US3755681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light operated variable impedance transducer
Assignee: Schneider Electric USA Inc
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Filing: 1971-12-17
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Granted: 1973-08-28
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Expires: 1991-12-17
Abstract
Abstract A light operated transducer having a light emitting diode as a light source and a photosensitive transistor as a light responsive element. The light input to the transistor is varied by a member which is movable between the diode and transistor and formed of transparent material to have shaded areas formed according to a predetermined pattern so the intensity of light input to the transistor is varied in response to the movement of the member.
Inventors
- 👤 R Montross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:08
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
201 words
A contactless variable impedance device comprising: a housing having an internal cavity and a passageway extending along a plane passing through the cavity and walls of the housing, a light source, a light responsive element having a pair of terminals and providing a change in resistive impedance between the terminals in response to a change in the intensity of a light input to the element, means mounting the light source and the light responsive element in the cavity at opposite sides of the plane so the light output from the light source passes through the plane and is transmitted as a light input to the light responsive element, a pair of laminated strip-like parts movable in the passage-way and having an elongated window movable in the passage-way between the light source and the light responsive element, a member positioned between the laminated parts and having a portion extending in the elongated window, said member being formed of a transparent material and said portion having a pattern thereon, said pattern varying from transparent to opaque for gradually the intensity of the light input to the light responsive element in stepless degrees in response to the movement of the member in the plane.
Claim 2
Dependent Claim
201 words
A contactless variable impedance device comprising: a housing having an internal cavity and a passageway extending along a plane passing through the cavity and walls of the housing, a light source, a light responsive element having a pair of terminals and providing a change in resistive impedance between the terminals in response to a change in the intensity of a light input to the element, means mounting the light source and the light responsive element in the cavity at opposite sides of the plane so the light output from the light source passes through the plane and is transmitted as a light input to the light responsive element, a pair of laminated strip-like parts movable in the passage-way and having an elongated window movable in the passage-way between the light source and the light responsive element, a member positioned between the laminated parts and having a portion extending in the elongated window, said member being formed of a transparent material and said portion having a pattern thereon, said pattern varying from transparent to opaque for gradually the intensity of the light input to the light responsive element in stepless degrees in response to the movement of the member in the plane.
Claim 3
Dependent Claim
18 words
The variable impedance device as recited in claim 1 wherein the member is a thin sheet of orthofilm.
Claim 4
Dependent Claim
28 words
The variable impedance device as recited in claim 1 wherein the pattern variation is provided by juxtaposed strip-like areas on the member which progressively vary step-by-step in transparency.
Claim 5
Dependent Claim
26 words
The variable impedance device as recited in claim 3 wherein the strip-like areas on the member are formed by opaque and transparent areas on the member.
Claim 6
Dependent Claim
36 words
The variable impedance device as recited in claim 4 wherein one of the strip-like areas is opaque and centrally located on the member between strip-like areas having transparent areas which are provided by spaced transparent dots.
Claim 7
Dependent Claim
30 words
The variable impedance device as recited in claim 4 wherein the strip-like areas having transparent dots are located between the opaque strip-like area and a transparent area of the member.
Claim 8
Dependent Claim
29 words
The variable impedance device as recited in claim 1 wherein the light source is provided by a light emitting diode and the light responsive element is a photosensitive transistor.
Claim 9
Dependent Claim
43 words
The variable impedance device as recited in claim 7 wherein the housing includes a molded block-like base and a cover and wherein the cavity and passageway are included in the base and the cover provides a mounting for the diode and the transistor.
Claim 10
Dependent Claim
28 words
The variable impedance device as recited in claim 8 wherein the pattern variation is provided by juxtaposed strip-like areas oN the member which progressively vary step-by-step in transparency.
Claim 11
Dependent Claim
26 words
The variable impedance device as recited in claim 9 wherein the strip-like areas on the member are formed by opaque and transparent areas on the member.
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) | 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 |