JP2009145464A - Electro-optical device, and method of manufacturing the same, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and appropriately compensate retardation in an electro-optical device such as a liquid crystal device. <P>SOLUTION: The electro-optical device includes: a liquid crystal panel (100) comprising a liquid crystal layer (50) interposed between a pair of a first substrate (20) and a second substrate (10); a first polarizing plate (410) which is disposed on one of the incident side and the outgoing side of the light source light in the liquid crystal panel; a second polarizing plate (420) which is disposed on the other of the incident side and the outgoing side of the light source light in the liquid crystal panel, and of which the polarization axis deviates from the angular position corresponding to the angle of liquid crystal molecules in the liquid crystal layer by a predetermined angle; and at least an optical compensation plate (310) which is disposed between the first polarizing plate and the second polarizing plate, and of which the optical axis is tilted so as to compensate the retardation produced in the liquid crystal molecules of the liquid crystal layer, wherein the predetermined angle is set such that the retardation after compensation gets smaller than that when the polarization axis of the second polarizing plate does not deviate by the predetermined angle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electro-optical device such as a liquid crystal device and a manufacturing method thereof, and a technical field of 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, according to a study by the inventors of the present application, the phase difference generated in the light changes depending on the wavelength of the light and the polarization degree of the polarizing plate. For this reason, in order to appropriately compensate for the phase difference, it is better to compensate according to the wavelength of light and the degree of polarization of the polarizing plate.

  When the optical compensation plate is used to appropriately compensate for the phase difference as in the technique described above, the thickness of the optical compensation plate, the inclination of the optical axis, etc. are determined according to the wavelength of light and the polarization degree of the polarizing plate. Depending on the situation, it may be necessary to change each time. In other words, the above-described technique has a technical problem that if appropriate compensation is realized under various conditions, a significant increase in manufacturing period, cost, and the like is caused.

  SUMMARY An advantage of some aspects of the invention is that it provides an electro-optical device, a manufacturing method thereof, and an electronic apparatus that can easily and appropriately compensate for a phase difference.

  In order to solve the above problems, an electro-optical device of the present invention includes a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of first and second substrates, and a light source light incident side and an output side of the liquid crystal panel. The first polarizing plate arranged on one side and the other of the incident side and the outgoing side of the light source light in the liquid crystal panel are arranged such that the polarization axis is deviated from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer by a predetermined angle. The second polarizing plate arranged between the first polarizing plate and the second polarizing plate, wherein the optical axis is inclined so as to compensate for the phase difference generated in the liquid crystal molecules of the liquid crystal layer. Two optical compensators, and the predetermined angle is set so that a phase difference after the compensation is small compared to a case where the polarization axis of the second polarizing plate is not shifted by the predetermined angle. .

  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).

  In this invention, the 1st polarizing plate and the 2nd polarizing plate are arrange | positioned at the incident side and output side of the light source light in a liquid crystal panel. That is, the light source light incident on the liquid crystal panel is first incident on the liquid crystal panel in addition to the light vibration direction being aligned in a specific direction by the polarizing plate disposed on the incident side. The The light source light that has passed through the liquid crystal panel is incident on the output-side polarizing plate, and an image is displayed by the light source light that has passed through the output-side polarizing plate.

  In addition, at least one optical compensation plate is disposed between the first polarizing plate and the second polarizing plate. The position of the optical compensator with respect to the liquid crystal panel may be on the incident side of the light source light and on the outgoing side. When the liquid crystal in the liquid crystal layer is a TN (Twisted Nematic) liquid crystal, it is arranged more on the incident side and the outgoing side. It is also possible to obtain a high compensation effect. Note that the polarity of refractive index anisotropy of the optical compensation plate may be positive or negative.

  The optical compensator is tilted so that the optical axis compensates for the phase difference caused by the liquid crystal molecules in the liquid crystal layer. The “phase difference caused by the liquid crystal molecules in the liquid crystal layer” is typically an interface with the alignment film due to the pretilt imparted by the alignment film in TN liquid crystal or VA (Vertical Alignment) liquid crystal. It means the phase difference that occurs in nearby liquid crystal molecules. However, it may include a phase difference caused by other factors such as a phase difference caused by liquid crystal molecules slightly away from the interface with the alignment film, or birefringence in liquid crystal molecules. By compensating for such a phase difference, it is possible to prevent a decrease in contrast and a narrowing of the viewing angle. That is, the image quality of the displayed image can be improved.

  Here, in order to set the optical axis of the optical compensator to an ideal or theoretical angle that can minimize the phase difference, the mounting angle of the optical compensator may be finely adjusted. However, such attachment work is not easy in practice. In particular, according to the study by the present inventor, the phase difference generated in the light source light depends on the color of the liquid crystal panel (that is, the wavelength of the light source light), and further the type of polarizing plate (that is, It varies depending on the polarization degree of the polarizing plate. For this reason, the mounting operation of the optical compensator involves individual fine adjustments and is incompatible with mass production or automation.

  In contrast, in the present invention, in particular, the first and second polarizing plates are arranged so that the angle of the polarization axis of the second polarizing plate is deviated by a predetermined angle from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer. The “angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer” is an angle that changes according to the tilt angle of the liquid crystal molecules in the liquid crystal layer, and is the highest or relatively high when no phase difference occurs. It means an angle that allows display with contrast. Typically, it is set by matching with the rubbing direction of the alignment film in the liquid crystal panel. For example, in the case of a TN liquid crystal having a general crossed Nicol arrangement (orthogonal Nicol arrangement), the polarization axis is 90 ° with respect to the rubbing direction. It arrange | positions so that it may become. In the case of a VA liquid crystal, the polarizing axis is arranged at 45 ° with respect to the rubbing direction. The predetermined angle is set so that the phase difference after compensation is smaller than in the case where the polarization axis of the second polarizing plate is not shifted by the predetermined angle. In other words, the phase difference after compensation is reduced by shifting the polarization axis of the second polarizing plate by a predetermined angle. Considering only the phase difference, it is ideal and preferable that the phase difference after compensation is minimized or minimized. The predetermined angle is set, for example, by displaying an image while actually adjusting the angle of the polarization axis of the second polarizing plate. Note that if the deviation from the angle corresponding to the liquid crystal molecules is too large, the illuminance may decrease. For this reason, even if the phase difference after compensation cannot be minimized, minimized, or in the vicinity thereof, the predetermined angle is desirably 3 ° or less.

  The angle of the polarization axis of the second polarizing plate can be adjusted, for example, after the optical compensation plate is formed or attached. Therefore, it is possible to compensate for the phase difference more appropriately without increasing the period and cost for the optical compensator forming process and attachment process.

  As described above, according to the electro-optical device according to the present invention, it is possible to improve the image quality without increasing the manufacturing period or cost by shifting the polarization axis of the second polarizing plate by a predetermined angle. is there.

  In one aspect of the electro-optical device of the present invention, the first polarizing plate is disposed such that the polarization axis is an angle corresponding to the polarization axis of the second polarizing plate.

  According to this aspect, the arrangement angle of the first polarizing plate is an angle corresponding to the polarization axis of the second polarizing plate. That is, they are arranged at an angle corresponding to the polarization axis of the second polarizing plate shifted by a predetermined angle. The “angle corresponding to the polarization axis of the second polarizing plate” means an angle that takes into account the phase change in the liquid crystal panel with respect to the angle of the polarization axis of the second polarizing plate. For example, in the case of a TN liquid crystal having a general crossed Nicol arrangement (orthogonal Nicol arrangement), an angle shifted by 90 ° with respect to the angle of the polarization axis of the second polarizing plate is a corresponding angle. Similarly, in the case of VA liquid crystal, an angle shifted by 90 ° with respect to the angle of the polarization axis of the second polarizing plate is a corresponding angle.

  As described above, when the arrangement angle of the first polarizing plate is set to an angle corresponding to the polarization axis of the second polarizing plate, the polarization axis of the second polarizing plate is deviated from the angle corresponding to the liquid crystal molecules by a predetermined angle. Even so, the relative angles of the first and second polarizing plates can be made appropriate. Therefore, for example, it is possible to prevent the basic function of the pair of polarizing plates functioning on the assumption of the crossed Nicol arrangement or the like from being deteriorated. Therefore, it is possible to display a higher quality image.

  In another aspect of the electro-optical device according to the aspect of the invention, the first polarizing plate is disposed such that a polarization axis is shifted from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer by a predetermined angle.

  According to this aspect, in addition to the second polarizing plate, the first polarizing plate is also arranged such that the polarization axis is deviated from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer by a predetermined angle. In addition, it is assumed that the rotation directions when the polarization axes of the first polarizing plate and the second polarizing plate are shifted by a predetermined angle (that is, the direction of shifting the polarization axis) are the same.

  As described above, the first polarizing plate and the first polarizing plate are arranged by shifting the first polarizing plate even when the polarization axis of the second polarizing plate is deviated from the angle corresponding to the liquid crystal molecules by a predetermined angle. The relative angle of the two polarizing plates can be made appropriate. Therefore, for example, it is possible to prevent the basic function of the pair of polarizing plates functioning on the assumption of the crossed Nicol arrangement or the like from being deteriorated. Therefore, it is possible to display a higher quality image.

  In another aspect of the electro-optical device of the present invention, the predetermined angle is set for each wavelength of the light source light.

  According to this aspect, the polarization axis of the second polarizing plate is shifted from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer by a predetermined angle set for each wavelength of the light source light. In the aspect in which the polarization axis of the first polarizing plate is also shifted, the first polarizing plate is similarly shifted by a predetermined angle set for each wavelength of the light source light. The predetermined angle may be calculated using, for example, a formula from the wavelength of the light source light, or an image is actually displayed using the light source light of a different wavelength, and the relationship between the adjustment angle and the image quality is experimentally determined for each wavelength. It may be set by asking for.

  As described above, the phase difference generated in the light source light in a liquid crystal panel or the like varies depending on the wavelength of the light source light. Therefore, by setting a predetermined angle for each wavelength, the polarization axis of the polarizing plate can be shifted more easily and appropriately. Therefore, it is possible to improve the image quality more suitably.

  In another aspect of the electro-optical device of the present invention, the predetermined angle is set for each polarization degree of the first and second polarizing plates.

  According to this aspect, the polarization axis of the second polarizing plate is shifted from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer by a predetermined angle set for each degree of polarization of the first and second polarizing plates. In the above-described aspect in which the polarization axis of the first polarizing plate is also shifted, the first polarizing plate is similarly shifted by a predetermined angle set for each degree of polarization of the first and second polarizing plates. The predetermined angle may be calculated by using, for example, a formula or the like from the polarization degrees of the first and second polarizing plates, or an image is actually displayed using polarizing plates having different polarization degrees, and between the adjustment angle and the image quality. This relationship may be set by experimentally determining the degree of polarization for each degree of polarization.

  As described above, the phase difference generated in the light source light in a liquid crystal panel or the like varies depending on the polarization degree of the polarizing plate. Therefore, by setting a predetermined angle for each degree of polarization, it is possible to shift the polarization axis of the polarizing plate more easily and appropriately. Therefore, it is possible to improve the image quality more suitably.

  In another aspect of the electro-optical device of the present invention, the optical compensation plate is fixed to the liquid crystal panel.

  According to this aspect, since the optical compensation plate is fixed to the liquid crystal panel, the angle of the optical compensation plate cannot be adjusted. In other words, the phase difference of the light source light cannot be reduced by finely adjusting the tilt angle of the optical axis of the optical compensator. Further, if the optical compensator is adjusted before being fixed to the liquid crystal panel, it must be performed at a relatively early stage of the manufacturing process, so that it is difficult to adjust to an appropriate angle.

  Here, particularly in this embodiment, as described above, the phase difference of the light source light can be reduced by shifting the polarization axis of the polarizing plate by a predetermined angle. Therefore, even when the optical compensation plate is fixed to the liquid crystal panel, it is possible to improve the image quality suitably.

  In the aspect in which the above-described optical compensator is fixed to the liquid crystal panel, the optical compensator may function as dust-proof glass and may be configured to be bonded to the outer surface of the liquid crystal panel. .

  If comprised in this way, the optical compensator will be fixed by bonding together on the outer surface of a liquid crystal panel, and will function as dustproof glass of a liquid crystal panel. Therefore, it is possible to prevent the image quality from being deteriorated due to dust or the like adhering to the outer surface of the liquid crystal panel.

  Furthermore, as described above, the optical compensator is bonded to the outer surface of the liquid crystal panel, so that if the optical compensator is formed of a material having high heat dissipation, it can function as a heat sink. If the heat of the liquid crystal panel can be radiated by the optical compensator, the liquid crystal panel can be prevented from malfunctioning or malfunctioning. Thus, the “dust-proof glass” may have a heat resistance or heat dissipation function in addition to a dust-proof function, and may further have a defocus function. In that sense, it can also be called heat-resistant glass, heat radiating glass, defocused glass, or the like.

  In another aspect of the electro-optical device of the present invention, at least one of the first and second polarizing plates has a rotation mechanism.

  According to this aspect, since at least one of the first and second polarizing plates has a rotation mechanism, the angle of the polarization axis can be adjusted by rotating each polarizing plate. 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.

  If the polarizing plate is rotated using the rotating mechanism, the angle can be adjusted more easily than in the case where the rotating mechanism is not used. If the rotation mechanism can be adjusted with high accuracy, the angle of the polarization axis can be made more appropriate. Therefore, the phase difference generated in the light source light is further reduced.

  As described above, according to the electro-optical device according to this aspect, since the polarizing plate has the rotation mechanism, the image quality can be improved more suitably.

  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 phase difference generated in the liquid crystal panel or the like is more appropriately compensated. Accordingly, a projection display device, television, mobile phone, electronic notebook, word processor, viewfinder type or monitor direct-view type video tape recorder, workstation, video phone, POS terminal, touch panel capable of high-quality display Various electronic devices such as can be realized. Further, as the electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper can be realized.

  In addition, the electronic apparatus of the present invention exhibits further beneficial effects when it includes a plurality of the electro-optical devices described above. For example, when an electronic device displays a full color image by combining light of RGB three primary colors, the wavelengths of the light source light in the plurality of electro-optical devices are different. For this reason, if an appropriate compensation is made by the optical compensator, an optical compensator different for each wavelength is formed, or the mounting angle is finely adjusted, resulting in an increase in manufacturing period and cost.

  On the other hand, the electronic apparatus of the present invention can more appropriately compensate for the phase difference generated in the plurality of electro-optical devices by adjusting the angle of the polarization axis of the second polarizing plate to an appropriate angle. Become. Therefore, it is possible to improve the image quality more easily and appropriately.

  In order to solve the above problems, a method of manufacturing an electro-optical device according to the present invention includes a liquid crystal panel disposing step of disposing a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of first and second substrates, A first polarizing plate disposing step of disposing a first polarizing plate on one of the incident side and the emitting side of the light source light, and the polarizing axis on the other of the incident side and the emitting side of the light source light in the liquid crystal panel. A second polarizing plate disposing step of disposing a second polarizing plate so as to deviate a predetermined angle from an angle corresponding to an angle of liquid crystal molecules in the liquid crystal layer, and an optical axis between the first polarizing plate and the second polarizing plate. An optical compensator attaching step of attaching at least one optical compensator so as to compensate for the phase difference generated in the liquid crystal molecules of the liquid crystal molecules, wherein the predetermined angle is such that the polarization axis of the second polarizing plate is the predetermined angle When it does not shift And compare, are set so that the phase difference becomes smaller in after being the compensation.

  According to the method of manufacturing the electro-optical device according to the invention, in the second polarizing plate arranging step, the second polarizing plate is arranged so as to be shifted from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer by a predetermined angle. Therefore, as in the case of the electro-optical device of the present invention described above, it is possible to improve the image quality without increasing the manufacturing period and cost.

  In the electro-optical device manufacturing method of the present invention, various aspects similar to the various aspects of the electro-optical device of the present invention described above can be employed.

  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 6. FIG. 3 is a cross-sectional view showing the configuration of the electro-optical device according to the first embodiment, and FIGS. 4 and 5 are cross-sectional views showing comparative examples of the electro-optical device according to the first embodiment. . FIG. 6 is a perspective view showing the angle of the polarization axis in the polarizing plate. Hereinafter, a case where the liquid crystal of the liquid crystal layer 50 is a TN liquid crystal will be described as an example.

  In FIG. 3, the electro-optical device according to this embodiment includes the above-described liquid crystal panel 100, the first optical compensation plate 310, the first polarizing plate 410, and the second polarizing plate 420.

  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 second polarizing plate 420 and the liquid crystal panel 100. The first optical compensator 310 includes, for example, a crystal having refractive index anisotropy, and the optical axis is inclined so as to compensate for a phase difference generated in the liquid crystal molecules of the liquid crystal layer 50. More specifically, for example, the liquid crystal molecules are inclined so as to correspond to the inclination of the liquid crystal molecules near the interface with the alignment film, which is inclined due to the pretilt imparted by the alignment film.

  As shown in FIG. 4, the first optical compensation plate 310 may be disposed between the liquid crystal panel 100 and the first polarizing plate 410. That is, the first optical compensation plate 310 may be disposed on the light source light incident side or the light exit side of the liquid crystal panel 100. In addition, as shown in FIG. 5, the second optical compensation plate 320 may be disposed so as to face the first optical compensation plate 310 via the liquid crystal panel 100. That is, a plurality of optical compensation plates may be arranged. The arrangement shown in FIG. 5 exhibits a particularly high compensation effect when the liquid crystal of the liquid crystal layer 50 is a TN liquid crystal as in this embodiment.

  In FIG. 6, the first polarizing plate 410 and the second polarizing plate 420 are arranged such that their polarization axes are deviated from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer 50 by a predetermined angle. For example, as shown in the figure, when the rubbing direction of the alignment film on the incident side (that is, the counter substrate 20 side) in the liquid crystal panel 100 is the angle indicated by the arrow P3 (that is, the X direction in the figure), the first polarization The angle corresponding to the liquid crystal molecules in the plate 410 is an angle (that is, the Y direction in the drawing) that forms 90 ° with respect to the angle indicated by the arrow P3. On the other hand, in the electro-optical device according to the present embodiment, the angle of the polarization axis of the first polarizing plate 410 is the angle indicated by the arrow P1 that is deviated by a predetermined angle θ from the Y direction. Further, if the liquid crystal panel 100 is a TN liquid crystal having a general crossed Nicols arrangement (orthogonal Nicols arrangement), the rubbing direction of the alignment film on the emission side (that is, the TFT array substrate 10 side) is an angle indicated by the arrow P4 (that is, FIG. Middle Y direction). In this case, the angle corresponding to the liquid crystal molecules in the second polarizing plate 420 is an angle (that is, the X direction in the drawing) that forms 90 ° with respect to the angle indicated by the arrow P4. On the other hand, in the electro-optical device according to the present embodiment, the angle of the polarization axis of the second polarizing plate 420 is the angle indicated by the arrow P2 that is shifted from the X direction by a predetermined angle θ. Note that the polarization axes of the first polarizing plate 410 and the second polarizing plate 420 are both displaced by a predetermined angle θ from the angle corresponding to the angle of the liquid crystal molecules, and thus are in a crossed Nicols arrangement.

  Next, the angle of the polarization axis of the polarizing plate will be described in detail with reference to FIGS. FIG. 7 is a graph showing the relationship between the adjustment angle and contrast of the optical compensator for each color of the light source light, and FIG. 8 is a graph showing the relationship between the adjustment angle of the optical compensator and the contrast for each type of polarizing plate. is there. FIG. 9 is a graph showing the relationship between the angle of the polarization axis of the second polarizing plate and the contrast, and the relationship between the angle of the polarization axis of the second polarizing plate and the adjustment angle of the optical compensator. The graph shown in FIG. 9 shows the result of measurement using the first optical compensator 310 in which the light source light is green light, the crystal is formed to have a thickness of 10 nm and the optical axis angle is 25 °. It is a graph.

  In FIG. 7, according to a study by the present inventor, the relationship between the adjustment angle of the first optical compensation plate 310 and the contrast of the displayed image differs depending on the color (that is, wavelength) of the light source light. For this reason, when the adjustment angle is not changed depending on the wavelength of the light source light, the contrast may not be improved appropriately. In particular, in FIG. 7, the adjustment angle for obtaining the optimum contrast is greatly different between green light with high luminance and other red light and blue light. Therefore, for example, when a full-color image is displayed with the above-described three colors of red light, green light, and blue light, the first optical compensator 310 whose optical axis angle is adjusted according to red light and blue light is provided. If used, it is considered that the reduction in contrast becomes conspicuous. Further, even when the angle is adjusted in accordance with the green light, the two colors of red light and blue light are affected, and it is considered that the reduction in contrast becomes conspicuous. Therefore, when the three colors of light are combined, the color becomes inaccurate (for example, the projected color image is reddish or bluish).

  In FIG. 8, according to a study by the present inventor, the relationship between the adjustment angle of the first optical compensation plate 310 and the contrast of the displayed image varies depending on the type of polarizing plate (that is, the degree of polarization). . For example, as shown in the figure, when displaying an image using two types of polarizing plates A and B having different degrees of polarization, the adjustment angle for obtaining the optimum contrast depends on the type of polarizing plate. to differ greatly. For this reason, when the adjustment angle is not changed depending on the type of polarizing plate to be used, the contrast may not be improved appropriately.

  As a result, when the first optical compensation plate 310 is disposed, the contrast may not be improved properly unless the angle is adjusted according to the wavelength of the light source light and the polarization degree of the polarizing plate. However, installation work with such individual fine adjustment is not easy in practice and is incompatible with mass production or automation.

  On the other hand, in the electro-optical device according to the present embodiment, as described above, the polarization axes of the first polarizing plate 410 and the second polarizing plate 420 are predetermined from an angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer 50. By arranging so that the angle is shifted, the compensation effect by the first optical compensation plate 310 is adjusted to be higher.

  In FIG. 9, according to a study by the present inventor, the polarization axis of the second polarizing plate 420 is obtained when the contrast shown by the bar graph is to be maintained at a higher value compared to the case without the first optical compensator 310. It has been found that a linear relationship as shown by a line graph is established between the angle and the adjustment angle of the first optical compensation plate 310. That is, even when the adjustment angle of the first optical compensator 310 is slightly deviated from an appropriate angle, the contrast can be improved by shifting the polarization axis of the second polarizing plate 420. However, if the polarization axis of the second polarizing plate 420 is greatly shifted, the deviation from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer 50 becomes large, so that the illuminance decreases. Therefore, it is desirable that the angle by which the second polarizing plate 420 is shifted is within 3 °. In other words, the phase difference after compensation is made as small as possible by shifting the second polarizing plate 420 within 3 °. Even if the phase difference after compensation cannot be minimized, minimized, or in the vicinity thereof, it is preferable to avoid the predetermined angle being larger than 3 °.

  As described above, by shifting the angle of the polarization axis of the second polarizing plate 420 by a predetermined angle, it is possible to enhance the compensation effect by the first optical compensator 310 and improve the contrast. Further, since the polarization axis of the first polarizing plate 410 is also shifted by a predetermined angle, the relative angle between the first polarizing plate 410 and the second polarizing plate 420 does not deviate. For this reason, it can prevent that the basic function by a pair of polarizing plate falls by shifting a polarization axis. Therefore, it is possible to display a higher quality image. The specific value of the predetermined angle for shifting the polarization axis of the second polarizing plate 420 is set in advance, for example, by finely adjusting the angle of the second polarizing plate 420 while actually displaying an image. Is possible. Specifically, the predetermined angle here is obtained as the angle by which the second polarizing plate 420 is shifted when the compensated phase difference is as small as possible under the condition of 3 ° or less.

  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. 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 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 that has passed through the liquid crystal panel 100 is incident on the first optical compensation plate 310. Here, if the adjustment angle of the first optical compensation plate 310 is not adjusted to an appropriate angle, appropriate compensation is not performed and the contrast is lowered. However, in the electro-optical device according to the present embodiment, the polarization axis of the second polarizing plate 420 on which the light source light that has passed through the first optical compensation plate 310 is incident has an angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer 50. The angle is shifted by a predetermined angle. Therefore, in the second polarizing plate 420, it is possible to prevent light that is allowed to pass through or light that is not allowed to pass through from passing. 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, the angles of the polarization axes of the first polarizing plate 410 and the second polarizing plate 420 are determined from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer 50. By shifting the angle by a predetermined angle, the influence of the wavelength of the light source light and the polarization degree of the polarizing plate on the compensation effect of the first optical compensation plate 310 can be adjusted. Therefore, even when light sources having different wavelengths or polarizing plates having different polarization degrees are used, it is not necessary to adjust the angle of the optical axis of the first optical compensation plate 310. Therefore, it is possible to display a high-quality image easily and appropriately.

Second Embodiment
Next, an electro-optical device according to a second embodiment will be described with reference to FIG. FIG. 10 is a cross-sectional view showing the configuration of the electro-optical device according to the second embodiment. The second embodiment is different from the first embodiment in the configuration of the first optical compensation plate, and the other configurations are substantially the same. For this reason, in the second embodiment, the configuration of the first optical compensation plate will be described in detail, and description of other configurations will be omitted as appropriate. 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 second embodiment, the first optical compensation plate 310 is attached to the outer surface of the liquid crystal panel 100 and functions as dust-proof glass. In the figure, the first optical compensation plate 310 is attached to the surface of the TFT array substrate 10 on the light source light emission side of the liquid crystal panel 100, but is attached to the surface of the counter substrate 20 on the incident side. Also good. Moreover, you may make it attach to both the incident side and the output side. Since the first optical compensation plate 310 functions as dust-proof glass, it is possible to prevent the image quality from being deteriorated due to adhesion of dust or the like to the liquid crystal panel 100.

  Further, since the first optical compensation plate 310 is formed integrally with the liquid crystal panel 100, it is possible to realize space saving in the apparatus. In particular, when the space on the light source light emission side in the liquid crystal panel 100 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. Therefore, as shown in the figure, the first optical compensator 310 disposed on the light source light emitting side of the liquid crystal panel 100 is formed on the outer surface of the liquid crystal panel 100, thereby reducing the size and cost of the apparatus. It is possible to realize.

  Furthermore, if the first optical compensation plate 310 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 first optical compensator 310 can efficiently release the heat generated in the liquid crystal panel 100, it is possible to effectively prevent the liquid crystal panel from malfunctioning or malfunctioning.

  As described above, according to the electro-optical device according to the second embodiment, various effects that are beneficial in practice can be obtained in addition to the effects in the first embodiment described above.

<Third Embodiment>
Next, an electro-optical device according to a third embodiment will be described with reference to FIGS. FIG. 11 is a cross-sectional view illustrating the configuration of the electro-optical device according to the third embodiment, and FIG. 12 is a perspective view illustrating the configuration of the rotation mechanism. Compared with the first embodiment described above, the third embodiment is different in configuration in that the first and second polarizing plates have 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. 11, the same reference numerals are assigned to the same components as those according to the first embodiment.

  In FIG. 11, in the electro-optical device according to the third embodiment, a rotation mechanism 600 is provided on the first polarizing plate 410 and the second polarizing plate 420.

  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 polarizing plate 410 and the second polarizing plate 420 are fixed by the shaft 610 via the bearing 611. Hereinafter, a more specific configuration and operation of the rotation mechanism 600 will be described using the rotation mechanism in the second polarizing plate 420 as an example.

  In FIG. 12, a shaft 610 bent at 90 ° is attached to the upper part of the second polarizing plate 420. 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 second polarizing plate 420 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 second polarizing plate 420 can be adjusted and fixed to a desired angle. The structure as described above is merely an example of a rotation mechanism, and can be appropriately changed according to the structure of the apparatus. Further, the adjustment of the angle of the second polarizing plate 420 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.

  By providing the rotation mechanism 600 described above, when the polarization axes of the first polarizing plate 410 and the second polarizing plate 420 are shifted from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer 50 by a predetermined angle, Adjustment can be performed more suitably. Therefore, the phase difference generated in the liquid crystal panel 100 or the like is compensated more appropriately. Therefore, according to the electro-optical device according to the third embodiment, it is possible to display a higher quality image.

<Method of manufacturing electro-optical device>
Next, a method for manufacturing the above-described electro-optical device will be described with reference to FIG. FIG. 13 is a flowchart showing a method for manufacturing the electro-optical device. In the following, for convenience of explanation, only main steps in the manufacturing process will be described, and other detailed steps will be omitted as appropriate.

  In FIG. 13, when the electro-optical device is manufactured, the liquid crystal panel 100 is first disposed (step S1). That is, the liquid crystal panel is disposed at a position where the light source light is incident.

  Next, the 2nd polarizing plate 420 is arrange | positioned in the light emission light emission side in the liquid crystal panel 100 (step S2). Here, the angle of the second polarizing plate 420 is adjusted so that the polarization axis deviates from the angle corresponding to the liquid crystal molecules in the liquid crystal layer 50 by a predetermined angle (step S3). At this time, the predetermined angle is obtained by an experiment or the like as described above prior to the production, and is recorded in a memory or a record book. The recorded value is referred to when adjusting the angle. The

  Next, the 1st polarizing plate 410 is arrange | positioned in the incident side of the light source light in the liquid crystal panel 100 (step S4). Here, the polarization axis of the first polarizing plate 410 is adjusted similarly to the second polarizing plate (step S5). Note that the adjustment of the polarization axis in the first polarizing plate 410 may be performed so as to become a corresponding angle while viewing the angle of the second polarizing plate, for example, or without taking the correspondence with the second polarizing plate. The same adjustment can be performed by shifting the angle by a predetermined angle.

  Finally, the first optical compensation plate 310 is disposed between the first polarizing plate 410 and the liquid crystal panel 100, or between the second polarizing plate 420 and the liquid crystal panel 100 (step S6). Usually, in order to perform appropriate compensation by the first optical compensator 310, the angle of the optical axis of the first optical compensator 310 is determined by changing the wavelength of the light source light and the polarization degree of the first polarizer 410 and the second polarizer 420. It is better to set the angle according to the above. However, in the method for manufacturing the electro-optical device according to the present embodiment, the polarization axes of the first polarizing plate 410 and the second polarizing plate 420 are angle-adjusted in step S3 and step S5 described above. Therefore, the optical compensation plate 310 can appropriately compensate for the phase difference generated in the liquid crystal panel or the like.

  It should be noted that the above-described steps S1 to S5 can be interchanged in order. That is, as a result, if the polarization axes of the first polarizing plate 410 and the second polarizing plate 420 are arranged so as to deviate from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer 50 by any predetermined angle, Each member may be arranged in order. However, in order to appropriately adjust the angle of the second polarizing plate 420 for improving the contrast, it is preferable to dispose the second polarizing plate 420 before the first polarizing plate 410 as described above.

  As described above, the electro-optical device manufacturing method according to the present embodiment can manufacture an electro-optical device capable of displaying a higher quality image. Such a manufacturing method is particularly effective when manufacturing an electronic apparatus including a plurality of electro-optical devices using light source light having different wavelengths as described in detail below. That is, since it is not necessary to finely adjust the angle of the first optical compensation plate 310 for each wavelength, it is possible to effectively reduce the manufacturing period and manufacturing cost.

<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. 14 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. 14, a projector 1100 includes a lamp unit 1102 made up 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. 14, 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 embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. The manufacturing method and the electronic apparatus provided with the electro-optical device are 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 used for an electro-optical apparatus. 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 (part 1) illustrating a comparative example of the electro-optical device according to the first embodiment. 6 is a cross-sectional view (part 2) illustrating a comparative example of the electro-optical device according to the first embodiment. FIG. It is a perspective view which shows the angle of the polarization axis in a polarizing plate. It is a graph which shows the relationship between the adjustment angle of an optical compensator, and contrast according to the color of light source light. It is a graph which shows the relationship between the adjustment angle of an optical compensator, and contrast according to the kind of polarizing plate. It is a graph which shows together the relationship between the angle of the polarization axis of a 2nd polarizing plate, and the contrast, and the relationship between the angle of the polarization axis of a 2nd polarizing plate, and the adjustment angle of an optical compensator. 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. It is a perspective view which shows the structure of a rotation mechanism. 3 is a flowchart illustrating a method for manufacturing an electro-optical device. 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 (10)

A liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of first and second substrates;
A first polarizing plate disposed on one of the incident side and the emitting side of the light source light in the liquid crystal panel;
A second polarizing plate arranged on the other of the incident side and the outgoing side of the light source light in the liquid crystal panel so that the polarization axis is deviated from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer;
And at least one optical compensator disposed between the first polarizing plate and the second polarizing plate, the optical axis being inclined so as to compensate for a phase difference generated in the liquid crystal molecules of the liquid crystal layer,
The predetermined angle is set so that a phase difference after the compensation is smaller than a case where a polarization axis of the second polarizing plate is not shifted by the predetermined angle. .   2. The electro-optical device according to claim 1, wherein the first polarizing plate is disposed such that a polarization axis is an angle corresponding to a polarization axis of the second polarizing plate.   2. The electro-optical device according to claim 1, wherein the first polarizing plate is arranged such that a polarization axis is deviated from an angle corresponding to an angle of liquid crystal molecules in the liquid crystal layer by a predetermined angle.   The electro-optical device according to claim 1, wherein the predetermined angle is set for each wavelength of the light source light.   5. The electro-optical device according to claim 1, wherein the predetermined angle is set for each polarization degree of the first and second polarizing plates. 6.   The electro-optical device according to claim 1, wherein the optical compensation plate is fixed to the liquid crystal panel.   The electro-optical device according to claim 6, wherein the optical compensation plate also functions as a dust-proof glass and is bonded to the outer surface of the liquid crystal panel.   The electro-optical device according to claim 1, wherein at least one of the first and second polarizing plates has a rotation mechanism.   An electronic apparatus comprising the electro-optical device according to claim 1. A liquid crystal panel disposing step of disposing a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of first and second substrates;
A first polarizing plate arrangement step of arranging a first polarizing plate on one of the incident side and the outgoing side of the light source light in the liquid crystal panel;
A second polarizing plate arrangement in which the second polarizing plate is arranged on the other side of the incident side and the outgoing side of the light source light in the liquid crystal panel so that the polarization axis is shifted from the angle corresponding to the angle of the liquid crystal molecules in the liquid crystal layer by a predetermined angle. Process,
An optical compensator mounting step of mounting at least one optical compensator between the first polarizing plate and the second polarizing plate so that an optical axis is inclined so as to compensate for a phase difference generated in liquid crystal molecules of the liquid crystal layer; With
The predetermined angle is set so that a phase difference after the compensation is smaller than a case where a polarization axis of the second polarizing plate is not shifted by the predetermined angle. Manufacturing method.

Images