PURPOSE: To record, reproduce and erase a signal on an optical recording medium, by forming an optical spot giving the condition of temperature rise gradual cooling and that of temperature rise rapid cooling by a same aperture lens, and controlling the intensity of both spots as required.
CONSTITUTION: A circuit 116 driving a laser 103 controls the intensity of an optical spot M formed on a pit 51, being approximately elliptic or oval form and whose major axis is coincident with the lengthwise direction of the pit 51, and a circuit 117 driving a laser 101 controls the intensity of an almost circular optical spot L formed on the pit 51. The two optical spots are formed closely on a guide track, the one optical spot is almost circular and the other optical spot is an oval shape along the guide track, the lights include a desired intensity or signal and are irradiated on a recording thin film while being tracked on the guide track on an optical recording disc.
SATOU ISAO
OOHARA SHIYUNJI
KOISHI KENJI
KUROKI YUZURU
