# Patent

## Title
Curved lenses configured to decode three-dimensional content on television and computer screens

## Abstract

Curved lenses configured to decode three dimensional content and method of fabricating the same. The lenses decode three-dimensional content displayed on televisions or computer monitors. Sheets from which the lenses are cut have either (i) a polarizing axis of 0 degrees relative to horizontal and one sheet has a retarder axis at −45 degrees relative to horizontal and the other sheet has a retarder axis of +45 degrees relative to horizontal; (ii) a polarizing axis of −45 degrees relative to horizontal and one sheet has a retarder axis at 0 degrees relative to horizontal and the other sheet has a retarder axis of 90 degrees relative to horizontal; or (iii) a polarizing axis of +45 degrees relative to horizontal and one sheet has a retarder axis at 0 degrees relative to horizontal and the other sheet has a retarder axis of 90 degrees relative to horizontal.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 12/495,754 filed Jun. 30, 2009, which is a continuation-in-part of U.S. patent application Ser. No. 12/350,092 filed Jan. 7, 2009, which claims the benefit of U.S. Provisional Application No. 61/019,545 filed Jan. 7, 2008.


FIELD OF THE INVENTION
The embodiments of the present invention relate to lenses designed to decode three dimensional content displayed on television, movie, computer or similar screens or monitors.
BACKGROUND
Three dimensional movies for theatres have been around for decades. With technological advances, three dimensional content is being developed for television, computer monitors and home projectors. In the past, and even today, special glasses allow users to view three dimensional content. Flat paper eyeglasses using red and green film for lenses are the primary glasses being used today. However, flat paper eyeglasses are not very effective for facilitating the desired three dimension effect. In addition, the flat paper eyeglasses are not comfortable and are generally viewed as a novelty. Other flat lenses suffer from the same drawbacks.
One advancement has been the development of linear and circular polarization for decoding three dimensional content. Despite the advancement, the lens and eyeglass technology has not advanced significantly.
Thus, there is a need for lenses that take advantage of the linear and circular polarization technologies while more effectively creating the desired three dimensional effect. Advantageously, the lenses and eyeglasses should provide improved optics and contrast while providing user comfort and versatility. It is also beneficial if the lenses may be mounted into stylish frames.
SUMMARY
Accordingly, one embodiment of the present invention is a curved lens configured to decode three dimensional content comprising: a polarizing layer laminated with a polymeric material layer on one or both sides; a retarder layer laminated to a front of the polarizer layer directly or to the polymeric material to form a sheet, said retarder layer aligned to decode a desired circular polarization; and wherein a blank cut from the sheet is curved using a thermoforming process or high pressure process into a lens configured to decode three dimensional content.
Another embodiment is a lens configured to decode three dimensional content comprising: a polarizing layer laminated with a polymeric material layer on one or both sides; a retarder layer laminated to a front of the polarizer layer directly or to the polymeric material to form a sheet, said retarder layer aligned to decode a desired circular polarization; wherein a blank cut from the sheet is curved using a thermoforming process or high pressure process into an optical element configured to decode three dimensional content; and wherein said optical element is utilized in an injection molding process whereby one or more thickness layers are added to the optical element to form said lens.
Another embodiment of the present invention is a method of fabricating a curved lens configured to decode three dimensional content comprising: cutting lens blanks from sheets of material comprising: a polarizing layer laminated with a polymeric material layer on one or both sides; a retarder layer laminated to a front of the polarizer layer directly or the polymeric material, said retarder layer aligned to decode a desired circular polarization, and wherein said blanks are cut to maintain a specified alignment of a polarizing axis associated with said sheet; curving said blanks into lenses by: a. heating the blanks to a deformation temperature; and applying a vacuum suction and/or pressure; or b. applying high pressure.
In one embodiment, the retarder is a norbornene copolymer resin such as an Arton film (manufactured by JSR Corp.) or Zenor film (manufactured by Zeon corp.). Conventional adhesives (e.g., pressure sensitive adhesives) are used to bond the layers forming the lens. In one embodiment, a hard coating is applied to the front and back surfaces of the lens to allow for normal cleaning and extended life. In one embodiment, a lens thickness is between 750 and 1500 microns. In another embodiment, the lens thickness is between 250 and 1500 microns.
In an embodiment intended to decode 3D content displayed on computer screens or monitors, the blanks are cut from the sheet at a plus or minus 45 degree angle to correctly align the polarizing axis with the display of content on the television or computer screen.
Other variations, embodiments and features of the present invention will become evident from the following detailed description, drawings and claims.



BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 illustrate an exemplary specification sheet for a first lens embodiment of the present invention;
FIGS. 3 and 4 illustrate an exemplary specification sheet for a second lens embodiment of the present invention;
FIG. 5 illustrates a flow chart detailing one embodiment of manufacturing the lenses according to the embodiments of the present invention;
FIG. 6 illustrates a flow chart detailing a second embodiment of manufacturing the lenses according to the embodiments of the present invention; and
FIGS. 7a-7c illustrate various television and computer screen shots showing content parameters and polarizing axis alignment of corresponding 3D lenses.



DETAILED DESCRIPTION
For the purposes of promoting an understanding of the principles in accordance with the embodiments of the present invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive feature illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention claimed.
Traditionally flat lenses and frames have been used in 3D glasses. One problem with the flat 3D glasses is that the lenses are distanced from the user's face and more particularly the user's eyes. Thus, light is able to enter the user's eyes from the top, bottom and side of the lenses reducing the visual acuity and contrast thereby reducing the effectiveness and comfort of the 3D experience. This is especially true at home or other locations outside of dark movie theatres. Moreover, the current one-size-fits-all approach to flat 3D eyeglasses reduces the quality of the 3D experience and in many cases results in an uncomfortable fit for most users. Accordingly, the embodiments of the present invention seek to overcome the disadvantages of the prior art flat 3D eyeglasses by creating 3D lenses and eyeglasses which are more akin to normal curved lenses and eyeglasses. Consequently, the lenses described herein are generally thicker than traditional flat 3D lenses and curved to prevent ambient light from interfering with the 3D experience and allow for better fitting glasses. Conventional flat 3D paper lenses are 0.3 to 0.4 mm thick while the embodiments of the present invention are substantially in a range of 0.75 mm to 1.5 mm. In an alternative embodiment, the lenses may be in range of 0.25 mm to 0.75 mm for use with an injection molding process as described below. The curvature further enables a better fit on the user's head. In addition, the thicker lenses enable them to be mounted into stylish frames to which people are more accustomed.
FIGS. 1-4 show specifications associated with lenses made utilizing the embodiments of the present invention. FIGS. 1 and 2 depict charts 100 and 105 listing lens specifications according to a first embodiment. The charts 100 and 105 depict dimensions, including width 110 and length 115, polarization angle 120, retardation angle 125, transmittance percentage 130, polarizing efficiency 135, thickness 140 and retardation 145. As shown in charts 100 and 105, the width ranges from 495 mm to 505 mm; length from 700 mm to 710 mm; polarization angle from −1.0 degree to 1.0 degree; retardation angle from 44.0 degrees to 46.0 degrees (or 134 degrees to 136 degrees); transmittance percentage from 37.5% to 42.5% v; polarizing efficiency of 99% or greater; thickness of 1020 microns to 1080 microns (or 1.02 mm to 1.08 mm) and retardation of 110 to 150 nm. Larger ranges are possible for each of the aforementioned categories. Charts 101 and 106 shown in FIGS. 3 and 4, respectively, depict similar lens specifications according to a second embodiment of the present invention.
Fabrication of the lenses is accomplished using lamination and thermoforming techniques. FIG. 5 shows a flow chart 200 detailing one method of fabricating lenses according to the embodiments of the present invention. At 205, sheets are formed and, at 210, lens blanks are cut from the sheets of material comprising: polyvinylalcohol polarizer film, polyethylene terephthalate or similar material laminated with triacetate on one or both surfaces (i.e., linear polarized film) and a retarder film laminated on a front surface thereof creating a circular polarized film. While triacetate is one material that can be used, others include polycarbonate, poly(methyl methacrylate), polystyrene, polyamide, cellulose acetate butyrate (CAB), cellulose acetate, cellulose diacetate (DAC) or cellulose triacetate (TAC), diacetate and similar stress-free (no birefringence) materials. The triacetate, diacetate or other materials may also be laminated onto the back (bottom) of the polarizer film to eliminate any unwanted retardation effects. A laminator machine forms the sheets of materials such that the axis of the polarizing film and retarder film are aligned properly to small tolerances. In one embodiment, the retarder is an Arton film (manufactured by JSR Corp.) or Zenor (manufactured by Zeon corp.). Other materials, such as polyurethanes, cellulose diacetate and polycarbonates, may also be used as the retardation film. Adhesives bind the materials together. The size of the blanks is dictated by the intended frame size. A typical size is 50 mm×70 mm. At 215, the blanks are placed into a thermoforming machine which heats the blanks to a deformation temperature (e.g., 90° C. to 130° C.). At 220, the heated blanks are curved using thermoforming techniques to an optically correct curved surface utilizing vacuum suction and/or pressure. To generate the desired base curve (e.g., 4, 6 and 8), a different combination of unique temperatures and times may be required. Once formed, at 225, the curved blanks are cooled and removed from the machine. At 230, the blanks, now lenses, can be finished with conventional lens dry cutting machines. At 235, a hard coating is applied over the curved lenses. The hard coating allows normal cleaning and extended use while protecting the operational materials forming the lenses. The hard coat may also be applied prior to the thermoforming process by using a thermoformable hard coat material. At 240, protective, removable sheets are applied to protect the lenses during subsequent operations including installation into frames, packaging and shipping. The protective sheets may also be applied to the sheets of the material prior to thermoforming process.
While thermoforming techniques are referenced in the flow chart 200, extreme pressures may also be used to create the curved lenses. A machine known as the Wheel or similar machines generate extreme pressures and can be used to curve a blank into a lens. The process is known as press polishing whereby heat and pressure are applied to the blank via both sides of highly polished molds.
The triacetate and diacetate may comprises multiple layers themselves and have qualities, including transparency, low birefringence, lightweight and strength. Moreover, triacetate and diacetate are responsive to lamination and thermoforming processes and techniques as disclosed herein.
For the circular polarized lenses utilized in the embodiments of the present invention the polyvinylalcohol polarizer film is tinted and stretched in a linear direction to orient the polymer molecules. Polyiodine molecules are commonly used to allow polarizing efficiency and transmission to reach acceptable levels (e.g., >99% and >35%, respectively). Alternatively, dichroic dyes can be used to provide improved resistance to heat and humidity, but may have slightly lower polarizing efficiency and transmission. Both embodiments can produce the desired 3D decoding effect.
The curved lenses disclosed herein have numerous advantages over the flat 3D glasses of the prior art. The curved lenses provide a clearer and natural vision of 3D images with greater acuity and contrast. More particularly, the curved lenses reduce light entering the user's eyes from the side, top or bottom of the eyeglass frames thereby increasing the comfort and contrast associated with the viewed 3D images. The curved lenses can be fitted into commercial eyeglass frames to create a stylish pair of eyeglasses.
In another embodiment, as shown in the flow chart 300 of FIG. 6, an optical element is made using the aforementioned process for use in an injection molded lens. Steps 305-330 coincide with steps 205-230 described above except that the resultant blanks are thinner than the lenses formed using the steps of flow chart 200. At 335, the blank becomes part of the final thicker lenses via an injection molding process. In other words, a thinner version of the lens described above is used as an optical element to make low cost injection molded polycarbonate (or polymethylmethacrylate and polymide) lenses. In this embodiment, the thermoformed optical elements are in a range of about 250-750 microns with a final injected 3D lens in a range of about 1000 to 2200 microns. Such lenses can be optically corrected with increased thickness and rigidity. In one embodiment, a back polymer layer of the lens is the same material as the injected material to provide good adhesion and reliability.
FIGS. 7a-7c show various television and computer screens depicting content and polarizing axis orientation or alignment for corresponding 3D lenses. FIG. 7a shows a television 400 displaying 3D content on a screen 401 configured with a vertical polarizing axis 402 and retarder axes 403, 404 aligned at −45 and +45 degrees, respectively, relative to horizontal. Lenses 405, 410 have a polarizing axis 415 aligned at 0 degrees (i.e., horizontal). A retardation axis 406 associated with the left lens 405 is at −45 degrees (i.e., rotated clockwise) relative to horizontal and a retardation axis 411 associated with the right lens 410 is at +45 degrees (i.e., rotated counter-clockwise) relative to horizontal. Accordingly, the left lens 405 and right lens 410 each allow only similarly polarized content emitted by the television screen to pass through thus creating the 3D effect. The configuration of lenses 405, 410 is the same as the configuration of the movie lenses discussed above.
FIG. 7b shows a first computer 450 displaying 3D content on a screen 451 with a polarizing axis 452 at +45 degrees from the horizontal and retarder axes 453, 454 aligned at 0 degrees (horizontal) and 90 degrees (vertical), respectively, from the horizontal. Lenses 455, 460 have a polarizing axis 465 aligned at −45 degrees from the horizontal. A retardation axis 456 associated with the left lens 455 is at 90 degrees and a retardation axis 461 associated with the right lens 460 is at 0 degrees relative to horizontal.
FIG. 7c shows a second computer 480 displaying 3D content on a screen 481 with a polarizing axis 482 at −45 degrees from the horizontal and retarder axes 483, 484 aligned at 0 degrees (horizontal) and 90 degrees (vertical), respectively, from the horizontal. Lenses 485, 490 have a polarizing axis 495 aligned at +45 degrees from the horizontal. A retardation axis 486 associated with the left lens 485 is at 0 degrees and a retardation axis 491 associated with the right lens 490 is at 90 degrees relative to horizontal.
Although the invention has been described in detail with reference to several embodiments, additional variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.

## Claims

1. Glasses configured to decode three dimensional content comprising:
two lenses having:
a polarizing layer laminated with a polymeric material layer on one or both sides;
a retarder layer laminated to a front of the polarizer layer directly or to the polymeric material to form a sheet, said retarder layer configured to decode a desired circular polarization;
wherein a blank cut from a first sheet is curved into a first lens and a blank cut from a second sheet is curved into a second lens wherein together the first and second lens are able to decode three dimensional content; and
wherein the first and second sheet are configured such that:
(i) the first and second sheet have a polarizing axis of 0 degrees relative to horizontal and one sheet has a retarder axis at −45 degrees relative to horizontal and the other sheet has a retarder axis of +45 degrees relative to horizontal;
(ii) the first and second sheet have a polarizing axis of −45 degrees relative to horizontal and one sheet has a retarder axis at 0 degrees relative to horizontal and the other sheet has a retarder axis of 90 degrees relative to horizontal; or
(iii) the first and second sheet have a polarizing axis of +45 degrees relative to horizontal and one sheet has a retarder axis at 0 degrees relative to horizontal and the other sheet has a retarder axis of 90 degrees relative to horizontal.

2. The glasses of claim 1 wherein said polarizing layer, polymeric layer and retarder layer have a combined thickness of 250-1500 microns.

3. The glasses of claim 1 wherein said first and second lens in combination are configured to decode three dimensional content displayed on a computer or television monitor.

4. Glasses configured to decode three dimensional content comprising:
two optical elements having:
a polarizing layer laminated with a polymeric material layer on one or both sides;
a retarder layer laminated to a front of the polarizer layer directly or to the polymeric material to form a sheet, said retarder layer configured to decode a desired circular polarization;
wherein a blank cut from a first sheet is curved into a first optical element and a blank cut from a second sheet is curved into a second optical element;
wherein the first and second sheet are configured such that:
(i) the first and second sheet have a polarizing axis of 0 degrees relative to horizontal and one sheet has a retarder axis at −45 degrees relative to horizontal and the other sheet has a retarder axis of +45 degrees relative to horizontal;
(ii) the first and second sheet have a polarizing axis of −45 degrees relative to horizontal and one sheet has a retarder axis at 0 degrees relative to horizontal and the other sheet has a retarder axis of 90 degrees relative to horizontal; or
(iii) the first and second sheet have a polarizing axis of +45 degrees relative to horizontal and one sheet has a retarder axis at 0 degrees relative to horizontal and the other sheet has a retarder axis of 90 degrees relative to horizontal.

5. The glasses of claim 4 wherein said polarizing layer, polymeric layer and retarder layer have a combined thickness in a range of about 250-750 microns.

6. The glasses of claim 5 wherein said polarizing layer, polymeric layer, retarder layer and one or more thickness layers have a combined thickness in a range of about 1000 to 2200 microns.

7. The glasses of claim 4 wherein said pair of lenses is configured to decode three dimensional content displayed on a computer monitor.

8. A method of fabricating curved lenses configured to decode three dimensional content comprising:
cutting blanks from sheets of material comprising: a polarizing layer laminated with a polymeric material layer on one or both sides; a retarder layer laminated to a front of the polarizer layer directly or the polymeric material, said retarder layer aligned to decode a desired circular polarization, and wherein a first and second blank used to form a left and right lens are cut from first and second sheets configured such that:
(i) the first and second sheet have a polarizing axis of 0 degrees relative to horizontal and one sheet has a retarder axis at −45 degrees relative to horizontal and the other sheet has a retarder axis of +45 degrees relative to horizontal;
(ii) the first and second sheet have a polarizing axis of −45 degrees relative to horizontal and one sheet has a retarder axis at 0 degrees relative to horizontal and the other sheet has a retarder axis of 90 degrees relative to horizontal; or
(iii) the first and second sheet have a polarizing axis of +45 degrees relative to horizontal and one sheet has a retarder axis at 0 degrees relative to horizontal and the other sheet has a retarder axis of 90 degrees relative to horizontal; and

curving said first and second blanks into lenses by:
applying high pressure with controlled heating from both sides of a polished mold.

9. The method of claim 8 further comprising fabricating said lens with said polarizing layer, polymeric layer and retarder layer having a combined thickness of 250-1500 microns.

10. The method of claim 8 further comprising fabricating said lens with said polarizing layer, polymeric layer and retarder layer having a combined thickness of 250-750 microns.

11. The method of claim 10 further comprising utilizing an injection molding process to add thickness to said lenses.

12. The method of claim 11 further comprising fabricating said lens with said polarizing layer, polymeric layer, retarder layer and one or more injection molding layers having a combined thickness of 1000-2200 microns.