Patent ID: 12204122

MODES FOR CARRYING OUT THE INVENTION

Hereinafter, description is given in detail, with reference to the drawings, of embodiments for carrying out the present disclosure. It is to be noted that the description is given in the following order.

1. EMBODIMENT (FIGS.1TO4)

An example of displaying respective different television programs on the front and back of a transmissive transparent screen

2. MODIFICATION EXAMPLES

Modification Example A: An example of displaying an image acquired by data communication on the front and back of a transparent screen (FIGS.5and6)Modification Example B: An example of preforming display control using an input unit configured by a mobile terminal, a smartphone, a keyboard, a mouse, or the like (FIGS.7to10)Modification Example C: An example of providing a reflective transparent screen (FIG.11)Modification Example D: An example of a transparent screen attached to a glass plate (FIGS.12and13)

3. APPLICATION EXAMPLES

Application Example 1: An example of a display apparatus provided as a partition in a kitchen (FIGS.14and15)Application Example 2: An example of a display apparatus provided as a screen of a game machine (FIG.16)Application Example 3: An example of a display apparatus provided on a reception table (FIG.17)

1. EMBODIMENT

Configuration

FIG.1illustrates an example of a cross-sectional configuration of a display apparatus1according to an embodiment of the present disclosure. The display apparatus1includes an HOE (Holographic Optical Element; holographic optical element) screen10, which is a transparent screen, and displays an image on each surface of the HOE screen10. The screen10corresponds to a specific example of a “transparent screen” of the present disclosure. The HOE screen10is configured by a transmissive volume hologram. The HOE screen10diffracts light incident at an angle near such an angle as to satisfy Bragg's diffraction condition for the transmissive volume hologram, out of light (image light La1described later) incident on a first main surface Sa, to side of a second main surface Sb. The diffracted light at this time is emitted as image light La2from the second main surface Sb. The HOE screen10further diffracts light incident at an angle near such an angle as to satisfy the Bragg's diffraction condition for the transmissive volume hologram, out of light (image light Lb1described later) incident on the second main surface Sb, to side of the first main surface Sa. The diffracted light at this time is emitted as image light Lb2from the first main surface Sa. An interference fringe with an inclination angle (a slant angle θ1) is formed on the HOE screen10. Here, the inclination angle (slant angle θ1) refers to an angle formed between a surface of the transmissive volume hologram and the interference fringe. The interference fringe is formed from the inside of the transmissive volume hologram to the surface thereof. The interference fringe satisfies the Bragg condition.

The display apparatus1further includes an AR (Anti-Reflection; antireflection) film20adisposed on the side of the first main surface Sa of the HOE screen10, and an AR film20bdisposed on the side of the second main surface Sb of the HOE screen10. The AR film20ais attached to the first main surface Sa of the HOE screen10, for example, to suppress reflection of unnecessary incident light (e.g., external light or secondary image light La1by interfacial reflection). The AR film20bis attached to the second main surface Sb of the HOE screen10, for example, to suppress reflection of incident light (e.g., image light Lb1or external light). It is to be noted that at least one of the AR film20aor the AR film20bmay be omitted, as necessary.

The display apparatus1further includes two image projection sections50aand50b. The image projection section50acorresponds to a specific example of a “first image projection section” of the present disclosure. The image projection section50bcorresponds to a specific example of a “second image projection section” of the present disclosure.

The image projection section50aprojects the image light La1onto the first main surface Sa. The image projection section50ais disposed on the side of the first main surface Sa of the HOE screen10, and is disposed at a location corresponding to a lower end of the HOE screen10. The image projection section50ais configured to cause the image light La1to be incident on the first main surface Sa at an angle near such an angle as to satisfy the Bragg's diffraction condition for the transmissive volume hologram. The image projection section50ais further configured to cause the image light La1to be diffracted to the side of the second main surface Sb in the transmissive volume hologram.

The image projection section50bprojects the image light Lb1onto the second main surface Sb. The image projection section50bis disposed on the side of the second main surface Sb of the HOE screen10, and is disposed at a location corresponding to an upper end of the HOE screen10. The image projection section50bis configured to cause the image light Lb1to be incident on the second main surface Sb at an angle near such an angle as to satisfy the Bragg's diffraction condition for the transmissive volume hologram. The image projection section50bis further configured to cause the image light Lb1to be diffracted to the side of the first main surface Sa in the transmissive volume hologram.

The display apparatus1further includes two eave sections30aand30band two base sections40aand40b. The base section40acorresponds to a specific example of a “first light-shielding section” of the present disclosure. The eave section30bcorresponds to a specific example of a “second light-shielding section” of the present disclosure.

The eave sections30aand30bare each disposed at a location corresponding to the upper end of the HOE screen10. The eave section30aand the eave section30bare disposed at positions opposed to each other with the HOE screen10interposed therebetween. The eave section30ais disposed on the side of the first main surface Sa of the HOE screen10, and the eave section30bis disposed on the side of the second main surface Sb of the HOE screen10. The eave sections30aand30bhold the location corresponding to the upper end of the HOE screen10. The eave section30ahas an inclined surface with an angle θ2larger than the slant angle θ1of the volume hologram. The eave section30bhas an inclined surface with the angle θ2larger than the slant angle θ1of the volume hologram. The eave sections30aand30b(in particular, the inclined surfaces) are each positioned at a distance of a tangent at the slant angle θ1of the volume hologram, from the location corresponding to the upper end of the HOE screen10. The eave section30b(particularly, the inclined surface) prevents external light from being directly incident on the second main surface Sb at least at the same incident angle as that of the image light Lb1from side of the eave section30b.

The base sections40aand40bare each disposed at a location corresponding to the lower end of the HOE screen10. The base section40aand the base section40bare disposed at positions opposed to each other with the HOE screen10interposed therebetween. The base section40ais disposed on the side of the first main surface Sa of the HOE screen10, and the base section40bis disposed on the side of the second main surface Sb of the HOE screen10. The base sections40aand40bhold the location corresponding to the lower end of the HOE screen10. The base section40ahas an inclined surface with the angle θ2larger than the slant angle θ1of the volume hologram. The base section40bhas an inclined surface with the angle θ2larger than the slant angle θ1of the volume hologram. The base sections40aand40b(in particular, the inclined surfaces) are each positioned at a distance of a tangent at the slant angle of the volume hologram, from the location corresponding to the lower end of the HOE screen10. The base section40a(particularly, the inclined surface) prevents external light from being directly incident on the first main surface Sa at least at the same incident angle as that of the image light La1from side of the base section40a.

In a case where at least a portion of the inclined surface of the eave section30bis configured by a material that transmits the image light Lb1, the image projection section50bmay irradiate the second main surface Sb with the image light Lb1through a location, of the inclined surface of the eave section30b, configured by the material that transmits the image light Lb1. At this time, the image projection section50bis disposed (accommodated) inside the eave section30b. In a case where at least a portion of the inclined surface of the base section40ais configured by a material that transmits the image light La1, the image projection section50amay irradiate the first main surface Sa with the image light La1through a location, of the inclined surface of the base section40a, configured by the material that transmits the image light La1. At this time, the image projection section50ais disposed (accommodated) inside the base section40a.

Next, description is given of inner configurations of the image projection sections50aand50b.

The image projection sections50aand50bare each a device that projects an image based on an externally inputted image signal Din onto the HOE screen10, for example, as illustrated inFIG.2. The image projection sections50aand50beach include, for example, a video signal processing circuit51, a laser drive circuit52, a light source part53, a scanner part54, and a scanner drive circuit55.

The video signal processing circuit51generates a projection image signal for each color on the basis of the image signal Din. On the basis of the projection image signal for each color, the laser drive circuit52controls a peak value of a current pulse to be applied to light sources53R,53G, and53B described later.

The light source part53includes a plurality of light sources, for example, the three light sources53R,53G, and53B. The three light sources53R,53G, and53B are used as respective laser light sources that emit laser light beams of wavelengths of red (R), green (G), and blue (B), for example. The respective laser light beams emitted from the three light sources53R,53G, and53B are, for example, substantially collimated by collimating lenses, and thereafter combined into a single laser light beam by beam splitters53sR,53sG, and53sB, etc. The beam splitter53sR reflects red light, for example. The beam splitter53sG reflects green light, and transmits red light, for example. The beam splitter53sB reflects blue light, and transmits red light and green light, for example.

The laser light beams transmitted and reflected by the beam splitters53sR,53sG, and53sB are incident on the scanner part54. The scanner part54is configured by using one biaxial scanner, for example. The incident laser light beam is modulated by the biaxial scanner in terms of an irradiation angle in horizontal and vertical directions, and then projected onto the screen. It is to be noted that the scanner part54may be configured to use two uniaxial scanners for scanning in a horizontal direction and a vertical direction.

Typically, the scanner part54includes a sensor that detects an irradiation angle of the biaxial scanner or the like, and the sensor outputs horizontal and vertical angular signals. The angular signals are inputted to the scanner drive circuit55. On the basis of the horizontal angular signal and the vertical angular signal inputted from the scanner part54, for example, the scanner drive circuit55drives the scanner part54to have a desired irradiation angle. It is to be noted that the image projection sections50aand50bare not limited to the above-described configurations, and may be configured differently from the above-described configurations.

FIG.3illustrates an example of functional blocks of a display unit1A incorporated in the display apparatus1.FIG.4illustrates an example of functional blocks of a display unit1C incorporated in the display apparatus1. The display unit1A includes the above-described image projection section50a. The display unit1C includes the above-described image projection section50b. The display apparatus1includes the display unit1A, the display unit1C, and a remote-control (remote control) transmitter1B for remote operation of the display units1A and1C. The remote-control transmitter1B may be a device dedicated to the remote operation of the display units1A and1C, or may be a mobile terminal such as a smartphone in which an application enabling the remote operation of the display units1A and1C is installed.

The display unit1A is, for example, a projector that is able to receive a television broadcasting signal by wire or wirelessly. The display unit1A includes, for example, an antenna terminal501, a digital tuner502, a demultiplexer503, and an arithmetic circuit504. The display unit1A further includes, for example, a decoder505, the image projection section50a, an audio signal processing circuit506, an audio amplification circuit507, a speaker508, and a remote-control receiving circuit509.

The antenna terminal501is a terminal to which a television broadcasting signal received by a reception antenna (unillustrated) is inputted. The digital tuner502processes the television broadcasting signal inputted to the antenna terminal501, for example, to output a predetermined transport stream corresponding to a channel selected by a user. The demultiplexer503extracts a partial TS (Transport Stream) corresponding to the channel selected by the user, for example, from the transport stream obtained by the digital tuner502.

The arithmetic circuit504controls an operation of each of the sections of the display unit1A. The arithmetic circuit504transmits, for example, the partial TS obtained by the demultiplexer503to the decoder505. In addition, the arithmetic circuit504controls an operation of the demultiplexer503and the operation of each of the sections of the display unit1A, for example, on the basis of setting information inputted from the remote-control receiving circuit509. On the basis of the setting information inputted from the remote-control receiving circuit509, for example, the arithmetic circuit504further generates image data for a UI (User Interface) to be used for screen displaying, and outputs the generated image data to the image projection section50a(video signal processing circuit51).

The decoder505performs decode processing, for example, on an image PES (Packetized Elementary Stream) packet included in the partial TS obtained by the demultiplexer503to thereby obtain image data. In addition, the decoder505performs the decode processing, for example, on an audio PES packet included in the partial TS obtained by the demultiplexer503to thereby obtain audio data.

On the basis of the image data inputted from the decoder505, the image projection section50agenerates the image light La1, and irradiates the first main surface Sa.

The audio signal processing circuit506performs processing such as D/A conversion, for example, on the audio data obtained by the decoder505. The audio amplification circuit507amplifies the audio signal outputted from the audio signal processing circuit506, for example, to supply the amplified audio signal to the speaker508.

The remote-control receiving circuit509receives a remote-control signal transmitted from the remote-control transmitter1B, for example, to supply the received remote-control signal to the arithmetic circuit504.

The display unit1C is, for example, a projector that is able to receive a television broadcasting signal by wire or wirelessly. The display unit1C includes, for example, an antenna terminal511, a digital tuner512, a demultiplexer513, and an arithmetic circuit514. The display unit1C further includes, for example, a decoder515, an inverting input section525, the image projection section50b, an audio signal processing circuit516, an audio amplification circuit517, a speaker518, and a remote-control receiving circuit519.

The antenna terminal511is a terminal to which a television broadcasting signal received by a reception antenna (unillustrated) is inputted. The digital tuner512processes the television broadcasting signal inputted to the antenna terminal511, for example, to output a predetermined transport stream corresponding to a channel selected by a user. The demultiplexer513extracts a partial TS corresponding to the channel selected by the user, for example, from the transport stream obtained by the digital tuner512.

The arithmetic circuit514controls an operation of each of the sections of the display unit1C. The arithmetic circuit514transmits, for example, the partial TS obtained by the demultiplexer513to the decoder515. In addition, the arithmetic circuit514controls an operation of the demultiplexer513and the operation of each of the sections of the display unit1C, for example, on the basis of setting information inputted from the remote-control receiving circuit519. On the basis of the setting information inputted from the remote-control receiving circuit519, for example, the arithmetic circuit514further generates image data for a UI to be used for screen displaying, and outputs the generated image data to the inverting input section525. The inverting input section525generates inverted image data in which the image data is inverted vertically, and outputs the generated inverted image data to the image projection section50b(video signal processing circuit51).

The decoder515performs decode processing, for example, on an image PES packet included in the partial TS obtained by the demultiplexer513to thereby obtain image data. In addition, the decoder515performs the decode processing, for example, on an audio PES packet included in the partial TS obtained by the demultiplexer513to thereby obtain audio data.

On the basis of the image data inputted from the decoder515, the image projection section50bgenerates the image light Lb1, and irradiates the second main surface Sb.

The audio signal processing circuit516performs processing such as D/A conversion, for example, on the audio data obtained by the decoder515. The audio amplification circuit517amplifies the audio signal outputted from the audio signal processing circuit516, for example, to supply the amplified audio signal to the speaker518.

The remote-control receiving circuit519receives a remote-control signal transmitted from the remote-control transmitter1B, for example, to supply the received remote-control signal to the arithmetic circuit514.

Operation

Next, description is given of an operation of the display apparatus1according to the present embodiment.

An observer100uses the remote-control transmitter1B, for example, to perform channel selection of images to be displayed on the first main surface Sa and the second main surface Sb. Then, the remote-control transmitter1B generates a remote-control signal according to an operation by the observer100to transmit the generated remote-control signal to the remote-control receiving circuits509and519. The remote-control receiving circuits509and519output the received remote-control signal to the arithmetic circuits504and514. In a case where the inputted remote-control signal is a signal related to image display on the side of the second main surface Sb, the arithmetic circuit504performs control based on the inputted remote-control signal. In a case where the inputted remote-control signal is a signal related to image display on the side of the first main surface Sa, the arithmetic circuit514performs control based on the inputted remote-control signal. Suppose, in this example, that the inputted remote-control signal is a signal related to image display on each of the first main surface Sa and the second main surface Sb.

The demultiplexer513extracts the partial TS corresponding to a selected channel on the side of the first main surface Sa from the transport stream obtained by the digital tuner512. The decoder515performs the decode processing on the image PES packet included in the partial TS obtained by the demultiplexer513to thereby obtain image data. In addition, the decoder515performs the decode processing on the audio PES packet included in the partial TS obtained by the demultiplexer513to thereby obtain audio data.

On the basis of the image data inputted from the decoder515, the image projection section50bgenerates the image light Lb1, and irradiates the second main surface Sb. The image light Lb1is incident on the second main surface Sb at an angle near such an angle as to satisfy the Bragg's diffraction condition for the transmissive volume hologram, and is diffracted to the side of the first main surface Sa. As a result, the diffracted light is emitted as the image light Lb2from the first main surface Sa, and an image corresponding to the selected channel on the side of the first main surface Sa is displayed on the first main surface Sa. The audio signal processing circuit516performs processing such as D/A conversion for the audio data obtained by the decoder515. The audio amplification circuit517amplifies the audio signal outputted from the audio signal processing circuit516to supply the amplified audio signal to the speaker518. The speaker518outputs an audio corresponding to the inputted audio signal toward the front of the first main surface Sa (i.e., the observer100).

Meanwhile, the demultiplexer503extracts a partial TS corresponding to the selected channel on the side of the second main surface Sb from the transport stream obtained by the digital tuner502. The decoder505performs the decode processing on the image PES packet included in the partial TS obtained by the demultiplexer503to thereby obtain image data. In addition, the decoder505performs the decode processing on the audio PES packet included in the partial TS obtained by the demultiplexer503to thereby obtain audio data.

On the basis of the image data inputted from the decoder505, the image projection section50agenerates the image light La1, and irradiates the first main surface Sa. The image light La1is incident on the first main surface Sa at an angle near such an angle as to satisfy the Bragg's diffraction condition for the transmissive volume hologram, and is diffracted to the side of the second main surface Sb. As a result, the diffracted light is emitted as the image light La2from the second main surface Sb, and an image corresponding to the selected channel on the side of the second main surface Sb is displayed on the second main surface Sb. The audio signal processing circuit506performs processing such as D/A conversion for audio data obtained by the decoder505. The audio amplification circuit507amplifies the audio signal outputted from the audio signal processing circuit506to supply the amplified audio signal to the speaker508. The speaker508outputs an audio corresponding to the inputted audio signal toward the front of the second main surface Sb (i.e., an observer200).

In this manner, the image display is performed on each surface of the HOE screen10.

Workings and Effects

Next, description is given of workings and effects of the display apparatus1according to the present embodiment.

In the present embodiment, the base section40aprevents external light from being directly incident on the first main surface Sa at least at the same incident angle as that of the image light La1from the side of the base section40a. In addition, the eave section30bprevents external light from being directly incident on the second main surface Sb at least at the same incident angle as that of the image light Lb1from the side of the eave section30b. This makes it possible to prevent diffracted external light from being superimposed on the image light La2and the image light Lb2. As a result, it is possible to clearly display an image in a bright environment.

In addition, in the present embodiment, the image projection section50ais disposed at the location corresponding to the lower end of the HOE screen10, and the image projection section50bis disposed at the location corresponding to the upper end of the HOE screen10. This makes it possible to dispose the image projection sections50aand50bwithout impairing a design property.

In addition, in the present embodiment, the image projection section50ais disposed inside the base section40a, and the image projection section50bis disposed inside the eave section30b. This makes it possible to dispose the image projection sections50aand50bwithout impairing a design property.

In addition, in the present embodiment, the base section40ais positioned at a distance of a tangent at the slant angle θ1of the volume hologram, from the location corresponding to the lower end of the HOE screen10. In addition, the eave section30bis positioned at a distance of a tangent at the slant angle θ1of the volume hologram, from the location corresponding to the upper end of the HOE screen10. This allows the base section40ato prevent external light from being directly incident on the first main surface Sa at least at the same incident angle as that of the image light La1from the side of the base section40a. In addition, the eave section30bprevents external light from being directly incident on the second main surface Sb at least at the same incident angle as that of the image light Lb1from the side of the eave section30b. This makes it possible to prevent diffracted external light from being superimposed on the image light La2and the image light Lb2. As a result, it is possible to clearly display an image in a bright environment.

In addition, in the present embodiment, the base sections40aand40bhold the location corresponding to the lower end of the HOE screen10, and the eave sections30aand30bhold the location corresponding to the upper end of the HOE screen10. This allows, for example, the base sections40aand40bto be fixed to a table and the eave sections30aand30bto be fixed to the ceiling, thereby enabling installation of the HOE screen10. In this manner, in the present embodiment, it is possible to install the HOE screen10without impairing a design property.

In addition, in the present embodiment, the AR films20aand20bare provided on the first main surface Sa and the second main surface Sb. This makes it possible to prevent an image quality from being impaired by external light reflection at the first main surface Sa and the second main surface Sb. In addition, in the present embodiment, in a case where the AR film20ais provided only on the first main surface Sa, it is possible to prevent the image quality from being impaired by the external light reflection at the first main surface Sa. In addition, in the present embodiment, in a case where the AR film20bis provided only on the second main surface Sb, it is possible to prevent the image quality from being impaired by the external light reflection at the second main surface Sb.

2. MODIFICATION EXAMPLES

Modification Example A

In the foregoing embodiment, an image by television broadcasting is displayed. However, in the foregoing embodiment, an image other than that of the television broadcasting (e.g., image by data communication) may be displayed. At this time, the display unit1A may include, for example, a communication section521and an arithmetic circuit522, instead of the antenna terminal501, the digital tuner502, the demultiplexer503, the arithmetic circuit504and the decoder505, as illustrated inFIG.5. In addition, the display unit1C may include, for example, a communication section523and an arithmetic circuit524, instead of the antenna terminal511, the digital tuner512, the demultiplexer513, the arithmetic circuit514and the decoder515, as illustrated inFIG.6.

The communication sections521and523are able to communicate with external apparatuses via a network. Here, the network is, for example, a network that performs communication using a communication protocol (TCP/IP) utilized normally in the Internet. The network may be, for example, a secure network that performs communication using an own communication protocol of the network. The network is, for example, the Internet, an intranet, or a local area network. For example, coupling between the network and the communication sections521and523may be made by a wired LAN (Local Area Network) such as Ethernet (registered trademark), or may be made by a wireless LAN such as Wi-Fi, a mobile phone line, or the like.

The communication section521outputs image data acquired from an external apparatus via a network to the arithmetic circuit522. The communication section523outputs image data acquired from an external apparatus via a network to the arithmetic circuit524.

The arithmetic circuit522acquires image data via the communication section521and the network on the basis of setting information inputted from the remote-control receiving circuit509, for example. The arithmetic circuit522outputs the acquired image data to the image projection section50a, and outputs audio data included in the acquired image data to the audio signal processing circuit506. The arithmetic circuit524acquires image data via the communication section523and the network on the basis of setting information inputted from the remote-control receiving circuit509, for example. The arithmetic circuit524outputs the acquired image data to the inverting input section525, and outputs audio data included in the acquired image data to the audio signal processing circuit516.

In the present modification example, an image other than that of television broadcasting (e.g., image by data communication) is displayed on each surface of the HOE screen10. This makes it possible to achieve various types of image display.

Modification Example B

In the foregoing embodiment and modification example thereof, as illustrated inFIGS.7,8,9, and10, a communication section526may be provided instead of the remote-control receiving circuit509, a communication section527may be provided instead of the remote-control receiving circuit519, and an input unit1D may be provided instead of the remote-control transmitter1B.

The input unit1D is configured by, for example, a mobile terminal, a smartphone, or the like, and is able to communicate with the communication sections526and527, for example, via a network. The communication sections526and527are able to communicate with the input unit1D, for example, via the network. Here, the network is, for example, a network that performs communication using a communication protocol (TCP/IP) utilized normally in the Internet. The network may be, for example, a secure network that performs communication using an own communication protocol of the network. The network is, for example, the Internet, an intranet, or a local area network. For example, coupling between the network and the communication sections526and527may be made by a wired LAN such as Ethernet (registered trademark), or may be made by a wireless LAN such as Wi-Fi, a mobile phone line, or the like.

It is to be noted that the input unit1D may be configured by a keyboard, a mouse, or the like. At this time, for example, the input unit1D may be able to communicate with the communication sections526and527via the network described above, or may be able to communicate with the communication sections526and527in a wired manner.

Modification Example C

In the foregoing embodiment, the HOE screen10configured by the transmissive volume hologram is used. However, in the foregoing embodiment, an HOE screen60configured by a reflective volume hologram may be used, for example, as illustrated inFIG.7. At this time, the HOE screen60is configured by the reflective volume hologram. At this time, the HOE screen60diffracts light incident at an angle near such an angle as to satisfy Bragg's diffraction condition for the reflective volume hologram, out of light (image light La1) incident on the first main surface Sa, toward the front of the first main surface Sa. The diffracted light at this time is emitted as image light La3from the first main surface Sa. The HOE screen60further diffracts light incident at an angle near such an angle as to satisfy the Bragg's diffraction condition for the transmissive volume hologram, out of light (image light Lb1) incident on the second main surface Sb, toward the front of the second main surface Sb. The diffracted light at this time is emitted as image light Lb3from the second main surface Sb. An interference fringe with an inclination angle (slant angle θ1) is formed on the HOE screen60. Here, the inclination angle (slant angle θ1) refers to an angle formed between a surface of the reflective volume hologram and the interference fringe. The interference fringe is formed from the inside of the reflective volume hologram to the surface thereof. The interference fringe satisfies the Bragg condition.

In the present modification example, the image projection section50ais configured to cause the image light La1to be incident on the first main surface Sa at an angle near such an angle as to satisfy the Bragg's diffraction condition for the reflective volume hologram. The image projection section50ais further configured to cause the image light La1to be diffracted toward the front of the first main surface Sa in the reflective volume hologram. The image projection section50bis configured to cause the image light Lb1to be incident on the second main surface Sb at an angle near such an angle as to satisfy the Bragg's diffraction condition for the reflective volume hologram. The image projection section50bis further configured to cause the image light Lb1to be diffracted toward the front of the second main surface Sb in the reflective volume hologram.

In the present modification example, in a case where an inputted remote-control signal is a signal related to image display on the side of the first main surface Sa, the arithmetic circuit504performs control based on the inputted remote-control signal. In a case where the inputted remote-control signal is a signal related to image display on the side of the second main surface Sb, the arithmetic circuit514performs control based on the inputted remote-control signal.

In the present modification example, the image light Lb1is incident on the second main surface Sb at an angle near such an angle as to satisfy the Bragg's diffraction condition for the reflective volume hologram, and is diffracted toward the front of the second main surface Sb. As a result, the diffracted light is emitted as the image light Lb3from the second main surface Sb, and an image corresponding to the selected channel on the side of the second main surface Sb is displayed on the second main surface Sb. Meanwhile, the image light La1is incident on the first main surface Sa at an angle near such an angle as to satisfy the Bragg's diffraction condition for the reflective volume hologram, and is diffracted toward the front of the first main surface Sa. As a result, the diffracted light is emitted as the image light La3from the first main surface Sa, and an image corresponding to the selected channel on the side of the first main surface Sa is displayed on the first main surface Sa.

In the present modification example, the eave sections30aand30bhave configurations similar to those of the foregoing embodiment. Further, in the present modification example, the base sections40aand40bhave configurations similar to those of the foregoing embodiment. Therefore, in the present modification example, it is possible to prevent diffracted external light from being superimposed on the image light La2and the image light Lb2, similarly to the foregoing embodiment, thus making it possible to clearly display an image in a bright environment.

Modification Example D

In the foregoing embodiment and modification examples thereof, a glass plate may be provided between the HOE screen10or60and one of the AR film20aand the AR film20b. For example, as illustrated inFIGS.12and13, a glass plate70may be provided between the HOE screen10or60and the AR film20b. In this case, the image projection section50bis disposed in consideration of refraction by the glass plate70. The glass plate70is, for example, a window glass or a show window. It is to be noted that a transparent resin plate, instead of the glass plate70, may be provided between the HOE screen10or60and one of the AR film20aand the AR film20b. Also in such a case, effects similar to those of the foregoing embodiment and modification examples thereof are obtained.

3. APPLICATION EXAMPLES

Next, description is given of application examples of the display apparatus1according to the foregoing embodiment and modification examples thereof.

Application Example 1

FIGS.14and15each illustrate an example in which the display apparatus1according to the foregoing embodiment and modification examples thereof is installed as a partition in a kitchen300. The HOE screens10and60are each a transparent screen as described above. Therefore, even in a case where the HOE screen10or60is installed as a partition in the kitchen300, it is possible to view around a living room space from a space of the kitchen300.

Now suppose that a mother is cooking in the space of the kitchen300and that a child of the mother is playing in the living room. At this time, the mother operates the remote-control transmitter1B or the input unit1D to thereby display a cooking program TV1on a surface (e.g., first main surface Sa), of the HOE screen10or60, on side of the kitchen300, and display a children's program TV2on a surface (e.g., second main surface Sb), of the HOE screen10or60, on side of the living room, for example, as illustrated inFIG.14. In such a case, the mother is able to confirm a state of the child through a location, of the HOE screen10or60, where the cooking program TV1is not displayed, while watching the cooking program TV1. In addition, the child is able to confirm a state of the mother through a location, of the HOE screen10or60, where the children's program TV2is not displayed, while watching the children's program TV2.

In addition, suppose that the mother is cooking in the space of the kitchen300and that the child of the mother is playing in the living room. At this time, the mother operates the remote-control transmitter1B or the input unit1D to thereby display a recipe video DT1on a surface (e.g., first main surface Sa), of the HOE screen10or60, on the side of the kitchen300, and display an animation video DT2on a surface (e.g., second main surface Sb), of the HOE screen10or60, on the side of the living room, for example, as illustrated inFIG.15. In such a case, the mother is able to confirm a state of the child through a location, of the HOE screen10or60, where the recipe video DT1is not displayed, while watching the recipe video DT1. In addition, the child is able to confirm a state of the mother through a location, of the HOE screen10or60, where the animation video DT2is not displayed, while watching the animation video DT2.

Application Example 2

FIG.16illustrates an example in which the display apparatus1according to the foregoing embodiment and modification examples thereof is used as a screen of a game machine400. For example, the display apparatus1is provided one by one for each of seats for persons playing the game machine400. The HOE screens10and60are each a transparent screen as described above. Therefore, game players are able to confirm a state of an event being performed by the game machine400through the HOE screen10while sitting in the seat.

Now suppose that the game machine400is provided for a game that involves running racehorses410,420, and430to predict a winner. At this time, the game player operates the remote-control transmitter1B or the input unit1D to thereby display, for example, data DT3on the racehorses410,420, and430that are visible through the HOE screen10or60on a surface (e.g., first main surface Sa), of the HOE screen10or60, on side of the game player. At this time, data DT4on a current ranking of the racehorses410,420, and430is displayed on a surface (e.g., second main surface Sb), of the HOE screen10or60, on side opposite to the game player. In such a case, the game player is able to confirm the data DT3and the data DT4displayed on the HOE screen10or60provided for the game player facing the screen while watching a state in which racehorses410,420, and430are running.

Application Example 3

FIG.17illustrates an example in which the display apparatus1according to the foregoing embodiment and modification examples thereof is installed on a reception table500. The HOE screens10and60are each a transparent screen as described above. Therefore, even in a case where the HOE screen10or60is installed on the reception table500, it is possible to view around the surrounding space from a space of the reception.

Now suppose that a reception lady stands in the back of the reception table500and that a foreign visitor stands in front of the reception table500. At this time, the reception lady operates the remote-control transmitter1B or the input unit1D to thereby display, for example, a Japanese guide map MAP1on a surface (e.g., first main surface Sa), of the HOE screen10or60, on back side of the reception table500, and display an English guide map MAP2on a surface (e.g., second main surface Sb), of the HOE screen10or60, on front side of the reception table500. In such a case, the reception lady is able to explain a route to a destination to the foreign visitor while viewing the Japanese guide map MAP1, and the foreign visitor is able to listen to the explanation of the reception lady while viewing the English guide map MAP2.

Although the description has been given hereinabove of the present disclosure with reference to the embodiment and modification examples thereof, and the application examples, the present disclosure is not limited to the foregoing embodiments, etc., and various modifications may be made. It is to be noted that the effects described herein are merely illustrative. The effects of the present disclosure are not limited to those described herein. The present disclosure may have other effects than those described herein.

In addition, the present disclosure may have the following configurations.

(1)

A display apparatus including:a transparent screen configured by a transmissive or reflective volume hologram;a first image projection section that is disposed on side of a first main surface of the transparent screen, and projects first image light onto the first main surface;a second image projection section that is disposed on side of a second main surface of the transparent screen, and projects second image light onto the second main surface;a first light-shielding section that prevents external light from being directly incident on the first main surface at least at same incident angle as the first image light; anda second light-shielding section that prevents external light from being directly incident on the second main surface at least at same incident angle as the second image light.
(2)

The display apparatus according to (1), in whichthe first image projection section is disposed at a location corresponding to a lower end of the transparent screen, andthe second image projection section is disposed at a location corresponding to an upper end of the transparent screen.
(3)

The display apparatus according to (1) or (2), in whichthe first light-shielding section is disposed at a location corresponding to the lower end of the transparent screen,the second light-shielding section is disposed at a location corresponding to the upper end of the transparent screen,the first image projection section is disposed inside the first light-shielding section, andthe second image projection section is disposed inside the second light-shielding section.
(4)

The display apparatus according to any one of (1) to (3), in whichthe first light-shielding section is positioned at a distance of a tangent at a slant angle of the volume hologram from the location corresponding to the lower end of the transparent screen, andthe second light-shielding section is positioned at a distance of a tangent at a slant angle of the volume hologram from the location corresponding to the upper end of the transparent screen.
(5)

The display apparatus according to any one of (1) to (4), in whichthe first light-shielding section holds the location corresponding to the lower end of the transparent screen, andthe second light-shielding section holds the location corresponding to the upper end of the transparent screen.
(6)

The display apparatus according to any one of (1) to (5), further including an AR film on at least one of the first main surface or the second main surface.

The display apparatus according to an embodiment of the present disclosure includes the first light-shielding section that prevents external light from being directly incident on the first main surface at least at the same incident angle as the first image light, and the second light-shielding section that prevents external light from being directly incident on the second main surface at least at the same incident angle as the second image light, thus making it possible to clearly display an image in a bright environment. It is to be noted that the effects of the present disclosure are not necessarily limited to the effects described here, and may be any of the effects described herein.

This application claims the benefit of Japanese Priority Patent Application JP2018-230783 filed with the Japan Patent Office on Dec. 10, 2018, the entire contents of which are incorporated herein by reference.

It should be understood by those skilled in the art that various modifications, combinations, sub-combinations, and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.