APPARATUS FOR DETECTING SYNCHRONOUS SIGNAL

摘要

PURPOSE: An apparatus for detecting a synchronous signal is provided to prevent the failure in image quality as well as to reduce the assembly process by reducing the number of elements. CONSTITUTION: An apparatus(130) for detecting a synchronous signal includes a light flux detection sensor and a focusing lens(108). The light flux detection sensor generates the synchronous signal to synchronize the light flux forming the electrostatic afterimage with the starting position. The focusing lens(108) is placed between the detection path of the light flux forming the electrostatic afterimage on the photosensitive material to form the detection path of the light flux from the light flux detection sensor to the light source for generating the light flux. And, the focusing lens(108) focuses the portion of the light flux traveling to the photosensitive material and reflects the focused light flux to the sensing region of the light flux detection sensor.