Patent ID: 8287145

Claim:
A lamp including a semiconductor light-emitting element as a light source, a circuit unit configured to cause the semiconductor light-emitting element to emit light, and an envelope having an outer tube and a base, the semiconductor light-emitting element and the circuit unit being housed in the envelope, the lamp comprising: a light guide configured to guide emission light of the semiconductor light-emitting element along an axial direction of the outer tube, wherein the semiconductor light-emitting element is disposed in a region at a side of an axially central section of the outer tube facing the base and oriented so that a main emission direction points away from the base, at least one component of the circuit unit is disposed in a region at a side of the axially central section of the outer tube opposite the semiconductor light-emitting element, and the light guide is disposed between the at least one component of the circuit unit and the semiconductor light-emitting element and has a light-diffusing section corresponding in position to the axially central section of the outer tube.