Abstract: A collimating image-forming apparatus comprising a first linear polarizer is disclosed. A first quarterwave plate is disposed adjacent the first polarizer and has its fast and slow axes at substantially 45° to the plane of polarization of the first polarizer. The apparatus further comprises a beam-splitting curved mirror having a convex surface adjacent the first polarizer and facing towards the first quarter-wave plate, a second quarter-wave plate adjacent the concave side of the curved mirror, the second quarterwave plate having its having its fast and slow axes oriented with respect to the corresponding axes of the first quarter-wave plate at angles substantially equal to a first integral multiple of 90°, and a reflective-transmissive polarizing member adjacent the second quarter-wave plate.

Abstract: A collimating image-forming apparatus comprising a first linear polarizer is disclosed. A first quarterwave plate (14) is disposed adjacent the first polarizer (12) and has its fast and slow axes at substantially 45° to the plane of polarization of the first polarizer. The apparatus further comprises a beam-splitting curved mirror (16) having a convex surface adjacent the first polarizer and facing towards the first quarter-wave plate, a second quarter-wave plate (22) adjacent the concave side of the curved mirror, the second quarterwave plate having its having its fast and slow axes oriented with respect to the corresponding axes of the first quarter-wave plate at angles substantially equal to a first integral multiple of 90°, and a reflective-transmissive polarizing member (24) adjacent the second quarter-wave plate.

Abstract: A collimating image-forming apparatus comprising a first linear polarizer is disclosed. A first quarterwave plate is disposed adjacent the first polarizer and has its fast and slow axes at substantially 45° to the plane of polarization of the first polarizer. The apparatus further comprises a beam-splitting curved mirror having a convex surface adjacent the first polarizer and facing towards the first quarter-wave plate, a second quarter-wave plate adjacent the concave side of the curved mirror, the second quarterwave plate having its having its fast and slow axes oriented with respect to the corresponding axes of the first quarter-wave plate at angles substantially equal to a first integral multiple of 90°, and a reflective-transmissive polarizing member adjacent the second quarter-wave plate.

Abstract: A first embodiment is a lens system having a plurality of refractive and reflective spherical elements that work as a magnifier to produce a distortion free, less than 1%, image with optical correction over a wide field of view. The system has at least one concave reflecting surface, and at least three convex refracting surfaces with the sign of the radius of one of the convex refracting surfaces being opposite of the sign of the radius of remaining two convex refracting surfaces. A second embodiment is a lens having a concave reflecting element which is on a substrate that is a negative lens by transmission with an index of refraction between 1.6<nd>2.0 and a dispersion 49<?d>15. This is used in combination with at least 3 positive refracting surfaces with less dispersive power than the negative element and with the sign of the radius of one of the positive elements being opposite from the sign of the radius of the remaining positive elements.