1. Field of the Invention
The present invention generally relates to the technical field of optics such as sunglasses, contact lenses, goggles and binoculars and more particularly, the present invention relates to the field of optics such as sunglasses which enables a user to see true neutral color and not have the vision distorted by the tinted color of the sunglasses.
2. Description of the Prior Art
In the past, individuals have sought to improve optics by providing various innovations to lenses. The following ten (10) patents are pertinent to this field of art:                1. U.S. Pat. No. 4,793,669 issued to Perilloux on Dec. 27, 1988 for “Multilayer Optical Filter For Producing Colored Reflected Light And Neutral Transmission” (hereafter the “'669 Perilloux Patent”);        2. U.S. Pat. No. 4,896,928 issued to Perilloux on Jan. 30, 1990 for “Chromatically Invariant Multilayer Dielectric Thin Film Coating” (hereafter the “'928 Perilloux patent”);        3. U.S. Pat. No. 5,054,902 issued to King on Oct. 8, 1991 for “Light Control With Color Enhancement” (hereafter the “'902 King patent”);        4. U.S. Pat. No. Re. 33,729 issued to Perilloux on Oct. 29, 1991 for “Multilayer Optical Filter For Producing Colored Reflected Light And Neutral Transmission” (hereafter the “'729 Perilloux patent”);        5. U.S. Pat. No. 5,173,800 issued to King on Dec. 22, 1992 for “Light Control With Color Enhancement” (hereafter the “'800 King patent”);        6. U.S. Pat. No. 5,731,898 issued to Orzi on Mar. 24, 1998 for “Optical Filter Arrangement” (hereafter the “Orzi patent”);        7. U.S. Pat. No. 6,145,984 issued to Farwig on Nov. 14, 2000 for “Color-Enhancing Polarized Lens” (hereafter the “Farwig patent”);        8. U.S. Pat. No. 6,250,759 B1 issued to Kerns on Jun. 26, 2001 for “Eyeglass Lens With Multiple Optical Zones Having Varying Optical Properties For Enhanced Visualization Of Different Scenes In Outdoor Recreational Activities” (hereafter the “Kerns patent”);        9. U.S. Pat. No. 6,334,680 B1 issued to Larson on Jan. 1, 2002 for “Polarized Lens With Oxide Additive” (hereafter the “Larson patent”);        10. United States Patent No. U.S. 2002/0018824 A1 issued to Buazza on Feb. 14, 2002 for “Plastic Lens Systems, Compositions, And Methods” (hereafter the “Buazza patent”);        11. U.S. Pat. No. 5,408,278 issued to Christman on Apr. 18, 1995 for “Method And Device For Enhancing Visual And Color Perception” (hereafter the “Christman patent”).        
The three Perilloux patents disclose optical filters of varying coloration. Specifically, the '669 Perilloux patent has as its unique feature a coating on the substrate's surface including layers of material having a high refractive index and substantially quarter-wave optical thickness alternating with layers of material having low refractive index and substantially quarter-wave optical thickness, the thickness of each of said layers being selected so that the lens has a reflectance spectrum with a ripple over a first segment in the visible range but has no significant ripple in a second segment in the visible range, so that reflected light having wavelength within the first segment is sufficient to give the filter a desired aesthetic color, and the thickness of each layer being selected so that the lens reflects substantially all electromagnetic radiation having wavelengths in the near-infrared range.
The '928 Perilloux patent is an improvement on the prior device. In this case, the technology is the same but the improvement is that the desired aesthetic color in the lens is substantially independent of incidence angle.
The third in the group which is the '729 reissued Perilloux patent essentially is a similar innovation which includes a short-wave-pass optical filter that includes a partially absorbing or transparent substrate coated by a set of layers having specified quarter-wave optical thickness, and is designed to reflect visible radiation of a selected color while transmitting visible radiation and maintaining a neutral color balance. The coating includes layers having a high refractive index alternating with layers having a low refractive index. The refractive indices and layer thicknesses are selected so that the filter's reflectance spectrum exhibits a ripple over a first segment of the visible spectrum but no significant ripple over a second segment of the visible spectrum. The filters may be used as sunglass lenses that have a selected color (such as blue, orange, or violet) when viewed by one other than the sunglass wearer, while permitting the wearer to perceive transmitted light with a correct color balance. The design of the inventive filter is preferably optimized to have the desired optical properties while being conveniently and repeatably manufacturable.
The '902 King patent discloses a method for maintaining optical neutrality for the user while projecting a color scheme to an outside observer. Overall, the innovation of the '902 King patent can be summarized in claim 1 which recites “A lens for sunglasses which recites (1) a light transmissive substrate constituting the lens body, and having a first side for facing the wearer and a second side for facing outwardly from the wearer; (2) a semireflective layer intimately bonded to the second side; and (3) a dielectric layer over the semireflective layer, said dielectric layer being of substantially uniform thickness.”
The '800 King patent deals with light control on a window as opposed to light control used with glasses.
The Orzi patent discloses a method for the creation of a filter using bronze, purple or blue while maintaining optical neutrality. It includes an optical filter arrangement which comprises at least two optical filter elements including a transparent substrate and an optical coating typically comprising at least two overlying optical thin films. The coating defines a first patterned area and a second surround area bordering the first area. The first area has substantially the same optical transmittance characteristics as the second area and different optical reflectance characteristics over at least a portion of the visible spectrum. The distinction between the first area and the second area is visually perceptible when viewed from one side of the optical filter arrangement and substantially visibly imperceptible when viewed from the opposite side of the optical filter arrangement. As a result, a colored pattern or logo is only visible when viewed from one side of the filter arrangement.
The Farwig patent discloses a method for rendering a sunglass lens colorless to the viewer by the use of different colored filtered elements therewithin. It comprises a front lens element and a rear lens element. By way of example, when using a 1 mm. thick rear lens element, the pale purplish color of the glass can be rendered undetectable to the wearer by using a common variety of slightly bluish-grey polarizers having about 25% transmission. Tint-neutralization is also achieved on an uncoated lens by using appropriate tints in the front element and a polarizer. One lens element can be glass, then there is a brown polarizer and a green A lens element which makes a good neutral grey combination.
The Kerns patent discloses an eyeglass lens having different regions of reflectivity within the lens. Each region is comprised of a different colored tint for increased performance and visualization. There is a first optical zone positioned in the upper portion of the lens body and a second optical zone positioned in the lower portion of the lens body. The concept of this invention is a lens for eyeglasses where there are two or more optical zones on the lens body having different optical properties that enhance visualization of different scenes whether looking up, down, etc. through different portions of the lens body.
The Larson patent discloses a polarized lens that has improved color discrimination characteristics. It includes a lens wafer containing a rare earth oxide such as neodymium that provides relatively high light transmittance and relatively low light transmittance. A polarized filter is included to reduce glare.
The Buazza patent discloses a method for the combination of various colors including blue, yellow, green and red, to produce a neutral optical filter for sunglasses. It discloses an apparatus for preparing a plastic eyeglass lens which includes a coating unit and a lens curing unit. The apparatus is preferably configured to allow the operation of both the coating unit and the lens curing unit. The apparatus may also include a post-cure unit and a controller. The controller is configured to control the operation of the coating unit, the lens curing unit and the post-cure unit. A lens forming composition may include an aromatic containing polyether polyethylenic functional monomer, a photoinitiator, and a coinitiator. The lens forming composition may be cured by the application of activating light or activating light and heat.
The Christman patent discloses a device to enhance visual color perception; however, each lens is limited by the fact that each lens transmits over fifty percent of light in either the wavelength range 400–550 nm or 550–750 nm while transmitting less than fifty percent of the visible light in the other of these ranges.
There is still a significant need to provide a cost effective and efficient way to produce tinted optics such as sunglasses which enable a user to see true white light.