WO2018180271A1

WO2018180271A1 - Optical element and optical device

Info

Publication number: WO2018180271A1
Application number: PCT/JP2018/008496
Authority: WO
Inventors: 橋川　広和
Original assignee: パイオニア株式会社
Priority date: 2017-03-30
Filing date: 2018-03-06
Publication date: 2018-10-04
Also published as: JPWO2018180271A1; JP6806880B2; JP2021056523A

Abstract

This optical element has a plurality of optical layers (20, 30, 40) each including a liquid crystal layer (21, 31, 41), a pair of alignment films (22, 23, 32, 33, 42, 43) sandwiching the liquid crystal layer, and a pair of translucent electrode layers (24, 25, 34, 35, 44, 45) formed on the pair of alignment films, one (25, 35, 45) of the pair of translucent electrode layers in a single optical layer from among the plurality of optical layers having a plurality of openings (25A, 35A, 45A) arranged in a matrix, and one of the pair of translucent electrode layers in the other optical layers from among the plurality of optical layers having a plurality of openings disposed so as to be superposed on a region between the openings of the one translucent electrode layer in the single optical layer when viewed from the direction perpendicular to the single optical layer.

Description

Optical element and optical device

The present invention relates to an optical element and an optical device including a microlens array using a liquid crystal layer.

Conventionally, microlens arrays using liquid crystal lenses are known. The microlens array functions as, for example, a screen that scatters and emits light from a projector. For example, Patent Document 1 discloses a transmission screen for a rear projection type projection television using a liquid crystal microlens array.

JP 2006-153982 A

In an optical element using a microlens array, it is required to accurately and efficiently perform optical processing on input (incident) light. For example, in the optical element, it is preferable that the optical processing is performed with high resolution, the utilization efficiency of incident light is high, and noise is not superimposed on the processed light. For example, when the optical element is used for display purposes, for example, when used as a screen, it is preferable to display a high-luminance image (video) with high resolution and little noise.

The present invention has been made in view of the above points, and it is an object of the present invention to provide an optical element and an optical device capable of performing optical processing of incident light while suppressing generation of noise with high utilization efficiency. One.

The invention described in claim 1 includes a plurality of optical layers each including a liquid crystal layer, a pair of alignment films sandwiching the liquid crystal layer, and a pair of light-transmitting electrode layers formed on the pair of alignment films. One of the pair of transparent electrode layers in one of the optical layers has a plurality of openings arranged in a matrix, and the pair of transparent electrodes in the other optical layer of the plurality of optical layers. One of the photoelectrode layers has a plurality of openings arranged so as to overlap with a region between the openings of one light-transmitting electrode layer in one optical layer when viewed from a direction perpendicular to the one optical layer. It is characterized by.

The invention according to claim 5 includes a liquid crystal layer, a pair of alignment films sandwiching the liquid crystal layer, and a pair of transparent electrode layers formed on the pair of alignment films, and one of the pair of transparent electrode layers is in a matrix form A first optical layer having a plurality of openings arranged in a pair, a liquid crystal layer, a pair of alignment films sandwiching the liquid crystal layer, and a pair of transparent electrode layers formed on the pair of alignment films. When one of the photoelectrode layers is viewed from a direction perpendicular to the first optical layer, the photoelectrode layer has a plurality of openings arranged so as to overlap a region between the openings of the one transparent electrode layer in the first optical layer. When viewed from the direction perpendicular to the second optical layer and the first optical layer, each of the first and second optical layers is disposed at a position overlapping with the region between the openings of the one transparent electrode layer. And a light shielding layer.

The invention according to claim 6 has a plurality of optical elements that are separated from each other in the direction along the optical axis of incident light from the outside, and a drive circuit that selectively drives each of the plurality of optical elements. Each of the optical elements has a plurality of optical layers each including a liquid crystal layer, a pair of alignment films sandwiching the liquid crystal layer, and a pair of transparent electrode layers formed on the pair of alignment films. One of the pair of transparent electrode layers in one of the optical layers has a plurality of openings spaced apart from each other and arranged in a matrix, and the pair of transparent electrodes in the other optical layer of the plurality of optical layers. One of the photoelectrode layers has a plurality of openings arranged so as to overlap with a region between the openings of one light-transmitting electrode layer in one optical layer when viewed from a direction perpendicular to the one optical layer. It is characterized by.

1 is a diagram schematically illustrating a configuration of a display device according to Example 1. FIG. 1 is a plan view of an optical element according to Example 1. FIG. 1 is a cross-sectional view of an optical element according to Example 1. FIG. 3 is a diagram schematically showing an electrode configuration of each optical layer in the optical element according to Example 1. FIG. 3 is a diagram schematically showing an electrode configuration of each optical layer in the optical element according to Example 1. FIG. 6 is a plan view of an optical element according to Example 2. FIG. 6 is a cross-sectional view of an optical element according to Example 2. FIG. FIG. 6 is a diagram schematically illustrating a configuration of an optical device according to a third embodiment.

Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1 is a diagram schematically illustrating the configuration of the display device 10 according to the first embodiment. In the present embodiment, the display device 10 can be installed in the dashboard DB of the vehicle. The display device 10 is, for example, a head-up display that displays a virtual image VI on a vehicle windshield FG. In FIG. 1, the virtual image VI displayed by the display device 10 is indicated by a broken line. FIG. 1 also shows the position of the eyes of an observer who observes the virtual image VI, for example, the driver of the vehicle, as the viewpoint EY.

In this specification, the direction along the observation direction of the observer observing the virtual image VI is defined as the z-axis direction, and the directions perpendicular to the z direction and perpendicular to each other are defined as the x-axis direction and the y-axis direction, respectively. . The x-axis direction may be referred to as the width direction (left-right direction), the y-axis direction may be referred to as the height direction (up-down direction), and the z-axis direction may be referred to as the depth direction (front-rear direction). Further, the direction from the viewpoint EY toward the virtual image VI is assumed to be the front. That is, the virtual image VI is displayed in front of the observer.

The display device 10 includes a light source 11 that generates and emits emitted light L1 (in this embodiment, light for projecting the virtual image VI). For example, the light source 11 is a projector that projects an image (video). The light source 11 generates light for performing color expression and gradation expression of an image as the emitted light L1.

In the present embodiment, the light source 11 is a laser light source that generates laser light as the emitted light L1. The light source 11 is a scanning laser projector that emits laser light that scans the laser light and displays an image in a predetermined area. For example, the light source 11 includes a laser element (not shown) that generates laser light as the emitted light L1, and a scanning element (not shown) that scans the laser light. For example, a laser light source as the light source 11 uses a predetermined area as a scanning area and scans the laser light by raster scanning.

The display device 10 includes an optical element 12 that scatters the emitted light L1 from the light source 11 to generate the scattered light L2 and outputs the scattered light L2. Outgoing light L 1 from the light source 11 is incident on the optical element 12. In this embodiment, the optical element 12 functions as a display screen (projection screen) that outputs the scattered light L2 as display light (projection light).

The display device 10 also includes a concave mirror 13 that reflects the scattered light L2 from the optical element 12 toward the windshield FG. The light reflected by the concave mirror 13 is projected onto the windshield FG as projection light L3.

When the observer observes the windshield FG from the viewpoint EY, the observer can visually recognize the virtual image VI on the back side (front in the z-axis direction) of the windshield FG. Specifically, the observer visually recognizes the virtual image VI formed at a position corresponding to the distance between the screen (optical element 12) and the windshield FG and the curvature of the concave mirror 13 through the windshield FG. It becomes.

The display device 10 includes an image data generation unit (not shown) that generates image data to be incident on the optical element 12 in order to display the virtual image VI. The image data generation unit obtains, for example, vehicle information indicating the state of the vehicle, peripheral information indicating information around the vehicle, navigation information for guiding driving of the vehicle, and the like from the outside, and displays the information. Generate image data.

Further, the display device 10 has a drive circuit (not shown) for driving the light source 11. The drive circuit generates a light source drive signal for driving the light source 11 based on the image data generated by the image data generation unit. The drive circuit supplies the light source drive signal to the light source 11. The light source 11 generates and emits emitted light L1 based on the light source drive signal.

FIG. 2A is a schematic plan view of the optical element 12. FIG. 2A is a diagram schematically showing the incident surface S1 of the emitted light L1 from the light source 11 in the optical element 12. FIG. FIG. 2B is a schematic cross-sectional view of the optical element 12. FIG. 2B is a cross-sectional view taken along line VV in FIG. 2A, but shows only a part thereof. The configuration of the optical element 12 will be described with reference to FIGS. 2A and 2B. In the following, the emitted light L1 from the light source 11 may be referred to as incident light of the optical element 12.

First, the optical element 12 has an incident surface S1 on which incident light L1 from the light source 11 is incident, and an exit surface S2 from which scattered light L2 generated by the optical element 12 is emitted. The optical element 12 has an incident region R1 for incident light L1 on the incident surface S1 and an exit region R2 for scattered light L2 on the exit surface S2. For example, when the light source 11 is a laser light source, the incident surface S1 is a laser light irradiated surface, and the incident region R1 corresponds to a laser light scanning region.

The optical element 12 includes three optical layers (first, second, and third optical layers) 20, 30, and 40, which are stacked along the optical axis AX of the incident light L1. In this embodiment, the optical element 12 includes a light transmitting plate 12A having one of the main surfaces as the incident surface S1 for the incident light L1, and a light transmitting plate 12B having one of the main surfaces as the emitting surface S2 for the scattered light L2. Have Each of the optical layers 20 to 40 is formed so as to be sandwiched between the other main surfaces of the

light transmitting plates

12A and 12B.

In the present embodiment, the light transmitting plate 12C formed between the

optical layers

20 and 30 and the light transmitting plate 12D formed between the

optical layers

30 and 40 are provided. In this embodiment, the optical layer 20 is formed on the translucent plate 12A, and the optical layer 40 is formed on the translucent plate 12D. That is, in this embodiment, the optical element 12 has a structure in which the optical layers 20 to 40 are integrally formed. Each of the translucent plates 12A to 12D is made of a material having translucency with respect to the incident light L1, such as a glass material or a resin material.

In the present embodiment, each of the optical layers 20 to 40 has a plurality of

lenses

20L, 30L, and 40L, respectively. That is, each of the optical layers 20 to 40 constitutes a microlens array. Each of the plurality of lenses 20L to 30L in each of the optical layers 20 to 40 is formed on the incident region R1 of the incident light L1.

In this embodiment, the optical layer 20 has a structure in which a plurality of lenses 20L are arranged in a regular triangular lattice shape (hexagonal lattice shape). The optical layers 30 and 40 each have a structure in which a plurality of

lenses

30L and 40L are arranged in a regular triangular lattice. Further, the optical element 12 includes the lens 30L of the optical layer 30 or the lens 40L of the optical layer 40 in a region between adjacent lenses of the plurality of lenses 20L of the optical layer 20 in the direction along the optical axis AX of the incident light L1. It is configured to be arranged.

More specifically, as shown in FIG. 2B, the optical layer 20 is formed on the liquid crystal layer 21 containing liquid crystal molecules, the pair of

alignment films

22 and 23 sandwiching the liquid crystal layer 21, and the

alignment films

22 and 23, respectively. Transparent electrode layers (hereinafter simply referred to as electrode layers) 24 and 25. In the present embodiment, the electrode layer 25 has a plurality of openings 25A each having a circular shape and arranged in a regular triangular lattice.

For example, the liquid crystal layer 21 includes liquid crystal molecules constituting a nematic liquid crystal. The

alignment films

22 and 23 include, for example, grooves that align the liquid crystal molecules in the liquid crystal layer 21 in a predetermined direction. The electrode layers 24 and 25 adjust (change) the orientation of the liquid crystal molecules of the liquid crystal layer 21 by applying a voltage. The electrode layers 24 and 25 are made of a conductive material having translucency with respect to the incident light L1, for example, ITO or IZO.

Similarly, the optical layer 30 includes a liquid crystal layer 31 containing liquid crystal molecules, a pair of

alignment films

32 and 33 sandwiching the liquid crystal layer 31, and a transparent electrode layer (hereinafter simply referred to as “alignment film 32”). 34 and 35). In the present embodiment, the electrode layer 35 has a plurality of openings 35A each having a circular shape and arranged in a regular triangular lattice.

The optical layer 40 includes a liquid crystal layer 41 containing liquid crystal molecules, a pair of

alignment films

42 and 43 sandwiching the liquid crystal layer 41, and a transparent electrode layer (hereinafter simply referred to as an electrode) formed on the

alignment films

42 and 43, respectively. 44 and 45). In the present embodiment, the electrode layer 45 has a plurality of openings 45A each having a circular shape and arranged in a regular triangular lattice.

In the present embodiment, each of the electrode layers 24, 34 and 44 is formed so as to cover the entire surface of the liquid crystal layers 21, 31 and 41. In other words, in the present embodiment, the optical layer 20 includes a pair of electrode layers 24 and 25 sandwiching the liquid crystal layer 21, one electrode layer 24 being a full surface electrode, and the other electrode layer 25 being a pattern electrode. Similarly, in the

optical layers

30 and 40, the electrode layers 34 and 44 are full surface electrodes, and the electrode layers 35 and 45 are pattern electrodes.

The optical element 12 applies (supplies) a drive voltage (drive signal) between the electrode layers 24 and 25, between the electrode layers 34 and 35, and between the electrode layers 44 and 45 in each of the optical layers 20 to 40, and optically. A driving circuit (not shown) for driving each of the layers 20 to 40 is included.

First, when a driving voltage is applied between the electrode layers 24 and 25 of the optical layer 20, the orientation of liquid crystal molecules in the liquid crystal layer 21 changes. Further, in the region of the liquid crystal layer 21 sandwiched between the opening 25A of the electrode layer 25 and the electrode layer 24, the alignment of liquid crystal molecules is not uniform.

Therefore, the refractive index is not uniform in the region in the liquid crystal layer 21 sandwiched between the opening 25A of the electrode layer 25 and the electrode layer 24. Thereby, the region corresponding to the opening 25A of the electrode layer 25 in the liquid crystal layer 21 functions as the lens 20L. By adjusting the voltage value applied between the electrode layers 24 and 25, the refractive index distribution in the liquid crystal layer 21, that is, the lens shape of the lens 20L can be adjusted. Thereby, the scattering angle distribution of the incident light L1 incident on the lens 20L can be adjusted.

In other words, the lens 20 L of the optical layer 20 is formed in the region of the liquid crystal layer 21 sandwiched between the opening 25 A of the electrode layer 25 and the electrode layer 24. Similarly, the lens 30 L of the optical layer 30 is provided in the region of the liquid crystal layer 31 sandwiched between the opening 35 A of the electrode layer 35 and the electrode layer 34. The lens 40 L of the optical layer 40 is provided in the region of the liquid crystal layer 41 sandwiched between the opening 45 A of the electrode layer 45 and the electrode layer 44.

As shown in FIG. 2B, in this embodiment, the electrode layer 25 of the optical layer 20 has an opening region A1 that is a region where the opening 25A is provided and a region between adjacent openings 25A. A certain inter-opening region A2 is provided. The opening region A1 of the electrode layer 25 corresponds to a region in the optical layer 20 where the lens 20L is provided, that is, a lens region. The inter-opening region A2 of the electrode layer 25 corresponds to an inter-lens region that is a region between adjacent lenses 20L.

Further, in this embodiment, when viewed from the direction along the optical axis AX of the incident light L1, the opening of the electrode layer 35 of the optical layer 30 is located on the region A2 between the openings of the electrode layer 25 of the optical layer 20. An opening 45A of the electrode layer 45 of the part 35A or the optical layer 40 is provided. Accordingly, when viewed from the direction along the optical axis AX of the incident light L1, the

lens

30L or 40L of the other

optical layer

30 or 40 is formed on the inter-lens region A2 in the optical layer 20.

Therefore, as shown in FIG. 2A, when viewed from the direction along the optical axis AX of the incident light L1, that is, from the direction perpendicular to the incident surface S1 of the incident light L1 in the optical element 12, it is within the incident region R1 of the incident light L1. Is provided with at least one

lens

20L, 30L or 40L. Therefore, the incident light L1 is necessarily incident on any of the lenses 20L to 40L.

Therefore, all of the incident light L1 is scattered L2 by the optical element 12. That is, the incident light L1 is prevented from being transmitted (passing through) each of the optical layers 20 to 40 as it is. Therefore, the incident light L1 can be used as the scattered light L2 (display light in this embodiment) with high efficiency.

3A and 3B, the structure of the electrode layers 25, 35, and 45 in each of the

optical layers

20, 30, and 40 will be described in detail. First, as shown in FIG. 3A, each of the openings 25A of the electrode layer 25 in the optical layer 20 has a circular shape with a diameter D and is arranged in a regular triangular lattice with a pitch P. Each of the openings 35A of the electrode layer 35 in the optical layer 30 and each of the openings 45A of the electrode layer 45 in the optical layer 40 has a circular shape with a diameter D, like the opening 25A of the electrode layer 25, and They are arranged in a regular triangular lattice at a pitch P.

Further, as shown in FIG. 3B, each of the openings 35A of the electrode layer 35 of the optical layer 30 extends from each of the openings 25A of the electrode layer 25 of the optical layer 20 in a direction perpendicular to one side of the equilateral triangular lattice. They are arranged at positions offset by a distance L. Each of the openings 45A of the electrode layer 45 of the optical layer 40 is disposed at a position offset from each of the openings 35A of the electrode layer 35 of the optical layer 30 by a distance L. Each of the openings 25A of the electrode layer 25 of the optical layer 20 is disposed at a position offset by a distance L from each of the openings 45A of the electrode layer 45 of the optical layer 40.

Here, in each of the

openings

25A, 35A, and 45A, the diameter D and the arrangement pitch P satisfy the relationship of D ≧ (2/3) P. The distance L between the

openings

25A and 35A of the

optical layers

20 and 30 and the distance L between the

openings

35A and 45A of the

optical layers

30 and 40 satisfy the relationship L = (1/3 ^1/2 ) P. . For example, the diameter D is about 75 μm and the pitch P is about 150 μm.

As a result, as shown in FIG. 3B, when viewed from the direction along the optical axis AX of the incident light L1, only an area where only one opening (for example, the opening 25A) is provided, that is, only one lens is provided. In addition, a single lens area AA and a plurality of lens areas AB provided around the single lens area AA and overlapped with a plurality of lenses are formed. Further, the single lens area AA is provided by the number of all the lenses 20L to 40L.

In other words, in the optical element 12, the electrode layers 25 to 45 in each of the optical layers 20 to 40 have a plurality of openings 25A to 45A that are spaced apart from each other and arranged in a matrix. Further, when viewed from the direction perpendicular to the optical layer 20, the region AA in which only the opening of the electrode layer in any one of the optical layers 20 to 40 is disposed, and the optical layers 20 to 40 And an area AB where the openings of the electrode layers of at least two optical layers overlap.

Therefore, the scattered light L2 output from the optical element 12 includes light that has passed through the single lens area AA and light that has passed through the plurality of lens areas AB. Thereby, a decrease in resolution in the scattered light L2 scattered by the optical element 12 is suppressed, and noise is suppressed.

Specifically, the number of single lens areas AA corresponds to the resolution of the scattered light L2 output as display light. Accordingly, the same number of single lens areas AA as the number of lenses 20L to 40L are formed in the entire optical layers 20 to 40, so that the resolution of the scattered light L2 is maintained.

Moreover, the noise of the scattered light L2 is significantly reduced by providing the plurality of lens areas AB around the single lens area AA. Specifically, the light transmitted through the plurality of lens areas AB is light that has passed through at least two of the

lenses

20L, 30L, and 40L, and has a more complicated optical path than light that has passed through the single lens area AA. Continue on. Therefore, the light that has passed through the plurality of lens areas AB is greatly scattered compared to the light that has passed through the single lens area AA. Therefore, the noise of the scattered light L2 is greatly reduced. For example, when laser light is used as the incident light L1, speckle noise is greatly reduced.

Further, as described above, the optical layers 20 to 40 and the light transmitting plates 12A to 12D are all made of a member having a light transmitting property between the incident region R1 and the emitting region R2. Therefore, when the optical element 12 is used as a transmission screen, a bright image can be visually recognized over the entire display area of the screen.

In the present embodiment, the display device 10 has a laser light source that scans and emits laser light as the light source 11. That is, the incident light L1 incident on the optical element 12 is a laser beam.

If the incident region R1 of the optical element 12 is provided with a region where no lens is provided, that is, a transmission region (non-scattering region) of the incident light L1, the laser light is transmitted as it is and emitted toward the observer. May be. This may cause the observer's eyes to fatigue early.

On the other hand, in the present embodiment, in the optical element 12, any lens is arranged in the entire incident region R1. Therefore, only the scattered light L2 can be reliably emitted to the observer, and an image that does not cause fatigue to the eyes of the observer can be displayed.

In this embodiment, the case where the optical element 12 has a structure in which the three optical layers 20 to 40 are laminated has been described. However, the configuration of the optical element 12 is not limited to this. For example, the optical element 12 may be composed of a plurality (at least two) of optical layers, for example, the

optical layers

20 and 30 only.

In this case, for example, the electrode layer 25 of the optical layer 20 has a plurality of openings 25A arranged in a matrix, and the electrode layer 35 of the optical layer 30 is in the direction along the optical axis AX of the incident light L1. The electrode layer 25 may be disposed so as to overlap the inter-opening region A2. In this case, the shape of the opening 35A of the electrode layer 35 is not limited to a circular shape.

In the present embodiment, the case where each of the electrode layers 25, 35 and 45 has

circular openings

25A, 35A and 45A having the same diameter D and the same pitch P has been described. However, each of the

openings

35A and 45A in the electrode layers 35 and 45 as a whole fills the inter-opening region A2 of the electrode layer 25 and partially overlaps the opening region A1 of the electrode layer 25. It only has to be arranged. Accordingly, the

openings

25A, 35A, and 45A may have different sizes and arrangement configurations.

Further, in the present embodiment, the case where the openings 25A are arranged in a regular triangular lattice shape has been described. However, the arrangement of the opening 25A is not limited to this. For example, each of the openings 25A may be arranged in a square lattice pattern. That is, the optical layer 20 only needs to have a plurality of openings 25A in which the electrode layer 25 (one of the pair of electrode layers 24 and 25) is arranged in a matrix.

In this embodiment, each of the optical layers 20 to 40 has a structure in which full-surface electrodes (electrode layers 24, 34 and 44) and pattern electrodes (electrode layers 25, 35 and 45) are alternately stacked. Have Specifically, for example, between the

optical layers

20 and 30, from the incident surface S1 side of the incident light L1, the electrode layer 24 (entire electrode), the electrode layer 25 (pattern electrode), the electrode layer 34 (full electrode), and Electrode layers 35 (pattern electrodes) are alternately formed.

That is, in this embodiment, the entire surface electrode is interposed between the pattern electrodes. Thereby, the liquid crystal layer 21 in the optical layer 20 is suppressed from being affected by the potential applied by the pattern electrode of the other optical layer (for example, the electrode layer 35 of the optical layer 30). Therefore, it is possible to accurately control the alignment of the liquid crystal molecules in the liquid crystal layer 21 and to configure a desired lens.

As described above, each of the optical elements 12 includes a liquid crystal layer (liquid crystal layers 21 to 41), a pair of alignment films (

alignment films

22 and 23, 32 and 33, and 42 and 43) sandwiching the liquid crystal layer, and the pair. A plurality of optical layers 20 to 40 including a pair of transparent electrode layers (electrode layers 24 and 25, 34 and 35, and 44 and 45) formed on the alignment film.

Of the optical layers 20 to 40, one of the pair of transparent electrode layers (electrode layer 25) in one optical layer 20 has a plurality of openings 25A arranged in a matrix, and the optical layers 20 to One of the pair of translucent electrode layers (the electrode layer 35 or 45) in the other

optical layer

30 or 40 of the 40 when viewed from a direction perpendicular to the one optical layer 20, the one optical layer 20 The plurality of openings 35 A or 45 A are arranged so as to overlap with the area A 2 between the openings of the one transparent electrode layer 25.

Therefore, it is possible to provide the optical element 12 capable of performing the optical processing of the incident light L1 with high utilization efficiency and suppressing generation of noise.

FIG. 4A is a plan view of the optical element 14 according to the second embodiment. 4A is a plan view schematically showing an incident surface S1 of the incident light L1 in the optical element 14. FIG. FIG. 4B is a schematic cross-sectional view of the optical element 14. 4B is a cross-sectional view taken along line WW in FIG. 4A. The configuration of the optical element 14 will be described with reference to FIGS. 4A and 4B.

The optical element 14 has two optical layers (first and second optical layers) 20 and 30. In the present embodiment, each of the

optical layers

20 and 30 has a plurality of

lens portions

20L and 30L arranged in a matrix, similarly to the optical element 12.

Specifically, as shown in FIG. 4B, the optical layer 20 has an electrode layer 25 that forms a lens portion 20L by application of a voltage, and the electrode layer 25 has a plurality of openings 25A arranged in a matrix. Have The optical layer 30 includes an electrode layer 35 having a plurality of openings 35A arranged in a matrix. In the present embodiment, the opening 35A of the electrode layer 35 in the optical layer 30 is a region A21 between the openings of the opening 25A of the electrode layer 25 in the optical layer 20 when viewed from the direction perpendicular to the optical layer 20. Is arranged.

In this embodiment, the optical element 14 includes a region (overlapping aperture) where an inter-opening region A21 of the optical layer 20 and an inter-opening region A22 provided between the openings 35 of the electrode layer 35 in the optical layer 30 overlap. The light shielding layer 50 is provided in the inter-region A3. For example, the light shielding layer 50 is made of a material that absorbs the incident light L1, for example, a resin material.

That is, as shown in FIG. 4A, the optical element 14 is provided with a light shielding layer 50 in a region of the two

optical layers

20 and 30 that does not overlap any of the

lenses

20L and 30L. Accordingly, the two

optical layers

20 and 30, that is, the portions where the inter-lens regions of the two microlens arrays overlap are shielded from light.

As in this embodiment, for example, when the

circular lenses

20L and 30L are arranged in a matrix and stacked, a portion where the inter-lens regions of the

optical layers

20 and 30 overlap (inter-opening overlap region A3) may occur. Accordingly, the incident light L1 passes through in this inter-lens region. Therefore, pure scattered light L2 may not be obtained.

On the other hand, in this embodiment, the light shielding layer 50 is provided in the overlapping inter-opening region A3 where the inter-opening regions A22 and A23 in the

optical layers

20 and 30 overlap. Therefore, it is suppressed that the incident light L1 is emitted from the optical element 14 as it is. Therefore, when the

optical layers

20 and 30 scatter the incident light L1 to obtain the desired scattered light L2, the light shielding layer 50 suppresses the transmission of the incident light L1, thereby generating high noise and generating noise. It is possible to perform the optical processing of the incident light L1 while suppressing the above.

As described above, in this embodiment, each of the optical elements 14 includes a liquid crystal layer (liquid crystal layers 21 and 31), a pair of alignment films (

alignment films

22 and 23 and 32 and 33) sandwiching the liquid crystal layer, and The light-shielding layer 50 includes first and second

optical layers

20 and 30 including a pair of transparent electrode layers (electrode layers 24 and 25 and 34 and 35) formed on the pair of alignment films.

In addition, one of the pair of transparent electrode layers (electrode layer 25) in the first optical layer 20 has a plurality of openings 25A arranged in a matrix, and the pair of transparent electrodes in the second optical layer 30. One of the electrode layers (electrode layer 35) overlaps the inter-opening region A21 of the one transparent electrode layer 25 in the first optical layer 20 when viewed from the direction perpendicular to the first optical layer 20. It has a plurality of openings 35A arranged.

The light shielding layer 50 is a region where the regions A21 and A22 between the openings of the electrode layers 25 and 35 in the first and second

optical layers

20 and 30 overlap when viewed from the direction perpendicular to the first optical layer 20. Arranged at A3. Therefore, it is possible to provide the optical element 14 that can perform the optical processing of the incident light L1 with high utilization efficiency and suppressing generation of noise.

FIG. 5 is a diagram schematically illustrating the configuration of the optical device 15 according to the third embodiment. The optical device 15 has a structure in which a plurality (three in the present embodiment) of the optical elements 12 according to the first embodiment are spaced apart from each other. In addition, the optical device 15 includes a drive circuit 15A that selectively drives each of the plurality of optical elements 12.

That is, the optical device 15 includes a plurality of optical elements 12 and a plurality of optical elements 12 that are selectively spaced apart from each other in the direction along the optical axis AX of the incident light L1 and a drive circuit 15A that selectively drives the plurality of optical elements 12.

In this embodiment, the drive circuit 15A is connected to each electrode layer in each of the optical elements 12. The drive circuit 15 A supplies a drive signal (drive voltage) to each of the optical elements 12. In the present embodiment, the drive circuit 15A is configured to drive any one of the three optical elements 12 (perform lens operation).

For example, the optical device 15 can be mounted in place of the optical element 12 in the display device 10 according to the first embodiment. In this case, the optical device 15 can display the virtual image VI corresponding to the driven element by switching the driven optical element 12 (driven element). For example, when the light source 11 emits image light as the incident light L1 to the optical device 15, a plurality of images formed at positions corresponding to the driven elements in the depth direction are selectively displayed (projected). Can do. Therefore, the optical device 15 can display an image and a video at an arbitrary position.

Further, for example, by driving the three optical elements 12 sequentially and by driving the light source 11 so as to switch the incident light L1 in accordance with the driven element, the virtual image VI is formed so that a plurality of images overlap in the depth direction. Can be displayed. Therefore, the observer can visually recognize images and videos with depth.

Thus, in this embodiment, the optical device 15 selectively selects each of the plurality of optical elements 12 and the plurality of optical elements 12 that are separated from each other in the direction along the optical axis AX of the incident light L1 from the outside. And a drive circuit 15A for driving.

Each of the optical elements 12 includes a liquid crystal layer (liquid crystal layers 21 to 41), a pair of alignment films (

alignment films

22 and 23, 32 and 33, and 42 and 43) sandwiching the liquid crystal layer, and the pair of alignment films. A plurality of optical layers 20 to 40 each including a pair of transparent electrode layers (electrode layers 24 and 25, 34 and 35, and 44 and 45).

Also, one of the pair of transparent electrode layers (electrode layer 25) in one of the optical layers 20 to 40 has a plurality of openings 25A arranged in a matrix, and the optical layers 20 to One of the pair of translucent electrode layers (the electrode layer 35 or 45) in the other

optical layer

Therefore, it is possible to provide the optical device 15 capable of performing the optical processing of the incident light L1 with high utilization efficiency and suppressing generation of noise.

DESCRIPTION OF SYMBOLS 10 Display apparatus 11

Light source

12, 14

Optical element

21, 31, 41

Liquid crystal layer

25, 35, 45

Transparent electrode layer

25A, 35A, 45A Aperture part A2, A21, A22 Area between opening part A3 Area between overlapping opening part 50 Light shielding Layer 15A drive circuit

Claims

Each has a plurality of optical layers including a liquid crystal layer, a pair of alignment films sandwiching the liquid crystal layer, and a pair of transparent electrode layers formed on the pair of alignment films,
One of the pair of transparent electrode layers in one optical layer of the plurality of optical layers has a plurality of openings arranged in a matrix,
One of the pair of light transmitting electrode layers in the other optical layer of the plurality of optical layers is the one light transmitting electrode in the one optical layer when viewed from a direction perpendicular to the one optical layer. An optical element comprising a plurality of openings arranged so as to overlap a region between openings of a layer.
The plurality of optical layers have first, second and third optical layers,
One of the pair of transparent electrode layers in each of the first, second and third optical layers has a plurality of openings arranged in a matrix,
When viewed from a direction perpendicular to the first optical layer, the plurality of openings of the one transparent electrode layer in any one of the first, second, or third optical layers And a region where the plurality of openings of the one transparent electrode layer overlap in at least two of the first, second and third optical layers. The optical element according to claim 1.
The plurality of openings of the one transparent electrode layer in each of the first, second, and third optical layers have a circular shape with a diameter D and are arranged in a regular triangular lattice with a pitch P,
Each of the plurality of openings in the first optical layer is offset from each of the plurality of openings in the second and third optical layers by a distance L in a direction perpendicular to one side of the equilateral triangular lattice. Placed in the position
Each of the plurality of openings in the second optical layer is offset from each of the plurality of openings in the third optical layer by the distance L in a direction perpendicular to one side of the equilateral triangular lattice. The optical element according to claim 2, wherein the optical element is disposed at a position.
The diameter D and the pitch P satisfy the relationship of D ≧ (2/3) P,
The optical element according to claim 3, wherein the distance L and the pitch P satisfy a relationship of L = (1/3 1/2 ) P.
A plurality of liquid crystal layers, a pair of alignment films sandwiching the liquid crystal layer, and a pair of transparent electrode layers formed on the pair of alignment films, wherein one of the pair of transparent electrode layers is arranged in a matrix A first optical layer having an opening;
A liquid crystal layer; a pair of alignment films sandwiching the liquid crystal layer; and a pair of transparent electrode layers formed on the pair of alignment films, wherein one of the pair of transparent electrode layers is perpendicular to the first optical layer A second optical layer having a plurality of openings disposed so as to overlap an area between the openings of the one light-transmissive electrode layer in the first optical layer when viewed from any direction;
A light-shielding layer disposed at a position overlapping with a region between openings of the one light-transmissive electrode layer in each of the first and second optical layers when viewed from a direction perpendicular to the first optical layer; An optical element.
A plurality of optical elements spaced apart from each other in a direction along the optical axis of incident light from the outside, and a drive circuit that selectively drives each of the plurality of optical elements;
Each of the plurality of optical elements has a plurality of optical layers each including a liquid crystal layer, a pair of alignment films sandwiching the liquid crystal layer, and a pair of transparent electrode layers formed on the pair of alignment films,
One of the pair of transparent electrode layers in one optical layer of the plurality of optical layers has a plurality of openings arranged in a matrix,
One of the pair of light transmitting electrode layers in the other optical layer of the plurality of optical layers is the one light transmitting electrode in the one optical layer when viewed from a direction perpendicular to the one optical layer. An optical device comprising a plurality of openings arranged so as to overlap a region between openings of a layer.