RESPONDER, INTEGRATED CIRCUIT CHIP, NONCONTACT IC CARD, AND SELF POWER NEEDLESS TYPE DEVICE IN NONCONTACT IC CARD COMMUNICATION SYSTEM, AND AUTOMATIC ADJUSTMENT METHOD FOR SELF POWER NEEDLESS TYPE DEVICE

Title:

Document Type and Number:

WIPO Patent Application WO/1998/029828

Kind Code:

A1

Abstract:

A noncontact IC card where a driver (5) switches the resonance frequency of a resonance circuit (1) in order, a reference voltage generator (6) receives the output voltage of the resonance circuit (1) and outputs a certain reference voltage, an output value measurer (7) measures the magnitude of the output voltage of the resonance circuit (1) at each resonance frequency, with this reference voltage as a reference, an output value storage (8) stores the measurement value (output value), and a mode determiner (9) selects the largest one out of the output values stored in the output value storage (8) and determines the switching mode corresponding to this as an appropriate switching mode. In this way, the noncontact IC card is provided with the appropriate switching mode in which it can receive power supply most efficiently.

Inventors:

IKEFUJI YOSHIHIRO (JP)
CHIMURA SHIGEMI (JP)
YOSHIOKA SATOSHI (JP)

Application Number:

PCT/JP1997/004505

Publication Date:

July 09, 1998

Filing Date:

December 08, 1997

Export Citation:

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Assignee:

ROHM CO LTD (JP)
IKEFUJI YOSHIHIRO (JP)
CHIMURA SHIGEMI (JP)
YOSHIOKA SATOSHI (JP)

International Classes:

G06K19/07; G06K19/077; G06K19/00; H04B1/59; (IPC1-7): G06K19/00

Foreign References:

JPS572145A	1982-01-07
JPH08167012A	1996-06-25

Other References: