Patent ID: 6666557
Filing Date: 2003-12-23
Classification: H04N

Abstract:
A reflection type projector comprising:a light source for emitting an input light; a first dichroic mirror, disposed along an optical path of the input light, for dividing the input light into a first transmitted light beam and a first reflected light beam, the first dichroic mirror transmitting the first transmitted light beam and reflecting the first reflected light beam according to a wavelength; a first optical path changing unit for changing the path of the first transmitted light beam from the first dichroic mirror, the first optical path changing unit including only one prism; a first image forming unit for forming an image from the first transmitted light beam passing through the first optical path changing unit; a second dichroic mirror, disposed along an optical path of the first reflected light beam from the first dichroic mirror, for dividing the first reflected light beam into a second transmitted light beam and a second reflected light beam, the second dichroic mirror transmitting the second transmitted light beam and reflecting the second reflected light beam according to a wavelength; a second optical path changing unit for changing the path of the second reflected light beam from the second dichroic mirror, the second optical path changing unit including only one prism; a second image forming unit for forming an image from the second reflected light beam passing through the second optical path changing unit; a third optical path changing unit for changing the path of the second transmitted light beam from the second dichroic mirror; a third image forming unit for forming an image from the second transmitted light beam passing through the third optical path changing unit, the third optical path changing unit including only one prism; a dichroic beam splitter having a first and a second mirror surface for selectively transmitting and reflecting the input light passing through the first, second and third optical path changing units in one direction according to wavelength; and a projection lens unit for enlarging and transmitting the input light from the dichroic beam splitter.