US3869207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser telemeter
Assignee: Alcatel Lucent SAS
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Filing: 1973-05-30
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Granted: 1975-03-04
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Expires: 1993-05-30
Abstract
Abstract Laser telemeter comprising a receiving photo-diode polarised in a break-down state and a servo-adjusting device regulating the polarisation voltage of that photo-diode at a level which may cause the triggering of a chronometer device receiving the pulses of that photo-diode. That telemeter comprises, moreover, a device for temporarily lowering that polarisation voltage during the interval of time separating the emission of a laser pulse and the receiving thereof on the photo-diode.
Inventors
- 👤 Pierre Hermet
- 👤 Rodolphe Laesser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:27
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/48; G01S7/483; G01S7/486; G01S7/4861
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
278 words
Laser telemeter comprising: A laser generator capable of emitting a light pulse towards a target; A photo-sensitive receiver constituted by a photodiode to receive an echo of said light pulse, said photo-diode operating in the breakdown region; A threshold device responsive to the electric output pulses of said photodiode for blocking the electric pulses having a level lower than a predetermined threshold and for transmitting the electric pulses having a level higher than said predetermined threshold; A measuring device triggered at the instant of emission of said light pulse and responsive to the electric pulses transmitted by said threshold device for measuring the interval of time separating the emission of said light pulse and the receiving of the electric pulse transmitted by said threshold device; A servo-adjusting device receiving the output noise of said photo-diode and controlling the reverse polarization voltage in the breakdown state of said photo-diode to be maintained at a first level so as to hold said noise at a constant value, said first level being sufficiently high to enable the operation of the servo-adjusting device; A device for lowering temporarily the bias level of said photodiode, the duration of said lowering being less than the response time of said servoadjusting device; Characterized in that said temporary lowering device comprises means for holding said reverse polarization voltage at a second level during the interval of time separating the emission of said light pulse and the receiving thereof by sid photo-diode, said second level being lower than said first level but sufficiently high for the level of the electric pulse sent out by said photodiode on receiving said echo to be higher than said predetermined threshold.
Claim 2
Dependent Claim
278 words
Laser telemeter comprising: A laser generator capable of emitting a light pulse towards a target; A photo-sensitive receiver constituted by a photodiode to receive an echo of said light pulse, said photo-diode operating in the breakdown region; A threshold device responsive to the electric output pulses of said photodiode for blocking the electric pulses having a level lower than a predetermined threshold and for transmitting the electric pulses having a level higher than said predetermined threshold; A measuring device triggered at the instant of emission of said light pulse and responsive to the electric pulses transmitted by said threshold device for measuring the interval of time separating the emission of said light pulse and the receiving of the electric pulse transmitted by said threshold device; A servo-adjusting device receiving the output noise of said photo-diode and controlling the reverse polarization voltage in the breakdown state of said photo-diode to be maintained at a first level so as to hold said noise at a constant value, said first level being sufficiently high to enable the operation of the servo-adjusting device; A device for lowering temporarily the bias level of said photodiode, the duration of said lowering being less than the response time of said servoadjusting device; Characterized in that said temporary lowering device comprises means for holding said reverse polarization voltage at a second level during the interval of time separating the emission of said light pulse and the receiving thereof by sid photo-diode, said second level being lower than said first level but sufficiently high for the level of the electric pulse sent out by said photodiode on receiving said echo to be higher than said predetermined threshold.
Claim 3
Dependent Claim
61 words
Telemeter according to claim 1, characterised in that the said temporary lowering device comprises, moreover, means for lowering, during a portion of said interval of time, the said polarisation voltage to a third level lower than the said second level and sufficiently low for the level of the output pulses of the said photo-diode to be lower than the pre-determined threshold.
References Cited (Backward Citations)
US3516751A
Cited
US3666367A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |