Stereoscopic projector

• US 5,121,983 A
• Filed: 12/12/1990
• Issued: 06/16/1992
• Est. Priority Date: 12/14/1989
• Status: Expired due to Term

• Current Assignee: Goldstar Jewellery LLC
• Original Assignee: Goldstar Jewellery LLC
• Inventors: Lee, Dong H.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Dowling, William C.
• Application Number:
  US07/626,550
• Time in Patent Office: 552 Days
• Field of Search: 353/8, 353/7, 353/20, 353/30, 353/33, 353/82, 353/94, 353/31, 353/32, 353/102, 353/81, 353/34, 350/132, 350/130, 358/88, 358/3, 359/464, 359/465, 359/471, 359/475
• US Class Current: 353/8
• CPC Class Codes: G03B 35/26 using polarised or coloured light separating different viewpoint images
• CPC Class Codes: G09F 19/18 involving the use of optical projection means, e.g. projection of images on clouds projection apparatus per se G03B
• CPC Class Codes: H04N 13/337 using polarisation multiplexing
• CPC Class Codes: H04N 13/363 using image projection screens volumetric display H04N13/388

Abstract

A stereoscopic projector includes a condenser member for leading a beam from a lamp to advance in parallel, an infrared ray filter for removing heat component in the beam from the condenser system, a polarizing beam splitter for splitting an incident beam into two beams, a liquid crystal display panel or a slide film for obtaining image signals, and a reflective mirror for converting the beam path a field lens and a projection lens, whereby the projector prevents the keystoning phenomenon, since the light utilizing efficiency is high, the power loss is reduced, and the infrared filter removes the thermal line from the beam so that the separate cooling system is not required.

Claims

1. A stereoscopic projector comprising:

a condenser member for leading a beam from a light source to advance in parallel to an optical axis thereof, said condenser member including;

a light source for generating a light containing three primary color lights,

a non-spherical reflective mirror having an angle range about 2π

(Steradian unit) from said light source for leading a beam emitted backward from the light source to advance forward in parallel,

a beam guide unit arranged in front of the light source for allowing the beams in parallel with the optical axis of the condenser member among the beams from sid non-spherical reflective mirror and light source to pass therethrough and having a plurality of cylinders whose radiuses become gradually increased and has an axis-symmetrical structure with the condenser member, and

a reflective mirror member including a plurality of ringular band-type spherical mirrors having a center of curvature identical to that of the light source for reflecting the beams emitted forward in a ringular band-type toward the light source,

a first polarizing beam splitter arranged such that parallel beams from said condenser member are incident thereupon perpendicularly for splitting said parallel beams into two polarizing beams having the polarizing directions perpendicular to each other,

first and second mirrors arranged in slant at 45°

with respect to the advancing direction of said two polarizing beams for reflecting said two polarizing beams splitted in perpendicular to each other from said first polarizing beam splitter so as to be crossed with each other,

a second polarizing beam splitter, a field lens, and a projection lens arranged such that said two polarizing beams reflected at the first mirror and the second mirror, respectively, are added to each other and allowed to pass through said field lens and projection lens, and

first and second LCD panels arranged between said second polarizing beam splitter and said first and second mirror for allowing said two polarizing beams reflected at the first and second mirrors to pass therethrough, respectively, and for transmitting a liquid crystal display image signal to the projection lens by means of said two polarizing beams.

2. The stereoscopic projector of claim 1, wherein the polarizing beam splitter includes a pair of perpendicular prisms bonded at slant surfaces with each other and provided therebetween with a multilayer dielectric film coated at a Brewster'"'"'s angle or a polarizing angle with respect to an incident beam so that the incident beam can be splitted into a pair of beams having the polarizing directions perpendicular to each other.

3. A stereoscopic projector comprising:

a condenser member for leading a beam from a light source to advance in parallel to an optical axis of said condenser member,

a first polarizing beam splitter arranged such that parallel beams from said condenser member are incident thereupon perpendicularly for splitting said parallel beams into two polarizing beams having the polarizing directions perpendicular to each other,

a reflective mirror for changing the advancing direction of one polarizing beam out of the two polarizing beams splitted into perpendicular to each other from said polarizing beam splitter so that the advancing direction of two polarizing beams are in parallel with each other, and

a pair of LCD panels, a pair of field lenses, and a pair of projection lenses arranged in order in the advancing directions of the two polarizing beams, respectively for transmitting the image signal from the LCD panels to a screen.

4. The stereoscopic projector of claim 3, wherein said condenser member includes:

a light source for generating a light containing three primary color lights,

a non-spherical reflective mirror having an angle range about 2π

(Steradian unit) from said light source for leading a beam emitted backward from the light source to advance forward in parallel,

a beam guide unit arranged in front of the light source for allowing the beams in parallel with the optical axis of the condenser member among the beams from said non-spherical reflective mirror and light source to pass therethrough and having a plurality of cylinders whose radiuses become gradually increased and has an axis-symmetrical structure with the condenser member, and

a reflective mirror member including a plurality of ringular band-type spherical mirrors having a center of curvature identical to that of the light source for reflecting the beams emitted forward in a ringular band-type toward the light source.

5. A stereoscopic projector comprising:

two condenser members for leading beams from two light sources to advance in parallel with the optical axis thereof,

a polarizing beam splitter arranged with said two condenser members so that said two parallel beams from said two condenser members are incident upon in perpendicular to each other two adjacent surfaces of said polarizing beam splitter for splitting said two parallel beams into two polarizing beams having the polarizing directions perpendicular to each other,

two LCD panels, arranged between the adjacent surfaces of said polarizing beam splitter and the two condenser members for generating stereoscopic image signals, and

a field lens and a projection lens for generating a stereoscopic image consisting of two polarizing beams having the polarizing directions perpendicular to each other on a screen by allowing one beam out of the beams having the two stereoscopic image signals emitted from the polarizing beam splitter to pass therethrough.

6. The stereoscopic projector of claim 5, wherein said condenser member includes:

a light source for generating a light containing three primary color lights,

a non-spherical reflective mirror having an angle range about 2π

(Steradian unit) said light source for leading a beam emitted backward from the light source to advance forward in parallel,

a beam guide unit arranged in front of the light source for allowing the beams in parallel with the optical axis of the condenser member among the beams from said non-spherical reflective mirror and light source to pass therethrough and having a plurality of cylinders whose radiuses become gradually increased and has an axis-symmetrical structure with the condenser member, and

a reflective mirror member including a plurality of ringular band-type spherical mirrors having a center of curvature identical to that of the light source for reflecting the beams emitted forward in a ringular band-type toward the light source.