Patent ID: 7690827

Claim:
An illumination apparatus comprising: a cylinder-shaped light guide member; and a plurality of point light sources disposed at intervals on a lower end portion of the cylinder-shaped light guide member along the light guide member, wherein said light guide member comprising: the lower end portion for introducing the light of the point light sources; an upper end portion for outputting the light; and a light guide portion having a pair of side faces and for guiding the light of the point light sources from the lower end portion to the upper end portion, and wherein the lower end portion includes a groove portion for receiving the output light of each of the point light sources and diffusing the output light of the point light sources to at least three directions from an incident side toward an output side, and wherein the groove portion of the light guide member provided along a circumference direction of said cylinder-shaped light guide member corresponding to positions of said plurality of point light sources and comprises; a flat portion; and a pair of slope faces each having an opposite inclination direction and for refracting the output light of the point light sources to one side face direction and to the other side face direction of the light guide portion.