JP2009128663A - Electro-optic device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display a high-quality image in an electro-optic device such as a liquid crystal device while downsizing and cost-saving the device. <P>SOLUTION: The electro-optic device includes: a liquid crystal panel (100) having a liquid crystal layer (50) held between a pair of a first substrate (20) and a second substrate (10); a first optical compensation plate (310) placed in an incident side of source light in the liquid crystal panel and comprising a positive uniaxial crystal whose optical axis is inclined corresponding to the inclination of liquid crystal molecules of the liquid crystal layer on an interface with one of the first and second substrates; and a second optical compensation plate (320) placed in the exit side of the source light in the liquid crystal panel and comprising a positive uniaxial crystal whose optical axis is inclined corresponding to the inclination of liquid crystal molecules of the liquid crystal layer on an interface with the other of the first and second substrates. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  As this type of electro-optical device, for example, there is a device that displays an image by irradiating a liquid crystal panel with light. The irradiated light is incident on the liquid crystal panel after the phases are aligned by, for example, a polarizing plate, etc., but the phase is shifted in an optical element such as a liquid crystal panel or a microlens array, resulting in a decrease in contrast and a viewing angle. May be narrowed. For this reason, a technique of using an optical phase difference compensation element has been proposed to compensate for a phase shift of incident light.

  For example, Patent Document 1 discloses a technique in which two optical compensation elements are provided on the light emission side of a liquid crystal panel to compensate for a phase shift of incident light.

JP 2002-14345 A

  However, according to the above-described technique, a relatively large space is provided for providing two optical compensation elements on the light emission side with respect to the liquid crystal panel. When the space on the exit side of the liquid crystal panel is increased, for example, the optical path length of incident light or the back focus of a projection lens that projects an image may be increased. In addition, when combining and projecting light using a combining prism or the like, the combining prism may be increased in size. Thus, the above-described technique has a technical problem that it is difficult to reduce the size and cost of the apparatus.

  The present invention has been made in view of the above-described problems, for example, and an electro-optical device capable of displaying a high-quality image while realizing a reduction in size and cost of the device, and the electro-optical device. It is an object to provide an electronic device including the above.

  In order to solve the above problems, the electro-optical device of the present invention is arranged on a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of first and second substrates, and on the light source light incident side of the liquid crystal panel. A first optical compensator comprising a positive uniaxial crystal, the optical axis of which is tilted to correspond to the tilt of liquid crystal molecules at the interface of the liquid crystal layer with one of the first and second substrates; A positive light source disposed on a light source light emitting side of the liquid crystal panel, the optical axis being inclined so as to correspond to an inclination of liquid crystal molecules at an interface between the liquid crystal layer and the other of the first and second substrates; And a second optical compensator comprising a uniaxial crystal.

  According to the electro-optical device of the present invention, during operation, light source light such as projection light and backlight is incident on the liquid crystal panel, so that an image is displayed as, for example, a projected image or a direct-view image. The liquid crystal panel is configured by a pair of first and second substrates sandwiching a liquid crystal layer, and is driven by, for example, a TFT (Thin Film Transistor).

  Here, in the present invention, in particular, a first optical compensation plate including a positive uniaxial crystal is disposed on the light source light incident side of the liquid crystal panel. Further, a second optical compensation plate including a positive uniaxial crystal is disposed on the light source light emission side of the liquid crystal panel. That is, two optical compensators including positive uniaxial crystals are arranged so as to sandwich the liquid crystal panel.

  When two optical compensators are arranged with respect to the liquid crystal panel, in addition to the arrangement in which the liquid crystal panel is sandwiched (hereinafter referred to as “sandwich arrangement” as appropriate), 2 on the light source light incident side in the liquid crystal panel. There can be considered a case where two optical compensators are arranged and a case where two optical compensators are arranged on the light source light emission side of the liquid crystal panel. However, according to the research of the present inventor, it has been found that when two optical compensation plates are arranged on the incident side of the liquid crystal panel, the compensation effect is reduced as compared with the sandwich arrangement. . On the other hand, when two optical compensators are arranged on the exit side of the liquid crystal panel, the compensation effect is not lowered, but the optical path length of light and the back focus of the projection lens for projecting an image become long. Further, when light is combined and projected using a combining prism or the like, the combining prism becomes large. That is, there is a possibility that a sufficient compensation effect cannot be obtained in an arrangement other than the sandwich arrangement, or the size of the apparatus is increased and the cost is increased.

  However, in the present invention, in particular, the first and second optical compensation plates are sandwiched and arranged, so that the above-described disadvantage does not occur. Therefore, sufficient compensation can be performed while realizing downsizing and cost saving of the apparatus.

  Furthermore, the compensation effect when compensation is performed in the sandwich arrangement differs depending on whether the optical compensation element included in the optical compensation plate is a positive uniaxial crystal or a negative uniaxial crystal. According to the research of the present inventor, if an optical compensator including a positive uniaxial crystal is used, a higher compensation effect can be obtained as compared with the case of using an optical compensator including a negative uniaxial crystal. It has been found.

  In particular, the first and second optical compensators in the present invention include positive uniaxial crystals as described above. Therefore, the compensation effect by the first and second optical compensators is further enhanced.

  Specifically, the first optical compensation plate is tilted so that the optical axis corresponds to the tilt of the liquid crystal molecules at the interface between the liquid crystal layer and one of the first and second substrates. The second optical compensation plate is tilted so that the optical axis corresponds to the tilt of the liquid crystal molecules at the interface between the liquid crystal layer and the other of the first and second substrates. That is, the first optical compensation plate and the second optical compensation plate are configured such that the optical axis corresponds to the inclination of one of the liquid crystal molecules different from each other at the interface between the liquid crystal layer and the first substrate and the second substrate. It is inclined. Typically, the optical axis of the first optical compensation plate is tilted so as to correspond to the tilt of the liquid crystal molecules at the interface with the first substrate, and the optical axis of the second optical compensation plate is aligned with the second substrate. It is tilted so as to correspond to the tilt of the liquid crystal molecules at the interface.

  By disposing the first and second optical compensation plates in this way, the phase difference generated at the interface between the first substrate and the second substrate of the liquid crystal layer is compensated by the first and second optical compensation plates, respectively. It becomes possible. That is, the first and second optical compensators individually compensate for the phase difference generated at different positions. Therefore, the phase difference generated in the light source light is more reliably compensated.

  As described above, according to the electro-optical device of the present invention, it is possible to display a high-quality image while realizing miniaturization and cost saving of the device.

  In one aspect of the electro-optical device of the present invention, an alignment film is formed on each surface of the first and second substrates facing the liquid crystal, and the liquid crystal layer has an interface with the one substrate. The liquid crystal molecules at the interface between the molecule and the other substrate are respectively provided with pretilt by the alignment film, and the first optical compensator is inclined by the pretilt of the liquid crystal molecule at the interface with the one. The second optical compensator is tilted so as to compensate for a phase difference generated in the light source light due to the light source light, and the light source light is caused by the tilt due to the pretilt of the liquid crystal molecules at the interface with the other. Is tilted so as to compensate for the phase difference occurring in

  According to this aspect, the alignment films are formed on the surfaces of the first and second substrates facing the liquid crystal layer, and the liquid crystal molecules at the interface between the liquid crystal layer and the first and second substrates are pretilt by the alignment film. Are given respectively. That is, the liquid crystal molecules at the interface between the liquid crystal layer and the first and second substrates are each inclined by the alignment film.

  Here, in the present embodiment, in particular, the first and second optical compensators are arranged to be inclined so as to compensate for the phase difference of the light source light caused by the inclination of the liquid crystal molecules due to the pretilt described above. That is, the first optical compensation plate is tilted so as to correspond to the tilt due to the pretilt of the liquid crystal molecules at the interface between the first substrate and the second substrate, and the second optical compensation plate is in contact with the other substrate. The liquid crystal molecules are inclined so as to correspond to the inclination due to the pretilt of the liquid crystal molecules at the interface.

  By arranging the first and second optical compensation plates as described above, the phase difference generated at the interface between the liquid crystal layer and the first substrate and the phase difference generated at the interface between the liquid crystal layer and the second substrate can be reliably ensured. Compensated. Therefore, according to the electro-optical device according to this aspect, it is possible to display a high-quality image.

  In another aspect of the electro-optical device of the present invention, at least one of the first optical compensation plate and the second optical compensation plate has a predetermined optical axis from the normal direction of the first and second substrates. It is formed so as to be inclined by an angle.

  According to this aspect, the optical axis of at least one of the first and second optical compensation plates is inclined at the stage of formation. Specifically, for example, a positive uniaxial crystal is cut by a cutting line oblique to the optical axis and polished to have a predetermined thickness. As polishing, for example, various polishing techniques such as CMP (Chemical Mechanical Polishing) by tilting the crystal plate can be applied.

  As described above, when the first and second optical compensators are formed, for example, the first optical compensator and the second optical compensator are arranged at predetermined positions, so that the respective optical axes are the first and second optical axes. The substrate is inclined by a predetermined angle from the normal direction of the substrate. Therefore, according to this aspect, the process of arranging the first and second optical compensation plates can be simplified.

  In another aspect of the electro-optical device of the present invention, at least one of the first optical compensation plate and the second optical compensation plate includes the first optical compensation plate and the second optical compensation plate themselves in the liquid crystal panel. The optical axis is inclined by being arranged obliquely.

  According to this aspect, the first and second optical compensation plates themselves are arranged obliquely with respect to the liquid crystal panel, so that the optical axes of the first and second optical compensation plates are inclined. That is, the first and second optical compensators are arranged so that the optical axis is inclined at an angle that allows appropriate compensation.

  As described above, if the first and second optical compensation plates are arranged, the first and second optical compensation plates are arranged regardless of the angle of the optical axis at the stage of formation. It is possible to adjust by the angle. In other words, even if the optical axis is not formed so as to be inclined at a predetermined angle in advance, it is possible to perform appropriate correction. Therefore, according to this aspect, the process of forming the first and second optical compensation plates can be simplified.

  In another aspect of the electro-optical device of the present invention, the first optical compensation plate has a rotation mechanism that is rotatable with respect to an optical axis of the light source light.

  According to this aspect, since the first optical compensation plate has the rotation mechanism, even after the first optical compensation plate and the second optical compensation plate are arranged, the first optical compensation plate is For example, the angle can be adjusted by rotating around the optical axis of the light source light. In other words, the angle of the first optical compensation plate can be adjusted by rotating the first optical compensation plate by the rotation mechanism. Note that the rotational motion by the rotation mechanism may be a simple rotational motion in which the rotational axis is fixed, but it is a more complex motion with the rotational shaft moving or a combination of rotational motion and parallel movement. May be. Further, such a rotation mechanism is preferably configured to be fixed at a desired rotation angle. That is, it preferably includes a fixing mechanism. However, it is also possible to provide a fixing mechanism that fixes the angle separately from the rotating mechanism.

  The incident-side space of the liquid crystal panel in which the first optical compensation plate is disposed is larger than the exit-side space in which the second optical compensation plate is disposed. Therefore, the first optical compensator can be provided with a rotation mechanism that takes up a relatively large space.

  When the phase difference of light is compensated by a plurality of optical compensators, the angles of the plurality of optical compensators are extremely important, and high accuracy is required. For this reason, if the angle between the first optical compensation plate and the second optical compensation plate is not set to a predetermined angle, appropriate compensation of the light source light is not performed, and the effect of improving the image quality by compensation is reduced. End up.

  However, in this embodiment, in particular, as described above, since the first optical compensation plate has a rotation mechanism, the angle formed by the first optical compensation plate and the second optical compensation plate should be appropriate. Can do. That is, by adjusting the angle of the second optical compensator with respect to the fixed second optical compensator, the angles of each other can be made more appropriate. Therefore, compensation by the first and second optical compensation plates is performed more appropriately. Therefore, a high quality image can be displayed.

  In another aspect of the electro-optical device of the present invention, a microlens array is built in or externally attached to at least one of the first and second substrates.

  According to this aspect, the microlens array is built in or externally attached to at least one of the first and second substrates, and the light use efficiency is increased by condensing the incident light source light. . Since the microlens array refracts the light source light at the time of condensing, there is a higher possibility that a phase difference will occur in the light source light compared to a case where no microlens array is provided. That is, there is a high possibility that the contrast or the like of the displayed image is lowered.

  However, in this embodiment, in particular, the first and second optical compensators including positive uniaxial crystals are sandwiched and arranged, so that the phase difference of the light source light generated at the interface of the liquid crystal layer is appropriately compensated. Can do. Therefore, according to the electro-optical device according to this aspect, it is possible to display a high-quality image.

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

  According to the electronic apparatus of the present invention, since the electro-optical device according to the present invention described above is provided, a projection display capable of performing high-quality display while realizing downsizing and cost saving. Various electronic devices such as a 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, a POS terminal, and a touch panel can be realized. Further, as the electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper can be realized.

  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 present invention will be described with reference to the drawings.

<LCD panel>
First, a liquid crystal panel used in the electro-optical device according to the present embodiment will be described with reference to FIGS. FIG. 1 is a plan view showing the configuration of the liquid crystal panel according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the line HH ′ of FIG. In the following, as an example of the liquid crystal panel according to the present embodiment, a TFT active matrix driving type liquid crystal panel with a built-in driving circuit is taken as an example.

  1 and 2, in the liquid crystal panel 100 according to the present embodiment, the TFT array substrate 10 which is an example of the “second substrate” of the present invention, and the counter substrate 20 which is an example of the “first substrate” of the present invention. Are arranged opposite to each other. The TFT array substrate 10 is a transparent substrate such as a quartz substrate, a glass substrate, or a silicon substrate. The counter substrate 20 is also a transparent substrate, like the TFT array substrate 10. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20. The TFT array substrate 10 and the counter substrate 20 are bonded to each other by a sealing material 52 provided in a sealing region located around the image display region 10a provided with a plurality of pixel electrodes.

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

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

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

  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.

  In FIG. 2, on the TFT array substrate 10, an alignment film is formed on the pixel electrode 9a after the pixel switching TFT, the scanning line, the data line and the like are formed. The pixel electrode 9a is made of a transparent conductive film such as an ITO (Indium Tin Oxide) film, and the alignment film is made of an organic film such as a polyimide film. On the other hand, on the counter substrate 20, a lattice-shaped or striped light-shielding film 23 is formed, and then a counter electrode 21 is provided over the entire surface, and an alignment film is formed on the uppermost layer portion. Yes. The counter electrode 21 is made of a transparent conductive film such as an ITO film, and the alignment film is made of an organic film such as a polyimide film. A liquid crystal layer 50 is formed between the TFT array substrate 10 and the counter substrate 20 that are configured as described above and are arranged so that the pixel electrode 9a and the counter electrode 21 face each other. The liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films.

  1 and 2, on the TFT array substrate 10, in addition to the drive circuits such as the data line drive circuit 101 and the scanning line drive circuit 104, the image signal on the image signal line is sampled to obtain data. Sampling circuit that supplies lines, precharge circuit that supplies pre-charge signals of a predetermined voltage level to multiple data lines in advance of image signals, inspection of quality, defects, etc. of the electro-optical device during production or shipment An inspection circuit or the like may be formed.

<Electro-optical device>
Next, an electro-optical device having the above-described liquid crystal panel 100 will be described with reference to FIGS. In the following drawings, detailed members of the liquid crystal panel 100 shown in FIGS. 1 and 2 are omitted as appropriate, and only directly related members are shown.

<First Embodiment>
First, the configuration of the electro-optical device according to the first embodiment will be described with reference to FIGS. 3 to 5. FIG. 3 is a cross-sectional view showing the configuration of the electro-optical device according to the first embodiment, and FIG. 4 is a perspective view conceptually showing the relationship between the optical axis of the optical compensator and the tilt of liquid crystal molecules. is there. FIG. 5 is a cross-sectional view illustrating a modification of the electro-optical device according to the first embodiment. Hereinafter, a case where the liquid crystal of the liquid crystal layer 50 is a TN (Twisted Nematic) type liquid crystal will be described as an example.

  3, the electro-optical device according to the present embodiment includes the liquid crystal panel 100, the first optical compensation plate 310, the second optical compensation plate 320, the first polarizing plate 410, and the second polarizing plate 420. It is configured with.

  In the liquid crystal panel 100, the liquid crystal layer 50 is sandwiched between the TFT array substrate 10 and the counter substrate 20, and the flexible substrate 200 is electrically connected to the external circuit connection terminal 102 (see FIG. 1). The end of the flexible substrate 200 that is not connected to the liquid crystal panel 100 is electrically connected to, for example, a circuit board (not shown).

  The first polarizing plate 410 is disposed on the light source light incident side with respect to the liquid crystal panel 100, and the second polarizing plate 420 is disposed on the light source light emitting side with respect to the liquid crystal panel 100. A first optical compensation plate 310 is disposed between the first polarizing plate 410 and the liquid crystal panel 100. In addition, a second optical compensation plate 320 is disposed between the second polarizing plate 420 and the liquid crystal panel 100. The first optical compensation plate 310 and the second optical compensation plate 320 are made of an optical compensation element including a positive uniaxial crystal such as crystal.

  As shown in FIG. 4, the liquid crystal molecules in the liquid crystal layer 50 are twisted by 90 ° between the incident side and the outgoing side of the light source light. The inclination of the liquid crystal molecules is set by an alignment film provided at the interface between the liquid crystal layer 50 and the TFT array substrate 10 and the counter substrate 20.

  Here, the first optical compensation plate 310 is disposed so as to correspond to the inclination of the liquid crystal molecules on the incident side of the light source light in the liquid crystal layer 50, and the second optical compensation plate 320 is the emission side of the light source light in the liquid crystal layer 50. The liquid crystal molecules are arranged so as to correspond to the inclination of the liquid crystal molecules. More specifically, the optical axis of the crystal as the optical compensation element included in the first optical compensation plate 310 is tilted so as to compensate for the phase difference generated in the light source light due to the tilt of the liquid crystal molecules on the incident side. The In other words, the first optical compensator 310 is arranged so that its optical axis is tilted opposite to the tilt of the liquid crystal molecules on the incident side, as shown in the figure. The optical axis of the crystal as the optical compensation element included in the second optical compensation plate 320 is tilted so as to compensate for the phase difference generated in the light source light due to the tilt of the liquid crystal molecules on the incident side. That is, as shown in the drawing, the second optical compensator 320 is arranged so that its optical axis is inclined opposite to the inclination of the liquid crystal molecules on the emission side.

  Note that the optical axis of the first optical compensation plate 310 may be inclined so as to correspond to the liquid crystal molecules on the emission side. In this case, if the optical axis of the second optical compensator 320 is inclined so as to correspond to the liquid crystal molecules on the incident side, the same effect as described above can be obtained.

  The inclination of the optical axis in the first optical compensation plate 310 and the second optical compensation plate 320 described above is inclined, for example, when the first optical compensation plate 310 and the second optical compensation plate 320 are formed. Specifically, for example, it is formed by cutting a positive uniaxial crystal along a cutting line oblique to the optical axis and polishing it to a predetermined thickness by CMP or the like. If formed in this way, for example, as shown in FIG. 1, even if the first optical compensation plate 310 and the second optical compensation plate 320 are arranged in parallel with other substrates, the optical axes thereof are shown in FIG. As shown in FIG.

  As shown in FIG. 5, the first optical compensation plate 310 and the second optical compensation plate 320 themselves may be arranged obliquely with respect to the liquid crystal panel 100, so that the optical axis may be inclined. If the first optical compensation plate 310 and the second optical compensation plate 320 are arranged in this way, the first optical compensation plate 310 and the second optical compensation plate 320 are formed regardless of the angle of the optical axis in the formed stage. 2 The optical axis can be adjusted according to the angle at which the optical compensator 320 is disposed. That is, even if the optical axis is not formed in advance so as to be inclined at a predetermined angle, appropriate correction can be performed.

  Next, the arrangement positions of the first optical compensation plate 310 and the second optical compensation plate 320 with respect to the liquid crystal panel 100 will be described with reference to FIGS. 6 to 9 in addition to FIG. 6 and 7 are cross-sectional views illustrating comparative examples of the electro-optical device according to the embodiment. FIG. 8 is a graph showing the relationship between the arrangement of the optical compensator and the contrast when the first and second optical compensators include negative uniaxial crystals. FIG. 9 shows the first and second optical compensators. It is a graph which shows the relationship between arrangement | positioning of an optical compensator, and contrast when a compensator contains a positive uniaxial crystal.

  As shown in FIG. 3, in the electro-optical device according to the present embodiment, the first optical compensation plate 310 and the second optical compensation plate 320 are arranged so as to sandwich the liquid crystal panel 100. When compensation is performed using two optical compensators, in addition to the sandwiching arrangement as in the electro-optical device according to the present embodiment, two pieces are provided on the emission side of the liquid crystal panel 100 as shown in FIG. It is conceivable that two optical compensators are arranged on the incident side of the liquid crystal panel 100 as shown in FIG. In the following, the arrangement of the optical compensator in the electro-optical device according to this embodiment shown in FIG. 3 is (a), the arrangement of the optical compensator shown in FIG. 6 is (b), and the optical compensator shown in FIG. Each compensation effect will be described with the arrangement as (c) arrangement.

  In FIG. 8, when both of the two optical compensators include a negative uniaxial crystal, the contrast of the displayed image has a value as shown in the graph. That is, in the (b) arrangement, a relatively high contrast can be obtained, but the contrast in the (a) arrangement and the (c) arrangement is lower than that in the (b) arrangement.

  In FIG. 9, when both of the two optical compensators include a positive uniaxial crystal, the displayed image has a contrast as shown in the graph. That is, in the (c) arrangement, the contrast becomes low, but in the (a) arrangement and the (b) arrangement, a relatively high contrast can be obtained.

  Here, (b) arrangement can obtain a relatively high contrast regardless of whether the optical compensation element is positive or negative. However, since two optical compensation plates are arranged on the emission side of the liquid crystal panel 100, (a) arrangement and ( c) Compared with the arrangement, a relatively large space must be taken on the light emission side of the liquid crystal panel 100. However, if the space on the emission side of the liquid crystal panel 100 is increased, for example, the back focus of the projection lens that projects an image on a screen or the like becomes longer. This increases the size of the lens and the number of lenses. In addition, the optical engine itself increases in size as the optical path length increases. Further, when the light is combined and projected using a combining prism or the like as in an electronic device described later, the combining prism is increased in size. As a result, the cost increases significantly. That is, when the optical compensator is arranged in the (b) arrangement, there is a possibility that the size of the apparatus is increased and the cost is increased.

  On the other hand, according to the electro-optical device according to the present embodiment, the first optical compensation plate 310 and the second optical compensation plate 320 each include a positive uniaxial crystal, and are arranged in (a) arrangement. Therefore, high contrast can be obtained without causing the above-described disadvantages.

  Next, the operation of the electro-optical device according to the present embodiment will be described with reference to FIG. In the following, the operation of each unit described above will be described according to the path of the light source light.

  In FIG. 3, the light source light is first incident on the first polarizing plate 410. The first polarizing plate 410 is configured so that only light that vibrates in a predetermined direction can pass therethrough. Therefore, the light source light incident on the first polarizing plate 410 becomes linearly polarized light.

  The light source light that has passed through the first polarizing plate 410 is incident on the first optical compensation plate 310. As shown in FIG. 4, the optical axis of the first optical compensation plate 310 is inclined so as to correspond to the liquid crystal molecules at the interface on the counter substrate 20 side. Therefore, here, the phase shift generated in the light source light when passing through the liquid crystal molecules at the interface on the counter substrate 20 side is compensated.

  Subsequently, the light source light enters the liquid crystal panel 100. That is, the light enters the liquid crystal layer 50 through the counter substrate 20. Here, a voltage is applied to the liquid crystal layer 50, and the inclination of the liquid crystal molecules contained in the liquid crystal layer 50 changes depending on the applied voltage. However, for example, near the interface between the counter substrate 20 and the TFT array substrate 10, there are liquid crystal molecules that do not rise completely even when a voltage is applied, or liquid crystal molecules that do not fully rise during halftone display. Therefore, the phase of the light source light incident on the liquid crystal layer 50 is shifted near the interface. Here, as described above, the phase shift due to the liquid crystal molecules at the interface on the counter substrate 20 side is already compensated by the first optical compensator 310. Therefore, the phase shift generated in the light source light that has passed through the liquid crystal panel 100 is due to liquid crystal molecules at the interface on the TFT array substrate 10 side.

  The light that has passed through the liquid crystal panel 100 is incident on the second optical compensation plate 320. As shown in FIG. 4, the optical axis of the second optical compensation plate 320 is inclined so as to correspond to the liquid crystal molecules at the interface on the TFT array substrate 10 side. Therefore, here, the phase shift generated in the light source light when passing through the liquid crystal molecules at the interface on the TFT array substrate 10 side is compensated.

  The light that has passed through the second optical compensation plate 320 is incident on the second polarizing plate 420. As described above, the light source light is in a state where there is little or no phase shift by the first optical compensation plate 310 and the second optical compensation plate 320, so that light passing therethrough is transmitted through the second polarizing plate 420. It is possible to prevent light that is not passed or not passed. Therefore, it is possible to increase the contrast of the displayed image.

  As described above, according to the electro-optical device according to the first embodiment, a phase shift that occurs in the liquid crystal layer 50 or the like can be compensated more favorably, so that a high-quality image can be displayed. It is.

Second Embodiment
Next, an electro-optical device according to a second embodiment will be described with reference to FIGS. FIG. 10 is a cross-sectional view showing the configuration of the electro-optical device according to the second embodiment, and FIG. 11 is a perspective view showing the configuration of the rotation mechanism. Compared with the first embodiment described above, the second embodiment differs in configuration in that it includes a rotation mechanism, and the other configurations are generally the same. For this reason, in 2nd Embodiment, a rotation mechanism is demonstrated in detail and description is abbreviate | omitted suitably about another structure. In FIG. 10, the same reference numerals are given to the same components as those according to the first embodiment.

  In FIG. 10, in the electro-optical device according to the present embodiment, a rotation mechanism 600 is provided on the first optical compensation plate 310. The rotation mechanism 600 includes a shaft 610, a bearing 611, and a fixing screw 612. The bearing 611 is fixed to a part of the electro-optical device or a part of a device having the electro-optical device. That is, the first optical compensation plate 310 is fixed by the shaft 610 via the bearing 611. Hereinafter, a more specific configuration and operation of the rotation mechanism 600 will be described.

  In FIG. 11, a shaft 610 bent at 90 ° is attached to the upper portion of the first optical compensation plate 310. The shaft 610 is held through a fixed bearing 611 so that it can freely rotate in the direction of the arrow P1 in the figure. As the shaft 610 rotates, the first optical compensator 310 is rotated in the direction of the arrow P2 in the figure. The bearing 611 is provided with a fixing screw 612. By tightening the fixing screw 612, the shaft 610 is fixed so as not to rotate. Therefore, the first optical compensation plate 310 can be adjusted and fixed to a desired angle. The structure as described above is merely an example of a rotation mechanism of the first optical compensation plate 310, and can be appropriately changed according to the structure of the apparatus. Further, the adjustment of the angle of the first optical compensation plate 310 by the rotation mechanism 600 may be performed manually, or may be performed semiautomatically or fully automatically using a dedicated jig or an electric tool.

  When the phase difference of light is compensated by a plurality of optical compensators, the angles of the plurality of optical compensators are extremely important, and high accuracy is required. For this reason, if the angle between the first optical compensation plate 310 and the second optical compensation plate 320 is not a predetermined angle, appropriate compensation of the light source light is not performed, and the effect of improving the image quality due to the compensation is reduced. Resulting in.

  On the other hand, in the electro-optical device according to the second embodiment, the rotation mechanism 600 is used to set an appropriate angle between the first optical compensation plate 310 and the second optical compensation plate 320. It is possible. Therefore, compensation by the first optical compensation plate 310 and the second optical compensation plate 320 is performed more appropriately, and a high-quality image can be displayed.

<Third Embodiment>
Next, an electro-optical device according to a third embodiment will be described with reference to FIG. FIG. 12 is a cross-sectional view showing the configuration of the electro-optical device according to the third embodiment. The third embodiment differs from the first and second embodiments described above in that it includes a microlens array, and other configurations are generally the same. For this reason, in the third embodiment, the influence of the microlens array will be described in detail, and description of other components will be omitted as appropriate. In FIG. 12, the same reference numerals are given to the same components as those according to the first and second embodiments.

  In FIG. 12, in the electro-optical device according to the third embodiment, a microlens array substrate 800 is provided between the first polarizing plate 410 and the liquid crystal panel 100. The microlens array substrate 800 condenses incident light source light. Thereby, it is possible to increase the light use efficiency in the liquid crystal panel 100.

  However, since the microlens array substrate 800 refracts the light source light at the time of condensing, there is a higher possibility that a phase difference will occur in the light source light than when the microlens array substrate 800 is not provided. That is, there is a high possibility that the quality of the displayed image is deteriorated.

  On the other hand, in the electro-optical device according to the third embodiment, as described above, the first optical compensation plate 310 and the second optical compensation plate 320 are arranged so that effective compensation can be performed. Therefore, the phase shift occurring in the liquid crystal layer 50 is reliably compensated.

  As described above, according to the electro-optical device according to the third embodiment, the phase shift due to the provision of the microlens array substrate 800 can also be appropriately compensated for, while improving the utilization efficiency of the light source light. It is possible to display a high-quality image.

<Electronic equipment>
Next, the case where the above-described electro-optical device is applied to various electronic devices will be described. FIG. 12 is a plan view showing a configuration example of the projector.

  As shown in FIG. 12, a projector 1100 includes a lamp unit 1102 made of a white light source such as a halogen lamp. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

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

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

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

  In addition to the electronic device described with reference to FIG. 12, a mobile personal computer, a mobile phone, a liquid crystal television, a viewfinder type, a monitor direct-view type video tape recorder, a car navigation device, a pager, an electronic device Examples include a notebook, a calculator, a word processor, a workstation, a videophone, a POS terminal, and a device equipped with a touch panel. Needless to say, the present invention can be applied to these various electronic devices.

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

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

It is a top view which shows the whole structure of the liquid crystal panel which concerns on embodiment. It is the HH 'sectional view taken on the line of FIG. 1 is a cross-sectional view illustrating a configuration of an electro-optical device according to a first embodiment. It is a perspective view which shows notionally the relationship between the optical axis of an optical compensator, and the inclination of a liquid crystal molecule. FIG. 6 is a cross-sectional view illustrating a modification of the electro-optical device according to the first embodiment. FIG. 3 is a cross-sectional view (No. 1) illustrating a comparative example of the electro-optical device according to the embodiment. FIG. 6 is a cross-sectional view (No. 2) illustrating a comparative example of the electro-optical device according to the embodiment. It is a graph (the 1) which shows the relationship between arrangement | positioning of an optical compensator, and contrast. It is a graph (the 2) which shows the relationship between arrangement | positioning of an optical compensation board, and contrast. FIG. 6 is a cross-sectional view illustrating a configuration of an electro-optical device according to a second embodiment. It is a perspective view which shows the structure of a rotation mechanism. FIG. 6 is a cross-sectional view illustrating a configuration of an electro-optical device according to a third embodiment. It is a top view which shows the structure of the projector which is an example of the electronic device to which the electro-optical apparatus is applied.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... TFT array substrate, 10a ... Image display area, 20 ... Counter substrate, 50 ... Liquid crystal layer, 100 ... Liquid crystal panel, 200 ... Flexible substrate, 310 ... 1st optical compensator, 320 ... 2nd optical compensator, 410 ... First polarizing plate 420 ... second polarizing plate 600 ... rotating mechanism 610 ... shaft 611 ... bearing 612 ... fixing screw 800 ... micro lens array substrate

Claims (7)

A liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of first and second substrates;
A positive light source disposed on the light source light incident side of the liquid crystal panel, the optical axis tilted to correspond to the tilt of liquid crystal molecules at the interface of the liquid crystal layer with one of the first and second substrates; A first optical compensator comprising a uniaxial crystal;
A positive light source disposed on a light source light emitting side of the liquid crystal panel, the optical axis being inclined so as to correspond to an inclination of liquid crystal molecules at an interface between the liquid crystal layer and the other of the first and second substrates; An electro-optical device comprising: a second optical compensation plate including a uniaxial crystal. An alignment film is formed on each of the surfaces of the first and second substrates facing the liquid crystal,
A pretilt is imparted to the liquid crystal molecules at the interface with the one substrate of the liquid crystal layer and the liquid crystal molecules at the interface with the other substrate, respectively, by the alignment film,
The first optical compensation plate is tilted so as to compensate a phase difference generated in the light source light due to the tilt of the liquid crystal molecules at the interface with the one due to the pretilt,
The second optical compensation plate is tilted so as to compensate for a phase difference generated in the light source light due to the tilt of the liquid crystal molecules at the interface with the other due to the pretilt. The electro-optical device according to 1.   At least one of the first optical compensation plate and the second optical compensation plate is formed so that the optical axis is inclined by a predetermined angle from the normal direction of the first and second substrates. The electro-optical device according to claim 1 or 2.   At least one of the first optical compensation plate and the second optical compensation plate is configured such that the first optical compensation plate and the second optical compensation plate themselves are disposed obliquely with respect to the liquid crystal panel. The electro-optical device according to claim 1, wherein the axis is inclined.   5. The electro-optical device according to claim 1, wherein the first optical compensation plate includes a rotation mechanism that is rotatable with respect to an optical axis of the light source light.   6. The electro-optical device according to claim 1, wherein a microlens array is built in or externally attached to at least one of the first and second substrates.   An electronic apparatus comprising the electro-optical device according to claim 1.

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