| 摘要 |
A lamp 1 includes a semiconductor light-emitting element 12 as a light source, a circuit unit 40 that causes the semiconductor light-emitting element 12 to emit light, and an envelope 2 having an outer tube 30 and a base 60. The semiconductor light-emitting element 12 and the circuit unit 40 are housed in the envelope 2. The semiconductor light-emitting element 12 is disposed in a region at a side of an axially central section of the outer tube 30 facing the base 60 and oriented so that a main emission direction points away from the base 60. At least one component of the circuit unit 40 is disposed in a region at a side of the axially central section of the outer tube opposite the semiconductor light-emitting element 12. A light guide 50 that guides emission light of the semiconductor light-emitting element 12 along the axial direction is disposed between the at least one component of the circuit unit 40 and the semiconductor light-emitting element 12. The light guide 50 has a light-diffusing portion corresponding in position to the axially central section of the outer tube 30. |
