US3635135A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light-measuring means for microfilm camera
Assignee: Agfa Gevaert AG
•
Filing: 1970-02-18
•
Granted: 1972-01-18
•
Expires: 1990-02-18
Abstract
Abstract A light-measuring device for microfilm cameras which is adapted to measure in a point-by-point manner the brightness of an object plane. A small area of an object plane is projected by means of suitable light source via a measuring objective lens onto a measuring photoelectric cell. Light-conducting means are optically aligned with the objective lens and the light source. The photoelectric cell is mounted in the light-conducting means and has an end surface which is coplanar with an end surface of the light-conducting means. The measuring objective lens serves to also project a pattern of light defined by the shape of the end surface of the light-conducting means onto the object plane.
Inventors
- 👤 Kasimir Ambraschka
- 👤 Horst Bickl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:46
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/4209; G01J1/4219; G01J1/02; G01J1/04; G01J1/0407; G01J1/0455; G03; G03B; G03B27/00; G03B27/72; G01J1/0488
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
161 words
For use with a microfilm camera, a device for measuring the brightness of a predetermined area of an object plane, comprising in combination, a light source operatively mounted in said device, light-conducting means having a first end surface mounted in alignment with said light source in said device and a second end surface for producing in cooperation with said light source a pattern of light on said object plane indicative of the measuring field size, photoelectric measuring means having a front surface coplanar with said second end surface of said light-conducting means and being mounted within a recess in said light-conducting means, and objective lens means mounted in optical alignment with said light-conducting means and photoelectric measuring means, said light source being adapted to project a beam of light through said light-conducting means, thereby projecting a pattern of light defined by the shape of said second end surface of said light-conducting means via said objective lens means onto said object plane.
Claim 2
Dependent Claim
161 words
For use with a microfilm camera, a device for measuring the brightness of a predetermined area of an object plane, comprising in combination, a light source operatively mounted in said device, light-conducting means having a first end surface mounted in alignment with said light source in said device and a second end surface for producing in cooperation with said light source a pattern of light on said object plane indicative of the measuring field size, photoelectric measuring means having a front surface coplanar with said second end surface of said light-conducting means and being mounted within a recess in said light-conducting means, and objective lens means mounted in optical alignment with said light-conducting means and photoelectric measuring means, said light source being adapted to project a beam of light through said light-conducting means, thereby projecting a pattern of light defined by the shape of said second end surface of said light-conducting means via said objective lens means onto said object plane.
Claim 3
Dependent Claim
36 words
The device for measuring brightness of a predetermined area of an object plane as set forth in claim 1, wherein said light-conducting means is generally cylindrical and said recess is coaxially arranged within said light-conducting means.
Claim 4
Dependent Claim
43 words
The device for measuring the brightness of a predetermined area of an object plane as set forth in claim 2, wherein said second end surface is formed as an annular surface which is concentric with the front surface of said photoelectric measuring means.
Claim 5
Dependent Claim
46 words
The device for measuring the brightness of a predetermined area of an object plane as set forth in clAim 3, wherein said photoelectric measuring means includes a photoelectric cell having a cylindrical configuration said device further including a chamber in which said light source is disposed.
Claim 6
Dependent Claim
30 words
The device for measuring the brightness of a predetermined area of an object plane as set forth in claim 4, wherein said light-conducting means consists of a transparent cylindrical body.
Claim 7
Dependent Claim
37 words
The device for measuring the brightness of a predetermined area of an object plane as set forth in claim 5, wherein said recess is formed as a conical bore along the axis of said transparent cylindrical body.
Claim 8
Dependent Claim
35 words
The device for measuring the brightness of a predetermined area of an object plane as set forth in claim 1, including light-filter means mounted in said device between said object plane and said light-conducting means.
Claim 9
Dependent Claim
69 words
The device for measuring the brightness of a predetermined area of an object plane as set forth in claim 1, wherein said device is movably mounted with respect to said object plane, and including lens focusing means operatively connected to said objective lens means, said lens focusing means being adapted to adjust said objective lens means in accordance with the distance changes between the object plane and the device.
References Cited (Backward Citations)
US1864442A
Cited
US3068697A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |