GB2160053A - Stereoscopic viewing system for television/visual display unit screens - Google Patents

Abstract

A stereoscopic viewing system for television/visual display unit screens comprising a grid or grating system consisting of two grids C, D each of which consists of vertical bars with gaps between the bars. The grids are disposed parallel to each other and parallel to a television or visual display unit screen. The screen is viewed through the gaps between the vertical bars. The bar and gap widths in the grid nearest the viewer are less than the bar and gap widths in the grid nearest the screen. The invention presupposes that the screen images have been specially prepared and processed into vertical, narrow, alternate strips. The invention allows the left and right images to be seen only by the left or right eye as appropriate, giving an overall stereoscopic or 3-dimensional quality to the image. <IMAGE>

Description

SPECIFICATION Stereoscopic viewing system for television/visual display unit screens This invention relates to a device for viewing a T.V.

screen or visual display monitor in stereoscopic vision. The perception of distance by a normallysighted person relates in part to the fact that each eye sees an object from a slightly different angle.

The brain then translates the different angles into an impression in the mind of distance, depth and solidarity to that object. If a suitable grid or grating system is spaced in front of a standard television or visual display unit screen (colour or black and white), a stereoscopic image can be seen by the viewer when a specially prepared or processed image is displayed on the screen.

The invention relates to the grid or grating device. In practice the use of the device presupposes that the V.D.U. or T.V. picture image has been arranged or processed so that each eye of the viewer sees a separate image or picture to the other eye when the invention is placed between the screen and the person viewing. The nature of the image or picture to be ultimately viewed will of course vary according to the application but it is to be understood to include video games, specially prepared television material and also charts, graphs and sections for educational, business and scientific use.

Whilst the principal of stereoscopic or 3-dimensional viewing is not new, it has previously involved the viewer in the wearing of polarised spectacles or spectacles with different coloured filters. My invention will, I believe enable the viewer to view a screen stereoscopically without such spectacles, with the screen image being in colour or black and white.

According to the present invention there is provided a grid or grating system consisting of two grids which the viewer disposes parallel to each other and parallel to the screen. The grid system is portable and removable. The screen is viewed through the grid system. At a certain distance from the screen (when viewed normally) the viewer's left eye can only see certain sections of the screen, the right eye can only see the other sections of the screen.

The grid system consists of a number of vertical opaque bars. The viewer sees the screen through the gaps between the vertical bars.

A specific embodiment of the invention will now be described by way of an example, and with reference to the accompanying drawings of which: Figure 1 is a simplified non-scale plan view of a portion of the invention showing the operating principle of the invention. It shows how, for one point on the final picture each eye will see a separate point when viewed through the invention. It also illustrates how angular differences between these two images may be perceived as a stereoscopic image.

Figure 2 shows how the screen cannot be viewed incorrectly, as the juxtapositioning of the grids prevents the screen being seen properly if the head is to the left or right of the ideal viewing positions. This figure also annotates some of the interdependent factors governing the sizes of the grid bars and spacings.

Referring to Figure 1, the left eye L sees a point on the screen A but not point B as the opaque grid bars are in the way. Point A (and similar points across the screen) has been prepared or processed to be seen by the left eye. Similarly, the right eye R sees point B but not point A. The brain tends to translate these two images into a single image of the point, and perceives this single point as being at position P conferring a 3-dimensional appearance to the image. In practice, position P can be made to appear to be in front of or behind the television or visual display unit screen. The overall picture will consist of many such points, giving a final impression of stereoscopic, 3-dimensional depth.

Still or moving pictures, in colour or black and white may be viewed.

My invention would thus require the left and right eye T.V. or V.D.U. images (often known in optics as the stereoscopic pair) to be split into thin alternative vertical strips, each alternate strip is then viewed by either the left eye or the right eye as appropriate.

Referring to Figure 2 the invention is comprised of two grids C and D. If only one grid C were used, movement of the viewer's head to the left or right would result in the correct and then the incorrect images being seen alternately.

The employment of the second grid D ensures that any movement of the head left or right results in either the correct image or no image at all being seen. This is a result of the incorrect positions (i.e.

where the left eye might see the image designated for the right eye and vice versa) being blanked off from view as shown in Figure 2 where L is the left eye.

Screen D thus makes it impossible to see a wrong image and facilitates viewing. The viewer moves his head left or right slightly until the brightest image occurs. The brightest image co-incides with the optimum viewing position.

The variable measurements E (screen to grid C), F (distance between the grids) together with the width of the grid bars and the width of the grid spaces for grid C and the width of the grid bars and spaces for grid D depend essentially on the measurements of the screen picture image and the size of the units or points into which the screen sections can be conveniently divided.

Distances E and F can be adjusted for viewing by placing the grids in movable frames or supports.

The width of the bars and gaps could be adjusted uniformly or differentially across each grid if it was required to compensate for distortions in individual screens or to allow for larger or smaller screens to be viewed. One method of varying the apparent width of the bars and gaps is to make the grid out of a flexible material. Curving the flexible material would make the width of some of the bars and gaps in the grids appear larger or smaller. As the grid bars are only to blank out a part of the view er's line of vision they can be made in a variety of forms. For example, the grid may be made of a series of rods or a series of lines painted, etched or stuck onto glass or transparent material. The grid could also be stamped out, cut out, milled or otherwise formed from sheets of material which allow these processes.

It is to be understood that the essential featurf- of the invention lies in the fact that the bar width and gap width in grid D (Figures 1 and 2) are less than the bar width and gap width in grid C in such a way that the sum of the width of any adjacent bars and gaps in grid D is less than the sum of the widths of the same number of adjacent bars and gaps in grid C, where grid C will be the nearest grid to the viewing screen.

Claims (9)

1. A stereoscopic viewing system for television/ visual display unit screens comprising a grid or grating system consisting of two grids each of which consists of vertical bars with gaps between the bars. The grids are disposed parallel or almost parallel to each other and parallel or almost parallel to a television or visual display unit screen. The television screen or visual display unit screen is viewed through the gaps between the vertical bars.

The bar and gap widths in the grid nearest the viewer are less than the bar and gap widths in the grid nearest the screen in such a way that the sum of the width of any adjacent bars and gaps in the grid nearest the viewer is less than the sum of the widths of the same number of adjacent bars and gaps in the grid nearest the screen.

2. A grid or grating system as claimed in claim 1 wherein the system is portable and removable.

3. A grid system as claimed in claim 1 or claim 2 wherein the bars are made of rods.

4. A grid system as claimed in any preceding claim wherein the grids are mounted in a stand or support to enable them to be placed in front of a screen.

5. A grid system as claimed in any preceding claim wherein the grids are mounted in a stand or support to enable the distance between the grids to be varied.

6. A grid system as claimed in any preceding claim wherein the bars are attached to, painted on or etched on a glass or transparent material.

7. A grid system as claimed in any preceding claim wherein the grids may be made in a flexible form to allow them to be curved, individually or to.

gether, in one or more planes.

8. A grid system as claimed in any preceding claim wherein the width of the opaque and trans parent portions of the grids may be varied at the point of manufacture or by the user.

9. A grid or grating system constructed sub stantially as hereinbefore described with reference to the accompanying drawings.