Patent attributes
An image forming apparatus for recording an image on a recording medium according to an inputted diagnostic image signal, including: a recording medium loading section capable of loading plural types of recording media; an exposing device for forming latent images by exposing with predetermined plural test exposure values; a developing device to form developed images on the recording medium; a density measuring device for measuring densities of the developed images; a memory device for storing predetermined density values correlated to the predetermined plural test exposure values; a selecting device for selecting a predetermined number of images among the developed images; and a calibration section for creating LUT that determines a relationship between exposure values and input image signals, based on measured densities of the selected predetermined number of images and stored predetermined density values correlated to the test exposure values.