Method for manufacturing optical scanning systems

A method for manufacturing scanning optical systems, by which the scanning optical systems with different effective scanning widths can be obtained by changing a polygon mirror alone without changing an imaging optical system including a scanning lens and an optical system for receiving light, the method comprising the steps of:

• designing a first scanning optical system using a first polygon mirror corresponding to a first value of effective scanning width;
• designing a second scanning optical system provided with a second polygon mirror corresponding to a second value of effective scanning width, the second value being smaller than the first value, wherein a reference point of deflection is located at a position of the reference point of deflection of the first scanning optical system, the reference point of deflection being a point of reflection on a reflecting surface of a ray of light when an angle of deflection of a reflected ray is 0;
• and
• adjusting a size and a position of the scanning lens so as to adjust a lateral magnification in a cross section in a sub-scanning direction of the imaging optical system.