Retina projection type image display device and optometric device

Abstract

To miniaturize a device that can make an exit pupil movable.SOLUTION: A retinal projection type image display device has: a first light source; an optical scanning unit that forms an image by scanning light from the first light source; an eyepiece optical system that guides an exit pupil of the light from the optical scanning unit to an eyeball of an observer; and a variable optical system that changes an incidence position upon the optical scanning unit of the light emitted from the first light source. The variable optical system is arranged between the first light source and the optical scanning unit, and can move the exit pupil.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a retinal projection image display device and an ophthalmological apparatus. [Background technology]

[0002] 2. Description of the Related Art Retinal projection image display devices are known that project images onto the retina of a wearer, thereby allowing the wearer to view the images.

[0003] For example, Patent Document 1 discloses an optical scanning display device having a mechanism for moving an eyepiece optical system that guides a light beam from a scanning optical system to the exit pupil in order to move the exit pupil. Summary of the Invention [Problem to be solved by the invention]

[0004] However, the device described in Patent Document 1 has a mechanism for moving the eyepiece optical system, which may result in the device becoming larger in size.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to reduce the size of an apparatus capable of moving an exit pupil. [Means for solving the problem]

[0006] A retinal projection type image display device according to one embodiment of the present invention comprises a first light source, an optical scanning unit that forms an image by scanning light from the first light source, an eyepiece optical system that directs the exit pupil of light from the optical scanning unit to an observer's eyeball, and a variable optical system that changes the incident position of light emitted from the first light source onto the optical scanning unit, wherein the variable optical system is disposed between the first light source and the optical scanning unit and is capable of moving the exit pupil. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce the size of an apparatus capable of moving an exit pupil. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic top view showing the overall configuration of a retinal projection image display device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic top view showing a light scanning unit included in the retinal projection image display device according to the first embodiment of the present invention. [Figure 3] 1 is a schematic top view showing a movable mirror provided in a variable optical system of a retinal projection type image display device according to a first embodiment of the present invention. [Figure 4] FIG. 2 is a block diagram showing the hardware configuration of a control unit included in the retinal projection image display device according to the first embodiment of the present invention. [Figure 5] FIG. 2 is a block diagram showing the functional configuration of a control unit included in the retinal projection image display device according to the first embodiment of the present invention. [Figure 6] 3A and 3B are schematic diagrams illustrating an outline of the movement operation of the exit pupil in the retinal projection type image display device according to the first embodiment of the present invention. [Figure 7] FIG. 1 is a first schematic diagram showing details of the movement operation of the exit pupil in the retinal projection type image display device according to the first embodiment of the present invention. [Figure 8] FIG. 2 is a second schematic diagram showing details of the movement operation of the exit pupil in the retinal projection type image display device according to the first embodiment of the present invention. [Figure 9] FIG. 3 is a third schematic diagram showing details of the movement operation of the exit pupil in the retinal projection type image display device according to the first embodiment of the present invention. [Figure 10] 5A to 5C are schematic diagrams illustrating the operation of the retinal projection image display device according to the first embodiment of the present invention. [Figure 11] FIG. 10 is a schematic top view showing a retinal projection type image display device according to a second embodiment of the present invention. [Figure 12] 10A and 10B are schematic diagrams showing the movement of the exit pupil in a retinal projection type image display device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A retinal projection image display device and an optometry device according to embodiments of the present invention will be described in detail with reference to the drawings. However, the following embodiments are merely examples of the retinal projection image display device and the optometry device according to the present invention, and are not intended to limit the scope of the present invention.

[0010] Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of components described in the embodiments of the present invention are not intended to limit the scope of the embodiments of the present invention, but are merely illustrative examples. The sizes, positional relationships, etc. of components shown in each drawing may be exaggerated for clarity. In the following description, the same names and symbols indicate the same or similar components, and detailed descriptions will be omitted as appropriate.

[0011] In the following, for ease of understanding, the arrangement and configuration of each part may be explained using one of the XYZ Cartesian coordinate system, the αβγ Cartesian coordinate system, or the abc Cartesian coordinate system. The three axes in each of the XYZ Cartesian coordinate system, the αβγ Cartesian coordinate system, and the abc Cartesian coordinate system are orthogonal to each other.

[0012] In the XYZ Cartesian coordinate system, the direction in which the X axis extends is referred to as the "X direction," the direction in which the Y axis extends is referred to as the "Y direction," and the direction in which the Z axis extends is referred to as the "Z direction." The direction in which the arrow indicating the X axis points is referred to as the +X direction, and the direction opposite to the +X direction is referred to as the -X direction. The direction in which the arrow indicating the Y axis points is referred to as the +Y direction, and the direction opposite to the +Y direction is referred to as the -Y direction. The direction in which the arrow indicating the Z axis points is referred to as the +Z direction, and the direction opposite to the +Z direction is referred to as the -Z direction. In this specification, a view of an object viewed from the +Y direction is referred to as a top view.

[0013] In the αβγ Cartesian coordinate system, the direction in which the α axis extends is called the "α direction," the direction in which the β axis extends is called the "β direction," and the direction in which the γ axis extends is called the "γ direction." The direction in which the arrow indicating the α axis points is called the +α direction, and the direction opposite to the +α direction is called the -α direction. The direction in which the arrow indicating the β axis points is called the +β direction, and the direction opposite to the +β direction is called the -β direction. The direction in which the arrow indicating the γ axis points is called the +γ direction, and the direction opposite to the +γ direction is called the -γ direction.

[0014] In the abc Cartesian coordinate system, the direction in which the a-axis extends is called the "a direction," the direction in which the b-axis extends is called the "b direction," and the direction in which the c-axis extends is called the "c direction." The direction in which the arrow indicating the a-axis points is called the +a direction, and the direction opposite to the +a direction is called the -a direction. The direction in which the arrow indicating the b-axis points is called the +b direction, and the direction opposite to the +b direction is called the -b direction. The direction in which the arrow indicating the c-axis points is called the +c direction, and the direction opposite to the +c direction is called the -c direction.

[0015] However, the above directional expressions merely describe the relationship of relative position, orientation, direction, etc., and do not necessarily correspond to the relationship during use. Furthermore, these directions are unrelated to the direction of gravity.

[0016] In this specification and claims, the term "image" includes not only still images but also moving images. Moving images can also be called images. In this specification and claims, "match" does not require perfect match, but allows for some degree of error that can be considered to be an error in assembly or processing. Furthermore, "parallel" does not require perfect parallelism, but allows for some degree of error that can be considered to be an error in assembly or processing.

[0017] [First embodiment] <Configuration of a retinal projection image display device according to the first embodiment of the present invention> The configuration of a retinal projection image display device according to a first embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a schematic top view showing an example of the overall configuration of a retinal projection image display device 100 according to a first embodiment of the present invention. Figure 2 is a schematic top view showing an example of an optical scanning unit 2 included in the retinal projection image display device 100 according to the first embodiment of the present invention. Figure 3 is a schematic top view showing an example of a movable mirror 41 included in the variable optical system 4 of the retinal projection image display device 100 according to the first embodiment of the present invention.

[0018] The retinal projection image display device 100 shown in Fig. 1 is a wearable device, and is a retinal projection head mounted display (HMD) that projects an image directly onto the observer's retina by optical scanning using Maxwellian vision. In the example shown in Fig. 1, the retinal projection image display device 100 projects an image onto the right eyeball 50 of the observer U. However, the retinal projection image display device 100 is not limited to projecting an image onto the right eyeball 50 of the observer U, and can also project an image onto the left eyeball, and can also project images onto both eyeballs in parallel.

[0019] 1, the retinal projection image display device 100 includes a first light source 1, an optical scanning unit 2 that forms an image by scanning light L1 from the first light source 1, and an eyepiece optical system 3 that guides the exit pupil of light from the optical scanning unit 2 to the eyeball 50 of an observer U. The retinal projection image display device 100 also includes a variable optical system 4 that changes the incident position of the light emitted from the first light source 1 on the optical scanning unit 2. The variable optical system 4 is disposed between the first light source 1 and the optical scanning unit 2. The retinal projection image display device 100 is capable of moving the exit pupil E.

[0020] In the example shown in FIG. 1 , the retinal projection image display device 100 includes a first lens 5 disposed between a first light source 1 and a variable optical system 4, which transmits light L1 from the first light source 1; a prism 6 onto which the light L1 transmitted through the first lens 5 is incident; and a fixed mirror 7 which reflects light L2 emitted from the prism 6 toward a holographic optical element 32 included in the eyepiece optical system 3. The retinal projection image display device 100 also includes a detection unit 8 which detects the position of the pupil 51 or cornea of the observer U, and a control unit 9 which controls the operation of the light scanning unit 2 and the variable optical system 4 in accordance with the position of the pupil 51 or cornea of the observer U detected by the detection unit 8. The cornea of the observer U corresponds to the position of region P on the corneal surface in FIG. 1 . The retinal projection image display device 100 also includes a spectacle-type support 11 including temples 111. In the example shown in Figure 1, the first light source 1, the optical scanning unit 2, the eyepiece optical system 3, the variable optical system 4, the first lens 5, the prism 6, the fixed mirror 7, the detection unit 8 and the control unit 9 are each arranged inside the temple 111.

[0021] In the example shown in FIG. 1 , light L1 emitted from the first light source 1 passes through a first lens 5 and then enters a prism 6. The light L1 that enters the prism 6 passes through a variable optical system 4 and enters the optical scanning unit 2. The light L2 scanned by the optical scanning unit 2 passes through a second lens 31 included in the eyepiece optical system 3 and is reflected by a fixed mirror 7 toward a holographic optical element 32. The light L2 that enters the holographic optical element 32 is reflected by the holographic optical element 32 while being focused toward an eyeball 50 of an observer U. The light L2 reflected by the holographic optical element 32 passes through an exit pupil E and a pupil 51 of the eyeball 50 and reaches a retina 52. An image formed by the light L2 scanned by the optical scanning unit 2 is projected onto the retina 52. The observer U can visually recognize the image projected onto the retina 52.

[0022] In recent years, technologies and products related to virtual reality (VR) and augmented reality (AR) have been attracting attention. AR technology, in particular, is expected to be applied to consumer and industrial sectors as a means of expanding the visual perception of the real world and integrating digital information into real space, thereby creating new added value. Toward this goal, image display devices such as wearable head-mounted displays (HMDs) that can be used in active and work environments are being developed. To simultaneously view the real world and an image, see-through (transparent) HMDs are the mainstream. Wearable HMDs that display virtual images in front of the eyes through eyepiece optics, such as partially reflective films or image guide structures, have been introduced to the market. While optical quality that blends seamlessly into everyday life is an important factor for HMDs used in real space, style and design are also crucial. Compared to conventional eyeglass frames, the HMDs currently available on the market are significantly larger and less fashionable, which has, needless to say, alienated consumers. The pursuit of style is a major challenge in this industry. Wearable head-mounted displays are required to have a style that impresses with beauty, and also to deliver new added value by adding digital images to users with sufficient visual quality.

[0023] In light of the above, retinal projection image display devices using a laser to project an image directly onto the retina have attracted attention. Conventional image display devices displaying virtual images require focusing on an image drawn at a fixed depth, limiting the depth plane in which both real-world objects and the image can be simultaneously focused, hindering natural human behavior (tasks). On the other hand, laser-based retinal projection utilizes Maxwellian vision to focus an image on the pupil and then project it onto the retina. This allows for focus-free viewing, regardless of the observer's visual acuity or focal depth position. This allows for clear viewing of the image regardless of the focus position in the external world. However, due to the characteristic of focusing an image on the pupil, retinal projection devices tend to have a narrow eyebox (visual field). Here, the eyebox refers to the spatial region around the eye where the observer can move their gaze without losing track of the image. When the eyebox is narrow, even a slight change in the observer's line of sight can cause the image to disappear.

[0024] For example, in FIG. 1 , the relative position of the eyeball 50 with respect to the eyeglass-type support 11 varies depending on the face shape, size of the eyeball 50, etc. of the observer U. If the relative position of the eyeball 50 with respect to the eyeglass-type support 11 differs for each observer U, the exit pupil E may be misaligned with the pupil 51, which may cause the light L2 to stop passing through the pupil 51 and not reach the retina 52. Furthermore, if the observer U changes the line of sight and the position of the pupil 51 or the cornea changes, the exit pupil E may be misaligned with the pupil 51, which may cause the light L2 to stop passing through the pupil 51 and not reach the retina 52. If the light L2 does not reach the retina 52, the observer U cannot view the image. If the observer U moves the eyeball 50 while viewing an image and the light L2 no longer passes through the pupil 51, the light L2 will not reach the retina 52, and the image viewed by the observer U will disappear.

[0025] Patent Document 1 discloses a device that uses a mechanism for moving an eyepiece optical system to move the eyepiece optical system in accordance with the position of a pupil 51, thereby moving an exit pupil E, thereby making it easier for light incident on an eyeball 50 to pass through the pupil 51 and reach a retina 52. However, the device described in Patent Document 1 has a large mechanism for moving the eyepiece optical system, which can result in the device becoming large.

[0026] In the retinal projection image display device 100 according to this embodiment, the variable optical system 4 is disposed between the first light source 1 and the optical scanning unit 2 and changes the incident position of the light emitted from the first light source 1 onto the optical scanning unit 2. The eyepiece optical system 3 collimates the light L2 scanned by the optical scanning unit 2 and converges the light L2 at different positions depending on the incident position on the optical scanning unit 2, thereby forming an exit pupil. This configuration converts the change in the incident position onto the optical scanning unit 2 by the variable optical system 4 into a movement (shift) of the exit pupil E, and the retinal projection image display device 100 is capable of moving the exit pupil E. In this embodiment, the exit pupil E can be moved without a mechanism for moving the eyepiece optical system 3, thereby enabling a device capable of moving the exit pupil E to be miniaturized. Furthermore, in this embodiment, the movable exit pupil E reduces the possibility that the light L2 incident on the eyeball 50 will be blocked by the pupil 51 due to, for example, the tilt of the eyeball 50, thereby making it easier for the light L2 to reach the retina 52. As a result, in this embodiment, the eyebox of the observer U can be enlarged.

[0027] 1, the variable optical system 4 converts the light L1 emitted from the first light source 1 into collimated light, and then makes it incident on the optical scanning unit 2. With this configuration, even if the distance between the variable optical system 4 and the optical scanning unit 2 is changed, the angle of incidence of the light L1 incident on the optical scanning unit 2 can be kept the same without changing the performance of the function of converting a change in the incident position on the optical scanning unit 2 by the variable optical system 4 into a movement of the exit pupil E.

[0028] In the retinal projection image display device 100 shown in FIG. 1, the variable optical system 4 includes a movable mirror 41 and a concave mirror 42 that converts light L1 from the movable mirror 41 into collimated light. The variable optical system 4 changes the reflection angle of the light L1 by changing the tilt of the movable mirror 41, thereby changing the incident position of the light L1 on the optical scanning unit 2. The variable optical system 4 also converts the light L1 from the movable mirror 41 into collimated light, for example, by using the concave mirror 42 to reflect the light L1 from the movable mirror 41 and convert it into parallel light. With a simple configuration consisting of the movable mirror 41 and the concave mirror 42, the retinal projection image display device 100 can cause the collimated light L1 to be incident on the optical scanning unit 2 and change the incident position of the light L1 on the optical scanning unit 2.

[0029] In the retinal projection image display device 100 shown in FIG. 1, the light scanning unit 2 and the variable optical system 4 are arranged on the temples 111 so as to be aligned in the direction in which the temples 111 extend. The direction in which the temples 111 extend is a direction approximately perpendicular to the direction in which the eyes of the observer U wearing the eyeglass-type support member 11 are aligned. In the example shown in FIG. 1, the direction in which the eyes of the observer U wearing the eyeglass-type support member 11 are aligned corresponds to the X direction, and the direction approximately perpendicular to the direction in which the eyes are aligned corresponds to the Z direction. By arranging the light scanning unit 2 and the variable optical system 4 aligned in the direction in which the temples 111 extend, the temples 111 can be made thinner, and the retinal projection image display device 100 can be made more compact, compared to when the light scanning unit 2 and the variable optical system 4 are arranged in a direction approximately perpendicular to the direction in which the temples 111 extend. The light scanning unit 2 and the variable optical system 4 may be arranged inside the temples 111 or on the surface of the temples 111.

[0030] 1, the eyepiece optical system 3 is disposed opposite the eyeball 50 of the observer U and includes a holographic optical element 32 that reflects and focuses the light L2 from the optical scanning unit 2 toward the eyeball 50. The holographic optical element 32 has both the function of reflecting and the function of focusing the light L2, which simplifies the configuration of the eyepiece optical system 3 and enables the eyepiece optical system 3 to be made smaller than when a component that reflects and a component that focuses the light L2 are provided separately. By making the eyepiece optical system 3 smaller, the retinal projection image display device 100 can be made smaller.

[0031] In the retinal projection image display device 100 shown in Fig. 1, when the optical scanning unit 2 and the variable optical system 4 are not operating, the reflective mirror 92a of the optical scanning unit 2 and the reflective surface 14 of the variable optical system 4 are arranged in opposing directions. In other words, the direction in which the reflective mirror 92a of the optical scanning unit 2 faces (-X direction) is opposite to the direction in which the reflective surface 14 of the variable optical system 4 faces (+X direction). The reflective mirror 92a of the optical scanning unit 2 and the reflective surface 14 of the variable optical system 4 each correspond to an "optical scanning surface." This configuration allows the retinal projection image display device 100 to be made smaller.

[0032] 1 has the detection unit 8 and the control unit 9, and therefore can control the operation of the light scanning unit 2 and the variable optical system 4 so that the light L2 passes through the pupil 51 of the eyeball 50, even when the observer U changes the line of sight and changes the position of the pupil 51 or cornea. This reduces the blocking of the light L2 by the pupil 51 depending on the position of the pupil 51 or cornea, and can enlarge the eyebox of the observer U.

[0033] 1, the detection unit 8 includes a second light source 81 and a light receiving unit 82 that receives light L3 emitted from the second light source 81 and reflected by the eyeball 50 of the observer U and outputs information related to the light reception position. The light scanning unit 2 is capable of scanning the light L3 that is emitted from the second light source 81 and incident on the eyeball 50 of the observer U. Because the light scanning unit 2 is capable of scanning the light L2, even when the observer U significantly changes the direction of their line of sight and the position of the pupil 51 or cornea becomes larger, it is possible to reduce the possibility that the light L3 reflected by the eyeball 50 will not be received by the light receiving unit 82, making it easier to detect the position of the pupil 51 or cornea.

[0034] The configuration of the retinal projection image display device 100 and the elements that make up the retinal projection image display device 100 will be described in detail below.

[0035] (Glasses type support 11) The eyeglass-type support 11 has the shape and appearance of an eyeglass frame. In the example shown in Fig. 1, the eyeglass-type support 11 includes temples 111, as well as rims 112 connected to the temples 111, and eyeglass lenses 113 held by the rims 112. The eyeglass lenses 113 include prescription eyeglass lenses.

[0036] The first light source 1 may be disposed outside the temple 111, and light L1 emitted from the first light source 1 may be guided inside the temple 111. The control unit 9 may be provided inside the temple 111. The control unit 9 may be provided outside the temple 111, and a drive signal from the control unit 9 may be supplied to the inside of the temple 111. In the eyeglass-type support 11, the angle formed by the longitudinal direction of the temple 111 and the longitudinal direction of the rim 112 does not necessarily have to be perpendicular and can be selected appropriately.

[0037] (1st light source 1) In the example shown in FIG. 1, the first light source 1 is a semiconductor laser that emits laser beams of a single or multiple wavelengths. More specifically, the first light source 1 includes a red semiconductor laser, a green semiconductor laser, and a blue semiconductor laser. The first light source 1 emits light L1, which is a time-modulated laser beam, in response to a drive signal D1 from the control unit 9. Since the first light source 1 includes a red semiconductor laser, a green semiconductor laser, and a blue semiconductor laser, the retinal projection image display device 100 can display color images. However, the retinal projection image display device 100 can also display only monochrome images. When the retinal projection image display device 100 displays only monochrome images, the first light source 1 may emit light of a single color.

[0038] The light intensity of the light L1 emitted from the first light source 1 is preset to an appropriate light intensity that fully considers the safety of the eyes of the observer U. However, the retinal projection image display device 100 may be equipped with an optical element that reduces the light intensity of the light L1, as necessary. The retinal projection image display device 100 also has a light-receiving element, such as a photodiode, that receives the light L1 emitted by the first light source 1 and outputs a signal corresponding to the light intensity of the light L1. Based on the output signal from the light-receiving element, the light intensity of the light L1 can be controlled to ensure the safety of the eyes of the observer U. The light intensity that can ensure the safety of the eyes of the observer U refers to a light intensity below Class 1 defined in IEC (International Electrotechnical Commission) 60825-1, an international standard regarding the safety of laser light. The first light source 1 is not limited to a semiconductor laser, and may be a solid-state laser or a gas laser.

[0039] The retinal projection image display device 100 can change the current or voltage applied to the first light source 1 to change the light intensity of the light L1 emitted from the first light source 1. This allows the retinal projection image display device 100 to adjust the brightness of the image to be displayed in accordance with the brightness of the surrounding environment in which the retinal projection image display device 100 is used.

[0040] (Optical scanning unit 2) The optical scanning unit 2 shown in FIG. 2 includes a support substrate 91, a movable unit 92, a serpentine beam unit 93, a serpentine beam unit 94, and an electrode connection unit 95.

[0041] The optical scanning unit 2 is a MEMS (Micro Electro Mechanical Systems) mirror that swings (rotates) around two axes that are approximately perpendicular to each other. The optical scanning unit 2 has a reflective mirror 92a on a movable unit 92 connected to a support substrate 91. The optical scanning unit 2 swings the movable unit 92 to change the angle of the reflective mirror 92a, thereby scanning light L2, which is reflected light of light L1 incident on the reflective mirror 92a. The optical scanning unit 2 can form an image using the scanned light L2.

[0042] 1, the main scanning direction, in which pixels are drawn successively over time to form a series of pixel groups, corresponds to the Z direction at the position of the optical scanning unit 2 and to the X direction at the position of incidence on the eyeball 50. The sub-scanning direction, which is perpendicular to the main scanning direction and arranges a series of pixel groups, corresponds to the Y direction at both the position of the optical scanning unit 2 and the position of incidence on the eyeball 50. The scanning speed in the main scanning direction is set higher than the scanning speed in the sub-scanning direction.

[0043] In the example shown in FIG. 2, the serpentine beam portion 93 has a plurality of folded portions and is formed in a serpentine shape, with one end connected to the support substrate 91 and the other end connected to the movable portion 92. The serpentine beam portion 93 includes a beam portion 93a including three beams and a beam portion 93b including three beams. The beams of the beam portion 93a and the beams of the beam portion 93b are formed alternately. Each of the beams included in the beam portion 93a and the beam portion 93b is independently equipped with a piezoelectric element. The number of beams included in the beam portion 93a is not limited to three and may be any number.

[0044] In the example shown in FIG. 2, the serpentine beam portion 94 has a plurality of folded portions and is formed in a serpentine shape, with one end connected to the support substrate 91 and the other end connected to the movable portion 92. The serpentine beam portion 94 includes a beam portion 94a including three beams and a beam portion 94b including three beams. The beams of the beam portion 94a and the beams of the beam portion 94b are formed alternately. Each of the beams included in the beam portion 94a and the beam portion 94b is independently provided with a piezoelectric element. The number of beams included in the beam portion 94b is not limited to three and may be any number.

[0045] The piezoelectric elements included in each of beams 93a, 93b, 94a, and 94b are provided as piezoelectric layers in, for example, a portion of each layer of a multi-layered beam. Hereinafter, the piezoelectric elements included in beams 93a and 94a may be referred to as piezoelectric elements 95a, and the piezoelectric elements included in beams 93b and 94b may be referred to as piezoelectric elements 95b. When voltage signals of opposite phases are applied to piezoelectric elements 95a and 95b to warp the serpentine beam 94, adjacent beams bend in different directions. This warping accumulates, generating a rotational force that causes the reflecting mirror 92a to reciprocate around axis A, which is parallel to the β direction.

[0046] 2, the movable portion 92 is formed so as to be sandwiched in the β direction between a serpentine beam portion 93 and a serpentine beam portion 94. The movable portion 92 includes a reflecting mirror 92a, a torsion bar 92b, a piezoelectric member 92c, and a support portion 92d.

[0047] The reflecting mirror 92a is formed, for example, by depositing a metal thin film containing aluminum, gold, silver, etc. on a base material. One end of the torsion bar 92b is connected to the reflecting mirror 92a, and the torsion bar 92b extends in the positive and negative α directions to rotatably support the reflecting mirror 92a.

[0048] One end of the piezoelectric element 92c is connected to the torsion bar 92b, and the other end is connected to the support 92d. When a voltage is applied to the piezoelectric element 92c, the piezoelectric element 92c is bent and deformed, causing a twist in the torsion bar 92b. The twist in the torsion bar 92b acts as a rotational force, causing the reflecting mirror 92a to rotate around the B axis, which is parallel to the α direction.

[0049] When the reflecting mirror 92a rotates around the A axis, the light L1 incident on the reflecting mirror 92a is scanned in the α direction. When the reflecting mirror 92a rotates around the B axis, the light L1 incident on the reflecting mirror 92a is scanned in the β direction.

[0050] The support portion 92d is formed to surround the reflecting mirror 92a, the torsion bar 92b, and the piezoelectric member 92c. The support portion 92d is connected to the piezoelectric member 92c and supports the piezoelectric member 92c. The support portion 92d indirectly supports the torsion bar 92b connected to the piezoelectric member 92c and the reflecting mirror 92a.

[0051] Support substrate 91 is formed to surround movable portion 92, serpentine beam portion 93, and serpentine beam portion 94. Support substrate 91 is connected to and supports serpentine beam portion 93 and serpentine beam portion 94. Support substrate 91 indirectly supports movable portion 92, which is connected to serpentine beam portion 93 and serpentine beam portion 94.

[0052] The optical scanning unit 2 is a MEMS mirror formed by micromachining silicon or glass, for example, using micromachining technology. Micromachining technology allows highly accurate, movable, tiny mirrors to be formed on a substrate, integrated with drive units such as serpentine beams. Specifically, for example, a single SOI (Silicon On Insulator) substrate is shaped by etching or other processes. A reflective mirror, serpentine beams, piezoelectric members, electrode connections, and other components are integrally formed on the shaped substrate, thereby forming the MEMS mirror. The reflective mirror and other components may be formed after or during the shaping of the SOI substrate.

[0053] An SOI substrate is a substrate in which a silicon oxide layer is provided on a silicon support layer made of single-crystal silicon (Si), and a silicon active layer made of single-crystal silicon is further provided on the silicon oxide layer. Because the silicon active layer is thinner in the γ direction than in the α or β directions, a member made only of the silicon active layer functions as an elastic part. The SOI substrate does not necessarily have to be flat, and may have curvature, etc. Furthermore, the member used to form the MEMS mirror is not limited to an SOI substrate, as long as it can be integrally formed by etching or other processes and can be made partially elastic.

[0054] The optical scanning unit 2 is not limited to a biaxial MEMS mirror, but may be a vector scan MEMS mirror or a configuration using two uniaxial MEMS mirrors. Furthermore, optical elements capable of scanning light, such as polygon mirrors or galvanometer mirrors, may be used, or a combination of these may be used. However, using a MEMS mirror is preferable because it allows the retinal projection image display device 100 to be made smaller and lighter. In particular, a configuration using only one MEMS mirror is even more preferable because it allows the retinal projection image display device 100 to be made smaller and lighter. The driving method for the MEMS mirror may be any of electrostatic, piezoelectric, electromagnetic, etc.

[0055] (eyepiece optical system 3) The holographic optical element 32 in the eyepiece optical system 3 is composed of at least one holographic film. The hologram region functions as a volume hologram and reflects light L2, which is directly or indirectly incident from the optical scanning unit 2, toward the eyeball 50 of the observer U, forming an exit pupil E. The holographic film may be made of Bayfol® HX, available from Bayer MaterialScience AG, or a photopolymer film available in the art. When reflecting and focusing light of multiple wavelengths, the holographic optical element 32 may be composed of a single layer of wavelength-multiplexed holographic film. Alternatively, the holographic optical element 32 may be composed of a stack of multiple holographic film layers, each containing a band corresponding to one of the multiple wavelengths to be reflected and focused. Alternatively, the holographic optical element 32 may be an angle-multiplexed hologram.

[0056] The optical element that reflects the light L2 incident directly or indirectly from the optical scanning unit 2 toward the eyeball 50 of the observer U and forms the exit pupil E is not limited to the holographic optical element 32, but may include a diffractive optical element using a liquid crystal or a surface relief, a free-form surface mirror, etc. However, the holographic optical element 32 has the advantage that it can be configured to be thin and provides clear visibility of the outside world.

[0057] The eyepiece optical system 3 may be composed of only the holographic optical element 32. The eyepiece optical system 3 may also include other components such as a fixed mirror 7 in addition to the second lens 31 and the holographic optical element 32. The holographic optical element 32 is not limited to being disposed on the surface of the eyeglass lens 113, and may be integrated with the eyeglass lens 113.

[0058] (Variable Optical System 4) The movable mirror 41 shown in FIG. 3 is a vector scan MEMS mirror. The movable mirror 41 shown in FIG. 3 has a reflective surface 14 on a movable part 101 connected to a support substrate 102. The movable mirror 41 can selectively switch the light reflection direction by driving the movable part 101 to change the attitude of the reflective surface 14. The movable mirror 41 is rotatable about an A-axis along the β-axis, and its attitude can be controlled at any position within its movable range by a drive voltage signal. The movable mirror 41 is also rotatable about a B-axis along the α-axis, and its attitude can be controlled at any position within its movable range by a drive voltage signal. That is, the movable mirror 41 can reflect light L1 incident from the first lens 5 to any position within the αβ plane within its movable range, and reflects the light L1 toward the concave mirror 42. The movable mirror 41 is also disposed between the first light source 1 and the optical scanning unit 2. The movable mirror 41 is also disposed so that its support substrate 102 is parallel to the longitudinal direction of the temple 111.

[0059] The movable mirror 41 shown in Figure 3 has a movable part 101 that reflects incident light L1, and a support substrate 102 that supports a first member 110, a second member 120, a third member 130, and a fourth member 140 that are connected to the movable part 101 and have piezoelectric driving parts (113a, 113b, 113c, 113d) that drive the movable part 101. The movable mirror 41 shown in Figure 3 also has a connection portion 102a that connects the first member 110 and the movable portion 101, a connection portion 102b that connects the second member 120 and the movable portion 101, a connection portion 102c that connects the third member 130 and the movable portion 101, a connection portion 102d that connects the fourth member 140 and the movable portion 101, and electrode connection portions 150a to 150h that electrically connect the piezoelectric driving portions (113a, 113b, 113c, 113d) to the control device.

[0060] 3, one SOI substrate is shaped by etching or the like, and the reflective surface 14, piezoelectric driving units (113a, 113b, 113c, 113d), electrode connecting units 150a to 150h, etc. are formed on the shaped substrate, thereby integrally forming each component. Note that the formation of each of the above components may be performed after or during the shaping of the SOI substrate.

[0061] In the example shown in Figure 3, the SOI substrate is a substrate in which a silicon oxide layer is provided on a silicon support layer made of single-crystal silicon (Si), and a silicon active layer made of single-crystal silicon is further provided on the silicon oxide layer. Because the silicon active layer is thinner in the γ direction than in the α or β direction, a member made only of the silicon active layer functions as an elastic part. The SOI substrate does not necessarily have to be flat, and may have curvature, etc. Furthermore, the member used to form the MEMS mirror is not limited to an SOI substrate, as long as it can be integrally formed by etching or other processes and can be made partially elastic.

[0062] 3 is made of a metal thin film containing, for example, aluminum, gold, silver, or the like. The movable part 101 may also have a rib formed on the -γ side surface of the movable part base 103 for reinforcing the movable part. The rib is made of, for example, a silicon support layer 124 and a silicon oxide layer 125, and can suppress distortion of the reflecting surface 14 caused by movement.

[0063] 3, the shape or configuration of the first member 110, the second member 120, the third member 130, and the fourth member 140 may be, for example, a meander structure or a cantilever structure. Furthermore, some kind of sensor may be formed in the first member 110, the second member 120, the third member 130, and the fourth member 140, separately from the piezoelectric driving units (113a, 113b, 113c, 113d). The sensor may be, for example, a displacement detection sensor (piezoelectric type, strain resistance type, etc.) that outputs a signal in response to deformation of the member, or a temperature sensor.

[0064] The detailed shape of the connection parts (102a, 102b, 102c, 102d) that connect the members and the movable part 101 is not limited to that shown in FIG. 3. Furthermore, it is desirable that the angle formed by the lines formed by the connection parts (102a, 102b, 102c, 102d) and the center of the movable part 101 is approximately 90 degrees in a plan view. However, this is not limited to this. Furthermore, the piezoelectric driving parts (113a, 113b, 113c, 113d) may have a function other than driving. For example, the driving part may have a function of detecting displacement, heating, or electrical wiring. Furthermore, the shape of the movable part 101 is not limited to that shown in FIG. 3.

[0065] The piezoelectric actuators (113a, 113b, 113c, 113d) shown in FIG. 3 are driven by a piezoelectric actuator. However, the actuators (113a, 113b, 113c, 113d) are not limited to the piezoelectric actuator. For example, the actuators may be driven by an electromagnetic field to deform the support, an electrostatic actuator in which comb-shaped electrodes are formed on the support, or a thermoelectric actuator utilizing the difference in thermal expansion between different materials. Coils or magnet arrays may be formed on the support substrate 102. Among these, the piezoelectric actuator is preferable from the viewpoint of efficiently arranging the piezoelectric actuators (113a, 113b, 113c, 113d) and preventing the overall size of the movable mirror 41 from increasing. For example, the electrostatic actuator requires comb-shaped electrodes to be arranged around the outer periphery of the actuator, which tends to increase the overall size of the movable mirror. Furthermore, the electromagnetic actuator is difficult to design, as it requires wiring layout for each of the multiple actuators and magnet arrangements that apply magnetic fields to each, which tends to increase the overall size of the movable mirror. The piezoelectric driving units (113a, 113b, 113c, 113d) shown in FIG. 3 are not limited to being arranged on only one surface (the +γ side surface) of the silicon active layer 126, which is the elastic unit, but may be arranged on another surface (for example, the -γ side surface) of the elastic unit, or on both one surface and the other surface of the elastic unit.

[0066] An insulating layer made of a silicon oxide film may be disposed on at least one of the +γ side surfaces of the upper electrodes of the piezoelectric drive units (113a, 113b, 113c, 113d) and the +γ side surface of the support substrate 102. In this case, electrode wiring may be disposed on the insulating layer, and the insulating layer may be partially removed or not disposed at only the connection spots where the upper or lower electrodes are connected to the electrode wiring to form openings. This increases the degree of freedom in designing the piezoelectric drive units (113a, 113b, 113c, 113d) and the electrode wiring, and further prevents short circuits due to contact between electrodes.

[0067] The silicon oxide film in the movable mirror 41 shown in Figure 3 also functions as an anti-reflection material. When a positive or negative voltage is applied to the piezoelectric portion of each of the piezoelectric drive units (113a, 113b, 113c, 113d) in the polarization direction, deformation (e.g., expansion and contraction) occurs in proportion to the potential of the applied voltage, thereby exhibiting the so-called inverse piezoelectric effect. The deformation of the piezoelectric portion causes bending deformation of the piezoelectric drive units (113a, 113b, 113c, 113d), and a driving force about the rotation axis acts on the movable unit 101 via the connection units (102a, 102b, 102c, 102d), causing the movable unit 101 to move about the rotation axis of the A axis parallel to the β axis or the B axis parallel to the α axis.

[0068] The first member 110 is positioned at approximately 45 degrees with respect to each of the A-axis and the B-axis. In other words, the rotation of the movable part 101 caused by the oscillation of the first member 110, the second member 120, the third member 130, and the fourth member 140 all has vectors of both the A-axis and the B-axis. For example, when a voltage is applied to the piezoelectric actuators (113a, 113b) but not to the piezoelectric actuators (113c, 113d), the movable part 101 tilts around the B-axis as the rotation axis. Similarly, when a voltage is applied to the piezoelectric actuators (113a, 113d) but not to the piezoelectric actuators (113c, 113d), the movable part 101 tilts around the A-axis as the rotation center. In particular, when a drive frequency that does not match the resonant frequency inherent to the structure is used, the rotation direction of the movable part 101 can be arbitrarily controlled by the drive signal. That is, by controlling the independent driving of each of the piezoelectric driving units (113a, 113b, 113c, 113d) or the combined driving, the movable unit 101 can be swung in a desired direction, thereby enabling vector scanning.

[0069] The reference voltage of the piezoelectric driving units (113a, 113b, 113c, 113d) may be 0V or any voltage within the maximum amplitude of the applicable voltage. It may be different between the piezoelectric driving units (113a, 113b, 113c, 113d). The signal waveform of the applied voltage may be a periodic waveform such as a sine wave, a square wave, or a sawtooth wave, or may be a more complex periodic waveform. The piezoelectric driving units (113a, 113b, 113c, 113d) may be DC driven.

[0070] The movable mirror 41 is not limited to a vector scan MEMS mirror, and may be configured using two uniaxial MEMS mirrors. However, using a vector scan MEMS mirror is preferable because it allows the retinal projection image display device 100 to be made smaller and lighter. Alternatively, a single uniaxial MEMS mirror may be used. In this case, the movable mirror 41 can reflect the light L1 input from the first lens 5 in the Y-axis direction or the Z-axis direction in FIG. 1, and the direction of expansion of the eyebox is limited to one dimension.

[0071] The concave mirror 42 converts the incident light L1 into collimated light. The concave mirror 42 can be made of a material including a resin material, a glass material, or the like. A metal film may be disposed on the surface of the resin material, the glass material, or the like. The concave surface of the concave mirror 42 may be spherical, or may include at least a partial aspherical surface.

[0072] (1st lens 5) The first lens 5 can be made of a material including a glass material, a resin material, or the like having a transmittance of 60% or more for the peak wavelength of the light L1 emitted from the first light source 1. Note that the first lens 5 is not limited to being made up of one lens, and may include two or more lenses.

[0073] (Prism 6) The prism 6 guides the light L1 incident from the first lens 5 to each of the optical scanning unit 2 and the variable optical system 4. However, the configuration for guiding the light L1 from the first lens 5 to each of the optical scanning unit 2 and the variable optical system 4 is not limited to using the prism 6 and can be changed as appropriate. The prism 6 can be made of a glass material having a transmittance of 60% or more for the peak wavelength of the light L1 emitted from the first light source 1.

[0074] (Detection unit 8) The second light source 81 in the detection unit 8 is a vertical cavity surface emitting laser (VCSEL) that irradiates light L3 toward the pupil 51 of the eyeball 50, an array light source having multiple light-emitting elements such as an LDA (Laser Diode Array), or a semiconductor laser that emits laser beams of a single or multiple wavelengths.

[0075] The wavelength of the light L3 emitted from the second light source 81 is preferably a wavelength of near-infrared light, which is invisible light, so as not to impede the visibility of the observer U whose line of sight direction is detected. However, the wavelength is not limited to invisible light and may be visible light. The second light source 81 is disposed opposite the light scanning unit 2 via the prism 6 so that the emitted light L3 is incident on the light scanning unit 2.

[0076] The light receiving unit 82 is at least one photodiode that receives light L3 that is emitted from the second light source 81, passes through the holographic optical element 32 and the like, is incident on the eyeball 50, and is reflected by the eyeball 50. In FIG. 1, the corneal surface, which corresponds to the surface of the eyeball 50 of the observer U, is a transparent body that contains water and generally has a reflectance of approximately 2 to 4%. The light L3 that has entered the eyeball 50 of the observer U is reflected by an area P of the corneal surface of the eyeball 50 and is then incident on the light receiving unit 82. The light receiving unit 82 is not limited to a photodiode, and may be a position sensitive detector (PSD), which is a position detecting element, or an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

[0077] The detection unit 8 is not limited to having a second light source 81 and a light receiving unit 82, and can also detect the position of the pupil 51 or cornea of the observer U using, for example, a light receiving unit arranged inside or outside the peripheral area of the eyeglass lens 113.

[0078] (Control unit 9) The control unit 9 receives image data that is the basis of the image to be formed, and controls the emission of light L1 from the first light source 1 based on the received image data. The control unit 9 also controls the emission of light L3 from the second light source 81. The control unit 9 also controls the operation of the optical scanning unit 2 based on the emission timing of each light-emitting unit in the second light source 81 and the position of the pupil 51 or cornea of the observer U, which is detected based on information S related to the light-receiving position from the light-receiving unit 82, thereby controlling the scanning of light L2 by the optical scanning unit 2. The control unit 9 also controls the operation of the movable mirror 41, thereby controlling the position of light L1 that is incident on the optical scanning unit 2 directly or indirectly from the movable mirror 41. The configuration of the control unit 9 will be described in detail later with reference to FIGS. 4 and 5.

[0079] (Behavior of light inside the retinal projection image display device 100) The behavior of light within the retinal projection image display device 100 will be described in more detail with reference to Figure 1. In the example shown in Figure 1, light L1, which is divergent light emitted from the first light source 1, is focused by the first lens 5 so as to form a focal point on the mirror surface of the movable mirror 41. The light L1 focused by the first lens 5 is reflected by the reflective surface of the prism 6 and enters the movable mirror 41. The movable mirror 41 reflects the incident light L1 to any position in the YZ plane within its movable range. The light L1 reflected by the movable mirror 41 is entered into the concave mirror 42. The collimated light reflected by the concave mirror 42 is reflected by the reflective surface within the prism 6 and enters the optical scanning unit 2.

[0080] The optical scanning unit 2 scans the incident light L1 in two axial directions and forms an image with the scanned light L2. The light L2 is reflected by a reflecting surface within the prism 6, enters the second lens 31, and is then reflected by the fixed mirror 7 before entering the holographic optical element 32. The holographic optical element 32 reflects the incident light L2 toward the eyeball 50 of the observer U, forming an exit pupil E. When the position of the pupil 51 of the observer U and the position of the exit pupil E are aligned, the light L2 passes through the pupil 51 and enters the inside of the eyeball 50. The light L2 entering the inside of the eyeball 50 is first focused near the center of the pupil 51 by the light focusing function of the hologram region of the holographic optical element 32, and then forms an image on the retina 52 at the back of the eyeball 50.

[0081] The above-described visual state is generally referred to as Maxwellian vision. Because light passing near the center of the pupil 51 reaches the retina 52 regardless of the focusing ability of the crystalline lens, it is generally understood that the observer U can clearly view a projected image in focus regardless of where in real space he or she focuses his or her eye. However, in reality, the light incident on the eyeball 50 has a small but finite diameter, and the lens effect of the crystalline lens is not insignificant. Therefore, it is desirable to design the optical scanning unit 2 and the holographic optical element 32 so that the diameter of the light L2 incident on the eyeball 50 is 300 μm or more and 800 μm or less, and the beam divergence angle is a positive finite value, i.e., divergent light, due to the optical focusing action of the optical scanning unit 2 and the holographic optical element 32. With this design, the image formed by the light L2 scanned by the optical scanning unit 2 reaches the retina 52 via the holographic optical element 32 without being affected by the focusing ability of the crystalline lens. This allows the observer U to always clearly view the image on the retina 52 regardless of where in real space he or she focuses his or her eye. In other words, the image formed by the light L2 scanned by the light scanning unit 2 is viewed by the observer U in a focus-free state.

[0082] When the reflecting surface in the prism 6 is made to function as a polarizing beam splitter surface, i.e., a reflecting surface made of a dielectric multilayer film, a quarter-wave plate can be placed in an appropriate location. By providing a polarizing beam splitter surface and a quarter-wave plate, the retinal projection type image display device 100 can improve the light utilization efficiency.

[0083] 1, light L3 emitted from the second light source 81 is incident on the optical scanning unit 2. The light L3 incident on the optical scanning unit 2 and reflected by the optical scanning unit 2 is reflected by a reflecting surface within the prism 6, incident on the second lens 31, and after being reflected by the fixed mirror 7, incident on the holographic optical element 32. The light L3 is irradiated onto the eyeball 50 along the same optical path as the light L2.

[0084] It is preferable that the light L3 is reflected by the optical scanning unit 2 at a scanning timing that is greater than the deflection angle of the optical scanning unit 2. This allows the light L3 to pass through an area of each of the second lens 31, the fixed mirror 7, and the holographic optical element 32 that is closer to the outer edge than the position through which the light L2 passes. The fixed mirror 7 and the holographic optical element 32 can be specifically designed so that only the area on which the light L3 is incident has an optical function different from that of the area on which the light L2 is incident. By sharing the components through which the light L2 and the light L3 pass, the retinal projection type image display device 100 can be made smaller and lighter.

[0085] <Configuration of control unit 9> (Hardware configuration) Fig. 4 is a block diagram showing an example of the hardware configuration of the control unit 9. The control unit 9 shown in Fig. 4 has a CPU (Central Processing Unit) 911, a ROM (Read Only Memory) 912, a RAM (Random Access Memory) 913, a light source drive circuit 914, a scan drive circuit 915, and a deflection drive circuit 916. These are electrically connected to each other via a system bus B.

[0086] The CPU 911 is a computing device that reads programs and data from storage devices such as the ROM 912 onto the RAM 913, executes processing, and realizes the overall control and functions of the control unit 9. The ROM 912 is a non-volatile storage device that can retain programs and data even when the power is turned off. The ROM 912 stores processing programs and data that the CPU 911 executes to control each function of the retinal projection image display device 100. The RAM 913 is a volatile storage device that temporarily stores programs and data.

[0087] The light source drive circuit 914 is an electric circuit that is electrically connected to the first light source 1 and the second light source 81 and applies a current or a voltage to each of the first light source 1 and the second light source 81 to drive each of the first light source 1 and the second light source 81. The first light source 1 turns on or off the emission of light L1 and changes the light intensity of the emitted light L1 in response to a drive signal D1 output from the light source drive circuit 914. The second light source 81 turns on or off the emission of light L3 and changes the light intensity of the emitted light L3 in response to a drive signal D4 output from the light source drive circuit 914.

[0088] The scan drive circuit 915 is an electric circuit electrically connected to the optical scanning unit 2 and applies a voltage to drive the optical scanning unit 2. The optical scanning unit 2 changes the angle of the reflecting mirror 92a provided in the movable unit 92 in response to a drive signal D2 output from the scan drive circuit 915.

[0089] The deflection drive circuit 916 is an electric circuit that is electrically connected to the movable mirror 41 and applies a voltage to drive the movable mirror 41. The movable mirror 41 changes the tilt angle of the reflecting surface 14 of the movable part 101 in response to a drive signal D3 output from the deflection drive circuit 916.

[0090] The external I / F 917 is an interface with an external device, a network, etc. Examples of external devices include higher-level devices such as a PC (Personal Computer), and storage devices such as a USB (Universal Serial Bus) memory, an SD card, a CD, a DVD, a HDD, and an SSD. Examples of networks include a CAN (Controller Area Network) in an automobile, a LAN (Local Area Network), the Internet, etc. The external I / F 917 may have any configuration as long as it enables connection or communication with an external device, and an external I / F 917 may be provided for each external device.

[0091] In the control unit 9, the CPU 911 acquires image data from an external device or a network via the external I / F 917. Note that any configuration is acceptable as long as the CPU 911 is capable of acquiring video information, and the image data may be stored in the ROM 912 within the control unit 9, or a storage device such as an SD card may be newly provided within the control unit 9 and the image data may be stored in that storage device. The control unit 9 can realize the following functional configuration using instructions from the CPU 911 and the hardware configuration shown in FIG.

[0092] (Functional configuration) Fig. 5 is a block diagram showing an example of the functional configuration of the control unit 9. The control unit 9 shown in Fig. 5 has an estimation unit 901, a light source control unit 902, a scanning control unit 903, and a deflection control unit 904. Note that, when the image viewed by the viewer U has distortion or the like, the control unit 9 may further have a function of correcting the distortion or the like.

[0093] The functions of the estimation unit 901, light source control unit 902, scan control unit 903, and deflection control unit 904 can be realized by an external I / F 917 and the CPU 911 executing processes defined in a program stored in a ROM 912. Part of the functions of the light source control unit 902 may be realized by a light source drive circuit 914. Part of the functions of the scan control unit 903 may be realized by a scan drive circuit 915. Part of the functions of the deflection control unit 904 may be realized by a deflection drive circuit 916. The functions of the estimation unit 901, light source control unit 902, scan control unit 903, and deflection control unit 904 may be included in a configuration other than the control unit 9. For example, an external device such as a microcomputer or PC capable of communicating with the control unit 9 may have at least some of the functions of the estimation unit 901, light source control unit 902, scan control unit 903, and deflection control unit 904.

[0094] Each function of the control unit 9 can also be realized by one or more processing circuits. The processing circuit includes an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), a DSP (Digital Signal Processor), an electric circuit, or the like, which can execute each of the above functions. Some of the above functions of the control unit 9 may be realized by an external device, such as a microcomputer or a PC, communicably connected to the control unit 9. Furthermore, some of the above functions of the control unit 9 may be realized by distributed processing between the control unit 9 and the external device.

[0095] The estimation unit 901 estimates the position of the pupil 51 or cornea of the observer U based on the light emission timing of each light emitting unit of the second light source 81 and information S related to the light receiving position output from the light receiving unit 82. The estimation unit 901 acquires image data Im obtained from an external device, and converts the image data into control signals based on the information related to the position of the pupil 51 or cornea estimated by the estimation unit 901, and outputs the control signals to each of the light source control unit 902, the scanning control unit 903, and the deflection control unit 904.

[0096] Based on the control signal input from the estimation unit 901, the light source control unit 902 outputs a drive signal D1 to the first light source 1 and a drive signal D4 to the second light source 81, thereby driving the first light source 1 and the second light source 81. Based on the control signal input from the estimation unit 901, the scanning control unit 903 outputs a drive signal D2 to the light scanning unit 2, thereby driving the light scanning unit 2. Based on the control signal input from the estimation unit 901, the deflection control unit 904 outputs a drive signal D3 to the movable mirror 41, thereby driving the movable mirror 41.

[0097] <Movement of the Exit Pupil E in the Retinal Projection Image Display Device 100> The movement operation of the exit pupil E by the retinal projection image display device 100 will be described with reference to Figs. 6 to 9. Fig. 6 is a schematic diagram showing an overview of an example of the movement operation of the exit pupil E by the retinal projection image display device 100 according to the first embodiment of the present invention. Fig. 7 is a first schematic diagram showing details of an example of the movement operation of the exit pupil E by the retinal projection image display device 100 according to the first embodiment of the present invention. Fig. 8 is a second schematic diagram showing details of an example of the movement operation of the exit pupil E by the retinal projection image display device 100 according to the first embodiment of the present invention. Fig. 9 is a third schematic diagram showing details of an example of the movement operation of the exit pupil E by the retinal projection image display device 100 according to the first embodiment of the present invention.

[0098] Figures 6 to 9 show a simplified configuration for moving the exit pupil E using the retinal projection image display device 100 shown in Figure 1, and show the chief rays of light L1 and light L2 passing through the retinal projection image display device 100 as straight lines.

[0099] In the example shown in FIG. 6, light L1 emitted from the first light source 1 is converged by the first lens 5 so as to form a focal point on the reflecting surface 14 of the movable mirror 41. In FIG. 6, the movable mirror 41 can control the reflection direction of the light L1 along the b-axis. The light L1 reflected by the movable mirror 41 is converted into collimated light by the concave mirror 42. As a result, the light L1 incident on the optical scanning unit 2 directly or indirectly from the movable mirror 41 becomes collimated light at all tilt angles within the tilt angle control range of the reflecting surface 14 of the movable mirror 41.

[0100] The optical scanning unit 2 is configured so that when light L1 incident from the movable mirror 41 is scanned to form an image, the light L1 incident from the movable mirror 41 falls within the effective diameter of 92a of the optical scanning unit 2. By configuring the light L1 to fall within the effective diameter of 92a of the optical scanning unit 2, the control range of the tilt angle of the reflecting surface 14 of the movable mirror 41 is limited to the range in which the light L1 is incident on the effective diameter of the reflecting mirror 92a of the optical scanning unit 2, but can be arbitrarily controlled within that constraint. The light L2 incident from the optical scanning unit 2 to the eyepiece optical system 3 is collimated light.

[0101] As described above, the eyepiece optical system 3 collimates the light L2 scanned by the optical scanning unit 2 and converges the light L2 at different positions depending on the incident position on the optical scanning unit 2, thereby forming an exit pupil. The holographic optical element 32 converges the light L2 incident directly or indirectly from the optical scanning unit 2 to form an exit pupil E. In the retinal projection type image display device 100, the passage position of the light L2 on the image side of the eyepiece optical system 3 moves in the direction b depending on the tilt angle of the reflecting surface 14 of the movable mirror 41. As a result, when the tilt of the reflecting surface 14 of the movable mirror 41 forms the exit pupil E at the normal position E2, tilting the reflecting surface 14 of the movable mirror 41 around the a-axis as the axis of rotation makes it possible to move the exit pupil E to position E1 or E3.

[0102] The retinal projection image display device 100 can control the tilt angle of the reflective surface 14 in two dimensions using the movable mirror 41, which is a vector scan MEMS mirror. The retinal projection image display device 100 can also move the exit pupil E in the a direction by tilting the reflective surface 14 of the movable mirror 41 around the b axis as the rotation axis. The size of the eyebox in the retinal projection image display device 100 is determined by the effective diameter of the reflective mirror 92a of the optical scanning unit 2 and the lateral magnification of the eyepiece optical system 3. The lateral magnification of the eyepiece optical system 3 is determined by the ratio between the focal lengths of the second lens 31 and the holographic optical element 32. For example, if the effective diameter of the reflective mirror 92a of the optical scanning unit 2 is 2 mm and the lateral magnification is 2x, the size of the eyebox is 4 mm.

[0103] In the retinal projection type image display device 100, the exit pupil E can also be moved in the direction c by combining control of the tilt angle of the reflecting surface 14 of the movable mirror 41 with image formation control that generates the light L2 in a time-division manner. In other words, in the retinal projection type image display device 100, the exit pupil E can be moved in three-dimensional directions.

[0104] Figure 7 shows the state where the exit pupil E has moved in the -b direction compared to the normal position E2, and Figure 8 shows the state where the exit pupil E has moved in the +b direction compared to the normal position E2.

[0105] In the retinal projection image display device 100, the detector 8 first identifies the position of the center of the pupil 51 when the observer U is viewing a scene straight ahead. The tilt angle of the reflecting surface 14 of the movable mirror 41 is determined so that the exit pupil E is formed at the identified position of the pupil 51 of the observer U. In the state shown in FIG. 7 , the position of the observer U's eyeball 50 is shifted in the −b direction compared to the normal position E2. In the example shown in FIG. 7 , light L1 emitted from the first light source 1 is focused by the first lens 5 to form a focal point on the reflecting surface 14 of the movable mirror 41. The reflecting surface 14 is tilted around the a-axis as its rotation axis, and its reflection direction is changed in the +b direction. The light L1 focused and reflected by the reflecting surface 14 is converted into parallel light by the concave mirror 42 and enters the optical scanning unit 2. At this time, the incident position of the light L1 on the reflecting mirror 92a of the optical scanning unit 2 is shifted in the +b direction compared to the normal position E2. Here, the incident position on the optical scanning unit 2 by the variable optical system 4 corresponds to the position of the light L1 incident on the reflecting mirror 92a.

[0106] Light L1 incident on the optical scanning unit 2 is scanned by the optical scanning unit 2 to form an image. The scanned light L2 enters the eyepiece optical system 3, is once focused at an intermediate point by the second lens 31, and is then converted back into parallel light by the holographic optical element 32, forming an exit pupil E at position E3. At this time, the exit pupil E located at position E3 is aligned with or overlaps with the pupil 51 of the observer U when the observer U is viewing directly ahead. Therefore, light L2 incident on the pupil 51 can pass through the pupil 51.

[0107] In the state shown in FIG. 8, the position of the eyeball 50 of the observer U is shifted in the +b direction compared to the normal position E2. In the example shown in FIG. 8, light L1 emitted from the first light source 1 is focused by the first lens 5 to form a focal point on the reflecting surface 14 of the movable mirror 41. The reflecting surface 14 is tilted around the a-axis as its rotation axis, and its reflection direction changes in the -b direction. The light L1 focused and reflected on the reflecting surface 14 is converted into parallel light by the concave mirror 42 and enters the optical scanning unit 2. At this time, the incident position on the reflecting mirror 92a of the optical scanning unit 2 has shifted in the -b direction compared to the normal position E2. The light L1 entering the optical scanning unit 2 is scanned by the optical scanning unit 2 to form an image. The light L2 scanned by the optical scanning unit 2 enters the eyepiece optical system 3, forms an intermediate focal point by the second lens 31, and is then converted back into parallel light by the holographic optical element 32, forming an exit pupil E at position E1. At this time, when the observer U is viewing straight ahead, the exit pupil E is aligned with or overlaps with the pupil 51 of the observer U. Therefore, light L2 incident on the pupil 51 can pass through the pupil 51.

[0108] As described above, in the retinal projection image display device 100, the exit pupil E can be moved by controlling the tilt angle of the reflecting surface 14 of the movable mirror 41. Generally, the distance between the pupils 51 of the two eyes differs for each observer U. In the retinal projection image display device 100, regardless of where the center of the pupil 51 is located when viewing directly ahead, the exit pupil E can be formed at a position where the light L2 passes through the pupil 51. This allows the observer U to view images over a predetermined finite angle of view.

[0109] The angle of view visible through the exit pupil W formed when viewing a scene straight ahead is finite. If the observer U tilts his / her eyeball 50 and moves his / her line of sight beyond this finite angle of view, the light L2 is blocked by the pupil 51 of the observer U, causing the image to disappear. For this reason, the retinal projection-type image display device 100 constantly monitors the position of the pupil 51 of the observer U using the detection unit 8. When the observer U moves his / her line of sight beyond the finite angle of view visible through the exit pupil E formed when viewing a scene straight ahead, the tilt angle of the reflecting surface 14 of the movable mirror 41 is controlled to move the exit pupil E and align the pupil 51 of the observer U with the exit pupil E. By aligning the pupil 51 and the exit pupil E, the light L2 can pass through the pupil 51 and form an image on the retina 52. In this way, the retinal projection-type image display device 100 can enlarge the eyebox by moving the exit pupil E according to the position of the pupil 51 of the observer U.

[0110] Furthermore, in the retinal projection image display device 100, the eyepiece optical system 3 collimates the light L2 scanned by the optical scanning unit 2 and converges the light L2 at different positions depending on the incident position on the optical scanning unit 2, thereby forming an exit pupil. Therefore, even if the exit pupil E is moved by the movable mirror 41, the state of the light L2 incident on the eyeball 50 does not change. This makes it possible to provide uniform image quality and a large angle of view in any field of view provided by either system.

[0111] Furthermore, in the retinal projection image display device 100, the movable mirror 41 is a vector scan MEMS mirror. This allows the tilt angle of the reflecting surface 14 to be controlled in two dimensions. The retinal projection image display device 100 can move the exit pupil E not only in the direction b but also in the direction a. In other words, in the retinal projection image display device 100, the exit pupil E can be moved in two dimensions and the eyebox can be enlarged simply by controlling the tilt angle of the reflecting surface 14 of the movable mirror 41.

[0112] Next, Fig. 9 shows a state in which the exit pupil E has moved in the c direction compared to the normal position E2. In the example shown in Fig. 9, the reflecting surface 14 of the movable mirror 41 rotates around the a axis as the rotation axis, and is controlled in a time-division manner to reflect at the normal position E2 and in the -b direction. In Fig. 9, the light L1 (solid line) reflected at the normal position E2 and the light L1 (dashed line) reflected in the -b direction are converted into parallel light by the concave mirror 42 and are incident on different positions of the optical scanning unit 2.

[0113] In the example shown in FIG. 9 , light L1 (solid line) reflected at normal position E2 is emitted at a predetermined scanning angle. Light L2 (dashed line) is reflected by the movable mirror 41 in the −b direction and incident at a position shifted in the −b direction from normal position E2, and then emitted at a predetermined scanning angle. Light L2 intersects with light L2 at a position shifted in the −c direction from the exit pupil E in FIG. 7 by the eyepiece optical system 3, forming an exit pupil E at position E4. In the retinal projection image display device 100, the movable mirror 41 can be tilted to any position within the tilt angle control range of the reflecting surface 14. By combining this with the scanning range of the optical scanning unit 2, it is possible to generate any light beam within a predetermined finite range. Therefore, by selecting an appropriate light beam from among the countless light beams and combining it with time-division image formation control, the exit pupil E can be moved in the c direction. This allows the observer U to view an image even if the position of the observer U's eyeball 50 is shifted in the c direction from the normal position E2. In this way, in the retinal projection type image display device 100, the exit pupil E can be moved in three dimensions, and the eyebox can be expanded in three dimensions.

[0114] <Example of Operation of the Retinal Projection Image Display Device 100> FIG. 10 is a schematic diagram showing an example of the operation of the retinal projection image display device 100 according to the first embodiment of the present invention.

[0115] 10, light L1 emitted from the first light source 1 is focused by the first lens 5 so as to form a focal point on the reflecting surface 14 of the movable mirror 41. The light L1 focused by the first lens 5 is reflected by the reflecting surface of the prism 6 and is incident on the movable mirror 41. When the observer U is viewing a scene straight ahead, the detection unit 8 identifies where the center of the pupil 51 of the observer U is located, and the tilt angle of the reflecting surface 14 of the movable mirror 41 is determined so that the exit pupil E is formed at the identified position of the pupil 51.

[0116] 10, the position of pupil 51 is shifted in the −X direction from its normal position. Movable mirror 41 is tilted around the Y axis as its rotation axis so that exit pupil E is formed at the position of pupil 51, and the reflection direction of light L1 reflected by movable mirror 41 changes in the +Z direction. Light L1 reflected by movable mirror 41 is converted into collimated light by concave mirror 42, reflected by a reflecting surface within prism 6, and incident on optical scanning unit 2. Light L2 scanned in two axial directions by optical scanning unit 2 is reflected by the reflecting surface of prism 6 and incident on second lens 31, reflected by fixed mirror 7, and then incident on holographic optical element 32.

[0117] The holographic optical element 32 reflects and focuses the incident light L2 toward the eyeball 50, forming an exit pupil E. In the eyepiece optical system 3, the area incident on the holographic optical element 32 changes depending on the tilt angle of the reflecting surface 14 of the movable mirror 41, and the exit pupil E moves in the -X direction. This causes the center of the pupil 51 and the position of the exit pupil E to align or overlap. The light L2 reflected by the holographic optical element 32 is first focused near the center of the pupil 51, and then reaches the retina 52 of the observer U. The observer U can visually recognize the image formed on the retina 52.

[0118] Light propagating in the -Z direction from the object 70 in real space is light with a wide wavelength band that includes the visible light range. The holographic optical element 32 has excellent transparency because the hologram functions only for wavelengths in a very narrow band compared to the visible light range. Therefore, most of the light propagating from real space toward the eyeball 50 of the observer U passes through the holographic optical element 32 and reaches the retina 52 of the observer U. This allows the image of the object 70 in real space to be viewed with sufficient brightness. In this way, the observer U wearing the retinal projection image display device 100 can view the image and the image of the object 70 in real space side by side, and can view both the image and the image in real space in a bright state.

[0119] In the retinal projection image display device 100, the detection unit 8 constantly monitors the position of the pupil 51 of the observer U. The retinal projection image display device 100 identifies, by the detection unit 8, where the center of the pupil 51 is located when the observer U is viewing straight ahead, and controls the tilt angle of the reflecting surface 14 of the movable mirror 41 and image formation so that the exit pupil E is formed at the identified position of the pupil 51. In this way, although there are generally individual differences in the interpupillary distance between the two eyes and the interpupillary distance differs for each observer U, when the observer U wears the retinal projection image display device 100, the observer U can instantly view an image within a predetermined finite angle of view, regardless of where the pupil 51 is located.

[0120] In the retinal projection image display device 100, the viewable angle of view through the exit pupil E formed when the observer U is viewing a scene straight ahead is finite. If the position of the exit pupil E is fixed, moving the observer U's line of sight beyond the finite angle of view causes the image to be blocked by the observer U's pupil 51, resulting in the image disappearing. In the retinal projection image display device 100, when the observer U moves their line of sight beyond the finite angle of view visible through the exit pupil E formed when viewing a scene straight ahead, the tilt angle of the reflective surface 14 of the movable mirror 41 is controlled to move the exit pupil E and align the pupil 51 with the exit pupil E. This allows an image to be constantly displayed in the viewer U's line of sight, enabling the display of an image that follows the viewer U's line of sight. For example, if the image is always the same regardless of the viewer U's line of sight, the retinal projection image display device 100 can always display the same image regardless of where the observer U is looking. This is useful for supporting work sites such as manufacturing where information needs to be constantly displayed in the viewer's line of sight, and for general consumer applications such as digitally checking additional information about objects the observer is looking at in everyday life.

[0121] Furthermore, when the image displayed in the field of view changes depending on the movement of the gaze, for example, by presetting the necessary information or data to be displayed in the direction of the gaze, the necessary information can be confirmed by directing the gaze to the set area in the field of view when needed. In other words, an image experience can be achieved that is at the observer's discretion, allowing them to view the information when they want. As a result, for example, if the observer U is a manufacturing worker or an infrastructure inspection worker, a clear field of view prevents interference with work in real space, and the observer U can clearly view digital content such as work instructions only by moving their gaze when needed. Furthermore, focus-free operation allows the observer U to work without visual stress. In this way, the retinal projection image display device 100 allows anyone to easily enjoy the new added value of adding images with sufficient visual quality, making it a technology with wide application potential, including educational support, surgical support, and lifestyle support.

[0122] In the retinal projection image display device 100, the eyepiece optical system 3 collimates the light L2 scanned by the optical scanning unit 2, and converges the light L2 at different positions depending on the incident position on the optical scanning unit 2, thereby forming an exit pupil. Therefore, even if the exit pupil E is moved by the movable mirror 41, the state of the light L2 does not change, making it possible to provide uniform image quality in any field of view provided.

[0123] In the retinal projection image display device 100, the surface of the support substrate 91 of the optical scanning unit 2 and the surface of the support substrate 102 of the movable mirror 41 are arranged parallel to each other via the prism 6 and are also arranged parallel to the longitudinal direction of the temple 111. This allows for a thin folded light-guiding structure. In the retinal projection image display device 100, the exit pupil E can be moved two-dimensionally, horizontally and vertically, simply by controlling the drive voltage of the movable mirror 41, which is a MEMS mirror. It can also be moved in the depth direction by combining the movable mirror 41 with image formation control. This eliminates the need for mechanisms or devices that require physical repositioning or movement. Furthermore, control and operation can be completed within the temple 111 without changing the external appearance, allowing for a compact retinal projection image display device 100 and a stylish, compact eyeglass-type support body 11.

[0124] [Second embodiment] Next, a retinal projection image display device according to a second embodiment will be described. Note that the same names and symbols as those in the previously described embodiments indicate the same or similar components or configurations, and detailed descriptions will be omitted as appropriate. This also applies to the following embodiments.

[0125] <Configuration of a retinal projection image display device according to a second embodiment of the present invention> (Overall composition) FIG. 11 is a schematic top view showing an example of a retinal projection type image display device 100a according to the second embodiment of the present invention.

[0126] The retinal projection image display device 100a differs from the first embodiment described above mainly in that it further includes a magnifying optical system 12 that is arranged between the optical scanning unit 2 and the eyepiece optical system 3 and that magnifies the eyebox by changing the incident position of the light L2 emitted from the optical scanning unit 2 onto the eyepiece optical system 3.

[0127] The size of the eyebox in the retinal projection image display device 100a is determined by the effective diameter of the reflecting mirror 92a of the optical scanning unit 2 and the lateral magnification of the eyepiece optical system 3. Increasing the lateral magnification of the eyepiece optical system 3 to increase the size of the eyebox results in a trade-off in which the angle of view of the image displayed becomes smaller. Therefore, a design that strikes a balance between the angle of view and the size of the eyebox is required, and there are constraints.

[0128] In this embodiment, the eyebox is enlarged by using the magnifying optical system 12 to change the incident position of the light L2 emitted from the optical scanning unit 2 onto the eyepiece optical system 3. This makes it possible to both enlarge the size of the eyebox and widen the angle of view.

[0129] 11, the light L2 incident from the optical scanning unit 2 to the magnifying optical system 12 is collimated light. With this configuration, even if the distance between the optical scanning unit 2 and the magnifying optical system 12 is changed, the performance of the function of magnifying the eyebox does not change, and the incident angle of the light L2 incident on the magnifying optical system 12 can be kept the same.

[0130] The retinal projection image display device 100a shown in Fig. 11 has two magnifying optical systems 12, including a first magnifying optical system 12-1 and a second magnifying optical system 12-2. By having two magnifying optical systems 12, the retinal projection image display device 100a can increase the magnification of the eyebox and the angle of view compared to when there is only one magnifying optical system 12. The number of magnifying optical systems 12 is not limited to two, and may be three or more. The magnification of the eyebox and the angle of view increases depending on the number of magnifying optical systems 12.

[0131] A retinal projection image display device 100a shown in FIG. 11 has a spectacle-type support 11 including temples 111, and multiple magnifying optical systems 12 are arranged on the temples 111 in a line extending in the direction of the temples 111. The extension direction of the temples 111 is a direction substantially perpendicular to the line of the eyes of a viewer U wearing the spectacle-type support device 11. In the example shown in FIG. 11, the line of the eyes of the viewer U wearing the spectacle-type support device 11 corresponds to the X direction, and the direction substantially perpendicular to the line of the eyes corresponds to the Z direction. By arranging the multiple magnifying optical systems 12 in a line extending in the direction of the temples 111, the temples 111 can be made thinner, and the retinal projection image display device 100a can be made more compact than when multiple magnifying optical systems 12 are arranged in a direction substantially perpendicular to the line of the temples 111. The multiple magnifying optical systems 12 may be arranged inside the temples 111 or on the surface of the temples 111.

[0132] In the retinal projection image display device 100a shown in FIG. 11, the first magnification optical system 12-1 includes a first magnification lens 13-1, a first magnification prism 14-1, a first magnification concave mirror 15-1, and a first magnification movable mirror 16-1. The second magnification optical system 12-2 includes a second magnification lens 13-2, a second magnification prism 14-2, a second magnification concave mirror 15-2, and a second magnification movable mirror 16-2. The control unit 9 drives the first magnification movable mirror 16-1 by outputting a drive signal D4-1. The control unit 9 also drives the second magnification movable mirror 16-2 by outputting a drive signal D4-2.

[0133] Each of the first magnification movable mirror 16-1 and the second magnification movable mirror 16-2 can be a vector scan MEMS mirror having a configuration similar to that of the movable mirror 41 shown in Fig. 3. In the example shown in Fig. 11, the first magnification movable mirror 16-1 and the second magnification movable mirror 16-2 are arranged so that the surfaces of their respective support substrates 102 are parallel to the longitudinal direction of the temples 111. This allows the surfaces of the support substrate 102 of the first magnification movable mirror 16-1, the support substrate 102 of the second magnification movable mirror 16-2, and the support substrate 91 of the optical scanning unit 2 to be arranged on the same plane. As a result, the first magnification movable mirror 16-1, the second magnification movable mirror 16-2, and the optical scanning unit 2 can be mounted on, for example, a common circuit board.

[0134] The first magnifying optical system 12-1 includes the first magnifying prism 14-1, which allows for a more compact light-guiding structure and therefore a more compact first magnifying optical system 12-1. The second magnifying optical system 12-2 includes the second magnifying prism 14-2, which allows for a more compact light-guiding structure and therefore a more compact second magnifying optical system 12-2. However, the configuration of the magnifying optical system 12 is not limited to including the first magnifying prism 14-1 and the second magnifying prism 14-2, and can be changed as appropriate depending on the specifications of the retinal projection image display device 100a, etc.

[0135] The first magnification movable mirror 16-1 and the second magnification movable mirror 16-2 are not limited to vector scan MEMS mirrors, and may be configured using, for example, two uniaxial MEMS mirrors. However, using vector scan MEMS mirrors for the first magnification movable mirror 16-1 and the second magnification movable mirror 16-2 can reduce the size and weight of the retinal projection image display device 100a. Furthermore, the first magnification movable mirror 16-1 and the second magnification movable mirror 16-2 may be configured using a single uniaxial MEMS mirror. In this case, the magnification direction of the eyebox is limited to one dimension.

[0136] <Movement of the Exit Pupil E by the Retinal Projection Type Image Display Device 100a> FIG. 12 is a schematic diagram showing an example of the movement of the exit pupil E by the retinal projection type image display device 100a according to the second embodiment of the present invention.

[0137] Figure 12 shows a simplified configuration for moving the exit pupil E using the retinal projection image display device 100a shown in Figure 11, and also shows the chief rays of light L1 and light L2 passing through the retinal projection image display device 100a as straight lines.

[0138] 12, the passing position of light L1 on the image side of first magnifying optical system 12-1 moves in direction b according to the tilt angle of reflecting surface 14 of movable mirror 41. As a result, the incident position of light L1 on reflecting surface 14 of first magnifying movable mirror 16-1 changes according to the tilt angle of reflecting surface 14 of movable mirror 41. Light L1 received from first magnifying optical system 12-1 is configured to fall within the effective diameter of reflecting surface 14 of first magnifying movable mirror 16-1. The control range of the tilt angle of reflecting surface 14 of movable mirror 41 and the lateral magnification of first magnifying optical system 12-1 are restricted by the range of incidence on the effective diameter of reflecting surface 14 of first magnifying movable mirror 16-1, but can be selected arbitrarily within these restrictions.

[0139] 12, the second magnification optical system 12-2 is configured to have a lateral magnification of 1. Since the lateral magnification of the second magnification optical system 12-2 is 1, even if the tilt angle of the reflecting surface 14 of the first magnification movable mirror 16-1 changes, the incident position of light L1 on the second magnification movable mirror 16-2 will be the same as the incident position on the first magnification movable mirror 16-1, but light L2 scanned by the optical scanning unit 2 can be made to enter from a different incident direction. The effective diameter of the reflecting surface 14 of the second magnification movable mirror 16-2 is determined so that the light L2 received from the second magnification optical system 12-2 will fit within the effective diameter of the reflecting surface 14 of the second magnification movable mirror 16-2.

[0140] In the example shown in FIG. 12, the eyepiece optical system 3 is configured to have a lateral magnification of 4. The size of the eyebox generated by the retinal projection image display device 100a is determined by the effective diameter of the reflecting surface 14 of the second magnifying movable mirror 16-2 and the lateral magnification of the eyepiece optical system 3. For example, if the effective diameter of the reflecting surface 14 of the second magnifying movable mirror 16-2 is 2 mm, the size of the eyebox is 8 mm. Thus, in the retinal projection image display device 100a, the size of the finally formed eyebox can be determined by the relationship between the tilt angle control range of the reflecting surface 14 of the movable mirror 41, the lateral magnification of the first magnifying optical system 12-1, and the lateral magnification of the eyepiece optical system 3. The incident position of light L2 emitted from the optical scanning unit 2 on the eyepiece optical system 3 corresponds to the incident position of light L2 on the second lens 31.

[0141] By tilting the reflecting surface 14 of the movable mirror 41 around the b-axis as the axis of rotation, the exit pupil E can be moved in the a-direction. In the retinal projection type image display device 100a, the exit pupil E can be moved arbitrarily within the size of the eyebox simply by controlling the tilt angle of the reflecting surface 14 of the movable mirror 41.

[0142] The retinal projection image display device 100a includes a first magnifying optical system 12-1 and a second magnifying optical system 12-2 in addition to a variable optical system 4 for controlling the exit pupil E. The first magnifying optical system 12-1 and the second magnifying optical system 12-2 are disposed between the optical scanning unit 2 and the eyepiece optical system 3, and serve not only to expand the angle of view of the light L2 scanned by the optical scanning unit 2 but also to move the position of the image displayed within the field of view of the observer U. In other words, the angle of incidence of the light L2 incident on the eyeball 50 of the observer U can be changed. Although the angle of view of the image formed by the optical scanning unit 2 is fixed, the position at which the image can be displayed within the field of view of the observer U can be freely changed, thereby enabling image display that follows the movement of the eye without causing vignetting of the image due to movement of the eye.

[0143] The retinal projection method has the drawback of having a narrow viewing zone due to the characteristic of focusing an image once on the pupil. To overcome this drawback and enable the observer U to enjoy a stress-free retinal projection image experience, it is desirable to accommodate individual differences in interpupillary distance, to eliminate vignetting of the image due to changes in the line of sight, and to be able to freely switch the image position in response to line of sight movement, but no prior art exists that can satisfy all of these requirements. This embodiment makes it possible to achieve all of these, and can achieve projection that is linked to the line of sight, without being selective about the observer U, and is free of vignetting due to line of sight movement, regardless of the observer U, once worn.

[0144] [Third embodiment] Next, an optometry apparatus according to a third embodiment will be described.

[0145] The retinal projection image display device 100 and the retinal projection image display device 100a described above can also be applied to optometry devices. An optometry device refers to a device capable of performing various tests, such as visual acuity tests, eye refraction tests, intraocular pressure tests, and axial length tests. An optometry device is a device capable of performing non-contact tests on the eyeball. It includes a support unit that supports the subject's face, an examination window, a display unit that projects test information onto the subject's eyeball during the eye examination, a control unit, and a measurement unit. The subject fixes their face on the support unit and gazes at the test information projected by the display unit through the examination window. Since the eyeball position and the projection direction that is most easily visible vary from subject to subject, the optical device of this embodiment can be used as a display unit. Furthermore, the retinal projection image display device 100 and the retinal projection image display device 100a can be used to realize a glasses-type optometry device. This eliminates the need for space and a large optometry device, enabling the examination to be performed anywhere with a simple configuration.

[0146] In addition, when it is required to gaze at one point without moving the eyeball (line of sight) in order to improve the measurement accuracy of the measurement unit, information regarding the position of the pupil 51 or cornea of the eyeball 50 obtained by the detection unit 8 can be fed back to the control unit 9, making it possible to perform measurements according to the pupil position information of the eyeball 50.

[0147] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments of the present invention without departing from the scope of the claims.

[0148] All ordinal numbers, quantitative numbers, and other figures used in the description of the embodiments of the present invention are provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the illustrated figures. Furthermore, the connection relationships between components are provided as examples to specifically explain the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0149] For example, aspects of the present invention are as follows. <1> A retinal projection type image display device comprising: a first light source; an optical scanning unit that forms an image by scanning light from the first light source; an eyepiece optical system that directs the exit pupil of light from the optical scanning unit to an observer's eyeball; and a variable optical system that changes the incident position of light emitted from the first light source onto the optical scanning unit, wherein the variable optical system is disposed between the first light source and the optical scanning unit and is capable of moving the exit pupil. <2> the variable optical system converts the light emitted from the first light source into collimated light, and then makes the light incident on the optical scanning unit; <1> 1. A retinal projection type image display device according to claim 1. <3> the variable optical system includes a movable mirror and a concave mirror that converts light from the movable mirror into collimated light; <2> 1. A retinal projection type image display device according to claim 1. <4> The optical scanning unit and the variable optical system are arranged on the temples in a direction in which the temples extend. <1> From the above <3> The retinal projection type image display device according to any one of the above items. <5> When the optical scanning unit and the variable optical system are not driven, the optical scanning surfaces of the optical scanning unit and the variable optical system are arranged in opposing directions. <4> 1. A retinal projection type image display device according to claim 1. <6> the eyepiece optical system is disposed opposite the eyeball of the observer and includes a holographic optical element that reflects and focuses the light from the optical scanning unit toward the eyeball; <1> From the above <5> The retinal projection type image display device according to any one of the above items. <7> The optical system further includes a magnifying optical system that is disposed between the optical scanning unit and the eyepiece optical system and that magnifies an eyebox by changing an incident position of the light emitted from the optical scanning unit onto the eyepiece optical system. <1> From the above <6> The retinal projection type image display device according to any one of the above items. <8> The light incident on the magnifying optical system from the optical scanning unit is collimated light. <7> 1. A retinal projection type image display device according to claim 1. <9> The optical system includes a plurality of the magnifying optical systems. <7> 1. A retinal projection type image display device according to claim 1. <10> The eyeglass-type support includes temples, and the plurality of magnifying optical systems are arranged on the temples in a line in a direction in which the temples extend. <9> 1. A retinal projection type image display device according to claim 1. <11> a detection unit that detects the position of the pupil or cornea of the observer, and a control unit that controls the operation of the optical scanning unit and the variable optical system in accordance with the tilt of the eyeball of the observer detected by the detection unit, <1> From the above <10> The retinal projection type image display device according to any one of the above items. <12> the detection unit includes a second light source and a light receiving unit that receives light emitted from the second light source and reflected by the eyeball of the viewer and outputs information related to the light receiving position, and the optical scanning unit is capable of scanning the light emitted from the second light source and incident on the eyeball of the viewer. <11> 1. A retinal projection type image display device according to claim 1. <13> The aforementioned <1> From the above <12> An ophthalmological apparatus having the retinal projection image display device according to any one of the above. [Explanation of symbols]

[0150] 1 1st light source 2 Optical scanning unit 3 Eyepiece optical system 31 Second lens 32 Holographic Optical Elements 4 Variable optical system 41 Movable mirror 14 Reflective surface 102 Support substrate 102a, 102b, 102c, 102d Connections 113a, 113b, 113c, 113d Piezoelectric drive unit 110 First member 120 Second member 130 Third Component 140 Fourth Element 42 Concave mirror 5 First lens 6 Prism 7 Fixed mirror 8. Detection unit 81 Second light source 82 Light receiving section 9 Control Unit 911 CPU 912 ROM 913 RAM 914 Light source driving circuit 915 Scanning drive circuit 916 Deflection drive circuit 917 External I / F 901 Estimation Department 902 Light source control unit 903 Scanning control section 904 Deflection control section 11 Spectacle-shaped support 111 Crane 112 rims 113 Eyeglass Lenses 12 Magnification optical system 12-1 First magnifying optical system 12-2 Second magnifying optical system 13-1 First magnifying lens 13-2 Second magnifying lens 14-1 First magnifying prism 14-2 Second magnifying prism 15-1 First magnifying concave mirror 15-2 Second magnifying concave mirror 16-1 First magnifying movable mirror 16-2 Second magnifying movable mirror 50 Eyeball 51 Pupil 52 Retina 91 Support substrate 92 Moving parts 92a Reflective mirror 92b Torsion Bar 92c Piezoelectric material 92d Support part 93a Beam section 93 Serpentine beam 94 Serpentine beam 95 Electrode connection part 100, 100a Retinal projection image display device B System Bus D1~D4 drive signal E exit pupil E1~E3 position Im Image Data L1~L3 light P Corneal surface area S Information about the light receiving position U Observer [Prior art documents] [Patent documents]

[0151] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-294605

Claims

1. A first light source; a light scanning unit that forms an image by scanning light from the first light source; an eyepiece optical system that guides an exit pupil of light from the optical scanning unit to an eyeball of an observer; a variable optical system that changes the incident position of the light emitted from the first light source onto the optical scanning unit, the variable optical system is disposed between the first light source and the optical scanning unit, A retinal projection image display device in which the exit pupil is movable.

2. 2. The retinal projection type image display device according to claim 1, wherein the variable optical system converts the light emitted from the first light source into collimated light, and then makes the light incident on the light scanning unit.

3. The variable optical system is A movable mirror; 3. The retinal projection type image display device according to claim 2, further comprising: a concave mirror that converts the light from said movable mirror into collimated light.

4. a spectacle-type support including temples; The retinal projection type image display device according to claim 1 , wherein the optical scanning unit and the variable optical system are arranged on the temples so as to be aligned in a direction in which the temples extend.

5. When the optical scanning unit and the variable optical system are not driven, the optical scanning surfaces of the optical scanning unit and the variable optical system are arranged in opposing directions.

5. A retinal projection image display device according to claim 4.

6. 2. The retinal projection type image display device according to claim 1, wherein the eyepiece optical system is disposed opposite the eyeball of the observer and includes a holographic optical element that reflects and focuses the light from the optical scanning unit toward the eyeball.

7. 2. The retinal projection type image display device according to claim 1, further comprising a magnifying optical system arranged between the optical scanning unit and the eyepiece optical system, which enlarges the eyebox by changing the incident position of the light emitted from the optical scanning unit onto the eyepiece optical system.

8. 8. The retinal projection type image display device according to claim 7, wherein the light incident on the magnifying optical system from the optical scanning unit is collimated light.

9. 8. The retinal projection type image display device according to claim 7, comprising a plurality of said magnifying optical systems.

10. a spectacle-type support including temples; 10. The retinal projection type image display device according to claim 9, wherein the plurality of magnifying optical systems are arranged on the temples in a line in a direction in which the temples extend.

11. a detection unit that detects the position of the pupil or cornea of the observer; 2. The retinal projection type image display device according to claim 1, further comprising: a control unit that controls operations of the light scanning unit and the variable optical system in accordance with the position of the pupil or cornea of the viewer detected by the detection unit.

12. The detection unit A second light source; a light receiving unit that receives light emitted from the second light source and reflected by the eyeball of the observer, and outputs information relating to a light receiving position, 12. The retinal projection image display device according to claim 11, wherein the light scanning section is capable of scanning the light emitted from the second light source and incident on the eyeball of the viewer.

13. An ophthalmological apparatus comprising the retinal projection image display device according to any one of claims 1 to 12.

Images