| 摘要 |
A solid-state lighting device includes a light source section, a light emitting section, a light receiving section, a light guiding section, and a protection circuit. The light source section has a semiconductor laser including a light emitting layer made of nitride, and a driving circuit. The light source section emits laser light having a wavelength range from bluish purple to blue. The light emitting section includes a heat conduction part which includes a wavelength conversion layer absorbs the laser light and emits wavelength-converted light, and an optical part which is capable of guiding the laser light. The light receiving section is capable of detecting returning light from the optical part. The light guiding section guides the laser light from the light source section toward the optical part, and guides returning light from the optical part toward the light receiving section. The protection circuit outputs a driving stop signal toward the driving circuit if it is detected that amount of the returning light is not included in a prescribed range using an electrical signal output from the light receiving section. The driving circuit stops driving the semiconductor laser if the driving stop signal is input. |
