Display device

Abstract

The present invention addresses the problem of providing a display device capable of changing an aerial image and capable of being reduced in size. A display device (100) according to the present invention includes, inside a housing (110), a disc-shaped retroreflective sheet (120) in which a plurality of patterns (P) are formed at different positions, an LED light source (140) that irradiates the retroreflective sheet (120), a beam splitter (130), and a motor (150) that rotates and moves the retroreflective sheet (120). An aerial image (Q) of the pattern (P) irradiated by the LED light source (140) can be switched by rotating and moving the retroreflective sheet.

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 making an aerial image variable. Background Art

[0002] Aerial Imaging by Retro-Reflection (AIRR) is known. For example, Patent Document 1 discloses a display device that uses two retro-reflective components to enable observation of an image formed in the air from a wider angle. In addition, Patent Document 2 discloses a display device in which a light source and a retro-reflective component are positioned so that light that is regularly reflected on the retro-reflective component does not enter the observation range, thereby suppressing a decrease in contrast or visual recognition.

[0003] Prior art literature:

[0004] Patent Literature:

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-107165

[0006] Patent Document 2: Japanese Patent Application Publication No. 2022-150245 Summary of the invention

[0007] Problems to be solved by the invention:

[0008] The AIRR-type aerial image display device uses a liquid crystal display (LCD) or a light emitting diode (LED) as a light source. Figure 1 1 is a diagram showing a schematic configuration of a display device using an LCD as a light source. The display device 10 is configured with an LCD 30, an optical system including a retroreflective member 40, a beam splitter 50, etc., 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 for a user to perform an input operation, and the 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 since the size of the LCD 30 itself is large, there is a problem that the size of the entire optical system becomes large.

[0009] Figure 2 is a diagram showing a schematic structure of a display device using LED as a light source, Figure 2 (A) is a perspective view showing the entire display device, Figure 2 (B) is a schematic cross-sectional view. Figure 2As shown in (B), the display device 500 includes, for example, LEDs 70, a retroreflective layer 80, and a beam splitter or a half mirror 90 in a housing 60. The retroreflective layer 80 is provided with a pattern P including cutouts or openings for generating an original image of an aerial image Q.

[0010] The light emitted from the LED 70 irradiates the retroreflective layer 80, and the light after passing through the pattern P is retroreflected between the retroreflective layer 80 and the beam splitter 90, and the aerial image Q of the pattern P is displayed above the housing 60. Since such a display device 500 uses the LED 70, the entire device can be miniaturized, but on the other hand, the characters or icons based on the pattern P are fixed, so there is a problem that the aerial image Q is also fixed.

[0011] An object of the present invention is to solve such conventional problems and to provide a display device that makes an aerial image variable and can be reduced in size.

[0012] Means used to solve the problem:

[0013] The display device involved in the present invention can use retroreflection to display an aerial image, and includes: a retroreflective component, which is formed with a pattern including a cutout or an opening; a light source, which illuminates the retroreflective component from the back side; an optical component, which is arranged above the retroreflective component and can transmit the retroreflected light; and a moving part, which moves the retroreflective component, and when the retroreflective component is moved, the aerial image of the pattern changes.

[0014] In a certain embodiment, a plurality of patterns are formed on the retroreflective member, and when the retroreflective member is moved, the aerial image is switched to another aerial image. In a certain embodiment, when the retroreflective member is moved, the aerial image moves by the movement of the pattern. In a certain embodiment, the retroreflective member is installed to be rotatable, and the moving part rotates the retroreflective member, so that an aerial image of a pattern that repeats the irradiation position of the light source is displayed. In a certain embodiment, the retroreflective member has a strip-shaped retroreflective sheet wound between a pair of rotating members, and the moving part moves the retroreflective sheet in a horizontal direction, so that an aerial image of a pattern that repeats the irradiation position of the light source is displayed. In a certain embodiment, a plurality of retroreflective sheets are wound in parallel between the pair of rotating members, and at least one pattern is formed on each of the plurality of retroreflective sheets. In a certain embodiment, the moving part drives the plurality of retroreflective sheets individually. In a certain embodiment, the display device further includes a diffuser between the light source and the retroreflective member. In a certain embodiment, the display device further includes a polarizer between the light source and the retroreflective member.

[0015] Effect of the invention:

[0016] According to the present invention, a retroreflective member having a pattern including a cutout or an opening is irradiated from the back side with a light source, and the retroreflective member is moved, so that the pattern irradiated by the light source can be changed, thereby changing the aerial image. In addition, since a light source such as an LED is utilized, the size of the display device can be miniaturized. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram showing a schematic structure of a conventional aerial image display device.

[0018] Figure 2 This is a diagram showing a schematic structure of a conventional aerial image display device.

[0019] Figure 3 A display device according to a first embodiment of the present invention is shown. Figure 3 (A) is a three-dimensional diagram showing the overall structure. Figure 3 (B) is an enlarged view of the retroreflective sheet. Figure 3 (C) is Figure 3 (B) is a schematic cross-sectional view taken along line AA.

[0020] Figure 4 It is a diagram for explaining the operation of the display device involved in the first embodiment of the present invention.

[0021] Figure 5 This is a block diagram showing the electrical structure of a display device according to the first embodiment of the present invention.

[0022] Figure 6 It is a perspective view showing the overall structure of a display device according to a second embodiment of the present invention and a diagram showing its main parts.

[0023] Figure 7 It is a diagram showing a modified example of the second embodiment of the present invention.

[0024] Description of reference numerals:

[0025] 100, 300, 300A: Display device

[0026] 110, 310: Shell

[0027] 120, 330: Retroreflective sheeting

[0028] 130: Beam splitter

[0029] 140, 340: LED light source

[0030] 150, 370: Electric motor

[0031] P: Pattern

[0032] Q: Aerial image DETAILED DESCRIPTION

[0033] The display device of the present invention displays an aerial image using retroreflection in a three-dimensional space even without wearing special glasses. In addition, the display device of the present invention 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 displays for the purpose of making the invention easier to understand, and do not represent the shape or proportion of the actual product as it is.

[0034] [Example]

[0035] Next, the first embodiment of the present invention will be described in detail. Figure 3 is a diagram showing a display device according to a first embodiment of the present invention. Figure 3 (A) is a perspective view showing the overall structure of the display device. Figure 3 (B) is an enlarged view of the retroreflective sheet. Figure 3 (C) is Figure 3 (B) is a schematic cross-sectional view taken along line AA.

[0036] The display device 100 of this embodiment has a retroreflective sheet 120 , a beam splitter 130 , an LED light source 140 , a motor 150 , a circuit board, etc. disposed inside a rectangular housing 110 , and displays an aerial image Q above the beam splitter 130 .

[0037] 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, prism-type retroreflective elements such as triangular pyramid-type retroreflective elements and full cube-corner-type retroreflective elements, or bead-type retroreflective elements.

[0038] The shape of the retroreflective sheet 120 is not particularly limited, and for example, includes a disc-shaped base and is pasted thereon. 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 substantially disc shape as a whole. A shaft 126 is provided on the back 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, near the periphery of the retroreflective sheet 120, other retroreflective sheets 128 are provided as if the retroreflective sheet 120 is a continuous surface. The other retroreflective sheets 128 are fixed to the bottom of the housing 110. When the aerial image Q is displayed, if an area without a retroreflective surface is generated in the portion opposite to the beam splitter 130, the visual recognition or contrast of the aerial image Q is reduced, so such a phenomenon is suppressed by configuring other retroreflective sheets 128.

[0039] A pattern P is formed by a cutout or an opening on each of the plurality of inclined surfaces 124. Here, four inclined surfaces 124 are provided on the retroreflective sheet 120, and four different patterns P are formed on each of the inclined surfaces 124. The pattern P represents, for example, an icon to be operated by the user, and when the pattern P is illuminated by the LED light source 140, it becomes the original image of the aerial image Q.

[0040] An 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 from the back side of the retroreflective sheet 120. 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 a plurality of LEDs, the LED light source 140 is disposed substantially parallel to the inclined surface 124, and preferably, the entire back side of one inclined surface 124 of the retroreflective sheet 120 is efficiently and completely irradiated. In addition, in addition to light emitting diodes, laser diodes may also be used for the LED light source 140.

[0041] A beam splitter 130 is disposed above the retroreflective sheet 120. The beam splitter 130 is an optical component that splits incident light into transmitted light and reflected light at a certain ratio. The beam splitter 130 may also be a half mirror.

[0042] 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 pattern P is formed to the irradiation position of the LED light source 140. The motor 150 controls the rotation of the retroreflective sheet 120 through a controller as described later.

[0043] like Figure 4 As shown, when a certain inclined surface 124_1 is rotated and moved to the irradiation position of the LED light source 140 by the motor 150 (in the example shown in the figure, the pattern P representing 0 is rotated and moved to the irradiation position), the LED light source 140 irradiates the inclined surface 124_1 from the back side, and the light passes through or transmits the cutout or opening constituting the pattern P, thereby generating the original image of the pattern P. The light after transmitting the pattern P is reflected by the beam splitter 130, and then retroreflected by the retroreflective sheet 120. The reflected light transmits the beam splitter 130, and the aerial image Q of the pattern P is displayed. The aerial image Q is displayed at a position symmetrical to the pattern P with respect to the surface of the beam splitter 130.

[0044] Next, when the retroreflective sheet 120 is rotated by the motor 150 and the next inclined surface 124_2 is rotated and moved to the irradiation position of the LED light source 140, an aerial image Q of the pattern P formed on the next inclined surface 124_2 is displayed, and the aerial image is switched to another aerial image.

[0045] Thus, according to this embodiment, by rotating the retroreflective sheet 120, the pattern P, i.e., the original image, irradiated by the LED light source 140 can be switched, and accordingly the aerial image Q can be changed or switched. In addition, since a display such as a liquid crystal is not used as a light source, the overall size of the housing 110 can be miniaturized.

[0046] Figure 5 1 is an example of a block diagram showing the electrical configuration of the display device of the present embodiment. The display device 100 includes: a controller 200 for controlling the rotation of the retroreflective sheet 120, a motor driving unit 210 for driving the motor 150, an input unit 220 for receiving instructions from an external source or a detection result from an operation detection unit 230 and providing it to the controller 200, and an operation detection unit 230 for detecting whether there is an input operation to the aerial image Q by the user. For example, when the operation detection unit 230 detects an input operation to the aerial image Q, the controller 200 rotates the retroreflective sheet 120 to display the aerial image Q of the next pattern P, or rotates the retroreflective sheet 120 in response to an instruction from an external source to display the aerial image Q of another pattern.

[0047] In the above embodiment, the retroreflective sheet 120 is set to be disc-shaped, but this is an example and other shapes are also possible. In addition, a pattern is formed on each of the four inclined surfaces, but the number of patterns and the type of patterns (characters, icons, etc.) are arbitrary. In addition, a motor is used as a means for rotating the retroreflective sheet, but a mechanism other than a motor can also be used to rotate the retroreflective sheet. Furthermore, the retroreflective sheet can also not only rotate but also move linearly.

[0048] Next, a second embodiment of the present invention will be described. Figure 6 is a diagram showing a display device according to a second embodiment. Figure 6 (A) is a perspective view showing the overall structure of the display device. Figure 6 (B) is a diagram showing its main parts.

[0049] The first embodiment shows an example of switching an aerial image to another aerial image by rotating the retroreflective sheet, while the second embodiment relates to a structure for adding motion to the aerial image. Figure 6 As shown, the display device 300 is housed in a rectangular housing 310. Figure 6The strip-shaped retroreflective sheet 330, LED light source 340, diffuser 350, polarizer 360, motor 370, and rotating pin 380 shown in (B) are configured by mounting polarization beam splitter 320 on the surface of housing 310. Thus, an aerial image Q is displayed at a certain height from polarization beam splitter 320, and when the retroreflective sheet 330 is moved by motor 370, aerial image Q moves in the direction of Y1 or Y2.

[0050] The retroreflective sheet 330 is wound between a pair of rotating pins 380 to form an endless (ring-shaped) belt. A motor 370 is connected to one of the rotating pins 380, and the rotating pin 380 is rotated by the driving of the motor 370, thereby moving the retroreflective sheet 330 in the Y1 or Y2 direction. In addition, at least one pattern P is formed on the retroreflective sheet 330. The pattern P is composed of a cutout or an opening as in the first embodiment.

[0051] LED light source 340, diffusion plate 350, and polarizing plate 360 ​​are arranged in the space between the upper and lower portions of retroreflective sheet 330. LED light source 340 is a substantially rectangular surface light source formed by arranging a plurality of LEDs in two dimensions, and is arranged between a pair of rotating pins 380 with a certain length.

[0052] A diffusion plate 350 is disposed above the LED light source 340. The diffusion plate 350 is, for example, an optical element such as a substantially rectangular optical film or a diffusion sheet. The diffusion plate 350 has, for example, substantially 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 diffused light from the top surface side, and irradiates the polarizing plate 360 ​​located above it substantially uniformly.

[0053] A polarizing plate 360 ​​is disposed above the diffuser 350. The polarizing plate 360 ​​is an optical element such as a polarizing filter or a DBEF (reflective polarizing element), and transmits light of a certain polarization state (e.g., linear polarization) among the light from the diffuser 350. The polarization state of the polarizing plate 360 ​​is determined based on the relationship with the polarization state of the polarization beam splitter 320.

[0054] When the polarizing plate 360 ​​is used, a λ / 4 film may be provided as a phase difference film on the surface of the retroreflective sheet 330. The phase difference film provides a phase difference between the incident light and the outgoing light. For example, if the λ / 4 film is used, a phase difference of λ / 4×2 (round trip) is generated between the incident light and the outgoing light.

[0055] A polarization beam splitter 320 is disposed above the retroreflective sheet 330. The polarization beam splitter 320 is an optical element that transmits a portion of incident light and reflects a portion thereof, and is a polarization separation element that separates the incident light into a p-polarization component and an s-polarization component. For example, the polarization beam splitter 320 transmits a portion of light in a certain polarization state and reflects a portion thereof.

[0056] The light emitted from the LED light source 340 is diffused on the diffuser 350, and then converted into light in a polarization state as the polarizer 360, and irradiates substantially the entire upper portion of the retroreflective sheet 330 from the back side. The retroreflective sheet 330 is formed with a pattern P, and the light emitted from the polarizer 360 passes through the cutout or opening of the pattern P, and the light after passing through is reflected on the polarization beam splitter 320, and the reflected light is retroreflected by the retroreflective sheet 320, and the retroreflected light is transmitted through the polarization beam splitter 320, and an aerial image Q of the pattern P is displayed. The aerial image Q is displayed at a position symmetrical to the pattern P with respect to the main surface of the polarization beam splitter 320.

[0057] Here, when the motor 370 rotates the rotating pin 380, the retroreflective sheet 330 moves in the Y1 or Y2 direction, and the pattern P also moves horizontally. The pattern P is illuminated by the LED light source 340 while moving horizontally, so the aerial image Q also moves in the Y1 or Y2 direction.

[0058] As described above, according to this embodiment, by moving the retroreflective sheet with a pattern, motion can be added to the aerial image. In addition, since a display such as a liquid crystal is not used as a light source of the display device, the display device can be miniaturized. In the above example, one pattern is shown on the retroreflective sheet 330, but it is not limited to this. By forming multiple types of patterns such as characters, icons (cutouts) on the strip-shaped retroreflective sheet and irradiating / non-irradiating the pattern with an LED light source, it can also be applied to the switching of the aerial image.

[0059] Next, Figure 7 A modified example of the second embodiment is shown. The display device 300A shown in the figure arranges a plurality of strip-shaped retroreflective sheets 330_1, 330_2, 330_3, 330_4, and 330_5 in parallel, and arranges the LED light source 340 in a direction orthogonal to the conveying direction of the strip so that the LED light source 340 overlaps with the plurality of retroreflective sheets at the same time. In the example shown in the figure, patterns P1, P2, and P3 (cutouts of characters A, B, and C) are formed on the retroreflective sheets 330_1 to 330_5, respectively, and the pattern P1 of the retroreflective sheets 330_1 to 330_5 overlaps with the irradiation position of the LED light source 340 at the same time. As a result, five aerial images Q1 corresponding to the five patterns P1 are displayed above the polarization beam splitter 320.

[0060] Here, when the motor 370 rotates the rotating pin 380 and moves the retroreflective sheets 330_1 to 330_5 in the horizontal direction, for example, if the pattern P2 of each retroreflective sheet overlaps the irradiation position of the LED light source 340, an aerial image Q2 of the pattern P2 is displayed, switching from the aerial image Q1 to the aerial image Q2.

[0061] In the above example, the retroreflective sheets 330_1 to 330_5 are driven simultaneously by the motor 370, but the retroreflective sheets 330_1 to 330_5 may be driven individually by a plurality of motors, for example. Thus, the selected one or more aerial images can be switched.

[0062] In the above example, the same patterns P1, P2, and P3 are formed on the retroreflective sheets 330_1 to 330_5, but different patterns may be formed on each retroreflective sheet, and the patterns are not limited to characters, but may also be icons, etc. According to the combination of the patterns formed on each retroreflective sheet, multiple types of buttons, etc. can be displayed.

[0063] In the above example, one pattern of each retroreflective sheet overlaps with the irradiation position of the LED light source 340, but multiple patterns of each retroreflective sheet may overlap with 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 patterns P1 and P2 of each retroreflective sheet are displayed simultaneously. Furthermore, the LED light source 340 may overlap with the irradiation position of the LED light source 340. Figure 6 In the second embodiment shown, the pair of rotating pins 380 are also extended, so that when the motor 370 is driven, the plurality of aerial images Q1 are given motion. Figure 7 In the illustrated configuration, by shortening the distance between the pair of rotating pins 380 and shortening the length of the belt, the display device 300A can be miniaturized.

[0064] The display device of this embodiment can be applied to information display or user input of various devices, for example, it can be applied to computer devices, vehicle-mounted electronic devices, ATMs in banks, ticket machines in stations, input buttons in elevators, etc.

[0065] Although specific 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 can be made within the scope of the gist of the invention described in the claims.

Claims

1. A display device capable of displaying an aerial image by utilizing retroreflection, wherein: include: A retroreflective member formed with a pattern including cutouts or openings; a light source, illuminating the retroreflective member from the back side; an optical component, disposed above the retroreflective component, capable of transmitting the retroreflected light; as well as a moving part, which moves the retroreflective component; When the retroreflective member is moved, the aerial image of the pattern changes.

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

3. The display device according to claim 1, wherein: When the retroreflective member is moved, the pattern moves, and the aerial image moves.

4. The display device according to claim 1, wherein: The retroreflective member is rotatably mounted, and the moving part rotates the retroreflective member. An aerial image of a pattern that overlaps the irradiation position of the light source is displayed.

5. The display device according to claim 1, wherein: The retroreflective member includes a strip-shaped retroreflective sheet wound between a pair of rotating members, and the moving portion moves the retroreflective sheet in a horizontal direction. An aerial image of a pattern that overlaps the irradiation position of 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 pattern is formed on each of the plurality of retroreflective sheets.

7. The display device according to claim 6, wherein: The moving unit drives the plurality of retroreflective sheets individually.

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

9. The display device according to claim 8, wherein: The display device also includes a polarizer between the light source and the retroreflective member.

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