JP2007187745A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the focus adjustment of a projection part with simple constitution in an image display device where a plurality of projection parts are arranged to display a stereoscopic image. <P>SOLUTION: The image display device 100 constituted by arranging the projection parts 10 for displaying an image by modulating light emitted from a light source by a spatial optical modulation part and projecting it to a screen 30 by a projection optical system in a predetermined state is equipped with a base member 40 where holes for attaching the plurality of projection parts are arranged. The projection part 10 is equipped with: a projection lens group comprising a plurality of projection lenses; a video display panel; a position adjusting part performing the focus adjustment by moving horizontally forward and backward on an optical axis; and a guide shaft 17 guiding the horizontal movement of the position adjusting part and used also as a shaft for positioning when the projection part is attached to the base member 40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a projection-type image display device suitable for application to, for example, an apparatus including a plurality of projection units for displaying a stereoscopic image.

  Conventionally, various methods have been proposed as techniques for displaying stereoscopic images. The most common one uses stereoscopic glasses. In this method, the right eye image and the left eye image are displayed separately by glasses using the convergence angle (binocular parallax) of both eyes to obtain stereoscopic vision. However, in this case, since the image seen with perspective in stereoscopic view and the screen surface which is the focal position of the eye are shifted, there is a problem that the eye feels uncomfortable or the eye becomes tired when viewed for a long time. is there.

  On the other hand, a plurality of projection devices that modulate and project light from a light source are used to modulate and emit light corresponding to a stereoscopic image within the viewing angle of the display surface. Patent Document 1 discloses a three-dimensional (stereoscopic) image generation technique for displaying a simple image.

  The principle of three-dimensional image generation by the method disclosed in Patent Document 1 will be described with reference to FIGS. 9 (a) and 9 (b). FIG. 9A and FIG. 9B schematically show the direction and intensity of the light beam with arrows when displaying a normal two-dimensional image and when displaying a three-dimensional image. As shown in FIG. 9A, in a display device such as a so-called rear projector that displays a normal two-dimensional image, the surface of the screen 2 is a diffusion surface having no anisotropy in the diffusion direction. The image of one projector is projected from behind 2, and the image is displayed. On the other hand, in order to display a three-dimensional image, as shown in FIG. 9B, for example, the image light emitted from each position a, b, and c behind the screen 2 It is configured to emit light while maintaining the passing angle, particularly the horizontal angle. By doing so, parallax information corresponding to the three-dimensional image enters the pupils e on the left and right of the observer, and a stereoscopic image is recognized. In order to realize the three-dimensional image generation method described in Patent Document 1, it is necessary to include parallax information corresponding to a three-dimensional image for the left and right eyes of a human as described above. For this reason, as shown in the schematic block diagram of the example in FIG. 10, many projection parts 10 are arrange | positioned behind the screen 2. As shown in FIG. In particular, the screen 2 has a diffusion angle characteristic that diffuses relatively widely in the vertical direction indicated by the arrow y in the figure and hardly diffuses in the horizontal direction indicated by the arrow x. . With such a configuration, the horizontal emission angle of the light passing through each pixel as described above can be maintained, and separate image information can be input to the left and right eyes.

  At this time, since the light displayed from one projection unit is diffused only in the vertical direction by the diffusion angle anisotropy of the screen, the left and right eyes can see it as vertical line display light. In the adjacent display line, since the display light from the adjacent projection unit enters the eye, necessary information enters each eye from a plurality of projection units.

  Thus, in an image display device that displays a stereoscopic image, a plurality of projection units and a screen that limits the horizontal diffusion angle are used. In this case, in order to reproduce more stereoscopic and high-quality stereoscopic display, it is necessary to project as much image data as possible in various directions, and a large number of projection units are required to be arranged at high density. .

Special table 2000-509591

  However, when the projection lens is provided with a function for focusing, the projection lens becomes larger, and the projection unit becomes larger accordingly, so the projection unit cannot be arranged at high density in the image display device. As a result, there is a problem that the number of light rays decreases and the stereoscopic effect of the displayed image is impaired. In addition, when adjustment is performed after installation without having the focus adjustment mechanism in the projection unit, there are a plurality of axes such as x-axis, y-axis, z-axis, θx-axis, θy-axis, and θz-axis that are axes in the direction that requires adjustment. There is a problem that a production facility having a complicated adjustment jig for adjusting the shaft is required, resulting in high costs. Furthermore, in order to accurately install the projection unit at a predetermined position in the image display device, when the outer diameter of the projection unit is used as a positioning reference, the projection unit is actually installed with the assumed position. There is also a problem that an error may occur between the position and the position, which causes a distortion of the stereoscopic image formed on the screen.

  The present invention has been made in view of such a point, and an object of the present invention is to facilitate the adjustment of the focus of the projection unit and to project a high-quality stereoscopic image.

  The present invention provides an image display device configured by arranging, in a predetermined state, a projection unit that modulates light emitted from a light source by a spatial light modulation unit and projects the light onto a screen by a projection optical system. A base member in which through holes to which a plurality of projection units are attached are arranged, and the projection unit includes a projection lens group including a plurality of projection lenses, a video display panel, and a horizontal movement back and forth on the optical axis. Is provided with a position adjusting unit that adjusts the focus by a guide, and a guide shaft that guides the horizontal movement of the position adjusting unit and is also used as a positioning shaft when attached to the through hole of the base member.

  By doing so, each projection unit is installed in the image display device while maintaining a state in which the focus is accurately adjusted, and the position where the projection unit is installed in the image display device is also accurate. Therefore, a higher quality stereoscopic image can be displayed.

  According to the present invention, the focus of the projection unit can be adjusted with a simple configuration, and a stereoscopic image can be displayed with a simple adjustment.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  First, the configuration of the image display apparatus 100 in this example will be described with reference to FIGS. FIG. 1 is a diagram illustrating a configuration example of an image display device. On the front side of the apparatus, a projector base 40 on which a plurality of projection units 10 are arranged, a substrate 50 that sends video signals to each projection unit 10, a substrate holding plate 51 that holds the substrates 50, and a substrate holding base 52 are arranged. It is. A light source and a one-dimensional spatial light modulation unit are provided in the projection unit 10 so as to project image light corresponding to a video signal sent from the substrate 50. A screen 30 is arranged to face the projection light exit surface. The screen 30 is held by a screen frame 31. A mirror 60 is provided on the side surface of the space where the projection unit 10 and the screen 30 face each other. Of the projection light Lp projected from the projection unit 10, the projection light not incident on the screen 30 is reflected, and the screen 30 side is reflected. As a configuration for projecting. The mirror 60 is held by a mirror holder 61, and the mirror holder 61 is held by a mirror holder holding frame 62. The screen frame 31 is held by the upper frame 91, the mirror holder holding frame 62 is held by the side frame 90, and all devices are disposed on the base 80.

  FIG. 2 is a diagram illustrating a projection state of image light from each projection unit of the image display apparatus 100 of the present example. As shown in FIG. 2, a plurality of projection units 10 are arranged in the horizontal direction, and the emission surface of the projection light Lp from each projection unit 10 is arranged in a juxtaposed manner so that they are substantially aligned with one plane. Each projection unit 10 is held by the projector base 40 shown in FIG. Details of the mounting state of the projection unit 10 to the projector base 40 will be described later. Each projection unit 10 includes a light source and a spatial light modulation unit such as a liquid crystal panel, and is configured to function as an independent projection device. And the screen 30 is arrange | positioned facing the projection light emission surface of each projection part 10. As shown in FIG. The screen 30 includes a diffusion plate having a diffusion anisotropy having a large diffusion angle in the vertical direction and a minute diffusion angle in the horizontal direction.

  FIG. 3 is a diagram showing the projector base 40 of this example. The projector base 40 is configured using a plate material having a predetermined thickness, and through holes 41 for mounting the projection unit 10 are provided at regular intervals in the vertical and horizontal directions. In correspondence with the outer shape of the lens holder 26 of the projection unit 10, each of the through holes 41 has a curved upper part and a lower part, and left and right side parts are linear. A first guide pin through hole 29a is provided on the upper right side of each through hole 41, and a second guide pin through hole 29b is provided on the lower left side of each through hole 41. is there. As shown in FIG. 3, here, a direction corresponding to the horizontal direction of the surface of the screen 30 is defined as a direction x, and a direction corresponding to the vertical direction of the surface of the screen 30 is defined as a direction y. The positions in the x direction of the respective through holes 41 arranged in six stages in FIG. 3 are slightly shifted positions. When viewed in the x direction, all the projection units 10 arranged in a plurality of stages (six stages) It will be in the state arranged at the position which shifted.

  FIG. 4 is a perspective view illustrating a configuration example of the projection unit 10, in which only members corresponding to a housing such as a cover and a holder are cut away and an internal arrangement state is illustrated. A light source 11 is disposed at the rear end (right side in FIG. 4) of the projection unit 10. A light pipe 12 is disposed on the light emission side of the light emitted from the light source 11, and is configured to convert the light emitted from the light source 11 into parallel light. The light pipe 12 is fixed inside the light holder 13. A transmissive liquid crystal panel 14 is disposed on the optical path of the light converted into parallel light by the light pipe 12, and is configured to display an image corresponding to the input video signal. The liquid crystal panel 14 is held between the liquid crystal cover 15 and the liquid crystal holder 16. The liquid crystal cover 15 and the liquid crystal holder 16 in this example are bonded with an adhesive. Further, the liquid crystal cover 15 and the light holder 13 are coupled by fixing screws 23A and 23B (the fixing screw 23B is not shown in FIG. 4). On the optical path of the light transmitted through the liquid crystal panel 14, a projection lens group 25 made up of a plurality of projection lenses is arranged in a shape held by a lens holder 26, and image light emitted from the liquid crystal panel 14 is received. The light is condensed and enlarged, and is projected onto a screen 30 (not shown). A diaphragm portion 26a is also integrally provided at a predetermined position of the lens holder 26 to which the projection lens group 25 is fixed. In addition, the liquid crystal panel 14, the liquid crystal cover 15, and the liquid crystal holder 16 have guide pins 17A and 17B attached to the upper right and lower left of the lens holder 26 (in the direction facing the light source 13), and the guide pins 17A and 17B The tip is exposed outside the lens holder 26. A coil spring is wound around one guide pin 17B as described later (see FIGS. 6 and 7). The liquid crystal panel 14, the liquid crystal cover 15, and the liquid crystal holder 16 are movable on the optical axis in the incident direction and the outgoing direction about the guide pins 17 </ b> A and 17 </ b> B, and the final lens surface of the projection lens group 25. And a position adjustment mechanism that adjusts the distance between the liquid crystal panel 14 and the object plane to adjust the focus. Details of the position adjustment mechanism will be described later.

  Next, the principle of displaying a three-dimensional image in the image display apparatus of this example will be described with reference to FIG. First, a stereoscopic image to be displayed in advance is captured from a plurality of directions by, for example, an imaging device, and n pieces of image information (n is a plurality, for example, 100 or more) necessary for stereoscopic image display are prepared and stored in a storage device (not shown). Remember. FIG. 5 schematically shows an image display mode using the plurality of image information. For example, projection light is projected toward the screen 30 from one projection unit 10m in the projection unit 10 as indicated by arrows m1 to m5. In addition, by disposing the mirror 60 on the side surface of the space where the projection unit 10 and the screen 30 face each other, the light reflected by the mirror 60 is also incident on the screen 30 as indicated by the arrow m1 ′, and the observer on the screen 30 The effect of widening the viewing angle is obtained.

  The angles at which the light indicated by m1 ′ and m2 to m5 pass through the screen 30 are substantially maintained by configuring the screen 30 to have only a small diffusion angle in the horizontal direction. Here, the light indicated by these arrows m1 ′ and m2 to m5 is part of image information divided in the vertical direction among a plurality of pieces of image information P1 to Pn constituting a stereoscopic image prepared in advance. p2m to pnm are displayed. In this case, since the screen 30 has a large diffusion angle in the vertical direction and a small diffusion angle in the horizontal direction, information of one projection unit is diffused only in the vertical direction. It appears as a vertical line display. That is, when the position on the screen 30 through which the light indicated by the arrows m1 ′ and m2 to m5 passes is defined as a unit pixel, the vertical lines constituting the stereoscopic image are formed from the unit pixels extending in the vertical direction toward the viewer's pupil. Image information p2m to pnm is emitted.

  Here, in the display line of the unit pixel adjacent to the screen 30, display information from the adjacent projection unit enters the eye. Therefore, by allowing necessary information to enter the eyes from a plurality of projection units, the image on the screen 30 observed by the left and right eyes can be seen as a composite image of vertical line display by each projection unit. In this case, if the screen 30 is configured to have a minute diffusion angle of, for example, less than about 1 ° in the horizontal direction, a good stereoscopic image display can be achieved without generating a gap between these vertical lines displayed by each projection unit. It can be performed.

  Incidentally, as described above, in the image display device shown in FIG. 5, the image on the screen 30 that is visible to the left and right eyes appears as a composite image of the vertical line display by each projection unit 10, but the horizontal direction of the diffusion plate of the screen 30 When the diffusion angle is almost 0 degrees, a gap is formed between the vertical lines displayed by the projection units 10, and thus vertical stripes are conspicuous. For this reason, the gap between the vertical lines can be filled by setting the horizontal diffusion angle to be less than about 1 ° as described above.

  Next, the configuration of the projection unit 10 and the position adjustment mechanism will be described with reference to FIGS. 6 and 7. FIG. 6 is an exploded perspective view illustrating a configuration example of the projection unit 10. The liquid crystal panel 14, the liquid crystal cover 15, and the liquid crystal holder 16 are bonded by an adhesive, and the liquid crystal cover 15 and the light holder 13 are coupled by a fixing screw 23A and a fixing screw 23B. The fixing screw 23A and the fixing screw 23B are inserted into holes provided in the liquid crystal cover 15 through the fixing screw 23A through hole 24A and the fixing screw 23B through hole 24B provided in the light holder 13, respectively. Further, although the coupling portion is not shown, the light source 11 and the light holder 13 are also coupled by screws. The guide pin 17A passes through the guide pin 17B through groove 18 provided on the side surface of the lens holder 26, and is press-fitted into a hole provided in the liquid crystal holder 16. The guide pin 17B is also provided in the lens holder 26. The liquid crystal holder 16 is press-fitted through the guide pin 17B through-hole 19. A coil spring 20 is wound around the guide pin 17A, and the coil spring 20 is arranged in a compressed shape between the liquid crystal holder 16 and the lens holder 26, so that both parts are pressed in the incident direction and the outgoing direction, respectively. It is supposed to be issued. As shown in FIG. 7, the coil spring 20 is fitted into the lens holder side groove 27 and the liquid crystal holder side groove 28 as shown in FIG. The adjusting screw 21 connects the liquid crystal holder 16 and the lens holder 26 with a force opposite to this. The adjustment screw 21 passes through an adjustment screw through hole 22 provided in the lens holder 26 and is inserted into a hole provided in the liquid crystal holder 16. The adjustment screw 21 is screwed in by rotating clockwise and loosened by rotating counterclockwise. By adjusting the rotation of the adjusting screw 21, the distance between the liquid crystal holder 16 and the lens holder 26 is expanded and contracted to adjust the focus. The focus adjustment is performed while viewing the image projected on the screen 30.

  Next, an example in which the guide pins 17A and the guide pins 17B of the projection unit 10 also function as positioning pins in the image display device will be described with reference to FIG. FIG. 8 is a perspective view illustrating a configuration example in a state where the projection unit 10 is assembled. Guide pins 17A and 17B used as horizontal movement guide shafts of the position adjustment mechanism protrude outside the lens holder 26, and through holes 29a and 29b (FIG. 3) for storing these pins 17A and 17B are provided. It is provided on the projector base 40 of the image display device 100. By fitting the projection unit 10 into the through hole 41 of the projector base 40, the guide pin 17A of the projection unit 10 is inserted into the through hole 29a and the guide pin 17B is inserted into the through hole 29b.

  With this configuration, since the guide pins 17A and 17B used for focus adjustment in the projection unit 10 are used as they are as positioning axes of the projection unit in the image display device, the projection unit 10 has the focus. It is installed in the image display device 100 while maintaining an accurately adjusted state. For this reason, it is not necessary to adjust the focus after installation, and since the focused projection light is projected from each projection unit 10, the stereoscopic effect of the image displayed on the screen 30 is improved.

  In addition, when the projection unit 10 is installed in the image display device 100, not only the outer diameter of the projection unit 10 but also the guide pins 17A and 17B are used as positioning references, so that the installation position is accurate. As a result, the light emitted from the projection unit 10 is accurately applied to the position assumed in advance on the screen 30, and a more stereoscopic stereoscopic image can be displayed.

  Further, since a simple mechanism using the adjusting screw 21 and the coil spring 20 is used as the focus adjustment mechanism of the projection unit 10, it is possible to reduce the number of parts and the manufacturing cost.

  Furthermore, since the position adjustment mechanism of the projection unit 10 has been simplified, the projection unit 10 can be miniaturized and arranged on the projector base 40 in the image display device 100 with high density, so that the parallax projected on the screen 30 The number of videos increases, and a higher quality stereoscopic image can be displayed.

  In the embodiment described so far, a transmissive liquid crystal display panel is used as the projection unit 10. However, a projection unit using other video display means may be used. Moreover, the external shape and lens arrangement | positioning of a projection part show an example, and are not limited to the structure shown in each figure.

1 is a perspective view illustrating a configuration example of an image display device according to an embodiment of the present invention. It is a top view which shows the example of the arrangement | sequence of the projection part by one embodiment of this invention. 1 is a perspective view illustrating a configuration example of an image display device according to an embodiment of the present invention. It is a fragmentary sectional view which shows the structural example of the projection part by one embodiment of this invention. It is explanatory drawing which shows the example of an image display mode of the image display apparatus by one embodiment of this invention. It is a disassembled perspective view which shows the structural example of the projection part by one embodiment of this invention. It is a perspective view which shows the structural example of the projection part by one embodiment of this invention. It is a side view which shows the example of the spring attachment to the projection part by one embodiment of this invention. (A) is explanatory drawing of the conventional two-dimensional image display method, (b) is explanatory drawing of the conventional three-dimensional image display method. It is explanatory drawing which shows the example of the conventional 3D image generation method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3, 10 ... Projection part, 11 ... Light source, 12 ... Light pipe, 13 ... Light holder, 14 ... Liquid crystal panel, 15 ... Liquid crystal cover, 16 ... Liquid crystal holder, 17 ... Guide pin, 18 ... Guide pin through groove, 19 , 29: Guide pin through hole, 20: Coil spring, 21 ... Adjustment screw, 22 ... Adjustment screw through hole, 23 ... Fixing screw, 24 ... Fixing screw through hole, 25 ... Projection lens group, 26 ... Lens holder, 27: Lens holder side groove, 28 ... Liquid crystal holder side groove, 2, 30 ... Screen, 31 ... Screen frame, 40 ... Projector base, 41 ... Through hole, 50 ... Substrate, 51 ... Substrate holding plate, 52 ... Substrate holding base, 60 ... Mirror, 61 ... Mirror holder, 62 ... Mirror holder holding frame, 80 ... Base, 90 ... Side frame, 91 ... Upper frame, 100 ... Image display device, A to C ... Light emitting point e ... Hitomi

Claims (2)

An image projection apparatus configured by arranging a plurality of projection units arranged in a predetermined state to modulate light emitted from a light source by a spatial light modulation unit and project the light onto a screen by a projection optical system. ,
A base member on which through holes to which the plurality of projection units are attached are arranged;
The projection unit is
A projection lens group comprising a plurality of projection lenses;
A lens holder for fixing the projection lens group;
A video display panel;
A position adjusting unit that includes a holder and a cover that protect the image display panel, and adjusts the focus by moving horizontally back and forth on the optical axis;
An image display apparatus comprising: a guide shaft that guides horizontal movement of the position adjusting unit and is also used as a positioning shaft when attached to a through hole of the base member. The image display device according to claim 1,
2. The image display device according to claim 1, wherein the movement of the position adjusting unit is configured by rotation of a screw that couples the holder and the lens holder.

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