Gary Jun Asakawa
Massage Therapy at Bison Rdg Dr, Colorado Springs, CO

5525928, Jun 11, 1996

Feb 27, 1995

8/394749

Gary J. Asakawa - Colorado Springs CO

Silicon Systems, Inc. - Tustin CA

H04B 110

327552

A filter boost preattenuator provides controlled, rapid variable signal preattenuation at the input of a filter to optimally compensate for the absolute gain increase of the filter caused by increasing the high frequency boost level of the filter. The amplitude of the filter output exhibits very little change during boost variations that dynamically occur in applications such as data and servo signal recovery in disk drives. Using the present invention, disk space overhead needed to allow for readjustment of the automatic gain control system of a read/write channel is minimized. In the present invention, the feedforward signal provided from the variable gain boost circuit is applied to a feedback circuit and subtracted from the system input. The feedback forces a drop in the overall gain of the filter that increases with boost gain. Therefore, when the boost gain value is raised, as occurs when a read channel transitions between "data" and "servo" modes in a disk drive, the overall gain of the filter decreases to compensate, reducing the performance load on the automatic gain control circuitry.

6107840, Aug 22, 2000

Dec 18, 1998

9/216567

Scott Cameron - Woodland Park CO
Randall L. Sandusky - Divide CO
Gary Asakawa - Colorado Springs CO

Texas Instruments Incorporated - Dallas TX

G01R 1900

327 62

A circuit to generate a servo burst signal, including a circuit to generate a first differential signal and a second differential signal, a first half wave rectifier to rectify the first differential signal and to generate a first rectified signal, a second half wave rectifier to rectify the second differential signal and to generate a second rectified signal, a first peak detector to detect a first peak of the first rectified signal, a second peak detector to detect a second peak of the second rectified signal, and a circuit to generate the servo burst signal based on the first peak signal and the second peak signal.

5825571, Oct 20, 1998

Jul 3, 1997

8/887684

Randall L. Sandusky - Divide CO
Gary J. Asakawa - Colorado Springs CO

Texas Instruments Incorporated - Dallas TX

G11B 502, G11B 509, G11B 1512

360 67

A circuit for input switching for a read channel is described. The present invention suppresses unwanted signals at the input of a read channel. The present invention uses an open impedance switching circuit to inhibit AC transients during DC bias restoration. One embodiment of the present invention uses a low impedance switching circuit to provide rapid restoration of DC bias levels. Coordination of the operation of the open impedance switching circuit and the low impedance switching circuit is provided to maximize suppression of unwanted signals.

5121260, Jun 9, 1992

Jun 22, 1989

7/369741

Gary J. Asakawa - Colorado Springs CO
Robert Y. Noguchi - Colorado Springs CO
Joe Rinaldis - Colorado Springs CO

Digital Equipment Corporation - Maynard MA

G11B 2736, G11B 502, G11B 509

36 31

A method of correcting read channel signal compensation in magnetic storage data storage systems with calibration data stored on select portions of the magnetic recording medium.