PURPOSE: To improve light shielding property and the field of view, by constituting a light filter by a liquid crystal body whose light transmittance can be adjusted by applying a voltage.

CONSTITUTION: A light filter mechanism which is constituted by the liquid crystal body 7, a polarizer 2, a light-sensor 3, and transparent electrodes 4 and 4' is mounted on a wind shield glass part and the like of the automobile. In this constitution, natural light is polarized by the polarizer 2, and enters the liquid crystal body 7. The polarization axis is rotated by 90°. Then light passes the light sensor 3. Therefore the glass is transparent. When the voltage is applied to the electrodes 4 and 4', the light is shielded by the light sensor 3 because the polarization axis is not polarized by the liquid crystal body 7. If said electrode 4 and 4' are divided into a plurality of parts and the electrodes to which the voltage is applied can be selected, light can be shielded only at the necessary areas. Therefore the shielding property and the field of view can be improved.