Optical recording/reproducing apparatus

An apparatus for forming multiple marks, which are associated with information to be recorded, in an information layer of an information carrier by irradiating the information layer with a pulsed radiation beam such that optical characteristics of the information layer are locally changed, the apparatus comprising:

• information write means for generating write pulses in forming each said mark and for modulating the radiation beam with the write pulses;
• information readout means for sensing a variation in the optical characteristics of respective parts of the information layer where the marks have been formed;
• a long mark data generator for getting at least one test mark written in the information layer by the information write means, the length of the test mark being equal to or greater than a preselected length;
• and
• a mark width comparator for determining whether or not the test mark includes a read-error-inducing portion in which the optical characteristics have not changed sufficiently for reading out a signal associated with the test mark correctly,
• wherein if there is the read-error-inducing portion in the test mark, an average power of the radiation beam is increased from an initialized level in forming a mark with a length at least equal to that of the test mark, thereby correcting the power in such a manner as to eliminate the read-error-inducing portion from the mark.

An apparatus A method for forming multiple marks, which are associated with information to be written, in an information layer of a rewritable information carrier by irradiating the information layer with a pulsed radiation beam such that optical characteristics of the information layer are locally changed,

• wherein a test recording operation is performed, the test recording operation comprising the steps of:
• a) writing at least one test mark in the information layer, the length of the test mark being equal to or greater than a preselected length;
• b) sensing a variation in the optical characteristics of part of the information layer where the test mark has been formed;
• and
• c) determining whether or not the test mark includes a read-error-inducing portion in which the optical characteristics have not changed sufficiently for reading out a signal associated with the test mark correctly, and
• wherein if it has been determined in the step c) that there is the read-error-inducing portion in the test mark, an average power of the radiation beam is increased from an initialized level in forming a mark with a length at least equal to that of the test mark.

An apparatus for forming multiple marks, which are associated with information to be written, in an information layer of a rewritable information carrier by irradiating the information layer with a pulsed radiation beam such that optical characteristics of the information layer are locally changed, the apparatus comprising:

• a memory where information defining a pulse train, which will drive a source of the radiation beam, is stored;
• a write circuit for generating the pulse train in accordance with the information stored on the memory;
• a read circuit for reading out data associated with the marks that have been formed in the information layer;
• and
• a controller, connected to the write and read circuits, for controlling write and read operations,
• wherein the controller is programmed in such a manner as to perform the write and read operations for a mark with a length equal to or greater than a preselected length and to update the information stored on the memory such that the pulse train is optimized for the mark with the length.