| 摘要 |
PURPOSE:To record surely recording signals of high frequency and keep the quantity of light at an optimum value when the level and the duty ratio of recording signals are varied, by controlling variably the quantity of light in accordance with the peak value of the quantity of light of an optical beam or the frequency of recording signals. CONSTITUTION:A part of a laser beam of a laser generator 3 is supplied to a detector 4 for a recording signal (a), and the detection signal is supplied to an equalizer 5. The equalizer 5 generates an equalizing signal (b), whose amplitude is changed in accordance with the frequency, and supplies this signal to a peak detector 6, and the detector 6 detects the peak of the signal (b) and inverts it to generate a control signal (d) and supplies this signal (d) to a laser modulator 2. The modulator 2 superposes the signal (a) onto the signal (d) to generate a driving current (e) and supplies this current to the generator 3. Thus, the quantity of light of the laser light outputted from the generator 3 is increased in proportion to the current (e) according as the frequency is higher. |
