Display device

Abstract

To provide a display device which can change an aerial image and can be downsized.SOLUTION: A display device 100 of the present invention includes: a disc-like retroreflection sheet 120 in a housing 110, with a plurality of designs P formed in different positions; an LED light source 140 for illuminating the retroreflection sheet 120; a beam splitter 130; and a motor 150 for rotationally moving the retroreflection sheet 120. The retroreflection sheet is rotationally moved and an aerial image Q of the design P illuminated by the LED light source 140 can be switched.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an aerial image display device having a function of displaying an image in the air by utilizing retroreflection, and more particularly to a display device having a function of varying an aerial image. [Background technology]

[0002] Aerial imaging by retroreflection (AIRR) is known. For example, Patent Document 1 discloses a display device using two retroreflection members so that an image formed in the air can be observed from a wider angle. Patent Document 2 discloses a display device that suppresses deterioration of contrast and visibility by positioning a light source and a retroreflection member so that light regularly reflected by the retroreflection member does not enter the observation range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-107165 A [Patent Document 2] Patent Publication No. 2022-150245 Summary of the Invention [Problem to be solved by the invention]

[0004] An AIRR type aerial image display device uses a liquid crystal display (LCD) or a light emitting diode (LED) as a light source. FIG. 1 is a diagram showing a schematic configuration of a display device using an LCD as a light source. A display device 10 has an optical system including an LCD 30, a retroreflective member 40, a beam splitter 50, etc. arranged inside a housing 20, and displays an aerial image Q of an image displayed on the LCD 30. The aerial image Q is, for example, an icon that allows a user to perform an input operation, and this operation is detected by a sensor S. Such a display device 10 can change the aerial image Q by changing the image displayed on the LCD 30, but there is a problem in that the size of the entire optical system becomes large due to the large size of the LCD 30 itself.

[0005] Fig. 2 shows a schematic configuration of a display device using an LED as a light source, with Fig. 2(A) being a perspective view showing the entire display device, and Fig. 2(B) being a schematic cross-sectional view. As shown in Fig. 2(B), a display device 50 has, for example, an LED 70, a retroreflective layer 80, and a beam splitter or half mirror 90 arranged inside a housing 60. A design P including a notch or an opening for generating an original image of an aerial image Q is formed in the retroreflective layer 80.

[0006] Light emitted from the LED 70 illuminates the retroreflective layer 80, and the light that passes through the design P is retroreflective between the retroreflective layer 80 and the beam splitter 90, and an aerial image Q of the design P is displayed above the housing 60. Such a display device 50 can be made smaller overall because it uses the LED 70, but on the other hand, there is a problem in that the characters and icons of the design P are fixed, and therefore the aerial image Q is also fixed.

[0007] An object of the present invention is to solve the above-mentioned problems in the prior art and to provide a display device that can vary the aerial image and can be made compact. [Means for solving the problem]

[0008] The display device of the present invention is capable of displaying an aerial image by utilizing retroreflection, and includes a retroreflective member having a design including a cutout or opening formed therein, a light source that irradiates the retroreflective member from the back side, an optical member that is arranged above the retroreflective member and is capable of transmitting retroreflected light, and a moving means for moving the retroreflective member, and when the retroreflective member is moved, the aerial image of the design is changed.

[0009] In one embodiment, a plurality of designs are formed on the retroreflective member, and when the retroreflective member is moved, the aerial image is switched to another aerial image. In one embodiment, when the retroreflective member is moved, the design moves, thereby moving the aerial image. In one embodiment, the retroreflective member is rotatably attached, and the moving means rotates the retroreflective member to display an aerial image of the design overlapping the irradiation position of the light source. In one embodiment, the retroreflective member has a belt-shaped retroreflective sheet wound between a pair of rotating members, and the moving means moves the retroreflective sheet in a horizontal direction to display an aerial image of the design overlapping the irradiation position of the light source. In one embodiment, a plurality of retroreflective sheets are wound in parallel between the pair of rotating members, and at least one design is formed on each of the plurality of retroreflective sheets. In one embodiment, the moving means drives the plurality of retroreflective sheets separately. In one embodiment, the display device further includes a diffusion plate between the light source and the retroreflective member. In one embodiment, the display device further includes a polarizing plate between the light source and the retroreflective member. Effect of the Invention

[0010] According to the present invention, the retroreflective member on which a design including a notch or an opening is formed is illuminated from the back side by a light source, and the retroreflective member is moved, so that the design illuminated by the light source can be changed, and thus the aerial image can be changed. In addition, since a light source such as an LED is used, the size of the display device can be reduced. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a conventional aerial image display device. [Diagram 2] FIG. 1 is a diagram showing a schematic configuration of a conventional aerial image display device. [Diagram 3] 3 shows a display device according to a first embodiment of the present invention, in which FIG. 3(A) is a perspective view showing the overall configuration, FIG. 3(B) is an enlarged view of a retroreflective sheet, and FIG. 3(C) is a schematic cross-sectional view taken along line AA in FIG. 3(B). [Figure 4] FIG. 2 is a diagram illustrating the operation of the display device according to the first embodiment of the present invention. [Diagram 5] 1 is a block diagram showing an electrical configuration of a display device according to a first embodiment of the present invention. [Figure 6] FIG. 11 is a perspective view showing the overall configuration of a display device according to a second embodiment of the present invention, and shows a main part thereof. [Figure 7] FIG. 11 is a diagram showing a modified example of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The display device according to the present invention displays an aerial image in three-dimensional space using retroreflection without the need for special glasses. The display device according to the present invention also has a function of changing the aerial image using a light source such as an LED. It should be noted that the drawings referred to in the following description of the embodiments include exaggerated representations to facilitate understanding of the invention, and do not directly represent the shape and scale of the actual product. EXAMPLES

[0013] Next, a first embodiment of the present invention will be described in detail. Fig. 3 shows a display device according to the first embodiment of the present invention, in which Fig. 3(A) is a perspective view showing the overall configuration of the display device, Fig. 3(B) is an enlarged view of a retroreflective sheet, and Fig. 3(C) is a schematic cross-sectional view taken along line AA in Fig. 3(B).

[0014] Display device 100 of this embodiment has, for example, a rectangular housing 110 inside which a retroreflective sheet 120, a beam splitter 130, an LED light source 140, a motor 150, a circuit board, etc. are arranged, and an aerial image Q is displayed above beam splitter 130.

[0015] The retroreflective sheet 120 is an optical member that reflects light in the same direction as the incident light, and is composed of, for example, triangular pyramid retroreflective elements, full cube corner retroreflective elements, or other prism-type retroreflective elements, or bead-type retroreflective elements.

[0016] The shape of the retroreflective sheet 120 is not particularly limited, but may include, for example, a disk-shaped base, and the retroreflective sheet 120 is attached to the disk-shaped base. The retroreflective sheet 120 includes a flat top surface 122 and a plurality of flat inclined surfaces 124 inclined from the top surface 122, and has a generally disk-like shape as a whole. A shaft 126 is provided on the back surface of the top surface 122, and the shaft 126 is connected to the rotating shaft of the motor 150. When the motor 150 is rotated, the retroreflective sheet 120 is configured to rotate around the shaft 126. In addition, another retroreflective sheet 128 is provided near the periphery of the retroreflective sheet 120 as if the retroreflective sheet 122 were a continuous surface. The other retroreflective sheet 128 is fixed to the bottom of the housing 110. When an aerial image Q is displayed, if there is an area facing the beam splitter 130 where there is no retroreflective surface, the visibility and contrast of the aerial image Q will decrease, so this phenomenon is suppressed by arranging a separate retroreflective sheet 128.

[0017] A design P is formed by a notch or an opening on each of the multiple inclined surfaces 124. Here, four inclined surfaces 124 are provided on the retroreflective sheet 120, and four different types of designs P are formed on each of these inclined surfaces 124. The designs P represent, for example, icons to be operated by the user, and when the designs P are illuminated by the LED light source 140, they become the original image of the aerial image Q.

[0018] The LED light source 140 is disposed below the retroreflective sheet 120. The LED light source 140 is fixed to the bottom of the housing 110 and irradiates the retroreflective sheet 120 from the rear side. The LED light source 140 includes, for example, one or more LEDs, and irradiates light in a predetermined direction. When the LED light source 140 is a surface light source including multiple LEDs, the LED light source 140 is disposed so as to be approximately parallel to the inclined surface 124, and preferably irradiates the entire rear surface of one inclined surface 124 of the retroreflective sheet 120 efficiently and evenly. The LED light source 140 may be a type that uses a laser diode in addition to a light-emitting diode.

[0019] A beam splitter 130 is disposed above the retroreflective sheet 120. The beam splitter 130 is an optical member that splits incident light into transmitted light and reflected light at a fixed ratio. The beam splitter 130 may be a half mirror.

[0020] The motor 150 is disposed below the retroreflective sheet 120, and is connected to the shaft 126 of the retroreflective sheet 120 as described above. The motor 150 rotates the retroreflective sheet 120 to rotate and move the inclined surface 124 on which the design P is formed to the irradiation position of the LED light source 140. The motor 150 controls the rotation of the retroreflective sheet 120 by a controller as described below.

[0021] As shown in Fig. 4, when a certain inclined surface 124_1 is rotated and moved by a motor 150 to the irradiation position of the LED light source 140 (in the example shown in the figure, a design P representing a circle is rotated and moved to the irradiation position), the LED light source 140 illuminates the inclined surface 124_1 from the back side, and the light passes through or transmits the notch or opening that constitutes the design P, thereby generating an original image of the design P. The light that has transmitted through the design P is reflected by the beam splitter 130, and then retroreflected by the retroreflective sheet 120, and the reflected light transmits through the beam splitter 130, and an aerial image Q of the design P is displayed. The aerial image Q is displayed at a position symmetrical to the design P with respect to the surface of the beam splitter 130.

[0022] Next, the retroreflective sheet 120 is rotated by the motor 150, and when the next inclined surface 124_2 rotates and moves to the irradiation position of the LED light source 140, an aerial image Q of the design P formed on the next inclined surface 124_2 is displayed, and the aerial image is switched to another aerial image.

[0023] As described above, according to this embodiment, the design P irradiated by the LED light source 140, i.e., the original image, can be switched by rotating the retroreflective sheet 120, and the aerial image Q can be changed or switched accordingly. In addition, since a display such as a liquid crystal display is not used as the light source, the overall size of the housing 110 can be reduced.

[0024] 5 is an example of a block diagram showing the electrical configuration of the display device of this embodiment. The display device 100 includes a controller 200 that controls the rotation of the retroreflective sheet 120, a motor driving unit 210 that drives the motor 150, an input unit 220 that receives an instruction from an external source or a detection result from an operation detection unit 230 and provides it to the controller 200, and an operation detection unit 230 that detects whether or not a user has performed an input operation on the aerial image Q. For example, when an input operation on the aerial image Q is detected by the operation detection unit 230, the controller 200 rotates the retroreflective sheet 120 to display the aerial image Q of the next design P, or rotates the retroreflective sheet 120 in response to an instruction from an external source to display the aerial image Q of another design.

[0025] In the above embodiment, the retroreflective sheet 120 is disk-shaped, but this is just one example and other shapes are also possible. Furthermore, although designs are formed on each of the four inclined surfaces, the number of designs and the type of designs (characters, icons, etc.) are arbitrary. Furthermore, although a motor is used as a means for rotating the retroreflective sheet, the retroreflective sheet may be rotated using a mechanism other than a motor. Furthermore, the retroreflective sheet may not only rotate but also move linearly.

[0026] Next, a second embodiment of the present invention will be described. Fig. 6 shows a display device according to the second embodiment, with Fig. 6(A) being a perspective view showing the overall configuration of the display device and Fig. 6(B) being a view showing the main part thereof.

[0027] The first embodiment shows an example of switching an aerial image to another aerial image by rotating a retroreflective sheet, but the second embodiment relates to a structure for adding movement to an aerial image. As shown in Fig. 6, the display device 300 is configured by, for example, accommodating a belt-shaped retroreflective sheet 330, an LED light source 340, a diffusion plate 350, a polarizing plate 360, a motor 370, and a rotating pin 380 as shown in Fig. 6(B) in a rectangular housing 310, and attaching a polarizing beam splitter 320 to the surface of the housing 310. As a result, an aerial image Q is displayed at a certain height from the polarizing beam splitter 320, and when the retroreflective sheet 330 is moved by the motor 370, the aerial image Q moves in the direction Y1 or Y2.

[0028] The retroreflective sheet 330 is wound around, for example, a pair of rotating pins 380 to form an endless belt. A motor 370 is connected to one of the rotating pins 380, and the motor 370 drives the rotating pin 380 to rotate, thereby moving the retroreflective sheet 330 in the Y1 or Y2 direction. At least one design P is formed on the retroreflective sheet 330. The design P is formed by a notch or an opening, similar to the first embodiment.

[0029] An LED light source 340, a diffusion plate 350, and a polarizing plate 360 ​​are disposed in the space between the upper and lower portions of the retroreflective sheet 330. The LED light source 340 is a roughly rectangular surface light source in which a plurality of LEDs are arranged two-dimensionally, and is disposed between a pair of rotation pins 380 with a certain length therebetween.

[0030] The diffusion plate 350 is disposed above the LED light source 340. The diffusion plate 350 is, for example, an optical element such as a generally rectangular optical film or diffusion sheet. The diffusion plate 350 has, for example, approximately the same size as the LED light source 340, and receives light from the LED light source 340 from the bottom surface side, and emits the diffused light from the top surface side, irradiating the polarizing plate 360 ​​located above it generally uniformly.

[0031] A polarizing plate 360 ​​is disposed above the diffusion plate 350. The polarizing plate 360 ​​is an optical element such as a polarizing filter or DBEF (reflective polarization element), and transmits light of a certain polarization state (for example, linearly polarized light) from the light from the diffusion plate 350. The polarization state of the polarizing plate 360 ​​is determined in relation to the polarization state of the polarizing beam splitter 320.

[0032] When the polarizing plate 360 ​​is used, for example, a λ / 4 film may be provided as a retardation film on the surface of the retroreflective sheet 330. The retardation film provides a phase difference between the incident light and the outgoing light, and for example, in the case of a λ / 4 film, a phase difference of λ / 4×2 (round trip) occurs between the incident light and the outgoing light.

[0033] A polarizing beam splitter 320 is disposed above the retroreflective sheet 330. The polarizing beam splitter 320 is an optical element that transmits a part of incident light and reflects a part of it, and is a polarization separation element that splits the incident light into a p-polarized component and an s-polarized component. For example, the polarizing beam splitter 320 transmits a part of light in a certain polarization state and reflects a part of it.

[0034] The light emitted from the LED light source 340 is diffused by the diffusion plate 350, and then converted into polarized light by the polarizing plate 360, and irradiates almost the entire upper portion of the retroreflective sheet 330 from the back side. The retroreflective sheet 330 has a design P formed thereon, and the light emitted from the polarizing plate 360 ​​passes through a notch or an opening in the design P. The transmitted light is reflected by the polarizing beam splitter 320, and the reflected light is retroreflected by the retroreflective sheet 320. The retroreflected light passes through the polarizing beam splitter 320, and an aerial image Q of the design P is displayed. The aerial image Q is displayed at a position symmetrical to the design P with respect to the main surface of the polarizing beam splitter 320.

[0035] When the rotation pin 380 is rotated by the motor 370, the retroreflective sheet 330 moves in the Y1 or Y2 direction, and the design P also moves horizontally. Since the design P is illuminated by the LED light source 340 while being moved horizontally, the aerial image Q also moves in the Y1 or Y2 direction.

[0036] Thus, according to this embodiment, by moving the retroreflective sheet on which the design is formed, it is possible to add movement to the aerial image. In addition, since a display such as a liquid crystal display is not used as the light source of the display device, the display device can be made smaller. In the above example, one design is shown on the retroreflective sheet 330, but this is not limited to this, and multiple types of designs such as letters and icons (cutouts) can be formed on the belt-shaped retroreflective sheet, and the designs can be illuminated / non-illuminated by the LED light source, which can also be used to switch the aerial image.

[0037] Next, a modified example of the second embodiment is shown in FIG. 7. In the display device 300A shown in the figure, a plurality of belt-shaped retroreflective sheets 330_1, 330_2, 330_3, 330_4, and 330_5 are arranged in parallel, and an LED light source 340 is arranged in a direction perpendicular to the conveying direction of the belt so as to overlap the plurality of retroreflective sheets at the same time. In the example shown in the figure, designs P1, P2, and P3 are formed on each of the retroreflective sheets 330_1 to 330_5 (notches of letters A, B, and C), and the design P1 of the retroreflective sheets 330_1 to 330_5 is shown to overlap the irradiation position of the LED light source 340 at the same time. As a result, five aerial images Q1 corresponding to the five designs P1 are displayed above the polarizing beam splitter 320.

[0038] Here, when the rotating pin 380 is rotated by the motor 370 and the retroreflective sheets 330_1 to 330_5 are moved horizontally, for example, if the design P2 of each retroreflective sheet overlaps with the irradiation position of the LED light source 340, an aerial image Q2 of the design P2 is displayed and aerial image Q1 is switched to aerial image Q2.

[0039] In the above example, the retroreflective sheets 330_1 to 330_5 are driven simultaneously by the motor 370, but for example, a plurality of motors may be used to drive the retroreflective sheets 330_1 to 330_5 individually, thereby making it possible to switch between one or more selected aerial images.

[0040] In the above example, the same designs P1, P2, and P3 are formed on the retroreflective sheets 330_1 to 330_5, but different designs may be formed on each retroreflective sheet, and the designs are not limited to characters but may be icons, etc. Depending on the combination of designs formed on each retroreflective sheet, various types of button displays, etc., can be made possible.

[0041] In the above example, one design of each retroreflective sheet is overlapped at the irradiation position of the LED light source 340, but multiple designs of each retroreflective sheet may be overlapped at the irradiation position of the LED light source 340. For example, the width of the LED light source 340 in the conveying direction of the belt may be widened so that the aerial images Q1 and Q2 of the designs P1 and P2 of each retroreflective sheet are displayed simultaneously. Furthermore, by extending the LED light source 340 between a pair of rotating pins 380 as in the second embodiment shown in FIG. 6, it is also possible to give movement to the multiple aerial images Q1 when the motor 370 is driven. Furthermore, in the configuration shown in FIG. 7, the distance between the pair of rotating pins 380 is shortened and the length of the belt is shortened, thereby making it possible to reduce the size of the display device 300A.

[0042] The display device of this embodiment can be applied to displaying information and user input from any device, such as computer equipment, in-vehicle electronic devices, ATMs at banks, ticket vending machines at stations, elevator input buttons, etc.

[0043] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the gist of the invention described in the claims. [Explanation of symbols]

[0044] 100, 300, 300A: Display device 110, 310: Housing 120, 330: Retroreflective sheet 130: Beam splitter 140, 340: LED light source 150, 370: Motor P: Design Q: Aerial image

Claims

1. A display device capable of displaying an aerial image using retroreflection, A retroreflective member having a design including a notch or an opening; A light source that illuminates the retroreflective member from the back side; an optical member disposed above the retroreflective member and capable of transmitting retroreflected light; A moving means for moving the retroreflective member, A display device that changes the aerial image of the design when the retroreflective member is moved.

2. A plurality of designs are formed on the retroreflective member, The display device according to claim 1 , wherein the aerial image is switched to another aerial image when the retroreflective member is moved.

3. The display device according to claim 1 , wherein when the retroreflective member is moved, the design moves, thereby moving the aerial image.

4. The retroreflective member is rotatably attached, and the moving means rotates the retroreflective member, The display device according to claim 1 , wherein an aerial image of a design overlapping with a position illuminated by the light source is displayed.

5. The retroreflective member has a belt-like retroreflective sheet wound between a pair of rotating members, and the moving means moves the retroreflective sheet in a horizontal direction, The display device according to claim 1 , wherein an aerial image of a design overlapping with a position illuminated by the light source is displayed.

6. The display device according to claim 5 , wherein a plurality of retroreflective sheets are wound in parallel between the pair of rotating members, and at least one design is formed on each of the plurality of retroreflective sheets.

7. The display device according to claim 6 , wherein the moving means drives a plurality of retroreflective sheets separately.

8. The display device according to claim 1 , further comprising a diffusion plate between the light source and the retroreflective member.

9. The display device according to claim 8 , further comprising a polarizing plate between the light source and the retroreflective member.

Images