Aerial floating image display device

Abstract

To provide a more appropriate aerial floating image display device.SOLUTION: An aerial floating image display device provided herein comprises a display device for generating an image, a retroreflective member configured to reflect image light from the display device, and an image capturing unit. When a plurality of persons are present in a captured image produced by the image capturing unit, the aerial floating image display device displays information in the form of an aerial floating image, notifying a user of the aerial floating image display device that the user is being peeped.SELECTED DRAWING: Figure 27

Description

Technical Field

[0001] The present invention relates to a spatial floating image display device.

Background Art

[0002] As a prior art, there is Japanese Patent Application Laid-Open No. 2019-128722 (Patent Document 1). This publication describes "reducing the misdetection of operations on an image formed in the air".

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, if there is someone behind the user who performs a touch operation or the like on the spatial floating image, there is a risk that the displayed information will be peeked at by others. Then, the safety of the spatial floating image display device will be reduced.

[0005] Therefore, an object of the present invention is to provide a spatial floating image display device capable of improving the safety for spatial floating images.

Means for Solving the Problems

[0006] In order to solve the above problems, for example, the configuration described in the claims is adopted. This application includes a plurality of means for solving the above problems. If an example is given, the spatial floating image display device includes a display device that generates an image, a retroreflective member that reflects the image light from the display device, and an imaging unit. When a plurality of people are shown in the captured image generated by the imaging unit, the spatial floating image display device displays, as a spatial floating image, information notifying the user of the spatial floating image display device that they are being peeked at.

Advantages of the Invention

[0007] According to the present invention, a more suitable spatial floating image display device can be realized. Other problems, configurations, and effects will be clarified in the following description of the embodiments.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the description of the embodiments, and various changes and modifications can be made by those skilled in the art within the scope of the technical idea disclosed in this specification. Also, in all the drawings for explaining the present invention, those having the same function are given the same reference numerals, and the repeated description thereof may be omitted.

[0010] The following embodiments relate to a spatial floating image display device capable of transmitting an image by image light from an image light source through a transparent member that partitions a space such as glass and displaying it as a spatial floating image outside the transparent member.

[0011] According to the following embodiments, for example, a spatial floating image display device suitable for use in bank ATMs, station ticket vending machines, digital signage, etc. can be realized. For example, currently, in bank ATMs, station ticket vending machines, etc., a touch panel is usually used. However, by using a transparent glass surface or a light-transmissive plate material, high-resolution video information can be displayed in a spatially floating state on this glass surface or light-transmissive plate material. At this time, by reducing the divergence angle of the emitted video light, that is, making it an acute angle, and further aligning it with a specific polarization, only the regular reflected light can be efficiently reflected by the retroreflective member. Therefore, the light utilization efficiency is high, and ghost images that occur in addition to the main spatial floating image, which was a problem in the conventional retroreflective method, can be suppressed, and a clear spatial floating image can be obtained. In addition, an apparatus including the light source of this embodiment can provide a novel and highly usable spatial floating image display device (spatial floating image display system) capable of significantly reducing power consumption. Further, for example, a spatial floating image display device for a vehicle that can display a so-called unidirectional spatial floating image visible inside and / or outside the vehicle can be provided.

[0012] On the other hand, in the conventional technology, an organic EL panel or a liquid crystal panel is combined with a retroreflective member 151 as a high-resolution color display video source 150. In the conventional technology, since the video light diffuses at a wide angle, in addition to the reflected light regularly reflected by the retroreflective member 151, as shown in FIG. 24, ghost images 301 and 302 are generated by the video light incident obliquely on the retroreflective member 2a, deteriorating the image quality of the spatial floating image. Also, as shown in FIG. 23, in addition to the regular spatial floating image 300, a plurality of first ghost images 301, second ghost images 302, etc. are generated. For this reason, the same spatial floating image, which is a ghost image, is monitored not only by the monitor but also by others, posing a major security issue. <Example 1 of Spatial Floating Image Display Device>

[0013] FIG. 1 and FIG. 32 are diagrams showing an example of the usage form of a spatial floating image display device according to an embodiment of the present invention, and are diagrams showing the overall configuration of the spatial floating image display device according to this embodiment. For example, FIG. 32 is a diagram illustrating an image displayed as a spatial floating image. In FIG. 32(A), a keypad for inputting numbers and arithmetic expressions is illustrated as the spatial floating image 3. Note that the image displayed as the spatial floating image is not limited to these, and for example, various buttons used as a user interface for an ATM at a bank, a keyboard such as that used in a personal computer, or a selection button for selecting a product or the like may also be used.

[0014] The transparent structural member 60 in FIG. 32(B) is provided to facilitate the position recognition of the spatial floating image 3 by a monitor.

[0015] Regarding the specific configuration of the spatial floating image display device, it will be described in detail using FIG. 2 and the like. Light with a specific polarization and a sandwiching angle directivity exits from the display device 1 as an image light beam, once enters the retroreflective member 2, is retroreflected, passes through a transparent member 100 (such as glass), and forms a real image, an aerial image (spatial floating image 3), outside the glass surface.

[0016] Also, in a store or the like, a space is partitioned by a show window (also referred to as "window glass") 105, which is a translucent member such as glass. According to the spatial floating image display device of this embodiment, it is possible to display a floating image in one direction with respect to the outside and / or inside of the store (space) through such a transparent member.

[0017] In FIG. 1(A), the inside (inside the store) of the window glass 105 is shown in the depth direction, and the outside (for example, the sidewalk) is in the foreground. On the other hand, by providing means for reflecting a specific polarization on the window glass 105, it is also possible to form an aerial image at a desired position inside the store.

[0018] FIG. 1(B) is a schematic block diagram showing the configuration of the above-described spatial floating image display device 1000. The spatial floating image display device 1000 includes an image display unit that displays the original image of the aerial image, an image control unit that converts the input image according to the resolution of the panel, and an image signal receiving unit that receives the image signal. The image signal receiving unit supports wired input signals such as HDMI (High-Definition Multimedia Interface) input and wireless input signals such as Wi-Fi (Wireless Fidelity), and can function independently as an image receiving and displaying device. It can also display video information from tablets, smartphones, etc. Furthermore, if a laptop PC or the like is connected, it can be provided with capabilities such as computing processing and video analysis processing.

[0019] FIG. 2 is a diagram showing an example of the main configuration and the retroreflective part configuration of the spatial floating image display device according to an embodiment of the present invention. Using FIG. 2, the configuration of the spatial floating image display device will be described more specifically. As shown in FIG. 2(A), in the diagonal direction of a transparent member 100 such as glass, a display device 1 that diverges the video light of a specific polarization at an included angle is provided. The display device 1 includes a liquid crystal display panel 11 and a light source device 13 that generates light of a specific polarization having diffusion characteristics at an included angle.

[0020] The video light of a specific polarization from the display device 1 is reflected by a polarization separation member 101 having a film that selectively reflects the video light of a specific polarization provided on the transparent member 100 (in the figure, the polarization separation member 101 is formed in a sheet shape and adhered to the transparent member 100), and enters the retroreflective member 2. A λ / 4 plate 21 is provided on the video light incident surface of the retroreflective member. The video light is polarization-converted from a specific polarization to the other polarization by passing through the λ / 4 plate 21 twice, when entering and exiting the retroreflective member. Here, since the polarization separation member 101 that selectively reflects the video light of a specific polarization has the property of transmitting the polarization of the other polarization that has been polarization-converted, the video light of the specific polarization after polarization conversion passes through the polarization separation member 101. The video light that has passed through the polarization separation member 101 forms a spatial floating image 3 that is a real image outside the transparent member 100.

[0021] Note that the light forming the spatial floating image 3 is a collection of light rays converging from the retroreflective member 2 to the optical image of the spatial floating image 3, and these light rays continue to travel straight even after passing through the optical image of the spatial floating image 3. Therefore, unlike the diffused image light formed on a screen by a general projector or the like, the spatial floating image 3 is an image with high directivity. Thus, in the configuration of FIG. 2, when viewed by the user from the direction of arrow A, the spatial floating image 3 is viewed as a bright image. However, when viewed by another person from the direction of arrow B, the spatial floating image 3 cannot be viewed as an image at all. This characteristic is very suitable for use in systems that display images requiring high security or images with high confidentiality that need to be concealed from people facing the user.

[0022] Depending on the performance of the retroreflective member 2, the polarization axes of the reflected image light may become uneven. In this case, some of the image light with uneven polarization axes is reflected by the polarization separation member 101 described above and returns to the display device 1. This light may be re-reflected by the image display surface of the liquid crystal display panel 11 constituting the display device 1, generating a ghost image and degrading the image quality of the spatial floating image. Therefore, in this embodiment, an absorption-type polarizing plate 12 is provided on the image display surface of the display device 1. By allowing the image light emitted from the display device 1 to pass through the absorption-type polarizing plate 12 and absorbing the reflected light returning from the polarization separation member 101 with the absorption-type polarizing plate 12, the above re-reflection can be suppressed. Thereby, it is possible to prevent degradation of the image quality due to the ghost image of the spatial floating image.

[0023] The above-described polarization separation member 101 may be formed of, for example, a reflective polarizing plate or a metal multilayer film that reflects a specific polarization wave.

[0024] Next, as a typical retroreflective member 2 in FIG. 2(B), the surface shape of the retroreflective member manufactured by Nippon Carborundum Co., Ltd. used in this study is shown. The light rays incident inside the regularly arranged hexagonal prisms are reflected by the wall surfaces and bottom surfaces of the hexagonal prisms and exit as retroreflected light in the direction corresponding to the incident light, displaying a spatial floating image that is a real image based on the video displayed on the display device 1. The resolution of this spatial floating image depends greatly on the outer shape D and pitch P of the retroreflective part of the retroreflective member 2 shown in FIG. 2(B) in addition to the resolution of the liquid crystal display panel 11. For example, when using a 7-inch WUXGA (1920×1200 pixels) liquid crystal display panel, even if one pixel (one triplet) is about 80 μm, if the diameter D of the retroreflective part is 240 μm and the pitch is 300 μm, for example, one pixel of the spatial floating image corresponds to 300 μm. Therefore, the effective resolution of the spatial floating video is reduced to about 1 / 3. Therefore, in order to make the resolution of the spatial floating video equivalent to that of the display device 1, it is desirable to make the diameter and pitch of the retroreflective part closer to one pixel of the liquid crystal display panel. On the other hand, in order to suppress the occurrence of moiré due to the retroreflective member and the pixels of the liquid crystal display panel, it is good to design by deviating the respective pitch ratios from an integer multiple of one pixel. Also, it is good to arrange the shape so that none of the sides of the retroreflective part overlap any of the sides of one pixel of the liquid crystal display panel.

[0025] On the other hand, in order to manufacture the retroreflective member at a low cost, it is good to use the roll press method for molding. Specifically, it is a method of aligning the retroreflective parts and shaping them on a film. The inverse shape of the shaping shape is formed on the roll surface, an ultraviolet curable resin is applied on the fixing base material, and it is passed between the rolls to shape the required shape and irradiate it with ultraviolet rays to cure it, obtaining the retroreflective member 2 with the desired shape. <<Installation Method of Spatial Floating Video Display Device>>

[0026] Next, a method for installing the spatial floating image display device will be described. The spatial floating image display device can freely change the installation method according to the usage form. FIG. 3A is a diagram showing an example of the installation method of the spatial floating image display device. The spatial floating image display device shown in FIG. 3A is installed horizontally so that the surface on which the spatial floating image 3 is formed faces upward. That is, in FIG. 3A, the spatial floating image display device is installed such that the transparent member 100 faces upward, and the spatial floating image 3 is formed above the spatial floating image display device.

[0027] FIG. 3B is a diagram showing another example of the installation method of the spatial floating image display device. The spatial floating image display device shown in FIG. 3B is installed vertically so that the surface on which the spatial floating image 3 is formed faces sideways (in the direction of the user 200). That is, in FIG. 3B, the spatial floating image display device is installed such that the transparent member 100 faces sideways, and the spatial floating image 3 is formed sideways (in the direction of the user 200) of the spatial floating image display device. <<Configuration of the Spatial Floating Image Display Device>>

[0028] Next, the configuration of the spatial floating image display device 1000 will be described. FIG. 3C is a block diagram showing an example of the internal configuration of the spatial floating image display device 1000.

[0029] The spatial floating image display device 1000 includes a retroreflective portion 1101, an image display portion 1102, a light guide 1104, a light source 1105, a power supply 1106, an operation input portion 1107, a non-volatile memory 1108, a memory 1109, a control portion 1110, an image signal input portion 1131, an audio signal input portion 1133, a communication portion 1132, an air operation detection sensor 1351, an air operation detection portion 1350, an audio output portion 1140, an image control portion 1160, a storage portion 1170, an imaging portion 1180, etc.

[0030] Each component of the spatial floating image display device 1000 is housed in a housing 1190. Note that the imaging portion 1180 and the air operation detection sensor 1351 shown in FIG.  3C may be provided outside the housing 1190.

[0031] The retroreflective portion 1101 in FIG. 3C corresponds to the retroreflective member 2 in FIG. 2. The retroreflective portion 1101 retroreflects the light modulated by the video display portion 1102. Among the reflected light from the retroreflective portion 1101, the spatial floating video 3 is formed by the light output to the outside of the spatial floating video information device 1000.

[0032] The video display portion 1102 in FIG. 3C corresponds to the liquid crystal display panel 11 in FIG. 2. The light source 1105 in FIG. 3C corresponds to the light source device 13 in FIG. 2. And the video display portion 1102, the light guide 1104, and the light source 1105 in FIG. �C correspond to the display device 1 in FIG. 2.

[0033] The video display portion 1102 is a display portion that modulates the transmitted light based on the video signal input under the control of a video control portion 1160 described later to generate a video. The video display portion 1102 corresponds to the liquid crystal display panel 11 in FIG. 2. As the video display portion 1102, for example, a transmissive liquid crystal panel is used. Also, as the video display portion 1102, for example, a reflective liquid crystal panel or a DMD (Digital Micromirror Device: registered trademark) panel that modulates the reflected light may be used.

[0034] The light source 1105 generates light for the video display portion 1102 and is a solid light source such as an LED light source or a laser light source. The power supply 1106 converts the AC current input from the outside into a DC current and supplies power to the light source 1105. Also, the power supply 1106 supplies the necessary DC current to each part in the spatial floating video display device 1000.

[0035] The light guide 1104 guides the light generated by the light source 1105 and irradiates the video display portion 1102. The combination of the light guide 1104 and the light source 1105 can also be referred to as the backlight of the video display portion 1102. Various methods are conceivable for the combination of the light guide 1104 and the light source 1105. Specific configuration examples of the combination of the light guide 1104 and the light source 1105 will be described in detail later.

[0036] The air operation detection sensor 1351 is a sensor that detects the operation of the spatial floating image 3 by the finger of the user 200. The air operation detection sensor 1351 senses, for example, a range that overlaps with the entire display range of the spatial floating image 3. Note that the air operation detection sensor 1351 may sense only a range that overlaps with at least a part of the display range of the spatial floating image 3.

[0037] Specific examples of the air operation detection sensor 1351 include distance sensors using invisible light such as infrared rays, invisible light lasers, ultrasonic waves, etc. Further, the air operation detection sensor 1351 may be configured by combining a plurality of sensors in a plurality of ways so as to be able to detect the coordinates of a two-dimensional plane. Further, the air operation detection sensor 1351 may be composed of a ToF (Time of Flight) type LiDAR (Light Detection and Ranging) or an image sensor.

[0038] The air operation detection sensor 1351 only needs to be able to sense, for example, a touch operation by the user's finger on the object displayed as the spatial floating image 3. Such sensing can be performed using existing technologies.

[0039] The air operation detection unit 1350 acquires a sensing signal from the air operation detection sensor 1351, and based on the sensing signal, determines the presence or absence of contact of the object of the spatial floating image 3 by the finger of the user 200, and calculates the position (contact position) where the finger of the user 200 contacts the object, etc. The air operation detection unit 1350 is composed of, for example, a circuit such as an FPGA (Field Programmable Gate Array). Further, some functions of the air operation detection unit 1350 may be realized by software by, for example, a spatial operation detection program executed by the control unit 1110.

[0040] The air operation detection sensor 1351 and the air operation detection unit 1350 may be incorporated into the spatial floating image display device 1000, or may be provided externally as a separate unit from the spatial floating image display device 1000. When provided as a separate unit from the spatial floating image display device 1000, the air operation detection sensor 1351 and the air operation detection unit 1350 are configured to be able to transmit information and signals to the spatial floating image display device 1000 via a wired or wireless communication connection path or a video signal transmission path.

[0041] Also, the air operation detection sensor 1351 and the air operation detection unit 1350 may be provided as separate units. Thereby, it is possible to construct a system in which the spatial floating image display device 1000 without the air operation detection function is used as the main body and only the air operation detection function can be added as an option. Also, only the air operation detection sensor 1351 may be a separate unit, and the air operation detection unit 1350 may be incorporated into the spatial floating image display device 1000. When it is desired to arrange the air operation detection sensor 1351 more freely with respect to the installation position of the spatial floating image display device 1000, etc., there is an advantage in a configuration in which only the air operation detection sensor 1351 is a separate unit.

[0042] The imaging unit 1180 is a camera having an image sensor, and images the space near the spatial floating image 3 and / or the face, arm, finger, etc. of the user 200. A plurality of imaging units 1180 may be provided. By using a plurality of imaging units 1180 or by using an imaging unit with a depth sensor, it is possible to assist the air operation detection unit 1350 during the detection process of the touch operation of the spatial floating image 3 by the user 200.

[0043] For example, when the air operation detection sensor 1351 is configured as an object intrusion sensor that detects the presence or absence of an object entering a plane (intrusion detection plane) including the display surface of the spatial floating image 3, the air operation detection sensor 1351 may not be able to detect information such as how far an object (e.g., a user's finger) that has not entered the intrusion detection plane is from the intrusion detection plane or how close the object is to the intrusion detection plane.

[0044] In such a case, by using information such as the depth calculation information of the object based on the captured images of the plurality of imaging units 1180 and the depth information of the object by the depth sensor, the distance between the object and the intrusion detection plane can be calculated. Then, these information and various information such as the distance between the object and the intrusion detection plane are used for various display controls for the spatial floating image 3.

[0045] Also, without using the air operation detection sensor 1351, the air operation detection unit 1350 may detect a touch operation on the spatial floating image 3 by the user 200 based on the captured image of the imaging unit 1180.

[0046] Also, the imaging unit 1180 may capture the face of the user 200 who operates the spatial floating image 3, and the control unit 1110 may perform identification processing of the user 200. Further, in order to determine whether there is someone standing around or behind the user 200 who operates the spatial floating image 3 and whether the person is peeping at the operation of the user 200 on the spatial floating image 3, the imaging unit 1180 may capture a range including the user 200 who operates the spatial floating image 3 and the peripheral area of the user 200.

[0047] The operation input unit 1107 is, for example, an operation button or a light receiving unit of a remote controller, and inputs a signal for an operation different from the air operation (touch operation) by the user 200. Separately from the above-mentioned user 200 who performs a touch operation on the spatial floating image 3, the operation input unit 1107 may be used, for example, by an administrator to operate the spatial floating image display device 1000.

[0048] The video signal input unit 1131 connects to an external video output device and inputs video data. The audio signal input unit 1133 connects to an external audio output device and inputs audio data. The audio output unit 1140 can perform audio output based on the audio data input to the audio signal input unit 1133. Also, the audio output unit 1140 may output built-in operation sounds or error warning sounds.

[0049] The non-volatile memory 1108 stores various data used in the spatial floating image display device 1000. The data stored in the non-volatile memory 1108 includes, for example, data for various operations to be displayed in the spatial floating image 3, display icons, data of objects for the user to operate, layout information, and the like. The memory 1109 stores video data to be displayed as the spatial floating image 3, control data of the device, and the like.

[0050] The control unit 1110 controls the operations of each connected unit. Further, the control unit 1110 may perform arithmetic processing based on information acquired from each unit within the spatial floating image display device 1000 in cooperation with a program stored in the memory 1109. The communication unit 1132 communicates with external devices, external servers, etc. via a wired or wireless interface. Through the communication via the communication unit 1132, various data such as video data, image data, and audio data are transmitted and received.

[0051] The storage unit 1170 is a storage device that records various data and various information such as video data, image data, and audio data. For example, various information such as various data such as video data, image data, and audio data may be recorded in the storage unit 1170 in advance at the time of product shipment. Further, the storage unit 1170 may record various information such as various data such as video data, image data, and audio data acquired from external devices or external servers via the communication unit 1132.

[0052] The video data, image data, etc. recorded in the storage unit 1170 are output as the spatial floating image 3 via the video display unit 1102 and the retroreflective unit 1101. Video data, image data, etc. such as display icons and objects for the user to operate, which are displayed as the spatial floating image 3, are also recorded in the storage unit 1170.

[0053] Layout information such as display icons and objects displayed as the spatial floating image 3, various metadata information about the objects, etc. are also recorded in the storage unit 1170. The audio data recorded in the storage unit 1170 is output as audio from, for example, the audio output unit 1140.

[0054] The video control unit 1160 performs various controls on the video signal input to the video display unit 1102. For example, the video control unit 1160 performs control such as video switching, which determines which video signal among the video signals stored in the memory 1109 and the video signals (video data) input to the video signal input unit 1131 is input to the video display unit 1102.

[0055] Also, the video control unit 1160 may generate a superimposed video signal by superimposing the video signal stored in the memory 1109 and the video signal input from the video signal input unit 1131, and perform control to form a composite video as the spatial floating image 3 by inputting the superimposed video signal to the video display unit 1102.

[0056] Also, the video control unit 1160 may perform control to perform image processing on the video signal input from the video signal input unit 1131, the video signal stored in the memory 1109, etc. Examples of image processing include scaling processing such as enlarging, reducing, and deforming an image, brightness adjustment processing for changing brightness, contrast adjustment processing for changing the contrast curve of an image, and Retinex processing for decomposing an image into light components and changing the weighting for each component.

[0057] Also, the video control unit 1160 may perform special effect video processing or the like to assist the user 200's air operation (touch operation) on the video signal input to the video display unit 1102. The special effect video processing is performed based on, for example, the detection result of the user 200's touch operation by the air operation detection unit 1350 and the captured image of the user 200 by the imaging unit 1180.

[0058] As described so far, the spatial floating image display device 1000 is equipped with various functions. However, the spatial floating image display device 1000 does not necessarily need to have all of these functions, and it may have any configuration as long as it has the function of forming the spatial floating image 3. <Example 2 of Spatial Floating Image Display Device>

[0059] FIG. 4 is a diagram showing another example of the main configuration of a spatial floating image display device according to an embodiment of the present invention. The display device 1 includes a liquid crystal display panel 11 and a light source device 13 that generates light of a specific polarization having a diffusion characteristic at a sandwiching angle. For example, it is composed of a small liquid crystal display panel with a screen size of about 5 inches to a large liquid crystal display panel exceeding 80 inches. A polarization separation member 101 such as a reflective polarizing plate is provided on the surface of the folding mirror 22, and the video light from the liquid crystal display panel 11 is reflected toward the retroreflective member 2. The video light of a specific polarization from the display device 1 is reflected by a film (sheet 101 is adhered in the figure) that selectively reflects the video light of the specific polarization provided on the transparent member 100 and enters the retroreflective member 2.

[0060] A λ / 4 plate 21 is provided on the light incident surface of the retroreflective member. By passing the video light twice, the polarization is converted and the specific polarization is converted to the other polarization, so that it passes through the polarization separation member 101 and a spatial floating image 3 that is a real image is displayed outside the transparent member 100. An absorption type polarizing plate is provided on the outer light incident surface of the transparent member 100. In the above-described polarization separation member 101, since the polarization axis becomes uneven due to retroreflection, some of the video light is reflected and returns to the display device 1. This light is reflected again on the video display surface of the liquid crystal display panel 11 constituting the display device 1, generating a ghost image and significantly degrading the image quality of the spatial floating image. Therefore, in this embodiment, an absorption type polarizing plate 12 is provided on the video display surface of the display device 1 to transmit the video light and absorb the above-described reflected light, thereby preventing the image quality from degrading due to the ghost image of the spatial floating image. Further, in order to reduce the image quality degradation caused by sunlight or illumination light outside the set, it is preferable to provide an absorption type polarizing plate 12 on the surface of the transparent member 100. The polarization separation member 101 is formed of a reflective polarizing plate or a metal multilayer film that reflects a specific polarization.

[0061] Next, as shown in FIG. 5, a plurality of sensors 44 having a TOF (Time of Fly) function are arranged in multiple layers so as to sense the relationship between the distance and position of the object with respect to the spatial floating video obtained by the above-described spatial floating video display device, and in addition to the coordinates of the object in the planar direction, the coordinates in the depth direction and the moving direction and moving speed of the object can also be sensed. In order to read two-dimensional distance and position, a combination of an ultraviolet light emitting part and a light receiving part is arranged linearly in a plurality, the light from the light emitting point is irradiated onto the object, and the reflected light is received by the light receiving part. The distance to the object is clarified by the product of the difference between the time of emission and the time of reception and the speed of light. Also, the coordinates on the plane can be read from the coordinates at the part where the difference between the emission time and the reception time is the smallest by a plurality of light emitting parts and light receiving parts. By the above, it is also possible to obtain three-dimensional coordinate information by combining the coordinates of the object in the plane (two-dimensional) and a plurality of the above-described sensors.

[0062] Furthermore, a method for obtaining a three-dimensional spatial floating video as the above-described spatial floating video display device will be described with reference to FIG. 6. FIG. 6 is an explanatory diagram of the principle of three-dimensional video display used in the spatial floating video display device. A horizontal lenticular lens is arranged in accordance with the pixels of the video display screen of the liquid crystal display panel 11 of the display device 1 shown in FIG. 4. As a result, as shown in FIG. 6, in order to display the motion parallax from three directions of the motion parallax P1, P2, P3 in the horizontal direction of the screen, the videos from the three directions are taken as one block for every three pixels, and the video information from the three directions is displayed for every pixel. By the action of the corresponding lenticular lens (indicated by a vertical line in FIG. 6), the emission direction of the light is controlled and separated and emitted in three directions. As a result, a stereoscopic image with three parallaxes can be displayed. <Reflection type polarizing plate>

[0063] In the spatial floating image display device of this embodiment, the polarization separation member 101 is used to improve the contrast performance that determines the image quality of the image, compared with a general half mirror. As an example of the polarization separation member 101 of this embodiment, the characteristics of a reflective polarizing plate will be described. FIG. 7 is an explanatory diagram of a measurement system for evaluating the characteristics of a reflective polarizing plate. The transmission characteristics and reflection characteristics with respect to the light ray incident angle from the vertical direction with respect to the polarization axis of the reflective polarizing plate in FIG. 7 are shown in FIGS. 8 and 9 as V-AOI, respectively. Similarly, the transmission characteristics and reflection characteristics with respect to the light ray incident angle from the horizontal direction with respect to the polarization axis of the reflective polarizing plate are shown in FIGS. 10 and 11 as H-AOI, respectively.

[0064] As shown in FIGS. 8 and 9, the characteristics of the reflective polarizing plate with a grid structure deteriorate for light from the vertical direction with respect to the polarization axis. For this reason, specifications along the polarization axis are desirable, and the light source of this embodiment that can emit the outgoing image light from the liquid crystal display panel at an included angle becomes an ideal light source. Also, the characteristics in the horizontal direction similarly deteriorate for light from an oblique direction. Considering the above characteristics, hereinafter, a configuration example of this embodiment will be described in which a light source that can emit the outgoing image light from the liquid crystal display panel at a larger included angle is used as the backlight of the liquid crystal display panel. Thereby, a high-contrast spatial floating image can be provided. <Display device>

[0065] Next, the display device 1 of this embodiment will be described with reference to the drawings. The display device 1 of this embodiment includes a light source device 13 that constitutes its light source together with an image display element 11 (liquid crystal display panel). In FIG. 12, the light source device 13 is shown as an exploded perspective view together with the liquid crystal display panel.

[0066] As shown by arrow 30 in Fig. 12, this liquid crystal display panel (image display element 11) has a sandwiching angle diffusion characteristic with respect to the light from the light source device 13 which is a backlight device, that is, it obtains an illumination light beam having characteristics similar to a laser beam with strong directivity (linear propagation property) and with the polarization planes aligned in one direction, and forms a spatial floating image which is a real image by reflecting the image light modulated according to the input video signal by the retroreflective member 2 and transmitting it through the transparent member 100. (See Fig. 1). Further, in Fig. 12, the liquid crystal display panel 11 constituting the display device 1, further, the light direction conversion panel 54 for controlling the directivity characteristics of the emitted light beam from the light source device 13, and, if necessary, a sandwiching angle diffusion plate (not shown) are provided. That is, polarizing plates are provided on both surfaces of the liquid crystal display panel 11, and the image light of a specific polarization modulates the light intensity according to the video signal and is emitted (see arrow 30 in Fig. 12). Thereby, a desired image is projected as light of a specific polarization with high directivity (linear propagation property) through the light direction conversion panel 54 toward the retroreflective member 2, and after being reflected by the retroreflective member 2, it is transmitted toward the eyes of a monitor outside the store (space) to form the spatial floating image 3. Note that a protective cover 50 (see Figs. 13 and 14) may be provided on the surface of the above-described light direction conversion panel 54.

[0067] In this embodiment, in order to improve the utilization efficiency of the emitted light beam 30 from the light source device 13 and significantly reduce the power consumption, in the display device 1 configured to include the light source device 13 and the liquid crystal display panel 11, the light (refer to arrow 30 in FIG. 12) from the light source device 13 is projected toward the retroreflective member 2, and after being reflected by the retroreflective member 2, a transparent sheet (not shown) provided on the surface of the transparent member 100 (such as the windshield 105) can also control the directivity so as to form a floating image at a desired position. Specifically, this transparent sheet controls the imaging position of the floating image while imparting high directivity by optical components such as a Fresnel lens or a linear Fresnel lens. According to this, the image light from the display device 1 can efficiently reach an observer outside the show window 105 (for example, on the sidewalk) with high directivity (straightness) like laser light. As a result, it is possible to display a high-quality floating image with high resolution and significantly reduce the power consumption of the display device 1 including the LED element 201 of the light source device 13. <Example 1 of Display Device>

[0068] FIG. 13 shows an example of the specific configuration of the display device 1. In FIG. 13, the liquid crystal display panel 11 and the light direction conversion panel 54 are arranged on the light source device 13 of FIG. 12. This light source device 13 is formed of, for example, plastic on the case shown in FIG. 12, and houses the LED element 201 and the light guide 203 inside. On the end face of the light guide 203, as also shown in FIG. 12 and the like, in order to convert the divergent light emitted from each LED element 201 into a substantially parallel light beam, it has a shape in which the cross-sectional area gradually increases toward the light receiving part, and has a lens shape that has an effect of gradually reducing the divergence angle by total reflection multiple times when propagating inside. The liquid crystal display panel 11 constituting the display device 1 is attached to its upper surface. Further, on one side surface (the left end surface in this example) of the case of the light source device 13, an LED (Light Emitting Diode) element 201 which is a semiconductor light source and an LED substrate 202 on which its control circuit is mounted are attached, and a heat sink which is a member for cooling the heat generated by the LED element and the control circuit may be attached to the outer surface of the LED substrate 202.

[0069] Further, on a frame (not shown) of a liquid crystal display panel attached to the upper surface of the case of the light source device 13, a liquid crystal display panel 11 attached to the frame and, further, an FPC (Flexible Printed Circuits) (not shown) electrically connected to the liquid crystal display panel are attached and configured. That is, the liquid crystal display panel 11, which is a liquid crystal display element, together with the LED element 201, which is a solid light source, generates a display image by modulating the intensity of transmitted light based on a control signal from a control circuit (not shown) that constitutes an electronic device. At this time, since the generated video light has a narrow diffusion angle and only a specific polarization component, a novel display device close to a surface-emitting laser video source driven by a video signal can be obtained. At present, it is impossible technically and from a safety perspective to obtain a laser light beam of the same size as the image obtained by the above-described display device 1 using a laser device. Therefore, in this embodiment, for example, light close to the above-described surface-emitting laser video light is obtained from a light beam from a general light source including an LED element.

[0070] Subsequently, the configuration of the optical system housed in the case of the light source device 13 will be described in detail with reference to FIG. 14 together with FIG. 13.

[0071] Since FIGS. 13 and 14 are cross-sectional views, only one of the plurality of LED elements 201 constituting the light source is shown, and these are converted into substantially collimated light by the shape of the light-receiving end face 203a of the light guide 203. For this reason, the light-receiving part of the light guide end face and the LED element are attached while maintaining a predetermined positional relationship. Note that each of these light guides 203 is formed of a light-transmissive resin such as acrylic. And the LED light-receiving surface at the end of this light guide has, for example, an outer peripheral surface of a conical convex shape obtained by rotating a parabolic cross-section. At the top, it has a concave portion formed with a convex portion (that is, a convex lens surface) at the central portion thereof, and at the central portion of the flat portion, it has a convex lens surface protruding outward (alternatively, it may be a concave lens surface recessed inward) (not shown). Note that the outer shape of the light-receiving part of the light guide to which the LED element 201 is attached has a parabolic shape forming an outer peripheral surface of a conical shape, and is set within a range of an angle that enables total reflection of the light emitted from the LED element in the peripheral direction inside the light guide, or a reflecting surface is formed.

[0072] On the other hand, the LED elements 201 are respectively arranged at predetermined positions on the surface of the LED substrate 202 which is the circuit board thereof. This LED substrate 202 is arranged and fixed with respect to the LED collimator (light-receiving end face 203a) such that the LED elements 201 on its surface are respectively positioned at the central portions of the above-described concave portions.

[0073] According to such a configuration, due to the shape of the light-receiving end face 203a of the light guide 203, the light emitted from the LED element 201 can be taken out as substantially parallel light, and it becomes possible to improve the utilization efficiency of the generated light.

[0074] As described above, the light source device 13 is configured by attaching a light source unit in which a plurality of LED elements 201, which are light sources, are arranged on a light receiving end face 203a, which is a light receiving part provided on the end face of the light guide 203. The divergent light beam from the LED element is made into substantially parallel light by the lens shape of the light receiving end face 203a of the light guide end face, and as shown by the arrow, it is guided inside the light guide 203 (in the direction parallel to the drawing), and is emitted by the light beam direction conversion means 204 toward the liquid crystal display panel 11 arranged substantially parallel to the light guide (in the direction perpendicular to the front from the drawing). By optimizing the distribution (density) of this light beam direction conversion means according to the shape inside or on the surface of the light guide, the uniformity of the light beam incident on the liquid crystal display panel 11 can be controlled. The above-described light beam direction conversion means 204 emits the light beam propagated inside the light guide toward the liquid crystal display panel 11 arranged substantially parallel to the light guide (in the direction perpendicular to the front from the drawing) by providing, for example, a portion with a different refractive index on the shape of the light guide surface or inside the light guide. At this time, when comparing the relative luminance ratio when comparing the luminance of the center of the screen and the peripheral part of the screen in a state where the liquid crystal display panel 11 faces the center of the screen and the viewing point is placed at the same position as the diagonal dimension of the screen, if it is 20% or more, there is no practical problem, and if it exceeds 30%, it has even better characteristics.

[0075] Note that FIG. 13 is a cross-sectional layout view for explaining the configuration and operation of the light source of this embodiment that performs polarization conversion in the light source device 13 including the above-described light guide 203 and LED element 201. In FIG. 13, the light source device 13 is composed of, for example, a light guide 203 provided with a light beam direction conversion means 204 on its surface or inside formed of plastic or the like, an LED element 201 as a light source, a reflection sheet 205, a retardation plate 206, a lenticular lens, etc. On its upper surface, a liquid crystal display panel 11 provided with polarizing plates on the light source light incident surface and the video light emission surface is attached.

[0076] Further, a film or sheet-like reflective polarizing plate 49 is provided on the light source light incident surface (the lower surface in the figure) of the liquid crystal display panel 11 corresponding to the light source device 13, and one-sided polarization (for example, P wave) 212 of the natural light beam 210 emitted from the LED element 201 is selectively reflected, reflected by the reflection sheet 205 provided on one surface (the lower side in the figure) of the light guide 203, and then directed toward the liquid crystal display panel 52 again. Therefore, a retardation plate (λ / 4 plate) is provided between the reflection sheet 205 and the light guide 203 or between the light guide 203 and the reflective polarizing plate 49, and the reflected light beam is converted from P polarization to S polarization by being reflected by the reflection sheet 205 and passing through twice, thereby improving the utilization efficiency of the light source light as video light. The video light beam whose light intensity is modulated by the video signal in the liquid crystal display panel 11 (arrow 213 in FIG. 13) enters the retroreflective member 2, and as shown in FIG. 1, after reflection, it passes through the windshield 105 to obtain a spatial floating image that is a real image inside or outside the store (space).

[0077] FIG. 14 is a cross-sectional layout diagram for explaining the configuration and operation of the light source of this embodiment for polarization conversion in the light source device 13 including the light guide 203 and the LED element 201, similar to FIG. 13. Similarly, the light source device 13 is composed of, for example, a light guide 203 provided with a light beam direction conversion means 204 on its surface or inside formed of plastic or the like, an LED element 201 as a light source, a reflection sheet 205, a retardation plate 206, a lenticular lens, etc. A liquid crystal display panel 11 having polarizing plates on the light source light incident surface and the video light exit surface is attached as a video display element on its upper surface.

[0078] Also, a film or sheet-like reflective polarizing plate 49 is provided on the light source light incident surface (the lower surface in the figure) of the liquid crystal display panel 11 corresponding to the light source device 13, and one-sided polarization (for example, S wave) 211 of the natural light beam 210 emitted from the LED light source 201 is selectively reflected, reflected by the reflection sheet 205 provided on one surface (the lower side in the figure) of the light guide 203, and then directed back toward the liquid crystal display panel 11. A retardation plate (λ / 4 plate) is provided between the reflection sheet 205 and the light guide 203 or between the light guide 203 and the reflective polarizing plate 49, and the light is reflected by the reflection sheet 205 and passed through twice to convert the reflected light beam from S polarization to P polarization, thereby improving the utilization efficiency of the light source light as image light. The video light beam whose light intensity is modulated by the video signal in the liquid crystal display panel 11 (arrow 214 in FIG. 14) enters the retroreflective member 2, and as shown in FIG. 1, after reflection, it passes through the windshield 105 to obtain a spatial floating image that is a real image inside or outside the store (space).

[0079] In the light source device shown in FIGS. 13 and 14, in addition to the action of the polarizing plate provided on the light incident surface of the corresponding liquid crystal display panel 11, since the reflective polarizing plate reflects one-sided polarization components, the theoretically obtainable contrast ratio is the reciprocal of the cross transmittance of the reflective polarizing plate multiplied by the reciprocal of the cross transmittance obtained by the two polarizing plates attached to the liquid crystal display panel. As a result, high contrast performance is obtained. Actually, it was experimentally confirmed that the contrast performance of the displayed image was improved by more than 10 times. As a result, a high-quality video comparable to that of self-emissive organic EL was obtained. <Example 2 of the display device>

[0080] FIG. 15 shows another example of the specific configuration of the display device 1. The light source device 13 in FIG. 15 is the same as the light source device in FIGS. 17 and the like. This light source device 13 is configured by housing an LED, a collimator, a composite diffuser block, a light guide, etc. in a case made of, for example, plastic, and a liquid crystal display panel 11 is attached to its upper surface. Further, on one side surface of the case of the light source device 13, LED (Light Emitting Diode) elements 14a and 14b which are semiconductor light sources and an LED substrate 102 on which its control circuit is mounted are attached, and on the outer surface of the LED substrate 102, a heat sink 103 which is a member for cooling the heat generated by the LED element and the control circuit is attached (see also FIGS. 17 and 18).

[0081] Also, on the liquid crystal display panel frame attached to the upper surface of the case, the liquid crystal display panel 11 attached to the frame and, further, an FPC (Flexible Printed Circuits) 403 (see FIG. 7) electrically connected to the liquid crystal display panel 11 are attached and configured. That is, the liquid crystal display panel 11 which is a liquid crystal display element, together with the LED elements 14a and 14b which are solid light sources, generates a display image by modulating the intensity of transmitted light based on a control signal from a control circuit (not shown here) that constitutes the electronic device. <Example 3 of the display device>

[0082] Subsequently, another example of the specific configuration of the display device 1 will be described with reference to FIG. 16. The light source device of this display device 1 converts the divergent light beam of natural light (mixing P-polarized wave and S-polarized wave) from the LED into a substantially parallel light beam by the LED collimator 18 and reflects it toward the liquid crystal display panel 11 by the reflective light guide 304. The reflected light is incident on a wave plate and a reflective polarizing plate 49 arranged between the liquid crystal display panel 11 and the reflective light guide 304. A specific polarization (for example, S-polarized wave) is reflected by the reflective polarizing plate, the phase is converted by the wave plate, returns to the reflection surface, passes through the retardation plate again, and is converted into a polarization (for example, P-polarized wave) that passes through the reflective polarizing plate.

[0083] As a result, the natural light from the LED is aligned to a specific polarization (e.g., P polarization), enters the liquid crystal display panel 11, is luminance-modulated according to the video signal, and a video is displayed on the panel surface. A plurality of LEDs constituting the light source are shown as in the above example (however, only one is shown in FIG. 16 due to the longitudinal section), and these are attached to the LED collimator 18 at predetermined positions. Note that each of these LED collimators 18 is formed of a light-transmissive resin or glass such as acrylic. And this LED collimator 18 has an outer peripheral surface in a conical convex shape obtained by rotating a parabolic cross-section, and at its top, it has a concave portion with a convex portion (i.e., a convex lens surface) formed at its central portion. Also, at the central portion of its flat portion, it has a convex lens surface protruding outward (alternatively, it may be a concave lens surface recessed inward). Note that the parabolic surface forming the conical outer peripheral surface of the LED collimator 18 is set within a range of an angle capable of total reflection of the light emitted from the LED in the peripheral direction inside it, or a reflecting surface is formed.

[0084] The above configuration is the same as the light source device of the display device shown in FIGS. 17, 18, etc. Further, the light converted into substantially parallel light by the LED collimator 15 shown in FIG. 16 is reflected by the reflective light guide 304, and the light of a specific polarization is transmitted by the action of the reflective polarizing plate 49. The light of the other reflected polarization passes through the light guide 304 again and is reflected by a reflector 271 provided on the other surface of the light guide that does not contact the liquid crystal display panel 11. At this time, the light is polarization-converted by passing twice through a retardation plate (λ / 4 plate) 270 disposed between the reflector 271 and the liquid crystal display panel 11, passes through the light guide 304 again, passes through the reflective polarizing plate 49 provided on the opposite surface, and is incident on the liquid crystal display panel 11 with the polarization directions aligned. As a result, all the light of the light source can be utilized, so the light utilization efficiency is doubled.

[0085] The light emitted from the liquid crystal display panel has the same diffusion characteristics in both the horizontal direction of the screen (displayed on the X-axis in Fig. 22(a)) and the vertical direction of the screen (displayed on the Y-axis in Fig. 22(b)) in a conventional TV set. In contrast, for the diffusion characteristics of the light beam emitted from the liquid crystal display panel of this embodiment, for example, as shown in Example 1 of Fig. 22, the viewing angle at which the luminance becomes 50% of the front view (angle 0 degrees) is set to 13 degrees, which is 1 / 5 of the conventional 62 degrees. Similarly, for the viewing angle in the vertical direction, the reflection angle of the reflective light guide and the area of the reflection surface are optimized so that the viewing angle is uneven up and down, and the upper viewing angle is suppressed to about 1 / 3 of the lower viewing angle. As a result, the amount of video light directed toward the monitoring direction is significantly improved compared to a conventional liquid crystal TV, and the luminance becomes 50 times or more.

[0086] Furthermore, in terms of the viewing angle characteristics shown in Example 2 of Fig. 22, the viewing angle at which the luminance becomes 50% of the front view (angle 0 degrees) is set to 5 degrees, which is 1 / 12 of the conventional 62 degrees. Similarly, for the viewing angle in the vertical direction, the reflection angle of the reflective light guide and the area of the reflection surface are optimized so that the viewing angle is even up and down and is suppressed to about 1 / 12 of the conventional value. As a result, the amount of video light directed toward the monitoring direction is significantly improved compared to a conventional liquid crystal TV, and the luminance becomes 100 times or more. As described above, by using the viewing angle as the included angle, the amount of light beam directed toward the monitoring direction can be concentrated, so the light utilization efficiency is significantly improved. As a result, even when using a conventional liquid crystal display panel for a TV, by controlling the light diffusion characteristics of the light source device, it is possible to achieve a significant increase in luminance with the same power consumption, and it can be made into a display device corresponding to a spatial floating video display device for a bright outdoor environment.

[0087] When using a large liquid crystal display panel, the light around the screen is directed inward so that it heads toward the viewer when the viewer is facing the center of the screen, thereby improving the overall uniformity of the screen brightness. Fig. 20 shows the convergence angles of the long side and the short side of the panel when the distance L from the viewer to the panel and the panel size (screen ratio 16:10) are used as parameters. When monitoring with the screen in a vertical orientation, the convergence angle can be set according to the short side. For example, when using a 22" panel vertically and the monitoring distance is 0.8 m, setting the convergence angle to 10 degrees can effectively direct the video light from the four corners of the screen toward the viewer.

[0088] Similarly, when monitoring in the vertical direction of a 15" panel, if the monitoring distance is 0.8 m, the convergence angle should be set to 7 degrees so that the video light from the four corners of the screen can be effectively directed towards the viewer. As described above, by directing the video light around the screen to the viewer who is at the optimal position for monitoring the center of the screen according to the size of the liquid crystal display panel and whether it is used vertically or horizontally, the overall uniformity of the screen brightness can be improved.

[0089] As a basic configuration, as shown in FIG. 16, a light beam with a sandwiching angle directivity characteristic is incident on the liquid crystal display panel 11 by a light source device, and the video information displayed on the screen of the liquid crystal display panel 11 is modulated in luminance according to the video signal, and the space floating image reflected by the retroreflective member is displayed outdoors or indoors through the transparent member 100. <Example 1 of Light Source Device>

[0090] Subsequently, the configuration of the optical system such as the light source device housed in the case will be described in detail with reference to FIGS. 17, 18(a) and (b).

[0091] FIGS. 17 and 18 show the LEDs 14a and 14b that constitute the light source, and these are attached to the LED collimator 15 at predetermined positions. The LED collimator 15 is formed of a light-transmissive resin such as acrylic, for example. As shown in FIG. 18(b), the LED collimator 15 has an outer peripheral surface 156 in a conical convex shape obtained by rotating a parabolic cross section, and at its top, it has a concave portion 153 in which a convex portion (i.e., a convex lens surface) 157 is formed at its central portion. Also, at the central portion of its flat portion, it has a convex lens surface (or a concave lens surface recessed inward may also be acceptable) 154 that protrudes outward. The parabolic surface 156 that forms the conical outer peripheral surface of the LED collimator 15 is set within a range of angles that can totally reflect the light emitted from the LEDs 14a and 14b in the peripheral direction inside it, or a reflecting surface is formed.

[0092] Also, the LEDs 14a and 14b are respectively arranged at predetermined positions on the surface of the LED substrate 102, which is their circuit board. This LED substrate 102 is arranged and fixed with respect to the LED collimator 15 such that the LEDs 14a or 14b on its surface are respectively positioned at the central portions of the recesses 153 thereof.

[0093] According to such a configuration, among the light emitted from the LED 14a or 14b, particularly, the light emitted upward (rightward in the figure) from the central portion thereof is condensed by the two convex lens surfaces 157 and 154 forming the outer shape of the LED collimator 15 to become parallel light. Also, the light emitted from other portions in the peripheral direction is reflected by the parabolic surface forming the conical outer peripheral surface of the LED collimator 15 and is similarly condensed to become parallel light. In other words, according to the LED collimator 15 having a convex lens formed at its central portion and a parabolic surface formed at its peripheral portion, almost all of the light generated by the LED 14a or 14b can be taken out as parallel light, and it becomes possible to improve the utilization efficiency of the generated light.

[0094] Note that a polarization conversion element 21 is provided on the light emission side of the LED collimator 15. As is also apparent from FIG. 18, this polarization conversion element 21 is configured by combining a columnar (hereinafter, parallelogram column) light transmissive member having a parallelogram cross section and a columnar (hereinafter, triangular column) light transmissive member having a triangular cross section, and is arranged in an array of a plurality of them in parallel to a plane orthogonal to the optical axis of the parallel light from the LED collimator 15. Further, a polarization beam splitter (hereinafter, abbreviated as "PBS film") 211 and a reflection film 212 are alternately provided at the interfaces between adjacent light transmissive members arranged in this array. Also, a λ / 2 phase plate 213 is provided on the emission surface from which the light that has entered the polarization conversion element 21 and has passed through the PBS film 211 is emitted.

[0095] On the exit surface of this polarization conversion element 21, a rectangular composite diffusion block 16 shown in Fig. 18(a) is further provided. That is, the light emitted from the LED 14a or 14b becomes parallel light by the action of the LED collimator 15 and enters the composite diffusion block 16, and after being diffused by the texture 161 on the exit side, it reaches the light guide 17.

[0096] The light guide 17 is a member formed in a rod shape with a substantially triangular cross section (see Fig. 18(b)) by a light-transmissive resin such as acrylic, and as is clear from Fig. 17, a light guide light incident portion (surface) 171 facing the exit surface of the composite diffusion block 16 via the first diffusion plate 18a, a light guide light reflection portion (surface) 172 forming an inclined surface, and a light guide light exit portion (surface) 173 facing the liquid crystal display panel 11, which is a liquid crystal display element, via the second diffusion plate 18b.

[0097] On the light guide light reflection portion (surface) 172 of this light guide 17, as shown in Fig. 17 which is a partial enlarged view thereof, a large number of reflection surfaces 172a and connection surfaces 172b are alternately formed in a sawtooth shape. And the reflection surface 172a (the line segment rising to the upper right in the figure) forms an angle αn (n is a natural number, and in this example, for example, 1 to 130) with the horizontal plane shown by the dashed line in the figure. As an example, here, αn is set to 43 degrees or less (however, 0 degrees or more).

[0098] The light guide light incident portion (surface) 171 is formed in a curved convex shape inclined toward the light source side. According to this, the parallel light from the exit surface of the composite diffusion block 16 is diffused and incident via the first diffusion plate 18a, and as is clear from the figure, it reaches the light guide light reflection portion (surface) 172 while being slightly bent (deflected) upward by the light guide light incident portion (surface) 171, and is reflected here and reaches the liquid crystal display panel 11 provided on the upper exit surface of the figure.

[0099] According to the display device 1 described in detail above, it is possible to further improve the light utilization efficiency and its uniform illumination characteristics, and at the same time, it is possible to manufacture it in a small size and at low cost, including the modularized light source device of the S-polarized light wave. In the above description, the polarization conversion element 21 is described as being attached behind the LED collimator 15, but the present invention is not limited thereto, and the same effects can also be obtained by providing it in the optical path leading to the liquid crystal display panel 11.

[0100] Note that a large number of reflecting surfaces 172a and connecting surfaces 172b are alternately formed in a sawtooth shape on the light guide light reflecting portion (surface) 172. The illumination light beam is totally reflected on each reflecting surface 172a and travels upward. Further, a sandwiching angle diffusion plate is provided on the light guide light emitting portion (surface) 173 and enters the light direction conversion panel 54 that controls the directivity characteristics as a substantially parallel diffused light beam, and enters the liquid crystal display panel 11 from an oblique direction. In this embodiment, the light direction conversion panel 54 is provided between the light guide light emitting portion (surface) 173 and the liquid crystal display panel 11, but the same effect can also be obtained by providing it on the light emitting surface of the liquid crystal display panel 11. <Example 2 of the light source device>

[0101] Another example of the configuration of the optical system such as the light source device 13 is shown in FIG. 19. Similar to the example shown in FIG. 18, a plurality (two in this example) of LEDs 14a and 14b constituting the light source are shown, and these are attached to the LED collimator 15 at predetermined positions. Note that each of these LED collimators 15 is formed of a light-transmissive resin such as acrylic. And similar to the example shown in FIG. 18, this LED collimator 15 has an outer peripheral surface 156 having a conical convex shape obtained by rotating a parabolic cross section, and at the top, it has a concave portion 153 formed with a convex portion (that is, a convex lens surface) 157 at the central portion thereof. Further, at the central portion of the flat portion, it has a convex lens surface protruding outward (or a concave lens surface recessed inward may also be used) 154. Note that the parabolic surface 156 forming the conical outer peripheral surface of the LED collimator 15 is set within a range of an angle that enables the light emitted from the LED 14a in the peripheral direction to be totally reflected inside it, or a reflecting surface is formed.

[0102] Also, LEDs 14a and 14b are respectively arranged at predetermined positions on the surface of an LED substrate 102, which is their circuit board. This LED substrate 102 is arranged and fixed with respect to the LED collimator 15 such that the LEDs 14a or 14b on its surface are respectively positioned at the central portions of the recesses 153 thereof.

[0103] According to such a configuration, among the light emitted from the LED 14a or 14b, particularly the light emitted upward (rightward in the figure) from the central portion thereof, is condensed by the two convex lens surfaces 157 and 154 forming the outer shape of the LED collimator 15 to become parallel light. Also, the light emitted from other portions in the peripheral direction is reflected by the parabolic surface forming the conical outer peripheral surface of the LED collimator 15 and similarly condensed to become parallel light. In other words, according to the LED collimator 15 having a convex lens formed at its central portion and a parabolic surface formed at its peripheral portion, almost all of the light generated by the LED 14a or 14b can be taken out as parallel light, and it becomes possible to improve the utilization efficiency of the generated light.

[0104] Note that a light guide 170 is provided via a first diffusion plate 18a on the light emission side of the LED collimator 15. The light guide 170 is a member formed in a rod shape with a substantially triangular cross section (see Fig. 19(a)) by a light-transmissive resin such as acrylic, and as is clear from Fig. 19(a), it includes a light guide light incident portion (surface) 171 facing the light emission surface of the diffusion block 16 via the first diffusion plate 18a, a light guide light reflection portion (surface) 172 forming an inclined surface, and a light guide light emission portion (surface) 173 facing the liquid crystal display panel 11, which is a liquid crystal display element, via a reflective polarizing plate 200.

[0105] If, for example, an object with the property of reflecting P-polarized light (transmitting S-polarized light) is selected for this reflective polarizing plate 200, it reflects the P-polarized light among the natural light emitted from the LED serving as the light source. After passing through the λ / 4 plate 202 provided on the light guide light reflection part 172 shown in Fig. 19(b), it is reflected by the reflection surface 201, and is converted into S-polarized light by passing through the λ / 4 plate 202 again. All the light beams incident on the liquid crystal display panel 11 are unified into S-polarized light.

[0106] Similarly, if an object with the property of reflecting S-polarized light (transmitting P-polarized light) is selected as the reflective polarizing plate 200, it reflects the S-polarized light among the natural light emitted from the LED serving as the light source. After passing through the λ / 4 plate 202 provided on the light guide light reflection part 172 shown in Fig. 19(b), it is reflected by the reflection surface 201, and is converted into P-polarized light by passing through the λ / 4 plate 202 again. All the light beams incident on the liquid crystal display panel 52 are unified into P-polarized light. Polarization conversion can also be realized with the configuration described above. <Example 3 of the light source device>

[0107] Another example of the configuration of the optical system such as the light source device will be described with reference to Fig. 16. In the third example, as shown in Fig. 16, the divergent light beam of natural light (mixing P-polarized light and S-polarized light) from the LED 102 is converted into a substantially parallel light beam by the collimator lens 18, and is reflected by the reflective light guide 304 toward the liquid crystal display panel 11. The reflected light is incident on the reflective polarizing plate 206 disposed between the liquid crystal display panel 11 and the reflective light guide 304. A specific polarization wave (for example, S-polarization wave) is reflected by the reflective polarizing plate 206 and passes through the surface connecting the reflection surface of the light guide 304, and is reflected by the reflector 271 disposed facing the opposite surface of the light guide 304. After passing through the phase plate (λ / 4 wavelength plate) 270 twice, polarization conversion occurs, and it passes through the light guide and the reflective polarizing plate and is incident on the liquid crystal display panel 11 and is modulated into image light. At this time, by aligning the specific polarization wave and the polarization plane after polarization conversion, the utilization efficiency of light becomes twice that of normal, and the polarization degree (extinction ratio) of the reflective polarizing plate is also added to the extinction ratio of the entire system. Therefore, by using the light source device of this embodiment, the contrast ratio of the information display system is significantly improved.

[0108] As a result, the natural light from the LED is aligned to a specific polarization (e.g., P polarization). Similar to the above example, a plurality of LEDs constituting the light source are provided (however, only one is shown in FIG. 16 for the longitudinal section), and these are attached to the LED collimator 18 at predetermined positions. Note that each of these LED collimators 18 is formed of, for example, a translucent resin such as acrylic or glass. And this LED collimator 18 has an outer peripheral surface of a conical convex shape obtained by rotating a parabolic cross-section, and at its top, it has a concave portion with a convex portion (i.e., a convex lens surface) formed at its central portion. Also, at the central portion of its flat portion, it has a convex lens surface protruding outward (alternatively, it may be a concave lens surface recessed inward). Note that the parabolic surface forming the conical outer peripheral surface of the LED collimator 18 is set within a range of angles that can totally reflect the light emitted from the LED 18 in the peripheral direction inside it, or a reflecting surface is formed.

[0109] Also, the LEDs are respectively arranged at predetermined positions on the surface of the LED substrate 102, which is their circuit board. This LED substrate 102 is arranged and fixed with respect to the LED collimator 18 such that the LEDs on its surface are respectively located at the central portions of the concave portions.

[0110] According to such a configuration, by the LED collimator 18, among the light radiated from the LED, in particular, the light radiated from its central portion is condensed by the two convex lens surfaces forming the outer shape of the LED collimator 18 and becomes parallel light. Also, the light emitted from other portions in the peripheral direction is reflected by the parabolic surface forming the conical outer peripheral surface of the LED collimator 18 and, similarly, is condensed and becomes parallel light. In other words, according to the LED collimator 18 that constitutes a convex lens at its central portion and forms a parabolic surface at its peripheral portion, almost all of the light generated by the LED can be taken out as parallel light, and it becomes possible to improve the utilization efficiency of the generated light. <Example 4 of Light Source Device>

[0111] Furthermore, another example of the configuration of an optical system such as a light source device will be described with reference to FIG. 25. Two optical sheets 207 for converting the diffusion characteristics in the vertical and horizontal directions (not shown in the front-back direction of the drawing) of the drawing are used on the light-emitting side of the LED collimator 18, and the light from the LED collimator 18 is made to enter between the two optical sheets 207 (diffusion sheets). When this optical sheet 207 is composed of a single sheet, the vertical and horizontal diffusion characteristics are controlled by the fine shapes of the front and back surfaces. Also, a plurality of diffusion sheets may be used to share the functions. Depending on the front surface shape and back surface shape of the optical sheet 207, the diffusion angle of the light from the LED collimator 18 in the vertical direction of the screen is adjusted according to the width of the vertical plane of the reflection surface of the diffusion sheet, and in the horizontal direction, the quantity of LEDs and the divergence angle from the LED substrate (optical element) 102 are optimally designed using the surface density of the light beam emitted from the liquid crystal display panel 11 as a design parameter so that it becomes uniform. That is, instead of the light guide, the diffusion characteristics are controlled by the surface shapes of a plurality of diffusion sheets. In this embodiment, the polarization conversion is performed in the same manner as in Example 3 of the light source device described above. On the other hand, a polarization conversion element 21 may be provided between the LED collimator 18 and the diffusion film 207, and after performing polarization conversion, the light source light may be made to enter the diffusion sheet 207.

[0112] For the above-described reflective polarizing plate 206, if an object having the property of reflecting S-polarized light (transmitting P-polarized light) is selected, the S-polarized light among the natural light emitted from the LED, which is the light source, is reflected, passes through the retardation plate 270 shown in FIG. 25, is reflected by the reflection surface 271, and is converted into P-polarized light by passing through the retardation plate 270 again and then enters the liquid crystal display panel 11. The thickness of this retardation plate needs to be selected as an optimal value according to the incident angle of the light beam on the retardation plate, and the optimal value exists in the range from λ / 16 to λ / 4. <Lenticular lens>

[0113] In order to control the diffusion distribution of the video light from the liquid crystal display panel 11, a lenticular lens can be 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 by optimizing the lens shape, the emission characteristics in one direction can be controlled. Furthermore, by arranging the microlens array in a matrix, the emission characteristics of the video light beam from the display device 1 in the X-axis and Y-axis directions can be controlled, and as a result, a spatial floating video display device having desired diffusion characteristics can be obtained.

[0114] The action of the lenticular lens will be described. By optimizing the lens shape, the lenticular lens can efficiently obtain a spatial floating image by transmitting or reflecting through the transparent member 100 emitted from the above-described display device 1. That is, for the video light from the display device 1, two lenticular lenses are combined, or a sheet for controlling the diffusion characteristics by arranging a microlens array in a matrix is provided, and in the X-axis and Y-axis directions, the luminance (relative luminance) of the video light can be controlled according to its reflection angle (0 degrees in the vertical direction). In this embodiment, such a lenticular lens makes the luminance characteristic in the vertical direction steeper as shown in Fig. 22(b) compared with the prior art, and by further changing the balance of the directivity characteristics in the up and down (positive and negative directions of the Y-axis) directions to increase the luminance (relative luminance) of the light due to reflection and diffusion, it is possible to obtain video light with a narrow diffusion angle (high straightness) and only a specific polarization component like the video light from a surface-emitting laser video source, suppress the ghost image generated by the retroreflective member in the case of using the prior art, and control so that the spatial floating image due to retroreflection can reach the eyes of the viewer efficiently.

[0115] Also, by the above-described light source device, a display device that emits light of a specific polarization having a video light beam that is nearly parallel to a specific direction can be realized by making the emission characteristics in both the X-axis direction and the Y-axis direction have a large included angle with respect to the emission light diffusion characteristics (denoted as conventional in the figure) from a general liquid crystal display panel shown in Figs. 22(a) and (b).

[0116] FIG. 21 shows an example of the characteristics of the lenticular lens adopted in this embodiment. In this example, in particular, the characteristics in the X direction (vertical direction) are shown. For characteristic O, the peak of the light emission direction is at an angle of around 30 degrees upward from the vertical direction (0 degrees), showing a luminance characteristic that is symmetric up and down. Also, characteristics A and B in FIG. 21 show examples of characteristics in which the video light above the peak luminance is condensed at around 30 degrees to increase the luminance (relative luminance). Therefore, in these characteristics A and B, at angles exceeding 30 degrees, the luminance (relative luminance) of the light rapidly decreases compared to characteristic O.

[0117] That is, according to the optical system including the above-described lenticular lens, when the video light beam from the display device 1 is made incident on the retroreflective member 2, the emission angle and the viewing angle of the video light aligned at the included angle by the light source device 13 can be controlled, and the degree of freedom in installing the retroreflective sheet (retroreflective member 2) can be greatly improved. As a result, the degree of freedom in the relationship of the imaging position of the spatial floating image that is reflected or transmitted through the transparent member 100 and imaged at a desired position can be greatly improved. As a result, it becomes possible to efficiently reach the eyes of outdoor or indoor monitors as light with a narrow diffusion angle (high straight-ahead property) and only a specific polarization component. According to this, even if the intensity (luminance) of the video light from the display device is reduced, the monitor can accurately recognize the video light and obtain information. In other words, by reducing the output of the display device, it becomes possible to realize a spatial floating video display device with low power consumption. <Measures against peeping at touch operations>

[0118] FIG. 26 illustrates a case where the spatial floating video 3 is applied as a user interface such as an ATM in a bank, and is a diagram for explaining a situation where another person stands behind a user 200 of an ATM or the like (hereinafter simply referred to as the user 200). In FIG. 26, another person 250 stands behind the user 200, and a situation where the other person 250 peeks at the touch operation of the user 200 is shown. In this case, the operation of the user 200 may be seen by the other person 250, and there is a risk that important information such as a password may be known to others. Here, measures against peeping at touch operations by the other person 250 will be described.

[0119] Figure 27 is a flowchart showing an example of processing when someone stands behind the user. Figure 27 includes steps S10 to S80. In step S10, it is determined whether two or more people are shown in the captured image generated by the imaging unit 1180. That is, in step S10, it is determined whether someone stands behind the user 200. For example, the control unit 1110 performs image analysis processing on the captured image output from the imaging unit 1180, extracts people from the captured image, and detects the number of people included in the captured image, thereby determining whether someone stands behind the user 200.

[0120] When the number of people included in the captured image is one, that is, when only the user 200 is shown in the captured image (NO), the control unit 1110 determines that no one stands behind the user 200, and the touch operation by the user 200 continues (step S20). On the other hand, when the number of people included in the captured image is two or more (YES), the control unit 1110 determines that someone 250 stands behind the user 200 and proceeds to step S30.

[0121] Note that even when it is determined in step S10 that no one 250 stands behind the user 200 and the touch operation continues, the process of step S10 may be performed again, and the determination as to whether someone 250 stands behind the user 200 may be repeatedly performed.

[0122] In step S30, based on the determination result in step S10, the user 200 is notified that there is someone 250 standing behind them to raise an alert. FIG. 28 is a diagram illustrating a display image for notifying the user when there is someone standing behind the user. In step S30, for example, as shown in FIG. 28(a), a display image (alert image) IMG11 indicating that a touch operation has been attempted on the person 250 standing behind is displayed. The display image IMG11 may be displayed near the object where the touch operation is performed, or may be displayed so as to overlap the object. The control regarding the display of the display image IMG11 is performed by the video control unit 1160, for example, based on an instruction from the control unit 1110.

[0123] Note that the alert to the user 200 may be made by voice. The alert by voice is made, for example, by supplying voice data for alert to the voice output unit 1140 according to an instruction from the control unit 1110.

[0124] When the user 200 is alerted by the display image IMG11 and / or voice, the process proceeds to step S40.

[0125] In step S40, it is a waiting period after the user 200 has been alerted. When a predetermined waiting time has elapsed and the waiting period ends, the process proceeds to step S50. In step S50, the same process as in step S10 is performed to determine whether there is someone 250 standing behind the user 200.

[0126] In step S50, when only the user 200 appears in the captured image (NO), the control unit 1110 determines that no one is standing behind the user 200, and the touch operation by the user 200 continues (step S20). On the other hand, when the number of people included in the captured image is two or more (YES), the control unit 1110 determines that there is someone 250 standing behind the user 200, and the process proceeds to step S60.

[0127] In step S60, for example, a selection image IMG12 for allowing the user to select whether to transition to the menu screen, which is the initial screen shown in FIG. 28(b), is displayed. Note that as the selection image, an image for selecting whether to end the screen display may be displayed.

[0128] In step S70, the user 200 refers to the selection image IMG12 and makes a selection as to whether to transition to the menu screen. If the user does not transition to the menu screen (NO), the user 200 selects "No" on the selection image IMG12 and continues the touch operation.

[0129] On the other hand, if the user transitions to the menu screen (YES), the user 200 selects "Yes" on the selection image IMG12. As a result, the displayed content switches to the menu screen, and the touch operation ends (step S80).

[0130] According to this configuration, it is possible to prevent peeping at the touch operation of the user 200 by the other person 250 and improve the safety during the touch operation. <When no operation is performed for a predetermined time>

[0131] Next, processing when no touch operation is performed by the user 200 for a predetermined time will be described. FIG. 29 is a flowchart showing an example of the processing when no operation is performed for a predetermined time. FIG. 29 includes steps S110 to S170.

[0132] In step S110, the user 200 is detected. Step S110 detects the user 200 by performing image processing on the captured image, for example, in the same manner as step S10 in FIG. 27. When the user 200 is detected in step S110 (YES), the process proceeds to step S120.

[0133] In step S120, it is detected whether there is a touch operation by the user 200. For example, the air operation detection unit 1350 acquires a sensing signal from the air operation detection sensor 1351, and detects whether there is a touch operation based on the sensing signal. In step S120, if it is determined that there is a touch operation (NO), the operation by the user 200 continues (step S130).

[0134] On the other hand, in step S120, if it is determined that there is no touch operation (YES), the process proceeds to step S140, and a guidance image for notifying the user 200 of the operation status is displayed. FIG. 30 is a diagram illustrating the guidance image. When the user 200 is recognized but there is no touch operation, for example, it is assumed that the user 200 is too close to the floating image 3 in space, or the display position (display surface) of the floating image 3 in space does not match the position of the finger of the user 200 (operation position).

[0135] Therefore, for example, the air operation detection unit 1350 and the control unit 1110 detect the position of the finger or body of the user 200 as a sensing result based on the sensing signal of the air operation detection sensor 1351. At this time, the position of the finger or body of the user 200 may be detected as a sensing result by combining the image processing result for the captured image and the sensing result. The detection of the sensing result may be performed in step S120, may be performed in step S140, or may be performed between steps S120 and S140.

[0136] For example, when the finger or body of the user 200 is embedded in the display surface of the floating image 3 in space and a touch operation cannot be detected, for example, as shown in FIG. 30(a), a guidance image IMG21 for prompting the user 200 to move away from the display screen, which is the floating image 3 in space, is displayed.

[0137] The guidance image IMG21 may be displayed near the object on which the touch operation is performed, or may be displayed so as to overlap the object. The control regarding the display of the guidance image IMG21 is performed by, for example, the video control unit 1160 based on an instruction from the control unit 1110 or the air operation detection unit 1350. The same applies to the guidance images described below.

[0138] Next, for example, when the finger of the user 200 has not reached the display surface of the spatial floating image 3 and a touch operation cannot be detected, for example, as shown in Fig. 30(b), a guidance image IMG22 for notifying the user 200 that a touch operation cannot be detected is displayed. Note that the guidance image IMG22 may include content that prompts the user 200 to perform an operation such as pushing the finger forward because the finger of the user 200 has not reached the display surface of the spatial floating image 3.

[0139] Next, when the finger of the user 200 has reached the display surface of the spatial floating image 3 but the touch operation cannot be detected because the object is not accurately touched, for example, as shown in Fig. 30(c), a guidance image IMG23 for notifying the user 200 that the touch position is inaccurate is displayed.

[0140] Note that the guidance to the user 200 may be performed by voice. The voice guidance is performed, for example, by supplying voice guidance data to the voice output unit 1140 according to an instruction from the control unit 1110. At this time, for example, an image (Fig. 30(d)) indicating that voice guidance is being performed may be displayed.

[0141] When the guidance to the user 200 is performed by the guidance image and / or voice, the process proceeds to step S150.

[0142] In step S150, after guiding user 200, the presence or absence of a touch operation by user 200 is detected again. The process of step S150 is the same as that of step S120. In step S150, if it is determined that there is a touch operation (NO), the operation by user 200 continues (step S130).

[0143] On the other hand, also in step S150, if it is determined that there is no touch operation again (YES), the process proceeds to step S160, and a guidance image notifying the transition to the menu screen is displayed. In step S160, for example, as shown in FIG. 30(e), a guidance image IMG31 that displays the time until the transition to the menu screen and a guidance image IMG32 that allows user 200 to select whether to transition to the menu screen are displayed.

[0144] When a predetermined time has elapsed or when the transition to the menu screen is selected, the menu screen is displayed (step S170). Note that if it is selected not to transition from the guidance image IMG32 to the menu image, for example, the processes of steps S110 and S120 may be performed again. Note that the guidance images IMG31 and IMG32 may be images that display the time until the display ends or images that allow selection of whether to end the display instead of the menu screen.

[0145] Also, in step S110, if user 200 is not detected (NO), the process proceeds to step S160, and for example, a guidance image IMG31 that displays the time until the transition to the menu screen is displayed.

[0146] According to this configuration, since guidance for user 200 can be performed based on the sensing result, it is possible to improve convenience. <Acceptance Stop of Touch Operation by User>

[0147] Next, the process of stopping accepting touch operations by user 200 will be described. For example, when user 200 is touching a plurality of objects simultaneously and subsequent processes cannot be executed, the acceptance of touch operations by user 200 is stopped. For example, in step S120 of FIG. 29, even when user 200 is touching a plurality of objects simultaneously, the process may proceed to step S140. In this case, in step S140, for example, a guidance image notifying that a plurality of buttons are being touched simultaneously may be displayed. Note that a determination step of whether a plurality of objects are being touched simultaneously may be provided between steps S120 and S130.

[0148] Then, in step S150, when a plurality of objects are being touched simultaneously, for example, FIG. 30(e) is displayed to stop accepting touch operations by user 200.

[0149] Also, for example, when a plurality of people are shown in the captured image, the acceptance of operations by user 200 may be stopped. In this case, for example, a determination step of whether there is someone standing behind user 200, similar to step S10 of FIG. 27, is provided between steps S110 and S120 of FIG. 29. When it is determined that there is someone standing behind user 200, the process proceeds to step S140, and by displaying a guidance image indicating that someone is peeking at the touch operation, it becomes possible to alert user 200. Then, after step S140, a determination step of whether there is someone standing behind user 200 again is provided, and also in this step, when it is determined that someone is peeking, the process proceeds to step S150 to stop accepting touch operations by user 200. Thereby, it becomes possible to prevent someone 250 from peeking at touch operations.

[0150] Also, for example, when the spatial floating image 3 is not displayed at a brightness that can be recognized by the user 200, the reception of operations by the user 200 may be stopped. In this case, for example, an illuminance detection step of detecting the brightness of the surrounding environment using, for example, an illuminance sensor is provided before and after step S110 in FIG. 29. Then, after this illuminance detection step, a determination step of comparing the brightness of the surrounding environment with the luminance (brightness) of the displayed spatial floating image 3 is provided to determine whether the user 200 can recognize the spatial floating image 3. And in this determination step, if it is determined that the user 200 cannot recognize the spatial floating image 3, for example, a transition is made to step S160, and a guidance image notifying that the user has shifted to the menu screen because the spatial floating image 3 cannot be recognized may be displayed.

[0151] Also, for example, when the temperature of the spatial floating image display device rises to a temperature equal to or higher than a predetermined threshold value, the reception of operations by the user 200 may also be stopped. In this case, for example, steps of measuring and determining the temperature of the spatial floating image display device are provided before and after step S110 in FIG. 29. When the temperature of the spatial floating image display device is equal to or higher than the predetermined threshold value, a transition is made to step S160, and a guidance image notifying that the user has shifted to the menu screen because the temperature of the spatial floating image display device has risen may be displayed. Also, in this case, the display of the spatial floating image 3 may be stopped without displaying the guidance image.

[0152] Note that the temperature measurement and determination of the spatial floating image display device are performed in a flow different from that in FIG. 27. When the temperature of the spatial floating image display device becomes equal to or higher than a predetermined threshold value, an interrupt is sent to the control unit 1110 to stop the display of the guidance image and the display of the spatial floating image 3.

[0153] According to this configuration, it is possible to provide guidance to the user 200 according to various situations, so that the convenience can be improved. <Brightness adjustment of spatial floating image>

[0154] Next, the brightness adjustment of the floating image 3 in space will be described. Depending on the environment of the installation location of the floating image display device in space, the floating image 3 in space may be difficult for the user 200 to see. For example, when the environment of the installation location is bright, the difference between the brightness of the floating image 3 in space and the brightness of the surrounding environment becomes small, making the floating image 3 in space difficult to see. In this case, the brightness of the floating image 3 in space is adjusted so that it can be seen more easily.

[0155] The brightness of the surrounding environment is detected by, for example, an illuminance sensor. This illuminance sensor may be incorporated in the floating image display device in space, or may be connected as an external device to the floating image display device 1000, for example, by wire or wirelessly. The illuminance sensor detects the brightness of the surrounding environment and outputs the detected brightness to the floating image display device 1000 as illuminance sensing information. The illuminance sensing information input to the floating image display device 1000 is stored in, for example, the memory 1109.

[0156] When continuously recording the illuminance sensing information, each illuminance sensing information may be recorded in, for example, the storage 1170. Each illuminance sensing information is recorded in the storage 1170 in association with its respective acquisition time.

[0157] The control unit 1110 controls the power supply 1106 based on the illuminance sensing information and adjusts the power supplied from the power supply 1106 to the light source 1105, thereby adjusting the brightness (luminance) of the floating image 3 in space. Note that the control unit 1110 can calculate the brightness of the floating image 3 in space based on the power supplied from the power supply 1106 to the light source 1105. Therefore, the control unit 1110 can compare the illuminance sensing information supplied from the illuminance sensor with the calculated brightness of the floating image 3 in space and adjust the brightness of the floating image 3 in space. As a result, it becomes possible to appropriately set the brightness of the floating image 3 in space.

[0158] Also, when the surrounding environment becomes dark, the difference between the brightness of the floating image 3 in space and the brightness of the surrounding environment increases, so the user 200 will feel that the floating image 3 in space is dazzling. In this case, the control unit 1110 performs control to reduce the brightness of the floating image 3 in space. As a result, the brightness of the floating image 3 in space can be appropriately set according to the brightness of the surrounding environment, and the user 200 will no longer feel that the floating image 3 in space is dazzling.

[0159] Next, a method for adjusting the brightness of the floating image 3 in space according to time will be described. For example, when the floating image display device is continuously installed at a predetermined location for a long time, the brightness of the surrounding environment changes periodically. Therefore, the control unit 1110 adjusts the brightness of the floating image 3 in space every time according to the periodic change in the brightness of the surrounding environment. The periodic change in the brightness of the surrounding environment, that is, the brightness of the surrounding environment at each time, is measured in advance using an illuminance sensor and recorded in, for example, the storage 1170. According to this configuration, it is possible to appropriately set the brightness of the floating image 3 in space according to the brightness of the surrounding environment.

[0160] Note that the adjustment of the brightness of the floating image 3 in space may be performed by changing the floating image 3 in space. For example, when the difference between the brightness of the floating image 3 in space and the brightness of the surrounding environment is small, the control unit 1110 instructs the video control unit 1160 to change to a brighter video than the currently displayed video. Based on the instruction from the control unit 1110, the video control unit 1160 outputs video data of a brighter video to the video display unit 1102 with the same display content as, for example, an object related to a touch operation. The video display unit 1102 displays a floating image 3 in space that is brighter than before based on the newly supplied video data.

[0161] On the other hand, when the surrounding environment becomes dark and the difference between the brightness of the floating image 3 in space and the brightness of the surrounding environment increases, the control unit 1110 instructs the video control unit 1160 to change to a darker video than the currently displayed video.

[0162] When adjusting the brightness of the floating image 3 by changing the image, the light source 1105 may not be controlled, or the light source 1105 may be controlled in conjunction with the change of the image. <Automatic display of floating image>

[0163] Next, the automatic display of the floating image will be described. FIG. 31 is a diagram showing a configuration example of a floating image display device that performs automatic display of a floating image. In the floating image display device of FIG. 31, a human sensor 260 is provided. The human sensor 260 is a sensor that detects a person using, for example, infrared rays, visible light, ultrasonic waves, etc. Also, a temperature sensor or the like that detects the temperature of the display area of the floating image 3 can also be used as a human sensor. The human sensor 260 is connected to the floating image display device 1000 by wire or wirelessly, for example, and outputs a person sensing signal to the floating image display device 1000.

[0164] When the user 200 approaches the floating image display device 1000, a person sensing signal is output from the human sensor 260. For example, based on the person sensing signal, the control unit 1110 instructs the video control unit 1160 to display the floating image 3. The video control unit 1160 outputs video data for display to the video display unit 1102 based on the instruction from the control unit 1110. Thereby, the floating image 3 is displayed when a person approaches.

[0165] FIG. 32 is a diagram illustrating an image displayed as the floating image as described above. In FIG. 32, for example, a keypad for inputting numbers and calculation formulas is illustrated. The transparent structural member 60 in FIG. 32(b) is provided to facilitate the position recognition of the floating image 3 by the monitor.

[0166] Note that the image displayed as the floating image is not limited to these, and may be, for example, a keyboard used in a personal computer or the like, or a selection button for selecting a product or the like.

[0167] According to this configuration, the user 200 is notified that the device has been activated, and the touch operation can be started immediately. This improves the convenience for the user 200 and enables reduction of power consumption.

[0168] Although various embodiments have been described in detail above, however, the present invention is not limited to only the above-described embodiments, and includes various modifications. For example, the above-described embodiments have described the entire system in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

Description of Reference Numerals

[0169] 1... display device, 2... retroreflective member, 3... spatial image (spatial floating image), 105... windshield, 100... transparent member, 101... polarization separation member, 12... absorption type polarizing plate, 13... light source device, 54... light direction conversion panel, 151... retroreflective member, 102, 202... LED substrate, 203... light guide, 205, 271... reflective sheet, 206, 270... retardation plate, 300... spatial floating image, 301... ghost image of spatial floating image, 302... ghost image of spatial floating image, 200... user, 250... other person, 260... human sensor, 1000... spatial floating image display device, 1110... control unit, 1160... video control unit, 1180... imaging unit, 1102... video display unit, 1350... air operation detection unit, 1351... air operation detection sensor.

Claims

1. A spatial floating image display device, a display device that generates an image, a retroreflective member that reflects the image light from the display device to form a spatial floating image, an air operation detection sensor that detects a touch operation by the user on the spatial floating image, an imaging unit that images the user from the back side of the touch operation surface of the spatial floating image, and the spatial floating image display device when a plurality of people are shown in the captured image captured by the imaging unit from the back side of the touch operation surface of the spatial floating image, displays information notifying the user of being spied on on the spatial floating image. Spatial floating image display device.

2. In the spatial floating image display device according to Claim 1, when a plurality of people are shown in the captured image after the information is displayed, the spatial floating image display device displays information for allowing the user to select whether to shift to a menu screen as a spatial floating image. Spatial floating image display device.

3. In the spatial floating image display device according to Claim 2, when the user selects not to shift to the menu screen, the operation by the user on the spatial floating image continues. Spatial floating image display device.

4. In the spatial floating image display device according to Claim 1, when the spatial floating image display device detects the user based on the captured image and the air operation detection sensor does not detect the user's operation, the spatial floating image display device displays guidance information for notifying the user of the operation status as a spatial floating image. Spatial floating image display device.

5. In the spatial floating image display device according to Claim 4, after the spatial floating image display device displays the guidance information, when no operation by the user is detected, it displays guidance information for allowing the user to select whether to shift to a menu screen as a spatial floating image. Spatial floating image display device.

6. In the spatial floating image display device according to Claim 4, when the user touches a plurality of objects included in the spatial floating image at the same time, the acceptance of the operation by the user is stopped. Spatial floating image display device.

7. In the spatial floating image display device according to Claim 4, when a plurality of people are shown in the captured image, the acceptance of the operation by the user is stopped. Spatial floating image display device.

8. In the spatial floating image display device according to claim 4, when a spatial floating image is not being displayed at a brightness recognizable by the user, reception of operations by the user is stopped. Spatial floating image display device.

9. In the spatial floating image display device according to claim 4, when the temperature of the spatial floating image display device rises to a temperature equal to or higher than a predetermined threshold value, reception of operations by the user is stopped. Spatial floating image display device.

10. In the spatial floating image display device according to claim 1, an illuminance sensor that detects the brightness of the surrounding environment, and the spatial floating image display device adjusts the brightness of the spatial floating image based on the brightness of the surrounding environment detected by the illuminance sensor. Spatial floating image display device.

11. In the spatial floating image display device according to claim 1, a human presence sensor that detects a person, and when the human presence sensor detects a person, the spatial floating image display device starts displaying a spatial floating image. Spatial floating image display device.

Images