| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical output device with which a luminous flux of which the divergent angle is sufficiently small is projected by using a light emitting diode. SOLUTION: A composite lens 25 of which the central part 27 is a concave lens and the peripheral part 26 is a convex lens is arranged as a second lens group 22 in front of a light emitting diode unit 10 provided with a convex lens 16 which serves as a first lens group 21 at the end of the unit. An A-mode luminous flux directly outputted from the light emitting diode 12 of the light emitting diode unit becomes a parallel luminous flux by means of the first lens group 21 and the peripheral part 26 of the second lens group, and a B-mode luminous flux which is outputted from the light emitting diode 12 and reflected on a rear cone-shaped reflection surface 14 also becomes a parallel luminous flux by means of the first lens group 21 and the central part 27 of the second lens group. Thus, a luminous flux 55 having a small divergent angle, which is composed of the A-mode and B-mode luminous fluxes, is outputted. |
