JP2021189260A - Electro-optical device and electronic apparatus - Google Patents

Abstract

To provide an electro-optical device and an electronic apparatus that can appropriately prevent both diffraction caused by the arrangement of a plurality of pixel electrodes having a large refractive index and reflection on an interface having a large refractive index difference.SOLUTION: In a first substrate 10 of an electro-optical device 1, pixel electrodes 9a each include ITO, and a space width W between the pixel electrodes is 100 nm or more and 300 nm or less. In the first substrate 10, a dielectric film 17 covering the pixel electrodes 9a is formed, and a first alignment film 16 is laminated on a plane of the dielectric film 17 on the opposite side of the pixel electrodes 9a. The refractive index n of the dielectric film 17 is between the refractive index of the pixel electrodes 9a and the refractive index of the first alignment film 16. When the film thickness of the dielectric film 17 at portions overlapping the pixel electrodes 9a is d, the refractive index of the dielectric film 17 is n, and the wavelength λ of incident light on the pixel electrodes 9a is 550 nm, the film thickness d is half or more and λ/2n or less of the space width W between the pixel electrodes 9a.SELECTED DRAWING: Figure 6

Description

The present invention relates to an electro-optic device and an electronic device provided with a plurality of pixel electrodes.

In a transmissive electro-optic device used as a light bulb or the like of a projection type display device, a plurality of pixel electrodes are arranged in a display area via a predetermined space. An alignment film is laminated on the surface of the pixel electrodes, and an alignment film is formed in the space between the pixel electrodes. The pixel electrode is made of ITO or the like, and the alignment film is made of silicon oxide or the like.

Patent Document 1 proposes a technique of filling a space between pixel electrodes with silicon nitride to make a base forming an alignment film a continuous flat surface. According to such an embodiment, since the alignment film can be formed on a flat surface, it is possible to form an alignment film having an orientation regulating force without disturbance.

Patent Document 2 proposes a technique in which an insulating film such as aluminum oxide is provided between a pixel electrode and an alignment film with a substantially constant film thickness. According to such an embodiment, the difference in refractive index at the interface existing between the pixel electrode and the alignment film can be reduced by aluminum oxide, so that reflection at the interface can be suppressed.

Japanese Unexamined Patent Publication No. 2009-175493 Japanese Unexamined Patent Publication No. 2019-8099

In the structure in which the space between the pixel electrodes is filled with the alignment film covering the pixel electrodes, the difference in refractive index between the portion where the pixel electrodes exist and the portion corresponding to the space between the pixel electrodes is large, so that the phase difference is large. It is large and prone to diffraction. Such diffraction is not preferable because it causes a decrease in contrast. Further, in the structure in which the portion corresponding to the space between the pixel electrodes is filled with silicon nitride as in the configuration described in Patent Document 1, diffraction is alleviated, but the interface where the pixel electrodes have a large difference in refractive index from the alignment film. Therefore, the reflectance at the interface is large. In the configuration in which an insulating film having a high refractive index such as aluminum oxide is provided between the pixel electrode and the alignment film with a thin film thickness as in the configuration described in Patent Document 2, the portion corresponding to the space between the pixel electrodes is provided. Since it cannot be sufficiently filled with an insulating film having a high refractive index, the occurrence of diffraction cannot be sufficiently suppressed. Therefore, in the prior art, there is a problem that both diffraction caused by arranging a plurality of pixel electrodes having a large refractive index and reflection at an interface having a large difference in refractive index cannot be appropriately suppressed. ..

In order to solve the above problems, one aspect of the electro-optical device according to the present invention includes a plurality of pixel electrodes containing indium tin oxide, each having a space width of 100 nm or more and 300 nm or less, and the plurality of pixel electrodes. When the refractive index of the dielectric film is n and the wavelength λ of the light incident on the pixel electrodes is 550 nm, the dielectric film is provided. The thickness of the portion of the body film that overlaps with the pixel electrodes is ½ or more of the space width and λ / 2n or less.

The electro-optic device according to the present invention can be used for various electronic devices. When the electronic device is a projection type display device, the electronic device includes a light source unit that emits illumination light incident on the electro-optical device, a projection optical system that projects modulated light emitted from the electro-optical device, and the like. Is provided.

The plan view which shows one aspect of the liquid crystal panel used in the electro-optics apparatus to which this invention was applied. The explanatory view which shows typically the cross section of the electro-optics apparatus which concerns on Embodiment 1 of this invention. Explanatory drawing which enlarges and shows a part of the cross section shown in FIG. A plan view of a plurality of adjacent pixels in the liquid crystal panel shown in FIG. 1. FIG. 4 is a cross-sectional view taken along the line FF'of the liquid crystal panel shown in FIG. Explanatory drawing in the vicinity of the pixel electrode shown in FIG. The explanatory view which shows the specific example 1 of the electro-optics apparatus which concerns on Embodiment 1 of this invention. Explanatory drawing which shows the specific example 2 of the electro-optics apparatus which concerns on Embodiment 1 of this invention. Explanatory drawing of the electro-optic apparatus which concerns on Embodiment 2 of this invention. Explanatory drawing of the electro-optic apparatus which concerns on Embodiment 3 of this invention. Schematic diagram of a projection type display device using an electro-optic device to which the present invention is applied.

Embodiments of the present invention will be described with reference to the drawings. In the figures referred to in the following description, the scales are different for each layer and each member in order to make each layer and each member recognizable in the drawing. Further, in the following description, when the layer formed on the first substrate 10 is described, the upper layer side or the surface side is opposite to the side where the substrate main body 19 is located (the side where the second substrate 20 is located). The lower layer side means the side on which the substrate main body 19 is located.

[Embodiment 1]
1. 1. Configuration of Electro-Optical Device FIG. 1 is a plan view showing one aspect of the liquid crystal panel 100 used in the electro-optic device 1 to which the present invention is applied, and shows the state of the electro-optic device 1 as viewed from the second substrate 20 side. be. FIG. 2 is an explanatory diagram schematically showing a cross section of the electro-optic device 1 according to the first embodiment of the present invention. FIG. 3 is an enlarged explanatory view showing a part of the cross section shown in FIG.

As shown in FIGS. 1, 2 and 3, the electro-optic device 1 has a liquid crystal panel 100 in which a first substrate 10 and a second substrate 20 are bonded by a sealing material 107 through a predetermined gap. In the liquid crystal panel 100, the first substrate 10 and the second substrate 20 face each other. The sealing material 107 is provided in a frame shape along the outer edge of the second substrate 20, and serves as an electro-optic layer 50 in a region surrounded by the sealing material 107 between the first substrate 10 and the second substrate 20. A liquid crystal layer is arranged. The sealing material 107 is an adhesive having photocurability, or an adhesive having photocurability and thermosetting, and is made of glass fiber, glass beads, or the like for setting a predetermined distance between both substrates. Gap material is blended. Both the first substrate 10 and the second substrate 20 are rectangular, and a display region 10a is provided as a rectangular region in substantially the center of the electro-optic device 1. Corresponding to such a shape, the sealing material 107 is also provided in a substantially quadrangular shape.

The first substrate 10 has a translucent substrate such as a quartz substrate or a glass substrate as the substrate main body 19. On one side 19s side of the second board 20 side of the board body 19, a data line drive circuit 101 and a plurality of terminals 102 are formed along one side of the first board 10 on the outside of the display area 10a, and a plurality of terminals 102 are formed on this side. The scanning line drive circuit 104 is formed along the other adjacent sides. A flexible wiring board 105 is connected to the terminal 102, and various potentials and various signals are input to the first board 10 via the flexible wiring board 105. On one surface 19s of the substrate main body 19, in the display region 10a, a plurality of translucent pixel electrodes 9a made of an ITO (Indium Tin Oxide) film or the like, and each of the plurality of pixel electrodes 9a are electrically connected. A transistor (not shown in FIG. 2) connected to is formed in a matrix. In the first substrate 10, the first alignment film 16 is formed on the side of the electro-optic layer 50 with respect to the pixel electrode 9a. Therefore, the substrate main body 19 to the first alignment film 16 correspond to the first substrate 10. A dustproof translucent substrate may be bonded to the other surface 19t of the substrate body 19 of the first substrate 10 on the opposite side of the second substrate 20 by an adhesive or the like.

As shown in FIG. 3, in the display region 10a, the first substrate 10 is provided with a grid-like light-shielding member 18 between the substrate main body 19 and the pixel electrode 9a, and the light-shielding member 18 is provided in a plan view. , Extends along between adjacent pixel electrodes 9a. In the present embodiment, the light-shielding member 18 is composed of a light-shielding film 8a, a scanning line 3a, a capacitance line 5a, and a data line 6a, which will be described later with reference to FIGS. 4 and 5.

As shown in FIGS. 2 and 3, a lens member is configured on the first substrate 10. In the present embodiment, the first substrate 10 is provided with a first lens member 51 and a second lens member 52, which will be described later, as lens members.

Again, in FIGS. 1, 2 and 3, the second substrate 20 has a translucent substrate such as a quartz substrate or a glass substrate as the substrate main body 29. A translucent counter electrode 21 made of an ITO film or the like is formed on one side 29s side of the substrate main body 29 facing the first substrate 10, and on the side of the electro-optic layer 50 with respect to the counter electrode 21. The second alignment film 26 is formed. The counter electrode 21 is formed on substantially the entire surface of the substrate main body 29, and is covered with the second alignment film 26. Therefore, the substrate main body 29 to the second alignment film 26 correspond to the second substrate 20. A dustproof translucent substrate may be bonded to the other surface 29t of the substrate body 29 of the second substrate 20 on the opposite side of the first substrate 10 with an adhesive or the like.

A light-shielding film 27a made of a resin, a metal or a metal compound is formed between the substrate main body 29 and the counter electrode 21, and a translucent film 22 made of silicon oxide or the like is formed between the light-shielding film 27a and the counter electrode 21. Is formed. The light-shielding film 27a is provided as a frame-shaped parting line extending along the outer peripheral edge of the display area 10a outside the display area 10a. The light-shielding film 27a shields the transistor constituting a circuit such as a drive circuit provided outside the display area 10a from light-shielding. Further, the light-shielding film 27a is provided as an alignment mark for positioning in the manufacturing process and the inspection process of the electro-optic device 1. In this embodiment, the second substrate 20 is not provided with the light-shielding film 27a in the display area 10a.

On the first substrate 10, a dummy pixel electrode 9b simultaneously formed with the pixel electrode 9a is formed in a region overlapping the light-shielding film 27a in a plan view. The first substrate 10 has an electrode for inter-board conduction for conducting electrical conduction between the first substrate 10 and the second substrate 20 in a region outside the sealing material 107 and overlapping the corner portion of the second substrate 20. 109 is formed. An inter-board conduction material 109a containing conductive particles is arranged on the inter-board conduction electrode 109, and the counter electrode 21 of the second substrate 20 is via the inter-board conduction material 109a and the inter-board conduction electrode 109. , Is electrically connected to the first substrate 10 side. Therefore, a common potential is applied to the counter electrode 21 from the side of the first substrate 10.

In the electro-optic device 1 of the present embodiment, the pixel electrode 9a and the counter electrode 21 are formed of a translucent conductive film such as an ITO film, and the electro-optic device 1 is configured as a transmissive electro-optical device. Therefore, the light incident on the electro-optic layer 50 from one of the first substrate 10 and the second substrate 20 is modulated while being emitted through the other substrate to display an image. In this embodiment, as shown by the arrow L, the light incident on the electro-optic layer 50 from the side of the first substrate 10 is modulated while being emitted through the second substrate 20 to display an image. Therefore, the second substrate 20 is provided on the incident side of the light, and the first substrate 10 faces the second substrate 20 on the light emitting side.

2. 2. Configuration of the electro-optic layer 50 and the like The first alignment film 16 and the second alignment film 26 are inorganic alignment films made of oblique vapor deposition films such as SiOx (x ≦ 2), TiO2, MgO, and Al2O3. Therefore, the first alignment film 16 and the second alignment film 26 are composed of columnar structures in which columnar bodies called columns are formed obliquely with respect to the second substrate 20 and the first substrate 10. Therefore, in the first alignment film 16 and the second alignment film 26, the liquid crystal molecules 50a having a negative dielectric anisotropy used for the electro-optical layer 50 are obliquely inclined with respect to the first substrate 10 and the second substrate 20. The liquid crystal molecule 50a is tilted and oriented, and the liquid crystal molecule 50a is pre-tilted.

Here, in a state where no voltage is applied between the pixel electrode 9a and the counter electrode 21, the direction perpendicular to the first substrate 10 and the second substrate 20 and the long axis direction (orientation direction) of the liquid crystal molecule 50a are The angle formed is the pretilt angle. In this embodiment, the pretilt angle is, for example, 5 °.

In this way, the electro-optic device 1 is configured as an electro-optic device in VA (Vertical Alignment) mode. In the electro-optic device 1, when a voltage is applied between the pixel electrode 9a and the counter electrode 21, the liquid crystal molecule 50a has a smaller tilt angle with respect to the first substrate 10 and the second substrate 20 in the direction of pretilt. Displace in the direction. The direction of such displacement is the so-called clear view direction. In this embodiment, as shown in FIG. 1, when the side to which the flexible wiring substrate is connected is the 6 o'clock direction of the clock, the orientation direction P (clear view direction) of the liquid crystal molecule 50a is the plan view. The direction is from 4:30 to 10:30 on the clock.

3. 3. Specific Example of Pixel Configuration FIG. 4 is a plan view of a plurality of adjacent pixels in the liquid crystal panel 100 shown in FIG. 1. FIG. 5 is a cross-sectional view taken along the line FF'of the liquid crystal panel 100 shown in FIG. In FIG. 4, each film is represented by the following line. Further, in FIG. 4, for films whose ends overlap each other in a plan view, the positions of the ends are shifted so that the shape of the film and the like can be easily understood. Further, in FIG. 5, the positions of the contact holes are shifted.
Light-shielding film 8a = Thin and long dashed line Semiconductor film 31a = Thin and short dotted line Scanning line 3a = Thick solid line Drain electrode 4a = Thin solid line Data line 6a and relay electrode 6b = Thin one-dot chain line Capacity line 5a = Thick one-dot chain line Relay electrode 7b = Thin two-dot chain line Pixel electrode 9a = thick dashed line

As shown in FIG. 4, a pixel electrode 9a is formed on each of a plurality of pixels on the surface of the first substrate 10 facing the second substrate 20, and an interpixel region sandwiched by adjacent pixel electrodes 9a. A data line 6a and a scanning line 3a are formed along the line. The inter-pixel region extends vertically and horizontally, the scanning line 3a extends linearly along the first inter-pixel region extending in the first direction X in the inter-pixel region, and the data line 6a extends. It extends linearly along the second pixel-to-pixel region extending in the second direction Y. The transistor 30 is formed corresponding to the intersection region 15 of the data line 6a and the scanning line 3a. In this embodiment, the transistor 30 utilizes the intersection region 15 of the data line 6a and the scanning line 3a and its vicinity. Is formed. A capacitance line 5a is formed on the first substrate 10, and a common potential is applied to the capacitance line 5a. The capacitance line 5a extends so as to overlap the scanning line 3a and the data line 6a and is formed in a grid pattern. A light-shielding film 8a is formed on the lower layer side of the transistor 30, and the light-shielding film 8a extends in a grid pattern so as to overlap the scanning lines 3a and the data lines 6a.

Therefore, the light-shielding film 8a, the scanning line 3a, the capacitance line 5a, and the data line 6a constitute the light-shielding member 18 in a grid pattern, and the region surrounded by the light-shielding member 18 is the transmission region 180 through which light is transmitted. In the light-shielding member 18, the scanning line 3a, the capacitance line 5a, and the data line 6a as a part thereof overlap the transistor 30 from the side of the second substrate 20. Therefore, among the light incident on the first substrate 10 from the side of the second substrate 20, the light that is about to enter the transistor 30 can be blocked by the scanning line 3a, the capacitance line 5a, and the data line 6a. Therefore, it is possible to prevent the transistor 30 from malfunctioning due to the photocurrent. Further, even if the light emitted from the first substrate 10 returns to the first substrate 10 as light and is incident on the transistor 30, the light shielding film 8a can suppress the return from being incident on the transistor 30. Therefore, it is possible to prevent the transistor 30 from malfunctioning due to the photocurrent.

As shown in FIG. 5, in the display region 10a, the lens surface 510 of the first lens member 51, which will be described later, is formed on one surface 19s side of the substrate body 19 of the first substrate 10, with respect to the lens surface 510. A translucent insulating film 41 made of silicon oxynitride or the like is formed on the side of the pixel electrode 9a.

A light-shielding film 8a made of a conductive film such as a metal film or a metal compound film is formed on the upper layer of the insulating film 41. The light-shielding film 8a extends along the scanning line 3a and the data line 6a between the substrate main body 19 and the transistor 30, and an opening is formed in a region overlapping the pixel electrode 9a in a plan view. .. The light-shielding film 8a includes a light-shielding film such as aluminum, tungsten silicide (WSi), tungsten, and titanium nitride. The light-shielding film 8a may be configured as a scanning line, and in this case, the gate electrode 3b and the light-shielding film 8a, which will be described later, are made conductive.

A translucent insulating film 42 made of silicon oxide or the like is formed on the upper layer side of the light-shielding film 8a, and a transistor 30 having a semiconductor film 31a is formed on the upper layer side of the insulating film 42. The transistor 30 extends, for example, into a semiconductor film 31a whose long side direction is directed in the extending direction of the data line 6a and a direction extending in a direction orthogonal to the length direction of the semiconductor film 31a and is centered in the length direction of the semiconductor film 31a. It is provided with a gate electrode 3b that overlaps the portion. In this embodiment, the gate electrode 3b is composed of a part of the scanning line 3a. The transistor 30 has a translucent gate insulating film 32 between the semiconductor film 31a and the gate electrode 3b. The semiconductor film 31a includes a channel region 31g facing the gate electrode 3b via the gate insulating film 32, and also includes a source region 31b and a drain region 31c on both sides of the channel region 31g. In this embodiment, the transistor 30 has an LDD structure. Therefore, each of the source region 31b and the drain region 31c has a low concentration region on both sides of the channel region 31g, and has a high concentration region in a region adjacent to the low concentration region on the opposite side of the channel region 31g.

The semiconductor film 31a is made of a polysilicon film or the like. The gate insulating film 32 has a two-layer structure consisting of a first gate insulating film 32a made of silicon oxide obtained by thermally oxidizing a semiconductor film 31a and a second gate insulating film 32b made of silicon oxide formed by a reduced pressure CVD method or the like. .. The gate electrode 3b and the scanning line 3a include a conductive film such as a metal film or a metal compound film. In this embodiment, the scanning line 3a is made of a light-shielding film containing aluminum, tungsten silicide, tungsten, titanium nitride and the like.

A translucent insulating film 43 made of silicon oxide or the like is formed on the upper layer side of the gate electrode 3b, and a drain electrode 4a is formed on the upper layer of the insulating film 43. The drain electrode 4a includes a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film. The drain electrode 4a is formed so as to partially overlap the drain region 31c of the semiconductor film 31a, and is conductive to the drain region 31c via the contact hole 43a penetrating the insulating film 43 and the gate insulating film 32.

A translucent capacitive insulating film 48 made of silicon oxide or the like is formed on the upper layer side of the drain electrode 4a, and a capacitive wire 5a is formed on the upper layer side of the capacitive insulating film 48. As the capacitive insulating film 48, a silicon compound such as silicon oxide or silicon nitride can be used. The capacitance line 5a is made of a conductive film such as a metal film or a metal compound film. In this embodiment, the capacitance line 5a includes a light-shielding film such as aluminum, tungsten silicide, tungsten, and titanium nitride. The capacitance line 5a overlaps with the drain electrode 4a via the capacitive insulating film 48, and constitutes a holding capacitance 5c.

A translucent insulating film 44 made of silicon oxide or the like is formed on the upper layer side of the capacitance line 5a, and the same conductive film as the data line 6a and the relay electrode 6b is formed on the upper layer side of the insulating film 44. Is formed by. The data line 6a and the relay electrode 6b include a conductive film such as a metal film or a metal compound film. In this embodiment, the data line 6a and the relay electrode 6b include a light-shielding film such as aluminum, tungsten silicide, tungsten, and titanium nitride. The data line 6a is conducted to the source region 31b via the contact hole 44a penetrating the insulating films 44 and 43 and the gate insulating film 32. The relay electrode 6b is conductive to the drain electrode 4a via the contact hole 44b penetrating the insulating film 44.

A translucent insulating film 45 made of silicon oxide or the like is formed on the upper layer side of the data line 6a and the relay electrode 6b, and the relay electrode 7b is formed on the upper layer side of the insulating film 45. The relay electrode 7b includes a conductive film such as a metal film or a metal compound film. The relay electrode 7b is conductive to the relay electrode 6b via the contact hole 45a penetrating the insulating film 45.

Translucent insulating films 46 and 47 made of silicon oxide and silicon oxynitride are sequentially formed on the upper layer side of the relay electrode 7b, and the surface of the insulating film 47 is flattened. A pixel electrode 9a made of ITO is formed on the upper layer side of the insulating film 47. A contact hole 47a that reaches the relay electrode 7b is formed in the insulating film 47, and the pixel electrode 9a is electrically connected to the relay electrode 7b via the contact hole 47a. As a result, the pixel electrode 9a is electrically connected to the drain region 31c of the transistor 30 via the relay electrode 7b, the relay electrode 6b, and the drain electrode 4a. A dielectric film 17 and a first alignment film 16, which will be described later, are formed on the surface side of the pixel electrode 9a. Inside the contact hole 47a, the pixel electrode 9a is electrically connected to the relay electrode 7b at the bottom of the contact hole 47a, but the inside of the contact hole 47a is filled with a metal film such as tungsten as a plug to form a pixel. A configuration may be adopted in which the electrode 9a is electrically connected to the relay electrode 7b via a plug inside the contact hole 47a.

4. Configuration of Lens Member of First Substrate 10 As shown in FIG. 3, in the first substrate 10, a lens member that overlaps the pixel electrode 9a in a plan view is provided between the substrate main body 19 and the pixel electrode 9a. In this embodiment, the first lens member 51 is provided between the substrate main body 19 and the light-shielding member 18, and the second lens member 52 is provided between the light-shielding member 18 and the pixel electrode 9a. The first lens member 51 and the second lens member 52 each overlap the pixel electrode 9a in a plan view.

More specifically, as shown in FIGS. 3 and 5, a plurality of lens surfaces 510 formed of concave curved surfaces overlapping each of the plurality of pixel electrodes 9a in a plan view are formed on one surface 29s of the substrate main body 29. There is. Further, a translucent insulating film 41 is laminated on one surface 29s of the substrate body 29, and the surface of the insulating film 41 opposite to the substrate body 29 is a flat surface. The refractive index of the substrate main body 29 and the insulating film 41 are different, and the lens surface 510 constitutes the lens surface of the first lens member 51. In this embodiment, the refractive index of the insulating film 41 is larger than the refractive index of the substrate main body 29. For example, the substrate body 29 is made of a quartz substrate (silicon oxide, SiO2) and has a refractive index of 1.48, whereas the insulating film 41 is made of silicon oxynitride (SiON) and has a refractive index of 1.58. ~ 1.68. Therefore, the first lens member 51 has a positive power to converge the light.

On the surface of the insulating film 46 opposite to the substrate main body 19, a plurality of lens surfaces 520 formed of convex curved surfaces that overlap each of the plurality of pixel electrodes 9a in a plan view are formed. Further, the insulating film 47 is laminated on the surface of the insulating film 46 opposite to the substrate body 29, and the surface of the insulating film 47 opposite to the substrate body 19 is a flat surface. The insulating film 46 and the insulating film 46 have different refractive indexes, and the lens surface 520 constitutes the lens surface of the second lens member 52. In this embodiment, the refractive index of the insulating film 46 is larger than the refractive index of the insulating film 47. For example, the insulating film 47 is silicon oxide, whereas the insulating film 46 is silicon oxynitride. Therefore, the second lens member 52 has a positive power to converge the light.

As described above, in the first substrate 10 of the electro-optic device 1 of the present embodiment, the second lens member 52 is provided between the grid-shaped light-shielding member 18 and the pixel electrode 9a. Therefore, among the light incident on the first substrate 10 from the side of the second substrate 20, the light that tends toward the light-shielding member 18 can be guided to the light-transmitting region 180 surrounded by the light-shielding member 18. Therefore, since the amount of light emitted from the electro-optic device 1 can be increased, a bright image can be displayed.

Further, a first lens member 51 is provided between the grid-shaped light-shielding member 18 and the substrate main body 19. Therefore, the inclination of the light beam emitted from the electro-optic device 1 can be optimized by the first lens member 51. Therefore, when the electro-optic device 1 is used as a light valve of a projection type display device described later, projection is performed. Vignetting due to the optical system can be suppressed. Therefore, a bright and high-quality image can be displayed.

Further, the second substrate 20 is not provided with a lens member having a positive power. Therefore, the focused light emitted from the lens member does not enter the electro-optic layer 50. Therefore, in the electro-optic layer 50, deterioration due to irradiation of the focused light emitted from the lens member provided on the second substrate 20 does not occur.

5. Configuration of the vicinity of the pixel electrode 9a FIG. 6 is an explanatory diagram of the vicinity of the pixel electrode 9a shown in FIG. In FIG. 6, of the plurality of pixel electrodes 9a, the width W of the space 9s between the adjacent pixel electrodes 9a is a viewpoint of preventing a short circuit in either the first direction X or the second direction Y. It is set to 100 nm or more, and 300 nm or less from the viewpoint of high-definition image. Further, the entire pixel electrode 9a is made of ITO.

A dielectric film 17 is formed on the first substrate 10 to cover a plurality of pixel electrodes 9a and fill a space 9s between adjacent pixel electrodes 9a, and is formed on a surface of the dielectric film 17 opposite to the pixel electrodes 9a. The first alignment film 16 is laminated. The surface of the dielectric film 17 opposite to the pixel electrode 9a is a continuous flat surface. Therefore, the first alignment film 16 is laminated on the plane opposite to the pixel electrode 9a of the dielectric film 17. Such a structure can be realized by forming a film of the dielectric film 17 and then flattening the surface of the dielectric film 17 by chemical mechanical polishing or the like. Further, the film thickness of the dielectric film 17 is formed by a film forming method such as ALD (Atomic Layer Deposition) in which the film thickness can be easily controlled, or HDP-CVD (high density plasma CVD method). , It is preferable to use a film forming method suitable for embedding in the recess.

The refractive index n of the dielectric film 17 is between the refractive index of the pixel electrode 9a and the refractive index of the first alignment film 16. More specifically, when the incident light is 550 nm, the refractive index of ITO contained in the pixel electrode 9a is about 1.85, and the refractive index of silicon oxide contained in the first alignment film 16 is about 1.46. Therefore, the refractive index n of the dielectric film 17 is between 1.46 and 1.85. For example, the dielectric film 17 has an oxynitride silicon (SiON) having a refractive index of 1.58 to 1.68, silicon nitride (SiN _x ) having a refractive index of about 1.65, and a refractive index of about 1.80. It contains at least one of aluminum oxide (Al ₂ O _3). Here, it is preferable that the refractive index n of the dielectric film 17 is closer to the refractive index of the pixel electrode 9a than the refractive index of the first alignment film 16. For example, the refractive index of the dielectric film 17 is preferably 1.70 or more and less than 1.85.

Further, when the film thickness of the portion of the dielectric film 17 overlapping the pixel electrode 9a is d, the refractive index of the dielectric film 17 is n, and the wavelength λ of the incident light on the pixel electrode 9a is 550 nm, the film thickness d. Is 1/2 or more and λ / 2n or less of the width W of the space 9s of the pixel electrode 9a.

For example, Table 1 shows values corresponding to W / 2 and λ / 2n when the width W of the space 9s between the pixel electrodes 9a is changed to 50 nm, 100 nm, 200 nm, and 300 nm. As can be seen from Table 1, when the space width W is 50 nm and the refractive index n is 1.9, the film thickness d of the dielectric film 17 is 25 nm or more and 144.7 nm or less. When the space width W is 100 nm and the refractive index n is 1.8, the film thickness d of the dielectric film 17 is 50 nm or more and 152.8 nm or less. When the space width W is 200 nm and the refractive index n is 1.7, the film thickness d of the dielectric film 17 is 100 nm or more and 161.8 nm or less. When the space width W is 300 nm and the refractive index n is 1.8, the film thickness d of the dielectric film 17 is 150 nm or more and 171.9 nm or less.

As described above, in the electro-optic device 1 of the present embodiment, the space 9s between the pixel electrodes 9a is filled with the dielectric film 17 covering the pixel electrodes 9a. Therefore, when focusing on the light incident perpendicular to the first substrate 10, the difference between the optical path length passing through the space 9s between the pixel electrodes 9a and the optical path length passing through the pixel electrode 9a covers the pixel electrode 9a. The 1 alignment film 16 is smaller than the structure in which the space 9s between the pixel electrodes 9a is filled.

Further, the film thickness d of the portion of the dielectric film 17 that covers the pixel electrodes 9a is ½ or more of the space width W of the pixel electrodes 9a, and the optical path length passing through the space 9s between the pixel electrodes 9a and the pixel electrodes 9a are set. The film thickness is sufficient to reduce the difference from the optical path length. Therefore, when light passes through the layer provided with the pixel electrode 9a, diffraction is unlikely to occur, so that it is possible to suppress a decrease in contrast due to diffraction.

Further, since the dielectric film 17 is interposed between the pixel electrode 9a and the first alignment film 16, the pixel electrode 9a does not form an interface having a large difference in refractive index from the first alignment film 16. Further, when the wavelength λ of the incident light on the pixel electrode 9a is 550 nm, the film thickness d of the portion of the dielectric film 17 covering the pixel electrode 9a is λ / 2n or less. Therefore, the light that passes through the pixel electrode 9a has a small reflection. Since the film thickness d of the portion of the dielectric film 17 that covers the pixel electrodes 9a is λ / 2n or less, the absorption of light by the dielectric film 17 and the decrease in the voltage applied to the electro-optic layer 50 are suppressed. be able to.

Therefore, both the diffraction caused by the arrangement of the plurality of pixel electrodes 9a having a large refractive index and the reflection at the interface having a large difference in the refractive index can be appropriately suppressed.

6. Configuration of Optical Compensation Member 70 An optical compensation member 70 is provided in the electro-optical device 1 of the present embodiment. Therefore, the contrast, the viewing angle characteristic, and the like can be improved. In the present embodiment, the optical compensation member 70 is provided on the incident side of light from the first lens member 51 and the second lens member 52. More specifically, the optical compensation member 70 is provided on the incident side of the light from the second substrate 20. Therefore, in the display region 10a, there is no grid-like light-shielding member 18 or lens member having a diffraction action between the electro-optic layer 50 and the optical compensating member 70. Therefore, an angle shift due to diffraction by the light-shielding member 18 or the lens is unlikely to occur between the light rays incident on the optical compensation member 70 and the light rays passing through the electro-optical layer 50, so that the effect of optical compensation is large. ..

Here, the optical compensating member 70 includes at least an optical compensating member having a negative uniaxial refractive index anisotropy, an optical compensating member having a positive uniaxial refractive index anisotropy, and a substrate body 29 of the second substrate 20. Includes either an optical compensator with a uniaxial or biaxial index of refraction elliptical tilted relative to one surface. For example, the optical compensating member 70 includes any of an A plate, a C plate, and an O plate. The optical compensation member 70 is defined as follows with respect to the refractive index ellipsoid (three-dimensional distribution of the refractive index).

The coordinate axis in the substrate surface of the first substrate 10 or the second substrate 20 is the xy axis, and the normal direction is the z axis. The main refractive index in the x-axis direction is Nx, the main refractive index in the y-axis direction is Ny, and the main refractive index in the z-axis direction is Nz.
The A plate (positive A plate) has the following conditional expression Nx> Ny = Nz.
Meet.

The C plate (negative C plate) has the following conditional expression Nx = Ny> Nz.
Meet. In such a C plate, the optical axis points to the normal line with respect to the first substrate 10 and the second substrate 20, and the C plate is optically isotropic in the substrate surface, but optically in the plane perpendicular to the substrate surface. Has anisotropy. Therefore, since the phase difference of the light incident on the electro-optic layer 50 from an oblique direction can be compensated by the optical compensating member 70, the contrast and the viewing angle characteristics can be improved.

When the C plate is composed of an inorganic film, the C plate is composed of, for example, an inorganic film in which high refractive index layers and low refractive index layers are alternately laminated. The high refractive index layer is made of a tantalum oxide film, a niobium oxide film, a titanium oxide film, a silicon nitride film, silicon oxynitride, or the like. For example, the high refractive index layer is formed of a niobium oxide film having a refractive index of 2.3, and the low refractive index layer is formed of silicon oxide having a refractive index of 1.5.

The refractive index ellipsoid itself is tilted with respect to the substrate. For example, the O plate is tilted at a certain angle from the board normal with the Y axis as the rotation axis with respect to Nx> Ny> Nz. Therefore, the optical axis of the O plate is deviated from the normal direction with respect to the first substrate 10 and the second substrate 20 and is oriented in an oblique direction, and is optically anisotropic in the surface of the substrate and in the plane perpendicular to the surface of the substrate. Has. Two O-plates may be arranged, in which case the two O-plates have their optical axes oriented in different directions when viewed from the substrate normal direction and are sandwiched between the optical axes of the two O-plates. The orientation direction P of the liquid crystal molecule 50a is located within the angle range. When the O-plate is composed of an inorganic film, the O-plate is formed by orthorhombic vapor deposition of an inorganic film such as a tantalum oxide film.

The refractive index characteristics, thickness, and the like of the optical compensating member 70 are set so that the overall phase difference is suitably compensated.

[Specific Example 1 of Embodiment 1]
FIG. 7 is an explanatory diagram showing a specific example 1 of the electro-optic device 1 according to the first embodiment of the present invention. Since the basic configurations of this embodiment and the embodiments described below are the same as those of the first embodiment, the common parts are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 7, in this embodiment, when the electro-optic device 1 is used as a light bulb or the like of a projection type display device described later, the other side of the board body 29 of the second board 20 opposite to the first board 10. A dustproof first translucent substrate 61 is bonded to the direction 29t with an adhesive or the like. Further, a dustproof second translucent substrate 62 is bonded to the other surface 19t of the substrate body 19 of the first substrate 10 on the opposite side of the second substrate 20 by an adhesive or the like. Therefore, since foreign matter such as dust does not directly adhere to the first substrate 10 and the second substrate 20, it is possible to suppress the foreign matter from being reflected in the image.

In the electro-optic device 1 having such a configuration, the optical compensating member 70 is provided on the surface of the first translucent substrate 61 joined to the second substrate 20 on the side opposite to the second substrate 20. Therefore, in the display region 10a, there is no grid-like light-shielding member 18 or lens member having a diffraction action between the electro-optic layer 50 and the optical compensating member 70. Therefore, the effect of optical compensation is great.

Here, the optical compensation member 70 is made of, for example, an inorganic film 71 formed on the first translucent substrate 61. As the optical compensating member 70, a member having a negative uniaxial refractive index ellipsoid tilted, such as a substrate such as sapphire or alumina, may be used. In this case, the optical compensating member 70 may be adhered to the first translucent substrate 61, or the optical compensating member 70 may be opposed to the first translucent substrate 61 without being adhered to the first translucent substrate 61. Further, the optical compensating member 70 may be a C plate arranged obliquely with respect to the second substrate 20 on the side opposite to the second substrate 20 with respect to the first translucent substrate 61.

[Specific Example 2 of Embodiment 1]
FIG. 8 is an explanatory diagram showing a specific example 2 of the electro-optic device 1 according to the first embodiment of the present invention. As shown in FIG. 8, in the electro-optic device 1 of the present embodiment, the optical compensating member 70 is provided on the light emitting side of the second substrate 20 as in the first and second embodiments. In this embodiment, the optical compensation member 70 is provided between the second substrate 20 and the first translucent substrate 61. The optical compensating member 70 is, for example, an inorganic film 71 formed on the surface of the first translucent substrate 61 on the second substrate 20 side, and the first translucent substrate 61 is an inorganic film 71 and a second substrate 20. And are glued together. Further, the optical compensation member 70 may be an inorganic film 71 formed on the surface of the second substrate 20 on the side of the first translucent substrate 61, and in this case, the first translucent substrate 61 and the inorganic film 71. And are glued together. In any case, in the display region 10a, there is no grid-like light-shielding member 18 or lens having a diffraction action between the electro-optic layer 50 and the optical compensating member 70. Therefore, the effect of optical compensation is great.

[Embodiment 2]
FIG. 9 is an explanatory diagram of the electro-optic device 1 according to the second embodiment of the present invention. As shown in FIG. 9, in the present embodiment, the optical compensation member 70 is an inorganic film 71 provided between the counter electrode 21 and the substrate main body 29 of the second substrate 20. More specifically, the optical compensation member 70 is provided between the substrate main body 29 of the second substrate 20 and the translucent film 22. Therefore, in the display region 10a, there is no grid-like light-shielding member 18 or lens having a diffraction action between the electro-optic layer 50 and the optical compensating member 70. Therefore, the effect of optical compensation is great. The optical compensation member 70 may be provided between the translucent film 22 and the counter electrode 21. Further, the optical compensating member 70 may be configured by the translucent film 22.

[Embodiment 3]
FIG. 10 is an explanatory diagram of the electro-optic device 1 according to the third embodiment of the present invention. As shown in FIG. 10, in the present embodiment, the optical compensation member 70 is an inorganic film 71 provided between the second lens member 52 and the pixel electrode 9a. Therefore, in the display region 10a, there is no grid-like light-shielding member 18 or lens having a diffraction action between the electro-optic layer 50 and the optical compensating member 70. Further, in the present embodiment, diffraction when light passes through the layer provided with the pixel electrode 9a is suppressed. Therefore, even when the optical compensation member 70 is provided between the second lens member 52 and the pixel electrode 9a, the effect of optical compensation is large.

[Embodiment 4]
In constructing the optical compensation member 70, for example, an inclined surface is formed on a base such as one surface 29s of the substrate main body 29 so as to correspond to each of the plurality of pixel electrodes 9a, and the inclined surface is optical. The inorganic film 71 constituting the compensating member 70 may be formed to have a substantially constant thickness. In the case of such a configuration, the optical compensating member 70 is provided along an inclined surface inclined in the orientation direction P shown in FIG. Further, the translucent film 22 is formed so as to cover the optical compensating member 70, and the surface of the translucent film 22 opposite to the optical compensating member 70 is a flat surface.

The inorganic film 71 constituting the optical compensation member 70 alternates between a low refractive index layer such as silicon oxide and a high refractive index layer such as tantalum oxide film, niobium oxide film, titanium oxide film, silicon nitride film, and silicon oxynitride. It consists of a multilayer film laminated on the surface.

In such a structure, an etching mask is formed on the substrate (board body 29) with a gray scale mask or the like, and then etching is performed to form an inclined surface. At that time, the shape of the inclined surface may be further adjusted by using etching or the like. Next, the optical compensation member 70 is formed by a CVD method or a PVD method, and then the translucent film 22 is formed. Next, the surface of the translucent film 22 is flattened.

In this embodiment, the substrate on which the inclined surface is formed is the substrate main body 29, but a translucent film such as silicon oxide may be used. Further, in the present embodiment, the optical compensating member 70 having an inclined surface is formed on the second substrate 20, but as shown in the third embodiment, the optical compensating member having an inclined surface with respect to the first substrate 10 is formed. 70 may be provided.

[Other embodiments]
In the above embodiment, the case where the light is incident from the side of the second substrate 20 has been described, but the present invention may be applied when the light is incident from the side of the first substrate 10. In the above embodiment, the optical compensating member 70 is provided at one position on the light emitting side with respect to the second lens member 52. For example, one electro-optic device 1 is provided with the optical compensating member 70 shown in FIG. , The optical compensating member 70 shown in FIG. 10 may be provided, or the optical compensating member 70 may be provided at a plurality of places of one electro-optical device 1. In the above embodiment, the case where the first translucent substrate 61 and the second translucent substrate 62 for dustproofing are provided is exemplified, but the first translucent substrate 61 and the second translucent substrate 62 are provided. The present invention may be applied to an electro-optic device 1 in which one or both are not provided. In the above embodiment, the present invention is applied to the VA mode electro-optic device, but the present invention may be applied to the TN mode, IPS mode, FFS mode, and OCB mode electro-optic device.

[Example of mounting on electronic devices]
FIG. 11 is a schematic configuration diagram of a projection type display device using the electro-optic device 1 to which the present invention is applied. In the following description, a plurality of light bulbs (red light bulb 1 (R), green light bulb 1 (G), and blue light bulb 1 (B)) to which light in different wavelength ranges are supplied. However, the electro-optical device 1 to which the present invention is applied is used for any of the light bulbs. At that time, the first polarizing plate 141 and the second polarizing plate 142 are arranged on the cross Nicol with respect to the electro-optic device 1.

The projection type display device 210 shown in FIG. 11 is a front projection type projector that projects an image on a screen 211 provided in the front. The projection type display device 210 includes a light source unit 212, dichroic mirrors 213 and 214, and three light valves (red light valve 1 (R), green light valve 1 (G), and blue light valve 1 (B). )), A projection optical system 218, a cross dichroic prism 219 (color synthesis optical system), and a relay system 230.

The light source unit 212 is composed of, for example, an ultrahigh pressure mercury lamp that supplies light source light including red light, green light, and blue light. The dichroic mirror 213 is configured to transmit the red light LR from the light source unit 212 and to reflect the green light LG and the blue light LB. Further, the dichroic mirror 214 is configured to transmit the blue light LB among the green light LG and the blue light LB reflected by the dichroic mirror 213 and to reflect the green light LG. As described above, the dichroic mirrors 213 and 214 constitute a color separation optical system that separates the light emitted from the light source unit 212 into red light LR, green light LG, and blue light LB. An integrator 221 and a polarization conversion element 222 are arranged in order from the light source unit 212 between the dichroic mirror 213 and the light source unit 212. The integrator 221 equalizes the illuminance distribution of the light emitted from the light source unit 212. The polarization conversion element 222 converts the light from the light source unit 212 into linearly polarized light having a specific vibration direction such as s-polarized light.

The red light valve 1 (R) modulates the red light LR (illumination light) transmitted through the dichroic mirror 213 and reflected by the reflection mirror 223 according to the image signal, and crosses the modulated red light LR (modulated light). It emits light toward the dichroic prism 219.
The green light valve 1 (G) modulates the green light LG (illumination light) reflected by the dichroic mirror 213 and then reflected by the dichroic mirror 214 according to the image signal, and modulates the green light LG (modulated green light LG). Modulated light) is emitted toward the cross dichroic prism 219.

The blue light valve 1 (B) is reflected by the dichroic mirror 213, and after passing through the dichroic mirror 214, the blue light LB (illumination light) that has passed through the relay system 230 is modulated according to the image signal and modulated blue light. LB (modulated light) is emitted toward the cross dichroic prism 219.

The relay system 230 includes relay microlenses 224a and 224b and reflection mirrors 225a and 225b. The relay microlenses 224a and 224b are provided to prevent light loss due to the long optical path of the blue light LB. The relay microlens 224a is arranged between the dichroic mirror 214 and the reflection mirror 225a.

The relay microlens 224b is arranged between the reflection mirrors 225a and 225b. The reflection mirror 225a is arranged so as to transmit the blue light LB emitted from the relay microlens 224a through the dichroic mirror 214 and to be reflected toward the relay microlens 224b. The reflection mirror 225b is arranged so as to reflect the blue light LB emitted from the relay microlens 224b toward the blue light bulb 1 (B).

The cross dichroic prism 219 is a color synthesis optical system in which two dichroic films 219a and 219b are arranged orthogonally in an X shape. The dichroic film 219a reflects the blue light LB and transmits the green light LG. The dichroic film 219b reflects the red light LR and transmits the green light LG.

Therefore, the cross dichroic prism 219 has red light LR, green light LG, and blue modulated by each of the red light valve 1 (R), the green light valve 1 (G), and the blue light valve 1 (B). It is configured to synthesize light LB and emit light toward the projection optical system 218. The projection optical system 218 has a projection microlens (not shown), and is configured to project the light synthesized by the cross dichroic prism 219 onto the screen 211.

[Other electronic devices]
The electro-optical device 1 to which the present invention is applied uses an LED light source, a laser light source, or the like that emits light of each color as a light source unit in a projection type display device, and different electro-optics each color light emitted from the light source. It may be configured to supply the device.

Further, the electro-optic device 1 is not limited to the front projection type projector that projects from the side for observing the projected image, and may be used for the rear projection type projector that projects from the side opposite to the side for observing the projected image.

Further, the electronic device to which the electro-optic device 1 can be applied is not limited to the projection type display device 210. The electro-optical device 1 is, for example, a projection type HUD (head-up display), a direct-view type HMD (head-mounted display), an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type, or a monitor direct-view type. It may be used as a display unit of an information terminal device such as a video recorder, a car navigation system, an electronic notebook, or a POS.

1 ... Electro-optical device, 3a ... Scanning line, 3b ... Gate electrode, 5a ... Capacitive line, 6a ... Data line, 8a, 27a ... Light-shielding film, 9a ... Pixel electrode, 9s ... Space, 10 ... First substrate, 10a ... Display area, 16 ... first alignment film, 17 ... dielectric film, 18 ... light-shielding member, 19, 29 ... substrate body, 20 ... second substrate, 21 ... counter electrode, 22 ... translucent film, 26 ... second orientation Film, 30 ... Transistor, 31a ... Semiconductor film, 50 ... Electro-optical layer, 51 ... First lens member, 52 ... Second lens member, 61 ... First translucent substrate, 62 ... Second translucent substrate, 70 ... Optical compensation member, 71 ... Inorganic film, 100 ... Liquid crystal panel, 210 ... Projection type display device, 212 ... Light source unit, 218 ... Projection optical system

Claims (9)

A plurality of pixel electrodes containing indium tin oxide, each having a space width of 100 nm or more and 300 nm or less,
A dielectric film that covers the plurality of pixel electrodes and fills the space between the adjacent pixel electrodes.
Equipped with
When the refractive index of the dielectric film is n and the wavelength λ of the light incident on the pixel electrode is 550 nm, the film thickness of the portion of the dielectric film overlapping with the pixel electrode is 1/2 of the space width. The electro-optical device, which is characterized by the above and λ / 2n or less. In the electro-optic device according to claim 1,
An electro-optic device characterized in that the surface of the dielectric film on the side opposite to the pixel electrode is a continuous flat surface. In the electro-optic device according to claim 1 or 2.
An alignment film is laminated on the surface of the dielectric film opposite to the pixel electrode.
The dielectric film is an electro-optical device having a refractive index between the refractive index of the alignment film and the refractive index of the pixel electrode. In the electro-optic device according to claim 3,
The alignment film contains silicon oxide and contains silicon oxide.
An electro-optic device comprising the dielectric film containing at least one of silicon oxynitride, silicon nitride, and aluminum oxide. In the electro-optic device according to claim 3 or 4.
An electro-optical device, wherein the refractive index n of the dielectric film is closer to the refractive index of the pixel electrode than the refractive index of the alignment film. In the electro-optic device according to any one of claims 1 to 5.
An electro-optic device comprising a lens member between a substrate main body and the pixel electrode. In the electro-optic device according to claim 6,
An electro-optic device comprising a grid-like light-shielding member between the substrate main body and the pixel electrodes. In the electro-optic device according to claim 6 or 7.
An electro-optic device including an optical compensating member arranged on the light incident side of the lens member. An electronic device comprising the electro-optic device according to any one of claims 1 to 8.

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