US4861142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection type liquid crystal displaying device
Assignee: Seiko Precision Inc
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Filing: 1987-05-12
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Granted: 1989-08-29
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Expires: 2007-05-12
Abstract
Abstract Light emitted from a single light source is split into beams of bidirectional parallel light which are orthogonal to each other. Beams of the parallel light in each direction are reflected by a reflection optical system in such a direction that they become orthogonal to each other. A dichroic mirror is disposed at a point of intersection thereof and liquid crystal panels are provided between each individual reflection optical system and the dichroic mirror resulting in a low cost device which can be structurally miniaturized and which requires less process steps in fabrication.
Inventors
- 👤 Sakae Tanaka
- 👤 Tadahiko Yamaoka
- 👤 Shingo Takahashi
- 👤 Tomoaki Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:29
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; H04N9/315; H04N9/3167
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
182 words
A projection type liquid crystal displaying device comprising: a light source; condenser lenses for splitting light emitted from said light source into two orthogonal groups of beams of substantially parallel light; two optical reflection means, each in the path of one of the beams of light, for effecting the beams of the light of the two groups to reflect at a right angle to an area in which the beams of light of the two groups cross each other; a dichroic mirror disposed in said area for synthesizing beams of the light from the two optical reflection means including means for transmitting the light coming from one of said optical reflection means and for reflecting the light from the other of said optical reflection means; a liquid crystal panel comprising green picture elements disposed between said dichroic mirror and one of said optical reflection means; a liquid crystal panel comprising red and blue picture elements disposed between said dichroic mirror and the other of said optical reflection optical means; and projection means for projecting beams of the light from said dichroic mirror.
Claim 2
Dependent Claim
182 words
A projection type liquid crystal displaying device comprising: a light source; condenser lenses for splitting light emitted from said light source into two orthogonal groups of beams of substantially parallel light; two optical reflection means, each in the path of one of the beams of light, for effecting the beams of the light of the two groups to reflect at a right angle to an area in which the beams of light of the two groups cross each other; a dichroic mirror disposed in said area for synthesizing beams of the light from the two optical reflection means including means for transmitting the light coming from one of said optical reflection means and for reflecting the light from the other of said optical reflection means; a liquid crystal panel comprising green picture elements disposed between said dichroic mirror and one of said optical reflection means; a liquid crystal panel comprising red and blue picture elements disposed between said dichroic mirror and the other of said optical reflection optical means; and projection means for projecting beams of the light from said dichroic mirror.
Claim 3
Dependent Claim
200 words
A projection type liquid crystal displaying device comprising: a light source; first condenser lenses for splitting the light emitted from said light source into two orthogonal groups of beams of substantially parallel light; two optical reflection means, each in the path of one of the beams of light, for effecting the beams of light of the two groups to reflect at a right angle to an area in which the beams of the light of the two groups cross each other; a dichroic mirror disposed in said area for synthesizing beams of light from said optical reflection means including means for transmitting the light coming from one of said optical reflection means and for reflecting the light from the other of said optical reflection means; a liquid crystal panel comprising green picture elements disposed between said dichroic mirror and one of said optical reflection means; a liquid crystal panel comprising red and blue picture elements disposed between said dichroic mirror and the other of said optical reflection means; second condenser lenses for converging the light transmitted through each of said liquid crystal panels at a given angle; and projection means for projecting beams of the light from said dichroic mirror.
Claim 4
Dependent Claim
200 words
A projection type liquid crystal displaying device comprising: a light source; first condenser lenses for splitting the light emitted from said light source into two orthogonal groups of beams of substantially parallel light; two optical reflection means, each in the path of one of the beams of light, for effecting the beams of light of the two groups to reflect at a right angle to an area in which the beams of the light of the two groups cross each other; a dichroic mirror disposed in said area for synthesizing beams of light from said optical reflection means including means for transmitting the light coming from one of said optical reflection means and for reflecting the light from the other of said optical reflection means; a liquid crystal panel comprising green picture elements disposed between said dichroic mirror and one of said optical reflection means; a liquid crystal panel comprising red and blue picture elements disposed between said dichroic mirror and the other of said optical reflection means; second condenser lenses for converging the light transmitted through each of said liquid crystal panels at a given angle; and projection means for projecting beams of the light from said dichroic mirror.
Claim 5
Dependent Claim
22 words
The projection type liquid crystal displaying device as set forth in claim 2, wherein the given angle ranges from 0° to 5°.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |