US4730919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slide viewer
Assignee: Osram GmbH
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Filing: 1985-10-01
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Granted: 1988-03-15
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Expires: 2005-10-01
Abstract
Abstract A folding slide viewer has a rear projection screen which swings into a ft position for storage. In a second, operating position, the projection screen it is provided with a lightproof bellows. The optical axis of the lens system is inclined at an angle with respect to the horizontal base of the housing. A reflector is along the optical axis of the lens system, when the screen is in its operating position, to reflect an image onto the screen. An image trap is swingable between a first position perpendicular to a longitudinal axis of the slide magazine and a second position perpendicular to the optical axis of the lens system.
Inventors
- 👤 Albert Schuch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:52
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/30
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
235 words
A slide viewer comprising a housing having a horizontal base surface, said housing comprising a light source, a lens system having an optical axis, an image trap, an image changer and a reflector, said housing provided with a back projection screen and a magazine guide having a longitudinal and substantially horizontal axis, wherein the optical axis of the lens system is inclined at an angle to the horizontal base surface of the housing, said projection screen pivotally connected within the housing and swingable between a first position in which said projection screen is lying at the upper side of the housing, and a second, operating position and is provided with a lightproof screen, the image trap is hinged and is swingable between a first position in which it is arranged in a plane perpendicular to said longitudinal axis of the magazine guide, and a second position in which it is arranged in a plane perpendicular to said optical axis of the lens system, and the reflector arranged in the optical axis of the lens system when the projection screen is in its second position, whereby a film slide may be transported by means of said image changer from a magazine positioned in said magazine guide into said image trap being in its first position, and further transported to a projecting position by means of the image trap by swinging the latter to its second position.
Claim 2
Dependent Claim
235 words
A slide viewer comprising a housing having a horizontal base surface, said housing comprising a light source, a lens system having an optical axis, an image trap, an image changer and a reflector, said housing provided with a back projection screen and a magazine guide having a longitudinal and substantially horizontal axis, wherein the optical axis of the lens system is inclined at an angle to the horizontal base surface of the housing, said projection screen pivotally connected within the housing and swingable between a first position in which said projection screen is lying at the upper side of the housing, and a second, operating position and is provided with a lightproof screen, the image trap is hinged and is swingable between a first position in which it is arranged in a plane perpendicular to said longitudinal axis of the magazine guide, and a second position in which it is arranged in a plane perpendicular to said optical axis of the lens system, and the reflector arranged in the optical axis of the lens system when the projection screen is in its second position, whereby a film slide may be transported by means of said image changer from a magazine positioned in said magazine guide into said image trap being in its first position, and further transported to a projecting position by means of the image trap by swinging the latter to its second position.
Claim 3
Dependent Claim
27 words
A slide viewer according to claim 1, wherein said lightproof screen is formed of a foldable bellows which is secured to the upper side of the housing.
Claim 4
Dependent Claim
18 words
A slide viewer according to claim 1, wherein the image trap is mechanically coupled with the image changer.
Claim 5
Dependent Claim
65 words
A slide viewer according to claim 3, wherein the image changer has a sliding gate adapted to be moved in a plane perpendicular to said longitudinal axis of the magazine guide and is provided with a cam acting on the image trap to move the image trap between its first and second positions, the image trap resting against a stop in either of said positions.
Claim 6
Dependent Claim
31 words
A slide viewer according to claim 1, wherein the image trap, when being in its first position, is arrested by means of a releasable latch device actuated by said image changer.
Claim 7
Dependent Claim
20 words
A slide viewer according to claim 1, wherein the image trap is biased by a spring into its second position.
Claim 8
Dependent Claim
47 words
A slide viewer according to claim 1 wherein the reflector is arranged in the housing so as to be slidable in substantially vertical guides between a first, upper position in which it is arranged in said optical axis of the lens system, and a second, lower position.
Claim 9
Dependent Claim
31 words
A slide viewer according to claim 7, wherein the reflector is biased by a spring into its first, upper position and is resting against stop when in said first, upper position.
Claim 10
Dependent Claim
30 words
A slide viewer according to claim 7, wherein the reflector, when in its second, lower position, cooperates with an electric switch to which at least said light source is connected.
Claim 11
Dependent Claim
29 words
A slide viewer according to claim 7, wherein said foldable bellows is fastened at the upper side and substantially in the middle of the rear side of the reflector.
Claim 12
Dependent Claim
16 words
A slide viewer according to claim 1, wherein the lens system comprises two aspherical condensor lenses.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |