JP2018205391A - Aerial video display device and input device - Google Patents

Abstract

To provide an aerial video display device and an input device with which it is possible to enable a beam of light to be entered to an optical plate at an optimum angle of incidence while reducing the angle formed by an object that could obstruct a reduction in device profile and the optical plate and thereby achieve both a reduced profile and a high-luminance aerial video.SOLUTION: The aerial video display device includes a deflecting optical element arranged near an object and designed so as to deflect a beam of light from the object. The deflecting optical element consists of a structure the surface on side of which is planar and the surface of the other side extends in one direction with the same shape, a plurality of the structure being arranged in a row. The deflecting optical element is arranged with a side thereof including the structure facing the object, and the beam of light heading from the object toward the surface on the light incident side of the optical plate is deflected, when passing through the deflecting optical element, to the side on which the incident angle, with the normal on surface on the light incident side as a point of reference, becomes large.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an aerial image display device and an input device that form a real image of an object in the air.

  In recent years, an aerial image display apparatus has been proposed in which a real image of an object is formed in the air using a special optical plate so that an observer can observe the real image. Normally, the image formation position of a real image (aerial image) in the air is a position that is plane-symmetric with the object with respect to the optical plate, so that it is far away from the optical plate in order to provide an easy-to-view image to the observer. When forming an image on the optical plate, it is necessary to greatly separate the object from the optical plate. Therefore, there is a problem that the space between the optical plate and the object is increased, and the display device is increased in size.

  On the other hand, if it is attempted to reduce the distance between the object and the optical plate in order to reduce the size of the display device, the light incident angle with respect to the optical plate deviates from the optimum angle (45 ° to 50 °). As a result, there is a problem in that the efficiency of reflection is lowered, the aerial image becomes dark, and an image called a ghost other than a regular real image can be seen.

  On the other hand, Patent Document 1 discloses an example in which the thickness is reduced while taking into consideration the efficiency of the optical plate. According to the technique of Patent Document 1, by arranging an optical element having a prism shape on one side in the vicinity of an optical plate and deflecting the light beam from the object, the light beam from the object with respect to the optical plate Even when the angle is neglected, the light beam can be incident on the optical plate at an optimum angle, so that it is possible to reduce inefficiencies and ghosts while reducing the size of the display device.

JP 2017-26734 A

  However, Patent Document 1 does not specifically mention the problem regarding the angle of light emitted from the object. This problem will be specifically described. When a general display such as an LCD is considered as the object, the light amount emitted in the vertical direction of the display surface is the largest, and the light from the display is normal to the optical plate as in Patent Document 1. When the light is incident on the optical plate at a large angle (referred to as a shallow angle with respect to the optical plate), the display is arranged such that the angle φ formed by the display and the optical plate is large. As a result, even if it is attempted to reduce the thickness of the apparatus by making the incident light from the display a shallow angle with respect to the optical plate, the angle of the display will be an obstacle to the reduction of the thickness. Patent Document 1 does not mention the countermeasure.

  The present invention has been made in view of the above circumstances, and at an optimal incident angle with respect to the optical plate while reducing the angle formed between the object and the optical plate, which can be an obstacle to thinning the apparatus. It is an object of the present invention to provide an aerial image display device and an input device that can achieve both a reduction in thickness and securing an aerial image with high brightness by allowing light rays to enter.

The aerial image display device of the present invention includes an optical plate having a plurality of reflecting surfaces orthogonal to each other in a plan view, and reflects light from an object on the plurality of reflecting surfaces, and An aerial image display device that guides a real image of the object to the air on the side opposite to the light incident side, and forms a real image of the object in the air,
A deflecting optical element that is disposed in the vicinity of the object and deflects a light beam from the object;
In the deflection optical element, one surface is a flat surface, and the other surface is formed in parallel with a plurality of structures extending in the same shape in one direction.
The deflecting optical element is disposed with the surface having the structure facing the object, and light rays traveling from the object to the light incident side of the optical plate are transmitted through the deflecting optical element. In this case, the incident angle with respect to the normal of the surface on the light incident side is deflected to the side where the incident angle becomes larger.

  According to the present invention, it is possible to make light incident at an optimum incident angle with respect to the optical plate while reducing the angle formed between the object and the optical plate, which can be an obstacle to thinning the apparatus. Therefore, it is possible to provide an aerial image display device and an input device that can achieve both a reduction in thickness and securing an aerial image with high brightness.

(A) is a figure which shows typically the whole structure of the aerial image display apparatus 1 of this embodiment, (b) is the figure which looked at the structure of Fig.1 (a) in the arrow IB direction. 3 is a perspective view showing a schematic configuration of an optical plate 3. FIG. 3 is a perspective view of one plate-like member 21. FIG. 3 is a perspective view of one plate-like member 31. FIG. It is a figure which shows the imaging principle of the real image in two dimensions (in ZX plane). It is a figure which shows typically reflection of the light ray in a three-dimensional space (XYZ coordinate system). In a three-dimensional space, it is a figure which shows typically a mode that the several light ray emitted from the point light source O condenses to one point via a separate reflective surface. It is the figure which looked at the deflection optical element 4 and the display 2 from the side. FIG. 4 is an enlarged view showing a structure 4a of a deflection optical element 4. (A) shows the layout of an aerial image display device that does not use the deflecting optical element 4, and (b) shows the layout of the aerial image display device that uses the deflecting optical element 4. It is sectional drawing which shows the reference example 1 of a deflection | deviation optical element. It is sectional drawing which shows the reference example 2 of a deflection | deviation optical element. When the normal of the light emitting surface of the light source is in the -90 ° direction and the light distribution characteristic is 90 ° half-value angle, the angular distribution of the light beam after passing through the deflecting optical element with a prism angle of 25 ° is shown. FIG. The angle distribution of the light beam after passing through the deflecting optical element with a prism angle of 40 ° when the light distribution characteristic is 90 ° half-value when the normal line of the light emitting surface of the light source is in the −90 ° direction. FIG. When the normal of the light emitting surface of the light source is in the −90 ° direction and the light distribution characteristic is a half-value angle of 90 °, the angle distribution of the light beam after passing through the deflecting optical element with a prism angle of 50 ° is shown. FIG. When the normal of the light emitting surface of the light source is in the −90 ° direction and the light distribution characteristic is 90 ° half-value angle, the angle distribution of the light beam after passing through the deflecting optical element with the prism angle set to 60 ° FIG. It is a figure which shows the angle distribution of the light ray when the normal line of the output surface of a surface light source has faced the -90 degree direction, and the light distribution characteristic is set to Lambertian. It is a figure which shows angle distribution of the light ray when the normal line of the output surface of a surface light source has faced the -90 degree direction, and the light distribution characteristic is 90 degrees of half-value angles. It is a figure which shows the angle distribution of a light ray when the normal line of the output surface of a surface light source has faced the -90 degree direction, and the light distribution characteristic is a half-value angle of 60 degrees. It is a figure which shows the arrangement | positioning relationship between the surface light source used for simulation, and a deflection | deviation optical element. The figure which shows angle distribution of the light ray after passing through the deflection | deviation optical element of 40 degrees of prism angles in the state where the normal line of the output surface of a surface light source has faced the -90 degree direction and the light distribution characteristic is a Lambertian It is. The angle distribution of the light beam after passing through the deflecting optical element with a prism angle of 40 ° when the normal line of the exit surface of the surface light source is in the −90 ° direction and the light distribution characteristic is 90 ° half-value angle. FIG. The angle distribution of the light beam after passing through the deflecting optical element with a prism angle of 40 ° when the light distribution characteristic is 60 ° half-value with the normal of the exit surface of the surface light source directed in the −90 ° direction. FIG. It is the schematic of the input device 10 concerning another embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a diagram schematically showing the overall configuration of the aerial video display device 1 of the present embodiment, and FIG. 1B is a diagram of the configuration of FIG. FIG. The aerial image display device 1 forms a real image of an object as an image M in the air, and includes a display 2, an optical plate 3, a deflection optical element 4, and a casing 5 that holds these. Yes. The housing 5 exposes the outer surface 3 a of the optical plate 3.

  The display 2 is, for example, an LCD that emits light to display an image. Note that a three-dimensional object may be arranged instead of the display 2. Therefore, the above-described objects include the display 2, the display device, and the object itself, but in a broad sense, the image projected on the screen and the image displayed on the display device are also included.

  The optical plate 3 internally reflects the light from the display 2 and forms an image M in the air. Examples of the optical plate 3 include a one-layer structure in which reflecting surfaces orthogonal to each other (V-shaped (L-shaped) in plan view) are arranged in an array on the same surface, or a plurality of reflecting surfaces in parallel. It is possible to use a two-layer structure in which two optical panels are used and two optical panels are stacked so that the reflecting surfaces are orthogonal to each other in plan view. The detailed configuration of the optical plate 3 will be described later.

  The deflecting optical element 4 has a function of deflecting light from the display 2 and guiding it to the optical plate 3. Details of the deflection optical element 4 will be described later.

  In the above configuration, the light from the display 2 enters the deflecting optical element 4 and is then deflected and emitted to the side where the incident angle is increased with reference to the normal of the surface on the light incident side. And is reflected by a plurality of reflecting surfaces of the optical plate 3 and then guided to the air on the side opposite to the light incident side with respect to the optical plate 3. Thereby, the real image of the image projected on the display 2 is formed in the air as the image M.

(Optical plate)
Next, the above-described optical plate 3 will be described. Here, the optical plate 3 having a two-layer structure will be described. FIG. 2 is a perspective view showing a schematic configuration of the optical plate 3. The optical plate 3 is configured by laminating two optical panels 20 and 30. The optical panel 20 has a plurality of plate-like members 21 adjacent to each other in one direction (for example, the X direction) of two directions perpendicular to each other in a plane perpendicular to the stacking direction (for example, the Z direction) of the optical panels 20 and 30. Are formed by lining up. The optical panel 30 is formed by arranging a plurality of plate-like members 31 adjacent to each other in the other direction (for example, the Y direction) of the two directions.

  FIG. 3 is a perspective view of one plate-like member 21. The plate-like member 21 has a rectangular parallelepiped transparent substrate 21a made of transparent glass or resin. The transparent substrate 21a extends in the Y direction, and a reflective film 21b is formed by vapor deposition on one of two opposing surfaces (for example, two surfaces along the YZ surface). The reflective film 21b may be formed on both opposing surfaces of the transparent substrate 21a.

  FIG. 4 is a perspective view of one plate-like member 31. The plate-like member 31 has a rectangular parallelepiped transparent substrate 31a made of transparent glass or resin. The transparent substrate 31a extends in the X direction, and a reflective film 31b is formed by vapor deposition on one of two opposing surfaces (for example, two surfaces along the ZX surface). Note that the reflective film 31b may be formed on both opposing surfaces of the transparent substrate 31a. The reflection films 21b and 31b are made of a metal film such as aluminum, for example, and the film thickness is appropriately controlled so that all incident light is reflected.

  By arranging the plurality of plate-like members 21 extending in the Y direction so as to be adjacent to each other in the X direction, the plurality of reflective films 21b are arranged in the X direction at intervals corresponding to the width of the plate-like member 21 in the X direction. Similarly, by arranging a plurality of plate-like members 31 extending in the X direction adjacent to each other in the Y direction, a plurality of reflection films 31b are arranged in the Y direction at intervals corresponding to the width of the plate-like member 31 in the Y direction. To position. And by such arrangement | positioning of the several plate-shaped members 21 and 31, the reflective film 21b (reflective surface) of each plate-shaped member 21 and the reflective film 31b (reflective surface) of each plate-shaped member 31 are planar view. The positions are orthogonal to each other (viewed from the Z-axis direction).

  Next, the principle of image formation by the optical plate 3 will be described. FIG. 5 shows the imaging principle of a real image in two dimensions (in the ZX plane). A plurality of light rays emitted from the point light source P are respectively reflected by a reflecting surface (reflective film 21b) parallel to the Z axis, and a position P ′ opposite to the point light source P with respect to the X axis (point light source P and Condensed at a position symmetrical to the X axis). Thereby, a real image of the point light source P is formed at the position P ′.

  FIG. 6 schematically shows the reflection of light rays in a three-dimensional space (XYZ coordinate system). In the three-dimensional space, the light beam A emitted from the point light source O is decomposed into a light beam a1 in the ZX plane and a light beam a2 in the YZ plane, and the ZX plane of each of the light beams a1 and a2 according to FIG. By considering the reflection in the inner or YZ plane, the intersection of the ray A with the Z axis can be obtained. That is, the light ray a1 in the ZX plane is reflected by the reflective surface (reflective film 21b) parallel to the YZ plane and then goes to the Z axis, and the light ray a2 in the YZ plane is reflective surface (reflective) parallel to the ZX plane. After being reflected by the film 31b), it goes to the Z axis. These light rays a1 and a2 intersect at one point on the Z axis, that is, at the point O '. Therefore, the light ray A is reflected twice by the reflective film 21b and the reflective film 31b, and then travels toward the point O 'on the Z axis.

  FIG. 7 schematically shows a state in which a plurality of light beams emitted from the point light source O are condensed at one point via separate reflecting surfaces in a three-dimensional space. A plurality of light rays emitted from the point light source O are reflected by the reflective surface (reflective film 21b) parallel to the YZ plane and the reflective surface (reflective film 31b) parallel to the ZX plane in the same manner as in FIG. Focus on the same point O ′ above. Thereby, a real image of the point light source O is formed at the point O ′.

  In the above description, the imaging principle of the optical plate 3 having the two-layer structure in which the optical panels 20 and 30 are laminated is shown. However, two reflecting surfaces arranged in a V shape (L shape) are arranged in an array. The imaging principle is the same for the optical plate 3 having a single layer structure.

(Deflection optical element)
Next, the deflection optical element 4 will be described. The deflecting optical element 4 is disposed close to the object (herein, the display 2) side with respect to the optical plate 3 and has a function of deflecting light from the object and guiding it to the optical plate 3.

  FIG. 8 is a view of the deflection optical element 4 and the display 2 as seen from the side. The transparent optical element 4 made of glass or resin has a flat surface portion 4b, and a plurality of structures 4a (prisms) are formed side by side along the surface of the flat surface portion 4b on the display 2 side.

  Here, for convenience of explanation below, three directions perpendicular to each other are defined as an x direction, a y direction, and a z direction, respectively. Among these, the z direction corresponds to the thickness direction of the aerial image display device 1 and also corresponds to the Z direction (stacking direction of the optical panels 20 and 30) shown in FIG. This corresponds to the X direction and the Y direction shown in FIG. 2 and the like and a direction that forms an angle of 45 ° in the XY plane. The x direction is a direction perpendicular to the yz plane.

  Each structure 4a is formed to extend in one direction (for example, the x direction) with the same shape (for example, a right-angled triangle). The plurality of structures 4a are arranged in parallel, that is, aligned in a direction perpendicular to the x direction (for example, the y direction). The cross-sectional shape and prism angle θ (angle formed with the prism-shaped flat portion) of each structure 4a may all be the same or different. The prism angle refers to an angle formed by the slope of the structure 4a that is a prism and the flat surface portion 4b (or a surface parallel to the flat surface portion 4b). The plane part 4b may be inclined with respect to the xy plane.

  The deflecting optical element 4 is arranged so that the flat portion 4b is positioned on the optical plate 3 (FIG. 1) side and the plurality of structures 4a are positioned on the display 2 side. Further, it is preferable that the deflecting optical element 4 is arranged so as to be in contact with the display 2 on the light emitting side of the display 2 (so that each structure 4a hits the display 2).

  FIG. 9 is an enlarged view showing the structure 4 a of the deflection optical element 4. The deflecting optical element 4 deflects light from the display 2 only in a plane (in the yz plane in FIG. 8) perpendicular to one direction (the vertical direction in FIG. 9) in which the plurality of structures 4a extend in the same shape. . More specifically, in FIG. 9, the light beam L emitted from the display 2 is refracted when it enters the inclined surface 4c of the structure 4a, and is refracted when it is emitted from the plane portion 4b. As a result, the light beam L is deflected at the deflection angle γ by passing through the deflecting optical element 4.

  In other words, the light beam traveling from the display 2 toward the light incident side surface (inner surface) 3b of the optical plate 3 is based on the normal line NL (FIG. 1) of the inner surface 3b when passing through the deflecting optical element 4. It will be deflected to the side where the incident angle becomes larger. In the following description, all “incident angles” refer to angles with reference to the normal line NL.

  By the way, in order to reduce the thickness of the aerial image display device 1 in the depth direction, the angle of the object, for example, the display 2 becomes the bottleneck (maximum distance Δ shown in FIG. 10A). In order to reduce the thickness further without using the deflecting optical element 4, as shown in FIG. 10A, the angle α formed by the deflecting optical element 4 and the optical plate 3 can be reduced (angle α ′). However, if it does so, the light ray angle β incident on the optical plate 3 becomes smaller (angle β ′) with respect to the normal line NL of the optical plate 3, which causes a problem such as a decrease in luminance of the aerial image and occurrence of ghost.

  More specifically, when the incident angle of the light beam with respect to the optical plate 3 becomes extremely larger than a desired angle (for example, 45 ° to 50 °) (that is, when the light beam is incident from a direction such that it falls to the optical plate 3 side). Multiple reflection occurs on the same reflecting surface of the optical plate 3, thereby causing a phenomenon in which the aerial image is deteriorated. In order to avoid such a problem, the optical plate 3 can be tilted as indicated by a dotted line, but this further increases the size of the apparatus.

  Therefore, in the present embodiment, the deflection optical element 4 that deflects the light beam emitted from the display 2 is disposed in the vicinity of the display 2. “Neighborhood” means a position within 10 mm, and it is more preferable that both are in contact. The reason is that the deflecting optical element has an effect of deflecting the light beam only in one specific direction. Therefore, when the air distance from the display 2 is increased, the image displayed on the display 2 is deflected by the deflecting optical element. The image will be extended only in the direction. Therefore, it is desirable that the display 2 and the deflecting optical element be arranged as close as possible, but it is desirable that the display 2 and the deflecting optical element be arranged at a position within 10 mm as a condition that the above-described image distortion is within an allowable range.

  As shown in FIG. 9B, the light beam L incident in the normal direction of the deflecting optical element 4 is emitted at an angle of deflection γ by passing through the deflecting optical element 4, and as shown in FIG. In addition, the incident light beam can be deflected in the direction in which the angle β ″ with the normal line NL of the optical plate 3 increases. As a result, the angle α ″ formed between the display 2 and the optical plate 3 can be reduced while the optical plate 3 can be incident at an optimal angle with respect to 3, so that the size of the aerial image display device 1 and the deterioration of the aerial image M can be suppressed.

  At this time, in order to reduce the total reflection of light inside the deflecting optical element 4, it is desirable that one side surface of the deflecting optical element 4, that is, the exit surface of the plane portion 4 b is a plane, and the light beam is directed in a certain direction. Therefore, it is desirable that a plurality of structures 4a extending in the same shape in one direction be formed in parallel on the other surface. Similarly, in order to reduce the total reflection of light inside the deflecting optical element 4, the surface on which the structure 4a is formed is arranged facing the light incident side, that is, the display 2 side. It is desirable.

  Furthermore, by making one side surface of the deflecting optical element 4 into a structure 4a extending in a prism shape in one direction, it becomes possible to efficiently deflect the light beam incident from the object in one direction.

  By the way, if the prism shape of the structure 4a is such that one of the apex angles in contact with the flat surface portion 4b is not a right angle, the light beam L ′ emitted in the direction opposite to the direction to be originally deflected increases. There is a risk that moldability may be impaired. Specifically, as in Reference Example 1 shown in FIG. 11, when both the apex angles θ1 and θ2 in contact with the flat surface portion 4b are smaller than 90 °, the direction in which the light L is refracted depends on the incident position of the light L, The light rays emitted in the opposite direction will increase. On the other hand, as in Reference Example 2 shown in FIG. 12, when one of the apex angles (θ2) in contact with the flat portion 4b is larger than 90 °, the prism shape is removed from the mold when the deflection optical element 4 is molded. It will not come out and the molding difficulty will increase. Therefore, as shown in FIG. 9, in the prism shape, it is desirable that one of the apex angles in contact with the flat portion is a right angle.

  Further, referring to FIG. 9, when the prism shape of the structure 4a is such that one of the apex angles in contact with the flat surface portion 4b is a right angle, the light ray L ″ incident and refracted in the vicinity of the tip of the inclined surface 4c is vertical. After the total reflection at the surface 4d, there is a risk that the light will be emitted in the opposite direction. To prevent this, the vertical surface 4d is used as a diffusing surface to reduce the total reflection, and thereby the light ray L "emitted in the opposite direction is emitted. Can be reduced. In order to make the vertical surface 4d a diffusion surface, for example, a transfer surface of a mold for forming the vertical surface 4d may be roughened.

  Furthermore, there is a moire phenomenon as one of the problems when using the deflecting optical element 4 in which a plurality of structures 4a extending in the same shape in one direction are formed in parallel. When the deflecting optical element 4 is disposed close to a display 2 such as an LCD, which is a display element having two-dimensional pixels, the pitch of the structures 4a of the deflecting optical element 4 and the pixel pitch in the display 2 such as the LCD There is a possibility that a moire phenomenon may occur due to a minute shift. Therefore, the pitch of the structures 4a of the deflecting optical element 4 (the interval between adjacent prism shapes) P and the pitch of pixels (not shown) such as LCDs are substantially matched, and are arranged with almost no deviation, so that the moire phenomenon occurs. Can be suppressed. The “substantially coincidence” includes a case where there is a difference within ± 10% with respect to the pitch P. Further, “substantially no deviation” includes the case where the mutual deviation amounts are within ± 10% of the pitch P.

  Furthermore, in order to reduce the above-described moire phenomenon, an optical element (such as a diffusion plate) that diffuses light can be disposed between the deflection optical element 4 and the display 2 such as an LCD. By using the diffusing optical element, the contour between pixels such as an LCD can be blurred, and as a result, moire can be reduced. It is more effective to perform the installation of the optical element to be diffused and the matching of the pitches described above at the same time.

  By the way, referring to FIG. 9, the deflection optical element 4 changes the angle at which the light beam is deflected depending on the prism angle θ of the structure 4a. For example, if the material of the deflection optical element 4 is PMMA, the deflection angle γ is about 13 ° when the prism angle θ is 25 °, the deflection angle γ is about 22 ° when the prism angle θ is 40 °, and the prism angle θ is 50 °. When the deflection angle γ is about 29 ° and the prism angle θ is 60 °, the deflection angle γ is about 38 °. Therefore, in order to increase the deflection angle γ, the prism angle θ may be increased. On the other hand, when the prism angle θ increases, the light that is totally reflected by the vertical surface 4d of the prism and is changed in the opposite direction. Will increase.

The inventor estimated the angular distribution of the light beam after passing through the deflecting optical element when the apex angle of the prism was changed by simulation. The simulation results are shown in FIGS. According to the simulation result, as shown in FIG. 16, when the prism angle θ is 60 °, the amount of light that is deflected in two directions other than the angle that is deflected in principle is larger. This is undesirable because it increases. On the other hand, as shown in FIG. 13, when the prism angle θ is 25 °, the light distribution characteristic is good, but the deflection angle γ is small, and the original purpose of the device is not sufficiently miniaturized. End up. On the other hand, when the prism angle θ shown in FIGS. 24 and 25 is 40 ° and 50 °, the light quantity in the deflection angle γ direction is sufficient. Therefore, it can be said that the prism shape preferably satisfies the following conditional expression.
25 ° ≦ θ ≦ 50 ° (1)
here,
θ: Prism angle

  Further, when a light beam is incident on the deflection optical element 4 from the display 2, the behavior of the light beam after passing through the deflection optical element changes depending on the spread angle of the light beam emitted from the display 2. Therefore, when the display 2 is regarded as a light source, the present inventor has changed the light beam spreading direction (that is, the light distribution characteristic) and confirmed the light beam angle characteristic after passing through the deflecting optical element by simulation. The light distribution characteristics of the surface light source used for the simulation are shown in FIG. 17 for the Lumbershan, FIG. 18 for the half-value angle of 90 °, and FIG. 19 for the case of the half-value angle of 60 °.

  Here, it is assumed that the deflection optical element 4 has a prism angle θ = 40 °, and is arranged in close contact with the deflection optical element 4 as shown in FIG. FIG. 21 shows a simulation result of the angle characteristic of the deflection optical element 4 using the light distribution characteristic of the surface light source as a Lambertian, and the simulation result of the angle characteristic of the deflection optical element 4 with the light distribution characteristic of the surface light source set to a half-value angle of 90 °. FIG. 23 shows a simulation result of the angle characteristics of the deflecting optical element 4 with the light distribution characteristics of the surface light source set to a half-value angle of 60 °.

  It can be seen that as the light distribution characteristic of the surface light source is narrowed, the amount of light in the direction in which the light beam is deflected increases in principle. Therefore, by arranging an optical element that narrows the spread angle of light between the object and the deflecting optical element, for example, a viewing angle control filter for ensuring privacy, the light in the direction to be deflected is increased. Will be able to.

  FIG. 24 is a schematic diagram of an input device 10 according to another embodiment. 24, the input device 10 includes the aerial video display device 1 and the detection device 6 shown in FIG. The detection device 6 diffuses infrared light having a wavelength in the infrared band as a specific wavelength, transmits an infrared diffusion sheet 7 that transmits visible light, and a light source 8 that emits infrared light toward the infrared diffusion sheet 7. And an infrared camera 9 that captures the aerial image M within an angle of view, and a processing unit PROC as a detection unit that processes information captured by the infrared camera 9. The infrared camera 9 may capture both visible light and infrared light. Further, it is preferable that the infrared diffusing sheet 7 is disposed close to the exit side of the deflecting optical element 4. The specific wavelength is not limited to the infrared band, and may be a single wavelength in the visible light range.

  There is a need for a device that not only displays aerial images, but also allows contactless input using aerial images. Especially in scenes where sanitary input is required, such as food processing sites and medical sites, devices that can input information without touching directly are desired. In order to realize such a device, it is necessary to recognize that the hand touches the aerial image and detect the touched position.

  In the present embodiment, when infrared light is emitted from the light source 8 toward the infrared diffusion sheet 7 while the aerial image display device 1 is displaying an aerial image, the infrared diffusion sheet 7 is infrared on the surface thereof. Light is diffused and reflected, and the reflected infrared light is reflected by the optical plate 3 to form a curtain-like infrared image IM at a position corresponding to the infrared diffusion sheet 7 in the vicinity of the aerial image M. . Since the infrared image IM is an invisible image, the observer can pass through the aerial image M. When such a state is picked up by the infrared camera 9, a curtain-like infrared image IM formed on the aerial image M is picked up.

  Here, when the observer brings an object such as a finger or a pointing rod close to the aerial image M, the object blocks a part of the curtain-like infrared image IM and creates a shadow of infrared light. I don't notice it. However, the image signal captured by the infrared camera 9 is processed by the processing unit PROC, so that the position where the infrared image IM is blocked is known.

  Specifically, the image signal obtained by imaging by the infrared camera 9 before the object approaches the aerial image M, and the image signal obtained by the infrared camera 9 when the object approaches the aerial image M. By taking the difference from the obtained image signal, the position of the shadow of the infrared light can be known, and therefore the position where the object is close can be obtained. On the other hand, since the processing unit PROC to which the image signal is input from the infrared camera 9 is connected to the driving unit of the display 2, the processing unit PROC obtains the position of the aerial image M corresponding to the blocked position of the infrared image IM. Can do. In other words, information to be input can be read and output in the same manner as using a touch panel while being non-contact. According to the input device 10 of the present embodiment, an observer who visually recognizes the aerial image M can input necessary information in a non-contact manner. Expected to be used in necessary scenes.

  The present invention is not limited to the embodiments described in the specification, and it is apparent to those skilled in the art from the embodiments and ideas described in the present specification that other embodiments and modifications are included. It is. The description and examples are for illustrative purposes only, and the scope of the invention is indicated by the following claims.

DESCRIPTION OF SYMBOLS 1 Aerial video display apparatus 2 Display 3 Optical plate 3a Outer surface 3b Inner surface 4 Deflection optical element 4a Structure 4b Plane part 4c Slope 4d Vertical surface 5 Case 6 Detection apparatus 7 Infrared diffusion sheet 8 Light source 9 Camera 10 Input apparatus 20 Optical panel 21 Plate-shaped member 21a Transparent substrate 21b Reflective film 30 Optical panel 31 Plate-shaped member 31a Transparent substrate 31b Reflective film IM Infrared image M Camera M Aerial video PROC Processing section

Claims (9)

An optical plate having a plurality of reflecting surfaces orthogonal to each other in plan view, wherein light from the object is reflected by the plurality of reflecting surfaces, and is opposite to the light incident side with respect to the optical plate An aerial image display device that guides to the air and forms a real image of the object in the air,
A deflecting optical element that is disposed in the vicinity of the object and deflects a light beam from the object;
In the deflection optical element, one surface is a flat surface, and the other surface is formed in parallel with a plurality of structures extending in the same shape in one direction.
The deflecting optical element is disposed with the surface having the structure facing the object, and light rays traveling from the object to the light incident side of the optical plate are transmitted through the deflecting optical element. An aerial image display device that is deflected to the side where the incident angle becomes larger with respect to the normal of the surface on the light incident side.   The aerial image display device according to claim 1, wherein the deflecting optical element is provided with the structure as a prism shape on one surface of a flat portion.   The aerial image display device according to claim 2, wherein the prism shape has a vertical surface and an inclined surface in contact with the flat portion. The aerial image display device according to claim 3, wherein the prism shape satisfies the following conditional expression.
25 ° ≦ θ ≦ 50 ° (1)
here,
θ: angle formed by the inclined surface of the prism shape and the flat surface portion   The aerial image display device according to claim 4, wherein the prism-shaped vertical surface is a diffusion surface.   The object is a display element having two-dimensional pixels, and the interval between adjacent prism shapes of the prism shape is substantially the same as the interval between the pixels of the display element, and the objects are arranged with almost no deviation. The aerial image display device according to any one of 2 to 5.   The aerial image display device according to claim 1, wherein an optical element that narrows a spread angle of a light beam from the object is disposed between the deflection optical element and the object. .   The aerial image display device according to claim 1, wherein an optical element that diffuses light is disposed between the deflection optical element and the object. An input device comprising the aerial video display device according to any one of claims 1 to 8 and a detection device,
The detection device is disposed between the object and the optical plate, diffuses light of a specific wavelength and transmits other light, and emits light of the specific wavelength toward the sheet. A light source that performs imaging, a camera that captures the real image of the object within an angle of view, and a detection unit that detects that an object has approached the real image based on information obtained by imaging the camera. An input device.