公开(公告)号：JPH10241165A

公开(公告)日：1998-09-11

申请号：JP995598

申请日：1998-01-21

Applicant: IBM

Inventor： ALAN ROBERT CLARKE ,  ROBERT ALLEN HUTCHINS

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/125

Abstract: PROBLEM TO BE SOLVED: To provide a programmable writing system for an optical disc driver which can meet the requirements of generating pulse position modulation(PPM) pulses and generating pulse width modulation(PWM) pulses. SOLUTION: A pattern detector 310 detects input data in response to a PPM/ PWM mode command. The detected data are programmed and supplied to a pulse selection mechanism 316 in order to select one of or both of a pulse output value and a pulse duration time. The pulse selection mechanism makes a pulse generating mechanism 336 operate so as to set the pulse output level or/and the duration time of the pulse of the generated laser pulse signal. In the PWM mode, the pattern detector 310 supplies a toggle signal in accordance with the respective detected signals and the pulse selection mechanism performs the supply of one of or both of a mark pulse output value and a mark pulse duration time and the supply of a space duration value alternately in response to the toggle signal. With this constitution, alternate mark signals and space signals are provided.

公开(公告)号：JPH1069732A

公开(公告)日：1998-03-10

申请号：JP10554397

申请日：1997-04-23

Applicant: IBM

Inventor： HUTCHINS ROBERT ALLEN ,  GLEN ALAN JIYAKUETSUTA ,  ALAN ROBERT CLARKE

IPC: G11B20/14 ,  G11B7/005 ,  G11B19/12 ,  G11B20/18

Abstract: PROBLEM TO BE SOLVED: To provide a readout-detection channel and an improved method for decoding the data stored in a data storing medium. SOLUTION: A readout-detection channel 20 includes a tracking threshold value circuit 34 which generates variable threshold value signals and a detection circuit which can be configured into a plurality of various configurations each of which corresponds to one of a plurality of various data forms. Furthermore, a first embodiment of the readout detection channel 20 includes the structural circuit which automatically selects one structure of the data detection circuit in response to detection in the form of input data stream. This first embodiment allows the data bits coded in a plurality of divergent data forms to be decoded using a singly constructible readout detection channel.