US3754815A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotatable mirror angular position electronic measuring system for activating a digital display
Assignee: Del Mar Engineering Laboratories
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Filing: 1972-03-17
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Granted: 1973-08-28
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Expires: 1992-03-17
Abstract
Abstract An electronic measuring system is provided which measures the angular position of a rotatable mirror so as to provide an electrical output signal suitable for activating a digital display, or for introduction into a computer for further processing. The mirror, for example, may be incorporated into a galvanometer, gas analyzer, or other measuring instrument. In the practice of the invention, a moving light spot is directed to the mirror for reflection thereby to a photo-detector assembly. The reflected light spot reaches the photo-detector after a time interval which is dependent upon the angular position of the mirror, so that an electrical output signal representative of the angular position of the mirror may be obtained.
Inventors
- 👤 C Sanctuary
- 👤 D Woods
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:10
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/28; G01D5/30; G01R; G01R13/00; G01R13/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
180 words
An electro-optical reflective angular position measuring system incluDing: a measuring unit having a mirror therein rotatable about an axis and whose angular position with respect to said axis is an indication of a value being measured; a light source mounted with respect to said measuring unit so as to direct a beam of light towards said mirror and reflect said light beam therefrom, and including means for moving the light beam along a line lying essentially in a plane perpendicular to said axis producing a light beam trace discernible at the mirror; a photodetector assembly positioned to receive the light from said source as reflected by said mirror and for producing an electric output signal in response thereto; means interposed between said mirror and said photo-detector assembly for causing only a portion of the reflected trace to reach said photo-detector assembly; and means for comparing said electric output signal with said light beam trace to determine which portion of said reflected trace is being detected, said comparing means indicating the angular position of said mirror with respect to said axis.
Claim 2
Dependent Claim
180 words
An electro-optical reflective angular position measuring system incluDing: a measuring unit having a mirror therein rotatable about an axis and whose angular position with respect to said axis is an indication of a value being measured; a light source mounted with respect to said measuring unit so as to direct a beam of light towards said mirror and reflect said light beam therefrom, and including means for moving the light beam along a line lying essentially in a plane perpendicular to said axis producing a light beam trace discernible at the mirror; a photodetector assembly positioned to receive the light from said source as reflected by said mirror and for producing an electric output signal in response thereto; means interposed between said mirror and said photo-detector assembly for causing only a portion of the reflected trace to reach said photo-detector assembly; and means for comparing said electric output signal with said light beam trace to determine which portion of said reflected trace is being detected, said comparing means indicating the angular position of said mirror with respect to said axis.
Claim 3
Dependent Claim
34 words
The measuring system defined in claim 1, in which said last-named means includes a plate having a pinhole therein, and a lens system for focusing said portion of the reflected light into said pinhole.
Claim 4
Dependent Claim
15 words
The system defined in claim 1, in which said light source comprises a cathode-ray tube.
Claim 5
Dependent Claim
28 words
The system defined in claim 3, and which includes an electric circuit responsive to input clock pulses for causing the light periodically to be scanned along said line.
Claim 6
Dependent Claim
65 words
The system defined in claim 4, and which includes a bistable flip-flop circuit responsive to said input clock pulses to be set to a first state, and responsive to the output from said photo-detector to be set to a second state, said bistable flip-flop circuit producing an output pulse having a width proportional to the angular position of said mirror with respect to said axis.
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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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |