EVALUATOR FOR CHARACTERISTIC OF 3-WAVELENGTH REGION EMISSION TYPE FLUORESCENT LAMP

摘要

PURPOSE:To evaluate the degree of the chromaticity point of a 3-wavelengh region emission type fluorescent lamp having the correlative color temp. in a 5,000+ or -2,000K range deviated from a black body locus by calculating the value (R/G) of the ratio between the spectral radiation energy at about 610nm wavelength and the spectral radiation energy at about 545nm wavelength. CONSTITUTION:The radiated light from a sample light source 1 enters a photodetecting part 3 through a lens 2. The part 3 is constituted of a filter having spectral transmittance at about 545nm wavelength and filter having spectral transmittance at about 610nm wavelength. The electrical signals corresponding to the spectral radiation energy at about 545nm wavelength of the sample light source 1 itself and the spectral radiation energy at about 610nm wavelength are obtd. from the light transmitted through the photodetecting part 3 in a photoelectric conversion part 4. The value R/G is calculated from the output signal from the part 4 in a divider 5 and the value of DUV (the value obtd. by multiplying the distance between the chromaticity point of the lamp and black body locus by 10<3> times) is obtd. from said value by an R/G-D converter and is displayed 7.