| 摘要 |
PURPOSE:To provide the variable wavelength filter which does not depend upon polarized light and can widen the wavelength variation range in a polarized-light independent area. CONSTITUTION:Transparent electrodes 13 and 23, reflecting films 14 and 24, and orientation films 15 and 25 are laminated in this order on opposite surfaces of two glass substrates 11 and 21, and liquid crystals 16 and 26 are sandwiched between the opposite orientation films 15 and 25 to constitute a liquid crystal etalon type variable wavelength filter; and the 1st liquid crystal layer 10 twists and orients molecules of the liquid crystal 16 positioned between the opposite orientation films 15 by npi/2, where (n) is a positive odd number, and the 2nd liquid crystal layer 20 twists and orients molecules of the liquid crystal 26 positioned between the opposite orientation films 25 by -npi/2, where (n) is positive odd number. Those 1st liquid crystal layer 10 and 2nd liquid crystal layer 20 are put one over the other. At this time, projection-side liquid crystal molecule axes of the 1st liquid crystal layer 10 and incidence-side liquid crystal molecule axes of the 2nd liquid crystal layer 20 are each other. |
