Optical and display devices

Abstract

To provide an optical device using an angle selection type transmission element in which a decrease in vignetting or numerical aperture is suppressed and eyepiece observation and sight line detection are enabled while reducing ghosts due to light from behind a user.SOLUTION: A head mounted display (HMD) 1 having a sight line detection function comprises angle selection type transmission elements 6, 7 arranged in finder optical paths for user's eyes, respectively, and a light projection and a light reception unit for sight line detection, with the direction of the finder being adjustable to the detected sight line direction. The angle selection type transmission elements 6, 7 have a first to a third opening, the respective directions of which are different. The first and the second openings respectively limit light passage directions in first and second regions in the finder paths. The third opening is formed centering around a line linking an eyepoint and the light receiving element.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a ghost reduction technique for head-mounted displays, binoculars, camera viewfinders, and the like, and more particularly to an optical device and a display device that include an angle-selective transmission element. [Background technology]

[0002] When a user uses a head-mounted display or a camera viewfinder outdoors, there is a possibility that ghost images may be generated by light coming from behind the user. Patent Document 1 discloses a technology that blocks the light that causes ghost images by placing a louver film on the eye side of the display unit.

[0003] Furthermore, cameras with a line-of-sight detection function that detects the direction of the user's line of sight and thereby realizes functions such as distance measurement point selection have been put into practical use (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-215908 [Patent Document 2] Patent No. 3186072 Summary of the Invention [Problem to be solved by the invention]

[0005] With conventional technology, problems arise such as vignetting due to the narrow eye box and a reduced aperture ratio. Also, measures are needed to prevent vignetting of the light from the infrared light source (LED) that travels from the eye point to the gaze detection sensor. An object of the present invention is to enable ocular observation and line of sight detection while suppressing vignetting and a decrease in aperture ratio and reducing ghosts caused by light from behind the user in an optical device that uses an angle-selective transmission element. [Means for solving the problem]

[0006] An apparatus according to one embodiment of the present invention is an optical apparatus equipped with a finder having an eyepiece lens system, the apparatus comprising: an angle-selective transmission element disposed in an optical path of the finder and having a plurality of openings for restricting the passing direction of a light beam; and detection means for detecting a line of sight by light passing through the angle-selective transmission element. a mechanism capable of adjusting the angle of the rotation direction of the finder based on the line of sight direction detected by the detection means, The angle-selective transmission element is located between the eyepoint corresponding to the position of the user's eyes and the eyepiece lens system. [Effects of the Invention]

[0007] According to the present invention, in an optical device using an angle-selective transmission element, vignetting and a decrease in aperture ratio are suppressed, and ghosts caused by light from behind the user are reduced, making it possible to perform eyepiece observation and line of sight detection. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an external view of a display device (head-mounted display) to which the present invention is applied. [Figure 2] FIG. 10 is a diagram showing a state in which the display device is worn by a user on the head. [Figure 3] 3 is a diagram showing a state in which the display unit is flipped up from the state in FIG. 2. FIG. [Figure 4] FIG. 2 is a cross-sectional view showing the configuration of the display device when in use. [Figure 5] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 6] FIG. 2 is a cross-sectional view showing the relationship between the user's head and eyeballs and the display device. [Figure 7] FIG. 7 is a detailed view showing part B in FIG. 6. [Figure 8] FIG. 2 is a diagram showing the first surface side of the angle-selective transmission element. [Figure 9] FIG. 9 is a cross-sectional view taken along line CC in FIG. 8. [Figure 10] FIG. 10 is a diagram showing optical paths during gaze detection. [Figure 11] FIG. 2 is a cross-sectional view showing a configuration during gaze detection. [Figure 12] FIG. 2 is a schematic diagram of an eyeball image during gaze detection. [Figure 13] FIG. 10 is a diagram showing the first surface side of an angle-selective transmission element according to a second embodiment. [Figure 14] FIG. 14 is a cross-sectional view taken along line DD in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. A head-mounted display (hereinafter referred to as HMD) is shown as an example of a display device that uses an angle-selective transmission element arranged in the optical path of a viewfinder, etc. Note that the present invention is not limited to HMDs and can be applied to various optical devices.

[0010] [First Example] An electronic viewfinder (hereinafter referred to as EVF) with a gaze detection function according to this embodiment will be described with reference to Figs. 1 to 12. Fig. 1 is an external view showing an example of the configuration of an HMD 1. The HMD 1 comprises a main body 2, EVFs 3 and 4, and a head-mounted unit 5. The pair of EVFs corresponds to both eyes of the user and is made up of an EVF 3 for the left eye and an EVF 4 for the right eye.

[0011] The main body 2 and head-mounted unit 5 of the HMD 1 are rotatable via hinges 2a on the main body 2 side and hinges 5a on the head-mounted unit 5 side, and are joined in a state in which the distance between the main body 2 and the user's eyes (Fig. 5: distance E1 between eyepoint 13 and eye-side surface 6a) can be adjusted. The left-eye EVF 3 and right-eye EVF 4 are held relative to the main body 2 in a state in which the interpupillary distance can be adjusted.

[0012] Figures 2 and 3 show the state in which a user wears the HMD 1 on their head. Figure 2 shows the state in which the user is looking at the display screen, and Figure 3 shows the state in which the main body 2 of the HMD 1 is flipped up so that the user can see the surroundings.

[0013] Angle-selective transmission elements 6 and 7 are attached to the portions where the user looks into the EVFs 3 and 4, respectively. In this embodiment, the angle-selective transmission elements 6 and 7 have the same configuration, but by differentiating the configuration of the two elements, it is possible to optimize the convergence angle between the right and left eyes and the ghost cutting characteristics. In the following, the side of the angle-selective transmission elements 6 and 7 that is closest to the optical axis of the viewfinder is defined as the inside, and the side that is away from the optical axis of the viewfinder is defined as the outside.

[0014] FIG. 4 is a cross-sectional view showing the configuration of the main body 2 and EVF 3 when the HMD 1 is in use, illustrating the portion corresponding to the user's left eye. The display unit 9 and eyepiece system 10 are provided inside the exterior member 11 of the EVF 3. The display unit 9 has an organic EL (Electro-Luminescence) display panel. The surface of the eyepiece system 10 facing the angle-selective transmission element 6 is curved. The angle-selective transmission element 6 is disposed on the exterior member 11 at a position facing the user's left eye. The first surface 6a of the angle-selective transmission element 6 is the surface facing the user's eye, and the second surface 6b is the surface facing the eyepiece system 10. Details of the optical path splitting prism unit 21 disposed between the display unit 9 and the eyepiece system 10 will be described later.

[0015] The angle-selective transmission element 6 is provided with a plurality of openings 6c, which have the function of restricting the direction in which light passes. The plurality of openings 6c are open in the direction of the light beam that travels from the eyepiece lens system 10 toward the eyepoint 13, which is the position of the user's eye. Figure 4 shows a schematic diagram of the viewfinder light beam 12 that reaches the eyepoint 13 out of the light beams emitted from the eyepiece lens system 10. The eyepoint 13 is determined by the eyepiece lens system 10.

[0016] The exterior member 14 of the main body 2 contains a control circuit 15 that controls the entire HMD 1. The control circuit 15 controls the display unit 9, and light from the display unit 9 is collected by the eyepiece system 10 and passes through multiple openings 6c provided in the angle-selective transmission element 6, allowing the information displayed on the display unit 9 to be observed by the eye at eyepoint 13.

[0017] Figure 5 is a cross-sectional view taken along line AA in Figure 2, showing the relationship between the EVF 3 and EVF 4 and the head and eyes when using the HMD 1. Figure 6 shows the relationship between the head and eyes and the HMD 1 when using the HMD 1. Figure 7 is a detailed view of part B shown in Figure 6.

[0018] Figure 5 shows the adjustable parts in relation to the EVF3, EVF4 and the eyeball. Because the user can only view the display from near the eyepoint, it is necessary to keep the eye position near the eyepoint at all times. To achieve this, the HMD1 detects the direction of the user's line of sight and has first to third mechanisms that can adjust the position by using the line of sight detection results.

[0019] The first mechanism is configured to adjust the interpupillary distance (W) to match the distance between the user's eyes. Specifically, the EVFs 3 and 4 are guided by guide bars or the like relative to the main body 2, allowing them to move independently. The second mechanism is configured to adjust the distance (E1) between the eyepoint 13 and the eye-side surface 6a of the angle-selective transmission element 6 (7). The third mechanism is configured to adjust the rotational angle (θ) to prevent vignetting or changes in aperture ratio due to eyeball rotation, such as when the line of sight is moved or the convergence angle is changed. By detecting the user's line of sight, the EVF 3 (EVF 4) can be adjusted in the rotational direction (θ direction) around the area 40 where the eye-side surface 6a and the optical axis of the eyepiece lens system 10 intersect. Specifically, the EVF 3 (EVF 4) constitutes a unit of the HMD 1 that can be adjusted in the rotational direction around the area 40. The HMD1 unit is attached to the main body 2 so that the interpupillary distance (W) is adjustable. Because the EVFs 3 and 4 each have a mechanism that allows them to move independently, the HMD 1 is structured so that the EVFs 3 and 4 can be adjusted to the optimal positions for the user's left and right eyes using gaze detection units located respectively for the user's left and right eyes. In other words, the control unit of the HMD 1 calculates the positions of the user's eyes by detecting the gaze, and then calculates the difference from a reference position to align the EVFs 3 and EVFs 4 with the positions of the left and right eyes, thereby adjusting them to the optimal positions.

[0020] By combining the line of sight detection function with an angle-selectable transmission element, it is possible to solve the problems of vignetting and reduced aperture ratio due to a narrow eye box. In addition, there are two types of adjustable parts in the first to third mechanism parts: a configuration in which the user moves them manually using a lever or the like, and a configuration in which a motor or the like is incorporated as a power source and moves them automatically, and either configuration can be used.

[0021] When using the HMD 1 shown in Figure 6, assume that the light is completely from the front, that is, from a direction in which the user faces away from the light source (such as the sun). In this case, most of the light that enters the angle-selective transmission element 6 and the eyepiece system 10 is blocked by the user's head. However, if the user rotates their face sideways from this state by an angle of several tens of degrees, the light that passes through the side of their face (light that passes through the cross-hatched area in Figure 6) reaches the position of the angle-selective transmission element 6 and the eyepiece system 10.

[0022] The area in the eyepiece lens system 10 where reverse light may cause ghosts is the cross-hatched area in the case of the left eye, as shown by line 17 connecting point 16 and the side of the head in Figure 6. In this embodiment, multiple openings 6c are provided from eyepoint 13 toward the eyepiece lens system 10. In order for light to reach the eyepiece lens system 10 located on the side farther from the multiple openings 6c than the user, a light source must be located in the direction of the holes in the openings 6c. Line 17 in Figure 6 indicates the position where the direction of the multiple openings 6c and the direction of the light rays are closest, making it easier for reverse light to reach the eyepiece lens system 10.

[0023] As shown in FIG. 7 , the multiple openings 6c inside the angle-selective transmission element 6 are separated by walls 6d between adjacent holes. In this embodiment, the multiple openings 6c are filled with a transparent solid having a small refractive index difference from air. Filling the angle-selective transmission element 6 with a transparent solid having a small refractive index difference from air prevents dust from entering the multiple openings 6c. It also prevents the walls 6d from being deformed by external forces. In this embodiment, a porous transparent material containing 90% or more air is used as the transparent solid having a small refractive index difference from air, and the refractive index difference from air is 0.1 or less. This results in almost no reflection at the interface with air. Inside the multiple openings 6c, there is almost no reflection at the transparent solid surface having a small refractive index difference from air, both on the first surface 6a facing the eye and the second surface 6b facing the eyepiece lens system 10. Light entering the multiple openings 6c from the outside enters the interior with almost no reflection.

[0024] In the angle-selective transmission element 6, anti-reflection treatment is applied to the second surface 6b on the eyepiece lens system 10 side, the first surface 6a on the eye side, and the inner wall portions 6d of the multiple openings 6c. The angle-selective transmission element can be created using a 3D printer, and the anti-reflection treatment can be achieved by applying an anti-reflection coating.

[0025] In Figure 7, light ray 18 represents light that has passed through the side of the user's head. Light ray 18 enters the interior through the holes of the multiple openings 6c provided on the first surface 6a of the angle-selective transmission element 6. The light that enters the multiple openings 6c reaches the wall 6d, but the reflected light is attenuated because the wall 6d is anti-reflection treated. Therefore, even if the reflected light reaches the eyepiece lens system 10, almost no ghosting occurs.

[0026] The thickness of the angle-selective transmission element 6 is denoted as t, the opening width of the opening 6c is denoted as w, and the incident angle of the unwanted light is denoted as θ0. The condition for preventing the unwanted light from directly reaching the eyepiece lens system 10 is given by the following equation (1). t≧w / tanθ0(1) Tan represents a tangent function, and in this embodiment, the condition of formula (1) is satisfied.

[0027] FIG. 8 is a diagram schematically showing the first surface 6a of the angle-selective transmission element 6. The angle-selective transmission element 6 has inner openings 6e1 and 6e2 and a plurality of openings 6c around them. FIG. 9 is a cross-sectional view taken along CC in FIG. 8. The plurality of openings 6c provided in the angle-selective transmission element 6 are formed in a hexagonal shape on the second surface 6b, which is the entrance side of the viewfinder light rays, and on the first surface 6a, which is the exit side of the viewfinder light rays. Adjacent hexagonal portions are separated by walls 6d, and the interior is filled with a transparent solid whose refractive index is small compared to air.

[0028] Figure 9 (cross-sectional view taken along CC in Figure 8) shows the orientation of the multiple openings 6c. The orientation of the multiple openings 6c is set so that it follows the direction of light heading toward eyepoint 13. The distance between eyepoint 13 and first surface 6a is denoted as E1, and the distance between eyepoint 13 and second surface 6b is denoted as E2. The formation pitch of the multiple openings 6c on first surface 6a is denoted as P1.

[0029] The multiple openings 6c are provided at equal pitches, and the distance from the center of the optical axis is represented as Hi. In the right half of FIG. 9, with the center of the optical axis as the reference, i in "Hi" represents any natural number from 1 to 9. H1=P1 H2=P1×2 · · H8=P1×8 H9=P1×9 In other words, the relationship is "Hi = P1 x i".

[0030] With the center of the optical axis as the reference, the angle of each line connecting the eye point 13 and the plurality of openings 6c is expressed as θi, where i in “θi” represents any natural number from 1 to 9. θ1=tan -1 (H1 / E1) θ2=tan -1 (H2 / E1) · · θ8=tan -1 (H8 / E1) θ9=tan-1 (H9 / E1) tan -1 represents the arctangent function, and "θi = tan -1 (Hi / E1)" relationship. The pitch P2 of the plurality of openings 6c on the second surface 6b is as shown in the following formula (2). P2=E2×tanθ1 (2) In FIG. 9, the right half surface has been described with reference to the center of the optical axis, but the same relationship as above also applies to the left half surface since the configuration is symmetrical with respect to the optical axis.

[0031] When the eyepiece system 10 is viewed from the user's eye, using eyepoint 13 as a reference, the eyepiece system 10 is visible through the multiple openings 6c. The wall 6d is approximately parallel to the direction of light reaching the user's eye, making it almost invisible. Furthermore, when the user's eye is located at eyepoint 13, the first surface 6a is close to the eye, and the image is not in focus. Because the wall 6d is made thin, the flat portion at the entrance of the wall 6d is also almost invisible.

[0032] The user can only view the displayed information from the vicinity of eyepoint 13, and therefore the position of the eyes must be fixed near eyepoint 13. In this embodiment, the head-mounted unit 5 fixes the relative positional relationship between the user's head and HMD 1, thereby enabling the eyes to be placed at eyepoint 13.

[0033] Figure 10 is a perspective view showing the configuration of the EVF portion. Figure 11 is a cross-sectional view of the EVF portion on the optical axis. The diagram shows, in order from the side closest to the eyepoint 13, the angle-selective transmission element 6, the eyepiece lens system 10, the second optical-path splitting prism 20, the first optical-path splitting prism 19, and the display unit 9.

[0034] The first optical path splitting prism 19 and the second optical path splitting prism 20 constitute an optical path splitting prism unit 21. The optical path splitting prism unit 21 is an optical path splitting means formed by bonding the first optical path splitting prism 19 and the second optical path splitting prism 20 together.

[0035] The infrared LEDs 22 and 23 are light-emitting elements that illuminate the eye for gaze detection. The infrared LEDs 22 and 23 constitute a light-projecting unit and are arranged on the first surface 6a side of the angle-selective transmission element 6. The infrared LEDs 22 and 23 are arranged so that they each emit infrared light toward different positions, and are used in pairs to detect the distance between the EVF portion (including the light-receiving unit) and the viewer's eye. The lens 24 is a gaze-imaging lens of the gaze detection optical system. The sensor 25 that constitutes the light-receiving unit is a gaze detection sensor.

[0036] Light from the eyeball illuminated by the infrared LEDs 22 and 23 passes through the angle-selective transmission element 6 and the eyepiece lens system 10 and enters the second optical path splitting prism 20 from the second surface 20a. This is shown by optical path 26a in Figure 6. A dichroic film that reflects infrared light is formed on the first surface 20b of the second optical path splitting prism 20.

[0037] Light from the eyeball illuminated by the infrared LEDs 22 and 23 is reflected by the first surface 20b of the second optical path splitting prism 20. The light is reflected toward the second surface 20a. This reflected optical path is indicated by optical path 26b. The light along reflected optical path 26b is totally reflected by the second surface 20a, and the light along imaging optical path 26c is imaged on the gaze detection sensor 25 by the gaze imaging lens 24.

[0038] To detect the line of sight, the corneal reflection image formed by specular reflection of infrared LED light from the cornea is used in addition to the eyeball image created by illumination. Figure 10 shows the optical path of light emitted from infrared LEDs 22 and 23 reflected by the cornea 27 of the eyeball.

[0039] FIG. 11 shows optical paths 26a, 26b, and 26c, which are paths of light reflected by the cornea 27 and directed toward the gaze detection sensor 25. Of these optical paths, the direction of optical path 26a is not the same as the direction of opening 6c, which is set to direct light from the eyepiece lens system 10 toward the eyepoint 13. Inner openings 6e1 and 6e2 (see FIG. 8) in the angle-selective transmission element 6, through which light along optical path 26a passes, are formed substantially parallel to optical path 26a to prevent vignetting. Furthermore, since there are individual differences in the way light exits from optical path 26a (differences in corneal curvature), openings 6e1 and 6e2 are formed larger than the adjacent opening 6c. By increasing the openings of openings 6e1 and 6e2, light passing through the side of the user's head can more easily enter the openings. However, by increasing the thickness of the angle-selective transmission element 6, light is reflected more times within openings 6e1 and 6e2, resulting in attenuation. In this embodiment, the thickness of the portion 6f of the angle-selective transmission element 6 is greater than that of the peripheral portion. That is, the thickness of the portion 6f of the angle-selective transmission element 6 increases along the surface (curved surface) facing the eyepiece lens system 10, and openings 6e1 and 6e2 are formed in this portion.

[0040] FIG. 12 is a schematic diagram illustrating the interocular distance between an eyeball image and a corneal reflection image. It shows an iris 28, a pupil 29, and corneal reflection images 30 and 31 generated by infrared LEDs 22 and 23 for illumination. The gaze direction is detected from the relationship between the center of the pupil 29 and the corneal reflection image. A known method for gaze detection utilizes reflected light obtained by illuminating the observer's eyeball. For example, gaze correction involves acquiring a correction coefficient for correcting individual differences in the user's eyeball, followed by gaze input processing, where the gaze direction angle and coordinate values ​​on the observation surface are calculated using an arithmetic equation corresponding to the correction coefficient. Specifically, this method can be realized using the method disclosed in Patent Document 2, and detailed explanations thereof are omitted.

[0041] In a configuration in which the opening direction of the angle-selective transmission element is set to the direction of light going from the lens to the eyepoint, measures are required to prevent vignetting due to a narrow eyebox and a decrease in the aperture ratio. Also, measures are required to suppress vignetting of the infrared LED light going from the eyepoint to the gaze detection sensor.

[0042] In this embodiment, in a finder using an angle-selective transmission element, measures can be taken by detecting the direction of the user's line of sight and using the line of sight detection results. Also, it is possible to provide a finder with a line of sight detection function that realizes functions such as focus point selection while reducing ghosts caused by light arriving from behind the user.

[0043] [Second Example] A second embodiment of the present invention will be described with reference to Figures 13 and 14. Explanation of matters similar to those in the first embodiment will be omitted, and only differences from the first embodiment will be described. This method of omitting explanations will be the same for the embodiments described later.

[0044] In this embodiment, an example is shown in which the line-of-sight detection sensor 25 is arranged near the angle-selective transmission element 6. Fig. 13 is an external view of the angle-selective transmission element 6 of this embodiment, showing the first surface 6a side. Fig. 14 is a configuration diagram of the DD cross section in Fig. 13.

[0045] In this embodiment, the gaze detection sensor 25 is disposed outside the eyepiece lens system 10. An angle-selective transmission element 6 is provided on the front side (eyepoint 13 side) of the infrared LEDs 22, 23 and the gaze detection sensor 25. This configuration makes it difficult for sunlight, which is external light, to be directly incident on the gaze detection sensor 25, thereby making it possible to reduce the occurrence of false detections.

[0046] 14, light traveling from eyepoint 13 toward gaze detection sensor 25 is shown as optical path 32. The direction of optical path 32 is not the same as the direction of opening 6c, which is set in the direction of light traveling from eyepiece lens system 10 toward eyepoint 13. Opening 6g of angle-selective transmission element 6, through which light traveling along optical path 32 passes, is formed in a cone shape with its axis approximately parallel to optical path 32 and with a taper angle (see θt in FIG. 14) to prevent vignetting.

[0047] [Third Example] Next, a third embodiment of the present invention will be described. This embodiment differs from the previous embodiments in that the angle-selective transmission element 6 is made of an infrared-transmitting resin material.

[0048] The angle-selective transmission element 6 is made of a material that transmits infrared light and absorbs visible light. According to this embodiment, it is possible to suppress the intrusion of external light such as sunlight without changing the orientation of the opening of the angle-selective transmission element 6 in accordance with the optical path from the eye point 13 to the gaze detection sensor 25.

[0049] According to the above-described embodiment, it is possible to provide an optical device having a gaze detection function that can suppress vignetting and a decrease in aperture ratio by detecting the direction of the user's gaze, and can realize functions such as selecting a focus point while reducing ghosting caused by light arriving from behind the user. Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and variations are possible within the scope of the invention. [Explanation of symbols]

[0050] 3,4 EVF 6,7 Angle-selective transmission element 6c,6e1,6e2,6g opening

Claims

1. An optical device having a finder with an eyepiece lens system, an angle-selective transmission element disposed in an optical path of the viewfinder and having a plurality of openings that restrict the passing direction of a light beam; a detection means for detecting a line of sight by light passing through the angle-selective transmission element; a mechanism capable of adjusting the angle of the rotation direction of the finder based on the line of sight direction detected by the detection means, The angle-selective transmission element is located between the eyepoint corresponding to the position of the user's eyes and the eyepiece lens system. An optical device characterized by:

2. An optical device having a finder with an eyepiece lens system, an angle-selective transmission element disposed in an optical path of the viewfinder and having a plurality of openings that restrict the passing direction of a light beam; a detection means having a light projecting unit and a light receiving unit, and performing line of sight detection using light passing through the angle-selective transmission element; the angle-selective transmission element is located between an eye point corresponding to the position of a user's eye and the eyepiece lens system; a first opening of the plurality of openings has a first angle with respect to an optical axis of the viewfinder, the first opening has a first angle that limits the passing direction of the light beam in a first region, a second opening has a second angle that limits the passing direction of the light beam in a second region, and a third opening has a third angle that is defined by a line connecting the eyepoint in the viewfinder and the light receiving unit, The third opening has a larger opening than the first or second opening. An optical device characterized by:

3. An optical device having a finder with an eyepiece lens system, an angle-selective transmission element disposed in an optical path of the viewfinder and having a plurality of openings that restrict the passing direction of a light beam; a detection means having a light projecting unit and a light receiving unit, and performing line of sight detection using light passing through the angle-selective transmission element; the angle-selective transmission element is located between an eye point corresponding to the position of a user's eye and the eyepiece lens system; a first opening of the plurality of openings has a first angle with respect to an optical axis of the viewfinder, the first opening has a first angle that limits the passing direction of the light beam in a first region, a second opening has a second angle that limits the passing direction of the light beam in a second region, and a third opening has a third angle that is defined by a line connecting the eyepoint in the viewfinder and the light receiving unit, The portion of the angle-selective transmission element where the third opening is formed has a thickness greater than that of the surrounding portion of the portion. An optical device characterized by:

4. A mechanism is provided that can adjust the angle of the rotation direction of the finder based on the line of sight detected by the detection means.

4. The optical device according to claim 2 or 3.

5. the detecting means has a light projecting section and a light receiving section, A first opening of the plurality of openings has a first angle that limits the passing direction of the light beam in a first region with respect to the optical axis of the viewfinder, a second opening has a second angle that limits the passing direction of the light beam in a second region, and a third opening has a third angle that is defined by a line connecting the eye point in the viewfinder and the light receiving unit.

2. The optical device according to claim 1.

6. The third opening has a larger opening than the first or second opening.

6. The optical device according to claim 3 or 5.

7. The third opening is formed closer to the optical axis of the finder than the first opening.

7. The optical device according to claim 2, wherein the optical element is a lens.

8. The portion of the angle-selective transmission element where the third opening is formed has a thickness greater than that of the surrounding portion of the portion.

6. The optical device according to claim 5.

9. The portion of the angle-selective transmission element where the third opening is formed is formed along a curved surface facing the eyepiece lens system.

9. The optical device according to claim 8.

10. The third opening is formed at a position farther from the optical axis of the finder than the first opening.

7. The optical device according to claim 2, wherein the optical element is a lens.

11. a plurality of the finders corresponding to each of the eyes; The viewfinder can be adjusted independently of the detected line of sight 11. The optical device according to claim 1.

12. The angle-selective transmission element is formed of an infrared-transmitting material.

12. The optical device according to claim 1.

13. An optical device according to any one of claims 1 to 12, The viewfinder has a display means A display device characterized by:

14. an optical path splitting prism unit is provided between the display means and the eyepiece lens system; The detecting means detects light that has passed through the optical path splitting prism unit.

14. The display device according to claim 13.

15. The detecting means has a light projecting section and a light receiving section disposed between the eyepiece lens system and the angle-selective transmission element.

14. The display device according to claim 13.

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