Abstract:
An electro-optical device includes a first substrate; a second substrate; an electro-optical material, the electro-optical material being disposed between the first and second substrates; prismatic portions that collect light incident on the first substrate, each prismatic portion being in the form of a groove having an opening, disposed in the first substrate, and being adjacent to the electro-optical material; a functional layer that drives the electro-optical material, the functional layer being disposed on a side of the first substrate, the side being adjacent to the electro-optical material; and the functional layer extending over the openings; and first light-shielding portions disposed on the second substrate, each light-shielding portion overlapping a corresponding one of the prismatic portions when viewed in plan.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    An aspect of the invention relates to an electro-optical device or a projector. 
         [0003]    2. Related Art 
         [0004]    A projection display, such as a projector, mainly include a light source; a light valve that modulates light emitted from the light source; and a projection lens that projects light modulated by the light valve onto a screen or the like. A liquid-crystal device is often used as the light valve that modulates light. 
         [0005]    The liquid-crystal device used as the light valve has a structure in which a pair of substrates holds a liquid-crystal material therebetween. Such a liquid-crystal device is required to have high efficiency for light utilization in order to allow light from a light source to contribute to display as much as possible. For example; JP-A-2000-330101 discloses a technique for forming microlenses on a pair of substrates as a method for enhancing efficiency for light utilization. In this technique, the formation of the microlenses on each of the substrates enhances the effect of collecting light into pixel regions, thereby increasing efficiency for light utilization. 
         [0006]    On the other hand, there are problems as follows: difficulty in alignment for adjusting the foci of the microlenses, the occurrence of loss (Fresnel loss) due to the passage of light through the plurality of microlenses, an increase in cost due to the formation of the microlenses on each substrate, and the like. In contrast, it is known that a technique in which by bonding a prismatic substrate onto the outer side of one substrate of the pair of substrates, the prismatic substrate including prismatic elements which are each in the form of a groove and which are disposed in interpixel regions, reflecting light coming through the one substrate is reflected from the grooves of the prismatic elements into the pixel regions. This technique can collect light into the pixel regions and improve efficiency for light utilization without the occurrence of the above-described problems. 
         [0007]    In the liquid-crystal device, the pixel regions are arrayed in a matrix. The interpixel regions include leads, active elements, and the like. Irradiation of the leads and the active elements with light causes electrical failures. Thus, the interpixel regions are usually covered with light-shielding portions. In the prismatic substrate, the opposite substrate is generally bonded on a surface in which the prismatic elements are disposed. Each of the light-shielding portions is disposed on the opposite substrate so as to overlap a corresponding one of the prismatic elements when viewed in plan. 
         [0008]    However, in the case where the prismatic elements are disposed on the substrate, the prismatic elements are remote from the light-shielding portions by the thickness of the opposite substrate. Thus, light rays traveling obliquely to the normal to the substrate through the pixel regions, which are located between the prismatic elements, and light rays reflected from the prismatic elements and then coming through the pixel regions are partially absorbed by the light-shielding portions, in some cases. These light rays are light rays originally designed to be emitted from the liquid-crystal device and to contribute to display. Thus, efficiency for light utilization is reduced because of absorption of light. Other electro-optical devices also have this problem as well as the liquid-crystal device. 
         [0009]    An advantage of some aspects of the invention is to provide an electro-optical device having improved efficiency for light utilization and a projector. 
         [0010]    An electro-optical device according to an aspect of the invention includes a first substrate; a second substrate; an electro-optical material, the electro-optical material being disposed between the first and second substrates; prismatic portions that collect light incident on the first substrate, each prismatic portion being in the form of a groove having an opening, disposed in the first substrate, and being adjacent to the electro-optical material; a functional layer that drives the electro-optical material, the functional layer being disposed on a side of the first substrate, the side being adjacent to the electro-optical material, and the functional layer extending over the openings; and first light-shielding portions disposed on the second substrate, each light-shielding portion overlapping a corresponding one of the prismatic portions when viewed in plan. 
         [0011]    The term “electro-optical device” is a collective term including a device that converts electrical energy into light energy in addition to a device having the electro-optical effect in which a change in the refractive index of a material due to an electric field changes light transmittance Examples of the electro-optical device include liquid-crystal display devices using liquid-crystal materials as electro-optical materials, organic electro-luminescent (EL) devices using organic EL materials, inorganic EL devices using inorganic EL materials, and plasma display devices using plasma gases as electro-optical materials. The electro-optical device may further include electrophoretic displays (EPDs) and field-emission displays (FEDs). The term “functional layer” includes an electrode layer for applying a predetermined voltage to an electro-optical material and a lead layer connected to the electrode layer. 
         [0012]    An electro-optical device according to an aspect of the invention includes the first substrate; the second substrate; the electro-optical material, the electro-optical material being disposed between the first and second substrates; the prismatic portions that collect light incident on the first substrate, each prismatic portion being in the form of a groove having an opening, disposed in the first substrate, and being adjacent to the electro-optical material; the functional layer that drives the electro-optical material, the functional layer being disposed on the side of the first substrate, the side being adjacent to the electro-optical material, and the functional layer extending over the openings; and the first light-shielding portions disposed on the second substrate, each light-shielding portion overlapping a corresponding one of the prismatic portions when viewed in plan. The first substrate serves as a prismatic substrate and an opposite substrate. That is, the absence of the opposite substrate having a thickness between the prismatic elements and the light-shielding portions reduces the prismatic portions and the first light-shielding portions, thereby reducing absorption of light by the first light-shielding portions to improve efficiency for light utilization. 
         [0013]    With respect to light incident obliquely to the normal to a surface of the substrate, in the known structure, the shift distance of light in the direction perpendicular to the surface of the substrate is increased by the thickness of the opposite substrate, as compared with the structure in the invention. As a result, the shift distance of light in the direction parallel to the surface of the substrate is also increased. For example, in the known structure, light collected by the prismatic portions is excessively collected to the middle portion of each pixel region because of the increased shift distance, thereby reducing the light-transmitting region. In contrast, in the structure of the invention, light is not excessively collected to the middle portion of each pixel region because of the absence of the opposite substrate having thickness between the prismatic portions and the light-shielding portions, thereby increasing the light-transmitting region compared with the known structure. The inventive structure including the opposite substrate also serving as the prismatic substrate has a larger light-transmitting region than that in the known structure, thus substantially increasing the aperture ratio to improve efficiency for light utilization. 
         [0014]    Furthermore, when light is excessively collected to the middle portion of each pixel region, light comes through only the middle portion of each pixel region. Thus light scarcely comes through the periphery of the pixel region, causing nonuniformity in light-intensity distribution. In contrast, in the structure of the invention, light is not excessively collected to the middle portion of the pixel region; hence, light uniformly comes through a wide range of each pixel region. 
         [0015]    Preferably, the electro-optical device further include second light-shielding portions, each second light-shielding portion facing a corresponding one of the openings and being disposed on a side of the functional layer opposite the side adjacent to the electro-optical material. 
         [0016]    In the invention, the electro-optical device further include the second light-shielding portions, each second light-shielding portion facing a corresponding one of the openings and being disposed on the side of the functional layer opposite the side adjacent to the electro-optical material. Thus, light other than light used for display can be surely shielded. That is, direct irradiation of a switching element and the like disposed in the electro-optical device with light can be surely inhibited, resulting in the prevention of malfunction of the electro-optical device. 
         [0017]    An electro-optical device according to the invention includes a first substrate; a second substrate; an electro-optical material, the electro-optical material being disposed between the first and second substrates; prismatic portions that collect light incident on the first substrate, each prismatic portion being in the form of a groove having an opening, disposed in the first substrate, and being adjacent to the electro-optical material; a functional layer that drives the electro-optical material, the functional layer being disposed on a side of the first substrate, the side being adjacent to the electro-optical material, and the functional layer extending over the openings; and second light-shielding portions, each second light-shielding portion facing a corresponding one of the openings and being disposed on an opposite side of the functional layer from the electro-optical material. 
         [0018]    According to the invention, the electro-optical device includes the first substrate; the second substrate; the electro-optical material, the electro-optical material being disposed between the first and second substrates; the prismatic portions that collect light incident on the first substrate, each prismatic portion being in the form of a groove having an opening, disposed in the first substrate, and being adjacent to the electro-optical material; the functional layer that drives the electro-optical material the functional layer being disposed on the side of the first substrate, the side being adjacent to the electro-optical material, and the functional layer extending over the openings; and the second light-shielding portions, each second light-shielding portion facing a corresponding one of the openings and being disposed on an opposite side of the functional layer from the electro-optical material. Thus, the second light-shielding portions are supported by the functional layer so as to face the openings. Therefore, for example, the second light-shielding portions are not disposed inside the prismatic portions, thus stabilizing the structure in the electro-optical device. The electro-optical material preferably may have a higher refractive index than that of the first substrate. 
         [0019]    According to the invention, the electro-optical material may have a higher refractive index than that of the first substrate. Thus, among light incident from the first substrate on the electro-optical material, in particular, light traveling toward the first light-shielding portions is allowed to refract toward regions between the first light-shielding portions. Therefore, light absorbed in the first light-shielding portions can be reduced to further improve efficiency for light utilization. 
         [0020]    Preferably, the prismatic portions are each in the form of a hollow groove. 
         [0021]    According to the invention, the prismatic portions may be each in the form of a hollow groove. Thus, the refractive index in the groove of each prismatic portion is significantly lower than that of the first substrate. As a result, the grooves of the prismatic portions can totally reflect light. In this way, a reduction in loss of light in the prismatic portions improves efficiency for light utilization. 
         [0022]    A filling having a lower refractive index than that of the first substrate is preferably disposed in the groove of each prismatic portion. 
         [0023]    According to the invention, the filling having a lower refractive index than that of the first substrate may be disposed in the groove of each prismatic portion. As a result, the grooves of the prismatic portions can totally reflect light, thereby improving efficiency for light utilization. Furthermore, the functional layer is disposed on the filling in the grooves, resulting in the prevention of failures of the functional layer and malfunctions of the electro-optical device. Furthermore, when the functional layer and the like are directly formed on the prismatic portions, advantageously, the layer and the like can be easily formed. 
         [0024]    A filling containing a light-reflecting material may be preferably disposed in the groove of each prismatic portion. 
         [0025]    According to the invention, the filling containing the light-reflecting material may be disposed in the groove of each prismatic portion. Thus, the grooves of the prismatic portions can reflect light at high reflectivity. Furthermore, light is not reflected on the basis of the difference in refractive index between the first substrate and each prismatic portion but is reflected by the filling containing the light-reflecting material. Thus, it is possible to surely reflect light at constant reflectivity, regardless of the incident angle of light incident on the groove of each prismatic portion, thereby improving efficiency for light utilization. 
         [0026]    A projector according to the invention includes the electro-optical device described above. 
         [0027]    According to the invention, the projector includes the electro-optical device having improved efficiency for light utilization. Therefore, it is possible to provide a projector capable of displaying a bright, high-contrast image. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
           [0029]      FIG. 1  schematically shows an overall structure of a projector according to a first embodiment of the invention. 
           [0030]      FIG. 2  is a plan view illustrating the structure of a liquid-crystal panel according to the embodiment. 
           [0031]      FIG. 3  is a cross-sectional view illustrating the structure of the liquid-crystal panel according to the embodiment. 
           [0032]      FIG. 4  is a process drawing showing a step of producing an opposite substrate of the liquid-crystal panel according to the embodiment. 
           [0033]      FIG. 5  is a process drawing showing a step of producing an opposite substrate of the liquid-crystal panel according to the embodiment. 
           [0034]      FIG. 6  is a process drawing showing a step of producing an opposite substrate of the liquid-crystal panel according to the embodiment. 
           [0035]      FIG. 7  is a process drawing showing a step of producing an opposite substrate of the liquid-crystal panel according to the embodiment. 
           [0036]      FIG. 8  is a cross-sectional view illustrating the structure of a liquid-crystal panel including a prismatic substrate bonded to an opposite substrate. 
           [0037]      FIG. 9  schematically shows a pixel region of a liquid-crystal panel. 
           [0038]      FIG. 10  is a cross-sectional view illustrating the structure of a liquid-crystal panel according to a second embodiment of the invention. 
           [0039]      FIG. 11  is a cross-sectional view illustrating the structure of a liquid-crystal panel according to a third embodiment of the invention. 
           [0040]      FIG. 12  is a cross-sectional view illustrating the structure of a liquid-crystal panel according to a fourth embodiment of the invention. 
           [0041]      FIG. 13  shows cross-sectional views each illustrating the fragmentary structure of a prismatic element of a liquid-crystal device according to the invention. 
       
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     First Embodiment 
     Projector 
       [0042]    The schematic structure of a projector according to a first embodiment of the invention will be described below. 
         [0043]    As shown in  FIG. 1 , an ultrahigh-pressure mercury lamp  101  as a light source emits light including a red light component (hereinafter, referred to as “R light”) as a first color light component, a green light component (hereinafter, referred to as “G light”) as a second color light component, and a blue light component (hereinafter, referred to as “B light”) as a third color light. An integrator  104  uniformizes illuminance distribution of light from the ultrahigh pressure mercury lamp  101 . Light having uniformized illuminance distribution is converted by a polarization converter  105  into polarized light, for example, s-polarized light having a specific vibration direction. The resulting s-polarized light is incident on an R-light-transmitting dichroic mirror  106 R constituting a color separating optical system. Hereinafter, R light will be described. The R-light-transmitting dichroic mirror  106 R transmits R light and reflects G light and B light. R light coming through the R-light-transmitting dichroic mirror  106 R is incident on a reflecting mirror  107 . The reflecting mirror  107  bends the optical path of R light at an angle of 90°. R light in which the optical path has been bent is incident on a first-color-light spatial modulator  110 R that modulates R light, which is the first color light, in response to an image signal. The first-color-light spatial modulator  110 R is a transmissive liquid-crystal display device that modulates R light in response to the image signal. The transmission of light through the dichroic mirror does not change the direction of polarization of light, thus maintaining R light incident on the first-color-light spatial modulator  110 R at s-polarized light. 
         [0044]    The first-color-light spatial modulator  110 R includes a half-wave plate  123 R, a glass plate  124 R, a first polarizing plate  121 R, a liquid-crystal panel  120 R, and a second polarizing plate  122 R. The detailed structure of the liquid-crystal panel  120 R will be described later. The half-wave plate  123 R and the first polarizing plate  121 R are in contact with the light-transmitting glass plate  124 R that does not change the polarization direction, thereby inhibiting the deformation of the first polarizing plate  121 R and the half-wave plate  123 R due to heat generation. In  FIG. 1 , the second polarizing plate  122 R is independently disposed. Alternatively, the second polarizing plate  122 R may be contact with the outgoing light side of the liquid-crystal panel  120 R or the incident light side of a cross dichroic prism  112 . 
         [0045]    s-Polarized light incident on the first-color-light spatial modulator  110 R is converted by the half-wave plate  123 R into p-polarized light. R light converted into p-polarized light comes through the glass plate  124 R and the first polarizing plate  121 R without change and is then incident on the liquid-crystal panel  120 R. p-polarized R light incident on the liquid-crystal panel  120 R is converted by modulation in response to an image signal into S-polarized light. R light converted by modulation through the liquid-crystal panel  120 R into s-polarized light emerges from the second polarizing plate  122 R. In this way, R light modulated through the first-color-light spatial modulator  110 R is incident on the cross dichroic prism  112 , which is a color combining optical system. 
         [0046]    G light will be described below. G light and B light are reflected from the R-light-transmitting dichroic mirror  106 R. As a result, the optical path of G light and B light are bent at an angle of 90°. G light and B light in which the optical path thereof has been bent are incident on a B-light-transmitting dichroic mirror  106 G. The B-light-transmitting dichroic mirror  106 G reflects G light and transmits B light. G light reflected from the B-light-transmitting dichroic mirror  106 G is incident on a second-color-light spatial light modulator  110 G that modulates G light, which is the second color light component, in response to an image signal. The second-color-light spatial light modulator  110 G is a transmissive liquid-crystal display device that modulates G light in response to the image signal. The second-color-light spatial light modulator  110 G includes a liquid-crystal panel  120 G, a first polarizing plate  121 G, and a second polarizing plate  122 G. The liquid-crystal panel  120 G will be described in detail later. 
         [0047]    G light converted into s-polarized light is incident on the second-color-light spatial light modulator  110 G. s-Polarized light incident on the second-color-light spatial light modulator  110 G transmits the first polarizing plate  121 G without change and is then incident on the liquid-crystal panel  120 G. s-Polarized G light incident on the liquid-crystal panel  120 G is converted by modulation in response to an image signal into p-polarized light. G light converted by modulation through the liquid-crystal panel  120 R into p-polarized light emerges from the second polarizing plate  122 G. In this way, G light modulated through the second-color-light spatial light modulator  110 G is incident on the cross dichroic prism  112 , which is a color combining optical system. 
         [0048]    B light will be described below. B light coming through the B-light-transmitting dichroic mirror  106 G is incident on a third-color-light spatial light modulator  110 B that modulates B light, which is the third color light component, in response to an image signal through two relay lenses  108  and two reflecting mirrors  107 . The third-color-light spatial light modulator  110 B is a liquid-crystal display device that modulates B light in response to the image signal. 
         [0049]    The reason for allowing B light to comes through the relay lenses  108  is that the length of the optical path of B light is longer than each of those of R light and G light. The use of the relay lenses  108  can bring B light coming through the B-light-transmitting dichroic mirror  106 G to the third-color-light spatial light modulator  110 B without change. The third-color-light spatial light modulator  110 B includes a half-wave plate  123 B, a glass plate  124 B, a first polarizing plate  121 B, a liquid-crystal panel  120 B, and a second polarizing plate  122 B. The third-color-light spatial light modulator  110 B has a structure similar to that of the first-color-light spatial modulator  110 R. Thus, the detailed description is omitted. B light converted into s-polarized light is incident on the third-color-light spatial light modulator  110 B. S-Polarized light incident on the third-color-light spatial light modulator  110 B is converted by the half-wave plate  123 B into p-polarized light. B light converted into p-polarized light comes through the glass plate  124 B and the first polarizing plate  121 B without change and is then incident on the liquid-crystal panel  120 B. p-Polarized B light incident on the liquid-crystal panel  120 B is converted by modulation in response to an image signal into s-polarized light. B light converted by modulation through the liquid-crystal panel  120 B into s-polarized light emerges from the second polarizing plate  122 B. B light modulated through the third-color-light spatial light modulator  110 B is incident on the cross dichroic prism  112 , which is a color combining optical system. In this way, the R-light-transmitting dichroic mirror  106 R and the B-light-transmitting dichroic mirror  106 G, which constitute color separating optical systems, separate light emitted from the ultrahigh pressure mercury lamp  101  into R light as the first color light component, G light as the second color light component, and B light as the third color light component. 
         [0050]    The cross dichroic prism  112 , which is a color combining optical system, includes two dichroic films  112   a  and  112   b , the dichroic film  112   a  being orthogonal to the dichroic film  112   b . The dichroic film  112   a  reflects B light and transmits G light. The dichroic film  112   b  reflects R light and transmits G light. In this way, the cross dichroic prism  112  combines R light, G light, and B light which are modulated through the first-color-light spatial modulator  110 R, the second-color-light spatial light modulator  110 G, and the third-color-light spatial light modulator  110 B, respectively. 
         [0051]    A projection lens  114  projects light combined through the cross dichroic prism  112  onto a screen  116 . Thereby, a full-color image can be obtained on the screen  116 . 
         [0052]    As described above, light components incident from the first-color-light spatial modulator  110 R and the third-color-light spatial light modulator  110 B on the cross dichroic prism  112  are adjusted to be s-polarized light components. Light incident from the second-color-light spatial light modulator  110 G on the cross dichroic prism  112  is adjusted to be p-polarized light. In this way, the light components emitted from these color light spatial light modulators are efficiently combined in the cross dichroic prism  112  by allowing the polarization directions of light components incident on the cross dichroic prism  112  to differs. The dichroic films  112   a  and  112   b  usually have satisfactory reflection properties of s-polarized light. Thus, R light and B light which are reflected from the dichroic films  112   a  and  112   b  are each modified to be s-polarized light. G light which transmits the dichroic films  112   a  and  112   b  is modified to be p-polarized light. 
       Liquid-Crystal Panel 
       [0053]    The liquid-crystal panel (electro-optical device) will be described in detail below with reference to  FIGS. 2 and 3 . A projector described in  FIG. 1  includes three liquid-crystal panels  120 R,  120 G, and  120 B. These three liquid-crystal panels  120 R,  120 G, and  120 B have the same basic configuration but differ in wavelength range of light modulated from each other. Hence, the liquid-crystal panel  120 R as an example will be described below.  FIG. 2  is a plan view of the structure of the liquid-crystal panel  120 R.  FIG. 3  is a cross-sectional view of the liquid-crystal panel  120 R. In  FIGS. 2 and 3 , the X-direction shown is defined as the transverse direction of the liquid-crystal panel  120 R. The Y-direction is defined as longitudinal direction of the liquid-crystal panel  120 R. 
         [0054]    As shown in  FIG. 2 , the liquid-crystal panel  120 R includes a TFT-array substrate  2  and an opposite substrate  3  which are composed of a transparent material such as glass; and a seal  4 , the TFT-array substrate  2  and the opposite substrate  3  being laminated with the seal  4  provided therebetween. A liquid-crystal layer  5  is disposed in a region surrounded by the seal  4 . The TFT-array substrate  2  and the opposite substrate  3  each have a refractive index of about 1.46. 
         [0055]    A peripheral partition  6  composed of a light-shielding material is disposed at an inner side of the seal  4 . A region surrounded by the peripheral partition  6  is defined as an optical modulation region  12  for modulating light from the ultrahigh pressure mercury lamp  101 . Pixel regions  13  capable of transmitting light from the ultrahigh pressure mercury lamp  101  are arrayed in a matrix in the optical modulation region  12 . Regions disposed between the pixel regions  13  are defined as interpixel regions  14  for shielding light from the ultrahigh pressure mercury lamp  101 . 
         [0056]    A data-line driving circuit  7  and an external-circuit mounting terminals  8  are disposed along a first side of the TFT-array substrate  2  and in a region outside the seal  4 . Scanning-line driving circuits  9  are each disposed along a corresponding one of the sides adjoining to the first side. A plurality of lines  10  for connection of the scanning-line driving circuits  9  disposed at both sides of an image-displaying region are disposed along the remaining side of the TFT-array substrate  2 . Inter-substrate conductors  11  for electrically connecting the TFT-array substrate  2  to the opposite substrate  3  are disposed at corners of the opposite substrate  3 . 
         [0057]    In place of the formation of the data-line driving circuit  7  and the scanning-line driving circuits  9  on the TFT-array substrate  2 , for example, a tape automated bonding substrate (TAB substrate) mounting a driving LSI may be electrically and mechanically connected to terminals disposed at the periphery of the TFT-array substrate  2  via an anisotropic conductive film. 
         [0058]    As shown in  FIG. 3 , the TFT-array substrate  2  includes pixel electrodes  24 , thin film transistors (TFTs)  21 , a planarization layer  26 , light-shielding portions  23 , and an alignment layer  25 . The pixel electrodes  24  are disposed in the pixel reactions  13  on the inner surface  2   a  of the TFT-array substrate  2 . The pixel electrodes  24  are each composed of a transparent conductive material such as indium tin oxide (ITO). The TFTs  21  functions as switching elements for feeding the pixel electrodes  24  with electric signals. The TFTs  21  are disposed in the interpixel regions  14  on the inner surface  2   a  of the TFT-array substrate  2 . The planarization layer  26  is composed of a transparent resin material or the like. The planarization layer  26  is disposed on substantially the entire surface of the inner surface  2   a  so as to cover the pixel electrodes  24  and the TFTs  21 . The light-shielding portions  23  are disposed in the interpixel regions  14  on the planarization layer  26 . The alignment layer  25  is stacked on the planarization layer  26  so as to cover the light-shielding portions  23 . 
         [0059]    As shown in  FIG. 3 , the opposite substrate  3  includes grooves  40 , light-shielding portions  33 , a common electrode  34 , and an alignment layer  35 . 
         [0060]    The grooves  40  are disposed in the interpixel regions  14  and on the inner surface  3   a  of the opposite substrate  3 . The grooves  40  are arrayed in the form of a grid so as to extend in the X-direction and Y-direction at regular intervals. The grooves  40  are disposed so as to overlap the light-shielding portions  23  when viewed in plan. The cross-sectional shape of each groove  40  is an isosceles triangle. The grooves  40  each have a hollow structure. The refractive index in each groove  40  is about 1.00. Thus, the refractive index (about 1.00) in each groove  40  differs from the refractive index (about 1.46) in the opposite substrate  3 . The difference in refractive index results in total reflection of light incident from the opposite substrate  3  on the grooves  40 . The grooves  40  arrayed in the form of a grid and extending in the X-direction and Y-direction constitute prismatic elements  30  functioning as optical-path deflecting portions. In this embodiment, the cross-sectional shape of each groove  40  is an isosceles triangle but is not limited thereto. For example, the cross-sectional shape may be a shape shown in  FIG. 13 . Furthermore, also in embodiments described below, the cross-sectional shape of each prismatic portion is not limited to an isosceles triangle but may be a shape shown in  FIG. 13 . 
         [0061]    The light-shielding portions  33  are light-shielding member directly disposed on the grooves  40  so as to cover the grooves  40 . Each light-shielding portion  33  has the same width as that of a corresponding one of the grooves  40 . Each groove  40  overlaps a corresponding one of the light-shielding portions  33  when viewed in plan. The common electrode is directly disposed on the inner surface  3   a  of the opposite substrate  3  so as to cover the light-shielding portions  33 . The alignment layer  35  is disposed on the surface of the common electrode  34 . 
         [0062]    The gap between the TFT-array substrate  2  and the opposite substrate  3  is filled with the liquid-crystal layer  5 . The liquid-crystal layer  5  is composed of a liquid-crystal compound, such as a fluorine-containing liquid-crystal compound or fluorine-free liquid-crystal compound. The liquid-crystal layer  5  is held between the TFT-array substrate  2  and the opposite substrate  3  so as to be in contact with the alignment layer  25  adjacent to the TFT-array substrate  2  and the alignment layer  35  adjacent to the opposite substrate  3 . The orientation of liquid crystal molecules is regulated by the alignment layer  25  and the alignment layer  35  in such a manner that the liquid-crystal molecules are aligned in a predetermined direction when a non-selective voltage is applied. The liquid-crystal layer  5  has a refractive index of about 1.75. That is, the liquid-crystal layer  5  has a refractive index higher than refractive index (about 1.46) of each of the TFT-array substrate  2  and the opposite substrate  3 . 
         [0063]    Light L 1  from the ultrahigh pressure mercury lamp  101  is incident from the upper side in  FIG. 3  on the liquid-crystal panel  120 R. The incident light comes through the side of the opposite substrate  3  (the opposite substrate  3 , the common electrode  34 , and alignment layer  35 ), is modulated by the liquid-crystal layer  5 , and comes through the side of the TFT-array substrate (the alignment layer  25 , the planarization layer  26 , the pixel electrodes  24 , and the TFT-array substrate  2 ). Light coming through the TFT-array substrate  2  travels toward the projection lens  114  (see  FIG. 1 ). 
         [0064]    Light L 2  from the ultrahigh pressure mercury lamp  101  is incident on the opposite substrate  3  in the same way as light L 1 . Light L 2  traveling in the opposite substrate  3  is totally reflected from an inclined face  40   a  of the groove  40  toward the pixel regions  13  to deflect the optical path. Light L 2  reflected from the inclined face  40   a  travels similarly to light L 1 , comes through the TFT-array substrate  2 , and travels toward projection lens  114  (see  FIG. 1 ). 
         [0065]    Light L 3  from the ultrahigh pressure mercury lamp  101  is incident on the opposite substrate  3  in the same way as light L 1 , comes through the side of the opposite substrate, and is incident on the liquid-crystal layer  5 . Light L 3  refracts toward the inner side of the pixel region  13  because the liquid-crystal layer  5  has a refractive index (1.75) higher than the refractive index (about 1.46° of the opposite substrate  3 . Even light (indicated by a dashed line in  FIG. 3 ) as light L 3  in which if light travels straight, light is incident on the light-shielding portion  23  to be absorbed therein contributes to display. 
       Production Process 
       [0066]    Referring to  FIGS. 4 to 7 , a process for forming the opposite substrate  3  of the liquid-crystal panel  120 R will be described below.  FIGS. 4 to 7  are each a cross-sectional view of a structure in each step of the process for forming the opposite substrate  3 . 
         [0067]    As shown in  FIG. 4 , the groove  40  of the prismatic element  30  is formed in the opposite substrate  3 . The groove  40  is formed by, for example, dry-etching the opposite substrate  3 . As shown in  FIG. 5 , a volatile solid member  50  is charged into the groove  40 . The volatile solid member  50  is composed of a material which is in the form of a solid at room temperature and, for example, evaporates at about 200° C., e.g., paraffin. The surface  50   a  of the volatile solid member  50  is flush with the surface  3   a  of the opposite substrate  3 . 
         [0068]    As shown in  FIG. 6 , the light-shielding portion  33  is formed on the surface  50   a  of the volatile solid member  50  in such a manner that the light-shielding portion  33  has the same width as that of the surface  50   a  of the volatile solid member  50 . As shown in  FIG. 7 , the common electrode  34  is formed so as to cover the surface  3   a  of the opposite substrate  3  and the light-shielding portion  33 . In the step of forming the common electrode  34 , an ITO film constituting the common electrode  34  is formed on the opposite substrate  3 . At this time, the ambient temperature around the opposite substrate  3  is about 300° C.; hence, the volatile solid member  50  evaporates to form the hollow groove  40 . Then, an alignment layer is formed on the common electrode  34  to complete the opposite substrate  3 . 
         [0069]    In the liquid-crystal panel  120 R according to this embodiment, the common electrode  34  and the light-shielding portions  33  are directly disposed on the surface  3   a  of the opposite substrate  3  and the prismatic elements  30 . The liquid-crystal panel  120 R does not include a portion corresponding to the known structure. In this embodiment, the absence of the opposite substrate having a thickness between the prismatic elements and the light-shielding portions reduces the distance between each prismatic element  30  and a corresponding one of the light-shielding portions  23 , thereby reducing absorption of light by the light-shielding portions  23  and  33  to improve efficiency for light utilization. 
         [0070]    Furthermore, in a structure in which the opposite substrate also serves as a prismatic substrate like this embodiments the pixel regions are substantially expanded compared with the known structure. 
         [0071]    This point will be described with reference to  FIGS. 8 and 9 .  FIG. 8  illustrates the structure of a known liquid-crystal panel  170 R including a prismatic substrate bonded to the outer surface of an opposite substrate.  FIG. 9  shows comparison between the light-transmitting region of the liquid-crystal panel  120 R according to this embodiment and the light-transmitting region of the known liquid-crystal panel  170 R. 
         [0072]    As shown in  FIG. 8 , the liquid-crystal panel  170  includes a prismatic substrate  153  bonded on the outer surface  182   a  of an opposite substrate  182  having a thickness of t with an adhesive layer  181 . Light-shielding portions  183  are disposed on the opposite substrate  182  and in interpixel regions. A common electrode  184  is disposed on substantially the entire surface of the opposite substrate  182  and covers the light-shielding portions  183 . An alignment layer  185  is disposed on a surface of the common electrode  184 . 
         [0073]    Light L 4  with which the liquid-crystal panel  170 R is irradiated is incident from the upper side in  FIG. 8  on the prismatic substrate  153  and reflected from a groove  190  in the prismatic substrate  153 . Light L 4  comes through the adhesive layer  181 , the opposite substrate  182 , the common electrode  184 , and the alignment layer  185 , is incident on a liquid-crystal layer  155  to be modulated in the liquid-crystal layer  155 , and then emerges from a TFT-array substrate  152 . 
         [0074]    Light L 4  is reflected from the groove  190  of a prismatic element  180  and then comes through the opposite substrate  182 ; hence, a shift distance in a direction parallel to the surface of the substrate, i.e., the shift distance toward the inner side of a pixel region  163  is increased. In the opposite substrate  182 , light L 4  shifts toward the inner side of the pixel region  163  by distance T (T=t×tan θ, wherein θ represents an incident angle when light L 4  is incident on the opposite substrate  182 ). In contrast, in the liquid-crystal panel  120 R according to this embodiment, since the opposite substrate also serves as the prismatic substrate, light does not shift in a direction parallel to the surface of the substrate, i.e., there is no shift of light corresponding to distance T described above. 
         [0075]    Therefore, a light-transmitting region  60  of the liquid-crystal panel  120 R according to this embodiment is substantially larger than a light-transmitting region  61  of the liquid-crystal panel  170 R by distance T as shown in  FIG. 9 . Accordingly, in this embodiment in which the opposite substrate also serves as the prismatic substrate, light-transmitting region is large to substantially increase an aperture ratio, thereby improving efficiency for light utilization. 
         [0076]    Furthermore, when the light-transmitting region  61  is small like the known liquid-crystal panel  170 R, light comes through only the middle portion of the pixel region. Thus, light scarcely comes through the periphery of the pixel region, causing nonuniformity in light-intensity distribution. In contrast, the liquid-crystal panel  120 R according to this embodiment has a large light-transmitting region  60 ; hence, light uniformly comes through a wide range of each pixel region  13 . 
         [0077]    In this embodiment, since the prismatic elements  30  have the hollow grooves  40 , the refractive index in the groove  40  of each prismatic elements  30  is smaller than that of the opposite substrate  3 . Thus, it is possible to totally reflect light from the grooves  40 . A reduction in loss of light due to the prismatic elements  30  results in the improvement of efficiency for light utilization. 
         [0078]    Furthermore, in this embodiment, the liquid-crystal layer  5  has a refractive index higher than that of the opposite substrate  3 . As a result, among light incident from the opposite substrate  3  on the liquid-crystal layer  5 , in particular, light traveling toward the light-shielding portions  23  is allowed to refract toward the inner side of each pixel region  13 . Even light in which if light travels straight, light is incident on the light-shielding portion  23  to be absorbed therein contributes to display; hence, efficiency for light utilization can be further improved. 
       Second Embodiment 
       [0079]    A second embodiment of the invention will be described below. 
         [0080]    As shown in  FIG. 10 , a liquid-crystal panel  220 R according to this embodiment has the same structure as in the first embodiment, except that a transparent filling  250  is disposed in grooves  240  disposed in an opposite substrate  203 . The filling  250  is composed of an acrylic resin material or the like. The filling  250  has a refractive index of about 1.40, which is smaller than the refractive index (about 1.46) of the opposite substrate  203 . Thus, light can be totally reflected from inclined faces  240   a  of the grooves  240 . 
         [0081]    The filling  250  may be composed of a transparent resin material, such as an epoxy resin, a melamine resin, or a polyimide resin, in addition to the acrylic resin. The acrylic resin is suitably used because the acrylic resin containing a precursor or a photosensitizing agent (photopolymerization initiator) is easily cured for a short time by light irradiation. Furthermore, a UV curable resin has low shrinkage on curing and is thus effective in ensuring reliability and morphological stability of prismatic elements  230 . Examples of the basic structure of the acrylic resin include prepolymers, oligomers, monomers, and photopolymerization initiators. 
         [0082]    Examples of the prepolymers and oligomers include acrylates, such as epoxy acrylates, urethane acrylates, polyester acrylates, polyether acrylates, and spiroacetal acrylates; and methacrylates, such as epoxy methacrylates, urethane methacrylates, polyester methacrylates, and polyether methacrylates. 
         [0083]    Examples of the monomers include monofunctional monomers, such as 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxymethyl methacrylate, N-vinyl-2-pyrrolidone, carbitol acrylate, tetrahydrofurfuryl acrylate, Isobornyl acrylate, dicyclopentenyl acrylate, and 1,3-butanediol acrylate; bifunctional monomers, such as 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, and pentaerythritol diacrylate; and multifunctional monomers, such as trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, and di pentaerythritol hexaacrylate. 
         [0084]    Examples of the photopolymerization initiators include acetophenones such as 2,2-dimethoxy-2-phenylacetophenone; butylphenones, such as α-hydroxyisobutylphenone and p-isopropyl-α-hydroxyisobutylphenone; halogenated acetophenones, such as p-tert-butyldichloroacetophenone, p-tert-butyltrichloroacetophenone, and α,α-dichloro-4-phenoxyacetophenone; benzophenones, such as benzophenone and N,N-tetraethyl-4,4-diaminobenzophenone; benzils, such as benzil and benzylmethyl methyl ketal; benzoins, such as benzoin and benzoin alkyl ethers; oximes such as 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime; xanthones, such as 2-methylthioxanthone and 2-chlorothioxanthone; and radical-generating compounds, such as Michler&#39;s ketone and benzyl methyl ketal. 
         [0085]    A method for using a sol-gel glass material as a flowable material may be employed. A fine resin powder, a fine metal powder, a fine glass material powder, a fine ceramic powder, and a fine mineral powder; and a resin material containing at least one of the powders may be used in a production process. According to need, a compound such as an amine in order to prevent inhibition of curing due to oxygen may be incorporated. To facilitate application, a solvent may be incorporated. Examples of the solvent usable include, but are not limited to, various organic solvents, such as propylene glycol monomethyl ether acetate, methoxymethyl propionate, ethoxyethyl propionate, ethyl lactate, ethyl pyruvate, and methyl amyl ketone. 
         [0086]    According to this embodiment, since the filling  250  having a refractive index lower than that of the opposite substrate  203  is disposed in the grooves  240  of the prismatic elements  230 , light can be reflected from the inclined face  240   a  of the grooves  240 . Thereby, efficiency for light utilization can be improved. Furthermore, the light-shielding portions  233  on the prismatic elements  230  are disposed on the filling  250 , thus stabilizing shapes of the light-shielding portions  233  and preventing the failure of the light-shielding portions  233 . 
       Third Embodiment 
       [0087]    A third embodiment of the invention will be described below. 
         [0088]    As shown in  FIG. 11 , a liquid-crystal panel  320 R according to this embodiment has the same structure as in the first embodiments except that a filling  350  is disposed in grooves  340  disposed in an opposite substrate  303 . The filling  350  contains a light-reflecting material, such as aluminum. The light-reflecting material contained in the filling  350  is preferably a metal material, such as chromium, having high reflectivity, in addition to aluminum. 
         [0089]    According to this embodiment, the filling  350  containing the light-reflecting material is disposed in the grooves  340  of prismatic elements  330 . Thus, inclined faces  340   a  of the groove  340  of each prismatic element  330  can reflect light at high reflectivity. Furthermore, light is not reflected on the basis of the difference in refractive index between the opposite substrate  303  and each prismatic element  330  but is reflected by the filling  350 . Thus, it is possible to surely reflect light at constant reflectivity, regardless of the incident angle of light incident on the inclined faces  340   a  of each groove  340 , thereby improving efficiency for light utilization. 
       Fourth Embodiment 
       [0090]    A fourth embodiment of the invention will be described below. 
         [0091]    As shown in  FIG. 12 , a liquid-crystal panel  420 R according to this embodiment has the same structure as in the first embodiment, except that a light-shielding portion is not disposed on an opposite substrate  403 , and a common electrode  434  is directly disposed on the inner surface  403   a  of the opposite substrate  403  and covers grooves  440  of prismatic elements  430 . The grooves  440  are hollow grooves. Thus, light-shielding portions  423  are disposed on a TFT-array substrate  402  alone. 
         [0092]    Even when a light-shielding portion is not disposed on the opposite substrate  403 , the distance between each prismatic element  430  and a corresponding one of the light-shielding portions  423  is reduced because the opposite substrate also serves as the prismatic substrate. Thus, among light rays which pass through pixel regions and are then absorbed in the light-shielding portions  423  when a prismatic substrate is bonded to the outer side of an opposite substrate, some of the light rays are not absorbed in this embodiment. Furthermore, light-transmitting regions are substantially large compared with the case in which the prismatic substrate is bonded on the outer side of the opposite substrate, thereby improving efficiency for light utilization. 
         [0093]    The technical range of the invention is not limited to the embodiments. Various modifications may be made without departing from the scope of the invention. 
         [0094]    In the above-described embodiments, the liquid-crystal devices are exemplified as electro-optical devices. However, the invention is not limited thereto. The invention may also be applied to other electro-optical devices, such as organic EL devices, inorganic EL devices, plasma displays, electrophoretic displays, and field-emission displays. 
         [0095]    In the fourth embodiment, the liquid-crystal panel  420 R including the prismatic elements  430  having the hollow grooves  440  is exemplified in the same way as in the first embodiment. Alternatively, a filling having a refractive index lower than that of the opposite substrate  403  may be disposed in the grooves  440  (see the second embodiment. Furthermore, a filling containing a reflective material may be disposed in the grooves  440 .