GB2337133A - Spectacle lens - Google Patents

Abstract

A spectacle lens comprises a transparent lens 11 and a long-sight lens 12 connected to a lower end of said transparent lens, said long-sight lens smoothly and curvingly extending down from said transparent lens, with an abutting area of said two lenses forming a curved line 13 with no step-like thickness difference to cause any visional obstacle.

Description

1 SPECTACLE LENS

BACKGROUND OF THE INVENTION

2337133 This invention relates to a spectacle lens,par- ticularly to one consisting of a transparent lens such as a parallel light lens or a long-sight lens combined with a long-sight lens in a proper inclination or cur ture, forming no step-like thickness difference to cause visional obstacles.

Old people generally are long-sighted because of visional degeneration, and need eyeglasses for correcing eyesight. They have to wear it in case of,seeing an object located near to-their eyes, but to take it down in case of seeing objects far from their eyes, which' is very troublesome to them. Therefore, to get rid of this embarrassment, opticians supply a kind of spectacle lens formed integral with a long-sight lens and a parallel light lens together so that a wearer may not need to put on or take down spectacles frequently for seeing objects near or far A first conventional spectacle lens 10 shown in Figs. 5, 6 and 7 includes an upper half portion 101 made of a parallel light lens and.a lower half portion 102 made of a long-sight lens.In fabricating the first con ventional spectacle lens 10, as shown in Fig. 8, a lower mold 20 is prepared, having a first lower mold 201 and a second mold 202 respectively having an upper cur- vature 203, 204, and an upper mold 30 is prepared, hav- 2 ing a single lower curvature 301, and then the lower mold and the upper mold 30 are placed together to form the spectacle lens 10.

But in practical use the first conventional spec tacle lens 10 has the following defects.

1. The parallel light lens 101 is a lens with no 2 degree, possible to be as thin as desired to have a light weight, and the center portion 103 and the outer edge 104 of it are of the same thickness. But the long- sight lens 102 has a thick center portion 105 and a thin outer edge 106. The upper end of the thickest center 105 of the longsight lens 102 is abutting on the center portion of the parallel light lens 101, so the parallel light lens 101 must be increased to the same thickness of the long-sight lens 102 so as not to form a step-like thickness difference, otherwise a step-like thickness difference is formed to cause.a visional obstacle. When the thickness is increased to that of the parallel light lens 101, the whole weight of the spectacle lens 10 becomes large, forming a burden to a wearer.

2. After the parallel light lens 101 is increased in its thickness, its outer edge 104 and the two side edges 106 of the long-sight lens 102 form a step-like thickness difference, causing a visional obstacle.

3. As the lower mold 20 is formed with the first and the 'second lower mold 201, 201, the abutting edges of the parallel light lens 101 and the long-sight lens 102 may be more evident to cause visional obstacles.

Next, another conventional spectacle lens 40 shown 3 in Figs. 9, 10 and 11 includes a large parallel light lens 401, and a small long-sight lens 402 formed near a center portion of the parallel light lens 401. In fabricating this lens 40, as shown in Fig. 12, a lower mold 50 provided with an upper single curved surface 501 is combined with an upper mold 60 provided with a lower single concave surface 601 and having a through hole 602 for placing a small mold 604, which has a different curvature from that of the surface 601 so that a long- sight lens 402 is formed in the parallel light lens 401.

However, this conventional spectacle lens 40 has the following defects in practical use.

1. As the long-sig ht lens 402 is formed in a front surface of the parallel light lens 401, and has to be restricted in its dimensions, an upper end of the long- sight lens 402 and the front surface of the parallel light lens 401 form a step-like thickness difference so that eyes of a person may see the upper edge of the long-sight lens 402, and be disturbed by it in seeing.

2. The small mold 603 of the upper mold 60 forms an upper edge 403 of the longsight lens 402 abut ting on the parallel light lens 401/ making an evident step-like thickness difference to cause a visional obstacle.

SUMMARY OF THE INVENTION

The main purpose of the invention is offer a kind of spectacle lens formed of a transparent lens combined with a lower long-sight lens which curves down from the 4 lower end of the transparent lens, with the abutting line curving down with no step-like thickness difference to cause no visional obstacle as the aforesaid conventional spectacle lenses do.

BRIEF DESCRIPTION OF DRAWINGS

This invention will be better understood by referring to the accompanying drawing, wherein:

Figure 1 is a perspective view of a spectacle lens of the present invention; Figure 2 is a front view of the spectacle lens of the present invention; Figure 3 is an upper view of the spectacle lens of the present invention; Figure 4 is a crosssectional view of the spec15 tacle lens and its mold of the present invention; Figure 5 is a perspective view of a first conven tional spectacle lens; Figure 6 is a front view of the first conventional spectacle lens; Figure 7 is an upper view of the first convent tional spectacle lens; Figure 8 is a cross-sectional view of the first conventional spectacle and its mold; Figure 9 is a perspective view of a second conven25 tional spectacle lens; Figure 10 is a front view of the second conventional spectacle lens; Figure 11 is an upper view of the second conven- tional spectacle lens; and, Figure 12 is a cross-sectional view of the second conventional spectacle lens and its mold.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of a spectacle lens in the present invention, as shown in Figs. 1, 2 and 3, includes a transparent lens 11 such as a parallel light lens or a long-sight lens, and a long-sight lens 12 connected to a lower end of the transparent lens 11 curving down from the lower end of the transparent lens 11. The abutting line 13 of the long-sight lens 12 andthe transparent lens 11 forms a natural curvature without any step-like thickness difference. The transparent lens 11 may be a parallel light lens 11 with no degrees is or a longsight lens having a different degree from the long-sight lens 12 so that the spectacle lens can be used for correcting sight of a person in seeing objects far and near.

As shown in Fig. 4, in fabricating this spectacle lens, a lower mold 2 is prepared to have two different surface curvatures 21, 22 on an upper surface, and an upper mold 3 is prepared to have a single curvature 31 in the lower surface. The curvature 21 and the curvature 22 are connected with an abutting area 23 smoothly curved with a certain curvature.

In designing a mold for this spectacle lens, the focus point of the transparent lens 11 and the first curvature 21 and the second curvature 22 of the long- 6 sight lens 12 are to be found out on the lower mold 2, then the abutting area 23 may be naturally and curvingly formed. So the abutting line 13 of the transparent lens 11 and the long-sight lens 12 is also subsequently formed.

The spectacle lens.in the present invention the following advantages.

1. It is lighter than the conventional ones, as the transparent lens 11 and the longsight lens 12 abut smoothly on each other, with the transparent lens not increased in its thickness.

2. It does not have any step-like thickness difference to cause any visional obstacles, as the longsight lens 12 and the transparent lens 11 are connected curvingly, with the transparent lens 11 not increased in its thickness.

3. The lower mold 2 for fabricating the transparent lens 11 and the longsight lens 12 is single, not as double for the conventional ones necessary to have two molds or a small mold put in a large mold, so the abutting line of the transparent lens 11 and the longsight lens 12 is smooth, without any step-like thickness difference to cause any visional obstacle.

4. The upper and the lower mold used are single, more simple to fabricate a spectacle lens than the conventional ones.

5. The transparent lens 11 may be a parallel light lens with no degrees or a long-sight lens with a different degree from the long-sight lens 12. If the long- j 1 has 7 sight lens with a different degree from the long-sight lens 12 is used, the spectacle lens can correct sight of a user to see objects both near or far clearly.

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Claims (3)

CLAIMS:

1. A spectacle lens comprising a transparent lens and a long-sight lens connected to a lower end of said transparent lens, and characterized by said long-sight lens smoothly and curvingly extending down from said transparent lens, witlian abutting area of said two lenses forming a curved line with no step-like thickness difference to cause any visional obstacle.

2. The spectacle lens as claime.d in Claim 1, wherein said transparent lens is a parallel light lens.

3. The spectacle lens as claimed in Claim 1,wherein said transparent lens is a long-sight lens with a different degree from said long-sight lens.