EP0254954A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Transponder useful in a system for identifying objects
Assignee: Amtech Corp
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Filing: 1987-07-14
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Granted: —
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Expires: 2007-07-14
Abstract
Abstract A reader transmits interrogating rf signals to a transponder including an antenna having a particular impedance. The signals received by the antenna (30) are converted to a direct voltage which is introduced to a first terminal of a switch such as an emitter of a semi-conductor device (42) having conductive and non-conductive states of operation. A second terminal of the switch, such as the base of the semi-conductor device, receives a voltage variable between first and second magnitudes in accordance with a pattern of binary 1's and 0's in a data source such as a read-only memory (ROM). This pattern of binary 1's and 0's is individual to an object identified by the reader The variable voltage on the base of the semi-conductor device causes the emitter-collector current of the semi-conductor device to vary between first and second amplitudes. When this current has the first amplitude, the impedance of the semi-conductor device and the ROM substantially matches the antenna impedance. When this current has the second amplitude, the impedance of the semi-conductor device and the ROM is substantially greater than the antenna impedance. Capacitance (54) may be connected to the collector of the semi-conductor device and the ROM to store energy in accordance with the current flow through the semi-conductor device. This stored energy provides for an energizing of the semi-conductor device and the ROM. A diode (56) may be connected between the emitter and collector of the semi-conductor device to increase the second amplitude of the current through the semi-conductor device.
Inventors
- 👤 Alfred R. Koelle
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 23:09
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/82; G06; G06K; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K19/077; G06K19/07749; G06K19/07773; G06K19/07786; B; B61; B61L; B61L25/00; B61L25/02; B61L25/04; B61L25/045; G01S13/75; G01S13/751; G01S13/758; G06K19/0723; G06K7/00; G06K7/0008
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
200 words
In a combination for use in a transponder (29) for sending signals to a reader (10) to identify an object associated with the transponder (29), antenna means (30) for receiving interrogating signals from the reader (10), the antenna (30) having a particular impedance, means responsive to such received signals for storing energy, switching means (42) having first and second states of operation and having a low impedance in the first state of operation and a high impedance in the second state of operation, a data source (52) for providing a sequence of binary indications individually identifying the object, means including the data source (52) and the switching means (42) for defining a load, with the switching means (42) having an impedance in the first state of operation corresponding to the impedance of the antenna means (30) and having an impedance in the second state of operation considerably higher than the impedance of the antenna means, (30), and means (50) responsive to the sequence of binary indications in the data source (52) for obtaining the operation of the switching means (42) in the first and second states of operation in accordance with the sequence of binary indications individually identifying the object.
Claim 2
Dependent Claim
200 words
In a combination for use in a transponder (29) for sending signals to a reader (10) to identify an object associated with the transponder (29), antenna means (30) for receiving interrogating signals from the reader (10), the antenna (30) having a particular impedance, means responsive to such received signals for storing energy, switching means (42) having first and second states of operation and having a low impedance in the first state of operation and a high impedance in the second state of operation, a data source (52) for providing a sequence of binary indications individually identifying the object, means including the data source (52) and the switching means (42) for defining a load, with the switching means (42) having an impedance in the first state of operation corresponding to the impedance of the antenna means (30) and having an impedance in the second state of operation considerably higher than the impedance of the antenna means, (30), and means (50) responsive to the sequence of binary indications in the data source (52) for obtaining the operation of the switching means (42) in the first and second states of operation in accordance with the sequence of binary indications individually identifying the object.
Claim 3
Dependent Claim
27 words
In a combination as set forth in claim 1, the switching means (42) being connected in series with the data source (52) and the antenna means (30).
Claim 4
Dependent Claim
43 words
In a combination as set forth in claim 1 or 2 connecting means (56) connected across the switching means (42) to pass a limited flow of current around the switching means (42) in the second state of operation of the switching means (42).
Claim 5
Dependent Claim
51 words
In a combination as set forth in claim 3, storage means (54) connected to the switching means (42) to receive energy in the first and second states of operation of the switching means (42) for operating the data source (52) to provide the sequence of binary indications individually identifying the object.
Claim 6
Dependent Claim
185 words
A combination as set forth in any one of the preceding claims wherein rectifier means (34,36) are connected to the antenna means (30) for rectifying energy received by the antenna means, said switching means is a semi-conductor device (42) having a base, and emitter and a collector and having said first and second states of operation the rectifier means (34,36) are connected to the emitter of the semi-conductor, device (42), means (50) are provided for introducing the signal cycles in the sequence from the data source (52) to the base of the semi-conductor device (42) to obtain an operation of the semi-conductor device in the first and second states in accordance with the sequence of signal cycles coding for the binary 1's and binary 0's in the individual pattern identifying the object, and means (52, 54) connected to the collector of the semi-conductor device (42) for providing for a flow of current through the semi-conductor device (42) between the emitter and the collector of the semi-conductor device in accordance with the sequence of the signal cycles introduced to the base of the semi-conductor device (42).
Claim 7
Dependent Claim
77 words
In a combination as set forth in claim 5, the semi-conductor device (42) and the means (52,54), including the data source (52), connected to the semi-conductor device (42) providing an impedance substantially corresponding to the impedance of the antenna means (30) in the first state of operation of the semi-conductor device (42) and providing an impedance considerably higher than the impedance of the antenna means (30) in the second state of operation of the semi-conductor device (42).
Claim 8
Dependent Claim
63 words
In a combination as set forth in claim 6, wherein said means (52,54) connected between the collector and the base of the semi-conductor device (42) comprise means (54) for storing energy from the current flowing through the semi-conductor device (42) in the first and second states of operation of the semi-conductor device (42) to facilitate the flow of current through the semi-conductor device.
Claim 9
Dependent Claim
43 words
In a combination as set forth in claim 7, wherein said storage means (54) is connected to the collector of the semiconductor device (42) for receiving energy from the flow of current through the semi-conductor device (42) to energize the data source (52).
Claim 10
Dependent Claim
22 words
In a combination as set forth in any one of the preceding claims, wherein said data source is a read-only memory (52).
Claim 11
Dependent Claim
40 words
In a combination as set forth in claims 3 and 5, wherein a diode (56) is connected between the emitter and collector of the semi-conductor device (42) to limit the first amplitude of the current through the semi-conductor device (42).
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