Shading correction method, photographic printer and index print production apparatus

摘要

A method of correcting the light amount irregularities for a photographic printer in which an image displayed on a two-dimensional display unit is exposed by transmitting or reflecting the light from a light source through or from the two-dimensional display unit is disclosed. An LED light source is turned on with a predetermined driving voltage applied to all the pixels of a liquid crystal panel. The image on the liquid crystal panel is exposed for a predetermined length of time by the light transmitted through the liquid crystal panel and developed thereby to produce a photographic print. The density at a point corresponding to each pixel of the liquid crystal panel is measured. The light transmittance correction amount for each pixel of the liquid crystal panel is determined in such a manner that the density measured at each point conforms to a predetermined reference density (a minimum value of density measurement, for example). The driving voltage correction data for each pixel of the liquid crystal panel is calculated on the basis of the light transmittance correction amount thus determined.