公开(公告)号：US5119360A

公开(公告)日：1992-06-02

申请号：US450679

申请日：1989-12-14

申请人： Tadashi Minakuchi

发明人： Tadashi Minakuchi

IPC分类号： G11B7/125

CPC分类号： G11B7/126

摘要： During playback of data from a recording medium, a light source emitting a light beam incident on the recording medium is driven by a first drive circuit. During this time, a first control circuit produces a control signal to the first driving circuit and controls the first drive circuit such that a power of the light beam is kept constant. During recording of data, on the other hand, a second drive circuit supplies a drive current in superimposition on a drive current from the first drive circuit with a timing corresponding to the recording data. During this time, the control of first drive circuit by the first control circuit is inhibited. However, the control signal immediately before the inhibition is held, and hence the light source is continually driven by the first drive circuit. Thus only a single reference level is necessary for the power control, thus permitting simplification of the construction and cost reduction.

摘要翻译： 在从记录介质回放数据期间，发射入射在记录介质上的光束的光源由第一驱动电路驱动。 在此期间，第一控制电路产生对第一驱动电路的控制信号，并控制第一驱动电路，使得光束的功率保持恒定。 另一方面，在记录数据期间，第二驱动电路以对应于记录数据的定时将来自第一驱动电路的驱动电流叠加在驱动电流上。 在此期间，第一控制电路对第一驱动电路的控制被禁止。 然而，紧接在禁止之前的控制信号被保持，因此光源被第一驱动电路连续驱动。 因此，功率控制仅需要单个参考电平，从而允许简化结构和降低成本。