US6234634B1 — Image projection system with a polarizing beam sp…

Claim 1

Independent Claim 377 words

An image projection system for providing a bright and clear image, the system comprising: a light source producing a visible light beam; a polarizing beam splitter located near the light source in the light beam and oriented at an angle with respect to the light beam, the beam splitter comprising a transparent substrate having a first surface located in the light beam with the light beam striking the first surface at an angle, and a generally parallel arrangement of thin, elongated elements supported by the substrate, the arrangement being configured and the elements being sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization oriented parallel with the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam; a reflective array located near the polarizing beam splitter in either the reflected or transmitted beam, the array modulating the polarization of the beam by selectively altering the polarization of the beam to encode image information thereon and creating a modulated beam, the array being oriented to direct the modulated beam back towards the polarizing beam splitter; the beam splitter further being located in the modulated beam and oriented at an angle with respect to the modulated beam, and the arrangement of elements of the beam splitter interacting with electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to the plane that includes at least one of the elements and the direction of the incident light beam, defining a second transmitted beam, and (ii) reflect light from the elements which has a polarization parallel with the plane that includes at least one of the elements and the direction of the incident light beam, defining a second reflected beam, to separate out the unaltered polarization from the modulated beam; a screen located in either the second reflected beam or the second transmitted beam for displaying the encoded image information.

Claim 2

Dependent Claim 377 words

An image projection system for providing a bright and clear image, the system comprising: a light source producing a visible light beam; a polarizing beam splitter located near the light source in the light beam and oriented at an angle with respect to the light beam, the beam splitter comprising a transparent substrate having a first surface located in the light beam with the light beam striking the first surface at an angle, and a generally parallel arrangement of thin, elongated elements supported by the substrate, the arrangement being configured and the elements being sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization oriented parallel with the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam; a reflective array located near the polarizing beam splitter in either the reflected or transmitted beam, the array modulating the polarization of the beam by selectively altering the polarization of the beam to encode image information thereon and creating a modulated beam, the array being oriented to direct the modulated beam back towards the polarizing beam splitter; the beam splitter further being located in the modulated beam and oriented at an angle with respect to the modulated beam, and the arrangement of elements of the beam splitter interacting with electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to the plane that includes at least one of the elements and the direction of the incident light beam, defining a second transmitted beam, and (ii) reflect light from the elements which has a polarization parallel with the plane that includes at least one of the elements and the direction of the incident light beam, defining a second reflected beam, to separate out the unaltered polarization from the modulated beam; a screen located in either the second reflected beam or the second transmitted beam for displaying the encoded image information.

Claim 3

Dependent Claim 15 words

The system of claim 1 , wherein the beam splitter is a generally planar sheet.

Claim 4

Dependent Claim 32 words

The system of claim 1 , wherein the beam splitter is oriented with respect to the light beam or the modulated beam at an incident angle between approximately 0 to 80 degrees.

Claim 5

Dependent Claim 34 words

The system of claim 1 , wherein the beam splitter is oriented with respect to the light beam or the modulated beam at incidence angles greater than 47 degrees or less than 43 degrees.

Claim 6

Dependent Claim 24 words

The system of claim 1 , wherein the light beam has a useful divergent cone with a half angle between approximately 12 and 25°.

Claim 7

Dependent Claim 19 words

The system of claim 1 , wherein the beam splitter is used at an F-number less than approximately f/2.5.

Claim 8

Dependent Claim 52 words

The system of claim 1 , wherein the beam splitter has a throughput of at least 50% defined by the product of the fractional amount of p-polarization transmitted light and the fractional amount of s-polarization reflected light; and wherein the s-polarization transmitted light and p-polarization reflected light are both less than 5%.

Claim 9

Dependent Claim 52 words

The system of claim 1 , wherein the beam splitter has a throughput of at least 50% defined by the product of the fractional amount of s-polarization transmitted light and the fractional amount of p-polarization reflected light; and wherein the p-polarization transmitted light and s-polarization reflected light are both less than 5%.

Claim 10

Dependent Claim 57 words

The system of claim 1 , wherein the beam splitter has a throughput for the light beam of at least 65%, defined by the product of the fractional amount of reflected light and the fractional amount of transmitted light; and wherein the percent of reflected light or the percent of transmitted light is greater than approximately 67%.

Claim 11

Dependent Claim 19 words

The system of claim 1 , further comprising a pre-polarizer disposed between the light source and the beam splitter.

Claim 12

Dependent Claim 18 words

The system of claim 1 , further comprising a post-polarizer disposed between the beam splitter and the screen.

Claim 13

Dependent Claim 26 words

The system of claim 1 , wherein the array is disposed in the reflected beam; and wherein the screen is disposed in the second transmitted beam.

Claim 14

Dependent Claim 26 words

The system of claim 1 , wherein the array is disposed in the transmitted beam; and wherein the screen is disposed in the second reflected beam.

Claim 15

Dependent Claim 47 words

The system of claim 1 , wherein the arrangement of elements has a period less than approximately 0.21 microns, wherein the elements have a thickness between approximately 0.04 to 0.5 microns, and wherein the elements have a width of between approximately 30 to 76% of the period.

Claim 16

Dependent Claim 45 words

The system of claim 1 , wherein the elements each have a cross section with a base, a top opposite the base, and opposite left and right sides; and wherein the sides form an angle with respect to the base greater than approximately 68 degrees.

Claim 17

Dependent Claim 361 words

An image projection system comprising: a light source producing a visible light beam having a wavelength between approximately 0.4 and 0.7 microns; a polarizing beam splitter located near the light source in the light beam and oriented at an angle with respect to the light beam, the beam splitter comprising a transparent substrate having a surface located in the light beam with the light beam striking the surface at an angle, and a generally parallel arrangement of thin, elongated elements supported by the substrate, the arrangement being configured and the elements being sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization oriented parallel with the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam; a reflective array located near the polarizing beam splitter in the reflected beam, the array modulating the polarization of the reflected beam by selectively altering the polarization of the reflected beam to encode image information thereon and creating a modulated beam, the array being oriented to direct the modulated beam back to the polarizing beam splitter; the polarizing beam splitter further being located in the modulated beam and oriented at an angle relative to the modulated beam, the arrangement of elements of the beam splitter interacting with electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization parallel with the plane that includes at least one of the elements and the direction of the incident light beam, to separate out the unaltered polarization from the modulated beam; and a screen disposed in the transmitted beam for displaying the encoded image information.

Claim 18

Dependent Claim 361 words

An image projection system comprising: a light source producing a visible light beam having a wavelength between approximately 0.4 and 0.7 microns; a polarizing beam splitter located near the light source in the light beam and oriented at an angle with respect to the light beam, the beam splitter comprising a transparent substrate having a surface located in the light beam with the light beam striking the surface at an angle, and a generally parallel arrangement of thin, elongated elements supported by the substrate, the arrangement being configured and the elements being sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization oriented parallel with the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam; a reflective array located near the polarizing beam splitter in the reflected beam, the array modulating the polarization of the reflected beam by selectively altering the polarization of the reflected beam to encode image information thereon and creating a modulated beam, the array being oriented to direct the modulated beam back to the polarizing beam splitter; the polarizing beam splitter further being located in the modulated beam and oriented at an angle relative to the modulated beam, the arrangement of elements of the beam splitter interacting with electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization parallel with the plane that includes at least one of the elements and the direction of the incident light beam, to separate out the unaltered polarization from the modulated beam; and a screen disposed in the transmitted beam for displaying the encoded image information.

Claim 19

Dependent Claim 32 words

The system of claim 16 , wherein the beam splitter is oriented with respect to the light beam or the modulated beam at an incident angle between approximately 0 to 80 degrees.

Claim 20

Dependent Claim 24 words

The system of claim 16 , wherein the light beam has a divergence cone with a useful half angle between approximately 12 and 25°.

Claim 21

Dependent Claim 19 words

The system of claim 16 , wherein the beam splitter is used at an F-number less than approximately f/2.5.

Claim 22

Dependent Claim 64 words

The system of claim 16 , wherein the beam splitter has a throughput for the light beam of at least 65%, defined by the product of the fractional amount of reflected light and the fractional amount of transmitted light; and wherein the fractional amount of reflected light or the fractional amount of the transmitted light of the modulated beam is greater than approximately 0.67.

Claim 23

Dependent Claim 47 words

The system of claim 16 , wherein the arrangement of elements has a period less than approximately 0.21 microns, wherein the elements have a thickness between approximately 0.04 to 0.5 microns, and wherein the elements have a width of between approximately 30 to 76% of the period.

Claim 24

Dependent Claim 371 words

An image projection system comprising: a light source producing a visible light beam having a wavelength between approximately 0.4 and 0.7 microns; a polarizing beam splitter located near the light source in the light beam and oriented at an angle with respect to the light beam, the beam splitter comprising a transparent substrate having a surface located in the light beam with the light striking the surface at an angle, and a generally parallel arrangement of thin, elongated elements supported by the substrate, the arrangement being configured and the elements being sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to the plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization oriented parallel with the plane that includes at least one of the elements and the direction of the incident light beam; a reflective array located near the polarizing beam splitter in the transmitted beam, the array modulating the polarization of the transmitted beam by selectively altering the polarization of the transmitted beam to encode image information thereon and creating a modulated beam, and being oriented to direct the modulated beam back to the beam splitter; the polarizing beam splitter further being located in the modulated beam and oriented at an angle with respect to the modulated beam, the arrangement of elements of the beam splitter interacting with electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, and (ii) reflect light from the elements which has a polarization parallel with the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam, to separate the altered polarization from the unaltered polarization in the modulated beam, thereby extracting the image information in the modulated beam; and a screen located in the reflected beam for displaying the extracted image information in the modulated beam.

Claim 25

Dependent Claim 371 words

An image projection system comprising: a light source producing a visible light beam having a wavelength between approximately 0.4 and 0.7 microns; a polarizing beam splitter located near the light source in the light beam and oriented at an angle with respect to the light beam, the beam splitter comprising a transparent substrate having a surface located in the light beam with the light striking the surface at an angle, and a generally parallel arrangement of thin, elongated elements supported by the substrate, the arrangement being configured and the elements being sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to the plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization oriented parallel with the plane that includes at least one of the elements and the direction of the incident light beam; a reflective array located near the polarizing beam splitter in the transmitted beam, the array modulating the polarization of the transmitted beam by selectively altering the polarization of the transmitted beam to encode image information thereon and creating a modulated beam, and being oriented to direct the modulated beam back to the beam splitter; the polarizing beam splitter further being located in the modulated beam and oriented at an angle with respect to the modulated beam, the arrangement of elements of the beam splitter interacting with electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, and (ii) reflect light from the elements which has a polarization parallel with the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam, to separate the altered polarization from the unaltered polarization in the modulated beam, thereby extracting the image information in the modulated beam; and a screen located in the reflected beam for displaying the extracted image information in the modulated beam.

Claim 26

Dependent Claim 32 words

The system of claim 22 , wherein the beam splitter is oriented with respect to the light beam or the modulated beam at an incident angle between approximately 0 to 80 degrees.

Claim 27

Dependent Claim 24 words

The system of claim 22 , wherein the light beam has a divergent cone with a useful half angle between approximately 12 and 25°.

Claim 28

Dependent Claim 19 words

The system of claim 22 , wherein the beam splitter is used at an F-number less than approximately f/2.5.

Claim 29

Dependent Claim 59 words

The system of claim 22 , wherein the beam splitter has a throughput for the light beam of at least 65%, defined by the product of the fractional amount of reflected light and the fractional amount of transmitted light; and wherein the fractional amount of reflected light or the fractional amount of transmitted light is greater than approximately 0.67.

Claim 30

Dependent Claim 47 words

The system of claim 22 , wherein the arrangement of elements has a period less than approximately 0.21 microns, wherein the elements have a thickness between approximately 0.04 to 0.5 microns, and wherein the elements have a width of between approximately 30 to 76% of the period.

Claim 31

Independent Claim 299 words

A method for projecting an image, the method comprising: producing a source light beam having a wavelength in a range between approximately 0.4 to 0.7 microns using a light source; substantially separating the polarizations of the source light beam using a polarizing beam splitter disposed in the source light beam, the polarizing beam splitter comprising a generally parallel arrangement of thin, elongated elements configured and sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization orientation that lies in the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam; modulating either the transmitted or reflected beam and creating a modulated beam by selectively altering the polarization of the beam using an array disposed in either the transmitted or reflected beam; substantially separating the polarizations of the modulated beam using the polarizing beam splitter disposed in the modulated beam, the elements interacting with electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to plane that includes at least one of the elements and the direction of the incident light beam, defining a second transmitted beam, and (ii) reflect light from the elements which has a polarization orientation that lies in the plane that includes at least one of the elements and the direction of the incident light beam, defining a second reflected beam; and displaying either the second transmitted beam or the second reflected beam on a screen.

Claim 32

Independent Claim 299 words

A method for projecting an image, the method comprising: producing a source light beam having a wavelength in a range between approximately 0.4 to 0.7 microns using a light source; substantially separating the polarizations of the source light beam using a polarizing beam splitter disposed in the source light beam, the polarizing beam splitter comprising a generally parallel arrangement of thin, elongated elements configured and sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization orientation that lies in the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam; modulating either the transmitted or reflected beam and creating a modulated beam by selectively altering the polarization of the beam using an array disposed in either the transmitted or reflected beam; substantially separating the polarizations of the modulated beam using the polarizing beam splitter disposed in the modulated beam, the elements interacting with electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to plane that includes at least one of the elements and the direction of the incident light beam, defining a second transmitted beam, and (ii) reflect light from the elements which has a polarization orientation that lies in the plane that includes at least one of the elements and the direction of the incident light beam, defining a second reflected beam; and displaying either the second transmitted beam or the second reflected beam on a screen.

Claim 33

Dependent Claim 320 words

An image display system for producing a visible image, the system comprising: a light source for emitting a source light beam having a wavelength in a range between approximately 0.4 to 0.7 microns; a liquid crystal array positioned and oriented for receiving and modulating at least a portion of the source light beam and creating a modulated beam, the modulated beam containing image information; a screen positioned and oriented for receiving and displaying at least a portion of the modulated beam; and a polarizing beam splitter disposed in both the source light beam and the modulated beam, the beam splitter being used at an F-number less than approximately f/2.5, the polarizing beam splitter comprising a generally parallel arrangement of thin, elongated elements configured and sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization orientation that lies in the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam, and interacts with the electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the modulated light beam, defining a second transmitted beam, and (ii) reflect light from the elements which has a polarization orientation that lies in the plane that includes at least one of the elements and the direction of the modulated light beam, defining a second reflected beam; and wherein the beam splitter is oriented with respect to the source light beam at an angle of incidence between approximately 10 to 80 degrees.

Claim 34

Dependent Claim 320 words

An image display system for producing a visible image, the system comprising: a light source for emitting a source light beam having a wavelength in a range between approximately 0.4 to 0.7 microns; a liquid crystal array positioned and oriented for receiving and modulating at least a portion of the source light beam and creating a modulated beam, the modulated beam containing image information; a screen positioned and oriented for receiving and displaying at least a portion of the modulated beam; and a polarizing beam splitter disposed in both the source light beam and the modulated beam, the beam splitter being used at an F-number less than approximately f/2.5, the polarizing beam splitter comprising a generally parallel arrangement of thin, elongated elements configured and sized to interact with electromagnetic waves of the source light beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the incident light beam, defining a transmitted beam, and (ii) reflect light from the elements which has a polarization orientation that lies in the plane that includes at least one of the elements and the direction of the incident light beam, defining a reflected beam, and interacts with the electromagnetic waves of the modulated beam to generally (i) transmit light through the elements which has a polarization oriented perpendicular to a plane that includes at least one of the elements and the direction of the modulated light beam, defining a second transmitted beam, and (ii) reflect light from the elements which has a polarization orientation that lies in the plane that includes at least one of the elements and the direction of the modulated light beam, defining a second reflected beam; and wherein the beam splitter is oriented with respect to the source light beam at an angle of incidence between approximately 10 to 80 degrees.

Claim 35

Dependent Claim 47 words

The system of claim 29 , wherein the arrangement of elements has a period less than approximately 0.21 microns, wherein the elements have a thickness between approximately 0.04 to 0.5 microns, and wherein the elements have a width of between approximately 30 to 76% of the period.

Claim 36

Dependent Claim 26 words

The system of claim 29 , wherein the array is disposed in the reflected beam, and wherein the screen is disposed in the second transmitted beam.

Claim 37

Dependent Claim 26 words

The system of claim 29 , wherein the array is disposed in the transmitted beam, and wherein the screen is disposed in the second reflected beam.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2004-05-21	2004-11-20	2005-05-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2008-05-21	2008-11-20	2009-05-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2012-05-21	2012-11-20	2013-05-22	$7700.00	Window Closed / Lapsed

Image projection system with a polarizing beam splitter

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