| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wavelength variable filter capable of making only one narrow half width transmittance peak, which is markedly narrowed than conventional one, appear in a predetermined observation wavelength range without reducing the response speed of liquid crystal, or capable of taking out a correct one from the plurality of transmittance peaks made to appear. <P>SOLUTION: This invention relates to the wavelength variable filter having a liquid crystal filter provided with a voltage source to be applied to liquid crystal cells 1, 2, 3, phase difference films 21, 22, 23 superimposed on the liquid crystal cells, polarizers 10, 11, 12, 13 sandwiching the compound layers consisting of the liquid crystal cells and the phase difference films, a liquid crystal filter provided with a voltage source 4 applied to the liquid crystal and having a two-dimensional photo-detector such as CCDs 32, 33, 34 (or 41) for detecting the exit light from the liquid crystal filter via a color filter, the liquid crystal filter generates a plurality of transmittance peaks to one voltage in the predetermined observation wavelength range according to the voltages applied from the voltage source. It is preferable that the color filter is comprised of the number of sheets (= the number of colors) not less than the number of the plurality of transmittance peaks, and/or the number of the transmittance peaks appearing in the transmission wavelength range of each color filter is not more than 1 or 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
