EP0237883A1
Expired / Lapsed
EP
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A card and terminal system
Assignee: Casio Computer Co Ltd
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Filing: 1987-03-06
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Granted: —
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Expires: 2007-03-06
Abstract
Abstract An IC card system comprises an IC card terminal (l) and an IC card which is inserted into the terminal (l), the terminal (l) including a power-supply circuit (35) for supplying data-writing power to a memory provided in the IC card, and a timer circuit (36) for measuring a period of time corresponding to the maximum time during which one unit of data can be written into the memory. The supply of power to the IC card is renewed every time the IC card sends a request for an unit of data, within the period of time set in the time-measuring circuit (36). The supply of power is stopped when the IC card makes no request for an unit of data within the above-mentioned period of time.
Inventors
- 👤 Yoshimi Pat.Dep. Dev.Div. Hamura R&D Shigenaga
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 22:52
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/0013; G06K7/0086; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K7/0008; G06Q; G06Q20/00; G06Q20/30; G06Q20/36; G06Q20/367
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
124 words
An IC card system comprising: IC card means (2) including at least one integrated circuit having a nonvolatile memory (65) for storing data; and card terminal means (l) for exchanging data with said IC card means (2) when said IC card means is electrically coupled to it (l); said card terminal means (l) including; power-supply means (35) for supplying data-writing power to the nonvolatile memory (65) provided within said IC card means (2); time-measuring means (36) for measuring a predetermined period of time; first detecting means (l7, 362) for detecting whether or not said IC card means (2) has made a response; and control means (l7) for controlling said power supply means (35) in accordance with an output signal of said first detecting means.
Claim 2
Dependent Claim
124 words
An IC card system comprising: IC card means (2) including at least one integrated circuit having a nonvolatile memory (65) for storing data; and card terminal means (l) for exchanging data with said IC card means (2) when said IC card means is electrically coupled to it (l); said card terminal means (l) including; power-supply means (35) for supplying data-writing power to the nonvolatile memory (65) provided within said IC card means (2); time-measuring means (36) for measuring a predetermined period of time; first detecting means (l7, 362) for detecting whether or not said IC card means (2) has made a response; and control means (l7) for controlling said power supply means (35) in accordance with an output signal of said first detecting means.
Claim 3
Dependent Claim
98 words
An IC card system according to claim l, characterized in that said control means (l7) includes second detecting means (l7) for detecting whether or not said time-measuring means has measured said predetermined period of time, and said control means (l7) initializes said time-measuring means (36) when said first detecting means (l7, 362) detects a response from said IC card means (2), and turns off said power-supply means (35) when said second detecting means (l7) detects the lapse of said predetermined period of time, if said first detecting means (l7) detects no response from said IC card means (2).
Claim 4
Dependent Claim
48 words
An IC card system according to claim 2, characterized in that said predetermined period of time is slightly longer than the maximum time during which data transferred from said card terminal means (l) to said IC card means (2) can be continuously written into said nonvolatile memory (65).
Claim 5
Dependent Claim
27 words
An IC card system according to claim 3, characterized in that said nonvolatile memory (65) provided in said IC card means (2) is an erasable programmable ROM.
Claim 6
Dependent Claim
60 words
An IC card system according to claim 2, characterized in that said IC card means (2) further includes means (57) for decrypting data transferred from said card terminal means (l), and means (56) for transmitting, to said card terminal means (l), a signal requesting supply of power, when data decrypted by the decryption means (57) signifies a command for data-writing.
Claim 7
Dependent Claim
66 words
An IC card system according to claim 5, characterized in that said IC card means (2) further includes means (56) for supplying said card terminal means (l) with a first response signal requesting more data, after one unit of data transferred from said card terminal means (l) has been written into said memory (65), and said time-measuring means (36) is initialized by said first response signal.
Claim 8
Dependent Claim
87 words
An IC card system according to claim 6, characterized in that said IC card means (2) further includes means for supplying said card terminal means (l) with a second response signal showing that all units of data transferred from said card terminal means (l) have been written into said nonvolatile memory (65), and said power-supply means (35) provided in said card terminal means (l) stops supplying power to said nonvolatile memory (65), in response to said second response signal, under the control of said control means (56).
Claim 9
Dependent Claim
19 words
An IC card system according to claim 2, characterized in that said time-measuring means (36) includes a down-counter (36l).
References Cited (Backward Citations)
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