Patent ID: 6628346
Filing Date: 2003-09-30
Classification: G02B,H04N

Abstract:
A reflection liquid crystal projector for synthesizing a first, a second and a third color light into a color image to be displayed on a screen through a projection lens and comprising: a light source for outputting a white light; a polarized light conversion element for converting the white light outputted from the light source to either an S-polarized light or a P-polarized light; a color separation element for separating the polarized light, outputted from the polarized light conversion element, into a first color light, a second color light and a third color light and outputting in the same direction two of the three color lights, the two color lights being differentiated in polarization, the color separation element comprising a first dichroic mirror for transmitting the first and second color lights while reflecting the third color light with respect to the polarized light outputted from the polarized light conversion element, a first total reflection mirror for reflecting the first and the second color lights, which have passed through the first dichroic mirror, in a direction altered by 90Â°, a second total reflection mirror for reflecting the third color light, which has been reflected by the first dichroic mirror, in a direction altered by 90Â°, a second dichroic mirror for transmitting one of the first and the second color lights, which have been reflected by the first total reflection mirror, while reflecting the other color light, and reflecting for output the third color light reflected by the second total reflection mirror, and a phase element provided in an optical path, through which the third color light reflected by the first dichroic mirror arrives at the second dichroic mirror by way of the second total reflection mirror, and designed for converting the direction of the polarization of the third color light reflected by the first dichroic mirror; a first polarization beam splitter for transmitting one of the two color lights outputted in the same direction from the color separation element, so as to fall on a corresponding one of a first, a second and a third reflection liquid crystal panel and be reflected thereby for being outputted while reflecting the other color light onto a corresponding one of the first, second and third reflection liquid crystal panels to be reflected thereby for being outputted; a second polarization beam splitter for letting the remaining color light, outputted from the color separation element, fall on a corresponding one of the first, second and third reflection liquid crystal panels for outputting the reflected light; and a dichroic prism for outputting the synthesized light of the first, second and third color-lights outputted from the first and second polarization beam splitters, wherein the first and second polarization beam splitters and the dichroic prism are integrated into a prism block and the phase element comprises the second total reflection mirror disposed so that the reflection face thereof is 45Â° to the incoming color light falling thereon and a Â¼ wavelength film securely attached to the reflection face of the second total reflection mirror.