. The optical compensation element is:
A second plate-like optical member disposed so as to sandwich the first optical anisotropic layer with the first plate-like optical member;
One surface of the second plate-shaped optical member facing the optically anisotropic layer is formed to be inclined with respect to the other surface of the second plate-shaped optical member facing the one surface. The liquid crystal device according to claim 9, wherein the liquid crystal device is a liquid crystal device.   The liquid crystal device according to claim 9, wherein the first optical axis and a clear viewing direction of the liquid crystal panel coincide with each other.

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