| 摘要 |
PURPOSE:To simply adjust the color purity or color temperature of a projected picture by arranging a pair of mirrors for reflecting 1st light out of red, blue and green beams and a pair of mirrors for reflecting 2nd light so as to be rotated as pairs respectively around axes vertical to incident and reflecting planes. CONSTITUTION:If a dichroic mirror 2 is rotated in the direction of 22 when a light source intensively contains a blue light component, the blue light component can be reduced by shifting the reflection characteristics of the mirror 22 to the short wavelength side. In said status however, the center of the optical axis is shifted to the right direction from a projection lens and projected light may be lost. When a mirror 4 which is a part of a pair with the dichroic mirror 2 is rotated in the direction of 42 which is the same direction as the mirror 2, the center of the optical axis is held at the center position of the projection lens, so that the loss of the projection light can be suppressed. If the red light component is small, the component can be increased by rotating dichroic mirrors 3, 5 as a pair. |
