SLIT EXPOSURE ILLUMINATING DEVICE

摘要

PURPOSE:To make a device small-sized and efficient and reduce the rise of temperature of a main reflecting mirror by forming the front part and the rear part of the main reflecting mirror to conduit shapes having elliptic sections and placing the rear end of the front part of the main reflecting mirror in the light source side and providing an aperture part in the connection part connecting the front part and the rear part of the main reflecting mirror. CONSTITUTION:Since the front end of a main reflecting mirror front part 2a is above a lens array 5, the light is prevented from striking the lens array. A main reflecting mirror rear part 2b has the elliptic section having an eccentricity lower than that of the main reflecting mirror front part 2a and condenses the light from a light source 1 to an exposure surface by one reflection to illuminate the exposure surface efficiently without the loss due to multiple reflections. Since a slit hole 6 is provided and the front end of the main reflecting mirror front part 2a is placed above the lens array 5, the main reflecting mirror front part 2a is ventilated well. Since the slit hole 6 is provided in a connection part 2c, the main reflecting mirror front part 2a and the main reflecting mirror rear part 2b are connected by only both end parts, and heat transmission from the main reflecting mirror rear part 2b to the main reflecting mirror front part 2a is reduced.