US3744892A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical projection device
Assignee: GRAFTON PRODUCTION
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Filing: 1971-04-08
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Granted: 1973-07-10
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Expires: 1991-04-08
Abstract
Abstract An optical projector which combines the dual functions of episcope and overhead projector is described. The projector comprises a single casing housing a pivotally mounted mirrored member movable between two positions in one of which it permits light from a source to traverse a Fresnel lens and a transparent carrier thereon to an overhead lens system forming part of the overhead projector. In its other position the mirrored member permits reflection of image-forming light reflected from an opaque carrier to be directed through a projection lens forming part of the episcope. The material to be projected is supported by a single surface of the casing and the operative modes are alternative.
Inventors
- 👤 R Shipsey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:09
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/132; Y; Y10; Y10S; Y10S353/00; Y10S353/03
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
206 words
An optical projection device combining an episcope and an overhead projector, comprising a casing having a light source therein, a projection lens system mounted on the casing and an overhead lens system supported by the casing, wherein the overhead projector is formed by a substantially transparent carrier adapted to receive information to be projected and a lens forming a surface of said casing and arranged to support said transparent carrier and to project light from the light source through the carrier towards said overhead lens system so as to form an image on a screen, and the episcope is formed by a removable support adjacent said lens for receiving an opaque information-bearing medium, said light source comprising two lamps, one of said lamps being disposed centrally under the transparent carrier for projecting said transparent carrier to said overhead lens system and the other being disposed to flood said support with light, said support being disposed between said one lamp and said lens, and a mirrored member having a flat mirror surface pivotally mounted for movement to a position intermediate said one lamp and said support, said flat mirror surface in said intermediate position reflecting the image of said opaque information-bearing medium into said projection lens system.
Claim 2
Dependent Claim
206 words
An optical projection device combining an episcope and an overhead projector, comprising a casing having a light source therein, a projection lens system mounted on the casing and an overhead lens system supported by the casing, wherein the overhead projector is formed by a substantially transparent carrier adapted to receive information to be projected and a lens forming a surface of said casing and arranged to support said transparent carrier and to project light from the light source through the carrier towards said overhead lens system so as to form an image on a screen, and the episcope is formed by a removable support adjacent said lens for receiving an opaque information-bearing medium, said light source comprising two lamps, one of said lamps being disposed centrally under the transparent carrier for projecting said transparent carrier to said overhead lens system and the other being disposed to flood said support with light, said support being disposed between said one lamp and said lens, and a mirrored member having a flat mirror surface pivotally mounted for movement to a position intermediate said one lamp and said support, said flat mirror surface in said intermediate position reflecting the image of said opaque information-bearing medium into said projection lens system.
Claim 3
Dependent Claim
52 words
An optical projection device according to claim 1, wherein the mirrored member activates electrical switches which control the two lamps so that said other lamp is switched on when said support is in said second position and said mirrored member lies in said position intermediate said one lamp and the transparent carrier.
Claim 4
Dependent Claim
15 words
An optical projection device according to claim 1, wherein said lens is a Fresnel lens.
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) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |