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:
Nov. 04, 2003
Filed:
Mar. 06, 2000
Kenji Kuroki, Fujisawa, JP;
Thomas R. Albrecht, San Jose, CA (US);
Fuminori Sai, Yokohama, JP;
Yuzo Nakagawa, Hiratsuka, JP;
Nobuhisa Koide, Chigasaki, JP;
Masashi Murai, Yamato, JP;
Keishi Takahashi, Fujisawa, JP;
Timothy C. Reiley, Losgatos, CA (US);
Erno H. Klassen, Santa Clara, CA (US);
Abstract
A method and apparatus to provide a retract circuit that can correspond to the tendency toward miniaturization and low supply voltage. When drive supply voltage Vcc is applied, a retract circuit charges a retract condenser Cr with boosted voltage Vup, equal to three times Vcc, generated by a booster circuit. Then, if the drive supply voltage Vcc is cut off and a VCM driver stops, the retract circuit detects power-off with a power OFF sense circuit, and provides retract delay time by a retract delay circuit. Furthermore, when the retract delay time elapses after the drive power supply is turned off, the retract driver switches the switching circuits on, discharges the retract condenser, charged at the boosted voltage, supplies discharge current to a voice coil, and retracts the head assembly.