JP2012014109A - Stereoscopic image display apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stereoscopic image display apparatus that can operate with a simple synchronizing system by eliminating a large-scale system for taking synchronization among an image generation device, a screen, and a projector.SOLUTION: A projector 2 emits image light corresponding to a depth image transmitted from the image generation device 1, and emits signal light to a plurality of places corresponding to each depth position of depth information. A plurality of light reception parts 5 receive only signal light corresponding to the depth position. A laminated screen 3 is constituted of a plurality of screens 3a that are selectively switched between a transmitting state and a dispersing state for an incident light, and the individual screen corresponding to the light reception part having received the signal light corresponding to the depth position is put into a transmitting state, and the other individual screen is put into a dispersing state.

Description

  The present invention relates to a stereoscopic video display device for observing a stereoscopic video.

  As a method for obtaining a stereoscopic image, a holography method, a liquid crystal glasses method, a lenticular method, a screen shift method, and the like have been proposed. The screen shift method is different from “a plurality of images corresponding to the depth direction” (hereinafter referred to as depth images) exemplified in tomographic images (cross-sectional images) taken by CT or MRI. In this method, the depth image is displayed in a three-dimensional manner by changing the screen position to be projected according to the depth information. The screen shift method is a three-dimensional display method that does not require glasses, does not cause eye fatigue due to congestion, and can reproduce moving images relatively easily.

  Patent Document 1 generally discloses the following contents. A stereoscopic image display device is configured by a projector that projects a depth image, a Fresnel lens that uses parallel light as the projection light from the projector, and a plurality of screens arranged on the exit side of the Fresnel lens. A specific screen corresponding to the plurality of screens is selected as the display mode by the synchronization signal transmitted together with the depth video signal, and the other screens operate as the transparent mode. Individual depth images are projected on a corresponding screen in time order to obtain a stereoscopic image.

JP 2002-228975 A

  By the way, in the stereoscopic video display device described in Patent Document 1, a pulse signal related to depth information is sent from a video generator that generates depth video to a projector and a plurality of screens, and selection of a screen to be displayed and focus adjustment of the projector are performed. A synchronization system to do was needed. There is a problem that a large-scale system is necessary in accordance with an increase in the number of screens stacked and an increase in screen size and projection distance.

  Accordingly, an object of the present invention is to provide a stereoscopic video display apparatus that can operate with a simple synchronization system without requiring a large-scale system for synchronizing the video generation apparatus, the screen, and the projector. .

In order to solve the above-described problems of the related art, the present invention emits video light corresponding to the depth video transmitted from the video generation device (1) and a plurality of depth information corresponding to each depth position of the depth information. A projector (2) that emits signal light to a place, a plurality of light receiving units (3) that receive only signal light corresponding to the depth position, and a transmission state and a scattering state for incident light are selectively switched. Only each of the individual screens (3a) corresponding to the light receiving unit that has received the signal light corresponding to the depth position is in a scattering state, and the other individual screens (3a) are in a transmissive state. And a laminated screen (3) to provide a stereoscopic video display device.
In addition, a projector (2) that emits image light corresponding to the depth image sent from the image generator (1) and emits signal light corresponding to the depth information, and a light receiving unit (5) that receives the signal light ), A control unit (6) for controlling the screen (3a) corresponding to the signal light received by the light receiving unit to be in a scattering state, and a screen other than the corresponding screen to be in a transmission state, and to the incident light A laminated screen (3) that includes a plurality of screens that can be selectively switched between a transmission state and a scattering state, wherein only the screen controlled by the control unit is in a scattering state, and the other screens in the screen are in a transmission state; A stereoscopic video display device characterized by comprising:

  According to the present invention, it is possible to operate with a simple synchronization system, eliminating the need for a large-scale system for synchronizing the video generator, the screen, and the projector.

It is a schematic block diagram which shows the three-dimensional video display apparatus of 1st Embodiment. It is explanatory drawing which shows one example of the depth image | video which can be observed with the three-dimensional video display apparatus of 1st Embodiment. FIG. 3 is a diagram showing three individual depth images constituting the depth image of FIG. 2 and showing how the depth images correspond to different screen surfaces of the laminated screen. It is explanatory drawing explaining the focus adjustment of the projector shown in FIG. FIG. 2 is a circuit diagram for explaining an operation of an active matrix liquid crystal device used as a display device of the projector shown in FIG. It is explanatory drawing which shows an example of the pixel arrangement | positioning of an active matrix type liquid crystal device. It is a perspective view which shows arrangement | positioning of the lamination | stacking screen shown in FIG. It is a circuit diagram which shows the connection relation of the light-receiving part corresponding to each screen which comprises a laminated screen. FIG. 3 is an arrangement diagram illustrating an example of a relative arrangement of a laminated screen 3 and a light receiving unit 5. It is explanatory drawing which shows the relationship between the photodiode and each depth image | video which operate | move when the depth image | video of FIG. 2 is projected. 5 is a flowchart illustrating a series of operations from when signal light is emitted until an image is displayed in the first embodiment. 12 shows a timing chart corresponding to the flowchart of FIG. It is a schematic block diagram which shows the outline of the three-dimensional video display apparatus of the 2nd Embodiment of this invention. It is a perspective view which shows arrangement | positioning of the lamination | stacking screen shown in FIG. 13, and a light-receiving part. 9 is a flowchart showing a series of operations from when signal light is emitted until an image is displayed in the second embodiment. Fig. 16 shows a timing chart of the sequence shown in Fig. 15. 10 is a flowchart illustrating a series of operations from when signal light is emitted until an image is displayed in the third embodiment. 18 shows a timing chart corresponding to the flowchart of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a schematic configuration diagram illustrating a stereoscopic image display apparatus according to a first embodiment of the present invention. The depth video is reproduced by the video generator 1 based on the video created by CAD, three-dimensional CG, or the like, or created by the video generator 4 itself. The depth video is transmitted from the video generator 1 to the projector 2 together with the depth information.
The depth image is displayed on the display device 21 of the projector 2, projected by the projection lens 25, and formed on the individual screens 3 a of the laminated screen 3. The observer 8 observes the images projected on the individual screens 3a.

  FIG. 2 is a diagram illustrating an example of a depth image that can be observed by the stereoscopic image display apparatus according to the first embodiment. The illustrated image 4 is an image of a composition in which an outside landscape is viewed from the indoor through the window. FIG. 3 is a diagram showing three individual depth images constituting the depth image of FIG. 2, and showing how these depth images correspond to different screen surfaces of the laminated screen 3. The foreground 41 of the image is a window frame. The background 43 of the image is a mountain range. The scenery 42 in the middle of the image is a single tree.

  Generally, in order to perform stereoscopic display, the depth number of a depth image needs to be at least two. In the images illustrated in FIGS. 2 and 3, the depth number is 3. A set of depth images having a depth number N is one frame. By the way, in order to reproduce a depth image without flicker, the frame frequency is required to be 60 Hz or more. Therefore, it is desirable to display the individual images constituting the depth image at a frequency equivalent to 120 Hz when the depth number N = 2 and 180 Hz when the depth number = 3. As the number (N) of depth images in one frame increases, a more natural stereoscopic effect can be obtained.

  In the stereoscopic video display device of this embodiment, when the video illustrated in FIGS. 2 and 3 is input, the video is divided into three individual depth videos according to the depth information and displayed on the laminated screen 3. The foreground 41 is projected onto the foreground screen as viewed from the observer 8.

  FIG. 4 is an explanatory diagram for explaining the focus adjustment of the projector 2 shown in FIG. In a normal projector, an entire group feeding mechanism that feeds back and forth while rotating the entire lens along the optical axis is generally used. However, in the present embodiment, the projection lens 25 of the projector 2 needs to be focused at high speed according to the depth information of the depth image so that an image is formed on each corresponding screen 3a of the laminated screen 3. Therefore, an actuator 23 is provided between the housing 22 of the projector 2 main body and the flange 24 of the projection lens 25.

  The actuator 23 changes to a preset thickness corresponding to the depth information in accordance with the depth information of the depth image. When the actuator 23 changes to a predetermined thickness, the focus of the projection lens 25 moves, and an image is formed on the corresponding individual screen 3a of the laminated screen 3 shown in FIG. 4A shows the case where the thickness of the actuator 23 is the maximum, and FIG. 4B shows the case where the thickness of the actuator 23 is the minimum.

  The focus adjustment condition of the projection lens 25 is set (memory 1) so that the closest image (foreground) is imaged on the screen 3a closest to the observer of the laminated screen 3. The focus adjustment condition of the projection lens 25 is set (memory 2) so that the image (background) located farthest is imaged on the screen farthest from the observer of the laminated screen 3. Imaging in the case of other intermediate images is performed step by step between the memory 1 and the memory 2 corresponding to the number of laminated screens.

  FIG. 5 is a circuit diagram for explaining the operation of the active matrix liquid crystal device used as the display device 21 of the projector 2 shown in FIG. The liquid crystal 79 is sandwiched between the reflective electrode 77 and the counter electrode 78. A pixel transistor 75 for pixel selection is connected to the reflective electrode 77. The storage capacitor 76 is a capacitor for storing charges applied to the liquid crystal 79 and is arranged in parallel with the liquid crystal 79. Each pixel is addressed by the gate line 73 from the V (vertical) shift register 71 and a charge corresponding to the image is applied to each pixel transistor 75 via the signal line 74 from the H (horizontal) shift register 72.

  FIG. 6 is an explanatory diagram showing an example of pixel arrangement of an active matrix liquid crystal device. An effective pixel region 702 is formed at the center of the active matrix liquid crystal device. A prepared pixel region 701 is provided around the effective pixel region 702. The H shift register 72 and the V shift register 71 are arranged outside the prepared pixel region 701. In a display device (referred to as full high-definition or FHD) expressed as effective pixels 1920 × 1080, for example, 8 pixels are added as adjustment pixels in both horizontal and vertical directions, so the total number of pixels is 1928 × 1088 pixels.

  The purpose of adding the adjustment pixel is first to ensure the flatness of the effective pixel region 702 and secondly to shift the image at the pixel level, but is rarely used in practice. Depth information is projected as signal light using the prepared pixel region 702. In the first embodiment, a plurality of signal light display areas 703 corresponding to the number of depths are provided in the prepared pixel area 702. The projector 2 displays a signal light display region 702 corresponding to the depth position based on the depth information, and emits signal light toward a plurality of corresponding locations near the laminated screen 3.

  FIG. 7 is a perspective view showing the arrangement of the laminated screen 3 shown in FIG. FIG. 8 is a circuit diagram showing the connection relationship between the light receiving sections 5 corresponding to the individual screens 3a constituting the laminated screen. The laminated screen 3 is composed of individual screens 3a arranged in parallel to each other. A corresponding light receiving section 5 is connected to each screen 3a. Each screen 3 a is a screen having a structure in which polymer dispersed liquid crystal (PDLC) 33 is sandwiched between glasses 31 and 32. Although not shown, a transparent electrode is formed on one side of each glass 31 and 32. The polymer-dispersed liquid crystal exhibits a scattering state in which light is scattered when no voltage is applied to the liquid crystal, and exhibits a transmission state in which light is transmitted when a predetermined voltage is applied to the liquid crystal. In the following description, a state in which no voltage is applied to the liquid crystal is referred to as a voltage low state, and a state in which a predetermined voltage is applied to the liquid crystal is referred to as a voltage high state.

  The light receiving unit 5 is connected to the transparent electrode on one side of each screen 3a. The other transparent electrodes are at ground potential. The light receiving unit 5 includes a photodiode 51 and a drive circuit. In a state where the signal light from the projector 2 is not irradiated onto the photodiode 51, the photodiode 51 is off (high resistance). The base potential of the transistor 52 becomes low due to the relationship between the resistor 53 and the resistance of the photodiode, and no emitter current flows. Therefore, there is no voltage drop due to the resistor 54, and a voltage of + V [v] is applied to the screen 3a (voltage high state). On the other hand, when the photodiode 51 is irradiated with signal light, the photodiode 51 is turned on (low resistance). At this time, the base potential of the transistor 52 becomes high and an emitter current flows. The voltage applied to the screen 3a becomes almost zero due to the voltage drop caused by the resistor 54 (voltage low state).

  When the signal light from the projector 2 is irradiated, only the liquid crystal of the screen 3a corresponding to the light receiving unit 5 that has received the signal light is in a low voltage state. As a result of the polymer-dispersed liquid crystal on the screen 3a being in a scattering state, image light can be imaged.

  FIG. 9 is an arrangement diagram showing an example of the relative arrangement of the laminated screen 3 and the light receiving unit 5. The light receiving sections 5 are arranged at a plurality of locations corresponding to a plurality of signal lights emitted from the signal light display region 703 in FIG. In FIG. 9, one light receiving unit 5 is provided in the vertical direction, one on the left side of the outer periphery of the projection area of the laminated screen 3. The light receiving portion 5 corresponding to the foremost screen 3a is installed at the upper left corner of the screen. Hereinafter, the light receiving unit 5 corresponding to the Nth screen from the front is provided at the Nth position from the upper left.

  FIG. 10 is an explanatory diagram showing the relationship between the operating light receiving unit 5 and individual depth images when the depth image of FIG. 2 is projected. In FIG. 10, it is assumed that N = 3. The figure on the left is the foreground 41, and the uppermost light receiving unit 5 operates. The middle figure is an object in the middle 42, and the second light receiving unit 5 operates. The right figure shows the background 43, and the third light receiving unit 5 operates. In this way, by determining the irradiation position of the signal light projected from the projector 2 and the position of the light receiving portion 5 of each screen, it is possible to instantaneously select the corresponding predetermined screen 3a from the laminated screen 3. It becomes possible.

  FIG. 11 is a flowchart showing a series of operations from when signal light is emitted until an image is displayed in the first embodiment. A start pulse is issued at the beginning of each field (step S801). Following the start pulse, signal light is output (step S804). Screen selection (step S805) and focus adjustment (step S806) are executed slightly after the signal light output. Screen selection (step S805) is a process in which the photodiode 51 of the corresponding light receiving unit 5 receives the signal light and sets the liquid crystal layer of the corresponding screen 3a to a voltage low state. Simultaneously with the screen selection, the focus adjustment of the projection lens 25 is performed (step S806). Specifically, when the actuator 23 of the projection lens 25 is displaced by the drive signal, the focus moves and the selected screen 3a is focused. After screen selection and focus adjustment, image light is projected, and an image is displayed on the selected screen 3a (step S807).

  FIG. 12 shows a timing chart corresponding to the flowchart of FIG. One sequence from S801 to S807 in FIG. 11 corresponds to one field in FIG. The individual steps are as described in FIG. From the above flicker viewpoint, one frame is set to 60 Hz. Individual depth images are displayed in a time-sharing manner within one frame. In the example of FIGS. 3 and 8, the depth number is 3, and one field is 180 Hz. In addition, by setting the start pulse, signal light output, screen selection, and focus adjustment periods as blanking periods during which video light is not transmitted (periods during which black is inserted), crosstalk in the depth direction of depth video is prevented.

<Second Embodiment>
FIG. 13: is a schematic block diagram which shows the outline of the three-dimensional video display apparatus of the 2nd Embodiment of this invention. In FIG. 13, the display device 21, the laminated screen 3, the video generator 1, and the projection lens 25 are the same as those in FIG. The difference from FIG. 1 is that one light receiving unit 5 is arranged closest to the screen 31 on the projector side. The display device 21 of the projector 2 may have a plurality of signal light display areas 703, one of which may be used, or only one signal light display area 703.

  FIG. 14 is a perspective view showing the arrangement of the laminated screen 3 shown in FIG. As in the case of FIG. 7, the laminated screen 3 is composed of individual screens 3a arranged in parallel to each other. In FIG. 7, the corresponding light receiving unit 5 is connected to each screen 3 a, but in FIG. 14, one light receiving unit 5 is arranged in the vicinity of the screen 31 on the projector side, and the light receiving unit 5 includes the control unit 6. Is connected.

  The control unit 6 demodulates the signal light received by the light receiving unit 5 and selects the corresponding screen 3a. Specifically, the signal light in the first embodiment is unmodulated, whereas in the present embodiment, the signal light is subjected to predetermined modulation. The modulated signal light is received by the light receiving unit 5 and demodulated by the control unit 6. Only the corresponding screen 3a is controlled to a voltage low state (scattering state), and the other screens are controlled to a voltage high state (transmission state). If the signal light is, for example, an 8-bit signal, a screen having a maximum of 256 layers can be switched theoretically.

  FIG. 15 is a flowchart showing a series of system operations from when signal light is emitted until video is displayed in the second embodiment. The difference from the first embodiment is that when the photodiode 51 receives a start pulse, the focus of the projection lens 25 moves to the screen 3a on which the light receiving unit 5 is arranged (step S802). This is to prevent the signal light from defocusing on the photodiode 51 of the light receiving unit 5 and to ensure the light receiving operation. Hereinafter, the screen on which the light receiving unit 5 is arranged is referred to as an origin screen.

  FIG. 16 shows a timing chart corresponding to the flowchart of FIG. When the start pulse is generated, the focus of the projection lens returns to the origin screen (step S802), and then the signal light is projected (step S804). The light receiving unit 5 receives the signal light, selects an optimal screen, and projects image light (steps S805, S806, and S807).

<Third Embodiment>
FIG. 17 is a flowchart showing a series of operations from when signal light is emitted until an image is displayed in the third embodiment. FIG. 18 shows a timing chart corresponding to the flowchart of FIG.
First, a start pulse is issued at the beginning of each field (step S801). Next, a 100% gradation signal is output with a delay from the start pulse (step S803). The difference from the first and second embodiments is that a 100% gradation signal is output. Thereafter, signal light is output (step S804).

  Outputting signal light after outputting a 100% grayscale signal eliminates false detection of signal light from the photodiode 51 due to factors such as changes in the light source and display device over time and the surrounding environment (temperature conditions, stray light, etc.) It is to do. In this embodiment, erroneous detection of signal light is prevented by detecting the difference in luminance between the 100% gradation signal and the modulated signal light. Further, there is an effect that it is not necessary to return the focus of the projection lens 25 to the origin screen.

  In other words, in the second embodiment, when the photodiode 51 of the light receiving unit 5 receives the start pulse, the focus of the projection lens is once returned to the origin screen because the signal light is defocused on the photodiode 51. This is for preventing and ensuring the light receiving operation. However, in the third embodiment, the focus of the projection lens 25 is returned to the origin screen in order to prevent erroneous detection of the signal light by detecting the difference in luminance between the 100% gradation signal and the modulated signal light. There is no need to let them.

  After the signal light output (step S804), screen selection (step S805) and focus adjustment (step S806) are performed, and then image light is projected (step S807).

  In the first to third embodiments, a liquid crystal device has been described as an example of a display device. However, in addition to a transmissive liquid crystal device and a reflective liquid crystal device, a DLP (Digital Light Processing) element, a MEMS, (Micro Electro Mechanical Systems) An element can also be used as a display element.

1 video generator,
2 projector, 21 display device, 22 projector housing,
23 Actuator, 24 Projection lens flange, 25 Projection lens 3 Laminated screen, 3a Individual screen,
31, 32 glass, 33 polymer dispersed liquid crystal (PDLC),
4 illustrated image, 41 foreground, 42 intermediate scene, 43 background 5 light receiving unit, 51 photodiode, 52 transistor,
53 resistance, 54 resistance,
6 Control unit,
71 V shift register, 72 H shift register, 73 gate lines,
74 signal lines, 75 pixel transistors, 76 holding capacitors, 77 reflective electrodes,
78 counter electrode, 79 liquid crystal, 701 adjustment pixel area, 702 effective pixel area,
703 signal light display area,
8 observers

Claims (2)

A projector that emits image light corresponding to a depth image sent from the image generator and emits signal light to a plurality of locations corresponding to respective depth positions of depth information;
A plurality of light receiving portions that receive only signal light corresponding to the depth position;
It is composed of a plurality of screens that can selectively switch between a transmission state and a scattering state for incident light, and only the individual screens corresponding to the light receiving portions that receive the signal light corresponding to the depth position are in a scattering state. Each of the screens is a transmissive screen,
A stereoscopic video display device comprising: A projector that emits image light corresponding to a depth image sent from the image generator, and emits signal light according to depth information;
A light receiving portion for receiving the signal light;
A control unit for controlling the screen corresponding to the signal light received by the light receiving unit to a scattering state and a screen other than the corresponding screen to a transmission state;
A laminated screen composed of a plurality of screens that can be selectively switched between a transmission state and a scattering state for incident light, wherein only the screen controlled by the control unit is in a scattering state, and the other screens in the screen are in a transmission state. When,
A stereoscopic video display device comprising:

Images