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Patent Searching and Data


Title:
METHOD FOR LOCATING OPERATOR WITHIN CONTROL AREA
Document Type and Number:
Japanese Patent JP3173766
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To provide a method for locating an operator within a control area, which is provided with a comparatively long detectable distance and reduces the influence of noise.
SOLUTION: A pair of electrodes 5a and 5b are made to face the boundary lines 3a to 3c of respective operation areas 2a to 2c being a small control area 1, and the potential difference of AC high voltage is applied to between both electrodes 5a and 5b to form an electric field 6 between them. Each operator 11 is made to hold an identification card 7 sending a radio wave signal 12 concerning previously stored identification information on each operator 11 in response to electric field intensity not less than a fixed value in the electric field 6. Only parts in which the electric field generated by the potential difference of the pair of electrodes 5a and 5b is not less than the value is made a passage 8 at the respective boundary lines 3a to 3c. The identification radio wave signals 12 from the identification cards 7 of all the operators 11 entering and leaving through the passage 8 are received and controlled by each control area to monitor the existence of each operator 11 to locate the operator 11 within the control area.


Inventors:
Matsuishi, Yoshihisa
Miura, Satoru
Imai, Michio
Ogasawara, Hiroaki
Nakagawa, Toru
Application Number:
JP1996000147163
Publication Date:
June 04, 2001
Filing Date:
June 10, 1996
Export Citation:
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Assignee:
KAJIMA CORP
NITTETSU HOKKAIDO SEIGYO SYST KK
International Classes:
G07C9/00; G07C11/00; H04B7/00; (IPC1-7): G07C11/00
Attorney, Agent or Firm:
市東 禮次郎