JP2009139622A - Electrooptical device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately compensate retardation in an electrooptical device such as a liquid crystal device, while comparatively facilitating the manufacturing process. <P>SOLUTION: The electrooptical device includes: a liquid crystal panel (100) having a liquid crystal layer (50) interposed between a first substrate (20) and a second substrate (10); polarizing elements (411, 421); and supporting substrates (412, 422) to support the polarizing elements, and is equipped with: a pair of polarizing plates (410, 420) respectively disposed on the incident side and the emission side of the liquid crystal panel; and an optical compensation plate (300) of which the polarity of anisotropy of refractive indexes is positive or negative, and which is disposed at least either on the incident side or on the emission side of the liquid crystal panel so as to be interposed between the polarizing plate and the liquid crystal panel. An optically compensating polarizing plate of the pair of polarizing plates, placed opposite to the liquid crystal panel via the optical compensation plate, is constructed in such a way that the supporting substrate has anisotropy of refractive indexes with a polarity reverse to that of the optical compensation plate and the supporting substrate is closer to the liquid crystal panel side than to the polarizing element. <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 of compensating for a phase difference of light by an optical compensation plate made of an inorganic material.

Japanese Patent No. 3864929

  However, in the above-described technique, in order to set the phase difference compensated by the optical compensation plate to an appropriate size, it is required to form the optical compensation plate by extremely thinly polishing the crystal as a material. Therefore, there is a technical problem in that manufacturing requires extremely accurate control and is very difficult to manufacture.

  The present invention has been made in view of the above-described problems, for example, and provides an electro-optical device that is relatively easy to manufacture and can appropriately compensate for a phase difference, and an electronic apparatus including the electro-optical device. Is an issue.

  In order to solve the above problems, an electro-optical device of the present invention has a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of first and second substrates, a polarizing element, and a support substrate that supports the polarizing element. A pair of polarizing plates respectively disposed on the incident side and the emission side of the light source light in the liquid crystal panel, and the polarity of refractive index anisotropy is positive or negative, and the incident side of the light source light in the liquid crystal panel and An optical compensator arranged to be sandwiched between the polarizing plate and the liquid crystal panel on at least one of the emission side, and faces the liquid crystal panel through the optical compensation plate of the pair of polarizing plates On the other hand, the optical compensation polarizing plate is configured such that the support substrate has a refractive index anisotropy opposite in polarity to the optical compensation plate, and the support substrate is closer to the liquid crystal panel than the polarizing element. .

  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).

  A pair of polarizing plates are arranged on the incident side and the emission side of the light source light in the liquid crystal panel, respectively. Each of the pair of polarizing plates includes a polarizing element and a support substrate that supports the polarizing element. An optical compensator is disposed on at least one of the incident side and the outgoing side of the light source light in the liquid crystal panel so as to be sandwiched between the polarizing plate and the liquid crystal panel.

  Here, in the present invention, in particular, the optical compensation polarizing plate, which is one of the pair of polarizing plates facing the liquid crystal panel through the optical compensation plate, has a refractive index anisotropy whose support substrate has a polarity opposite to that of the optical compensation plate. have. That is, if the optical compensation plate has a positive refractive index anisotropy, the support substrate of the optical compensation polarizing plate has a negative refractive index anisotropy, and the optical compensation plate has a negative refractive index difference. If it has directionality, the support substrate of the optical compensation polarizing plate has positive refractive index anisotropy.

  The optical compensation polarizing plate is configured such that the support substrate is closer to the liquid crystal panel than the polarizing element. For this reason, the support substrate in the optical compensation polarizing plate is disposed to face the liquid crystal panel or the optical compensation plate without using the polarizing plate. Note that an optical film other than the polarizing plate, an optical material, an optical member, or the like may be interposed between the optical compensation plate and the support substrate. However, it is not desirable that an optical element that generates a phase difference such as a liquid crystal panel is interposed.

  Since the support substrate in the optical compensation polarizing plate is arranged as described above, it has a function of compensating for the phase difference generated in the light source light, similarly to the optical compensation plate. That is, the optical compensation polarizing plate has a function as an optical compensation element in addition to a function as a polarizing plate.

  Here, if optical compensation elements having different polarities of refractive index anisotropy are arranged opposite to each other, the compensation effects by the respective compensation elements are canceled out. Therefore, the compensation effects of the optical compensation plate and the optical compensation polarizing plate cancel each other. The overall compensation effect of the optical compensation plate and the optical compensation polarizing plate together is determined by the difference in compensation effect between the optical compensation plate and the optical compensation polarizing plate. More specifically, it is determined by the magnitude of the phase difference compensated by the optical compensation plate and the optical compensation polarizing plate, the angle of each optical axis, and the like. Therefore, for example, when the compensation effect of the optical compensation plate and the optical compensation polarizing plate is not suitable for compensating for the phase difference generated in the liquid crystal panel or the like, by adjusting the compensation effect of the other, The compensation effect as a whole can be made appropriate.

  The adjustment of the compensation effect described above is typically performed by changing the thickness of the support substrate in the optical compensation plate and the optical compensation polarizing plate. Moreover, adjustment is also possible by changing the constituent material to one having a different refractive index.

  Although it is considered that the same effect can be obtained by providing another optical compensation plate or the like without providing the support substrate in the optical compensation polarizing plate on the liquid crystal panel side, the arrangement space, cost, etc. increase. There is a problem. In addition, a crystal plate such as sapphire having refractive index anisotropy is often used for the support substrate of the polarizing plate. Normally, the polarizing plate is intentionally applied so as not to affect the phase of the light source light. It is arranged on the side far from the LCD panel. In contrast, in the present invention, the support substrate is effectively used as an optical compensation element. That is, it is possible to enhance the compensation effect without making a significant design change.

  As described above, according to the electro-optical device according to the present invention, since the optical compensation plate and the optical compensation polarizing plate are provided, the phase difference generated in the light source light can be more appropriately compensated. Therefore, it is possible to display a higher quality image.

  In one aspect of the electro-optical device of the present invention, the supporting substrate in the optical compensation plate and the optical compensation polarizing plate is a refraction that brings the phase difference of the whole closer to a desired phase difference by canceling out the phase difference of each. Each has a rate and thickness.

  According to this aspect, the phase difference which the support substrate compensates in the optical compensation plate and the optical compensation polarizing plate cancel each other, whereby the phase difference of the whole is brought close to the desired phase difference. The “desired phase difference” means a phase difference value that is desired to be compensated in order to display an image with higher image quality. The “optical compensator” and the “support substrate” according to the present embodiment can also be referred to as a “retarder” for obtaining a desired retardation.

  The magnitude of the phase difference compensated by the optical compensation element depends on the thickness of the crystal plate constituting the material, the refractive index of the material, and the like. For this reason, the phase difference of the whole is brought close to a desired phase difference by changing the refractive index and thickness of the support substrate in the optical compensation plate and the optical compensation polarizing plate. That is, the phase difference compensated by the support substrate in the optical compensation plate and the optical compensation polarizing plate is adjusted by the respective refractive indexes and thicknesses.

  Here, the compensation effect required for the optical compensation element is often relatively small. Therefore, in order to adjust the compensation effect depending on the thickness of the crystal plate when there is no special configuration including the two optical compensation elements of the optical compensation plate and the optical compensation polarizing plate as described above, for example, several crystal plates are used. Polishing to a thickness of about μm to several tens of μm is required. That is, when forming an optical compensation element, extremely high accuracy is required. In other words, such a thin crystal plate is easily cracked or chipped during manufacturing, and even if manufactured, the finished product is fragile.

  However, in this embodiment, in particular, the mutual compensation effect is offset by the optical compensation plate and the optical compensation polarizing plate having different refractive index anisotropies. For this reason, for example, even when the support substrate in the optical compensation plate and the optical compensation polarizing plate is formed to be relatively thick, it is possible to realize a desired phase difference as a result of canceling out the compensation effect. . That is, the optical compensator and the support substrate do not need to be thinly polished until they have a thickness that can achieve a desired phase difference alone, and thus manufacturing can be greatly facilitated. From the viewpoint of downsizing an electro-optical device or the like on which the optical compensation plate is provided, it is desirable that the thickness of the optical compensation plate and the support substrate is small, but theoretically, the device can be physically disposed. As long as there is a space, a desired phase difference can be realized with any thickness. On the other hand, if the thickness of the two optical compensation elements is simply increased to an extent necessary to facilitate manufacture, there is little or almost no hindrance to downsizing of the apparatus.

  As described above, according to the electro-optical device according to this aspect, it is possible to facilitate manufacturing and display a higher quality image.

  In another aspect of the electro-optical device of the present invention, the optical axes of the support substrates in the optical compensation plate and the optical compensation polarizing plate are in the same direction.

  According to this aspect, since the optical axes of the supporting substrate in the optical compensation plate and the optical compensation polarizing plate are in the same direction, the optical axis as a whole is also the same as that of the supporting substrate in the optical compensation plate and the optical compensation polarizing plate. The direction is the same as the optical axis. The “same direction” on the optical axis of the support substrate in the optical compensation plate and the optical compensation polarizing plate does not indicate the exact same direction, and as will be described later, the direction of the optical axis as a whole and the level of compensation. It means a value with which the phase difference can be determined relatively easily. That is, the same direction here can also be called a substantially same direction.

  If the optical axes of the support substrate in the optical compensation plate and the optical compensation polarizing plate are not in the same direction, the optical axis as a whole is the optical axis of the support substrate in the optical compensation plate and the optical compensation polarizing plate. There is a possibility that it cannot be obtained unless complicated calculation is performed in consideration of the angle and the phase difference to be compensated.

  However, in this embodiment, in particular, as described above, since the optical axes of the support substrates in the optical compensation plate and the optical compensation polarizing plate are in the same direction, the optical axis as a whole is the optical compensation plate and the optical compensation polarizing plate. In the same direction as the optical axis of the support substrate. The phase difference compensated as a whole can also be obtained by simple addition / subtraction. Therefore, the electro-optical device according to this aspect can compensate for the phase difference more easily and appropriately. Therefore, it is possible to display a higher quality image.

  In another aspect of the electro-optical device of the present invention, the optical compensation plate is provided integrally with the liquid crystal panel.

  According to this aspect, since the optical compensation plate is provided integrally with the liquid crystal panel, a space for arranging the optical compensation plate can be reduced. Note that “provided integrally” means that at least one surface is in contact with each other, and typically refers to a state where they are fixed to each other. Including the state of being made rotatable. In the following embodiments, the same meaning is assumed.

  Further, the optical compensation plate can be formed as dust-proof glass on the outer surface of the liquid crystal panel. Since the optical compensator functions as dust-proof glass, it is possible to prevent the image quality from being deteriorated due to dust or dirt adhering to the liquid crystal panel. Furthermore, if the optical compensation plate is formed of a material having a relatively high heat dissipation property such as quartz, it can be made to function as a heat dissipation plate for a liquid crystal panel. If the optical compensator can efficiently release the heat generated in the liquid crystal panel, the liquid crystal panel can be effectively prevented from malfunctioning or malfunctioning.

  As described above, according to the electro-optical device according to this aspect, it is possible to display a high-quality image while realizing space saving and prevention of failure of the liquid crystal panel.

  In another aspect of the electro-optical device of the present invention, the optical compensation plate is provided integrally with the optical compensation polarizing plate.

  According to this aspect, since the optical compensation plate is provided integrally with the optical compensation polarizing plate, a space for arranging the optical compensation plate can be reduced. In the optical compensation polarizing plate, since the support substrate is disposed on the liquid crystal panel side (that is, on the optical compensation plate side) from the polarizing element, the optical compensation plate is in contact with the support substrate. Further, if the optical compensation plate and the support substrate are fixed, it is possible to prevent the angles of the optical axes from deviating from each other during arrangement. That is, the optical compensation plate and the support substrate can be arranged so that the optical axis is at an appropriate angle.

  As described above, according to the electro-optical device according to this aspect, it is possible to display a high-quality image while realizing space saving and simplification of arrangement of the optical compensation elements.

  In another aspect of the electro-optical device of the present invention, of the optical compensation plate and the support substrate in the optical compensation polarizing plate, the one having the positive polarity includes quartz.

  According to this aspect, of the optical compensation plate and the support substrate in the optical compensation plate, the one having a positive polarity is a crystal plate containing quartz. The crystal plate including the crystal is formed by polishing to a predetermined thickness by various polishing techniques such as CMP (Chemical Mechanical Polishing).

  Here, since quartz has high hardness, it is difficult to polish thinly. In addition, when compensation is performed using a crystal plate containing quartz alone, the birefringence is relatively high. Therefore, the phase difference cannot be properly compensated unless the substrate is polished thinly.

  However, in this embodiment, in particular, the phase difference to be compensated for the crystal plate including the crystal is canceled out by the negative one of the support substrates in the optical compensation plate and the optical compensation polarizing plate. Therefore, even if the crystal plate containing quartz is in a relatively thick state, the phase difference as a whole is appropriate. Therefore, according to the electro-optical device according to this aspect, it is possible to display a high-quality image while facilitating the manufacturing process.

  In another aspect of the electro-optical device of the present invention, of the optical compensation plate and the support substrate in the optical compensation polarizing plate, the one having the negative polarity includes sapphire.

  According to this aspect, of the optical compensation plate and the support substrate in the optical compensation plate, the one having a negative polarity is a crystal plate containing sapphire. The crystal plate containing sapphire is formed by polishing to a predetermined thickness by various polishing techniques such as CMP.

  Here, since sapphire has extremely high hardness, it is very difficult to polish thinly. Therefore, extremely high technology is required for manufacturing a crystal plate containing sapphire.

  However, particularly in this embodiment, the phase difference to be compensated for the crystal plate containing sapphire is canceled by the positive polarity of the support substrate in the optical compensation plate and the optical compensation polarizing plate. Therefore, even if the crystal plate containing sapphire is in a relatively thick state, the phase difference as a whole is appropriate. Therefore, according to the electro-optical device according to this aspect, it is possible to display a high-quality image while facilitating the manufacturing process.

  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, the projection display device, the television set, and the mobile phone that are easy to manufacture and can perform high-quality display. Various electronic devices such as a telephone, an electronic notebook, a word processor, a viewfinder type or a monitor direct-view type video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized. 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. In the following embodiments, a driving circuit built-in type TFT active matrix driving type liquid crystal device, which is an example of the electro-optical device of the present invention, is taken as an example.

<First Embodiment>
The electro-optical device according to the first embodiment will be described with reference to FIGS. In the first embodiment, a case where the liquid crystal layer of the liquid crystal panel is VA (Vertical Alignment) liquid crystal will be described as an example.

  First, the configuration of a liquid crystal panel used in the electro-optical device according to the present embodiment will be described with reference to FIGS. 1 and 2. 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.

  1 and 2, in the liquid crystal panel 100 according to the present embodiment, the TFT array substrate 10 and the counter substrate 20 are arranged to face 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.

  Next, the overall configuration of the electro-optical device according to the first embodiment will be described with reference to FIGS. 3 and 4. 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 cross-sectional view showing a modification of the electro-optical device according to the first embodiment.

  3, the electro-optical device according to the first embodiment includes the liquid crystal panel 100, the optical compensation plate 300, the first polarizing plate 410, and the second polarizing plate 420 described above.

  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 has a first polarizing element 411 and a first support substrate 412, and is disposed on the light source light incident side in the liquid crystal panel 100. The first polarizing element 411 is closer to the liquid crystal panel than the first support substrate 412. The second polarizing plate 420 includes a second polarizing element 421 and a first support substrate 422, and is disposed on the light source light emission side of the liquid crystal panel 100. The second support substrate 422 is disposed closer to the liquid crystal panel side 100 than the second polarizing element 421. That is, here, the second polarizing plate 420 is an example of the “optical compensation polarizing plate” of the present invention. The second support substrate 422 in the second polarizing plate 420 has a positive or negative refractive index anisotropy, and the optical axis is inclined so as to compensate for the phase difference generated in the liquid crystal molecules of the liquid crystal layer 50. ing.

  An optical compensation plate 300 is disposed between the second polarizing plate 420 and the liquid crystal panel 100. The optical compensation plate 300 has a refractive index anisotropy opposite to that of the second support substrate 422 described above. That is, when the second support substrate 422 has a positive refractive index anisotropy, the optical compensation plate 300 has a negative refractive index anisotropy, and the second support substrate 422 has a negative refractive index. In the case of having anisotropy, the optical compensation plate 300 has a positive refractive index anisotropy. Further, the optical axis of the optical compensation plate 300 is set to the same angle as the optical axis of the second support substrate 422. The optical compensation plate 300 and the second support substrate 422 will be described in detail later.

  As shown in FIG. 4, the optical compensation plate 300 may be disposed on the light source light incident side of the liquid crystal panel 100. In this case, in the first polarizing plate 410, the first support substrate 412 is closer to the liquid crystal panel 100 than the first polarizing element 411. In the second polarizing plate 420, the second polarizing element 421 is located closer to the liquid crystal panel 100 than the second support substrate 422. That is, in such a case, the first polarizing plate 410 is an example of the “optical compensation polarizing plate” of the present invention.

  Next, the optical compensation plate 300 and the second support substrate 422 will be described in detail with reference to FIGS. FIGS. 5 and 6 are perspective views conceptually showing the optical axes of the optical compensation plate and the support substrate, respectively. FIG. 7 shows the phase difference compensated by the optical compensation plate and the support substrate together with a comparative example. It is a graph to show. In the following description, as shown in FIG. 3, an example in which the optical compensation plate 300 is disposed on the light source light emission side of the liquid crystal panel 100 will be described. The optical compensation plate 300 has a positive refractive index anisotropy, and the second support substrate 422 has a negative refractive index anisotropy.

  In FIG. 5, the optical axis in the optical compensator 300 having positive refractive index anisotropy is conceptually represented by the inclination of the ellipsoidal crystal (that is, the inclination of the major axis or the central axis of the refractive index ellipsoid). Can do. Further, the optical axis of the second support substrate 422 having negative refractive index anisotropy can be conceptually expressed by the inclination of the crystal on the flat plate (that is, the inclination of the central axis of the flat refractive index ellipsoid). it can. As shown in the figure, the optical axes of the optical compensation plate 300 and the second support substrate 422 are configured to be inclined at a predetermined angle θ. That is, the optical axes of the optical compensation plate 300 and the second support substrate 422 are in the same direction. The predetermined angle θ is an angle corresponding to the inclination of the liquid crystal molecules near the interface with the alignment film, which is inclined due to, for example, the pretilt imparted by the alignment film. In the case where the liquid crystal panel 100 is a VA liquid crystal as in the present embodiment, for example, it is tilted by about 5 °.

  Here, assuming that the thickness of the optical compensation plate 300 is W1 and the thickness of the second support substrate 422 is W2 smaller than W1, the phase difference compensated by the optical compensation plate 300 is larger than the phase difference compensated by the second support substrate 422. It is assumed that the configuration is as follows. In this case, the phase difference of the optical compensation plate 300 and the second support substrate 422 is canceled out, and the phase difference to be compensated as a whole is obtained by subtracting the phase difference of the second support substrate 422 from the phase difference of the optical compensation plate 300. It becomes. That is, the phase difference compensated as a whole can be made relatively small. As shown in the figure, the refractive index anisotropy is positive because the optical compensator 300 is larger, and the angle of the optical axis is inclined by a predetermined angle θ for both the optical compensator 300 and the second support substrate 422. Therefore, it is similarly inclined by a predetermined angle θ.

  In FIG. 6, assuming that the thickness of the optical compensation plate 300 is W3 and the thickness of the second support substrate 422 is W4 larger than W3, the phase difference compensated by the optical compensation plate 300 is determined from the phase difference compensated by the second support substrate 422. Assume that it is configured to be small. In this case as well, the phase differences of the optical compensation plate 300 and the second support substrate 422 are canceled out each other, and the phase difference to be compensated as a whole is obtained by subtracting the phase difference of the optical compensation plate 300 from the phase difference of the second support substrate 422. Subtracted. That is, the phase difference compensated as a whole can be made relatively small. As shown in the figure, the refractive index anisotropy is negative because the phase difference of the second support substrate 422 is larger, and the angle of the optical axis is a predetermined angle for both the optical compensation plate 300 and the second support substrate 422. Since it is inclined by θ, it is similarly inclined by a predetermined angle θ.

  As described above, when the phase difference is compensated by the two optical compensation elements of the optical compensation plate 300 and the second support substrate 422, by adjusting the thicknesses of the optical compensation plate 300 and the second support substrate 422, respectively. A desired phase difference can be compensated. Therefore, for example, when a relatively small phase difference is to be compensated, it is not necessary to polish a crystal as a material thinly (for example, about several μm to several tens μm). Therefore, the manufacturing process can be made relatively simple. Hereinafter, specific examples of the optical compensation plate 300 and the second support substrate 422 will be described together with comparative examples.

  In FIG. 7, if an optical compensation element having a compensation phase difference of 200 nm is realized with only one sapphire crystal plate, the thickness is 25 μm, and the relationship between the arrangement angle and the phase difference is indicated by a solid line in the figure. As shown. On the other hand, when trying to realize a similar optical compensation element using a crystal plate of quartz in addition to a crystal plate of sapphire, for example, if the thickness of the crystal plate of crystal is 500 μm, the thickness of the sapphire crystal plate May be 645 μm. The relationship between the arrangement angle and the phase difference is as shown by a chain line in the figure, and it is possible to obtain a compensation effect similar to that in the case of only the sapphire crystal plate described above. That is, if two crystal plates having different refractive index anisotropies are used, the same compensation effect can be obtained even with a crystal plate having a very large thickness as compared with the case of one crystal plate. Therefore, in the electro-optical device that compensates for the phase difference using the two crystal plates of the optical compensation plate 300 and the second support substrate 422 as in the present embodiment, the phase difference is reduced while facilitating manufacture. It is possible to compensate appropriately. Since the phase difference to be compensated depends on the refractive index of the material, the thickness for obtaining the desired phase difference varies depending on the material, but can be obtained by a relatively simple calculation.

  Next, the operation of the electro-optical device according to the first 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. Here, in the first polarizing plate 410, the first polarizing element 411 is located closer to the liquid crystal panel 100 than the first support substrate 412. For this reason, even if the first support substrate 412 has a refractive index anisotropy (that is, a phase difference is generated in the light source light), the phase is shifted by the first polarizing element 411 in the subsequent stage. Aligned. Accordingly, the light source light that has passed through the first polarizing plate 410 becomes linearly polarized light.

  The light source light that has passed through the first polarizing plate 410 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.

  The light source light that has passed through the liquid crystal panel 100 is incident on the optical compensation plate 300. Further, after passing through the optical compensation plate 300, the light is incident on the second support substrate 422 in the second polarizing plate 420. For this reason, the phase difference generated in the liquid crystal panel 100 or the like is appropriately compensated by the optical compensation plate 300 and the second support substrate 422. Therefore, in the second polarizing element 421, it is possible to prevent the light that is allowed to pass or not pass the light that is allowed to pass, and to increase the contrast of the displayed image.

  As described above, according to the electro-optical device according to the first embodiment, the optical compensation plate 300 and the second support substrate 422 can appropriately compensate for the phase difference generated in the light source light. Therefore, it is possible to display a high quality image.

Second Embodiment
Next, an electro-optical device according to a second embodiment will be described with reference to FIG. FIG. 8 is a cross-sectional view showing the configuration of the electro-optical device according to the second embodiment. The second embodiment differs from the first embodiment described above in the configuration of the optical compensation plate 300, and the other configurations are generally the same. For this reason, in the second embodiment, the optical compensation plate 300 will be described in detail, and description of other components will be omitted as appropriate. In FIG. 8, the same reference numerals are assigned to the same components as the components according to the first embodiment shown in FIGS. 3 and 4.

  In FIG. 8, in the electro-optical device according to the second embodiment, an optical compensation plate 300 is formed on the outer surface of the liquid crystal panel 100. For this reason, the optical compensator 300 functions as a dust-proof glass of the liquid crystal panel 100 and can prevent the image quality from being deteriorated due to dust, dust, etc. adhering to the liquid crystal panel 100. Further, since the optical compensation plate 300 is formed integrally with the liquid crystal panel 100, space saving is also realized.

  Furthermore, if the optical compensation plate 300 is formed of a material having a relatively high heat dissipation property such as quartz, it can be made to function as a heat dissipation plate of the liquid crystal panel 100. If the optical compensator 300 can efficiently release the heat generated in the liquid crystal panel 100, the liquid crystal panel can be effectively prevented from malfunctioning or malfunctioning.

  As described above, according to the electro-optical device according to the second embodiment, it is possible to display a high-quality image more suitably.

<Third Embodiment>
Next, an electro-optical device according to a third embodiment will be described with reference to FIG. FIG. 9 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 embodiment described above in the configuration of the optical compensation plate 300, and the other configurations are generally the same. For this reason, in the third embodiment, the optical compensation plate 300 will be described in detail, and description of other components will be omitted as appropriate. In FIG. 9, the same reference numerals are assigned to the same components as the components according to the first embodiment shown in FIGS. 3 and 4.

  In FIG. 9, in the electro-optical device according to the third embodiment, the optical compensation plate 300 is formed on the outer surface of the second support substrate 422 in the second polarizing plate 420. That is, the optical compensation plate 300 and the second support substrate 422 that are optical compensation elements are fixed to each other.

  As described above, since the optical compensation plate 300 and the second support substrate 422 are fixed to each other, for example, when the optical compensation plate 300 is disposed, the angles of the optical axes of the optical compensation plate 300 and the second polarizing plate 420 are arranged. Can be prevented from shifting.

  If the angles of the optical axes of the optical compensator 300 and the second polarizing plate 420 are deviated, the angle of the optical axis as a whole changes. Further, the phase difference to be compensated as a whole also changes. That is, the phase difference may not be compensated appropriately.

  In contrast, in the electro-optical device according to the third embodiment, as described above, the optical compensation plate 300 and the second support substrate 422 are fixed to each other. Therefore, the optical compensation plate 300 and the second support substrate 422 can be arranged so that the optical axis is at an appropriate angle more easily. Therefore, it is possible to reliably compensate for the phase difference of the light source light. Further, since the optical compensation plate 300 is formed integrally with the second support substrate 422, space saving is also realized.

  As described above, according to the electro-optical device according to the third embodiment, it is possible to display a high-quality image more preferably.

<Fourth embodiment>
Next, an electro-optical device according to a fourth 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 fourth embodiment. FIGS. 11 and 12 are cross-sectional views showing modifications of the electro-optical device according to the fourth embodiment. . In the fourth embodiment, a case where the liquid crystal layer 50 of the liquid crystal panel 100 is a TN liquid crystal will be described as an example. 10 to 12, the same reference numerals are assigned to the same components as the components according to the first embodiment shown in FIGS. 3 and 4, and the first to third embodiments described above are duplicated. Description is omitted as appropriate.

  10, in the electro-optical device according to the fourth embodiment, the liquid crystal layer 50 in the liquid crystal panel 100 is a TN liquid crystal, and the optical compensation plate 300 is disposed on both the incident side and the emission side of the light source light in the liquid crystal panel 100. Has been. When the liquid crystal panel 100 is a TN liquid crystal as in the present embodiment, the compensation effect can be further enhanced by arranging the optical compensation plates 300 on the incident side and the emission side in this way.

  As for the 1st polarizing plate 410 and the 2nd polarizing plate 420, the support substrate is made into the liquid crystal panel 100 side from the polarizing element. That is, the first support substrate 412 is closer to the liquid crystal panel 100 than the first polarizing element 411, and the second support substrate 422 is closer to the liquid crystal panel 100 than the second polarizing element 421.

  Here, the two optical compensation plates 300, and the first support substrate 412 and the second support substrate 422 typically have liquid crystal molecules at one interface of the light source light incident side and the light output side in the liquid crystal layer 50. It arrange | positions so that it may each respond | correspond to inclination. That is, the phase difference generated at different positions is separately compensated by the incident-side optical compensation plate 300 and the first support substrate 412, and the emission-side optical compensation plate 300 and the second support substrate 422. Therefore, the phase difference generated in the liquid crystal panel 100 or the like is more reliably compensated. When the liquid crystal panel 100 is a TN liquid crystal, the inclination angle θ of the optical axis shown in FIGS. 3 and 4 is, for example, about 60 ° to 80 °.

  As shown in FIG. 11, if two optical compensators 300 are formed on the outer surface of the liquid crystal panel 100, various effects that are useful in practice can be obtained as described in the second embodiment. . Further, as shown in FIG. 12, even if two optical compensators are formed on the outer surfaces of the first polarizing plate 410 and the second polarizing plate 420, respectively, as described in the third embodiment, it is practically useful. Various effects can be obtained. In FIGS. 11 and 12, both the incident-side and emission-side optical compensation plates 300 are formed on the surface of the liquid crystal panel 100, the first polarizing plate 410, or the second polarizing plate 420. Only one optical compensation plate 300 may be formed on the surface of the liquid crystal panel 100 or the first polarizing plate 410 or the second polarizing plate 420.

  As described above, according to the electro-optical device according to the fourth embodiment, the two optical compensation plates 300, the first support substrate 412 and the second support substrate 422 can appropriately reduce the phase difference generated in the light source light. It is possible to compensate. Therefore, it is possible to display a high quality image.

<Electronic equipment>
Next, the case where the liquid crystal device which is the above-described electro-optical device is applied to various electronic devices will be described. FIG. 13 is a plan view showing a configuration example of the projector. Hereinafter, a projector using the liquid crystal device as a light valve will be described.

  As shown in FIG. 13, a projector 1100 includes a lamp unit 1102 made of a white light source such as a halogen lamp. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

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

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

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

  In addition to the electronic device described with reference to FIG. 13, 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. FIG. 6 is a cross-sectional view illustrating a modification of the electro-optical device according to the first embodiment. It is a perspective view (the 1) which shows notionally the optical axis in an optical compensation board and a support substrate. It is a perspective view (the 2) which shows notionally the optical axis in an optical compensation board and a support substrate. It is a graph which shows the phase difference compensated with an optical compensation board and a support substrate. FIG. 6 is a cross-sectional view illustrating a configuration of an electro-optical device according to a second embodiment. FIG. 6 is a cross-sectional view illustrating a configuration of an electro-optical device according to a third embodiment. FIG. 10 is a cross-sectional view illustrating a configuration of an electro-optical device according to a fourth embodiment. FIG. 10 is a cross-sectional view (No. 1) illustrating a modification of the electro-optical device according to the fourth embodiment. FIG. 14 is a cross-sectional view (No. 2) illustrating a modification of the electro-optical device according to the fourth 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, 300 ... Optical compensator, 410 ... 1st polarizing plate, 411 ... 1st polarized light Elements, 412 ... 1st support substrate, 420 ... 2nd polarizing plate, 421 ... 2nd polarizing element, 422 ... 2nd support substrate

Claims (8)

A liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of first and second substrates;
A polarizing plate and a supporting substrate for supporting the polarizing device, a pair of polarizing plates respectively disposed on the incident side and the outgoing side of the light source light in the liquid crystal panel;
An optical compensator having a refractive index anisotropy polarity of positive or negative, and disposed on at least one of an incident side and an emission side of light source light in the liquid crystal panel so as to be sandwiched between the polarizing plate and the liquid crystal panel; With
Of the pair of polarizing plates, the optical compensation polarizing plate which is opposite to the liquid crystal panel via the optical compensation plate has a refractive index anisotropy in which the support substrate has a polarity opposite to that of the optical compensation plate. The electro-optical device is configured so that the support substrate is closer to the liquid crystal panel than the polarizing element.   The support substrate in the optical compensation plate and the optical compensation polarizing plate has a refractive index and a thickness that make the phase difference of the whole approach a desired phase difference by canceling out the phase difference of each. The electro-optical device according to claim 1.   The electro-optical device according to claim 1, wherein the optical axes of the support substrates in the optical compensation plate and the optical compensation polarizing plate are in the same direction.   The electro-optical device according to claim 1, wherein the optical compensation plate is provided integrally with the liquid crystal panel.   The electro-optical device according to claim 1, wherein the optical compensation plate is provided integrally with the optical compensation polarizing plate.   6. The electro-optic according to claim 1, wherein, of the optical compensation plate and the support substrate in the optical compensation polarizing plate, the one having the positive polarity includes quartz. apparatus.   The electro-optic according to any one of claims 1 to 6, wherein, of the support substrates in the optical compensation plate and the optical compensation polarizing plate, the one having the negative polarity includes sapphire. apparatus.   An electronic apparatus comprising the electro-optical device according to claim 1.

Images