| 摘要 |
PURPOSE:To attain scanning with high freedon by setting up the number of times of scanning by a counter, preventing the positional shift of scanning and controlling a scanning step by an external signal. CONSTITUTION:Horizontal scanning is executed by driving a horizontal scanning driving coil 9 by a driving signal from a horizontal scanning driving circuit 10 and oscillating a scanning mirror, and vertical scanning is executed by rotating a rotary shaft 5 by a step motor 7 and moving a gimbal 2. The rotary shaft 5 is reciprocated between an upper limit switch 6a and a lower limit switch 6b several times from the input time of a reset signal. When said rotary shaft 5 has contacted with the upper limit switch 6a after reciprocated by the prescribed number of times, horizontal pulses outputted each scanning are counted by the prescribed number of times and then the scanning means can be reciprocated in the vertical direction every prescribed number of times of scanning and the scanning step also can be controlled. |
