Patent US4479706A successfully refreshed from Google Patents.
US4479706A
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Distance measuring circuit
Assignee: Ricoh Co Ltd
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Filing: 1981-09-03
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Granted: 1984-10-30
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Expires: 2001-09-03
Abstract
Abstract A distance measuring circuit controls in a given sequence a distance measuring operation in which a light beam is periodically projected to a target by means of a light projector and reflected light from the target is received by a light receiver, the output signal of which is utilized to determine the distance to the target. When the light projector is not energized, a capacitor is charged by a d.c. source, and discharges to drive the light projector when the light beam is to be projected.
Inventors
- 👤 Akira Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:36
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/30; G02B7/32; G01; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/08; G01S17/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
183 words
A distance measuring circuit comprising: a light projector means for projecting a light beam toward a target; a light receiver means for receiving reflected light from said target and outputting a signal; means for determining the level of said output signal from said light receiver wherein said determining means includes a noise elimination means for eliminating noises in said output signal from said light receiver means by means of a digital processing means, whereby the operation of said light projector means, said light receiver means and said determining means is controlled in a predetermined sequence by a control means; and a conversion circuit for converting said signal from said light receiver means into a binary digital signal, and wherein said noise elimination means detects the frequency of occurrence of a high level and a low level in the digital signal from said conversion circuit, the high and the low level being in a predetermined zone, and wherein the output of said noise elimination means is determined to be one of a high and a low level in accordance with said frequency of occurrence.
Claim 2
Dependent Claim
183 words
A distance measuring circuit comprising: a light projector means for projecting a light beam toward a target; a light receiver means for receiving reflected light from said target and outputting a signal; means for determining the level of said output signal from said light receiver wherein said determining means includes a noise elimination means for eliminating noises in said output signal from said light receiver means by means of a digital processing means, whereby the operation of said light projector means, said light receiver means and said determining means is controlled in a predetermined sequence by a control means; and a conversion circuit for converting said signal from said light receiver means into a binary digital signal, and wherein said noise elimination means detects the frequency of occurrence of a high level and a low level in the digital signal from said conversion circuit, the high and the low level being in a predetermined zone, and wherein the output of said noise elimination means is determined to be one of a high and a low level in accordance with said frequency of occurrence.
Claim 3
Dependent Claim
30 words
A distance measuring circuit according to claim 1 in which hysteresis is produced between said frequency of occurrence and the level of said output signal from said noise elimination means.
References Cited (Backward Citations)
US4032934A
Cited
US4256995A
Cited
US4268137A
Cited
US4313655A
Cited
US4303319A
Cited
US4298258A
Cited
US4344024A
Cited
US4300824A
Cited
US4302084A
Cited
US4357083A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-30 | 1988-04-30 | 1988-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-30 | 1992-04-30 | 1992-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-30 | 1996-04-30 | 1996-10-30 | $7700.00 | Window Closed / Lapsed |