CORRECTING DEVICE FOR QUANTITY OF LIGHT OF VARIABLE POWER COPYING MACHINE

摘要

PURPOSE:To uniformly correct the quantity of light in the whole magnification range by providing a light shield film on the reflecting surface of a mirror between a lens and a photosensitive body in such a profile that the quantity of light in enlargement becomes uniform. CONSTITUTION:A figure shows the reflecting surface of one of mirrors 8a, 8b, and 8c between the lens and photosensitive body. The effective surface 9a of reduction side, the effective surface 9b of unmagnification, and the effective surface 9c of enlargement side are shown in the figure and light shield films 10a and 10b of black dye, etc., are formed by coating at both breadthwise side parts of the reflecting surface of this mirror. Those light shield films 10a and 10b have reflecting surfaces in such a profile that the light in enlargement is reflected toward the photosensitive body 4 to the uniform quantity of light; the peak part is close to the effective surface 9b of unmagnification and both side parts form a gentle mountain shape so that both lengthwise end parts of the effective surface 9c are cut.