Patent US4677599A successfully refreshed from Google Patents.
US4677599A
Expired / Lapsed
US
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Ultra-sonic distance measuring apparatus and method
Assignee: Nissan Motor Co Ltd
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Filing: 1985-06-19
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Granted: 1987-06-30
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Expires: 2005-06-19
Abstract
Abstract An ultra-sonic sensor includes a driver circuit outputting a high-frequency driver signal which orders a transmitter to transmit ultra-sonic waves toward a target object. The driver circuit also sends the driver signal to a receiver. The driver signal is superimposed on a receiver signal. The receiver differentiates the receiver signal and compares the differentiated receiver signal level to a threshold level to detect reception of the reflected ultra-sonic wave. The receiver also detects when the transmitter is actively transmitting the ultra-sonic waves toward the object and disables the aforementioned comparison at such times. Accordingly, by comparing the differentiated receiver signal level with the threshold, the influence directly transmitted ultra-sonic waves on detection of the reflected ultra-sonic wave is successfully avoided. In addition, by interrupting the comparison during a period in which the transmitter is transmitting the ultra-sonic waves, the threshold level can be low enough to allow the system to detect the reflected ultra-sonic wave with great sensitivity.
Inventors
- 👤 Hiroaki Obayashi
- 👤 Hiroshi Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:05
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/02; G01S15/06; G01S15/08; G01S7/00; G01S7/52; G01S7/523; G01S7/526; G01S7/527; B; B60; B60G; B60G2400/00; B60G2400/25; B60G2400/252; B60G2400/80; B60G2400/82; B60G2400/821; B60G2401/00; B60G2401/17; B60G2401/176
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
171 words
An ultra-sonic distance measuring apparatus comprising: means for producing a trigger signal at a given timing and for a given duration; means for transmitting ultra-sonic waves toward an object in response to said trigger signal; means for receiving reflected ultra-sonic waves reflected by the object and producing a receiver signal having a value indicative of the amplitude of the received ultra-sonic waves; means for superimposing said trigger signal on said receiver signal to produce a superimposed signal; means for rectifying said superimposed signal to produce a rectified signal; means for differentiating said rectified signal to produce a differentiated signal; means for comparing said differentiated signal with a predetermined threshold level and producing a comparator signal when said differentiated signal exceeds said threshold level; means for blocking said comparator signal during said given duration of said trigger signal; and means for measuring elapsed time between the onset of said trigger signal and the onset of said comparator signal to derive the distance to said object on the basis of said elapsed time.
Claim 2
Dependent Claim
171 words
An ultra-sonic distance measuring apparatus comprising: means for producing a trigger signal at a given timing and for a given duration; means for transmitting ultra-sonic waves toward an object in response to said trigger signal; means for receiving reflected ultra-sonic waves reflected by the object and producing a receiver signal having a value indicative of the amplitude of the received ultra-sonic waves; means for superimposing said trigger signal on said receiver signal to produce a superimposed signal; means for rectifying said superimposed signal to produce a rectified signal; means for differentiating said rectified signal to produce a differentiated signal; means for comparing said differentiated signal with a predetermined threshold level and producing a comparator signal when said differentiated signal exceeds said threshold level; means for blocking said comparator signal during said given duration of said trigger signal; and means for measuring elapsed time between the onset of said trigger signal and the onset of said comparator signal to derive the distance to said object on the basis of said elapsed time.
Claim 3
Dependent Claim
156 words
An ultra-sonic distance measuring method comprising the steps of: producing a trigger signal at a given timing and for a given duration; transmitting ultra-sonic waves toward an object in response to said trigger signal; receiving reflected ultra-sonic waves reflected by the object and producing a receiver signal having a value indicative of the amplitude of the received ultra-sonic waves; superimposing said trigger signal on said receiver signal to produce a superimposed signal; rectifying said superimposed signal to produce a rectified signal; differentiating said rectified signal to produce a differentiated signal; comparing said differentiated signal with a predetermined threshold level and producing a comparator signal when said differentiated signal exceeds said threshold level; blocking said comparator signal during said given duration of said trigger signal; ad measuring elapsed time between the onset of said trigger signal and the onset of said comparator signal to derive the distance to said object on the basis of said elapsed time.
Claim 4
Dependent Claim
156 words
An ultra-sonic distance measuring method comprising the steps of: producing a trigger signal at a given timing and for a given duration; transmitting ultra-sonic waves toward an object in response to said trigger signal; receiving reflected ultra-sonic waves reflected by the object and producing a receiver signal having a value indicative of the amplitude of the received ultra-sonic waves; superimposing said trigger signal on said receiver signal to produce a superimposed signal; rectifying said superimposed signal to produce a rectified signal; differentiating said rectified signal to produce a differentiated signal; comparing said differentiated signal with a predetermined threshold level and producing a comparator signal when said differentiated signal exceeds said threshold level; blocking said comparator signal during said given duration of said trigger signal; ad measuring elapsed time between the onset of said trigger signal and the onset of said comparator signal to derive the distance to said object on the basis of said elapsed time.
References Cited (Backward Citations)
US2247749A
Cited
US3003783A
Cited
US3029089A
Cited
GB878111A
Cited
US3321210A
Cited
US3454922A
Cited
US3827538A
Cited
US3603612A
Cited
US3608925A
Cited
DE2053649A1
Cited
US3677561A
Cited
US3850027A
Cited
JPS5040970A
Cited
US3995883A
Cited
US3902691A
Cited
US3945664A
Cited
US3920283A
Cited
US3992039A
Cited
US4100795A
Cited
US4065154A
Cited
US4105216A
Cited
JPS5326021A
Cited
JPS5338022A
Cited
US4152000A
Cited
US4202049A
Cited
GB2006131A
Cited
JPS54103074A
Cited
US4349077A
Cited
DE2844028A1
Cited
US4363092A
Cited
US4327936A
Cited
JPS55109008A
Cited
JPS55114708A
Cited
JPS55141085A
Cited
JPS56665A
Cited
JPS5631861A
Cited
JPS5642739A
Cited
EP0027869A2
Cited
US4333668A
Cited
US4402375A
Cited
JPS56103307A
Cited
JPS56111009A
Cited
JPS56147107A
Cited
JPS56153268A
Cited
JPS56153267A
Cited
US4401310A
Cited
US4436318A
Cited
US4433386A
Cited
JPS5768574A
Cited
JPS5768575A
Cited
JPS5784375A
Cited
JPS5793271A
Cited
JPS57101144A
Cited
JPS57172808A
Cited
JPS57175266A
Cited
JPS57179678A
Cited
JPS57182506A
Cited
JPS57182544A
Cited
JPS5830817A
Cited
JPS5830816A
Cited
JPS5830818A
Cited
JPS5830819A
Cited
JPS5830542A
Cited
JPS5830544A
Cited
JPS5830814A
Cited
JPS5830815A
Cited
JPS5866079A
Cited
EP0080291A2
Cited
JPS5893614A
Cited
JPS5893615A
Cited
US4506909A
Cited
US4537275A
Cited
US4527676A
Cited
GB2119473B
Cited
JPS58149815A
Cited
JPS58167210A
Cited
EP0091017A2
Cited
JPS58180714A
Cited
JPS58182571A
Cited
US4473319A
Cited
JPS58189573A
Cited
GB2123952B
Cited
JPS596107A
Cited
JPS5918005A
Cited
JPS5937112A
Cited
JPS5942468A
Cited
JPS5950242A
Cited
JPS5957009A
Cited
US4555126A
Cited
JPS5973313A
Cited
US4572317A
Cited
JPS5997069A
Cited
US4526401A
Cited
JPS59106084A
Cited
US4506751A
Cited
JPS59121220A
Cited
JPS59145666A
Cited
US4483409A
Cited
EP0142733A2
Cited
US4600215A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |