Thin aerial image display device and non-contact input device using the same

Abstract

To provide a thin aerial image display device capable of forming a clear aerial image while being thin, and being excellent in space saving and installation freedom, and a non-contact input device using the same.SOLUTION: A non-contact input device 10 comprises: optical image formation means 18 formed in a flat plate state comprising an incidence plane 16 and an emission plane 17 which are arranged in parallel, and having a plurality of first light reflection planes and a plurality of second light reflection planes which are formed at a right angle to the incidence plane 16 and the emission plane 17 and arranged in parallel at prescribed intervals and arranged so as to be orthogonal in plan view; and a flat plate display 20 arranged on the incidence plane 16 side of the optical image formation means 18, and having a light emission plane 19 parallel to the incidence plane 16. The non-contact input device is composed of: a thin aerial image display device 11 for displaying an aerial image 12 on an image formation plane 21 which is inclined at an angle α to the emission plane 17 on the emission plane 17 side of the optical image formation means 18; and detection means 14 attached to the thin aerial image display device 11, for detecting the position of instruction means 13 in contact with the aerial image 12.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a thin aerial image display device in which a plurality of first and second strip-shaped light-reflecting surfaces (mirror surfaces), each arranged parallel to one another at a predetermined interval, display an aerial image based on an image on a flat display arranged parallel to the light-entering surface of an aerial image forming means arranged orthogonally in a planar view, and a non-contact input device using the same. [Background technology]

[0002] For example, a stereoscopic imaging device (optical imaging device) described in Patent Document 1 is known as a device that uses light (scattered light) emitted from the object surface (target object) to form a stereoscopic image (aerial image = real image) of the object in the air. This imaging device has first and second light control panels formed inside two transparent flat plates, each of which has a number of strip-shaped metal reflective surfaces arranged at a constant pitch perpendicular to one side of the transparent flat plates. The first and second light control panels are closely attached to each other with their one sides facing each other so that their respective light reflective surfaces are orthogonal to each other. In this optical imaging device, as shown in Figures 3, 5, and 6 of Patent Document 1, an object image M' or N' formed in the air is generated at a position symmetrical to the object M or N across the optical imaging device. This also applies when a display device such as a monitor is installed instead of the object M or N and an aerial image of an image displayed on the display device is formed. Therefore, even in a non-contact input device using this optical imaging device, as shown in FIG. 2 of Patent Document 2, for example, the angle a between the display that displays the image and the optical imaging means is equal to the angle a between the optical imaging means and the spatial image that is imaged in space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2009 / 131128 [Patent Document 2] Utility Model Registration No. 3219968 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, both the optical imaging device of Patent Document 1 and the non-contact input device of Patent Document 2 require a large installation space because the display device must be installed in an inclined state below the optical imaging device in order to tilt and form (float) an aerial image in the space above the optical imaging device based on the image displayed on the display device. This makes the optical imaging device and non-contact input device large and difficult to install, which has hindered the widespread use of optical imaging devices and non-contact input devices. The present invention has been made in consideration of the above circumstances, and aims to provide a thin aerial image display device that is thin yet capable of forming clear aerial images, and that is space-saving and easy to install, as well as a non-contact input device using the same. [Means for solving the problem]

[0005] A thin aerial image display device according to a first aspect of the present invention that achieves the above-mentioned object is formed in a flat plate shape having a light incident surface and a light exit surface that are arranged in parallel, the thin aerial image display device having a plurality of first light reflecting surfaces that are formed perpendicular to the light incident surface and the light exit surface and that are arranged in parallel at a predetermined interval, and a plurality of second light reflecting surfaces that are formed perpendicular to the light incident surface and the light exit surface and that are arranged in parallel at a predetermined interval, the thin aerial image display device comprising an optical imaging means in which the first light reflecting surfaces and the second light reflecting surfaces are arranged orthogonal to each other in a planar view, and which displays an aerial image on an imaging surface that is inclined at an angle α with respect to the light exit surface on the light exit surface side, When an image display means having a display surface that displays an image at a position symmetrical to the imaging surface across from the optical imaging means is virtually positioned on the front light surface side of the optical imaging means, light irradiated from the display surface toward the front light surface of the optical imaging means is reproduced on a flat display that is positioned on the front light surface side of the optical imaging means and has a light emitting surface parallel to the light entrance surface, and an aerial image corresponding to the image is formed on the imaging surface by light that is irradiated from the light emitting surface toward the front light surface of the optical imaging means and is reflected once by the first light reflecting surface and then once by the second light reflecting surface.

[0006] In the thin aerial image display device according to the first aspect of the present invention, the light-emitting surface of the flat display is preferably made up of a plurality of light-emitting elements arranged in a grid pattern.

[0007] In the thin aerial image display device according to the first aspect of the present invention, it is preferable that the central axis of the light emitted from each of the light emitting elements is perpendicular to the display surface of the image display means.

[0008] In the thin aerial image display device according to the first aspect of the present invention, it is preferable that the directivity angle of light emitted from each of the light emitting elements is within 40 degrees.

[0009] In the thin aerial image display device pertaining to the first aspect of the present invention, the light-emitting elements are preferably micro LEDs.

[0010] The non-contact input device of the second invention, which is in line with the above-mentioned object, is a non-contact input device that uses the thin aerial image display device of the first invention, and comprises the thin aerial image display device and a detection means attached to the thin aerial image display device for detecting the position of an instruction means that touches the aerial image.

[0011] In the non-contact input device according to the second aspect of the present invention, the detection means is preferably disposed parallel to the lower side of the aerial image.

[0012] In the non-contact input device of the second invention, it is preferable that the detection means has an emitting unit that irradiates detection light in a direction parallel to the aerial image to form a detection surface parallel to the aerial image, and a light receiving unit that receives reflected light reflected from the pointing means when the pointing means touches the detection surface at a position that overlaps the aerial image when viewed from the front. [Effects of the Invention]

[0013] The thin aerial image display device of the first invention can display an aerial image on an imaging surface inclined at an angle α with respect to the light exit surface on the light exit surface side of the optical imaging means, based on light irradiated toward the light entrance surface from a flat display having an emitting surface parallel to the light entrance surface of the optical imaging means, and is extremely compact and has excellent installation flexibility.

[0014] In the thin aerial image display device according to the first aspect of the present invention, when the light-emitting surface of the flat display is made up of a plurality of light-emitting elements arranged in a grid pattern, a high-quality, clear aerial image can be displayed.

[0015] In the thin aerial image display device of the first invention, when the central axis of the light emitted from each light-emitting element is perpendicular to the display surface of the image display means, the image displayed on the virtual image display means can be accurately reproduced on a flat display, and the aerial image can be reliably displayed on a predetermined imaging surface.

[0016] In the thin aerial image display device according to the first aspect of the present invention, when the directivity angle of light emitted from each light emitting element is within 40 degrees, a bright and clear aerial image can be obtained.

[0017] In the thin aerial image display device according to the first aspect of the present invention, when the light emitting elements are micro LEDs, a high-definition aerial image can be obtained, and the device has a long life and excellent energy saving properties.

[0018] The non-contact input device of the second invention is extremely thin, space-saving, and easy to install, by using a thin aerial image display device equipped with a flat display having an emitting surface parallel to the light entrance surface of the optical imaging means.

[0019] In the non-contact input device of the second invention, when the detection means is arranged parallel to the lower edge of the aerial image, the thin aerial image display device and the detection means can be integrated to simplify the configuration, resulting in excellent space-saving and mass-producible properties.

[0020] In the non-contact input device of the second invention, when the detection means has an emitting unit that irradiates detection light in a direction parallel to the aerial image to form a detection surface parallel to the aerial image, and a light receiving unit that receives reflected light from the pointing means when the pointing means touches the detection surface at a position that overlaps with the aerial image when viewed from the front, there is no need to install a separate emitting unit externally for irradiating detection light, thereby improving space saving and installation flexibility. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view showing a non-contact input device using a thin aerial image display device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional side view showing a main part of the non-contact input device. [Figure 3] 10A and 10B are a front cross-sectional view and a side cross-sectional view showing the operation of an optical imaging means in a thin aerial image display device used in the non-contact input device. [Figure 4] 3 is a schematic side view illustrating an image displayed on a flat display of the non-contact input device. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] A non-contact input device using a thin aerial image display device according to an embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1 and 2, a non-contact input device 10 according to one embodiment of the present invention comprises a thin aerial image display device 11 and a detection means 14 attached to the thin aerial image display device 11 for detecting the position of a pointing means 13 (here, a finger) such as a finger or a touch pen that touches the aerial image 12.

[0023] As shown in Fig. 2, the thin aerial image display device 11 comprises a flat optical imaging means 18 having parallel-arranged light entrance surface 16 and light exit surface 17, and a flat display 20 arranged on the light entrance surface 16 side of the optical imaging means 18 and having a light emitting surface 19 parallel to the light entrance surface 16, and displays an aerial image 12 on an imaging surface 21 inclined at an angle α with respect to the light exit surface 17 on the light exit surface 17 side. Here, the angle α is preferably in the range of approximately 30 to 60 degrees, but is not limited to this range and can be selected as appropriate. As shown in Figures 3(A) and (B), the optical imaging means 18 has a plurality of first light-reflecting surfaces 22 formed perpendicular to the light-entering surface 16 and the light-exiting surface 17 and arranged in parallel at a predetermined interval, and a plurality of second light-reflecting surfaces 23 formed perpendicular to the light-entering surface 16 and the light-exiting surface 17 and arranged in parallel at a predetermined interval, and the first light-reflecting surfaces 22 and the second light-reflecting surfaces 23 are arranged orthogonally in a planar view.

[0024] In manufacturing this optical imaging means 18, for example, a transparent resin is molded (for example, by injection molding, press molding, or roll molding) to produce a first molded body 27 having, on one side (here the upper side), a plurality of grooves 26 with a trapezoidal cross section that opens out to one side, one side being a vertical surface 24 and the other side being an inclined surface 25, arranged in parallel at predetermined intervals, and a second molded body 31 having, on the other side (here the lower side), a plurality of grooves 30 with a trapezoidal cross section that opens out to the other side, one side being a vertical surface 28 and the other side being an inclined surface 29, arranged in parallel at predetermined intervals, as shown in Figures 3(A) and (B). Then, the vertical surfaces 24, 28 of the grooves 26, 30 of the first molded body 27 and the second molded body 31 are covered with a metal reflective film 33, thereby forming a first light control section 35 having a plurality of first light reflecting surfaces 22 and a second light control section 36 having a plurality of second light reflecting surfaces 23. The metal reflective film 33 reflects light specularly (specularly) and is made of a metal such as aluminum, and can cover the vertical surfaces 24, 28 by methods such as sputtering, metal vapor deposition, spraying of metal microparticles, ion beam irradiation, or plating. Then, each groove 26 of the first light control unit 35 and each groove 30 of the second light control unit 36 are filled with a transparent adhesive 37, and in a state where the groove 26 and the groove 30 face each other, the first light reflecting surface 22 and the second light reflecting surface 23 are orthogonal in plan view. The first light control unit 35 and the second light control unit 36 are laminated (overlapped) in the thickness direction and joined and integrated, whereby the optical imaging means 18 is obtained.

[0025] Next, the operation of the optical imaging means 18 will be described. As shown in FIGS. 3(A) and (B), in the optical imaging means 18, among the light emitted from an object (not shown) and incident on the first light control unit 35 from the incident surface 16, for example, light L1 and L2 are incident on the first light control unit 35 from the positions of P11 and P21, respectively, and are reflected once at the positions of P1 and P2 on the first light reflecting surface 22 and then enter the second light control unit 36, and are reflected once at the positions of P13 and P23 on the second light reflecting surface 23, respectively, and are emitted from the second light control unit 36 into the air at the positions of P14 and P24 on the light emitting surface 17. Here, the light L1 and L2 are incident on the transparent adhesive 37 from the first molded body 27 at Q1 and Q2 in FIG. 3(B) and are incident on the second molded body 31 from the transparent adhesive 37 at S1 and S2 in FIG. 3(A). Since the refractive indices η1 and η2 of the first molded body 27 and the second molded body 31 are the same and approximate (substantially equal) to the refractive index η3 of the transparent adhesive 37, the influence of refraction is extremely small, and phenomena such as total reflection and spectroscopy do not occur. Therefore, an infinite number of lights emitted from the object, reflected once by the first light reflecting surface 22 of the optical imaging means 18, and then continuously reflected once by the second light reflecting surface 23 are imaged in the air, and an aerial image (not shown) that is a real image of the object is formed at a position symmetric to the object with the optical imaging means 18 interposed therebetween.

[0026] Note that light L1 and L2 are refracted at positions P11 and P21 on the light entrance surface 16 and P14 and P24 on the light exit surface 17, respectively. However, the transparent resin (first molded body 27 and second molded body 31) that forms the base material of the first light control section 35 and the second light control section 36 has the same refractive index and is homogeneous, and all light involved in the formation of the aerial image is refracted at a constant (same) angle at the light entrance surface 16 and the light exit surface 17, similar to light L1 and L2, regardless of the light entrance position and the light exit position, so these refractions do not affect the image formation. In addition, in Figures 3(A) and (B), the left side surface of the metal reflective film 33 serves as the first light reflecting surface 22 and the second light reflecting surface 23, but either the front or back surface (left or right in Figures 3(A) and (B)) of the metal reflective film 33 can function as the first light reflecting surface and the second light reflecting surface, and either the front or back surface of the metal reflective film 33 functions as the first light reflecting surface and the second light reflecting surface depending on the arrangement (reversal of front and back) of the first light control unit 35 and the second light control unit 36 ​​or the direction in which light enters.

[0027] In conventional aerial image display devices that combine this optical imaging means 18 with a display or other indicator, and in non-contact input devices that use this aerial image display device, in order to tilt the aerial image and form it (float it) in the space above the optical imaging means 18, the display must be installed in an inclined position below the optical imaging means 18, which increases the height (thickness) of the aerial image display device and non-contact input device, resulting in problems such as a lack of flexibility in installation and ease of handling. In contrast, in the thin aerial image display device 11 shown in Figures 1 and 2, when an image display means 40 having a display surface 39 that displays an image at a position symmetrical to the image surface 21 across the optical imaging means 18 (the position of the display in a conventional aerial image display device) is virtually placed on the light incident surface 16 side of the optical imaging means 18, the light irradiated from the display surface 39 toward the light incident surface 16 of the optical imaging means 18 is reproduced on a flat display 20 that is placed on the light incident surface 16 side of the optical imaging means 18 and has a light emitting surface 19 parallel to the light incident surface 16. 4, the flat display 20 can reproduce the image to be displayed on the display surface 39 by irradiating, from the light-emitting surface 19, each light contained in a bundle of light irradiated from a plurality of pixels 42 (four pixels are shown here as a representative) constituting an image to be displayed on the display surface 39 of the virtually arranged image display means 40 toward the light-entering surface 16 of the optical imaging means 18, and virtually concentrating the light from each pixel 41. In other words, the image to be displayed on the display surface 39 of the image display means 40 can be projected onto the light-emitting surface 19 of the flat display 20, and the image projected on the light-emitting surface 19 can be reconstructed and displayed by a plurality of light-emitting elements (not shown) arranged on the light-emitting surface 19.

[0028] In Fig. 2, the light-emitting surface 19 of the flat display 20 is composed of a plurality of light-emitting elements 42 arranged in a grid pattern (vertical and horizontal). Micro LEDs are preferably used as the light-emitting elements 42, but this is not a limitation. Light-emitting elements that combine three colors of light, R, G, and B, to display a color image may be used as appropriate. The central axis of light emitted from each light-emitting element 42 (a ray of light indicated by an arrow in Fig. 2) is perpendicular to the display surface 39 of the image display means 40, so the angle θ between the central axis of light emitted from each light-emitting element 42 and the light-emitting surface 19 is 90-α. The directivity angle of light emitted from each light-emitting element 42 is preferably within 40 degrees, but is not limited to this and may be selected as appropriate. In this way, instead of the conventional image display means 40 that is inclined at angle α toward the light incident surface 16 of the optical imaging means 18, the flat display 20 is arranged parallel to the light incident surface 16, thereby obtaining a thin aerial image display device 11. The thin aerial image display device 11 can form an aerial image 12 corresponding to the image on the image display means 40 on the imaging surface 21 by light that is irradiated from the light emitting surface 19 toward the light incident surface 16 of the optical imaging means 18, reflected once by the first light reflecting surface 22 (see FIG. 3(B)) and then reflected once by the second light reflecting surface 23 (see FIG. 3(A)).

[0029] Next, the detection means 14 will be described. 1 and 2, the detection means 14 is disposed inside the housing 43 of the thin aerial image display device 11 and parallel to the bottom side of the aerial image 12. An opening 44 parallel to the longitudinal direction of the detection means 14 is formed in the top surface of the housing 43, and the detection means 14 has a light-emitting unit (not shown) that irradiates detection light through the opening 44 in a direction parallel to the aerial image 12 to form a detection surface 45 parallel to the aerial image 12 (which coincides with the imaging surface 21 in this embodiment), and a light-receiving unit (not shown) that receives reflected light reflected from the pointing means 13 when the pointing means 13 touches the detection surface 45 at a position overlapping with the aerial image 12 in a front view. With the above configuration, the aerial image 12 (=imaging surface 21, detection surface 45) can function as a non-contact input screen, and when a user looks at the aerial image 12 and indicates a specific position on the aerial image 12 with the indicating means 13, that position is detected by the detecting means 14, and a character is input or a specific operation (command) is executed corresponding to the indicated position.

[0030] The detection unit 13 is preferably a flat bar-shaped (strip-shaped) optical sensor such as a zForce (registered trademark) AIR touch sensor or AIRBAR (registered trademark). The position of the pointing unit 13 pointing at the aerial image 12 can be detected by scanning the surface of the aerial image 12 (imaging plane 21) with detection light, such as laser light or infrared light, emitted from the detection unit 13 (light-emitting unit). While the detection unit 14 is housed inside the housing 43 in this embodiment, the detection unit 14 may be installed on the exterior top surface of the housing 43, thereby omitting the opening 44. The detection unit 14 may also be disposed parallel to the aerial image 12, on either the left or right side of the aerial image 12. In this case, the detection unit 14 is rotatably held in the housing 43 and placed on the top surface of the housing 43 when not in use, thereby achieving excellent compactness. The configuration of the detection unit is not limited to that of this embodiment, and may be any configuration capable of detecting the position of the pointing unit 13 touching the aerial image 12. For example, the detection means may be a frame-type sensor (a type of optical proximity sensor) formed in a frame shape along the outer periphery of the aerial image 12 and having a plurality of light-emitting elements and light-receiving elements arranged around the aerial image 12, or an infrared motion sensor, etc. Note that in this embodiment, the imaging plane 21 and the detection plane 45 coincide with each other, but the detection plane 45 may be arranged parallel to the imaging plane 21 with a gap in front of or behind the imaging plane 21.

[0031] The above describes an embodiment of the present invention, but the present invention is not limited to the configurations described in the above embodiment, and also includes other embodiments and modifications that are possible within the scope of the matters described in the claims. As a method for integrating the first light control unit and the second light control unit, the first light control unit and the second light control unit may be arranged facing each other, with one side of the first light control unit and the other side of the second light control unit, i.e., the sides on which the grooves are formed, facing each other, and a sheet-like transparent resin having a lower melting point than the first molded body and the second molded body is sandwiched between them, and the materials are heated and pressurized in a vacuum to melt and solidify the transparent resin alone. Alternatively, the grooves of the first light control unit and the second light control unit may be filled separately with molten transparent resin, which is solidified and molded into a flat plate shape and then bonded with a transparent adhesive or the like. In this case, in addition to the one side of the first light control unit and the other side of the second light control unit being arranged facing each other and bonded, the one side of the first light control unit and the one side of the second light control unit may also be arranged facing each other and bonded, or the other side of the first light control unit and the one side of the second light control unit may also be arranged facing each other and bonded. Furthermore, instead of the first and second light control units being formed separately from two transparent resin molded bodies and then joined together, the first and second light control units may be formed on both sides of a single transparent resin molded body.

[0032] In the above embodiment, the optical imaging means has been described as including a first light control unit and a second light control unit in which multiple light reflecting surfaces are arranged linearly (parallel), but it may also be possible to use an optical imaging means including a first light control unit in which multiple light reflecting surfaces are arranged radially and a second light control unit in which multiple light reflecting surfaces are arranged concentrically. In this case, the radial light reflecting surfaces of the first light control unit are arranged linearly around a reference point X, while the concentric light reflecting surfaces of the second light control unit are curved along concentric circles centered around a reference point Y that overlaps with the reference point X in a planar view, but the two light reflecting surfaces intersect at right angles in a planar view. Therefore, an aerial image can be formed, as in the above embodiment. Furthermore, as an optical imaging means, for example, as described in Japanese Patent Publication No. 5437436, first and second light control units having a number of strip-shaped reflective surfaces arranged perpendicularly (for example, at the same pitch) on one side surface may be used, which are superimposed and arranged so that the respective strip-shaped reflective surfaces are orthogonal in plan view. In the above embodiment, the grooves of the first and second molded bodies (first and second optical control units) are formed to have a trapezoidal cross section, but since the bottom surface of the groove is not an essential component of the optical imaging means, the dimensions (width) of the bottom surface do not need to be strictly controlled, and the groove may be formed to have a triangular cross section that widens to one side or the other, with one side being a vertical surface and the other being an inclined surface. [Explanation of symbols]

[0033] 10: non-contact input device, 11: thin aerial image display device, 12: aerial image, 13: pointing means, 14: detection means, 16: light incident surface, 17: light emitting surface, 18: optical imaging means, 19: light emitting surface, 20: flat display, 21: imaging surface, 22: first light reflecting surface, 23: second light reflecting surface, 24: vertical surface, 25: inclined surface, 26: groove, 27: first molded body, 28: vertical surface, 29: inclined surface, 30: groove, 31: second molded body, 33: metal reflective film, 35: first light control unit, 36: second light control unit, 37: transparent adhesive, 39: display surface, 40: image display means, 41: pixel, 42: light emitting element, 43: housing, 44: opening, 45: detection surface

Claims

1. a thin aerial image display device formed in a flat plate shape having parallel arranged light incident surfaces and light exit surfaces, the thin aerial image display device having a plurality of first light reflecting surfaces formed perpendicular to the light incident surface and the light exit surface and arranged parallel at predetermined intervals, and a plurality of second light reflecting surfaces formed perpendicular to the light incident surface and the light exit surface and arranged parallel at predetermined intervals, the thin aerial image display device comprising: an optical imaging means for forming the first light reflecting surfaces and the second light reflecting surfaces orthogonally in a planar view; and the thin aerial image display device for displaying an aerial image on an imaging surface inclined at an angle α with respect to the light exit surface on the light exit surface side, the thin aerial image display device comprising: When an image display means having a display surface for displaying an image at a position symmetrical to the imaging surface of the optical imaging means is virtually placed on the front light surface side of the optical imaging means, light irradiated from the display surface toward the front light surface of the optical imaging means is reproduced on a flat display placed on the front light surface side of the optical imaging means and having an emitting surface parallel to the light entrance surface, and an aerial image corresponding to the image is formed on the imaging surface by light irradiated from the emitting surface toward the front light surface of the optical imaging means, which is reflected once by the first light reflecting surface and then once by the second light reflecting surface.

2. 2. The thin aerial image display device according to claim 1, wherein the light-emitting surface of the flat display is made up of a plurality of light-emitting elements arranged in a grid pattern.

3. 3. The thin aerial image display device according to claim 2, wherein the central axis of the light emitted from each of said light emitting elements is perpendicular to said display surface of said image display means.

4. 3. The thin aerial image display device according to claim 2, wherein the directivity angle of the light emitted from each of said light emitting elements is within 40 degrees.

5. 3. The thin aerial image display device according to claim 2, wherein the light emitting element is a micro LED.

6. A non-contact input device using the thin aerial image display device according to any one of claims 1 to 5, comprising: the thin aerial image display device; and a detection means attached to the thin aerial image display device for detecting a position of an instruction means that touches the aerial image.

7. 7. A non-contact input device according to claim 6, wherein said detecting means is disposed parallel to a lower side of said aerial image.

8. 8. A non-contact input device according to claim 7, wherein the detection means comprises a light-emitting unit that irradiates detection light in a direction parallel to the aerial image to form a detection surface parallel to the aerial image, and a light-receiving unit that receives reflected light from the pointing means when the pointing means touches the detection surface at a position overlapping the aerial image when viewed from the front.

Images