FIELD: electricity.
SUBSTANCE: controller (11) LED assesses whether a temperature sensor (21) is normal in accordance with data of measured temperature, and controls brightness of LED (32), measured by an abnormal temperature sensor (21) in accordance with alternative data of temperature instead of temperature data measured by an abnormal temperature sensor (21).
EFFECT: increased homogeneity of light chromaticity and brightness, radiated with a unit of background lighting.
7 cl, 17 dwg
