Optical writing apparatus and image forming apparatus

An optical writing apparatus comprising:

• a light source panel including a plurality of light emitting elements linearly arranged on an elongate glass substrate, wherein the glass substrate is elongate in a longitudinal direction;
• an optical member that causes emergent light from the plurality of light emitting elements to form an image onto an object to be irradiated;
• a first holding member holding the optical member;
• a second holding member holding the glass substrate so that the glass substrate floats above the second holding member,
• wherein legs are provided below the first holding member on sides of both ends in a lateral direction of the glass substrate, the legs extending downward, lower ends of the legs being mounted and fixed on the second holding member, the first holding member and the second holding member surrounding the glass substrate such that a space is present above and below the glass substrate;
• and
• an integrated circuit that drives the light emitting elements to turn on provided on a lower surface on a side of one end of the glass substrate that is positioned inside the space surrounded by the first holding member and the second holding member,
• wherein a through hole is provided through an upper surface of the second holding member on a center side of and spaced from the integrated circuit in the longitudinal direction, and
• when cooling air for the integrated circuit flows from the side of the one end into the space surrounded by the first holding member and the second holding member, the cooling air is guided through the through hole to a space below a lower surface of the second holding member.