Title:
READER/WRITER OF IC CARD
Document Type and Number:
Japanese Patent JP3579899
Kind Code:
B2
Abstract:
PURPOSE: To extend a communication distance to an IC card by providing plural loop antennas and applying means applying voltage to each loop antenna.
CONSTITUTION: This reader/writer is provided with the plural loop antennas (loop coils 3a to 3d, e.g.) which generate a magnetic field and is arranged on the same flat and the applying means (a carrier generator 1 and driving circuits 2a to 2d) applying voltage to the plural loop antennas. Then voltage is applied to the plural loop coils 3a to 3d by the carrier generator 1 and the driving circuits 2a to 2d so that a magnetic field is generated from each of the plural loop coils 3a to 3d. Consequently, at the time of regarding the whole of the plural loop coils 3a to 3d as one coil, the coiling number of the coil is larger and a current flowing at the outer periphery of the coil is larger compared with a coil provided with the same cross sectional area as the area occupied by the plural loop coils 3a to 3d, then the intensity of the magnetic field can be improved.
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Inventors:
Katsuyuki Tanaka
Shigeru Arisawa
Shigeru Arisawa
Application Number:
JP375095A
Publication Date:
October 20, 2004
Filing Date:
January 13, 1995
Export Citation:
Assignee:
ソニー株式会社
International Classes:
G06K17/00; H01Q7/00; (IPC1-7): G06K17/00; H01Q7/00
Domestic Patent References:
| JP59174708U | ||||
| JP5033271U | ||||
| JP6169216A | ||||
| JP6009212U | ||||
| JP6252809A | ||||
| JP6164434A | ||||
| JP5136708A | ||||
| JP7007316A | ||||
| JP5283926A | ||||
| JP2010609U | ||||
| JP6197062A | ||||
| JP4305789A |
Attorney, Agent or Firm:
Yoshio Inamoto