Patent ID: 8144176

Claim:
An exposure apparatus irradiating a photoconductor drum with light for exposure, comprising: a plurality of light emitting elements which emit light for exposing the photoconductor drum according to image data; a light quantity measuring circuit which measures a plurality of emission quantities each of which is based on emission intensity and emission time of one of the plurality of light emitting elements; a difference acquisition circuit which acquires a plurality of first differences and a second difference, wherein the difference acquisition circuit sets a reference light quantity based on the plurality of emission quantities when the plurality of light emitting elements are supplied with an original gradation signal having specific values corresponding to the image data and emit light for a predetermined emission time, each of the plurality of first differences is a difference between the reference light quantity and each emission quantity, and the second difference is a difference between a target reference light quantity set corresponding to the image data and the reference light quantity; a gradation signal correction circuit generating a plurality of corrected gradation signals by correcting the original gradation signal based on the plurality of first differences so that the plurality of emission quantities of the plurality of light emitting elements in the emission time become close to the reference light quantity; and an emission time correction circuit correcting the emission time based on the second difference so that the plurality of emission quantities of the plurality of light emitting elements corresponding to the plurality of corrected gradation signals become close to the target reference light quantity.