| 摘要 |
PURPOSE:To detect automatically the degradation of a discharge lamp, by comparing the output voltage outputted from a photoelectric converting part with a set reference voltage in accordance with positins of the discharge lamp. CONSTITUTION:A detector for degradation of the discharge lamp consists of a charge coupled device 4 constituted of a light receiving part 4a where light receiving elements E1-En for receiving the reflected light from an original are arranged in parallel and a transfer part 4b consisting of registers R1-Rn for transferring the charge, a detecting part 20 which compares the output voltage read out and outputted from the device 4 with a set reference voltage to detect the reduction of the quantity of the light radiated from a fluorescent lamp, and an alarm part 30 which gives the alarm of degradation on a basis of the degradation of the detection output. If one of both end parts of the fluorescent lamp is degraded, one of registers R1 and Rn, at least, outputs an abnormality signal S0 synchronously with a clock pulse CP, and an replacement demand alarming lamp 41 is lit. When the degradation advances furthermore and the quantity of radiation in the center part is reduced, an emergency replacement lamp 38 is lit. |
