US 6,665,123 B2 · Projector

Abstract

In a projector, the precision of color synthesis is improved and the generation of vertical stripes in the projected image is suppressed by a dichroic prism used for color synthesis that employs at least the following aspects. (1) The dichroic prism is formed using triangular prisms, in which projections or grooves are provided that have two faces parallel to two pasted faces of the triangular prisms, the projections or grooves being integrally injection-molded on faces of the triangular prisms that are substantially perpendicular to the light beam (i.e., the faces through which no light beam passes); (2) the dichroic prism is positioned using marks on the pasted faces of the triangular prisms; or (3) the dichroic prism is formed by engaging triangular prisms in which recesses or projections are formed.

Claims8

Dependent claims

A projector comprising:

a light source;
color separating means for separating a light beam emitted from said light source into light beams of respective colors;
light valves which modulate the separated light beams of respective colors;
a dichroic prism which synthesizes the modulated light beams of respective colors that have been modulated via said light valves;
and
a projection lens which enlarges and projects the synthesized modulated light beam onto a screen;
wherein said dichroic prism is a prism formed by pasting together four triangular prisms which are substantially right-angled triangular prisms in cross section;
and
said triangular prisms have projections or grooves that have two faces forming planes parallel to two pasted faces of triangular prisms and are integrally molded in faces of the triangular prisms that are substantially perpendicular to the light beams.

6 more elements

Dependencies are inferred from the claim text.

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Abstract

Claims8