| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical scanning optical device capable of enhancing the detection accuracy of the writing position of an image and the output stability of a light source, and always acquiring a good image, and to provide an image forming device using the same. SOLUTION: The optical scanning optical device includes a light source means 1 and has a first optical system 42 to make incident light flux emitted from the light source means on a deflection means 10, a second optical system 43 to image-form the light flux reflected to deflection with the deflection means in an effective scanning area on a surface to be scanned 12, and a writing position detecting optical system 35 which guides at least a part of light flux among the light flux reflected to deflection by the deflection means with which the outside of the effective scanning area is scanned to a synchronous detection element 38, and controls the timing of a scanning starting position on the surface to be scanned by using a signal from the synchronous detection element. The light source means is always turned on even when the outside of the effective scanning area is scanned with the light flux. |
