Ainobu A Yoshimoto

US Patent:

7414929, Aug 19, 2008

Filed:

Sep 22, 2004

Appl. No.:

10/946866

Inventors:

Yuanping Zhao - San Jose CA, US
Ainobu Yoshimoto - Milpitas CA, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G11B 7/00

US Classification:

369 4432, 369 5319

Abstract:

A method for detecting and controlling disc tilt in an optical disc mechanism comprising the steps of (A) measuring a 2-dimensional displacement of an optical lens of the optical disc mechanism, (B) extracting an absolute value of a disc tilt angle in the optical disc mechanism based upon the 2-dimensional displacement and (C) controlling deflection of a tilt moving coil according to the absolute value of the disc tilt angle.

US Patent:

7558160, Jul 7, 2009

Filed:

Jun 14, 2005

Appl. No.:

11/152554

Inventors:

Ainobu Yoshimoto - Milpitas CA, US
Yuan Zheng - Newark CA, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G11B 7/00

US Classification:

369 4411, 369 5323

Abstract:

A method for demodulating a focusing error signal in an optical disc system, comprising the steps of (A) generating a beam strength signal and the focusing error signal, (B) sampling the beam strength signal and the focusing error signal at an appropriate sampling rate, (C) removing a static offset from the beam strength signal and the focusing error signal, (D) calibrating a peak-to-peak value of the beam strength signal and the focusing error signal, and (E) determining an appropriate phase to (i) demodulate the focusing error signal and (ii) calculate a vertical position of a lens in relation to a disc.

US Patent:

7558166, Jul 7, 2009

Filed:

Jan 25, 2008

Appl. No.:

12/020213

Inventors:

Ainobu Yoshimoto - Milpitas CA, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G11B 7/00

US Classification:

369 4429

Abstract:

A method for calibrating a center error signal in an optical disc system, comprising the steps of (i) measuring a peak-to-peak value of the center error signal, (ii) computing a nominal peak-to-peak value of the center error signal after locking to a particular track of an optical disc, (iii) computing the nominal peak-to-peak value of the center error signal for a run-out condition, and (iv) defining a calibration gain for the current value for the center error signal.

US Patent:

7583571, Sep 1, 2009

Filed:

Nov 14, 2005

Appl. No.:

11/273518

Inventors:

Ainobu Yoshimoto - Milpitas CA, US
Hung Phi Dang - Santa Clara CA, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G11B 7/00

US Classification:

369 475, 369 591, 369116

Abstract:

An apparatus comprising a first circuit, a second circuit and a third circuit. The first circuit may be configured to (i) generate a read power signal and (ii) control power of a laser beam emitted from an optical pick-up circuit during a read process. The second circuit may be configured to (i) generate a first write power signal and (ii) control one or more power levels of the laser beam during a write process in response to a second write power signal. The third circuit may be configured to generate the second write power signal and a third write power signal in response to a target write signal.

US Patent:

7613081, Nov 3, 2009

Filed:

Mar 31, 2005

Appl. No.:

11/095974

Inventors:

Ainobu Yoshimoto - Milpitas CA, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G11B 7/00

US Classification:

369 4425, 369 4428, 369 4434, 369 5328

Abstract:

A method for controlling a stepper motor in an optical disc system, comprising the steps of (A) measuring a static offset of a center error signal, (B) measuring a maximum value, minimum value and an average value of the center error signal in response to rotating the optical disc, (C) computing one or more upper threshold values and one or more lower threshold values of the center error signal, (D) sampling the center error signal, (E) comparing the center error signal to the one or more upper threshold values and to the one or more lower threshold values and (F) computing a control output to control the stepper motor in response to comparing the center error signal to the one or more upper and lower threshold values.

US Patent:

7633840, Dec 15, 2009

Filed:

Jun 9, 2006

Appl. No.:

11/450846

Inventors:

Ainobu Yoshimoto - Milpitas CA, US
Hung Phi Dang - Santa Clara CA, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G11B 7/00

US Classification:

369 4429

Abstract:

An apparatus comprising a focus controller, a photo-diode sensor, a data circuit, a focus error creation circuit and a focus offset circuit. The focus controller may be configured to control a lens in relation to a laser beam and allow the laser beam to focus on a disc. The photo-diode sensor may be configured to generate one or more photo-diode signals in response to the laser beam. The data circuit may be configured to generate one or more disc status signals in response to the one or more photo-diode signals. The focus error creation circuit may generate a focus error signal. The focus error signal may provide a first value based on a focus point of the laser beam. The focus offset circuit may be configured to offset the first value of the focus error signal to a second value in response to the disc status signals to allow the focus controller to move the lens to a position which will increase the focus point of the laser beam on the disc.

US Patent:

7830756, Nov 9, 2010

Filed:

Sep 8, 2004

Appl. No.:

10/936017

Inventors:

Ainobu Yoshimoto - Milpitas CA, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G11B 7/00

US Classification:

369 4428, 369 3013, 369 4755, 369 5323, 369 4427

Abstract:

A method for demodulating a tracking error signal comprising the steps of (A) demodulating the tracking error signal when starting motion, (B) demodulating the tracking error signal after motion has started, and (C) demodulating the tracking error signal before and after lens motion stops.

US Patent:

7920446, Apr 5, 2011

Filed:

Dec 7, 2009

Appl. No.:

12/632046

Inventors:

Ainobu Yoshimoto - Milpitas CA, US
Hung Phi Dang - Santa Clara CA, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G11B 7/00

US Classification:

369 4429

Abstract:

An apparatus includes a first circuit and a second circuit. The first circuit may be configured to generate status signals and an error signal in response to accessing a storage medium. The error signal provides a first value based on an accuracy of accessing the storage medium. The second circuit may be configured to offset the first value of the error signal to a second value to increase the accuracy of accessing said storage medium. The status signals include one or more of a data signal and a differential signal. In a first mode, an offset signal is generated in response to the data signal. In a second mode, the offset signal is generated in response to the differential signal.