Device for recording information on a record carrier having a radiation sensitive layer

Claim 1

A device for recording information on a record carrier comprising a radiation sensitive recording layer, which device comprises means for directing a write beam of radiation produced by a radiation source to the recording layer, drive means for realising a relative movement between the write beam and the record carrier, a control circuit for controlling the intensity of the radiation produced by the radiation source in conformity with the information to be recorded so as to form an information pattern of optically detectable marks representing the information, means for directing a verification beam of lower intensity than the write beam to the recording layer in such a way that the verification beam trails the write beam and is modulated by the information pattern formed by means of said write beam, detection means for converting the modulated verification beam into a corresponding read signal, characterized in that the radiation of the write beam and the verification beam originate from the same radiation source, the device further comprising a circuit for generating a correction signal which is an indication of the instantaneous intensity of the radiation produced by the radiation source, and a correction circuit for deriving from the correction signal and the read signal a corrected read signal which is indicative of the read signal divided by the instantaneous intensity of the radiation produced by the radiation source.

Claim 2

A device for recording information on a record carrier comprising a radiation sensitive recording layer, which device comprises means for directing a write beam of radiation produced by a radiation source to the recording layer, drive means for realising a relative movement between the write beam and the record carrier, a control circuit for controlling the intensity of the radiation produced by the radiation source in conformity with the information to be recorded so as to form an information pattern of optically detectable marks representing the information, means for directing a verification beam of lower intensity than the write beam to the recording layer in such a way that the verification beam trails the write beam and is modulated by the information pattern formed by means of said write beam, detection means for converting the modulated verification beam into a corresponding read signal, characterized in that the radiation of the write beam and the verification beam originate from the same radiation source, the device further comprising a circuit for generating a correction signal which is an indication of the instantaneous intensity of the radiation produced by the radiation source, and a correction circuit for deriving from the correction signal and the read signal a corrected read signal which is indicative of the read signal divided by the instantaneous intensity of the radiation produced by the radiation source.

Claim 6

A device as claimed in anyone of the Claims 1 to 4, for recording information in a preformed servo track on the record carrier, characterized in that, for deriving a tracking error signal which is indicative of the deviation between the centre of the landing spot of the write beam on the recording layer and the centre of the sevo track, the device comprises means for directing two satellite beams of radiation produced by the radiation source to the recording layer, one of the satellite beams preceding the write beam at a fixed distance and the other satellite beam following the write beam at a fixed distance in such a way that if the write beam is centred on the servo track each of the satellite beams is incident on one the two edges of the servo track, the device employing the trailing satellite beam as the verification beam.