| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To smoothly adjust an optical axis direction of a headlight by making motor characteristics such as starting torque and stopping performance constant in a position control of one to two phase alternate excitation for a step motor. <P>SOLUTION: By utilizing an increase of starting torque in a two-phase excitation state of the bipolar type constant current driving step motor as compared with a one-phase excitation state and shortening of stopping time in the one-phase excitation state as compared with the two-phase excitation state, the step motor is stopped in the one-phase excitation state (time t003 to time t004, etc.) by a microcomputer via a constant current motor driving circuit, and the step motor is started in operation in the two-phase excitation state (time t002 to time t003). As a result, the optical axis direction of the headlight of a vehicle is quickly and smoothly adjusted, and unnatural feeling is not impaired to a driver in a position control of the optical axis direction of the headlight. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
