| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability of displaying virtual images of vehicle related information.SOLUTION: A stepping motor 40, which rotates a reflector 32 to adjust a display position of a virtual image 36 when energized by a drive signal applied thereto, has an electrical stability point &thetas;e, where the motor is electrically stable while being energized, and a mechanical stability point &thetas;m where the motor is mechanically stable when not being energized. A control system 70 controls the drive signal fed to the stepping motor 40 in accordance with adjustment commands. With such a configuration, pole teeth 441, 442 of a certain phase, having greater magnetic attraction force between the same and a rotor 41 than that of pole teeth 451, 452 of a different phase when not being energized, are defined as stable pole teeth. The control system 70 sets the electrical stability point &thetas;e, where magnetic attraction force that produces holding torque while being energized is generated between the stable pole teeth 441, 442 and the rotor 41, as a target stability point &thetas;et and, when the adjustment command input is stopped, continues feeding the drive signal until the target stability point &thetas;et is reached. |
