# US 7,609,602 B2 · Method of generating a recording pulse train in accordance with a NRZI signal for recording information to a recording medium

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- Number: US 7,609,602 B2
- Document ID: US7609602B2
- Status: Granted
- Kind: B2
- Application number: 11/194,524
- Filed: 2005-08-02
- Published: 2005-12-01
- Granted: 2009-10-27
- Earliest claimed: 1999-04-13
- Assignees: Hitachi, Ltd.
- Inventors: Hidehiko Kando; Hiroyuki Minemura
- Web page: https://patentgrep.com/patent/US7609602B2

## CPC

- G11B 7/126: Circuits, methods or arrangements for laser control or stabilisation
- G11B 7/0045: Recording (G11B7/006, G11B7/0065 take precedence)
- G11B 7/00454: {involving phase-change effects}
- G11B 7/0062: {Overwriting strategies, e.g. recording pulse sequences with erasing level used for phase-change media}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

A method of generating a recording pulse train in accordance with a NRZI signal for recording information to a recording medium by irradiating a pulse chain including a first pulse, a middle pulse chain, a last pulse and a negative pulse following the last pulse, including adjusting an average power of the first pulse to a designated peak power level, adjusting an average power of the middle pulse chain to a designated peak power level, adjusting an average power of the last pulse to a designated power level, adjusting an average power of the negative pulse to a designated power level that is lower than the peak power level, and controlling a leading edge of the first pulse of the recording pulse train to start with a variable lapse of time from a leading edge of the NRZI signal, with a duration of the first pulse being fixed.

## Claims

### Claim 1

A method of generating a recording pulse train in accordance with a NRZI (Non-Return to Zero Inverted) signal for recording information to a recording medium by irradiating a pulse chain of an energy beam including a first pulse, a middle pulse chain, a last pulse and a negative pulse following the last pulse, comprising the steps:
adjusting average power of the first pulse to a designated peak power level that is recorded in a control data zone;
adjusting average power of the middle pulse chain to a designated peak power level that is recorded in the control data zone;
adjusting average power of the last pulse to a designated power level that is recorded in the control data zone;
adjusting average power of the negative pulse to a designated power level lower than the peak power level recorded in the control data zone;
wherein a leading edge of the first pulse of the recording pulse train is controlled to start with a variable lapse of time from a leading edge of the NRZI signal, and a duration of the first pulse is fixed.

### Claim 2 (depends on 1)

A method of generating a recording pulse train according to claim 1, further comprising the step of generating the middle pulse chain which includes generating pulses alternating between the power of the designated peak power level and the power of the designated power that is lower than the peak power level.