A vehicle headlamp device contains a rotation-state recognizing circuit operating
such that when any of Hall elements used for controlling a rotational position
of a drive motor for deflecting the optical axes in a headlamp device is abnormal,
a rotation-state recognizing circuit recognizes a rotational position of the drive
motor based on the output signals of the remaining Hall elements and a predetermined
angle prediction time computed using a rotational period of the drive motor. With
provision of the rotation-state recognizing circuit, even when any of the Hall
elements becomes defective, the rotation of the drive motor is normally controlled
to thereby secure a proper optical-axis deflection control in the headlamp device.
