Space suspension image information display system

Abstract

This spatial floating image information display system is provided with: a display panel (11) for displaying an image; a light source device (13) for the display panel (11); a retro-reflection member (2) that reflects the image light from the display panel (11) and displays spatial floating images (220A, 220B) of real images in the air by means of the reflected light; and a transmissive plate (110) on the surface of which a reflective polarizing plate (111) for changing the optical path of the image light is provided, the transmissive plate (110) being disposed between the retro-reflective member (2) and the display panel (11), and the mounting angle of an optical member and the position of the display panel (11) being adjusted in order to adjust the position at which the spatial floating images (220A, 220B) are formed.

Description

Technical Field

[0001] The invention relates to a space suspended image information display system and an optical system used in the system. Background Art

[0002] As a spatial floating information display system, there are known image display devices that directly display images to the outside and display methods that display images as spatial screens. In addition, for example, Patent Document 1 discloses a detection system that reduces erroneous detection of operations on an operation surface that displays a spatial image.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-128722 Summary of the invention

[0006] Problems to be solved by the invention

[0007] As a spatial floating information display system, there are known an image display device that directly displays an image toward the outside and a display method that displays the image as a spatial screen.

[0008] However, in the above-mentioned prior art spatial suspended image information display system, no means are considered to prevent the adverse situation caused when external light is incident on the retro-reflective component that generates the spatial suspended image. As a spatial suspended information display system, as a spatial image information display unit that can set the display position of the spatial suspended image according to customer requirements and a detection system that operates the displayed image in space, no optimization technology for the design including the light source of the image display device that becomes the image source of the spatial suspended image is considered.

[0009] The purpose of the present invention is to form a unit structure in a spatial floating information display system or a spatial floating image display device that has high visibility (resolution and contrast of appearance), can display a spatial floating image with reduced influence of external light, and can change the display position of the spatial floating image according to customer requirements, and to provide a method for operating the displayed image with high precision and a technology for displaying appropriate images.

[0010] Means for solving problems

[0011] In order to solve the above-mentioned problems, for example, a structure described in the scope of patent protection is adopted. The present application includes multiple means for solving the above-mentioned problems, and a spatial suspended image display device is cited as an example thereof. As an example of the present application, a spatial suspended image information display system includes a display panel in a unit, which displays an image; a light source device for the above-mentioned display panel; a retroreflective component, which reflects the image light and displays a real image of a spatial suspended image in the air; and an optical component, which temporarily transmits the image light from the above-mentioned display panel, and reflects the image light reflected by the retroreflective component with a λ / 4 plate provided on the surface. As a structure capable of changing the interval between the above-mentioned display panel and the optical component, a structure is provided so that the above-mentioned spatial suspended image is displayed at a desired position in the front-to-back direction, and the above-mentioned unit can be temporarily rotated, thereby displaying the above-mentioned spatial suspended image at a desired position in the up-down direction.

[0012] Effects of the Invention

[0013] According to the present invention, even if external light is incident, the image quality of the spatial floating image will not be reduced, and the spatial floating image information is appropriately displayed. In addition, the display position of the spatial floating image can be arbitrarily set. Moreover, the spatial floating image display device can perform operation input without directly touching the display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a principle diagram for explaining the principle and problem of forming a space floating image in the space floating image information display system of the present invention.

[0015] Figure 2 The figure shows the appearance and main structure of an embodiment of a spatial floating image information display unit according to one embodiment of the present invention, and the position where a spatial floating image is generated.

[0016] Figure 3 This is an explanatory diagram for explaining the appearance of a space floating image information system according to an embodiment of the present invention, a generation position of a space floating image, and horizontal and vertical viewing ranges.

[0017] Figure 4 It is a diagram showing the appearance and main part structure of a second embodiment of another spatial floating image information display system according to one embodiment of the present invention.

[0018] Figure 5 It is an explanatory diagram for explaining a sensing unit provided in the spatial floating image information display system according to an embodiment of the present invention.

[0019] Figure 6 This is a diagram showing another example of the specific structure of the light source device according to one embodiment of the present invention.

[0020] Fig. 7AThis is a structural diagram showing another example of the specific structure of a light source device of another embodiment.

[0021] Figure 7B This is a diagram showing a part of another example of a specific structure of a light source device of another embodiment.

[0022] Figure 7C This is a diagram showing a part of another example of a specific structure of a light source device of another embodiment.

[0023] Fig.7D This is a diagram showing a part of another example of a specific structure of a light source device of another embodiment.

[0024] Fig. 8A This is a structural diagram showing another example of the specific structure of a light source device of another embodiment.

[0025] Figure 8B This is a diagram showing another example of a specific structure of a light source device of another embodiment.

[0026] Fig. 9 This is an enlarged view of the surface shape of the light guide diffusion portion, showing another example of the specific structure of the light source device.

[0027] Fig.10 It is a cross-sectional view showing an example of a specific structure of the light source device.

[0028] Fig.11 It is a structural diagram showing an example of a specific structure of a light source device.

[0029] Fig.12 The following are a perspective view, a plan view, and a cross-sectional view showing an example of a specific structure of the light source device.

[0030] Fig.13 It is a perspective view and a plan view showing an example of a specific structure of the light source device.

[0031] Fig.14 This is an explanatory diagram for explaining the light source diffusion characteristics of the image display device.

[0032] Fig.15 This is an explanatory diagram for explaining the light source diffusion characteristics of the image display device.

[0033] Fig.16 This is an explanatory diagram for explaining the diffusion characteristics of the image display device.

[0034] Fig.17 This is an explanatory diagram for explaining the diffusion characteristics of the image display device.

[0035] Fig.18 This is a diagram showing a coordinate system for measuring visual characteristics of a liquid crystal panel.

[0036] Fig.19 This is a diagram showing the luminance angle characteristics (longitudinal direction) of a general liquid crystal panel.

[0037] Fig. 20 This is a diagram showing the luminance angle characteristics (short side direction) of a general liquid crystal panel.

[0038] Fig.21 This is a diagram showing the angular characteristics (longitudinal direction) of contrast of a general liquid crystal panel.

[0039] Fig. 22 This is a diagram showing the angular characteristics (in the short-side direction) of the contrast of a general liquid crystal panel. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the present invention is not limited to the contents of the embodiments described below (hereinafter, also referred to as "the present disclosure"). The present invention also relates to the scope of the spirit of the invention or the technical idea described in the patent protection scope or its equivalent scope. In addition, the structures of the embodiments (examples) described below are merely examples, and within the scope of the technical idea disclosed in this specification, those skilled in the art can make various changes and corrections.

[0041] In addition, in the drawings used to illustrate the present invention, the same figure marks are marked on parts having the same or similar functions, different names are used as appropriate, and on the other hand, repeated descriptions of functions, etc. are sometimes omitted. In addition, in the description of the following embodiments, the term "spatial floating image" is used to express an image suspended in space. This term can also be replaced by "aerial image", "spatial image", "aerial floating image", "spatial floating optical image of displayed image", "aerial floating optical image of displayed image", etc. The term "spatial floating image" mainly used in the description of the embodiments is used as a representative example of these terms.

[0042] The present disclosure relates to an information display system, which can transmit, for example, an image of image light from a large-area image light source through a transparent component that divides a space, such as a glass of a shop window, and display it as a spatially suspended image inside or outside a store (space). In addition, the present disclosure relates to a large-scale digital signage system composed of a plurality of such information display systems.

[0043] According to the following embodiments, for example, high-resolution image information can be displayed in a spatially suspended state on a glass surface of a display window or a light-transmitting plate. At this time, by making the divergence angle of the emitted image light smaller, even if it is an acute angle, and unifying it into a specific polarized wave, the retro-reflective component can efficiently reflect only regular reflected light. Therefore, the light utilization efficiency is high, and the ghost image generated in addition to the main spatially suspended image and the colored reflected light generated by the external light incident on the retro-reflective component, which have become problems in the previous retro-reflective method, can be suppressed, and a clear spatially suspended image can be obtained.

[0044] In addition, a device including the light source disclosed in the present invention can provide a novel spatial floating image information display system that can significantly reduce power consumption and is easy to use. In addition, according to the technology disclosed in the present invention, for example, a vehicle-use floating image information display system can be provided, which can display a so-called unidirectional spatial floating image, which can be visually confirmed outside the vehicle through shielding glass including the front glass, rear glass, and side glass of the vehicle.

[0045] On the other hand, in the existing spatial floating image information display system, as a high-resolution color display image source, an organic EL panel or a liquid crystal display panel (liquid crystal panel or display panel) is combined with a retro-reflective component. In the first retro-reflective component 2 used in the spatial floating image display device of the prior art, since the image light is diffused at a wide angle, Figure 1 In addition to the reflected light regularly reflected by the retro-reflective component of the first embodiment composed of a polyhedron, as shown in (B), Figure 1 As shown in (B), since the shape used in the retro-reflective portion 2a is a hexahedron, multiple ghost images are generated due to the image light incident from an oblique direction, which impairs the image quality of the spatial floating image. In addition, the same spatial floating image is also viewed as a ghost by people other than the viewer, which is also a major issue from the perspective of safety.

[0046] Next, the function of the retro-reflective component used in the space floating image display device and a specific embodiment of the space floating image display device are described. Figure 1As shown in (A), the reflective polarizing plate 101 reflecting light of a specific polarized wave provided on the second transmissive plate 100 provided at an angle of approximately 45 degrees relative to the image display device 1 is reflected, and a spatial floating image is obtained by the retro-reflective member 2 provided at approximately 45 degrees relative to the second transmissive plate 100 or the reflective polarizing plate 101. A λ / 4 plate 21 is provided on the surface of the retro-reflective member 2, and the image light is converted into another polarized wave by a phase difference plate before entering the retro-reflective member 2 and being reflected, and then passes through the reflective polarizing plate 101 and the absorptive polarizing plate 102 provided on the second transmissive plate 100, and a spatial floating image is obtained in the space separated by the second transmissive plate 100.

[0047] like Figure 1 As shown in (B), the retroreflective component 2 forms a structure in which polyhedral reflective surfaces are arranged and configured, and the image light is reflected twice by the polyhedron 2a (a hexahedron in the figure) to become retroreflected light, forming a spatial floating image. At this time, the resolution of the aerial floating image is usually determined by the spacing per unit area of ​​the polyhedron 2a set in the retroreflective component 2. The spatial image 220 formed by the image light reflected by the retroreflective component 2 is formed in the space separated by the second transmissive plate 100, and the distance from the retroreflective component 2 to the spatial image 220 is the same as the optical distance from the image display device 1 to the retroreflective component 2. At this time, if the diffusion angle of the image light is large, abnormal light other than the image light regularly reflected by the polyhedron set on the reflective surface of the retroreflective component 2 is generated, so that ghost images g1 and g2 are generated around the regular spatial image 220 (generated according to the number of reflective surfaces, but Figure 1 In order to reduce the ghosting, the diffusion angle of the light source 13 provided in the image display device 1 can be made narrow as described later.

[0048] <Configuration example of the first retro-reflective optical system or retro-reflective optical unit forming the spatial floating image information display system>

[0049] Figure 2 (A) represents an example of a method for realizing a regressive optical system (hereinafter also referred to as a "unit") of the spatial floating image information display system disclosed in the present invention. In addition, Figure 2 (B) describes the overall structure of the spatial suspended image information display system in this embodiment. The spatial suspended image display system or spatial suspended image display device having the light source device 13, the display panel 11, the retro-reflective component 2 and the first transparent plate 110 is assembled into a housing, and a part of the housing is provided with a component connected to the spatial suspended image display system or spatial suspended image display device.

[0050] Reference Figure 2(A), for example, according to the spatial floating information display system of the present disclosure (hereinafter, also referred to as "this system"), when the spatial floating image information display system is arranged on a table relative to an observer of the spatial floating image, the spatial floating image is observed downward. Figure 2 In (A), the image display device 1 and the retro-reflective component 2 are arranged in a manner that they are approximately parallel or parallel to each other. Specifically, the image display surface or image light emitting surface of the display panel 11 constituting the image display device 1 is arranged to face the reflection surface of the retro-reflective component 2. At this time, if the image display device 1 is moved in the left-right direction in the figure along the second transmissive plate 100, the imaging position of the spatial floating image ( Figure 2 The (A) 220A, 220B) moves up and down according to the movement amount. Figure 2 As shown in (A), the left-right movement of the image display device 1 here refers to the movement in the direction toward the retro-reflective component 2 and the direction away from the retro-reflective component 2. That is, even in the same system, by changing the position of the image display device 1, the imaging position of the spatial floating image can be arbitrarily changed.

[0051] The following describes the functions of the optical components constituting the above-mentioned retro-reflective optical system. The image display device 1 is composed of a light source device 13 having a narrow-angle diffusion characteristic and a liquid crystal display panel 11. As a result, in the spatial information display system of the present invention, image light of a specific polarized wave having a narrow-angle diffusion characteristic is obtained and directed toward the first transmissive plate 110. A reflective polarizing plate sheet 111 having a function as a polarization beam splitter is provided on one side surface of the first transmissive plate 110, but the light of the specific polarized wave from the image display device 1 is transmitted. At this time, a reflection prevention film or a sheet 113 having a moth-eye structure on the surface may be provided on the light incident surface of the first transmissive plate 110, and the moth-eye structure has the characteristic that the reflectivity does not change with respect to the incident angle and wavelength of the light.

[0052] The image light transmitted through the first transmissive plate 110 is retroreflected by the retroreflective member 2. The first transmissive plate 110 is arranged at an inclination angle θ1 (approximately 45 degrees) relative to the optical axis connecting the image display device 1 and the retroreflective member 2. When the inclination angle θ1 is set to be greater than 45 degrees, Figure 2 The imaging position of the air-floating image 220A shown in (A) is moved to the left side of the drawing. Figure 2 As described above, if the unit structure of the present invention is adopted, the imaging position of the spatial floating image 220A shown in (A) can be adjusted to a desired position by changing the configuration of the optical components constituting the unit, so that the basic structure of the unit can be made universal and the mass production efficiency can be improved.

[0053] The retroreflective member 2 not only forms retroreflected light, but also converts the image light of the specific polarized wave into another polarized wave through the λ / 4 plate provided on the surface, thereby reflecting through the reflective polarizing plate sheet 111 provided on one side surface of the first transmissive plate 110 and transmitting through the first transmissive plate 110 provided on the upper surface, thereby forming a spatial suspended image 220A. An antireflection film may be provided on the air side interface of the λ / 4 plate 21 provided on the surface of the retroreflective member 2, or a sheet 104 having a moth-eye structure on the surface, the moth-eye structure having a characteristic that the reflectivity does not change with respect to the incident angle and wavelength of the light.

[0054] By moving the image display device 1 in the left-right direction of the drawing to any position, the position where the spatial floating image 220A is generated can be set to, for example, the position 220B. Figure 2 As shown in (A), the image display device 1 and the retro-reflective component 2 are arranged to be substantially parallel or parallel to each other. At this time, if the suspension amount of the spatially suspended image (the distance from the first transparent plate 110) is to be increased, it is sufficient to increase the distance from the image display device 1 to the retro-reflective component 2. Figure 2 In the embodiment shown in (A), the image display device 1 can be moved to the right to be set. The floating amount here is the distance from the first transparent plate 110 to the spatial floating image.

[0055] The spatial suspended image display system or spatial suspended image display device of this embodiment may have a structure of moving the image display device 1 or the display panel 11. Specifically, the image display device 1 is fixed to the housing via an elastic component. In addition, the spatial suspended image display system or spatial suspended image display device may also have a structure for adjusting the configuration angle of the first transmittance plate 110. Specifically, the first transmittance plate 110 is fixed to the housing via an elastic component.

[0056] Therefore, the imaging position of the spatial suspended image changes according to the distance between the image display device 1 (or the display panel 11) and the first transmittance plate 110. That is, when the configuration angle of the first transmittance plate 110 is constant, the imaging position of the spatial suspended image is a position determined by the distance between the image display device 1 or the display panel 11 and the first transmittance plate 110. Alternatively, the imaging position of the spatial suspended image changes according to the configuration angle of the first transmittance plate 110. That is, when the distance between the image display device 1 and the first transmittance plate 110 is constant, the imaging position of the spatial suspended image is a position determined by the configuration angle of the first transmittance plate 110.

[0057] In this unit, the distance connecting an arbitrary point of the image display device 1 or the display panel 11 and the corresponding point of the first transmissive plate 110 and the distance connecting an arbitrary point of the spatially suspended image 220A and the corresponding point of the first transmissive plate 110 are equal at all positions in the left-right direction of the spatially suspended image 220A, so that the focusing sense of the formed spatial image is equal in the entire screen area, and a good spatially suspended image can be obtained. Specifically, the distance connecting an arbitrary point of the image light emitting surface of the display panel 11 and the corresponding point of the first transmissive plate 110 and the distance connecting an arbitrary point of the spatially suspended image 220A and the corresponding point of the first transmissive plate 110 are equal at all positions in the left-right direction of the spatially suspended image 220A.

[0058] Furthermore, the external light that enters the unit from the outside of the housing through the second transmissive plate 100 as the opening does not directly enter the surface of the retroreflective member 2 and the image display device 1 that are arranged approximately orthogonal to the first transmissive plate 110 and at a position away from the opening. Furthermore, the light of the same polarization wave as the image light of the specific polarization wave from the image display device 1 among the external light that enters the housing passes through the reflective polarizing plate sheet 111 that functions as a polarization beam splitter and is provided on one side surface of the first transmissive plate 110 and is absorbed by the light absorber 106, so that the image quality of the spatial floating image is not affected.

[0059] Moreover, the observer interacts with the spatial floating image by touching it, for example, in order to use it as a key input device, the sensing system 203 described later is arranged at the end of the spatial floating image so that the detection area is larger than the spatial floating image, thereby achieving good performance.

[0060] <Configuration example of a spatial floating image information display system>

[0061] Figure 2 (B) is a diagram showing the structure of the spatial floating image information display system disclosed in the present invention. Figure 2 The functions of the optical components of the unit shown in (A) are as described above, so they are omitted here. The spatial suspended image display system or spatial suspended image display device having the light source device 13, the display panel 11, the retro-reflective component 2 and the first transmissive plate 110 is assembled into a housing, and a part of the housing is provided with a component connected to the spatial suspended image display system or spatial suspended image display device.

[0062] Specifically, by fixing the main body 107 and the rotating structure 108 for supporting the unit, if referring to the spatial suspended image 204 (the imaging positions are shown as A1 and A2), for example, according to the present system disclosed herein, when the present system is arranged opposite to the observer of the spatial suspended image, the spatial suspended image is observed diagonally downward. At this time, in order to optimally arrange the imaging position of the spatial suspended image 204 relative to the present system in the front-to-back direction, if the position of the image display device 1 of the unit shown in the figure is moved in the up-down direction in the figure, it is moved forward and backward (left-right direction in the figure) according to the movement amount. That is, even if it is a system of the same type, by changing the position of the image display device 1, the imaging position of the spatial suspended image can be arbitrarily optimized according to the customer's requirements.

[0063] and Figure 2 (A) Similarly, the retroreflective member 2 not only forms retroreflected light, but also converts the image light of the specific polarized wave into another polarized wave through the λ / 4 plate provided on the surface, thereby reflecting and transmitting the second transmissive plate 100 provided on the upper surface through the reflective polarizing plate sheet 111 provided on one side surface of the first transmissive plate 110, thereby forming a spatial suspended image 220A. An antireflection film may be provided on the air side interface of the λ / 4 plate 21 provided on the surface of the retroreflective member 2, or a sheet 113 having a moth-eye structure on the surface, the moth-eye structure having a characteristic that the reflectivity does not change with respect to the incident angle and wavelength of the light.

[0064] By moving the image display device 1 in the vertical direction of the drawing, the position of the space floating image 204 can be set arbitrarily, for example, in the front-back direction toward the observer. At this time, if the floating amount of the space floating image (the distance from the second transparent plate 100) is to be increased, it is sufficient to increase the distance from the image display device 1 to the retroreflective member 2. Figure 2 In the embodiment shown in (B), the image display device 1 can be moved upward to set. Figure 2 As shown in (B), moving the setting position of the image display device 1 in the vertical direction here means moving the image display device 1 in the vertical direction along the second transparent plate 100, or moving the image display device 1 in the vertical direction relative to the second transparent plate 100.

[0065] In this unit, the distance connecting the center point of the image display device 1 or display panel 11 and the corresponding point of the first transmissive plate 110 and the distance connecting the center point of the spatial suspended image 204 and the corresponding point of the first transmissive plate 110 are equal at all positions in the vertical direction of the spatial suspended image, so the focus of the formed spatial image is equal in the entire screen area, and a good spatial suspended image can be obtained. The center point of the image display device 1 or display panel 11 here is the center point of the image light emitting surface of the image display device 1 or display panel 11.

[0066] In addition, external light that is transmitted from the outside of the shell through the second transparent plate 100 serving as an opening and enters the unit does not directly enter the surface of the retroreflective component 2 and the image display device 1 that are approximately orthogonal to the second transparent plate 100 and are arranged at a position away from the opening, and therefore does not affect the image quality of the spatially suspended image.

[0067] In addition, by interacting with the spatial floating image by touching it, for example, in order to use it as a key input device, the sensing system 203 described later is arranged inside the housing, thereby realizing a sensing system that reduces the influence of the use environment. In this case, the near-infrared light used for sensing passes through the first transmissive plate 110, so it does not affect the sensing performance. In addition, by making the detection area of ​​the sensing system larger than the spatial floating image 204, good performance can be obtained.

[0068] <Example of spatial floating image information display system>

[0069] Figure 3 (A) is a diagram showing the appearance of the spatial floating image information display system disclosed in the present invention. Figure 2 The unit shown in (B) generates a spatial suspended image A1 at a desired position by being fixed to a main body 107 and a rotating structure 108 (not shown) for supporting the unit. The formation position of the spatial suspended image can be changed by changing the setting angle θ3 of the unit configured inside the system. For example, when the reference setting position is A1, in order to make the formation position of the spatial suspended image the upper A2, the angle θ3 of the entire unit is made greater than the reference angle. Alternatively, the installation angle θ4 of the retroreflective component 2 can be set to an angle opened relative to the image display device 1. In addition, the same effect can be obtained even if the setting angle θ5 of the second transmissive plate 100 provided with the reflective polarizing plate sheet 101 is tilted more relative to the opening of the shell. At this time, the detection area 205 of the above-mentioned sensing system can be determined to include all spatial suspended images whose formation positions are changed according to the configuration of the optical components constituting the unit.

[0070] <Diffusion characteristics control technology for image display devices>

[0071] In the embodiment of the present invention, for the diffusion distribution of the image light from the liquid crystal display panel 11 as the image source of the image display device 1, the diffusion characteristics of the light source device 13 are adjusted by the shape and surface roughness of the surface of the light guide. In addition, the emission direction of the image light is controlled by providing a biconvex lens between the retroreflective component 2 and the liquid crystal display panel 11 or on the surface of the liquid crystal display panel 11 and optimizing the shape of the lens. That is, by optimizing the shape of the biconvex lens, the emission characteristics of the image light (hereinafter also referred to as "image light beam") emitted in one direction from the liquid crystal display panel 11 can be adjusted.

[0072] As an alternative or in addition, a microlens array may be arranged in a matrix on the surface of the liquid crystal display panel 11 (or between the light source device 13 and the liquid crystal display panel 11), and the arrangement may be adjusted. That is, by adjusting the arrangement of the microlens array, the emission characteristics of the image light beam emitted from the image display device 1 in the X-axis and Y-axis directions can be adjusted, and as a result, an image display device having a desired diffusion characteristic can be obtained.

[0073] As a further structural example, two biconvex lenses may be combined and arranged at the position where the image light emitted from the image display device 1 passes, or a microlens array may be arranged in a matrix to set a sheet for adjusting diffusion characteristics. By setting the structure of the optical system as such, the brightness (relative brightness) of the image light can be adjusted in the X-axis and Y-axis directions according to the reflection angle of the image light (the reflection angle based on the case of reflection in the vertical direction (0 degrees)).

[0074] In this embodiment, by using such a biconvex lens, Figure 3 (B) in "Example 1 (ZY direction)" and Figure 3 As shown in the graph (plotted curve) of (C) "Example 2 (ZX direction)", different diffusion characteristics can be obtained in each plane. Specifically, Figure 3 (B) "Example 1 (ZY direction)" and Figure 3 As shown in the graph of (C) "Example 2 (ZX direction)", by setting the horizontal viewing angle characteristic of the spatial floating image information device as characteristic O in the ZX plane, the diffusion characteristic in the other vertical direction is set to Figure 3 The characteristic A shown in (B) can independently control the diffusion characteristic. As a result, the optimal viewing angle characteristic can be obtained according to the purpose of the spatial floating image display device, and a high-brightness spatial floating image can be obtained compared to an image display device using a light source device with a conventional diffusion characteristic.

[0075] <Second Configuration Example of Spatial Floating Image Information Display System>

[0076] use Figure 4 The second embodiment of the spatial floating image information display system is described. Figure 4 Yes Figure 2 In the diagram (B) where the unit is arranged inside the housing 121, a sensing unit (not shown) is provided inside the first transmissive plate 110 to ensure a sensing area 205 of a sufficient size for the spatially suspended image A1. Figure 5 The sensing unit 203 shown is arranged inside the housing 121, and an O-ring or the like is provided on the housing side of the first transmissive plate 110 to prevent the intrusion of external moisture. The sensing unit 203 for sensing in the sensing area 205 covering the imaging area A1 of the spatial floating image display device is arranged inside the housing 121, and the sensing area is formed by transmitting the first transmissive plate 110.

[0077] In the second embodiment of the image information display system described above, the user can also perform spatial operation input on the displayed spatial floating image A1. In addition, the results of evaluating the contact of a finger using an actual device in the prototype show that by making the imaging position of the spatial floating image A1 more than 50 mm away from the first transparent plate 110, the operator can perform spatial operation input on the image information display system without touching the screen.

[0078] In addition, similarly to the above, Figure 4 The structure described in the embodiment can also be assembled into various display devices such as ATMs, automatic ticket machines, self-service terminals, and fixed display devices.

[0079] <Technical means for sensing spatial images>

[0080] The following describes a sensing technology for a viewer (operator) to virtually operate a spatial floating image via a spatial floating image display device for bidirectional connection with an information system.

[0081] In the spatial floating image information system, a two-dimensional sensor described later is used to read sensing information together with the spatial floating image, thereby enabling image manipulation of the displayed image.

[0082] The following describes a sensing technology for a viewer (operator) to virtually operate a spatial floating image via a spatial floating image display device for bidirectional connection with an information system. Figure 5This is a schematic diagram for explaining the sensing technology. A distance measuring device 203 is provided, and the distance measuring device 203 has a built-in TOF (Time of Flight) system corresponding to the space floating image. The LED (Light Emitting Diode) that emits near-infrared light as a light source is made to emit light in synchronization with the signal of the system. An optical element for adjusting the divergence angle is provided on the light emitting side of the LED, and a pair of highly sensitive avalanche diodes with a time resolution of picoseconds are arranged as a pair in the horizontal direction in a manner corresponding to the area as a light receiving element.

[0083] The LED as a light source emits light synchronously with the signal from the system, and the phase Δt is offset by the time it takes for the light to be reflected by the object to be measured (the tip of the observer's finger) and return to the light receiving unit. The distance to the object is calculated based on the time difference Δt, and the position and movement of the operator's finger are sensed as two-dimensional information together with the position information of multiple sensors arranged in parallel. As a result, a spatial floating information display system or spatial floating image display device with a sensing function that reduces false detection of spatial floating images can be realized.

[0084] <Technology for reducing ghosting>

[0085] When a 7-inch WUXGA (1920×1200 pixels) liquid crystal display panel is used as the liquid crystal panel 11 used in the image display device 1, even if one pixel (one triplet) is approximately 80 μm, for example, as long as the pitch B formed by the transmission portion d2 of the retroreflective portion being 400 μm and the light absorption portion d1 being 20 μm is 420 μm, it is possible to control sufficient transmission characteristics and diffusion characteristics of image light from the image display device that causes the generation of abnormal light in the retroreflective component, thereby reducing ghost images generated on both sides of the spatially suspended image.

[0086] An image light control sheet is provided on the surface of the liquid crystal panel 11. The image light control sheet prevents external light from the outside from invading the interior of the spatial suspended image display device and entering the liquid crystal panel 11, which is also related to the improvement of the reliability of the components. As the image light control sheet, for example, a viewing angle control film (VCF) of Shin-Etsu Polymer Co., Ltd. is suitable, and its structure is to alternately configure transparent silicon and black silicon, and configure synthetic resin on the light incident and emitting surfaces to form a sandwich structure, so that external light can be controlled.

[0087] <Performance of LCD Panel>

[0088] However, the brightness and contrast performance of a general TFT (Thin Film Transistor) liquid crystal panel varies depending on the direction of light emission and the characteristics of the liquid crystal and polarizing plate. Fig.18In the evaluation under the measurement environment shown in the figure, the characteristics of the brightness and viewing angle in the short side (up and down) direction of the panel are as follows Fig. 20 As shown, the characteristics at an angle slightly deviated from the vertical (0 degree) output angle of the panel surface (in this embodiment, +5 degrees) are excellent. The reason is that the characteristics of light twisting in the short side (up and down) direction of the liquid crystal panel will not become 0 degrees when the applied voltage is maximum.

[0089] On the other hand, Fig. 22 As shown, the contrast performance in the short side (up and down) direction of the panel is excellent in the range of -15 degrees to +15 degrees. If matched with the brightness characteristics, the best characteristics are obtained when used within the range of ±10 degrees centered at 5 degrees.

[0090] In addition, the characteristics of brightness and viewing angle in the length direction (left and right) of the panel are as follows Fig.19 As shown, the characteristics at an emission angle perpendicular to the panel surface (emission angle 0 degrees) are excellent. The reason for this is that the characteristic of twisting light on the long side (left-right direction) of the liquid crystal panel is 0 degrees when the applied voltage is maximum.

[0091] Similarly, the contrast performance in the length (left-right) direction of the panel is as follows: Fig.21 As shown, the range of -5 degrees to -10 degrees is excellent, and if it matches the brightness characteristics, the best characteristics are obtained by using the range of ±5 degrees with -5 degrees as the center. Therefore, regarding the emission angle of the image light emitted from the liquid crystal panel, the light is incident on the liquid crystal panel from the direction that obtains the best characteristics through the beam direction conversion unit (reflection surfaces 307, 314, etc.) set in the light guide body of the above-mentioned light source device 13, and light modulation is performed by the image signal, thereby improving the image quality and performance of the image display device 1.

[0092] In order to maximize the brightness and contrast characteristics of the liquid crystal panel as an image display element, the image quality of the spatial floating image can be improved by setting the incident light from the light source to the liquid crystal panel to the above range.

[0093] <Light source light control method>

[0094] In this embodiment, if Figure 6As shown, in order to improve the utilization efficiency of the outgoing light beam from the light source device 13 and significantly reduce power consumption, in the image display device 1 composed of the light source device 13 and the liquid crystal display panel 11, after the light source device 13 is incident on the liquid crystal panel 11 at the maximum incident angle of the characteristics of the liquid crystal panel 11, the image light that has been brightness modulated to match the image signal is emitted toward the retro-reflective component. At this time, in order to reduce the installation volume of the spatial floating image information display system, it is expected to increase the configuration freedom of the liquid crystal panel 11 and the retro-reflective component. In addition, after retro-reflection, in order to form a floating image at a desired position and ensure the best directivity, the following technical means are used.

[0095] On the image display surface of the liquid crystal panel 11, a transparent sheet composed of optical components such as a linear Fresnel lens shown on the front surface of the light direction conversion panel is arranged, and the emission direction of the incident light beam to the retro-reflective optical component is controlled in a state of giving high directivity, so as to determine the imaging position of the spatial suspended image. According to this structure, the image light from the image display device 1 reaches the observer efficiently with high directivity (straightness) like a laser, and as a result, a high-quality suspended image can be displayed with high resolution, and the power consumption of the image display device 1 including the light source device 13 can be greatly reduced.

[0096] <Example 1 of Image Display Device>

[0097] Fig.11 Another example of the specific structure of the image display device 1 is shown. Fig.11 The light source device and Fig.12 The light source device 13 is composed of a housing such as a plastic housing that contains an LED, a collimator, a synthetic diffusion block, a light guide, etc., and a liquid crystal display panel 11 is mounted on its upper surface. In addition, LED (Light Emitting Diode) elements 14a and 14b as semiconductor light sources and an LED substrate on which a control circuit is mounted are mounted on one side of the housing of the light source device 13, and a heat sink (not shown) that is a component for cooling heat generated by the LED elements and the control circuit is mounted on the outer side of the LED substrate.

[0098] In addition, a liquid crystal display panel frame mounted on the upper surface of the housing is mounted with a liquid crystal display panel 11 mounted on the frame and an FPC (Flexible Printed Circuits: flexible wiring substrate) (not shown) electrically connected to the liquid crystal display panel 11. That is, the liquid crystal display panel 11 as a liquid crystal display element and the LED elements 14a and 14b as solid light sources modulate the intensity of the transmitted light based on a control signal from a control circuit (not shown here) constituting the electronic device, thereby generating a display image.

[0099] <Example 1 of light source device of example 1 of image display device>

[0100] Next, refer to Fig.10 as well as Fig.12 (a) and (b) of FIG. 1 describe in detail the structure of the optical system such as the light source device housed in the housing. Fig.10 and Fig.11 14a and 14b constituting the light source are shown in FIG. 14, and they are installed at predetermined positions relative to the collimator 15. In addition, the collimator 15 is formed of a light-transmitting resin such as acrylic. Fig.11 As shown in (b), the collimator 15 has an outer peripheral surface 156 of a conical convex shape obtained by rotating a parabolic cross section, and has a concave portion 153 forming a convex portion (i.e., a convex lens surface) 157 in the central portion of its top (the side in contact with the LED substrate).

[0101] In addition, a convex lens surface 154 protruding outward (or a concave lens surface recessed inward) is provided at the center of the flat surface portion (the side opposite to the top) of the collimator 15. In addition, the parabola 156 forming the outer peripheral surface of the conical shape of the collimator 15 is set within an angle range that allows the light emitted from the LEDs 14a and 14b in the peripheral direction to be totally reflected inside it, or a reflecting surface is formed.

[0102] LEDs 14a and 14b are arranged at predetermined positions on the surface of a circuit board 102. The board 102 is arranged and fixed to the collimator 15 so that the LEDs 14a and 14b on the surface are located at the center of the recess 153 thereof.

[0103] According to this structure, through the above-mentioned collimator 15, the light emitted from the LED 14a or 14b, especially the light emitted from the central part toward the upper side (to the right of the figure), is converged by the two convex lens surfaces 157 and 154 forming the outer shape of the collimator 15 to become parallel light. In addition, the light emitted from other parts toward the peripheral direction is reflected by the parabola forming the outer peripheral surface of the conical shape of the collimator 15, and is similarly converged to become parallel light. In other words, according to the collimator 15 in which a convex lens is formed in its central part and a parabola is formed in its peripheral part, it is possible to extract almost all of the light generated by the LED 14a or 14b as parallel light, which can improve the utilization efficiency of the generated light.

[0104] In addition, a polarization conversion element 21 is provided on the light exit side of the collimator 15. The polarization conversion element 21 may also be referred to as a polarization conversion member. Fig.11As can be seen from (a), the polarization conversion element 21 is composed of a combination of a light-transmitting component having a parallelogram cross section (hereinafter referred to as a parallelogram column) and a light-transmitting component having a triangular cross section (hereinafter referred to as a triangular column), and a plurality of light-transmitting components are arranged in parallel in an array on a plane orthogonal to the optical axis of the parallel light from the collimator 15. Moreover, polarization beam splitters (hereinafter abbreviated as "PBS films") 211 and reflective films 212 are alternately arranged at the interface between these adjacent light-transmitting components arranged in an array, and a λ / 2 plate 213 is provided on the exit surface from which light that is incident on the polarization conversion element 21 and passes through the PBS film 211 is emitted.

[0105] The output surface of the polarization conversion element 21 is also provided with Fig.11 The rectangular composite diffusion block 16 shown in (a) is shown in FIG. That is, the light emitted from the LED 14a or 14b becomes parallel light through the action of the collimator 15 and enters the composite diffusion block 16, and reaches the light guide 17 after being diffused by the texture 161 on the emission side.

[0106] The light guide 17 is formed of a light-transmitting resin such as acrylic acid and has a substantially triangular cross-section (see Fig.11 (b)), and according to Figure 25, the light guide 17 includes: a light guide light incident portion (surface) 171, which is opposite to the output surface of the synthetic diffusion block 16 via the first diffusion plate 18a; a light guide light reflecting portion (surface) 172 forming an inclined surface; and a light guide light output portion (surface) 173, which is opposite to the liquid crystal display panel 11 serving as a liquid crystal display element via the second diffusion plate 18b.

[0107] In the light guide light reflecting portion (surface) 172 of the light guide 17, as shown in the partially enlarged view thereof, Fig.10 As shown, a plurality of reflecting surfaces 172a and connecting surfaces 172b are alternately formed into a sawtooth shape. Furthermore, the reflecting surface 172a (the upper right line segment in the figure) forms an αn (n: a natural number, in this example, for example, 1 to 130) relative to the horizontal plane represented by the single-point dashed line in the figure, and as an example, αn is set to be less than 43 degrees (wherein, more than 0 degrees).

[0108] The light guide incident portion (surface) 171 is formed into a curved convex shape inclined toward the light source side. As a result, parallel light from the emission surface of the synthetic diffusion block 16 is diffused and incident via the first diffusion plate 18a. Fig.10 It can be seen that the light passes through the light guide incident portion (surface) 171 and is slightly bent (deflected) upward to reach the light guide light reflecting portion (surface) 172, where it is reflected to reach the liquid crystal display panel 11 provided on the upper exit surface of the figure.

[0109] According to the image display device 1 described in detail above, it is possible to further improve the light utilization efficiency and its uniform lighting characteristics, and at the same time, the modular S-polarized wave light source device can be manufactured in a small size and at a low cost. In addition, in the above description, the polarization conversion element 21 is installed after the collimator 15, but the present invention is not limited to this. The same function and effect can be obtained by setting it in the light path reaching the liquid crystal display panel 11.

[0110] In addition, on the light reflecting portion (surface) 172 of the light guide, a plurality of reflecting surfaces 172a and connecting surfaces 172b are alternately formed in a sawtooth shape, and the illumination light beam is totally reflected on each reflecting surface 172a and directed upward, and then, an angle diffusion plate is provided on the light emitting portion (surface) 173 of the light guide, and the illumination light beam is incident on the light direction changing panel 54 for adjusting the directional characteristics as a substantially parallel diffused light beam, and is incident on the liquid crystal display panel 11 from an oblique direction. The outgoing light of the image display device 1 is adjusted in the outgoing direction by the light direction changing panel 54 provided on the upper surface of the light source device 13. As a result, the outgoing light from the liquid crystal display panel 11 is also controlled, and the light diffusion direction of the spatial floating image obtained by the spatial floating image information system using the image display device 1 is controlled. In the present embodiment, the light direction changing panel 54 is provided between the light guide emitting surface 173 and the liquid crystal display panel 11, but even if it is provided on the outgoing surface of the liquid crystal display panel 11, the same effect can be obtained.

[0111] The light emitted from the liquid crystal display panel 11 is generally used in a TV device, for example, Fig.17 "Conventional characteristics (X direction)" in (A) and Fig.17 As shown in the plot curve of "Conventional Characteristics (Y Direction)" in (B) of FIG. 30 , the display direction in the horizontal direction of the screen (the display direction corresponding to the X-axis of the graph of (A) of FIG. 30 ) and the vertical direction of the screen (the display direction corresponding to the X-axis of the graph of (A) of FIG. 30 ) are shown. Fig.17 The Y-axis of the curve graph (B) corresponds to the display direction) and has the same diffusion characteristics.

[0112] In contrast, the diffusion characteristics of the outgoing light beam from the liquid crystal display panel of this embodiment become, for example, Fig.17 (A) in "Example 1 (X direction)" and Fig.17 The diffusion characteristics shown in the plotted curve of "Example 1 (Y direction)" in (B).

[0113] In a specific example, when the viewing angle is set to 13 degrees so that the brightness is 50% (reduced to about half the brightness) relative to the front observation (angle 0 degrees), the angle is about 1 / 5 relative to the diffusion characteristics of a general home TV device (angle 62 degrees). Similarly, in an example where the vertical viewing angle is set to be unequal on the upper side and the lower side, the reflection angle of the reflective light guide, the area of ​​the reflection surface, etc. are optimized in such a way that the viewing angle on the upper side is suppressed (narrowed) to about 1 / 3 relative to the viewing angle on the lower side.

[0114] By setting the viewing angle and the like as described above, the amount of light of the image in the viewing direction of the user is significantly increased (the brightness of the image is greatly improved) compared to conventional liquid crystal TVs, and the brightness of the image is increased by more than 50 times.

[0115] Moreover, in the setting Fig.17 In the case of the viewing angle characteristics shown in "Example 2", when the viewing angle is set to 5 degrees relative to the brightness of the image obtained by front observation (angle 0 degrees) becoming 50% brightness (reduced to about half brightness), the angle becomes about 1 / 12 (narrow viewing angle) relative to the diffusion characteristics of a general home TV device (angle 62 degrees). Similarly, in an example of setting the vertical viewing angle equally on the upper and lower sides, the reflection angle and the area of ​​the reflection surface of the reflective light guide are optimized in a manner that the vertical viewing angle is suppressed (narrowed) to about 1 / 12 relative to the previous one.

[0116] By making such settings, the brightness (amount of light) of the image in the viewing direction (the direction of the user's line of sight) is greatly improved compared to conventional liquid crystal TVs, and the brightness of the image becomes more than 100 times.

[0117] As described above, by setting the viewing angle to an included angle, the amount of light beams in the viewing direction can be concentrated, thereby greatly improving the light utilization efficiency. As a result, even if a general liquid crystal display panel for TV use is used, by adjusting the light diffusion characteristics of the light source device, a significant increase in brightness can be achieved with the same power consumption, and it can become an image display device corresponding to an information display system facing bright outdoor environments.

[0118] When a large liquid crystal display panel is used, light from the periphery of the screen is directed inward so as to be directed toward the observer when the observer faces the center of the screen, thereby improving the overall brightness of the screen. Fig.14This is a diagram for finding the convergence angle between the long side of the LCD panel and the short side of the LCD panel when the distance L from the LCD panel to the observer and the panel size of the image display device (screen ratio 16:10) are used as parameters. In the diagram shown on the upper side, it is assumed that the screen of the LCD panel is set to be vertical (hereinafter also referred to as "vertical use") to watch the image. In this case, as long as the short side of the LCD panel (appropriately refer to Fig.14 The convergence angle can be set to match the direction of the arrow V in the figure.

[0119] As a more specific example, refer to Fig.14 As shown in the curve graph in FIG. 1 , for example, when a 22” panel is used in portrait mode and the viewing distance is 0.8 m, by setting the convergence angle to 10 degrees, image light from each corner (four corners) of the screen can be effectively projected or output toward the observer.

[0120] Similarly, when viewing with a 15" panel in portrait orientation, at a viewing distance of 0.8 m, if the convergence angle is set to 7 degrees, image light from the four corners of the screen can be effectively directed toward the observer. As described above, depending on the size of the liquid crystal display panel and whether it is used in portrait or landscape orientation, image light at the periphery of the screen is directed toward the observer who is in the most suitable position for viewing the center of the screen, thereby improving the overall brightness of the screen.

[0121] As a basic structure, as mentioned above Fig.17 As shown in the figures, a light beam with a narrow-angle directional characteristic is incident on a liquid crystal display panel 11 through a light source device, and brightness modulation is performed to match an image signal, thereby a spatial floating image obtained by reflecting image information displayed on a screen of the liquid crystal display panel 11 through a retroreflective component is displayed outdoors or indoors through a transparent component 100.

[0122] A plurality of other examples of the light source device will be described below. All of these other examples of the light source device can be used instead of the light source device of the above-mentioned example of the image display device.

[0123] When using a large liquid crystal display panel, as described above, light from the periphery of the screen is directed inward toward the observer when the observer is facing the center of the screen, thereby improving the overall brightness of the screen. However, on the other hand, binocular parallax is generated depending on which of the observer's left or right eyes performs visual recognition. Fig.15 Based on the positions of the left and right eyes, the convergence angle between the long side and the short side of the LCD panel is calculated using the distance L from the LCD panel to the observer and the panel size of the image display device (aspect ratio of 16:10) as parameters.

[0124] The smaller the panel size, the closer the viewing distance, and the larger the convergence angle when viewing with both eyes. In particular, when using a small panel of 7 inches or less, the convergence angle based on binocular parallax becomes an important factor. Fig.17 The light diffusion characteristics of the light source shown are magnified or made directional, and the image light is designed to be directed toward the optimal observation range of the system.

[0125] Furthermore, in order to obtain horizontal and vertical directivity characteristics and diffusion characteristics according to the required specifications of the system, the shape, surface roughness, inclination, etc. of the reflecting surface of the light guide of the above-mentioned light source device 13 need to be optimally designed.

[0126] <Example 1 of light source device>

[0127] Next, refer to Figure 6 Another example of the light source device will be described. Figure 6 (a) and Figure 6 (b) is a diagram in which a portion of the liquid crystal display panel 11 and the diffusion plate 206 are omitted for the purpose of explaining the light guide 311 .

[0128] Figure 6 The LED 14 constituting the light source is shown as being mounted on the substrate 102. The LED 14 and the substrate 102 are mounted at predetermined positions with respect to the reflector 300.

[0129] like Figure 6 As shown in (a), LEDs 14 are arranged in a row in a direction parallel to the side (the short side in this example) of the liquid crystal display panel 11 on the side where the reflector 300 is arranged. In the example shown in the figure, the reflector 300 is arranged corresponding to the arrangement of the LEDs. In addition, a plurality of reflectors 300 may also be arranged.

[0130] In a specific example, the reflectors 300 are formed of plastic materials. As another example, the reflectors 300 can also be formed of metal materials or glass materials, but since plastic materials are easier to shape, plastic materials are used in this embodiment.

[0131] like Figure 6 As shown in (b), the inner side (right side in the figure) of the reflector 300 has a reflecting surface (hereinafter sometimes referred to as "parabola") 305 in a shape obtained by cutting a parabola with a meridian plane. The reflector 300 reflects the divergent light emitted from the LED 14 on the reflecting surface 305 (parabola), thereby converting it into approximately parallel light, and causing the converted light to be incident on the end face of the light guide 311. In a specific example, the light guide 311 is a transmission type light guide.

[0132] The reflecting surface of the reflector 300 is asymmetrical with respect to the optical axis of the emitted light of the LED 14. The reflecting surface 305 of the reflector 300 is a parabola as described above, and by arranging the LED at the focus of the parabola, the reflected light beam is converted into substantially parallel light.

[0133] Since LED 14 is a surface light source, even if it is arranged at the focus of the parabola, it is impossible to convert the divergent light from the LED into completely parallel light, but this does not affect the performance of the light source of the present invention. LED 14 and reflector 300 are a pair. In addition, in order to ensure the predetermined performance when the mounting accuracy of LED 14 to substrate 102 is ±40 μm, the maximum number of LEDs mounted on the substrate should be less than 10, and if mass production is considered, it can be suppressed to about 5.

[0134] Although the LED 14 and the reflector 300 are close to each other in a part, the heat can be dissipated to the space on the opening side of the reflector 300, so the temperature rise of the LED can be reduced. Therefore, the reflector 300 of a plastic molded product can be used. As a result, according to the reflector 300, the shape accuracy of the reflecting surface can be improved by more than 10 times compared with the reflector of glass material, so the light utilization efficiency can be improved.

[0135] On the other hand, a reflecting surface is provided on the bottom surface 303 of the light guide 311. After the light from the LED 14 is converted into a parallel beam by the reflector 300, it is reflected on the reflecting surface and emitted toward the liquid crystal display panel 11 arranged opposite to the light guide 311. Figure 6 As shown in (a), a plurality of faces with different inclinations may exist in the traveling direction of the parallel light beam from the reflector 300. Each of the plurality of faces with different inclinations may have a shape extending in a direction perpendicular to the traveling direction of the parallel light beam from the reflector 300.

[0136] In addition, the shape of the reflective surface provided on the bottom surface 303 may also be a flat shape. In this case, the light reflected by the reflective surface provided on the bottom surface 303 of the light guide 311 is refracted by the refractive surface 314 provided on the surface of the light guide 311 opposite to the liquid crystal display panel 11, so that the light amount and the emission direction of the light beam toward the liquid crystal display panel 11 can be adjusted with high precision. As a result, the light amount and the emission direction of the incident light to the liquid crystal display panel 11 and the emission light from the liquid crystal display panel 11 can also be controlled with high precision, so that in a spatial image information display system using an image display device using this light source, the diffusion direction and the diffusion angle of the image light of the spatial floating image can be set to a desired value.

[0137] like Figure 6As shown in (a) and (b) of FIG. 3 , the refractive surface 314 may also have a plurality of surfaces with different inclinations in the traveling direction of the parallel light beam from the reflector 300. Each of the plurality of surfaces with different inclinations may have a shape extending in a direction perpendicular to the traveling direction of the parallel light beam from the reflector 300. The inclination of the plurality of surfaces causes the light reflected by the reflective surface provided on the bottom surface 303 of the light guide 311 to be refracted toward the liquid crystal display panel 11. In addition, the refractive surface 314 may also be a transmissive surface.

[0138] In addition, when a diffuser 206 is provided in front of the liquid crystal display panel 11, the light reflected by the above-mentioned reflective surface is refracted toward the diffuser 206 due to the above-mentioned multiple inclinations of the refractive surface 314. That is, the extension direction of the multiple surfaces with different inclinations of the refractive surface 314 is parallel to the extension direction of the multiple surfaces with different inclinations of the reflective surface provided on the bottom surface 303. By making the extension directions of the two parallel, the angle of light can be adjusted more appropriately. On the other hand, the LED 14 is soldered to the metallic substrate 102. Therefore, the heat generated by the LED can be dissipated into the air via the substrate.

[0139] In addition, the reflector 300 may be in contact with the substrate 102, or may be separated by a space. In the case of a space, the reflector 300 is bonded and arranged on the housing. By separating the space, the heat generated by the LED can be dissipated into the air, and the cooling effect is improved. As a result, the operating temperature of the LED can be reduced, so that the luminous efficiency can be maintained and the life can be extended.

[0140] <Another example 2 of light source device>

[0141] Next, refer to Fig. 7A , Figure 7B , Figure 7C and Fig.7D To explain in detail and Figure 6 The optical system structure of the light source device shown uses polarization conversion to increase the light utilization efficiency by 1.8 times. Fig. 7A The sub-reflector 308 is omitted in the figure.

[0142] Fig. 7A , Figure 7B as well as Figure 7C The LEDs 14 constituting the light source are shown as being mounted on the substrate 102 , and the reflector 300 and the LEDs 14 are formed as a pair of blocks, and the unit 312 includes a plurality of blocks.

[0143] in, Fig. 7AThe substrate 320 shown in (2) is the substrate of the substrate 102. Generally, since the metallic substrate 102 has heat, in order to insulate the heat of the substrate 102 (heat insulation), the substrate 320 can be made of plastic material or the like. The material and shape of the reflective surface of the reflector 300 can be different from the material of the reflector 300. Figure 6 Examples of light source devices of the same material and shape.

[0144] In addition, the reflective surface of the reflector 300 may also be asymmetrical with respect to the optical axis of the emitted light of the LED 14. Fig. 7A (2) explains the reason. In this embodiment, Figure 6 Similarly to the example of , the reflecting surface of the reflector 300 is a parabola, and the center of the light emitting surface of the LED as the surface light source is arranged at the focal position of the parabola.

[0145] In addition, due to the characteristics of the parabola, the light emitted from the four corners of the light-emitting surface also becomes approximately parallel light beams, but the emission directions are different. Therefore, even if the light-emitting portion has an area, as long as the interval between the polarization conversion element 21 and the reflector 300 arranged at the subsequent stage is short, the amount of light incident on the polarization conversion element 21 and the conversion efficiency are almost unaffected.

[0146] In addition, even if the installation position of LED 14 is offset in the XY plane relative to the focus of the corresponding reflector 300, due to the above reasons, an optical system that can reduce the reduction of light conversion efficiency can be realized. Moreover, even if the installation position of LED 14 deviates in the Z-axis direction, the converted parallel light beam only moves in the ZX plane, which can greatly reduce the installation accuracy of the LED as a surface light source. In this embodiment, a reflector 300 having a reflecting surface that cuts a part of a parabola meridian is also recorded, but an LED can also be configured on the entire surface of the parabola as a part of the cut reflecting surface.

[0147] On the other hand, in this embodiment, if Figure 7B (1) Figure 7C As shown in the figure, the following characteristic structure is formed: the divergent light from the LED 14 is reflected by the parabola 321 and converted into approximately parallel light, which is then incident on the end face of the polarization conversion element 21 at the subsequent stage and is unified into a specific polarization wave by the polarization conversion element 21. Due to this characteristic structure, in this embodiment, the light utilization efficiency is improved compared with the above-mentioned Figure 6 In the example above, the power consumption is 1.8 times that of the conventional light source, which can realize a highly efficient light source.

[0148] In this case, the substantially parallel light reflected by the parabola 321 from the divergent light from the LED 14 is not uniform. Therefore, by using the multiple inclined reflection surfaces 307 to adjust the angular distribution of the reflected light, the reflected light can be incident on the liquid crystal display panel 11 in a direction perpendicular to the liquid crystal display panel 11 .

[0149] Here, in the example of this figure, the direction of the light (main light) entering the reflector from the LED is arranged to be approximately parallel to the direction of the light entering the liquid crystal display panel. This arrangement is easy to arrange in design, and when the heat source is arranged below the light source device, air is discharged upward, thereby reducing the temperature rise of the LED, so it is preferred.

[0150] In addition, as shown in (1) of FIG. 70B , in order to improve the capture rate of the divergent light from the LED 14, the light beam that cannot be captured by the reflector 300 is reflected by the sub-reflector 308 provided on the light shielding plate 309 disposed on the upper part of the reflector, and is reflected by the inclined surface of the sub-reflector 310 at the lower part, and is incident on the effective area of ​​the subsequent polarization conversion element 21, thereby further improving the light utilization efficiency. That is, in this embodiment, a part of the light reflected by the reflector 300 is reflected by the sub-reflector 308, and the light reflected by the sub-reflector 308 is reflected by the sub-reflector 310 in the direction toward the light guide 306.

[0151] The substantially parallel light beams unified into a specific polarized wave by the polarization conversion element 21 are reflected toward the liquid crystal display panel 11 arranged opposite to the light guide 306 by the reflective shape set on the surface of the reflective light guide 306. At this time, the light quantity distribution of the light beam incident on the liquid crystal display panel 11 is optimally designed based on the shape and arrangement of the reflector 300 and the shape (cross-sectional shape) of the reflective surface of the reflective light guide, the inclination of the reflective surface, and the surface roughness.

[0152] As the shape of the reflective surface set on the surface of the light guide 306, multiple reflective surfaces are arranged opposite to the exit surface of the polarization conversion element 21, and the inclination, area, height and spacing of the reflective surfaces are optimized according to the distance from the polarization conversion element 21, thereby making the light amount distribution of the light beam incident on the liquid crystal display panel 11 a desired value as described above.

[0153] like Figure 7BAs shown in (2), the reflecting surface 307 provided on the reflective light guide is configured to have multiple inclinations on one surface, thereby enabling the adjustment of the reflected light to be achieved with higher precision. In addition, in the reflecting surface, as a structure having multiple inclinations on one surface, the area used as the reflecting surface can be multiple surfaces or multiple surfaces or a curved surface. Moreover, a more uniform light distribution is achieved through the diffusion effect of the diffuser 206. The light incident on the diffuser on the side close to the LED achieves a uniform light distribution by changing the inclination of the reflecting surface. As a result, the light amount and the emission direction of the light beam toward the liquid crystal display panel 11 can be adjusted with high precision. As a result, the light amount and the emission direction of the incident light to the liquid crystal display panel 11 and the emission light from the liquid crystal display panel 11 can also be adjusted with high precision, so in a spatial image information display system using an image display device using this light source, the diffusion direction and the diffusion angle of the image light of the spatial suspended image can be set to desired values.

[0154] In this embodiment, a plastic material such as heat-resistant polycarbonate is used as the base material of the reflection surface 307. In addition, the angle of the reflection surface 307 immediately after the light exits the λ / 2 plate 213 changes depending on the distance between the λ / 2 plate and the reflection surface.

[0155] In this embodiment, the LED 14 and the reflector 300 are also close to each other in part, but the heat can be dissipated to the space on the opening side of the reflector 300, which can reduce the temperature rise of the LED. Fig. 7A , Figure 7B , Figure 7C Configured upside down.

[0156] However, if the substrate 102 is disposed above, the substrate 102 is close to the liquid crystal display panel 11, so sometimes the layout becomes difficult. Therefore, as shown in the figure, when the substrate 102 is disposed on the lower side of the reflector 300 (the side away from the liquid crystal display panel 11), the structure in the device becomes simpler.

[0157] like Figure 7C As shown, a shading plate 410 can be provided on the light incident surface of the polarization conversion element 21 so that unnecessary light does not enter the subsequent optical system. By setting such a structure, a light source device that suppresses temperature rise can be realized. In the polarizing plate provided on the light incident surface of the liquid crystal display panel 11, the light beam with consistent polarization of the present invention is absorbed to reduce the temperature rise, but when reflected by the reflective light guide, the polarization direction rotates and a part of the light is absorbed by the incident side polarizing plate. In addition, due to the absorption of the liquid crystal itself and the temperature rise caused by the light incident on the electrode pattern, the temperature of the liquid crystal display panel 11 also rises, but there is sufficient space between the reflective surface of the reflective light guide 306 and the liquid crystal display panel 11, so it can be cooled naturally.

[0158] Fig.7D yes Figure 7B (1) and Figure 7C A modified example of the light source device. Fig.7D (1) Select Figure 7B The modified example is shown as a part of the light source device of (1). Figure 7B The structure of the light source device in (1) is the same as that in the above-mentioned light source device, so the illustration and repeated description are omitted.

[0159] First, in Fig.7D In the example shown in (1), the height of the concave portion 319 of the sub-reflector 310 is adjusted to be lower than the fluorescent body 114 so that the main light of the fluorescent light output from the fluorescent body 114 in the horizontal direction (X-axis direction) is Fig.7D (1), refer to the straight line extending in the direction parallel to the X-axis) from the recessed portion 319 of the sub-reflector 310. Moreover, the height of the light shielding plate 410 is adjusted to be low in the Z-axis direction relative to the position of the fluorescent body 114 so that the main light of the fluorescent light output laterally from the fluorescent body 114 is not blocked by the light shielding plate 410 and enters the effective area of ​​the polarization conversion element 21.

[0160] In addition, the reflective surface of the concavo-convex portion of the top of the sub-reflector 310 reflects the light reflected by the sub-reflector 308 in order to guide the light reflected by the sub-reflector 308 to the light guide 306. Therefore, the height of the convex portion 318 of the sub-reflector 310 is adjusted so that the light reflected by the sub-reflector 308 is reflected and incident on the effective area of ​​the polarization conversion element 21 at the subsequent stage, thereby further improving the light utilization efficiency.

[0161] In addition, if Fig. 7A As shown in (2), the sub-reflector 310 is extended in one direction to form a concave-convex shape. Moreover, at the top of the sub-reflector 310, the concave-convex having one or more concave parts is periodically arranged along one direction. By setting it to such a concave-convex shape, it is possible to configure the main light of the fluorescence output laterally from the fluorescent body 114 to be incident on the effective area of ​​the polarization conversion element 21.

[0162] In addition, the concavo-convex shape of the sub-reflector 310 is periodically arranged at a pitch at which the concave portion 319 reaches the position where the LED 14 is located. That is, the phosphor 114 is periodically arranged in one direction corresponding to the arrangement pitch of the concavo-convex concave portions of the sub-reflector 310. In addition, when the LED 14 has the phosphor 114, the phosphor 114 can also be expressed as a light-emitting portion of the light source.

[0163] in addition, Fig.7D (2) Selection Figure 7CAs for other structures, since it is similar to Figure 7C The structure of the light source device is the same as that of the light source device of FIG. 1 , and therefore illustration and repeated description are omitted. Fig.7D As shown in (2), there may be no sub-reflector 310, but Fig.7D (1) Similarly, the height of the light shielding plate 410 is adjusted to be low in the Z-axis direction relative to the position of the fluorescent body 114 so that the main light of the fluorescent light output laterally from the fluorescent body 114 is not blocked by the light shielding body 410 and is incident on the effective area of ​​the polarization conversion element 21.

[0164] In addition, about Fig. 7A , Figure 7B , Figure 7C , Fig.7D Light source device, such as Fig. 7A As shown in (1), in order to prevent dust from entering the space between the reflective surface of the reflective light guide 306 and the liquid crystal display panel 11, to prevent stray light from being generated to the outside of the light source device, and to prevent stray light from invading from the outside of the light source device, a side wall 400 may also be provided. When the side wall 400 is provided, it is configured in a manner that separates the space between the light guide 306 and the diffuser 206.

[0165] The light output surface of the polarization conversion element 21 that emits the light polarized by the polarization conversion element 21 faces the space surrounded by the side wall 400, the light guide 306, the diffuser 206, and the polarization conversion element 21. In addition, the space ( Figure 7B The surface of the portion of the space on the right side of the exit surface of the polarization conversion element 21 of (1) is a reflective surface having a reflective film or the like. That is, the surface of the side wall 400 facing the above space has a reflective area having a reflective film. By using this portion of the inner surface of the side wall 400 as a reflective surface, the light reflected by the reflective surface can be reused as light source light, which can improve the brightness of the light source device.

[0166] The surface of the inner side of the side wall 400 that covers the portion of the polarization conversion element 21 from the side is set to a surface with low light reflectivity (a black surface without a reflective film, etc.). This is because if reflected light is generated on the side of the polarization conversion element 21, light of an unexpected polarization state is generated, which becomes the cause of stray light. In other words, by setting the above-mentioned surface as a surface with low light reflectivity, the generation of stray light of the image and light of an unexpected polarization state can be prevented or suppressed. In addition, it can also be configured to improve the cooling effect by opening a hole for air to pass through in a part of the side wall 400.

[0167] in addition, Fig. 7A , Figure 7B , Figure 7C , Fig.7D The light source devices of the present invention have been described on the premise of using the polarization conversion element 21. However, the polarization conversion element 21 may be omitted from these light source devices. In this case, the light source device can be provided at a lower cost.

[0168] <Another example 3 of light source device>

[0169] Next, refer to Fig. 8A (1) Fig. 8A (2) Fig. 8A (3) and Figure 8B The optical system structure related to the light source device using the reflective light guide 304 based on the light source device shown in Example 1 of the light source device will be described in detail.

[0170] Fig. 8A The LED 14 constituting the light source is shown mounted on the substrate 102. They are composed of a unit 328 in which the collimator 18 and the LED 14 are set as a pair of blocks and have a plurality of blocks. The collimator 18 of this embodiment is close to the LED 14, so a glass material is used in consideration of heat resistance. The shape of the collimator 18 is the same as the shape described in the collimator 15 of FIG. 7. In addition, by providing a light shielding plate 317 at the front stage of the incident polarization conversion element 21, it is prevented or suppressed that unnecessary light is incident on the optical system of the rear stage, and the temperature rise caused by the unnecessary light is reduced.

[0171] Fig. 8A Other structures and effects of the light source shown are similar to Fig. 7A , Figure 7B , Figure 7C , Fig.7D The same, therefore repeated description is omitted. Fig. 8A The light source device can also be used with Fig. 7A , Figure 7B , Figure 7C The side wall is provided in the same manner as described in . The structure and effect of the side wall are as described above, so repeated description is omitted.

[0172] Figure 8B yes Fig. 8A A cross-sectional view of (2). Figure 8B The structure of the light source shown in FIG. 7 is partially the same as that of the light source shown in FIG. Fig.18 The above has been explained in , so the repeated explanation is omitted.

[0173] <Another example 4 of light source device>

[0174] then, Fig.12 The light source device of FIG. 8 is composed of a unit 328 having a plurality of blocks in which the collimator 18 and the LED 14 are set as a pair of blocks. Fig.12(a), (b), and (c) describe in detail the optical system structure associated with a light source device using LEDs disposed at both ends of the back surface of the liquid crystal display panel 11 and a reflective light guide 504 .

[0175] Fig.12 1 shows the state where the LED 14 constituting the light source is mounted on the substrate 505. They are composed of a plurality of blocks of units 503, in which the collimator 18 and the LED 14 are set as a pair of blocks. The units 503 are arranged at both ends of the back side of the liquid crystal display panel 11 (in this embodiment, three units are arranged in a row in the short side direction). The light output from the unit 503 is reflected by the reflective light guide 504 arranged opposite to each other and enters the liquid crystal display panel 11 (at Fig.12 (as shown in (c) of FIG. ).

[0176] like Fig.12 As shown in (c), the reflective light guide 504 is divided into two blocks corresponding to the units arranged at each end, and is arranged in a manner such that the central part is the highest. The collimator 18 is close to the LED 14, so a glass material is used in consideration of heat resistance to the heat generated by the LED 14. The shape of the collimator 18 is Fig.10 The collimator 15 is in the shape described above.

[0177] The light from the LED 14 is incident on the polarization conversion element 501 via the collimator 18. The distribution of the light incident on the subsequent reflective light guide 504 is adjusted by the shape of the optical element 81. That is, the light quantity distribution of the light beam incident on the liquid crystal display panel 11 is optimally designed by adjusting the shape and arrangement of the collimator 18, the shape and diffusion characteristics of the optical element 81, and the shape (cross-sectional shape) of the reflective surface of the reflective light guide, the inclination of the reflective surface, and the surface roughness of the reflective surface.

[0178] As the shape of the reflective surface set on the surface of the reflective light guide 504, Fig.12 As shown in (b), a plurality of reflecting surfaces are arranged opposite to the exit surface of the polarization conversion element, and the inclination, area, height, and spacing of the reflecting surfaces are optimized according to the distance from the polarization conversion element 21. In addition, by dividing the area that will become the same reflecting surface (i.e., the surface opposite to the polarization conversion element) into a polyhedron, the light amount distribution of the light beam incident on the liquid crystal display panel 11 can be made to a desired value (optimized) as described above. Therefore, the light amount and the exit direction of the light beam toward the liquid crystal display panel 11 can be adjusted with high precision. As a result, the light amount and the exit direction of the incident light to the liquid crystal display panel 11 and the exit light from the liquid crystal display panel 11 can also be adjusted with high precision, so in a spatial image information display system using an image display device using this light source, the diffusion direction and diffusion angle of the image light of the spatial suspended image can be set to a desired value.

[0179] The reflective surface of the reflective light guide is Figure 7B Similarly, the reflective light guide described in Fig.12 In the example of FIG. 14 , the XY plane is divided into 14 parts and is composed of different inclined surfaces), which can adjust the reflected light with higher precision. In addition, in order to prevent the reflected light from the reflective light guide from leaking from the side of the light source device 13, a light shielding wall 507 is provided to prevent the generation of leakage light in directions other than the desired direction (toward the liquid crystal display panel 11).

[0180] Alternatively, you can also configure Fig.12 The left and right units 503 of the reflective light guide 504 are replaced with the light source device of FIG. 7. That is, it is also possible to prepare a plurality of light source devices (substrate 102, reflector 300, LED 14, etc.) of FIG. 7, and to connect the plurality of light source devices as shown in FIG. Fig.12 They are arranged at positions opposite to each other as shown in (a), (b), and (c).

[0181] Fig.13 (B) is to Fig.13 The light source device shown in (A) is configured by arranging 6 units 503 in the upper part and 6 units in the lower part. Fig.13 The light source device shown in (B) is a structure in which the unit 503 with five LEDs arranged horizontally is configured as described above, and the desired brightness is obtained by current control through a single power supply. Therefore, as a light source device for illuminating a liquid crystal panel, the light source brightness can be controlled according to each area illuminated by each unit 503. Fig.13 In the structure shown, there are a reflection surface 222 and a reflection surface 502 different from the reflection surface 222. The reflection surface 222 is in a shape of horizontal grids or a strip shape having a predetermined width.

[0182] On the other hand, the reflecting surface 502 is shaped like a vertical and horizontal grid. By optimally designing the shape of these fine grids and the inclination of the dividing surface, the desired outgoing light distribution (the outgoing direction and diffusion characteristics of the outgoing light) is obtained. Therefore, the light amount and the outgoing direction of the light beam toward the liquid crystal display panel 11 can be adjusted with high precision. As a result, as in the above-mentioned two embodiments, the light amount and the outgoing direction of the incident light to the liquid crystal display panel 11 and the outgoing light from the liquid crystal display panel 11 can be controlled with high precision, so in a spatial image information display system using an image display device using this light source, the diffusion direction and diffusion angle of the image light of the spatial floating image can be set to the desired values.

[0183] Fig. 9206 is a cross-sectional view showing an example of the shape of the diffuser 206. As described above, the divergent light output from the LED is converted into substantially parallel light by the reflector 300 or the collimator 18, and after being converted into a specific polarized wave by the polarization conversion element 21, it is reflected by the light guide. Then, the light beam reflected by the light guide passes through the flat portion of the incident surface of the diffuser 206 and enters the liquid crystal display panel 11 (see FIG. Fig. 9 2 solid arrows in the figure representing “reflected light from the light guide”).

[0184] In addition, the divergent light beam in the light emitted from the polarization conversion element 21 is totally reflected on the inclined surface of the protrusion having an inclined surface provided on the incident surface of the diffuser 206, and is incident on the liquid crystal display panel 11. In order to make the light emitted from the polarization conversion element 21 totally reflected on the inclined surface of the protrusion of the diffuser 206, the angle of the inclined surface of the protrusion is changed based on the distance from the polarization conversion element 21. When the angle of the inclined surface of the protrusion on the side away from the polarization conversion element 21 or the side away from the LED is set to α, and the angle of the inclined surface of the protrusion on the side close to the polarization conversion element 21 or the side close to the LED is set to α', α is less than α' (α<α'). By such a setting, the light beam after polarization conversion can be effectively used.

[0185] <Diffusion characteristics control technology for image display devices>

[0186] As a method for adjusting the diffusion distribution of the image light from the liquid crystal display panel 11, a biconvex lens is provided between the light source device 13 and the liquid crystal display panel 11, or on the surface of the liquid crystal display panel 11, and the shape of the lens is optimized. That is, by optimizing the shape of the biconvex lens, the emission characteristics of the image light (hereinafter also referred to as "image light beam") emitted in one direction from the liquid crystal display panel 11 can be adjusted.

[0187] As an alternative or in addition, a microlens array may be arranged in a matrix on the surface of the liquid crystal display panel 11 (or between the light source device 13 and the liquid crystal display panel 11), and the arrangement may be adjusted. That is, by adjusting the arrangement of the microlens array, the emission characteristics of the image light beam emitted from the image display device 1 in the X-axis and Y-axis directions can be adjusted, and as a result, an image display device with desired diffusion characteristics can be obtained.

[0188] As a further structural example, two biconvex lenses may be combined and arranged at the position where the image light emitted from the image display device 1 passes, or a microlens array may be arranged in a matrix to set a sheet for adjusting the diffusion characteristics. By setting the structure of the optical system as such, the brightness (relative brightness) of the image light can be adjusted according to the reflection angle of the image light (the reflection angle based on the case of reflection in the vertical direction (0 degrees)) in the X-axis and Y-axis directions.

[0189] In this embodiment, by using such a biconvex lens, Fig.16 As shown in the graphs (plotted curves) of "Example 1 (Y direction)" and "Example 2 (Y direction)" in (b), it is possible to obtain excellent optical characteristics that are significantly different from the graphs (plotted curves) of the previous characteristics. Specifically, in the plotted curves of Example 1 (Y direction) and Example 2 (Y direction), by making the brightness characteristics in the vertical direction steep and then changing the balance of the directional characteristics in the up and down directions (positive and negative directions of the Y axis), it is possible to improve the brightness (relative brightness) of light based on reflection and diffusion.

[0190] Therefore, according to the present embodiment, image light having a narrow diffusion angle (high straightness) and only a specific polarization component, such as image light from a surface-emitting laser image source, can be used to suppress ghosting that occurs in the retroreflective component when using an image display device using the prior art, and can be adjusted so that a spatial suspended image based on retroreflection efficiently reaches the observer's eyes.

[0191] In addition, by the above-mentioned light source device, relative to Fig.17 The outgoing light diffusion characteristics from a general liquid crystal display panel shown in (A) and (B) (represented as "existing characteristics" in the figure) can have a directional characteristic with a significantly narrowed angle in both the X-axis direction and the Y-axis direction. In this embodiment, by having such a directional characteristic with a narrowed angle, an image display device that emits an image light beam that is nearly parallel to a specific direction and emits specific polarized light can be realized.

[0192] Fig.17 An example of the characteristics of the biconvex lens used in this embodiment is shown. In this example, the characteristics in the X direction (vertical direction) based on the Z axis are particularly shown, and the characteristic O shows that the peak of the light emission direction is an angle of about 30 degrees upward from the vertical direction (0 degrees) and the brightness characteristics are symmetrical up and down. In addition, Fig.17 The plotted curves of characteristic A and characteristic B shown in the graph also show an example of a characteristic in which the image light above the peak brightness is focused near 30 degrees to increase the brightness (relative brightness). Therefore, in these characteristic A and characteristic B, compared with the plotted curve of characteristic O, it can be seen that the brightness (relative brightness) of the light is sharply reduced in the area where the inclination (angle θ) from the Z axis to the X direction exceeds 30 degrees (θ>30°).

[0193] That is, according to the above-mentioned optical system including a double convex lens, when the image light beam from the image display device 1 is incident on the retro-reflective component, the emission angle and the field angle of the image light that are unified into a narrow angle by the light source device 13 can be adjusted, and the degree of freedom of setting the retro-reflective sheet can be greatly improved. As a result, the degree of freedom of the relationship between the imaging position of the spatial suspended image that is imaged at the desired position by reflecting or transmitting the window glass can be greatly improved. As a result, the light with a narrow diffusion angle (high straightness) and only a specific polarization component can efficiently reach the eyes of the observer outdoors or indoors. As a result, even if the intensity (brightness) of the image light from the image display device 1 is reduced, the observer can accurately identify the image light and obtain information. In other words, by reducing the output of the image display device 1, a low-power information display system can be achieved.

[0194] Various embodiments and examples (i.e., specific examples) to which the present invention is applied are described in detail above. On the other hand, the present invention is not limited to the above-mentioned embodiments (specific examples), but includes various modified examples. For example, the above-mentioned embodiments describe the embodiments of the entire system in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to embodiments having all the structures described. In addition, a part of the structure of a certain embodiment can be replaced with the structure of another embodiment, and in addition, the structure of another embodiment can be added to the structure of a certain embodiment. In addition, with respect to a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0195] The light source device described above is not limited to the spatial floating image display device, but can also be applied to information display devices such as HUD, tablet computers, digital signage, etc.

[0196] In the technology of this embodiment, by making high-resolution and high-brightness image information suspended in space to display a spatially suspended image, for example, a user can operate without feeling uneasy about contact infection of an infectious disease. If the technology of this embodiment is used in a system used by multiple unspecified users, a non-contact user interface that reduces the risk of contact infection of an infectious disease and can be used without feeling uneasy can be provided. The present invention that provides such a technology contributes to "3. Health and welfare for all" of the Sustainable Development Goals (SDGs) advocated by the United Nations.

[0197] In addition, in the technology of the above-mentioned embodiment, by reducing the divergence angle of the emitted image light and unifying it into a specific polarization wave, only the regular reflected light is efficiently reflected by the retroreflective component, so the light utilization efficiency is high, and a bright and clear spatial floating image can be obtained. According to the technology of this embodiment, a non-contact user interface with excellent usability that can significantly reduce power consumption can be provided. According to the present invention that provides such technology, it contributes to the "9. Foundation of industrial and technological innovation" and "11. Sustainable manufacturing" of the sustainable development goals (SDGs: Sustainable Development Goals) advocated by the United Nations.

[0198] Furthermore, in the technology involved in the above-mentioned embodiment, a spatial floating image based on image light with high directivity (straightness) can be formed. In the technology of this embodiment, it is possible to provide a non-contact user interface with low risk of peek-in of the spatial floating image by displaying highly directional image light even when displaying images requiring high security in bank ATMs or ticket machines at stations, or images with high concealment that are intended to be hidden from people facing the user. The present invention contributes to "11. Sustainable Manufacturing" of the Sustainable Development Goals (SDGs) advocated by the United Nations by providing the above-mentioned technology.

[0199] Description of Reference Numerals

[0200] 1…Image display device

[0201] 2…First retro-reflective component

[0202] A1, A2, 3, 220A, 220B, 204… Space image (space floating image)

[0203] 110 ... first transmissive plate

[0204] 111…Reflective polarizing sheet, (reflective polarizing plate)

[0205] 13…Light source device

[0206] 54…Light direction changing panel

[0207] 105…Linear Fresnel Sheet

[0208] 107…Rotation mechanism

[0209] 102…Absorptive polarizing sheet (absorptive polarizing plate)

[0210] 200…Flat panel display

[0211] 201…Housing

[0212] 203…Sensing system

[0213] 226…Sensing area

[0214] 102…Substrate

[0215] 11. 335…LCD panel

[0216] 206…Diffuser plate

[0217] 21…Polarization conversion element

[0218] 300…Reflector

[0219] 213…λ / 2 plate

[0220] 306…Reflective light guide

[0221] 307…Reflective surface

[0222] 308, 310…Sub-reflector

[0223] 204…Space Suspended Image

[0224] 334…Image light control sheet

[0225] 336…Transmission

[0226] 337…Light absorption part

[0227] 81…Optical components

[0228] 501…Polarization conversion element

[0229] 503…unit

[0230] 507…Light-shading wall

[0231] 401, 402…shading plate

[0232] 320…Base material

[0233] 511…Housing

[0234] 512…Support arm

[0235] 513…Hinge

[0236] 514…Rear hood

[0237] 515…Housing cover

[0238] 516…Housing base

[0239] 517, 518…Tilted linear Fresnel sheet

[0240] 519…Eccentric Fresnel Sheet.

Claims

1. A spatial suspended image information display system, characterized in that: The settings are: A display panel that emits image light; a light source device that supplies light to the display panel; A retro-reflective component that causes the image light of a specific polarized wave from the display panel to display a real image in the air; and a first transmissive plate, wherein a polarization conversion component for converting image light of a specific polarization wave into another polarization wave is arranged on the surface of the retroreflective component, and a polarization beam splitter is arranged between the display panel and the retroreflective component, the polarization beam splitter transmits the image light of the specific polarization wave and reflects the image light converted into another polarization wave after being reflected by the retroreflective component, The image light converted into another polarized wave after being reflected by the retroreflective member is reflected in a direction substantially orthogonal to an optical axis connecting the display panel and the retroreflective member disposed opposite thereto. The reflected image light is transmitted through a second transmissive plate provided at an opening of a housing of the spatial floating image information display system, thereby displaying a real spatial floating image in space.

2. The spatial suspended image information display system according to claim 1, characterized in that: The spatial floating image information display system assembles the display panel, the light source device, the retro-reflective component and the first transmissive plate to the housing, and has a structure connected to a part of the housing through a component combined with the spatial floating image information display system.

3. The spatial suspended image information display system according to claim 1, characterized in that: The spatial floating image information display system has a structure for changing the distance between the display panel and the first transmissive plate.

4. The spatial suspended image information display system according to claim 1, characterized in that: The first transmissive plate is fixed to the housing via an elastic member.

5. The spatial suspended image information display system according to claim 4, characterized in that: A light emitting part and a light receiving part of a sensing system for operating a spatial floating image to interact are arranged inside the shell.

6. The spatial suspended image information display system according to claim 1, characterized in that: The light source device comprises: Point or surface light source; a reflector that reflects light from the light source; and a light guide that guides the light from the reflector toward the display panel, The reflective surface of the reflector is asymmetrical with respect to the optical axis of the outgoing light of the light source.

7. The spatial suspended image information display system according to claim 6, characterized in that: The light guide is a reflective light guide.

8. The spatial suspended image information display system according to claim 6 or 7, characterized in that: The spatial suspended image information display system comprises: a diffuser plate that diffuses light from the light guide; and The side wall is configured to separate the light guide and the diffusion plate.

9. The spatial suspended image information display system according to claim 6, characterized in that: The reflector is made of plastic material, glass material or metal material.

10. A spatial suspended image information display system, characterized in that: have: a display panel that displays an image; a light source device; and A retro-reflective component reflects the image light from the display panel and displays a real image floating in the air using the reflected light. The light source device comprises: Point or surface light source; a reflector that reflects light from the light source; and a light guide that guides the light from the reflector toward the display panel, The light source light reflecting surface of the light guide body forms a structure in which a plurality of reflecting surfaces are arranged in a direction perpendicular to the optical axis of the light source light propagation, and the emission direction and diffusion angle of the light source light incident on the display panel are adjusted by the inclination angle of each of the reflecting surfaces. The spatial floating image information display system comprises an image display device, which controls the emission direction and diffusion angle of the emitted light from the display panel. The spatial suspended image information display system adjusts the emission direction and diffusion angle of the image light of the spatial suspended image.

11. A spatial suspended image information display system, characterized in that: A display panel for displaying an image, a light source device for the display panel, and a retro-reflective component for reflecting image light from the display panel and displaying a real image in the air through the reflected light are assembled in the same housing. The housing is provided with a supporting member, The spatial floating image information display system includes hinges fixed to the support member and a housing base of the spatial floating image information display system, and the housing includes a structure capable of changing an emission direction of image light of the spatial floating image by the hinges provided on the housing base.

12. The spatial suspended image information display system according to claim 11, characterized in that: The light source device comprises: Point or surface light source; a reflector that reflects light from the light source; and a light guide that guides the light from the reflector toward the display panel, The reflective surface of the reflector is asymmetrical with respect to the optical axis of the outgoing light of the light source.

13. The spatial suspended image information display system according to claim 12, characterized in that: The light guide is a reflective light guide.

14. The spatial suspended image information display system according to claim 12, characterized in that: The spatial suspended image information display system comprises: a diffuser plate that diffuses light from the light guide; and The side wall is configured to separate the light guide and the diffusion plate.

15. The spatial suspended image information display system according to claim 12, characterized in that: The reflector is made of plastic material, glass material or metal material.

Images