Patent US4420814A successfully refreshed from Google Patents.
Patent US4824210A successfully refreshed from Google Patents.
US4824210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal projector
Assignee: Casio Computer Co Ltd
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Filing: 1987-08-28
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Granted: 1989-04-25
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Expires: 2007-08-28
Abstract
Abstract A liquid crystal projector is disclosed, which comprises a light source, a TV type liquid crystal display panel and a projecting lens system. The liquid crystal display panel faces the screen and is inclined with respect to a line perpendicular to an optical axis connecting the center of the liquid crystal display panel and the center of a screen by the suitable visual field angle of the liquid crystal display panel.
Inventors
- 👤 Tatsuo Shimazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:03
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/74; H04N5/7416; H04N5/7441; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133382; G02F1/133385; G03; G03B; G03B21/00; G03B21/005; G03B21/006; G03B21/14; G03B21/16; G03B27/00; G03B27/32; G03B27/52; G03B27/68
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
321 words
A liquid crystal projector comprising: a case provided with a projecting window; a light source disposed within said case, said light source including a lamp and a reflecting mirror having an optical axis; means for converting light emitted from said light source into a parallel light; a liquid crystal display panel for displaying an image, said liquid crystal display panel being tilted at a predetermined angle with respect to said optical axis of said reflecting mirror and having a back surface irradiated with said parallel light; condenser lens means for condensing light passing through said liquid crystal display panel; projecting lens means for projecting in a magnified fashion the image displayed on said liquid crystal display panel by the light condensed by said condenser lens means through said projecting window of said case; screen means arranged to receive the magnified image projected from said projecting lens means thereon for displaying said magnified image, said screen means being tilted at a predetermined angle in a direction opposite to the tilting direction of said liquid crystal display panel; and means for cooling said liquid crystal display panel; an angle θ formed between said liquid crystal display panel and a line perpendicular to said optical axis of said reflecting mirror bearing the following relationship with an angle θ' formed between said liquid crystal display panel and a vertical line of said screen means: (Zo+y tan θ)(Zo'+y' tan θ')=f·f'=-f.sup.2 where: f: focal length of said projecting lens means on the side of said liquid crystal display panel; Zo: position on said optical axis of said reflecting mirror with "f" set as the origin; y: position on a line perpendicular to said optical axis; f': focal length of said projecting lens means on the side of said screen means; Zo': position on said optical axis of said reflecting mirror with "f'" set as the origin; and y': position on a line perpendicular to said optical axis.
Claim 2
Dependent Claim
321 words
A liquid crystal projector comprising: a case provided with a projecting window; a light source disposed within said case, said light source including a lamp and a reflecting mirror having an optical axis; means for converting light emitted from said light source into a parallel light; a liquid crystal display panel for displaying an image, said liquid crystal display panel being tilted at a predetermined angle with respect to said optical axis of said reflecting mirror and having a back surface irradiated with said parallel light; condenser lens means for condensing light passing through said liquid crystal display panel; projecting lens means for projecting in a magnified fashion the image displayed on said liquid crystal display panel by the light condensed by said condenser lens means through said projecting window of said case; screen means arranged to receive the magnified image projected from said projecting lens means thereon for displaying said magnified image, said screen means being tilted at a predetermined angle in a direction opposite to the tilting direction of said liquid crystal display panel; and means for cooling said liquid crystal display panel; an angle θ formed between said liquid crystal display panel and a line perpendicular to said optical axis of said reflecting mirror bearing the following relationship with an angle θ' formed between said liquid crystal display panel and a vertical line of said screen means: (Zo+y tan θ)(Zo'+y' tan θ')=f·f'=-f.sup.2 where: f: focal length of said projecting lens means on the side of said liquid crystal display panel; Zo: position on said optical axis of said reflecting mirror with "f" set as the origin; y: position on a line perpendicular to said optical axis; f': focal length of said projecting lens means on the side of said screen means; Zo': position on said optical axis of said reflecting mirror with "f'" set as the origin; and y': position on a line perpendicular to said optical axis.
Claim 3
Dependent Claim
68 words
The liquid crystal projector of claim 1, wherein said case has a bottom, and said liquid crystal display panel is supported by a supporting plate secured to the bottom of said case so as to face said projecting window of said cse; and further comprising a driving circuit mounted to said supporting plate and coupled to said liquid crystal display panel for driving said liquid crystal display panel.
Claim 4
Dependent Claim
258 words
A liquid crystal projector comprising: a light source including a lamp and a reflecting mirror having an optical axis; a liquid crystal display panel for displaying an image, said liquid crystal display panel being tilted at a predetermined angle with respect to said optical axis of said reflecting mirror and being illuminated on a backside thereof with light from said light source; projecting lens means for projecting in a magnified fashion the image displayed on said liquid crystal panel; and screen means arranged to receive the magnified image projected from said projecting lens thereon for displaying said magnified image, said screen means being tilted at a predetermined angle in a direction opposite to the tilting direction of said liquid crystal display panel; an angle θ formed between said liquid crystal display panel and a line perpendicular to said optical axis of said reflecting mirror bearing the following relationship with an angle θ' formed between said liquid crystal display panel and a vertical line of said screen means: (Zo+y tan θ)(Zo'+y' tan θ')=f·f'=-f.sup.2 where: f: focal length of said projecting lens means on the side of said liquid crystal display panel; Zo: position on said optical axis of said reflecting mirror with "f" set as the origin; y: position on a line perpendicular to said optical axis; f': focal length of said projecting lens means on the side of said screen means; Zo': position on said optical axis of said reflecting mirror with "f'" set as the origin; and y': position on a line perpendicular to said optical axis.
Claim 5
Dependent Claim
258 words
A liquid crystal projector comprising: a light source including a lamp and a reflecting mirror having an optical axis; a liquid crystal display panel for displaying an image, said liquid crystal display panel being tilted at a predetermined angle with respect to said optical axis of said reflecting mirror and being illuminated on a backside thereof with light from said light source; projecting lens means for projecting in a magnified fashion the image displayed on said liquid crystal panel; and screen means arranged to receive the magnified image projected from said projecting lens thereon for displaying said magnified image, said screen means being tilted at a predetermined angle in a direction opposite to the tilting direction of said liquid crystal display panel; an angle θ formed between said liquid crystal display panel and a line perpendicular to said optical axis of said reflecting mirror bearing the following relationship with an angle θ' formed between said liquid crystal display panel and a vertical line of said screen means: (Zo+y tan θ)(Zo'+y' tan θ')=f·f'=-f.sup.2 where: f: focal length of said projecting lens means on the side of said liquid crystal display panel; Zo: position on said optical axis of said reflecting mirror with "f" set as the origin; y: position on a line perpendicular to said optical axis; f': focal length of said projecting lens means on the side of said screen means; Zo': position on said optical axis of said reflecting mirror with "f'" set as the origin; and y': position on a line perpendicular to said optical axis.
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) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |