Illumination polarization conversion system
First Claim
1. A polarization converting relay which receives unpolarized light from a source and transmits polarized light to an object to be illuminated, said relay comprising:
- (a) a polarization separator for separating the unpolarized light from the source into first and second parts based on polarization; and
(b) a polarization converter for converting the polarization of one of those parts;
wherein;
(i) the first and second parts pass through the relay along optical paths which are of different lengths; and
(ii) the relay has an exit pupil which is telecentric or near telecentric.
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Accused Products
Abstract
An illumination polarization conversion system is provided in which unpolarized light from a source (e.g., a lamp (10) and a light integrator (16)) is separated by a polarization converting relay (13) into first and second parts (e.g., S-polarized and P-polarized light) and the polarization of one of the parts is converted to the polarization of the other part (e.g., the S-polarized light is converted to P-polarized light). The converted and non-converted parts are then used to illuminate an object, such as, a polarization converting pixelized panel (12). The polarization converting relay (13) preferably has a telecentric or near telecentric exit pupil formed by placing a hard aperture stop substantially in the back focal plane of a lens unit (L3) located at the light exiting end of the relay (13).
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Citations
23 Claims
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1. A polarization converting relay which receives unpolarized light from a source and transmits polarized light to an object to be illuminated, said relay comprising:
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(a) a polarization separator for separating the unpolarized light from the source into first and second parts based on polarization; and
(b) a polarization converter for converting the polarization of one of those parts;
wherein;
(i) the first and second parts pass through the relay along optical paths which are of different lengths; and
(ii) the relay has an exit pupil which is telecentric or near telecentric. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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9. A polarization converting relay which receives unpolarized light from a source and transmits polarized light to an object to be illuminated, said relay comprising:
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(a) a first lens unit which receives unpolarized light from the source;
(b) a polarization separator which receives unpolarized light from the first lens unit and separates that light into two parts based on polarization;
(c) a polarization converter which receives one of the two parts and converts the polarization of that part; and
(d) a second lens unit which receives polarized light from the polarization separator and the polarization converter and transmits that light to the object to be illuminated;
wherein;
(i) the first lens unit has a focal length f1;
(ii) the second lens unit has a focal length f2; and
(iii) 1.5≦
f2/f1≦
2.5.
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10. A polarization converting relay which receives unpolarized light from a source and transmits polarized light to an object to be illuminated, said relay comprising:
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(a) a first lens unit which receives unpolarized light from the source;
(b) a polarization separator which receives unpolarized light from the first lens unit and separates that light into two parts based on polarization;
(c) a polarization converter which receives one of the two parts and converts the polarization of that part; and
(d) a second lens unit which receives polarized light from the polarization separator and the polarization converter and transmits that light to the object to be illuminated;
wherein the polarization separator is a wire grid polarizer.
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11. An optical system comprising:
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(a) a source of unpolarized light;
(b) a polarization converting relay which receives unpolarized light from the source; and
(c) at least one polarization converting pixelized panel which receives light directly from the relay without any intervening elements having optical power;
wherein; FFL≧
2L,where FFL is the front focal length of the relay in the direction of the at least one polarization converting pixelized panel and L is the diagonal of the panel.
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12. An optical system comprising:
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(a) a source of unpolarized light comprising;
(i) a lamp; and
(ii) a light integrator;
(b) a polarization converting relay which receives unpolarized light from the source, said relay comprising;
(i) a first lens unit comprising at least one lens element; and
(ii) a second lens unit comprising at least one lens element; and
(c) at least one polarization converting pixelized panel which receives light from the relay;
wherein;
(i) the at least one polarization converting pixelized panel is a rectangular panel having a long axis;
(ii) the integrator is a tapered integrator which provides a large field with low divergence along the long axis of the panel; and
(iii) all lens elements of the first and second lens units comprise crown glass. - View Dependent Claims (13)
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Specification