Patent ID: 7556404

Claim:
A light source device, comprising: a light emitting diode (LED) device including an LED chip, which emits a blue light, and a fluorescent substance, which converts a part of the light from the LED chip; a lens located on a side of a light emitting face of the LED device; and a light diffusing sheet located between the LED device and the lens and located apart from at least one of the LED device and the lens to provide an air gap therebetween, said air gap assisting to equalize a distribution of the light emitted from the LED chip and the light converted by the florescent substance, wherein a periphery of the light diffusing sheet is adhered to the light emitting face of the LED device by an adhesive agent in a manner to provide the air gap therebetween, and wherein a thickness of the adhesive agent is such that the air gap is less than approximately 0.2 mm.