JP6318947B2 - Microlens array substrate, electro-optical device, and electronic device - Google Patents

Description

  The present invention relates to a microlens array substrate, an electro-optical device, and an electronic apparatus.

  There is known an electro-optical device including an electro-optical material such as liquid crystal between an element substrate and a counter substrate. Examples of the electro-optical device include a liquid crystal device used as a liquid crystal light valve of a projector. In the liquid crystal device, a light shielding portion is provided in a region where switching elements, wirings, and the like are arranged, and a part of incident light is shielded by the light shielding portion and is not used. Therefore, at least one of the substrates is provided with a microlens, and light that is blocked by the light blocking portion among the light incident on the liquid crystal device is collected and incident into the opening of the pixel, thereby improving the light utilization efficiency. The structure which tries is known (for example, refer patent document 1).

  The microlens array substrate described in Patent Document 1 includes an incident-side first lens having a positive refractive power and an emission-side second lens having a positive refractive power. The first lens is formed by processing the incident surface side of the substrate into a curved surface, and the second lens is formed by dividing the silicon oxide layer formed on the emission surface side of the substrate by a V-shaped groove. Are formed in a shape having a flat portion. With the microlens array substrate having such a first lens and a second lens, it is possible to irradiate substantially parallel light into the opening of the pixel while avoiding the light shielding layer provided on the TFT substrate side. It is said that.

JP 2013-246210 A

  However, in the microlens array substrate described in Patent Document 1, since the first lens on the incident side is curved, even if the incident light is parallel light, it is refracted toward the center by the first lens. As a result, oblique light inclined with respect to the normal direction of the incident surface is generated. In addition, since the variation in the phase depth (Δnd / λ) within the opening of the pixel is increased, oblique light is also generated by diffracting incident light. If such oblique light increases in the light emitted from the microlens array substrate, the amount of light shielded by the light-shielding portion may increase and the light use efficiency may decrease. There is a risk that the amount of light transmitted obliquely increases and the contrast ratio decreases.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A microlens array substrate according to this application example includes a substrate, a first microlens disposed on a first surface side of the substrate and having a first flat portion at a central portion, and the first A second microlens disposed on the opposite side of the first microlens to correspond to the first microlens and having a second flat portion at the center, from the substrate side In the plan view, the region of the first microlens includes the region of the second microlens, and the region of the second microlens includes the region of the first flat portion. Features.

  According to the configuration of this application example, the first microlens and the second microlens are provided in order from the substrate side, and both the first microlens and the second microlens have a condensing function. A first flat portion and a second flat portion that are not provided are provided in the central portion. Since the region of the second microlens is included in the region of the first microlens, only the light incident from the substrate side and transmitted through the first microlens is incident on the second microlens. And since the area | region of the 1st flat part is included in the area | region of the 2nd micro lens, all the parallel light which permeate | transmitted the 1st flat part injects into a 2nd micro lens. Therefore, the entire first microlens has a curved surface shape (in other words, does not have a flat portion), and is obliquely incident on the second microlens as compared to the case where incident parallel light is refracted. Light can be suppressed. Here, the average value of the thickness of the first microlens having the first flat portion is thinner than that of the first microlens having a curved surface shape. It has been found that the thinner the average thickness is, the less oblique light is generated by diffraction. Therefore, compared to the case where the first microlens is curved, oblique light generated by diffraction can be suppressed. As a result, it is possible to reduce the oblique light in the light emitted from the microlens array substrate and to suppress the variation in the angle of the oblique light.

  Application Example 2 In the microlens array substrate according to the application example, the diameter of the second microlens is equal to or smaller than the diameter of the first microlens and equal to or larger than the diameter of the first flat portion. Preferably there is.

  According to the configuration of this application example, the diameter of the second microlens is not more than the diameter of the first microlens and not less than the diameter of the first flat portion. Therefore, the region of the second microlens is included in the region of the first microlens, and the region of the first flat portion is included in the region of the second microlens.

  Application Example 3 In the microlens array substrate according to the application example described above, it is preferable that the thickness of the second microlens is thinner than the thickness of the first microlens.

  According to the configuration of this application example, since the thickness of the second microlens is thinner than the thickness of the first microlens, the oblique light generated by the diffraction in the second microlens is diffracted in the first microlens. It can be less than the oblique light generated by. Thereby, the oblique light in the light inject | emitted from a microlens array board | substrate can be decreased more.

  Application Example 4 A microlens array substrate according to the application example, wherein the first microlens and the second microlens are arranged in a lattice shape, and the first microlens is the substrate. A lens layer having a refractive index different from the refractive index of the substrate, which is disposed so as to fill a recess provided in the first surface of the first surface, and the diameter of the first microlens is It is preferable that the length is 95% or less of the length of a straight line connecting lattice points at diagonal positions.

  According to the configuration of this application example, the first microlens is configured by a lens layer disposed so as to fill the concave portion provided on the first surface of the substrate, and the diameter of the first microlens is the first microlens. It is 95% or less of the length of the diagonal line in the unit cell in which the microlenses are arranged in a lattice shape. Therefore, in the step of forming the recess by etching from the opening of the mask layer on the first surface side of the substrate, when the etching is finished, the first first portion of the substrate is located between the recesses adjacent to each other in the diagonal direction. The surface remains. Therefore, since the mask layer can be supported by the first surface of the substrate until the etching is completed, the mask layer can be prevented from floating or peeling off in the step of forming the recess.

  Application Example 5 In the microlens array substrate according to the application example described above, the diameter of the first flat portion is equal to or less than the arrangement pitch of the first microlens and the second microlens. preferable.

  According to the configuration of this application example, the diameter of the first flat portion is equal to or less than the arrangement pitch of the first microlenses. The larger the region of the first flat part that does not have the light collecting action, the more parallel light that passes through the first microlens. However, when the area of the first flat portion is increased in the area of the first microlens, the area having the light collecting action is relatively reduced. If it does so, the light which injects into the peripheral part of a 1st micro lens and will be refracted to the center side will decrease, As a result, the utilization efficiency of light will be caused. By setting the diameter of the first flat portion to be equal to or less than the arrangement pitch of the first microlenses, it is possible to secure a region where light at the peripheral portion is refracted while increasing a region through which parallel light is transmitted as it is.

  Application Example 6 In the microlens array substrate according to the application example described above, it is preferable that the first microlens has a first inclined surface at a peripheral portion.

  According to the configuration of this application example, the first microlens has the first inclined surface at the peripheral edge. Therefore, the light incident on the peripheral portion of the first microlens is refracted at substantially the same angle. Thereby, compared with the case where the 1st micro lens is curved-surface, while suppressing excessive refraction of incident light, the dispersion | variation in a refraction angle can be suppressed. In addition, since the first inclined surface is provided in the peripheral portion, the average value of the thickness of the first microlens is smaller than that in the case where the first microlens has a curved surface. Light can be suppressed. As a result, the oblique light in the light emitted from the microlens array substrate can be further reduced, and the angle variation of the oblique light can be further reduced.

  Application Example 7 In the microlens array substrate according to the application example, it is preferable that the second microlens has a second inclined surface at a peripheral edge portion.

  According to the configuration of this application example, since the second microlens has the second inclined surface at the peripheral portion, the second microlens also suppresses excessive refraction of incident light and has a refraction angle of It is possible to reduce the variation and to reduce oblique light caused by diffraction.

  Application Example 8 An electro-optical device according to this application example includes a switching element provided for each pixel, a light-shielding unit provided with an opening of the pixel so as to overlap the switching element in plan view, A second substrate that is disposed to face the first substrate, the first substrate, and the second substrate. The first microlens and the second microlens are arranged so as to overlap the pixel in plan view.

  According to the configuration of this application example, the electro-optical device includes the microlens array substrate that collects incident light and emits light with less oblique light and less angular variation on the second substrate. As a result, the amount of light that passes through the opening of the pixel without being blocked by the light blocking portion of the incident light can be increased, so that the light use efficiency is improved. Further, since the oblique light transmitted through the electro-optic layer is reduced and the variation in the angle of the light is suppressed, the contrast ratio is improved. As a result, it is possible to provide an electro-optical device that can display a bright image with a good contrast ratio.

  Application Example 9 In the electro-optical device according to the application example, the arrangement pitch of the first microlens and the second microlens is the same as the arrangement pitch of the pixels. The diameter of the flat portion is preferably not less than the difference between the arrangement pitch and the maximum width of the light-shielding portion and not more than the difference between the arrangement pitch and the minimum width of the light-shielding portion.

  According to the configuration of this application example, the diameter of the second flat portion is greater than or equal to the difference between the pixel arrangement pitch and the maximum width of the light shielding portion, and less than or equal to the difference between the pixel arrangement pitch and the minimum width of the light shielding portion. is there. That is, the diameter of the second flat portion is not less than the minimum width of the pixel opening and not more than the maximum width of the pixel opening. Therefore, the area of the second flat part that transmits the incident parallel light as it is in the second microlens is maximized within the opening of the pixel, and the overlap between the second flat part and the light shielding part is minimized. Can do. Accordingly, it is possible to provide an electro-optical device that can display a brighter image with a better contrast ratio.

  Application Example 10 An electronic apparatus according to this application example includes the electro-optical device according to the application example described above.

  According to the configuration of this application example, it is possible to provide an electronic apparatus that can display an image that is bright and has a good contrast ratio.

1 is a schematic plan view showing a configuration of a liquid crystal device according to a first embodiment. FIG. 2 is an equivalent circuit diagram illustrating an electrical configuration of the liquid crystal device according to the first embodiment. 1 is a schematic cross-sectional view illustrating a configuration of a liquid crystal device according to a first embodiment. FIG. 2 is a schematic plan view showing the shape and arrangement of a light shielding portion and a microlens of the liquid crystal device according to the first embodiment. 1 is a schematic cross-sectional view showing a configuration of a microlens array substrate according to a first embodiment. The figure which shows the simulation result of the diffracted light which generate | occur | produces with a micro lens. FIG. 3 is a schematic cross-sectional view showing the method for manufacturing the microlens array substrate according to the first embodiment. FIG. 3 is a schematic cross-sectional view showing the method for manufacturing the microlens array substrate according to the first embodiment. FIG. 3 is a schematic cross-sectional view showing the method for manufacturing the microlens array substrate according to the first embodiment. FIG. 3 is a schematic cross-sectional view showing the method for manufacturing the microlens array substrate according to the first embodiment. FIG. 6 is a schematic plan view showing the shape and arrangement of a light shielding part and a microlens of a liquid crystal device according to a second embodiment. FIG. 6 is a schematic plan view showing the shape and arrangement of a light shielding part and a microlens of a liquid crystal device according to a second embodiment. Schematic which shows the structure of the projector as an electronic device which concerns on 3rd Embodiment. FIG. 9 is a schematic plan view showing the shape and arrangement of a light shielding part and a microlens of a liquid crystal device according to Modification Example 1. FIG. 9 is a schematic plan view showing the shape and arrangement of a light shielding portion and a microlens of a liquid crystal device according to Modification 2.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. The drawings to be used are appropriately enlarged, reduced or exaggerated so that the part to be described can be recognized. In addition, illustrations of components other than those necessary for the description may be omitted.

  In the following embodiments, for example, when “on the substrate” is described, the substrate is disposed so as to be in contact with the substrate, or is disposed on the substrate via another component, or the substrate. It is assumed that a part is arranged so as to be in contact with each other and a part is arranged via another component.

(First embodiment)
<Electro-optical device>
In the first embodiment, as an electro-optical device, an active matrix liquid crystal device including a thin film transistor (TFT) as a pixel switching element will be described as an example. This liquid crystal device can be suitably used, for example, as a light modulation element (liquid crystal light valve) of a projection display device (projector) described later.

  First, a liquid crystal device as an electro-optical device according to the first embodiment will be described with reference to FIGS. 1, 2, and 3. FIG. 1 is a schematic plan view showing the configuration of the liquid crystal device according to the first embodiment. FIG. 2 is an equivalent circuit diagram showing an electrical configuration of the liquid crystal device according to the first embodiment. FIG. 3 is a schematic cross-sectional view illustrating the configuration of the liquid crystal device according to the first embodiment. FIG. 3 is a schematic cross-sectional view taken along the line A-A ′ of FIG. 1, and specifically corresponds to a cross section taken along the line A-A ′ of FIG. 4.

  As shown in FIGS. 1 and 3, the liquid crystal device 1 according to the present embodiment includes an element substrate 20 as a first substrate, a counter substrate 30 as a second substrate disposed to face the element substrate 20, and A sealing material 42 and a liquid crystal layer 40 as an electro-optic layer are provided. As shown in FIG. 1, the element substrate 20 is larger than the counter substrate 30, and both the substrates are bonded together via a sealing material 42 arranged in a frame shape along the edge of the counter substrate 30.

  The liquid crystal layer 40 is composed of liquid crystal having positive or negative dielectric anisotropy enclosed in a space surrounded by the element substrate 20, the counter substrate 30, and the sealing material 42. The sealing material 42 is made of an adhesive such as a thermosetting or ultraviolet curable epoxy resin. Spacers (not shown) are mixed in the sealing material 42 to keep the distance between the element substrate 20 and the counter substrate 30 constant.

  Inside the sealing material 42 arranged in a frame shape, the light shielding layers 22 and 26 provided on the element substrate 20 and the light shielding layer 32 provided on the counter substrate 30 are arranged. The light shielding layers 22, 26, and 32 have a frame-like peripheral portion, and are formed of, for example, a light shielding metal or metal oxide. Inside the frame-shaped light shielding layers 22, 26, 32 is a display area E in which a plurality of pixels P are arranged. The pixels P have, for example, a substantially rectangular shape and are arranged in a lattice shape (matrix shape).

  The display area E is an area that substantially contributes to display in the liquid crystal device 1. The light shielding layers 22 and 26 provided on the element substrate 20 are provided, for example, in a lattice shape in the display region E so as to partition the opening regions of the plurality of pixels P in a plane. The liquid crystal device 1 may include a dummy area that is provided so as to surround the display area E and does not substantially contribute to display.

  A data line driving circuit 51 and a plurality of external connection terminals 54 are provided along the first side on the side opposite to the display region E of the sealing material 42 formed along the first side of the element substrate 20. An inspection circuit 53 is provided on the display region E side of the sealing material 42 along the other second side facing the first side. Further, a scanning line driving circuit 52 is provided inside the sealing material 42 along the other two sides that are orthogonal to these two sides and face each other.

  On the display area E side of the sealing material 42 on the second side where the inspection circuit 53 is provided, a plurality of wirings 55 that connect the two scanning line driving circuits 52 are provided. Wirings connected to the data line driving circuit 51 and the scanning line driving circuit 52 are connected to a plurality of external connection terminals 54. In addition, a vertical conduction portion 56 is provided at a corner portion of the counter substrate 30 to establish electrical continuity between the element substrate 20 and the counter substrate 30. The arrangement of the inspection circuit 53 is not limited to this, and the inspection circuit 53 may be provided at a position along the inner side of the seal material 42 between the data line driving circuit 51 and the display area E.

  In the following description, the direction along the first side where the data line driving circuit 51 is provided is defined as the X direction as the first direction, and the direction along the other two sides orthogonal to the first side and facing each other. Is the Y direction as the second direction. The X direction is a direction along the line A-A ′ in FIG. 1. The light shielding layers 22 and 26 are provided in a lattice shape along the X direction and the Y direction. The opening area of the pixel P is partitioned by the light shielding layers 22 and 26 and arranged in a lattice shape along the X direction and the Y direction.

  Further, a direction perpendicular to the X direction and the Y direction and directed upward in FIG. In this specification, viewing from the normal direction (Z direction) of the surface of the liquid crystal device 1 on the counter substrate 30 side is referred to as “plan view”.

  As shown in FIG. 2, in the display area E, the scanning lines 2 and the data lines 3 are formed so as to intersect with each other, and pixels P are provided corresponding to the intersections of the scanning lines 2 and the data lines 3. Yes. Each pixel P is provided with a pixel electrode 28 and a TFT 24 as a switching element.

  A source electrode (not shown) of the TFT 24 is electrically connected to the data line 3 extending from the data line driving circuit 51. Image signals (data signals) S1, S2,..., Sn are supplied to the data lines 3 from the data line driving circuit 51 (see FIG. 1) in a line sequential manner. A gate electrode (not shown) of the TFT 24 is a part of the scanning line 2 extending from the scanning line driving circuit 52. The scanning lines 2 are supplied with scanning signals G1, G2,..., Gm from the scanning line driving circuit 52 in a line sequential manner. A drain electrode (not shown) of the TFT 24 is electrically connected to the pixel electrode 28.

  The image signals S1, S2,..., Sn are written to the pixel electrode 28 through the data line 3 at a predetermined timing by turning on the TFT 24 for a certain period. The image signal of a predetermined level written in the liquid crystal layer 40 through the pixel electrode 28 in this manner is constant by the liquid crystal capacitance formed between the common electrode 34 (see FIG. 3) provided on the counter substrate 30. Hold for a period.

  In order to prevent the held image signals S1, S2,..., Sn from leaking, a storage capacitor 5 is formed between the capacitor line 4 formed along the scanning line 2 and the pixel electrode 28. Arranged in parallel with the liquid crystal capacitor. Thus, when a voltage signal is applied to the liquid crystal of each pixel P, the alignment state of the liquid crystal changes depending on the applied voltage level. As a result, the light incident on the liquid crystal layer 40 (see FIG. 3) is modulated to enable gradation display.

  The liquid crystal constituting the liquid crystal layer 40 modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. For example, in the normally white mode, the transmittance for incident light decreases according to the voltage applied in units of each pixel P. In the normally black mode, the transmittance for incident light increases in accordance with the voltage applied in units of each pixel P, and light having a contrast ratio corresponding to the image signal is emitted from the liquid crystal device 1 as a whole. .

  As shown in FIG. 3, the counter substrate 30 according to the first embodiment includes a microlens array substrate 10, a light shielding layer 32, a protective layer 33, a common electrode 34, and an alignment film 35. The microlens array substrate 10 according to the first embodiment includes two-stage microlenses, that is, a first-stage microlens ML1 and a second-stage microlens ML2. Both the microlens ML1 and the microlens ML2 have positive refractive power.

  The microlens array substrate 10 includes a substrate 11, a lens layer 13, an intermediate layer 14, a lens layer 15, and a planarization layer 17. The substrate 11 is made of an inorganic material having optical transparency such as glass or quartz. A surface on the liquid crystal layer 40 side of the substrate 11 is a surface 11a as a first surface. The substrate 11 has a plurality of recesses 12 formed in the surface 11a.

  Each recess 12 is provided corresponding to the pixel P. The concave portion 12 includes a flat portion 12a as a first flat portion disposed in the central portion, a curved surface portion 12b disposed around the concave portion 12, and an inclined surface 12c as a first inclined surface disposed in the peripheral portion. have. The flat portion 12a, the curved surface portion 12b, and the inclined surface 12c are formed continuously.

The lens layer 13 is formed to be thicker than the depth of the recess 12 so as to fill the recess 12 and cover the surface 11 a of the substrate 11. The lens layer 13 is made of a material having optical transparency and a light refractive index different from that of the substrate 11. In the present embodiment, the lens layer 13 is made of an inorganic material having a higher refractive index than that of the substrate 11. Examples of such inorganic materials include SiON and Al ₂ O ₃ .

  By embedding the concave portion 12 with a material forming the lens layer 13, a convex microlens ML1 is formed toward the light incident side. Each microlens ML1 is provided corresponding to the pixel P. Further, the micro lens array MLA1 is configured by the plurality of micro lenses ML1. The surface of the lens layer 13 is a flat surface that is substantially parallel to the surface 11 a of the substrate 11.

The intermediate layer 14 is formed so as to cover the lens layer 13. The intermediate layer 14 is light transmissive, and is made of, for example, an inorganic material having substantially the same refractive index as that of the substrate 11. Examples of such an inorganic material include SiO ₂ . The intermediate layer 14 has a function of adjusting the distance (optical path length) from the microlens ML1 to the microlens ML2 to a desired value. The layer thickness of the intermediate layer 14 is appropriately set based on optical conditions such as the focal length of the microlens ML1 corresponding to the wavelength of light.

  The lens layer 15 is formed so as to cover the intermediate layer 14. The lens layer 15 has a plurality of convex portions 16 formed on the liquid crystal layer 40 side. Each convex part 16 is provided corresponding to the pixel P, and is arrange | positioned so that it may overlap with each concave part 12 by planar view. The convex portion 16 includes a flat portion 16a as a second flat portion disposed at the center portion, a curved surface portion 16b (see FIG. 5) disposed around the convex portion 16 and a second inclined surface disposed at the peripheral portion. And an inclined surface 16c (see FIG. 5). The flat portion 16a, the curved surface portion 16b, and the inclined surface 16c are formed continuously. The lens layer 15 has, for example, the same refractive index as that of the lens layer 13 and is formed of the same material as that of the lens layer 13.

The planarization layer 17 is formed to be thicker than the height of the convex portions 16 so as to fill the space between the convex portions 16 and cover the lens layer 15. The planarizing layer 17 is light transmissive, and is made of, for example, an inorganic material that is lower than the lens layer 15 and has substantially the same optical refractive index as the substrate 11. Examples of such an inorganic material include SiO ₂ . By covering the convex portion 16 of the lens layer 15 with the flattening layer 17, a microlens ML2 having a convex shape is formed toward the light emission side. Each microlens ML2 is provided corresponding to the pixel P. Further, a microlens array MLA2 is configured by the plurality of microlenses ML2.

  The planarization layer 17 has a function of adjusting a distance (optical path length) from the microlens ML2 to the light shielding layer 26 to a desired value. The layer thickness of the planarizing layer 17 is appropriately set based on optical conditions such as the focal length of the microlens ML2 corresponding to the wavelength of light. The surface of the planarization layer 17 is a substantially flat surface.

  The light shielding layer 32 is provided on the microlens array substrate 10 (flattening layer 17). The light shielding layer 32 is provided so as to surround the display area E (see FIG. 1) where the microlens ML1 and the microlens ML2 are arranged. The light shielding layer 32 is formed of, for example, a metal or a metal compound. The light shielding layer 32 may be provided in the display area E so as to overlap the light shielding layer 22 and the light shielding layer 26 of the element substrate 20 in a plan view. In this case, the light shielding layer 32 may be formed in a lattice shape, an island shape, a stripe shape, or the like, but is preferably disposed in a narrower range than the light shielding layer 22 and the light shielding layer 26 in a plan view.

  A protective layer 33 is provided so as to cover the microlens array substrate 10 (planarization layer 17) and the light shielding layer 32. The common electrode 34 is provided so as to cover the protective layer 33. The common electrode 34 is formed across a plurality of pixels P. The common electrode 34 is made of a transparent conductive film such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). The protective layer 33 covers the light shielding layer 32 so that the surface of the common electrode 34 on the liquid crystal layer 40 side is flat, but directly covers the conductive light shielding layer 32 without providing the protective layer 33. The common electrode 34 may be formed. The alignment film 35 is provided so as to cover the common electrode 34.

  The element substrate 20 includes a substrate 21, a light shielding layer 22, an insulating layer 23, a TFT 24, an insulating layer 25, a light shielding layer 26, an insulating layer 27, a pixel electrode 28, and an alignment film 29. . The substrate 21 is made of a light transmissive material such as glass or quartz.

  The light shielding layer 22 is provided on the substrate 21. The light shielding layer 22 is formed in a lattice shape so as to overlap the upper light shielding layer 26 in plan view. The light shielding layer 22 and the light shielding layer 26 are formed of, for example, a metal or a metal compound. The light shielding layer 22 and the light shielding layer 26 are disposed so as to sandwich the TFT 24 therebetween in the thickness direction (Z direction) of the element substrate 20. The light shielding layer 22 overlaps at least the channel region of the TFT 24 in plan view.

  Since the light shielding layer 22 and the light shielding layer 26 are provided, the incidence of light on the TFT 24 is suppressed, so that an increase in light leakage current in the TFT 24 and malfunction due to light can be suppressed. The light shielding layer 22 is composed of the light shielding layer 22 and the light shielding layer 26. The region surrounded by the light shielding layer 22 (inside the opening 22a) and the region surrounded by the light shielding layer 26 (inside the opening 26a) overlap each other in plan view, and light is transmitted through the region of the pixel P. Opening T

The insulating layer 23 is provided so as to cover the substrate 21 and the light shielding layer 22. The insulating layer 23 is made of an inorganic material such as SiO ₂ .

  The TFT 24 is provided on the insulating layer 23 and is disposed in a region overlapping the light shielding layer 22 and the light shielding layer 26 in plan view. The TFT 24 is a switching element that drives the pixel electrode 28. The TFT 24 includes a semiconductor layer, a gate electrode, a source electrode, and a drain electrode (not shown). A source region, a channel region, and a drain region are formed in the semiconductor layer. An LDD (Lightly Doped Drain) region may be formed at the interface between the channel region and the source region or between the channel region and the drain region.

  The gate electrode is formed on the element substrate 20 in a region overlapping with the channel region of the semiconductor layer in plan view via a part (gate insulating film) of the insulating layer 25. Although not shown, the gate electrode is electrically connected to the scanning line disposed on the lower layer side through a contact hole, and the TFT 24 is controlled to be turned on / off by applying a scanning signal.

The insulating layer 25 is provided so as to cover the insulating layer 23 and the TFT 24. The insulating layer 25 is made of an inorganic material such as SiO ₂ , for example. The insulating layer 25 includes a gate insulating film that insulates between the semiconductor layer of the TFT 24 and the gate electrode. The insulating layer 25 relieves surface irregularities caused by the TFT 24. A light shielding layer 26 is provided on the insulating layer 25. An insulating layer 27 made of an inorganic material is provided so as to cover the insulating layer 25 and the light shielding layer 26.

  The pixel electrode 28 is provided on the insulating layer 27 corresponding to the pixel P. The pixel electrode 28 is disposed in a region overlapping the opening 22 a of the light shielding layer 22 and the opening 26 a of the light shielding layer 26 in plan view. The pixel electrode 28 is made of a transparent conductive film such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). The alignment film 29 is provided so as to cover the pixel electrode 28. The liquid crystal layer 40 is sealed between the alignment film 29 on the element substrate 20 side and the alignment film 35 on the counter substrate 30 side.

  Although not shown, an electrode, wiring, relay electrode, and storage capacitor 5 (see FIG. 2) for supplying an electrical signal to the TFT 24 are provided in a region overlapping the light shielding layer 22 and the light shielding layer 26 in plan view. A capacitive electrode or the like is provided. The light shielding layer 22 and the light shielding layer 26 may be configured to include these electrodes, wiring, relay electrodes, capacitor electrodes, and the like.

  In the liquid crystal device 1 according to the first embodiment, for example, light emitted from a light source or the like is incident from the counter substrate 30 (substrate 11) side including the microlenses ML1 and ML2. In the following, the normal direction of the surface of the counter substrate 30 (substrate 11) is simply referred to as “normal direction”. The “normal direction” is a direction along the Z direction in FIG. 3 and is substantially the same as the normal direction of the element substrate 20 (substrate 21). In the present specification, light parallel to the normal direction is referred to as “parallel light”, and light inclined (with an angle) with respect to the normal direction is referred to as “oblique light”.

  Of the incident light, the parallel light L1 incident on the central portion (flat portion 12a) of the microlens ML1 along the normal direction travels straight without being refracted and goes to the central portion (flat portion 16a) of the microlens ML2. ). The light L1 is emitted from the microlens ML2 as parallel light without being refracted, passes through the liquid crystal layer 40, passes through the opening T of the pixel P, and is emitted toward the element substrate 20 side.

  On the other hand, when the entire first-stage microlens is formed of a curved surface portion as in the microlens array substrate described in Patent Document 1, the light L1 is centered on the first-stage microlens. Even if such parallel light is incident, it is condensed (refracted) toward the center of the microlens and becomes oblique light, which is incident on the second-stage microlens. Therefore, even if the light incident on the microlens array substrate is parallel light, more oblique light is incident on the liquid crystal layer than the microlens array substrate 10 of the present embodiment.

  If the parallel light L2 incident on the peripheral edge (curved surface 12b) of the microlens ML1 travels straight as it is, it is shielded by the light shielding layer 26 as indicated by the broken line. However, the light L2 is refracted toward the center side of the microlens ML1 from the optical path indicated by the broken line due to the difference in optical refractive index (positive refractive power) between the substrate 11 and the lens layer 13, and enters the microlens ML2. To do. The light L2 incident on the microlens ML2 is further refracted toward the center of the microlens ML2 due to the difference in optical refractive index (positive refractive power) between the lens layer 15 and the planarizing layer 17, and the pixel P Through the opening T and injected toward the element substrate 20.

  If the parallel light L3 incident on the peripheral edge (inclined surface 12c) of the microlens ML1 goes straight as it is, it is shielded by the light shielding layer 32 as indicated by the broken line. Due to the difference in optical refractive index between them, the light is refracted toward the center side of the microlens ML1 and enters the microlens ML2. The light L3 incident on the microlens ML2 is further refracted toward the center of the microlens ML2 due to the difference in optical refractive index between the lens layer 15 and the planarizing layer 17, and passes through the opening T of the pixel P. It passes through and is emitted to the element substrate 20 side.

  Note that the light incident on the inclined surface 12c of the microlens ML1 is refracted toward the center of the microlens ML1 at approximately the same angle if the incident angles are approximately the same. Therefore, as compared with the case where the entire microlens ML1 is configured by a curved surface portion, excessive refraction of incident light is suppressed, and variation in angle of light incident on the liquid crystal layer 40 is suppressed.

  As described above, in the liquid crystal device 1, the light L2 and L3 that are blocked by the light blocking layer 32 and the light blocking layer 26 when traveling straight as they are are opened by the action of the two-stage microlenses ML1 and ML2. The light can be refracted toward the center of T and pass through the opening T. As a result, since the amount of light emitted from the element substrate 20 side can be increased, the light utilization efficiency can be increased.

  Then, compared to the case where the entire microlens ML1 is formed of a curved surface portion, the parallel light incident on the central portion (flat portion 12a) of the microlens ML1 is directly advanced as it is and the central portion (flat portion 16a) of the microlens ML2. ) Is transmitted, the amount of parallel light passing through the opening T of the pixel P can be increased. Further, the inclined surface 12c of the microlens ML1 suppresses excessive refraction of incident light and variation in refraction angle. As a result, the variation in the angle of the light transmitted through the liquid crystal layer 40 with respect to the alignment direction of the liquid crystal molecules can be reduced, so that the contrast ratio of the image displayed on the liquid crystal device 1 can be improved.

  As described above, in the liquid crystal device 1 including the microlens array substrate 10 according to the first embodiment, it is possible to achieve both improvement in light utilization efficiency and improvement in contrast ratio. In addition, when the liquid crystal device 1 is used as a liquid crystal light valve of a projector, vignetting of light incident on the projection lens can be suppressed by suppressing oblique light, and light use efficiency and contrast ratio in the projector can be improved. Can do.

  When the intermediate layer 14 is made of a material having a lower optical refractive index than the lens layer 13 and the lens layer 15, the interface between the lens layer 13 and the intermediate layer 14, and the intermediate layer 14 and the lens layer 15 Light refraction also occurs at the interface. However, the refraction of light at these interfaces is slight compared to the refraction of light by the microlenses ML1 and ML2, and can be ignored.

<Microlens array substrate>
Next, the shape and arrangement of the light shielding unit and the microlenses ML1 and ML2 of the liquid crystal device according to the first embodiment will be described with reference to FIG. FIG. 4 is a schematic plan view showing the shape and arrangement of the light shielding portion and the microlens of the liquid crystal device according to the first embodiment. FIG. 5 is a schematic cross-sectional view showing the configuration of the microlens array substrate according to the first embodiment. Specifically, FIG. 5 is a schematic cross-sectional view along the line BB ′ in FIG.

  4 and 5 show one pixel P. FIG. The pixel P has a substantially rectangular planar shape. FIG. 4 shows an example in which the planar shape of the pixel P is a square. The plurality of pixels P having such a shape are arranged in a grid pattern at a predetermined arrangement pitch LP so that adjacent pixels P in the X direction and the Y direction are in contact with each other. Therefore, the length of one side of the pixel P is LP.

  A straight line connecting lattice points (vertices) at diagonal positions to each other in the pixels P arranged in a lattice shape, that is, a direction along the diagonal line is defined as a W direction. The W direction is a direction intersecting the X direction and the Y direction on a plane constituted by the X direction and the Y direction. Note that the B-B ′ line in FIG. 4 is a line along the W direction. The length of the diagonal line of the pixel P (hereinafter referred to as the diagonal length) is defined as LD. When the planar shape of the pixel P is a square, LD = √2LP.

  The light shielding portion S is provided in a lattice shape in which a portion extending in the X direction and a portion extending in the Y direction intersect so as to extend along the boundary between adjacent pixels P in the X direction and the Y direction. The light shielding portion S includes a light shielding layer 22 and a light shielding layer 26. In the example illustrated in FIG. 4, it is assumed that the light shielding portion S extends with the same width LB in the X direction and also extends with the same width LB in the Y direction.

  The light shielding portion S has an opening T corresponding to each of the plurality of pixels P. The opening T is a region where the opening 22a and the opening 26a overlap in a plan view, and has a substantially rectangular outline. Of the region of each pixel P, a region that overlaps the light shielding portion S in plan view is a non-opening region that does not transmit light, and a region that overlaps the opening T in plan view is an opening region that transmits light. The TFT 24 (see FIG. 3) is disposed in a region overlapping the light shielding portion S in plan view. In the example shown in FIG. 4, the width of the opening T is LP-LB.

  The microlens ML1 (concave portion 12) and the microlens ML2 (convex portion 16) are arranged at the same arrangement pitch LP corresponding to the pixels P. The microlens ML1 (concave portion 12) and the microlens ML2 (convex portion 16) are arranged so as to overlap each other and the opening T of the pixel P in plan view. The microlens ML1 (concave portion 12) and the microlens ML2 (convex portion 16) are both inscribed in the pixel P.

  The boundary between the microlenses ML1 and ML2 adjacent in the X direction and the Y direction is arranged in a region overlapping the portion extending in the X direction and the portion extending in the Y direction of the light shielding portion S in plan view. The microlenses ML1 (concave portions 12) and the microlenses ML2 (convex portions 16) that are adjacent in the X direction and the Y direction are connected to each other. Therefore, since more light enters the microlens ML1, more light can enter the microlens ML2. The adjacent microlenses ML1 (concave portions 12) and the microlenses ML2 (convex portions 16) are separated from each other in the direction along the diagonal line (W direction).

  The planar shape of the microlens ML1 (recessed portion 12) is a substantially rectangular shape with rounded four corners, but is virtually a circular shape that is smaller than the circumscribed circle of the pixel P and larger than the inscribed circle. When the diameter of the micro lens ML1 (the diameter of the virtual circle of the concave portion 12) is L2, the diameter L2 is desirably 95% or less of the diagonal length LD and larger than the arrangement pitch LP. Since the microlenses ML1 adjacent in the X direction and the Y direction are connected to each other, the width of the microlens ML1 in the X direction and the Y direction is equal to the arrangement pitch LP.

  The larger the diameter L2 of the micro lens ML1, the more light that is blocked by the light blocking portion S can be made incident into the opening T. Therefore, the diameter L2 is preferably larger than the arrangement pitch LP that is the diameter of the inscribed circle of the pixel P. However, if the diameter L2 is equal to or greater than the diagonal length LD that is the diameter of the circumscribed circle of the pixel P, the mask layer 72 (see FIG. 7D) is likely to float in the etching process for forming the recess 12 described later. Become. Accordingly, it is desirable that the diameter L2 is smaller than the diagonal length LD, more specifically, 95% or less of the diagonal length LD.

  The concave portion 12 includes a flat portion 12a disposed in the central portion, a curved surface portion 12b (see FIG. 5) disposed around the flat portion 12a, and an inclined surface 12c (see FIG. 5) disposed around the curved surface portion 12b. ). The flat portion 12a and the curved surface portion 12b are formed concentrically with a virtual outer shape (circular shape) of the concave portion 12. When the diameter of the flat portion 12a (the diameter of the circle) is L1, the diameter L1 is preferably larger than the maximum width of the openings T and not more than the arrangement pitch LP. In the example shown in FIG. 4, the width of the portion extending in the X direction and the portion extending in the Y direction of the light shielding portion S is LB, and the maximum width (= minimum width) of the opening T is LP-LB. Therefore, LP ≧ L1> (LP−LB).

  Since the incident parallel light passes through the flat portion 12a without being refracted, it is preferable to make the region of the flat portion 12a as large as possible. However, as described above, when the diameter L2 of the microlens ML1 is set to 95% or less of the diagonal length LD, if the area of the flat portion 12a is too large, the curved surface portion 12b and the inclined surface 12c of the microlens ML1 (recessed portion 12). The area becomes relatively small. As a result, the amount of light that is incident on the peripheral edge of the microlens ML1 and is refracted toward the center of the opening T decreases, and as a result, the light that is blocked by the light blocking portion S increases. A region in which light at the peripheral portion is refracted while the diameter L1 of the flat portion 12a is larger than the maximum width of the openings T and is equal to or smaller than the arrangement pitch LP, thereby increasing the region through which parallel light is transmitted as it is. Can be secured.

  The planar shape of the microlens ML2 (convex portion 16) is a substantially rectangular shape with rounded four corners, but may be virtually circular. The region of the microlens ML2 (convex portion 16) is included in the region of the microlens ML1 (concave portion 12) and includes the region of the flat portion 12a of the microlens ML1 (concave portion 12). When the diameter of the microlens ML2 (diameter when the virtual outer shape of the convex portion 16 is a circle or the length in the diagonal direction when the virtual outer shape of the convex portion 16 is a rectangle) is L3, the diameter L3 is the microlens ML1 (concave portion 12). And a diameter L1 or more of the flat portion 12a.

  Since the region of the micro lens ML2 (convex portion 16) is included in the region of the micro lens ML1 (concave portion 12), only the light transmitted through the micro lens ML1 is incident on the micro lens ML2. Further, since the region of the micro lens ML2 (convex portion 16) includes the region of the flat portion 12a of the micro lens ML1, all the parallel light transmitted through the flat portion 12a is incident on the micro lens ML2. Since the microlenses ML2 adjacent in the X direction and the Y direction are connected to each other, the width of the microlens ML2 in the X direction and the Y direction is equal to the arrangement pitch LP.

  The convex portion 16 includes a flat portion 16a disposed at the center portion, a curved surface portion 16b (see FIG. 5) disposed around the flat portion 16a, and an inclined surface 16c disposed around the curved surface portion 16b (FIG. 5). Reference). The flat portion 16a and the curved surface portion 16b are formed in a substantially circular concentric shape. When the diameter (circle diameter) of the flat portion 16a is L4, the diameter L4 is equal to or less than the maximum width of the opening T (difference between the arrangement pitch LP and the minimum width of the light shielding portion S) and the minimum width of the opening T. It is desirable that the difference be greater than or equal to (the difference between the arrangement pitch LP and the maximum width of the light shielding portion S).

  In the flat portion 16a, parallel light incident through the flat portion 12a is transmitted without being refracted, so that the flat portion 16a and the opening T overlap with each other while avoiding the overlap between the flat portion 16a and the light shielding portion S. It is desirable to maximize In the example shown in FIG. 4, the width of the portion extending in the X direction and the portion extending in the Y direction of the light shielding portion S is LB, and the maximum width (= minimum width) of the opening T is LP-LB. Therefore, it is desirable that L4 = LP−LB.

  As shown in FIG. 5, the cross-sectional shapes of the microlens ML <b> 1 (concave portion 12) and the microlens ML <b> 2 (convex portion 16) are substantially trapezoids with rounded corners. The flat part 12 a is the bottom part of the concave part 12, and the flat part 16 a is the upper bottom part of the convex part 16. When the depth of the concave portion 12, that is, the thickness of the microlens ML1, is E1, and the height of the convex portion 16, that is, the thickness of the microlens ML2, is E2, the thickness E2 of the microlens ML2 is equal to that of the microlens ML1. It is smaller than the thickness E1.

  The thicknesses E1 and E2, the diameters L2 and L3, the diameters L1 and L4 of the flat portions 12a and 16a, the angles of the inclined surfaces 12c and 16c, the optical refractive indexes of the lens layers 13 and 15, the intermediate layer 14 and the flattening. The layer thickness of the layer 17 and the like are appropriately set based on optical characteristics required for the microlenses ML1 and ML2 according to the type and characteristics of the light source, the shape of the light-shielding portion S, and the like.

  FIG. 5 shows, as a comparative example with respect to the present embodiment, a recess 92 formed in a curved surface shape (semispherical surface) with a diameter L2 by a two-dot chain line. When the depth of the recess 92 is E3, the depth (thickness of the microlens ML1) E1 of the recess 12 having the flat portion 12a is smaller than the depth E3 of the recess 92. In the example shown in FIG. 5, the concave portion 92 is hemispherical and E3 = L2 / 2. However, even if E3 <L2 / 2, if the concave portion 92 is curved, the depth E1 of the concave portion 12 is E3. Smaller than. Similarly, the height (thickness of the microlens ML2) E2 of the convex portion 16 having the flat portion 16a is also smaller than the height of the convex portion when formed in a curved shape with the diameter L3.

  As described above, in the microlens configured by the curved concave portion 92, the incident parallel light is condensed (refracted) toward the optical axis passing through the planar center of the concave portion 92. Therefore, in the microlens configured by the curved concave portion 92, more oblique light is refracted and emitted by the microlens than the microlens ML1 having the flat portion 12a in which the incident parallel light advances straight as it is.

  By the way, the microlens plays a role of improving the light use efficiency in the liquid crystal device by refracting the light that is blocked out of the light incident on the liquid crystal device and passing the light through the opening T of the pixel P. However, when the degree of condensing by the microlens is strong, a large amount of oblique light is generated due to refraction. As a result, even if the oblique light is shielded by the light shielding layer or passes through the opening T, the projection lens causes There are cases where the desired light use efficiency cannot be obtained due to kicking.

  Further, the oblique light is also generated by the diffraction of light incident on the microlens, and the more the diffracted light is, the more oblique light is generated. FIG. 6 is a diagram illustrating a simulation result of diffracted light generated by the microlens. FIG. 6 shows a simulation result using a one-stage microlens.

  In FIG. 6, the horizontal axis represents the phase depth (Δnd / λ). Δn is the difference in optical refractive index between the substrate and the lens layer, d is the thickness of the microlens (the depth of the recess), and λ is the wavelength of light. The phase depth (Δnd / λ) is a numerical value indicating the phase difference between light transmitted through a microlens having a certain thickness d and light not transmitted through the microlens. It is a phase, and if this value is 0.5, it indicates that the phase is opposite. The vertical axis represents the intensity of the diffracted light, and the relative intensities of the first-order diffracted light DL1, the second-order diffracted light DL2, and the third-order diffracted light DL3 with reference to the light emitted from the microlens in the normal direction (0th order light). Is shown.

  As shown in FIG. 6, the relative intensities of the first-order diffracted light DL1, the second-order diffracted light DL2, and the third-order diffracted light DL3 change according to the phase difference, but as the phase depth (Δnd / λ) increases, that is, The microlens thickness (depth of the recess) tends to increase as the thickness d increases. In other words, the greater the thickness (the depth of the recess) d of the microlens, the more diffracted light is generated, and the more oblique light is caused by diffraction.

  Although illustration is omitted, in the simulation result of the diffracted light generated by the microlens having a diameter different from that in the example shown in FIG. 6, the larger the microlens thickness (recess depth) d, the more diffracted light. The results that occur are obtained. In addition, among microlenses having different diameters, the thickness (the depth of the concave portion) d of the microlens increases as the diameter increases. Therefore, the larger the diameter, the more diffracted light is generated. Therefore, in order to reduce oblique light due to diffraction, it is desirable to make the thickness d of the microlens as small as possible.

  Returning to FIG. 5, in the microlens ML <b> 1 according to the present embodiment, the depth E <b> 1 of the recess 12 having the flat portion 12 a is smaller than that of the microlens configured by the curved recess 92 shown by the two-dot chain line. Therefore, the oblique light caused by diffraction can be reduced. Further, in the microlens ML1, since the concave portion 12 has the inclined surface 12c, the microlens ML1 (recessed portion) is compared with the case where the curved surface portion 12b is continuous to the surface 11a of the substrate 11 without the inclined surface 12c. Since the average thickness (depth) in the region 12) can be reduced, oblique light caused by diffraction can be further suppressed.

  And also about the micro lens ML2, since the convex part 16 has the flat part 16a and the inclined surface 16c similarly to micro lens ML1, the diagonal light resulting from a diffraction can be decreased. Further, since the thickness (height of the convex portion 16) E2 of the microlens ML2 is smaller than the thickness (depth of the concave portion 12) E1 of the microlens ML1, the microlens ML2 is caused by diffraction more than the microlens ML1. Diagonal light can be suppressed.

  As described above, in the microlens array substrate 10 according to this embodiment, since the microlenses ML1 and ML2 both have the flat portions 12a and 16a, the thicknesses E1 and E2 are suppressed to be small. On the other hand, oblique light generated by diffraction can be reduced. As described above, since both the microlenses ML1 and ML2 have the flat portions 12a and 16a, the parallel light incident on the central portion can be transmitted as it is, so that oblique light caused by refraction is also reduced. be able to.

  Therefore, in the microlens array substrate 10 according to the present embodiment, as compared with the case where the entire microlens ML1 is configured by a curved surface portion as in the microlens array substrate described in Patent Document 1, the oblique light generated by refraction is reduced. Since the oblique light generated by the diffraction is reduced, the light use efficiency in the liquid crystal device 1 can be further improved. And since the parallel light which injects into a center part is transmitted as it is, and the dispersion | variation in the angle of light is suppressed, the contrast ratio of the liquid crystal device 1 can be improved.

<Manufacturing method of microlens array substrate>
Next, a method for manufacturing the microlens array substrate 10 according to the first embodiment will be described. 7, 8, 9, and 10 are schematic cross-sectional views illustrating a method for manufacturing a microlens array substrate according to the first embodiment. Specifically, each of FIGS. 7, 8, 9, and 10 corresponds to a schematic cross-sectional view taken along the line BB ′ of FIG. 4, and is different from the cross-sectional views shown in FIGS. The direction (Z direction) is reversed.

First, as shown in FIG. 7A, a control film 70 made of an oxide film such as SiO ₂ is formed on the surface 11a of the light-transmitting substrate 11 made of quartz or the like. The control film 70 has an etching rate different from that of the substrate 11 in isotropic etching, and the width direction (W direction shown in FIG. 4) with respect to the etching rate in the depth direction (Z direction) when the recess 12 is formed. A function of adjusting the etching rate in the X direction and the Y direction).

  After forming the control film 70, the control film 70 is annealed at a predetermined temperature. The etching rate of the control film 70 varies depending on the annealing temperature. Therefore, the etching rate of the control film 70 can be adjusted by appropriately setting the temperature during annealing.

  Next, as shown in FIG. 7B, a mask layer 72 is formed on the control film 70. Then, the mask layer 72 is patterned to form openings 72 a in the mask layer 72. The opening 72a is substantially circular in a plan view like the flat portion 12a in the recess 12 to be formed, and its diameter is set to be substantially the same as the diameter L1 of the flat portion 12a. In other words, the shape and diameter L1 of the flat portion 12a in the recess 12 to be formed are determined by the shape and diameter of the opening 72a of the mask layer 72 (see FIG. 7C).

  Next, as shown in FIG. 7C, isotropic etching is performed on the substrate 11 covered with the control film 70 through the opening 72 a of the mask layer 72. For the isotropic etching, an etching solution (for example, hydrofluoric acid solution) is used such that the etching rate of the control film 70 is larger than the etching rate of the substrate 11. The control film 70 and the substrate 11 are etched from the opening 72 a by isotropic etching, so that the opening 70 a is formed in the control film 70 and the recess 12 is formed in the substrate 11. The portion overlapping the opening 72a of the mask layer 72 in the center (bottom) of the recess 12 in a plan view is the flat portion 12a.

  Next, as shown in FIG. 7D, the concave portion 12 is enlarged as the isotropic etching progresses, and a curved surface portion 12b and an inclined surface 12c are formed so as to surround the flat portion 12a. Here, when the control film 70 is not provided between the substrate 11 and the mask layer 72, the curved surface portion 12b is formed until it reaches the surface 11a of the substrate 11, as indicated by a broken line in FIG. Will be. In this embodiment, the control film 70 is provided between the substrate 11 and the mask layer 72, and the etching amount per unit time of the control film 70 in the isotropic etching is larger than the etching amount per unit time of the substrate 11. There are also many.

  Therefore, since the amount of expansion of the opening 70a of the control film 70 is larger than the amount of expansion of the recess 12 in the depth direction, the width direction of the recess 12 is also expanded as the opening 70a is expanded. Therefore, the etching amount per unit time in the width direction of the substrate 11 is larger than the etching amount per unit time in the depth direction. Thereby, the tapered inclined surface 12c is formed so as to surround the curved surface portion 12b.

  As described above, the shape and diameter L1 of the flat portion 12a can be controlled by the shape and diameter of the opening 72a of the mask layer 72. Further, the diameter L2 of the recess 12, the angle of the inclined surface 12c, and the depth E1 of the recess 12 are controlled by the etching rate in the width direction and the etching time with respect to the etching rate in the depth direction of the substrate 11, and the difference between the etching rates. Can be adjusted by setting the temperature of the control film 70 during annealing.

  In this step, the recesses 12 adjacent in the X direction and the Y direction are connected to each other, and the surface 11a of the substrate 11 is left between the recesses 12 adjacent in the W direction, more specifically, The isotropic etching is completed when the diameter L2 of the recess 12 is 95% or less of the diagonal length LD (see FIG. 4).

  If isotropic etching is performed until the recesses 12 adjacent in the W direction are connected to each other, the mask layer 72 may be lifted off from the substrate 11 and peeled off. In this embodiment, since the diameter L2 of the recess 12 is 95% or less of the diagonal length LD and the surface 11a of the substrate 11 remains between the adjacent recesses 12, the isotropic etching is finished. The mask layer 72 can be supported until the isotropic etching is completed. Thereby, the planar shape of the recessed part 12 becomes a substantially rectangular shape with rounded corners at four corners (see FIG. 4).

  The virtual planar shape of the recessed portion 12 to be formed is a circular shape in which the planar shape of the opening 72a of the mask layer 72 is enlarged, but the recessed portions 12 adjacent to each other in the X direction and the Y direction are connected to each other. The planar shape of 12 is a substantially rectangular shape with rounded corners at the four corners.

  Next, as shown in FIG. 8A, after removing the mask layer 72 from the substrate 11, the substrate 11 has a light transmissive property so as to cover the surface 11 a side of the substrate 11 and embed the recess 12. The lens material layer 13a is formed by depositing an inorganic material having a high refractive index. The lens material layer 13a can be formed using, for example, a CVD method. The microlens ML1 is configured by embedding the concave portion 12 with the lens material layer 13a. Since the lens material layer 13 a is formed so as to embed the recess 12, the surface of the lens material layer 13 a has an uneven shape reflecting the unevenness caused by the recess 12 of the substrate 11.

  Subsequently, a planarization process is performed on the lens material layer 13a. In the planarization process, for example, a CMP (Chemical Mechanical Polishing) process or the like is used to polish a portion where the surface irregularities of the lens material layer 13a are formed (a portion above the two-dot chain line shown in FIG. 8A). As a result, the surface of the lens material layer 13a is flattened. As a result of the flattening process, as shown in FIG. 8B, a lens layer 13 having a flattened surface is obtained.

  Although not shown, in a conventional microlens having a curved concave portion formed by etching, an opening smaller than that of the present embodiment is formed in the mask layer, and the substrate isotropic through the opening. By performing the etching process, the substrate is etched into a substantially spherical shape to form a curved concave portion. At this time, when the diameter of the concave portion to be formed is the same as the maximum diameter (the diameter in the W direction) of the concave portion 12 of the present embodiment, the depth of the curved concave portion is larger than the depth of the concave portion 12 of the present embodiment. Become deeper.

  In particular, when the arrangement pitch of the pixels P is increased, the diameter and depth of the recesses are increased corresponding to the arrangement pitch of the pixels P. Therefore, compared to the present embodiment, the amount of etching of the substrate and the amount of deposition of the material of the lens layer for filling the recesses increase, and the level difference on the surface of the lens layer also increases, so the amount of polishing in the CMP processing step also increases. As a result, man-hours in these processes are increased.

  According to the configuration of the microlens ML <b> 1 according to the present embodiment, the flat portion 12 a is provided in the central portion of the concave portion 12, so that the depth of the concave portion 12 becomes shallow. Therefore, etching, CVD in the manufacturing process of the microlens array substrate 10 is performed. Further, the number of steps such as CMP processing and the amount of the lens material layer 13a used can be reduced. Further, since the thickness of the deposited lens material layer 13a becomes more uniform and the uneven shape of the surface becomes smaller, the flatness of the surface of the lens material layer 13a can be improved.

  Next, as shown in FIG. 8C, an intermediate layer 14 is formed by depositing an inorganic material having light transmittance and a light refractive index similar to that of the substrate 11 so as to cover the lens layer 13. To do. Then, a lens material layer 15 a is formed by depositing an inorganic material having light transmittance and a higher light refractive index than the substrate 11 so as to cover the surface of the intermediate layer 14. The intermediate layer 14 and the lens material layer 15a can be formed using, for example, a CVD method.

  Next, as shown in FIG. 8D, a resist layer 74 is formed on the lens material layer 15a. The resist layer 74 is formed of, for example, a positive photosensitive resist whose exposed portion is removed by development. The resist layer 74 can be formed by, for example, a spin coat method or a roll coat method. Then, the resist layer 74 is exposed and developed through a mask layer 76 provided with a light shielding portion corresponding to the position where the convex portion 16 is formed.

  By exposing and developing the resist layer 74, as shown in FIG. 9A, regions other than the region overlapping the light shielding portion of the mask layer 76 are exposed and removed in the resist layer 74, and the subsequent steps. Thus, the convex portion 75 remains corresponding to the position where the convex portion 16 is formed. The remaining convex portions 75 are separated from each other in the X direction, the Y direction, and the W direction.

  Next, the remaining convex portion 75 in the resist layer 74 is softened (melted) by performing a heat treatment such as a reflow treatment. The molten convex part 75 becomes a fluid state, and the surface is deformed into a curved surface by the action of surface tension. As a result, as shown in FIG. 9B, the cross-sectional shape of the convex portion 75 remaining on the lens material layer 15a becomes a substantially elliptical spherical shape. The bottom side (lens material layer 15a side) of the convex part 75 after deformation has a substantially rectangular shape with four corners rounded in plan view, but the top part side (upward) of the substantially elliptical spherical shape of the convex part 75. Is substantially concentric in plan view.

  Here, since the fluidity of the melted convex portion 75 increases as the temperature of the heat treatment increases, the cross section (substantially elliptical spherical shape) of the convex portion 75 becomes flatter, and the convex shape increases as the temperature of the heat treatment decreases. Since the fluidity of the part 75 becomes small, the cross-section (substantially elliptical spherical shape) becomes a curved surface with a raised shape. The shape of the convex portion 75 is the basis of the shape of the convex portion 16 formed in a later step. Therefore, the convex portion 75 is controlled by controlling the shape of the convex portion 75 according to the size of the light shielding portion in the mask layer 76 (see FIG. 8D) when the resist layer 74 is exposed and the temperature of the heat treatment. The diameter L3 of 16, the diameter L4 of the flat part 16a, and the height E2 of the convex part 16 can be adjusted.

  Next, as shown in FIG. 9C, anisotropic etching such as dry etching is performed on the convex portion 75 and the lens material layer 15a from above. Thereby, the convex portion 75 is gradually removed, and the exposed portion of the lens material layer 15a is etched along with the removal of the convex portion 75. As a result, the shape of the convex portion 75 is transferred to the lens material layer 15a to form the convex portion 15b.

  In this anisotropic etching, if the etching conditions are such that the etching rate of the material (resist) of the convex portion 75 and the etching rate of the lens material layer 15a are substantially the same, the convex portion 75 and the convex portion 15b are substantially the same. It becomes the same shape. In the present embodiment, the inclined surface 15c is formed on the intermediate layer 14 side of the convex portion 15b by adjusting the etching amount in the width direction in accordance with the progress of anisotropic etching. The inclined surface 15c is preferably tapered, but may be a curved surface having a radius of curvature larger than the radius of curvature of the top of the convex portion 15b.

  Next, as shown in FIG. 10A, the same material as the convex portion 15b (lens material layer 15a) is further deposited so as to cover the intermediate layer 14 and the convex portion 15b by using, for example, a CVD method. Thereby, the lens layer 15 which has the convex part 16 corresponding to the convex part 15b is formed. The convex portion 16 has a substantially similar shape in which the convex portion 15b is enlarged. Therefore, an inclined surface 16c is formed on the convex portion 16 at a position corresponding to the inclined surface 15c.

  Next, as shown in FIG. 10B, the top portion of the convex portion 16 is polished and removed by using a CMP process or the like, whereby the flat portion 16a is formed on the top portion of the convex portion 16, and the flat portion 16a. And the inclined surface 16c is a curved surface portion 16b. The diameter L3 and the thickness E2 of the convex portion 16 shown in FIG. 5 can be controlled by the shape of the convex portion 75 serving as a base and the thickness of the lens material deposited on the convex portion 15b. The diameter L4 of the flat portion 16a can be controlled by the shape of the convex portion 75 serving as a base and the polishing amount of the convex portion 16. The angle of the inclined surface 16c can be controlled by adjusting the shape of the base convex portion 75 and adjusting the etching amount in the width direction in anisotropic etching.

  When the resist layer 74 is exposed, for example, by setting an exposure condition such that the exposure amount decreases toward the lower side, the cross-sectional shape of the remaining convex portion 75 may be substantially trapezoidal. Further, the convex portion 75 is formed to be approximately the same size as the convex portion 16 by increasing the light shielding portion of the mask layer 76, and the convex portion 16 is formed by adjusting the etching amount of the lens material layer 15a in anisotropic etching. By forming, the step of further depositing the lens material shown in FIG. 10A may be omitted.

  Next, as shown in FIG. 10C, the planarization layer 17 is formed so as to cover the lens layer 15 and fill the spaces between the convex portions 16, and the surface of the planarization layer 17 is planarized. . The microlens ML <b> 2 is configured by covering the convex portion 16 with the planarizing layer 17. As described above, the microlens array substrate 10 is completed.

  After the microlens array substrate 10 is completed, a light shielding layer 32, a protective layer 33, a common electrode 34, and an alignment film 35 are sequentially formed on the microlens array substrate 10 to face each other using a known technique. A substrate 30 is obtained. Further, a known method is sequentially applied to the light shielding layer 22, the insulating layer 23, the TFT 24, the insulating layer 25, the light shielding layer 26, the insulating layer 27, the pixel electrode 28, and the alignment film 29 on the substrate 21. The element substrate 20 is obtained by forming using them.

  Subsequently, the element substrate 20 and the counter substrate 30 are positioned, and a thermosetting or photocurable adhesive is disposed between the element substrate 20 and the counter substrate 30 as a sealing material 42 (see FIG. 1) and cured. Let them stick together. The liquid crystal device 1 is completed by enclosing and sandwiching liquid crystal in a space formed by the element substrate 20, the counter substrate 30, and the sealing material 42. Before the element substrate 20 and the counter substrate 30 are bonded together, the liquid crystal may be disposed in a region surrounded by the sealant 42.

(Second Embodiment)
<Electro-optical device>
The liquid crystal device according to the second embodiment has substantially the same configuration as the first embodiment except that the planar shape of the light shielding portion S is different. For example, when the planar shape and arrangement of the TFT 24 (not shown) are different, the planar shape of the light shielding portion S is also set to a shape corresponding to the planar shape and arrangement of the TFT 24 so that the TFT 24 can be reliably shielded from light. FIG. 11 and FIG. 12 are schematic plan views showing the shape and arrangement of the light-shielding portion and the microlens of the liquid crystal device according to the second embodiment. FIG. 11 and FIG. 12 show examples of the light shielding portions S having different planar shapes. Constituent elements common to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 11, in the liquid crystal device 1 </ b> A according to the second embodiment, the light-shielding portion S has portions protruding to the opening T side at the positions of the four corners of the pixel P, and the opening T Has a planar shape in which four corners of a substantially rectangular shape are recessed inward. For example, a part of the TFT 24, a relay electrode, a capacitor electrode, and the like (not shown) are arranged on the protruding portion of the light shielding portion S. By forming the light shielding portion S in such a shape, the TFT 24 can be reliably shielded from light even if the area of the light shielding portion S is reduced to increase the aperture ratio.

  The minimum width of the light shielding part S is LB1, and the maximum width of the protruding part of the light shielding part S is LB2. Here, it is assumed that the minimum width LB1 and the maximum width LB2 of the light shielding portion S are the same in the X direction and the Y direction. The maximum width of the opening T is LP-LB1, and the minimum width of the opening T is LP-LB2.

  In the second embodiment, the diameter L1 of the flat portion 12a of the micro lens ML1 (concave portion 12) is set to LP ≧ L1> (LP−LB1). Thereby, the area | region (refer FIG. 5) of the curved surface part 12b and the inclined surface 12c which refracts the light which injects into the peripheral part of micro lens ML1 can be ensured, enlarging the area | region where the flat part 12a and the opening part T overlap. Further, the diameter L4 of the flat portion 16a of the micro lens ML2 (convex portion 16) is set to (LP-LB1) ≧ L4 ≧ (LP-LB2). Thereby, the area where the flat portion 16a and the opening T overlap can be enlarged while avoiding the overlap between the flat portion 16a and the light shielding portion S.

  Other configurations of the microlenses ML1 and ML2 are the same as those in the first embodiment. FIG. 11 shows a case where the protruding portion of the light shielding portion S has a shape that is line symmetric with respect to both the center line along the X direction and the center line along the Y direction. As shown in FIG. 4, the protruding portion of the light shielding portion S may have a shape that is axisymmetric with respect to at least one of the center line along the X direction and the center line along the Y direction.

  In the liquid crystal device 1 </ b> B shown in FIG. 12, the light-shielding portion S has a portion that protrudes inward at two corners of the four corners of the pixel P, and the opening T has two substantially rectangular corners inside. It has a planar shape that is recessed. The minimum width of the light shielding portion S is LB1, the width of the protruding portion of the light shielding portion S in the X direction is LB2, and the width in the Y direction is LB3. Since the width LB3 is larger than the width LB2, the maximum width of the light shielding part S is LB3.

  In such a case, if the diameter L4 of the flat portion 16a is (LP−LB1) ≧ L4 ≧ (LP−LB3), when L4 = LP−LB3, the region of the flat portion 16a is located with respect to the opening T. It becomes too small. Therefore, for example, the diameter L4 of the flat portion 16a is set to (LP−LB1) ≧ L4 ≧ (LP−LB2), and the flat portion 16a and the opening T are formed while reducing the overlap between the flat portion 16a and the light shielding portion S. It is set as appropriate so that the overlapping area can be enlarged.

  As in the liquid crystal devices 1A and 1B according to the second embodiment, even in a configuration in which the planar shapes of the light shielding portion S and the opening portion T are non-symmetrical, oblique light generated by refraction as in the first embodiment. And oblique light generated by diffraction can be suppressed, so that the light use efficiency can be improved and the contrast ratio can be improved.

(Third embodiment)
<Electronic equipment>
Next, an electronic apparatus according to a third embodiment will be described with reference to FIG. FIG. 13 is a schematic diagram illustrating a configuration of a projector as an electronic apparatus according to the third embodiment.

  As shown in FIG. 13, a projector (projection display device) 100 as an electronic apparatus according to the third embodiment includes a polarization illumination device 110, two dichroic mirrors 104 and 105, and three reflection mirrors 106 and 107. , 108, five relay lenses 111, 112, 113, 114, 115, three liquid crystal light valves 121, 122, 123, a cross dichroic prism 116, and a projection lens 117.

  The polarization illumination device 110 includes a lamp unit 101 as a light source composed of a white light source such as an ultra-high pressure mercury lamp or a halogen lamp, an integrator lens 102, and a polarization conversion element 103. The lamp unit 101, the integrator lens 102, and the polarization conversion element 103 are disposed along the system optical axis Lx.

  The dichroic mirror 104 reflects red light (R) and transmits green light (G) and blue light (B) among the polarized light beams emitted from the polarization illumination device 110. Another dichroic mirror 105 reflects the green light (G) transmitted through the dichroic mirror 104 and transmits the blue light (B).

  The red light (R) reflected by the dichroic mirror 104 is reflected by the reflection mirror 106 and then enters the liquid crystal light valve 121 via the relay lens 115. The green light (G) reflected by the dichroic mirror 105 enters the liquid crystal light valve 122 via the relay lens 114. The blue light (B) transmitted through the dichroic mirror 105 enters the liquid crystal light valve 123 via a light guide system including three relay lenses 111, 112, 113 and two reflection mirrors 107, 108.

  The transmissive liquid crystal light valves 121, 122, and 123 as light modulation elements are disposed to face the incident surfaces of the cross dichroic prism 116 for each color light. The color light incident on the liquid crystal light valves 121, 122, 123 is modulated based on video information (video signal) and emitted toward the cross dichroic prism 116.

  The cross dichroic prism 116 is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface thereof. Yes. The three color lights are synthesized by these dielectric multilayer films, and the light representing the color image is synthesized. The synthesized light is projected onto the screen 130 by the projection lens 117 which is a projection optical system, and the image is enlarged and displayed.

  The liquid crystal light valve 121 is arranged with a gap between a pair of polarizing elements arranged in crossed Nicols on the incident side and emission side of colored light. The same applies to the other liquid crystal light valves 122 and 123. The liquid crystal light valves 121, 122, and 123 are ones to which any one of the liquid crystal device 1, the liquid crystal device 1A, and the liquid crystal device 1B according to the above embodiment is applied.

  According to the configuration of the projector 100 according to the third embodiment, the liquid crystal device 1 is provided that can obtain a bright display and excellent display quality even when the plurality of pixels P are arranged with high definition. Thus, it is possible to provide the projector 100 that can display an image that is bright and has a good contrast ratio.

  Note that the electronic apparatus to which the above-described liquid crystal devices 1, 1 </ b> A, and 1 </ b> B can be applied is not limited to the projector 100. The liquid crystal devices 1, 1 </ b> A, 1 </ b> B are, 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, and a viewfinder type video. It can be suitably used as a display unit for information terminal devices such as cameras, car navigation systems, electronic notebooks, and POS.

  The above-described embodiments merely show one aspect of the present invention, and can be arbitrarily modified and applied within the scope of the present invention. As modifications, for example, the following can be considered.

(Modification 1)
In the configuration of the microlens array substrate according to the above embodiment, the planar shapes of the flat portion 12a of the microlens ML1 (concave portion 12) and the flat portion 16a of the microlens ML2 (convex portion 16) are both circular. The invention is not limited to such a form. For example, the planar shape of the flat portions of the microlens ML1 and the microlens ML2 may be substantially rectangular. FIG. 14 is a schematic plan view illustrating the shape and arrangement of the light-shielding portion and the microlens of the liquid crystal device according to the first modification. Constituent elements common to the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 14, the liquid crystal device 6 according to the first modification includes a microlens ML1 (concave portion 62) and a microlens ML2 (convex portion 66), and the others are the liquid crystal device according to the first embodiment. 1 has the same configuration. The microlens ML1 (concave portion 62) has a flat portion 62a at the central portion, and the microlens ML2 (convex portion 66) has a flat portion 66a at the central portion. In the concave portion 62 and the convex portion 66 according to the first modification, the planar shapes of the flat portion 62a and the flat portion 66a are both substantially rectangular, and this is different from the concave portion 12 and the convex portion 16 according to the first embodiment. Yes. The planar shape of the flat part 62a and the flat part 66a is, for example, a substantially rectangular shape in which four corners are rounded. The cross-sectional shapes of the microlens ML1 (concave portion 62) and the microlens ML2 (convex portion 66) are substantially the same as the microlenses ML1 and ML2 shown in FIG.

  If the planar shape of the flat part 62a of the microlens ML1 and the flat part 66a of the microlens ML2 are substantially rectangular, the outline of the opening T of the pixel P is substantially rectangular, and the outline of the opening T is along the outline of the opening T. The flat part 62a and the flat part 66a can be arranged. Therefore, since the region where the incident parallel light travels straight through the micro lens ML1 and the micro lens ML2 becomes wider than when the flat portion is circular, more parallel light is transmitted through the liquid crystal layer 40 (see FIG. 3). Diagonal light can be reduced.

  Also in the first modification, it is desirable that the diameter (the length of the concave portion 62 in the diagonal direction) L2 of the micro lens ML1 is 95% or less of the diagonal length LD and larger than the arrangement pitch LP. When the width in the X direction and the Y direction of the flat portion 62a is L1a, the width L1a is preferably equal to or smaller than the arrangement pitch LP and larger than the maximum width of the opening T. In the example shown in FIG. 14, LP ≧ L1a> ( LP-LB). When the diameter (length in the diagonal direction) of the flat portion 62a is L1b, it is desirable that LT ≧ L1b> L1a. Here, LT is the length in the diagonal direction at the opening T.

  The region of the microlens ML2 (convex portion 66) is included in the region of the microlens ML1 (concave portion 62) and includes the region of the flat portion 62a of the microlens ML1. That is, the diameter (length in the diagonal direction) L3 of the microlens ML2 is not more than the diameter L2 of the microlens ML1 and not less than the diameter L1b of the flat portion 62a. When the width of the flat portion 66a in the X direction and the Y direction is L4a, the width L4a is preferably equal to or smaller than the maximum width of the opening T and equal to or larger than the minimum width of the opening T. In the example shown in FIG. -LB. When the diameter (length in the diagonal direction) of the flat portion 66a is L4b, it is desirable that L1b> L4b> L4a.

  When the planar shape of the flat portion 62a is substantially rectangular, the planar shape of the opening 72a may be rectangular in the step of forming the opening 72a in the mask layer 72 shown in FIG. Further, when the planar shape of the flat portion 66a is substantially rectangular, the size of the light shielding portion in the mask layer 76 when the resist layer 74 shown in FIG. 8D is exposed, and the heating shown in FIG. 9B. What is necessary is just to adjust suitably the temperature of a process, the etching conditions at the time of performing the anisotropic etching shown in FIG.9 (c).

  Note that the microlens ML1 (concave portion 62) and the microlens ML2 (convex portion 66) of Modification 1 may be applied to the liquid crystal devices 1A and 1B according to the second embodiment. Further, a configuration in which the microlens ML1 (concave portion 12) having the flat portion 12a and the microlens ML2 (convex portion 66) having the flat portion 66a are combined, or the microlens ML1 (concave portion 62) having the flat portion 62a and the flat portion. It is good also as a structure which combined microlens ML2 (convex part 16) which has 16a.

(Modification 2)
In the configuration of the liquid crystal device according to the above embodiment, the outer shape of the pixel P is a square, but the present invention is not limited to such a form. For example, the outer shape of the pixel P may be a rectangle. FIG. 15 is a schematic plan view illustrating the shape and arrangement of the light-shielding portion and the microlens of the liquid crystal device according to the second modification. Constituent elements common to the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 15 shows three pixels (sub-pixels) P. The liquid crystal device 8 according to Modification 2 includes a sub-pixel P (R) that transmits red (R), a sub-pixel P (G) that transmits green (G), and a sub-pixel P that transmits blue (B). (B). In the liquid crystal device 8, the sub-pixels P (R), P (G), and P (B) constitute a pixel Q that is one unit when forming an image. The liquid crystal device 8 can display various colors by appropriately changing the luminance of the sub-pixels P (R), P (G), and P (B) in each pixel Q. Hereinafter, when the colors are not distinguished, they are simply referred to as sub-pixels P.

  The sub-pixels P have a rectangular planar shape and are arranged in a lattice pattern. The sub-pixels P are arranged with a predetermined arrangement pitch LPx in the X direction and with a predetermined arrangement pitch LPy in the Y direction. Therefore, the length of one side along the X direction of the subpixel P is LPx, and the length of one side along the Y direction of the subpixel P is LPy. The diagonal length of the sub-pixel P is denoted by LD, and the length in the diagonal direction at the opening T is denoted by LT.

  The liquid crystal device 8 includes a microlens ML1 (concave portion 82) and a microlens ML2 (convex portion 86). The microlens ML1 (concave portion 82) has a flat portion 82a at the center, and the microlens ML2 (convex portion 86) has a flat portion 86a at the center. The planar shape of the concave portion 82, the flat portion 82a, the convex portion 86, and the flat portion 86a is, for example, a substantially rectangular shape in which four corners are rounded, but an elliptical shape (the concave portion 82 and the convex portion 86 are virtual). The outer shape may be elliptical).

  Also in the modification example 2, it is desirable that the diameter (the length of the concave portion 82 in the diagonal direction) L2 of the microlens ML1 is 95% or less of the diagonal length LD and is larger than the arrangement pitch LP. The width in the X direction of the microlens ML1 (concave portion 82) is equal to the arrangement pitch LPx, and the width in the Y direction is equal to the arrangement pitch LPy. It is desirable that LPx ≧ L1x> (LPx−LB) when the width in the X direction of the flat portion 82a is L1x, and LPy ≧ L1y> (LPy−LB) when the width in the Y direction is L1y. When the diameter (length in the diagonal direction) of the flat portion 82a is L1d, it is desirable that LT ≧ L1d.

  The region of the microlens ML2 (convex portion 86) is included in the region of the microlens ML1 (concave portion 82), and includes the region of the flat portion 82a of the microlens ML1. That is, the diameter (length in the diagonal direction) L3 of the microlens ML2 is not more than the diameter L2 of the microlens ML1 and not less than the diameter L1d of the flat portion 82a. The width in the X direction of the microlens ML2 (convex portion 86) is equal to the arrangement pitch LPx, and the width in the Y direction is equal to the arrangement pitch LPy.

  If the width of the flat portion 86a in the X direction is L4x, the width L4x is preferably not more than the maximum width in the X direction of the opening T and not less than the minimum width, and if the width of the flat portion 86a in the Y direction is L4y, The width L4y is preferably equal to or smaller than the maximum width in the Y direction of the opening T and equal to or larger than the minimum width. When the diameter (length in the diagonal direction) of the flat portion 86a is L4d, it is desirable that L1d> L4d.

  The liquid crystal device 8 including the pixel Q composed of such sub-pixels P (R), P (G), and P (B) can be suitably used for a direct-view type display. It can use suitably as a display part of electronic devices, such as a smart phone.

(Modification 3)
In the configuration of the microlens array substrate according to the above-described embodiment, the microlens ML1 (concave portion 12) and ML2 (convex portion 16) have a configuration including tapered inclined surfaces 12c and 16c on the peripheral edge portion. The present invention is not limited to such a form. For example, the concave portion 12 and the convex portion 16 may not have the inclined surfaces 12c and 16c, and the curved surface portions 12b and 16b may be formed from the periphery of the flat portions 12a and 16a to the peripheral edge portion. However, if the peripheral portions of the concave portion 12 and the convex portion 16 are curved surfaces, incident light may be greatly refracted or totally reflected. Moreover, since the average thickness in the area | region of micro lens ML1, ML2 becomes large compared with the case where it has the inclined surfaces 12c and 16c, there exists a possibility that the diagonal light resulting from a diffraction may increase. Therefore, it is preferable that the concave portion 12 and the convex portion 16 have the inclined surfaces 12c and 16c.

(Modification 4)
The manufacturing method of the microlens array substrate of the present invention is not limited to the manufacturing method of the microlens array substrate according to the above embodiment. For example, the method of forming the recess 12 includes forming a resist layer on the substrate 11, forming a shape serving as a base of the recess 12 in the resist layer by exposure using a gray scale mask, multistage exposure, or the like. And the substrate 11 may be anisotropically etched with substantially the same etching selectivity to transfer the shape thereof to form the recess 12. Similarly, in the method of forming the convex portion 16, a resist layer is formed on the lens material layer 15a, and the shape that forms the base of the convex portion 16 is formed on the resist layer by exposure using a gray scale mask or multistage exposure. The convex portion 16 may be formed by transferring the shape by anisotropic etching to the resist layer and the lens material layer 15a with substantially the same etching selectivity.

(Modification 5)
In the configuration of the microlens array substrate according to the above embodiment, the microlens ML1 has a convex shape toward the light incident side, and the microlens ML2 has a convex shape toward the light emission side. The present invention is not limited to such a form. For example, both the microlenses ML1 and ML2 may have a convex configuration toward the light incident side, or both the microlenses ML1 and ML2 may have a convex configuration toward the light emission side. May be.

(Modification 6)
In the liquid crystal devices 1, 1 </ b> A, and 1 </ b> B described above, the microlens array substrate 10 is provided on the counter substrate 30, but the present invention is not limited to such a form. For example, the microlens array substrate 10 may be provided on the element substrate 20.

  DESCRIPTION OF SYMBOLS 1,1A, 1B, 6,8 ... Liquid crystal device (electro-optical device), 10 ... Micro lens array substrate, 11 ... Substrate, 11a ... Surface (first surface), 12 ... Recess, 12a ... Flat part (first ), 12c... Inclined surface (first inclined surface), 13... Lens layer, 16a... Flat portion (second flat portion), 16c... Inclined surface (second inclined surface), 20. (First substrate), 24 ... TFT (switching element), 30 ... counter substrate (second substrate), 40 ... liquid crystal layer (electro-optical layer), 100 ... projector (electronic device), LP, LPx, LPy ... Arrangement pitch, ML1... Micro lens (first micro lens), ML 2... Micro lens (second micro lens), P... Pixel, S.

Claims (10)

A substrate,
A first microlens disposed on the first surface side of the substrate and projecting in the direction of the substrate and having a first flat portion at a central portion;
A second microlens is disposed on the opposite side of the first microlens from the substrate so as to correspond to the first microlens , protrudes on the opposite side of the direction of the substrate, and has a second flat portion at the center. A microlens, and
In plan view from the substrate side, the region of the first microlens includes the region of the second microlens, and the region of the second microlens includes the region of the first flat portion. A microlens array substrate characterized by comprising: The microlens array substrate according to claim 1,
The diameter of the second microlens is equal to or smaller than the diameter of the first microlens and equal to or larger than the diameter of the first flat portion. The microlens array substrate according to claim 1 or 2,
The microlens array substrate, wherein the thickness of the second microlens is thinner than the thickness of the first microlens. A microlens array substrate according to any one of claims 1 to 3,
The first microlens and the second microlens are arranged in a lattice pattern,
The first microlens is configured by a lens layer having a refractive index different from the refractive index of the substrate, which is disposed so as to fill a concave portion provided in the first surface of the substrate.
The diameter of the first microlens is 95% or less of the length of a straight line connecting lattice points that are diagonal to each other in the lattice. A microlens array substrate according to any one of claims 1 to 4,
The diameter of the first flat portion, a microlens array substrate, wherein the first microlens and the second or less placement pitch of the microlenses. A microlens array substrate according to any one of claims 1 to 5,
The microlens array substrate, wherein the first microlens has a first inclined surface at a peripheral portion. The microlens array substrate according to any one of claims 1 to 6,
The microlens array substrate, wherein the second microlens has a second inclined surface at a peripheral portion. A first substrate comprising: a switching element provided for each pixel; and a light shielding part having an opening of the pixel and provided to overlap the switching element in plan view;
A second substrate comprising the microlens array substrate according to any one of claims 1 to 7, and disposed to face the first substrate;
An electro-optic layer disposed between the first substrate and the second substrate,
The electro-optical device, wherein the first microlens and the second microlens are arranged so as to overlap the pixel in plan view. The electro-optical device according to claim 8,
Placement pitch of the first microlens and the second microlens is the same as the arrangement pitch of the pixels,
The diameter of the second flat portion is not less than the difference between the arrangement pitch and the maximum width of the light shielding portion, and is not more than the difference between the arrangement pitch and the minimum width of the light shielding portion. apparatus.   An electronic apparatus comprising the electro-optical device according to claim 8.

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