| 摘要 |
A photographic printer for exposing a photographic transparency onto a photosensitive medium, the photographic printer including a source of illumination for projecting light through the photographic transparency, a light sensor for sensing selected characteristics of the light projected through the photographic transparency, and a combination filter and shutter apparatus. The combination filter and shutter apparatus includes a rotatable wheel defining an exposure aperture, a calibration region for use in calibrating the light sensor, at least one opaque region of suitable size for blocking the light output of the source of illumination, and a neutral density filter region. Control means are provided for rotating the wheel to selectively position the calibration region between the source of illumination and the light sensor to enable the calibration of the light sensor. The control means further functions to selectively position the exposure aperture, neutral density filter region, or the opaque region between the source of illumination and the photosensitive medium to control the exposure of the photosensitive medium. |
