| 摘要 |
An optical filter uses two or more reflective polarizers together with retarders to form birefringent filters with controlled transmission. The energy reflected by these polarizers is absorbed by one or more dichroic elements, which can be adjacent to a reflective polarizer; or spaced apart from it by one or more retarder elements. These dichroic elements act as dampers, so the energy of rays undergoing multiple reflections is markedly reduced or virtually eliminated, and high image quality is maintained. This provides a filter arrangement with enhanced spectral range, image quality, or greater extinction, or lower cost, compared to filters using dichroic or prism-type polarizers. |
