| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a cross dichroic prism for a compact color separation means and/or a color synthesis means by making the length of perpendiculars drawn from one point of a prism ridge line to the non-bonding surfaces of respective prisms satisfy a specified condition. SOLUTION: A 1st prism 1 and a 3rd prism 3 are isosceles triangle prisms whose two sides have equal length, and both of them are similar figures different in size. A 2nd prism 2 and a 4th prism 4 are square pillar prisms and both of them have the same shape. The length of the perpendiculars drawn from one point of the prism ridge line (o) to the non-bonding surfaces S1 to S4 of the respective prisms 1 to 4 is (o, S1a)>(o, S2a)=(o, S3a)=(o, S4a). Then, the surfaces S1 and S3 are parallel with each other and the surfaces S2 and S4 are not parallel with each other. The area S1b of the surface S1 is different from the area S3b of the surface S3, and relation between them is S3b<S1b. Thus, the dichroic prism which is compact and easily produced is realized.</p> |
