JP2018146680A - Three-dimensional display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to mainly facilitate generating of parallel light different in an angle necessary for a three-dimensional display without mechanically moving a light source itself or providing many light sources.SOLUTION: The present invention relates to a three-dimensional display device 11 that includes: an image display device 13 that can display a discrete Fourier transformation image; illumination means 15 that exits parallel light 14 toward the image display device 13; and synchronization control means 16 that switches the discrete Fourier transformation image displayed on the image display device 13, and an angle 36 of the parallel light 14 exited from the illumination means 15 in a time-division. The illumination means 15 is configured to comprise: a laser light source 32 that exits laser light 31; route change means 33 that can change a route of the laser light 31 from the laser light source 32 in the time-division; a diffusion plate 35 that diffuses the laser light 31 having the route changed by the route change means 33 at an irradiation position; and a convex lens 37 that is located with a distance equal to a focal distance f on a side forward the diffusion plate 35, and converts the laser light 31 diffused by the diffusion plate 35 into the parallel light 14 of the angle 36 in accordance with the irradiation position on the diffusion plate 35.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a stereoscopic display device.

  Development of a stereoscopic display device that can perform stereoscopic display using a flat display device is underway (see, for example, Patent Document 1).

  Here, light is emitted in all directions from an actual object, and the observer recognizes the object three-dimensionally when the light reaches the observer. The stereoscopic display device of Patent Document 1 attempts to enable stereoscopic display with the naked eye without using auxiliary tools such as 3D glasses by reproducing such a light state.

JP 7-318858 A

  The stereoscopic display device disclosed in Patent Document 1 reproduces the state of light emitted from an actual object by changing the angle of light emitted from the display surface of the display unit in a time-sharing manner (switching instantaneously at high speed). I have to. In order to change the angle of light, the light source is mechanically moved, or a light source that is turned on is switched by providing a large number of light sources. Therefore, a mechanism for changing the angle of light becomes complicated, and there is a problem that it is difficult to reduce the size of the apparatus.

  Accordingly, the main object of the present invention is to solve the above-described problems.

In order to solve the above problems, the present invention provides:
An image display device capable of displaying a discrete Fourier transform image;
Illumination means for emitting parallel light toward the image display device;
In the three-dimensional display device provided with the synchronous control means for switching the discrete Fourier transform image displayed on the image display device and the angle of the parallel light emitted from the illumination means in a time division manner,
The illumination means is
A laser light source that emits laser light;
A path changing means capable of changing the path of the laser beam from the laser light source in a time-sharing manner;
A diffusion plate for diffusing the laser light whose path has been changed by the path changing means at the irradiation position;
A convex lens located on the front side of the diffusion plate and having a distance equal to the focal length, and converting the laser light diffused by the diffusion plate into parallel light having an angle corresponding to the irradiation position on the diffusion plate; With that
The image display device can display a Fourier transform image corresponding to the angle of the parallel light in a time division manner.

  According to the present invention, according to the above configuration, it is possible to easily create parallel light having different angles necessary for stereoscopic display without mechanically moving the light source itself or providing a large number of light sources.

It is a figure which shows how an object looks. It is a principle figure of the three-dimensional display using a display apparatus. 1 is a configuration diagram of a stereoscopic display device according to Example 1. FIG. It is explanatory drawing of a discrete Fourier-transform image. FIG. 6 is a configuration diagram of a stereoscopic display device according to Example 2; FIG. 10 is a diagram illustrating a state in which a stereoscopic display device is applied to a vehicle head-up display device as a third embodiment.

Hereinafter, the present embodiment will be described in detail with reference to the drawings.
1 to 6 are for explaining this embodiment.

  <Configuration> The configuration of the first embodiment will be described below.

  First, using FIG. 1, how an object looks and light rays will be described. This figure shows a state in which light 3 and 4 are emitted from each of the two objects 1 and 2 in all directions. Then, when these lights 3 and 4 reach the observer's eyes 5 at different angles for each of the objects 1 and 2, a sense of perspective is generated, and the objects 1 and 2 are recognized as a three-dimensional object by the observer. Is done.

  Therefore, as shown in FIG. 2, if the light 7 and 8 having different angles for each of the objects 1 and 2 can be emitted from the flat display surface of the display device 6 as in FIG. 4 can be reproduced, and stereoscopic display with the naked eye is possible without using auxiliary tools such as 3D glasses.

For this purpose, the following stereoscopic display device 11 is provided. As shown in FIG.
An image display device 13 capable of displaying a discrete Fourier transform image;
Illuminating means 15 for emitting parallel light 14 toward the image display device 13;
And a synchronous control means 16 for switching the discrete Fourier transform image displayed on the image display device 13 and the angle of the parallel light 14 emitted from the illumination means 15 in a time division manner.

  Here, the Fourier transform image will be described. As shown in FIG. 4, the (inverted) real image 23 of the object 22 placed at a position separated by a distance d1 from the front (left side in the drawing) of the lens 21 having the focal length f. However, when the lens 21 can be positioned behind the lens 21 (right side in the drawing) by the distance d2, the image at the focal point becomes the Fourier transform image 24. The Fourier transform image 24 recorded at this position has only the light intensity because the phase of the light is rejected. That is, the incident angle 25 of the light beam is converted into a distance from the optical axis 26.

  A discrete Fourier transform having a plurality of Fourier transform images 24 obtained as a result of performing a Fourier transform for each lens 21 using a two-dimensional lens array or the like in which a plurality of lenses 21 are two-dimensionally arranged. An image is recorded, and this discrete Fourier transform image is displayed on the image display device 13 of the stereoscopic display device 11. A specific method for creating and reproducing a discrete Fourier transform image is disclosed in Patent Document 1.

  The image display device 13 can be a display panel such as a liquid crystal panel. In the embodiment of FIG. 3, the illuminating means 15 is configured to transmit and display the image display device 13 from the back side as a backlight of the image display device 13. The synchronization control means 16 switches the discrete Fourier transform image displayed on the image display device 13 in a time-division manner for each light angle, and changes the angle of the parallel light 14 emitted from the illumination means 15 to a time-division of the discrete Fourier transform image. It is a control device that switches according to the switching at. By having such a configuration, the image display device 13 can generate light 8 and 7 having different angles for each of the objects 1 and 2 as shown in FIG. 2, and stereoscopic viewing with the naked eye is possible. become.

  Note that one frame of a plane image is recorded without special consideration of the direction of light and is reproduced using only light from one direction, whereas one frame of a three-dimensional image is various. It contains a large number of video elements recorded using light from various directions, and is reproduced by applying light from various directions. In order to shine light from various directions for each frame, means for switching light at high speed is required.

  In contrast to the basic configuration as described above, the stereoscopic display device 11 of this embodiment is configured to have the following configuration.

(1) The stereoscopic display device 11
The illumination means 15 is
A laser light source 32 for emitting laser light 31;
Path changing means 33 capable of changing the path of the laser beam 31 from the laser light source 32 in a time-sharing manner;
A diffusion plate 35 for diffusing the laser beam 31 whose path has been changed by the path changing means 33 at the irradiation position;
The laser beam 31 that is located on the near side of the diffusion plate 35 with a distance equal to the focal length f and diffused by the diffusion plate 35 is converted into parallel light 14 having an angle 36 corresponding to the irradiation position on the diffusion plate 35. By having a convex lens 37,
The image display device 13 can display the Fourier transform image 24 corresponding to the angle 36 of the parallel light 14 by time division.

  Here, the laser light source 32 can obtain a laser beam 31 having a high energy density with a uniform traveling direction, phase, and frequency.

  The path changing means 33 may be anything as long as the path of the laser beam 31 can be changed in a time-sharing manner, but is preferably an electronic element that changes the path using electrical means.

  The diffusion plate 35 is provided to diffuse the laser light 31 in various directions at the position where the laser light 31 is irradiated. Then, by installing the diffusing plate 35 at the position of the focal length f of the convex lens 37, the convex lens 37 can enter the laser beam 31 diffused by the diffusing plate 35 and convert it into the parallel light 14. At this time, the convex lens 37 can change the angle 36 of the parallel light 14 by displacing the position irradiated with the laser light 31 on the diffusion plate 35.

  Then, the synchronization control means 16 causes the illumination means 15 to emit parallel light 14 having different angles 36 in a time division manner, and the image display device 13 displays a Fourier transform image 24 corresponding to the angle 36 of the parallel light 14 in a time division manner. By controlling to do so, light in various directions is emitted from the image of the image display device 13, and stereoscopic display with the naked eye becomes possible.

  (2) The path changing means 33 can be an optical deflecting element 41 that can deflect a small mirror electromagnetically and change the angle 36 by time division.

  Here, the optical deflection element 41 is a MEMS (Micro-Electro-Mechanical Systems) element, and is a two-dimensional electromagnetic drive type in which the angle of the mirror 42 is driven to rotate around two axes by electromagnetic force. It is a mirror element. In this case, the laser beam 31 from the laser light source 32 can be scanned two-dimensionally (such as the vertical direction and the horizontal direction of the image display device 13) with one mirror 42.

  (3) The diffusion plate 35 may be curved (curved diffusion plate 51).

  Here, the curved surface shape is a shape provided on the diffusion plate 35 in order to correct the aberration of the convex lens 37, for example. For example, the diffusing plate 35 may be entirely or at least partially bent so as to be positioned at or near the focal plane of the convex lens 37.

  <Operation> The operation of this embodiment will be described below.

  In the stereoscopic display device 11, the image display device 13 displays an image, and the image display device 13 is illuminated by the illumination unit 15, whereby the image of the image display device 13 can be visually recognized.

  At this time, the image display device 13 displays the discrete Fourier transform image, and the synchronization control unit 16 displays the discrete Fourier transform image displayed on the image display device 13 and the angle 36 of the parallel light 14 emitted from the illumination unit 15. Switching is performed in a time-sharing manner, and the Fourier transform image 24 is switched at high speed according to the angle 36 of the parallel light 14 (for example, 60 frames / second). Three-dimensional display is possible.

  At this time, in the illumination device, the laser light source 32 emits the laser light 31, the path changing unit 33 changes the path of the laser light 31 from the laser light source 32 in a time-sharing manner, and the diffusion plate 35 is changed by the path changing unit 33. The laser beam 31 whose path has been changed is diffused at the irradiation position, and the convex lens 37 positioned at a distance equal to the focal length f on the front side of the diffusion plate 35 diffuses the laser beam 31 diffused by the diffusion plate 35. The light is converted into parallel light 14 having an angle 36 corresponding to the irradiation position on the plate 35. Thereby, the parallel light 14 in which the angle 36 is changed in a time division manner can be obtained.

  <Effect> According to this embodiment, the following effects can be obtained.

  (Effect 1) As the illumination means 15, a laser light source 32, a path changing means 33, a diffusion plate 35, and a convex lens 37 are used. Then, by using the path changing means 33 described above, for example, the position of the light source itself is moved or a light source that is turned on by switching a number of light sources is created in order to create the parallel light 14 having different angles 36 necessary for stereoscopic display. It is possible to eliminate the need to perform the operation, and it is possible to have a configuration without mechanical moving parts. Therefore, it becomes possible to easily create the parallel light 14 with different angles 36 and to greatly reduce the size of the apparatus. Further, since there are no mechanical movable parts, the mechanical load is greatly reduced and the control speed can be improved.

  (Effect 2) The light deflection element 41 may be used for the path changing means 33. This makes it possible to control the angle 36 of the light beam precisely and at high speed. Therefore, display accuracy can be increased (or high-quality display with high stereo reproducibility can be performed), and the apparatus configuration can be reduced in size. Furthermore, the use of the optical deflection element 41 makes it possible to finely adjust the path of the laser light 31, so that distortion and the like can be easily corrected. For example, a head-up mounted on a vehicle or the like as in Example 3 described later. When the stereoscopic display device 11 is employed in the display device (the vehicle head-up display device 61 in FIG. 6), by finely adjusting the path of the laser light 31 in accordance with the complicated curved surface shape of the front window glass 64, A virtual image display with little distortion can be obtained.

  (Effect 3) The diffusion plate 35 may be curved. Thus, by using the curved diffuser plate 35, for example, correction corresponding to the correction of the optical system such as correction of the aberration of the convex lens 37 can be performed, so that the parallelism of the parallel light 14 line is increased. This correction optical system can be omitted or simplified.

  FIG. 5 shows a stereoscopic display device 11 according to the second embodiment. In the embodiment described above, the image display device 13 is a transmissive type, and the illumination means 15 is installed on the back side of the image display device 13, whereas in this embodiment, the image display device 13 is reflected. The difference is that the illumination means 15 is installed on the surface side of the image display device 13 as a mold. At this time, the image display device 13 is installed obliquely with a required angle so that the reflected image reaches the observer's eyes 5.

  In addition, since it is the same as that of an above-described Example about a structure other than the above, an effect | action, and an effect, it is set as description of this Example by description of an above-described Example.

  FIG. 6 shows a stereoscopic display device 11 according to the third embodiment, in which the (transmission type) stereoscopic display device 11 of FIG. 3 is applied to a vehicle head-up display device 61.

  Here, the vehicle head-up display device 61 includes at least the image display device 13 and a reflection unit 63 capable of displaying an image of the image display device 13 as a virtual image 62 in front of the driver's seat. The reflector 63 can be a front window glass 64 or a reflector (combiner) installed in the passenger compartment 65. In addition, the front window glass 64 can reflect the image of the image display device 13 by using a glass having a wedge-shaped cross section or by providing a reflective film.

  One or a plurality of optical components 66 such as a plane mirror for changing the optical path and increasing the optical path length, and a concave mirror for further enlarging the image are provided between the image display device 13 and the reflection unit 63. Can do.

  Thus, by using the stereoscopic display device 11 for the vehicle head-up display device 61, it is possible to display information for assisting driving more easily.

  The vehicle head-up display device 61 can also be configured using a (reflective) stereoscopic display device 11 as shown in FIG. Since the configuration, operation, and effects other than those described above are the same as those in the above-described embodiment, the description of the above-described embodiment is used as the description of this embodiment.

DESCRIPTION OF SYMBOLS 11 Stereoscopic display apparatus 13 Image display apparatus 14 Parallel light 15 Illumination means 16 Synchronization control means 24 Fourier transform image 31 Laser light 32 Laser light source 33 Path changing means 35 Diffusion plate 36 Angle 37 Convex lens 41 Light deflection element 42 Mirror 51 Curved diffuser plate d1 distance d2 distance f focal length

Claims (3)

An image display device capable of displaying a discrete Fourier transform image;
Illumination means for emitting parallel light toward the image display device;
In the three-dimensional display device provided with the synchronous control means for switching the discrete Fourier transform image displayed on the image display device and the angle of the parallel light emitted from the illumination means in a time division manner,
The illumination means is
A laser light source that emits laser light;
A path changing means capable of changing the path of the laser beam from the laser light source in a time-sharing manner;
A diffusion plate for diffusing the laser light whose path has been changed by the path changing means at the irradiation position;
A convex lens located on the front side of the diffusion plate and having a distance equal to the focal length, and converting the laser light diffused by the diffusion plate into parallel light having an angle corresponding to the irradiation position on the diffusion plate; With that
The stereoscopic display device, wherein the image display device can display a Fourier transform image corresponding to the angle of the parallel light in a time-sharing manner. The stereoscopic display device according to claim 1,
The three-dimensional display device, wherein the path changing means is an optical deflecting element capable of changing the angle in a time division manner by electromagnetically deflecting a small mirror. The stereoscopic display device according to claim 1 or 2, wherein
A three-dimensional display device, wherein the diffusion plate is curved.