| 摘要 |
PURPOSE:To prevent the generation of the deterioration of are produced light by driving an optical head as specifying time S to irradiate one spot of a recording medium. CONSTITUTION:When an irradiation time, during which the characteristic of the recording medium is changed by the light irradiation to the recording medium, and an AF control loop comes impossible to be drawn in the optical head because of the change of the quantity of light, incident to a photodetector, is assumed to be T, and the number of times that the said recording medium is expected to be used, is assumed as N, the optical head is driven so that the time S, for which one spot of the recording medium is irradiated, comes to be S<(T/N). In concrete terms, a system controller sends a timer ON signal to a timer circuit 9 at a drawing finish signal, and makes it count the prescribed time. when the count of the prescribed time is finished, a finish signal is sent to the system controller 4, and the system controller 4 sends the signal for driving the optical head 5 or a card to the respective drivers 10, 11. Thus, the AF can be surely drawn in without receiving the influence of the reproduced light deterioration. |
