ALAN ROBERT CLARK
Pilots at Gray Eagle Ave, Tucson, AZ

5502711, Mar 26, 1996

Mar 20, 1995

8/407124

Alan R. Clark - Tucson AZ
Robert A. Hutchins - Tucson AZ
Ara S. Patapoutian - Westboro MA

International Business Machines Corporation - Armonk NY

G11B 700

369124

A digital phase lock loop channel is provided for threshold detection of a pulse width modulated binary data stream that has negative and positive transitions defining one binary state of the data stream. A threshold-establishing and transition-detecting network receives this data stream and provides a first output of one polarity corresponding to the detection of a positive transition, a second output of an opposite polarity corresponding to the detection of a negative transition, and a time-of-arrival output corresponding to a positive and a negative transition. A first and a second digital PLL is provided, each PLL having a transition input, a time-of-arrival input, a phase-error input, a phase error output a data-valid output, and a data output. Each PLL has an internal digital phase detector network connected to receive its transition input and its time-of-arrival input, and each PLL is operable to generate the phase error output therefrom. Each PLL has an internal digital loop filter connected to receive the phase error output generated by its phase detector network, and to receive the phase error output that is generated by the other PLL.

5825744, Oct 20, 1998

May 13, 1996

8/647490

Robert Allen Hutchins - Tucson AZ
Glen Alan Jaquette - Tucson AZ
Alan Robert Clark - Tucson AZ

International Business Machines Corporation - Armonk NY

G11B 700

369124

In a first embodiment, a read detection channel includes a tracking threshold circuit for generating a variable threshold signal and a detection circuit, which is configurable in a number of diverse configurations that each correspond to one of the multiple diverse data formats. In addition, the first embodiment of the read detection channel includes a configuration circuit that automatically selects one of the configurations of the data detection circuit in response to a detection of a format of the input data stream. The first embodiment of the read detection channel permits data bits encoded in multiple diverse data formats to be decoded utilizing a single configurable read detection channel. In a second embodiment, the configurable read detection channel includes a tracking threshold circuit that can be configured to generate a threshold output signal in response to an input signal or in response to the input signal and a phase error signal. The second embodiment of the read detection channel further includes a detection circuit, which indicates data bits detected within the input signal in response to the threshold output signal, and at least one phase-locked loop coupled to the detection circuit, which places each detected data bit within one of a plurality of bit cells within an output data stream.

5802031, Sep 1, 1998

Nov 18, 1997

8/972467

Alan Robert Clark - Tucson AZ
Robert Allen Hutchins - Tucson AZ

International Business Machines Corporation - New York NY

G11B 700

369 59

A programmable writing system for an optical disk drive which is adaptable for pulse position modulation (PPM) and pulse width modulation (PWM) pulse generation. The writing circuit is responsive to a PPM/PWM mode command for generating programmed laser pulse signals. Specifically, a pattern detector is responsive to the PPM/PWM mode command for detecting input data. The detected data is provided to a pulse selector for selecting programmed pulse power and/or duration values, which operate a pulse generator to set pulse power levels and/or to set the duration of the generated laser pulse signals. In PWM mode, the pattern detector provides a toggle signal with each detected signal and the pulse selector responds to the toggle signal to alternate between providing mark pulse power and/or duration values and providing space duration values to thereby provide alternating mark and space signals.

5978335, Nov 2, 1999

Jun 28, 1996

8/672862

Alan Robert Clark - Tucson AZ
Robert Allen Hutchins - Tucson AZ
Glen Alan Jaquette - Tucson AZ

G11B 700

369 54

An integrated calibration apparatus operates in multiple calibration modes of a multi-mode information storage system such as an optical disk drive to calibrate the drive in the multiple write modes. An event processing and measurement circuit is configurable in multiple configurations that each correspond to a different calibration measurement. Each configuration concurrently measures one or more parameters of readback data written to an optical disk by the optical disk drive operating in a particular write mode. A qualification circuit selects valid measurements for two different parameters or for two different qualification of the same parameter. A summation circuit sums valid measurements of each parameter measured and counts the number of measurements summed for each parameter. The calibration apparatus calculates average values for the measured parameters from the sums and counts, and then calibrates the multi-mode optical disk drive for its current write mode based on the average values.

5680383, Oct 21, 1997

Oct 2, 1996

8/726307

Alan Robert Clark - Tucson AZ
Robert Allen Hutchins - Tucson AZ
Glen Alan Jaquette - Tucson AZ
Ara Sarkis Patapoutian - Westboro MA
Pantas Sutardja - San Jose CA

International Business Machines Corporation - Armonk NY

G11B 700

369 59

In a pulse width modulated read signal channel for an optical disk drive, a data-transition threshold is maintained for data detection by a threshold tracking circuit that estimates the amplitude centerline data-transition threshold from the most recent maximum and minimum values of the read signal waveform. To improve the accuracy of the response of the centerline estimator, the threshold is increased or decreased based on the phase error at each read signal transition through the data-transition threshold. In addition, defects in the optical recording media are detected, and a defect present signal is used to inhibit the transition phase error input to the centerline estimator. This prevents the estimator from moving the threshold to an incorrect stable level. In addition, the defect present signal boosts the error feedback in the centerline estimator. The estimator then more quickly follows the read signal waveform.

5629914, May 13, 1997

Mar 20, 1995

8/407125

Alan R. Clark - Tucson AZ
Robert A. Hutchins - Tucson AZ
Glen A. Jaquette - Tucson AZ
Ara S. Patapoutian - Westboro MA
Pantas Sutardja - San Jose CA

International Business Machines Corporation - Armonk NY

G11B 700

369 59

In a pulse width modulated read signal channel for an optical disk drive, a data-transition threshold is maintained for data detection by a threshold tracking circuit that estimates the amplitude centerline data-transition threshold from the most recent maximum and minimum values of the read signal waveform. To improve the accuracy of the response of the centerline estimator, the threshold is increased or decreased based on the phase error at each read signal transition through the data-transition threshold. In addition, defects in the optical recording media are detected, and a defect present signal is used to inhibit the transition phase error input to the centerline estimator. This prevents the estimator from moving the threshold to an incorrect stable level. In addition, the defect present signal boosts the error feedback in the centerline estimator. The estimator then more quickly follows the read signal waveform.

2008001, Jan 17, 2008

Feb 8, 2007

11/672700

Alan Clark - Tucson AZ, US

H04Q 7/24

370338000

A wireless device for use with a plurality of wireless nodes that includes a controller node, the wireless device including a wireless transceiver for wirelessly communicating with the plurality of wireless nodes; a processor system; and memory storing a neighbor table, the memory also storing code which when executed on the processor causes the wireless device to initiate a discovery process during which the wireless device discovers neighbor nodes with which the wireless device establishes wireless communication links, identifies the discovered neighbor nodes in the neighbor table, and for each identified neighbor in the neighbor table indicates whether the corresponding link has an active status or a parked status, wherein the wireless device uses links having active status to send communications and does not use links having parked status to send communications.