EP0363871A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
IC card reader/ writer having a short-circuit detection capability
Assignee: Oki Electric Industry Co Ltd
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Filing: 1989-10-09
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Granted: —
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Expires: 2009-10-09
Abstract
Abstract An IC card reader/writer has a short-circuit detecting (54, 56) for determining, when an IC card (40) is inserted in the reader/writer, whether or not any of connecting terminal (51d, 51f) for feeding a current to the IC card (40) is short-circuited, and producing a resultant signal representative of a result of determination. A control means (52) is responsive to the resultant signal for performing, when said signal does not indicate short-circuit, control such that the current is fed to the IC card (40) via the connecting terminals. A reference voltage generator (55) generates a reference voltage, while the short-circuit detector (54, 56) determines whether any of the connecting terminals (51d, 51f) is short-circuit or not by using the generated reference voltage.
Inventors
- 👤 Hiroharu Oki Electric Industry Co. Ltd. Hirata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 21:34
CPC Classifications
G; G06; G06K; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K19/0701; G06K19/0715; G06K7/00; G06K7/0013; G06K7/0086; G11; G11C; G11C5/00; G11C5/14; G11C5/143
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
135 words
An IC (Integrated Circuit) card reader/writer comprising: short-circuit detecting means (54, 56) for determining, when an IC card (40) is inserted in said IC card reader/writer, whether or not a connecting terminal (51d, 51f) for feeding a current to the IC card (40) is short-circuited, and producing a resultant signal representative of a result of determination; and control means (52) responsive to the resultant signal for performing, when said signal does not indicate short-circuit, control such that the current is fed to the IC card (40) via the connecting terminal (51d, 51f) ; CHARACTERIZED IN THAT said IC card reader/writer further comprises reference voltage generating means (55) for generating a reference voltage; said short-circuit detecting means (54, 56) determining whether the connecting terminal (51d, 51f) is short-circuited or not by using the generated reference voltage.
Claim 2
Dependent Claim
135 words
An IC (Integrated Circuit) card reader/writer comprising: short-circuit detecting means (54, 56) for determining, when an IC card (40) is inserted in said IC card reader/writer, whether or not a connecting terminal (51d, 51f) for feeding a current to the IC card (40) is short-circuited, and producing a resultant signal representative of a result of determination; and control means (52) responsive to the resultant signal for performing, when said signal does not indicate short-circuit, control such that the current is fed to the IC card (40) via the connecting terminal (51d, 51f) ; CHARACTERIZED IN THAT said IC card reader/writer further comprises reference voltage generating means (55) for generating a reference voltage; said short-circuit detecting means (54, 56) determining whether the connecting terminal (51d, 51f) is short-circuited or not by using the generated reference voltage.
Claim 3
Dependent Claim
87 words
An IC card reader/writer in accordance with claim 1, CHARACTERIZED IN THAT said short-circuit detecting means (54, 56) comprises: a voltage applying circuit (54) for applying a detecting voltage to a power source terminal (43d, 43f) of the IC card (40) after insertion of said IC card (40) ; and a comparing circuit (56) for comparing a voltage drop ascribable to a current which is caused to flow by the detecting voltage with the reference voltage, and informing said control means (52) of a result of comparison.
Claim 4
Dependent Claim
64 words
An IC card reader/writer in accordance with claim 2, CHARACTERIZED IN THAT said voltage applying circuit (54) comprises a switching element (54a, 54b) which is turned on and off by said control means (52), said voltage applying circuit (54) feeding the detecting voltage to the power source terminal (43d, 43f) of the IC card (40) when said switching element (54a, 54b) is turned on.
Claim 5
Dependent Claim
33 words
An IC card reader/writer in accordance with claim 3, CHARACTERIZED IN THAT said voltage applying circuit (54) comprises a resistor (54c, 54d) which is connected in series with said switching element (54a, 54b).
Claim 6
Dependent Claim
27 words
An IC card reader/writer in accordance with claim 3, CHARACTERIZED IN THAT said switching element (54a, 54b) of said voltage applying circuit (5) comprises a PNP transistor.
Claim 7
Dependent Claim
27 words
An IC card reader/writer in accordance with claim 3, CHARACTERIZED IN THAT said switching element (54a, 54b) of said voltage applying circuit (54) comprises an NPN transistor.
Claim 8
Dependent Claim
28 words
An IC card reader/writer in accordance with claim 3, CHARACTERIZED IN THAT said switching element (54a, 54b) of said voltage applying circuit (54) comprises a field effect transistor.
Claim 9
Dependent Claim
58 words
An IC card reader/writer in accordance with claim 2, CHARACTERIZED IN THAT said comparing circuit (56) comprises an operational amplifier (56a, 56b) having one input terminal connected to said reference voltage generating means (55), another input terminal connected to an output terminal of said voltage applying circuit (54), and an output terminal connected to said control means (52).
Claim 10
Dependent Claim
19 words
An IC card reader/writer in accordance with claim 1, CHARACTERIZED IN THAT said control means (52) compises a microcomputer.
References Cited (Backward Citations)
No citation records indexed.
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