JPH0720812A - Polar coordinate scanning spherical projector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a spherical projection device that allows a large number of people to simultaneously view images without distortion with a sense of speed and stereoscopic effect. An image information storage means, a video signal generation means for reading out image information from the storage means to generate a video signal, a light modulation means for amplitude-modulating a laser beam by the video signal, and a light-modulated projection light. It is composed of a reflection type projection means for projecting the image on the spherical screen in a polar coordinate scanning manner, and a rotation synchronization control means for the video signal generation means and the reflection type projection means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polar coordinate scanning type spherical projection device in which projection light such as a laser beam is scanned in polar coordinates by a reflective projection means installed in the center of a spherical screen to project and display it on a spherical screen.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal projector for reproducing an image on a two-dimensional plane, a laser scan TV, or the like has been known as a means for allowing a plurality of people to simultaneously view image information. However, these image reproducing techniques project images in a rectangular shape on a two-dimensional plane, so that the viewing angle is limited and the images have a poor stereoscopic effect. On the other hand, the Omnimax type spherical projection device that projects a fisheye lens onto the all-sky dome screen even if the playback display image is a flat image can realize a wide viewing angle and provide a sense of depth and a three-dimensional effect. It has been known.

[0003]

However, in the omnimax type spherical projection device, an expensive and special lens system is required, and the rectangle cannot be reproduced as a rectangle, or the image is distorted depending on the viewing direction. There was a point.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is a polar coordinate scan in which the entire surface of the projection spherical screen is free of distortion and is clear, and the reproduced image is not distorted depending on the viewing direction. Provided is a spherical projection device.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a polar coordinate scanning type spherical projection device, and an object of the present invention is to store an image for display, and preset from the image information storage means. A video signal generating means for scanning the center point in the radial direction by polar coordinates to read information and generate a video signal; and a light modulating means for amplitude-modulating a light beam from a light source for projection to generate projection light by the video signal. A reflection type projection means for projecting the projection light onto a spherical screen by a rotary reflecting mirror, a video signal generating means and the reflection type projection means, and polar coordinates corresponding to a preset rotation angle for reading from the image information storage means. An image signal is read while rotating the scanning, and a projection signal rotation synchronization control means for rotating the reflection type projection means in correspondence with the read rotation angle. Kick is achieved by.

[0006]

According to the present invention, in the above-described structure, a clear image without distortion can be reproduced on the entire surface of the all-sky spherical screen, and a wide stereoscopic image can be displayed with a wide viewing angle. It is possible to provide a spherical projection device for multi-person viewing, which is improved.

[0007]

FIG. 1 is a block diagram showing an embodiment of a polar coordinate scanning type spherical projection device of the present invention. Image information from a television camera 1 or image information generated from a computer 2 such as a workstation. Is written as a digital signal through the switching means 3 to the image information storage means 4 formed of a semiconductor such as a dual port memory, and the address specified by the video signal generation means 5 is independent of the writing timing. The image data in the image information storage means 4 is sequentially read out in the radial direction of polar coordinates centering on a preset center point, and a video signal V1 is generated and input to the light modulation means 7. . Then,
The projection light output from the light source 6 having a constant amplitude composed of an oscillator such as a laser is amplitude-modulated by the light modulation means, and this output light PJ1 is incident on the reflection-type projection means 9 via the half mirrors 8A and 8B. The rotationally reflected light is projected on the spherical screen 11. A rotation synchronization control means 10 is coupled to the reflection type projection means 9 and the video signal generation means 5 to synchronize the image information reading speed in the polar coordinate direction with the drawing display speed of the projection light on the spherical screen 11 by the rotary reflecting mirror. The timing for reading the image information from the image information recording means 4 by controlling the polar coordinates by rotating the reading rotation angle and controlling the reflection projection means 9 by the reading rotation angle to draw the projection light on the spherical screen 11. It is also designed to control the synchronization with the timing to perform.

Further, FIG. 2 shows the reflection type projection means 9 in more detail. A first motor 91 which rotates in correspondence with a rotational angle for polar coordinate reading and a support coupled to the first motor 91. It is composed of an arm 92 and a second motor 93 fixed to the support arm 92, and a rotary reflecting mirror 94 driven by the second motor 93. The rotary shaft of the first motor 91 and the rotation of the second motor 93 are rotated. While being arranged so as to be orthogonal to the axis, the intersection OC of these rotation axes is set at the center point of the spherical screen 11, and the incident light axis of the projection light PJ and the rotation axis of the first motor 91 coincide with each other. It is designed to be arranged as follows. If the rotary reflecting mirror 94 is directly formed on the outer surface of the rotor of the second motor 93, the rotary reflecting means can be made compact. The installation state of the reflective projection means 9 with respect to the spherical screen 11 is the spherical screen 1
When viewed from above 1, the result is as shown in FIG. 3, and its side view is as shown in FIG.

The operation of such a configuration is shown in FIG.
Referring to the flowchart of FIG. 6 and the operation explanatory diagrams of FIGS. 6 and 7, first, after the power is turned on, the first motor 91 and the second motor 93 incorporated in the reflection type projection means 9 have a predetermined rotation speed ( For example, refresh rate 60Hz
Then, the first motor 91 is 30 rotations / sec, and the second motor 9 is assumed to have a polar coordinate scan of 15 KHz, which is reflected by a four-sided mirror.
3 is 3750 revolutions / second) until the motor rotation synchronization is waited (step S1). When the motor rotation synchronization is established, the display means is initialized by the control means such as a microprocessor (not shown) (step S1). S
2).

However, image information for display and reproduction is constantly written in the image information storage means 4 from the television camera 1 or the computer 2, and this written image information is stored at the center point 01 as shown in FIG. SC1, S in polar coordinate format with polar
C2, ..., SCN are read out in this order to generate a video signal V1, which is projected by the reflective projection means 9 onto the spherical screen 1.
1, the desired spherical projection image can be generated by displaying PJ1, PJ2, ..., PJN in the order shown in FIG.

The process of reading the image information from the image information storage means 4 in the polar coordinate format of FIG. 6 and drawing the projection light on the spherical screen 11 by the reflective projection means 9 as shown in FIG. 7 will be described in detail below. After the initialization of the display parameter of (step S2), the rotation synchronization control means 10 causes the polar coordinate rotation angle Θ (= 0 °) to the first motor of the reflection type projection means 9.
The rotation command to the position is output (step S3), and at the same time, the rotation synchronization control means 10 outputs the video signal generation command at the rotation angle Θ to the video signal generation means 5. Subsequently, the video signal generation means 5 generates a read address for the locus as shown by SC1 in FIG. 6 by the video signal generation command at the rotation angle Θ, and causes the second motor 93 of the reflection type projection means 9 to rotate. While synchronizing, the image information in the image information storage means 4 is read out in the direction of the locus SC1 in FIG. 6, converted into an analog video signal V1 in the video signal generation means 5 by the DA conversion means (not shown), and the light modulation means. 7 is input (step S3).

On the other hand, the projection light output from the light source 6 such as a laser is amplitude-modulated by the light amplitude modulation means 7 in accordance with the amplitude of the video signal V1, and the output light PJ is transmitted through the half mirrors 8A and 8B. The light enters the rotary reflecting mirror 94 and is projected on the spherical screen 11 in the direction of PJ1 shown in FIG. 7 (step S5).

Thus, reading of one line of image information
When the projection is completed, the read rotation angle Θ is Δ in the example of FIG.
It is rotated by Θ (= 45 °) and the read rotation angle is Θnew
= Θold + △ Θ (step S
6).

In the example of FIG. 6, the updated rotation angle Θnew
= 45 °, Θ new <180 ° (step S7), the process returns to step S3 and the trajectory SC2 of FIG.
The image information along with is read out, and P is displayed on the spherical screen 11.
Projected in the direction of J2. Thereafter, similarly, image information along the loci SC3 and SCN in FIG. 6 is read out and projected on the spherical screen 11 in the directions of PJ3 and PJN. When the projection of one screen is completed, the process returns to step S2 (step S7). ).

In the above description, N = 4 has been explained, but in reality N = 512 to 4096.
The number of times of reading is appropriate. When the read address corresponding to the rotation angle Θ is generated in step S3,
If the read address corresponding to each rotation angle is calculated in advance and registered in the look-up table format, the read address generation time required inside the video signal generation means 5 can be greatly shortened.

Further, in the explanation of FIG. 1, the means for guiding the projection light through the half mirror is shown as shown in FIG. 8 in order to match the rotation axis of the first motor with the incident light axis of the projection light. It is also possible to dispose the optical axis 6 and the optical modulator 7 directly on the extension line of the rotation axis of the first motor as shown in FIG.

When the scanning of the projection light as shown in FIG. 7 is performed, the scanning line density at the central portion becomes high and the scanning line density at the peripheral portion becomes low, so that the optical filter shown in FIG. If it is provided outside the projection means 9, the difference in brightness between the central portion and the peripheral portion can be corrected.

[0018]

As described above, in the polar coordinate scanning type spherical projection device of the present invention, it is possible to easily reproduce a square shape on a large all-sky spherical screen as a square shape without distortion.
A large number of people can watch images with a sense of speed and stereoscopic effect at the same time. In addition, it is easy to increase the resolution in the center of the screen where people's attention is concentrated, and
Even if the image observation position is changed, an image without distortion of the image can be reproduced, which is useful in a stereoscopic movie or a video game.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a structural example of a reflection type projection means of the present invention.

FIG. 3 is a view of the reflective projection means of the present invention viewed from above a spherical screen.

FIG. 4 is a view of the reflection type projection means of the present invention viewed from a side surface of a spherical screen.

FIG. 5 is a flow chart for explaining the operation of the present invention.

FIG. 6 is a diagram for explaining the order of reading image information from the image information storage means of the present invention.

FIG. 7 is a diagram for explaining the order of drawing projection light on a spherical screen by the reflective projection means of the present invention.

FIG. 8 is a diagram showing an example in which a rotation axis of a first motor and an incident optical axis of projection light are aligned with each other using a half mirror.

FIG. 9 is a diagram showing an example in which an optical system is arranged such that an incident optical axis of projection light is aligned with a rotation axis of a first motor.

FIG. 10 is a diagram showing an example in which brightness correction of a central portion and a peripheral portion of a screen is performed using an optical filter.

[Explanation of symbols]

 4 image information storage means 5 video signal generation means 6 light source 7 light modulation means 8, 8A, 8B half mirror 9 reflection type projection means 91, 93 motor 94 rotary reflector 10 rotation synchronization control means 11 spherical screen

Claims (5)

[Claims] 1. An image information storage means for storing a display image and a video signal generation means for generating a video signal by scanning a preset center point in the radial direction by polar coordinate scanning from the image information storage means. A light modulating means for amplitude-modulating a light beam from a light source for projecting with the video signal to generate projection light; a reflection-type projection means for projecting the projection light on a spherical screen by a rotary reflecting mirror; The image signal is read from the image information storage means while rotating the polar coordinate scan by a preset read rotation angle and is coupled to the generation means and the reflection projection means, and the reflection is performed corresponding to the read rotation angle. Polar coordinate scanning type spherical projection device, comprising: a rotation synchronization control means for a projection signal for rotating the projection means. 2. The first projection motor, wherein the reflection type projection means has an incident light axis of the projection light and a rotation axis thereof aligned with each other, and the first projection motor is coupled to the first motor and the rotation shaft of the first motor. The polar-coordinate scanning spherical projection device according to claim 1, wherein the polar-coordinate scanning spherical projection device is constituted by a second motor for a rotary reflecting mirror that rotates in a direction perpendicular to the direction and reflects the projection light. 3. The polar coordinate scanning type spherical projection device according to claim 1, wherein a brightness correction filter is interposed between the reflection type projection means and the spherical screen. 4. The incident optical axis of the projection light and the rotation axis of the first motor are aligned via a half mirror.
Alternatively, the polar coordinate scanning type spherical projection device according to claim 3. 5. The polar scanning spherical projection according to claim 2, wherein the light source and the light modulating means are installed so that an incident optical axis of the projection light coincides with a rotation axis of the first motor. apparatus.