Display device
Patent Information
- Application Number
- JP2022531685
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2020-06-15
- Filing Date
- 2021-06-07
- Publication Date
- 2025-03-27
- Estimated Expiration
- 2041-06-07
Smart Images

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Figure 0007652777000003
Abstract
Description
[Technical field]
[0001] The present technology relates to a display device that displays a projection image on a projection target. [Background technology]
[0002] Projectors are a type of display device that projects an image onto a projection target such as a screen. Examples of projectors include liquid crystal projectors, DLP (Digital Light Processing) projectors, and LCOS (Liquid Crystal On Silicon) projectors. These projectors are characterized by a light source and an image output. The device is provided separately, the number of parts is large, and the housing is large. Also, retinal direct imaging eyewear is known, which draws an image on the retina of the eye as a projection target. In this retinal direct imaging eyewear, light from a light source is combined with a MEMS mirror to draw an image on the retina. This type of eyewear requires an optical system with an area smaller than the lens area to be installed inside the lens part of the glasses. Since the drawing area is limited to this small area, the drawing viewing angle is narrow. In addition, it is difficult to provide high-quality images such as high resolution, wide viewing angle, high dynamic range, wide color gamut, and three-dimensional effect. Also, a head-mounted display type display device is known that displays a holographic image on a transparent lens part. This display device is composed of a micro LCOS display, a mirror, a prism, an optical waveguide substrate, and a holographic optical element. This display device is located far from the display and the eye, has a narrow rendering viewing angle, and has low resolution. In addition, it is difficult to provide high-quality images such as high resolution, wide viewing angle, high dynamic range, wide color gamut, and three-dimensional effect.
[0003] Patent Document 1 describes a display device in which optical information emitted from a display element is directly incident on the retina. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] US Patent Application Publication No. 2014 / 0043320 Summary of the Invention [Problem to be solved by the invention]
[0005] In a display device that projects light from a light-emitting element having multiple light-emitting pixels onto a projection object, if an attempt is made to display an image by directly projecting the information from the light-emitting pixels onto a projection object such as a screen or a retina, a problem arises in that diffuse light is projected onto the projection object due to the effects of diffraction, and the resolution of the image does not improve.
[0006] In view of the above circumstances, an object of the present technology is to provide a display device that displays a projected image with improved resolution. [Means for solving the problem]
[0007] In order to achieve the above object, a display device according to an embodiment of the present technology includes a light-emitting element, a microlens array, and a scanning mechanism. The light emitting element includes a plurality of first light emitting pixels and a plurality of second light emitting pixels. The microlens array has a plurality of lenses arranged at a pitch larger than the pixel pitch of the light-emitting pixels, which project the incident diffuse light emitted from the first light-emitting pixel and the second light-emitting pixel, respectively, to a first destination position and a second destination position, which are located at desired positions on a projection object. The scanning mechanism projects the diffused light emitted from the first light-emitting pixel to the first destination position via the microlens array, and then projects the diffused light emitted from the second light-emitting pixel to the second destination position via the microlens array.
[0008] According to this configuration, by using a microlens array having multiple lenses arranged at a pitch larger than the pixel pitch of the light-emitting pixels, the light can be concentrated more precisely and projected onto the target position on the projection object, thereby improving resolution. Furthermore, the use of a scanning mechanism improves the overall resolution of the image projected onto the projection target.
[0009] In order to achieve the above object, a display device according to an embodiment of the present technology includes a light-emitting element, a microlens array, and a scanning mechanism. The light emitting element has a plurality of light emitting pixels. The microlens array has a plurality of lenses arranged at a pitch larger than the pixel pitch of the light-emitting pixels, which project the light emitted from a first light-emitting pixel group and a second light-emitting pixel group, each of which is composed of a plurality of light-emitting pixels selected from the plurality of light-emitting pixels, onto a first destination position and a second destination position, each of which is located at a desired position different from each other, on a projection object. The scanning mechanism projects light emitted from a plurality of light-emitting pixels that constitute the first light-emitting pixel group and emit light of the same information onto the first destination position via the microlens array, and then projects light emitted from a plurality of light-emitting pixels that constitute the second light-emitting pixel group and emit light of the same information onto the second destination position via the microlens array.
[0010] According to such a configuration, light from a group of light emitting pixels, each of which is made up of a plurality of light emitting pixels that emit light of the same information, is projected onto the target position on the projection object, thereby improving resolution. Furthermore, the use of a scanning mechanism improves the overall resolution of the image projected onto the projection target.
[0011] The plurality of luminescent pixels constituting the first luminescent pixel group and the plurality of luminescent pixels constituting the second luminescent pixel group may be partially different.
[0012] The microlens array may be a microlens array configured with an array of a plurality of convex or concave lenses, or a liquid crystal microlens array configured with a plurality of liquid crystal lenses.
[0013] The microlens array may be a liquid crystal microlens array, and the liquid crystal microlens array may also function as the scanning mechanism.
[0014] The projection object may be a screen. The projection object may be the retina of the eye. The light emitting element may emit light such that information of the light to be projected differs between a foveal region of the retina and a peripheral portion of the foveal region. [Brief description of the drawings]
[0015] [Figure 1] FIG. 1 is a configuration diagram of a display device (projector) according to a first embodiment. [Diagram 2] FIG. 1 is a configuration diagram of a display device (projector) according to a first embodiment. [Diagram 3] FIG. 1 is a configuration diagram of a display device (projector) according to a first embodiment. [Figure 4] FIG. 11 is a configuration diagram of a display device (projector) according to a second embodiment. [Diagram 5] FIG. 11 is a configuration diagram of a display device (projector) according to a second embodiment. [Figure 6] FIG. 11 is a configuration diagram of a display device (projector) according to a second embodiment. [Figure 7] FIG. 11 is a diagram for explaining scanning in a display device (projector) according to a second embodiment. [Figure 8] 13A to 13C are diagrams illustrating an example of an image projected onto a screen (or a retina) by a display device according to the second (or seventh) embodiment, and a scanning trajectory. [Figure 9]FIG. 9 is a diagram for explaining a scanning method in a display device for displaying the image shown in FIG. 8, where (A) shows an example of output information from a light-emitting element and an example of an image projected onto a screen (or retina) at time t1, and (B) shows an example of an image projected onto a screen (or retina) at time t2. [Figure 10] FIG. 9 is a diagram for explaining a scanning method in a display device for displaying the image shown in FIG. 8, where (A) shows an example of output information from the light-emitting element and an example of an image projected onto a screen (or retina) at time t3, and (B) shows an example of an image projected onto a screen (or retina) at time t4. [Figure 11] FIG. 11 is a configuration diagram of a display device (projector) according to a third embodiment. [Figure 12] FIG. 13 is a configuration diagram of a display device (projector) according to a fourth embodiment. [Figure 13] FIG. 13 is a configuration diagram of a display device (projector) according to a fifth embodiment. [Figure 14] FIG. 13 is a configuration diagram of a display device (projector) according to a fifth embodiment. [Figure 15] FIG. 13 is a configuration diagram of a display device (eyewear) according to a sixth embodiment. [Figure 16] FIG. 13 is a configuration diagram of a display device (eyewear) according to a sixth embodiment. [Figure 17] FIG. 13 is a configuration diagram of a display device (eyewear) according to a sixth embodiment. [Figure 18] FIG. 13 is a configuration diagram of a display device (eyewear) according to a seventh embodiment. [Figure 19] FIG. 13 is a configuration diagram of a display device (eyewear) according to a seventh embodiment. [Figure 20] FIG. 13 is a configuration diagram of a display device (eyewear) according to a seventh embodiment. [Figure 21] FIG. 13 is a diagram for explaining scanning in a display device (eyewear) according to a seventh embodiment. [Figure 22] FIG. 1 is a diagram for explaining characteristics of the retina. [Figure 23] FIG. 13 is a schematic diagram for explaining the correspondence between the fovea and luminescent pixels that configure the display device (eyewear) according to the seventh embodiment. [Figure 24]FIG. 13 is a schematic diagram for explaining the correspondence between the fovea and luminescent pixels that configure the display device (eyewear) according to the seventh embodiment. [Diagram 25] FIG. 13 is a configuration diagram of a display device (eyewear) according to an eighth embodiment. [Figure 26] FIG. 13 is a configuration diagram of a display device (eyewear) according to a ninth embodiment. [Figure 27] FIG. 23 is a configuration diagram of a display device (eyewear) according to a tenth embodiment. [Figure 28] FIG. 15 is a configuration diagram of a display device (eyewear) according to an eleventh embodiment. [Figure 29] FIG. 23 is a configuration diagram of a display device (eyewear) according to a twelfth embodiment. [Diagram 30] FIG. 23 is a configuration diagram of a display device (eyewear) according to a thirteenth embodiment. [Diagram 31] FIG. 23 is a configuration diagram of a display device (eyewear) according to a fourteenth embodiment. [Diagram 32] FIG. 23 is a configuration diagram of a display device (eyewear) according to a fifteenth embodiment. [Diagram 33] FIG. 23 is a configuration diagram of a display device (eyewear) according to a sixteenth embodiment. [Diagram 34] FIG. 21 is a configuration diagram of a display device (eyewear) according to a seventeenth embodiment. [Diagram 35] FIG. 1 is a schematic diagram illustrating the positional relationship between a display device applied to eyewear and the eye. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Hereinafter, the present technology will be described with reference to the drawings. The present technology is applicable to a projector as a display device that projects an image onto a screen as a projection target, and to eyewear, head-mounted displays, etc. as display devices that project an image onto a retina as a projection target. In the following, first to fifth embodiments, examples of application to a projector will be given, and sixth to seventeenth embodiments, examples of application to eyewear will be given. In the following description, similar configurations are given similar reference symbols and descriptions thereof may be omitted.
[0017] <Example of application to projectors> [First embodiment] FIG. 1 is a schematic configuration diagram of a display device (projector) 10 according to the first embodiment. 1, the display device 10 has a light-emitting element 13 with a diffusion optical system, a microlens array 5, a concave lens 6, and an actuator 54 as a scanning mechanism. The light-emitting element 13 with a diffusion optical system is composed of a light-emitting element 1 and a diffusion optical system 14. The light emitted from the display device 10 is projected onto a screen 3 as a projection object, and an image is drawn on the screen 3.
[0018] The light-emitting element 1 has a plurality of light-emitting pixels 2. As the light-emitting element 1, for example, a light-emitting element having an organic light-emitting diode, an inorganic light-emitting diode, or a laser as the light-emitting pixel 2, or a liquid crystal panel having a backlight light source can be used. In this embodiment, a light-emitting element having an organic light-emitting diode as the light-emitting pixel is taken as an example, and the same applies to the other embodiments described below. The light emitting element 1 is configured by a two-dimensional array of light emitting pixels 2. The pixel pitch of the light emitting pixels 2, that is, the center-to-center distance between adjacent light emitting pixels 2, is, for example, 60 μm.
[0019] The light-emitting element 13 with a diffusion optical system has a shielding wall 11 provided to separate each light-emitting pixel 2. The shielding wall 11 constitutes a light guide path that guides light from each light-emitting pixel 2. The shielding wall 11 suppresses the spread of light from the light-emitting pixel 2. In the display device 10, the shielding wall 11 and an optical system such as a microlens array 5 and a concave lens 6 are used to determine the direction of the light from the light-emitting pixel 2 and make it reach a desired destination position on the screen 3 with a desired projection area. The shielding wall 11 may be provided only on the light-emitting element, or may be provided on an optical system other than the light-emitting element, such as a diffusion optical system, a microlens array, or a concave lens, and various modifications are possible. Hereinafter, in the description of the application example of the projector, the shielding wall 11 will be described regardless of the location where the shielding wall is provided. The shielding wall 11 can have any one of a reflecting structure, a light-shielding structure, and a light-absorbing structure.
[0020] Diffused light emitted from the light emitting element with diffusion optical system 13 is incident on the microlens array 5. The microlens array 5 emits the incident light towards the screen 3. More specifically, the light emitted from the microlens array 5 passes through the concave lens 6 and is projected onto the screen 3. A two-dimensional image can be displayed on the screen 3. The microlens array 5 is configured by arranging a plurality of minute convex lenses 53 two-dimensionally. The microlens array in the present technology includes an optical system having a function equivalent to that of the configuration in which a plurality of convex lenses are two-dimensionally arranged as in the present embodiment. For example, it includes a lens having a function equivalent to that of a configuration in which a plurality of convex lenses are two-dimensionally arranged, but having a flat surface in shape, a liquid crystal microlens array, a microlens array having a configuration in which a plurality of minute concave lenses are two-dimensionally arranged, a microlens array composed of liquid lenses, and the like. These other forms of microlens arrays will be described in other embodiments. The microlens array 5 includes a plurality of minute convex lenses 53 that convert the incident diffuse light into parallel or nearly parallel light. The light emitted from the entire light-emitting element 1 is redirected by the concave lens 6 so as to spread out, and is then projected onto the screen 3. A microlens array 5 and a concave lens 6 are provided so that light from each light-emitting pixel 2 of the light-emitting element 1 is projected in a spot shape when it reaches the screen 3. Hereinafter, the light projected in a spot shape onto the screen 3 may be referred to as a spot. In this embodiment, the pitch of adjacent minute convex lenses of the microlens array 5, that is, the center-to-center distance between adjacent convex lenses, is set to, for example, 3,400 μm.
[0021] In this embodiment, the resolution is increased by setting the pitch of the convex lenses in the microlens array 5 to be larger than the pitch of the light-emitting pixels 2 of the light-emitting element 1. The following will explain this. When light passes through a circular opening (hereafter referred to as a pinhole) and is projected onto a screen located at a certain distance, Fraunhofer diffraction causes the light to be projected onto the screen over an area larger than the diameter of the pinhole. For example, if the pinhole diameter is 60 μm, the diameter of the light projected onto a screen 1 m away will be 2.24 cm. Since the dot pitch of a typical 21-inch television is 0.533 mm, it is clear that 2.24 cm does not provide sufficient resolution. In contrast, in this embodiment, the pitch of the convex lenses 53 in the microlens array 5 is made larger than the pitch of the light-emitting pixels 2, thereby making the light-concentration point smaller and increasing the concentration state. Then, by setting the light-concentration point on the screen, the concentration of the spot of light emitted from a single light-emitting pixel 2 on the screen 3 can be increased, and the resolution can be increased. Hereinafter, the light-concentration point may be referred to as a point image. In this way, in this embodiment, light from a light-emitting pixel can be projected to a target arrival position on the screen with a high concentration state.
[0022] In this embodiment, the pixel pitch of the light-emitting pixels 2 is 60 μm, the pitch of the convex lenses 53 of the microlens array 5 is 3,400 μm, and the light emitted from one light-emitting pixel 2 is spaced 1 m apart. The diameter of the spot projected onto the clean 3 was configured to be 400 μm. As described above, the pitch of the convex lenses 53 in the microlens array 5 is set to be larger than the pixel pitch of the light-emitting pixels 2 of the light-emitting element 1. When the distance between the light-emitting element 1 and the screen 3 is in the range of 1 m to 2 m, the pitch of the convex lenses 53 in the microlens array 5 is preferably 50 times or more and 120 times or less than the pitch of the light-emitting pixels 2. In this way, by making the pitch of the convex lenses 53 in the microlens array 5 larger than the pixel pitch of the light-emitting pixels 2 of the light-emitting element 1, the light-converging point on the screen can be made sufficiently small, and the light-converging state can be made higher. This makes it possible to improve the resolution. If it is smaller than 50 times, the light-converging point on the screen cannot be made sufficiently small, and it is difficult to make the resolution sufficiently high. If it is larger than 120 times, the scanning frequency becomes 400 kHz or more, and the technical problem in realizing it becomes large.
[0023] The actuator 54 is a scanning mechanism that mechanically scans the microlens array 5 . In this embodiment, the microlens array 5 is mechanically scanned by the actuator 54 to project light onto the screen 3, thereby displaying an image on the screen 3. The scanning will be described with reference to FIGS. 1 to 3 are diagrams illustrating the configuration of the same display device 10, and are diagrams for explaining scanning. Fig. 1 shows the state of scanning at time t1, Fig. 2 shows the state of scanning at time t2, and Fig. 3 shows the state of scanning at time t3. Assuming that time passes in the order of t1, t2, and t3, scanning is performed in the order of Fig. 1, Fig. 2, and Fig. 3. As shown in FIGS. 1 to 3, the light emitting element 1 has a first light emitting pixel 2A, a second light emitting pixel 2B, and a third light emitting pixel 2C. The first to third light emitting pixels 2A to 2C are adjacent to each other. When it is not necessary to distinguish between the light emitting pixels 2A, 2B, and 2C, they are called light emitting pixels 2. In the following description, the target light arrival positions on the screen 3 are called a first arrival position 4A, a second arrival position 4B, and a third arrival position 4C. The first to third arrival positions 4A to 4C are located at different positions and adjacent to each other. When it is not necessary to distinguish between the first to third arrival positions 4A to 4C, they are called arrival positions 4.
[0024] As shown in FIG. 1, at time t1, diffused light emitted from a first light-emitting pixel 2A of a light-emitting element 1 is projected onto a first arrival position 4A on a screen 3 via a diffusion optical system 14, a microlens array 5 and a concave lens 6. 2, at time t2, the actuator 54 is driven to move the microlens array 5 upward in the drawing by the pixel pitch of the light-emitting pixel 2. In this state, the diffused light emitted from the second light-emitting pixel 2B of the light-emitting element 1 is projected onto the second arrival position 4B on the screen 3 via the diffusion optical system 14, the microlens array 5, and the concave lens 6. 3, at time t3, the actuator 54 is driven to move the microlens array 5 upward in the drawing by the pixel pitch of the light-emitting pixel 2. In this state, the diffused light emitted from the third light-emitting pixel 2C of the light-emitting element 1 is projected onto the third arrival position 4C on the screen 3 via the diffusion optical system 14, the microlens array 5, and the concave lens 6.
[0025] In this manner, in the display device 10, the microlens array 5 is mechanically scanned, and the light emitting pixels 2 that emit light in the light emitting element 1 are shifted by one pixel at a time, while the light is projected onto the first to third arrival positions 4A to 4C, which are located at different positions on the screen 3, in a time-division manner. In this way, an image is displayed on the screen 3. By performing scanning at a required frame rate, a human being recognizes a collection of one-dimensional point clouds formed by projecting onto each arrival position as a two-dimensional image. This makes it possible to increase the resolution of the entire image projected onto the screen 3.
[0026] As described above, the display device 10 can display a high-resolution image on the screen 3. Furthermore, the display device 10 has a small number of components and can be made compact. In this embodiment, an example in which the microlens array 5 is mechanically scanned has been given, but for example, the light-emitting element 1 may be mechanically scanned as long as the arrival position on the screen 3 can be changed by scanning. Note that the resolution is more reliably improved by fixing the light-emitting element 1 and mechanically scanning the microlens array 5. The same applies to the display devices of the embodiments described below.
[0027] [Second embodiment] FIG. 4 is a schematic diagram of a display device (projector) 20 according to the second embodiment. 4, light emitted from the display device 20 is projected onto the screen 3, and an image is displayed on the screen 3. The display device 20 is configured such that a light emitting element 21, a collimator lens 7, a concave lens 6, and a microlens array 5 are arranged in this order from a position farther from the screen 3 to a position closer to the screen 3. Furthermore, the display device 20 has an actuator 54 that mechanically scans the microlens array 5.
[0028] The light emitting element 21 has a plurality of light emitting pixels 22. The light emitting element 21 is configured such that the light emitting pixels 22 are arranged two-dimensionally. In this embodiment, the pixel pitch of the light-emitting pixels 22 is 60 μm, and the pitch of the convex lenses 53 in the microlens array 5 is 3,400 μm. The pitch of the convex lenses 53 in the lens array 5 is set to be larger than the pixel pitch of the light-emitting pixels 22 of the light-emitting elements 21. This makes it possible to make the light-converging point on the screen sufficiently small and to improve the light-converging state, thereby improving the resolution.
[0029] The collimator lens 7 collimates or nearly collimates the light incident from the light emitting element 21 and emits it to the concave lens 6. The light incident on the concave lens 6 passes through the concave lens 6 and the microlens array 5 and is projected onto the screen 3. In this embodiment, the shielding wall 11 is provided for the light emitting element 21 and the collimator lens 7 .
[0030] One light emitting pixel group 23 is composed of a portion of the light emitting pixels 22 selected from the plurality of light emitting pixels 22 of the light emitting element 21. The plurality of light emitting pixels 22 belonging to the same light emitting pixel group 23 simultaneously emit light of the same information. The light emitted from one light emitting pixel group 23 is projected in the form of a spot onto one arrival position 24 on the screen 3. In this way, the spot projected onto one arrival position 24 on the screen 3 is formed by the light from the plurality of light emitting pixels 22. This makes it possible to increase the concentration of light on the screen 3 and to increase the resolution. Hereinafter, the information of the light emitted from the light emitting pixels may be referred to as output information. The number of light emitting pixels constituting one light emitting pixel group 23 is, for example, 3,000 to 3,400. In this example, light is emitted from a light emitting pixel group 23 composed of 3,200 light emitting pixels 22, and the light is The light spot projected onto the distant screen 3 was configured to have a projection area of 400 μm in diameter.
[0031] Furthermore, in this embodiment, the microlens array 5 is mechanically scanned by the actuator 54 to project light onto the screen 3 and display an image. This makes it possible to increase the resolution of the entire image projected onto the screen 3. 4 to 6 are diagrams showing the configuration of the same display device 20, and are diagrams for explaining scanning. In Fig. 4, a first luminescent pixel group consisting of a plurality of luminescent pixels 22 that output the same information at time t1 is denoted by reference symbol 23A. In Fig. 4, a first arrival position on screen 3 where light from first luminescent pixel group 23A reaches at time t1 is denoted by reference symbol 24A. In Fig. 5, a second luminescent pixel group consisting of a plurality of luminescent pixels 22 that output the same information at time t2 is denoted by reference symbol 23B. In Fig. 5, a second arrival position on the screen 3 where light from the second luminescent pixel group 23B reaches at time t2 is denoted by reference symbol 24B. In Fig. 6, a third luminescent pixel group consisting of a plurality of luminescent pixels 22 that output the same information at time t3 is denoted by reference symbol 23C. In Fig. 6, a third arrival position on the screen 3 where light from the third luminescent pixel group 23C reaches at time t3 is denoted by reference symbol 24C. Assuming that time passes in the order of t1, t2, and t3, scanning is performed in the order of Figures 4, 5, and 6. When there is no need to distinguish between the first to third light emitting pixel groups 23A to 23C, they will be referred to as light emitting pixel group 23. When there is no need to distinguish between the first to third arrival positions 24A to 24C, they will be referred to as arrival positions 24. The size of the light emitted from one light emitting pixel 22 is smaller than the size of the spot projected at arrival position 24 on the screen 3.
[0032] In FIG. 4, at time t1, a plurality of luminescent pixels 22 belonging to the same first luminescent pixel group 23A simultaneously emit light having the same information. 4, at time t1, light emitted from the first light-emitting pixel group 23A is projected onto a first arrival position 24A on the screen 3 via the collimator lens 7, the concave lens 6, and the microlens array 5. Light from one first light-emitting pixel group 23A passes through one of the minute convex lenses 53 constituting the microlens array 5, and forms one spot at the first arrival position 24A on the screen 3. The spot is formed by light from a plurality of light-emitting pixels 22 that emit light having the same information.
[0033] Thereafter, as shown in FIG. 5, the actuator 54 is driven to move the microlens array 5 upward in the drawing by an amount equivalent to the pixel pitch of the luminescent pixels 2. In FIG. 5, at time t2, a plurality of luminescent pixels 22 belonging to the same second luminescent pixel group 23B simultaneously emit light having the same information. 5, at time t2, light emitted from the second light-emitting pixel group 23B is projected onto the second arrival position 24B on the screen 3 via the collimator lens 7, the concave lens 6, and the microlens array 5. Light from one second light-emitting pixel group 23B passes through one of the minute convex lenses 53 constituting the microlens array 5, and forms one spot at the second arrival position 24B on the screen 3. The spot is formed by light from a plurality of light-emitting pixels 22 that emit light of the same information. The first arrival position 24A, the second arrival position 24B, and a third arrival position 24C (described later) are located at different positions from each other. The detailed positional relationship will be described later. The luminescent pixels 22 constituting the first luminescent pixel group 23A, the second luminescent pixel group 23B, and a third luminescent pixel group 23C (described later) do not completely match each other between the luminescent pixel groups.
[0034] Thereafter, as shown in FIG. 6, the actuator 54 is driven to move the microlens array 5 upward in the drawing by the pixel pitch of the luminescent pixels 2. In FIG. 6, at time t3, a plurality of luminescent pixels 22 belonging to the same third luminescent pixel group 23C simultaneously emit light having the same information. 6, at time t3, light emitted from the third light-emitting pixel group 23C is projected onto a third arrival position 24C on the screen 3 via the collimator lens 7, the concave lens 6, and the microlens array 5. Light from one third light-emitting pixel group 23C passes through one of the minute convex lenses 53 constituting the microlens array 5, and forms one spot at the third arrival position 24C on the screen 3. The spot is formed by light from a plurality of light-emitting pixels 22 that emit light of the same information. In this manner, the microlens array 5 is scanned and an image is drawn and displayed on the screen 3.
[0035] In the display device 20, the microlens array 5 is mechanically scanned, and a plurality of light-emitting pixels 22 constituting a light-emitting pixel group 23 that emits light in the light-emitting element 21 are shifted by one pixel, so that light is projected in a time-division manner onto first to third arrival positions 24A to 24C that are located at different positions on the screen 3. This allows an image to be drawn on the screen 3, and the resolution of the entire image projected on the screen 3 can be increased.
[0036] Here, for example, a case will be taken where a spot with a diameter of 400 μm is formed on a screen 3 located 1 m away using the light emitting element 21. Here, it is assumed that a light emitting element with SVGA (800×600) and an effective display area of 48 mm×36 mm is used as the light emitting element 21. One pixel consisting of an R (red) element, a G (green) element, and a B (blue) element in the light emitting element 21 is a square with a length of 60 μm and a width of 60 μm, that is, the pixel pitch of the light emitting element 21 is 60 μm. In addition, the wavelength of the light is 550 m. To obtain a spot on the screen 3 with an Airy disk (the length from the center (brightest part) of the Airy pattern to the first dark ring) formed by Fraunhofer diffraction with a radius of 200 μm, it is necessary to display using light-emitting pixels 22 in an area of 3.355 mm in diameter in the light-emitting element 21. The area of 3.355 mm in diameter in the light-emitting element 21 corresponds to 3200 pixels. In other words, using 3200 light-emitting pixels, a spot with a diameter of approximately 400 μm can be drawn on the screen 3 located 1 m away.
[0037] As described above, the microlens array 5 is mechanically scanned. The scanning of the microlens array 5 will be described with reference to FIG. 7. In FIG. 7, a rectangle of 36 mm×48 mm indicates the light-emitting element 21. A plurality of small circles indicate an area 9 corresponding to a light-emitting pixel required for forming one spot of 400 μm in diameter on the screen 3. In FIG. 7, a line that extends from left to right, then extends downward, then further extends left, then extends downward, and so on in a rectangular shape indicates a trajectory 8 of the scanning of the microlens array 5. The trajectory 8 indicates the relative movement of the microlens array 5 with respect to the light-emitting element 21. The trajectory 8 corresponds to the trajectory of the center point of the area 9. In this embodiment, scanning is performed at a driving frequency of, for example, 192 kHz. The shape of the trajectory 8 is not limited to this, and may take various shapes.
[0038] The relative positions of the first to third luminescent pixel groups, the relative positions of the first to third arrival positions, and a more detailed scanning method will be described with reference to FIGS. 8 to 10. FIG.
[0039] FIG. 8(A) is a schematic diagram of an image 25 drawn on the screen 3. The image 25 is composed of a plurality of arrival positions 24 virtually arranged two-dimensionally. Each arrival position 24 is located at a different position from the others. FIG. 8(A) shows an example in which there are 8 arrival positions 24 vertically and 8 horizontally, totaling 64 arrival positions 24, for convenience. Output information A1 to A8, B1 to B8, C1 to C8, D1 to D8, E1 to E8, F1 to F8, G1 to G8, and H1 to H8 output from the light emitting pixel group 23 is projected onto each arrival position 24. The microlens array 5 is scanned to display the image 25. The size of the light emitted from one light emitting pixel 22 is smaller than the size of the spot projected onto the arrival position 24 on the screen 3. Fig. 8(B) is a diagram in which the locus 8 of the microlens array 5 shown in a thick line is superimposed on the image 25 shown in Fig. 8(A). For convenience, the locus 8 in Fig. 8(B) is illustrated in a simplified manner compared to the locus 8 shown in Fig. 7. Hereinafter, a time series change in output information from the light emitting element 21 for drawing an image 25 will be described with reference to Figs. 9 and 10. For convenience, the number of light emitting pixels constituting one light emitting pixel group will be described as 9. In reality, one light emitting pixel group may consist of 3,000 to 34 00 luminescent pixels. The number of luminescent pixels constituting one luminescent pixel group may be fixed, or may be configured to be variable.
[0040] Fig. 9(A) shows an example of output information from the pixel 2 at time t1, Fig. 9(B) shows an example of output information from the pixel 2 at time t2, Fig. 10(A) shows an example of output information from the pixel 2 at time t3, and Fig. 10(B) shows an example of output information from the pixel 2 at time t4. It is assumed that time passes in the order of t1, t2, t3, and t4. In each of Figs. 9(A) and (B) and Figs. 10(A) and (B), the light emitting element 21 is shown on the left side, and the image 25 drawn on the screen 3 is shown on the right side. In Figs. 9 and 10, one light emitting pixel group 23 is shown surrounded by a rectangular dashed line. In Figs. 9 and 10, the light emitting element 21 is shown as a rectangle, and each light emitting pixel 22 is shown as being divided by a plurality of vertical dashed lines and horizontal dashed lines drawn within the light emitting element 21. In the light emitting element 21 in each of Figs. 9(A) and (B) and Figs. 10(A) and (B), characters such as A1 to A8, B1 to B8, etc. written inside the light emitting pixel 22 indicate output information output by the light emitting pixel 22. A light emitting pixel 22 without characters indicating such output information indicates that it is a light emitting pixel 22 that does not output information, that is, does not contribute to display on the screen 3. In the images 25 displayed on the screen 3 in each of Figures 9(A) and (B) and Figures 10(A) and (B), the characters indicating the output information of the arrival position 24 to which the output information is projected at that time are shown in black, and the characters indicating the output information of the arrival position 24 to which the output information is not projected are shown in white. In this embodiment, the light emitting pixels 22 used for display on the screen 3 are changed over time, and the microlens array 5 is mechanically scanned to change the position on the screen 3 where the light reaches.
[0041] As shown in the trajectory 8 in FIG. 8(B) and in FIG. 9(A), at time t1, output information A1, A4, A7, D1, D4, D7, G1, G4, and G7 are projected onto each of the first arrival positions 24A on the screen 3. Light from one first light-emitting pixel group 23A, i.e., output information, is projected onto one first arrival position 24A. A plurality of light-emitting pixels 22 belonging to the same one first light-emitting pixel group 23A output the same information. That is, light from nine light-emitting pixels 22 in the light-emitting element 21 is projected onto one first arrival position 24A on the screen 3. As shown in FIG. 9(A), a plurality of first arrival positions 24A onto which light from each of a plurality of first light-emitting pixel groups 23A is projected are located at intervals from one another.
[0042] Next, as shown by the locus 8 in FIG. 8B and as shown in FIG. 9B, at time t2, the actuator 54 is driven to move the microlens array 5, and output information A2, A5, A8, D2, D5, D8, G2, G5, and G8 are projected onto the second arrival positions 24B on the screen 3, respectively. Light from one second light-emitting pixel group 23B, i.e., output information, is projected onto one second arrival position 24B. A plurality of light-emitting pixels 22 belonging to the same one second light-emitting pixel group 23B output the same information. That is, light from nine light-emitting pixels 22 in the light-emitting element 21 is projected onto one second arrival position 24B on the screen 3. 9(B), the second arrival positions 24B onto which the light from each of the second light-emitting pixel groups 23B is projected are spaced apart from one another. The second arrival positions 24B are adjacent to the first arrival position 24A and a third arrival position 24C, which will be described later. 9(A) and 9(B), in the light-emitting element 21, the second luminescent pixel group 23B is composed of luminescent pixels 22 that are obtained by shifting the first luminescent pixel group 23A by one pixel to the right in the figure as a whole. That is, the multiple luminescent pixels 22 that constitute the first luminescent pixel group 23A and the multiple luminescent pixels 22 that constitute the second luminescent pixel group 23B are partially the same but are different in other portions and do not completely match.
[0043] Next, as shown by the locus 8 in FIG. 8B and as shown in FIG. 10A, at time t3, the actuator 54 drives the microlens array 5 to move, and output information A3, A6, D3, D6, G3, and G8 is projected onto each of the third arrival positions 24C on the screen 3. Light from one third light-emitting pixel group 23C, i.e., output information, is projected onto one third arrival position 24C. A plurality of light-emitting pixels 22 belonging to the same third light-emitting pixel group 23C output the same information. That is, light from nine light-emitting pixels 22 in the light-emitting element 21 is projected onto one third arrival position 24C on the screen 3. As shown in FIG. 10(A), the third arrival positions 24C are spaced apart from one another. 9(B) and 10(A), in the light-emitting element 21, the third luminescent pixel group 23C is composed of luminescent pixels 22 that are obtained by shifting the second luminescent pixel group 23B by one pixel to the right in the figure as a whole. That is, the plurality of luminescent pixels 22 that constitute the second luminescent pixel group 23B and the plurality of luminescent pixels 22 that constitute the third luminescent pixel group 23C are partially the same, but are different in other parts and do not completely match. Also, the plurality of luminescent pixels 22 that constitute the third luminescent pixel group 23C and the plurality of luminescent pixels 22 that constitute the first luminescent pixel group 23A are partially the same, but are different in other parts and do not completely match.
[0044] Next, as shown by the locus 8 in FIG. 8B and FIG. 10B, at time t4, the actuator 54 drives the microlens array 5 to move, and output information B3, B6, E3, E6, H3, and H6 are projected onto the plurality of fourth arrival positions 24D on the screen 3, respectively. As shown by the locus 8 in FIG. 8B, the scanning from left to right up until now is now scanned downward. Light from one fourth light-emitting pixel group 23D, i.e., output information, is projected onto one fourth arrival position 24D. A plurality of light-emitting pixels 22 belonging to the same one fourth light-emitting pixel group 23D output the same information. That is, light from nine light-emitting pixels 22 in the light-emitting element 21 is projected onto one fourth arrival position 24D on the screen 3. As shown in FIG. 10(B), the plurality of fourth arrival positions 24D are spaced apart from one another. 10(A) and 10(B), in the light-emitting element 21, the fourth luminescent pixel group 23D is composed of luminescent pixels 22 which are obtained by shifting the third luminescent pixel group 23C by one pixel in the overall vertical direction in the figure. That is, the plurality of luminescent pixels 22 which constitute the third luminescent pixel group 23C and the plurality of luminescent pixels 22 which constitute the fourth luminescent pixel group 23D are partly the same, but are different in other parts and do not completely match. Also, the plurality of luminescent pixels 22 which constitute the fourth luminescent pixel group 23D and the luminescent pixels 22 of each of the first to third luminescent pixel groups 23A to 23C are partly the same, but are different in other parts and do not completely match.
[0045] Next, although examples of output information such as those shown in Figures 9 and 10 are omitted, as shown by trajectory 8 in Figure 8(B), at time t5, the microlens array 5 moves by driving the actuator 54, and output information B2, B5, B8, E2, E5, E8, H2, H5, and H8 are projected onto each of the multiple fifth arrival positions 24E on the screen 3. Next, as shown by trajectory 8 in Figure 8(B), at time t6, the microlens array 5 is moved by driving the actuator 54, and output information B1, B4, B7, E1, E4, E7, H1, H4, and H7 are projected onto each of the multiple sixth arrival positions 24F on the screen 3. Next, as shown by trajectory 8 in Figure 8 (B), at time t7, the microlens array 5 is moved by driving the actuator 54, and output information C1, C4, C7, F1, F4, and F7 are projected onto each of the multiple seventh arrival positions 24G on the screen 3. Next, as shown by trajectory 8 in Figure 8 (B), at time t8, the microlens array 5 is moved by driving the actuator 54, and output information C2, C5, C8, F2, F5, and F8 are projected onto each of the multiple eighth arrival positions 24H on the screen 3. Next, as shown by a trajectory 8 in FIG. 8B, at time t9, the microlens array 5 is moved by the actuator 54, and output information C3, C6, F3, and F6 are projected onto the screen 3 at each of the ninth arrival positions 24I. At these times t5 to t9, as with t1 to t4 described above, information (light) is projected to one destination position 24 on the screen 3 from one luminescent pixel group 23 made up of a plurality of luminescent pixels 22 that emit light of the same information. In this way, the arrival position 24 of the light on the screen 3 changes over time. Scanning is performed on the display device 20 so that the arrival position 24 moves from one spot to the next in sequence as time passes.
[0046] In this way, the display device 20 projects light of the same information emitted from a plurality of light emitting pixels 22 onto one arrival position 24 on the screen 3, so that the resolution of the displayed image can be increased. Furthermore, in the display device 20, the microlens array 5 is mechanically scanned. In the light emitting element 21, the light emitting pixels 22 constituting the light emitting pixel group 23 are shifted by one pixel over time to form the light emitting pixel group. Then, light from one light emitting pixel group is projected onto each of the arrival positions 24, which are located at different positions on the screen 3, in a time-division manner. As a result, an image 25 is displayed on the screen 3. A human being recognizes the collection of one-dimensional dots formed by projecting the light onto each arrival position on the screen 3 as a two-dimensional image. In this way, the microlens array 5 mechanically scans, thereby making it possible to increase the resolution of the entire image projected onto the screen 3. Furthermore, by configuring the luminescent pixel group 23 such that the luminescent pixels 22 constituting the luminescent pixel group 23 are shifted by one pixel over time, it is possible to project information on the number of luminescent pixels 22 possessed by the light-emitting element 21, and by making it possible to reflect the information on the number of luminescent pixels 22 on the screen 3, it is possible to increase the resolution of the entire image.
[0047] As described above, the display device 20 can display a high-resolution image on the screen 3. Furthermore, the display device 20 has a small number of components and can be made compact.
[0048] [Third embodiment] In the above-mentioned first and second embodiments, a microlens array 5 having a plurality of minute convex lenses is used, and the microlens array 5 is mechanically scanned, but the present invention is not limited to this. For example, a liquid crystal microlens array can be used as the microlens array. By using a liquid crystal microlens array, it is possible to provide a function equivalent to the mechanical scanning of the microlens array 5 described above, without physically moving the microlens array. In other words, the liquid crystal microlens functions as a scanning mechanism, and can be said to be a variable optical system. Hereinafter, with reference to FIG. 11, a display device 30 will be described which uses a liquid crystal microlens array and in which light of the same information is projected simultaneously from a plurality of light-emitting pixels 22 to a single destination position 24 on a screen 3 as in the second embodiment.
[0049] 11(A) to (C) are configuration diagrams of the same display device 30, and are schematic configuration diagrams of a display device (projector) 30 according to a third embodiment. Figs. 11(A) to (C) are diagrams for explaining scanning, and in the display device 30, scanning is performed in the order of Fig. 11(A) (time t1), Fig. 11(B) (time t2), and Fig. 11(C) (time t3). 11(A) to 11(C), light emitted from the display device 30 is projected onto the screen 3, and an image is displayed on the screen 3. The display device 30 is configured with a light emitting element 21, a collimator lens 7, and a liquid crystal microlens array 35 arranged in this order from a position farther from the screen 3 to a position closer to the screen 3. The light emitting element 21 has a plurality of light emitting pixels 22 .
[0050] The liquid crystal microlens array 35 has the functions of both the microlens array 5 and the concave lens 6 in the second embodiment. That is, the liquid crystal microlens array 35 has a function of an optical system having a function of making the light from the light emitting pixel group 23 consisting of a plurality of light emitting pixels 22 parallel or nearly parallel, and a function of refracting the light onto the screen 3. Furthermore, the liquid crystal microlens array 35 has a scanning mechanism. The liquid crystal microlens array 35 has a plurality of liquid crystal lenses, which will be described later. The liquid crystal microlens array 35 makes the incident light, which has been emitted from the light emitting pixels 22 and passed through the collimator lens 7, parallel or nearly parallel by each liquid crystal lens, and spreads and emits the light emitted from the entire light emitting elements 21, and projects it onto the screen 3. In this embodiment, the shielding wall 11 is provided for the light emitting element 21 and the collimator lens 7 .
[0051] The liquid crystal microlens array 35 is formed, for example, by sandwiching a liquid crystal layer between a pair of electrode substrates. A transparent electrode is formed as a solid film on the surface of one electrode substrate facing the liquid crystal layer. A plurality of circular transparent electrodes are formed on the surface of the other electrode substrate facing the liquid crystal layer. The plurality of circular transparent electrodes correspond to a plurality of fine liquid crystal lenses constituting the microlens array. By applying a voltage to the liquid crystal layer between the transparent electrode of one electrode substrate and the transparent electrode of the other electrode substrate, the liquid crystal layer is brought into a liquid crystal molecular orientation state that brings about lens characteristics. In this way, the liquid crystal layer having lens characteristics is called a liquid crystal lens. The liquid crystal lens corresponds to the fine convex lens in the microlens array 5, and the liquid crystal microlens array 35 has a plurality of liquid crystal lenses. In the liquid crystal microlens array 35, the optical axis and focal length of each liquid crystal lens can be changed by changing the liquid crystal molecular orientation state of the liquid crystal layer. By electrically controlling each liquid crystal lens of the liquid crystal microlens array 35, the liquid crystal microlens array 35 can be provided with a scanning function without physically moving the liquid crystal microlens array 35.
[0052] In this embodiment, the pixel pitch of the light-emitting pixels 22 is 60 μm, the liquid crystal lens pitch of the liquid crystal microlens array 35 is 3,400 μm, and the light emitted from one light-emitting pixel 2 is 1 m The diameter of the spot projected onto the distant screen 3 was arranged to be 400 μm. In the display device 30, light emitted from a plurality of light-emitting pixels 22 that emit light of the same information is projected onto a target position 24 on the screen 3 through one of the liquid crystal lenses that make up the liquid crystal microlens array 35, forming a single spot. Furthermore, as described above, the liquid crystal microlens array 35 can be given a scanning function by electrically controlling it, so the liquid crystal microlens array 35 can be fixed in place. This eliminates the need for a scanning mechanism such as an actuator that mechanically scans, simplifying the overall structure of the display device and enabling it to be made smaller.
[0053] 11(A) to (C) are diagrams illustrating the configuration of the same display device 30, and are diagrams for explaining scanning. In FIG. 11(A), a first luminescent pixel group consisting of a plurality of luminescent pixels 22 that output the same information at time t1 is denoted by reference numeral 23A. In FIG. 11(B), a second luminescent pixel group consisting of a plurality of luminescent pixels 22 that output the same information at time t2 is denoted by reference numeral 23B. In FIG. 11(C), a third luminescent pixel group consisting of a plurality of luminescent pixels 22 that output the same information at time t3 is denoted by reference numeral 23C. Time passes in the order of t1, t2, and t3, and scanning is performed in the order of FIG. 11(A), (B), and (C). When there is no need to particularly distinguish between the luminescent pixel groups 23A to 23C, they are referred to as the luminescent pixel group 23.
[0054] 11(A), at time t1, light emitted from the first light-emitting pixel group 23A is projected onto a first arrival position 24A on the screen 3 via the collimator lens 7 and the liquid crystal microlens array 35. Light from one first light-emitting pixel group 23A passes through one of the liquid crystal lenses constituting the liquid crystal microlens array 35, and forms one spot at the first arrival position 24A on the screen 3. The spot is formed by light from a plurality of light-emitting pixels 22 that emit light of the same information.
[0055] Thereafter, the liquid crystal microlens array 35 is driven so that the optical axis of each liquid crystal lens of the liquid crystal microlens array 35 changes. 11(B), at time t2, light emitted from the second light-emitting pixel group 23B is projected onto the second arrival position 24B on the screen 3 via the collimator lens 7 and the liquid crystal microlens array 35. Light from one of the first light-emitting pixel groups 23A passes through one of the liquid crystal lenses that make up the liquid crystal microlens array 35, and forms one spot at the second arrival position 24B on the screen 3. The spot is formed by light from a plurality of light-emitting pixels 22 that emit light of the same information.
[0056] Thereafter, the liquid crystal microlens array 35 is driven so that the optical axis of each liquid crystal lens of the liquid crystal microlens array 35 changes. 11(C), at time t3, light emitted from the third light-emitting pixel group 23C is projected onto the third arrival position 24C on the screen 3 via the collimator lens 7 and the liquid crystal microlens array 35. Light from one of the first light-emitting pixel groups 23A passes through one of the liquid crystal lenses that make up the liquid crystal microlens array 35, and forms one spot at the third arrival position 24C on the screen 3. The spot is formed by light from a plurality of light-emitting pixels 22 that emit light of the same information. In this manner, the image 25 is drawn and displayed on the screen 3 by scanning under electronic control of the liquid crystal microlens array 35 . In the display device 30 as well, scanning is performed in the same manner as the scanning described in the second embodiment with reference to FIGS.
[0057] In this way, in the display device 30, as in the second embodiment, light having the same information emitted from multiple light-emitting pixels 22 is projected onto one arrival position 24 on the screen 3, thereby enabling an increase in resolution. Furthermore, in the display device 30, scanning is performed by changing the optical axis of the liquid crystal lens by driving the liquid crystal microlens array 35. Then, light from one light emitting pixel group is projected to each of the arrival positions 24 located at different positions on the screen 3 in a time-division manner. In this way, in the display device 30, as in the second embodiment, although the scanning mechanism is different, scanning is performed so that the arrival positions 24 move from one to the next in sequence over time. This makes it possible to increase the resolution of the entire image projected on the screen 3.
[0058] In the scanning shown in Figures 11(A) to (C), the luminescent pixels 22 constituting the luminescent pixel group 23, which is made up of a plurality of luminescent pixels 22 that emit light of the same information at times t1 to t3, have the same physical structure and spatial position as each other, but the information emitted from the luminescent pixels 22 changes over time so as to be shifted by one pixel depending on the times t1 to t3. In this way, by changing the information output from the pixel group 23 over time, i.e., by performing electronic scanning, it is possible to achieve the same effect as in the second embodiment, i.e., to project information on the number of light-emitting pixels 22 possessed by the light-emitting element 21, without mechanical scanning, and, together with being able to reflect the information on the number of light-emitting pixels 22 on the screen 3, it is possible to obtain high resolution of the entire image.
[0059] As described above, the display device 30 can display a high-resolution image on the screen 3. Moreover, in the display device 30, a scanning mechanism for physically scanning the microlens array 5 as in the second embodiment is not necessary, and the liquid crystal microlens array 35 is configured to perform the functions of both the microlens array 5 and the concave lens 6, so that the number of parts is reduced and further miniaturization is possible. Furthermore, since no mechanical scanning is performed, the positional relationship between the optical system including the liquid crystal microlens array 35 and the light-emitting pixels can be fixed by, for example, integrating them, which is effective in maintaining the positional accuracy between the optical system and the light-emitting pixels. The liquid crystal microlens array may have only a collimating function and a scanning function, and a separate concave lens 6 may be provided. Even in this case, a mechanical scanning mechanism is not required, and therefore miniaturization is possible. In this embodiment, an example is given in which the liquid crystal microlens array also functions as a scanning mechanism by electrically controlling the liquid crystal microlens array to change the optical axis of each liquid crystal lens. However, it is also possible to physically move the liquid crystal microlens array by a scanning mechanism such as an actuator as in the second embodiment. The same applies to the following display devices using the liquid crystal microlens array.
[0060] [Fourth embodiment] A display device 40 according to a fourth embodiment will be described with reference to FIG. FIG. 12 is a schematic diagram of a display device (projector) 40. As shown in FIG. The display device 40 of this embodiment is configured such that the liquid crystal microlens array of the third embodiment further has the function of a collimator lens.
[0061] 12, the display device 40 includes a light emitting element 21 and a liquid crystal microlens array 45. The liquid crystal microlens array 45 includes a plurality of liquid crystal lenses. The liquid crystal microlens array 45 has an optical system function that has a function of making the light from the light emitting pixel group 23 consisting of a plurality of light emitting pixels 22 parallel or nearly parallel, a refracting function in the pupil direction, and a scanning function. The liquid crystal microlens array 45 makes the incident light from the light emitting pixels 22 parallel or nearly parallel, and further makes it parallel or nearly parallel by each liquid crystal lens, and the light emitted from the entire light emitting element 21 is spread and emitted, and projected onto the screen 3. In this embodiment, the shielding wall 11 is provided on the light emitting element 21 .
[0062] Like the liquid crystal microlens array 35, the liquid crystal microlens array 45 is capable of varying the optical axis and focal length of each liquid crystal lens by changing the alignment state of the liquid crystal molecules in the liquid crystal layer. The pitch of the light-emitting pixels 22 and the liquid crystal lens pitch in the liquid crystal microlens array 45 are the same as those in the above-described third embodiment. In the display device 40, a single spot is formed at a destination position 24 on the screen 3 by projecting light emitted from a plurality of light-emitting pixels 22 that emit light of the same information through one of the liquid crystal lenses that make up the liquid crystal microlens array 45. The display device 40 can also perform scanning in the same manner as the display device 30 of the third embodiment.
[0063] As described above, the display device 40 can display a high-resolution image on the screen 3. Moreover, in the display device 40, since it is not necessary to install the collimator lens 7, the number of parts is further reduced, and further miniaturization is possible, as compared with the third embodiment.
[0064] [Modifications of projectors (display devices)] In each of the above-described embodiments, an example has been described in which images are displayed by scanning and projecting light onto different arrival positions on the screen 3 in a time-division manner, but a configuration may be used in which scanning is not performed. In the first embodiment, a microlens array having a pitch larger than the pixel pitch of the light-emitting pixels is used, so that light from a single light-emitting pixel is projected with a higher concentration on the screen, thereby improving the resolution. In the second to fourth embodiments, light of the same information emitted from a plurality of light-emitting pixels is projected on the screen in a single spot, thereby improving the resolution. In each of the above-described embodiments, in addition to the above configurations, scanning is further performed to increase the resolution of the entire image projected onto the screen. In contrast, when scanning is not performed, the image projected onto the screen has adjacent spots spaced apart, and the overall resolution of the image does not increase. However, depending on the application or purpose that does not require high overall resolution, the projected image can be configured so that the necessary text information or image information can be read by humans, and even a configuration that does not perform scanning is useful.
[0065] [Fifth embodiment] Two other examples of the display device (projector) will be described with reference to FIGS. The display device 50 shown in Fig. 13 and the display device 55 shown in Fig. 14 each include a light-emitting element 51 and an optical system. Diffused light emitted from the light-emitting element 51 is projected onto the screen 3 via the optical system. In the display device 50 shown in Fig. 13, a concave lens 56 is used as the optical system. In the display device 60 shown in Fig. 14, a collimator lens 57 and a concave lens 56 are used as the optical system. The light emitting element 51 has a plurality of two-dimensionally arranged light emitting pixels 52. As the light emitting element 51, similar to the light emitting element 1 described in the first embodiment, a light emitting element having an organic light emitting diode, an inorganic light emitting diode, or a laser, or a liquid crystal panel having a backlight light source can be used. 13, light emitted from each light-emitting pixel 52 of the light-emitting element 51 is projected onto the screen 3 via a concave lens 56. The light emitted from the entire light-emitting element 51 is expanded by the concave lens 56 and projected onto the screen 3. 14, light emitted from each light-emitting pixel 52 of the light-emitting element 51 is projected onto the screen 3 via a collimator lens 57 and a concave lens 56. The light emitted from all of the light-emitting elements 51 is made parallel or nearly parallel by the collimator lens 57, and expanded by the concave lens 56 before being projected onto the screen 3.
[0066] In this way, in the display devices 50 and 55 applied to the projector according to the fifth embodiment, there is no need to form a real image of the display image generated by the light-emitting elements on a screen, and the number of parts can be reduced compared to general liquid crystal projectors, DLP projectors, LCOS projectors, etc., making it possible to reduce the overall size.
[0067] <Application to eyewear> [Sixth embodiment] FIG. 15 is a schematic diagram of a display device 60 applied to eyewear according to the sixth embodiment. 15, the display device 60 has a light emitting element 613 with a diffusion optical system, a microlens array 65, a plano-convex lens 66, and an actuator 67 as a scanning mechanism. The light emitting element 613 with a collimator lens is composed of a light emitting element 61 and a diffusion optical system 614.
[0068] Although an external view of the eyewear is not shown, the eyewear has, for example, a eyeglasses-type shape. When a user wears the eyeglasses-type eyewear, light emitted from the display device 60 is projected onto the retina 33 of the user's eye 31, and an image is drawn and displayed on the retina 33. The display device 60 is provided corresponding to each of the left and right lenses of the eyeglass-type eyewear. FIG. 35 is a schematic diagram showing an example of the positional relationship between the display device 60 applied to the eyewear and the eye 31. FIG. 35 corresponds to a view of a user wearing the eyewear viewed from above. The horizontal direction of the display device 60 when the eyewear is worn (corresponding to the vertical direction in FIG. 35) is located approximately parallel to the line connecting both ears of the user. The horizontal dimension of the display device 60 is 50 mm. The distance between the display device 60 and the eye 31 is approximately 15 mm. When a user wearing the eyeglass-type eyewear is viewed from the front, the center of the display device 60 in the horizontal direction does not coincide with the center of the eye 31 in the horizontal direction. The center of each display device 60 provided corresponding to each of the left and right eyes is located closer to the ear side than the center of the eye 31 in the horizontal direction. The distance from the nose side end of the display device 60 in the horizontal direction to the eye 31 is 20 mm, and the distance from the ear side end of the display device 60 in the horizontal direction to the eye 31 is 36 mm.
[0069] 15, the light emitting element 61 has a plurality of light emitting pixels 62. As the light emitting element 61, the same light emitting element as in the first embodiment can be used. The light emitting element 61 is configured by a two-dimensional array of light emitting pixels 62. The pixel pitch of the light emitting pixels 62, that is, the center-to-center distance between adjacent light emitting pixels 62, is, for example, 10 μm.
[0070] Further, the light emitting element 61 has a shielding wall 63 provided to separate each light emitting pixel 62. The shielding wall 63 constitutes a light guide path that guides light from each light emitting pixel 62. The shielding wall 63 suppresses the spread of light from the light emitting pixel 62. In the display device 60, the shielding wall 63 and an optical system such as a microlens array or a plano-convex lens are used to determine the direction of the light from the light emitting pixel 62 so that the light reaches a target destination position on the retina 33 with a desired projection area. The shielding wall 63 may be provided only on the light emitting element, or may be provided on an optical system other than the light emitting element, such as a microlens array or a plano-convex lens, and various modifications are possible. Hereinafter, in the description of the application example of eyewear, the shielding wall 63 will be described regardless of the location where the shielding wall is provided. The shielding wall 63 may have any of a reflecting structure, a light blocking structure, and a light absorbing structure.
[0071] Light emitted from the light emitting element with diffusion optical system 613 is incident on the microlens array 65. The microlens array 65 emits the incident light toward the retina 33 as a projection object, and projects it on the retina 33. More specifically, the light emitted from the microlens array 65 passes through a plano-convex lens 66 and is projected onto the retina 33. A two-dimensional image can be displayed on the retina 33. The microlens array 65 is configured by arranging a plurality of minute convex lenses 650 in a two-dimensional array. The microlens array in the present technology includes an optical system having a function equivalent to that of the configuration in which a plurality of convex lenses are arranged in a two-dimensional array as in the present embodiment. For example, it includes a lens having a function equivalent to that of a configuration in which a plurality of convex lenses are arranged in a two-dimensional array, but having a flat surface in shape, a liquid crystal microlens array, a microlens array having a configuration in which a plurality of minute concave lenses are arranged in a two-dimensional array, a microlens array composed of liquid lenses, and the like. A plurality of minute convex lenses 650 constituting the microlens array 65 collimates or nearly collimates incident light. The light emitted from the entire light-emitting element 61 is bent by the plano-convex lens 66 toward the pupil and projected onto the retina 33. The microlens array 65 and the plano-convex lens 66 are provided so that the light from each light-emitting pixel 62 of the light-emitting element 61 is projected in a spot shape when it reaches the retina 33. In this embodiment, the pitch of adjacent minute convex lenses 650 of the microlens array 65, that is, the center-to-center distance between adjacent convex lenses, is set to, for example, 2,700 μm.
[0072] Here, the structure of the eye 31 will be described with reference to FIG. The human eye 31 is spherical with a diameter of approximately 24 mm. In the eye 31, light entering through the cornea 34 passes through the pupil 36 and enters the lens 37. An inverted real image is always formed on the retina 33 by adjusting the thickness of the lens 37. At the center of the retina 33 is the fovea centralis 32. The retina 33 contains two types of photoreceptor cells: cone cells and rod cells. Cone cells can recognize colors in bright places, but their function decreases in darkness. Cone cells can sense red, green, and blue light. Rod cells cannot distinguish colors, but can sense even faint light and mainly function in dark places. In this way, the resolution of images recognized by the eye is largely determined by cone cells. FIG. 22 shows the distribution of photoreceptor cells in the retina. In the center of the retina 33, there is a part called the fovea centralis 32 where cells are densely distributed. The size of the fovea centralis 32 is about 400 μm in diameter, and the spacing between photoreceptor cells is about 2 μm. Cone cells are most abundant in the fovea centralis 32, and almost no cone cells are distributed around the fovea centralis 32. Rods are almost not distributed in the fovea centralis 32, but are distributed in large numbers in the peripheral area of the fovea centralis 32. The diameter of the cones located in the fovea centralis 32 is about 2.5 μm, and the diameter of the cones located in the peripheral area of the fovea centralis 32 is about 10 μm.
[0073] In this embodiment, the resolution is increased by setting the pitch of the convex lenses 650 in the microlens array 65 to be larger than the pitch of the light emitting pixels 62 of the light emitting elements 61. This will be described below. When light is projected through a pinhole onto the retina at a certain distance, Fraunhofer diffraction causes the light to be projected onto the retina over an area larger than the diameter of the pinhole. For example, if the pinhole has a diameter of 9.9 μm, the diameter of the light projected onto the retina at a distance of 34 mm will be 4.6 mm. This makes it difficult to project an image with sufficient resolution onto the retina. In contrast to this, in this embodiment, the pitch of the convex lenses 650 in the microlens array 65 is made larger than the pitch of the light-emitting pixels 62, thereby making the light-concentration point smaller and making the light-concentration state higher. Then, by setting the light-concentration point on the retina, the light spot emitted from a single light-emitting pixel 62 on the retina 33 can be made more concentrated, and the resolution can be increased. Thus, in this embodiment, light from the light-emitting pixel can be projected to a target arrival position on the retina with a high light-concentration state. In addition, since the diameter of a typical eyeball is about 24 mm, the distance between the surface of the eye and the display device provided on the frame of the eyeglasses-type eyewear is assumed to be 10 mm, and the distance between the pinhole and the retina is set to 34 mm in the above description. This value can be appropriately set depending on the shape of the eyewear in which the display device is mounted.
[0074] In this embodiment, the pixel pitch of the light-emitting pixels 62 is 9.9 μm, the pitch of the convex lenses 650 of the microlens array 65 is 2,700 μm, and three light beams emitted from one light-emitting pixel 62 are It was configured so that the diameter of the spot projected onto the retina 33, 4 mm away, was 12.6 μm. As described above, the pitch of the convex lenses 650 in the microlens array 65 is set to be larger than the pixel pitch of the light-emitting pixels 62 of the light-emitting element 61. When the distance between the light-emitting element 61 and the retina 33 is in the range of 30 mm to 40 mm, the pitch of the convex lenses 650 in the microlens array 65 is preferably 240 times or more and 322 times or less than the pitch of the light-emitting pixels 62. In this way, by setting the pitch of the convex lenses 650 in the microlens array 65 to be larger than the pixel pitch of the light-emitting pixels 62 of the light-emitting element 61, the light-focusing point on the retina can be made sufficiently small, and the light-focusing state can be made higher. This allows the resolution to be improved. If it is smaller than 240 times, the light-focusing point on the screen cannot be made sufficiently small, and it is difficult to make the resolution sufficiently high. If it is larger than 322 times, the scanning frequency becomes 5 MHz or more, and the technical problem in realizing it becomes large.
[0075] The actuator 67 is a scanning mechanism that mechanically scans the microlens array 65 . In this embodiment, the microlens array 65 is mechanically scanned by the actuator 67, and light is projected onto the retina 33 to perform drawing. Scanning will be described with reference to Figs. Figures 15 to 17 are diagrams of the configuration of the same display device 60, and are diagrams for explaining scanning. Figure 15 shows the state of scanning at time t1, Figure 16 shows the state of scanning at time t2, and Figure 17 shows the state of scanning at time t3. Assuming that time passes in the order of t1, t2, and t3, scanning is performed in the order of Figures 15, 16, and 17. As shown in FIGS. 15 to 17, the light emitting element 61 has a first light emitting pixel 62A, a second light emitting pixel 62B, and a third light emitting pixel 62C. The first to third light emitting pixels 62A to 62C are located at different positions and adjacent to each other. When it is not necessary to distinguish between the first to third light emitting pixels 62A to 62C, they are called light emitting pixels 62. In the following description, the target arrival positions of light on the retina 33 are called a first arrival position 64A, a second arrival position 64B, and a third arrival position 64C. In the example shown in the drawings, the first to third arrival positions 64A to 64C are located adjacent to each other. When it is not necessary to distinguish between the first to third arrival positions 64A to 64C, they are called arrival positions 64.
[0076] As shown in FIG. 15, at time t1, light emitted from the first light-emitting pixel 62A of the light-emitting element 61 is projected onto the first arrival position 64A on the retina 33 of the eye 31 via the microlens array 65 and the plano-convex lens 66. 16 , at time t2, the actuator 67 is driven to move the microlens array 65 upward in the drawing by a distance equal to the pitch of the light-emitting pixels 62. In this state, the light emitted from the second light-emitting pixel 62B of the light-emitting element 61 is projected onto a second arrival position 64B on the retina 33 of the eye 31 via the microlens array 65 and the plano-convex lens 66. 17, at time t3, the actuator 67 is driven to move the microlens array 65 upward in the drawing by the pitch of the light-emitting pixels 62. In this state, the light emitted from the third light-emitting pixel 62C of the light-emitting element 61 is projected onto the third arrival position 64C of the retina 33 via the microlens array 65 and the plano-convex lens 66.
[0077] In this manner, in the display device 60, the microlens array 65 is mechanically scanned, and the light emitting pixels 62 that emit light in the light emitting elements 61 are shifted by one pixel at a time, while the light is projected onto the first to third arrival positions 64A to 64C, which are located at different positions on the retina 33, in a time-division manner. As a result, an image is displayed on the retina 33. By performing scanning at a required frame rate, a human being recognizes a collection of one-dimensional point clouds formed by projecting onto each arrival position as a two-dimensional image. This allows the resolution of the entire image projected onto the retina 33 to be increased.
[0078] As described above, the display device 60 can display a high-resolution image on the retina 33. Furthermore, the display device 60 has a small number of parts and can be made compact.
[0079] [Seventh embodiment] FIG. 18 is a schematic diagram of a display device 70 applied to eyewear according to the seventh embodiment. 18, light emitted from the display device 70 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 70 is configured such that a light emitting element 71, a plano-convex lens 76, and a microlens array 77 composed of a plurality of minute concave lenses 770 are arranged in this order from a position farther from the retina 33 to a position closer to the retina 33. Furthermore, the display device 70 has an actuator 67 that mechanically scans the microlens array 77.
[0080] The light-emitting element 71 has a plurality of light-emitting pixels 72. As the light-emitting element 71, similar to the light-emitting element 1 described in the first embodiment, a light-emitting element having an organic light-emitting diode, an inorganic light-emitting diode, or a laser, or a liquid crystal panel having a backlight light source can be used. The light emitting element 71 is configured by arranging light emitting pixels 72 two-dimensionally.
[0081] The plano-convex lens 76 is an optical system having a function of bending the light incident from the light emitting element 71 in the direction of the pupil. The microlens array 77 has a function of making incident light from a light emitting pixel group 73 consisting of a plurality of light emitting pixels 72 having the same information parallel or nearly parallel. In this embodiment, the microlens array 77 is configured to be physically movable by the actuator 67. Light incident on the microlens array 77 passes through the microlens array 77 and is projected onto the retina 33. The microlens array 77 has a plurality of minute concave lenses 770 arranged two-dimensionally. In this embodiment, the shielding wall 63 is provided on the light emitting element 71 and the plano-convex lens 76, the light emitting element 71 and the plano-convex lens 76 are fixed, and the microlens array 77 is configured to be movable. In this embodiment, the pixel pitch of the light-emitting pixels 72 is 9.9 μm, and the pitch of the concave lenses 770 constituting the microlens array 77 is 2,700 μm.
[0082] The pitch of the concave lenses 770 of the microlens array 77 is set to be larger than the pitch of the light-emitting pixels 72 of the light-emitting element 71. When the distance between the light-emitting element 71 and the retina 33 is in the range of 30 mm to 40 mm, the pitch of the concave lenses 770 of the microlens array 77 is preferably 240 times or more and 322 times or less than the pixel pitch of the light-emitting pixels 72. In this way, by setting the pitch of the concave lenses 770 of the microlens array 77 to be larger than the pixel pitch of the light-emitting pixels 72 of the light-emitting element 71, the light-focusing point on the retina can be made sufficiently small, and the light-focusing state can be made higher. This allows the resolution to be improved. If it is larger than 322 times, the scanning frequency becomes 5 MHz or more, which increases the technical problem in realizing it.
[0083] One light-emitting pixel group 73 is composed of a portion of the light-emitting pixels 72 selected from the light-emitting pixels 72 of the light-emitting element 71. The light-emitting pixels 72 constituting the light-emitting pixel group 73 simultaneously emit light having the same information. The light emitted from one light-emitting pixel group 73 is projected in the form of a spot onto one arrival position 74 on the retina 33. In this way, the spot projected onto one arrival position 74 on the retina 33 is formed by light from the multiple light-emitting pixels 72. This makes it possible to increase the effective area of light on the retina 33 and improve the resolution.
[0084] Furthermore, in this embodiment, the microlens array 77 is mechanically scanned by the actuator 67 to project light onto the retina 33 and display an image. This makes it possible to increase the resolution of the entire image projected onto the retina 33. 18 to 20 are diagrams showing the configuration of the same display device 70, and are diagrams for explaining scanning. In Fig. 18, a first luminescent pixel group consisting of a plurality of luminescent pixels 72 that output the same information at time t1 is denoted by reference symbol 73A. In Fig. 18, a first arrival position on retina 33 where light from first luminescent pixel group 73A reaches at time t1 is denoted by reference symbol 74A. In Fig. 19, a second luminescent pixel group consisting of a plurality of luminescent pixels 72 that output the same information at time t2 is denoted by reference symbol 73B. In Fig. 19, a second arrival position on retina 33 where light from second luminescent pixel group 73B reaches at time t2 is denoted by reference symbol 74B. In Fig. 20, a third luminescent pixel group consisting of a plurality of luminescent pixels 72 that output the same information at time t3 is denoted by reference symbol 73C. In Fig. 20, a third arrival position on retina 33 where light from the third luminescent pixel group 73C reaches at time t3 is denoted by reference symbol 74C. Time passes in the order of t1, t2, and t3, and scanning is performed in the order of Figures 18, 19, and 20. When there is no need to distinguish between first to third light emitting pixel groups 73A to 73C, they will be referred to as light emitting pixel group 73. When there is no need to distinguish between first to third arrival positions 74A to 74C, they will be referred to as arrival position 74. The size of the light emitted from one light emitting pixel 72 is smaller than the size of the spot projected at arrival position 74 on retina 33.
[0085] In FIG. 18, at time t1, a plurality of luminescent pixels 72 belonging to the same first luminescent pixel group 73A simultaneously emit light having the same information. 18, at time t1, light emitted from the first light-emitting pixel group 73A is projected onto a first arrival position 74A on the retina 33 via a plano-convex lens 76 and a microlens array 77. Light from one first light-emitting pixel group 73A passes through one of the minute concave lenses 770 constituting the microlens array 77, and forms one spot at the first arrival position 74A on the retina 33. The spot is formed by light from a plurality of light-emitting pixels 72 that emit light having the same information.
[0086] Thereafter, as shown in FIG. 19, the actuator 67 is driven to move the microlens array 77 upward in the drawing by the pitch of the luminescent pixels 72. 19, at time t2, light emitted from the second light-emitting pixel group 73B is projected onto a second arrival position 74B on the retina 33 via a plano-convex lens 76 and a microlens array 77. Light from one second light-emitting pixel group 73B passes through one of the minute concave lenses 770 constituting the microlens array 77, and forms one spot at the second arrival position 74B on the retina 33. The spot is formed by light from a plurality of light-emitting pixels 72 that emit light having the same information. A first arrival position 74A, a second arrival position 74B, and a third arrival position 74C (described later) are located at different positions from each other and adjacent to each other, similarly to the second embodiment. As in the second embodiment, the luminescent pixels 72 constituting each of the first luminescent pixel group 73A, the second luminescent pixel group 73B, and a third luminescent pixel group 73C (described later) do not completely match each other between the luminescent pixel groups.
[0087] Thereafter, as shown in FIG. 20, the actuator 67 is driven to move the microlens array 77 upward in the drawing by the pitch of the luminescent pixels 72. 20, at time t3, light emitted from the third light-emitting pixel group 73C is projected onto a third arrival position 74C on the retina 33 via a plano-convex lens 76 and a microlens array 77. Light from one of the third light-emitting pixel groups 73C passes through one of the minute concave lenses 770 constituting the microlens array 77, and forms one spot at the third arrival position 74C on the retina 33. The spot is formed by light from a plurality of light-emitting pixels 72 that emit light having the same information. In this manner, the microlens array 5 is scanned and an image is displayed on the retina 33 .
[0088] In this embodiment, an OLED microdisplay of the M-OLED series manufactured by SONY, product number WCX335B, is taken as an example of the light-emitting element 71. The light-emitting element 71 has a light-emitting pixel 72 of 0.7 inches and 1920×RGB×1080 pixels. The estimated pixel size is 8.07 μm×8.07 μm.
[0089] If light from a light-emitting element is projected 34 mm away through a pinhole with a diameter of 213.32 μm, the radius of the projected light spot will be 106.68 μm. The pinhole area with a diameter of 213.32 μm corresponds to 460 pixels of the light-emitting element. An example will be given in which a spot with a diameter of 12.6 μm is formed on the retina 33 at a distance of 34 mm using a microlens array 77 with a pitch of 213.32 μm for the concave lenses 770 and a light emitting element 71. The value of 12.6 μm was set based on the diameter of the photoreceptor cells and the distance between the photoreceptor cells. To obtain a spot on the retina 33 with an Airy disk radius (the length from the center (brightest part) of the Airy pattern to the first dark ring) of 6.3 μm formed by Fraunhofer diffraction, it is necessary to draw an area with a diameter of 2.7 mm in the light-emitting element 71. The area with a diameter of 2.7 mm in the light-emitting element 71 corresponds to 70,000 pixels. In other words, an area with a diameter of approximately 12.6 μm on the retina 33 can be drawn using 70,000 light-emitting pixels.
[0090] As described above, the microlens array 77 is mechanically scanned. The scanning of the microlens array 77 will be described with reference to FIG. 21. In FIG. 21, a rectangle of 8.7 mm×15.5 mm indicates the light-emitting element 71. A plurality of small circles indicate an area 79 corresponding to light-emitting pixels required to form a spot with a diameter of 12.6 μm on the retina 33. In FIG. 21, a dashed line that extends from left to right, then extends downward, then extends further left, then extends downward, and so on in a rectangular shape indicates a trajectory 78 of the scanning of the microlens array 77. The trajectory 78 indicates the relative movement of the microlens array 77 with respect to the light-emitting element 71. The trajectory 78 corresponds to the trajectory of the center point of the area 79. In this embodiment, the scanning is performed at a driving frequency of, for example, 3.6 MHz. The shape of the trajectory 78 is not limited to this, and may take various shapes.
[0091] Next, the mutual positional relationships of the first to third luminescent pixel groups, the mutual positional relationships of the first to third arrival positions, and a more detailed scanning method will be described with reference to FIGS. 8 to 10. FIG.
[0092] Fig. 8(A) is a schematic diagram of an image 25 drawn on the retina 33. The image 25 is composed of a plurality of arrival positions 24 virtually arranged two-dimensionally. Fig. 8(A) shows an example in which there are 64 arrival positions 74 in total, 8 vertically and 8 horizontally. Output information A1 to A8, B1 to B8, C1 to C8, D1 to D8, E1 to E8, F1 to F8, G1 to G8, and H1 to H8 output from the light emitting pixel group 73 is projected onto each arrival position 74. To draw the image 25, the microlens array 77 is scanned. Fig. 8(B) is a diagram in which a trajectory 78 of a microlens array 77, shown by a thick line, is superimposed on the image 25 shown in Fig. 8(A). For convenience, the trajectory 78 in Fig. 8(B) is illustrated in a simplified manner compared to the trajectory 78 shown in Fig. 21. 9 and 10, a description will be given below of a time series change in output information from the light emitting element 71 for drawing the image 25. For convenience, the description will be given assuming that one light emitting pixel group is made up of 9 light emitting pixels. In reality, one light emitting pixel group is made up of 10,000 to 80,000 light emitting pixels. The number of light emitting pixels making up one light emitting pixel group may be fixed, or may be configured to be variable.
[0093] Fig. 9(A) shows an example of output information from the pixel 72 at time t1, Fig. 9(B) shows an example of output information from the pixel 72 at time t2, Fig. 10(A) shows an example of output information from the pixel 72 at time t3, and Fig. 10(B) shows an example of output information from the pixel 72 at time t4. It is assumed that time passes in the order of t1, t2, t3, and t4. In each of Figs. 9(A) and (B) and Figs. 10(A) and (B), the light emitting element 71 is shown on the left side, and the image 25 drawn on the retina 33 is shown on the right side. In Figs. 9 and 10, one light emitting pixel group 73 is shown surrounded by a dashed line. In Figs. 9 and 10, the light emitting element 71 is shown as a rectangle, and each light emitting pixel 72 is shown as being divided by a plurality of vertical dashed lines and horizontal dashed lines drawn within the light emitting element 71. In the light emitting element 71 in each of Figs. 9(A) and (B) and Figs. 10(A) and (B), characters such as A1 to A8, B1 to B8, etc. written inside the light emitting pixel 72 indicate output information output by the light emitting pixel 72. A light emitting pixel 72 without characters indicating such output information indicates that it is not outputting information, that is, it is a light emitting pixel 72 that does not contribute to display on the retina 33. In the image 25 drawn on the retina 33 in each of Figures 9(A) and (B) and Figures 10(A) and (B), the characters indicating the output information of the arrival position 74 to which the output information is projected at that time are shown in black, and the characters indicating the output information of the arrival position 74 to which the output information is not projected are shown in white. In this embodiment, the light emitting pixels 72 used for drawing on the retina 33 are changed over time, and the microlens array 77 is mechanically scanned to change the position on the retina 33 where the light reaches.
[0094] As shown in the trajectory 78 in FIG. 8(B) and in FIG. 9(A), at time t1, output information A1, A4, A7, D1, D4, D7, G1, G4, and G7 are projected onto each of the multiple first arrival positions 74A on the retina 33. Light (output information) from one first light-emitting pixel group 73A is projected onto one first arrival position 74A. The light-emitting pixels 72 belonging to the same one first light-emitting pixel group 73A output the same information. That is, light from nine light-emitting pixels 72 in the light-emitting element 71 is projected onto one first arrival position 74 on the retina 33. As shown in FIG. 9(A), the first arrival positions 74A are spaced apart from one another.
[0095] Next, as shown in the trajectory 78 in FIG. 8B and in FIG. 9B, at time t2, the actuator 67 drives the microlens array 77 to move, and the output information A2, A5, A8, D2, D5, D8, G2, G5, and G8 are projected onto the second arrival positions 74B on the retina 33. Light from one second light-emitting pixel group 73B is projected onto one second arrival position 74B. The light-emitting pixels 72 belonging to the same one second light-emitting pixel group 73B output the same information. That is, light from nine light-emitting pixels 72 in the light-emitting element 71 is projected onto one second arrival position 74B on the retina 33. 9B, the second arrival positions 74B are spaced apart from one another. The second arrival positions 74B are adjacent to the first arrival position 74A and a third arrival position 74C, which will be described later. 9(A) and 9(B), in the light-emitting element 71, the second light-emitting pixel group 73B is composed of light-emitting pixels 72 that are obtained by shifting the first light-emitting pixel group 73A by one pixel to the right in the figure as a whole. That is, the multiple light-emitting pixels 72 that constitute the first light-emitting pixel group 73A and the multiple light-emitting pixels 72 that constitute the second light-emitting pixel group 73B are partially the same but are different in other portions and do not completely match.
[0096] Next, as shown in the trajectory 78 in FIG. 8B and in FIG. 10A, at time t3, the actuator 67 drives the microlens array 77 to move, and output information A3, A6, D3, D6, G3, and G8 is projected onto each of the multiple third arrival positions 74C on the retina 33. Light from one third light-emitting pixel group 73C is projected onto one third arrival position 74C. The light-emitting pixels 72 belonging to the same one third light-emitting pixel group 73C output the same information. That is, light from nine light-emitting pixels 72 in the light-emitting element 71 is projected onto one third arrival position 74C on the retina 33. As shown in FIG. 10(A), the third arrival positions 74C are spaced apart from one another. 9(B) and 10(A), in the light-emitting element 71, the third luminescent pixel group 73C is composed of luminescent pixels 72 that are obtained by shifting the second luminescent pixel group 73B by one pixel to the right in the figure. That is, the plurality of luminescent pixels 72 that constitute the second luminescent pixel group 73B and the plurality of luminescent pixels 72 that constitute the third luminescent pixel group 73C are partially the same, but are different in other parts and do not completely match. Also, the plurality of luminescent pixels 72 that constitute the third luminescent pixel group 73C and the plurality of luminescent pixels 72 that constitute the first luminescent pixel group 73A are partially the same, but are different in other parts and do not completely match.
[0097] Next, as shown in the trajectory 78 in FIG. 8B and in FIG. 10B, at time t4, the actuator 67 drives the microlens array 77 to move, and output information B3, B6, E3, E6, H3, and H6 are projected onto the multiple fourth arrival positions 74D on the retina 33. As shown in the trajectory 78 in FIG. 8B, the scanning from left to right up until now is now performed downward. Light from one fourth light-emitting pixel group 73D is projected onto one fourth arrival position 74D. The light-emitting pixels 72 belonging to the same one fourth light-emitting pixel group 73D output the same information. That is, the light from nine light-emitting pixels 72 in the light-emitting element 71 is projected onto one fourth arrival position 74D on the retina 33. As shown in FIG. 10(B), the plurality of fourth arrival positions 74D are spaced apart from one another. 10(A) and 10(B), in the light-emitting element 71, the fourth luminescent pixel group 73D is composed of luminescent pixels 72 which are obtained by shifting the third luminescent pixel group 73C by one pixel in the overall vertical direction in the figure. That is, the plurality of luminescent pixels 72 which constitute the third luminescent pixel group 73C and the plurality of luminescent pixels 72 which constitute the fourth luminescent pixel group 73D are partly the same, but are different in other parts and do not completely match. Also, the plurality of luminescent pixels 72 which constitute the fourth luminescent pixel group 73D and the luminescent pixels 72 of each of the first to third luminescent pixel groups 73A to 73C are partly the same, but are different in other parts and do not completely match.
[0098] Next, examples of output information such as those shown in Figures 9 and 10 are not shown, but as shown by trajectory 78 in Figure 8(B), at time t5, the microlens array 77 moves by driving the actuator 67, and output information B2, B5, B8, E2, E5, E8, H2, H5, and H8 are projected onto each of multiple fifth arrival positions 74E on the retina 33. Next, as shown by trajectory 78 in Figure 8 (B), at time t6, the microlens array 77 moves by driving the actuator 67, and output information B1, B4, B7, E1, E4, E7, H1, H4, and H7 are projected onto each of multiple sixth arrival positions 74F on the retina 33. Next, as shown by trajectory 78 in Figure 8 (B), at time t7, the microlens array 77 is moved by driving the actuator 67, and output information C1, C4, C7, F1, F4, and F7 are projected onto each of multiple seventh arrival positions 74G on the retina 33. Next, as shown by trajectory 78 in Figure 8 (B), at time t8, the microlens array 77 is moved by driving the actuator 67, and output information C2, C5, C8, F2, F5, and F8 are projected onto each of the multiple eighth arrival positions 74H on the retina 33. Next, as shown by a trajectory 8 in FIG. 8B, at time t9, the microlens array 77 is moved by the actuator 67, and output information C3, C6, F3, and F6 are projected onto each of the multiple ninth arrival positions 24I on the retina 33. At these times t5 to t9, as with t1 to t4 described above, information (light) is projected to one destination position 74 on the retina 33 from one luminescent pixel group 73 consisting of multiple luminescent pixels 72 that emit light having the same information. In this way, the arrival position 74 on the retina 33 changes over time. Scanning is performed on the display device 70 so that the arrival position 74 moves from one spot to the next in sequence over time.
[0099] In this way, the display device 70 projects light having the same information emitted from a plurality of light-emitting pixels 72 onto one arrival position 74 on the retina 33, thereby making it possible to increase the resolution of the displayed image. Furthermore, in the display device 70, the microlens array 77 is mechanically scanned. In the light emitting element 71, the light emitting pixels 72 constituting the light emitting pixel group 73 are shifted by one pixel over time to form the light emitting pixel group. Then, light from one light emitting pixel group is projected onto each of the arrival positions 74, which are located at different positions on the retina 33, in a time-division manner. As a result, the image 25 is displayed on the retina 33. Humans recognize the collection of one-dimensional point clouds formed by projecting the light onto each arrival position as a two-dimensional image. In this way, by mechanically scanning the microlens array 77, it is possible to increase the resolution of the entire image projected onto the retina 33. Also, by configuring the light-emitting pixel group 73 such that the light-emitting pixels 72 constituting the light-emitting pixel group 73 are shifted by one pixel over time, it is possible to project information on the number of light-emitting pixels 72 possessed by the light-emitting element 71, and by making it possible to reflect the information on the number of light-emitting pixels 72 on the retina 33, it is possible to increase the resolution of the entire image. In this embodiment, an example has been given in which a plurality of luminescent pixels 72 that constitute a luminescent pixel group 73, which is made up of a plurality of luminescent pixels 72 that output the same information at each of times t1 to t3, change. However, the plurality of luminescent pixels that constitute the luminescent pixel group may be configured not to change over time.
[0100] As described above, the display device 70 can display a high-resolution image on the retina 33. Furthermore, the display device 70 has a small number of parts and can be made compact.
[0101] In eyewear that displays an image on the retina, output information from the light emitting element 71 may be controlled in consideration of the characteristics of the retina 33 of the eye 31. This allows the drive frequency to be lowered and a high frame rate to be achieved. This will be described below with reference to Figs. 23 to 25.
[0102] The diameter of the fovea is about 400 μm, the spacing between photoreceptors is about 2 μm, and since the fovea mainly contains cone cells, it is calculated that there are approximately 20,106 cone cells in the fovea. If one pixel corresponds to one cone cell, the 20,106 cone cells can be expressed as approximately 142 pixels x 142 pixels. If the pixel size of the light-emitting element is assumed to be 9.9 μm x 9.9 μm, then the area of the fovea, which is approximately 20,000 cone cells, corresponds to an area of the light-emitting element that is 1.4 mm x 1.4 mm.
[0103] 23 and 24 are diagrams showing a schematic relationship between the light-emitting pixels 72 of the light-emitting element 71 and the fovea 32. In Figs. 23 and 24, the large circle indicates an area 79 corresponding to a spot having a diameter of 12.6 µm on the retina 33. It is assumed that the area 79 includes an area corresponding to the fovea 32. The middle circle located within the area 79 indicates a fovea-corresponding area 82 that corresponds to the fovea. The region 79 has a diameter of 2.7 mm, and corresponds to approximately 70,000 light emitting pixels 72 in the light emitting element 71 . The diameter of the fovea corresponding region 82 is 1.4 mm, and the fovea corresponding region 82 corresponds to approximately 20,000 light emitting pixels 72 in the light emitting element 71 . The region 79 has a fovea corresponding region 82 and a peripheral region 83 corresponding to the periphery of the fovea corresponding region 82. The peripheral region 83 corresponds to approximately 50,000 light emitting pixels 72 in the light emitting element 71. The small circles arranged two-dimensionally in the figure indicate the optimal pinhole size. One pinhole corresponds to approximately 460 light-emitting pixels 72. Fig. 23 shows a case where the pupil 36 is located at the center of the eye when the eye 31 is viewed straight ahead. Fig. 24 shows a case where the pupil 36 is located at the edge of the eye when the eye 31 is viewed straight ahead.
[0104] As described above, cone cells are closely related to the resolution of an image recognized by the eye 31. Therefore, in the light emitting element 71, in the image to be drawn on the retina 33, information is output densely in a fovea corresponding region 82 corresponding to the fovea 32 where many cone cells exist, and information is output sparsely in a peripheral region 83 corresponding to the periphery of the fovea 32 where almost no cone cells exist. This makes it possible to lower the driving frequency while maintaining the image quality recognized by the eye. Specifically, for example, information is output from all of the approximately 20,000 light-emitting pixels 72 in the fovea corresponding region 82. When the approximately 20,000 pixels in the fovea corresponding region 82 are driven at a frame rate of 30, the drive frequency is 605 kHz. Meanwhile, for the approximately 50,000 light-emitting pixels 72 in the peripheral region 83, information is output that is less than the number of existing pixels by thinning out the pixels rather than using all of them, or by averaging multiple pixels. This allows the driving frequency to be lowered while maintaining the image quality perceived by the eye, compared to when information is uniformly and densely output across the entire 2.7 mm diameter region 79. This allows for a high frame rate, making it possible to provide videos that are more natural to the human eye. It also reduces power consumption. Here, for example, when 70,000 pixels in a 2.7 mm diameter region 79 are driven at a frame rate of 30, the drive frequency is 3.6 MHz. Even in this case, it is possible to provide a moving image that looks natural to the human eye, but by changing the way images are output in the fovea corresponding region 82 and the peripheral region 83 as described above, it is possible to provide a moving image that looks more natural to the human eye. In this way, the method of drawing on the fovea 32 and its surroundings can be changed according to the characteristics of the cones and rods in the retina, and the resolution and movement of the image or information projected onto the retina can be changed. This makes it possible to realize the recognition of resolution, moving objects, and smooth movements by outputting an appropriate amount of information. As a result, it becomes possible to reduce the power consumption of the light-emitting element.
[0105] The display device 70 may further include a sensing device such as an image sensor that senses the movement of the pupil 36 of the user's eye 31. Based on the change in the movement of the pupil acquired by the sensing device, the information output from the light-emitting element 71 and the drive of the microlens array 77 may be controlled so that the light from the light-emitting element 71 is reliably projected onto the pupil 36 even if the relative position or relative orientation between the pupil 36 and the light-emitting element 71 changes. This allows the user to continue viewing the image even if the position of the pupil changes. Furthermore, the display device 70 may be equipped with a sensing device that senses the inclination of the display device 70 itself. Based on a change in the position of the display device 70 acquired by the sensing device, even if the relative position or relative orientation between the pupil and the light-emitting element 71 changes, the information output from the light-emitting element 71 and the drive of the microlens array 77 may be controlled so that the light from the light-emitting element 71 is reliably projected onto the pupil. Either the sensing device that senses the movement of the pupil or the sensing device that senses the inclination of the display device 70 may be used, or both may be used in combination. Furthermore, when the user changes his / her line of sight and the pupil 36 moves to the edge of the eye 31 in the front view, the position of the fovea corresponding region 82 in the light-emitting element 71 changes as shown in Fig. 25. In such a case, the light-emitting element 71 may be controlled so that the light-emitting pixels 72 in the fovea corresponding region 82 output fine information and the light-emitting pixels 72 corresponding to the peripheral region 83 output coarse information according to the position of the fovea corresponding region 82. This makes it possible to lower the driving frequency while maintaining the image quality of the image recognized by the eye, even when the relative position or relative orientation between the pupil 36 and the light-emitting element 71 changes.
[0106] Next, other display devices applied to eyewear will be described as the eighth to seventeenth embodiments. All of these embodiments are of a form in which light emitted from a light emitting pixel group 73 (or 153) composed of a plurality of light emitting pixels 72 (or 152) that output the same information of a light emitting element 71 (or 151) is projected onto one arrival position 74 on the retina 33, as in the seventh embodiment described above. Scanning in the following embodiments is similar to that of the light emitting element in the seventh embodiment, and therefore description thereof will be omitted.
[0107] [Eighth embodiment] FIG. 25 is a schematic diagram of a display device 80 applied to eyewear according to the eighth embodiment. 25, light emitted from a display device 80 is projected onto a retina 33 of an eye 31, and an image is displayed on the retina 33. The display device 80 is configured such that a light emitting element 71, a plano-convex lens 86, and a microlens array 77 composed of a plurality of minute concave lenses 770 are arranged in this order from a position farther from the retina 33 to a position closer to the retina 33. Furthermore, the display device 80 has an actuator 67 that mechanically scans the microlens array 77. In this embodiment, the shielding wall 63 is provided on the light emitting element 71. The light emitting element 71 and the plano-convex lens 86 are fixed, and the microlens array 77 is configured to be movable.
[0108] [Ninth embodiment] FIG. 26 is a schematic diagram of a display device 90 applied to eyewear according to the ninth embodiment. 26, light emitted from the display device 90 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 90 is configured such that a light emitting element 71, a collimator lens 97, a plano-convex lens 86, and a microlens array 77 composed of a plurality of minute concave lenses 770 are arranged in this order from a position farther from the retina 33 to a position closer to the retina 33. Furthermore, the display device 90 has an actuator 67 that mechanically scans the microlens array 77. In this embodiment, the shielding wall 63 is provided to the light emitting element 71 and the collimator lens 97. The light emitting element 71, the collimator lens 97, and the plano-convex lens 86 are fixed, and the microlens array 77 is configured to be movable.
[0109] [Tenth embodiment] FIG. 27 is a schematic configuration diagram of a display device 100 applied to eyewear according to the tenth embodiment. 27, light emitted from the display device 100 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 100 is configured such that a light emitting element 71, a Fresnel lens 107, and a microlens array 77 composed of a plurality of minute concave lenses 770 are arranged in this order from a position farther from the retina 33 to a position closer to the retina 33. Furthermore, the display device 100 has an actuator 67 that mechanically scans the microlens array 77. In this embodiment, the shielding wall 63 is provided on the light emitting element 71 and the Fresnel lens 107. The light emitting element 71 and the Fresnel lens 107 are fixed, and the microlens array 77 is configured to be movable.
[0110] [Eleventh embodiment] FIG. 28 is a schematic diagram of a display device 110 applied to eyewear according to an eleventh embodiment. 28, light emitted from the display device 110 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 110 is configured such that a light emitting element 71, a collimator lens 97, a Fresnel lens 107, and a microlens array 77 composed of a plurality of minute concave lenses 770 are arranged in this order from a position farther from the retina 33 to a position closer to the retina 33. Furthermore, the display device 110 has an actuator 67 that mechanically scans the microlens array 77. In this embodiment, the shielding wall 63 is provided for the light emitting element 71, the collimator lens 97, and the Fresnel lens 107. The light emitting element 71, the collimator lens 97, and the Fresnel lens 107 are fixed, and the microlens array 77 is configured to be movable.
[0111] [Twelfth embodiment] FIG. 29 is a schematic configuration diagram of a display device 120 applied to eyewear according to the twelfth embodiment. 29, light emitted from the display device 120 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 120 is configured with a light emitting element 71 and a liquid crystal microlens array 125 arranged in order from a position farther from the retina 33 to a position closer to the retina 33. The liquid crystal microlens array 125 includes liquid crystal lenses that form a plurality of minute convex or concave lenses. The basic configuration of the liquid crystal microlens array 125 is similar to that of the liquid crystal microlens array 35 described in the above third embodiment. By using the liquid crystal microlens array 125, it is possible to provide a function equivalent to the mechanical scanning of the microlens arrays shown in the above seventh to eleventh embodiments without physical movement. In other words, the liquid crystal microlens can be said to be a variable optical system that functions as a scanning mechanism. The same applies to the liquid crystal microlens arrays in each embodiment described later. The liquid crystal microlens array 125 has a scanning function, as well as a function of an optical system having a function of making the light from the light emitting pixel group 73 consisting of a plurality of light emitting pixels 72 parallel or nearly parallel, and a function of refracting light in the pupil direction. Note that the scanning mechanism includes the mechanism described in the seventh embodiment that scans so that light is incident on the pupil in accordance with the movement of the pupil, and this also applies to the liquid crystal microlens arrays of each embodiment described later. In this embodiment, the shielding wall 63 is provided on the light-emitting element 71. The light-emitting element 71 and the liquid crystal microlens array 125 are fixed, and are configured so that neither of them physically moves. In this embodiment, the liquid crystal microlens array 125 can also function as a collimator lens or a plano-convex lens, so that the number of parts can be reduced, enabling further miniaturization.
[0112] [Thirteenth embodiment] Fig. 30 is a schematic diagram of a display device 130 applied to eyewear according to the 13th embodiment. As shown in Fig. 30, light emitted from the display device 130 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 130 has a configuration in which a collimator lens 97 is disposed between the light-emitting element 71 and a liquid crystal microlens array 135. In addition to functioning as a scanning mechanism, the liquid crystal microlens array 135 has a scanning function, as well as an optical system function that has the function of making the light from the light-emitting pixel group 73 consisting of a plurality of light-emitting pixels 72 parallel or nearly parallel, and a refracting function in the pupil direction. In this embodiment, the shielding wall 63 is provided to the light emitting element 71 and the collimator lens 97 .
[0113] [Fourteenth embodiment] Fig. 31 is a schematic diagram of a display device 140 applied to eyewear according to a fourteenth embodiment. As shown in Fig. 31, light emitted from the display device 140 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 140 is configured with a light emitting element 71, a collimator lens 97, a lens 146, and a liquid crystal microlens array 145 arranged in this order from a position farther from the retina 33 to a position closer to the retina 33. The lens 146 has the function of a plano-convex lens and is a lens having a flat surface in appearance. The lens 146 is an optical system that has the function of bending the light from the light-emitting pixels 72 toward the pupil. The liquid crystal microlens array 145 functions as a scanning mechanism, and also functions as an optical system having a function of collimating or nearly collimating the light from a light emitting pixel group 73 made up of a plurality of light emitting pixels 72 . In this embodiment, the shielding wall 63 is provided for the light emitting element 71 , the collimator lens 97 , and the lens 146 .
[0114] [Fifteenth embodiment] Fig. 32 is a schematic diagram of a display device 150 applied to eyewear according to a fifteenth embodiment. As shown in Fig. 32, light emitted from the display device 150 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 150 is configured such that, from a position farther from the retina 33 toward a position closer to the retina 33, a light emitting element 151 having a curved surface and a liquid crystal microlens array 155 having a curved surface are arranged in this order. The light emitting element 151 constitutes a plurality of light emitting pixels 152. A light emitting pixel group 153 is constituted by a plurality of light emitting pixels 152 that emit light having the same information. By using the light emitting element 151 having a curved surface and the liquid crystal microlens array 155, the distance from the display device 150 to the retina 33 of the light incident on the eye 31 can be made substantially uniform within the plane. This makes it possible to display an image with improved image quality on the retina 33. The display device 150 and the liquid crystal microlens array 155 are configured using a flexible substrate, and are therefore deformable to have a desired curved surface, for example, a curved surface that follows the curved surface of the eyeball. The liquid crystal microlens array 155 functions as a scanning mechanism, and also has a function of an optical system that has a function of making the light from the light emitting pixel group 153 parallel or nearly parallel, and a function of refracting the light in the pupil direction. In this embodiment, the shielding wall 63 is provided on the light emitting element 151 .
[0115] [Sixteenth embodiment] Fig. 33 is a schematic diagram of a display device 160 applied to eyewear according to a sixteenth embodiment. As shown in Fig. 33, light emitted from the display device 160 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 160 is configured such that, from a position farther from the retina 33 toward a position closer to the retina 33, a light emitting element 151 having a curved surface, a collimator lens 167 having a curved surface, and a liquid crystal microlens array 165 having a curved surface are arranged in this order. The liquid crystal microlens array 165 functions as a scanning mechanism, and also has a function of an optical system that has a function of making the light from the light emitting pixel group 153 parallel or nearly parallel, and a function of refracting the light in the pupil direction. In this embodiment, the shielding wall 63 is provided to the light emitting element 151 and the collimator lens 167 .
[0116] [Seventeenth embodiment] Fig. 34 is a schematic diagram of a display device 170 applied to eyewear according to a seventeenth embodiment. As shown in Fig. 34, light emitted from the display device 170 is projected onto the retina 33 of the eye 31, and an image is displayed on the retina 33. The display device 170 is configured such that, from a position farther from the retina 33 toward a position closer to the retina 33, a light emitting element 151 having a curved surface, a collimator lens 167 having a curved surface, a liquid crystal microlens array 165 having a curved surface, and a plano-convex lens 176 are arranged in this order. The liquid crystal microlens array 175 functions as a scanning mechanism, and also functions as an optical system having a function of collimating or nearly collimating the light from the light emitting pixel group 153 . In this embodiment, the shielding wall 63 is provided to the light emitting element 151 and the collimator lens 167 .
[0117] [Additional explanation] In each of the above-described embodiments, the resolution and movement of the projected image may be controlled by controlling an optical system such as a light-emitting element or a microlens array, thereby adjusting the target position on the projection object where the projected light reaches, the size of the image at the target position, or the reduction / enlargement state of the image. This reduces image distortion, uneven resolution, and uneven movement on the projection target. Image distortion refers to, for example, a trapezoidal image being projected onto a screen as a projection target, instead of a rectangular image that should be projected otherwise. This occurs because the display device is positioned at an angle to the screen, rather than facing it directly. The output information from the light-emitting element and the optical system may be controlled so that such image distortion is cancelled. For example, image distortion can be suppressed by partially reducing or enlarging the image projected onto the screen (corresponding to adjusting the reduction / enlargement state of the image as described above).
[0118] In some of the display device embodiments described above, examples have been given in which light emitted from a group of light-emitting pixels consisting of a plurality of light-emitting pixels that output the same information is projected in a time-division manner, but the light may also be configured to be projected at the same time. Further, in the display devices according to some of the embodiments described above, the number of light-emitting pixels constituting the light-emitting pixel group does not change. However, the number of light-emitting pixels constituting the light-emitting pixel group may be changed. Furthermore, the number of light emitting pixel groups that emit light at the same time may be configured to change over time. Furthermore, the position, shape, and size of a group of light-emitting pixels in a light-emitting element may be changeable by controlling the light emitted from the light-emitting pixels or by an optical system adjacent to the light-emitting pixels.
[0119] In the above-described embodiment, the light emitting element is exemplified as a light emitting element in which light emitting pixels are arranged two-dimensionally. However, the light emitting element may be a light emitting element in which light emitting pixels are arranged one-dimensionally or three-dimensionally.
[0120] In the above-described embodiment, the display device may be equipped with one or more cameras or the like for capturing moving images, still images, and sounds. The display device may display the images captured by the cameras on the projection target. The display device may display images and information acquired from an external device on a projection target. Furthermore, the display device may enlarge or reduce an image acquired by a built-in camera or an image or information acquired from an external device and display it on a projection object. In addition, the display device may change the resolution of images acquired by the built-in camera or images or information acquired from an external device, or process, edit, or modify the content, and display it on the projection object. The display device may also display on the projection object, changing the color tone or image quality of an image acquired by a built-in camera or an image acquired from an external device for each region. Here, each region refers to a region into which the image projected on the projection object is divided. For example, in order to highlight a part of the image projected on the projection object, the color tone or image quality of that part is changed. In addition, a display device applied to eyewear may be configured to acquire biometric information, such as estimating the blinking, eye direction, and eye expression of a user wearing the eyewear, from image information acquired by an installed camera. Furthermore, as described above, in a display device applied to eyewear, the light-emitting element and optical system may be controlled based on the results of sensing the movement of the pupil using a sensing device such as an installed camera, so that light is reliably emitted toward the pupil. The camera to be mounted may be, for example, an imaging device in which multiple lenses are arranged on a single image sensor.
[0121] In a display device applied to eyeglasses-like eyewear, for example, an area corresponding to the lens portion of eyeglasses may be configured to be able to transmit external light, and a superimposed image in which an image projected from the display device is superimposed on an external scene may be presented to a user. Furthermore, the amount of external light transmitted through the area corresponding to the lens portion of eyeglasses may be configured to be manually or automatically variable. In a display device applied to eyeglasses-like eyewear, for example, when the display device is disposed corresponding to the lens portion of eyeglasses, the lens portion may be configured to flip up. This allows the user to quickly switch between viewing the outside scenery and viewing the image projected from the display device. In addition, in such eyewear with a flip-up function, the lens portion for the left eye and the lens portion for the right eye may be configured to flip up independently. This allows for diversification of the usage forms of the eyewear.
[0122] A display device applied to eyewear may be equipped with a sensing device that acquires biometric information of a user, such as iris authentication, pupil state, fundus blood vessel contraction, development state, pulse wave, brain wave, etc. The display device may also be equipped with a sensing device, such as a microphone, that acquires external environmental information, such as sound.
[0123] Each of the above-mentioned display devices may be configured to be connectable to a network. For example, a display device applied to eyewear may be configured to generate information required for a user wearing the eyewear using biological information, environmental information, and network information acquired by the sensing device, and present the information to the user. Information presented to the user is not limited to image information, and may be information such as sound or vibration, and may be configured to be sensed by human vision, hearing, and touch. Information presentation means such as earphones, headphones, and speakers can be used to present information related to hearing. Information presentation means such as vibration, pressure, and temperature can be used to present information related to touch.
[0124] For example, in a display device applied to eyeglasses-type eyewear, the user's eye or an image resembling an eye may be displayed on the lens of the eyeglasses so as to be visible from the outside. The image of the eye may change according to the blinking, direction, and expression of the eye of the user wearing the eyewear.
[0125] In addition, in a display device applied to eyewear, a display device provided for the right eye and a display device provided for the left eye may display different two-dimensional images according to the parallax. This makes it possible to provide a stereoscopic image to the user. When a camera is mounted as described above, a camera is mounted for each of the right eye and the left eye.
[0126] The embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present technology. For example, in some of the above-mentioned embodiments, an example was given in which the microlens array was physically scanned in order to increase the resolution of the image on the projection object such as a screen or a retina. In contrast, a chip-shaped display device may be formed by integrating an optical system including a light-emitting element and a microlens array, and the chip-shaped display device may be scanned. This configuration is effective in maintaining the positional accuracy of the optical system and the light-emitting pixels, and a stable high-resolution image can be displayed. For example, the entire chip-shaped display device is mechanically scanned, and the output information to the light-emitting pixels is electrically scanned in the opposite direction to the mechanical scanning of the entire chip-shaped display device. This allows an effect equivalent to that of scanning the optical system relatively.
[0127] The present technology can also be configured as follows. (1) A light emitting element including a plurality of first light emitting pixels and a plurality of second light emitting pixels; a microlens array having a plurality of lenses arranged at a pitch larger than the pixel pitch of the light-emitting pixels, the microlens array projecting the incident diffuse light emitted from each of the first light-emitting pixel and the second light-emitting pixel to a first destination position and a second destination position that are located at desired positions on a projection object, the first destination position and the second destination position being different from each other; a scanning mechanism for projecting the diffused light emitted from the first light-emitting pixel to the first destination position via the microlens array, and then projecting the diffused light emitted from the second light-emitting pixel to the second destination position via the microlens array; A display device comprising:
[0128] (2) A light emitting element having a plurality of light emitting pixels; a microlens array having a plurality of lenses arranged at a pitch larger than the pixel pitch of the light-emitting pixels, the microlens array projecting the incident light emitted from a first light-emitting pixel group and a second light-emitting pixel group each composed of a plurality of light-emitting pixels selected from the plurality of light-emitting pixels onto a first destination position and a second destination position each located at a desired position different from each other on a projection object; a scanning mechanism for projecting light emitted from a plurality of light-emitting pixels constituting the first light-emitting pixel group and emitting light having the same information to the first destination position via the microlens array, and thereafter projecting light emitted from a plurality of light-emitting pixels constituting the second light-emitting pixel group and emitting light having the same information to the second destination position via the microlens array; A display device comprising:
[0129] (3) The display device according to (2) above, A plurality of light-emitting pixels constituting the first light-emitting pixel group and a plurality of light-emitting pixels constituting the second light-emitting pixel group are partially different from each other. Display device.
[0130] (4) The display device according to any one of (1) to (3) above, The microlens array is a microlens array formed by arranging a plurality of convex or concave lenses, or a liquid crystal microlens array formed by a plurality of liquid crystal lenses. Display device.
[0131] (5) The display device according to (4) above, the microlens array is the liquid crystal microlens array, The liquid crystal microlens array also serves as the scanning mechanism. Display device.
[0132] (6) The display device according to any one of (1) to (5) above, The projection object is a screen. Display device.
[0133] (7) The display device according to any one of (1) to (5) above, The projection object is the retina of the eye. Display device.
[0134] (8) The display device according to (7) above, The light emitting element emits light such that information of the light to be projected differs between a region of the fovea of the retina and a peripheral portion of the fovea. Display device. [Explanation of symbols]
[0135] 1, 21, 51, 61, 71, 151...Light emitting element 2, 22, 52, 62, 72, 152...light-emitting pixels 2A, 62A...first light-emitting pixel 2B, 62B...Second light-emitting pixel 2C, 62C...Third light-emitting pixel 3...Screen (projection object) 4, 24, 64, 74…Achieved position 4A, 24A, 64A, 74A...First arrival position 4B, 24B, 64B, 74B...Second arrival position 4C, 24C, 64C, 74C…Third reaching position 5, 65, 77…Microlens array 10, 20, 30, 40, 50, 55...Projector (display device) 23, 73, 153...luminous pixel group 23A, 73A...first light-emitting pixel group 23B, 73B...Second light-emitting pixel group 23C, 73C...Third light-emitting pixel group 23D, 73D...fourth light-emitting pixel group 24D, 74D…4th arrival position 24E, 74E…5th arrival position 24F, 74F…6th arrival position 24G, 74G...7th arrival position 24H, 74I…8th arrival position 24I, 74I…9th arrival position 33...Retina (projection object) 35, 45, 125, 135, 145, 155, 165, 175...Liquid crystal microlens array (microlens array, scanning mechanism) 53, 650...Convex lenses (lenses that make up the microlens array) 54, 6...Actuator (scanning mechanism) 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170...Eyewear (display devices) 770...Concave lens (lens that makes up the microlens array)
Claims
1. A light emitting element including a plurality of first light emitting pixels and a plurality of second light emitting pixels; a microlens array having a plurality of lenses arranged at a pitch larger than a pixel pitch of the light-emitting pixels, the microlens array projecting the incident diffuse light emitted from the first light-emitting pixel and the second light-emitting pixel to a first destination position and a second destination position that are different from each other on a projection target; a scanning mechanism for projecting the diffused light emitted from the first light-emitting pixel to the first destination position via the microlens array, and then projecting the diffused light emitted from the second light-emitting pixel to the second destination position via the microlens array; A display device comprising:
2. A light emitting element having a plurality of light emitting pixels; a microlens array having a plurality of lenses arranged at a pitch larger than the pixel pitch of the light-emitting pixels, the microlens array projecting the incident light emitted from a first light-emitting pixel group and a second light-emitting pixel group each composed of a plurality of light-emitting pixels selected from the plurality of light-emitting pixels to a first destination position and a second destination position each located at a desired position different from each other on a projection object; a scanning mechanism for projecting light emitted from a plurality of light-emitting pixels that constitute the first light-emitting pixel group and emit light having the same information to the first destination position via the microlens array, and thereafter projecting light emitted from a plurality of light-emitting pixels that constitute the second light-emitting pixel group and emit light having the same information to the second destination position via the microlens array; A display device comprising:
3. The display device according to claim 2, A plurality of light-emitting pixels constituting the first light-emitting pixel group and a plurality of light-emitting pixels constituting the second light-emitting pixel group are partially different from each other. Display device.
4. The display device according to claim 1 or 2, The microlens array is a microlens array configured by arranging a plurality of convex or concave lenses, or a liquid crystal microlens array configured by a plurality of liquid crystal lenses. Display device.
5. The display device according to claim 4, the microlens array is a liquid crystal microlens array, The liquid crystal microlens array also serves as the scanning mechanism. Display device.
6. The display device according to claim 1 or 2, The projection object is a screen. Display device.
7. The display device according to claim 1 or 2, The projection object is the retina of the eye. Display device.
8. The display device according to claim 7, The light emitting element emits light such that the information of the light projected is different between a region of the fovea of the retina and a peripheral portion of the fovea. Display device.
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