Optical: systems and elements – Projection screen – Unitary sheet comprising plural refracting areas
Patent
1990-12-03
1994-10-18
Wintercorn, Richard A.
Optical: systems and elements
Projection screen
Unitary sheet comprising plural refracting areas
G03B 2160
Patent
active
053573684
DESCRIPTION:
BRIEF SUMMARY
SCOPE OF THE INVENTION
This invention relates to an improved screen for the reproduction of three-dimensional static or moving images, and to a method for manufacturing it.
As will be explained, this screen improves the operation of the optical system for reproducing three-dimensional images by projection, a system developed by the same applicant and inventor as that of this invention, and claimed in previous patent records.
ANTECEDENTS OF THE INVENTION
In the Spanish patent, publication number 20000293 (corresponding to application 8603612, submitted on Dec. 29, 1986), as well as in Spanish patent application 8900722, submitted on Feb. 28, 1989, an optical system or device is described and claimed for reproducing three-dimensional, static or moving images. This device or system includes a screen by means of which (or in which) the images are projected, the optical effect of images in relief, static or moving, being obtained.
Among the systems capable of reproducing moving images in depth, a distinction is made between stereoscopic and three-dimensional images. The term "stereoscopic" is used to describe a system in which use is made, for the reproduction of two images captured at a distance which is approximately equal to the distance between the eyes of a human being. The term "three-dimensional" is used when a greater number of captured, reproduced images is used than that used in the previous system, allowing observation within a wide angle of vision, without disturbing the observers, providing them with optical filters or any other device.
Most of the three-dimensional reproduction devices so far constructed use a "diffusing surface" where the different images are generated, projected, transmitted, amplified, or simply imprinted.
The differentiation between the different images reproduced on the diffusing surface is achieved by reserving a different place for each of them, i.e. by means of what is called "scale differentiation of images".
All systems which contain a diffusing surface reserve for each image, employing different methods, a different position on it. This position establishes a very narrow vertical strip. The vision is produced by means of an optical grid of vertical cylindrical lenses whose focal lines are contained in a plane in which the diffusing surface is located.
The angle of orthoscopic vision coincides with the angle of opening of the cylindrical lenses mentioned.
For this reason the systems which are based on this scale differentiation of images with a high value of the angle of orthoscopic vision give rise to designs of vertical cylindrical lenses which result in highly expensive construction.
Among these systems the following may be mentioned:
The system described in U.S. Pat. No. 1,883,290, from Ives, which describes a system and its respective front projection method, a system and its respective rear projection method, as well as the different systems and orientated methods of producing a high angle of orthoscopic vision. It is deduced from a reading of this patent that the high angle of orthoscopic vision gives rise to cylindrical lenses which are very difficult to manufacture, and to a loss of quality when there is a large number of images. These difficulties, together with the brilliance due to specular reflection of the projectors in the case of frontal projection, or with the adjustment to the required accuracy in the case of rear projection, give rise to minimal practical use of the resultant products.
U.S. Pat. No. 4,078,584, from Yano, describes a device which consists essentially of two elements, a convergent optical system and a screen comprising two frames of vertical cylindrical lenses. In the first of them, corresponding to FIGS. 1 to 4 of the patent, a screen of translucent material located between the frames of vertical cylindrical lenses, the images appearing divided into fine vertical strips. In the second process, one of the frames is a frame of horizontal cylindrical lenses, but this system is considered as a simple variant of the system used for the f
REFERENCES:
patent: 3409351 (1968-11-01), Winnek
patent: 4078854 (1978-03-01), Yano
International Search Report.
LandOfFree
Screen for the reproduction of three-dimensional static or movin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Screen for the reproduction of three-dimensional static or movin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Screen for the reproduction of three-dimensional static or movin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2376408