Display device

Abstract

The present invention addresses the problem of providing a display device in which the visibility or contrast of aerial images is improved. The aerial image display device (100) comprises a light source (110) such as a display, a beam splitter (120) for separating incident light into transmitted light and reflected light at a certain ratio, and a retroreflective member (130) having a mountain shape. An aerial image (140) is displayed by the light (La) retro-reflected by the retro-reflection member (130), while the light (Lb) retro-reflected is oriented in a direction away from the aerial image (140). As a result, it is possible to suppress the user from observing a false aerial image caused by the regularly reflected light (Lb), and improve the visibility and contrast of the aerial image (140).

Description

Technical Field

[0001] The present invention relates to a display device for displaying an image in the air by utilizing retroreflection. 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] Figure 1 The aerial image display device 10 is a schematic cross-sectional view showing the structure of a conventional aerial image display device. The aerial image display device 10 includes a light source (eg, a display that outputs an image) 20 , a beam splitter 30 that separates incident light into reflected light and transmitted light at a predetermined ratio, and a retroreflective member 40 .

[0009] The image emitted from the light source 20 is reflected on the beam splitter 30, and the reflected light travels toward the retroreflective component 40. The retroreflective component 40 is an optical component that reflects light in the same direction as the incident light, and is composed of, for example, a corner cube type retroreflective element, a triangular pyramid type retroreflective element, a bead type retroreflective element, etc. The light reflected on the retroreflective component 40 travels toward the beam splitter 30 again, and the light that has passed through the beam splitter 30 is diffused again after convergence, and is formed as an aerial image 50 in front of the observer's eyes. The aerial image 50 is formed at a position symmetrical to the light source 20 relative to the surface of the beam splitter 30. The aerial image 50 that the user can observe is limited to the range in which the retroreflective component 40 can be seen from the user's viewpoint via the beam splitter 30.

[0010] Figure 2 (A) is a top view of a corner cube type retroreflective component, Figure 2 (B) is a top view showing a corner cube prism. Figure 2(C) is a schematic cross-sectional view of the retroreflective component. Figure 2 As shown in (B), it has a concave shape formed by combining the right-angled vertices of three isosceles right triangles (the right-angled vertices are the deepest part). The incident light Lin is reflected three times on each surface of the corner cube prism, and the reflected light Lout is emitted in the same direction as the incident light Lin. At this time, an optical path difference D is generated between the incident light Lin and the reflected light Lout.

[0011] Figure 3 (A) is a cross-sectional view showing a specific configuration example of a retroreflective component. The retroreflective component 40 is configured to include: a pattern forming portion 42 formed of a light-transmitting material, a reflective layer 44 (e.g., Al, etc.) formed on the inclined surface of the pattern forming portion 42, an adhesive 46 applied to the upper surface of the pattern forming portion 42, and a phase plate (e.g., a λ / 4 plate) 48 formed on the adhesive 46. The reflective layer 44 functions as a reflective layer, and the thickness including the adhesive 46 and the phase plate 48 is approximately 1 mm or less.

[0012] The light incident on the retroreflective member 40 is reflected multiple times by the reflective layer 44. Figure 3 As shown in (B), the reflected light Lout is emitted in the same direction as the incident light Lin. The reflected light La after retroreflection according to the optical characteristics of the retroreflective member 40 is the intended light (or desired light).

[0013] On the other hand, part of the light incident on the retroreflective member 40 is reflected on the surface of the phase plate 48 (reflected light L1). Figure 3 As shown in (C), the regularly reflected light is reflected at the relationship of the incident angle θ=the reflection angle θ, which is light that does not depend on the optical characteristics of the retroreflective member 40, that is, the unintended light Lb.

[0014] Figure 4 As described above, if the retroreflective component 40 generates unexpected reflected light Lb due to regular reflection, a pseudo aerial image is generated due to the reflected light Lb, and the pseudo aerial image is reflected in the range where the user observes the aerial image 60, causing the visual recognition or contrast of the aerial image 60 to decrease.

[0015] An object of the present invention is to solve such conventional problems and to provide a display device with improved visibility and contrast of an aerial image.

[0016] Means used to solve the problem:

[0017] The display device involved in the present invention can display an aerial image by using retroreflection, and includes: a light source that outputs an image; an optical component that separates incident light into reflected light and transmitted light in a certain ratio; and a retroreflective component that reflects light incident from the optical component, and light representing the image is incident on the retroreflective component via the optical component, and the aerial image is displayed by the light reflected by the retroreflective component, and the retroreflective component is inclined in a manner so that light generated by regular reflection of a portion of the light incident from the optical component is directed toward a direction away from the aerial image.

[0018] In one embodiment, the retroreflective member includes a first reflective surface and a second reflective surface intersecting the first reflective surface at a certain angle. In one embodiment, the retroreflective member is inclined relative to the main surface of the optical member. In one embodiment, the retroreflective member is inclined in a manner that light generated by regular reflection of a portion of light incident from the optical member deviates from the user's field of view.

[0019] Effect of the invention:

[0020] According to the present invention, the retroreflective component is tilted in a manner so that light generated by regular reflection of a portion of light incident from the optical component is directed toward a direction away from the aerial image, thereby suppressing the user from observing a pseudo aerial image caused by regular reflection within the range of observing the aerial image, thereby improving the visual recognizability and contrast of the aerial image. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram showing a configuration example of a conventional aerial image display device utilizing retroreflection.

[0022] Figure 2 is a diagram illustrating the optical properties of a corner cube type retroreflective component, Figure 2 (A) is the top view, Figure 2 (B) is a corner cube prism, Figure 2 (C) is a cross-sectional view.

[0023] Figure 3 (A) is a cross-sectional view showing a configuration example of a retroreflective component, Figure 3 (B) is a diagram schematically showing the relationship between incident light and reflected light on a reflector, etc. Figure 3 (C) is a diagram schematically showing the relationship between incident light and reflected light on the retroreflective plate.

[0024] Figure 4 A diagram for explaining problems of conventional aerial image display devices.

[0025] Figure 5It is a perspective view showing a schematic structure of an aerial image display device according to the first embodiment of the present invention.

[0026] Figure 6 is a diagram schematically showing the relationship between various parts and optical paths of a conventional aerial image display device. Figure 6 (A) is a stereogram viewed from above. Figure 6 (B) is the main view, Figure 6 (C) is a top view. Figure 6 (D) is a side view.

[0027] Figure 7 is a diagram schematically showing the relationship between the various parts and the optical path of the aerial image display device involved in the first embodiment of the present invention, Figure 7 (A) is a stereogram viewed from above. Figure 7 (B) is the main view, Figure 7 (C) is a top view. Figure 7 (D) is a side view.

[0028] Figure 8 (A) is Figure 7 (C) is a cross-sectional view of the YY line, Figure 8 (B) is Fig.10 (C) Y1-Y1 line cross-sectional view.

[0029] Fig. 9 It is a diagram showing a modified example of the first embodiment.

[0030] Fig.10 is a diagram schematically showing the relationship between the various parts and the optical path of the aerial image display device involved in the second embodiment of the present invention, Fig.10 (A) is a stereogram viewed from above. Fig.10 (B) is the main view, Fig.10 (C) is a top view. Fig.10 (D) is a side view.

[0031] Description of reference numerals:

[0032] 100, 100A, 100B: Aerial image display device

[0033] 110: Light source

[0034] 120: Beam splitter

[0035] 130, 150: Retroreflective components

[0036] 130A: 1st reflective surface

[0037] 130B: Second reflective surface

[0038] 130C: Top edge

[0039] 140: Aerial Image DETAILED DESCRIPTION

[0040] The display device of the present invention displays an image in the air by the AIRR method. The display device of the present invention can be applied to a user input interface using an aerial image. 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.

[0041] [Example]

[0042] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 5 1 is a perspective view showing the structure of an aerial image display device according to the first embodiment of the present invention. As shown in the figure, the aerial image display device 100 of the present embodiment is composed of: a light source 110 such as a display for displaying an image, a beam splitter (or a half mirror) 120 for separating incident light into transmitted light and reflected light in a certain ratio, and a mountain-shaped retroreflective component 130, and an aerial image 140 for displaying the image output to the light source 110 by the AIRR method.

[0043] In this embodiment, a characteristic configuration is that the retroreflective member 130 does not have a flat surface but has a mountain shape, thereby preventing the unintended reflected light Lb generated by the retroreflective member 130 from entering the field of view of the aerial image 140 as much as possible.

[0044] Figure 6 It is schematically indicated Figure 4 A stereoscopic view, a front view, a top view, and a side view showing the relationship between each part of a conventional aerial image display device and incident light / reflected light, Figure 7 It is a stereoscopic view, a front view, a top view, and a side view schematically showing the relationship between each part of the aerial image display device of the first embodiment and the incident light / reflected light. Figure 8 (A) is Figure 7 The operation of the aerial image display device of this embodiment will be described with reference to these figures.

[0045] like Figure 6As shown, in the conventional aerial image display device 10, a light source 20 and a retroreflective member 40 are respectively arranged below a beam splitter 30. The retroreflective member 40 has a substantially flat main surface, and displays an aerial image 50 by reflecting light La in the same direction as the incident light. On the other hand, since the main surface of the retroreflective member 40 is flat, the light Lb reflected by the retroreflective member 40 travels in the direction of the aerial image 50. If the light Lb reflected by the retroreflective member 40 enters the range (field of view) where the user can observe the aerial image 50, it appears as a pseudo aerial image.

[0046] In contrast, in the aerial image display device 100 of the present embodiment, as shown in FIG. Figure 7 As shown in FIG. 1 , the retroreflective member 130 has a mountain-shaped reflecting surface. Except for the configuration of the retroreflective member 130 , the other configurations are the same as those of the conventional aerial image display device 10 .

[0047] Here, the beam splitter 120 is configured such that its main surface is parallel to the XY plane. Figure 7 As shown in (C), it is a rectangle in the XY plane, having a first side 120X in the X direction and a second side 120Y in the Y direction. In addition, when the normal direction of the light source 110, such as the display surface of the display, is taken as the optical axis, the direction when the optical axis is projected onto the XY plane is the X direction, and is parallel to the first side 120X.

[0048] In a certain embodiment, the retroreflective member 130 has a first reflecting surface 130A which is substantially flat and rectangular, a second reflecting surface 130B which is substantially flat and rectangular, and a top side 130C where the first reflecting surface 130A and the second reflecting surface 130B intersect. The first reflecting surface 130A and the second reflecting surface 130B may be formed by bending one retroreflective member, or may be formed by combining two retroreflective members with an adhesive or the like. In addition, the first reflecting surface 130A and the second reflecting surface 130B may be configured to be symmetrical with respect to the top side 130C, or may be configured to be asymmetrical with respect to the top side 130C.

[0049] The retroreflective member 130 is configured such that the direction when the top edge 130C is projected onto the XY plane is parallel to the X direction, that is, the optical axis on the XY plane, and the top edge 130C is inclined in the Z direction relative to the main surface of the beam splitter 120. As a result, Figure 8 As shown in the YY line cross section of (A), the first reflecting surface 130A and the second reflecting surface 130B are inclined from the top edge 130C toward the side and away from the main surface of the beam splitter 120. In addition, the intersection angle α between the first reflecting surface 130A and the second reflecting surface 130B is set so that all or part of the light Lb after regular reflection is directed in a direction deviating from the range in which the user can observe the aerial image 140.

[0050] If the light source 110 outputs an image, the light representing the image is emitted in the direction of the optical axis, and the light is reflected on the beam splitter 120 and the retroreflective component 130, respectively, and then passes through the beam splitter 120 to display the aerial image 140. The retroreflective component 130 has reflecting surfaces 130A and 130B bent in a mountain shape, but based on its optical properties, the reflected light is emitted in the same direction as the incident light. That is, the reflected light La after being retroreflected by the retroreflective component 130, that is, the intended reflected light La, is different from the incident light. Figure 6 The retroreflective member 40 of the conventional aerial image display device 10 shown generates the aerial image 140 in the same manner.

[0051] On the other hand, a part of the light incident from the beam splitter 120 is regularly reflected on the retroreflective member 130, but since the first and second reflecting surfaces 130A and 130B are inclined from the top edge 130C toward the side, the incident angle of the light incident on the first and second reflecting surfaces 130A and 130B becomes larger than when the first and second reflecting surfaces 130A and 130B are not inclined toward the side. Therefore, the reflection angle of the reflected light Lb generated by regular reflection on the first and second reflecting surfaces 130A and 130B becomes larger, and the unintended light Lb caused by regular reflection is directed in a direction away from the aerial image 140. As a result, within the range where the user observes the aerial image 140, it is difficult to observe a pseudo aerial image caused by regular reflection, and the visual recognition and contrast of the aerial image 140 can be improved.

[0052] In the above embodiment, the direction of the top edge 130C when projected onto the XY plane is the X direction, that is, the same direction as the optical axis of the light source 110. However, the retroreflective member 130 may be rotated 90 degrees in the horizontal direction, for example. Fig. 9 In the aerial image display device 100A shown, the direction when the top edge 130C is projected onto the XY plane is the Y direction, which is orthogonal to the direction of the optical axis of the light source 110. In such a configuration, the light Lb after regular reflection by the retroreflective member 130 also goes in the direction away from the aerial image 140, so that the pseudo aerial image is not easily observed by the user.

[0053] Next, a second embodiment of the present invention will be described. Fig.10 is a diagram showing the structure of an aerial image display device 100B according to the second embodiment. Figure 7 The same components as those of the first embodiment are denoted by the same reference numerals.

[0054] In the second embodiment, the retroreflective member 150 provides a substantially flat main surface, but as Figure 8As shown in the Y1-Y1 line section of (B), the retroreflective component 150 is inclined at an angle α relative to the main surface of the beam splitter 120. The direction of the inclination can also be opposite. In other words, the retroreflective component 150 corresponds to one of the first reflecting surface 130A or the second reflecting surface 130B in the first embodiment. The angle α is set so that when a part of the light incident from the beam splitter 120 is reflected by the retroreflective component 150, the light Lb generated by the regular reflection is directed to the direction away from the field of view of the aerial image 140. As a result, the visual recognition and contrast of the aerial image 140 are improved.

[0055] As described above, according to this embodiment, since the light of regular reflection generated by the retroreflective member leaves the aerial image, the user is prevented from observing a pseudo aerial image caused by regular reflection within the range of observing the aerial image, thereby improving the visibility and contrast of the aerial image.

[0056] The shape or size of the beam splitter or retroreflective component shown in the above embodiment is an example, and other shapes or sizes may also be used. In addition, an example in which the retroreflective component has a mountain shape with the first and second reflecting surfaces is shown, but the retroreflective component may also be configured to have more than three reflecting surfaces, such as a triangular pyramid or a quadrangular pyramid. Furthermore, in the optical design of the aerial image, the angle of the mountain shape of the retroreflective component or the inclination angle α of the retroreflective component is appropriately selected.

[0057] The aerial image display device of this embodiment can be applied to user interfaces. For example, the aerial image can be applied to computer devices, vehicle-mounted electronic devices, ATMs in banks, ticket machines in stations, input buttons in elevators, etc.

[0058] 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 aerial images by retroreflection, wherein: include: Light source, output image; Optical components that separate incident light into reflected light and transmitted light in a certain proportion; as well as a retroreflective member that reflects light incident from the optical member, The light representing the image is incident on the retroreflective member via the optical member, and the aerial image is displayed by the light reflected by the retroreflective member. The retroreflective member is inclined so that light generated by regular reflection of a part of the light incident from the optical member is directed toward a direction away from the aerial image.

2. The display device according to claim 1, wherein: The retroreflective member includes a first reflecting surface and a second reflecting surface intersecting the first reflecting surface at a certain angle.

3. The display device according to claim 1, wherein: The retroreflective member is inclined with respect to the main surface of the optical member.

4. The display device according to claim 1, wherein: The retroreflective member is inclined so that light generated by regular reflection of a portion of light incident from the optical member deviates from a field of view of a user.

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