Information recorder and method, waveform data reproducer and method

Abstract

In a recording unit of an information recording apparatus which performs information recording on an optical disc and the like, recording waveform data defining a driving pulse to be supplied to a recording light source such as a laser diode is prepared as digital data. The digital data is produced in consideration of individual characteristics caused by the laser diode and the laser driver and the combination thereof so that preferred laser emitting waveforms can be obtained when the laser diode and the laser driver are utilized, and the data is stored in advance. During actual information recording, the prepared digital data are read out and the driving pulse waveforms are generated according to data to be recorded, a recording power and the like. The driving pulse waveforms are converted to analog signals, by which a laser diode is driven. Accordingly, effects of individual characteristics of the laser diode and the like are eliminated and appropriate information recording can be performed.

Description

technical field [0001] The present invention relates to the recording of information on optical discs. Background technique [0002] By driving a laser light source with a pulse signal corresponding to the recording data, generating recording laser light, and irradiating it onto the information recording surface of the optical disc, information recording can be achieved by recording information on a recordable optical disc on which Information is appendable and rewritable. As the laser light source, a semiconductor laser such as a laser diode can be utilized. The power of the recording laser can be controlled by controlling the magnitude of the current supplied to the laser diode by a drive circuit such as a laser driver. The laser driver switches multiple current sources and drives the laser diode, and the current magnitudes of the multiple current sources are preset according to the driving pulse signals corresponding to the information to be recorded. The driving pulse...

AI Technical Summary

Problems solved by technology

As mentioned above, since the buffer circuit limits the high-frequency components of the drive pulse signal, the signal is delayed

Thus, the rise time and fall time of the laser emission waveform are delayed

[0006] The second problem is that the snubber circuit does not work properly for both overshoot and undershoot conditions

Therefore, the snubber circuit cannot work simultaneously on the overshoot and undershoot frequencies, and cannot effectively eliminate them

[0007] The third problem is that the buffer circuit cannot correct the level tilt component of the laser emission waveform

Since the frequency of such level tilt is very low, it cannot be corrected by the buffer circuit

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