Patent EP0204542A2 successfully refreshed from Google Patents.
EP0204542A2
Expired / Lapsed
EP
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Identification system
Assignee: Pac International Ltd
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Filing: 1986-06-03
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Granted: —
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Expires: 2006-06-03
Abstract
Abstract An identification system comprises reading equipment (1) and an identification device (2) which can be inductively coupled via respective coils (L1, L2). The identification device (2) does not contain an internal battery but is energised by the reading equipment via the coupled coils (L1, L2). A control element such as a load resistor (R1) is provided in the identification device (2) and acts to modify the coupling of the coils (L1, L2) in a manner which can be interpreted by a reading circuit (8) in the reading equipment (1). The load resistor (R1) may be switched off and on by a transistor (TR) in a manner determined by coded digital signals derived from a data store (61.
Inventors
- 👤 Philip Hall Bertenshaw
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 18:52
CPC Classifications
G; G06; G06K; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K19/0723
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
128 words
An identification system comprising: reading equipment (1) having a first coupling device (Ll) and energising and reading circuits (7, 8) connected thereto; and an identification device (2) having a second coupling device (L2) and a control element (R1) adapted to be connected thereto; characterised in that coupling between said coupling devices (Ll, L2), when these are in proximity to each other and said first coupling device (Ll) is energised by said energising circuit (7), is arranged to be modified by said connection of said control element (Rl) to said second coupling device (L2), and said reading circuit (8) is arranged to be modified by said connection of said control element (R1)` to said second coupling device (L2), and said reading circuit (8) is arranged to interpret such modification.
Claim 2
Dependent Claim
128 words
An identification system comprising: reading equipment (1) having a first coupling device (Ll) and energising and reading circuits (7, 8) connected thereto; and an identification device (2) having a second coupling device (L2) and a control element (R1) adapted to be connected thereto; characterised in that coupling between said coupling devices (Ll, L2), when these are in proximity to each other and said first coupling device (Ll) is energised by said energising circuit (7), is arranged to be modified by said connection of said control element (Rl) to said second coupling device (L2), and said reading circuit (8) is arranged to be modified by said connection of said control element (R1)` to said second coupling device (L2), and said reading circuit (8) is arranged to interpret such modification.
Claim 3
Dependent Claim
22 words
A system according to claim 1, characterised in that the identification device (2) is in the form of a personal identification card.
Claim 4
Dependent Claim
28 words
A system according to claim 1 or 2, characterised in that the coupling devices (Ll, L2) comprise loops or coils between which an inductive link can be established.
Claim 5
Independent Claim
23 words
A system according to any one of claims 1 to 3, characterised in that the said control element (Rl) comprises a load element.
Claim 6
Dependent Claim
16 words
A system according to claim 4, characterised in that the load element (Rl) comprises a resistor.
Claim 7
Independent Claim
34 words
A system according to any one of claims 1 to 5, characterised in that the said control element (Rl) is arranged to be connected to the second coupling device in an identifiable coded manner.
Claim 8
Dependent Claim
31 words
A system according to claim 6, characterised in that said identifiable coded manner comprises the duration or frequency of connection of the control element (Rl) to the second coupling device (L2).
Claim 9
Dependent Claim
48 words
A system according to claim 7, characterised in that connection of the control element (Rl) to the second coupling device (L2) is arranged to be switched on and off in a predetermined pattern as determined and controlled by a time-based switching signal and a stored switching control code.
Claim 10
Dependent Claim
77 words
A system according to claim 8, characterised in that the identification device incorporates a controllable electronic switch (TR) between the control element (R1) and the second coupling device (L2), a digital storage device or measuring device (6) containing a coded series of switching on and off signals, and a time-based trigger circuit (5) which initiates a switching sequence as determined by the stored code and at a frequency determined by the time basis of the trigger circuit.
Claim 11
Dependent Claim
67 words
A system according to claim 9, characterised in that the time basis is derived from the energisation of the first coupling device (L1) in the reading equipment (1) and the identification device (2) includes power supply circuitry which derives power indirectly from the energisation of the first coupling device (L1) via the second coupling device (L2) to provide operating power for components of the identification device (2).
References Cited (Backward Citations)
No citation records indexed.
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