Eyeglasses in which a plurality of lenses formed of curved surface are coupled integrally

Abstract: Upper lens (2a) formed of a portion of a sphere having radius R₂ and lower lens (2b) formed of a portion of a sphere having radius R₁ are manufactured integrally by molding for forming the lens of eyeglasses (1). Radii R₁ and R₂ are slightly different from each other, so that the front view comes into eyes through lower lens (2b) when the user is in a normal posture, while the front view comes into eyes through upper lens (2a) when the user bends forward.

Description: The present invention relates to eyeglasses, and more particularly to a lens of eyeglasses for use in sports such as bicycle road racing. Description of the Background Art Fig. 8 is a perspective view showing eyeglasses for use in sports being actually worn by a person, which is disclosed in U.S. Patent No. 4,859,048, and Fig. 9 is a view seen in the direction of arrows "c" in Fig. 8. Referring to these figures, a lens 32 for eyeglasses affixed on a frame 33 is made of, for example, an integral transparent plastic as shown in Fig. 10, and its curved surface is formed of a part of the curved outer surface of a cylinder having a radius R. Therefore, eyeglasses 34 can serve as sunglasses for use in sports securing a wide view through lens 32. In conventional eyeglasses as mentioned above, the field of vision through lens 32 does not come into question because the line-of-sight of a person is in the direction of the arrow in solid line in Fig. 9 in the normal usage. A person, however, sometimes bends forward to look ahead during the use. In this case, the line-of-sight is in the direction of the arrow in broken line in Fig. 9, and accordingly the line-of-sight is interrupted by the structure of a frame 33, so that a sufficient front view cannot be secured. Therefore, capability of assuring safety by sight is reduced especially when a bicycle is running at high speed with a person bent forward. From FR-A-685 935 or from GB-A-649 245 an eyeglass is known comprising the features of the generic portion of claim 1. In the known eyeglasses the upper lens portions and the lower lens portions are formed in a cone shape. Therefore, it is the object of the present invention to provide an eyeglass which can provide an enlarged field of view with as little distortion as possible. This object is solved by the eyeglass according to claim 1. Preferred developments of the invention are given in the subclaims. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. Fig. 1 is a perspective view showing an outside structure of eyeglasses according to one embodiment of the present invention. Fig. 2 is a front view of lens 1 in Fig. 1. Fig. 3 is a view seen in the direction of arrows "a" in Fig. 2. Fig. 4 is a view seen in the direction of arrows "b" in Fig. 3. Fig. 5 is a side view showing eyeglasses having a lens for eyeglasses according to one embodiment of the present invention when set on a user. Fig. 6 is a side view showing eyeglasses having a lens for eyeglasses according to one embodiment of the present invention when used while a user bends forward. Fig. 7 shows a side structure of eyeglasses according to another embodiment of the present invention. Fig. 8 is a perspective view showing a conventional eyeglasses during use. Fig. 9 is a view seen in the direction of arrows "c" in Fig. 8. Fig. 10 shows the shape of curved surface of a lens for eyeglasses shown in Fig. 8. Fig. 1 is a perspective view showing an outside structure of eyeglasses according to one embodiment of the present invention. Referring to the figure, a nose piece 3 which can be fixed adjustably in accordance with the height of nose of a user, a pad 5 which is made of a resilient material and prevents inflow of wind from a space between the eyeglasses and a forehead during running, and support portions 7a and 7b for fixing temples, are mounted to a lens 1 having a spherical shape and made of a transparent material. Bar-shaped temples 9a and 9b which extend backwardly via hinge portions 13a and 13b are affixed rotatably to each of support portions 7a and 7b. Ear hooks 11a and 11b made of, for example, synthetic rubber are fitted slidably to temples 9a and 9b, respectively. Fig. 2 is a front view of lens 1 in Fig. 1, Fig. 3 is a view seen in the direction of arrows "a" in Fig. 2, and Fig. 4 is a view seen in the direction of arrows "b" in Fig. 3. Referring to these figures, the structure of lens 1 will be described. Lens 1 is made of a transparent plastic material such as acrylic, and structured by upper and lower lenses 2a and 2b. Upper lens 2a is shaped by a mold corresponding to a portion of a sphere having a radius R 2 , and lower lens 2b is shaped by a mold corresponding to a portion of a sphere having a radius R 1 as shown in Fig. 4. Center positions A, B of respective spheres are deviated from each other. In this embodiment, radius R 1 is set to 186mm and radius R 2 is set to 191.5mm. A nose piece mounting portion 15 for fixing the removable nose piece 3 is formed by removing a lower center portion of lower lens 2b in a triangle shape. Upper lens 2a and lower lens 2b may be fabricated separately and adhered to each other on a boundary surface. In this embodiment, however, in order to obtain a favorable view, a mold is made corresponding to portions of respective spheres, and upper and lower lenses 2a and 2b are formed integrally using such mold. Although back protruding portions 19a and 19b for fixing support portions 7a and 7b are formed integrally with lower lens 2b, back protruding portions 19a and 19b may be fabricated separately and connected and fixed to lower lens 2b because the field of vision is not particularly significant in these portions. Effects of setting the eyeglasses, which employs the lenses for eyeglasses according to one embodiment of the present invention, on a user will be described referring to Figs. 5 and 6. Fig. 5 is a side view showing eyeglasses having lens 1 according to one embodiment of the present invention when worn by a user in a normal posture. As shown in the figure, a line-of-sight from eye position E of the user is directed forward through lower lens 2b as shown in broken line. The eyeglasses is shown from the side in this figure, but when as apparent from the view of Fig. 3, lower lens 2b constitutes a portion of a sphere and distortion due to the curved surface of the lens is so small. Therefore, a favorable view can be obtained because all the lights coming from objects included in the view come in almost perpendicularly to the surface of lower lens 2b. Fig. 6 is a side view showing a state when a user bents forward on a bicycle such as a racer for road race. As shown in the figure, a forward line-of-sight of the user from eye position E is directed along the arrow shown in broken line in such a state. In this case, since the front view is coming into eyes of the user through upper lens 2a, there is nothing interrupting the field of vision compared to the direction shown in broken line in Fig. 9 showing the conventional case, whereby a favorable view can be secured. In addition, associated with the effect of pad 5 in Fig. 1, inflow of air through a space between a forehead and the eyeglasses can be prevented because upper lens 2a is inclined in the direction of the forehead of the user, and therefore so-called watery eye during exercising in sports can be prevented. Since upper and lower lenses 2a and 2b are shaped integrally using a single mold as described above, a favorable front view can be secured even at a boundary portion. Also, lens 1 has such a shape that a tip portion 4 thereof protrudes forward compared with the conventional lens formed of a portion of outer surface of a cylinder, and thus this is a favorable shape with respect to air resistance, for example, in high speed running. Both of the upper lens and the lower lens are made of, for example, a transparent plastic in the above embodiment, but the upper lens may be colored for use as sunglasses while using the transparent plastic for the lower lens, whereby the dazzle in the field of vision may be reduced during the normal use. Fig. 7 is a side view of sunglasses for use in sports according to another embodiment of the present invention. Referring to the figure, upper lens 2a which is colored and made of a portion of a sphere is affixed between upper frame 8a and lower frame 8b which constitute a frame 6. Temple 9b is connected via hinge portion 13b at a back portion of frame 6. Meanwhile, lower lens 2b, which is colored and made of a portion of a sphere having a radius different from a radius for upper lens 2a, is affixed to lower frame 8b at its upper portion. Therefore, unlike the previous embodiment, upper and lower lenses 2a and 2b are not formed integrally, but they are formed separately and fixed to each other via frame 6 in this embodiment. Consequently, a manufacturing cost of a spherical lens can be reduced compared to the previous embodiment, and also a wider variety of lenses are available. The transparent plastic may be used only for lower lens 2b for securing the field of vision efficiently. Although the present invention has applied to the sunglasses for use in sports in the above embodiments, it may apply to ordinary eyeglasses. The radius of the sphere for the upper lens is different from that of the lower lens in the above embodiments, but the radii may be made identical. Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being limited only by the terms of the appended claims.

Claims: An eyeglass comprising: a support frame (7a, 7b; 6, 8a, 8b) for mounting temples (9a, 9b) and a single lens (1) fixed to the support frame and having an upper lens portion (2a) formed of a first curved surface and a lower lens portion (2b) formed of a second curved surface, said first and second curved surfaces having different centers of curvature said upper lens portion (2a) and said lower lens portion (2b) being coupled on a curved line where respective curved surfaces meet, characterized in that the first curved surface is a portion of a sphere having a first radius (R 2 ) and the second curved surface is a portion of a sphere having a second radius (R 1 ). The eyeglass according to claim 1, wherein said upper lens portion (2a) and said lower lens portion (2b) are fixed to said support frame (6) sandwiching a portion (8b) of said support frame (6). The eyeglass according to claim 1 or 2, wherein the center of curvature (A) of said first curved surface and the center of curvature (B) of said second curved surface are positioned on the same side relative to the curved surfaces defined by said first and second lenses. The eyeglass according to one of claims 1 to 3, wherein the radius (R 1 ) of the sphere defining said first curved surface is smaller than the radius (R 2 ) of the sphere defining said second curved surface. The eyeglass according to one of claims 1 to 3, wherein the radius (R 1 ) of the sphere defining said first curved surface is equal to the radius (R 2 ) of the sphere defining said second curved surface. The eyeglass according to one of claims 1 or 3 to 5, wherein said upper and lower lens portions (2a,2b) are formed integrally using a mold. The eyeglass according to one of claims 1 or 3 to 5, wherein said upper and lower lens portions (2a,2b) are adhered to each other on said curved line. The eyeglass according to one of claims 1 to 7, wherein said upper lens portion (2a) is made of a colored plastic material, and said lower lens portion (2b) is made of a transparent plastic material. The eyeglass according to one of claims 1 to 8, further comprising: a pad (5) made of a long and narrow resilient material having a trench, and fixed detachably to said lens (1) via said trench.

Inventors: IIDA YOSHIAKI, IIDA, ,YOSHIAKI
Applicants: CATEYE CO LTD, CATEYE CO., LTD.
Application year: 1993
Main classification: G02C7
IPC codes: A61F9, G02C7, G02C1