CN200956073Y - Dual-cone non-sphere glasses lens - Google Patents

Abstract

The utility model relates to a double conical aspheric surface spectacle, which is provided with a double conical aspheric surface spectacle lens. The technical problem needs to be resolved by the utility model is that, by changing the shape of one surface of the spectacle lens and reducing the thickness of the spectacle lens, thereby obtaining the function of astigmatic correction and better effect of sight to the astigmatic sufferer with malignant myopia. The technical scheme is that, two refractive surfaces are comprised by the double conical aspheric surface spectacle lens. Wherein, at least one surface is a double conical surface. Setting the light axis to be the Z-axis, the figure can be expressed by a formulary, in which the value of z expresses the vector of height of somewhere on the surface. The Cx is the curvature of the arc vector surface. The Cy is the curvature of the acme of the double conical surface in the meridian plane. The kx is the conic constant of the curve which is the transversal of the double conical surface and the arc vector surface. The ky is the conic constant of the curve which is the transversal of the double conical surface and the meridian plane. The utility model can be used for astigmatic spectacles for malignant myopia.

Description

The bipyramid aspherical eyeglass lens

Technical field

The utility model relates to a kind of lens, is specifically related to a kind of bipyramid aspherical eyeglass lens.Be applicable to the high myopia mirror of band astigmatism.

Background technology

The lens that is used for myopia correction is generally the lens that comprise two refractive surfaces, and two refractive surfaces of conventional lenses are sphere, is convenient to processing.Yet in order to reach best visual effect, along with the increase of the eyeglass number of degrees, near-sighted edge can obviously thicken, and has both increased the weight of eyeglass, and sees that through lens periphery things has phenomenons such as distortion, distortion to take place.For reducing the thickness of high power lens, people begin to adopt big refraction materials to make lens, yet these glasses still can't solve through lens periphery and see that things has the problem of distortion.The appearance of aspherical lens not only makes the edge thickness of eyeglass reduce, and makes eyeglass thinner, more eliminates marginal aberration, gives wearer's nature eyesight.CN1412604A discloses a kind of aspherical eyeglass lens as the Chinese invention patent application, reduces lens edge and central thickness difference by introducing aspheric surface, and has considered that the average curvature of field overlaps with the far point sphere of requirement to strengthen comfort of wearing; Chinese invention patent application CN1710463A discloses the aspherical eyeglass lens of another form, has increased the control to conic constant, makes lens can do thinlyyer.Yet, according to reported in literature, in ametropic patient, accounting for 1/4th greater than the astigmatism of 1.0D, other has most people that the astigmatism of 0.25D-0.5D is arranged, and along with the increase of eyeglass lens power, astigmatism is obvious more.In existing aspheric surface design patent, owing to adopt rotational symmetry type structure, can't eliminate astigmatism, myopia or farsighted person with astigmatism wear this aspheric surface glasses, though thickness reduces greatly than traditional spherical mirror, but the object in two vertical planes of the meridian and the sagitta of arc can't focus on retina simultaneously, brings the fuzzy of imaging.

Summary of the invention

The technical problems to be solved in the utility model is: a kind of bipyramid aspherical eyeglass lens is provided, by changing the shape of eyeglass one side, reduce lens thickness, and have the function of astigmatism, thereby make the astigmatic patient of high myopia obtain higher visual effect, wear more comfortable.

The technical scheme that the utility model adopted is: a kind of bipyramid aspherical eyeglass lens, comprise two refractive surfaces, and wherein at least one surface is the bipyramid face, if optical axis is the Z axle, its shape is by following formulate,

$z=\frac{c_x{x}^2+c_y{y}^2}{1+\sqrt{1-(1+k_x){c_x}^2{x}^2-(1+k_y)c_y^2{y}^2}}$

Z is the rise in surperficial somewhere in the formula, and Cx, Cy are respectively the curvature of bipyramid vertex of surface in sagittal surface and the meridian ellipse, and kx, ky are respectively the conic constant of bipyramid face curve that cuts in sagittal surface and meridian ellipse.

Described eyeglass is concavees lens, and first surface is sphere or plane, and second surface is the bipyramid face.

Described lens material is a polycarbonate.

The beneficial effects of the utility model are: the utility model is introduced the face type of bipyramid face as the lens inside surface, makes eyeglass astigmatism effectively; In addition, bipyramid face meridian ellipse that the utility model is introduced and the conic constant in the sagittal surface can make the lens thickness attenuate effectively, and the curvature of field that obtains in two faces is overlapped substantially with the crooked of lens far point sphere, have improved image quality.

Description of drawings

Fig. 1 is a lateral plan of the present utility model.

Embodiment

The bipyramid aspherical eyeglass lens comprises two refractive surfaces, as shown in Figure 1, the direction that enters eyes by lens for light from left to right, on Z axle (optical axis) positive dirction, front surface is sphere or plane, the rear surface is the bipyramid face.The YZ plane is a meridian ellipse, and the XZ plane is a sagittal surface.

Present embodiment bipyramid face myopia eyeglass, eyeglass is concavees lens, and spherical degree is-4D, and astigmatism degree is-0.5D, and first is plane (radius-of-curvature is for infinitely great), and second is the bipyramid face, and lens shape can be by following formulate,

$z=\frac{c_x{x}^2+c_y{y}^2}{1+\sqrt{1-(1+k_x){c_x}^2{x}^2-(1+k_y)c_y^2{y}^2}}$

Z is the rise in surperficial somewhere in the formula, and Cx, Cy are respectively the curvature of sagittal surface (XZ plane) and the interior bipyramid vertex of surface of meridian ellipse (YZ face), and kx, ky are respectively the conic constant of bipyramid face curve that cuts in sagittal surface (XZ plane) and meridian ellipse (YZ face).

This routine lens material adopts PC (polycarbonate).

In the utility model, the hump curvature c that described bipyramid face is cut in sagittal surface and meridian ellipse _xAnd c _yCan obtain by spherical degree and the astigmatism degree that lens is required, corresponding conic constant can be obtained by the computing machine Automatic Optimal.

Usually, the outside surface of described eyeglass (direction that enters eyes by glasses along light is away from the plane of refraction of eyes) is traditional sphere or plane; Inside surface (along the direction that light enters eyes by glasses, the plane of refraction of close eyes) is the bipyramid face.The radius-of-curvature c on the curvature of outside surface and inside surface meridian ellipse summit _YCan match according to routine by the number of degrees that lens is required and obtain the curvature c of inside surface sagittal surface _XCan determine by the astigmatism degree that lens requires.Owing to introduce the conic constant item in meridian ellipse and the sagittal surface,, can under the situation that satisfies lens central area dissipation light, make the lens attenuate by the control conic constant.

The parameter of present embodiment myopia eyeglass sees Table 1:

Specification	The bipyramid face lens of design	The aspherical eyeglass lens of identical spherical degree
			Optic diameter	70mm
Spherical diopter	-4.0D
			The cylinder diopter	-0.5D	Can't realize
First curvature of face radius	Infinitely great	2930mm
			The second face noon radius-of-curvature	146.5058mm	139.5229mm
Second sagitta of arc radius-of-curvature	130.2273mm	139.5229mm
			Second interior meridian ellipse conic constant	-5.33	-7.5207
Second interior sagittal surface conic constant	-3.934	Do not have

Second interior meridian ellipse asphericity coefficient	Do not have	a 1＝-3.5570×10 -7 a 2＝1.8761×10 -10 a 3＝-8.5552×10 -14 a 4＝1.2663×10 -18
			Center thickness	1mm
Edge thickness	5.1	4.808
			Distortion	-4.6％	-4.911％
The index of refraction error	0.28	0.196

This routine bipyramid face lens has been realized the astigmatism correction effect of 0.5D, and this is that common non-spherical lens can't be realized.

Compare with the aspherical eyeglass lens of same specification, front surface is more smooth, and is more attractive in appearance, and edge thickness only increases 0.3mm, than the spheric glass minimizing 2.04mm of same specification.

The distortion of the bipyramid face lens that the utility model is designed is controlled in 5% scope, the curvature of field, and promptly average index of refraction error neither be very big, so all can meet the demands.

Because the utility model can be eliminated astigmatism effectively on the basis of attenuate glasses thickness, satisfied more users' demand.

Claims (3)

1. a bipyramid aspherical eyeglass lens comprises two refractive surfaces, it is characterized in that: at least one surface is for the bipyramid face, if optical axis is the Z axle, its shape is by following formulate,

$\frac{c_x{x}^2+c_y{y}^2}{1+\sqrt{1-(1+k_x){c_x}^2{x}^2-(1+k_y)c_y^2{y}^2}}$

Z is the rise in surperficial somewhere in the formula, and Cx, Cy are respectively the curvature of bipyramid vertex of surface in sagittal surface and the meridian ellipse, and kx, ky are respectively the conic constant of bipyramid face curve that cuts in sagittal surface and meridian ellipse.

2. bipyramid aspherical eyeglass lens as claimed in claim 1 is characterized in that: described eyeglass is concavees lens, and first surface is sphere or plane, and second surface is the bipyramid face.

3. bipyramid aspherical eyeglass lens as claimed in claim 1 is characterized in that: described lens material is a polycarbonate.

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