Recording-medium imaging device and image forming apparatus

摘要

An effective image area can be properly corrected in accordance with the quantity of light from an irradiation unit (41) by selecting, as the effective image area, pixels having light quantities more than or equal to a threshold value that allows accurate acquisition of a surface image of a recording medium (P), on the basis of a light quantity distribution of the light from the irradiation unit (41). This reduces the influence of mounting accuracy of the irradiation unit (41), and allows the recording medium (P) to be identified accurately.