Retinal projection display device, head-mounted display device, and optometry device

Abstract

To provide a retina projection display device, a head-mounted display device, and an optometric device capable of enlarging a viewing zone.SOLUTION: A retina projection display device according to one aspect of the present disclosure has an eyeglass-type support body including a temple, and projects an image onto the retina of a person wearing the eyeglass-type support body. The retina projection display device comprises: a light source; light scanning means that is arranged on the temple and scans light from the light source; projection means that projects an image formed by the light scanning means onto the retina; light deflection means that is arranged on the temple and changes a direction in which the image is projected by the light scanning means; and translation means that translates the light scanning means and the light deflection means in a direction in which the temple extends.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure relates to a retinal projection display device, a head-mounted display device, and an ophthalmic device.

Background Art

[0002] In recent years, VR (Virtual Reality) and AR (Augmented Reality) have attracted attention. In particular, AR is expected as a means to expand the vision of the real world and fuse digital information into the real space. Also, a retinal projection display device used for AR has been developed.

[0003] As a retinal projection display device, a device including a laser scanning projector, a holographic combiner, and an exit pupil selector has been disclosed in order to increase the viewing area (eyebox) (see, for example, Patent Document 1). In this device, the exit pupil selector is controllably switchable to each one of N types of arrangements and between them.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a retinal projection display device, a head-mounted display device, and an ophthalmic device that can increase the viewing area.

Means for Solving the Problems

[0005] A retinal projection display device according to an aspect of the present disclosure is a retinal projection display device having a glasses-type support including a temple, and projecting an image onto the retina of a person wearing the glasses-type support, the retinal projection display device including: a light source; a light scanning unit disposed on the temple and scanning light from the light source; a projection unit projecting an image formed by the light scanning unit onto the retina; a light deflection unit disposed on the temple and changing a projection direction of the image by the light scanning unit; and a translation unit translating the light scanning unit and the light deflection unit in a direction in which the temple extends.

Effects of the Invention

[0006] According to this disclosure, it is possible to provide a retinal projection display device, a head-mounted display device, and an optometric device that can enlarge the field of view. [Brief explanation of the drawing]

[0007] [Figure 1A] This figure shows an example configuration of a retinal projection display device according to the first embodiment. [Figure 1B] Figure 1B(a) is a front view of the retinal projection display device, Figure 1B(b) is the first example of detecting the gaze direction of a user wearing the retinal projection display device, and Figure 1B(c) is the second example of detecting the gaze direction of a user wearing the retinal projection display device. [Figure 2] This is a top view illustrating the oscillating mirror of the retinal projection display device shown in Figure 1A. [Figure 3] This is a top view illustrating the light deflection means of the retinal projection display device shown in Figure 1A. [Figure 4] This block diagram shows an example of the hardware configuration of the control means of the retinal projection display device shown in Figure 1A. [Figure 5] This block diagram shows an example of the functional configuration of the control means of the retinal projection display device shown in Figure 1A. [Figure 6] Figure 1A is a perspective view showing an example of the configuration of the translation means in the retinal projection display device. [Figure 7] This is a top view showing an example of the configuration of the projection means of the retinal projection display device shown in Figure 1A. [Figure 8A] Figure 1A is the first diagram showing an example of the operation of the projection means of the retinal projection display device. [Figure 8B] Figure 2 shows an example of the operation of the projection means of the retinal projection display device shown in Figure 1A. [Figure 8C] Figure 3 shows an example of the operation of the projection means of the retinal projection display device shown in Figure 1A. [Figure 9A] Figure 1A is the first example of exit pupil movement in a retinal projection display device. [Figure 9B] Figure 2 shows an example of exit pupil movement in the retinal projection display device shown in Figure 1A. [Figure 9C] Figure 3 shows an example of exit pupil movement in the retinal projection display device shown in Figure 1A. [Figure 9D] Figure 4 shows an example of exit pupil movement in the retinal projection display device shown in Figure 1A. [Figure 9E] Figure 5 shows an example of exit pupil movement in the retinal projection display device shown in Figure 1A. [Figure 9F] Figure 6 shows an example of exit pupil movement in the retinal projection display device shown in Figure 1A. [Figure 9G] Figure 7 shows an example of exit pupil movement in the retinal projection display device shown in Figure 1A. [Figure 9H] Figure 8 shows an example of exit pupil movement in the retinal projection display device shown in Figure 1A. [Figure 9I] Figure 9 shows an example of exit pupil movement in the retinal projection display device shown in Figure 1A. [Figure 10] Figure 1A is a diagram illustrating the operation of the retinal projection display device. [Modes for carrying out the invention]

[0008] The retinal projection display device, head-mounted display device, and optometric device according to the embodiments of this disclosure will be described in detail with reference to the drawings. However, the embodiments described below are illustrative of the retinal projection display device, head-mounted display device, and optometric device for realizing the technical concept of this embodiment, and are not limited thereto. Furthermore, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to limit the scope of this disclosure to those described therein, unless otherwise specified, but are merely illustrative examples. In addition, in the following description, the same name and reference numerals indicate the same or similar components, and detailed explanations will be omitted as appropriate.

[0009] In the drawings shown below, in order to represent directions, orthogonal coordinates having an X-axis, a Y-axis, and a Z-axis may be used. The X-axis direction and the Y-axis direction represent two orthogonal directions within a plane orthogonal to the Z-axis. In this specification, the top view refers to a view of the object seen from above. However, these directional expressions do not limit the directions of the embodiments.

[0010] The retinal projection display device according to the embodiment is a wearable device, and is a head-mounted display (HMD) of a retinal scanning method that uses Maxwell vision and directly forms an image on the retina of the wearable device wearer by laser scanning. In this specification, a retinal projection display device applied to the right eye of a person will be described as an example. However, the retinal projection display device according to the embodiment can also be applied to the left eye of the eyeball, and can also be applied to each of the eyeballs of both eyes.

[0011] In this specification, images include still images and moving images. Moving images may also be referred to as videos. Also in this specification, laser light rays and laser beams are synonymous. Laser light rays correspond to an example of light from a light source. Also in this specification, the term "substantially coincide" does not require complete coincidence, and means that errors within the extent recognized as assembly or processing errors are allowed. The term "substantially parallel" does not require complete parallelism, and means that errors within the extent recognized as assembly or processing errors are allowed.

[0012] [First Embodiment] <Example of the overall configuration of the retinal projection display device 100> FIG. 1A is a diagram showing an example of the configuration of a retinal projection display device 100 according to the first embodiment. The retinal projection display device 100 includes a glasses-type support 1, a light source 2, a lens 3, an optical scanning unit 4, an optical deflection unit 5, a projection unit 6, a line-of-sight detection unit 7, a control unit 8, a translation unit 9, and an operation unit 20. Note that the lens 3, the line-of-sight detection unit 7, and the operation unit 20 are not essential components in the retinal projection display device 100.

[0013] The spectacle-type support 1 has the shape and appearance of a spectacle frame. The spectacle-type support 1 includes temples 10, rims 11, and spectacle lenses 12. The temples 10 are the part of the spectacle-type support 1 that is located near the temples of the person wearing the spectacle-type support 1 when it is worn by a person. The temples 10 are the part that extends in the extension direction 15. The extension direction 15 is a direction that is approximately parallel to the Z axis and is approximately parallel to the line of sight direction (emmetropia direction) when the eyeball 60, which will be described later, is not rotated. The rims 11 hold the spectacle lenses 12. The spectacle-type support 1 is worn by a person operating the retinal projection display device 100. The person operating the retinal projection display device 100 is the user, administrator, etc. of the retinal projection display device 100. For the sake of explanation, the person wearing the spectacle-type support 1 will be referred to as the wearer from now on.

[0014] The eyeball 60 represents the wearer's eyeball in an emmetropic state. In a resting state, the line of sight of the eyeball 60 is parallel to the +Z direction. The pupil 61 represents the wearer's pupil. The retina 62 represents the wearer's retina 62. Region P represents the region of the corneal surface of the eyeball 60. The retinal projection display device 100 projects the image Im onto the retina 62 through the pupil 61. Since the image Im is projected onto the retina 62, the symbols for both the image Im and the retina 62 are shown together in Figure 1A.

[0015] The light source 2, lens 3, light scanning means 4, light deflection means 5, gaze detection unit 7, and control means 8 are arranged inside the temple 10. The projection means 6 is provided on the surface of the spectacle lens 12. The operating means 20 is provided on the outside of the temple 10.

[0016] Light source 2 is a semiconductor laser that emits a laser beam Lr1 with one or more peak wavelengths. Specifically, light source 2 is composed of a red semiconductor laser, a green semiconductor laser, and a blue semiconductor laser, etc. Light source 2 emits a time-modulated laser beam Lr1 in response to a first drive signal Dr1 from control means 8. When image Im is a monochrome image, light source 2 that emits a laser beam Lr1 with a single peak wavelength is used. On the other hand, when image Im is a color image, light source 2 that emits a laser beam Lr1 with multiple peak wavelengths is used.

[0017] The light intensity of the laser beam Lr1 emitted from the light source 2 is limited to an appropriate light intensity that takes into account the safety of the human eye. The retinal projection display device 100 may have an optical element that reduces the light intensity of the laser beam Lr1. The retinal projection display device 100 may also have at least one photodiode, and the output of this photodiode can be used to control the light intensity of the laser beam Lr1 so as not to exceed an appropriate light intensity that takes into account the safety of the human eye. Here, an appropriate light intensity that takes into account the safety of the human eye refers to a light intensity below Class 1 as defined in IEC (International Electro-technical Commission) 60825-1, an international standard for the safety of laser light. Note that the light source 2 is not limited to a semiconductor laser, but may also be a solid-state laser, a gas laser, etc.

[0018] The light source 2 may be located outside the crane 10. The laser beam Lr1 from the light source 2 may be guided from outside the crane 10 into the crane 10.

[0019] Lens 3 guides the laser beam Lr1 from light source 2 to optical scanning means 4.

[0020] The optical scanning means 4 is positioned on the crane 10 and scans the laser beam Lr1 from the light source 2 to form an image Im. The optical scanning means 4 includes a rocking mirror 41, a first mirror 42, a second mirror 43, and a shaping optical element 44. The optical scanning means 4 has a light guide structure that propagates light while folding the optical path along the direction of travel of the incident laser beam Lr1. The direction of travel of the laser beam Lr1 incident from the light source 2 to the optical scanning means 4 and the extension direction 15 of the crane 10 are substantially parallel. Note that the optical scanning means 4 is not limited to the configuration shown here, as long as it can scan the laser beam Lr1 from the light source 2 to form an image Im. For example, it can be modified in various ways depending on the number of folds required to propagate the laser beam Lr1 and the desired characteristics of the emitted light beam.

[0021] The oscillating mirror 41 is a MEMS (Micro Electro Mechanical System) mirror that oscillates (rotates) around two substantially orthogonal axes. The oscillating mirror 41 oscillates in response to a second drive signal Dr2 from the control means 8. The oscillating mirror 41 has a reflective mirror in a movable part connected to a support substrate. The optical scanning means 4 can scan the laser beam Lr1 incident on the optical scanning means 4 by oscillating the reflective mirror of the oscillating mirror 41 and changing its angle, thereby forming an image Im on the retina 62.

[0022] Pixels in image Im are drawn sequentially in time. The primary scanning direction in which a series of pixels in image Im are formed corresponds to the Z direction at the position of the oscillating mirror 41 and to the X direction at the incident position of the laser beam Lr1 on the eyeball 60. The secondary scanning direction, which is orthogonal to the primary scanning direction and arranges the series of pixels in image Im, corresponds to the Y direction at both the position of the oscillating mirror 41 and the incident position of the laser beam Lr1 on the eyeball 60. The scanning speed in the primary scanning direction is faster than the scanning speed in the secondary scanning direction.

[0023] The oscillating mirror 41 is positioned in the optical path between the light source 2 and the light deflection means 5. The support substrate surface of the oscillating mirror 41 is provided to be substantially parallel to the extending direction 15. The main scanning direction at the position of the oscillating mirror 41 is substantially parallel to the extending direction 15. The configuration of the oscillating mirror 41 will be described in detail separately with reference to Figure 2.

[0024] The oscillating mirror 41 is not limited to a two-axis MEMS mirror, but may also be configured to use two single-axis MEMS mirrors. The optical scanning means 4 may use a polygon mirror, a galvanometer mirror, etc. instead of the oscillating mirror 41, or a combination of the oscillating mirror 41, a polygon mirror, or a galvanometer mirror, etc. From the viewpoint of miniaturizing and lightening the retinal projection display device 100, it is preferable to use a MEMS mirror as the oscillating mirror 41. In particular, using only a two-axis MEMS mirror makes the retinal projection display device 100 smaller and lighter. The driving method for the MEMS mirror may be electrostatic, piezoelectric, electromagnetic, etc.

[0025] The light deflection means 5 reflects the laser beam Lr1 from the light scanning means 4 toward the projection means 6. The light deflection means 5 is positioned on the vine 10 and varies the projection direction 51 of the image Im formed by the light scanning means 4 by the projection means 6.

[0026] The optical deflection means 5 includes a vector scan MEMS mirror. The vector scan MEMS mirror has a reflective surface on a movable part connected to a support substrate. The reflective surface of the optical deflection means 5 oscillates in response to a third drive signal Dr3 from the control means 8. The optical deflection means 5 can selectively switch the direction of light reflection by changing the tilt of the reflective surface. The optical deflection means 5 is rotatable around an axis along the Y-axis. The tilt of the optical deflection means 5 can be controlled at any position within its movable range by the third drive signal Dr3.

[0027] The light deflection means 5 can also rotate around an axis along the Z-axis. The light deflection means 5 can control the tilt of the reflective surface at any position within its movable range by the third drive signal Dr3. Within its movable range, the light deflection means 5 can arbitrarily switch the projection direction 51 of the image Im formed by the light scanning means 4 along the X and Y directions. The retinal projection display device 100 can change the projection direction 51 of the image Im formed by the light scanning means 4 using the light deflection means 5. This allows the projection direction 51 of the image Im to be changed according to the position or tilt of the wearer's eyeball 60, thereby increasing the field of view of the retinal projection display device 100.

[0028] In this embodiment, the light deflection means 5 is positioned in the optical path between the light scanning means 4 and the projection means 6. However, the position in which the light deflection means 5 is positioned is not limited to the optical path between the light scanning means 4 and the projection means 6, and can be appropriately changed depending on the position of the light scanning means 4 or the projection means 6, as long as the projection direction 51 of the image Im by the projection means 6 is variable.

[0029] The optical deflection means 5 is provided such that its support substrate surface is substantially parallel to the extending direction 15. The support substrate surface of the oscillating mirror 41 in the optical scanning means 4 and the support substrate surface of the optical deflection means 5 are substantially on the same plane. That is, the reflective surface of the oscillating mirror 41 when no driving voltage is applied and the reflective surface of the optical deflection means 5 when no driving voltage is applied are provided to be substantially parallel. Note that "when no driving voltage is applied" refers to the state in which no driving voltage is applied and the reflective surfaces of the oscillating mirror 41 and the optical deflection means 5 are stationary. By arranging the optical scanning means 4 and the optical deflection means 5 as described above, the folding light guide structure can be made smaller, and the optical scanning means 4 and the optical deflection means 5 can be made thinner. By making the optical scanning means 4 and the optical deflection means 5 thinner, the temple 10 can be made thinner, and the retinal projection display device 100 can be made smaller. The configuration of the optical deflection means 5 will be described in detail separately with reference to Figure 3.

[0030] The light deflection means 5 may include two uniaxial MEMS mirrors. From the viewpoint of miniaturizing and lightening the retinal projection display device 100, it is preferable that the light deflection means 5 uses a vector scan MEMS mirror to vary the projection direction 51.

[0031] The optical deflection means 5 may be configured to use one single-axis MEMS mirror. In this case, the optical deflection means 5 can arbitrarily change the projection direction 51 of the image Im formed by the optical scanning means 4 along either the X direction or the Y direction. The hologram region included in the projection means 6, described below, is also limited to a one-dimensional arrangement, and the direction of expansion of the viewing area is limited to one dimension.

[0032] The projection means 6 projects the image Im formed by the optical scanning means 4 onto the retina 62. The projection means 6 includes a holographic optical element that has the function of reflecting and focusing the laser beam Lr1 received from the optical deflection means 5 toward the eyeball 60. The holographic optical element included in the projection means 6 is an example of a reflective and focusing element. The holographic optical element is composed of at least one holographic film.

[0033] A holographic optical element optically records l × n = x holographic regions, each with different light-gathering characteristics. l and n are integers greater than or equal to 1, and x is an integer greater than or equal to 2. When n=1, l=2, and vice versa. In this embodiment, an example is shown where l=5, n=2, and x=10. However, the embodiment is not limited to this example.

[0034] Each of the holographic regions described above reflects the laser beam Lr1 from the optical scanning means 4 toward the eyeball 60, forming an exit pupil. The material for the holographic film can be Bayfol® HX, available from Bayer MaterialScience AG, or a photopolymer film available in this technology. The configuration and operation of the projection means 6 will be described in detail separately with reference to Figure 7. The projection means 6 may be integrated with the spectacle lens 12. The spectacle lens 12 includes prescription spectacle lenses.

[0035] The gaze detection unit 7 detects the wearer's gaze. The gaze detection unit 7 includes a detection laser light source 71 and a photodetection element 72.

[0036] The detection laser light source 71 emits a detection laser beam Lr2 in response to a fourth drive signal Dr4 from the control means 8 and irradiates the cornea of ​​the eyeball 60. The detection laser light source 71 includes an array light source having multiple light-emitting parts such as a VCSEL (Vertical Cavity Surface Emitting Laser) or an LDA (Laser Diode Array). The peak wavelength of the detection laser beam Lr2 emitted from the detection laser light source 71 is preferably a near-infrared wavelength, which is invisible light, so as not to obstruct the wearer's vision. However, it is not limited to this, and may also be visible light.

[0037] The photodetector element 72 receives the detection laser beam Lr2 that is emitted from the detection laser light source 71, reflected by the reflecting element 73, incident on the eyeball 60, and reflected by the eyeball 60. The photodetector element 72 outputs a detection signal S corresponding to the light intensity of the received detection laser beam Lr2. The photodetector element 72 includes at least one photodiode. The corneal surface, which is the surface of the eyeball 60, is a transparent material containing water and generally has a reflectivity of about 2-4%. The detection laser beam Lr2 incident on the eyeball 60 is reflected by region P on the corneal surface of the eyeball 60 and incident on the photodetector element 72.

[0038] The photodetector element 72 is not limited to including a photodiode. For example, the photodetector element 72 may include a position-sensitive detector (PSD). Alternatively, the photodetector element 72 may use an image sensor such as a charge-coupled device (CCD) or a composite metal oxide semiconductor (CMOS) to receive a detection laser beam Lr2 and output a detection signal S by image processing based on the spatial intensity distribution of light incident on the imaging surface.

[0039] The detection laser light source 71 and the photodetector element 72 are provided within the temple 10 on the eyeglass lens 12 side relative to the optical scanning means 4. However, the gaze detection unit 7 may be provided outside the temple 10. The gaze detection unit 7 is not limited to having a detection laser light source 71 and a photodetector element 72, and various gaze direction detection technologies may be used depending on the embodiment. In this embodiment, the projection means 6 is provided in the approximately central region of the surface of the eyeglass lens 12. The location of each component of the gaze detection unit 7, such as the detection laser light source 71 and the photodetector element 72, is not particularly limited, but an example of providing them outside the temple 10 is a configuration where they are provided on the rim or the eyeglass lens 12. When provided on the eyeglass lens 12, it is preferable to provide them outside the region where the projection means is provided on the eyeglass lens 12, from the viewpoint of visibility of the projected image and visibility of the outside world.

[0040] Here, Figure 1B is an example of a diagram illustrating the configuration and operation of gaze detection unit 7A, which is another example of gaze detection unit 7 in the retinal projection display device 100. Figure 1B(a) shows a front view of the retinal projection display device 100.

[0041] The retinal projection display device 100 has at least one LED light source 11A (which emits infrared light) positioned on the face-facing side of the rim 21 of the glasses. In addition, multiple transparent infrared sensors 12A are formed on the face-facing side of the lens 22, along the rim 21 and on the inside of the rim 21. Both the LED light source 11A and the infrared sensors 12A are located on the face-facing side. Figure 1B shows only the configuration of the right lens 22, but the left lens 22 also has an LED light source 11A and infrared sensors 12A formed therein.

[0042] The LED light source 11A and the infrared sensor 12A are connected to a control unit, which will be described later, located in the temple 23, etc. The control unit controls the lighting of the LED light source 11A, and also acquires the output voltage output of the infrared sensor 12A when it detects infrared light.

[0043] The distance between the lens 22 and the eye can be the same as the distance between the lens 22 and the eye in typical eyeglasses. Therefore, by forming the infrared sensor 12A on the lens 22 as shown in Figure 1B, a retinal projection display device 100 with fewer design constraints can be provided. Furthermore, since the infrared sensor 12A is transparent or at least semi-transparent, the user's line of sight is not blocked from the outside world, and it can be used for applications such as AR (Augmented Reality) glasses. Naturally, it can also be used for applications such as VR (Virtual Reality) glasses, where the user's line of sight is blocked from the outside world.

[0044] Figure 1B(b) is an example of a diagram illustrating the detection of the gaze direction of a user wearing the retinal projection display device 100. Figure 1B(b) describes the illumination of the LED light source 11A and the output voltage of the infrared sensor 12A when the gaze direction is straight ahead.

[0045] Assume the eyeball is facing forward. In this case, the infrared light emitted by the LED light source 11A and reflected by the eyeball will be incident on all infrared sensors 12A approximately equally, so each infrared sensor 12A around the eyeball will output a similar output voltage. In other words, there is no infrared sensor 12A that outputs a particularly large output voltage. This relationship is the same regardless of the position of the lit LED light source 11A, so for example, if there is no infrared sensor 12A that outputs an output voltage above a threshold, it can be estimated that the line of sight is facing forward.

[0046] On the other hand, as shown in Figure 1B(c), when the line of sight is upward (12 o'clock direction) from the user's perspective, infrared light does not enter the infrared sensor 12A evenly, and infrared light reflected by the eyeball tends to enter the infrared sensor 12A at the 6 o'clock direction more frequently. Since this relationship is the same regardless of the position of the lit LED light source 11A, it can be estimated that the line of sight is approximately 180 degrees opposite to the infrared sensor 12A that outputs a large output voltage.

[0047] More specifically, by creating a pattern of which infrared sensor 12A detects a strong output voltage relative to the lit LED light source 11A and which infrared sensor 12A detects a weak output voltage, the direction of the line of sight can be estimated.

[0048] Thus, by forming a transparent or translucent infrared sensor 12A in the lens 22, the retinal projection display device 100 of this embodiment can be provided with fewer design constraints.

[0049] In Figure 1A, the control means 8 controls the operation of the optical scanning means 4 and the optical deflection means 5, respectively. Specifically, the control means 8 controls the scanning of the laser beam Lr1 by the optical scanning means 4 by outputting a second drive signal Dr2 to the optical scanning means 4. In addition, the control means 8 controls the tilt of the reflective surface of the optical deflection means 5 by outputting a third drive signal Dr3 to the optical deflection means 5.

[0050] The control means 8 can control the operation of the light source 2 based on image data. Specifically, the control means 8 receives image data that will be the basis for the image Im projected onto the retina 62, and controls the operation of the laser beam Lr1 from the light source 2 based on the image data.

[0051] The control means 8 sequentially lights up the light-emitting parts of the detection laser light source 71 and controls the emission of the detection laser beam Lr2. The control means 8 also estimates the position and line of sight of the eyeball 60 based on the timing of light emission from each light-emitting part of the detection laser light source 71 and the detection signal S from the photodetector element 72.

[0052] The control means 8 may be located inside the vine 10. Alternatively, the control means 8 may be located outside the vine 10, and each drive signal from the control means 8 may be supplied from outside the vine 10 to inside the vine 10.

[0053] The translation means 9 is positioned on the cradle 10 and, together with the optical scanning means 4 and the optical deflection means 5, translates the cradle 10 in the extending direction 15. The translation means 9 is positioned below the optical scanning means 4 (negative Y-axis direction).

[0054] The translation means 9 includes a rack and pinion mechanism. The optical scanning means 4 and the optical deflection means 5 are mounted on the rack and pinion mechanism in an aligned manner along the extending direction 15. The rack and pinion mechanism is a mechanism in which rotational force applied to the pinion is converted into linear motion by the rack. The translation means 9 translates the optical scanning means 4 and the optical deflection means 5 together as a unit by the rack and pinion mechanism according to the operation of the operator using the operating means 20. Note that the translation means 9 may also be mounted on and translated by components other than the optical scanning means 4 and the optical deflection means 5.

[0055] The translation means 9 has a configuration that allows for stepwise changes in the arrangement of the optical scanning means 4 and the optical deflection means 5. The translation means translates the optical scanning means 4 and the optical deflection means 5 together so that they can be positioned at each of a plurality of discrete positions along the extending direction 15. The optical scanning means 4 is translated along the extending direction 15 by the translation means 9 and can be controllably switched to N different arrangements. N is an integer of 1 or more. In this embodiment, an example is shown in which the arrangement can be switched to N=5. However, it is not limited to this. The configuration and operation of the translation means 9 will be described in detail separately with reference to Figure 6.

[0056] The retinal projection display device 100 can change the arrangement of the optical scanning means 4 and the optical deflection means 5 by translating the optical scanning means 4 and the optical deflection means 5 together using a translation means 9 located on the temple 10, thereby changing the projection direction 51 of the image Im formed by the optical scanning means 4. This allows the projection direction 51 of the image Im to be changed according to the position or tilt of the wearer's eyeball 60, thus increasing the field of view of the retinal projection display device 100. Furthermore, in this embodiment, since the translation means 9 translates the optical scanning means 4 and the optical deflection means 5 in the extending direction 15, it is not necessary to widen the width of the temple 10 in the direction perpendicular to the extending direction 15 according to the amount of translation. This makes it possible to narrow the width of the temple 10 in the direction perpendicular to the extending direction 15 compared to the case where the optical scanning means 4 and the optical deflection means 5 are translated in directions other than the extending direction 15, thus enabling miniaturization of the retinal projection display device 100. Thus, in this embodiment, a retinal projection display device 100 that can be miniaturized while increasing the field of view is provided.

[0057] The operating means 20 allows the translation means 9 to be operated so as to change the position of the optical scanning means 4 and the optical deflection means 5 according to the position and tilt of the wearer's eyeball 60. The operating means 20 is connected to the translation means 9. For example, the operating means 20 consists of a mechanism such as a dial or pinion connected via a pinion and shaft. The wearer manually operates the translation means 9 using the operating means 20 to translate the translation means 9, thereby translating the optical scanning means 4 and the optical deflection means 5 mounted on the translation means 9 together.

[0058] <Behavior of laser beam Lr1> In Figure 1A, the laser beam Lr1, which is divergent light emitted from the light source 2, is converted into substantially parallel light by the lens 3. Note that if the light source 2 emits substantially parallel light, the lens 3 is not necessarily required. Furthermore, measures such as increasing the number of lenses can be taken as needed. The laser beam Lr1, shaped into substantially parallel light by the lens 3, is incident on the optical scanning means 4. The direction of propagation and the extension direction 15 of the laser beam Lr1 incident on the first mirror 42 in the optical scanning means 4 are substantially parallel. Therefore, even if the arrangement of the optical scanning means 4 changes due to the translation means 9, it does not affect the optical characteristics after the beam is incident on the first mirror 42.

[0059] The laser beam Lr1 reflected by the first mirror 42 is incident on the oscillating mirror 41. The oscillating mirror 41 scans the laser beam Lr1 in two axial directions. The laser beam Lr1 scanned by the oscillating mirror 41 is reflected by the second mirror 43 and the light deflection means 5, respectively, and incident on the projection means 6. The projection means 6 reflects the incident laser beam Lr1 toward the eyeball 60, forming an exit pupil. When the pupil 61 and the exit pupil position are aligned, the laser beam Lr1 enters the inside of the eyeball 60 through the pupil 61. The laser beam Lr1 that enters the inside of the eyeball 60 is focused near the center of the pupil 61 by the focusing function of the hologram region of the projection means 6, and then forms a substantially image on the retina 62. The retinal projection display device 100 can project and display the image Im on the retina 62. Furthermore, image Im does not need to be a focused image (a formed image) in optical paths other than those on retina 62.

[0060] The above-described state of vision is generally known as Maxwell's vision, and it is generally understood that, because the laser beam Lr1 passing near the center of the pupil 61 reaches the retina 62 regardless of the focusing adjustment of the lens, the wearer can clearly see the projected image Im in focus, regardless of where the eye is focused in real space. On the other hand, in reality, the laser beam Lr1 incident on the eyeball 60 has a small but finite diameter, so the lensing effect of the lens is considerable. Therefore, in this embodiment, the focusing action of the optical scanning means 4 and the projection means 6 is designed so that the diameter of the laser beam Lr1 incident on the eyeball 60 is 300 μm or more and 600 μm or less, and the beam divergence angle is a positive finite value, i.e., divergent light. As a result, the image Im formed by the laser beam Lr1 scanned by the optical scanning means 4 reaches the retina 62 via the projection means 6 without being affected by the focusing adjustment of the lens. Therefore, the wearer can always clearly see the projected image Im, regardless of where their eyes focus in real space. In other words, the image formed by the laser beam Lr1 scanned by the optical scanning means 4 is visible to the wearer in a focus-free state.

[0061] Depending on the embodiment, the angle between the temple 10 and the rim 11 can be changed in any way. The retinal projection display device 100 can also change the light intensity of the emitted laser beam Lr1 by changing the current or voltage applied to the light source 2. This allows the brightness of the image to be adjusted according to the brightness of the surrounding environment in which the retinal projection display device 100 is used.

[0062] <Example configuration of the oscillating mirror 41> Figure 2 is a top view showing an example of the configuration of the oscillating mirror 41. In Figure 2, the directions indicated by the arrows are the α direction, β direction, and γ direction. The oscillating mirror 41 comprises a support base plate 91, a movable part 92, a meandering beam part 93, a meandering beam part 94, and an electrode connection part 95.

[0063] The meandering beam section 93 is formed in a meandering manner with multiple folded sections, one end connected to the support base plate 91 and the other end connected to the movable section 92. The meandering beam section 93 comprises a beam section 93a containing three beams and a beam section 93b containing three beams. The beams of beam section 93a and beam section 93b are formed alternately, one beam at a time. Each beam included in beam section 93a and beam section 93b is independently equipped with a piezoelectric member.

[0064] Similarly, the meandering beam section 94 is formed in a meandering manner with multiple folded sections, one end connected to the support base plate 91 and the other end connected to the movable section 92. The meandering beam section 94 comprises a beam section 94a containing three beams and a beam section 94b containing three beams. The beams of beam section 94a and beam section 94b are formed alternately, one beam at a time. Each beam included in beam sections 94a and 94b is independently equipped with a piezoelectric member. The number of beams in beam sections 93a and 93b is not limited to three and can be any number.

[0065] The piezoelectric members provided in beam sections 93a, 93b, 94a, and 94b are provided, for example, as piezoelectric layers in a part of the layers of each beam formed in a multilayer structure. Hereinafter, the piezoelectric members provided in beam sections 93a and 94a may be collectively referred to as piezoelectric member 95a, and the piezoelectric members provided in beam sections 93b and 94b may be collectively referred to as piezoelectric member 95b.

[0066] When voltage signals with opposite phases are applied to piezoelectric members 95a and 95b, causing the meandering beam section 94 to bend, adjacent beam sections will bend in different directions. This bending accumulates, generating a rotational force that causes the reflective mirror 92a to reciprocate around axis A in Figure 2.

[0067] The movable part 92 is formed so as to be sandwiched between the meandering beam section 93 and the meandering beam section 94 in the β direction. The movable part 92 comprises a reflective mirror 92a, a torsion bar 92b, a piezoelectric member 92c, and a support section 92d.

[0068] The reflective mirror 92a is formed, for example, by depositing a thin metal film containing aluminum, gold, silver, etc., onto a substrate. The torsion bar 92b is connected at one end to the reflective mirror 92a and extends in the positive and negative α directions to rotatably support the reflective mirror 92a.

[0069] One end of the piezoelectric member 92c is connected to the torsion bar 92b, and the other end is connected to the support part 92d. When a voltage is applied to the piezoelectric member 92c, it bends and deforms, causing a twist in the torsion bar 92b. This twist in the torsion bar 92b becomes a rotational force, causing the reflecting mirror 92a to rotate around the B axis.

[0070] Rotation of the reflective mirror 92a around the A axis causes the laser beam incident on the reflective mirror 92a to be scanned in the α direction. Rotation of the reflective mirror 92a around the B axis causes the laser beam incident on the reflective mirror 92a to be scanned in the β direction.

[0071] The support portion 92d is formed to surround the reflective 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 also indirectly supports the torsion bar 92b and the reflective mirror 92a, which are connected to the piezoelectric member 92c.

[0072] The support base plate 91 is formed to surround the movable part 92, the meandering beam part 93, and the meandering beam part 94. The support base plate 91 is connected to and supports the meandering beam part 93 and the meandering beam part 94. The support base plate 91 also indirectly supports the movable part 92 which is connected to the meandering beam part 93 and the meandering beam part 94.

[0073] The oscillating mirror 41 is formed by micro-machining silicon or glass, for example, using micro-machining technology. Micro-machining technology allows for the formation of highly accurate, minute movable mirrors on a substrate, integrated with drive units such as serpentine beams.

[0074] Specifically, for example, a single SOI (Silicon On Insulator) substrate is formed by etching or other processes. A reflective mirror, a serpentine beam section, a piezoelectric element, electrode connection sections, etc., are integrally formed on the formed substrate to create a MEMS mirror. The formation of the reflective mirror, etc., may be performed after the SOI substrate is formed, or it may be performed during the SOI substrate formation.

[0075] SOI substrates are substrates 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 provided on top of the silicon oxide layer. Because the silicon active layer is thinner in the γ direction than in the α or β direction, a component composed solely of the silicon active layer functions as an elastic part with elasticity.

[0076] SOI substrates do not necessarily have to be planar; they may have curvature or other properties. Furthermore, any substrate that can be integrally molded by etching or other processes and that can be partially elasticized is not limited to SOI substrates as a material for forming MEMS mirrors.

[0077] <Example of configuration of the optical deflection means 5> Figure 3 is a top view showing an example of the configuration of the light deflection means 5. In Figure 3, the directions indicated by the arrows are the α direction, β direction, and γ direction, respectively. The light deflection means 5 consists of a movable part 101 that reflects incident light, a support substrate 102 that supports a first member 110, a second member 120, a third member 130, and a fourth member 140 connected to the movable part 101 and having piezoelectric drive units (113a, 113b, 113c, 113d) that drive the movable part 101, and the first member 110 and the movable part It includes a connecting part 102a for connecting 101, a connecting part 102b for connecting the second member 120 and the movable part 101, a connecting part 102c for connecting the third member 130 and the movable part 101, a connecting part 102d for connecting the fourth member 140 and the movable part 101, and electrode connecting parts 150a to 150h for electrically connecting the piezoelectric drive units (113a, 113b, 113c, 113d) to the control means 8.

[0078] For example, a single SOI (Silicon On Insulator) substrate is formed by etching or other processes, and the reflective surface 14, piezoelectric drive parts 113a, 113b, 113c, 113d, electrode connection parts 150a to 150h, etc. are formed on the formed substrate, thereby integrally forming each component. The formation of each component may be performed after the SOI substrate is formed, or during the SOI substrate is formed.

[0079] SOI substrates are substrates 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 provided on top of the silicon oxide layer. Because the silicon active layer is thinner in the γ direction than in the α or β direction, a component composed solely of the silicon active layer functions as an elastic part with elasticity.

[0080] The SOI substrate does not necessarily have to be planar and may have curvature, etc. Furthermore, the material used to form the light deflection means 5 is not limited to an SOI substrate, as long as it is a substrate that can be integrally molded by etching or the like and can be partially elasticized. The reflective surface 14 is composed of a thin metal film containing, for example, aluminum, gold, or silver. In addition, the movable part 101 may have ribs for reinforcing the movable part formed on the -Z side surface of the movable part base 103. The ribs are composed of, for example, a silicon support layer 124 and a silicon oxide layer 125, and can suppress distortion of the reflective surface 14 caused by movement.

[0081] The shape and configuration of the first member 110, the second member 120, the third member 130, and the fourth member 140 are not particularly limited, and may, for example, be a meander structure or a cantilever structure. In addition, the first member 110, the second member 120, the third member 130, and the fourth member 140 may have some kind of sensor formed in addition to the piezoelectric drive unit (113a, 113b, 113c, 113d). The sensor is not particularly limited, but examples include a displacement detection sensor (piezoelectric, strain resistance, etc.) that outputs a signal in response to the deformation of the member, or a temperature sensor.

[0082] The details of the shapes of the connecting parts 102a, 102b, 102c, and 102d are not limited to this embodiment. Furthermore, while it is desirable that the angles formed by the straight lines between the connecting parts 102a, 102b, 102c, and 102d and the center of the movable part 101 be approximately 90 degrees in a plan view, this is not limited to this embodiment. The drive unit may also have functions other than driving, such as displacement detection, heating, or electrical wiring. The shape of the movable part is also not limited to this embodiment. In Figure 3, the drive method for the piezoelectric drive unit (113a, 113b, 113c, 113d) is piezoelectric drive, but for example, electromagnetic drive that deforms the support part using an electromagnetic field, electrostatic drive with comb-tooth electrodes formed on the support part, or thermoelectric drive that utilizes the difference in thermal expansion of different materials may also be used. Additionally, coils or magnet arrays may be formed on the support substrate 102.

[0083] Among the above, piezoelectric drive is preferred because it allows for the effective placement of the drive unit and suppresses an increase in the overall size of the optical deflector. For example, with electrostatic drive, comb-tooth electrodes are placed on the outer circumference of the drive unit, which tends to increase the overall size of the optical deflector. Also, with electromagnetic drive, it is difficult to lay out the wiring for each of the multiple drive units and to arrange the magnets so that a magnetic field is applied to each, which also tends to increase the overall size of the optical deflector.

[0084] In this embodiment, the case in which the piezoelectric drive units (113a, 113b, 113c, 113d) using piezoelectric thin films are formed only on one surface (the +Z side) of the silicon active layer 126, which is the elastic part, has been described as an example. However, they may also be provided on other surfaces of the elastic part (for example, the -Z side), or on both one and the other surface of the elastic part. Furthermore, an insulating layer made of a silicon oxide film may be formed on at least one of the +Z side surfaces of the upper electrode 123 of the piezoelectric drive unit or the +Z side surface of the support substrate 102. In this case, by providing electrode wiring on the insulating layer, and by partially removing or not forming the insulating layer as an opening only at the connection spots where the upper electrode 123 or lower electrode 121 is connected to the electrode wiring, the design freedom of the piezoelectric drive units 113a, 113b, 113c, 113d and electrode wiring can be increased, and short circuits due to contact between electrodes can be suppressed.

[0085] The silicon oxide film also functions as an anti-reflective material. When a positive or negative voltage is applied in the polarization direction to the piezoelectric parts 122a, 122b, 122c, and 122d of the piezoelectric drive units 113a, 113b, 113c, and 113d, deformation (e.g., expansion and contraction) proportional to the potential of the applied voltage occurs, exhibiting a so-called inverse piezoelectric effect. Due to the action of this deformation of the piezoelectric part 122, the piezoelectric drive units 113a, 113b, 113c, and 113d are bent, and a driving force around the rotation axis (oscillating axis) is applied to the movable part 101 via the connecting parts 102a, 102b, 102c, and 102d, causing the movable part 101 to move around the C axis or D axis. The C axis and D axis correspond to the rotation axes, respectively.

[0086] Next, the rotation axis of this embodiment will be described. The first member 110 is positioned at approximately 45 degrees with respect to the rotation axis of the C axis and the rotation axis of the D axis. In other words, the rotation of the movable part 101 due to the oscillation of the first member 110, the second member 120, the third member 130, and the fourth member 140 all have vectors of both the rotation axis of the C axis and the rotation axis of the D axis. For example, when voltage is applied to the piezoelectric drive units (113a, 113b) but not to the piezoelectric drive units (113c, 113d), the movable part 101 tilts around the rotation axis of the D axis. Similarly, when voltage is applied to the piezoelectric drive units (113a, 113d) but not to the piezoelectric drive units (113c, 113d), the movable part 101 tilts around the rotation axis of the C axis.

[0087] In particular, when using a drive frequency that does not match the structure's inherent resonant frequency, the rotation direction of the movable part 101 can be arbitrarily controlled by the drive signal. In other words, by controlling the independent or combined drives of each piezoelectric drive unit (113a, 113b, 113c, 113d), the movable part 101 can be swung in a desired direction, enabling vector scanning in the drawing area.

[0088] In a meander structure where each member has multiple beam sections connected in a folded manner, and piezoelectric drive unit group A and piezoelectric drive unit group B are alternately provided on the +Z side surface of each beam section, it is possible to control the deflection angle of the mirror to the + side or the - side without using a negative voltage by driving only piezoelectric drive unit group A or only piezoelectric drive unit group B. However, although piezoelectric drive unit group A and piezoelectric drive unit group B are distinguished in the above description, in this specification they are collectively referred to as piezoelectric drive unit or drive unit.

[0089] The reference voltage of the piezoelectric drive unit may be 0V, or any voltage within the maximum amplitude of the applicable voltage. It may differ between each piezoelectric drive unit, and if piezoelectric drive unit group A and piezoelectric drive unit group B are provided within each drive unit, it may differ between them. The signal waveform of the applied voltage is not limited to the embodiment example, and may be a periodic waveform such as a sine wave, square wave, or sawtooth wave, or a more complex periodic waveform. DC drive is also possible.

[0090] <Example of hardware configuration of control means 8> Figure 4 is a block diagram showing an example of the hardware configuration of the control means 8. The control means 8 includes an external I / F (Interface) 81, a CPU (Central Processing Unit) 82, a ROM (Read Only Memory) 83, a RAM (Random Access Memory) 84, a light source drive circuit 85, an optical scanning means drive circuit 86, and an optical deflection means drive circuit 87. These are electrically connected to each other via a system bus 88.

[0091] The CPU 82 is an arithmetic unit that reads programs and data from storage devices such as ROM 83 onto RAM 84, executes processing, and realizes the overall control and functions of the control means 8. RAM 84 is a volatile storage device that temporarily holds programs and data. ROM 83 is a non-volatile storage device that can retain programs and data even when the power is turned off. ROM 83 stores processing programs and data that the CPU 82 executes to control each function of the retinal projection display device 100.

[0092] The external I / F 81 is an interface that connects the control means 8 to an external device or network. External devices include, for example, a higher-level device such as a PC (Personal Computer), and storage devices such as USB memory, SD cards, CDs, DVDs, HDDs, and SSDs. Networks include, for example, a car's CAN (Controller Area Network) or LAN (Local Area Network), or the internet. The external I / F 81 only needs to be configured to enable connection or communication with an external device, and an external I / F 81 may be provided for each external device.

[0093] The light source drive circuit 85 is an electrical circuit that electrically connects to the light source 2 and the detection laser light source 71, and drives the light source 2 by applying current or voltage to it. The light source 2 turns the emission of the laser beam Lr1 ON or OFF and changes the light intensity of the emitted laser beam Lr1 in response to the first drive signal Dr1 output by the light source drive circuit 85. The detection laser light source 71 turns the emission of the detection laser beam Lr2 ON or OFF and changes the light intensity of the emitted detection laser beam Lr2 in response to the fourth drive signal Dr4 output by the light source drive circuit 85.

[0094] The optical scanning means drive circuit 86 is an electrical circuit that is electrically connected to the oscillating mirror 41 and drives the oscillating mirror 41 by applying a voltage to it. The oscillating mirror 41 changes the oscillation angle of the reflective mirror 92a provided by the movable part 92 in accordance with the second drive signal Dr2 output by the optical scanning means drive circuit 86.

[0095] The optical deflection means drive circuit 87 is an electrical circuit that is electrically connected to the optical deflection means 5 and drives the optical deflection means 5 by applying a voltage to it. The optical deflection means 5 changes the inclination angle of the reflective surface of the movable part in response to the third drive signal Dr3 output by the optical deflection means drive circuit 87.

[0096] In the control means 8, the CPU 82 acquires image data from an external device or network via the external I / F 81. The CPU 82 can acquire image data as long as it is configured to do so; for example, the image data may be stored in the ROM 83 within the control means 8. Alternatively, a storage device such as an SD card may be added within the control means 8, and the image data may be stored in that device.

[0097] The control means 8 can realize the following functional configuration through the instructions of the CPU 82 and the hardware configuration shown in Figure 4.

[0098] <Example of Control Means 8 Functional Configuration> Figure 5 is a block diagram showing an example of the functional configuration of the control means 8. The control means 8 has the following functions: a gaze direction estimation unit 801, an image formation control unit 802, a light source drive unit 803, an optical scanning means drive unit 804, and an optical deflection means drive unit 805. Of these, the functions of the gaze direction estimation unit 801 and the image formation control unit 802 are realized by the CPU 82 executing a predetermined program, etc.

[0099] The gaze direction estimation unit 801 estimates the position and gaze direction of the eyeball 60 based on the emission timing of each light-emitting part of the detection laser light source 71 and the detection signal S from the photodetector element 72.

[0100] The image forming control unit 802 acquires image data Id from an external device and, based on the field of view seen by the wearer estimated by the gaze direction estimation unit 801, converts a predetermined image data Id into a control signal and outputs it to the light source drive unit 803, the optical scanning means drive unit 804, and the optical deflection means drive unit 805. If the image Im seen by the wearer has distortion or other issues, control may be performed to correct the distortion or other issues.

[0101] The light source drive unit 803 is implemented by a light source drive circuit 85, etc., and drives the light source 2 or the detection laser light source 71 based on a control signal from the image formation control unit 802. The optical scanning means drive unit 804 is implemented by an optical scanning means drive circuit 86, etc., and drives the oscillating mirror 41 based on a control signal from the image formation control unit 802. The optical deflection means drive unit 805 is implemented by an optical deflection means drive circuit 87, etc., and drives the optical deflection means 5 based on a control signal from the image formation control unit 802.

[0102] <Example of the configuration of the translation means 9> Figure 6 is a perspective view showing an example of the configuration of the translation mechanism 9. The translation mechanism 9 includes a housing 900, a rack 901, a first pinion gear 902, a second pinion gear 903, and a shaft 904. The housing 900 houses an optical scanning mechanism 4 and an optical deflection mechanism 5 inside. In the translation mechanism 9, when rotational force is applied to the first pinion gear 902 and the second pinion gear 903, the rotational motion of the first pinion gear 902 and the second pinion gear 903 is converted into translational motion by the rack 901.

[0103] The translation means 9 can be switched in a stepwise manner. The translation direction by the translation means 9 is approximately parallel to the extension direction 15. By configuring the translation means 9 with a rack and pinion mechanism, the translation means 9 can be compactly mounted on the retinal projection display device 100.

[0104] In this embodiment, the optical scanning means 4 is translated along the extending direction 15 by the translation means 9, and can be switched to five different configurations by the wearer manually operating it. For example, the operating means 20 is composed of a first pinion gear 902 that meshes with the rack 901 and a second pinion gear 903 connected via a shaft 904. By providing this operating means 20 on the outside of the shackle 10, the wearer can manually operate the operating means 20.

[0105] The translation means 9 may be an electric actuator combining a rack and pinion mechanism and a motor. Alternatively, the translation means 9 may be configured to be electrically driven according to a drive signal from the operating means 20. Alternatively, the translation means 9 may be configured to be automatically driven based on the line of sight direction estimated by the line of sight direction estimation unit 801.

[0106] <Example of the configuration of projection means 6> Figure 7 illustrates an example of the configuration of a projection optical element. The projection means 6 is a holographic optical element. The projection means 6 has 10 separate hologram regions H1 to H10. Hologram regions H1 to H10 correspond to an example of a plurality of separate projectable regions. Each of the hologram regions H1 to H10 in the projection means 6 includes a holographic optical element as a reflecting and focusing element.

[0107] Each of the holographic regions H1 to H10 functions as a volumetric hologram. Each of the holographic regions H1 to H10 reflects and focuses light incident under predetermined incidence conditions to a predetermined position. The predetermined incidence conditions are the position and direction of the incident light defined for each of the holographic regions H1 to H10.

[0108] The projection means 6 reflects light of multiple wavelengths. When focusing light, the projection means 6 may consist of a single layer of wavelength-multiplexed holographic film. Alternatively, the projection means 6 may be constructed by laminating multiple holographic film layers, each containing a bandwidth of the multiple wavelengths to be reflected and focused. Alternatively, an angle-multiplexed hologram may be used.

[0109] In this embodiment, the projection means 6 may include a liquid crystal having the same function as a holographic optical element, or a diffractive optical element using surface relief. Note that the patterns of the hologram regions H1 to H10 shown in Figure 7 are illustrative and differ from the actual patterns.

[0110] <Example of operation of projection means 6> Figures 8A to 8C illustrate an example of the operation of the projection means 6. Figure 8A is a diagram illustrating the operation of the projection means 6, Figure 8B shows the movement of the exit pupil generated by the projection means 6, and Figure 8C illustrates the movement of the exit pupil generated by the projection means 6.

[0111] As shown in Figure 8A, each of the hologram regions H1 to H10 of the projection means 6 has the function of reflecting and focusing light incident under predetermined incident conditions toward a predetermined position. For example, when the image light L1 emitted from the exit region M1 satisfies the incident conditions, the image light reflected by any of the hologram regions H1 to H10 is focused, generating the exit pupil E1. Here, image light refers to the light that reaches the retina 62 and forms an image Im on the retina 62.

[0112] Generally, volume holograms provide maximum diffraction efficiency for light with a constant incident angle and wavelength, or phase-matched light. Furthermore, the incident conditions have a certain tolerance range for the incident angle or wavelength. Within a certain tolerance range for the incident angle or wavelength, the volume hologram still exhibits reflective and focusing behavior without excessive efficiency loss. Therefore, within this tolerance range, as shown in Figure 8B, the exit pupil can be moved from E1 to E2 by moving the exit position from exit region M1 to exit region M2 and changing the incident angle of the image light incident on any of the hologram regions H1 to H10. By extending these, as shown in Figure 8C, the incident angle of the image light incident on the hologram regions H1 to H10 can be controlled as long as it is within the tolerance range of the incident conditions that function as a volume hologram. For example, by moving the exit point to any position in the exit regions M1 to M1, the exit pupil can be moved to any position in M1 to M1. Note that i is an integer greater than or equal to 1. i can be set arbitrarily.

[0113] The exit regions M1 to Mi are virtual exit regions that change depending on, for example, the N different positions of the light deflection means 5, which are changed by the translation means 9, or the inclination of the reflective surface of the light deflection means 5. The exit pupils E1 to Ei are i regions that are in different positions on the visual field Ec within a predetermined eye box where the eyeball 60 is placed. If the exit regions M1 to Mi are not distinguished, they are collectively referred to as the exit region M. If the exit pupils E1 to Ei are not distinguished, they are collectively referred to as the exit pupil E.

[0114] The projection means 6 reflects only light with wavelengths in a very narrow band compared to the visible light wavelength band, and transmits light of other wavelengths. Therefore, most of the light traveling from real space to the wearer's eyeball 60 passes through the projection means 6 and enters the eyeball 60.

[0115] <Example of exit pupil movement> Figures 9A to 9I illustrate the movement of the exit pupil. Here, the movement of the exit pupil is horizontal, meaning it moves in a direction approximately parallel to the X direction. Figures 9A to 9I illustrate an example of how the formation position of the exit pupil moves according to the center position of the wearer's pupil 61 when looking straight ahead. When looking straight ahead, the eyeball is not rotated (emmetropia), and this refers to the position facing the +Z direction in Figures 9A to 9I. Figure 9A shows the case where the center of the pupil 61 is located within region a1, Figure 9B shows the case where the center of the pupil 61 is located within region a2, Figure 9B shows the case where the center of the pupil 61 is located within region a3, Figure 9C shows the case where the center of the pupil 61 is located within region a3, and Figure 9D shows the case where the center of the pupil 61 is located within region a4. Figure 9E shows the case where the center of the pupil 61 is located within region a5, Figure 9F shows the case where the center of the pupil 61 is located within region a6, Figure 9G shows the case where the center of the pupil 61 is located within region a7, Figure 9H shows the case where the center of the pupil 61 is located within region a8, and Figure 9H shows the case where the center of the pupil 61 is located within region a9.

[0116] In Figures 9A to 9I, the retinal projection display device 100 generates image light Lm by scanning a laser beam Lr1 with the optical scanning means 4 and directs it onto the optical deflection means 5. The image light Lm is deflected in different directions toward different positions along the X direction according to the inclination of the reflective surface of the optical deflection means 5 and incident onto the projection means 6. The projection means 6 changes the projection direction 51 (see Figure 1A) of the image Im according to the direction of the incident image light Lm. In other words, the optical deflection means 5 can vary the projection direction of the image Im by the projection means 6. Furthermore, the optical deflection means 5 can be translated along the extension direction 15 by the translation means 9 and can be switched to different positions Si in the extension direction 15.

[0117] The retinal projection display device 100 can switch the hologram region to which the image light Lm is incident by a combination of the position of the light deflection means 5 and the inclination of the reflective surface of the light deflection means 5. Furthermore, the image light Lm can be incident at a different incident angle on one of the hologram regions H1 to H10. In other words, the control means 8 shown in Figure 1A can control the operation of the light deflection means 5 so that light from the light scanning means 4 is irradiated on at least one of the hologram regions H1 to H10.

[0118] In this embodiment, an eyebox region Eb, which is a collection of exit pupils provided by the retinal projection display device 100, is pre-set. In this embodiment, an eyebox region Ec is set, which is divided into regions a1 to a9. First, the gaze detection unit 7 estimates which region a1 to a9 within the eyebox region Ec the center of the wearer's pupil 61 is located in when the wearer is looking straight ahead. In this embodiment, depending on which region a1 to a9 the center of the wearer's pupil 61 is located in when looking straight ahead, the hologram region H1 to H10 to be used for exit pupil formation, the position Si of the light deflection means 5, and the inclination of the reflective surface of the light deflection means 5 are determined.

[0119] As shown in Figure 9A, when the wearer's pupil 61 center is located within region a1 during frontal viewing, the light deflection means 5 is located at position S1. The retinal projection display device 100 uses hologram regions H1 to H3 out of hologram regions H1 to H10. The image light Lm formed by the light scanning means 4 is incident on the hologram region corresponding to the inclination of the reflective surface of the light deflection means 5. For example, the image light L2 shown by the dashed line in Figure 9A is incident on hologram region H1. The image light L1 shown by the solid line in Figure 9A is incident on hologram region H2. The image light L3 shown by the dashed line in Figure 9A is incident on hologram region H3.

[0120] Image light L2 satisfies the incident light beam conditions for the hologram to function with respect to the hologram region H1. Image light L1 satisfies the incident light beam conditions for the hologram to function with respect to the hologram region H2. Image light L3 satisfies the incident light beam conditions for the hologram to function with respect to the hologram region H3. As a result, image light L2 is reflected and focused in the hologram region H1 of the projection means 6, generating the exit pupil E1. Image light L1 is reflected and focused in the hologram region H2 of the projection means 6, generating the exit pupil E3. Image light L3 is reflected and focused in the hologram region H3 of the projection means 6, generating the exit pupil E5.

[0121] The exit pupil E3 is aligned with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E1 is located to the left from the wearer's perspective. The exit pupil E5 is located to the right from the wearer's perspective.

[0122] When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E3, the exit pupil E1 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E3, the exit pupil E5 aligns with or overlaps with the pupil 61. In other words, even when the gaze is moved to the left or right beyond a certain finite field of view visible through the exit pupil E3, the wearer can still view the image Im within a certain finite field of view. As a result, a visible area is provided across three fields of view, expanding the field of vision. The distance Ea between the exit pupil E1 and the exit pupil E3 is, for example, 2 mm. The distance between the exit pupil Ei and the exit pupil Ei+2 is also 2 mm.

[0123] As shown in Figure 9B, when the center of the wearer's pupil 61 is located within region a2 during frontal viewing, the light deflection means 5 is located at position S2. The retinal projection display device 100 uses hologram regions H1 to H3 out of hologram regions H1 to H10. The image light Lm formed by the light scanning means 4 is incident on the hologram region corresponding to the inclination of the reflective surface of the light deflection means 5. The image light L5 shown by the dashed line in Figure 9B is incident on hologram region H1. The image light L4 shown by the solid line in Figure 9B is incident on hologram region H2. The image light L6 shown by the dashed line in Figure 9B is incident on hologram region H3.

[0124] Image light L5 satisfies the incident light beam conditions for the hologram to function in the hologram region H1. Image light L4 satisfies the incident light beam conditions for the hologram to function in the hologram region H2. Image light L6 satisfies the incident light beam conditions for the hologram to function in the hologram region H3.

[0125] In Figure 9B, the incident angle of the image light when incident on the hologram regions H1 to H3 is smaller compared to the state in Figure 9A. Generally, in reflective diffractive optical elements, a smaller incident angle results in a smaller reflection angle. In other words, compared to Figure 9A, the position of the exit pupil formed by the hologram regions H1 to H3 shifts in the positive X-axis direction, which is the direction in which the reflection angle decreases. As a result, the image light L5 is reflected and focused by the hologram region H1 of the projection means 6, generating the exit pupil E2. The image light L4 is reflected and focused by the hologram region H2 of the projection means 6, generating the exit pupil E4. The image light L6 is reflected and focused by the hologram region H3 of the projection means 6, generating the exit pupil E6.

[0126] The exit pupil E4 is aligned with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E2 is located to the left from the wearer's perspective. The exit pupil E6 is located to the right from the wearer's perspective.

[0127] When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E4, the exit pupil E2 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E4, the exit pupil E6 aligns with or overlaps with the pupil 61. That is, similar to Figure 9A, even when the gaze is moved to the left or right beyond a certain finite field of view visible through the exit pupil E4, the wearer can still view the image Im within a certain finite field of view. As a result, a visible area is provided across three fields of view, expanding the field of view. The distance Ed between the exit pupils E1 and E2 is, for example, 1 mm. The distance between the exit pupils Ei and Ei+1 is also 1 mm.

[0128] The same applies to Figures 9C to 9I. As shown in Figure 9C, when the center of the wearer's pupil 61 is located within region a3 during frontal viewing, the light deflection means 5 is located at position S3. The retinal projection display device 100 uses hologram regions H1 to H3 among the hologram regions H1 to H10.

[0129] The exit pupil E5 is aligned with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E3 is located to the left from the wearer's perspective. The exit pupil E7 is located to the right from the wearer's perspective.

[0130] When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E5, the exit pupil E3 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E5, the exit pupil E7 aligns with or overlaps with the pupil 61.

[0131] As shown in Figure 9D, when the center of the wearer's pupil 61 is located within region a4 during frontal viewing, the light deflection means 5 is located at position S2. The retinal projection display device 100 uses hologram regions H2 to H4 out of hologram regions H1 to H10.

[0132] The exit pupil E6 is aligned with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E4 is located to the left from the wearer's perspective. The exit pupil E8 is located to the right from the wearer's perspective.

[0133] When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E6, the exit pupil E4 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E6, the exit pupil E8 aligns with or overlaps with the pupil 61.

[0134] As shown in Figure 9E, when the center of the wearer's pupil 61 is located within region a5 during frontal viewing, the light deflection means 5 is located at position S3. The retinal projection display device 100 uses hologram regions H2 to H4 among hologram regions H1 to H10.

[0135] The exit pupil E7 is aligned with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E5 is located to the left from the wearer's perspective. The exit pupil E9 is located to the right from the wearer's perspective.

[0136] When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E7, the exit pupil E5 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E7, the exit pupil E9 aligns with or overlaps with the pupil 61.

[0137] As shown in Figure 9F, when the center of the wearer's pupil 61 is located within region a6 during frontal viewing, the light deflection means 5 is located at position S4. The retinal projection display device 100 uses hologram regions H2 to H4 out of hologram regions H1 to H10.

[0138] The exit pupil E8 is aligned with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E6 is located to the left from the wearer's perspective. The exit pupil E10 is located to the right from the wearer's perspective.

[0139] When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E8, the exit pupil E6 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E8, the exit pupil E10 aligns with or overlaps with the pupil 61.

[0140] As shown in Figure 9G, when the center of the wearer's pupil 61 is located within region a7 during frontal viewing, the light deflection means 5 is located at position S3. The retinal projection display device 100 uses hologram regions H3 to H5 out of hologram regions H1 to H10.

[0141] The exit pupil E9 aligns with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E7 is located to the left of the wearer's perspective. The exit pupil E11 is located to the right of the wearer's perspective. When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E9, the exit pupil E7 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E9, the exit pupil E11 aligns with or overlaps with the pupil 61.

[0142] As shown in Figure 9H, when the center of the wearer's pupil 61 is located within region a8 during frontal viewing, the light deflection means 5 is located at position S4. The retinal projection display device 100 uses hologram regions H3 to H5 among the hologram regions H1 to H10.

[0143] The exit pupil E10 aligns with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E8 is located to the left from the wearer's perspective. The exit pupil E12 is located to the right from the wearer's perspective.

[0144] When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E10, the exit pupil E8 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E10, the exit pupil E12 aligns with or overlaps with the pupil 61.

[0145] As shown in Figure 9I, when the center of the wearer's pupil 61 is located within region a9 during frontal viewing, the light deflection means 5 is located at position S5. The retinal projection display device 100 uses hologram regions H3 to H5 among the hologram regions H1 to H10.

[0146] The exit pupil E11 is aligned with or overlaps with the wearer's pupil 61 when the wearer is looking straight ahead. The exit pupil E9 is located to the left from the wearer's perspective. The exit pupil E13 is located to the right from the wearer's perspective.

[0147] When the gaze is moved to the left beyond a certain finite field of view visible through the exit pupil E11, the exit pupil E9 aligns with or overlaps with the pupil 61. Conversely, when the gaze is moved to the right beyond a certain finite field of view visible through the exit pupil E11, the exit pupil E13 aligns with or overlaps with the pupil 61.

[0148] Thus, in the retinal projection display device 100, the position of the light deflection means 5, the inclination of the reflective surface of the light deflection means 5, and the combination of hologram regions used from among the hologram regions H1 to H10 can form the exit pupils E1 to E13 across the eye box region Eb. For example, if Ed = 1 mm, the eye box region Eb is Eb = 12 mm.

[0149] The position of the light deflection means 5 and the inclination of the reflective surface of the light deflection means 5 allow image light to be incident at different angles of incidence to the same hologram region. By satisfying the allowable range of the angle of incidence for each hologram region, the image light Lm can be focused onto the exit pupils E1 to E13.

[0150] In this embodiment, the gaze detection unit 7 estimates which region a1 to a9 within the eye box region Ec the center of the pupil 61 is located in when the wearer is looking straight ahead. This determines the position of the light deflection means 5, the inclination of the reflective surface of the light deflection means 5, and the combination of hologram regions H1 to H10 to be used. For example, if Ed = 1 mm, Ec = 8 mm. Generally, the interpupillary distance differs from person to person, but as long as the center of the pupil 61 is within the range of the eye box region Ec when looking straight ahead, the wearer can view the image Im across a finite field of view regardless of their position. Viewable areas are provided across three fields of view: left, center, and right. The wearer can selectively view the image Im by changing their gaze direction.

[0151] In the projection means 6, the hologram regions H1 to H5 are provided separately, allowing for optimization of the light-gathering characteristics of each hologram region. This makes it possible to provide uniform image quality in the field of view provided by any of the exit pupils E1 to E13.

[0152] The finite field of view angles provided by each of the exit pupils E1 to E13 in the retinal projection display device 100 may all be the same or different. These finite field of view angles are calculated as (horizontal field of view) × (vertical field of view), for example, 10 (degrees) × 6 (degrees), 15 (degrees) × 9 (degrees), 20 (degrees) × 12 (degrees), etc.

[0153] Figures 9A to 9I show an example in which the exit pupil is moved horizontally using hologram regions H1 to H5 as projection means 6, but the exit pupil may also be moved horizontally using hologram regions H6 to H10 as projection means 6. In this case, the eye box region Evb, which is the aggregate of exit pupils formed by hologram regions H6 to H10, is located in the positive Y-axis direction.

[0154] In this embodiment, the light deflection means 5 includes a vector scan MEMS mirror, which allows the image light to be deflected in different directions at different positions along the Y direction.

[0155] Holographic regions H6-H10 are located in the positive Y-axis direction compared to holographic regions H1-H5, and are positioned above the wearer. In other words, as long as the center of the pupil 61 during frontal viewing is within the range of region Ec in the eye box, the wearer can view the image Im across a finite field of view, regardless of their position. Three viewable areas are provided, spanning the upper left, upper center, and upper right.

[0156] The wearer can selectively view the image by changing their gaze direction. In other words, with the retinal projection display device 100, as long as the center of the pupil 61 when viewed from the front is within the range Ec inside the eye box, the wearer can view the image Im across a finite field of view, regardless of their position. The wearer is provided with six viewable areas across their field of view: left, center, right, upper left, upper center, and upper right. The wearer can selectively view the image Im by changing their gaze direction.

[0157] Figure 10 illustrates the operation and function of the retinal projection display device 100. In Figure 10, the laser beam Lr1 is scanned by the oscillating mirror 41 to become image light Lm, which is reflected by the reflective surface of the light deflection means 5 and then incident on the projection means 6. Subsequently, it is reflected by the projection means 6, focused near the center of the pupil 61 of the wearer's eyeball 60, and then projected onto the wearer's retina 62. The wearer can see the image Im projected onto the retina 62.

[0158] Light propagating from an object 70 in real space in the negative Z-axis direction is light with a broad wavelength band that includes the visible light range. The projection means 6 has excellent transmittance because the hologram functions only in wavelengths with a very narrow bandwidth compared to the visible light range. Therefore, much of the light propagating from real space toward the wearer's eyeball 60 passes through the projection means 6 and reaches the wearer's retina 62. As a result, the image of the object 70 in real space is visible with sufficient brightness. In this way, the wearer can see the image Im and the image of the object 70 in real space in parallel. The wearer can see both the image Im and the image in real space in a bright state.

[0159] In this embodiment, Maxwell's vision is used to directly form an image Im on the wearer's retina 62, allowing the wearer to see the image Im clearly and in parallel, regardless of the position in real space the wearer focuses on. On the other hand, the retinal drawing method using Maxwell's vision has the disadvantage of a relatively narrow field of view due to its characteristic of first focusing the image light Lm into the pupil 61. In situations with a narrow field of view, the image Im may disappear due to slight changes in the line of sight.

[0160] In this embodiment, the optical deflection means 5 can change the projection direction of the image Im onto the projection means 6 in the X and Y directions. Furthermore, the optical deflection means 5 can be translated in the extending direction 15 by the translation means 9, thereby switching its position to different positions Si in the extending direction 15. In other words, the retinal projection display device 100 can switch the hologram region into which the image light Lm is incident by a combination of the position of the optical deflection means 5 and the inclination of the reflective surface of the optical deflection means 5. The retinal projection display device 100 can incident the image light Lm to a single hologram region at different incident angles.

[0161] In this embodiment, an eyebox region Eb, which is a collection of exit pupils provided by the retinal projection display device 100, is pre-set, and further inside, an eyebox region Ec is set, which is divided into regions a1 to a9. First, the gaze detection unit 7 estimates which region a1 to a9 within the eyebox region Ec the center of the pupil 61 is located in when the wearer is looking straight ahead. In this embodiment, the position Si of the hologram region and light deflection means 5 used for exit pupil formation, as well as the inclination of the reflective surface of the light deflection means 5, are determined by which region a1 to a9 the center of the wearer's pupil 61 is located in when looking straight ahead, and the wearer manually operates the translation means 9 to translate to the desired position of the light deflection means 5. As a result, although the interpupillary distance generally differs from person to person, as long as the center of the pupil 61 is within the range of the eyebox region Ec when looking straight ahead, the wearer can view the image Im over a certain finite field of view, regardless of where the pupil is located. The wearer is provided with six visible areas across their field of view: left, center, right, upper left, upper center, and upper right. By changing their gaze direction, the wearer can selectively view the image Im.

[0162] In this embodiment, the hologram region used for forming the exit pupil, the position Si of the light deflection means 5, and the inclination of the reflective surface of the light deflection means 5 are uniquely determined by which region a1 to a9 within the eye box region Ec the center of the wearer's pupil 61 is located when viewed from the front. Therefore, after attaching the retinal projection display device 100 to the wearer's head, the wearer only needs to translate the translation means 9 according to the instructions. In other words, in this embodiment, the position of the exit pupil and the position of the wearer's pupil 61 can be aligned or overlapped by a semi-automated, simplified process. This makes it possible to expand the field of view in which the image can be seen, even though it is a retinal drawing method.

[0163] In this embodiment, a gaze direction estimation unit 801 (see Figure 5) is provided, which can estimate which of the six fields of view the wearer's gaze is directed towards. By controlling the inclination of the reflective surface of the light deflection means 5 so that an image is displayed in the estimated field of view, the wearer can see the image no matter which area of ​​the six fields of view they are looking at. In other words, the wearer can see the image in one of the six fields of view that their gaze is directed towards. This makes it possible to always display an image in the direction the gaze is directed, as long as it is within the range of the six fields of view, enabling image projection that follows the gaze. The images projected into each of the six fields of view may be the same or different. For example, if the image is always the same regardless of the direction of gaze, it will be possible to always display the same image no matter where the wearer looks within the range of the six fields of view. This is useful for supporting work sites in manufacturing and other industries where it is necessary to always display information in the direction of the gaze, and for general consumers to check information about what they are looking at in their daily lives.

[0164] If different images are displayed in each field of view, for example, by pre-determining and setting the necessary information and data to be displayed in the line of sight, the necessary information can be viewed by shifting one's gaze to the designated field of view when needed. In other words, a video experience that relies on the wearer's will to see what they want to see when they want to see it becomes possible. This cannot be achieved with conventional field-of-view replication methods commonly seen in disclosure technologies. As a result, for example, if the wearer is a manufacturing worker or an infrastructure inspection worker, they can work in the real world without their work being hindered by a clear field of view, and can clearly see digital content such as work instructions only when they shift their gaze at the necessary time. Furthermore, because it is focus-free, they can work without visual stress, and thus even greater work efficiency can be expected compared to conventional technologies.

[0165] As described above, the retinal projection display device 100 can provide a new added value by adding digital images with sufficient visual quality, and is therefore a technology that can be widely applied to educational support, surgical support, and daily living support, in addition to the above.

[0166] Furthermore, in this embodiment, the field of view of the image Im formed by the optical scanning means 4 remains within a single field of view, and the projection direction 51 of the image Im is switched to the field of view in which the wearer's gaze is directed, among the six fields of view, by the control of the third drive signal Dr3 of the optical deflection means 5. In other words, the resolution does not change depending on the field of view, and the resolution for scanning within a single field of view is maintained in every field of view. Generally, in image display based on laser scanning, the resolution decreases as the field of view of the image to be shown to the wearer increases, but in the retinal projection display device 100, the area in which the display can be seen, the field of view, is expanded, and the field of view in which the image Im can be displayed without degrading the resolution is expanded.

[0167] Furthermore, in this embodiment, the optical scanning means 4 and the optical deflection means 5 may be aligned along the extending direction 15 to which the temple 10 extends. This is because the length of the temple 10 in the direction perpendicular to the extending direction 15 can be shortened, thereby enabling miniaturization of the retinal projection display device 100. In particular, it is preferable that the support substrate surface of the oscillating mirror 41 in the optical scanning means 4 and the support substrate surface of the optical deflection means 5 are on the same plane and are arranged to be substantially parallel to the extending direction 15. This makes it possible to make the folded light guide structure even thinner. In addition, since the optical scanning means 4 is translated along the extending direction 15 by the translation means 9, it is possible to complete the operation inside the temple 10. This makes it possible to maintain the appearance even after the translation operation and to create a small and stylish support structure.

[0168] After manual operation following attachment, the exit pupil can be switched simply by controlling the third drive signal Dr3 of the light deflection means 5, which consists of a MEMS mirror. This allows for an expansion of the field of view without the use of mechanisms or devices that require physical movement. As a result, the retinal projection display device 100 can be made compact, and the support can be made as compact as a conventional eyeglass frame.

[0169] The translation means 9 may be configured to translate the optical scanning means 4 and the optical deflection means 5 together, so as to be able to be positioned for each of a plurality of discrete positions (positions S1 to S5) along the extending direction 15. This makes it possible to easily change the position in which the exit pupil is formed.

[0170] Furthermore, although the optical scanning means 4 and the optical deflection means 5 have been described as an integrated unit in each of the embodiments described above, the invention is not limited to this configuration. For example, the translation means 9 may translate the optical scanning means 4 and the optical deflection means 5, which are configured separately, in the extending direction 15 of the vine 10. In this case, it is preferable to translate them in such a way that the relative positions of the optical scanning means 4 and the optical deflection means 5 do not change.

[0171] The projection means 6 may have a plurality of separated projectable regions (hologram regions H1 to H10). The light deflection means 5 may be arranged in the optical path between the light scanning means 4 and the projection means 6. The control means 8 may control the operation of the light deflection means 5 so that light from the light scanning means 4 is irradiated onto at least one of the plurality of separated projectable regions. This makes it possible to make the retinal projection display device 100 thinner while improving the imaging performance by the projection means 6 and improving the quality of the image Im.

[0172] The reflective light-gathering element (projection means 6) may be a holographic optical element. This can improve the imaging performance of the projection means 6 and improve the quality of the image Im.

[0173] The control means 8 may control the operation of the light deflection means 5 according to the position and tilt of the wearer's eyeball 60. This ensures that the field of view in which the image can be seen is maintained even when the eyeball 60 moves.

[0174] The retinal projection display device 100 may have an operating means 20 that allows the translation means 9 to be operated to change the position of the light scanning means 4 and the light deflection means 5 according to the position and tilt of the wearer's eyeball 60. This makes it easy to maintain a field of view in which the image can be seen, even if there are differences in the size of the eyeball 60 for each wearer.

[0175] The control means 8 may control the operation of the light source 2 based on the image data. This allows the image Im based on the image data to be projected and displayed on the retina 62.

[0176] [Other Preferred Embodiments] In the first embodiment described above, the retinal projection display device 100 was shown as a head-mounted display that is a wearable terminal, but it is not limited to this. The retinal projection display device 100 as a head-mounted display may not only be directly attached to a person's head, but may also be attached indirectly to a person's head via a fixing part or other component, i.e., a head-mounted display device.

[0177] In addition to the embodiments described above, for example, the retinal projection display device according to this embodiment can also be used in an optometric device. An optometric device refers to a device that can perform various tests such as visual acuity tests, refractive power tests, intraocular pressure tests, and axial length tests. An optometric device is a device that can perform eye examinations without contact with the eyeball and includes a support unit that supports the subject's face, an eye examination window, a display unit that projects examination information onto the subject's eyeball during the examination, a control unit, and a measurement unit. The subject fixes their face to the support unit and stares at the examination information projected by the display unit through the eye examination window. At this time, since the position of the eyeball and the projection direction that is easy to see differ for each subject, the optical device of this embodiment can be used as the display unit. Furthermore, by using the image display device of this embodiment, it becomes possible to realize an optometric device in the form of glasses. As a result, the space required for the examination and the large optometric device are not needed, and the examination can be performed with a simple configuration regardless of the location.

[0178] Furthermore, if it is required to keep the eyes (line of sight) still and stare at a single point in order to improve the measurement accuracy of the measurement unit, a retinal projection display device having a line of sight detection unit 7 as shown in Figure 1A can be used. By feeding back the line of sight information obtained by the line of sight detection unit 7 to the control unit, it becomes possible to perform measurements according to the position of the pupil of the eye.

[0179] Although preferred embodiments have been described in detail above, the invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0180] Each function of the control means 8 described above can be realized by one or more processing circuits. Hereinafter, "processing circuit" as used herein includes processors programmed to execute each function by software, such as processors implemented by electronic circuits, and devices such as ASICs (Application Specific Integrated Circuits), DSPs (digital signal processors), FPGAs (field programmable gate arrays), and conventional circuit modules designed to execute each function of the retinal projection display device 100 described above.

[0181] Examples of the present invention are as follows: <1> A retinal projection display device having a spectacle-type support including temples, which projects an image onto the retina of a person wearing the spectacle-type support, comprising: a light source; an optical scanning means disposed on the temples and scanning light from the light source; a projection means for projecting the image formed by the optical scanning means onto the retina; an optical deflection means disposed on the temples and varying the projection direction of the image by the optical scanning means; and a translation means for translating the optical scanning means and the optical deflection means in the direction in which the temples extend. <2> The light source emits light in a direction substantially parallel to the direction in which the vine extends, <1> This is a retinal projection display device as described above. <3> The optical scanning means includes a reflective surface that reflects light from the light source, and the reflective surface is provided so as to be substantially parallel to the direction in which the vine extends when no driving voltage is applied. <1> This is a retinal projection display device as described above. <4> The light deflection means includes a reflective surface that reflects light from the light source, and the reflective surface is provided so as to be substantially parallel to the direction in which the vine extends when no driving voltage is applied. <1> This is a retinal projection display device as described above. <5> The optical scanning means includes a reflective surface that reflects light from the light source, and the optical deflection means includes a reflective surface that reflects light from the light source, and the reflective surface of the optical scanning means and the reflective surface of the optical deflection means when no driving voltage is applied are arranged to be substantially parallel to each other. <1> This is a retinal projection display device as described above. <6> The optical scanning means and the optical deflection means are arranged along the direction in which the vine extends. <1> This is a retinal projection display device as described above. <7> The translation means translates the optical scanning means and the optical deflection means together so that they can be positioned for each of a plurality of discretely arranged positions along the direction in which the vine extends. <1> from the above <6> It is a retinal projection display device described in any one of the following. <8> The projection means has a plurality of separated projectable regions, the projection means is arranged in the optical path between the optical scanning means and the projection means, and the control means controls the operation of the optical deflection means so that light from the optical scanning means is shone onto at least one of the plurality of separated projectable regions. <1> from the above <7> It is a retinal projection display device described in any one of the following. <9> The projection means includes a reflective light-collecting element corresponding to each of the separated plurality of projectable regions. <8> This is a retinal projection display device as described above. <10> The aforementioned reflective light-collecting element is a holographic optical element. <9> This is a retinal projection display device as described above. <11> The optical scanning means and the optical deflection means each have a control means for controlling their respective operations, wherein the control means controls the operation of the optical deflection means according to the position and tilt of the eyeball of the person wearing the glasses-type support. <1> from the above <10> It is a retinal projection display device as described in any one of the items. <12> The translation means has an operating means that allows the translation means to be operated so as to change the position of the light scanning means and the light deflection means according to the position and tilt of the eyeball of the person wearing the glasses-type support, <1> from the above <11> It is a retinal projection display device described in any one of the following. <13> The light scanning means and the light deflection means each have control means for controlling their respective operations, and the control means further controls the operation of the light source based on image data. <1> from the above <12> It is a retinal projection display device described in any one of the following. <14> A retinal projection display device that projects an image onto the retina of the person wearing it, comprising a light source and The retinal projection display device comprises: an optical scanning means for scanning light from the aforementioned light source; an optical deflection means for deflecting the light scanned by the optical scanning means; a projection means for projecting the light deflected by the optical deflection means onto the retina; and a translation means for translating the optical scanning means and the optical deflection means substantially parallel to the normal viewing direction of the person wearing the device. <15> The aforementioned <1> from the above <14> A head-mounted display device having a retinal projection display device described in any one of the above. <16> The aforementioned <1> from the above <14> An ophthalmoscope having a retinal projection display device described in any one of the following. [Explanation of symbols]

[0182] 1 Spectacle-shaped support 10 Cranes 11 rim 12 eyeglass lenses 14 Reflective surface 15 Extending direction 2 light source 3 lenses 4. Optical scanning means 41 Oscillating mirror 42 First Mirror 43 Second Mirror 44 Shaping Optical Elements 5 Light deflection means 51 Projection direction 6 Projection means 7. Eye-line detection unit 70 Objects 71 Laser light source for detection 72 Photodetector 73 Reflectors 8 Control means 81 External I / F 82 CPU 83 ROM 84 RAM 85 Light source driving circuit 86 Optical scanning means drive circuit 87 Optical deflection means driving circuit 88 System Bus 801 Gaze direction estimation unit 802 Image Forming Control Unit 803 Light source drive unit 804 Optical scanning means drive unit 805 Optical deflection means drive unit 9 Translation means 900 units 901 Rack 902 First pinion gear 903 Second pinion gear 904 Shaft 20 Operating means 60 Eyeball 61 Pupil 62 Retina 92a Reflective mirror 100 Retinal projection display device a1~a9 area Dr1 First drive signal Dr2 Second drive signal Dr3 Third drive signal Dr4 4th drive signal E, E1~Ei exit pupil Eb, Evb eyebox area Ec eyebox internal area Ea, Ed distance H1~H10 Hologram Region ID Image Data Im Image Lm, L1~L6 Image Light Lr1 laser beam Lr2 detection laser beam M, M1~Mi emission area P area S detection signal S1~S5, Si position [Prior art documents] [Patent Documents]

[0183] [Patent Document 1] Patent No. 6769974

Claims

1. A retinal projection display device having a spectacle-type support including temples, which projects an image onto the retina of a person wearing the spectacle-type support, Light source and A light scanning means is arranged on the aforementioned vine and scans the light from the aforementioned light source, A projection means for projecting the image formed by the optical scanning means onto the retina, An optical deflection means is arranged on the aforementioned vine and changes the projection direction of the image by the optical scanning means, A retinal projection display device comprising: a translation means for translating the light scanning means and the light deflection means in the direction in which the temple extends.

2. The retinal projection display device according to claim 1, wherein the light source emits light in a direction substantially parallel to the direction in which the temple extends.

3. The optical scanning means includes a reflective surface that reflects light from the light source, The retinal projection display device according to claim 1, wherein the reflective surface is provided so as to be substantially parallel to the direction in which the temple extends when no driving voltage is applied.

4. The light deflection means includes a reflective surface that reflects light from the light source, The retinal projection display device according to claim 1, wherein the reflective surface is provided so as to be substantially parallel to the direction in which the temple extends when no driving voltage is applied.

5. The optical scanning means includes a reflective surface that reflects light from the light source, The light deflection means includes a reflective surface that reflects light from the light source, The retinal projection display device according to claim 1, wherein the reflective surface of the optical scanning means and the reflective surface of the optical deflection means are provided to be substantially parallel when no driving voltage is applied.

6. The retinal projection display device according to claim 1, wherein the light scanning means and the light deflection means are arranged along the direction in which the temple extends.

7. The retinal projection display device according to claim 1 or 2, wherein the translation means translates the optical scanning means and the optical deflection means together so that they can be positioned for each of a plurality of discretely arranged positions along the direction in which the temple extends.

8. The system includes control means for controlling the operation of the optical scanning means and the optical deflection means, respectively. The projection means has a plurality of separate projectable regions, The light deflection means is arranged in the optical path between the light scanning means and the projection means. The retinal projection display device according to claim 1 or 2, wherein the control means controls the operation of the light deflection means to irradiate at least one of the separated plurality of projectable regions with light from the light scanning means.

9. The retinal projection display device according to claim 8, wherein the projection means includes a reflective and light-collecting element corresponding to each of the separated plurality of projectable regions.

10. The retinal projection display device according to claim 9, wherein the reflective light-collecting element is a holographic optical element.

11. The system includes control means for controlling the operation of the optical scanning means and the optical deflection means, respectively. The retinal projection display device according to claim 1 or 2, wherein the control means controls the operation of the light deflection means according to the position and tilt of the eyeball of a person wearing the glasses-type support.

12. The retinal projection display device according to claim 1 or 2, further comprising an operating means for operating the translation means to change the position of the light scanning means and the light deflection means in accordance with the position and tilt of the eyeball of a person wearing the glasses-type support.

13. The system includes control means for controlling the operation of the optical scanning means and the optical deflection means, respectively. The retinal projection display device according to claim 1 or claim 2, wherein the control means further controls the operation of the light source based on image data.

14. A retinal projection display device that projects an image onto the retina of the person wearing it, Light source and A light scanning means for scanning light from the aforementioned light source, A light deflection means for deflecting light scanned by the aforementioned light scanning means, A projection means for projecting light deflected by the light deflection means onto the retina, A retinal projection display device comprising: a translation means for translating the light scanning means and the light deflection means substantially parallel to the direction of normal vision of the person wearing the device.

15. A head-mounted display device having a retinal projection display device according to claim 1 or claim 2.

16. An ophthalmoscope having a retinal projection display device according to claim 1 or claim 2.

Images