| 摘要 |
Provided are a color separating and combining prism and an optical system using the same for a projector. A color separating and combining prism (DP) includes dichroic films (B, R) that reflect the light of the wavelength range of either a first or third range from among the first wavelength range of a blue region, a second wavelength range of a green region, and a third wavelength range of a red region, and pass the light of the remaining two adjacent wavelength ranges, and at a specific angle of incidence, the average reflectance in the two wavelength ranges which the films pass is lower than the wavelength average reflectance of the wavelength region sandwiched by the two wavelength ranges. |
| 主权项 |
1. A color separating and combining prism incorporated in a projector including an illumination optical system that guides illumination light radiated by blue, green, and red laser light sources to an image display device, and a projection optical system that guides projection light from the image display device to a projection lens, wherein
the color separating and combining prism separates illumination light and combines projection light rays, the color separating and combining prism comprises a dichroic film, from among a first wavelength range in a blue region, a second wavelength range in a green region, and a third wavelength range in a red region, the dichroic film reflects light in one of the first or third wavelength range, and transmits light in the other two wavelength ranges, the other two wavelength ranges are adjacent to each other, and at a predetermined angle of incidence, an average reflectance for the light transmitted through the dichroic film in the other two wavelength ranges is lower than a wavelength-averaged reflectance in a wavelength region sandwiched between the other two wavelength ranges. |
