Slide viewer

• US 4,730,919 A
• Filed: 10/01/1985
• Issued: 03/15/1988
• Est. Priority Date: 10/05/1984
• Status: Expired due to Fees

• Current Assignee: Patent-Treuhand-Gesellschaft Fur Elektrische Gluhlampen mbH (Ams-Osram AG)
• Original Assignee: Patent-Treuhand-Gesellschaft Fur Elektrische Gluhlampen mbH (Ams-Osram AG)
• Inventors: Schuch, Albert
• Primary Examiner(s): Frankfort, Charles
• Assistant Examiner(s): Scanlon, Patrick R.
• Application Number:
  US06/782,705
• Time in Patent Office: 896 Days
• Field of Search: 353/75, 353/77, 353/79, 353/80, 353/95, 353/103, 353/113, 353/114, 353/115, 353/116, 353/117, 353/22, 353/23, 353/78, 353/68, 353/122
• US Class Current: 353/79
• CPC Class Codes: G03B 21/30 adapted to collapse or fold, e.g. for portability

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.

Claims

1. 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.

2. 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.

3. A slide viewer according to claim 1, wherein the image trap is mechanically coupled with the image changer.

4. 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.

5. 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.

6. A slide viewer according to claim 1, wherein the image trap is biased by a spring into its second position.

7. 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.

8. 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.

9. 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.

10. 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.

11. A slide viewer according to claim 1, wherein the lens system comprises two aspherical condensor lenses.