Abstract:
Eyewear for a person includes at least a frame for supporting at least one lens; and a nose bridge affixed to the frame. The nose bridge has first and second nose pads adapted for contact with first and second sides of a person&#39;s nose, wherein the nose pads are retained in a fixed position relative to the frame at a sagittal angle A of greater than 38 degrees. The eyewear may be safety glasses, goggles, sunglasses, cosmetic glasses, and/or vision correction glasses. The eyewear may include only one lens, or may include two separate lenses.

Description:
TECHNICAL FIELD 
     Eyewear for a person that exhibits improved fit, in particular relative to the nose of a wearer. 
     BACKGROUND OF THE INVENTION 
     Eyeglasses, which are intended to correct a person&#39;s vision to normal or near-normal, and safety glasses, which are intended to protect a person&#39;s eyes from harm, have been known for centuries. Both types of eyewear typically rest on the nose, and on each ear of a person. A person&#39;s perception of how well a pair of glasses fit is influenced primarily by how well the glasses fit on the nose and over the ears, perhaps together with whether the lenses of the glasses are too close to the person&#39;s eyes or face, or other factors. 
     One method used to improve the fit of glasses is to provide two nose pads, one of which contacts each side of a person&#39;s nose, and to mount each nose pad on a small, flexible spring or wire referred to as a pad arm. The pad arm can then be permanently deformed by an optical professional so that each nose pad contacts its respective side of the person&#39;s nose at an acceptable position. If a person puts on the glasses in a slightly different manner, or in a slightly different location, the pad arm can resiliently deform to provide minor but automatic adjustments in use. 
     Glasses with pad arm nose pads are widely used, but they have some known problems. First, they are more expensive than fixed nose-bridge glasses, which can be mass-produced with a pad or pads at predetermined positions. Second, they typically require that an optical professional spend several minutes making manual adjustments to the pad arms before they can be given to a person for use, which increases the staffing requirements and costs of the optical business. Third, if the glasses are struck or crushed, the spring or wire pad arm supporting a nose pad may be permanently deformed, which typically requires the wearer to return to the office of an optical professional to have the glasses fixed and re-fit. 
     Glasses with fixed nose bridges have also been widely used, in particular, as sun glasses or safety glasses. The fixed nose bridge is designed to fit a typical person&#39;s nose, and although the fit may not be highly satisfactory, the cost of the glasses is often low enough that users are willing to trade comfort for cost-savings. However, it would be desirable to provide glasses for a person that provide an improved fit, particularly in the nose area, without increasing the costs of the glasses or requiring manual adjustments by an optical professional. 
     Certain prior techniques for attempting to improve the fit of certain types of glasses are described in U.S. Pat. No. 4,762,407 (Anger et al.), U.S. Pat. No. 6,074,058 (Anger), and U.S. Pat. No. 7,648,235 (Rosenfield). 
     SUMMARY OF THE INVENTION 
     In one embodiment of the present invention, eyewear for a person is disclosed, comprising a frame for supporting at least one lens; and a nose bridge affixed to the frame, wherein the nose bridge comprises first and second nose pads adapted for contact with first and second sides of a person&#39;s nose, wherein the nose pads are retained in a fixed position relative to the frame at a sagittal angle A of greater than 38 degrees. In another embodiment, the sagittal angle A is between 41 degrees and 43 degrees. In yet another embodiment, the sagittal angle A is greater than 41 degrees, and the nose pads are also retained in a fixed position at a transverse angle B of greater than 25 degrees. In a further embodiment, the sagittal angle A is between 41 degrees and 43 degrees, and the nose pads are also retained in a fixed position at a transverse angle B of between 27 degrees and 29 degrees. 
     The eyewear of the present invention may be safety glasses, goggles, sunglasses, cosmetic glasses, and/or vision correction glasses. The eyewear may include only one lens, or may include two separate lenses. These and other features of the invention are described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is described with reference to the Figures, in which identical structures are identified by identical reference numbers among two or more Figures, and in which: 
         FIG. 1  is an elevated perspective view of a fixture used in connection with the present invention; 
         FIG. 2  is an elevated perspective view of a pair of fixed nose-bridge eyewear positioned on the fixture shown in  FIG. 1 ; 
         FIG. 3  is a rear view of a pair of fixed nose-bridge eyewear according to the present invention; 
         FIG. 4  is a bottom view of a pair of fixed nose-bridge eyewear according to the present invention; and 
         FIG. 5  is a side view of a pair of fixed nose-bridge eyewear according to the present invention. 
     
    
    
     In one embodiment of the present invention, the glasses and their components shown in the Figures are not proportionally accurate, but in other embodiments of the present invention the glasses and their components shown in the Figures are proportionally accurate and the Figures may be used to exemplify certain angles, relative distances, or other relationships directly. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present inventors have determined that by controlling certain critical parameters, within ranges not believed to have been identified previously, glasses with fixed nose-bridges can provide fit that users perceive as a significant improvement over conventional fixed nose-bridge glasses. In particular, if fixed nose-bridges are designed so that they exhibit one, two, or three critical parameters as described below, the fit of the glasses on the user&#39;s nose is thought to be significantly improved. These and other aspects of the invention will be described in detail herein. 
     To facilitate a complete understanding of the present invention, certain terms will be used to reference particular angular relationships that are thought to be critical to the successful implementation of various embodiments of the present invention.  FIG. 1  shows a fixture or jig on which almost any pair of eyewear may be placed, as shown in  FIG. 2 . By using a fixture of this type, the angles or distances or other dimensional characteristics for almost any pair of eyewear can be compared on an equivalent basis. 
     Fixture  10  is illustrated in detail in  FIG. 1 . The fixture includes a base plate  12  and a back plate  14  attached to the base plate so that the back plate extends vertically, perpendicular to the base plate. The base plate  12  measures 200 millimeters (mm) wide and 125 mm deep, and the back plate measures 200 mm wide and 70 mm high. A support pin  16  is affixed to the back plate midway along its width, with the center of the support pin being 22.8 mm below the top of the back plate. The support pin extends above and parallel to the base plate for a total distance of 125 mm. The base portion  16 B of the support pin has a length of 86.6 mm and a diameter of 30 mm, and the nose pad support portion  16 A has a length of 38.4 mm and a diameter of 20 mm. The change in diameter between the nose pad support portion  16 A and base portion  16 B acts as a stop  16 C for positioning eyewear to be evaluated, when the eyewear are pushed toward the back plate until they touch the stop. The top  18  of the back plate acts as a support for the eyewear bows or stems. 
     Three reference planes, defined relative to the test fixture  10 , are used to determine certain angles associated with eyewear. With the base plate positioned horizontally and viewing the fixture from the free end of support pin (which may be referred to as the front of the fixture), the sagittal plane  20  bisects or divides the support pin  16  vertically into imaginary left and right halves. The transverse plane  22  bisects the support pin  16  horizontally into imaginary upper and lower halves. And the frontal plane  24  is orthogonal to both the sagittal and transverse planes, tangent to the most forward portion of the lens surface. 
     Certain angles measured relative to these planes will be described in further detail below, with reference to  FIGS. 3, 4, and 5 . 
       FIG. 2  illustrates a representative pair of eyewear  30  positioned on the fixture  10  that is shown in  FIG. 1 . The eyewear have been pushed up against stop  16 C, and the bows or stems  32  rest on top  18  of back plate  18 , which places the eyewear generally in the position they would occupy when worn by a person. Eyewear may include a single structure that extends over the bridge of the nose and provides a nose pad on each side of a wearer&#39;s nose, or an individual, separate nose pad structure on each side, and those arrangements are considered to be equivalent for purposes of the present invention. With each pair of eyewear positioned as shown certain angles measured from one pair of eyewear can be compared to the corresponding angle measured from another pair of eyewear, even if their construction is not identical. 
       FIGS. 3, 4, and 5  illustrate the relevant portions of a pair of eyewear  30  designed in accordance with the present invention, as well as sagittal plane  20 , transverse plane  22 , and frontal plane  24 . For clarity, the test fixture  10  is not shown, but the three planes are illustrated as though the eyewear  30  were positioned on the fixture as shown in  FIG. 2 . Sagittal angle A is illustrated in  FIG. 3 , and it is defined as the angle between the sagittal plane  20  and nose pad surface  50 , extending parallel to the frontal plane  24 . Transverse angle B is illustrated in  FIG. 4 , and it is defined as the angle between the sagittal plane  20  and the nose pad surface  50 , extending parallel to the transverse plane  22 . Frontal angle C is illustrated in  FIG. 5 , and it is defined as the angle between the nose pad surface and the frontal plane  24 , extending parallel to the sagittal plane  20 . In each case, for measurement purposes the nose pad surface was considered to be a flat surface tangential to the bearing surface of the nose pad. The angles described above assume that the eyewear are symmetrical, and that only half of the angle described needs to be measured, but it is also clearly within the scope of the invention to measure the entire angle directly (for example in the case of the sagittal angle A, measuring from one nose pad to the opposite nose pad). Furthermore, it is assumed that the nose pads for each side of the nose are symmetrical, but variations that typically occur in manufacturing may occur. 
     Using the angles specified above, the present inventors have determined that the optimal range(s) for the nose pad surfaces of fixed nose-bridge eyewear for a certain population of people are as follows:
         Sagittal angle A: preferably greater than 38 degrees, more preferably greater than 41 degrees, and most preferably between 41 degrees and 43 degrees.   Transverse angle B: preferably greater than 25 degrees, more preferably greater than 27 degrees, and most preferably between 27 degrees and 29 degrees.   Frontal angle C: preferably between 12 degrees and about 16 degrees, and most preferably between about 13 degrees and about 14 degrees.       

     Each of the angles identified above, and each combination of two or all three of these angles is believed to be critical to the performance of certain embodiments of the claimed invention. Specifically, in one embodiment, the sagittal angle A is a critical parameter. In another embodiment, sagittal angle A and transverse angle B are both critical parameters. In a further embodiment, angle B is a critical parameter, and so on. Fixed nose-bridge eyewear having one, or two, or all three angles within the ranges specified have been found to provide a better fit for certain people having facial characteristics thought to be typical of people of Asian descent. More significantly, fixed nose-bridge eyewear said to be designed for “Asian-fit” in the past do not exhibit the angles described and claimed herein, and in fact appear not even to exhibit angles close to the invention described and claimed herein. This is explained with reference to an example of a pair of fixed nose-bridge eyewear made in accordance with the present invention, compared to a number of pairs of fixed nose-bridge eyewear that are currently publicly available, as described in detail below. 
     EXAMPLES 
     Example 1 
     An example of fixed nose-bridge eyewear according to the present invention were injection molded using a optical thermoplastic polycarbonate polymer. The nose pads were formed integrally with the frame of the eyewear, which were designed for use as safety glasses. The nose pads had a 4.6 mm×14.9 mm approximately rectangular bearing surface with an area of 68.5 mm 2 . Nose pads were set in the frame of the glasses at a fixed spatial orientation and spaced 19 mm apart from their centers. The stems of the eyewear were spaced 99.1 mm apart. 
     The sagittal, transverse, and frontal angles of the exemplary eyewear described above were measured and are shown in Table 1. The eyewear as described was believed to be well-suited for a typical Asian face, and when Asian wearers tested the fit of the glasses according to this embodiment of the present invention, the glasses were subjectively thought to fit well. 
     Comparative Examples 
     Several pairs of eyewear with fixed nose pads that are currently commercially available were evaluated relative to the three angles described above. The results are shown in Table 1. 
     
       
         
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                 DISTANCE 
                   
                   
                   
               
               
                 Maker/Model (if 
                   
                 Ex- 
                 Between 
                 ANGLE 
                 ANGLE 
                 ANGLE 
               
               
                 available) 
                 Obtained from: 
                 ample 
                 Pads 
                 A 
                 B 
                 C 
               
               
                   
               
             
             
               
                 Example of 
                   
                 E1 
                 19.7 mm 
                 42.° 
                 28° 
                 13° 
               
               
                 Present Invention 
                   
                   
                   
                   
                   
                   
               
               
                 Oakley (Asian Fit) 
                 USA 
                 C1 
                 17.2 mm 
                  16° 
                 12° 
                 29° 
               
               
                 Model # 03-324 
                 (www.MBstores.com) 
                   
                   
                   
                   
                   
               
               
                 Nike Skylon Exp.R 
                 USA 
                 C2 
                 12.6 mm 
                  25° 
                  8° 
                 34° 
               
               
                 (Asian Fit) 
                 (www.MBstores.com) 
                   
                   
                   
                   
                   
               
               
                 Model # Ev0153403 
                   
                   
                   
                   
                   
                   
               
               
                 Sperian 
                 USA 
                 C3 
                 18.0 mm 
                  33° 
                 12° 
                 12° 
               
               
                 Yamamoto 
                 Japan 
                 C4 
                 16.9 mm 
                  27° 
                  4° 
                 11° 
               
               
                 Model # 337S 
                   
                   
                   
                   
                   
                   
               
               
                 Yamamoto 
                 Japan 
                 C5 
                 16.0 mm 
                  31° 
                  7° 
                 16° 
               
               
                 Model # SN-730 
                   
                   
                   
                   
                   
                   
               
               
                 Riken 
                 Japan 
                 C6 
                 12.9 mm 
                  25° 
                  1° 
                 −2° 
               
               
                 Model # RSX-IIB 
                   
                   
                   
                   
                   
                   
               
               
                 Riken 
                 Japan 
                 C7 
                 17.4 mm 
                  25° 
                  8° 
                 17° 
               
               
                 Model # 80B 
                   
                   
                   
                   
                   
                   
               
               
                 Worksafe Strider II 
                 Korea 
                 C8 
                 17.9 mm 
                  27° 
                 13° 
                 12° 
               
               
                 Otis 
                 Korea 
                 C9 
                 13.1 mm 
                  31° 
                 18° 
                  9° 
               
               
                 Model # 701 
               
               
                   
               
             
          
         
       
     
     As is evident in the evaluation results, the eyewear of the present invention have fixed-position nose pads at angular positions much different from the other eyewear measured. More importantly, the special positioning of the nose pads of the present invention are believed to be directly responsible for the improved fit of the eyewear of the present invention, and accordingly the data presented above is believed to represent a significant improvement in the field. 
     The eyewear of the present invention has now been described with reference to several different embodiments, which are intended to exemplify the present invention, but not to limit it. For example, the eyewear may include only a single lens extending across the user&#39;s field of view, or may include two separate lenses. The eyewear may be safety glasses, sunglasses, glasses for the correction of vision, goggles, or a combination of these and other types of glasses.