Title: Magnetic dust-removing blackboard writing deivce
Application Number: 85106172 Application Date: 1985.08.14
Publication Number: 1009077 Publication Date: 1987.03.04
Approval Pub. Date: Granted Pub. Date: 1989.11.08
International Classifi-cation: B43L21/00,B43L21/02,C09D13/00
Applicant(s) Name: Wang Fengqi Address:
Inventor(s) Name:
Attorney & Agent:
Abstract:
     The dust is cleaned by magnetic principle. It maintained convenience of conventional chalk-blackboard writing system and clearness of handwriting. Its cost is lower. The invention can eliminate greatly clouds of dust flew up. Original blackboard still was used.
Time: 7
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