US4888477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Range measurement for active optical recognition devices
Assignee: Lockheed Martin Corp
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Filing: 1988-11-03
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Granted: 1989-12-19
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Expires: 2008-11-03
Abstract
Abstract An inexpensive, reliable analog ramped-voltage timing device (34, 36, 38, 40, 44) can be used in a laser echo ranging device capable of resolution in the decimeter range by using a very steep ramp (42), and a flash A/D converter (50) to instantaneouly sample the ramped voltage upon receipt of the laser echo.
Inventors
- 👤 Donald B. Nankivil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:55
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/08; G01S17/10; G01S17/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
180 words
A laser range echo device for measuring distances in the decimeter range, comprising: (a) laser beam transmitting means for transmitting a pulse of laser light toward a target; (b) start pulse generating means for generating a start pulse upon transmission of said laser pulse; (c) laser receiver means for generating a stop pulse in response to the receipt of the reflection of said laser light pulse from said target; (d) a high-speed switch arranged to be actuated for a predetermined time following the onset of said start pulse; (e) capacitive means for producing a ramp voltage in response to the actuation of said switch, said ramped voltage changing substantially linearly from a starting value to an ending value in a matter of nanoseconds; and (f) a flash A/D converter arranged to sample the instantaneous value of said ramped voltage in response to said stop pulse; (g) whereby said flash A/D converter provides a digital representation of said instantaneous value with an accuracy sufficient to digitally represent the travel distance of said laser light pulse in increments in the decimeter range.
Claim 2
Dependent Claim
180 words
A laser range echo device for measuring distances in the decimeter range, comprising: (a) laser beam transmitting means for transmitting a pulse of laser light toward a target; (b) start pulse generating means for generating a start pulse upon transmission of said laser pulse; (c) laser receiver means for generating a stop pulse in response to the receipt of the reflection of said laser light pulse from said target; (d) a high-speed switch arranged to be actuated for a predetermined time following the onset of said start pulse; (e) capacitive means for producing a ramp voltage in response to the actuation of said switch, said ramped voltage changing substantially linearly from a starting value to an ending value in a matter of nanoseconds; and (f) a flash A/D converter arranged to sample the instantaneous value of said ramped voltage in response to said stop pulse; (g) whereby said flash A/D converter provides a digital representation of said instantaneous value with an accuracy sufficient to digitally represent the travel distance of said laser light pulse in increments in the decimeter range.
Claim 3
Dependent Claim
24 words
The device of claim 1, further comprising a one-shot multivibrator which is triggered by said start pulse, and whose output actuates said high-speed switch.
Claim 4
Dependent Claim
33 words
The device of claim 1, further comprising a one-shot multivibrator triggered by said stop pulse, the output of said multivibrator being operatively applied to said flash A/D converter to sample said instantaneous value.
Claim 5
Dependent Claim
40 words
The device of claim 3, further comprising a delay line interposed between said multivibrator and said flash A/D converter to delay said multivibrator output so as to compensate for delays in the production and transmission of said ramp voltage signal.
Claim 6
Dependent Claim
69 words
The device of claim 1, further comprising: (h) a pair of multivibrators triggered, respectively, by said start and stop pulses to produce pulses of predetermined duration for operating said high-speed switch means and said flash A/D converter, said multivibrators being ECL logic devices while said switch means and converter are TTL logic devices, and (i) an ECL-to-TTL converter interposed, respectively, between said multivibrators and said switch means and converter.
Claim 7
Dependent Claim
28 words
The device of claim 5, further comprising: (j) a TTL delay line interposed between said ECL-to-TTL converter and said flash A/D converter for delaying said converter operating pulse.
Claim 8
Dependent Claim
17 words
The device of claim 1, further comprising limiting means for limiting the range of said ramp voltage.
Claim 9
Dependent Claim
16 words
The device of claim 1, further including a stable DC supply for said flash A/D converter.
References Cited (Backward Citations)
US4139301A
Cited
US4464048A
Cited
US4699508A
Cited
US4538907A
Cited
US4734587A
Cited
US4770526A
Cited
US4827317A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-18 | 1993-06-19 | 1993-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-18 | 1997-06-19 | 1997-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-18 | 2001-06-19 | 2001-12-19 | $7700.00 | Window Closed / Lapsed |