EP0316157A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
An electrically powered portable medium
Assignee: Toshiba Corp
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Filing: 1988-11-09
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Granted: —
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Expires: 2008-11-09
Abstract
Abstract An IC card 10 which is substantially a portable medium incorporates data memory 31 and control element composed of CPU 28. This IC card is provided with a keyboard 12 and a display 13. In addition, IC card 10 also incorporates a calender circuit 33 which is constantly operated by internal battery 25, and battery checking circuit 24 which causes resistor 146 and Zener diode 149 to generate a reference voltage. Battery checking circuit 24 allows current to flow through the system constituents only when the power switch 12h is activated for operating IC card 10. To implement power-saving operation of the system, semiconductor switches 141 and 142 are installed between the internal battery 25 and the battery checking circuit 24.
Inventors
- 👤 Seietsu C/O Patent Division Nara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 17:36
CPC Classifications
G; G06; G06F; G06F17/00; G06K; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K19/0701; G06K19/0702; G06K19/0705; G01; G01R; G01R19/00; G01R19/165; G01R19/16533; G01R19/16538; G01R19/16542; G06K19/06187; G06K19/06206; G06K19/077; G06K19/07701; G06K19/07703
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
52 words
A portable medium (10) having a battery (25) in the medium for supplying electric power to the medium, characterised by the provision of detecting means (24) responsive to electric power received from the battery only for a prescribed limited time for comparing the voltage of the battery with a predetermined threshold level.
Claim 2
Dependent Claim
52 words
A portable medium (10) having a battery (25) in the medium for supplying electric power to the medium, characterised by the provision of detecting means (24) responsive to electric power received from the battery only for a prescribed limited time for comparing the voltage of the battery with a predetermined threshold level.
Claim 3
Dependent Claim
69 words
A portable medium as claimed in claim 1 characterised by the provision of a central processing unit (CPU) (28) for processing data, and means (26) for generating a clock signal corresponding to actual time, the medium having a plurality of operational modes, including a HALT mode wherein the clock signal is not supplied to the CPU, and an ON mode wherein the clock signal is supplied to the CPU.
Claim 4
Dependent Claim
45 words
A portable medium as claimed in claim 1 or 2 characterised in that the detecting means includes circuit means (145) for comparing the voltage of the battery with the predetermined threshold level for the limited time only when the medium is in the ON state.
Claim 5
Dependent Claim
26 words
A portable medium as claimed in claim 1, 2, or 3 characterised in the provision of timekeeping means for activating the detecting means at predetermined intervals.
Claim 6
Dependent Claim
45 words
A portable medium as claimed in claim 1 characterised in that the detecting means includes reference voltage generating means (149) for generating a reference voltage having the predetermined threshold level and comparison means (145) for comparing the reference voltage with the voltage of the battery.
Claim 7
Dependent Claim
21 words
A portable medium as claimed in claim 5 characterised in that the reference voltage generating means includes a Zener diode (149).
Claim 8
Dependent Claim
29 words
A portable medium as claimed in claim 6 characterised in that the detecting means further includes switching means (141) for selectively allowing current to flow through the Zener diode.
Claim 9
Dependent Claim
49 words
A portable medium as claimed in claim 5 further characterised by including a memory (31) having digital data stored therein, and wherein the reference voltage generating means includes means for producing an analogue signal in response to the digital data, the analogue signal being supplied to the comparison means.
Claim 10
Dependent Claim
71 words
A portable medium as claimed in claim 8 characterised in that the digital data includes a plurality of data elements each having a corresponding value, and the reference voltage generating means (140) includes means for automatically selecting one of the data elements having a value corresponding to the value of the majority of the data elements, the reference voltage generating means being responsive to the selected one of the data elements.
Claim 11
Dependent Claim
42 words
A portable medium as claimed in claim 1 characterised in that the detecting means includes dividing means (157) for generating a checking voltage corresponding to the voltage of the battery and the dividing means includes resistor means for stabilising the checking voltage.
References Cited (Backward Citations)
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