| 摘要 |
PROBLEM TO BE SOLVED: To inform a user of the appropriate exchange time of a light source in accordance with the variation or the fluctuation of the life of the light source and also to use the light source as long as possible in an optical measuring instrument equipped with an automatic output control circuit for the light source. SOLUTION: The optical measuring instrument is provided with a life monitoring means 22 deciding that the life of the light source 11 ends and informing the user of the result of decision by comparing voltage obtained from the output signal from a photodetector for life-monitoring 16 converting light from the light source 11 into an electrical signal with reference voltage when light output from the light source 11 begins to be lowered because a current restriction resistance 31 restricting the driving current of the light source 11 is inserted in the driving current path of the light source 11 so that it is connected to the automatic output control circuit 21 in series, the deterioration of the light source 11 progresses, and control by the control circuit 21 does not sufficiently work due to the resistance 31. COPYRIGHT: (C)2004,JPO
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