Patent ID: 7556410

Claim:
A headlight device for a motorcycle, which comprises: a pair of headlight units disposed laterally on right and left sides with respect to the motorcycle, in which at least one of those headlight units is a movable headlight unit including a light distribution adjusting mechanism for changing a range of illumination during a cornering of the motorcycle; and a bank angle detector for detecting a bank angle of the motorcycle, including a gyroscope to measure a rotational angular velocity of the motorcycle, a speedometer for measuring a traveling velocity of the motorcycle, and a bank angle calculator for calculating a bank angle of the motorcycle using the rotational angular velocity and the traveling velocity of the motorcycle, wherein the light distribution adjusting mechanism adjusts the movable headlight unit based on the detected bank angle, and the light distribution adjusting mechanism includes a light distribution changing mechanism configured for shifting to change the range of illumination and a driving unit for shifting the light distribution changing mechanism, wherein the light distribution adjusting mechanism also includes a position detector for detecting a position of the light distribution changing mechanism, and wherein the driving unit and the position detector are positioned on one side of a center of the movable headlight unit and adjacent a mid-center plane in the width direction of the motorcycle.