Patent ID: 7414734

Claim:
An image position detecting device that detects a position of an image based on a reflected light from an image carrier that reflects a light irradiated from a light emitting source, comprising: first and second light receivers that are spaced apart by a predetermined distance in a moving direction of the image carrier such that the first light receiver detects a toner image adhered on and being moved by the image carrier first, and the second light receiver detects the toner image later; a first amplifier that receives a first analog signal from the first light receiver and amplifies the first analog signal; a second amplifier that receives a second analog signal from the second light receiver and amplifies the second analog signal; wherein the first and second amplifiers have different amplification factors that produce respective first and second amplified analog signals having different peak levels that overlap in time; and a comparison output unit configured to compare the first and second amplified analog signals having the different peak levels that overlap in time to determine whether a level of the first amplified analog signal is higher than a level of the second amplified analog signal, and outputs the comparison result as an output signal in binary form.