| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drive circuit for an electromagnetic actuator which can reduce the number of power transistors for current switching and the number of pieces of wiring. <P>SOLUTION: A drive circuit 1 for a focus coil 42 and a tracking coil 44 has a step-up DC-DC converter 2 which generates voltage 2Vcc double the voltage Vcc of an external supply power source, and a 2Vcc line 4 is supplied with boosting voltage, and a Vcc line 12 is supplied with power voltage Vcc. Power transistors Q1 and Q2 constituting the drive circuit section 5 of the focus coil are connected in series between the 2Vcc line 4 and a ground line 6, and power transistors Q3 and Q4 constituting the drive circuit part 8 of the tracking coil are connected likewise. The coil 42 is connected between the junction 7 between Q1 and Q2 and the line 12, and the coil 44 is connected between the junction 9 between Q3 and Q4 and the Vcc line 12, too, and the bidirectional energization of each coil 42 and 44 can be performed by the ON-OFF control of Q1 and Q2, and Q3 and Q4. <P>COPYRIGHT: (C)2004,JPO |
