| 摘要 |
PURPOSE:To prevent a recording state from being changed due to the temperature change of environment in use by providing a temperature sensor, and controlling the strength of a recording signal corresponding to the output of the temperature sensor. CONSTITUTION:The output signal of the temperature sensor 12 arranged at a position approaching the recording point of a magneto-optical disk 1 is supplied to a target value setting circuit 13 as a control signal. To the target value setting circuit 13, a signal SR representing a reference value is supplied, and a signal SP' representing a target value is formed so as to go to a value equal to the level of the output signal SD of a monitor diode 10 at a time when it is the optimum recording laser power value at respective temperature, and is supplied to a comparator 11. At the comparator 11, the level of the output signal SD of the monitor diode 10 is compared with that of the signal SP', and a comparison error signal from the comparator 11 is supplied to a modulator 4 as the control signal, and the amplitude of a signal outputted from the modulator 4 is controlled, and the laser power value of a laser beam generated from a laser diode 6 is controlled. |
