Optical unit and projector including the same
AssigneeKonica Minolta, Inc.
InventorMasahiro TERADA
Life of this patent
Estimating the term…
Abstract
An optical unit includes a digital micromirror device in which each of micro-mirrors is driven biaxially in ON/OFF control, a first prism directs illumination light to the digital micromirror device, a second prism including an OFF-light reflecting surface reflects OFF light reflected from the micro-mirrors in an OFF state and transmits ON light reflected from the micro-mirrors in an ON state, and a third prism emits the ON light incident from the second prism toward a projection side. The micro-mirrors reflect the OFF light so that an optical axis of the OFF light is directed away from a projection-optical-axis plane including an optical axis of the ON light and an optical axis of the illumination light.
Claims17
-13. (canceled)
An optical unit comprising:
- a digital micromirror device that forms an image by such illumination light intensity modulation that in an image display plane formed of a plurality of micro-mirrors, a surface of each of the micro-mirrors is tilted by ON/OFF control, each of the micro-mirrors being driven biaxially in the ON/OFF control;
- and
- a second prism including an OFF-light reflecting surface that reflects OFF light reflected from the micro-mirrors in an OFF state and transmits ON light reflected from the micro-mirrors in an ON state,
- wherein the micro-mirrors reflect the OFF light so that an optical axis of the OFF light is directed away from a projection-optical-axis plane including an optical axis of the ON light and an optical axis of the illumination light,
- the second prism's first area on one side of the projection-optical-axis plane is formed longer along a line normal to the projection-optical-axis plane than the second prism's second area on another side of the projection-optical-axis plane, and
- the first area includes the optical axis of the OFF light.
Dependencies are inferred from the claim text.