US3900253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical projecting apparatus
Assignee: Lindaco Ltd
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Filing: 1973-04-20
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Granted: 1975-08-19
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Expires: 1993-04-20
Abstract
Abstract There is provided an optical projecting apparatus comprising a combined overhead-episcopic projector, a diascopic projector and/or a film projector, wherein one light source is arranged to be placed in different positions corresponding to transmission of light to the different projection systems. The light may be guided from the light source to the different systems by means of glass fibre optics. A TV-set may be mounted at the table of the apparatus so that a TV-image may be projected by means of the combined projector.
Inventors
- 👤 Jan-Erik Astero
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:15
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/132
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
198 words
Projection apparatus of the overhead type, comprising: a TVset, the picture tube surface of which is arranged hOrizontally; a mirror positioned above said picture tube surface for deflecting light from said picture tube surface, and a lens system for projecting the image of the picture tube surface, support means for mounting said TV-set, said support means at its top side being provided with a sheet of transparent material, light means for illuminating said sheet from a position above said surface, whereby said projection apparatus is a combined overhead and episcopic projector which functions to project an image from said picture tube by directing light orginating from said picture tube to said mirror and reflecting it thereby through said lens system; to project an image from a full size transparency placed on said transparent material by directing light originating from said picture tube through said transparency and to said mirror where it is reflected through said lens system; and to project an image from an opaque picture placed on said sheet of transparent material by directing light originating from said light means to said opaque picture and thence to said mirror where it is reflected through said lens system.
Claim 2
Dependent Claim
198 words
Projection apparatus of the overhead type, comprising: a TVset, the picture tube surface of which is arranged hOrizontally; a mirror positioned above said picture tube surface for deflecting light from said picture tube surface, and a lens system for projecting the image of the picture tube surface, support means for mounting said TV-set, said support means at its top side being provided with a sheet of transparent material, light means for illuminating said sheet from a position above said surface, whereby said projection apparatus is a combined overhead and episcopic projector which functions to project an image from said picture tube by directing light orginating from said picture tube to said mirror and reflecting it thereby through said lens system; to project an image from a full size transparency placed on said transparent material by directing light originating from said picture tube through said transparency and to said mirror where it is reflected through said lens system; and to project an image from an opaque picture placed on said sheet of transparent material by directing light originating from said light means to said opaque picture and thence to said mirror where it is reflected through said lens system.
Claim 3
Dependent Claim
15 words
The projection apparatus according to claim 1 wherein the transparent material is a glass sheet.
Claim 4
Dependent Claim
57 words
Projecting apparatus in accordance with claim 1 further comprising a diascopic projector having a second lens system and wherein said light means includes at least one light source and at least one reflector, said light source and reflector being selectively movable for either providing light to said combined overhead and episcopic projector or to said diascopic projector.
Claim 5
Dependent Claim
30 words
Apparatus according to claim 3 further comprising a strip film projector having a third lens system, said light means being arranged for transmission of light to the said film projector.
Claim 6
Dependent Claim
70 words
Apparatus according to claim 3 wherein said light means is a first light means and further comprising a second light means containing at least one light source and at least one reflector, said second light means being arranged above said transparent sheet adjacent to the mirror in order to increase the luminance of episcopic images and in order to assist in reducing ghost pictures when stacked overhead transparencies are shown.
Claim 7
Dependent Claim
15 words
Apparatus according to claim 5, characterised in that the second light means has variable luminance.
Claim 8
Dependent Claim
48 words
Apparatus according to claim 5, including means for turning on said second light means when the first light means is directed towards the transparent sheet and for turning off said second light means when the first light means is directed towards the film projector or the diascopic projector.
Claim 9
Dependent Claim
48 words
Apparatus according to claim 3, including a rotatable and axially shiftable shaft, the first light means being mounted on said shaft, said shaft being arranged to position said first light means for transmission of light to the various projectors and the apparatus includes means for locking the shaft.
Claim 10
Dependent Claim
46 words
Apparatus according to claim 3, comprising also a table, characterised in that the top surface of the table is composed of a mirror, which is coated with a transparent binder, for example cellulose lacquer, which on its part is coated with and binds a glass powder.
Claim 11
Dependent Claim
34 words
Apparatus according to claim 9, characterised in that the glass powder is spread in an amount of about 90 - 100 grs per 8.5 dm2 and has a corn diameter of about 0.40 mm.
Claim 12
Dependent Claim
102 words
Apparatus according to claim 3 wherein said projectors each are provided with a light guide, each of said light guides having a first and second outer end, said first outer end being coupled to one of said projectors, said light means being mounted in a housing, said apparatus including means to revolve said housing in a path of revolution for cooperating with the second outer end of said light guide of any of the projectors, said second outer ends of the light guides of the projectors being gathered along a circular path, corresponding to the path of revolution of the housing. >
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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |