JP2013025074A - Electro-optic device and projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-optic device showing high reflection efficiency on a side face of a groove formed in a light-transmitting substrate, even when an opening of the groove is sealed with a light-transmitting film to render the groove into a hollow state, and to provide a projection type display device including the electro-optic device.SOLUTION: An electro-optic device 100 includes a second substrate 20, in which a hollow groove 260 that opens to a region between pixel electrodes 9a (an inter-pixel region 10f) is formed, and an opening 265 of the groove 260 is sealed with a light-transmitting insulating film 27. Thereby, side faces 261, 262 of the hollow groove 260 function as reflection planes caused by the difference in refractive index between the medium (vacuum) in the groove 260 and the medium of the second substrate 20. The light-transmitting insulating film 27 is a magnesium fluoride film or the like and has a refractive index lower than that of a substrate body 10w. Therefore, even in a part of the side faces 261, 262 of the groove 260, the part in contact with the light-transmitting film 27, functions as a reflection plane.

Description

  The present invention relates to an electro-optical device such as a liquid crystal device, and a projection display device including the electro-optical device.

  Among various electro-optical devices, the liquid crystal device includes a first substrate on which a plurality of pixel electrodes and switching elements are provided, and a second substrate disposed opposite to the first substrate. A liquid crystal layer as an electro-optical material layer is provided between the second substrate. Among liquid crystal devices, in the TN (Twisted Nematic) mode and VA (Vertical Alignment) mode liquid crystal devices, a common electrode is formed on the second substrate, and the alignment of the liquid crystal layer is between the common electrode and the pixel electrode. To control. In such a liquid crystal device, for the purpose of efficiently guiding light incident from the second substrate side to the pixel electrode, a cross-section V-shaped opening is formed between the pixel electrodes in the dust-proof glass constituting a part of the second substrate. In addition, a technique has been proposed in which a light-transmitting cover glass is attached to dust-proof glass with an adhesive, and the side surface of a hollow groove filled with air is used as a reflective surface.

JP 2006-215427 A

  However, in making the groove hollow, the configuration in which the cover glass is attached to the dust-proof glass with an adhesive to close the opening of the groove as in the technique described in Patent Document 1, the productivity is extremely low. is there.

  The inventor of the present application proposes that after forming a groove on the second substrate, a silicon oxide film is formed and the opening of the groove is closed with the silicon oxide film, thereby making the groove hollow. is there. However, if a silicon oxide film is formed after the trench is formed, the silicon oxide film is also formed inside the trench. The refractive index of the silicon oxide film is the same as that of the quartz substrate or glass substrate used for the second substrate. For this reason, the portion of the side surface of the groove that is in contact with the silicon oxide film does not function as a reflective surface, and there is a problem that the reflection efficiency is significantly reduced.

  In view of the above problems, the problem of the present invention is that the reflection efficiency on the side surface of the groove is high even when the opening of the groove formed in the light-transmitting substrate is closed with a light-transmitting film to make the groove hollow. An object of the present invention is to provide an electro-optical device and a projection display device including the electro-optical device.

  In order to solve the above problems, an electro-optical device according to the present invention includes a first substrate provided with a plurality of pixel electrodes and switching elements corresponding to each of the plurality of pixel electrodes, and opposed to the first substrate. A second substrate, and an electro-optical material layer provided between the first substrate and the second substrate, wherein one of the first substrate and the second substrate is: A translucent substrate, comprising: a hollow groove that opens between adjacent pixel electrodes in the plurality of pixel electrodes; and a translucent film that closes the opening of the groove, and the translucent film The refractive index is less than the refractive index of the translucent substrate.

  In the present invention, one of the first substrate and the second substrate is a light-transmitting substrate, and the light-transmitting substrate has a plurality of pixel electrodes facing between adjacent pixel electrodes. An open hollow groove is formed, and the opening of the groove is closed by a translucent film. For this reason, the side surface of the hollow groove serves as a reflection surface due to a difference in refractive index between the medium (air or vacuum) in the groove and the medium of the translucent substrate. Therefore, in the light-transmitting substrate, the light that goes between the pixel electrodes can be reflected by the side surface of the groove and directed toward the pixel electrode, so that the ratio of the light that contributes to display or the like is high. Further, in the present invention, since the light-transmitting film is used in closing the opening of the groove, the opening of the groove can be closed only by forming the light-transmitting film. Therefore, productivity is high compared with the case where the cover glass is bonded to close the opening. In addition, since the opening of the groove is closed by the light-transmitting film, the light traveling toward the light-transmitting film is not prevented from going toward the pixel electrode. Furthermore, the refractive index of the translucent film is less than the refractive index of the translucent substrate. For this reason, total reflection occurs also in the part which is in contact with the translucent film among the side surfaces of the groove. Therefore, even when the groove opening formed in the light-transmitting substrate is closed with a light-transmitting film to make the groove hollow, the reflection efficiency on the side surface of the groove is high.

  In this invention, it is preferable that the refractive index of the said translucent film is 1.43 or less. According to such a configuration, even when a quartz substrate or a glass substrate is used as the translucent substrate, the refractive index of the translucent film is less than the refractive index of the translucent substrate. For this reason, since the part which is in contact with the translucent film among the side surfaces of the groove also functions as a reflection surface, the reflection efficiency at the side surface of the groove is high.

  In the present invention, it is preferable that the translucent film is formed in the groove so as to fill a part of the groove, and is not formed outside the groove. If a light-transmitting film having a low refractive index is formed outside the groove, the reflectance at the interface between the light-transmitting substrate and the light-transmitting film increases, and the amount toward the pixel electrode decreases. However, such a problem does not occur unless the translucent film is provided outside the groove.

  In the present invention, the light-transmitting film is preferably a magnesium fluoride film, a borosilicate glass film, a phosphosilicate glass film, or a borophosphosilicate glass film.

  In the present invention, the groove may adopt a configuration provided in the second substrate. According to such a configuration, it is possible to employ a configuration in which light is incident from the second substrate side, and there is an advantage that light is not easily incident on the switching element.

  In this case, the pixel electrode and the first substrate can adopt a structure having translucency. According to this configuration, a transmissive electro-optical device can be configured.

  In the present invention, it is preferable that the groove has a V-shaped cross section in which a side surface is inclined between the adjacent pixel electrodes. According to such a configuration, the light that is to be directed between the pixel electrodes can be reflected by the side surfaces of the grooves and can be efficiently directed to the pixel electrodes.

  In the present invention, the groove is preferably in a vacuum state. According to this configuration, the side surface of the hollow groove can be a reflective surface with high reflectivity. Further, if the inside of the groove is in a vacuum state, there is an advantage that the film may be formed in a vacuum atmosphere when the opening of the groove is closed with a light-transmitting film.

  The electro-optical device according to the present invention is preferably used for a projection display device. In this case, the projection display device includes a light source unit that emits light incident on the electro-optical device from the one substrate, and the electro-optical device. A projection optical system for projecting light modulated by the apparatus. Particularly in the case of a projection display device, since the use efficiency of incident light is required to be high, the effect when the present invention is applied to an electro-optical device is remarkable.

It is a schematic block diagram of the projection type display apparatus to which this invention is applied. FIG. 2 is an explanatory diagram showing a basic configuration of a liquid crystal panel used for a liquid crystal light valve (electro-optical device / liquid crystal device) in the projection display device shown in FIG. 1. FIG. 6 is an explanatory diagram illustrating a specific configuration example of a liquid crystal panel used in the electro-optical device according to Embodiment 1 of the invention. FIG. 3 is an explanatory diagram of a pixel of the electro-optical device according to the first embodiment of the invention. FIG. 6 is an explanatory diagram of a reflection portion formed on a second substrate of the electro-optical device according to Embodiment 1 of the invention. 6 is a graph showing a result of simulating the relationship between the refractive index of the light-transmitting film used in the electro-optical device according to Embodiment 1 of the present invention and the brightness of the projected image from the projection display device shown in FIG. 1. FIG. 6 is an explanatory diagram illustrating a method for manufacturing the electro-optical device according to the first embodiment of the invention. In the manufacturing method of the electro-optical device according to Embodiment 1 of the present invention, it is an explanatory view when a light-transmitting film is formed by a low pressure CVD method using tetraethoxysilane.

  With reference to the drawings, a projection display device using an electro-optical device (liquid crystal device) to which the present invention is applied, an electro-optical device, and a method for manufacturing the electro-optical device will be described. In the drawings to be referred to in the following description, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing.

[Embodiment 1]
(Configuration of projection display device)
With reference to FIG. 1, a projection display device using the electro-optical device according to the first embodiment of the present invention as a light valve will be described. FIG. 1 is a schematic configuration diagram of a projection display device to which the present invention is applied.

  In FIG. 1, a projection display device 110 is a so-called projection type projection display device that irradiates light on a screen 111 provided on the viewer side and observes light reflected by the screen 111. The projection display device 110 includes a light source unit 130 including a light source 112, dichroic mirrors 113 and 114, liquid crystal light valves 115 to 117 (electro-optical device 100 / liquid crystal device), a projection optical system 118, and a cross dichroic prism. 119 and a relay system 120.

  The light source 112 is composed of an ultrahigh pressure mercury lamp that supplies light including red light, green light, and blue light. The dichroic mirror 113 is configured to transmit red light from the light source 112 and reflect green light and blue light. The dichroic mirror 114 is configured to transmit blue light and reflect green light among the green light and the blue light reflected by the dichroic mirror 113. Thus, the dichroic mirrors 113 and 114 constitute a color separation optical system that separates the light emitted from the light source 112 into red light, green light, and blue light.

  Here, between the dichroic mirror 113 and the light source 112, an integrator 121 and a polarization conversion element 122 are sequentially arranged from the light source 112. The integrator 121 is configured to uniformize the illuminance distribution of the light emitted from the light source 112. Further, the polarization conversion element 122 is configured to change the light from the light source 112 into polarized light having a specific vibration direction such as s-polarized light.

  The liquid crystal light valve 115 is a transmissive electro-optical device 100 that modulates the red light transmitted through the dichroic mirror 113 and reflected by the reflecting mirror 123 in accordance with an image signal. The liquid crystal light valve 115 includes a λ / 2 phase difference plate 115a, a first polarizing plate 115b, a liquid crystal panel 115c, and a second polarizing plate 115d. Here, the red light incident on the liquid crystal light valve 115 remains s-polarized light because the polarization of the light does not change even if it passes through the dichroic mirror 113.

  The λ / 2 phase difference plate 115a is an optical element that converts s-polarized light incident on the liquid crystal light valve 115 into p-polarized light. The first polarizing plate 115b is a polarizing plate that blocks s-polarized light and transmits p-polarized light. The liquid crystal panel 115c is configured to convert p-polarized light into s-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to the image signal. Furthermore, the second polarizing plate 115d is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Therefore, the liquid crystal light valve 115 is configured to modulate the red light according to the image signal and emit the modulated red light toward the cross dichroic prism 119.

  Note that the λ / 2 phase difference plate 115a and the first polarizing plate 115b are disposed in contact with a light-transmitting glass plate 115e that does not convert polarized light, and the λ / 2 phase difference plate 115a and the first polarizing plate 115b. It is possible to avoid distortion of 115b due to heat generation.

  The liquid crystal light valve 116 is a transmissive electro-optical device 100 that modulates green light reflected by the dichroic mirror 114 after being reflected by the dichroic mirror 113 in accordance with an image signal. Similarly to the liquid crystal light valve 115, the liquid crystal light valve 116 includes a first polarizing plate 116b, a liquid crystal panel 116c, and a second polarizing plate 116d. Green light incident on the liquid crystal light valve 116 is s-polarized light that is reflected by the dichroic mirrors 113 and 114 and then incident. The first polarizing plate 116b is a polarizing plate that blocks p-polarized light and transmits s-polarized light. The liquid crystal panel 116c is configured to convert s-polarized light into p-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to the image signal. The second polarizing plate 116d is a polarizing plate that blocks s-polarized light and transmits p-polarized light. Accordingly, the liquid crystal light valve 116 is configured to modulate green light in accordance with the image signal and emit the modulated green light toward the cross dichroic prism 119.

  The liquid crystal light valve 117 is a transmissive electro-optical device 100 that modulates blue light reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114 and then passed through the relay system 120 in accordance with an image signal. Similarly to the liquid crystal light valves 115 and 116, the liquid crystal light valve 117 includes a λ / 2 retardation film 117a, a first polarizing plate 117b, a liquid crystal panel 117c, and a second polarizing plate 117d. Here, since the blue light incident on the liquid crystal light valve 117 is reflected by the two reflecting mirrors 125a and 125b described later of the relay system 120 after being reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114, the s-polarized light is reflected. It has become.

  The λ / 2 phase difference plate 117a is an optical element that converts s-polarized light incident on the liquid crystal light valve 117 into p-polarized light. The first polarizing plate 117b is a polarizing plate that blocks s-polarized light and transmits p-polarized light. The liquid crystal panel 117c is configured to convert p-polarized light into s-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to the image signal. Furthermore, the second polarizing plate 117d is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Accordingly, the liquid crystal light valve 117 is configured to modulate blue light in accordance with an image signal and emit the modulated blue light toward the cross dichroic prism 119. The λ / 2 phase difference plate 117a and the first polarizing plate 117b are disposed in contact with the glass plate 117e.

  The relay system 120 includes relay lenses 124a and 124b and reflection mirrors 125a and 125b. The relay lenses 124a and 124b are provided to prevent light loss due to a long blue light path. Here, the relay lens 124a is disposed between the dichroic mirror 114 and the reflection mirror 125a. The relay lens 124b is disposed between the reflection mirrors 125a and 125b. The reflection mirror 125a is disposed so as to reflect the blue light transmitted through the dichroic mirror 114 and emitted from the relay lens 124a toward the relay lens 124b. The reflection mirror 125b is arranged to reflect the blue light emitted from the relay lens 124b toward the liquid crystal light valve 117.

  The cross dichroic prism 119 is a color combining optical system in which two dichroic films 119a and 119b are arranged orthogonally in an X shape. The dichroic film 119a is a film that reflects blue light and transmits green light, and the dichroic film 119b is a film that reflects red light and transmits green light. Therefore, the cross dichroic prism 119 is configured to combine the red light, the green light, and the blue light modulated by the liquid crystal light valves 115 to 117 and emit the resultant light toward the projection optical system 118.

  Note that light incident on the cross dichroic prism 119 from the liquid crystal light valves 115 and 117 is s-polarized light, and light incident on the cross dichroic prism 119 from the liquid crystal light valve 116 is p-polarized light. Thus, by making the light incident on the cross dichroic prism 119 into different types of polarized light, the light incident from the liquid crystal light valves 115 to 117 in the cross dichroic prism 119 can be synthesized. Here, in general, the dichroic films 119a and 119b are excellent in s-polarized reflection transistor characteristics. Therefore, red light and blue light reflected by the dichroic films 119a and 119b are s-polarized light, and green light transmitted through the dichroic films 119a and 119b is p-polarized light. The projection optical system 118 has a projection lens (not shown) and is configured to project the light combined by the cross dichroic prism 119 onto the screen 111.

  Since the projection type display device 110 configured as described above requires high utilization efficiency of the light emitted from the light source 112, the electro-optical device 100 as the liquid crystal light valves 115 to 117 will be described below. Configuration is adopted.

(Overall configuration of electro-optical device 100)
FIG. 2 is an explanatory diagram showing a basic configuration of a liquid crystal panel used in the liquid crystal light valve (electro-optical device 100 / liquid crystal device) in the projection display device shown in FIG. 1, and FIGS. These are an explanatory view schematically showing a basic structure of a liquid crystal panel and a block diagram showing an electrical configuration of the electro-optical device 100. Note that the liquid crystal light valves 115 to 117 and the liquid crystal panels 115c to 117c shown in FIG. 1 differ only in the wavelength range of light to be modulated and have the same basic configuration. The liquid crystal panels 115c to 117c will be described as a liquid crystal panel 100p.

  As shown in FIG. 2A, the electro-optical device 100 includes a liquid crystal panel 100p in a TN (Twisted Nematic) mode or a VA (Vertical Alignment) mode. The liquid crystal panel 100p includes a first substrate 10 and a second substrate 20 facing the first substrate 10, and modulates the light incident from the second substrate 20 side to start from the first substrate 10 side. This is a transmissive liquid crystal panel that emits light. The first substrate 10 and the second substrate 20 are bonded to and opposed to each other via a sealing material (not shown), and a liquid crystal layer 50 is held in an inner region of the sealing material. As will be described in detail later, island-like pixel electrodes 9a and the like are formed on the surface side of the first substrate 10 facing the second substrate 20, and the surface side of the second substrate 20 facing the first substrate 10 is A common electrode 21 is formed on substantially the entire surface. In addition, the second substrate 20 is configured with a reflecting portion 16 using a groove 260 described later.

  As shown in FIG. 2B, in the electro-optical device 100 of the present embodiment, the liquid crystal panel 100p includes an image display region 10a (pixel region) in which a plurality of pixels 100a are arranged in a matrix in the central region. Yes. In the liquid crystal panel 100p, on the first substrate 10 (see FIG. 2 and the like), a plurality of data lines 6a and a plurality of scanning lines 3a extend vertically and horizontally inside the image display region 10a and correspond to the intersections thereof. The pixel 100a is configured at the position where the image is to be processed. In each of the plurality of pixels 100a, a pixel transistor 30 (switching element) made of a field effect transistor and a pixel electrode 9a (see FIG. 2 and the like) are formed. The data line 6 a is electrically connected to the source of the pixel transistor 30, the scanning line 3 a is electrically connected to the gate of the pixel transistor 30, and the pixel electrode 9 a is electrically connected to the drain of the pixel transistor 30. Has been.

  On the first substrate 10, a scanning line driving circuit 104 and a data line driving circuit 101 are provided on the outer peripheral side of the image display area 10 a. The data line driving circuit 101 is electrically connected to each data line 6a, and sequentially supplies the image signal supplied from the image processing circuit to each data line 6a. The scanning line driving circuit 104 is electrically connected to each scanning line 3a, and sequentially supplies a scanning signal to each scanning line 3a.

  In each pixel 100a, the pixel electrode 9a is opposed to the common electrode 21 (see FIG. 2 and the like) formed on the second substrate 20 via the liquid crystal layer 50, thereby forming a liquid crystal capacitor 50a. Further, a storage capacitor 55 is added to each pixel 100a in parallel with the liquid crystal capacitor 50a in order to prevent fluctuation of the image signal held in the liquid crystal capacitor 50a. In this embodiment, in order to form the storage capacitor 55, the first electrode layer 5a straddling the plurality of pixels 100a is formed as a capacitor electrode layer. In this embodiment, the first electrode layer 5a is electrically connected to the common potential line 5c to which the common potential Vcom is applied.

(Specific configuration example of the electro-optical device 100)
FIG. 3 is an explanatory diagram showing a specific configuration example of the liquid crystal panel 100p used in the electro-optical device 100 according to Embodiment 1 of the present invention, and FIGS. 3A and 3B respectively show the liquid crystal panel 100p. FIG. 6 is a plan view of each of the components together with each component viewed from the second substrate side, and its HH ′ sectional view. In FIG. 3B, the reflection unit 26 described later is not shown.

  As shown in FIGS. 3A and 3B, in the liquid crystal panel 100p, the first substrate 10 and the second substrate 20 are bonded together with a sealing material 107 through a predetermined gap, and the sealing material 107 is The two substrates 20 are provided in a frame shape along the outer edge. The sealing material 107 is an adhesive made of a photo-curing resin, a thermosetting resin, or the like, and is mixed with a gap material such as glass fiber or glass beads for setting the distance between both substrates to a predetermined value.

  In the liquid crystal panel 100p having such a configuration, the first substrate 10 and the second substrate 20 are both square, and the image display area 10a described with reference to FIG. Is provided. Corresponding to this shape, the sealing material 107 is also provided in a substantially rectangular shape, and a substantially rectangular peripheral region 10b is provided in a frame shape between the inner peripheral edge of the sealing material 107 and the outer peripheral edge of the image display region 10a. Yes. In the first substrate 10, the data line driving circuit 101 and the plurality of terminals 102 are formed along one side of the first substrate 10 outside the image display region 10 a, and along another side adjacent to this one side. A scanning line driving circuit 104 is formed. Note that a flexible wiring substrate (not shown) is connected to the terminal 102, and various potentials and various signals are input to the first substrate 10 through the flexible wiring substrate.

  As will be described in detail later, on the one surface 10s side of the one surface 10s and the other surface 10t of the first substrate 10, the pixel transistor 30 and the pixel described in the image display region 10a with reference to FIG. Pixel electrodes 9a electrically connected to the transistors 30 are formed in a matrix, and an alignment film 19 is formed on the upper side of the pixel electrodes 9a.

  In addition, on the one surface 10s side of the first substrate 10, a dummy pixel electrode 9b (see FIG. 3B) that is formed simultaneously with the pixel electrode 9a is formed in the peripheral region 10b. For the dummy pixel electrode 9b, a configuration in which the dummy pixel transistor is electrically connected, a configuration in which the dummy pixel transistor is not provided, and a configuration in which the dummy pixel electrode is directly electrically connected to the wiring, or a floating state in which no potential is applied The structure which exists in is adopted. The dummy pixel electrode 9b compresses the height positions of the image display region 10a and the peripheral region 10b when the surface on which the alignment film 19 is formed on the first substrate 10 is flattened by polishing, and the alignment film 19 is formed. This contributes to the flat surface. Further, if the dummy pixel electrode 9b is set to a predetermined potential, it is possible to prevent the disorder of the alignment of the liquid crystal molecules at the outer peripheral side end of the image display region 10a.

  A common electrode 21 is formed on the one surface 20 s of the second substrate 20 on one side 20 s facing the first substrate 10, and an alignment film 29 is formed on the common electrode 21. ing. The common electrode 21 is formed across the plurality of pixels 100a as substantially the entire surface of the second substrate 20 or as a plurality of strip electrodes. In this embodiment, the common electrode 21 is formed on substantially the entire surface of the second substrate 20. Further, a frame-shaped light shielding layer 108 is formed on the one surface 20s side of the second substrate 20 along the outer peripheral edge of the image display region 10a, and the light shielding layer 108 functions as a parting. Here, the outer peripheral edge of the light shielding layer 108 is located with a gap between the inner peripheral edge of the sealing material 107 and the light shielding layer 108 and the sealing material 107 do not overlap.

  In the liquid crystal panel 100p configured as described above, the first substrate 10 is electrically connected between the first substrate 10 and the second substrate 20 in a region overlapping the corner portion of the second substrate 20 outside the sealant 107. An inter-substrate conducting electrode 109 for conducting is formed. The inter-substrate conducting electrode 109 is provided with an inter-substrate conducting material 109 a containing conductive particles, and the common electrode 21 of the second substrate 20 is interposed between the inter-substrate conducting material 109 a and the inter-substrate conducting electrode 109. Thus, it is electrically connected to the first substrate 10 side. For this reason, the common potential Vcom is applied to the common electrode 21 from the first substrate 10 side. The sealing material 107 is provided along the outer peripheral edge of the second substrate 20 with substantially the same width dimension. For this reason, the sealing material 107 is substantially rectangular. However, the sealing material 107 is provided so as to pass inside avoiding the inter-substrate conduction electrode 109 in a region overlapping with the corner portion of the second substrate 20, and the corner portion of the sealing material 107 has a substantially arc shape.

  In the electro-optical device 100 having such a configuration, when the pixel electrode 9a and the common electrode 21 are formed of a light-transmitting conductive film such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), a transmissive liquid crystal device is configured. be able to. On the other hand, when the common electrode 21 is formed of a light-transmitting conductive film such as ITO or IZO and the pixel electrode 9a is formed of a reflective conductive film such as aluminum, a reflective liquid crystal device can be configured. When the electro-optical device 100 is of a reflective type, light incident from the second substrate 20 side is modulated while being reflected by the substrate on the first substrate 10 side and emitted, thereby displaying an image. In the case where the electro-optical device 100 is a transmissive type, the light incident from one of the first substrate 10 and the second substrate 20 is modulated while being transmitted through the other substrate to be emitted. indicate.

  The electro-optical device 100 can be used as a color display device for electronic devices such as a mobile computer and a mobile phone. In this case, a color filter (not shown) and a protective film are formed on the second substrate 20. In the electro-optical device 100, a retardation film, a polarizing plate, and the like are arranged in a predetermined direction with respect to the liquid crystal panel 100p according to the type of the liquid crystal layer 50 to be used and the normally white mode / normally black mode. Is done.

  In this embodiment, the electro-optical device 100 is used as an RGB light valve in the projection display device (liquid crystal projector) described with reference to FIG. In this case, the color filters are not formed in each of the RGB electro-optical devices 100 because the light of each color separated through the RGB color separation dichroic mirror is incident as projection light.

  Hereinafter, the case where the electro-optical device 100 is a transmissive liquid crystal device and light incident from the second substrate 20 is transmitted through the first substrate 10 and emitted will be mainly described. In the present embodiment, the electro-optical device 100 will be described focusing on the case where the liquid crystal layer 50 includes a VA mode liquid crystal panel 100p using a nematic liquid crystal compound having a negative dielectric anisotropy.

(Specific pixel configuration)
4A and 4B are explanatory diagrams of pixels of the electro-optical device 100 according to Embodiment 1 of the present invention. FIGS. 4A and 4B are plan views of adjacent pixels on the first substrate 10, respectively. FIG. 5 is a cross-sectional view of the electro-optical device 100 cut at a position corresponding to the line FF ′ in FIG. In FIG. 4A, each region is represented by the following line.
Scanning line 3a = thick solid line Semiconductor layer 1a = thin and short dotted line Data line 6a and drain electrode 6b = dot and dash line First electrode layer 5a and relay electrode 5b = thin and long broken line Second electrode layer 7a = two-dot chain line Pixel electrode 9a = Thick and short dashed line

  As shown in FIG. 4A, a rectangular pixel electrode 9a is formed on each of the plurality of pixels 100a on the first substrate 10, and the vertical and horizontal inter-pixel regions sandwiched between adjacent pixel electrodes 9a. A data line 6a and a scanning line 3a are formed along a region overlapping with 10f. More specifically, in the inter-pixel region 10f, the scanning line 3a extends along the region overlapping the first inter-pixel region 10g extending along the scanning line 3a, and extends along the data line 6a. A data line 6a extends along a region overlapping the second inter-pixel region 10h. Each of the data line 6a and the scanning line 3a extends linearly, and a pixel transistor 30 is formed in a region where the data line 6a and the scanning line 3a intersect. On the first substrate 10, the first electrode layer 5 a (capacitive electrode layer) described with reference to FIG. 2B is formed so as to overlap the data line 6 a.

  As shown in FIGS. 4A and 4B, the first substrate 10 includes a translucent substrate main body 10w such as a quartz substrate or a glass substrate, and a surface of the substrate main body 10w on the liquid crystal layer 50 side (on the one surface 10s side). The pixel electrode 9a, the pixel transistor 30 for pixel switching, and the alignment film 19 are mainly formed. The second substrate 20 includes a translucent substrate body 20w such as a quartz substrate or a glass substrate, a common electrode 21 formed on the surface of the liquid crystal layer 50 side (one surface side facing the first substrate 10), and alignment. The film 29 is mainly used.

  In the first substrate 10, a scanning line 3 a made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal film compound is formed on one surface side of the substrate body 10 w. In this embodiment, the scanning line 3 a is made of a light-shielding conductive film such as tungsten silicide (WSi), and also functions as a light-shielding film for the pixel transistor 30. In this embodiment, the scanning line 3a is made of tungsten silicide having a thickness of about 200 nm. An insulating film such as a silicon oxide film may be provided between the substrate body 10w and the scanning line 3a.

An insulating film 12 such as a silicon oxide film is formed on the upper side of the scanning line 3a on the one surface 10s side of the substrate body 10w, and the pixel transistor 30 including the semiconductor layer 1a on the surface of the insulating film 12 is formed. Is formed. In this embodiment, the insulating film 12 is formed by, for example, a silicon oxide formed by a low pressure CVD method using tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ) or a plasma CVD method using tetraethoxysilane and oxygen gas. It has a two-layer structure of a film and a silicon oxide film (HTO (High Temperature Oxide) film) formed by a high temperature CVD method.

  The pixel transistor 30 extends in a direction perpendicular to the length direction of the semiconductor layer 1a, and a semiconductor layer 1a having a long side direction in the extending direction of the scan line 3a in the intersection region of the scan line 3a and the data line 6a. The gate electrode 3c is provided so as to overlap the central portion in the length direction of the semiconductor layer 1a. Further, the pixel transistor 30 has a light-transmitting gate insulating layer 2 between the semiconductor layer 1a and the gate electrode 3c. The semiconductor layer 1a includes a channel region 1g opposed to the gate electrode 3c via the gate insulating layer 2, and includes a source region 1b and a drain region 1c on both sides of the channel region 1g. In this embodiment, the pixel transistor 30 has an LDD structure. Accordingly, each of the source region 1b and the drain region 1c includes the low concentration regions 1b1, 1c1 on both sides of the channel region 1g, and the high concentration in the region adjacent to the low concentration regions 1b1, 1c1 opposite to the channel region 1g. Regions 1b2 and 1c2 are provided.

  The semiconductor layer 1a is composed of a polycrystalline silicon film or the like. The gate insulating layer 2 has a two-layer structure of a first gate insulating layer 2a made of a silicon oxide film obtained by thermally oxidizing the semiconductor layer 1a and a second gate insulating layer 2b made of a silicon oxide film or the like formed by a CVD method or the like. Consists of. The gate electrode 3c is made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal film compound, and contacts that penetrate the second gate insulating layer 2b and the insulating film 12 on both sides of the semiconductor layer 1a. It is electrically connected to the scanning line 3a through the holes 12a and 12b. In this embodiment, the gate electrode 3c has a two-layer structure of a conductive polysilicon film having a thickness of about 100 nm and a tungsten silicide film having a thickness of about 100 nm.

  In this embodiment, when the light after passing through the electro-optical device 100 is reflected by another member, the reflected light is incident on the semiconductor layer 1a and a malfunction due to the photocurrent occurs in the pixel transistor 30. In order to prevent this, the scanning line 3a is formed of a light shielding film. However, the scanning line may be formed in the upper layer of the gate insulating layer 2 and a part thereof may be used as the gate electrode 3c. In this case, the scanning line 3a shown in FIG. 4 is formed only for light shielding.

A translucent interlayer insulating film 41 made of a silicon oxide film or the like is formed on the upper layer side of the gate electrode 3c. On the upper layer of the interlayer insulating film 41, the data line 6a and the drain electrode 6b are made of the same conductive film. Is formed. The interlayer insulating film 41 is made of, for example, a silicon oxide film formed by a plasma CVD method using silane gas (SH ₄ ) and nitrous oxide (N ₂ O).

  The data line 6a and the drain electrode 6b are made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal film compound. In this embodiment, the data line 6a and the drain electrode 6b are formed of a titanium (Ti) film having a thickness of 20 nm, a titanium nitride (TiN) film having a thickness of 50 nm, an aluminum (Al) film having a thickness of 350 nm, and a film thickness. It has a four-layer structure in which 150 nm TiN films are stacked in this order. The data line 6a is electrically connected to the source region 1b (data line side source / drain region) through a contact hole 41a penetrating the interlayer insulating film 41 and the second gate insulating layer 2b. The drain electrode 6b is formed so as to partially overlap the drain region 1c (pixel electrode side source / drain region) of the semiconductor layer 1a in a region overlapping the first inter-pixel region 10g. It is electrically connected to the drain region 1c through a contact hole 41b that penetrates the gate insulating layer 2b.

  A translucent interlayer insulating film 42 made of a silicon oxide film or the like is formed on the upper side of the data line 6a and the drain electrode 6b. The interlayer insulating film 42 is made of, for example, a silicon oxide film formed by a plasma CVD method using tetraethoxysilane and oxygen gas.

  On the upper layer side of the interlayer insulating film 42, the first electrode layer 5a and the relay electrode 5b are formed of the same conductive film. The first electrode layer 5a and the relay electrode 5b are made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal film compound. In this embodiment, the first electrode layer 5a and the relay electrode 5b have a two-layer structure of an Al film having a thickness of about 200 nm and a TiN film having a thickness of about 100 nm. Similar to the data line 6a, the first electrode layer 5a extends along a region overlapping the second inter-pixel region 10h. The relay electrode 5b is formed so as to partially overlap the drain electrode 6b in a region overlapping the first inter-pixel region 10g, and is electrically connected to the drain electrode 6b through a contact hole 42a penetrating the interlayer insulating film 42. ing.

  An interlayer insulating film 44 such as a silicon oxide film is formed as an etching stopper layer on the upper side of the first electrode layer 5a and the relay electrode 5b, and the interlayer insulating film 44 is formed in a region overlapping the first electrode layer 5a. An opening 44b is formed. In this embodiment, the interlayer insulating film 44 is made of a silicon oxide film or the like formed by a plasma CVD method using tetraethoxysilane and oxygen gas. Here, although not shown in FIG. 4A, the opening 44b is a portion extending along a region overlapping with the first inter-pixel region 10g starting from an intersection region between the data line 6a and the scanning line 3a. And a portion extending along a region overlapping the second inter-pixel region 10h starting from the intersection region of the data line 6a and the scanning line 3a.

  A translucent dielectric layer 40 is formed on the upper layer side of the interlayer insulating film 44, and a second electrode layer 7 a is formed on the upper layer side of the dielectric layer 40. The second electrode layer 7a is made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal film compound. In this embodiment, the second electrode layer 7a is made of a TiN film having a thickness of about 100 nm. As the dielectric layer 40, a silicon compound such as a silicon oxide film or a silicon nitride film can be used, and an aluminum oxide film, a titanium oxide film, a tantalum oxide film, a niobium oxide film, a hafnium oxide film, a lanthanum oxide film, zirconium A dielectric layer having a high dielectric constant such as an oxide film can be used. The second electrode layer 7a includes a portion extending along a region overlapping the first inter-pixel region 10g starting from an intersection region between the data line 6a and the scanning line 3a, and an intersection region between the data line 6a and the scanning line 3a. And a portion extending along a region overlapping with the second inter-pixel region 10h. Therefore, a portion of the second electrode layer 7 a that extends along the region overlapping with the second inter-pixel region 10 h is the first electrode layer 5 a via the dielectric layer 40 in the opening 44 b of the interlayer insulating film 44. It overlaps with. In this way, in the present embodiment, the first electrode layer 5a, the dielectric layer 40, and the second electrode layer 7a constitute the storage capacitor 55 in a region overlapping the first inter-pixel region 10g.

  In the second electrode layer 7a, the portion extending along the region overlapping the first inter-pixel region 10g partially overlaps the relay electrode 5b and penetrates the dielectric layer 40 and the interlayer insulating film 44. It is electrically connected to the relay electrode 5b through the contact hole 44a.

  A translucent interlayer insulating film 45 is formed on the upper layer side of the second electrode layer 7a, and a translucent conductive film such as an ITO film having a thickness of about 140 nm is formed on the upper layer side of the interlayer insulating film 45. A pixel electrode 9a is formed. The pixel electrode 9a partially overlaps the second electrode layer 7a in the vicinity of the intersection region between the data line 6a and the scanning line 3a, and the second electrode layer 7a is connected via a contact hole 45a penetrating the interlayer insulating film 45. Is conducting.

An alignment film 19 is formed on the surface of the pixel electrode 9a. The alignment film 19 is made of a resin film such as polyimide or an oblique deposition film such as a silicon oxide film. In this embodiment, the alignment film 19 is an obliquely deposited film such as SiO _x (x <2), SiO ₂ , TiO ₂ , MgO, Al ₂ O ₃ , In ₂ O ₃ , Sb ₂ O ₃ , Ta ₂ O _5. An inorganic alignment film (vertical alignment film).

In the second substrate 20, a translucent conductive film such as an ITO film is formed on the surface of the translucent substrate body 20 w such as a quartz substrate or a glass substrate on the liquid crystal layer 50 side (a surface facing the first substrate 10). A common electrode 21 is formed, and an alignment film 29 is formed so as to cover the common electrode 21. Similar to the alignment film 19, the alignment film 29 is composed of a resin film such as polyimide or an oblique vapor deposition film such as a silicon oxide film. In this embodiment, the alignment film 29 is an obliquely deposited film such as SiO _x (x <2), SiO ₂ , TiO ₂ , MgO, Al ₂ O ₃ , In ₂ O ₃ , Sb ₂ O ₃ , and Ta ₂ O _5. An inorganic alignment film (vertical alignment film). The alignment films 19 and 29 vertically align the nematic liquid crystal compound having negative dielectric anisotropy used for the liquid crystal layer 50, and the liquid crystal panel 100p operates as a normally black VA mode.

  Here, the substrate main body 20w of the second substrate 20 is configured with a reflection portion 26 having a groove 260 described below with reference to FIG. 5 and the like, and the first substrate 10 with respect to the reflection portion 26 is formed. The common electrode 21 and the alignment film 29 are formed on this side.

(Detailed configuration of the second substrate 20)
FIGS. 5A and 5B are explanatory diagrams of the reflection portion formed on the second substrate 20 of the electro-optical device 100 according to the first embodiment of the invention. FIGS. 5A and 5B are cross-sectional views of the second substrate 20. It is explanatory drawing which shows the figure and the planar structure of a reflection part. In FIG. 5A, the alignment film 19 and the like on the first substrate 10 side are not shown.

  As shown in FIGS. 5A and 5B, in the electro-optical device 100 of the present embodiment, the light incident from the second substrate 20 side is optically modulated for each pixel by the liquid crystal layer 50, and then the first substrate. 10 exits. For this reason, in order to efficiently use the incident light, it is necessary to efficiently guide the incident light toward the pixel electrode 9a. Therefore, in the present embodiment, the reflection portion 26 is formed that reflects the light incident from the second substrate 20 side toward the pixel electrodes 9a (inter-pixel region 10f). Has been.

  In the present embodiment, the reflecting portion 26 extends along a region overlapping in a plan view between the pixel electrodes 9a (inter-pixel region 10f) on the one surface 20s side of the substrate body 20w (translucent substrate) of the second substrate 20. The grooves 260 are formed in a lattice shape, and the grooves 260 are opened toward the inter-pixel region 10f. In this embodiment, the opposite side surfaces 261 and 262 of the groove 260 are inclined toward the inter-pixel region 10f, and the groove 260 has a V-shaped cross section. More specifically, the groove 260 has a substantially isosceles triangular cross section with the side surfaces 261 and 262 as one side, and the apex of the triangular shape is located at the center in the width direction of the inter-pixel region 10f. Yes. The width dimension of the groove 260 (the length of the base of the triangular shape) is set to be approximately the same as or slightly wider than the width dimension of the inter-pixel region 10f.

  In this embodiment, the opening 265 of the groove 260 is closed with a light transmissive film 27 formed on the one surface 20s side of the substrate body 20w. For this reason, the groove 260 is hollow, and the inside of the groove 260 is a vacuum or an air layer. In this embodiment, the inside of the groove 260 is evacuated. Here, the translucent film 27 is a low refractive index translucent insulating film having a refractive index lower than that of the substrate body 20w (translucent substrate). More specifically, the substrate body 20w is made of a quartz substrate or a glass substrate, and the refractive index of the translucent substrate is about 1.52. On the other hand, the translucent film 27 is a translucent insulating film having a refractive index of less than 1.52. In this embodiment, a light-transmitting insulating film having a refractive index of 1.43 or less is used for the light-transmitting film 27 for the reason described later with reference to FIG.

In this embodiment, the light-transmitting film 27 is made of magnesium fluoride (MgF ₂ ), borosilicate glass (BSG) film, phosphosilicate glass (PSG) film, or borophosphosilicate glass (BPSG) film. Of these translucent insulating films, magnesium fluoride has a refractive index of 1.37. Borosilicate glass film, phosphosilicate glass film, and borophosphosilicate glass film have a refractive index of 1.43 to 1.45, but the refractive index can be further reduced by changing the amount of boron or phosphorus. It is.

In the groove 260 configured as described above, the light-transmitting film 27 closes the opening 265 so as to fill a part of the groove 260 on the opening 265 side of the groove 260, but is formed deep inside the groove 260. It has not been. For this reason, the inside of the groove 260 is in a hollow state (vacuum state). Therefore, when the refractive index of the medium (vacuum) inside the groove 260 is compared with the refractive index of the medium (glass or the like) of the substrate body 20w, the following relationship is satisfied: <refractive index inside the groove 260 <refractive index of the substrate body 20w> is there. For this reason, the side surfaces 261 and 262 of the groove 260 function as reflecting surfaces. Further, the refractive index of the substrate main body 20w and n _11, the refractive index of the groove 260 and n _12, if the incident angle of light relative to the normal of the side surface 261 and 262 was set to θ _1, n _11> n ₁₂ met And n ₁₁ , n ₁₂ , and θ ₁ are the following expressions: sin θ ₁ > n ₁₂ / n ₁₁
Is satisfied, total reflection occurs on the side surfaces 261 and 262.

In this embodiment, the translucent film 27 fills part of the groove 260 on the opening 265 side of the groove 260, and part of the side surfaces 261 and 262 is in contact with the translucent film 27. Still, in this embodiment, when the refractive index of the light-transmitting film 27 (medium) and the refractive index of the medium (glass or the like) of the substrate body 20w are compared, the following relationship is satisfied: The refractive index of the light-transmitting film 27 <the substrate body 20w. Refractive index. For this reason, of the side surfaces 261 and 262 of the groove 260, the portion in contact with the translucent film 27 also functions as a reflective surface. Further, the refractive index of the substrate main body 20w and n _11, the refractive index of the translucent film 27 and n _13, if the incident angle of light relative to the normal of the side surface 261 and 262 and the theta _2, at n _11> n ₁₃ N ₁₁ , n ₁₃ , and θ ₂ are expressed by the following equation: sin θ ₂ > n ₁₃ / n ₁₁
If the above condition is satisfied, total reflection occurs at the portion of the side surfaces 261 and 262 that are in contact with the transparent film 27. Therefore, according to this embodiment, the reflection efficiency at the reflection portion 26 is high.

  In the electro-optical device 100 configured as described above, the translucent film 27 is formed inside the groove 260 so as to fill a part of the groove 260, but is not formed outside the groove 260. Further, the surface of the translucent film 27 constitutes a flat surface that is continuous with the one surface 20s of the substrate body 20w. The surface includes an insulating film 28 made of a silicon oxide film, a common electrode 21 made of an ITO film, and An alignment film 29 is formed. Therefore, in this embodiment, the light-transmitting film 27 and the substrate body 20 w are not in contact with each other outside the groove 260, and there is no interface between the light-transmitting film 27 and the substrate body 20 w outside the groove 260. Further, the translucent film 27 is in contact with the insulating film 28 only in a portion overlapping the groove 260 in plan view, and the interface between the translucent film 27 and the insulating film 28 exists only in a portion overlapping with the groove 260 in plan view. doing.

(Operational effect of the reflection part 26)
In the electro-optical device 100 configured as described above, light having various incident angles is incident from the light source unit 130 described with reference to FIG. 1, and light traveling toward the pixel electrode 9a among the incident light is indicated by an arrow L1. As it is shown, proceed as it is. Further, as indicated by an arrow L2, light traveling in a direction away from the pixel electrode 9a (direction toward the inter-pixel region 10f) is reflected by the side surfaces 261 and 262 of the groove 260 as indicated by an arrow L3, and the pixel It is directed to the electrode 9a.

  Here, the groove 260 has a substantially isosceles triangular cross section with the side surfaces 261 and 262 as one side, and the apex of the triangular shape is located at the center in the width direction of the inter-pixel region 10f. The width of the groove 260 is set to be substantially the same as the width of the inter-pixel region 10f or slightly wider. For this reason, the light traveling in a direction greatly deviating from the pixel electrode 9a is also reflected toward the pixel electrode 9a and can be used effectively. The inclination of the side surfaces 261 and 262 is set so that, for example, the angle formed with the normal to the substrate surface of the substrate body 20w is 10 ° or less, and further 3 ° or less. According to this configuration, when light is reflected by the side surfaces 261 and 262, the incident light can be deflected while reducing the increase in the light beam angle, and the incident light can be projected, for example, with an F number of 2.5. It can be converted into light having a light beam angle that can be sufficiently captured by the optical system (see FIG. 1). Therefore, it is possible to improve the contrast and the brightness of the projected image.

(Relationship between refractive index of translucent film 27 and brightness of projected image)
FIG. 6 shows the result of simulating the relationship between the refractive index of the translucent film 27 used in the electro-optical device 100 according to Embodiment 1 of the present invention and the brightness of the projected image from the projection display device 110 shown in FIG. It is a graph which shows. In FIG. 6, the refractive index of the translucent film 27 and the projected image when the incident angle with respect to the second substrate 20 is 0 °, 1.48 °, 1.58 °, 1.68 °, 1.78 °. Are respectively shown by lines L11, L12, L13, L14, and L15.

  As can be seen from FIG. 6, when the refractive index of the translucent film 27 is 1.43 or less, the brightness level is high, and when the refractive index of the translucent film 27 is 1.44, the brightness level is high. When the level is slightly lowered and the refractive index of the translucent film 27 exceeds 1.44, the brightness level is drastically lowered. Therefore, the refractive index of the translucent film 27 is preferably 1.43 or less.

(Manufacturing method of the second substrate 20)
With reference to FIG. 7, a process of manufacturing the reflecting portion 26 among the processes of manufacturing the electro-optical device 100 will be described. FIG. 7 is an explanatory diagram showing a method for manufacturing the electro-optical device 100 according to Embodiment 1 of the present invention. FIG. 8 is an explanatory diagram when the translucent film 27 is formed by the low pressure CVD method using tetraethoxysilane in the method of manufacturing the electro-optical device 100 according to the first embodiment of the present invention. 7 and 8, the one surface 20 s of the second substrate 20 is shown upward, as opposed to FIG. 5.

  In order to manufacture the second substrate 20 of this embodiment, in the groove forming step, first, as shown in FIG. 7A, the thickness is applied to one surface 20s of the substrate body 20w by using a photolithography technique. A 5 to 10 μm mask 269 is formed. Next, dry etching is performed on the substrate body 20w. For such dry etching, an ICP (ICP-RIE / Inductive Coupled Plasma-RIE) dry etching apparatus capable of forming high-density plasma is used, and the etching selection ratio between the substrate body 20w and the mask is set to, for example, 4 or more: 1. As a result, as shown in FIG. 7B, a groove 260 having a V-shaped cross section having a depth four times or more the thickness of the mask 269 is formed.

Next, in the translucent film forming step shown in FIG. 7C, the CVD (Chemical Vapor Deposition) method, the PVD (Physical Vapor Deposition) method, tetraethoxysilane The light-transmitting film 27 is formed by a CVD method using a liquid source such as the above, and other embedding methods, and the opening 265 of the groove 260 is closed by the light-transmitting film 27, so that the inside of the groove 260 is made hollow. In this embodiment, a magnesium fluoride film is formed as the light-transmitting film 27 by a vacuum vapor deposition method. Alternatively, in this embodiment, a borosilicate glass film, a phosphosilicate glass film, or a borophosphosilicate glass film is formed as the light-transmitting film 27 by a CVD method. More specifically, when atmospheric pressure CVD is performed using silane gas and oxygen gas, PH ₃ (phosphine) or B ₂ H ₆ (diborane) is added to the film forming gas. During the film formation, the light-transmitting film 27 is formed so as to protrude inward from the opening edge of the groove 260. Therefore, the translucent film 27 is formed so as to partially fill the opening 265 side of the groove 260 when the opening 265 is closed, but is not formed to the inside of the groove 260. For this reason, the groove 260 is in a hollow state. In this embodiment, since the film is formed in a vacuum atmosphere, the inside of the groove 260 is in a vacuum state.

  Next, in the polishing step shown in FIG. 7D, the surface of the light transmitting film 27 is polished, and the light transmitting film 27 is left inside the groove 260 so as to fill a part of the groove 260, while the outside of the groove 260. Then, the translucent film 27 is removed. In this polishing step, chemical mechanical polishing is performed in this embodiment. In this chemical mechanical polishing, a smooth polished surface can be obtained at high speed by the action of chemical components contained in the polishing liquid and the relative movement of the abrasive and the second substrate 20 (substrate body 20w). More specifically, in the polishing apparatus, while relatively rotating the surface plate to which the polishing cloth (pad) made of nonwoven fabric, polyurethane foam, porous fluororesin, etc. is attached, and the holder for holding the second substrate 20, Polish. At that time, for example, an abrasive containing cerium oxide particles having an average particle diameter of 0.01 to 20 μm, an acrylate derivative as a dispersant, and water is supplied between the polishing cloth and the second substrate 20.

  Thereafter, the insulating film 28, the common electrode 21 and the alignment film 29 are sequentially formed on the one surface 20s side of the substrate body 20w to obtain the second substrate 20.

  When forming the light-transmitting film 27 in the light-transmitting film forming step, a borosilicate glass film, a phosphosilicate glass film, a borophosphosilicate glass film, or the like may be formed by a low pressure CVD method using tetraethoxysilane. Good. In such a film forming method, since the coverage is high, the translucent film 27 penetrates deeply into the groove 260 as shown in FIG. In such a case, the portions of the side surfaces 261 and 262 of the groove 260 that are in contact with the light transmissive film 27 are widened, but the refractive index of the light transmissive film 27 is less than the refractive index of the substrate body 20w. For this reason, in the reflection part 26, since total reflection occurs over a wide angle range, high reflection efficiency is obtained.

(Main effects of this form)
As described above, in the electro-optical device 100 according to this embodiment, of the first substrate 10 and the second substrate 20, the second substrate 20 is opened toward the pixel electrodes 9a (inter-pixel region 10f). A hollow groove 260 is formed, and an opening 265 of the groove 260 is closed by the translucent film 27. For this reason, the side surfaces 261 and 262 of the hollow groove 260 are reflection surfaces due to a difference in refractive index between the medium (vacuum) in the groove 260 and the medium of the second substrate 20. Accordingly, the light incident on the second substrate 20 can be reflected by the side surfaces 261 and 262 of the groove 260 and directed toward the pixel electrode 9a, thereby contributing to display and the like. High light ratio. Further, in this embodiment, the light-transmitting film 27 is used to close the opening 265 of the groove 260. Therefore, the opening 265 of the groove 260 can be closed only by forming the light-transmitting film 27. Therefore, productivity is high compared with the case where the cover glass is bonded to close the opening. In addition, since the opening 265 of the groove 260 is closed by the light-transmitting film 27, the light traveling toward the light-transmitting film 27 is not prevented from going toward the pixel electrode 9a.

  Moreover, the refractive index of the translucent film 27 is less than the refractive index of the substrate body 20w (translucent substrate). For this reason, the part which is in contact with the translucent film 27 among the side surfaces of the groove 260 also functions as a reflecting surface. For this reason, even when the opening 265 of the groove 260 formed in the substrate body 20w is closed by the light-transmitting film 27 and the groove 260 is in a hollow state, the reflection efficiency at the side surfaces 261 and 262 of the groove 260 is high. Moreover, in this embodiment, the refractive index of the translucent film 27 is 1.43 or less. For this reason, even when a quartz substrate or a glass substrate is used as the substrate body 20w (translucent substrate), the refractive index of the translucent film 27 is considerably smaller than the refractive index of the substrate body 20w. Therefore, total reflection occurs in the portion of the side surfaces 261 and 262 of the groove 260 that are in contact with the light-transmitting film 27, so that the reflection efficiency at the side surfaces 261 and 262 of the groove 260 is high. Therefore, according to this embodiment, since the amount of display light is large, a bright image can be displayed.

  Further, in this embodiment, the translucent film 27 is formed in the groove 260 so as to fill a part of the groove 260, and is not formed outside the groove 260. For this reason, reflection at the interface between the substrate main body 20w and the translucent film 27 does not occur. The groove 260 has a V-shaped cross section in which the side surfaces 261 and 262 are inclined toward the inter-pixel region 10f. For this reason, the light which is going to go to the inter-pixel region 10f can be reflected by the side surfaces 261 and 262 of the groove 260 and can be efficiently directed to the pixel electrode 9a. Further, since the groove 260 is in a vacuum state, the side surfaces 261 and 262 can be reflective surfaces having high reflectivity. Therefore, since the amount of display light is large, a bright image can be displayed. Furthermore, if the inside of the groove 260 is in a vacuum state, there is an advantage that it can be realized if the film is formed in a vacuum atmosphere when the opening 265 of the groove 260 is closed with the light transmitting film 27.

  In this embodiment, the groove 260 is provided in the second substrate 20. Therefore, it is possible to adopt a configuration in which light is incident from the second substrate 20 side, and there is an advantage that light is not easily incident on the pixel transistor 30. Furthermore, since the surface opposite to the groove 260 of the translucent film 27 is a flat surface, the common electrode 21 can be formed on the flat surface.

[Embodiment 2]
In the above embodiment, the insulating film 28, the common electrode 21 and the alignment film 29 are formed in this order on the one surface 20s of the substrate body 20w. However, the insulating film 28 is not formed and one surface of the substrate body 20w is formed. A structure in which the common electrode 21 and the alignment film 29 are formed in this order in 20 s may be adopted.

[Other embodiments]
In the first and second embodiments, since light enters from the second substrate 20 side, the reflection portion 26 (groove 260) is formed in the substrate body 20w of the second substrate 20, but from the first substrate 10 side. When light is incident, the present invention may be applied to form the reflecting portion 26 (groove 260) in the substrate body 20w of the first substrate 10.

  In the first and second embodiments, the first substrate 10 and the pixel electrode 9a are translucent. However, the reflective electro-optical device 100 in which the pixel electrode 9a is formed of a reflective metal film. The present invention may be applied to.

  In the first and second embodiments, the inside of the groove 260 is vacuum, but it may be configured to be filled with air or the like.

  FIG. 1 illustrates a projection type display device using three light valves. However, when the electro-optical device 100 includes a color filter, light of each color is sequentially supplied to one electro-optical device 100. The present invention may be applied to the electro-optical device 100 used in a projection display device that is incident.

  In the above embodiment, the transmissive electro-optical device 100 used in the projection display device is exemplified as the electro-optical device. However, the direct-view electro-optical device that displays an image using the light emitted from the backlight device as incident light. The present invention may be applied to the apparatus 100.

  Further, in the above embodiment, the liquid crystal device has been described as an example of the electro-optical device 100. However, in the electrophoretic display device, when the reflecting portion 26 (groove 260) is formed for the purpose of increasing the amount of display light, The invention may be applied. In addition, the reflection portion 26 (groove 260) is formed for the purpose of preventing color mixing in an electro-optical device that displays an image on the image display surface by modulated light emitted from a self-luminous element, such as an organic electroluminescence device. In this case, the present invention may be applied.

9a ··· Pixel electrode, 10 · · First substrate, 10f · · Inter-pixel region (between pixel electrodes), 20 · · Second substrate, 20w · · Substrate body (translucent substrate), 26 · · Reflector 27..Translucent film, 28..Insulating film, 30..Pixel transistor (switching element), 100..Electro-optical device, 260..Groove, 261, 262..Side, 265..Opening

Claims (9)

A first substrate provided with a plurality of pixel electrodes and a switching element corresponding to each of the plurality of pixel electrodes;
A second substrate disposed opposite the first substrate;
An electro-optic material layer provided between the first substrate and the second substrate;
Have
One of the first substrate and the second substrate is a light-transmitting substrate, and a hollow groove opening between adjacent pixel electrodes in the plurality of pixel electrodes, and the groove A translucent film that closes the opening, and
An electro-optical device, wherein a refractive index of the translucent film is less than a refractive index of the translucent substrate.   The electro-optical device according to claim 1, wherein a refractive index of the translucent film is 1.43 or less.   The electro-optical device according to claim 1, wherein the translucent film is formed in the groove so as to fill a part of the groove, and is not formed outside the groove.   4. The electro-optical device according to claim 1, wherein the light-transmitting film is a magnesium fluoride film, a borosilicate glass film, a phosphosilicate glass film, or a borophosphosilicate glass film. .   The electro-optical device according to claim 1, wherein the groove is provided in the second substrate.   The electro-optical device according to claim 5, wherein the pixel electrode and the first substrate have translucency.   7. The electro-optical device according to claim 1, wherein the groove has a V-shaped cross section in which a side surface is inclined between the adjacent pixel electrodes.   The electro-optical device according to claim 1, wherein the groove has a vacuum inside. A projection display device using the electro-optical device according to any one of claims 1 to 8,
A projection display comprising: a light source unit that emits light incident on the electro-optical device from the one substrate; and a projection optical system that projects light modulated by the electro-optical device. apparatus.

Images