Light source device and light source device for image reading device

A light source device for an image reading device, the light source device comprising:

• a substrate;
• a first light emitting element emitting red color light for reading image information of an image of an original by the emitted light being at least one of transmitted through and reflected by the original, the first light emitting element including a secondary peak emission, a wavelength of which corresponds to infrared ray wavelength region;
• a second light emitting element emitting infrared rays, which are invisible, utilized for detecting defect portions of the original and dust existing on an optical path of an optical system;
• and
• a light damping member for damping the light in an infrared ray wavelength of the first light emitting element and disposed on the path by which the light emitted by the first emitting element reaches an image pick-up device of the image reading device,
• wherein the first light emitting element and the second light emitting element are disposed on the substrate.

A light source device comprising:

• at least one first substrate;
• at least one second substrate;
• first light emitting elements, which emit red color light;
• and
• second light emitting elements, which emit infrared rays,
• wherein the first light emitting elements are disposed on the first substrate, and
• the second light emitting elements are disposed on the second substrate.