US3770965A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photosensitive control apparatus with movable light control member
Assignee: Lewis Engineering Co
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Filing: 1972-05-01
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Granted: 1973-11-06
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Expires: 1992-05-01
Abstract
Abstract A novel control device for use in a servo apparatus of the type employing a galvanometer movement connected in a servo feedback loop arrangement. The device comprises a photosensitive transducer having an expansive sensing surface, means providing a beam of light to strike said surface, and a movable, tapered light-control member disposed in the path of the light beam to produce illuminated areas disposed on either side of an elongate shadowed area on the sensing surface. The relative size of the illuminated and shadowed areas changes in response to movement of the member, thus varying the transducer response. The control device is employed in a servo apparatus comprising a bridge circuit, one leg of which includes the photosensitive transducer and the other leg of which contains a condition-responsive transducer. Amplifying means are provided, having input terminals connected with the bridge to receive signals therefrom and having output terminals connected to a galvanometer to drive the latter. The light control member is directly carried by the galvanometer movement. Any change in the output of the condition-responsive transducer is sensed by the amplifiers, which drive the glavanometer upscale (or downscale), thus changing the position of the light control member in such a way as to direct more (or less) light on the photosensitive transducer and thereby reestablish balance of the bridge. In this way, changes of the condition-responsive transducer are reflected by a corresponding change in the position of the galvanometer, which can be calibrated in convenient units intended to form the basis for the particular measurement desired.
Inventors
- 👤 H Edwards
- 👤 S Bottorf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:38
CPC Classifications
G; G01; G01B; G01B11/00; G01J; G01J1/00; G01J1/42
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
137 words
A control apparatus comprising in combination: a. a photosensitive device having an expansive sensing surface, b. electrically energized means providing a beam of constant light to strike said sensing surface and illuminate the same, c. movable means interposed in the path of said beam for producing a defined elongate shadowed area on said sensing surface bounded on both sides by illuminated areas of said surface, d. said movable means producing a pair of spaced apart lines of separation between the shadowed area and the illuminated areas the spacing of which varies in accordance with a predetermined pattern whereby the expanse of the illuminated areas on the sensing surface continuously varies in response to gradual movement of said movable means, thus altering the response of the photosensitive device as the movable member changes its position with respect thereto.
Claim 2
Dependent Claim
137 words
A control apparatus comprising in combination: a. a photosensitive device having an expansive sensing surface, b. electrically energized means providing a beam of constant light to strike said sensing surface and illuminate the same, c. movable means interposed in the path of said beam for producing a defined elongate shadowed area on said sensing surface bounded on both sides by illuminated areas of said surface, d. said movable means producing a pair of spaced apart lines of separation between the shadowed area and the illuminated areas the spacing of which varies in accordance with a predetermined pattern whereby the expanse of the illuminated areas on the sensing surface continuously varies in response to gradual movement of said movable means, thus altering the response of the photosensitive device as the movable member changes its position with respect thereto.
Claim 3
Dependent Claim
53 words
A control apparatus as in claim 1, wherein: a. said movable means comprises an elongate opaque member for blocking a portion of the light beam passing from said electrically energized means to said photosensitive device, and b. means turnably mounting said opaque member for movement across the path of said beam of light.
Claim 4
Dependent Claim
22 words
A control apparatus as in claim 2, wherein: a. said opaque member comprises a segment of the lateral surface of a cylinder.
Claim 5
Dependent Claim
15 words
A control apparatus as in claim 2, wherein: a. said opaque member is substantially crescent-shaped.
Claim 6
Dependent Claim
22 words
A control apparatus as in claim 1, wherein: a. the illuminated areas on the sensing surface are substantially coextensive with each other.
Claim 7
Dependent Claim
54 words
A control apparatus as in claim 1, wherein: a. said movable member comprises a substantially flat sheet having a transparent portion through which light can pass, and an elongate opaque portion located in said transparent portion, and b. means mounting said member for rotation about an axis perpendicular to the plane of the sheet.
Claim 8
Dependent Claim
16 words
A control apparatus as in claim 6, wherein: a. said opaque portion has a wedge-like configuration.
Claim 9
Dependent Claim
21 words
A control apparatus as in claim 7, wherein: a. the width of the opaque portion varies according to a predetermined pattern.
Claim 10
Dependent Claim
56 words
A control apparatus as in claim 1, wherein: a. said movable member comprises a substantially flat sheet having a light reflecting portion and an elongate light-absorbing portion, b. said light reflecting portion producing illumination on said sensing surface, and c. means mounting said member for rotation about an axis perpendicular to the plane of the sheet.
Claim 11
Dependent Claim
21 words
A control apparatus as in claim 9, wherein: a. said light-absorbing portion has a wedge-like configuration disposed within said reflecting portion.
Claim 12
Dependent Claim
158 words
A control apparatus as in claim 1, and further including: a. a bridge having four legs which constitute interrelated circuits, b. condition-responsive means connected with one leg of said bridge for effecting an unbalance of the latter in response to changes in a condition, c. said bridge having terminals comprising output means connected to said legs, d. amplifying means having input and output circuitry, said input circuitry being connected to said output means to receive energy therefrom, e. said photosensitive device being connected with said bridge output means, f. a galvanometer connected to the output circuitry of the amplifying means to be operated thereby, g. said movable means comprising a light-control member coupled to the galvanometer to be Actuated thereby, whereby any change in said condition which causes an unbalance of the bridge results in a deflection of the galvanometer to alter the light striking said photosensitive device in a manner that causes reestablishment of the bridge balance.
Claim 13
Dependent Claim
26 words
A control apparatus as in claim 11, wherein: a. the light-control member is carried directly by the moving system of the galvanometer and has arcuate movement.
Claim 14
Dependent Claim
287 words
A control apparatus comprising in combination: a. a photosensitive device having an expansive sensing surface, b. electrically energized means providing a beam of constant light to strike said sensing surface and illuminate the same, c. movable means interposed in the path of said beam for producing a defined elongate shadowed area on said sensing surface bounded on both sides by illuminated areas of said surface, d. said movable means producing a pair of spaced apart lines of separation between the shadowed area and the illuminated areas the spacing of which varies in accordance with a predetermined pattern whereby the expanse of the illuminated areas on the sensing surface continuously varies in response to gradual movement of said movable means, thus altering the response of the photosensitive device as the movable member changes its position with respect thereto, e. a bridge having four legs which constitute interrelated circuits, f. condition-responsive means connected with one leg of said bridge for effecting an unbalance of the latter in response to changes in a condition, g. said bridge having terminals comprising output means connected to said legs, h. amplifying means having input and output circuitry, said input circuitry being connected to said output means to receive energy therefrom, i. said amplifying means comprising a positioning amplifier and a null amplifier, j. a galvanometer connected to the output circuitry of said amplifiers to be energized and actuated therefrom, k. said movable means comprising a light-control member coupled to the galvanometer to be actuated thereby, whereby any change in said condition which causes an unbalance of the bridge results in a deflection of the galvanometer to alter the light striking said photosensitive device in a manner that causes reestablishment of the bridge balance.
Claim 15
Dependent Claim
287 words
A control apparatus comprising in combination: a. a photosensitive device having an expansive sensing surface, b. electrically energized means providing a beam of constant light to strike said sensing surface and illuminate the same, c. movable means interposed in the path of said beam for producing a defined elongate shadowed area on said sensing surface bounded on both sides by illuminated areas of said surface, d. said movable means producing a pair of spaced apart lines of separation between the shadowed area and the illuminated areas the spacing of which varies in accordance with a predetermined pattern whereby the expanse of the illuminated areas on the sensing surface continuously varies in response to gradual movement of said movable means, thus altering the response of the photosensitive device as the movable member changes its position with respect thereto, e. a bridge having four legs which constitute interrelated circuits, f. condition-responsive means connected with one leg of said bridge for effecting an unbalance of the latter in response to changes in a condition, g. said bridge having terminals comprising output means connected to said legs, h. amplifying means having input and output circuitry, said input circuitry being connected to said output means to receive energy therefrom, i. said amplifying means comprising a positioning amplifier and a null amplifier, j. a galvanometer connected to the output circuitry of said amplifiers to be energized and actuated therefrom, k. said movable means comprising a light-control member coupled to the galvanometer to be actuated thereby, whereby any change in said condition which causes an unbalance of the bridge results in a deflection of the galvanometer to alter the light striking said photosensitive device in a manner that causes reestablishment of the bridge balance.
Claim 16
Dependent Claim
27 words
A control apparatus as in claim 13, wherein: a. the light control member is carried directly by the moving system of the galvanometer and has arcuate movement.
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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) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |