PURPOSE: To switch an irradiation angle according to telephotography and wide-angle photography by arranging a liquid crystal member in the optical path of a projector, and applying a voltage or varying the voltage and varying the irradiation angle of light projection transmitted through the liquid crystal member.
CONSTITUTION: The liquid crystal member 13 has dynamic scattering structure and also has dynamic light scattering effect when applied with an AC voltage and transparency like plane glass when not. Namely, when the liquid crystal member 13 is fed with electricity, reflected light from a reflecting mirror 12 is scattered by the member 13 and projected. The degree of the light scattering is determined by the voltage value and increases when the voltage is raised. When no electricity is fed, light emitted by a xenon discharge tube 11 is transmitted through the member 13 by the reflecting mirror 12 and projected. For the purpose, the member 13 is stopped from being fed electrically and the irradiation light is converged to obtain a normal irradiation angle, so illumination light for standard photography is obtained; when the member 13 is fed electrically, the illumination light is scattered to obtain a wide irradiation angle, thereby obtaining the illumination light for wide-angle photography.
YANAI KAZUO
OKI KENJI
TANAKA HIROKAZU
| JPS5397819A | 1978-08-26 | |||
| JP54158625B |