JPS6198224U - - Google Patents

Description

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of this invention, Fig. 2 is a waveform diagram showing a focus actuator drive signal at startup, and Fig. 3 is a diagram showing a conventional automatic focus control starting device for an optical pickup. FIG. 4 is a cross-sectional view showing the structure of the focus actuator, and FIG. 5 is a waveform diagram showing the focus actuator drive signal. The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] An objective lens arranged to focus the projected light onto the optical disk, a focus actuator that drives this objective lens in the optical axis direction, and a focus actuator that drives the objective lens in the optical axis direction. a focus error detection device that outputs a focus error signal according to the focal shift of the focal point, a lamp signal generation circuit, and a lamp signal from this circuit and the focus error signal that are switched and applied to the focus actuator. The changeover switch is configured to apply the lamp signal when the focus actuator is activated, and apply the focus error signal to the focus actuator when the focus error signal becomes less than a predetermined value after activation. An automatic focus control starting device for an optical pickup equipped with a control circuit for controlling the optical pickup includes a pulse signal generation circuit that generates a pulse signal at the rising edge of the lamp signal, and an adder circuit that superimposes this pulse signal on the lamp signal. An automatic focus control starting device for an optical pickup, characterized in that: