U.S. Philips Corporation

Martin A Farla

Hendricus F Van Tongeren

A method and apparatus are described for recording a binary information signal (FIG. 2a) on a record carrier (1) having an information layer (2) whose optical properties are modified upon heating. An information pattern corresponding to this information signal (FIG. 2a) is obtained in that the record carrier 1 is moved relative to an optical system (3) for focussing a radiation beam (4) on the information layer (2), a subsequent recording mark (5) being written on the information layer (2) in selected time intervals (.tau.) by locally heating the information layer by means of the radiation beam (4). The amount of radiation energy (E) applied in a selected time interval depends on the position of the selected time interval (.tau.) in the sequence of consecutive selected time intervals (.tau.). This provides compensation for the influence of the radiation energy (E) applied in the preceding time interval (.tau.) on the temperature at the location of the recording mark (5) to be written in the time interval (.tau.) so that for each recording mark (5) the temperature (T.sub.r) which is reached in the information layer (2) and hence the size of the recording mark (5) is substantially the same.

Binary optical signal recorder providing preheating pulse before an

A method and apparatus are described for recording a binary information signal on a record carrier having an information layer whose optical properties are modified upon heating. An information pattern corresponding to the information signal is obtained by moving the record carrier relative to an optical system which focuses a radiation beam onto the information layer. A recording mark is written on the information layer is selected time intervals by locally heating the information layer with the focussed radiation beam. The amount of radiation energy applied during a selected time interval depends on the position of the selected time interval in the sequence of consecutive selected time intervals. This provides compensation for the increase in the temperature at the location where the mark is to be recorded due to heating of the layer during recording of a mark in the preceding time interval. The amount of radiant energy that is applied is chosen so that for each recording mark the temperature which is reached in the information layer, and hence the size of the recording mark, is substantially the same.

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Eindhoven, Netherlands

Martin A Farla