GB2289589A

GB2289589A - Three-dimensional image display screen

Info

Publication number: GB2289589A
Application number: GB9409738A
Authority: GB
Inventors: John Lane
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-05-16
Filing date: 1994-05-16
Publication date: 1995-11-22
Anticipated expiration: 2014-05-16
Also published as: GB9409738D0; GB2289589B

Abstract

A transparent or reflective screen 1 has a matrix of spherical (concave) pits 2 on its surface. When a thin beam of light intersects the surface, the direction at which the light leaves the screen is dependent upon the position within the area of the pit that the light beam intersected. By controlling the colour and intensity of the light beam according to the position of the beam as it is scanned over the screen, three-dimensional images will be seen by an observer. <IMAGE>

Description

THREE-DIMENSIONAL IMAGE DISPLAY UNIT This invention relates to a display unit which produces three-dimensional images.

There are currently two basic ways of presenting three-dimensional images to an observer. The first method is the production of a holographic image (a hologram) whereby the image of an object may be reproduced on a two-dimensional media by using any one of a number of standard techniques.

The second method is to present a different (two-dimensional) image to each eye, such that the brain is fooled into 'seeing' a single three-dimensional image.

The problem with the first method is that the image is static and is thus unsuitable for producing real-time sequences. The second method is suitable for producing real-time sequences, but is inconvenient because the observer must wear specially adapted glasses or some form of headset, and can also be expensive, especially when there are a number of observers.

According to the present invention there is provided a three-dimensional image display unit comprising a transparent (refractive) or reflective screen containing a matrix of spherical (concave) pits on its surface, a means by which one or many beams of light may be directed at the screen such that the position at which it or they intersect the screen may be controlled, and a means by which the colour and intensity of the beam may be controlled.

Two specific embodiments of the invention will now be described by way of example with reference to the accompanying drawing in which Figure 1 shows in perspective, a portion of the screen; Figure 2 shows in cross-section, a portion of the screen; Figure 3 shows in cross-section, how a beam of light is directed by a spherical pit when the screen is made of a transparent material; Figure 4 shows in cross-section, how a beam of light is directed by a spherical pit when the screen is made of a reflective material; Figure 5 shows how three-dimensional images may be produced using a transparent screen; Figure 6 shows how three-dimensional images may be produced using a reflective screen.

The basis of the invention is a transparent or reflective screen (1) which has a matrix of spherical (concave) pits (2) on its surface.

Each of the pits (2) in the transparent screen acts as a diverging lens due to its concave shape, and as such a beam of light (3) that intersects the pit away from its axis will be bent further away from that axis. If now the light beam is moved across the pit is either the horizontal or vertical plane, then the refracted beam will sweep out an arc. If this is extended to both horizontal and vertical planes and the beam is scanned across the whole area of the pit, then the refracted beam will sweep out a cone.

This means that by controlling the position on the screen at which the light beam is directed, the direction at which the beam emerges from any of the pits may be altered.

If, however, the light beam is scanned over the entire surface but the colour and intensity of the beam is altered in conjunction, three-dimensional images may then be observed.

A typical arrangement of apparatus for a transparent screen is shown in Figure 5 where a light source (6) generates a beam which is subsequently scanned across the area of the screen by suitable apparatus (5) and then focused by a converging lens (4) before striking the screen (2). A computer (7) detects the position of the beam and then adjusts the colour and intensity of the beam accordingly.

A reflective screen may also be used if the light source is in front of the screen, and a typical arrangement in this case is shown in Figure 6.

The number of pits on the screen would be similar to the number of picture elements on a standard television, and the rate at which the screen is scanned would also be comparable. This way real-time three-dimensional sequences may be produced.

Claims

1. A three-dimensional image display unit comprising a transparent (refractive) or reflective screen containing a matrix of spherical (concave) pits on its surface, a means by which one or many beams of light may be directed at the screen such that the position at which it or they intersect the screen may be controlled, and a means by which the colour and intensity of the beam may be controlled.

2. A three-dimensional image display unit as described in Claim 1 wherein light may be scanned across the screen in both horizontal and vertical directions and the exact position at which the light beam intersects the surface may be determined accurately.

3. A three-dimensional image display unit as described in Claim 1 or Claim 2 wherein different colours of coherent light may be combined and focused into a single thin beam in order to be scanned across the screen.

4. A three-dimensional image display unit as described in Claim 3 wherein the intensity of any and all components of the light beam may be controlled and will be determined as a function of the position at which the light beam intersects the screen.

5. A three-dimensional image display unit as described in any preceding claim wherein a computer detects the position at which the light beam intersects the screen and then alters the colour and intensity of the light beam accordingly.

6. A three-dimensional image display unit as described herein with reference to Figures 1 - 6 of the accompanying drawing.

Amendments to the claims have been filed as follows CLAIMS 1. A three-dimensional image display unit comprising a transparent (refractive) or reflective screen containing a matrix of concave pits on its surface, a means by which one or many beams of light may be directed at the screen such that the position at which the beam or beams intersect the screen may be controlled, and a means by which the colour and intensity of the beam or beams may be controlled.

2. A three-dimensional image display '-flit as described in Claim 1 wherein one or many beams of light may be scanned across the screen in both horizontal and vertical directions, and the position at which the beam or beams intersect the screen at any time may be determined.

3. A three-dimensional image display unit as described in Claim 1 or Claim 2 wherein light beams of different colours may be directed at the screen separately or combined into a single beam which is then directed at the screen.

4. A three-dimensional image display unit as described in Claim 1 or Claim 3 wherein the colour and intensity of any and all light beams directed at the screen may be altered according to the position at which any particular beam intersects the screen.

5. A three-dimensional image display unit as described in any preceding claim wherein an electro-mechanical device detects the position at which any and all beams intersect the screen at any tiire, a td alters the colour and intensity of the beam or beams accordingly.