| 摘要 |
PURPOSE:To easily and inexpensively perform color separation, by providing an interference filter provided with a specific interference film, a driving means which varies the wavelength band of the transmission light of the filter, and an optical sensor which detects the transmission light. CONSTITUTION:On the transmission plane 24 of the interference filter, the interference film which passes the transmission light 28 of a narrow band by utilizing the interference of light is fixed, and the film thickness of the interference film is varied consecutively extending over the longitudinal direction of a transmission plane 24 so as to set the different wavelength bands of the transmission light 28 in order. And in the interference filter 20, the optical sensor 30 to detect the transmission light 28 is provided by fixing its position. Furthermore, the cylindrical interference filter 20 is fixed on a rotary table 40 connected directly to a motor 38, and is constituted so that it can be driven rotatably around an axis. In such a way, since it is possible to perform the separation of input light with high accuracy only by using one interference filter having the annular transmission plane 24 without preparing a large number of interference filters, a device can be constituted simply and inexpensively. |
