Title:
NON-CONTACT ID CARD SYSTEM AND IDENTIFYING DEVICE
Document Type and Number:
Japanese Patent JPH01191282
Kind Code:
A
Abstract:
PURPOSE:To reduce a malfunction due to an impulsive noise without deteriorating sensitivity and to reduce the generation of an unnecessary signal and the deterioration of a signal quality by providing a detecting means for detecting the presence and the absence of the noise and a control means for removing the noise at the position of any circuit block after an AM demodulating part. CONSTITUTION:To the constitution of the conventional device, an impulse detecting part 21, a timer part 22 and level control parts 23a, 23b are added. The impulse is detected from the output of an AGC circuit 7 in the impulse detecting part 21 and a level is deteriorated in a level control part 23 only for a constant period by the timer part 22, thereby, a signal by the impulse is not outputted from a detecting circuit 9 but the malfunction due to the impulse noise can be lowered without deteriorating the sensitivity.
Inventors:
YAMASHITA KOJI
KAWAI MASANORI
HONDA KAZUHIRO
NAKATOI KAZUO
KAWAI MASANORI
HONDA KAZUHIRO
NAKATOI KAZUO
Application Number:
JP1503188A
Publication Date:
August 01, 1989
Filing Date:
January 26, 1988
Export Citation:
Assignee:
MATSUSHITA ELECTRIC WORKS LTD
International Classes:
G06K17/00; H01Q1/48; H01Q3/44; H01Q13/08; H01Q23/00; H04B1/59; (IPC1-7): G06K17/00
Domestic Patent References:
| JPS62129476A | 1987-06-11 | |||
| JP60068729B |
Attorney, Agent or Firm:
Ishida Choshichi
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