| 摘要 |
PURPOSE:To facilitate high integration, to miniaturize a device and to improve productivity by forming a control information generation means into a digital circuit. CONSTITUTION:The light receiving elements 31(a), 31(b), 31(c), and 31(d) output respectively the signals A, B, C, and D according to the light strength of incident laser light 44 to A/D converter 29(a), 29(b), 29(c) and 29(d). A/D converters 29(a), 29(b), 29(c) and 29(d) are connected respectively to a control circuit 22 through a data bus 49 and an address bus 50. The control circuit 2 performs the control operation in accordance with a program memorized by ROM 23 and others which are also connected to the data bus 49 and the address bus 50. The data bus 49 and the address bus 50 are connected to the D/A converters 24 and 25. At the D/A converters 24 and 25, the signals converted into the analog signals are given to the actuator coils 27 and 28 through a driving circuit 26. |
