Patent US4556913A successfully refreshed from Google Patents.
US4556913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for preventing virtual images in projection television receivers
Assignee: RCA Licensing Corp
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Filing: 1984-01-13
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Granted: 1985-12-03
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Expires: 2004-01-13
Abstract
Abstract A rear projection television receiver has an image source, first and second mirrors, and a screen. Light travels from the image source to the screen along a first light path via the first and second mirrors and along a second path that bypasses the mirrors. A light baffle assembly comprising a plurality of elongated baffle elements is located in both the first and second light paths. The angle of the individual baffle elements is adjusted so that light rays are unaffected along the first light path and substantially completely blocked along the second light path.
Inventors
- 👤 Bertram VanBreemen
- 👤 William L. Wilson
- 👤 Duane L. Roberts
- 👤 Tom W. Branton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:02
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; H04N5/00; H04N5/74; H04N5/7475; H04N2005/7483
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
110 words
In a rear projection television receiver having an image source, first and second mirrors, and a screen, in which light from said image source follows a first light path to said screen that incorporates said first and second mirrors and which follows a second light path to said screen that bypasses said first and second mirrors, means for occluding said second light path comprising light baffle means disposed within said first light path after said first mirror and before said second mirror and disposed within said second light path, said light baffle means appearing substantially transparent along said first light path and appearing substantially opaque along said second light path.
Claim 2
Dependent Claim
110 words
In a rear projection television receiver having an image source, first and second mirrors, and a screen, in which light from said image source follows a first light path to said screen that incorporates said first and second mirrors and which follows a second light path to said screen that bypasses said first and second mirrors, means for occluding said second light path comprising light baffle means disposed within said first light path after said first mirror and before said second mirror and disposed within said second light path, said light baffle means appearing substantially transparent along said first light path and appearing substantially opaque along said second light path.
Claim 3
Dependent Claim
35 words
The arrangement defined in claim 1, wherein said light baffle means comprises a plurality of elongated baffle elements, each of said baffle elements disposed at a predetermined angle with respect to said first light path.
Claim 4
Dependent Claim
15 words
The arrangement defined in claim 2, wherein said elongated baffle elements are made of paper.
Claim 5
Dependent Claim
15 words
The arrangement defined in claim 2, wherein said elongated baffle elements are made of metal.
Claim 6
Dependent Claim
15 words
The arrangement defined in claim 2, wherein said elongated baffle elements are made of plastic.
Claim 7
Dependent Claim
18 words
The arrangement defined in claim 2, wherein said elongated baffle elements absorb substantially all light that impinges thereon.
Claim 8
Dependent Claim
118 words
In a rear projection television receiver having an image source, first and second mirrors, and a screen, in which light from said image source follows a first light path to said screen that incorporates said first and second mirrors and which follows a second light path to said screen that bypasses said first and second mirrors, means for occluding said second light path comprising light baffle means disposed within said first light path after said first mirror and before said second mirror and disposed within said second light path, said light baffle means presenting a low aspect ratio to light along said first light path and presenting a high aspect ratio to light along said second light path.
Claim 9
Dependent Claim
118 words
In a rear projection television receiver having an image source, first and second mirrors, and a screen, in which light from said image source follows a first light path to said screen that incorporates said first and second mirrors and which follows a second light path to said screen that bypasses said first and second mirrors, means for occluding said second light path comprising light baffle means disposed within said first light path after said first mirror and before said second mirror and disposed within said second light path, said light baffle means presenting a low aspect ratio to light along said first light path and presenting a high aspect ratio to light along said second light path.
Claim 10
Dependent Claim
124 words
In a rear projection television receiver having an image source, a first mirror, a second mirror disposed above said first mirror, and a screen, in which light rays from said image source follow a first light path to said screen via said first and second mirrors, respectively, and which follow a second light path to said screen that bypasses said first and second mirrors, means for occluding said second light path comprising light baffle means disposed within said first light path and disposed within said second light path, said light baffle means disposed above substantially all of the light rays between said image source and said first mirror and disposed below substantially all of the light rays between said second mirror and said screen.
Claim 11
Dependent Claim
124 words
In a rear projection television receiver having an image source, a first mirror, a second mirror disposed above said first mirror, and a screen, in which light rays from said image source follow a first light path to said screen via said first and second mirrors, respectively, and which follow a second light path to said screen that bypasses said first and second mirrors, means for occluding said second light path comprising light baffle means disposed within said first light path and disposed within said second light path, said light baffle means disposed above substantially all of the light rays between said image source and said first mirror and disposed below substantially all of the light rays between said second mirror and said screen.
Claim 12
Dependent Claim
107 words
A rear projection television receiver, comprising: an image source; a first mirror; a second mirror disposed above said first mirror; a screen; and light baffle means comprising: a quadrilateral frame having a first side of said frame disposed adjacent to the upper edge of said first mirror and having a second side opposite said first side disposed adjacent to the lower edge of said second mirror; and a plurality of elongated baffle elements disposed within said frame and extending substantially parallel to said first and second sides of said frame, each of said elongated baffle elements being disposed at a predetermined angle with respect to said frame.
Claim 13
Dependent Claim
107 words
A rear projection television receiver, comprising: an image source; a first mirror; a second mirror disposed above said first mirror; a screen; and light baffle means comprising: a quadrilateral frame having a first side of said frame disposed adjacent to the upper edge of said first mirror and having a second side opposite said first side disposed adjacent to the lower edge of said second mirror; and a plurality of elongated baffle elements disposed within said frame and extending substantially parallel to said first and second sides of said frame, each of said elongated baffle elements being disposed at a predetermined angle with respect to said frame.
Claim 14
Dependent Claim
112 words
In a rear projection television receiver having an image source, first and second mirrors, and a screen, in which light from said image source follows a first light path to said screen that incorporates said first and second mirrors and which follows a second light path to said screen that bypasses said first and second mirrors, means for occluding said second light path comprising a plurality of light baffle means disposed within said first light path and disposed within said second light path, said light baffle means presenting a low aspect ratio to light along said first light path and presenting a high aspect ratio to light along said second light path.
Claim 15
Dependent Claim
112 words
In a rear projection television receiver having an image source, first and second mirrors, and a screen, in which light from said image source follows a first light path to said screen that incorporates said first and second mirrors and which follows a second light path to said screen that bypasses said first and second mirrors, means for occluding said second light path comprising a plurality of light baffle means disposed within said first light path and disposed within said second light path, said light baffle means presenting a low aspect ratio to light along said first light path and presenting a high aspect ratio to light along said second light path.
Claim 16
Dependent Claim
75 words
A rear projection television receiver, comprising: an image source comprising a cathode ray tube and a lens assembly; a first mirror; a second mirror disposed above said first mirror; a screen; and light baffle means comprising: a frame disposed adjacent to said image source; and a plurality of substantially parallel elongated baffle elements disposed within said frame, each of said elongated baffle elements being disposed at a predetermined angle with respect to said image source.
Claim 17
Dependent Claim
75 words
A rear projection television receiver, comprising: an image source comprising a cathode ray tube and a lens assembly; a first mirror; a second mirror disposed above said first mirror; a screen; and light baffle means comprising: a frame disposed adjacent to said image source; and a plurality of substantially parallel elongated baffle elements disposed within said frame, each of said elongated baffle elements being disposed at a predetermined angle with respect to said image source.
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) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |