Document Type and Number:
Japanese Patent JPH03117996
Kind Code:
U
Application Number:
JP2607690U
Publication Date:
December 05, 1991
Filing Date:
March 14, 1990
Export Citation:
International Classes:
H04R1/44; G01S7/52; G01S7/521; H04R17/00; (IPC1-7): H04R1/44; G01S7/52; H04R17/00
Foreign References:
| US4555938A | 1985-12-03 |