摘要 |
The invention concerns a colour filter device (10) comprising at least a first (12), a second (14), and a third (16) element. Each of the first (12) and the second (14) elements comprises a polarizer. The first (12) and the second (14) elements are arranged such that an optical path (24) is formed between them. The third element (16) comprises a birefringent means positioned on the optical path (24) between the polarizers (12, 14) and is arranged to transmit electromagnetic radiation. The third element (16) and at least one of the first (12) and the second (14) elements are controllably arranged in such a manner that, concerning the first (12) and the second (14) elements, the direction of polarization of the element is variable and concerning the third (16) element, the birefringent means is rotatable. By said control of the elements (12, 14, 16), the transmitted spectral range may be changed. |