| 摘要 |
PURPOSE:To obtain a sharp recording image of high quality at all times by starting automatic focusing operation according to an operation signal from a temperature control means and adjusting the focusing of a laser beam. CONSTITUTION:A temperature adjusting circuit 14 monitors the temperature variation of a solid laser element 1 through a thermistor 6 at all times and supplies a DC current to a Peltier element 7 according to the quantity of the variation to cool the solid laser element 1. Thus, the temperature variation quantity of the solid laser element 1 is outputted from the temperature adjusting circuit 14 to an automatic focusing control part 15 and when the variation quantity exceeds a set value, automatic focusing operation is performed, so the focusing of the laser beam is accurately performed in consideration of the piezoelectric effect of the Peltier element 7 which is a semiconductor. Consequently, sharp image recording of high quality is performed at all times without reference to environmental variation of temperature, humidity, etc. |
