| 摘要 |
PURPOSE: To minimize laser feedback during data recording by providing a controlling means for enabling the establishment of a state a little out of focus selected during the data recording operation. CONSTITUTION: An optical disk 10 reflects a beam supplied from a laser 11 through an objective condenser lens 19 and an optical system 300. The optical system 300 changes the direction of a reflected light, and directs it along an optical path 22 to a focus detector 304. The focus detector 304 supplies a focal error signal to a condensing circuit 23'. The circuit 23' is connected to a focal coil 303 so that a proper focus control signal for activating the movement of a lens carriage 32 can be supplied. In this constitution, it is preferable that a focus 330 is not directly abutted to the reaction layer of the optical disk 10 by shifting a little the focus of the lens during a writing processing. Therefore, the focus servo of the circuit 23' can establish and hold the focus 330 at a position out of focus relatively to the surface of the optical disk 10. |
