Abstract: A fluorescent lamp includes a phosphor layer containing a blue phosphor having an emission peak in the 440 to 470 nm wavelength range, a green phosphor having an emission peak in the 505 to 530 nm wavelength range, a green phosphor having an emission peak in the 540 to 570 nm wavelength range, and a red phosphor having an emission peak in the 600 to 670 nm wavelength range. The ratio I1/I2 of the emission peak energy I1 in the wavelength range of 505 to 530 nm to the emission peak energy I2 in the wavelength range of 540 to 570 nm is not less than 0.06. The color temperature of the lamp is not more than 3700 K.

Abstract: A discharge lamp which radiates visible light having the following lights combined: light having an emission peak in 400 to 490 nm wavelength range in a blue spectral region; light having an emission peak in a 500 to 550 nm wavelength range in a green spectral region; and light having an emission peak in 600 to 670 nm wavelength range in a red spectral region. The color point of the radiated light lies within a region common to the following regions: a region bounded by an ellipse with a color point (u, v)=(0.224, 0.330) as a center thereof, a major axis of 0.056, a minor axis of 0.024, and an angle from the u axis of 20 degrees in the CIE 1960 UCS diagram; a region bounded by an ellipse with a color point (u, v)=(0.224, 0.330) as a center thereof, a major axis of 0.078, a minor axis of 0.014, and an angle from the u axis of 30 degrees in the CIE 1960 UCS diagram; a region bounded by an ellipse with a color point (u, v)=(0.235, 0.335) as a center thereof, a major axis of 0.

Abstract: A discharge lamp for an automobile headlight has a light color that lies in a region common to the following three regions: a region bounded by an ellipse with a color point (u, v)=(0.224, 0.331) as a center thereof, a major axis of 0.080, a minor axis of 0.024, and an angle from a u axis of 35 degrees in the CIE 1960 UCS diagram; a region bounded by an ellipse with a color point (u, v)=(0.220, 0.332) as a center thereof, a major axis of 0.060, a minor axis of 0.022, and an angle from a u axis of 15 degrees in the CIE 1960 UCS diagram; and a region bounded by an ellipse with a color point (u, v)=(0.235, 0.335) as a center thereof, a major axis of 0.060, a minor axis of 0.030, and an angle from a u axis of 30 degrees in the CIE 1960 UCS diagram.

Abstract: A light source for categorical color perception has major light emitting bands in ranges from 530 to 580 [nm] and from 600 to 650 [nm], with correlated color temperature of the lamp light color in a range from 1700 to 6500 [K] and with DUV (distance from perfect radiator locus on UV coordinates) in a range from 0 to 70, and allows categorical perception of at least red, green, blue, yellow and white of surface colors of an illuminated object.

Abstract: A light source for categorical color perception has major light emitting bands in ranges from 530 to 580 and from 600 to 650, with correlated color temperature of the lamp light color in a range from 1700 to 6500 and with DUV (distance from perfect radiator locus on UV coordinates) in a range from 0 to 70, and allows categorical perception of at least red, green, blue, yellow and white of surface colors of an illuminated object.

Abstract: A display device includes an ambient light sensor positioned adjacent a display screen so as to confront an occupant in front of the display device, and a luminance level setting unit for inputting a desired luminance level. An output from the ambient light sensor is fed to a screen luminance calculating unit for calculating the adjustable range of screen luminance to be adjusted on the basis of an output signal from the ambient light sensor. A luminance determining unit determines a proper screen luminance based on an output signal from the screen luminance calculating unit and an output signal from the luminance level setting unit. A screen luminance control unit operates in response to an output signal from the luminance determining unit to adjust the screen luminance to the proper screen luminance.