| 摘要 |
PROBLEM TO BE SOLVED: To provide a light guide and an irradiation unit that are capable of a high-luminance lighting with enhanced light density, while attenuation due to optical fiber transmission of emission intensity of a light source is suppressed. SOLUTION: In the light guide where a light beam entering an incident end 3b is emitted from an exiting end 3c of an optical fiber bundle 3a, wherein a plurality of optical fibers 9 having a fixed diameter from one end to the other are formed into the bundle 3a, with the one end used as the incident end 3b and the other used as the exiting end 3c; and a numerical aperture is made different for the incident end 3b and for the exiting end 3c, setting the numerical aperture NA1 of the incident end 3b to be larger than the numerical aperture NA2 of the exiting end 3c. COPYRIGHT: (C)2007,JPO&INPIT |
