US3920322A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Micro film viewer
Assignee: Northern Engraving Co Inc
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Filing: 1974-01-02
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Granted: 1975-11-18
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Expires: 1994-01-02
Abstract
Abstract A portable, compact viewer for illuminating, enlarging and viewing individual microfilm frames which are carried on a filmstrip prepackaged in a cassette. The viewer is provided with electrical drive means for transporting the filmstrip within the cassette in a forward or reverse direction, at a high speed for traversing or at a low speed for scanning. Means integral with the drive means are provided to inhibit overrun of the transport, so as to provide accurate location and alignment of single frames and to provide substantial inching control. The viewer includes a cassette receiving compartment whose cover may be spring biased toward operative positions, and which cover aids in aligning the cassette with the optical system, and may additionally cooperate to prevent excessive heating from a heat source such as an illumination bulb. The viewer housing is of an improved construction which assures a high-contrast image under normal light conditions.
Inventors
- 👤 Arnis E Peters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:03
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/10; G03B21/11; G03B21/111
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
293 words
In a microfilm viewer, for receiving therein a reel-to-reel film cassette of microfilm and for illuminating, projecting, enlarging and displaying a selected frame of the microfilm upon a viewing screen, and the path of projection of the illuminated frame including first and second mirror means and a viewing screen, the improvement comprising, in combination: elongated housing means for housing therein illuminating means and projection means and including an elongated upper casing having a viewing screen mounted therein at the distal end and a cassette receiving compartment provided therein at the proximal end, means carried by the upper casing for maintaining fixed optical alignment of a film cassette with said illumination means and projection means, and fixed optical attitude of the viewing screen and of said first mirror means against which the illuminated image is projected by the projection means, a movable lower casing part, the second mirror means being fixedly positioned upon said lower casing part and being movable with said lower casing part between an inoperative, stored-away position and an operative position in which the second mirror means is deployed to receive the image reflected from the first mirror means and to reflect same upon the viewing screen, said movable lower casing part serving in its operative position as part of the support means for the viewer so as to incline the viewing screen relative to a support surface upon which the viewer may be positioned, the second mirror means being supported on the movable lower casing part at an incline to the exterior surface plane of the lower casing part, and the exterior surface of said lower casing part being indented toward the second mirror means carried thereon, to provide a recessed storage compartment for a power cord for the viewer.
Claim 2
Dependent Claim
293 words
In a microfilm viewer, for receiving therein a reel-to-reel film cassette of microfilm and for illuminating, projecting, enlarging and displaying a selected frame of the microfilm upon a viewing screen, and the path of projection of the illuminated frame including first and second mirror means and a viewing screen, the improvement comprising, in combination: elongated housing means for housing therein illuminating means and projection means and including an elongated upper casing having a viewing screen mounted therein at the distal end and a cassette receiving compartment provided therein at the proximal end, means carried by the upper casing for maintaining fixed optical alignment of a film cassette with said illumination means and projection means, and fixed optical attitude of the viewing screen and of said first mirror means against which the illuminated image is projected by the projection means, a movable lower casing part, the second mirror means being fixedly positioned upon said lower casing part and being movable with said lower casing part between an inoperative, stored-away position and an operative position in which the second mirror means is deployed to receive the image reflected from the first mirror means and to reflect same upon the viewing screen, said movable lower casing part serving in its operative position as part of the support means for the viewer so as to incline the viewing screen relative to a support surface upon which the viewer may be positioned, the second mirror means being supported on the movable lower casing part at an incline to the exterior surface plane of the lower casing part, and the exterior surface of said lower casing part being indented toward the second mirror means carried thereon, to provide a recessed storage compartment for a power cord for the viewer.
Claim 3
Dependent Claim
29 words
A viewer as in claim 1 including latch means on the movable lower casing part for latchably securing said casing part selectively in either the operative or inoperative position.
Claim 4
Dependent Claim
59 words
A viewer as in claim 1 wherein the movable lower casing part carries light shield means that telescope into the upper casing when the lower casing part is in its inoperative, stored-away position, and which cooperate with the upper casing to substantially exclude exterior light from the interior of the viewer when the lower casing part is operatively deployed.
Claim 5
Dependent Claim
62 words
A viewer as in claim 3 wherein spring means are carried within the upper casing and are positioned to be engaged by a portion of the shield means on the lower casing part when the lower casing part is in stored-away position, and said spring means cooperating with the shield means tending to urge the lower casing part towards its deployed position.
Claim 6
Dependent Claim
55 words
A viewer as in claim 1 including means on the lower casing part arranged for cooperation with portions of the upper casing so as to locate the second mirror means at a precise attitude relative to the first mirror means and to the viewing screen when the lower casing part is in its deployed position.
Claim 7
Dependent Claim
55 words
A viewer as in claim 3 wherein abutments are provided on the light shield means which cooperate with portions of the upper casing to locate the second mirror means substantially at a precise attitude relative to the first mirror means and to the viewing screen when the lower casing part is in its deployed position.
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) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |