| 摘要 |
PROBLEM TO BE SOLVED: To achieve stable light emission even under a vibrating environment.SOLUTION: A lamp 50 includes: semiconductor light-emitting elements 11a, 11b for emitting excitation light; a wavelength conversion element 10 for converting the excitation light into light having a wavelength different from that of the excitation light; and a concave mirror 13 arranged so as to reflect the excitation light emitted from each of the semiconductor light-emitting elements 11a, 11b, make the light incident in the wavelength conversion element 10, and reflect and emit the light emitted from the wavelength conversion element 10 to the outside of the lamp. A beam diameter of the excitation light is defined as D, length of the wavelength conversion element 10 in the direction vertical to an optical axis of the concave mirror 13 is defined as Dphos, a focal distance of the concave mirror 13 is defined as f, and an opening radius of the concave mirror 13 is defined as R, a distance y1 between an optical axis of the semiconductor light-emitting element 11a and the optical axis of the concave mirror 13 satisfies (D+Dphos)/2≤y1≤4f, and a distance y2 between the optical axis of the semiconductor light-emitting element 11b and the optical axis of the concave mirror 13 satisfies 4f<y2≤R. |
