US3652160A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light beam rangefinder
Assignee: Paillard SA
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Filing: 1969-09-15
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Granted: 1972-03-28
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Expires: 1989-09-15
Abstract
Abstract A rangefinder comprises a projector furnishing a modulated light beam directed on to the object to be ranged and a receiver to pick up the reflected rays. The rangefinder is designed to avoid disturbances of the readings by chance interference signals. The receiver has a photoelectric cell at the front and rear of a mirror on to which some of the reflected rays are converged by a lens. The photocells are mounted for axial displacement so as to adjust for equal light reception according to the convergence and hence the range of the rays reflected from the object. The signals from the photocells are cut off and connected by a device actuated in rhythm to conform to a constant phase relationship with the light beam modulation. The cut off device connects the receiver to a storage device for the measured signals in which the stored sums of the interfering signals give a substantially nil value. The storage device is an RC element whose time constant is several times that of the beam modulation. The circuit includes a differential amplifier. Output signals from ''''gate'''' circuits control the axial displacements of the photocells by supplying a motor driving a threaded shaft bearing a tapped nut supporting the photocells. A camera incorporating the rangefinder has an objective adjustment ring coupled to respond to rotation of the shaft.
Inventors
- 👤 Giovanni Odone
- 👤 Heinrich Kunz
- 👤 Willy Buch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:10
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/48; G01S7/491; G01S7/493; G01S17/00; G01S17/02; G01S17/06; G01S17/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
144 words
A rangefinder comprising a projector furnishing a modulated light beam directed on to the object whose distance is to be determined, a receiver adapted to pick up the rays of said modulated light beam reflected by the object, said rays being subject to disturbances arising from chance interference signals, said receiver comprising at least one photoelectric element furnishing an electrical signal in response to the reflected light rays, said rangefinder comprising a make-and-break device for cutting off and connecting the signal furnished by the receiver, said device being actuated in rhythm with the modulation of the light beam by having a constant phase relationship with respect to said modulation, said make-and-break device connecting the receiver to a storage device for the measured signals and for the interference signals as well, in which the stored sums of the interference signals give an appreciably nil value.
Claim 2
Dependent Claim
144 words
A rangefinder comprising a projector furnishing a modulated light beam directed on to the object whose distance is to be determined, a receiver adapted to pick up the rays of said modulated light beam reflected by the object, said rays being subject to disturbances arising from chance interference signals, said receiver comprising at least one photoelectric element furnishing an electrical signal in response to the reflected light rays, said rangefinder comprising a make-and-break device for cutting off and connecting the signal furnished by the receiver, said device being actuated in rhythm with the modulation of the light beam by having a constant phase relationship with respect to said modulation, said make-and-break device connecting the receiver to a storage device for the measured signals and for the interference signals as well, in which the stored sums of the interference signals give an appreciably nil value.
Claim 3
Dependent Claim
35 words
A rangefinder according to claim 1, wherein said storage device is constituted by an RC element whose time constant is several times greater than the duration of a period of the modulation of the beam.
Claim 4
Dependent Claim
66 words
A rangefinder according to claim 2, comprising two photoconductors connected respectively to two inputs of a differential amplifier, one output of which is connected to a terminal of a condenser of which the other terminal is connected to a resistance to form said RC element, the two terminals of the condenser being connected to earth by two electronic interruptors controlled so as to be alternately conductive.
Claim 5
Dependent Claim
180 words
A rangefinder according to claim 2, comprising at least one differential amplifier of which the two inputs are connected to two photoconductors furnishing two signals of opposite signs, said two photoconductors being displaceable to enable the determination of the point of convergence of the reflected rays picked up by the receiver, said differential amplifier comprising two make-and-break devices actuated in phase opposition with respect to one another, each device acting on one of the said signals so as to furnish pulses of one polarity for one of the signals and of the other polarity for the other signal, said pulses of each polarity being applied to the input of a trigger at an input threshold, the output of said trigger is applied to a differentiator, the pulses of alternate polarities furnished by said differentiator being applied to two ''''gate'''' circuits controlled respectively in phase and counter-phAse with the modulation of the light beam, the output signals of one of said gate circuit and of the other controlling the displacements of the photoconductors in one direction and the other direction respectively.
Claim 6
Dependent Claim
31 words
A rangefinder according to claim 4, including displacement means for said photoconductors comprising an electric motor driving a threaded shaft, a tapped nut riding on said shaft and supporting the photoconductors.
Claim 7
Dependent Claim
180 words
A rangefinder comprising a projector furnishing a modulated light beam directed on the object whose distance is to be determined, a receiver adapted to pick up the rays of said modulated light beam reflected by the object, said rays being subject to disturbances arising from chance interference signals, said receiver comprising two photoconductors furnishing electrical signals in response to the reflected light rays, said two photoconductors being each connected to two resistances to form therewith a bridge, a differential amplifier having two input transistors, two condensers each connected to one of said two input transistors to apply thereto the output signal of said bridge, said rangefinder comprising a make-and-break device for cutting off and connecting the signal furnished by the receiver, said device being actuated in rhythm with the modulation of the light beam by having a constant phase relationship with respect to said modulation, said make-and-break device connecting the receiver to a storage device for the measured signals and for the interference signals as well, in which the stored sums of the interference signals give an appreciably nil value.
Claim 8
Dependent Claim
180 words
A rangefinder comprising a projector furnishing a modulated light beam directed on the object whose distance is to be determined, a receiver adapted to pick up the rays of said modulated light beam reflected by the object, said rays being subject to disturbances arising from chance interference signals, said receiver comprising two photoconductors furnishing electrical signals in response to the reflected light rays, said two photoconductors being each connected to two resistances to form therewith a bridge, a differential amplifier having two input transistors, two condensers each connected to one of said two input transistors to apply thereto the output signal of said bridge, said rangefinder comprising a make-and-break device for cutting off and connecting the signal furnished by the receiver, said device being actuated in rhythm with the modulation of the light beam by having a constant phase relationship with respect to said modulation, said make-and-break device connecting the receiver to a storage device for the measured signals and for the interference signals as well, in which the stored sums of the interference signals give an appreciably nil value.
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) | 1975-03-28 | 1975-09-27 | 1976-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-28 | 1979-09-27 | 1980-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-28 | 1983-09-27 | 1984-03-28 | $7700.00 | Window Closed / Lapsed |