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EP0325837A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Rapid signal validity checking apparatus

Assignee: Amtech Systems Inc
•
Filing: 1988-11-01
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Granted: —
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Expires: 2008-11-01
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Abstract

Abstract This invention relates to an improved signal reader for reading signals from transponders placed on moveable objects such as ship containers, automobiles or railroad cars. The reader sends out a continuous signal, which is modified by the information contained in the transponder attached to the moveable object. Multiple antennas, each of which receive separate signals, may be multiplexed at the reader. The improved circuit of the invention provides quick recognition of the receipt of a valid signal from a transponder or, in the alternative, the absence of such a valid signal. The circuit of the invention first provides a detection pulse stream. Each pulse of the detection pulse stream coincides in time with an expected edge of the predetermined pulse stream reflected back to the reader from the transponder. A detection circuit is connected to receive the detection pulse stream at the same time it receives signals to be evaluated. The detection circuit detects the presence of pulse edges which are coincident with the pulses from the detection pulse stream, and provides a detection output signal in the event of such coincidence. A counter counts the number of detection output signals from the detection circuit and provides a validity signal depending upon the number of detection output signals received for a given number of detection pulses. A preferred embodiment of the invention also detects the number of background noise pulses when there are no pulses from the detection pulse stream. These coincidences indicate the receipt of invalid data, and are subtracted in the counter as an invalidity signal. The apparatus of the invention is thus capable of rapidly separating valid pulse streams from invalid ones and providing a validity or invalidity signal which may be used to control the multiplexing of a reader from one antenna to another.

Inventors

  • 👤 Alfred R. Koelle
  • 👤 Donald F. Speirs
  • 👤 Peter L. Hendrick

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-30 15:29
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; H; H03; H03K; H03K5/00; H03K5/19; G01S13/75; G01S13/751; G01S13/758; G06; G06K; G06K7/00; G06K7/0008

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 110 words
A circuit for early detection of a predetermined pulse stream having a given periodicity, comprising: means for providing a detection pulse stream wherein the width of the pulses include the expected edges of said predetermined pulse stream; detecting means connected to receive said predetermined pulse stream for detecting the presence of said expected edge coincident with the duration of pulses of said detection pulse stream, and for providing an output signal in the event of such detection; means for counting the number of said detection output signals and for providing a validity signal depending on the number of such detection output signals received for a given number of detection pulses.
Claim 2
Dependent Claim 110 words
A circuit for early detection of a predetermined pulse stream having a given periodicity, comprising: means for providing a detection pulse stream wherein the width of the pulses include the expected edges of said predetermined pulse stream; detecting means connected to receive said predetermined pulse stream for detecting the presence of said expected edge coincident with the duration of pulses of said detection pulse stream, and for providing an output signal in the event of such detection; means for counting the number of said detection output signals and for providing a validity signal depending on the number of such detection output signals received for a given number of detection pulses.
Claim 3
Dependent Claim 166 words
A circuit for early detection of a predetermined pulse stream having a given periodicity, comprising: means for providing a detection pulse stream wherein the width of the pulses include the expected edges of said predetermined pulse stream; detecting means connected to receive said predetermined pulse stream for detecting the presence of said expected edge coincident with the duration of each pulse of said detection pulse stream and for providing a first detection output signal in the event of such detection, and for detecting the presence of a pulse edge during the time that pulses are absent from said detection pulse stream, and for providing a second detection output signal in the event of such detection; means for counting the number of said first and second detection output signals and for providing a validity signal directly related to the number of such first detection output signals received and inversely related to the number of such second detection output signals received, for a given number of detection pulses.
Claim 4
Dependent Claim 166 words
A circuit for early detection of a predetermined pulse stream having a given periodicity, comprising: means for providing a detection pulse stream wherein the width of the pulses include the expected edges of said predetermined pulse stream; detecting means connected to receive said predetermined pulse stream for detecting the presence of said expected edge coincident with the duration of each pulse of said detection pulse stream and for providing a first detection output signal in the event of such detection, and for detecting the presence of a pulse edge during the time that pulses are absent from said detection pulse stream, and for providing a second detection output signal in the event of such detection; means for counting the number of said first and second detection output signals and for providing a validity signal directly related to the number of such first detection output signals received and inversely related to the number of such second detection output signals received, for a given number of detection pulses.
Claim 5
Dependent Claim 55 words
The circuit of claim 2 wherein said counting means is incremented once for the receipt of each first detection output signal and decremented once for the receipt of each second detection output signal, said counting means providing a validity signal when its net count reaches a predetermined number during a given number of detection pulses.
Claim 6
Dependent Claim 182 words
A circuit for early detection of a predetermined pulse stream having a given periodicity, comprising: means for providing a detection pulse stream wherein the width of the pulses include the expected edges of said predetermined pulse stream; first detecting means connected to receive said predetermined pulse stream for detecting the presence of the expected pulse edges during the duration of every other pulse of said detection pulse stream, and for providing an output signal in the event of such detection; second detecting means also for detecting the presence of the expected pulse edges during the duration of every other pulse of said detection pulse stream, and for providing an output signal in the event of such detection, said second detecting means being out of phase with said first detecting means; means for counting the number of said detection output signals from each of said detecting means and for providing a validity signal depending on the number of such output signals received from the one of the first and second detection means having the higher count for a given number of detection pulses.
Claim 7
Dependent Claim 182 words
A circuit for early detection of a predetermined pulse stream having a given periodicity, comprising: means for providing a detection pulse stream wherein the width of the pulses include the expected edges of said predetermined pulse stream; first detecting means connected to receive said predetermined pulse stream for detecting the presence of the expected pulse edges during the duration of every other pulse of said detection pulse stream, and for providing an output signal in the event of such detection; second detecting means also for detecting the presence of the expected pulse edges during the duration of every other pulse of said detection pulse stream, and for providing an output signal in the event of such detection, said second detecting means being out of phase with said first detecting means; means for counting the number of said detection output signals from each of said detecting means and for providing a validity signal depending on the number of such output signals received from the one of the first and second detection means having the higher count for a given number of detection pulses.
Claim 8
Dependent Claim 60 words
The circuit of claim 4 wherein said first and second detecting means also detect the presence of a pulse edge in said predetermined pulse stream in the absence of coincidence with a pulse of said detection pulse stream, and the number of such invalid detected pulses is used as an invalidity indicator for the detection of said predetermined pulse stream.
Claim 9
Dependent Claim 31 words
The circuit of claim 5 where the number of such invalid detected pulses is subtracted from the number of detection output signals from each of said first and second detecting means.

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