| US 7,583,462 B2 | ||
| Head amplifier with a heat controller | ||
| Naoki Ohta, Tokyo (Japan); and Tetsuya Kuwashima, Tokyo (Japan) | ||
| Assigned to TDK Corporation, Tokyo (Japan) | ||
| Filed on Sep. 06, 2007, as Appl. No. 11/851,043. | ||
| Claims priority of application No. 2006-272846 (JP), filed on Oct. 04, 2006. | ||
| Prior Publication US 2008/0084628 A1, Apr. 10, 2008 | ||
| Int. Cl. G11B 5/09 (2006.01); G11B 21/02 (2006.01) | ||
| U.S. Cl. 360—59 [360/75] | 11 Claims |
| 1. A head amplifier comprising:
write amplifying means for applying a write current to a write head element;
read amplifying means for amplifying a read voltage output from a read head element and outputting a read signal;
heating element drive means for applying a heat generating current to a heating element for adjusting a flying height; and
heat control means for controlling the heating element drive means during at least one of a read operation and a write operation,
the heat control means comprising:
memory means for storing a state variable table;
state variable managing means for retrieving a required value from the state variable table;
output comparing means for comparing the read signal with a corresponding value in the state variable table and outputting
a comparing result; and
drive control means for outputting a control signal to the heating element drive means based on the comparing result.
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