| 摘要 |
PURPOSE:To detect the color of a member to be detected without using an optical wave divider such as an interference filter, prism, etc. by such an arrangement wherein a light of which wavelength has been selected by a light wavelength variable filter is converted into electrical output by a photoelectric conversion element and from the electrical output, light energy by wavelength is detected. CONSTITUTION:A light radiated from a light wavelength variable filter 5 is guided into a photoelectric conversion element 6 through an optical fiber 7. It becomes possible to tune the central wavelength of the filter by varying an impressed voltage Vc by the control of a timing control circuit 11, and of those components of a reflected light from a member to be detected 1 guided by a light guide A, a light power of a desired wavelength can be introduced into a light guide B. The light power introduced into the light guide B is photoelectrically converted by th photoelectric conversion element 6 through the optical fiber 7 and the electrical signal thus converted is amplified by an amplifier 70 and further converted into digital signals by an A/D converter 8 and sent into a CPU10 where a light power by wavelength is calculated. Since the spectral characteristic of the reflected light from the member to be detected can be known from the result of the above calculation, the color of the member can be judged. |
