| 摘要 |
PURPOSE:To make it possible to judge lamp characteristics by a simple method, by providing a plurality of filters having different light transmitting wavelength regions, and computing a ratio with respect to the radiation energy component of the total visual area. CONSTITUTION:A filter 8 transmits a visual region of 380-780nm, a filter 9 a wavelength region of 445-475nm, a filter 10 a wavelength region of 525-555nm, and a filter 11 a wavelength region of 595-625nm. The light beams transmitted through the filters 8-11 are inputted to photoelectric converters 12-15 and converted into electric signals. The output signals of the converters 13-15 are inputted in an adder 5 and added. The output signal of the converter 12 and the output signal of the adder 5 are inputted to a subtractor 6. A ratio between the radiation energy component of the three-wavelength regions (445-475, 525-555, and 595-625nm) of a lamp to be measured and the radiation energy of the total visible region is computed and displayed by a display part 7. |
