| 摘要 |
PURPOSE:To commonly use for a type to be controlled to be stopped by a different type by driving a focus adjusting motor for a predetermined period of time in an indefinite direction when an object to be focused is indefinite, and then driving the motor in response to the output of an indefinite end sensing switch. CONSTITUTION:Infrared rays projected from an infrared light emitting diode 1 pass through a projection lens 2, and are reflected on an object and introduced into a photosensor 4 through a photodetecting lens 3. The output of the sensor 4 is input to a microcomputer 9 through an amplifier 5, a synchronous detector 6, an integrator 7 and a comparator 8. The microcomputer 9 drives a focus adjusting motor 10 in response to an input signal. Then, if it is judged as an indefinite mode as a result of distance measurement, the set time motor 10 of a soft timer 9a is driven in an indefinite direction. After a set time is elapsed, the motor 10 is driven in response to the output of an indefinite end sensing switch 12. |
