JP5474530B2 - Stereoscopic image display device - Google Patents

Description

  The present invention relates to a stereoscopic image display apparatus that allows a viewer to recognize a stereoscopic image by displaying a parallax image.

  Since the human eyes are several centimeters apart, the images obtained with the right and left eyes are misaligned. The human brain recognizes the depth using this misalignment as a clue. In other words, by adjusting the positional deviation amount (offset) of the image to be copied to both eyes, the brain can be made to recognize the depth in a pseudo manner. Using this binocular parallax, various methods for causing the brain to recognize a planar image as a stereoscopic image have been put into practical use. Broadly classified, there are a glasses method and a naked eye method, a glasses method includes a shutter glasses method, a polarized glasses method, and an anaglyph glasses method, and a naked eye method includes a parallax barrier method and a lenticular lens method.

  A stereoscopic image display device, based on the principle of recognizing a stereoscopic image using binocular parallax, cannot obtain a natural stereoscopic image even if the same parallax image is used and the screen size for displaying it is different. There is a problem. In order to cope with this problem, for example, Patent Document 1 acquires display screen size information of a stereoscopic video determined in association with a stereoscopic video, and sets an offset between the left eye video and the right eye video based on this information. Thus, a technique for adjusting the stereoscopic effect of the displayed video is disclosed.

Japanese Patent Laid-Open No. 2004-180069

  In recent years, the development of projectors that can reproduce stereoscopic images has been underway. The size of the screen varies depending on the environment due to the characteristic that the projector projects an image on a projection surface such as a screen. For this reason, in the conventional technique such as Patent Document 1 described above, it is considered that display screen size information is not prepared when the screen size is unspecified as in a projector.

  The present invention has been made in view of such a situation, and an object thereof is to provide a stereoscopic image display technique for displaying a stereoscopic image having an optimal display parallax amount regardless of the display screen size.

  In order to solve the above-described problems, an aspect of the present invention provides a stereoscopic image display apparatus that projects and displays a stereoscopic image on a projection plane. This apparatus includes a projection unit that projects and displays a parallax image composed of a first image and a second image having a predetermined parallax with respect to the first image in a predetermined display area, and a display area on the projection plane A display size determination unit that determines whether or not the size is equal to or larger than an upper limit size determined based on a limit value of a parallax amount that allows a parallax image to be recognized as a stereoscopic image.

  It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between a method, an apparatus, a system, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to display a stereoscopic image having an optimal display parallax amount regardless of the display screen size.

1 is a diagram illustrating a configuration of a stereoscopic image display system according to Embodiment 1. FIG. (A), (b) is a figure which shows the internal structure of a projection type video display apparatus. (A)-(c) is a figure which shows the modification of the attachment position of a polarization switcher. It is a figure explaining the relationship between screen display size and the amount of left-right parallax. 2 is a functional block diagram of the projection display apparatus according to Embodiment 1. FIG. (A), (b) is a figure explaining the horizontal direction shift of a parallax image. It is a figure explaining the method of calculating a display screen size based on the picked-up image of a camera. 6 is a functional block diagram of a projection display apparatus according to Embodiment 2. FIG. It is a figure which shows an example of the image for glasses confirmation. (A)-(e) is a figure which shows the example of the image for glasses confirmation. It is a figure which shows an example of the image for reverse view confirmation. 10 is a flowchart of a process for performing glasses confirmation operation and reverse vision confirmation operation according to the second embodiment. It is a figure which shows an example of the image for glasses confirmation. It is a figure which shows a mode that a multiview three-dimensional image | video is projected on an autostereoscopic display. It is a figure which shows the image for reverse viewing confirmation of a multiview type | formula three-dimensional video. (A)-(c) is a figure explaining a mode that the direction in which a person exists is switched to the lower side of a screen. (A), (b) is a figure which shows the structure of the light-receiving part of the infrared synchronizing signal provided in shutter glasses. It is a figure which shows handheld shutter glasses. (A)-(c) is a figure which shows the shape and reflection direction of a silver screen. (A)-(c) is a figure which shows the example of the protection plate which protects the uneven surface of a silver screen.

Embodiment 1 FIG.
[Configuration of stereoscopic image display system]
FIG. 1 is a diagram showing a configuration of a stereoscopic image display system 10 according to Embodiment 1 of the present invention. The stereoscopic image display system 10 includes a projection display apparatus 100, a camera (not shown), a screen 21, and glasses 30 that are provided adjacent to or built in the projection display apparatus.

  The projection display apparatus 100 as an image display unit is a so-called short focus projector that can extremely shorten the installation distance to a projection surface such as a screen. As shown in FIG. 1A, the projection display apparatus 100 according to the present embodiment is installed on the floor and projects an image onto a display area 23 on a screen 21 that is also arranged on the floor. As shown in (b), an image is projected on the display area 23 on the screen 21 which is installed on the wall surface and similarly disposed on the wall surface. As can be seen from the figure, if a short focus projector is employed, the projection distance can be shortened, so that the space can be used effectively. However, the projection display apparatus 100 may be a conventional projector that projects an image on a screen on a remote wall surface.

  The projection display apparatus 100 temporally displays a first image and a second image having a predetermined parallax with respect to the first image (hereinafter collectively referred to as “parallax image”) in the display area 23. Or, it is divided and displayed spatially.

  Each observer of a stereoscopic image wears glasses for observation 30 and looks at the screen. When the shutter glasses method is adopted as the glasses 30, the projection display apparatus 100 displays a parallax image composed of the first image and the second image in a time division manner. For example, the right eye image and the left eye image are alternately displayed. In this case, the glasses 30 open the right eye shutter and close the left eye shutter when the right eye image is displayed, and open the left eye shutter and open the right eye when the left eye image is displayed. It operates to close the shutter. In order to synchronize this operation with the display of the parallax image, the projection display apparatus 100 and the shutter glasses 30 transmit and receive a synchronization signal.

  When the polarized glasses method is adopted as the glasses 30, the projection display apparatus 100 displays a parallax image composed of the first image and the second image by dividing the space. For example, a phase difference plate is installed only in the even rows in the subsequent stage of the display element so that the light emitted from the pixels in the odd rows and the even rows has different polarizations. As a result, the odd-numbered and even-numbered rows of the image formed on the screen have different polarizations. Or when displaying the parallax image which consists of a 1st image and a 2nd image in a time division | segmentation, while the projection type video display apparatus 100 displays the image for right eyes and the image for left eyes alternately, a projection lens The left-eye image and the right-eye image are projected with different polarizations by the polarization switcher 40 that switches the polarized light arranged in front of the screen. In this case, the glasses 30 are configured such that the left eye transmits the polarization of the left-eye image and the right eye transmits the polarization of the right-eye image. In addition to temporally and spatially dividing the first image and the second image, a method of projecting a right-eye image and a left-eye image with different polarizations using two projectors is also possible. is there. By observing the image with polarized glasses, it is possible to show images corresponding to the left and right eyes, respectively.

  A camera (for example, a CCD camera) captures an image including at least the display area 23 and supplies the image to the projection display apparatus 100.

[Configuration of Projection Display Device]
FIG. 2 is a diagram showing the internal structure of the projection display apparatus 100. As shown in FIG. 2A is an internal perspective view of the projection display apparatus 100 as viewed from the side, and FIG. 2B is an internal perspective view of the projection display apparatus 100 as viewed from above. The arrangement configuration of each optical component in the optical engine 200 is shown.

  A projection port 101 for image light is formed on the front surface of the projection display apparatus 100. Since the projection display apparatus 100 of the present embodiment is a short focus projector, the projection port 101 is installed to face obliquely downward. As a result, an image can be projected onto a projection plane located close to the apparatus 100.

  Inside the projection display apparatus 100, an optical engine 200, a rear refractive optical system 300, a reflective mirror 400, a front refractive optical system 500, and a curved mirror 600 are arranged.

  The optical engine 200 generates video light modulated according to the video signal. In the optical engine 200, each optical component (a liquid crystal panel, a dichroic prism, etc.) is installed in a predetermined arrangement in the casing.

  As shown in FIG. 2B, the optical engine 200 includes a light source 201, a light guide optical system 202, three transmissive liquid crystal panels 203, 204, and 205, and a dichroic prism 206.

  White light emitted from the light source 201 is converted into light in the red wavelength band (hereinafter referred to as “R light”), light in the green wavelength band (hereinafter referred to as “G light”), and blue wavelength by the light guide optical system 202. The light is separated into band light (hereinafter referred to as “B light”) and applied to the liquid crystal panels 203, 204, and 205. The R light, G light, and B light modulated by the liquid crystal panels 203, 204, and 205 are color-combined by the dichroic prism 206 and emitted as video light.

  In addition to the transmissive liquid crystal panels 203, 204, and 205, a reflective liquid crystal panel or a MEMS device can be used as the light modulation element disposed in the optical engine 200. Further, instead of the three-plate type as described above, for example, a single-plate type optical system using a color wheel may be used.

  A rear refractive optical system 300 is attached to the image light exit of the optical engine 200. The image light generated by the optical engine 200 is incident on the rear refractive optical system 300. The rear refractive optical system 300 includes a plurality of lenses. As shown in FIG. 2A, the liquid crystal panels 203, 204, 205 and the dichroic prism 206 are arranged shifted from the optical axis L1 of the rear refractive optical system 300 in the Z-axis direction (the curved mirror 600 side). .

  A reflection mirror 400 is arranged in front of the rear refractive optical system 300. The reflection mirror 400 is disposed in a state orthogonal to the XZ plane and inclined by 45 degrees with respect to the XY plane.

  A front refractive optical system 500 is disposed above the reflection mirror 400. The front refractive optical system 500 includes a plurality of lenses, and the optical axis L2 of these lenses is parallel to the Z axis and parallel to the image light exit surface of the dichroic prism 206. In addition, the optical axis L2 of the front refractive optical system 500 is perpendicular to the optical axis L1 and the bottom surface of the rear refractive optical system 300, and on the reflection mirror 400, the optical axis L1 of the rear refractive optical system 300 and Crosses. That is, the front refractive optical system 500 forms one refractive optical system in cooperation with the rear refractive optical system 300, and is reflected by the reflection mirror 400 interposed between the two refractive optical systems 300 and 500. The optical axis of the lens group is converted from a direction perpendicular to the exit surface of the dichroic prism 206 to a direction parallel thereto.

  The image light that has entered the rear refractive optical system 300 passes through the rear refractive optical system 300, the reflection mirror 400, and the front refractive optical system 500, and then enters the curved mirror 600 disposed above the front refractive optical system 500. .

  The curved mirror 600 has a concave reflecting surface. As shown in FIG. 2A, the curved mirror 600 has an effective reflection region on the optical engine 200 side with respect to the optical axis L2 of the front refractive optical system 500. The curved mirror 600 can be aspherical, free curved, or spherical.

  The image light incident on the curved mirror 600 is reflected by the curved mirror 600 and enlarged and projected on the projection surface through the projection port 101. At this time, the image light is expanded after being converged most in the vicinity of the projection port 101.

  Returning to FIG. 1, when the polarized glasses method is adopted, a polarization switcher 40 is attached to the projection port of the projection display apparatus 100. The polarization switcher 40 is configured to receive the synchronization signal supplied from the projection display apparatus 100 and change the polarization direction in accordance with the synchronization signal. The image that has passed through the polarization switcher 40 is polarized in a time-division manner into polarized images that are orthogonal to each other. A three-dimensional image can be recognized by projecting this image onto a screen that maintains polarization and observing image light diffusely reflected on the screen with polarized glasses. The polarized light may be linearly polarized light or circularly polarized light, that is, right circularly polarized light and left circularly polarized light.

  The polarization switcher 40 is disposed non-parallel to the screen 21. At this time, it is preferable that the vertical incident angle to the polarization switcher 40 is equal in the positive direction (θ1 in FIG. 1) and the negative direction (θ2 in FIG. 1). In this way, the cross-sectional area of the light beam passing through the polarization switcher 40 is minimized, so that the polarization switcher can be miniaturized. For the same reason, it is preferable to arrange the incident angles in the left and right directions to the polarization switcher so that they are equal in the positive direction and the negative direction. Moreover, the polarization performance by a switcher can be improved by making the incident angle with respect to a polarization switcher as small as possible.

  As shown in FIG. 1, the polarization switcher may be disposed inside the apparatus 100 instead of being attached to the projection port of the projection display apparatus 100. 3A to 3C show modified examples of the mounting position of the polarization switcher 40. FIG. As shown in FIG. 3A, the polarization switcher 40 may be arranged after the curved mirror 600 of the projection system, or may be arranged in front of the curved mirror 600 as shown in FIG. If it arrange | positions so that it may become substantially perpendicular | vertical with respect to a light beam like FIG.3 (c), a polarization switcher can be reduced in size.

  In any case, the polarization switcher 40 is preferably configured to be easily removable from the projection display apparatus 100. This is because it is preferable to remove the polarization switcher in order to prevent a decrease in the amount of light when a normal two-dimensional image is displayed on the projection display apparatus or when a three-dimensional image is displayed using the shutter glasses method.

[Prevention of excessive parallax]
FIG. 4 is a diagram for explaining a problem that occurs when a projection display apparatus 100 is used to enlarge and project a parallax image on a screen. FIG. 4 shows how the parallax image I1 displayed on the relatively small display S1 is observed with both eyes, and how the similar parallax image I2 displayed on the large screen S2 is observed with both eyes. Note that this problem is not limited to the shutter glasses method and the polarized glasses method described above, and may occur in any stereoscopic image display method using binocular parallax.

  In general, the amount of parallax between the left and right images in a stereoscopic image increases in proportion to the size of the display screen. Therefore, on the relatively small display S1, even if the parallax image allows the stereoscopic lines to be observed by intersecting the lines of sight from both eyes, the lines of sight from both eyes do not intersect on the large screen S2, thereby making stereoscopic viewing impossible. Thus, there is a close relationship between the screen size and the amount of parallax to be set between the left and right images. In particular, with regard to distant parallax where the line of sight does not intersect, if the amount of parallax between the left and right images exceeds the distance between human eyes, in principle, stereoscopic viewing becomes impossible. When the line of sight intersects nearby, there is no limit in principle, but there is a physiological limit of the observer.

  Therefore, the present embodiment provides a technique for adjusting the display parallax amount between parallax images when a stereoscopic image is projected onto a projection surface such as a screen.

[Functions of the projection display device]
FIG. 5 is a functional block diagram of the projection display apparatus 100. These configurations can be realized by an arbitrary processor, memory, or other LSI in terms of hardware, and can be realized by a program loaded in the memory in terms of software, but here by their cooperation. Draw functional blocks. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  The image signal holding unit 11 holds an image signal supplied from the outside. The image processing unit 13 appropriately processes the image signal held in the image signal holding unit 11 in accordance with an instruction from the adjustment unit 20.

  The projection unit 14 projects light corresponding to the image generated by the image processing unit 13 onto the display area 23. The synchronization signal generation unit 15 generates a signal synchronized with the projection timing of each frame image by the projection unit 14. The synchronization signal transmission unit 16 transmits the synchronization signal generated by the synchronization signal generation unit 15 by wired communication, infrared communication, or other short-range wireless communication. In the case of the shutter glasses method, the synchronization signal is transmitted to the glasses 30, and in the case of the polarization glasses method, the synchronization signal is transmitted to the polarization switcher 40.

The display size determination unit 22 calculates the display size of the screen displayed on the screen based on the image taken by the camera 25 provided adjacent to or built in the projection display apparatus 100. Then, it is determined whether or not the display size of the screen is greater than or equal to a predetermined upper limit size.
Here, the “upper limit size” is defined as the display size of the screen when the maximum amount of parallax between the left and right images constituting the parallax image is equal to the human interocular distance (for example, 65 mm). That is, when the display size of the screen is equal to or larger than the upper limit size, the amount of parallax between the left and right images exceeds the interocular distance, which can be said to be a limit size that makes stereoscopic viewing impossible.

  More specifically, the display size determination unit 22 performs corresponding point matching between the left-eye image and the right-eye image constituting the parallax image, thereby corresponding to each parallax amount between the left and right images. You can ask for points. Then, the maximum parallax amount for each corresponding point is specified as the “maximum parallax amount”. If the maximum parallax amount in pixel units is known, the maximum parallax amount in actual distance units (for example, mm) can be easily calculated with respect to the display size of the screen. The display size of the screen when the maximum parallax amount of the actual distance is equal to the interocular distance is the “upper limit size”.

  Note that the maximum parallax amount of the parallax image is not necessarily the maximum value among all corresponding points in the image. Since the subject to which the observer pays attention is limited, for example, the maximum value among the corresponding points of the main subject in the image may be adopted. Whether or not the subject is the main subject can be determined by a known image analysis method.

  Further, the interocular distance may be fixed at a standard 65 mm, or a limit value of the parallax amount serving as an alternative value of the interocular distance is input to the display size determination unit 22 using an input device (not shown). Also good. Alternatively, even when the actual parallax image is displayed on the screen, the parallax amount between the left and right images is gradually widened, and the limit value at which the user can no longer view stereoscopically is set as an alternative value for the interocular distance. Good.

  When the display size of the screen is equal to or larger than the upper limit size, the warning display unit 24 causes the projection unit 14 to display an image including a message that informs the observer that the displayed image may have high parallax.

  Alternatively, when the screen display size is equal to or larger than the upper limit size, the adjustment unit 20 instructs the image processing unit 13 to reduce the screen display size. In response to this, the image processing unit 13 reduces the image so that the display size of the screen is equal to or smaller than the upper limit size. Alternatively, when the zoom function is installed in the projection lens of the projection display apparatus 100, the display size of the screen may be reduced by adjusting the zoom.

  Further, when the display size of the screen is equal to or larger than the upper limit size, the adjustment unit 20 may instruct the image processing unit 13 to reduce the amount of parallax between the left and right images constituting the parallax image. . In response to this, the image processing unit 13 horizontally moves each image so that the parallax amount of the left and right images constituting the parallax image is smaller than before, that is, the direction in which the left and right images approach.

  FIG. 6 shows how the amount of parallax is reduced. In FIG. 6A, since the amount of parallax between the left and right images is excessive as shown in the drawing, the left-eye image is moved to the right and the right-eye image is moved to the left, so that the stereoscopic image with a small amount of parallax is obtained. An image suitable for viewing can be obtained. The horizontal movement at this time is preferably performed until the amount of parallax after the movement becomes equal to the interocular distance.

  As described above, the display size determination unit 22 calculates the display size of the screen based on the image of the display area captured by the camera. This will be described with reference to FIG.

  FIG. 7 shows a method for calculating the display size b of the screen. As shown in the figure, it is assumed that the projection lens of the projection display apparatus 100 and the camera 25 are arranged at a distance w in the horizontal direction. It is assumed that an image having a width b is projected from the projection lens onto the screen, and the camera 25 is shooting a range of the width a including the entire width b. When the camera 25 does not use the zoom function, the screen size b can be obtained as follows.

First, a display area is detected from a photographed image by the camera 25 using a matching method or the like, and ratios R = c / b and S = d / b between the width b of the screen size and the left and right shift amounts c and d are obtained. The ratios R and S can be easily obtained from the number of pixels in the horizontal direction in the image. R and S can be expressed as follows from the geometric relationship.
R = c / b = {(ab) / 2 + w} / b
S = d / b = {(ab) / 2-w} / b
From the above two formulas, b = 2w / (R−S) from R−S = 2w / b. Since w is known, the screen size b is obtained.

  As described above, according to the present embodiment, when a stereoscopic image is displayed on the projection plane using the projection display apparatus, the amount of parallax between the left and right images of the displayed parallax image is calculated, and the parallax is calculated. It can be determined whether the amount is appropriate. At this time, an image is captured by the camera, and the maximum amount of parallax is calculated based on the captured image. Therefore, even when the display screen size is not constant as in the projector, the above processing is performed without preparing information in advance. Can do. Furthermore, when the amount of parallax is inappropriate, it is possible to adjust the amount of parallax by changing the screen size or horizontally moving the left and right images.

  In the above description, the case where the amount of parallax between the left and right images is too large, that is, the case where the display size of the screen is equal to or larger than the upper limit size has been described. It is also possible to determine that the stereoscopic view is not good when it is too small (for example, when the amount of parallax is less than or equal to a physiological limit), that is, because the display size of the screen is less than or equal to a predetermined lower limit size. In this case, the warning display unit 24 causes the projection unit 14 to display a message that tells the observer that the amount of parallax is too small. Alternatively, the adjustment unit 20 instructs the image processing unit 13 to enlarge until the display size of the screen is equal to or larger than the lower limit size. Alternatively, when the zoom function is installed in the projection lens of the projection display apparatus 100, the display size of the screen may be increased by adjusting the zoom. Furthermore, the adjustment unit 20 may instruct the image processing unit 13 to move horizontally in the direction in which the left and right images are separated in order to increase the amount of parallax between the left and right images constituting the parallax image.

In the above description, obtaining the maximum amount of parallax between the left and right images constituting the parallax image by corresponding point matching has been described. Alternatively, when information on the maximum amount of parallax is added as meta information for each parallax image, it may be used.
In the above description, the predetermined upper limit size is calculated so that the maximum amount of parallax is equal to the interocular distance. Alternatively, when information on the upper limit size is added as meta information for each parallax image. You may use it.

  In the above description, the display size determination unit 22 calculates the display size of the screen based on the image captured by the camera 25. However, the display size determination unit 22 calculates the projection angle and the projection distance from the zoom and focus states of the camera 25. The display size may be obtained.

  So far, the case where the projection image by the projection display apparatus is a still image has been described. When the projected image is a moving image, it is necessary to compare information such as a predetermined maximum parallax amount and a screen display size for each frame. However, if stereoscopic viewing is possible with most frames but stereoscopic viewing is not possible with only some of the frames, if the moving image is stopped even though it is hardly an obstacle for observation, troublesome.

  Therefore, in the case of a moving image, the following is performed. For example, information such as the maximum amount of parallax and screen size in all frames is added as meta information of moving images, and if there is a frame that exceeds the maximum amount of parallax with reference to the meta information before playback, observe that You may comprise so that it may notify with respect to a person.

  Alternatively, if information such as the maximum parallax amount or screen size is added to each frame, and the frame being projected exceeds the predetermined upper limit size, the frame is reduced without notifying the user You may set the coping method of displaying. Or, in order to prevent a sense of incongruity at the time of viewing or to prevent the production effect, even when some frames exceed a predetermined upper limit size, a coping method that allows a state where the maximum amount of parallax is large for a certain period is allowed. You may set it.

  Moreover, the structure performed by a user's intention may be sufficient as the change of the parallax amount of a right-and-left image. Even in this case, if it is determined that the maximum parallax amount is exceeded during the setting, the same correction processing as described above may be performed.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described.

  In general, since there are two viewpoint images of a left eye image and a right eye image in a stereoscopic image, the correspondence between each image and the viewpoint position may be unclear. If the left-eye image and the right-eye image are reproduced in the wrong order, the viewer may see a stereoscopic image that is opposite to the original or may not be able to see the stereoscopic image well. This is called reverse viewing. That is, reverse vision is a state in which the left eye image is viewed by the right eye and the right eye image is viewed by the left eye.

  Since the correct stereoscopic effect cannot be obtained in the reverse viewing state, a reverse button for the image display order or the glasses operation order is attached to a projector or shutter glasses, and the reverse button is pressed when the user feels reverse viewing. Some products are urging. However, users who are not accustomed to stereoscopic vision must be in the reverse vision state because the reverse vision state is not experienced on a daily basis and the human brain determines the context based on perspective experience. Often not noticed. Therefore, it is not expected that the user spontaneously presses the reverse button.

  In order to determine reverse viewing, it is preferable to distinguish between left-eye and right-eye images in each image constituting a stereoscopic video, but since such a unified standard has not been established, There are many cases where I do not know.

  In order to solve this problem, for example, in Japanese Patent Application Laid-Open No. 2006-72455, a first storage unit that stores a group of test images in which it is unknown whether the viewpoint order is assigned from the right position or the left position. And a second storage means for storing a reference image group in which it is known in advance whether the viewpoint order is assigned in order from the right position or the left position, and the test image and the reference image are synchronized A viewpoint position identification device to be displayed is disclosed.

  However, this method has a problem that a test image group and a reference image group must be prepared for one stereoscopic video, and the burden is large.

  Therefore, Embodiment 2 provides a technique for determining the display order of multi-viewpoint images and preventing reverse viewing without preparing a reference image group.

  FIG. 8 is a functional block diagram of the projection display apparatus 150 according to the second embodiment. These configurations can be realized by an arbitrary processor, memory, or other LSI in terms of hardware, and can be realized by a program loaded in the memory in terms of software, but here by their cooperation. Draw functional blocks. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  The projection display apparatus 150 includes an image signal holding unit 11, an image processing unit 13, a projection unit 14, a synchronization signal generation unit 15, and a synchronization signal transmission unit 16. Since these have the same functions as the corresponding blocks of the projection display apparatus 100 described in the first embodiment, detailed description thereof will be omitted.

  In response to a request from the user or at a predetermined timing, the glasses operation confirmation unit 26 determines whether the shutter glasses worn by the observer of the stereoscopic image are operating and the left and right shutters are normally synchronized. An image for checking glasses for checking whether or not the image is present is displayed on the projection unit 14.

  The backsight confirmation unit 28 projects a backsight confirmation image for confirming whether a multi-viewpoint stereoscopic image is displayed in the correct order in response to a request from the user or at a predetermined timing. 14 is displayed. In the case of a two-viewpoint stereoscopic image, a reverse-view confirmation image for confirming whether the right-eye image and the left-eye image are alternately displayed in the display area in the correct order is displayed.

  The user operation unit 27 receives a user response to the confirmation image displayed by the glasses operation confirmation unit 26 or the backsight confirmation unit 28. The response by the user appears, for example, as a selection for the displayed option, and the user operates a button or the like provided on the projection display apparatus 150 or a remote controller (not shown) to select any option. It is configured.

  Next, glasses operation confirmation by the glasses operation confirmation unit 26 and backsight determination by the backsight confirmation unit 28 will be described.

[Check glasses operation]
When displaying a stereoscopic image by the shutter glasses method, it is desirable to check the operation of the shutter glasses worn by the observer. However, particularly when there are a large number of observers, it is very time-consuming to confirm the operation of each person's shutter glasses individually. However, even if you ask the observer whether or not the stereoscopic image was correctly viewed by running a stereoscopic image on a trial basis, especially if the observer is a beginner, it is not possible to tell whether it is correctly judged. Can not.

  Therefore, in the present embodiment, the glasses operation confirmation unit 26 confirms the operation of the shutter glasses using a random dot image. When the user presses the glasses operation confirmation button, the glasses operation confirmation unit 26 does not know what is three-dimensionally displayed when the glasses are not worn, but displays a glasses operation confirmation image that can be seen when the glasses are worn. Display.

  FIG. 9 shows a method for creating such a glasses operation confirmation image. First, two images are cut out from one random dot image B at slightly different positions in the left-right direction, and set as a background image BR for the right eye and a background image BL for the left eye, respectively. Next, the objects B1 (rectangle) and B2 (circle) cut out from another random dot image are arranged on the right-eye background image BR and the left-eye background image BL so as to have a parallax, and are used for the right-eye. An image IR and a left eye image IL are formed.

  As described above, the background image is cut out from a slightly different position of the random dot image because if the background image is the same on the left and right, only the object part changes the image on the left and right. This is because it can be recognized. When it is not desired to add parallax to the background image, for example, two or more sets of random dot images may be held and sequentially displayed when used. As a result, the background image is also switched, so that the object is not recognized.

  FIGS. 10A to 10C are diagrams for explaining how the right-eye image IR and the left-eye image IL configured as described above are observed when wearing shutter glasses. . When a stereoscopic image is not observed as shown in FIG. 10A, it can be determined that the shutter glasses are not operating due to a failure or battery exhaustion. As shown in FIG. 10B, when the object B1 pops out to the near side and the object B2 appears to have a depth, it can be determined that the observer's shutter glasses are operating normally. As shown in FIG. 10 (c), when the object B1 appears to have a depth and the object B2 appears to pop out toward the near side, the shutter glasses of the observer are operating with the left and right shutters operating in reverse. Judgment can be made.

  As shown in FIGS. 10D and 10E, the object may be an image in which the front and back are clearer, instead of a square or a circle. Alternatively, the object may be a stepped image or a bulging image. Further, the glasses operation confirmation image may be configured as a moving image that transitions from a planar state to a state of popping forward. In this way, when the shutter of the shutter glasses operates in the opposite direction, it is easy to notice an abnormality. Alternatively, the movement state of the glasses may be determined from the movement of the observer's head and the change in the face direction by moving the object up and down, left and right, and back and forth.

  The random dot image may be color instead of black and white. Moreover, since the resolution for the glasses operation check image is not required, the glasses operation check image may be held at a small resolution and may be enlarged and displayed during use.

[Confirm reverse view]
The reverse vision confirmation unit 28 displays a screen for confirming the display order of the left and right images when there is a stereoscopic video whose order of viewpoint is unknown from which of the right eye image and the left eye image starts. In this stereoscopic video, since it is certain that the right-eye image and the left-eye image are alternately arranged even if the viewpoint order is unknown, in the following, the stereoscopic video is image 1, image 2, image 1, image 2,.・ Assuming that they are arranged in the order of

  The backsight confirmation unit 28 displays a backsight confirmation screen as shown in FIG. 11 for a stereoscopic video whose viewpoint order is unknown. This screen includes two regions D1 and D2 arranged vertically. In the case of a time-division type stereoscopic image such as the shutter glasses method, the reverse vision confirmation unit 28 displays images in the order of image 1, image 2, image 1, image 2. Are displayed in the order of image 2, image 1, image 2, image 1,. In the case of a spatially divided stereoscopic image such as the polarized glasses method, the reverse vision confirmation unit 28 displays the image 1 in the odd order, the image 2 in the even order in the region D1, and the image 2 in the odd order in the region D2. Image 1 is displayed in even order.

  As described above, when the processing capacity of the apparatus is insufficient to simultaneously display two areas on the screen, the areas D1 and D2 are alternately displayed at predetermined intervals (for example, 1 second). May be displayed.

  As described above, in the state where the two viewpoint images having different orders are displayed in the regions D1 and D2, the user is inquired about which region of the image is easy to see. The user can use any input means to select one of the four options C1 to C4 from which the upper display (D1) is easy to see, the lower display (D2) is easy to see, do not know, or check the glasses operation. Select one from. When C1 or C2 is selected, the user operation unit 27 instructs the image processing unit 13 to display images in the order selected by the user. In response to this, the image processing unit 13 determines the display order of the video. Alternatively, the operation timing of the shutter glasses may be reversed. The operation when C3 or C4 is selected will be described later with reference to FIG.

  Such display of the reverse vision confirmation screen may be configured to operate when the user performs a predetermined menu operation or button operation. Alternatively, the image processing unit 13 can determine that the image in the image signal holding unit 11 is a stereoscopic image, but cannot determine which of the left-eye image and the right-eye image is arranged first. At this time, the display of the reverse vision confirmation screen may be automatically executed. For example, the following timing can be considered.

1. 1. When the projection display apparatus is switched from the 2D display mode to the 3D display mode. 2. When information indicating a stereoscopic image is obtained as meta information of a video When it is determined that the image is a 3D image by some automatic detection method.
3-1. When a boundary that divides an image horizontally is detected, and it is determined that they are stereoscopic images from the correspondence between the left and right images.
3-2. When a boundary that vertically divides an image is detected, and it is determined that they are stereoscopic images from the correspondence between the upper and lower images.
3-3. When it is determined that they are stereoscopic images from the correspondence between a pair of consecutive frames and one skipped frame. In the case of a stereoscopic image, for example, since the correlation between skipped frames is stronger than the correlation between consecutive frames, it can be determined that the image is a stereoscopic image.

FIG. 12 is a flowchart of a process for executing the glasses confirmation operation and the reverse vision confirmation operation according to the second embodiment.
When the user performs a predetermined menu operation or button operation during playback of a stereoscopic video, or when the image processing unit 13 cannot determine which of the left-eye image and the right-eye image is arranged first, the glasses operation confirmation unit 26 first determines whether or not the glasses operation confirmation completion flag is 0 (S10). If the flag is 1 (N in S10), the process proceeds to S20. If the flag is 0 (Y in S10), since the glasses operation confirmation has not been completed, the glasses operation confirmation unit 26 displays the glasses operation confirmation image (S12). FIG. 13 is an example of an eyeglass operation confirmation image. The user selects one of the three options C5 to C7 in the figure using an arbitrary input means. When the “visible (end)” option is selected, the glasses operation check unit 26 sets the operation check completion flag to 1 (S18), and ends this flow. When the “invisible” option is selected, the glasses operation confirmation unit 26 displays a message prompting the user to confirm whether the glasses are turned on (S16). If the power is on, this flow is terminated. If the power is not turned on, the process returns to S12 and the confirmation operation is repeated.

  In S12, when the option of “visible (proceed to 3D display confirmation)” is selected, the glasses operation confirmation unit 26 sets the operation confirmation completion flag to 1 (S14), and then the backsight confirmation unit 28 displays the video. It is determined whether there is information for distinguishing left and right images in the meta information (S20). When there is information for discriminating between the left and right images (Y in S20), a message “Recommend to display as it is without confirming the reverse view” is displayed (S22). If the user follows this recommendation, the flow ends. If it is desired to confirm the reverse view, the process proceeds to S24. When there is no information for discriminating between the left and right images (N in S20), the reverse vision confirmation unit 28 displays a reverse vision confirmation image as shown in FIG. 11 (S24). As described above, the reverse vision confirmation unit 28 displays images in different orders in the region D1 and the region D2. Then, the user is prompted to input which display is easy to see as a solid. When the user selects “upper display (D1)”, the video is displayed as it is. When the user selects “lower display (D2)”, the order is reversed and displayed (S26). When the user selects “I don't know”, for example, “It is considered that the 2D image is displayed or the image has little stereoscopic effect. Please press the confirmation button again in another scene.” A message is displayed (S28). When “Confirm glasses operation” is selected, the process returns to S12 and the confirmation of the glasses operation is repeated.

  As described above, according to the second embodiment, when there is a stereoscopic video whose viewpoint order is unknown, the reverse vision confirmation screen including two regions for reproducing images in different orders is displayed. By simultaneously reproducing and displaying images having different display orders in this way, the user can easily determine which order is correct.

  In the present embodiment, a dedicated confirmation image for confirming reverse viewing is prepared. Instead of this, it may be possible to display the images with the display order reversed in order on the screen and ask the user which one is easier to see, but this determination is often difficult for beginners in particular. As described above, by simultaneously displaying the images whose order is reversed vertically (or left and right), it is easy for even a beginner to determine whether or not they are in reverse viewing. Further, even when observing by a plurality of people, it is easier to check which display is correct when two images are displayed simultaneously.

  Instead of displaying a reverse-view confirmation screen in which two screens whose order has been reversed are displayed in parallel, the image display order may be reversed simply by pressing a predetermined button. If the user is accustomed to observing a stereoscopic image, it can be determined which one is correct only by switching the inversion. Either a first mode in which the display order is simply reversed when the button is pressed, or a second mode in which the above-mentioned reverse-view confirmation screen is displayed when the button is pressed can be selected. May be. When in the first mode, if the button is pressed more than once (for example, 4 times in 10 seconds) during the predetermined time, it is determined that the reverse view check is not successful, and the reverse view check is performed. A configuration screen may be displayed.

If the reverse view confirmation is executed during the reproduction of the content, the user cannot concentrate on the content. Therefore, when the reverse view confirmation is executed during the reproduction of the content, the content may be reproduced by rewinding to the time when the reverse view confirmation is started. A message for selecting whether or not to rewind the content may be issued to allow the user to select.
Further, even if the content is a moving image, any frame may be captured and a still image may be displayed in the reverse view confirmation image.

  Although the case of the shutter glasses method has been described for the second embodiment, confirmation of reverse viewing can also occur in the case of the polarization glasses method. That is, the synchronization signal of the polarization switcher is shifted so that the right-eye image is projected with the left-eye polarization and the left-eye image is projected with the right-eye polarization. Also in this case, the correct order of the left-eye image and the right-eye image can be selected by using the reverse vision confirmation image as shown in FIG.

  Up to this point, the case of two-viewpoint stereoscopic video has been described, but the present embodiment can also be applied to reverse viewing confirmation of n-viewpoint stereoscopic video.

  FIG. 14 shows how a four-viewpoint stereoscopic image is projected by an autostereoscopic display. As shown in the figure, a parallax barrier 252 for displaying different images at a plurality of viewpoints by blocking the light path is disposed on the front surface of the display 250. The parallax barrier 252 uses a switch liquid crystal. Four pixels are alternately displayed on the display 250 to give four viewpoints. And, the position where the straight line connecting the position of each viewpoint 1 to 4 and the position of the pixel for that viewpoint 1 intersects with the parallax barrier 252 becomes transparent, and light is blocked at other positions, The liquid crystal of the parallax barrier 252 is controlled. By doing so, it is possible to perform stereoscopic viewing at two adjacent viewpoints among the viewpoints 1 to 4. In the example of the figure, the viewpoint 2 is observed as a right eye image and the viewpoint 3 is observed as a left eye image. Whether such a multi-view display displays images for four viewpoints in the order of pixel 1, pixel 2, pixel 3, and pixel 4, or whether pixel 4, pixel 3, pixel 2, and pixel 1 are displayed in this order. May become unknown. Accordingly, in the same manner as described above, a confirmation image is displayed so that a video suitable for the user can be confirmed.

  FIG. 15 shows an example of a confirmation image. An image is displayed in the order of pixel 1, pixel 2, pixel 3, and pixel 4 in the first area D1, and an image is displayed in order of pixel 4, pixel 3, pixel 2, and pixel 1 in the second area D2. Then, the user is allowed to select the one that looks correct.

Embodiment 2 can also be realized in the following manner.
(1) A video display device for displaying a stereoscopic video,
When the stereoscopic video is composed of multi-viewpoint images, for reverse vision confirmation including a first area for reproducing and displaying the stereoscopic video in the first order and a second area for reproducing and displaying the reverse in the first order A reverse view confirmation unit for displaying a screen;
A user operation unit that allows the user to select one of the first region and the second region that can be easily stereoscopically viewed;
A display unit that displays stereoscopic images in the order of playback and display in an area selected by the user;
A video display device comprising:
(2) The backsight confirmation unit displays a backsight confirmation screen when it is determined that the video to be reproduced is a stereoscopic video, but the viewpoint order cannot be determined (1) Video display device.
(3) The video display device according to (1) or (2), wherein the stereoscopic video is a spatially divided stereoscopic video or a time-division stereoscopic video.
(4) The display unit plays back the stereoscopic video by rewinding to the point of time when the reverse viewing confirmation screen is first displayed after the user selects either the first region or the second region. (1)-(3) video display apparatus.

  The present invention has been described based on some embodiments. It is understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. By the way. Hereinafter, such modifications will be described.

(Switch screen orientation)
The short focus projector described in the first and second embodiments is very suitable for projection onto a floor surface because it can project at a close distance. However, unlike the projection onto the wall surface, in the projection onto the floor surface, it always becomes a problem which direction should be the lower side of the screen.

  Therefore, it is preferable to provide a switch button for changing the screen orientation on the main body of the projection display apparatus, the remote controller, or both. For example, each time the switch button is pressed, the side far from the projection display apparatus and the left and right sides may be sequentially switched to the lower side of the screen. As another configuration, as shown in FIGS. 16A to 16C, a person approaching the vicinity of the projection area is detected by a CCD camera or an infrared sensor connected to the projection display apparatus. May be automatically switched to the lower side of the screen.

  When switching the screen direction, it is more preferable to change the emission direction of the synchronization signal. For example, two infrared LEDs for sending synchronization signals are provided in the projection display apparatus, and each infrared LED is attached so as to face right or left when viewed from the front of the apparatus. When the screen direction of the projection area is switched, the synchronization signal is transmitted from the infrared LED on the side close to the lower side of the screen. By doing so, it is possible to increase the reception sensitivity of the synchronization signal in the glasses worn by the observer near the lower side of the screen.

[Directivity of shutter glasses]
When performing stereoscopic viewing using the shutter glasses method, the observer must keep wearing the shutter glasses while the video continues. This is not a problem for applications such as watching movies for a long period of time, such as watching movies. The frequency of observation is high. In such a case, if the shutter glasses continue to receive the synchronization signal from the projection display apparatus, the shutter operation continues even when the screen is not being viewed, and a normal scene that is not a three-dimensional image is displayed. It becomes an obstacle when seeing. If the shutter glasses are removed, there is no problem, but for example, it is very complicated to remove the glasses every time a note is taken.

  Therefore, it is preferable to configure the shutter glasses so that the shutter is inoperative when the line of sight is removed from the screen. FIGS. 17A and 17B show the configuration of the light receiving unit for infrared sync signals provided in the shutter glasses. As shown in the drawing, the shutter glasses are provided with a light shielding cylinder 72 that covers the entire circumference of the infrared light receiving unit 70 and extends in the line-of-sight direction. As shown in FIG. 17B, a lens 74 may be provided at the other end of the light shielding cylinder 72 to further control the direction of directivity. With this configuration, the synchronization signal coming from the direction A in the figure is displayed inside the light-shielding cylinder 72 when the observer wearing the shutter glasses is looking at the screen, that is, when the line of sight is substantially horizontal. The incoming light receiving unit 70 is reached. On the other hand, when the observer removes his / her line of sight from the screen, that is, when his / her line of sight is not substantially horizontal, the light is blocked by the light blocking cylinder 72 and does not reach the light receiving unit 70.

  In addition to the above configuration, if the shutter of the shutter glasses is set to normally white, when the observer removes his line of sight from the screen, the synchronization signal will not reach the light receiving part of the shutter glasses, and the shutters of both eyes will open and the field of view will be reduced. It can be cleared.

  In the case of an application in which the observer often removes his / her line of sight from the screen, handheld shutter glasses 60 as shown in FIG. 18 may be used. The glasses 60 are provided with a handle 62 that extends downward from either the center or the left and right ends of the glasses, instead of the ear hooks of the shutter glasses 30 shown in FIG. Since the observer only needs to bring the shutter glasses 60 in front of the eyes only when he / she wants to see the screen with the handle 62, the troublesomeness of wearing / removing the glasses can be reduced.

  In the hand-held shutter glasses 60, there is a risk of observing the glasses with the wrong side. If the front and back sides are mistaken, the open / close timing of the left and right shutters is reversed, so that a stereoscopic image cannot be viewed correctly. In view of this, the eyeglasses may be provided with a mark for making a mistake in the front and back, or a nose pad 64 may be provided.

〔screen〕
The screen that projects the stereoscopic image must be a screen that maintains the polarization of the projection light. This is generally a silver screen in which a silver paint is applied to a normal screen. Since the polarizing screen has a low diffusivity, as shown in FIG. 19A, it has a characteristic that many light beams are reflected at an emission angle equal to the incident angle. When such a polarizing screen and a short focus projector are used in combination, there is a problem that the uniformity of lightness on the screen is lowered because the variation in incident angle is theoretically large in the short focus projector.

  Therefore, when a polarizing screen is used together with a short focus projector, it is preferable to prepare a silver screen formed so as to guide light in a predetermined direction as shown in FIG. The silver screen 80 is formed to be a part of the concentric Fresnel lens shown in FIG.

  20A to 20C show examples of the protective plate 82 that protects the uneven surface of the silver screen 80. When the silver screen 80 is arranged on the floor surface, it is preferable to provide a protective plate 82 so that an observer can get on the screen. The protective plate 82 may be the upper surface as shown in FIG. 20 (a), or the protective plate 82 may be the lower surface as shown in FIG. 20 (b). Alternatively, as shown in FIG. 20C, the protective plate 84 may be formed in a shape that fits the uneven surface of the silver screen 80.

  In the embodiment, the glasses method has been described for displaying two images of the first image and the second image, but in the shutter glasses method, two or more images are displayed and then two images are selected. It is also possible to observe it. For example, when displaying the first image, the second image, and the third image in order, and selecting whether to observe the first image and the second image or to observe the second image and the third image according to the position of the observer There is. Even in such a case, the present invention can be applied.

  DESCRIPTION OF SYMBOLS 10 stereoscopic image display system, 11 Image signal holding | maintenance part, 13 Image processing part, 14 Projection part, 15 Synchronization signal generation part, 16 Synchronization signal transmission part, 20 Adjustment part, 22 Display size determination part, 24 Warning display part, 26 Glasses Operation check unit, 27 User operation unit, 28 Reverse view check unit, 30 glasses, 100, 150 Projection-type image display device.

Claims (4)

A stereoscopic image display device that projects and displays a stereoscopic image on a projection plane,
A projection unit that projects and displays a parallax image composed of a first image and a second image having a predetermined parallax with respect to the first image in a predetermined display area;
A display size determination unit that determines whether or not the size of the display area on the projection plane is equal to or larger than an upper limit size determined based on a limit value of a parallax amount that allows the parallax image to be recognized as a stereoscopic image;
An adjustment unit that adjusts the stereoscopic image to reduce the amount of parallax when the size of the display area is equal to or larger than the upper limit size;
Equipped with a,
The adjustment unit reduces the amount of parallax by reducing the size of the display area . A camera for photographing the display area;
The stereoscopic image display apparatus according to claim 1, wherein the display size determination unit calculates a size of the display area based on an area occupied by the display area in an image captured by the camera. The display size determination unit sets the size of the display area when the parallax amount between the first image and the second image is equal to a preset limit value of the parallax amount as the upper limit size. The stereoscopic image display apparatus according to claim 1 or 2 . The display size determining unit, according to claim 3 to perform the corresponding point matching of the first image and the second image, the parallax amount of largest of the first image and the second image of the distance between corresponding points 3D image display device.