| 摘要 |
PURPOSE:To attain stable spot control by widening the band of luminous quantity control more than the band of the spot control (controlling up to higher frequencies) to make the luminous quantity constant in the range of the band of the spot control thereby and eliminating the effect of mutual interference. CONSTITUTION:A laser light source 710 to radiate a laser beam onto an optical disk, a luminous quantity control means 720 controlling the luminous quantity from the laser light source 710, and a spot control means 730 to focus the laser beam onto a track of the optical disk and to be traced to the track of the optical disk. Then the band of the luminous quantity control means 720 is selected wider than the band of the spot control means 730. Thus, the laser luminous quantity and the servo signal are not mutually interfered and the spot control is made stable. Thus, the luminous quantity is constant within the band of the spot control and stable control is obtained. |
