Patent ID: 8237762

Claim:
An exposure device comprising: a light emitting element; a reference current generating unit that generates a reference current corresponding to a target value of a light amount of the light emitting element, for each image of respective colors formed by exposure using the light emitting element; a photoelectric current generating unit that generates a photoelectric current in response to the light amount of the light emitting element; a driving unit that drives the light emitting element by providing a drive voltage from a drive voltage holding unit to the light emitting element; a first controller that controls the driving unit so that the photoelectric current becomes equal to the reference current; a comparison current generating unit that generates a predetermined comparison current; and a difference current generating unit that generates a difference current for each color, having a value corresponding to a difference between the reference current of each color and the predetermined comparison current, wherein the first controller compares a value obtained by adding the difference current of each color to the photoelectric current with the predetermined comparison current to provide the drive voltage to the drive voltage holding unit such that the photoelectric current becomes equal to the reference current.