The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 1995
Filed:
Nov. 23, 1993
Tamotsu Mitsuyasu, Kamakura, JP;
Takuji Sekiguchi, Machida, JP;
Nippon Hoso Kyokai, Tokyo, JP;
Abstract
A head drum apparatus includes a cylindrical piezoelectric ceramic member formed of a polarized ceramic material and having inner and outer peripheral surfaces. A plurality of electrodes are formed on at least one of the inner and outer peripheral surfaces of the piezoelectric ceramic member. The piezoelectric ceramic member vibrates in response to an AC voltage applied to the electrodes. A cylindrical stationary head drum having an inner peripheral surface and an outer peripheral surface around a portion of which a magnetic tape is wound is caused to vibrate in a bending mode under vibration of the piezoelectric ceramic member. The stationary head drum includes a cylindrical stationary portion, a cylindrical vibratory portion and a cylindrical thin wall portion provided between the stationary portion and the vibratory portion. The piezoelectric ceramic member is coupled to the vibratory portion so that the vibratory portion is caused to vibrate under vibration of the piezoelectric ceramic member. Tape data indicative of types of the tapes is read out for driving the piezoelectric ceramic member by the AC voltage having a frequency and an amplitude determined on the basis of the tape data.