US3788741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distance indicating optical probe
Assignee: Systems Research Laboratories Inc
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Filing: 1972-07-26
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Granted: 1974-01-29
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Expires: 1992-07-26
Abstract
Abstract An optical probe for monitoring the distance to an object includes at least a pair of fiber optic bundles, each bundle having the image of its end surface focused at a plane preferably located on either side of the normal position of an object. Each fiber optic bundle includes one or more fibers used as a receiver and one or more additional fibers used as light transmitters. When the image of the end of the fiber optic bundle is in focus on the object, the light observed by the receiving fiber is at a minimum. As the focus is changed, light from the transmitting fibers will increasingly cover the area observed by the receiving fibers, the intensity of the received light being a function of the out-of-focus distance. By using a pair of optical fiber bundles, the surface of which are focused at different planes, an unambiguous output may be obtained which can be converted directly into a distance measurement from the probe to an object under observation. Reflectivity of the surface of the object may be compensated for by comparing the light received by the receiving optical fibers. In one alternative embodiment, an image is formed by a single transmitter-receiver combination and the focal distance is modified by means of a high index of refraction material which is periodically interposed in the light path. In other embodiments, a beam splitter is used with two transmitterreceiver combinations and the light sources are separated by a means such as, by alternately switching the lights and detectors on and off, by light filters, or by use of polarized light.
Inventors
- 👤 L Buechler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:06
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/026; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/08
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
122 words
Distance measuring apparatus comprising projection means directing at least a pair of focused light patterns at an object, each said light pattern having a predetermined geometric shape and being focused by said projection means at a pair of axially spaced planes, each said pattern being characterized by at least one relatively dark area which area is most precisely defined only at the associated plane of focus thereof, detector means responsive to light falling in said dark areas on said object and providing a pair of electric signals which varies with variations in distance of said object from each of said planes, and signal comparing means providing an indication of the axial spacing of said object from the median distance between said planes.
Claim 2
Dependent Claim
122 words
Distance measuring apparatus comprising projection means directing at least a pair of focused light patterns at an object, each said light pattern having a predetermined geometric shape and being focused by said projection means at a pair of axially spaced planes, each said pattern being characterized by at least one relatively dark area which area is most precisely defined only at the associated plane of focus thereof, detector means responsive to light falling in said dark areas on said object and providing a pair of electric signals which varies with variations in distance of said object from each of said planes, and signal comparing means providing an indication of the axial spacing of said object from the median distance between said planes.
Claim 3
Dependent Claim
30 words
The apparatus of claim 1 wherein said projecting and detector means comprise a pair of separate projectors and a corresponding pair of separate detectors forming a pair of projector-detector combinations.
Claim 4
Dependent Claim
48 words
The apparatus of claim 1 in which said projection means comprises a single projector and said detector means comprises a single detector aligned essentially on an optical path in common with said projector, and image shifting means movable selectively in said path defining said axially spaced image planes.
Claim 5
Dependent Claim
61 words
The apparatus of claim 1 further comprising a projection lens, said projection and detector means comprise a pair of separate projectors and a corresponding pair of separate detectors forming a pair of projector-detector combinations located on a common optical path to said lens, beam splitting means interposed between said lens and said projector-detector pair, and means alternately activating said projector-detector combinations.
Claim 6
Dependent Claim
65 words
The apparatus of claim 1 further comprising a projection lens, said projection and detector means comprise a pair of separate projectors and a corresponding pair of separate detectors forming a pair of projector-detector combinations located on a common optical path to said lens, beam splitting means interposed between said lens and said projector-detector pair, and filter means in separate light paths activating said projector-detector combinations.
Claim 7
Dependent Claim
46 words
The apparatus of claim 2 further comprising a projection lens, and each of said projector-detector combinations being incorporated in separate fiber-optic bundles having terminal ends, said lens arranged to project the images of said bundle terminal ends defining said light patterns in said axially spaced planes.
Claim 8
Dependent Claim
19 words
The apparatus of claim 5 in which bundle terminal ends are positioned in closely adjacent but axially spaced relation.
Claim 9
Dependent Claim
38 words
The apparatus of claim 5 wherein each of said fiber optic bundles includes a central optical fiber functioning as a detector and a plurality of optIcal fibers functioning as light transmitters positioned adjacent to and surrounding said detector.
Claim 10
Dependent Claim
91 words
The apparatus of claim 1 wherein said light patterns are formed by at least a pair of fiber optic bundles terminating in a pair of axially spaced planes, each of said bundles including a centrally positioned fiber defining a receiving element and a plurality of peripherally arranged fibers surrounding said central fiber defining light transmitting fibers, and wherein the intensity of the light image of said transmitting fibers falling within the image of said light receiving fiber is a function of the distance of the object from the plane of focus.
Claim 11
Dependent Claim
223 words
High resolution optical distance measuring apparatus for measuring the displacement of an object from a given position along an optical axis, comprising first detector means including first light image forming means defining a light image of predetermined shape at a first plane displaced on one axial side of said position and optical sensor means focused on said first plane in the region of said image and being responsive to an out-of-focus condition thereof on either side of said first plane; second detector means including second light image forming means defining a second light image of predetermined shape at a second plane axially spaced from and at the axially opposite side of said position, and second optical sensor means focused on said second plane in the region of said second light image and responsive to an out-of focus condition thereof on either side of said second plane; each of said detector means further including transducer means providing electric signals proportional to the degree of deviation or displacement of an image formed on said object from said given position; control means providing a pair of electrical output signals representative of the deviation of said object from each of said planes; and comparison means responsive to the difference between said output signals providing an indication of the actual displacement of said object from said given position.
Claim 12
Dependent Claim
223 words
High resolution optical distance measuring apparatus for measuring the displacement of an object from a given position along an optical axis, comprising first detector means including first light image forming means defining a light image of predetermined shape at a first plane displaced on one axial side of said position and optical sensor means focused on said first plane in the region of said image and being responsive to an out-of-focus condition thereof on either side of said first plane; second detector means including second light image forming means defining a second light image of predetermined shape at a second plane axially spaced from and at the axially opposite side of said position, and second optical sensor means focused on said second plane in the region of said second light image and responsive to an out-of focus condition thereof on either side of said second plane; each of said detector means further including transducer means providing electric signals proportional to the degree of deviation or displacement of an image formed on said object from said given position; control means providing a pair of electrical output signals representative of the deviation of said object from each of said planes; and comparison means responsive to the difference between said output signals providing an indication of the actual displacement of said object from said given position.
Claim 13
Dependent Claim
40 words
The apparatus of claim 10 including lens means defining each of said images into a given pattern of light and dark areas, and said sensor means being responsive through said lens means principally to the dark areas of said patterns.
Claim 14
Dependent Claim
27 words
The apparatus of claim 11 in which said pattern defining means comprises an annular reflector, and said detector is responsive to light received through the reflector annulus.
Claim 15
Dependent Claim
32 words
The apparatus of claim 11 in which said pattern defining means comprises an array of transmitter and receiver optical fibers, and said detector means is connected to receive through said receiving fibers.
Claim 16
Dependent Claim
72 words
The apparatus of claim 10 further including circuit means responsive to the sum of said output signals to provide a measurement of the reflectivity of the surface of said object, and further circuit means for dividing a signal representing the difference between said output signals by the sum of said output signals to provide an output representing the distance which is substantially independent of reflectivity or the intensity of the light images.
Claim 17
Dependent Claim
65 words
The apparatus of claim 10 further including separate detector means for sensing the light reflected from the surface of said object, and circuit means for dividing a signal representing the difference between said output signals by the output of said separate detector means to provide a distance measurement which is substantially independent of either reflectivity of the object or the intensity of said light images.
Claim 18
Independent Claim
142 words
The method of measuring the distance along an axis of an object from a desired position comprising the steps of: focusing a light image of a predetermined shape on a plane axially spaced to one side of said position, measuring the light reflected from an object on said axis in a pattern complementary to said light image pattern as an indication of displacement of said object from said plane; forming a sEcond light image of predetermined shape on a second plane axially spaced to the other side of said position; measuring the light reflecting from said object in a pattern complementary to said second light pattern as an indication of the displacement of said object from said second plane; and comparing the intensity of said reflector light patterns as an indication of the total displacement of said object from said desired position.
Claim 19
Independent Claim
142 words
The method of measuring the distance along an axis of an object from a desired position comprising the steps of: focusing a light image of a predetermined shape on a plane axially spaced to one side of said position, measuring the light reflected from an object on said axis in a pattern complementary to said light image pattern as an indication of displacement of said object from said plane; forming a sEcond light image of predetermined shape on a second plane axially spaced to the other side of said position; measuring the light reflecting from said object in a pattern complementary to said second light pattern as an indication of the displacement of said object from said second plane; and comparing the intensity of said reflector light patterns as an indication of the total displacement of said object from said desired position.
Claim 20
Dependent Claim
22 words
The method of claim 16 in which said light images are focused at equal distances on either side of said predetermined position.
Claim 21
Dependent Claim
15 words
The method of claim 16 in which each of said light image patterns are identical.
Claim 22
Dependent Claim
38 words
The method of claim 16 in which said comparing step includes forming electric signals corresponding to the intensities of said reflected light from said patterns and taking the difference of said signal as representative of said total displacement.
Claim 23
Dependent Claim
31 words
The method of claim 19 including the further step of dividing said difference signal by the sum of said signals to eliminate error due to variations in reflectivity of said object.
References Cited (Backward Citations)
US3719421A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |