US4479706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
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 01:59
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.
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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 |