LIGHT QUANTITY CONTROLLER

Japanese Patent JPH03212611

A

PURPOSE:To allow the control of the irradiation light quantity to a surface to be irradiated with high accuracy over a long period of time even if a high-output laser is used as a light source by disposing a parallel plane plate having a pair of light passage surfaces in the optical path between the light source and the surface to be irradiated and controlling the incident light quantity of the surface to be irradiated. CONSTITUTION:The parallel plane plate 13 disposed in the optical path between the light source 10 and the surface 14 to be irradiated consists of quartz, fluorite, etc., which do not substantially absorb the luminous flux of the short wavelength from the light source 10. The light transmission surface thereof is formed in the original state of a black material which is not formed with a coating film, etc. The parallel plane plate 13 is turned in the luminous flux by a driving means 11 in accordance with the output signal from a detecting means 17 disposed near the surface 14 to be irradiated is turned in the luminous flux to an adequately set an incident angle theta, by which a part of the irradiation light quantity is reflected and the transmitted light quantity is controlled to control the irradiation light quantity to be made incident on the surface 14 to be irradiated. The parallel plane plate 13 has no absorption and since the materials to absorb light are not formed at all on both surfaces, the long-term durability as the optical element is maintained.

TORIGOE MAKOTO
SUZUKI AKIYOSHI

JP789190A

September 18, 1991

January 17, 1990

Click for automatic bibliography generation  

CANON KK

G02B26/02; G03B27/32; G03B27/54; (IPC1-7): G02B26/02; G03B27/32; G03B27/54

Takanashi Yukio

Previous Patent: Wallet

Next Patent: PRODUCTION OF LIQUID CRYSTAL DISPLAY ELEMENT OF PERPENDICULAR ORIENTATION TYPE