CHAO S CHI
Radio and Television Technicians in San Diego, CA

4954825, Sep 4, 1990

Mar 22, 1989

7/327073

Chao S. Chi - San Diego CA

Eastman Kodak Company - Rochester NJ

H03M 506

341 64

A method for modulating binary data into a format suitable for encoding and decoding information, that employs a non-return-to-zero (NRZ) technique. The modulating method includes: defining within a recording medium an event-cell as the time between two adjacent clock transitions having a similar, unique characteristic; and, selectively writing to the recording medium within the event-cell, at an arbitrary time, either a first or a second information. The selective writing step includes generating a first event and a corresponding first read signal in response to a first information and generating a second event and a corresponding second read signal in response to the second information. The method can be employed for a first situation where the information transfer rate during the modulating process is well-regulated, and is advantageously employed for a second situation where the information transfer rate is dependent on unpredictable and variable transfer rate velocities and accelerations.

4802033, Jan 31, 1989

Nov 7, 1986

6/928332

Chao S. Chi - San Diego CA

Eastman Kodak Company - Rochester NY

G11B 558, G11B 2110

360 7704

Trackwise disparity between inductive record and magneto-resistive playback heads which are built on a common support is measured and memorized. Thereafter, during head-positioning, the memorized disparity is employed as a track-address bias for proper registration of the playback head, irrespective of its widthwise disparity relative to the record head. To achieve the aforesaid measurement, the invention provides for a self-calibrating algorithmic routine that generates the aforesaid bias.