| 摘要 |
PROBLEM TO BE SOLVED: To embody a color synthesis prism which is capable of well maintaining the flatness of two kinds of multilayered dichroic films as a color synthesis means used for a projection type display device. SOLUTION: Four prisms 101 to 104 of a triangular prism shape having an approximately rectangular equilateral triangular shape in section are formed. At this time, the intersection angle of the two flanks holding the rectangular part is set slightly smaller than 90 deg.. The multilayered blue reflection dichroic films 105, 107 are formed on the one-side flanks of the prisms 101, 104 and the multilayered red reflection dichroic films 108, 106 are formed on the other side flanks of the prisms 101, 102. These multilayered optical films are so positioned by using a plane butting table in such a manner that the films are formed to an X shape. Next, these prisms are fixed by transparent adhesives having the refractive index equal to the refractive index of the prisms, by which the color synthesis prism is produced. |
