Microlens imbedded liquid crystal projection panel including thermal insulation layer

• US 5,815,229 A
• Filed: 08/22/1996
• Issued: 09/29/1998
• Est. Priority Date: 11/21/1994
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Proxima Corporation (Ask ASA)
• Inventors: Shapiro, Leonid
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Parker, Kenneth
• Application Number:
  US08/701,495
• Time in Patent Office: 768 Days
• Field of Search: 349/122, 349/138, 349/105, 349/95, 349/62
• US Class Current: 349/95
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133565 inside the LC elements, i.e. between the cell substrates

Abstract

A liquid crystal projection panel construction includes an incident light substrate assembly spaced apart from an light exiting substrate assembly having a plurality of pixel elements for enclosing a liquid crystal assembly therebetween. The incident light substrate assembly includes a microlens array having a plurality of microlenses disposed at about a surface of engagement between the incident light substrate assembly and the liquid crystal assembly for converging light through corresponding pixel elements. The incident light substrate assembly further includes a plurality of interference filters disposed at about the surface of engagement, and in registration with the corresponding microlenses and pixel elements for projecting a bright, high quality, full color image.

Claims

1. A liquid crystal projection panel construction, comprising:

liquid crystal assembly means being disposed between said glass substrate to form said panel construction, and including a liquid crystal material for modulating light to generate an image to be projected;

a light exiting glass substrate;

an incident light glass substrate;

said light exiting glass substrate including a plurality of pixel elements for controlling said liquid crystal material;

said incident light glass substrate spaced apart from said light exiting glass substrate for enclosing said liquid crystal assembly means therebetween to form said panel construction, wherein said liquid crystal assembly means and said incident light glass substrate abut at a surface of engagement;

said incident light glass substrate including microlens means having a plurality of lenslets disposed closely spaced by a given optical distance relative to said pixel elements and in registration therewith for focusing light through said pixel elements to enable substantially all of the light to be used for generating said image;

an optical assembly being thin as compared to the thickness of said incident light glass substrate and being disposed between said liquid crystal assembly means and said microlens means at about a surface of engagement with said liquid crystal assembly means for determining the focal distance by spacing said microlens means from said liquid crystal assembly means;

said optical assembly includes a plurality of individual interface filters corresponding to said lenslets and pixel elements and aligned in registration therewith for passing selectively incident light therethrough to facilitate the generation of a full color image, at least one neutral density layer disposed between said lenslets and said surface for adjusting said focal distance, and an insulation layer disposed between the neutral density layer and the lenslets to reduce the amount of heat produced by the interaction of the light with said filters; and

whereby the occurrence of optical cross talk between adjacent lenslets is substantially reduced.

2. A panel construction according to claim 1, wherein said plurality of optical filters includes at least a red filter, a green filter and a blue filter to facilitate the generation of full color images.

3. A panel construction according to claim 1, wherein said optical assembly means further includes another neutral density layer disposed between said plurality of lenslets and said surface.

4. A panel construction according to claim 1, wherein said optical assembly means further includes a black matrix.

5. A panel construction according to claim 1, wherein said light exiting substrate assembly means further includes a light exiting optical assembly means including another plurality of lenslets for collimating light after it has passed through said liquid crystal material, said another plurality of lenslets corresponding to, and aligned in registration with, said plurality of lenslets, said plurality of optical filters and said plurality of pixel elements to facilitate the focusing of the image.

6. A panel construction according to claim 5, wherein said light exiting optical assembly means further includes a neutral density layer disposed between said another plurality of lenslets and said liquid crystal assembly means.

7. A panel construction according to claim 6, wherein said plurality of lenslets and said another plurality of lenslets have a substantially equivalent effective focal length.

8. A method of making a liquid crystal projection panel construction, comprising:

using a liquid crystal assembly means including a liquid crystal material, a light exiting substrate assembly means including a plurality of pixel elements, and an incident light substrate assembly means including an optical assembly means having microlens means comprising a plurality of lenslets;

disposing said liquid crystal assembly means between said incident light substrate assembly means and said light exiting substrate assembly means to enclose it therebetween, wherein said liquid crystal assembly means and said incident light substrate assembly means abut at a surface of engagement;

disposing said optical assembly means sufficiently close to said surface at a relatively short focal distance to focus light through said pixel elements with said optical assembly means to enable substantially all of the light to be used for generating an image;

disposing a plurality of individual interface filters corresponding to said lenslets and pixel elements in aligned registration therewith for passing selectively incident light therethrough to facilitate the generation of a full color image;

disposing at least one neutral density layer between said lenslets and said surface for adjusting said focal distance, and

disposing an insulation layer between the neutral density layer and the lenslets to reduce the amount of heat produced by the interaction of the light with said filters; and

whereby the occurrence of optical cross talk between adjacent lenslets is substantially reduced.

9. A method according to claim 8, further including positioning the plurality of lenslets from said surface of engagement by a spacing distance of up to about 300 microns.

10. A method according to claim 9, wherein said spacing distance is between about 20 microns and about 100 microns.

11. A method according to claim 10, wherein said spacing distance is between about 30 microns and about 50 microns.

12. A method according to claim 11, wherein said spacing distance is 40 microns.

13. A method according to claim 8, further including disposing another neutral density layer within said optical assembly means and between said plurality of lenslets and said surface.

14. A method according to claim 8, further including disposing a black matrix within said optical assembly means.

15. A method according to claim 8, further including disposing another plurality of lenslets within said light exiting substrate assembly means, and aligning said another plurality of lenslets in registration with said plurality of lenslets, said plurality of optical filters and said plurality of pixel elements.

16. A liquid crystal display projector, comprising:

a liquid crystal projection panel construction including a liquid crystal assembly means including a liquid crystal material for modulating light to generate an image to be projected, light exiting substrate assembly means including a plurality of pixel elements for controlling said liquid crystal material, incident light substrate assembly means spaced apart from said light exiting substrate assembly means for enclosing said liquid crystal assembly means therebetween, wherein said liquid crystal assembly means and said incident light substrate assembly means abut at a surface of engagement, said incident light substrate assembly means including an optical assembly means disposed at about said surface for focusing light through said pixel elements to enable substantially all of the light to be used for generating said image, whereby the occurrence of optical cross talk is substantially reduced;

said optical assembly means being thin as compared to the thickness of said incident light glass substrate and being disposed between said liquid crystal assembly means and said microlens means at about said surface of engagement with paid liquid crystal assembly means for determining the focal distance by spacing said microlens means from said liquid crystal assembly means;

said optical assembly means includes a plurality of individual interface filters corresponding to said lenslets and pixel elements and aligned in registration therewith for passing selectively incident light therethrough to facilitate the generation of a full color image, at least one neutral density layer disposed between said lenslets and said surface for adjusting said focal distance, and an insulation layer disposed between the neutral density layer and the lenslets to reduce the amount of heat produced by the interaction of the light with said filters; and

a light source for producing the light to illuminate said liquid crystal projection panel construction; and

a projection lens means for projecting the image.