JP2021144071A - Aerial display device - Google Patents

Abstract

To provide an areal display device which can be reduced in thickness and occupied volume regardless of the size of a displayed aerial image.SOLUTION: An aerial display device according to an embodiment comprises a retroreflective sheet, a transparent display device, and a half mirror. The transparent display device is placed roughly in parallel with the retroreflective sheet on a retroreflective-surface side of the retroreflective sheet. The half mirror is placed on a light exit side of the transparent display device.SELECTED DRAWING: Figure 2

Description

The present invention relates to an aerial display device.

An aerial display device in which a half mirror and a retroreflective sheet are arranged at an angle of 45 ° is disclosed (see, for example, Patent Documents 1 to 5 and the like).

Further, there is disclosed an aerial display device in which a light source having an inclined light emitting surface is arranged to emit light obliquely between a half mirror arranged parallel to each other and a retroreflective sheet (for example, Patent Document). See 6 mag).

JP-A-2019-129378 Japanese Unexamined Patent Publication No. 4-339488 Japanese Patent Publication No. 7-501161 Special Table 2001-511915 Special Table 2002-517779 Japanese Unexamined Patent Publication No. 2019-300133

However, in the configuration in which the half mirror and the retroreflective sheet are arranged at an angle of 45 °, there is a problem that the occupied volume of the entire device becomes large and the applicable place is limited. For example, even when it is desired to use an aerial display as various indicators in an automobile, it is difficult to mount the device because the occupied volume of the device is large. Further, although FIGS. 2 and 4 of Patent Document 1 disclose an example in which a two-sided corner reflector (orthogonal mirror lattice) is used as an optical element, even when such an optical element is used, it is disclosed. The occupied volume of the device became large, and it was difficult to miniaturize the device.

In addition, in the configuration in which a light source with an inclined light emitting surface is arranged between the half mirrors arranged parallel to each other and the retroreflective sheet, the device is slightly thin when the aerial display is small. However, it cannot be dealt with when the aerial display is large. That is, since the inclined light source is arranged near the end of the device, if the light emitting surface of the light source is enlarged according to the aerial display, the thickness of the device becomes considerable, and it is difficult to reduce the thickness of the device. be.

The present invention has been made in view of the above, and provides an aerial display device capable of reducing the thickness of the device regardless of the size of the aerial display and reducing the occupied volume of the device. With the goal.

In order to solve the above-mentioned problems and achieve the object, the aerial display device according to one aspect of the present invention includes a retroreflective sheet, a transparent display device, and a half mirror. The transparent display device is arranged on the retroreflective surface side of the retroreflective sheet substantially parallel to the retroreflective sheet. The half mirror is arranged on the light emitting surface side of the transparent display device.

The aerial display device according to one aspect of the present invention can be made thinner regardless of the size of the aerial display, and the occupied volume of the device can be reduced.

FIG. 1 is a bottom view showing an example of an aerial display device according to an embodiment. FIG. 2 is a cross-sectional view taken along the line YY in FIG. FIG. 3 is a diagram showing a configuration example of the light emitting unit. FIG. 4 is a diagram showing a configuration example of a linear light source. FIG. 5 is a cross-sectional view taken along the line YY in FIG. FIG. 6 is a diagram showing another configuration example of the linear light source. FIG. 7 is a cross-sectional view taken along the line YY in FIG. FIG. 8 is a diagram showing a mechanism for aerial display in the embodiment. FIG. 9 is a diagram showing a mechanism of aerial display in the comparative example. FIG. 10 is a diagram (1) showing an example of performing an inclined aerial display. FIG. 11 is a diagram (2) showing an example of performing an inclined aerial display. FIG. 12 is a diagram (3) showing an example of performing an inclined aerial display. FIG. 13 is a diagram showing an example of application to an in-vehicle room lamp. FIG. 14 is a diagram showing an example of changing the position of the aerial display. FIG. 15 is a diagram showing an example of application to an automobile console. FIG. 16 is a diagram showing an application example to a door panel of a house, a hotel, or the like.

Hereinafter, the aerial display device according to the embodiment will be described with reference to the drawings. The present invention is not limited to this embodiment. In addition, the relationship between the dimensions of each element in the drawing, the ratio of each element, and the like may differ from the reality. Even between drawings, there may be parts where the relationship and ratio of dimensions are different from each other. Further, in principle, the contents described in one embodiment or modification are similarly applied to other embodiments or modifications.

FIG. 1 is a bottom view showing an example of the aerial display device 1 according to the embodiment. FIG. 2 is a cross-sectional view taken along the line YY in FIG. The aerial display device 1 in FIGS. 1 and 2 is assumed to be installed on the ceiling surface of an automobile or the like, and the display surface faces downward.

In FIGS. 1 and 2, in the aerial display device 1, a linear light source 3 and a light guide plate 4 constituting the transparent display device are arranged in a frame 2 in which a substantially rectangular opening 2a is formed. The linear light source 3 is a light source that emits light linearly along the longitudinal direction of the light incoming side surface 4a of the light guide plate 4. Details of the linear light source 3 will be described later. The light guide plate 4 is formed of a transparent material such as polycarbonate or acrylic, guides the light incident from the light incoming side surface 4a, and reflects the light by the light emitting portion 4b formed by the prism or the like provided on the non-display surface side. Then, the light is emitted in the direction in which the eye point EP on the display surface side does not exist (lower right side in FIG. 2). The eye point EP is a position that is expected to be visually recognized by the user.

Further, on the back surface (non-display surface) side of the frame 2, a retroreflective sheet 5 is arranged so as to cover the opening 2a. The retroreflective sheet 5 is a sheet in which transparent minute glass bead balls or the like are arranged on the surface without gaps, and has a property of emitting incident light through the same path (incident angle and emission angle are the same). The retroreflective sheet 5 uses the inner surface of the apex of a cube, which is a combination of three flat plates called corner cubes, which have the property of reflecting light, at right angles to each other, in addition to the glass bead sphere. Can also be used. In this case, the cost is slightly higher, but there are advantages that the light utilization efficiency is high and the blurring of the aerial display (aerial image) is reduced.

Further, a half mirror 6 is arranged on the display surface side of the frame 2 so as to cover the opening 2a, and a top cover 7 is superposed on the half mirror 6 on the outside. The half mirror 6 is an optical element having a property of reflecting about half of the incident light and transmitting the other half. The top cover 7 is made of a transparent material and is for protecting the half mirror 6. By lowering the transparency of the top cover 7, it becomes difficult to see the inside of the aerial display device 1 from the outside, and only the stereoscopic display can be easily seen.

FIG. 3 is a diagram showing a configuration example of the light emitting unit 4b. The light emitting unit 4b in the upper part of FIG. 3 shows an icon (five short radial lines on one side of a circle by a line) indicating a state in which the lamp is emitting light, and the center of the lower part is of the light emitting part 4b. This is an enlargement of the part indicated by the broken line of the square. In this enlarged view, three prisms 4c1 to 4c3 are shown. The lower left and lower right views show the structures of these prisms 4c1 to 4c3 in the cross-sectional direction. The lower left figure shows the case where the convex prisms 4c1 to 4c3 are used. The lower right figure shows the case where the concave prisms 4c1 to 4c3 are used. In any prism structure, by adjusting the angle of the inclined surface of the prism, the light incident on the prism can be reflected with good directivity in the oblique direction on the side where the eye point EP does not exist. In other words, the structure of the prism formed on the light guide plate 4 allows the main optical axis to be set on the side where the eye point EP does not exist.

FIG. 4 is a diagram showing a configuration example of the linear light source 3. FIG. 5 is a cross-sectional view taken along the line YY in FIG. In FIGS. 4 and 5, in the linear light source 3, light is emitted from a light source 32 such as an LED (Light Emitting Diode) provided on a substrate 31 on both sides of the end portion in the direction in which the linear light source 3 extends. It includes a rod-shaped light bar 33 to be incident. The light bar 33 has a rectangular cross-sectional shape, and both ends are tapered.

Further, on the light guide plate 4 side (emission side) of the light bar 33, a rod-shaped prism bar 34 having a rectangular cross section and a plate-shaped diffusion film 35 having a rectangular cross section are formed along the direction in which the linear light source 3 extends. Are arranged in order. The light emitted from the diffusion film 35 enters the light entering side surface 4a of the light guide plate 4.

The light bar 33 emits the light incident from the end portion to the light guide plate 4 side. The prism bar 34 adjusts the light distribution of the light incident from the light bar 33. The diffusion film 35 equalizes the brightness of the light incident from the prism bar 34.

FIG. 6 is a diagram showing another configuration example of the linear light source 3. FIG. 7 is a cross-sectional view taken along the line YY in FIG. In FIGS. 6 and 7, the linear light source 3 is a light source 37 formed by a plurality of LEDs or the like arranged along the direction in which the linear light source 3 extends on the strip-shaped substrate 36, and on the exit side of the light source 37. It is provided with a light bar 39 which is arranged and has irregularities formed such that the distance from the light source 37 changes according to the arrangement pitch of the light source 37 along the direction in which the light source 37 is arranged. The non-light source side of the light bar 39 is in contact with the light incoming side surface 4a of the light guide plate 4. Diffuse reflection sheets 38 are provided from both ends of the substrate 36 in the lateral direction to the ends of the light bar 39 and the light guide plate 4 to prevent the light from the light source 37 from leaking to the outside to prevent a decrease in brightness.

FIG. 8 is a diagram showing a mechanism for aerial display in the above embodiment. In FIG. 8, about half of the light emitted from the light emitting portion 4b of the light guide plate 4 constituting the transparent display device in the path L1 is reflected by the half mirror 6, passes through the light guide plate 4 by the path L2, and is a retroreflective sheet 5. It hits. The light that hits the retroreflective sheet 5 returns to the half mirror 6 by the path L3 at the same exit angle as the incident angle, and about half of the light is transmitted. Since the light emitted from a certain point of the light emitting unit 4b passes through the same position outside the aerial display device 1 due to the geometrical relationship even if the position of the path L1 changes, it is in the air outside the half mirror 6 and the top cover 7. The aerial display I by the image is performed, and it can be visually recognized from the user's eye point EP.

FIG. 9 is a diagram showing a mechanism of aerial display in the comparative example. In FIG. 9, about half of the light emitted from the display device 45'on the path L1'is reflected by the beam splitter 46' and hits the retroreflective sheet 47'by the path L2'. The light that hits the retroreflective sheet 47'returns to the beam splitter 46'by the path L3'at the same exit angle as the incident angle, and about half of the light is transmitted. Since the light emitted from a certain point of the display device 45'passes the same position outside the device due to the geometrical relationship even if the position of the path L1'changes, the aerial image 11'is outside the beam splitter 46'. It is done and can be seen by the user.

As is clear from the embodiment of FIG. 8 and the comparative example of FIG. 9, in the embodiment, the device can be significantly reduced in thickness, and the occupied volume of the device can be reduced. Therefore, it can be applied to places that could not be implemented in the comparative example. Further, in the embodiment of FIG. 8, the aerial display I can be increased by expanding the light emitting unit 4b on the light guide plate 4, and the aerial display I can be increased without affecting the thinning of the aerial display device 1. be able to. Even if the aerial display I is increased, the display content is not significantly affected by the transparent display device using the light guide plate 4.

<Inclination of aerial display I>
10 to 12 are views showing an example of performing an inclined aerial display I, and show the main components of the aerial display device 1 in a cross-sectional view (the same viewpoint as in FIG. 2). By performing the aerial display I diagonally, it is expected that the visibility will be improved and the operability will be improved when the user touches the aerial display I with a finger. It should be noted that the thickness of the aerial display device 1 is slightly increased by making the aerial display I slanted, but the thickness of the aerial display device 1 is not affected by the size of the aerial display I, as described above. As a result, the aerial display device 1 can be made thinner as a whole.

In FIG. 10, the light guide plate 4 and the retroreflective sheet 5 constituting the transparent display device are arranged in parallel, and the half mirror 6 and the top cover 7 are separately arranged in parallel with the half mirror 6 and the top cover 7. Are arranged at an angle with respect to the light guide plate 4. In this case, the aerial display I is displayed at a position symmetrical with the light emitting unit 4b with the half mirror 6 as a boundary, and is displayed at a position slightly facing the eye point EP from the surface of the top cover 7 in the illustrated example.

In FIG. 11, the light guide plate 4 constituting the transparent display device, the retroreflective sheet 5, and the half mirror 6 are arranged in parallel, and the top cover 7 is arranged so as to be inclined with respect to the light guide plate 4 and the like. Also in this case, the aerial display I is displayed at a position symmetrical with the light emitting unit 4b with the half mirror 6 as a boundary, and is displayed at a position slightly facing the eye point EP from the surface of the top cover 7 in the illustrated example. ..

In FIG. 12, the light guide plate 4 constituting the transparent display device, the retroreflective sheet 5, and the top cover 7 are arranged in parallel, and the half mirror 6 is arranged so as to be inclined with respect to the light guide plate 4 and the like. Also in this case, the aerial display I is displayed at a position symmetrical with the light emitting unit 4b with the half mirror 6 as a boundary, and is displayed at a position slightly facing the eye point EP from the surface of the top cover 7 in the illustrated example. ..

<Application example of aerial display device 1>
FIG. 13 is a diagram showing an application example to the vehicle-mounted room lamp 110. In FIG. 13, an aerial display I corresponding to a button of a switch is performed from an in-vehicle room lamp 110 installed on a ceiling surface or the like of an automobile. The illustrated aerial display I uses an inclined one having any of the configurations shown in FIGS. 10 to 12. When the user touches the aerial display I with the finger F, the finger F is detected by an IR (infrared) sensor (not shown) provided on the vehicle-mounted room lamp 110, and the on / off of the lamp is controlled. Since the user's finger F only touches the aerial display I and does not touch the actual button or the like, it can be desirable in terms of hygiene.

In FIG. 13, it is desirable that the position of the aerial display I changes in order to show that the button of the switch responds when the user touches the aerial display I with the finger F. FIG. 14 is a diagram showing an example of changing the position of the aerial display, in which another light emitting unit 4b2 is placed at a position deviated from the light emitting unit 4b1 inside the half mirror 6 (a position where the distance from the half mirror 6 is different). By arranging and emitting light from any of them, the aerial display can be changed to the aerial display I1 and the aerial display I2. The two light emitting units 4b1 and 4b2 may be provided with the light guide plate 4 respectively, or the light guide plate 4 itself may be mechanically moved. Further, the number of light emitting units may be three or more.

FIG. 15 is a diagram showing an example of application to the console 120 of an automobile. In FIG. 15, the design can be improved by performing the speedometer or the like of the console 120 of the automobile by the aerial display I. The illustrated aerial display I uses an inclined one having any of the configurations shown in FIGS. 10 to 12.

FIG. 16 is a diagram showing an application example to a door panel 130 of a house, a hotel, or the like. In FIG. 16, operability and design can be improved by performing a password input screen or the like for opening and closing a door on a door panel 130 of a house or a hotel by aerial display I. The detection of the user's finger F is performed by an IR sensor or the like. The illustrated aerial display I uses an inclined one having any of the configurations shown in FIGS. 10 to 12.

Further, as another embodiment, the above-mentioned transparent display device may be used in combination with the optical element shown in Patent Document 1. Since the above-mentioned transparent display device is excellent in directivity, even when it is combined with the optical element of Patent Document 1, direct light is not visually recognized, and aerial display with excellent visibility is possible.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

As described above, the aerial display device according to the embodiment includes a retroreflective sheet, a transparent display device arranged substantially parallel to the retroreflective sheet on the retroreflective surface side of the retroreflective sheet, and light emission of the transparent display device. It is equipped with a half mirror arranged on the surface side. As a result, the device can be made thinner regardless of the size of the aerial display, and the occupied volume of the device can be reduced.

Further, in the transparent display device, the main optical axis is set on the side where the eye point set outside the half mirror does not exist. As a result, less light rays are emitted directly from the transparent display device toward the eye point, and the user's consciousness can be focused on the aerial display, so that sufficient aerial display can be performed.

In addition, it has a top cover arranged on the opposite side of the transparent display device of the half mirror, and the transparent display device, the half mirror and the top cover are arranged in parallel, or the half mirror and the top cover are arranged in parallel. Whether the half mirror and the top cover are tilted with respect to the transparent display device, or the transparent display device and the half mirror are arranged in parallel and the top cover is tilted with respect to the transparent display device. , The transparent display device and the top cover are arranged in parallel, and the half mirror is arranged at an angle with respect to the transparent display device. As a result, it is possible to realize an aerial display parallel to the top cover and an aerial display inclined with respect to the top cover.

Further, the transparent display device includes a light guide plate provided with a prism for light reflection on the main surface on the retroreflective sheet side, and a linear light source that emits light to the light input side surface of the light guide plate. Thereby, the transparent display device can be easily realized.

Further, the linear light source includes a light bar in which the light source is arranged at the end in the direction in which the linear light source extends, and a prism bar in which the light source is arranged on the exit side of the light bar along the direction in which the light bar extends. A diffuser film is provided on the exit side of the prism bar along the extending direction of the prism bar, and the light entry side surface of the light guide plate is arranged on the exit side of the diffuser film. Thereby, the transparent display device can be easily realized.

Further, the linear light source is arranged on the exit side of the light source along the direction in which the linear light source is arranged, and the plurality of light sources arranged in the extending direction of the linear light source, and the distance between the linear light source and the light source at the arrangement pitch of the light source. It is provided with a light bar in which the light source changes, and the light entry side surface of the light guide plate is arranged on the light source side of the light bar. Thereby, the transparent display device can be easily realized.

Further, the transparent display device includes a plurality of light emitting units having different distances from the half mirror. As a result, the aerial display can be changed.

Moreover, the present invention is not limited by the above-described embodiment. The present invention also includes a configuration in which the above-mentioned components are appropriately combined. Further, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

1 Aerial display, 2 Frame, 3 Linear light source, 4 Light guide plate, 4b, 4b1, 4b2 Light emitting part, 4c1 to 4c3 prism, 5 Retroreflective sheet, 6 Half mirror, 7 Top cover, EP eye point, I, I1 , I2 aerial display, F finger

Claims (7)

Retroreflective sheet and
A transparent display device arranged substantially parallel to the retroreflective sheet on the retroreflective surface side of the retroreflective sheet.
A half mirror arranged on the light emitting surface side of the transparent display device and
An aerial display device equipped with. A top cover arranged on the opposite side of the half mirror to the transparent display device is provided.
Whether the transparent display device, the half mirror, and the top cover are arranged in parallel.
Whether the half mirror and the top cover are arranged in parallel, and the half mirror and the top cover are arranged at an angle with respect to the transparent display device.
Whether the transparent display device and the half mirror are arranged in parallel and the top cover is inclined with respect to the transparent display device.
The transparent display device and the top cover are arranged in parallel, and the half mirror is arranged at an angle with respect to the transparent display device.
The aerial display device according to claim 1. In the transparent display device, the main optical axis is set on the side where the eye point set outside the half mirror does not exist.
The aerial display device according to claim 1 or 2. The transparent display device is
A light guide plate provided with a prism for light reflection on the main surface on the retroreflective sheet side, and
A linear light source that emits light to the light entering side surface of the light guide plate,
The aerial display device according to any one of claims 1 to 3. The linear light source is
A light bar in which the light source is arranged at the end in the direction in which the linear light source extends, and
A prism bar arranged on the exit side of the light bar along the direction in which the light bar extends,
A diffusion film arranged on the exit side of the prism bar along the direction in which the prism bar extends,
With
The light entry side surface of the light guide plate is arranged on the exit side of the diffusion film.
The aerial display device according to claim 4. The linear light source is
A plurality of light sources arranged in a direction in which the linear light sources extend, and
A light bar that is arranged on the exit side of the light source along the direction in which the light source is arranged and whose distance from the light source changes according to the arrangement pitch of the light source.
With
The light entry side surface of the light guide plate is arranged on the exit side of the light bar.
The aerial display device according to claim 4. The transparent display device includes a plurality of light emitting units having different distances from the half mirror.
The aerial display device according to any one of claims 1 to 6.

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