JP2019082573A - Display device and display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a large-sized three-dimensional stereoscopic image while ensuring a wide viewing angle. A display device according to one aspect of the disclosed technique is a display device that displays a holographic image, in which a plurality of light deflection elements are two-dimensionally arranged to form a wave surface corresponding to the holographic image. Based on the data of the regenerated light, the incident coherent light is deflected for each of the light deflection elements to generate the regenerated light, and the regenerated light is formed at a first position where the regenerated light is formed. In a plane intersecting with the optical axis of the above, the scanning means for scanning the regenerated light and the regenerated light generated by the optical deflection element array in response to the scanning are controlled, and the scanned regenerated light is connected to each other. It has a reproduction control means for forming the holographic image, and the size of the reproduced light in the first position in the plane is the size in the second position where the optical deflection element array is arranged. It is characterized by being equal to. [Selection diagram] Fig. 2

Description

  The present invention relates to a display device and a display method.

  Holography technology is known as a display technology of a three-dimensional solid image in which none of binocular parallax, convergence, and adjustment of eyes are consistent. In addition, a two-dimensional wavefront modulation device such as a liquid crystal display (LCD), a liquid crystal on silicon (LCOS), or a digital mirror device (DMD) generates reproduction light having a wavefront corresponding to a three-dimensional image, and generates a frame rate. There is known a technique for displaying a moving image of a three-dimensional solid image, that is, a holographic image by switching the reproduction light accordingly.

  As a holographic image display technology, for example, a technique is disclosed for enlarging the viewing area angle of a holographic image by raising the wavefront modulation accuracy of reproduction light by a two-dimensional wavefront modulation apparatus (for example, Patent Document 1) reference). In addition, the reproduction light by the DMD is expanded in the vertical direction and reduced in the horizontal direction, and the horizontal viewing angle of the holographic image is obtained by joining the reproduction light in the reproduction space while scanning this in the horizontal direction with the galvano mirror. An expanding technique is disclosed (see, for example, Non-Patent Document 1).

  However, according to the technique of Patent Document 1, it is necessary to expand reproduction light in order to display a large-size three-dimensional solid image, and since the angle of view decreases by the enlargement, a large size is obtained at a wide angle of view. It was difficult to display a three-dimensional stereoscopic image of

  Further, in the technique of Non-Patent Document 1, the size of the galvano mirror is a limitation, and there is a limitation in displaying a large size three-dimensional solid image.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to display a three-dimensional three-dimensional image of a large size while securing a wide viewing angle.

  A display device according to an aspect of the disclosed technique is a display device that displays a holographic image, and a plurality of light deflection elements are two-dimensionally arranged, and a reproduction light having a wavefront according to the holographic image is provided. A light deflection element array for deflecting the incident coherent light for each light deflection element based on data to generate the reproduction light, and an optical axis of the reproduction light at a first position where the reproduction light forms an image The scanning means for scanning the reproduction light and the generation of the reproduction light by the light deflection element array are controlled in accordance with the scanning in the intersecting plane, and the scanned reproduction light is joined to form the holographic image And the size of the reproduction light at the first position in the plane is the size at the second position where the light deflection element array is disposed. If equal, characterized in that.

  A large size three-dimensional solid image can be displayed while securing a wide viewing angle.

It is a figure explaining recording and reproduction | regeneration of the three-dimensional solid image by holography. It is a figure which shows an example of a structure of the display apparatus of 1st Embodiment. It is a figure which shows an example of the hardware constitutions of the display apparatus of 1st Embodiment. It is a figure which shows an example of a function structure of the display apparatus of 1st Embodiment. It is a flowchart which shows an example of the processing flow by the control apparatus of the display apparatus of 1st Embodiment. It is a figure which illustrates typically the hologram formed of a light deflection element array. It is a figure which shows an example of an apparatus configuration when a variable magnification lens is provided in the display apparatus of 1st Embodiment. It is a figure explaining the composition of the light deflection element array in a 1st embodiment. It is a figure explaining the drive method of the light deflection | deviation element in 2nd Embodiment. It is a figure which shows one structural example of the display apparatus of 3rd Embodiment. It is a figure which shows one structural example of the display apparatus of 4th Embodiment.

  First, the principle of holography will be described using FIG. 1 as a premise of the present embodiment. Hereinafter, the three-dimensional three-dimensional image is simply referred to as a three-dimensional image.

  FIG. 1A illustrates the recording of a stereoscopic image by holography. In FIG. 1 (a), an object 101 is irradiated with irradiation light. The irradiation light 102 is coherent light such as a laser. The object light 103 reflected by the object 101 overlaps and interferes with the reference light 104 obtained by amplitude division or wavefront division of the irradiation light 102. Interference fringes 105 due to interference between the object beam 103 and the reference beam 104 are recorded on a recording medium such as a photographic plate. A photographic plate is a type of photosensitive material in which a photographic emulsion is coated on a colorless and transparent glass plate. The photographic plate is developed to obtain a hologram 106 in which the interference fringes 105 are recorded.

  FIG. 1 (b) illustrates the reproduction of a stereoscopic image by holography. When the hologram 106 is irradiated with the same reference light 104 as at the time of recording, the reference light 104 is diffracted by the interference fringes 105 recorded in the hologram 106 and becomes the reproduced light 107 which behaves in the same manner as the object light 103. When the hologram 106 is observed from the side opposite to the side irradiated with the reference light 104 by the reproduction light 107, the three-dimensional image 108 of the object 101 is reproduced at the position where the object 101 was present. The three-dimensional image 108 in this case is a virtual image formed by the first-order diffracted light of the reference light 104 by the hologram 106. On the other hand, on the observer side, a real image formed by + first-order diffracted light of the reference light 104 by the hologram 106 is reproduced.

  The above is analog holography for recording and reproducing interference fringes on a photographic plate, but the interference fringes, that is, the hologram can be formed by a digital device called a two-dimensional wavefront modulation device. Then, by irradiating the reference light to the two-dimensional wavefront modulation device acting as a hologram, a three-dimensional image can be reproduced and displayed. Also, by switching the stereoscopic image according to the frame rate, it is possible to display a moving image of the stereoscopic image, that is, a holographic image.

Interference fringes obtained by interference between the object light and the reference light can be obtained by computer calculation. Computer-generated interference fringes are called CGH (Computer Generated Hologram). In the present embodiment, reproduction and display of holographic video using CGH data will be described as an example.
First Embodiment
A first embodiment will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

  FIG. 2 shows an example of the configuration of the display device of the present embodiment. FIG. 2A shows the arrangement of parts in the display device 200 and the front view of a space in which a three-dimensional image is reproduced by the display device 200. FIG. 2B shows the positional relationship between the stereoscopic image reproduced by the display device 200 and the observer.

  In FIG. 2A, the display device 200 includes a light source 201r, 201b, and 201g. The light sources 201r, 201b, and 201g are lasers that emit coherent light having wavelengths of red, blue, and green, and are respectively semiconductor lasers, for example. Alternatively, a light source with higher coherence, ie, a longer coherence distance, such as a DPSS (Diode Pumped Solid State) laser may be used.

  The display device 200 also includes a control device 202 and light deflection element arrays 203r, 203b, and 203g. The control device 202 is connected to the light deflection element arrays 203r, 203b and 203g, and outputs CGH data corresponding to red, blue and green, respectively. The CGH data is an example of data of reproduction light having a wavefront according to the holographic image.

  The light deflection element arrays 203r, 203b, and 203g are devices in which a plurality of light deflection elements are two-dimensionally arranged. The plurality of light deflection elements move independently in accordance with CGH data input from the control device 202, and form interference fringes having a two-dimensional pattern, that is, holograms. The positions at which the light deflection element arrays 203r, 203b, and 203g are disposed are each an example of a second position at which the light deflection element array is disposed.

  The light deflection element arrays 203r, 203b, and 203g modulate the irradiation light by deflecting the light irradiated from the light sources 201r, 201b, and 201g, and generate reproduction light. Further, by switching the CGH data input from the control device 202 in time series, the generated reproduction light is switched in time series.

  The reproduction light generated by the light deflection element arrays 203r, 203b and 203g is an example of the reproduction light having a wavefront according to the holographic image. The configuration of the light deflection element array and the details of the movement will be described later.

  The display device 200 further includes light shielding plates 204r, 204b and 204g, a combining prism 205, and a micro mirror 206.

  Each of the light shielding plates 204r, 204b, and 204g is, for example, a pinhole in which a minute through hole is formed in a thin metal plate. In order to prevent the reflected light from the metal thin plate causing flare light, the surface of the metal thin plate is subjected to a treatment such as applying a flocked paper. The light shielding plates 204r, 204b, and 204g shield the reflected light of the light deflection element in the OFF state as described later.

  The combining prism 205 combines the light having passed through the light blocking plates 204r, 204b and 204g. The three monochromatic reproduction lights generated by the light deflection element arrays 203r, 203b and 203g are combined by the combining prism 205 into one color reproduction light.

  The micro mirror 206 reflects the light combined by the combining prism 205 and scans the reflected light horizontally and vertically. In FIG. 2A, the X direction indicated by the arrow is the horizontal direction, and the Y direction is the vertical direction.

  The micro mirror 206 is, for example, a micro electro mechanical system (MEMS) device. In the micro mirror 206, a movable portion having a light reflecting surface is formed so as to be rotatable around a first axis parallel to the X direction and a second axis parallel to the Y direction. The micro mirror 206 two-dimensionally scans the light reflected by the light reflection surface in the target area by the movable portion rotating around each axis. The micro mirror 206 is manufactured by micromachining silicon or glass by, for example, a semiconductor process technology.

  The reproduction space 207 is a space where the reproduction light by each of the light deflection element arrays 203r, 203b and 203g forms an image or substantially forms an image. In other words, the reproduction space 207 is a three-dimensional space in which a three-dimensional image reproduced by the light deflection element arrays 203r, 203b and 203g acting as a hologram is displayed. Here, the term “generally imaging” means not only the completely imaged state, ie, completely in focus, but also allowing some imaging deviation, ie, defocus. Although the three-dimensional image displayed in the present embodiment is a real image, it may be configured to display a virtual image.

  The reproduction light is scanned by the micro mirror 206 in the XY plane 207 a. The XY plane 207a is a plane cut out from the reproduction space 207, and is, for example, a plane shown by a two-dot chain line in FIG. 2 (b).

  The optical axis of the reproduction light passes through the center of the light beam of the reproduction light scanned by the micro mirror 206, and is an axis parallel to the propagation direction of the reproduction light. For example, in FIG. 2A, reference numeral 207b indicated by an alternate long and short dash line is an optical axis of the luminous flux 207c of the reproduction light. The direction of the optical axis of the reproduction light changes in accordance with the scanning angle by the micro mirror 206.

  The XY plane 207a is an example of a plane intersecting with the optical axis of the reproduction light.

  Further, the position of the XY plane 207a in the direction orthogonal to the XY plane 207a is the position at which the reproduced light by each of the light deflection element arrays 203r, 203b and 203g, that is, the reproduced light having a wavefront according to the holographic image forms an image It is an example of the position of 1.

  Furthermore, the micro mirror 206 is an example of a scanning unit that scans the reproduction light in a plane intersecting the optical axis of the reproduction light at a first position where the reproduction light is imaged. In addition to the micro mirror 206, for example, a polygon mirror, an acousto-optic element, or the like may be used in combination as a scanning unit.

  The reproduction light of one color generated by the light deflection element arrays 203 r, 203 b and 203 g and combined by the combining prism 205 is reflected by the micro mirror 206. The reflected light is applied to a partial area 208 in the XY plane 207a. In the area 208, a stereoscopic image corresponding to the CGH data is reproduced and displayed. The three-dimensional image in this case is a part of the three-dimensional image obtained by the two-dimensional scanning by the micro mirror 206, and is hereinafter referred to as a partial three-dimensional image.

  Next, the CGH data input from the control device 202 is switched, and reproduction light of the next color is generated by the light deflection element arrays 203r, 203b and 203g. In addition, the micro mirror 206 changes its direction, and the reflection direction is changed. As a result, the next color reproduction light is irradiated to the area adjacent to the area 208 in the XY plane 207a, for example. In the area adjacent to the area 208, a partial stereo image by reproduction light of the next color according to CGH is reproduced and displayed.

  The operation of repeating such CGH data switching, generation of color reproduction light by the light deflection element arrays 203r, 203b and 203g, and change of reflection direction of reproduction light by the micro mirror 206 as one set is repeated. . In the XY plane 207a, the area irradiated with the color reproduction light is changed along the arrow 209.

  The above operation is repeated, and the whole reproduction light of the color is irradiated to the whole of the XY plane 207a along the arrow 209, whereby partial solid images according to the CGH data are joined together on the XY plane 207a. An image is formed.

  The change of the reflection direction of the reproduction light by the micro mirror 206 is continuously performed in the scanning of the reproduction light by the micro mirror 206. Therefore, in order to connect partial solid images, it is necessary to execute switching of CGH data and generation of color reproduction light at predetermined timing in synchronization with scanning while scanning the reproduction light by the micro mirror 206. There is.

  In the present embodiment, the processing of joining partial solid images in the XY plane 207a is, for example, so-called tiling processing in which adjacent partial solid images are not overlapped.

  Specifically, for example, the size of one partial solid image in the XY plane 207a in the X direction is Sx, the distance from the micro mirror 206 to the XY plane 207a is Z, and the scanning speed by the micro mirror 206 is V. Based on Sx, Z, and V, time t in which adjacent partial solid images do not overlap is previously determined, CGH data is switched every time t, and color reproduction is performed by the light deflection element arrays 203r, 203b, and 203g. Generate light. In this way, adjacent partial stereo images can be joined together without regions overlapping each other. The same applies to the case where partial solid images are joined in the Y direction.

  In order to synchronize switching of CGH data and scanning by the micro mirror 206, the display device 200 has synchronization detection means. The synchronization detection means is realized by, for example, a PD (Photo Diode) provided in a part of the area where the color reproduction light is scanned by the micro mirror 206.

  The PD detects the timing at which the color reproduction light passes through the light receiving surface. Based on this timing, time may be measured by counting the clock, CGH data may be switched every time t, and color reproduction light may be generated by the light deflection element arrays 203r, 203b, and 203g.

  For synchronous detection in the X direction and the Y direction, it is necessary to provide at least one PD in each of the scanning regions of the color reproduction light in the X direction and the Y direction by the micro mirror 206.

  The operation of forming the whole image of the three-dimensional image is performed within the period of the frame rate, and the whole image of the three-dimensional image is displayed as an image at the frame rate. The entire image of the three-dimensional image is hereinafter simply referred to as a three-dimensional image.

  In FIG. 2B, the stereoscopic image 211 formed in the reproduction space 207 is observed by the observer 212 in the illustrated positional relationship. 207a shown with a dashed-two dotted line in FIG.2 (b) is XY plane. The transparent plate 210 is for protecting the inside of the display device 200, and has no optical function in the present embodiment.

  In addition, although only the optical system for red light is shown for convenience in FIG.2 (b), the optical system for blue and green light is also the same.

  Next, an example of the hardware configuration of the display device 200 according to the present embodiment will be described with reference to FIG. As shown in FIG. 3, the display device 200 includes a control device 202, a light source 201, a micro mirror 206, and a light deflection element array 203, which are electrically connected to one another. The light source 201 includes light sources 201r, 201b, and 201g, and the light deflection element array 203 includes light deflection element arrays 203r, 203b, and 203g.

  Among them, the control device 202 includes a central processing unit (CPU) 300, a random access memory (RAM) 301, a read only memory (ROM) 302, a field-programmable gate array (FPGA) 303, and an external I / F 304. , A light source driver 305, a micro mirror driver 306, and a light deflection element array driver 307.

  The CPU 300 is an arithmetic device that reads programs and data from a storage device such as the ROM 302 or the like onto the RAM 301 and executes processing to realize overall control and functions of the control device 202.

  The RAM 301 is a volatile storage device that temporarily holds programs and data.

  The ROM 302 is a non-volatile storage device that can hold programs and data even after the power is turned off, and stores processing programs and data that the CPU 300 executes to control each function of the display device 200. .

  The FPGA 303 is a circuit that outputs control signals suitable for the light source driver 305, the micro mirror driver 306, and the light deflection element array driver 307 in accordance with the processing of the CPU 300.

  The external I / F 304 is, for example, an interface with an external device or a network. For example, a host device such as a PC (Personal Computer), a USB (Universal Serial Bus) memory, an SD (Secure Digital) card, a CD (Compact Disc), a DVD (Digital Versatile Disc), an HDD (hard disk drive). And a storage device such as a solid state drive (SSD). The network is, for example, a LAN (Local Area Network), the Internet, or the like. The external I / F 304 may be configured to enable connection or communication with an external device, and the external I / F 304 may be prepared for each external device.

  The light source driver 305 is an electric circuit that outputs a drive signal such as a drive voltage to the light source 201 in accordance with the input control signal. The light source driver 305 includes light source drivers 305 r, 305 b, and 305 g that output driving signals to the light sources 201 r, 201 b, and 201 g, respectively.

  The micro mirror driver 306 is an electric circuit that outputs a drive signal such as a drive voltage to the micro mirror 206 in accordance with the input control signal.

  The light deflection element array driver 307 is an electric circuit that outputs a drive signal such as a drive voltage to the light deflection element array 203 in accordance with the input control signal. The light deflection element array driver 307 includes light deflection element array drivers 307r, 307b, and 307g that output driving signals to the light deflection element arrays 203r, 203b, and 203g, respectively.

  The output of the PD for synchronizing switching of CGH data, generation of reproduction light by the light deflection element array 203, and scanning by the micro mirror 206 is input to, for example, the CPU 300, the FPGA 303, and the like.

  In the control device 202, the CPU 300 acquires drive information and reproduction information from an external device or a network via the external I / F 304. The drive information and the reproduction information may be stored in the ROM 302 or the FPGA 303 in the control device 202 as long as the CPU 300 can obtain the drive information and the reproduction information. Alternatively, a storage device such as an SSD may be provided, and drive information and reproduction information may be stored in the storage device.

  Here, the drive information and the reproduction information are information indicating how to display a stereoscopic image in the reproduction space 207. For example, the drive information is the irradiation intensity of the light source, the movable range of the micro mirror, etc., and the reproduction information is CGH data, switching timing of CGH data according to scanning, etc.

  The control device 202 can realize the functional configuration described below by the instruction of the CPU 300 and the hardware configuration shown in FIG. 3.

  Next, the functional configuration of the control device 202 of the display device 200 will be described using FIG. FIG. 4 is a functional block diagram of an example of the control device 202 of the display device 200. As shown in FIG.

  As shown in FIG. 4, the control device 202 has a control unit 400 and a drive signal output unit 401 as functions. The control unit 400 is realized by, for example, the CPU 300, the FPGA 303, etc., acquires drive information and reproduction information from an external device, converts these into control signals, and outputs the control signals to the drive signal output unit 401.

  The control unit 400 includes a drive control unit 400a and a reproduction control unit 400b, and the drive signal output unit 401 includes a light source drive signal output unit 401a, a micro mirror drive signal output unit 401b, and a light deflection element array drive. And a signal output unit 401c.

  The drive control unit 400a acquires, for example, the irradiation intensity of the light source or the movable range of the micro mirror from the external device or the like as drive information, generates control signals from these by predetermined processing, and generates the light source drive signal output unit 401a and the micro It outputs to the mirror drive signal output unit 401b.

  Further, the reproduction control unit 400b acquires, for example, CGH data, switching timing of CGH data according to scanning, etc. from external devices as reproduction information, generates a control signal from the CGH data by predetermined processing, It outputs to the light deflection element array drive signal output unit at the timing of As described above, the predetermined timing is for performing tiling processing, and can be set by the number of clocks to be counted after receiving the output signal from the PD.

  The reproduction control unit 400b is an example of the reproduction control unit.

  The light source drive signal output unit 401 a is realized by, for example, the light source driver 305. The micro mirror drive signal output unit 401 b is realized by, for example, the micro mirror driver 306. The light deflection element array drive signal output unit 401 c is realized by, for example, the light deflection element array driver 307. The light source drive signal output unit 401 a, the micro mirror drive signal output unit 401 b, and the light deflection element array drive signal output unit 401 c are connected to the light source 201, the micro mirror 206, and the light deflection element array 203 based on the input control signals. Output a drive signal.

  The drive signal is a signal for controlling the drive of the light source 201, the light deflection element array 203, or the micro mirror 206. For example, in the light source 201, the driving voltage is used to control the irradiation timing and the irradiation intensity of the light source. Also, for example, in the micro mirror 206, the timing is for moving the light reflecting surface of the micro mirror 206, and the driving voltage for controlling the movable range. Also, for example, in the light deflection element array 203, the timing is for moving the plurality of light deflection elements of the light deflection element array 203 according to the CGH data, and a drive voltage for controlling the movable range.

  The drive control unit 400a and the reproduction control unit 400b are connected to each other, and the processing can be coordinated.

  Next, processing of causing the display device 200 to display a stereoscopic image in the reproduction space 207 will be described with reference to FIG. FIG. 5 is a flowchart of an example of processing of the control device 202 in the display device 200.

  First, in step S51, the drive control unit 400a acquires drive information from an external device or the like.

  Subsequently, in step S53, the drive control unit 400a generates a control signal from the acquired drive information, and outputs the control signal to the light source drive signal output unit 401a and the micro mirror drive signal output unit 401b.

  Subsequently, at step S55, the light source drive signal output unit 401a outputs a drive signal to the light source 201 based on the input control signal, and the micro mirror drive signal output unit 401b generates the drive signal based on the input control signal. , And outputs a drive signal to the micro mirror 206. The light source 201 emits light based on the input drive signal, and the micro mirror 206 moves the light reflecting surface based on the input drive signal, and the reproduction light generated by the light deflection element array 203 is Scan.

  Subsequently, in step S57, the reproduction control unit 400b acquires reproduction information from an external device or the like. The reproduction information may be stored in advance in a RAM or the like in the control device 202, and the reproduction control unit 400b may acquire the reproduction information from the RAM or the like.

  Subsequently, in step S59, the reproduction control unit 400b generates a control signal from the acquired reproduction information, and outputs the control signal to the light deflection element array drive signal output unit 401c.

  Subsequently, in step S61, the light deflection element array drive signal output unit 401c outputs a drive signal to the light deflection element array 203 based on the input control signal. The light deflection element array 203 moves each light deflection element at a predetermined timing based on the input drive signal and the output signal of the PD for synchronizing with scanning. Thereby, a partial stereoscopic image is displayed in the reproduction space 207.

  Subsequently, in step S63, the control device 202 determines whether display of all partial stereoscopic images has ended, and if not, returns to step S57 and continues the processing.

  When display of all partial stereoscopic images is completed, the control device 202 determines whether display of all stereoscopic images is completed in step S65, and if not completed, the process returns to step S57 and processing is performed. continue.

  If display of all three-dimensional images is finished in step S65, the process ends.

  Thus, partial stereo images corresponding to the CGH data are scanned, and a stereo image in which they are joined together in the XY plane 207a is displayed.

  In the display device 200, one control device 202 has a device and a function of controlling the light source 201, the light deflection element array 203, and the micro mirror 206, but the present invention is not limited thereto. A controller for the light source, a controller for the light deflection element array, and a controller for the micromirror may be provided separately.

  Further, in the display device 200, the function of the control unit 400 and the function of the drive signal output unit 401 are provided in one control device 202, but the present invention is not limited thereto. These functions may exist separately, and for example, a drive signal output device having a drive signal output unit 401 separately from the control device 202 having the control unit 400 may be provided.

  Next, a pattern of interference fringes formed by the light deflection element array 203r, that is, a hologram will be described with reference to FIG.

  The light deflection element array 203 r forms a hologram in accordance with the CGH data input from the control device 202. In the following, for convenience of explanation, reproduction of a three-dimensional image by red light by the light deflection element array 203r will be described, but by blue and green lights using the light deflection element array 203b and the light deflection element array 203g. The same applies to reproduction and display of a stereoscopic image.

  FIG. 6 shows a hologram formed by the light deflection element array 203r. FIG. 6A shows a state in which a plurality of light deflection elements are two-dimensionally arranged in the light deflection element array 203r. Reference numeral 301r denotes one light deflection element, and the light deflection elements are two-dimensionally arrayed to constitute a light deflection element array 203r. The light deflection element has a light reflection surface, and each can move independently.

  FIG. 6B shows that each light deflection element is moved independently according to the CGH data. In FIG. 6B, the light deflection element 301r-a shown in the non-black state is in the ON state, and the light deflection element 301r-b shown in the black state is in the OFF state.

  In the present embodiment, the movable of the light deflection element is ON or OFF. When it is ON, the light reflection surface of the light deflection element is inclined at a predetermined angle with respect to the plane in which the light deflection elements are arranged, for example. In addition, when it is OFF, the light reflection surface of the light deflection element is inclined with respect to the plane in which the light deflection elements are arranged at an angle different from that in the case where it is ON. When it is OFF, the reflected light from the light reflecting surface is blocked by the light blocking plate 204r, and does not contribute to the reproduction of a three-dimensional image.

  FIG. 6C shows an example of an interference fringe pattern expressed by combining the ON state and the OFF state of the light deflection element. In FIGS. 6A and 6B, each light deflection element is schematically shown enlarged so that each one of the light deflection elements can be easily recognized. However, FIG. 6C shows each light The deflection element is shown without enlargement.

  In FIG. 6C, when light enters the light deflection element array 203r, the reflected light is modulated according to the interference fringe pattern. That is, the reflected light is modulated to a state in which the light deflection element of ON contributes to the reproduction of the three-dimensional image and the light deflection element of OFF does not contribute to the reproduction of the three-dimensional image. Thus, the light deflection element array 203r acts as a hologram for modulating incident light. In the above, two cases where the movement of the light deflection element is ON and OFF are shown, but more than two ways may be used to perform more detailed modulation.

  Here, in the display device 200 of the present embodiment, the reproduction light is at the first position, that is, the position where the reproduction light is imaged or substantially imaged, and the second position, that is, the position where the light deflection element array is disposed. The size of the reproduction light in the plane intersecting the optical axis of is equal.

  The size of the reproduction light refers to the size of the reproduction light generated by the light deflection element array in a plane intersecting the optical axis, that is, in the XY plane 207a of FIG.

  The size of the reproduction light in the horizontal direction, that is, the X direction is synonymous with the length (width) in the horizontal direction, that is, the X direction of the reproduction light by the light deflection element array. The size of the reproduction light in the vertical direction, that is, the Y direction is synonymous with the length (height) in the vertical direction, that is, the Y direction of the reproduction light by the light deflection element array.

  In addition, the following can be separately stated about the equal size of the reproduction light at the first position and the second position. That is, assuming that the size of one light deflection element in the X and Y directions is px and py, and the number of light deflection elements in the light deflection element array is Nx and Ny, the size of the reproduction light at the first position is X In the direction, it is Nx × px, and in the Y direction, it is Ny × py.

  The equal size of the reproduction light at the first position and the second position means that the size of the reproduction light is not expanded at the first position, and the viewing angle does not decrease at the first position. It means that. Here, the viewing area angle refers to an angle range in which an object can be observed or an eye angle in which the entire object can be observed. As the viewing angle is larger, a more three-dimensional stereoscopic image is obtained.

  The visual field angle φ of the three-dimensional image to be reproduced and the minimum width δ of the interference fringes have the following relationship (1). Where λ is the wavelength of the light source.

（１）式によれば、例えば、δが１．０μｍの場合は、φは約３０度である。

According to the equation (1), for example, when δ is 1.0 μm, φ is approximately 30 degrees.

  If the reproduction light from the light deflection element array is expanded at the first position, the minimum width δ of the interference fringes is also expanded, so the viewing angle decreases according to the expansion of δ according to the equation (1). .

  In this embodiment, since the reproduction light from the light deflection element array is not expanded, the minimum width δ of interference fringes at the position of the light deflection element array is maintained even at the first position, and the viewing angle is maintained. For example, assuming that the size of one light deflection element is 1.0 μm in the X and Y directions and the number of light deflection elements in the light deflection element array is 1000, the reproduced light at the first position and the second position is The size of both is 1 mm. Since the minimum width δ of the interference fringes is equal to the size of one deflection element and is 1 μm, it becomes possible to observe a stereoscopic image at about 30 degrees of the viewing angle when δ is 1.0 μm.

  In order to equalize the size of the reproduction light at the first position and the second position, for example, as shown in FIG. 7, even if the variable magnification lens 213 is provided in the optical path of the reproduction light by the light deflection element array 203r. Good. The variable magnification lens 213 acts so that the size of the reproduction light becomes equal while maintaining the relationship in which the reproduction light by the light deflection element array 203 r is formed at the first position when the magnification change lens 213 is not provided.

  Since the hologram formed by the light deflection element array 203 r is a kind of lens, the hologram by the light deflection element array 203 r and the variable power lens 213 constitute a synthetic optical system. The focal length of the combining optical system is set such that the optical magnification is 1 × while maintaining the imaging relationship in the case of only the hologram. This makes it possible to equalize the size of the reproduction light at the first position and the second position.

  The variable magnification lens 213 may be configured by combining a plurality of optical systems such as a lens. Further, in order to suppress the influence on the display performance of a three-dimensional image, it is preferable to use, as the magnification varying lens 213, one in which an aberration such as a chromatic aberration is reduced.

  By the way, in order to maintain the viewing angle, the horizontal and vertical lengths Rx and Ry of the reproduction light in the plane intersecting the optical axis of the reproduction light at the first position are the following (2) And (3) the relationship may be satisfied.

但し、Ｎｘ、Ｎｙは、光偏向素子アレイにおける光偏向素子の水平、鉛直方向の個数であり、λは入射したコヒーレント光の波長である。

Here, Nx and Ny are the numbers in the horizontal and vertical directions of the light deflection elements in the light deflection element array, and λ is the wavelength of the incident coherent light.

  In the structure having a length smaller than λ, no diffraction effect is obtained, and in order to reflect light in the light deflection element array, it is considered that the size of the light deflection element needs to be λ / 2 or more. Therefore, Rx is set to a value of Nx × λ / 2 or more of the value obtained by multiplying λ / 2 by the number of light deflection elements.

  Also, considering that stereoscopic vision is performed with both eyes, it is considered that the viewing angle allowed for being sufficiently stereoscopic is up to half the viewing angle in the case where the wavelength λ is the minimum width of the interference fringes. Be Therefore, Rx is a value equal to or less than 2 × N ×× λ of a value obtained by multiplying the number of light deflection elements by the width 2λ of interference fringes for obtaining a viewing angle of 1/2 of the viewing angle according to λ.

  If, for example, the distance from the micro mirror 206 to the XY plane 207a is short, the size of the reproduction light may differ depending on the area of the XY plane 207a to which the reproduction light is irradiated by scanning. For example, the size of the reproduction light may be different in the vicinity of the center and in the vicinity of the end of the XY plane 207a. Since the size of the reproduction light is different for each area of the XY plane 207a, it becomes a problem in which area the size of the reproduction light should be the size of the reproduction light at the first position.

  In this case, since the size of the reproduction light is determined by the scanning angle by the micro mirror 206, for example, the size of the reproduction light may be normalized by the scanning angle. If normalization is performed by the scanning angle, the difference in size of the reproduction light depending on the area can be eliminated, and thus the size of the standardized reproduction light may be set as the size of reproduction light at the first position. Alternatively, for example, the size of the reproduction light near the center in the XY plane 207a may be used as a representative value to be the size of the reproduction light at the first position.

  As described above, the size of the reproduction light at the first position is made wider by equalizing or substantially equaling the size of the reproduction light at the second position, that is, the position where the light deflection element array is disposed. The viewing angle can be secured.

  Further, as described above, in the display device 200 according to the present embodiment, a large three-dimensional image is displayed by joining partial three-dimensional images at the XY plane 207a while scanning the reproduction light by the light deflection element array with the micromirror 206. be able to.

  As described above, according to the display device 200 of the present embodiment, a large-sized three-dimensional image can be displayed while securing a wide viewing angle.

  Although the display of a stereoscopic image using CGH data has been described above, the display device 200 of the present embodiment displays a three-dimensional stereoscopic image by photographing based on the principle of holography and using the recorded hologram data. It can also be applied to

  Next, an example of the structure of the light deflection element according to the present embodiment will be described in detail with reference to FIG. In FIG. 8, (a) is a plan view of the light deflection element, and (b) is a cross-sectional view taken along a dashed-dotted line in (a) of FIG.

  In FIG. 8, the light deflection element 800 includes a substrate 801, regulating members 802a, 802b, 802c and 802d, fulcrum members 803a and 803b, a plate member 804, electrodes 805a and 805b, and a contact portion 807. Have.

  The substrate 801 is a silicon semiconductor substrate. The use of materials generally used in semiconductor processes and liquid crystal processes, such as silicon and glass, enables miniaturization of the structure. Further, by forming a silicon substrate having a (100) plane orientation, it can be formed on the same substrate as the drive system circuit, and can be manufactured easily and at low cost.

  The restricting members 802a, 802b, 802c, and 802d restrict the movable range of the plate-like member 804 having a light reflection surface to a predetermined space. For example, one restriction member 802a has four cylindrical members and a stopper 806 provided on the upper portion of the cylindrical members. The restricting members 802 a, 802 b, 802 c, and 802 d are arranged at positions corresponding to the four corners of the rectangular plate-like member 804 at predetermined intervals. The stopper 806 limits the movable range in the upward direction of the plate member 804 by pressing the plate member 804 from above. The restriction members 802a, 802b, 802c, and 802d are formed of, for example, a silicon oxide film or a chromium oxide film. The number and arrangement of the restriction members are not limited to the above, and a large number of restriction members may be arranged in the entire region corresponding to the outer periphery of the plate-like member 804.

  The plate-like member 804 is a member formed of a thin film such as aluminum having high reflectance. The surface of the plate member 804 functions as a light reflecting surface. The plate-like member 804 is supported in contact with the tops of the fulcrum members 803a and 803b, and can be inclined and movable with the top as a fulcrum. The plate member 804 has a conductive portion at least in part. The plate member 804 may be made of a conductor.

  When a voltage is applied to the electrodes 805a and 805b, electrostatic attraction is generated between the conductive portion of the plate member 804 and the electrodes 805a and 805b. As described above, the movable range of the plate-like member 804 is limited by the restriction members 802 a, 802 b, 802 c, and 802 d in the upper direction, and limited in the lower direction by the substrate 801. The plate member 804 is formed of a thin film and is lightweight. Thereby, the impact when colliding with the substrate 801 and the regulating members 802a to 802d is alleviated.

  The fulcrum members 803 a and 803 b are, for example, conical members provided on the upper surface of the substrate 801. The top of the cone acts as a fulcrum at which the plate member 804 inclines. The shape of the fulcrum members 803a and 803b is not limited to a cone, and can be optimized according to the performance required for the light deflection element 800.

  The fulcrum members 803a and 803b are formed of, for example, a silicon oxide film or a silicon nitride film. However, when taking the potential of the plate-like member 804 through the fulcrum members 803a and 803b, it is necessary to form the conductive material such as various metal films.

  The electrodes 805 a and 805 b are disposed to face the plate member 804. When a voltage is applied to the electrodes 805a and 805b, electrostatic attraction is generated between the electrodes 805a and 805b and the conductive portion of the plate member 804. The plate-like member 804 can be inclined by pulling the end by the electrostatic attraction. The inclination angle of the plate member 804 is switched according to the voltage applied to the electrodes 805a and 805b. The deflection direction of light incident on the plate member 804 can be determined by using the size of the plate member 804, the incident angle of light incident on the plate member 804, and the inclination angle of the plate member 804 as parameters. .

  The contact portion 807 is provided on the substrate 801, and is a portion to which the end of the plate member 804 is brought into contact when the plate member 804 is inclined.

  As an example of the action of the light deflection element 800, the light incident on the plate member 804 is white as shown in FIG. 8A because the plate member 804 is inclined with the tops of the fulcrum members 803a and 803b as a supporting point. It is deflected in the direction along arrow 808. For example, the light beam incident on the plate member 804 is reflected in the direction 1 when the light deflection element is ON, and is reflected in the direction 2 when the light deflection element is OFF.

  The light deflection element described above can be manufactured, for example, by a semiconductor manufacturing process of silicon, and the light deflection element array can be manufactured by two-dimensionally arranging the light deflection elements.

  Next, the features of the light deflection element array of the present embodiment will be described in detail.

  In this embodiment, the light deflection element array is driven by a so-called active matrix method. Here, the active matrix method is a driving method used for driving a liquid crystal panel or the like. Specifically, in addition to the simple matrix type structure in which the pixels of the intersection are driven by extending the conducting wire in two directions of X and Y directions and applying a voltage from both directions, an active element is disposed in each pixel. is there. The active element switches its state to ON or OFF by the voltage of the conductor in the X direction, and the target pixel at the intersection is driven when a voltage is also applied to the conductor in the Y direction when the active element is ON. Thereby, only the target pixel can be driven reliably. Compared with the simple matrix type, there are few afterimages, wide viewing angle, high contrast, and fast response speed.

  In the present embodiment, one light deflection element in the light deflection element array is a “pixel”. By employing the active matrix method, the number of transistors immediately below one light deflection element can be reduced. As a result, it is possible to two-dimensionally arrange fine light deflection elements each having a side length of about 1 μm, and it is possible to manufacture a light deflection element array provided with fine pixels.

  In the present embodiment, the size of the light deflection element, that is, the length of one side in the X and Y directions is, for example, 1.2 μm. The size of the plate-like member 804 in the light deflection element is, for example, 1.0 μm in both the X and Y directions. The plate member 804 can be inclined at an angle of 10 degrees or more.

  The number of light deflection elements in the light deflection element array of this embodiment is, for example, 1000 in both the X and Y directions. Therefore, the light deflection element array has a total of one million light deflection elements, and at the second position, the size of the reproduction light formed by the light deflection element array is 1.2 mm in both the X and Y directions.

  In the XY plane 207a, the range scanned by the micro mirror 206 is, for example, 30 inches diagonally, and the size of a solid image formed by joining partial solid images is, for example, 540 mm in both the X and Y directions. Thus, it is possible to display a stereoscopic image on a large screen.

  In addition, since the light deflection element array of this embodiment can be manufactured by a silicon semiconductor manufacturing process, it is possible to drive all the pixels of the light deflection element array, that is, all light deflection elements in parallel by the active matrix method. . Driving each light deflection element in parallel by the active matrix method, and reducing the size and weight of the plate-like member 804 which is a movable portion, can speed up the display time of one partial solid image to, for example, 57 ns. it can. Thus, a stereoscopic image can be displayed at a practical frame rate of 60 fps (frames per second).

  Since the plate-like member 804 is formed of a thin plate having no fixed end such as a hinge, a restoring force does not occur at the time of tilting. Since the resistance at the time of inclination is suppressed by this, it can be made to move with a lower voltage. Moreover, miniaturization is easy. Furthermore, if the vacuum sealing package is used together, further speeding up can be achieved.

  In the present embodiment, since the size of the light deflection element is about the same as the wavelength of the incident light, the light deflection element array configured in a periodic structure by the light deflection elements acts like a diffraction grating. That is, light deflected by the light deflection element array can be made to behave like diffracted light by the light deflection element array.

  In the light deflection element array of the present embodiment, the action of the blazed diffraction grating can be obtained by inclining each light deflection element so as to have a periodic structure. For example, if the light deflection element array is designed to act as a blazed diffraction grating capable of obtaining the maximum diffraction efficiency in + 1st order diffracted light, high diffraction efficiency can be obtained, and a bright stereoscopic image can be displayed.

As described above, according to the present embodiment, a bright three-dimensional image can be displayed at a practical frame rate by using the light deflection element array configured by the light deflection elements. Further, as described above, a wide viewing angle can be secured by equalizing the size of the reproduction light at the first position and the second position, and the reproduction light is scanned at the first position and joined together, A large-sized three-dimensional image can be displayed.
Second Embodiment
Next, a display device of a second embodiment will be described. Descriptions of parts that overlap the first embodiment will be omitted, and differences will be described.

  A method of driving the light deflection element in the display device of the present embodiment will be described in detail with reference to FIG.

  FIG. 9 is a diagram schematically illustrating the relationship between the drive voltage applied to the light deflection element 800 and the operation of tilting the plate member 804. As shown in FIG. The plate member 804 is made of a conductor.

  The figures shown on the left side in FIGS. 9A, 9B, and 9C respectively represent cross-sectional views corresponding to the cross section taken along line A-A in FIG. 8A. The table shown on the right side shows the voltages applied to the electrodes 805a and 805b in the light deflection element 800 and the fulcrum member 803 acting as an electrode. The middle column in the table shows the voltage applied to one light deflection element, and the rightmost column shows the voltage applied to the light deflection element driven next to the one light deflection element. Hereinafter, one light deflection element is referred to as a light deflection element 800, and a light deflection element to be driven next to the one light deflection element is referred to as a light deflection element 800n.

  FIG. 9A shows a state immediately before the plate-like member 804 starts to tilt immediately after the drive voltage is applied to the light deflection element 800. The application of the drive voltage generates an electrostatic attractive force between the plate member 804 and the electrode 805 a, and the left end portion of the plate member 804 is pulled by the electrostatic attractive force in the direction of the white arrow 901. There is.

  In this state, in the light deflection element 800, X (V) is applied to the electrode 805a, and 0 (V) is applied to the electrode 805b and the fulcrum member 803. In the light deflection element 800n, the electrodes 805a and 805b are in an electrically floating state, that is, in a floating state, and the voltage is approximately 0 (V). 0 (V) is applied to the fulcrum member 803.

  Even in a moment, when the voltage is in this state, the above-mentioned electrostatic attraction is generated in the direction of the white arrow 901 on the plate member 804 of the light deflection element 800. Thus, the plate member 804 starts to tilt. The plate-like member 804 in the light deflection element 800 does not have a hinge, so that a restoring force that hinders the operation of tilting does not occur. Therefore, even if the voltage is applied to the electrode 805a and the application of the voltage to the electrode 805a is stopped immediately after the plate member 804 starts to tilt, the action of electrostatic attraction continues and the plate member 804 operates in the tilt To continue. In other words, even if the application of the voltage to the electrode 805a is stopped immediately after the plate-like member 804 starts to tilt, the plate-like member 804 can be tilted.

  Next, FIG. 9B shows a state in which a driving voltage is applied to the light deflection element 800 and the plate member 804 is in the process of tilting. In this state, although the application of the drive voltage is stopped, as indicated by the dotted white arrow 902 in the figure, the electrostatic attraction remains. In this case, the electrode 805a of the light deflection element 800 is in the electrically floating state of Float and is in the state of transitioning from X (V) to 0 (V). Similarly, the electrode 805 b is in the state of an electrically floating Float, and is in the state of transitioning from X (V) to 0 (V). To the fulcrum member 803, 0 (V) is applied.

  At this time, in the light deflection element 800n, X (V) is applied to the electrode 805an, and 0 (V) is applied to the electrode 805bn and the fulcrum member 803n. Then, in the light deflection element 800n, the plate member 804n starts to be inclined.

  Next, FIG. 9C shows a state after the operation of tilting the plate member 804 is finished. The plate-like member 804 comes in contact with the contact portion 807 on the substrate 801 and stops, and ends the tilting operation. In the light deflection element 800 of the present embodiment, the plate-like member 804 is not fixed and does not have the restoring force by the hinge. Therefore, even when the voltage is not applied and the electrostatic attraction does not act, the inclined state, that is, the state of FIG. 9C can be maintained. In this case, the electrode 805a and the electrode 805b are approximately 0 (V) in the electrically floating state. 0 (V) is applied to the fulcrum member 803.

  In the state of FIG. 9C, in the light deflection element 800n, no voltage is applied to the electrode 805an, and the state is an electrically floating Float, and transition from X (V) to 0 (V) It is in the state of doing. Similarly, the electrode 805bn is also in the electrically floating state of Float and is in the state of transitioning from X (V) to 0 (V). To the fulcrum member 803, 0 (V) is applied.

  As described above, the application of the voltage to the light deflection element 800 may be performed only for the moment when the plate member 804 starts to tilt. Thereafter, the application of the voltage is stopped, and the plate member 804 continues the operation of tilting even in the electrically float state. And, even after the end of the tilting operation, the inclined state is maintained as it is. Therefore, the voltage application can be stopped immediately after applying a voltage instantaneously to one light deflection element, and the voltage application to the next light deflection element can be started. By this, for example, it is possible to eliminate the waiting time in voltage application to the light deflection element, and to drive the light deflection element array at higher speed.

  By further increasing the speed of driving the light deflection element array, it is possible to further increase the frame rate of stereoscopic image display by the display device.

The drive of the light deflection element array described above outputs the control signal generated by the reproduction control unit 400b to the light deflection element array drive signal output unit 401c, and the light deflection element array drive signal output unit 401c deflects the drive signal as light. It is realized by outputting to the element array 203. The above-described functions of the reproduction control unit 400b and the light deflection element array drive signal output unit 401c are performed by the reproduction control means to apply “a driving voltage for tilting the plate-like member to one light deflection element and then 1 light deflection It is an example of the function which applies the said drive voltage to other light deflection elements, before the operation | movement of the inclination of the plate-shaped member which an element has is complete | finished.
Third Embodiment
Next, a display device 220 of the third embodiment will be described using FIG. Descriptions of parts overlapping with the first and second embodiments will be omitted, and differences will be described.

  Depending on the image to be displayed as a partial stereoscopic image, the reproduction light from the light deflection element arrays 203r, 203b and 203g may spread widely and propagate. In addition, when the reproduction light from each of the light deflection element arrays 203r, 203b and 203g is combined by the combining prism 205 and is guided to the micro mirror 206, the combined light may spread widely and propagate. In such a case, when the size of the reproduction light or the synthetic light becomes larger than the light reflection surface of the micro mirror 206 at the position where the micro mirror 206 is arranged, that is, the third position, a part of the reproduction light or the synthetic light. Is vignetted by the micro mirror 206 and does not contribute to the display of a partial solid image.

  Although it is not necessary for all of the reproduction light from the light deflection element arrays 203r, 203b and 203g to be incident on the light reflection surface of the micro mirror 206, the brightness of the partial solid image is increased when the amount of light not contributing to the display of the partial solid image is large. Problems such as a decrease in

  According to the display device 220 of the present embodiment, for example, it is possible to prevent an increase in the amount of light that does not contribute to the display of the partial stereoscopic image, and to prevent problems such as a decrease in the brightness of the partial stereoscopic image.

  In FIG. 10, the display device 220 of the present embodiment has a lens 221. The lens 221 is provided between the combining prism 205 and the micro mirror 206 in the optical path of the reproduction light by the light deflection element arrays 203 r, 203 b and 203 g. The lens 221 is an example of the “first optical system”.

  The lens 221 has positive power, and functions to suppress the spread of light toward the micro mirror 206. For example, assuming that the focal length of the lens 221 is f (mm), the optical axis of the reproduction light is separated by f (mm) in the direction from the light deflection element arrays 203r, 203b and 203g toward the micro mirror 206. The lens 221 is provided in such a manner that the optical axis of the lens 221 substantially matches.

  Thereby, the spherical wave whose light emitting point is the position of the light deflection element arrays 203r, 203b and 203g is collimated by the lens 221, and the spread is suppressed. Then, light which is eclipsed by the micro mirror 206 and does not contribute to the display of the partial solid image can be reduced, and problems such as a decrease in brightness of the partial solid image can be reduced.

  In the above case, vignetting by the micro mirror 206 can be further suppressed by shortening the focal length of the lens 221 or increasing the diameter of the lens 221. In order to suppress the influence on the display performance of a three-dimensional image, it is preferable to use, as the lens 221, one in which an aberration such as chromatic aberration is reduced.

Although an example in which the spherical wave whose light emitting point is the position of the light deflection element arrays 203r, 203b and 203g is collimated by the lens 221 having positive power has been described above, the present invention is not limited thereto. Various modifications can be made, such as focusing by the lens 221 or combining lenses having negative power.
Fourth Embodiment
Next, the display device 230, the display device 240, and the display device 250 according to the fourth embodiment will be described with reference to FIG. Descriptions of parts overlapping with the first to third embodiments will be omitted, and differences will be described.

  FIG. 11A is an example of the configuration of the display device 230 according to the present embodiment. In FIG. 11A, the display device 230 has a lens 231 between the micro mirror 206 and the reproduction space in the optical path of reproduction by the light deflection element arrays 203r, 203b and 203g. The lens 231 has positive power and is scanned by the micro mirror 206 to suppress the spread of light toward the reproduction space. In the lens 231, the surface of the display device 230 in contact with the outside is flat.

  When the lens 231 is not provided, the light scanned by the micro mirror 206 spreads toward the reproduction space. Thus, a viewer who observes the reproduction space from the direction facing the micro mirror 206 across the reproduction space observes a three-dimensional image with reduced brightness or a three-dimensional image with reduced viewing angle. May.

  The lens 231 can suppress the spread of light toward the reproduction space, so that the observer can observe a bright three-dimensional large image with a bright viewing angle maintained. The light ray 232 in FIG. 11A shows that the propagation direction of the light directed to the reproduction space is changed by the lens 231.

  FIG. 11B is an example of the configuration of the display device 240 of the present embodiment. The point different from the display device 230 is that a lens 241 is provided instead of the lens 231. The surface of the lens 241 in contact with the outside of the display device 240 has a convex shape directed to the outside of the display device 240. The action of the lens 241 is similar to that of the lens 231, and the display device 240 is one of the modified examples of the display device 230.

  In order to suppress the influence on the display performance of a three-dimensional image, it is preferable to use lenses 231 and 241 with reduced aberrations such as chromatic aberration.

  Note that, in the display device 230 or the display device 240, the lens 231 or the lens 241 may be provided at the position of the transparent plate 210 in FIG. 2 instead of the transparent plate 210. Thus, the lens 231 or the lens 241 can be used as a member for protecting the inside of the display device 230 or the display device 240.

  FIG. 11C is an example of the configuration of the display device 250 of the present embodiment. A different point from the display device 230 or the display device 240 is that a curved mirror 251 is provided instead of the lens 231 or the lens 241. The curved mirror is a mirror in which the light reflecting surface has a curved shape such as a spherical surface or a paraboloid surface.

  Since the scanning light by the micro mirror 206 is reflected by the curved mirror 251, the reproduction space is on the side of the micro mirror 206 as viewed from the curved mirror 251. The stereoscopic image in the reproduction space is observed by the observer 253.

  The point where the spread of light toward the reproduction space can be suppressed by the curved mirror 251 is the same as the action by the lenses 231 and 241, and the display device 250 is one of the modified examples of the display devices 230 and 240. However, since reflection is used, there are different effects on the display devices 230 and 240, such as suppression of chromatic aberration.

  The lens 231, the lens 241, or the curved mirror 251 may be made to act so as to form a three-dimensional image by the display device on the eyeball or retina of the observer.

  The lens 231, the lens 241, or the curved mirror 251 is also effective in improving the fθ characteristic in scanning of the reproduction light, that is, improving the uniform velocity of the scanning speed.

  The lens 231, the lens 241, and the curved mirror 251 in FIG. 11 are examples of the “second optical system”.

  While examples of embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and various modifications may be made within the scope of the present invention as set forth in the claims. Modifications and changes are possible.

108, 211 Three-dimensional image 200, 230, 240, 250 Display 201, 201r, 201b, 201g Light source 202 Controller 203, 203r, 203b, 203g Light deflection element array 204 Light shielding plate 205 Composite prism 206 Micro mirror 207 Reproduction space 207a XY Plane (an example of a plane intersecting the optical axis of reproduction light)
207 b Optical axis of reproduction light 207 c Luminous flux of reproduction light 213 Variable magnification lens 221 lens (an example of a first optical system)
231, 241 lenses (an example of the second optical system)
251 Curved mirror (an example of the second optical system)
305 light source driver 306 micro mirror driver 307 light deflection element array driver 400 control section 400 a drive control section 400 b reproduction control section 401 a light source drive signal output section 401 b micro mirror drive signal output section 401 c light deflection element array drive signal output section 800 light deflection element 801 substrates 802a, 802b, 802c, 802d regulating members 803, 803a, 803b fulcrum members 804 plate members 805a, 805b electrodes

Patent No. 5015969

APPLIED OPTICS Vol. 48, No. 17 10 June 2009

Claims (9)

A display device for displaying a holographic image,
A plurality of light deflection elements are two-dimensionally arrayed, and incident coherent light is deflected for each of the light deflection elements based on data of the reproduction light having a wavefront corresponding to the holographic image, and the reproduction light is generated. A light deflection element array,
A scanning unit configured to scan the reproduction light in a plane intersecting the optical axis of the reproduction light at a first position where the reproduction light forms an image;
Reproduction control means for controlling generation of the reproduction light by the light deflection element array according to the scanning, and combining the scanned reproduction light to form the holographic image;
A display device characterized in that the size in the plane of the reproduction light at the first position is equal to the size at a second position where the light deflection element array is disposed. A display device for displaying a holographic image,
A light source that emits coherent light;
A plurality of light deflection elements are two-dimensionally arrayed, and light from the light source is deflected for each of the light deflection elements based on data of the reproduction light having a wavefront corresponding to the holographic image to generate the reproduction light A light deflection element array
A scanning unit configured to scan the reproduction light in a plane intersecting the optical axis of the reproduction light at a first position where the reproduction light forms an image;
Reproduction control means for controlling generation of the reproduction light by the light deflection element array according to the scanning, and combining the scanned reproduction light to form the holographic image;
A display device characterized in that the size in the plane of the reproduction light at the first position is equal to the size at a second position where the light deflection element array is disposed. A display device for displaying a holographic image,
A plurality of light deflection elements are two-dimensionally arrayed, and incident coherent light is deflected for each of the light deflection elements based on data of the reproduction light having a wavefront corresponding to the holographic image, and the reproduction light is generated. A light deflection element array,
A scanning unit configured to scan the reproduction light in a plane intersecting the optical axis of the reproduction light at a first position where the reproduction light forms an image;
Reproduction control means for controlling generation of the reproduction light by the light deflection element array according to the scanning, and combining the scanned reproduction light to form the holographic image;
A display device characterized in that Rx and Ry representing the size in the plane of the reproduction light at the first position satisfy the relationship of the following equation.

Here, Nx and Ny are the numbers in the horizontal and vertical directions of the light deflection elements in the light deflection element array, and λ is the wavelength of the incident coherent light. The light sources are two or more light sources having different wavelengths,
The light deflection element array is provided for each of the wavelengths,
3. The display device according to claim 2, further comprising means for combining the reproduction light generated by the light deflection element array for each wavelength. The light deflection element includes a substrate, a fulcrum member, a plurality of regulating members, a plate-like member, and a plurality of electrodes.
The fulcrum member has a top and is provided on the upper surface of the substrate.
Each of the regulating members has a stopper at the top, and is provided at an end of the plate-like member,
The plate-like member has a light reflecting surface and a conductive portion, and one surface of the plate-like member is supported by the fulcrum member by being in contact with the top portion, and does not have a fixed end. It is movable in the range defined by the substrate and the regulating member,
Each of the electrodes is provided on the substrate opposite to the conductive portion of the plate-like member,
The plate member is inclined with the top portion as a fulcrum by electrostatic attraction generated between the conductive portion and the electrode, thereby deflecting the reflected light from the light reflecting surface.
The display device according to any one of claims 1 to 4, characterized in that:   The reproduction control means applies a drive voltage for inclining the plate-like member to one of the light deflection elements, and before the operation of the inclination of the plate-like member in the one light deflection element is completed, The display device according to claim 5, wherein the drive voltage is applied to another light deflection element.   A first setting of the size of the reproduction light at the third position in the optical path of the reproduction light between the position where the light deflection element array is arranged and the third position where the scanning means is arranged The display device according to any one of claims 1 to 6, comprising an optical system.   A second optical system having a large size with respect to the holographic image formed by changing the propagation direction of the reproduction light and joining together the scanned reproduction light. The display device according to any one of 1 to 7. A display method for displaying a holographic image,
A plurality of light deflection elements are two-dimensionally arranged, and the coherent light incident is deflected by the light deflection element array that deflects the incident coherent light for each of the light deflection elements based on data of the reproduction light having a wavefront corresponding to the holographic image. Generating the reproduction light;
Scanning the reproduction light in a plane intersecting the optical axis of the reproduction light at a first position where the reproduction light forms an image;
Controlling the generation of the reproduction light according to the scanning, and combining the scanned reproduction light to form the holographic image;
The display method, wherein the size in the plane of the reproduction light at the first position is equal to the size at a second position where the light deflection element array is disposed.

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