US 5,274,406 A · Image projecting device

Abstract

An image projecting device includes structure for correcting the distortion of an image and/or the defocusing of an image, which will be caused in a situation in which the optical axis of a projection lens is inclined with respect to a screen. The device includes a screen positioned along a predetermined plane, a source for emitting light which forms an optical image on the screen, with the optical axis of the source and the screen plane being inclined with respect to each other so that they are not optically normal with respect to each other, and a reflecting surface for reflecting light from the source towards the screen along a separate optical axis. The reflecting surface is optically positioned between the screen and the source and has a predetermined three-dimensional shape which is adapted to correct for trapezoidal distortion of the optical image projected onto the screen.

Claims30

Dependent claims

An image projecting device comprising:

a screen that is positioned along a predetermined plane;
a source for emitting light which forms an optical image on said screen, said source having an optical axis, wherein said optical axis of said source and said screen plane are inclined with respect to each other so that they are not optically normal with respect to each other;
and
correcting means for correcting for trapezoidal distortion of said optical image on said screen, said correcting means consisting of means for reflecting said light from said source toward said screen along another optical axis, said reflecting means being optically positioned between said screen and said source, said reflecting means having a reflecting surface with a predetermined three-dimensional shape that is adapted to correct for said trapezoidal distortion of said optical image on said screen.

1 more element

Dependencies are inferred from the claim text.

Image projecting device

Life of this patent

Image projecting device

Life of this patent

Abstract

Claims30