Document Type and Number:
Japanese Patent JPS49131441
Kind Code:
A
Application Number:
JP4555373A
Publication Date:
December 17, 1974
Filing Date:
April 20, 1973
Export Citation:
International Classes:
G03B19/18; G03B31/00; G03B31/02; G11B15/675; (IPC1-7): G03B31/02