Patent ID: 8545083

Claim:
A light-emitting device, comprising: a light source comprising an element mounting substrate, a light-emitting diode (LED) element mounted thereon by flip-chip connection and a sealing portion for sealing the LED element on the element mounting substrate; and a light guide plate comprising a housing hole for housing the light source, wherein the housing hole extends from a first surface side to a second surface side of the light guide plate and an area of an inner surface thereof on which a light is incident from the light source is parallel to a thickness direction of the light guide plate, wherein the light source is housed in the housing hole so that the element mounting substrate is located on the second surface side of the light guide plate, emits the light toward the first surface side of the light guide plate in the housing hole and an inner surface side of the housing hole, and has an optical axis parallel to the thickness direction of the light guide plate, wherein a solid angle of the inner surface of the housing hole with respect to a center of an upper surface of the light source is not less than 4.44 steradians, and wherein a formula, 90°−sin −1 [{sin(90°−α)}/n]+α≧sin −1 (1/n), is satisfied, where α is an angle of an inner surface of the housing hole with respect to the second surface of the light guide plate and n is a refractive index of the light guide plate.