ORIGINAL READER, LIGHT AMOUNT ADJUSTMENT METHOD ON ORIGINAL READING AND LIGHT AMOUNT ADJUSTMENT PROGRAM

PROBLEM TO BE SOLVED: To provide an original reader which can set a light amount in short time by light emitting means without need of drive data of the light emitting means when adjustment is completed in previous time and to provide a light amount adjustment method upon original reading and a program.SOLUTION: Light amount data acquisition means 13 acquires light emission time per light emission by light emitting means 11 or a current value per light emission when the light emitting means 11 emits light for unit time as light amount data in a range for achieving the light amount which is one fraction of the light amount requested from a reference white original in a plurality of kinds. A linear approximate expression is calculated by using a signal level of light receiving means 12, which corresponds to the light amount data. Light amount adjustment completion estimation value calculating means 16 calculates a light amount adjustment completion estimation value. Since light amount adjusting means 17 adjusts the light amount in response to the estimation value, processing time is shortened.