JP2006184673A - Liquid crystal device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a configuration capable of achieving a higher contrast than heretofore by suppressing degradation of transmittance in the initial alignment state or light leakage in a vertical alignment mode liquid crystal device. <P>SOLUTION: The liquid crystal device 10 comprises a pair of substrates 11, 12, a liquid crystal layer 14 disposed between the pair of substrates and electric field applying structures 11c, 12g for applying an electric field to the liquid crystal layer. The liquid crystal device is provided with an initial alignment state in which liquid crystal molecules in the liquid crystal layer are substantially aligned in the substrate normal N direction when no voltage is applied and the liquid crystal molecules have a pre-tilt angle less than 90° in the initial alignment state. Further, in the liquid crystal device, azimuth angles of pre-tilt of the liquid crystal molecules are substantially aligned within a prescribed range at least in substrate surface and an optical axis deflection means which allows the optical axis Ax of light made incident on the substrate normal N direction to incline to the azimuth side of the pre-tilt angle of the liquid crystal molecules is disposed at least within a prescribed range in a substrate surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal device and an electronic apparatus, and more particularly to a vertical alignment mode liquid crystal device in which liquid crystal is aligned substantially perpendicular to the inner surface of a substrate in the absence of an electric field.

  Conventional liquid crystal devices generally have a cell structure in which liquid crystal is sealed between a pair of substrates, and are configured to modulate light by controlling the alignment state of the liquid crystal by an electric field. As such a liquid crystal device, a TN mode liquid crystal in which the alignment direction of the liquid crystal is twisted 90 degrees in the thickness direction of the liquid crystal layer when no electric field is applied, and the liquid crystal is aligned substantially perpendicular to the inner surface of the substrate when the electric field is applied. There are devices and IPS mode liquid crystal devices in which the alignment direction of the liquid crystal rotates on a plane parallel to the inner surface of the substrate in the presence or absence of an electric field, but there is a problem that the viewing angle is narrow in the TN mode. However, although a wide viewing angle can be secured, there are problems such as a slow response speed, insufficient light transmittance, and difficulty in manufacturing.

  Therefore, a VA (Vertical Aligned) mode liquid crystal display device has been developed as a method that can satisfy other characteristics while ensuring a wide viewing angle. This liquid crystal device generally uses a liquid crystal having a negative dielectric anisotropy, and the liquid crystal is oriented substantially perpendicularly to the inner surface of the substrate when no voltage is applied. It is comprised so that it may orientate substantially parallel to. The drawback of this VA mode liquid crystal device is that it is difficult to control the azimuth angle at which the liquid crystal tilts when an electric field is applied. Since the azimuth angle of the liquid crystal has a great influence on the optical characteristics, it is usually configured so that the liquid crystal is slightly tilted toward a predetermined orientation in the initial alignment state, that is, has a pretilt angle of less than 90 degrees. By predefining the azimuth angle of the pretilt angle, the azimuth direction of the liquid crystal is controlled.

  In direct-view liquid crystal display devices, viewing angle dependence occurs when the azimuth angle of the liquid crystal is deviated. Therefore, alignment control structures such as protrusions and slits (electrode pattern openings) are usually formed on the inner surface of the substrate. The orientation control structure is configured so that the orientation in which the liquid crystal falls is not biased to reduce the viewing angle dependency (see, for example, Patent Document 1 below).

  Furthermore, the pixel region is divided into a plurality of subdots, and the alignment control structure (protrusions and electrode openings) is provided for each subdot, thereby controlling the alignment state of the liquid crystal in the pixel by the alignment control structure. A method for improving the performance has also been proposed (see, for example, Patent Documents 2 and 3 below). In this structure, in addition to the above, the shape of the sub-dots can be rotated, such as a circle or square, to further improve the alignment controllability, and by adding a chiral agent to the liquid crystal, alignment defects (discrete) The occurrence of display defects such as roughness (spots whose display mode changes depending on the viewing angle) due to (nation) is prevented.

On the other hand, a liquid crystal device generally has a structure in which a plurality of pixels are arranged in a matrix form vertically and horizontally in order to form a desired display mode or projected image, but light is transmitted between these pixels. There is a problem that an unshielded light shielding region is provided, and this light shielding region lowers the aperture ratio of the liquid crystal device and reduces the brightness of display and images. In particular, in an active matrix type liquid crystal device provided with a switching element for each pixel, the aperture ratio is further reduced because it is necessary to shield a region where the switching element is provided, and the transflective liquid crystal device Then, there is a problem that the aperture ratio is greatly reduced in order to realize both transmissive display and reflective display. Therefore, as a method for solving this problem, a microlens array having a condensing lens corresponding to the pixel of the liquid crystal device is formed, and incident light is condensed by each condensing lens of the microlens array. A method is known in which the same effect as that in the case of substantially increasing the structural aperture ratio is obtained by introducing the inside (see, for example, Patent Document 4 below).
JP-A-11-258606 JP 2002-202511 A JP 2003-43525 A JP 2000-275627 A

  However, since the pixels themselves are small in the liquid crystal light valve, it is difficult to produce the ribs and slits described above, and even if they can be produced, they are expected to be affected by a decrease in the aperture ratio and the influence of the electric field between the pixels. It is difficult to control the orientation. Further, in the conventional vertical alignment mode liquid crystal device, since the liquid crystal molecules have a pretilt angle of less than 90 degrees in the initial alignment state, the liquid crystal molecules are slightly tilted with respect to the substrate normal line. The light incident direction is slightly different from the major axis direction of the liquid crystal molecules, and when configured to be in a light transmissive state when no electric field is applied, the light transmittance decreases, and the light is blocked when no voltage is applied. However, there is a problem that light leakage occurs.

  Further, in the liquid crystal device provided with the microlens array, a recess is formed on the inner surface of the substrate on the light incident side so that the azimuth angle of the pretilt of the liquid crystal molecules becomes radial and corresponds to the recess. By forming the convex portion on the outer surface of the substrate on the light incident side, the incident light is condensed in such a manner that the major axis direction of the liquid crystal molecules aligned substantially perpendicular to the inner surface of the concave portion is parallel to the incident light incident direction. As a result, it is said that high contrast can be obtained. However, it is extremely difficult to form the concave portion on the inner surface of the substrate and the convex portion on the outer surface of the substrate in a corresponding shape. In fact, a high-precision optical system cannot be formed, and the liquid crystal molecules are formed on the inner surface of the substrate. Rather than being oriented completely perpendicular to (i.e., the pretilt angle is 90 degrees), rather than being tilted to some extent (i.e., the pretilt angle is less than 90 degrees), Even if it can be formed accurately, a sufficient effect cannot be obtained, and an optical compensator or the like needs to be used as an auxiliary.

  Therefore, the present invention solves the above-mentioned problems, and the problem is that in a vertical alignment mode liquid crystal device, a lower contrast in the initial alignment state or light leakage is suppressed, thereby providing a higher contrast than conventional. It is to provide a configuration that can be realized.

  In view of such circumstances, the liquid crystal device of the present invention has a pair of substrates, a liquid crystal layer disposed between the pair of substrates, and an electric field application structure for applying an electric field to the liquid crystal layer, In the liquid crystal device having an initial alignment state in which the liquid crystal molecules in the liquid crystal layer are substantially aligned in the normal direction of the substrate during heating, the liquid crystal molecules have a pretilt angle of less than 90 degrees in the initial alignment state. And, the azimuth angle of the pretilt of the liquid crystal molecules is substantially aligned at least within a predetermined range within the substrate surface, and is incident from the normal direction of the substrate at least within the predetermined range within the substrate surface. An optical axis deflecting means for tilting the optical axis of light toward the azimuth side of the pretilt angle of the liquid crystal molecules is provided.

  According to the present invention, the azimuth angles of the pretilts of the liquid crystal molecules are substantially aligned at least within a predetermined range, and the optical axis deflecting means is at least within the predetermined range and the optical axis deflecting means is incident on the substrate normal direction. By tilting the optical axis toward the azimuth side of the pretilt of the liquid crystal molecules in the liquid crystal layer, the optical axis of the incident light can be configured to approach the major axis direction of the liquid crystal molecules in the initial alignment state. When it corresponds to the light transmission state, a decrease in light transmittance can be suppressed, and when the initial alignment state corresponds to the light blocking state, light leakage can be suppressed. Therefore, the contrast of the liquid crystal device can be increased.

  In the present invention, it is preferable that the optical axis deflecting unit tilts the optical axis at an angle substantially corresponding to the pretilt angle. According to this, since the optical axis can be set substantially parallel to the major axis direction of the liquid crystal molecules, the contrast can be further enhanced.

  In the present invention, it is preferable that the optical axis deflecting unit is composed of a photorefractive element disposed on the light incident side with respect to the liquid crystal layer. According to this, by providing a photorefractive element such as a prism on the light incident side of the liquid crystal layer, the optical axis can be easily and reliably inclined with respect to the normal direction of the substrate.

  In the present invention, it is preferable that the optical axis deflection unit is provided on a substrate disposed on the light incident side with respect to the liquid crystal layer. By providing the optical axis deflecting means on the light incident side substrate, it is not necessary to provide an optical element as a separate part, which facilitates manufacture and handling.

  In the present invention, a plurality of pixels configured to be able to apply an electric field substantially independently, and a micro optical element array disposed on the incident side with respect to the liquid crystal layer and having an optical element portion for each pixel. Furthermore, it is preferable that the optical axis deflecting unit is realized by an asymmetric structure with respect to a substrate normal line of the optical element portion. This makes it possible to tilt the optical axis in accordance with each of the azimuth angles in a plurality of pixels.

  In the present invention, the optical element section preferably has an asymmetric condenser lens structure. According to this, the optical axis deflecting means can be configured by the asymmetrical condensing lens structure, and at the same time, the aperture ratio of the liquid crystal device can be substantially increased by condensing each pixel.

  The optical element section preferably has a symmetric condensing lens structure and an asymmetrical light refraction structure laminated in the substrate normal direction. According to this, it is possible to easily form an asymmetric structure with respect to the substrate normal by separately forming a symmetric condensing lens structure and an asymmetric photorefractive structure and laminating them in the substrate normal direction. At the same time, the light condensing function and the optical axis tilting function of the optical element section can be realized with high accuracy.

  An electronic apparatus according to the present invention includes the liquid crystal device according to any one of the above, and a control unit that controls the liquid crystal device. The electronic apparatus according to the present invention includes the above-described liquid crystal display device, whereby an apparatus having a display screen with high display quality can be configured. Examples of the electronic device include a projection display device, a mobile phone, a portable information terminal, an electronic timepiece, and a personal computer.

  Another electronic device of the present invention has a pair of substrates, a liquid crystal layer disposed between the pair of substrates, and an electric field application structure for applying an electric field to the liquid crystal layer, and no electric field is applied. A liquid crystal device having an initial alignment state in which liquid crystal molecules in the liquid crystal layer are substantially aligned in a substrate normal direction, and a light source that irradiates light to the liquid crystal device, The liquid crystal molecules in the initial alignment state have a pretilt angle of less than 90 degrees, and at least within a predetermined range in the substrate surface, the azimuth angles of the liquid crystal molecules are substantially aligned. The optical axis of light incident from the light source with respect to the normal direction of the substrate is tilted toward the azimuth side of the pretilt angle of the liquid crystal molecules in the liquid crystal device at least within the predetermined range in the substrate surface. thing And it features. Here, it is preferable that the optical axis is inclined with respect to the normal direction of the substrate at an angle substantially corresponding to the pretilt angle. Moreover, it is preferable that an optical element for tilting the optical axis of the incident light is disposed on the light incident side of the liquid crystal device.

  Furthermore, it is particularly preferable that the electronic apparatus of the present invention is a projection display device having a light projection unit that projects an image light-modulated by the liquid crystal device.

  Next, embodiments of a liquid crystal device and an electronic apparatus according to the present invention will be described in detail with reference to the accompanying drawings. Each embodiment described below is usually configured to have a panel structure in which a pair of substrates is basically bonded with a sealing material and liquid crystal is sealed between the substrates. Since this is a well-known and commonly used technique, a detailed description is omitted, and an outline of the panel structure and a portion corresponding to one pixel region formed in a plurality of arrays in each panel structure will be described below. Each figure is merely schematic, and the dimensions of each part, including the size of the liquid crystal molecules, are drawn greatly different from the actual ones for convenience of illustration.

[First Embodiment]
A first embodiment of a liquid crystal device according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic longitudinal sectional view showing a cross-sectional structure of one pixel of a liquid crystal device, FIG. 2 is an explanatory view showing a relationship between liquid crystal molecules and an optical axis, FIG. 3 is a cross-sectional view of the entire configuration of the liquid crystal device, and FIG. It is a schematic longitudinal cross-sectional view which shows the formation area of TFT (thin film transistor) formed in this.

  As shown in FIG. 3, the liquid crystal device 10 is formed by bonding a pair of transparent substrates 11 and 12 such as glass and plastic with a sealing material 13 at a predetermined interval (for example, an interval of about 3 to 10 μm). A liquid crystal layer 14 is formed by sealing a liquid crystal in a region surrounded by a sealing material 13 between 11 and a substrate 12. Polarizing plates 15 and 16 are disposed on the outer surface of the substrate 11 and the outer surface of the substrate 12. The substrate 12 is provided with a substrate overhanging portion 12t that projects outward from the outer shape of the substrate 11, and a semiconductor device 17 in which a liquid crystal driver circuit or the like is formed is mounted on the surface of the substrate overhanging portion 12t. Further, an input terminal row conductively connected to the semiconductor device 17 is formed at the end portion of the substrate overhanging portion 12t, and a flexible wiring board 18 is mounted on the end portion so as to be conductively connected to the input terminal row. ing.

As shown in FIG. 1, on the inner surface of the substrate 11, a light-shielding film 11a is formed on the periphery of the pixel region P with a metal such as Cr or black resin, and an inorganic insulator such as SiO ₂ or acrylic is formed thereon. An insulating film 11b is formed of a synthetic resin such as a resin, and a counter electrode 11c is formed of a transparent conductor such as ITO (indium tin oxide) on the insulating film 11b. On the counter electrode 11c, a vertical film direction film 11d made of an oblique vapor deposition film such as SiO ₂ is formed.

  On the inner surface of the substrate 12, a light shielding film 12a is formed at the periphery of the pixel region P, and an insulating film 12b is formed on the insulating film 12b with an inorganic insulator or synthetic resin. A TFT (thin film transistor) described later is formed on the insulating film 12b. ) Or the like is formed. The switching element 12c is connected to a scanning line (not shown). An insulating film 12d is formed on the switching element 12c, and a data line 12e electrically connected to the switching element 12c is formed on the insulating film 12d. The data line 12e is configured to extend in a direction orthogonal to the scanning line. An insulating film 12f is further formed on the data line 12e, and a pixel electrode 12g is formed of a transparent conductor on the insulating film 12f. On the pixel electrode 12g, a vertical alignment film 12h made of an oblique deposition film similar to the above is formed.

  The liquid crystal device 10 of this embodiment is a so-called VA mode liquid crystal device, and the liquid crystal layer 14 is composed of a liquid crystal having negative dielectric anisotropy, for example, a negative type nematic liquid crystal. A large number of liquid crystal molecules 14m are arranged in the liquid crystal layer 14 in a predetermined alignment state. Specifically, in the liquid crystal layer 14, the liquid crystal molecules 14 m are substantially parallel to the substrate normal N when no electric field is applied between the counter electrode 11 c and the pixel electrode 12 g (when no electric field is applied). The liquid crystal layer is a vertical alignment mode liquid crystal layer (which is in an initial alignment state). Further, when an electric field is applied between the counter electrode 11c and the pixel electrode 12g, the liquid crystal molecules 14m are aligned so as to tilt toward a predetermined azimuth angle according to the electric field strength.

  A micro optical element array 19 is formed on the outer surface of the substrate 11. The micro optical element array 19 includes a first optical layer 19A formed on the outer surface of the substrate 11, and a second optical layer 19B formed on the first optical layer 19A. The first optical layer 19A and the second optical layer 19B can be formed of a light-transmitting synthetic resin made of different materials. In the case of the illustrated example, the optical refractive index of the first optical layer 19A is larger than the optical refractive index of the second optical layer 19B.

  The micro optical element array 19 is formed with an optical element portion 19C having a predetermined optical function for each pixel region P in the first optical layer 19A and the second optical layer 19B, and the plurality of optical element portions 19C are pixels. It is arranged in a state consistent with the arrangement mode of the region P. The optical element portion 19C has a condensing function for condensing light incident in the direction of the substrate normal N from the light incident side (lower side in the figure), and the optical axis Ax of the incident light with respect to the substrate normal N. An optical axis tilting function that tilts toward the liquid crystal layer 14 is provided. As described above, the optical refractive index of the first optical layer 19A is larger than the optical refractive index of the second optical layer 19B, so that the optical system constituted by the bonding interface between the first optical layer 19A and the second optical layer 19B. The optical element portion 19 </ b> C exhibits a light condensing function by forming the curved surface convex toward the light incident side. Further, the optical surface is configured asymmetrically with respect to the substrate normal N, whereby the optical element portion 19C exhibits an optical axis tilt function. In other words, the first optical layer 19A functions as a convex lens-shaped condensing element and also functions as an optical axis deflecting element (photorefractive element) such as a prism. In the illustrated example, when the substrate normal N passing through the center in the pixel region P is a symmetric axis, the optical surface of the optical element portion 19C has an asymmetric surface shape on the left and right in FIG. Although not shown, the optical surface of the optical element portion 19C has a symmetrical shape in the front-rear direction with respect to the front-rear direction orthogonal to the paper surface of FIG.

  The liquid crystal molecules 14m in the liquid crystal layer 14 shown in FIG. 1 have a posture in which the major axis direction is substantially parallel to the direction of the substrate normal N in the initial alignment state, as shown by a solid line in FIG. Oriented. However, the major axis direction of the liquid crystal molecules 14m is not completely parallel to the substrate normal N, and has a slight angle difference θt. The pretilt angle θp of the liquid crystal molecules 14m is 90−θt, that is, less than 90 degrees. The pretilt angle θp is normally set within a range of 85 to 90 degrees, and particularly preferably within a range of 87 to 89 degrees.

The pretilt angle θp varies depending on the type of liquid crystal molecules 14m, the thickness of the liquid crystal layer 14 (cell gap), the types and structures of the vertical alignment films 11d and 12h, and the like. For example, in the present embodiment, as the vertical alignment films 11d and 12h, oblique deposition films formed by depositing SiO ₂ at an angle of about 50 degrees with respect to the surfaces of the substrates 11 and 12 are used, and the pretilt angle θp is 88. I am trying. As shown in FIG. 2B, when viewed from the direction of the substrate normal N, the liquid crystal molecules 14m are inclined at a pretilt angle θp toward the azimuth represented by the azimuth angle θd.

  In the present embodiment, the azimuth angle θd of the pretilt of the liquid crystal molecules 14m is aligned over the entire liquid crystal layer 14. In FIG. 1, the pretilt azimuth angles θd are all set on the right side of the figure. Such a configuration can be very easily manufactured when the vertical alignment films 11d and 12h are formed of an oblique vapor deposition film, since it is determined by the vapor deposition orientation of the oblique vapor deposition film.

  When a predetermined voltage is applied between the counter electrode 11c and the pixel electrode 12g with the pretilt azimuth angle θd of the liquid crystal molecules 14m set as described above, the liquid crystal molecules 14m are directed toward the azimuth angle θd. Orient to fall down. This makes it possible to control the orientation direction of the liquid crystal molecules 14m when an electric field is applied, and to prevent undesired optical characteristics from appearing.

  The optical axis tilting function of the optical element portion 19C described above is such that the optical axis Ax of light incident from the direction of the substrate normal N is the pretilt orientation of the liquid crystal molecules 14m with respect to the substrate normal N inside the liquid crystal layer 14. It acts to incline toward the corner. That is, in FIG. 1, when the azimuth angle is directed to the right side in the figure, the optical axis Ax is inclined to the right side in the figure. At this time, the tilt angle of the optical axis Ax is configured to substantially coincide with the pretilt angle θp, that is, the optical axis Ax and the major axis direction of the liquid crystal molecules 14m in the initial alignment state are parallel to each other. Desirably configured.

  The optical element portion 19C acts optically on the light incident side of the liquid crystal layer 14. At this time, the optical axis Ax is refracted variously at the interface between the micro optical element array 19 and the substrate 12, the interface between the substrate 12 and the liquid crystal layer 14, and other interfaces. It is only necessary that the optical axis Ax is inclined to the azimuth angle side of the pretilt when the light enters. Therefore, the optical axis deflecting means may not be on the outer surface of the substrate 12 but may be disposed away from the outer surface of the substrate 12, or may be formed by the inner shape of the substrate 12, and It may be formed on the inner surface of the substrate 12.

  FIG. 4 is an enlarged cross-sectional view showing a more detailed structure of the switching element 12c provided in each pixel region P of the above embodiment. As described above, the light shielding film 12a and the insulating film 12b are formed on the substrate 12, and the semiconductor layer 12ca formed of a silicon thin film or the like is formed in a region shielded by the light shielding film 12a on the insulating film 12b. . The semiconductor layer 12ca is covered with a gate insulating film 12cb, and a gate electrode 12cg is formed on the gate insulating film 12cb at a position facing the active region (channel region) of the semiconductor layer 12ca. The gate electrode 12cg is conductively connected to a scanning line (not shown).

  Further, the data line 12e is conductively connected to the source region of the semiconductor layer 12ca through a contact hole formed in the insulating film 12d, and the contact hole formed in the insulating films 12d and 12f is formed in the drain region of the semiconductor layer 12ca. The pixel electrode 12g is conductively connected through the via. Further, a part of the capacitor line 12cc is disposed opposite to the semiconductor layer 12ca via the gate insulating film 12cb.

  FIGS. 5A to 5C are process explanatory views showing the manufacturing process of the micro optical element array 19 in the present embodiment. In this embodiment, as shown in FIG. 5 (a), a base material 19a made of uncured acrylic resin or the like is applied on the outer surface of the substrate 12 by a spin coating method or the like, and this is molded with a mold 1 to be predetermined. (E.g., light (ultraviolet) irradiation treatment if the substrate 19a is a light (ultraviolet) curable resin, heat treatment if the substrate 19a is a thermal effect resin, cooling if the substrate 19a is a thermoplastic resin) Alternatively, the first optical layer 19A is formed as shown in FIG. Then, an uncured base material is further applied on the first optical layer 19A by a spin coating method or the like so that the surface becomes flat, and is cured to form the second optical layer 19B.

  In addition, the manufacturing method of the micro optical element array 19 in the present embodiment is not limited to the above method, and a predetermined mask is formed on the surface of the optical layer such as glass or transparent resin by a photolithography method or the like. An optical surface constituting the optical element portion 19C may be formed by performing isotropic etching or the like. In this case, the above processing may be performed on the substrate 12, or an optical film may be formed by performing the above processing, and the optical film may be attached to the substrate 12.

  In the present embodiment, as shown in FIG. 1, when an incident light beam La enters in the direction of the substrate normal N, it is condensed by the optical element portion 19C, and its optical axis Ax is inclined with respect to the substrate normal N. Since the tilt direction coincides with the azimuth angle of the pretilt of the liquid crystal molecules 14m, the traveling direction of light incident on the liquid crystal layer 14 tilts in the major axis direction of the liquid crystal molecules 14m. Since the angular difference in the axial direction is reduced, the retardation of the incident light by the liquid crystal layer 14 in the initial alignment state is reduced. Therefore, when the polarization transmission axes of the polarizing plates 15 and 16 are made to coincide with each other and the light transmission state is realized in the initial alignment state, the light transmittance of the liquid crystal device 10 can be increased. Further, when the polarizing transmission axes of the polarizing plates 15 and 16 are orthogonal to each other and the light blocking state is realized in the initial alignment state, the light leakage of the liquid crystal device 10 can be reduced. In particular, as described above, in the initial alignment state, by configuring the optical axis Ax and the major axis direction of the liquid crystal molecules 14m to be parallel, the above-described reduction in light transmittance and light leakage can be greatly reduced. .

  The emitted light beam Lb is emitted slightly obliquely because the optical axis Ax is slightly inclined with respect to the direction of the substrate normal N. However, if there is no problem in this state, the configuration shown in the drawing is used. If it is necessary to correct the optical axis of the emitted light beam Lb again in the direction of the substrate normal N, it can be restored by using an optical axis restoring means separately provided on the substrate 11. Further, this optical axis restoring means may be realized by an optical system provided separately from the liquid crystal device.

  In the present embodiment, the optical element portion 19C constituting the optical axis deflecting unit is formed integrally with the substrate 12 on the light incident side, so that the optical axis Ax is reliably set on the incident side of the liquid crystal layer 14. In addition to being able to incline, handling during manufacture is facilitated by integration with the substrate 12. In addition, since the optical element portion 19C is formed on the outer surface of the substrate 12, it does not affect the application of an electric field to the liquid crystal layer 14.

  Furthermore, in this embodiment, since the optical element portion 19C also has a light condensing function, incident light can be efficiently introduced into the pixel region P, and the aperture ratio of the liquid crystal device 10 can be substantially improved. Can do. Further, since this condensing function is ensured by the optical element portion 19C constituting the optical axis deflecting means, it is not necessary to separately form a condensing lens portion. As a result, the optical element portion 19C can be thinned and the manufacturing process can be reduced. Simplification can be achieved.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. Since this embodiment has the same basic structure as the first embodiment, the same reference numerals are given to the same parts, and the description thereof is omitted. Since this embodiment is different from the first embodiment only in the structure of the micro optical element array 19 ′ formed on the outer surface of the substrate 12, the structure of the micro optical element array 19 ′ will be described below.

  As shown in FIG. 6, the micro optical element array 19 ′ includes a first optical layer 19 </ b> D, a second optical layer 19 </ b> E, and a third optical layer 19 </ b> F stacked on the outer surface of the substrate 12. The first optical element portion 19G and the second optical element portion 19H have a structure laminated in the direction of the substrate normal N. Here, the optical refractive index of the first optical layer 19D> the optical refractive index of the second optical layer 19E> the optical refractive index of the third optical layer 19F. The first optical layer 19D constitutes a prismatic optical axis deflecting element (photorefractive element). The second optical layer 19E constitutes a convex lens-shaped condensing element.

  The first optical element portion 19G is configured by an optical surface formed by a bonding interface between the second optical layer 19E and the third optical layer 19F, and the optical surface has a concentrating optical axis that is parallel to the substrate normal N. It has a lens function. The second optical element portion 19H is configured by an optical surface formed by a bonding interface between the first optical layer 19D and the second optical layer 19E, and the optical surface is inclined with respect to a plane orthogonal to the substrate normal N. Thus, the optical axis of the incident light beam La is inclined with respect to the substrate normal N by a predetermined angle.

  FIGS. 7A to 7E are process explanatory views showing the manufacturing process of the micro optical element array 19 ′ of the present embodiment. In this embodiment, as shown in FIG. 7A, after applying a base material 19d such as uncured resin on the outer surface of the substrate 12 by a spin coating method or the like, as shown in FIG. The base material 19 is shape | molded using the type | mold 2, and it hardens | cures by a predetermined process similarly to 1st Embodiment, and forms 1st optical layer 19D. Next, as shown in FIG. 7 (c), a base material 19e made of uncured resin is applied on the first optical layer 19D, and then, using a mold 3 as shown in FIG. 7 (d). The second optical layer 19E is formed by molding the substrate 19e and curing it. Finally, as shown in FIG. 7E, a base material made of an uncured resin is applied on the second optical layer 19E so that the surface becomes flat, and is cured to obtain the third optical layer. Layer 19F is formed.

  In the present embodiment, in addition to the effects of the first embodiment, a first optical element section (condensing lens) 19G having a condensing function and a second optical element section that exhibits an optical axis tilt function as an optical axis deflecting unit By being configured separately from 19H, each structure (in the illustrated case, an optical surface constituting each optical element) can be formed easily and with high accuracy. That is, in the first embodiment, it is necessary that the optical surface constituting the optical element portion 19C is asymmetric with respect to the substrate normal N and has a curved surface shape having a condensing function. In this embodiment, the optical surface of the first optical element unit 19G having a condensing function and the optical surface of the second optical element unit 19H having an optical axis tilting function are in the substrate normal line N. Since they are arranged separately in the direction, the number of manufacturing steps increases, but it becomes possible to improve the yield of each manufacturing process and the optical surface accuracy.

[Third Embodiment]
Next, a configuration example of an electronic apparatus according to the invention will be described as a third embodiment with reference to FIG. FIG. 8 shows an example of the configuration of a projection display device provided with a liquid crystal device as a light modulation means. The projection display device 100 includes a light source 120, a color separation / synthesis system 140, and a projection optical system 160. Here, as will be described later, the transmissive liquid crystal light valve constituting the liquid crystal device according to the present invention is light-modulated for each color light of R (Red: red), G (Green: green), and B (blue: blue). As a means.

  The light source 120 includes a lamp 121 such as a high-pressure mercury lamp or a metal halide lamp, a reflector 122 that reflects the light from the lamp 121, and two fly-eye lenses 123 and 124 for making the illuminance distribution of the light from the lamp 121 uniform. And a polarization conversion plate 126 that aligns the polarization direction of light in one direction.

  Here, the two fly-eye lenses 123 and 124 are, for example, a plurality of 6 × 8 lenses 123a and 124a arranged vertically and horizontally, and the light L of the lamp 121 is two fly-eye lenses. By sequentially transmitting through 123 and 124, the illuminance distribution of the light L is made uniform.

  The polarization conversion plate 126 includes a polarization beam splitter array (PBS array) (not shown) provided on the two fly-eye lens sides, and a ½ wavelength plate array (not shown) that converts the polarization direction of polarized light reflected by the PBS array. The light L of the lamp 121 is arranged so that the polarization direction of the light is aligned in one direction without impairing the luminance.

  The color separation / synthesis system 140 includes dichroic mirrors 141 and 142, reflection mirrors 143, 144 and 145, relay lenses 146, 147 and 148, liquid crystal light valves 151, 152 and 153, and a cross dichroic prism 155. Have.

  The dichroic mirrors 141 and 142 are formed by, for example, laminating a dielectric multilayer film on the glass surface, and selectively reflect predetermined colored light and transmit light of other wavelengths. Specifically, the dichroic mirror 141 transmits the red light LR out of the light L of the light source 120 and reflects the blue light LB and the green light LG. The dichroic mirror 142 transmits the blue light LB and reflects the green light LG among the blue light LB and the green light LG reflected by the dichroic mirror 141.

  As a result, the red light LR out of the light incident from the light source 120 passes through the dichroic mirror 141, is reflected by the reflection mirror 145, and enters the liquid crystal light valve 151 for red light. The green light LG is reflected by the dichroic mirror 141 and enters the liquid crystal light valve 152 for green light. The blue light LB passes through the dichroic mirror 142 and then passes through the relay system 140a including the relay lens 146, the reflection mirror 143, the relay lens 147, the reflection mirror 144, and the relay lens 148, and then enters the liquid crystal light valve 153 for blue light. It is designed to be incident.

  The liquid crystal light valves 151, 152, and 153 are configured as, for example, active matrix transmissive liquid crystal light valves, and are driven by a drive circuit based on image signals that have undergone signal processing. The colored light modulated by the liquid crystal light valves 151, 152, and 153 is incident on the cross dichroic prism 155.

  The cross dichroic prism 155 has a structure in which right angle prisms are bonded together, and a mirror surface that reflects the red light LR and a mirror surface that reflects the blue light LB are formed in a cross shape on the inner surface. Therefore, the cross dichroic prism 155 combines the three color lights LR, LG, and LB with these mirror surfaces to form combined light for displaying a color image.

  The projection optical system 160 includes projection lenses 161, 162, and 163 and a screen 165. The projection lenses 161, 162, and 163 enlarge and project the combined light formed by the cross dichroic prism 155 onto the screen 165. As a result, a color image is displayed on the screen 165.

  In the present embodiment, the liquid crystal light valves 151, 152, and 153 can be configured by the liquid crystal devices 10 and 10 ′ described in the first embodiment or the second embodiment, respectively. As a result, the optical axis deflecting means can improve the light transmittance or reduce the light leakage, and increase the brightness by the light collecting function.

  Note that the liquid crystal device 10 ″ shown in FIG. 9 can be used as the liquid crystal light valves 151, 152, 153 of the present embodiment. In this case, the liquid crystal device 10 ″ is the liquid crystal device 10, 10 ′. In this configuration, the micro optical element arrays 19 and 19 'are removed (or only the optical axis deflecting means is removed and the condenser lens is left). In addition, the liquid crystal layer of the liquid crystal device 10 ″ is configured so that the pretilt azimuth angles of the liquid crystal molecules are aligned as a whole. In this case, the liquid crystal device 10 ″ is not provided with an optical axis deflecting unit, but is projected. The optical axis deflecting means is configured by the positional relationship between the optical system in the type display device 100 and the liquid crystal device 10 ″. That is, the liquid crystal device 10 ″ is configured by the color separation / synthesis system 140 shown in FIG. The direction of the substrate normal N is fixed at a predetermined angle with respect to the optical axis Bx of the optical path. As a result, in the liquid crystal layer of the liquid crystal device 10 ″, the optical axis Bx is inclined toward the azimuth side of the pretilt of the liquid crystal molecules with respect to the substrate normal N. Also in this case, the liquid crystal layer It is preferable that the inclination of the optical axis Bx is set to an angle corresponding to the pretilt angle of the liquid crystal molecules, and the optical axis Bx and the major axis direction of the liquid crystal molecules are substantially parallel in the liquid crystal layer.

  FIG. 10 is a schematic configuration diagram showing another configuration example of the present embodiment. In this configuration example, a prism-shaped optical axis deflecting element serving as an optical axis deflecting means is provided on the light incident side of the liquid crystal device 10 ″ configured as the liquid crystal light valves 151, 152, and 153 in the projection display device 100. (Optical refraction element) 19J is disposed.The optical axis deflecting element 19J deflects the optical axis Cx of the optical path, and the light having the deflected optical axis is incident on the liquid crystal device 10 ″. Similarly, the optical axis Cx in the liquid crystal layer is configured to be inclined toward the azimuth angle of the pretilt of the liquid crystal molecules with respect to the substrate normal. In particular, the optical axis Cx is inclined with respect to the substrate normal in the liquid crystal layer by an angle corresponding to the pretilt angle, and as a result, the optical axis Cx and the major axis of the liquid crystal molecules are configured to be parallel. Preferably it is.

  Further, a prism-shaped optical axis deflecting element 19K which is an optical axis deflecting means for returning the optical axis Cx deflected as described above is disposed on the light emitting side of the liquid crystal device 10 ″. The optical axis deflecting element 19K deflects the optical axis Cx inclined as described above with respect to the substrate normal N of the liquid crystal device 10 ″ so as to be parallel to the substrate normal N, and as a result, the liquid crystal device. The optical axis Cx of the light emitted from 10 ″ is configured to coincide with (or become parallel to) the optical axis before entering the optical axis deflecting element 19J. Without any particular adjustment, it is possible to configure the projection display device with the same configuration as the conventional one.

  In order to configure a projection display device, a bright and high-contrast display mode is required. In this embodiment, in the liquid crystal device provided as the light modulation unit, the inside of the liquid crystal layer is formed by the optical axis deflection unit. By tilting the optical axis at the side of the pretilt azimuth angle of the liquid crystal molecules with respect to the substrate normal, it is possible to improve light transmittance and reduce light leakage, so that the above requirements can be easily satisfied. It becomes possible.

[Fourth Embodiment]
FIG. 11 is a schematic configuration diagram illustrating an overall configuration of a control system (display control system) for the liquid crystal device 10 in the electronic apparatus of the present embodiment. The electronic apparatus shown here includes a display control circuit 290 including a display information output source 291, a display information processing circuit 292, a power supply circuit 293, and a timing generator 294. Further, the liquid crystal device 10 is provided with a panel structure 10P having the above-described configuration and a drive circuit 10D for driving the panel structure 10P. The drive circuit 10D is composed of electronic components (such as a semiconductor IC) that are directly mounted on the panel structure 10P. However, in addition to the above-described aspect, the drive circuit 10D may be a circuit pattern formed on the substrate surface of the panel structure 10P, or a semiconductor IC chip mounted on a circuit board conductively connected to the panel structure 10P or It can also be configured by a circuit pattern or the like.

  The display information output source 291 includes a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), a storage unit such as a magnetic recording disk or an optical recording disk, and a tuning circuit that tunes and outputs a digital image signal. The display information is supplied to the display information processing circuit 292 in the form of an image signal or the like of a predetermined format based on various clock signals generated by the timing generator 294.

  The display information processing circuit 292 includes various known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and executes processing of input display information to obtain image information. Are supplied to the drive circuit 10D together with the clock signal CLK. The drive circuit 10D includes a scanning line drive circuit, a signal line drive circuit, and an inspection circuit. The power supply circuit 293 supplies a predetermined voltage to each of the above-described components.

  FIG. 12 shows the appearance of a mobile phone which is an embodiment of the electronic apparatus according to the present invention. The electronic device 1000 includes an operation unit 1001 and a display unit 1002, and a circuit board 1003 is disposed inside a housing of the display unit 1002. The liquid crystal device 10 is mounted on the circuit board 1003. And it is comprised so that the display area of the said panel structure 10P can be visually recognized in the surface of the display part 1002. FIG. In this case, a backlight (not shown) is disposed behind the liquid crystal device 10, and the optical axis of light from the backlight is configured to be deflected by the optical axis deflecting means.

  The present invention is not limited to the above-described embodiments, and various modifications can be made as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Moreover, it is included in the technical scope of the present invention. For example, in the above embodiment, the active matrix type liquid crystal display device provided with switching elements such as TFT and TFD has been described. However, the present invention is a device configuration having no switching elements, for example, a passive matrix type device. It is also possible to apply to the configuration.

  The optical axis deflecting means of the first and second embodiments is composed of an optical element having a condensing function. However, the optical element portion does not have a condensing function and only the optical axis deflecting function is provided. You may comprise so that it may be implement | achieved.

1 is a schematic enlarged longitudinal sectional view of a liquid crystal device according to a first embodiment. Explanatory drawing (a) and (b) for demonstrating the effect of 1st Embodiment. 1 is a schematic cross-sectional view illustrating an overall configuration of a liquid crystal device according to a first embodiment. FIG. 3 is an enlarged partial cross-sectional view showing a structure of a switching element of the liquid crystal device of the first embodiment. Schematic process drawing (a)-(c) which shows the manufacturing process of the micro optical element array of 1st Embodiment. FIG. 4 is a schematic enlarged longitudinal sectional view of a liquid crystal device according to a second embodiment. Schematic process drawing (a)-(e) which shows the manufacturing process of the micro optical element array of 2nd Embodiment. The schematic block diagram which shows the whole structure of the projection type display apparatus of 3rd Embodiment. Explanatory drawing which shows the fixed attitude | position of the liquid crystal light valve in the other structural example of 3rd Embodiment. The schematic block diagram of the liquid crystal light valve vicinity in another example of a structure of 3rd Embodiment. The schematic block diagram of the display control system of the electronic device of 4th Embodiment. The schematic perspective view which shows the external appearance of the example of the electronic device of 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal device, 11, 12 ... Board | substrate, 11c ... Counter electrode, 12c ... Switching element, 12g ... Pixel electrode, 11d, 12h ... Vertical alignment film, 14 ... Liquid crystal layer, 14m ... Liquid crystal molecule, (theta) p ... Pretilt angle, 19 , 19 '... micro optical element array, 19A ... first optical layer, 19B ... second optical layer, 19C ... optical element part, 19D ... first optical layer, 19E ... second optical layer, 19F ... third optical layer, 19G ... 1st optical element part (condensing lens), 19H ... 2nd optical element part (optical axis deflection | deviation element), 100 ... Electronic device (projection type display apparatus), 290 ... Display control circuit, 1000 ... Electronic device (portable) phone)

Claims (12)

A pair of substrates, a liquid crystal layer disposed between the pair of substrates, and an electric field application structure for applying an electric field to the liquid crystal layer, wherein the liquid crystal molecules in the liquid crystal layer are substantially free when no electric field is applied. In a liquid crystal device having an initial alignment state aligned in the substrate normal direction,
In the initial alignment state, the liquid crystal molecules have a pretilt angle of less than 90 degrees, and at least within a predetermined range in the substrate surface, the azimuth angles of the liquid crystal molecules are substantially aligned.
Characterized in that it comprises optical axis deflecting means for tilting the optical axis of light incident from the normal direction of the substrate within the predetermined range within the substrate plane toward the azimuth side of the pretilt angle of the liquid crystal molecules. Liquid crystal device.   The liquid crystal device according to claim 1, wherein the optical axis deflecting unit tilts the optical axis to an angle substantially corresponding to the pretilt angle.   3. The liquid crystal device according to claim 1, wherein the optical axis deflecting unit includes a photorefractive element disposed on a light incident side with respect to the liquid crystal layer.   The liquid crystal device according to claim 1, wherein the optical axis deflecting unit is provided on a substrate disposed on a light incident side with respect to the liquid crystal layer. A plurality of pixels configured to be able to apply an electric field substantially independently; and a micro optical element array disposed on the incident side with respect to the liquid crystal layer and having an optical element portion for each pixel;
5. The liquid crystal device according to claim 1, wherein the optical axis deflecting unit is realized by an asymmetric structure with respect to a substrate normal line of the optical element unit.   The liquid crystal device according to claim 5, wherein the optical element portion has an asymmetric condenser lens structure.   The liquid crystal device according to claim 5, wherein the optical element unit has a symmetric condensing lens structure and an asymmetrical light refraction structure laminated in the normal direction of the substrate.   An electronic apparatus comprising: the liquid crystal device according to claim 1; and a control unit that controls the liquid crystal device. A pair of substrates, a liquid crystal layer disposed between the pair of substrates, and an electric field application structure for applying an electric field to the liquid crystal layer, wherein the liquid crystal molecules in the liquid crystal layer are substantially free when no electric field is applied. A liquid crystal device having an initial alignment state aligned in the substrate normal direction;
A light source for irradiating the liquid crystal device with light;
Comprising
In the liquid crystal device, the liquid crystal molecules have a pretilt angle of less than 90 degrees in the initial alignment state, and the pretilt azimuth angles of the liquid crystal molecules are substantially aligned at least within a predetermined range in the substrate surface. Composed of
The optical axis of light incident from the light source with respect to the normal direction of the substrate is tilted toward the azimuth side of the pretilt angle of the liquid crystal molecules in the liquid crystal device at least within the predetermined range in the substrate surface. An electronic device characterized by that.   The electronic apparatus according to claim 9, wherein the optical axis is inclined with respect to the normal direction of the substrate at an angle substantially corresponding to the pretilt angle.   The electronic device according to claim 9, wherein an optical element that tilts an optical axis of the incident light is disposed on a light incident side of the liquid crystal device. The electronic apparatus according to claim 8, wherein the electronic apparatus is a projection display device having a light projection unit that projects an image light-modulated by the liquid crystal device.

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