US3901607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High aperture reflection photodetector apparatus
Assignee: Xerox Corp
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Filing: 1974-02-21
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Granted: 1975-08-26
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Expires: 1994-02-21
Abstract
Abstract An optical sensing device to monitor the flow of cut sheet material is disclosed. A light source and photodetector are mounted on one side of the flow path and a concave reflector on the other side. In one embodiment, the reflector is spherical with its center of curvature midway between light source and photodetector. In another embodiment, the reflector is ellipsoidal having its foci at the light source and photodetector. In either case, the entire cone of light from the light source subtended by the reflector is directed to the photodetector. Material flowing in discrete units between the light sourcephotodetector and the reflector alternately closes and opens optical communication in the device for purposes of controlling some related function.
Inventors
- 👤 David O Kingsland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:00
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/65; B; B65; B65H; B65H7/00; B65H7/02; B65H7/14; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/62; G03B27/6207; G03B27/625; G03G2215/00; G03G2215/00362; G03G2215/00367; G03G2215/00371; G03G2215/00535; G03G2215/00611; G03G2215/00616; G03G2215/00717; G03G2215/00721
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
132 words
An optical sensing device for sensing the presence and absence of material flowing in discrete units alonG a flow path, including: a light source, a photodetector, an opaque divider between said light source and said photodetector, a reflector having a spherical reflecting surface, the center of curvature of said reflecting surface lying midway between said light source and said photodetector, said light source and said photodetector being respectively in object and image conjugate relationship with said reflector, said light source, photodetector, and divider being positioned on one side of said flow path, and said reflector being positioned on the opposite side of said flow path so that material flowing therealong in discrete units alternately closes and opens optical communication along an optical path including said light source, said reflector, and said photodetector.
Claim 2
Dependent Claim
132 words
An optical sensing device for sensing the presence and absence of material flowing in discrete units alonG a flow path, including: a light source, a photodetector, an opaque divider between said light source and said photodetector, a reflector having a spherical reflecting surface, the center of curvature of said reflecting surface lying midway between said light source and said photodetector, said light source and said photodetector being respectively in object and image conjugate relationship with said reflector, said light source, photodetector, and divider being positioned on one side of said flow path, and said reflector being positioned on the opposite side of said flow path so that material flowing therealong in discrete units alternately closes and opens optical communication along an optical path including said light source, said reflector, and said photodetector.
Claim 3
Dependent Claim
23 words
An optical sensing device as defined in claim 1 in which said light source, said photodetector, and said divider are an integral unit.
Claim 4
Dependent Claim
122 words
An optical sensing device for sensing the presence and absence of material flowing in discrete units along a flow path, including: a light source, a photodetector, an opaque divider between said light source and said photodetector, a reflector having a concave reflecting surface facing said light source and said photodetector, said light source and said photodetector being respectively in object and image conjugate relationship with said reflector, said light source, photodetector, and divider being positioned on one side of said flow path, and said reflector being positioned on the opposite side of said flow path so that material flowing therealong in discrete units alternately closes and opens optical communication along an optical path including said light source, said reflector, and said photodetector.
Claim 5
Dependent Claim
122 words
An optical sensing device for sensing the presence and absence of material flowing in discrete units along a flow path, including: a light source, a photodetector, an opaque divider between said light source and said photodetector, a reflector having a concave reflecting surface facing said light source and said photodetector, said light source and said photodetector being respectively in object and image conjugate relationship with said reflector, said light source, photodetector, and divider being positioned on one side of said flow path, and said reflector being positioned on the opposite side of said flow path so that material flowing therealong in discrete units alternately closes and opens optical communication along an optical path including said light source, said reflector, and said photodetector.
Claim 6
Dependent Claim
43 words
An optical sensing device as defined in claim 3 in which said concave reflecting surface is ellipsoidal being defined by two focal points, one of said focal points being at said light source, the other of said focal points being at said photodetector.
Claim 7
Dependent Claim
23 words
An optical sensing device as defined in claim 3 in which said light source, said photodetector, and said divider are an integral unit.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |