| 摘要 |
<p>PURPOSE:To correct a measuring error by monitoring an output light emitted from a light source by an interference filter, converting a spectral variation of the light source to an electric signal and correcting the calculation of an arithmetic unit. CONSTITUTION:A part of an output light of an LED 1 is split by a half mirror 27, split into two by a beam splitter 29, and one of them is made incident on a photodiode 31 and converted to an electric signal, amplified 33, and thereafter, fed back to a driving circuit 3, and the output of a light source is controlled so as to become constant. Also, the other output light split into two by the beam splitter 29 passes through an interference filter 35 and made incident on a photodiode 37, converted to an electric signal, amplified 39 and inputted to an arithmetic unit 41, and a spectral variation of the LED 1 is detected. On the other hand, an output from an amplifier 25 is calculated by the unit 41 and a voltage is derived. In such a way, an applied voltage being proportional to the output of the amplifier 25 is derived, and in accordance with the spectral variation of the LED 1, a correction can be executed. After the calculation is ended, said light is outputted to a display device 43 and an output terminal 45.</p> |
