Light irradiation system, image scanning apparatus, and image forming apparatus

A light irradiation system for irradiating light to an irradiation area extending in a main scanning direction of a document face when placed on an image scanning apparatus, comprising:

• a light source;
• a light guiding member to guide light emitted from the light source;
• and
• a reflector to reflect a part of light exiting from the light guiding member to the document face,
• wherein a direction that emission light intensity of the light emitted from the light source becomes the strongest is different from a direction extending from the light source to the irradiation area irradiated by light,
• wherein the irradiation area is irradiated by a reflection light reflected by the reflector after exiting from the light guiding member, and a direct light exiting from the light guiding member without reflection at the reflector,
• wherein the light guiding member including an incidence surface where the light from the light source enters;
• an exit surface where the light entered from the incidence surface exits;
• and
• a light guiding part to guide a part of the light entering from the incidence surface to the exit surface, wherein the light guiding part including a total reflection face to totally reflect a part of the light entering from the incidence surface to the irradiation area,
• wherein light quantity irradiated to the document face by the reflection light is smaller than light quantity irradiated to the document face by the direct light.