Projection display system using polarized light

• US 6,995,917 B1
• Filed: 04/08/1999
• Issued: 02/07/2006
• Est. Priority Date: 04/08/1999
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Sampsell, Jeffrey B., Florence, James M.
• Primary Examiner(s): MACK, RICKY LEVERN
• Application Number:
  US09/289,327
• Time in Patent Office: 2,497 Days
• Field of Search: 359/618, 359/634, 349/750, 349/751, 349/9, 353/34, 353/37, 353/82
• US Class Current: 359/634
• CPC Class Codes: G02B 27/123 The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

A projection display system using polarized light comprises a light source for generating a light beam having at least two light components, wherein the light components are polarized and at least one of the light components is polarized differently than another of the light components. The projection display system has a projection system having a plurality of polarized light modulators, each modulator generating a light-component-specific image associated with one of the light components. The projection display system also has a projection lens for projecting an image combined from the light-component-specific images from the modulators. The present invention also provides a polarization converter for use with a light source that generates a light beam having at least two light components. The polarization converter comprises an optics array capable of separating the light beam into at least one light component having a polarization that is different than another light component.

Claims

1. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having a least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components and said one of said light components has a color that is different than said another of said light components;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects at least one of said light components and transmits at least another of said light components and a plurality of LCD panels, and LCD panel generating a light-component-specific image associated with one of said light components; and

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCD'"'"'s;

(d) wherein said light source includes a lamp and a filter stack having a cholesteric color filter mechanism located between said lamp and said projection system for pre-filtering said light beam to transmit red p-polarized light, green s-polarized light and blue s-polarized light.

2. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having a least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components and said one of said light components has a color that is different than said another of said light components;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects at least one of said light components and transmits at least another of said light components and a plurality of LCD panels, and LCD panel generating a light-component-specific image associated with one of said light components; and

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCD'"'"'s;

(d) wherein said light source includes a polarization converter for pre-filtering said light beam;

(e) wherein said light source includes a lamp for generating said light beam and a pre-filtering illumination mechanism located between said lamp and said projection system for pre-filtering said light beam to provide a red p-polarized light component to said projection system, wherein said pre-filtering illuminating mechanism includes a red-transmitting dichroic filter, a pair of polarizing beam splitters, a pair of light absorbing stops, a half-wave plate, and a red-reflecting dichroic filter;

wherein said light beam impinges said red-transmitting dichroic filter, wherein said light beam is split into a reflected red light component and transmitted green light and blue light components;

said reflected green and blue light components impinge on a polarizing beam splitter, which reflects a green s-polarized light component and said blue light component, wherein said green s-polarized light component and said blue light component impinge said red-reflecting dichroic filter, which transmits said green s-polarized light component and a blue s-polarized light component to said projection system; and

wherein said reflected red light component impinges another polarizing beam splitter, which transmits a red s-polarized light component through said half-wave plate, which changes said red s-polarized light component to a red p-polarized light component, which red p-polarized light component impinges said red-reflecting dichroic filter and is reflected to said projection system.

3. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having at least three light components, wherein one of said light components is p-polarized and two of said light components are s-polarized;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects one of said light components and transmits another of said light components and LCD panels, each LCD panel generating a light-component-specific image associated with each light component, wherein said polarizing beam splitters and said dichroic filters are arranged in a substantially x-shaped configuration, wherein said dichroic filters are normal to said polarizing beam splitters and arranged to intersect adjacent an edge thereof; and

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCDs;

(d) wherein said light source includes a lamp and a filter stack having a cholesteric color filter mechanism located between said lamp and said projection system for pre-filtering said light beam.

4. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having at least three light components, wherein one of said light components is p-polarized and two of said light components are s-polarized;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects one of said light components and transmits another of said light components and LCD panels, each LCD panel generating a light-component-specific image associated with each light component, wherein said polarizing beam splitters and said dichroic filters are arranged in a substantially x-shaped configuration, wherein said dichroic filters are normal to said polarizing beam splitters and arranged to intersect adjacent an edge thereof; and

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCDs;

(d) wherein said light beam from said light source impinges on a blue-transmitting dichroic filter at substantially 45 degrees, then impinges on a polarizing beam splitter at substantially 45 degrees, then impinges on an LCD panel having said light-component-specific image displayed thereon, substantially normal thereto, and is reflected therefrom carrying a color image component, then impinges a polarizing beam splitter at substantially 45 degrees, then impinges a blue-reflecting dichroic filter at substantially 45 degrees prior to transmitting said projection lens.

5. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having at least three light components, wherein one of said light components is p-polarized and two of said light components are s-polarized;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects one of said light components and transmits another of said light components and LCD panels, each LCD panel generating a light-component-specific image associated with each light component, wherein said polarizing beam splitters and said dichroic filters are arranged in a substantially x-shaped configuration, wherein said dichroic filters are normal to said polarizing beam splitters and arranged to intersect adjacent an edge thereof; and

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCDs;

(d) wherein said light source includes a lamp for generating said light beam and a pre-filtering illumination mechanism located between said lamp and said projection system from pre-filtering said light beam to provide a red p-polarized light component, a green s-polarized light component and a blue s-polarized light component to said projection system, wherein said pre-filtering illumination mechanism includes;

a red-transmitting dichroic filter, a pair of polarizing beam splitters, a pair of light absorbing stops, a half-wave plate, and a red-reflecting dichroic filter;

wherein said light beam impinges said red-transmitting dichroic filter, wherein said light beam is split into a reflected red light component and transmitted green light and blue light components;

said reflected green and blue light components impinge on a polarizing beam splitter, which reflects a green s-polarized light component and said blue light component, wherein said green s-polarized light component and said blue light component impinge said red-reflecting dichroic filter, which transmits said green s-polarized light component and a blue s-polarized light component to said projection system; and

wherein said reflected red light component impinges another polarizing beam splitter, which transmits a red s-polarized light component through said half-wave plate, which changes said red s-polarized light component to a red p-polarized light component, which red p-polarized light component impinges said red-reflecting dichroic filter and is reflected to said projection system.

6. A projection display system using polarized light, comprising:

(a) a light source for generating a light beam having at least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components and said one of said light components has a color that is different than said another of said light components;

(b) a projection system having a plurality of polarized light modulators, each modulator generating a light-component-specific image associated with one of said light components; and

(c) a projection lens for projecting an image combined from the light-component-specific images from said modulators;

(d) wherein said light source includes a lamp and a filter stack having a cholesteric color filter mechanism located between said lamp and said projection system for pre-filtering said light beam to transmit red p-polarized light, green s-polarized light and blue s-polarized light.

7. A projection display system using polarized light comprising:

(a) a light source for generating a generally white light beam having at least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components, and said at least two components are provided to a projection system as a single beam, wherein the one light component and the other light component are within a single light beam, and said one light component has a different color than said other light component;

(b) said projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects at least one of said light components and transmits at least another of said light components and a plurality of LCD panels, each LCD panel generating a light-component-specific image associated with one of said light components; and

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCDs;

(d) wherein said light source includes a lamp and a filter stack having a cholesteric color filter mechanism located between said lamp and said projection system for pre-filtering and light beam to transmit red p-polarized light, green s-polarized light and blue s-polarized light.

8. A projection display system using polarized light comprising:

(a) a light source for generating a generally white light beam having at least two light components wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components, and said at least two components are provided to a projection system as a single beam, wherein the one light component and the other light component are within a single light beam, and said one light component has a different color than said other light component;

(b) said projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects at least one of said light components and transmits at least another of said light components and a plurality of LCD panels, each LCD panel generating a light-component-specific image associated with one of said light components; and

(c) a projection lens for protecting an image combined from the light-component-specific images from the LCDs;

(d) wherein said light source includes a lamp for generating said light beam and a pre-filtering illumination mechanism located between said lamp and said projection system for pre-filtering and said light beam to provide a red p-polarized light component to said projection system, wherein said pre-filtering illuminating mechanism includes a red-transmitting dichroic filter, a pair of polarizing beam splitters, a pair of light absorbing stops, a half-wave plate, and red-reflecting dichroic filter;

wherein said light beam impinges on red-transmitting dichroic filter, wherein said light beam is split into a reflected red light component and transmitted green light and blue light components;

said reflected green and blue light components impinge on a polarizing beam splitter, which reflects a green s-polarized light component and said blue light component, wherein said green s-polarized light component and said blue light component impinge said red-reflecting dichroic filter, which transmits said green s-polarized light component and a blue s-polarized light component to said projection system; and

wherein said reflected red light component impinges another polarizing beam splitter, which transmits a red-s-polarized light component through said half-wave plate, which changes said red s-polarized light component to a red p-polarized light component, which red p-polarized light component impinges said red-reflecting dichroic filter and is reflected to said projection system.

9. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having at least three light components, wherein one of said light components is s-polarized and two of said light components are p-polarized;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects one of said light components and transmits another of said light components and LCD panels, each LCD panel generating a light-component-specific image associated with each light component, wherein said polarizing beam splitters and said dichroic filters are arranged in a substantially X-shaped configuration, wherein said dichroic filters are normal to said polarizing beam splitters and arranged to intersect adjacent an edge thereof; and

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCDs, wherein said light source includes a lamp and a filter stack having a cholesteric color filter mechanism located between said lamp and said projection system for pre-filtering said light beam.

10. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having at least three light components, wherein one of said light components is s-polarized and two of said light components are p-polarized;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects one of said light components and transmits another of said light components and LCD panels, each LCD panel generating a light-component-specific image associated with each light component, wherein said polarizing beam splitters and said dichroic filters are arranged in a substantially X-shaped configuration, wherein said dichroic filters are normal to said polarizing beam splitters and arranged to intersect adjacent an edge thereof; and

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCDs, wherein said light beam from said light source impinges on a blue-transmitting dichroic filter at substantially 45 degrees, then impinges on a polarizing beam splitter at substantially 45 degrees, then impinges on an LCD panel having said light-component-specific image displayed thereon, substantially normal thereto, and is reflected therefrom carrying a color image component, then impinges a polarizing beam splitter at substantially 45 degrees, then impinges a blue-reflecting dichroic filter at substantially 45 degrees prior to transmitting said projection lens.

11. A projection display system using polarized light, comprising:

(a) a light source for generating a generally white light beam having at least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components, and said at least two light components are provided to a projection system as a single beam;

(b) said projection system having a plurality of polarized light modulators, each modulator generating a light-component-specific image associated with one of said light components; and

(c) a projection lens for projecting an image combined from the light-component-specific images from said modulators, wherein said light source includes a lamp and filter stack having a cholesteric color filter mechanism located between said lamp and said projection system for pre-filtering said light beam to transmit red p-polarized light, green s-polarized light and blue s-polarized light.

12. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having at least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects at least one of said light components and transmits at least another of said light components and a plurality of LCD panels, each LCD panel generating a light-component-specific image associated with one of said light components;

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCDs; and

(d) wherein said light source includes a lamp and a filter stack having a cholesteric color filter mechanism located between said lamp and said projection system for pre-filtering said light beam to transmit red p-polarized light, green s-polarized light and blue s-polarized light.

13. A projection display system using polarized light comprising:

(a) a light source for generating a light beam having at least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components;

(b) a projection system having plural polarizing beam splitters and dichroic filters therein, wherein each polarizing beam splitter and dichroic filter reflects at least one of said light components and transmits at least another of said light components and a plurality of LCD panels, each LCD panel generating a light-component-specific image associated with one of said light components;

(c) a projection lens for projecting an image combined from the light-component-specific images from the LCDs; and

(d) wherein said light source includes a lamp for generating said light beam and a pre-filtering illumination mechanism located between said lamp and said projection system for pre-filtering said light beam to provide a red p-polarized light component to said projection system, wherein said pre-filtering illuminating mechanism includes;

a red-transmitting dichroic filter, a pair of polarizing beam splitters, a pair of light absorbing stops, a half-wave plate, and a red-reflecting dichroic filter;

wherein said light beam impinges said red-transmitting dichroic filter, wherein said light beam is split into a reflected red light component and transmitted green light and blue light components;

said reflected green and blue light components impinge on a polarizing beam splitter, which reflects a green s-polarized light component and said blue light component, wherein said green s-polarized light component and said blue light component impinge said red-reflecting dichroic filter, which transmits said green s-polarized light component and a blue s-polarized light component to said projection system; and

wherein said reflected red light component impinges another polarizing beam splitter, which transmits a red s-polarized light component through said half-wave plate, which changes said red s-polarized light component to a red p-polarized light component, which red p-polarized light component impinges said red-reflecting dichroic filter and is reflected to said projection system.

14. A projection display system using polarized light, comprising:

(a) a light source for generating a light beam having at least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components;

(b) a projection system having a plurality of polarized light modulators, each modulator generating a light-component-specific image associated with one of said light components;

(c) a projection lens for projecting an image combined from the light-component-specific images from said modulators; and

(d) wherein said light source includes a lamp and a filter stack having a cholesteric color filter mechanism located between said lamp and said projection system for pre-filtering said light beam to transmit red p-polarized light, green s-polarized light and blue s-polarized light.

15. A projection display system using polarized light, comprising:

(a) a light source for generating a light beam having at least two light components, wherein said light components are polarized and at least one of said light components is polarized differently than another of said light components;

(b) a projection system having a plurality of polarized light modulators, each modulator generating a light-component-specific image associated with one of said light components;

(c) a projection lens for projecting an image combined from the light- component-specific images from said modulators; and

(d) wherein said light source includes a polarization converter, and wherein said polarization converter has a first dichroic filter and a second filter complimentary to said first dichroic filter, and wherein each dichroic filter is sandwiched between two quarter waveplates.