Light irradiation device, light irradiation system, and image forming apparatus

A light irradiation device comprising:

• a light emitting unit that emits light while generating heat;
• a cooling unit that includes a channel through which a coolant flows, a first surface on which the light emitting unit is mounted, and a second surface that faces a direction opposite to the first surface;
• a supply unit having a rectangular parallelepiped shape extending in a depth direction of the light irradiation device, and the supply unit is disposed facing the second surface in one direction that the second surface faces, the supply unit supplying the coolant to the cooling unit and a length of the supply unit in a width direction of the light irradiation device is shorter than a length of the cooling unit in the width direction of the light irradiation device;
• and
• a driving unit that is disposed facing the second surface in the one direction, the driving unit including:
• a driving board that drives the light emitting unit;
• a bracket with which the driving board is fixed to the second surface of the cooling unit, and the bracket extends in the depth direction of the light irradiation device, wherein the bracket comprises:
• a bottom plate whose plate surface is in contact with the second surfaces of the cooling unit;
• and a side plate whose plate surface faces the width direction of the light irradiation device;
• and
• a plurality of spacers, being interposed between the driving board and the side plate.