Optical: systems and elements – Holographic system or element – Using a hologram as an optical element
Patent
1995-04-24
1995-12-05
Lerner, Martin
Optical: systems and elements
Holographic system or element
Using a hologram as an optical element
359452, 359599, G02B 502, G02F 11335, G03B 2160
Patent
active
054734541
ABSTRACT:
A display screen of a projection system embodying a cathode ray tube, liquid crystal light valve, laser or the like is formed of a plastic sheet (22, 22a) that has embedded therein a number of microsphere diffuser particles (24, 24a) initially having a spherical shape and distributed in a uniformly isotropic density. The plastic sheet and its embedded particles are heated and stretched in a single direction and allowed to cool in their elongated form so that the diffuser particles (24a) then have an elongated elliptical shape and a density that is greater along one axis than it is along an orthogonal axis. The particle elongation and decreased density in the direction of stretch cause the diffusing sheet to have a diffusion cone angle (44), as measured in a plane containing the axis of stretch, that is significantly decreased, but with increased screen gain, whereas the diffusion angle (42) in the orthogonal unstretched direction remains relatively large, and also has an increased screen gain. The decreased diffusion angle is oriented in a vertical direction in a common display because the viewer's eye, in looking at a display screen, is most commonly positioned within a relatively small vertical cone angle, although the horizontal angle of view may be considerably larger.
REFERENCES:
patent: 1399566 (1921-12-01), Lazarus
patent: 2287556 (1942-06-01), Land
patent: 4936659 (1990-06-01), Anderson et al.
patent: 4989933 (1991-02-01), Duguay
patent: 5307205 (1994-04-01), Ludwig, Jr. et al.
patent: 5384658 (1995-01-01), Ohtake et al.
IBM Tech. Dis. Bull., vol. 29, No. 1. "Light Diffuser . . . " pp. 276-279, Jun. 1986.
Denson-Low W. K.
Gudmestad Terje
Hughes Aircraft Company
Lerner Martin
LandOfFree
Elliptical diffuser does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Elliptical diffuser, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Elliptical diffuser will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1377964