Nikon Corporation

Jun Nagatsuka

Takashi Mori

Tsuyoshi Naraki

Shigeru Hagiwara

Haruo Ozawa

Shinichi Hasegawa

Jin Yamada

An optical illumination device reflects and condenses light from a mercury-arc lamp by a light reflecting and condensing member and then reflects and deflects the light, thereafter the reflected and deflected light is transferred to a relay-lens system through a collimator lens or input lens, band-pass filter and fly-eye lens. Gas from which impurities are removed by a filter is flown around optical elements to separate the optical elements from air containing material causing clouding of the optical elements to thereby restrain clouding of the optical elements. On the other hand, or in addition, the reflectance of the light reflecting and condensing member and/or miller for the light of the absorption band of sulfur dioxide is made small to prevent the optical elements from clouding.

Optical illumination device

A light source device houses a lamp such as a mercury discharge tube for generating a high temperature heat, and a reflective optical member such as an elliptic, mirror surrounding the lamp, in a lamp case. When the lamp is forcibly cooled by air, a device for substantially uniformly heating or heat-insulating a reflection surface of the reflective optical member is provided to prevent overcooling of the reflective optical member.

Illumination light source device

Growing community of inventors

Kawasaki, Japan

Jun Nagatsuka