EXPOSURE DEVICE FOR PHOTOGRAPHIC PRINTER

摘要

PURPOSE:To facilitate photometry of the light of the same nature as irradiation light to the plane of a negative film by providing the photodetector in a photometric part in a lens barrel, leading this out by using a light guide and performing photometry. CONSTITUTION:A photometric prism 16 and a prism surface diffusion plate 17 on the top surface thereof are provided near the inside wall of a lens barrel 13, and the diffused and mixed light of roughly the same nature as that of the light irradiated to a negative film surface 15 is conducted through a prism 16 and a light guide such as optical fiber and the quantity of the irradiation light is measured with a detector. If the internal light of a lens barrel 12 for diffusion is measured in this way, the measurement of the light of the same nature as the irradiation light onto the negative film surface is made possible.