Constant color temperature and intensity illumination source.

摘要

A source of illumination of constant color temperature and intensity including a lamp 41 the color temperature of the light from which is dependent on the power applied to the lamp 41. There is a device 154 for measuring the intensity of portions of the spectrum of the light and for providing signals indicative of those intensities. Means 174, 45 responsive to the signals adjust the power to achieve the selected color temperature. A light modulator 48 adjusts the intensity without affecting color temperature. There is a spherical mirror 46 centered on the lamp 41 and the modulator 48 is located between the lamp 41 and the mirror 46 and controls the brightness of the image of the lamp 41 formed on the lamp 41 by the spherical mirror 46.