Imaging system, writing head, and image forming apparatus

An imaging system, comprising:

• a plurality of incidence faces composed of a plurality of optical faces through which light enters and having an image focusing function;
• a plurality of prisms;
• and
• a plurality of exit faces,
• wherein the plurality of incidence faces is arranged with a first pitch along a first axial direction, the plurality of prisms is arranged with a second pitch along the first axial direction, the plurality of the exit faces is arranged with a third pitch along the first axial direction,
• wherein the first axial direction is set as a Y direction,
• wherein a normal line direction of a face top of an optical face of the incidence face in a plane perpendicular to the first axial direction is set as a X direction,
• wherein a direction perpendicular to the Y direction and the X direction is set as a Z direction, and
• wherein in a XZ cross-section plane, a width of the prism in the Z direction is smaller than a width of the optical face of the incidence face in the Z direction.