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:
Dec. 03, 2002
Filed:
Apr. 08, 1999
Keiko Watanabe, Tsuchiura, JP;
Tetsuya Hamaguchi, Ibaraki-ken, JP;
Takashi Yoshida, Ibaraki-ken, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A magnetic disk apparatus includes that a head positioning actuator assembly is retracted to a predetermined position for retraction at the time of stop of power supply from a power source, an electric power to be supplied to a driving circuit of the actuator assembly at the time of stop of power supply from the power source is supplied in three separate steps with time differences therebetween. First, an electric power for stopping the actuator assembly is supplied. With a second power supply using a small electric power, the actuator assembly starts a retracting operation at a sufficiently low speed so that it reaches the vicinity of a ramp. Thereafter, a third power supply is performed to accelerate the actuator assembly so that it is surely retracted to the predetermined position for retraction. Since the speed of impingement of the actuator assembly upon the ramp at this time can be set to a sufficiently low value, it is possible to reduce the damage of the ramp.