TWM562406U - Optical lens - Google Patents

Abstract

This invention provides an optical lens, which comprises, in order from an object side to an image-forming side, a first lens group having positive refraction power and a second lens group having negative refraction power. The first lens group comprises: in order from the object side to the image-forming side, a first lens having refraction powder and a second lens having refraction powder. The second lens group comprises: in order from the object side to the image-forming side, a third lens having refraction powder and a fourth lens having refraction powder. The optical lens satisfies at least one of the following conditions: a thickness of the first lens group is less than a distance between the first lens group and the second lens group; and, a distance between a projected position which an effective diameter of an object-side surface of the fourth lens projected on the optical axis and a first intersection point which the object-side surface of the fourth lens and the optical axis is [delta]7, a thickness of the fourth lens is D4, and | [delta]7/D4 | ≥ 2.

Description

Optical lens

The present invention proposes an optical lens, and in particular relates to an optical lens that is small in size and excellent in imaging quality.

In recent years, due to the ever-changing technology of smart phones and handheld tablets, various mobile devices have increased optical image quality requirements for their camera devices; and because of the thin and light design of mobile devices, the thickness of optical lenses of camera devices also needs to change. thin. Optical lenses are usually made up of several lenses. In order to increase the competitive advantage in the market, miniaturization, high image quality and cost reduction have always been the goals of product development.

Therefore, it is urgent to propose a new optical lens, which achieves the purpose of miniaturizing the optical lens and improving the image quality while reducing the manufacturing cost.

The present invention relates to an optical lens. Under the premise of reducing manufacturing costs, the optical lens is miniaturized and the image quality is improved.

The present invention proposes an optical lens. The optical lens includes, in order from the object side to the image side, a first lens group having positive refracting power and a negative refracting power The second lens group. The first lens group sequentially includes a first lens having a refracting power and a second lens having a refracting power from the object side to the image side; the second lens group sequentially includes a third lens having a refracting power from the object side to the image side. A fourth lens having diopter. The optical lens satisfies at least one of the following conditions: a thickness of the first lens group is smaller than a distance between the first lens group and the second lens group; and an effective diameter of one of the object side surfaces of the fourth lens is projected to a light The maximum length of the position of the axis to the intersection of the object side surface of the fourth lens and the optical axis is δ7, and the thickness of the fourth lens is D4, and | δ7/D4 | ≧2.

The present invention further proposes an optical lens. The optical lens includes a first lens, a second lens, a third lens and a fourth lens from the object side to the image side, the first lens has a positive refractive power, the second lens, the third lens and the fourth lens The lens has diopter. The thickness of the first lens is D1, the thickness of the second lens is D2, the distance from one image side of the first lens to the object side of the second lens is D12, and one of the image sides of the second lens to the third lens The distance of the side is D23, and the optical lens satisfies at least one of the following conditions: (D1+D12+D2)≦D23; and an effective path of the object side surface of the fourth lens is projected to an optical axis position to the The maximum length of the intersection of the object side surface of the four lens and the optical axis is δ7, the thickness of the fourth lens is D4, and | δ7/D4 | ≧2.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

D23‧‧‧Distance

D4‧‧‧ thickness

F‧‧‧Filter

G1‧‧‧first lens group

G2‧‧‧second lens group

H8‧‧‧first distance

H8‧‧‧Second distance

I‧‧‧ imaging surface

IF‧‧‧recurve

L1‧‧‧ first lens

L2‧‧‧ second lens

L3‧‧‧ third lens

L4‧‧‧4th lens

OA‧‧‧ optical axis

OL1, OL2‧‧‧ optical lens

S, T‧‧‧ curve

S1~S11‧‧‧ surface

St‧‧‧Light

Δ7‧‧‧ length

δ8‧‧‧Extended length

FIG. 1 illustrates an optical lens according to an embodiment of the present invention.

2A is a graph showing a field curvature of an optical lens according to an embodiment of the present invention.

FIG. 2B is a diagram showing a distortion curve of an optical lens according to an embodiment of the present invention.

FIG. 3 illustrates an optical lens according to another embodiment of the present invention.

FIG. 4A is a graph showing a field curvature of an optical lens according to another embodiment of the present invention.

FIG. 4B is a diagram showing distortion curves of an optical lens according to another embodiment of the present invention.

The various embodiments of the present invention are described in detail below with reference to the drawings. In addition to the detailed description, the present invention may be widely practiced in other embodiments, and any alternatives, modifications, and equivalent variations of the described embodiments are included in the scope of the present invention, and the scope of the following patents is quasi. In the description of the specification, numerous specific details are set forth in the description of the invention. In addition, well-known steps or elements are not described in detail to avoid unnecessary limitations of the present invention. The same or similar elements in the drawings will be denoted by the same or similar symbols. It is specifically noted that the drawings are for illustrative purposes only and do not represent the actual dimensions or quantities of the components unless otherwise specified.

FIG. 1 illustrates an optical lens OL1 according to a first embodiment of the present invention. In order to reveal the features of the embodiment, only the structure related to the present embodiment is shown, and the rest of the structure is omitted. The optical lens OL1 of this embodiment may be a certain focal length mirror The head can be applied to a device having an image projection or capture function, such as a handheld communication system, a vehicle imaging lens, a monitoring system, a digital camera, a digital camera, or a projector.

As shown in FIG. 1 , in the present embodiment, the optical lens OL1 from the object side to the image-forming side sequentially includes: a first lens group G1 having a positive refracting power and a negative lens. The second lens group G2 of diopter. The first lens group G1 sequentially includes a first lens L1 having a refracting power and a second lens L2 having a refracting power from the object side to the image side. The second lens group G2 sequentially includes a third lens L3 having a refracting power and a fourth lens L4 having a refracting power from the object side to the image side, wherein the object side surface of the fourth lens L4 is a concave surface.

In one embodiment, the first lens group G1 having positive refracting power is combined with the second lens group G2 having negative refracting power.

Further, the object side surface S8 of the fourth lens L4 is a concave surface that is curved toward the image side, and particularly, the object side surface S8 near the optical axis OA is a negative refracting power.

In an embodiment, the optical lens OL1 can satisfy the following conditions: 0.1<| F1/F2 |<0.5

Wherein F1 is the focal length of the first lens L1, and F2 is the focal length of the second lens L2.

Furthermore, in an embodiment, the optical lens OL1 can also satisfy the following conditions: -0.12<1/(F12+F34-D23)<0

Here, F12 is the focal length of the first lens group G1, and F34 is the focal length of the second lens group G2, and has a distance D23 from the image side of the first lens group G1 to the object side of the second lens group G2. Specifically, F12 is the first lens L1 and the first The integrated focal length of the second lens L2, F34 is the integrated focal length of the third lens L3 and the fourth lens L4; the distance D23 is the distance from the image side surface S5 of the second lens L2 to the object side surface S6 of the third lens L3. The image side surface S5 of the second lens L2 may be substantially equivalent to the surface code S5 in Tables 1 and 3 herein, and the object side surface S6 of the third lens L3 may be substantially equivalent to those in Tables 1 and 3 herein. Surface code S6.

Next, in an embodiment, in the optical lens OL1, a large distance exists between the first lens group G1 and the second lens group G2 with respect to the thickness of the first lens group G1. That is, the optical lens OL1 can satisfy the condition that the thickness of the first lens group G1 is smaller than the distance between the first lens group G1 and the second lens group G2. That is, the thickness of the first lens group G1 is < D23.

Here, D23 is a distance from the image side of the first lens group G1 to the object side of the second lens group G2. Taking FIG. 1 as an example, D23 may be a distance from the image side S5 of the second lens L2 to the object side S6 of the third lens L3.

In a specific embodiment, along the optical axis, the thickness of the first lens group G1 is smaller than the distance between the first lens group G1 and the second lens group G2.

In other words, taking the first picture as an example, the optical lens OL1 can also satisfy any of the following conditions: (D1+D12+D2)≦D23 and (D1+D12+D2)-D23≦0

Here, D1 is the thickness of the first lens L1, D2 is the thickness of the second lens L2, and D12 is the distance from the image side of the first lens L1 to the object side of the second lens L2.

As shown in FIG. 1, the image side surface of the fourth lens L4 has an inflection point IF, and the shortest distance from the inflection point IF of the fourth lens L4 to the optical axis OA is a first distance h8, and the fourth lens L4 The shortest distance from the outer diameter to the optical axis OA is a second Distance H8.

In an embodiment, the optical lens OL1 can satisfy the condition of |h8/H8 |<0.4.

Specifically, the inflection point IF is located on the image side surface S9 of the fourth lens L4 from the adjacent optical axis OA to the periphery of the lens; the second distance H8 may be the optical effective aperture of the fourth lens L4. The image side surface S9 of the fourth lens L4 may be substantially equivalent to the surface code S9 listed in Tables 1 and 3 below.

On the other hand, taking FIG. 1 as an example, in one embodiment, the fourth lens L4 has a larger effective diameter, and the object side surface S8 of the fourth lens L4 is from the optical axis to the periphery away from the optical axis, The surface curvature exhibits a more dramatic change toward the object side, so that the object side surface S8 is more prominently visible on the macroscopic side and deeper toward the image side to be bowl-shaped. That is, as a whole, the fourth lens L4 appears to be relatively thick in the optical axis direction.

As shown in Fig. 1, the object side surface S8 of the fourth lens L4 has an effective diameter φ7, which is projected to the position of the optical axis OA to the intersection of the object side surface S8 and the optical axis OA by a length δ7; the fourth lens The intersection of the image side surface S9 of the L4 and the optical axis OA to the position where the inflection point IF is projected to the optical axis OA has an extension length δ8; the fourth lens L4 has a thickness D4 along the optical axis OA, wherein the thickness D4 may also be The thickness of the center point of the four lens L4.

In an embodiment, the optical lens OL1 can satisfy | δ7/D4 | ≧ 2, | δ7 / D4 | ≧ 2.5, | δ7 / D4 | ≧ 3, | δ7 / D4 | ≧ 3.5, | δ7 / D4 | ≧ 4, | δ7/D4 |≧4.5 and | δ7/D4 |≧4.8 and other conditions.

In another embodiment, the optical lens OL1 can satisfy the condition of |δ8/D4 |<0.22.

Specifically, in the optical lens OL1 of the embodiment, the fourth lens The image side surface S9 of the L4 is an aspherical surface. For the image side surface S9 of the fourth lens L4, the image side surface S9 of the fourth lens L4 may first face the image of the optical lens OL1 from the outer diameter to the optical axis OA direction. The side extension and the recursion extend toward the object side. Therefore, the inflection point IF of the fourth lens L4 can be said to be substantially the position at which the image side surface S9 of the fourth lens L4 is closest to the image plane I.

In one embodiment, the diopter of the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are interspersed in a positive and negative staggered manner.

For example, the first lens L1 has a positive refracting power, the second lens L2 has a negative refracting power, the third lens L3 has a positive refracting power, and the fourth lens L4 has a negative refracting power.

In one embodiment, at least one of the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 may be an aspheric lens or a free-form lens, wherein the aspheric lens has at least one aspheric surface, free The curved lens has at least one free curved surface.

In another embodiment, the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 may each be an aspherical lens, and each aspherical lens has at least one aspherical surface, and each aspherical surface Can satisfy the following mathematical formulas: Z is the coordinate value in the direction of the optical axis OA, the light transmission direction is the positive direction, A4, A6, A8, A10, A12 and A14 are aspherical coefficients, K is the quadratic constant, C=1/R, R is The radius of curvature, Y is a coordinate value orthogonal to the optical axis OA direction, and the direction away from the optical axis OA is a positive direction. In addition, the values of the parameters or coefficients of the aspherical mathematical formula of each aspherical lens can be individually set to determine the focal length of the position on the surface of each aspherical lens.

In addition, in one embodiment, the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 may each adopt a plastic lens, wherein the material of the plastic lens may include, but is not limited to, polycarbonate ( A polycarbonate, a cyclic olefin copolymer (for example, APEL), a polyester resin (for example, OKP4 or OKP4HT), or the like, or a mixed material including at least one of the foregoing three.

In an embodiment, the object side surface S1 and the image side surface S2 of the first lens L1 may both be aspherical. As shown in Fig. 1, the object side surface S1 of the first lens L1 is a convex surface that is convex toward the object side, the image side surface S2 is a concave surface that is concave toward the object side, and both the object side surface S1 and the image side surface S2 have Positive diopter. Further, the first lens L1 may employ a convex-concave lens.

In the first embodiment, the object side surface S4 of the second lens L2 is substantially concave toward the image side, and the image side surface S5 is substantially concave toward the object side. The side surface S5 is near the optical axis OA, that is, at the center thereof, a convex surface that is convex toward the image side; the object side surface S4 and the image side surface S5 of the second lens L2 have negative refracting power at the optical axis OA. Further, the object side surface S4 of the second lens L2 may be concave toward the image side away from the optical axis OA, but is not limited to the present invention. The object side surface S4 and the image side surface S5 of the second lens L2 may both be aspherical.

In the first embodiment, the object side surface S6 of the third lens L3 is a concave surface that is concave toward the image side, the image side surface S7 is a convex surface that is convex toward the image side, and the object side of the third lens L3. The surface S6 and the image side surface S7 each have a negative refracting power at the optical axis OA. Further, the third lens L3 may employ a meniscus lens. The object side surface S6 and the image side surface S7 of the third lens L3 may both be aspherical.

In the first embodiment, the object side surface S8 of the fourth lens L4 is a concave surface that is concave toward the image side, and the image side surface S9 is convexly convex toward the image side, and is close to the optical axis. The OA is a concave surface that is concave toward the object side; the object side surface S8 of the fourth lens L4 has a negative refracting power at the optical axis OA, and the image side surface S9 has a positive refracting power at the optical axis OA. Further, the fourth lens L4 may adopt a concave lens having a concave surface at both central positions on both sides. The object side surface S8 and the image side surface S9 of the fourth lens L4 may both be aspherical.

Furthermore, in the first drawing, the optical lens OL1 further includes a stop St and a filter F. The aperture St can be disposed between the image side of the first lens L1 and the object side of the second lens L2; the filter F is disposed between the fourth lens L4 and the imaging surface I, wherein the filter F can be an infrared Filter. Further, an image capturing unit having a photoelectric conversion function that senses a light beam that penetrates the optical lens OL1 is disposed on the imaging surface I. In addition, in the embodiment, the filter F can be used as a cover glass of the image capturing unit. On the other hand, the stop St can also be used before the first lens L1, between the lenses, or after the fourth lens L4, and is not limited to the arrangement of the foregoing embodiment.

Table 1 is a first embodiment of the optical lens OL1, which includes the curvature radius, thickness, refractive index, dispersion coefficient, and the like of each lens. The surface code of the lens is sequentially arranged from the object side to the image side. For example, "S1" represents the surface S1 of the first lens L1 toward the object side, and "S2" represents the surface S2 of the first lens L1 toward the image side, "S3" The representative pupil position, "S10" and "S11" represent the surface S10 of the filter F toward the object side, the surface S11 toward the image side, and the like, respectively. In addition, "thickness" represents the distance between the surface and a surface adjacent to the image side, for example, The "thickness" of the surface S1 is the distance between the surface S1 and the surface S2.

All surfaces of the first lens L1 to the fourth lens L4 in the embodiment of the optical lens OL1 exemplified in FIG. 1 are the surface numbers "S1", "S2", "S4", "S5", For the "S6", "S7", "S8" and "S9", if the surface is aspherical, the coefficients in the aspherical mathematical formula are shown in Table 2.

FIG. 2A is a graph showing a field curvature of the optical lens OL1 according to an embodiment of the present invention. The curves T and S respectively show the chromatic aberrations of the optical lens OL1 for the Tangential Rays and the Sagittal Rays. The figure shows that the tangent field curvature and the sagittal field curvature of the beam are both controlled within a good range.

FIG. 2B is a diagram showing a distortion diagram of the optical lens OL1 according to an embodiment of the present invention. The figure shows that the distortion rate of the beam is controlled within the range of (0%, +4%).

FIG. 3 illustrates an optical lens OL2 according to another embodiment of the present invention. The configuration of the optical lens OL2 of the present embodiment is substantially the same as that of the optical lens OL1 of the embodiment shown in Fig. 1, and the main difference lies in the difference in radius of curvature, thickness, refractive index, dispersion coefficient, and the like of each lens. The same description can be used in the same place, and will not be described again.

Table 3 lists details of an embodiment of the optical lens OL2 as shown in Fig. 3, which includes the radius of curvature, thickness, refractive index, dispersion coefficient, and the like of each lens. Each of the code numbers is the same as the foregoing embodiment, and details are not described herein again.

All the surfaces of the first lens L1 to the fourth lens L4 in the embodiment of the optical lens OL2 exemplified in FIG. 3, that is, the surface numbers are "S1", "S2", "S4", "S5", If "S6", "S7", "S8" and "S9" are aspherical surfaces, the coefficients in the aspherical mathematical formula can be as shown in Table 4.

FIG. 4A is a graph showing the curvature of field of the optical lens OL2 according to another embodiment of the present invention. Among them, the curves T and S respectively show the chromatic aberration of the optical lens OL2 with respect to the tangential beam and the sagittal beam. The figure shows that the tangent field curvature and the sagittal field curvature of the beam are both controlled within a good range.

FIG. 4B is a graph showing distortion of the optical lens OL2 according to another embodiment of the present invention. The figure shows that the distortion rate of the beam is controlled within the range of (0%, +3%).

As can be seen from FIGS. 2A to 2B and FIGS. 4A to 4B, the field curvature and distortion of the optical lenses OL1 and OL2 of the present embodiment can be well corrected. Therefore, the root According to the embodiment of the present invention, the optical lenses OL1 and OL2 can produce high-quality images of high resolution and low chromatic aberration under the conditions of cost reduction and miniaturization.

In summary, although the present invention has been disclosed above in the preferred embodiments, it is not intended to limit the present invention. Those skilled in the art can make various changes and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this new type is subject to the definition of the scope of the patent application.

Claims (10)

An optical lens comprising, in order from the object side to the image side, a first lens group having positive refracting power, and a first lens having diopter and a second lens having diopter sequentially from the object side to the image side; a second lens group having a negative refracting power, comprising a third lens having a refracting power and a fourth lens having a refracting power from the object side to the image side, and the optical lens satisfies at least one of the following conditions: the first a thickness of the lens group is smaller than a distance between the first lens group and the second lens group; and an effective diameter of an object side surface of the fourth lens is projected to an optical axis position to the fourth lens The maximum length of the intersection of the object side surface and the optical axis is δ7, the thickness of the fourth lens is D4, and | δ7/D4 | ≧2. An optical lens includes a first lens, a second lens, a third lens and a fourth lens from the object side to the image side, the first lens has a positive power, the second lens, the third lens The lens and the fourth lens have a refracting power, the first lens has a thickness D1, the second lens has a thickness D2, and the distance from the image side of the first lens to the object side of the second lens is D12. The distance from the image side of one of the second lenses to the object side of the third lens is D23, and the optical lens satisfies at least one of the following conditions: (D1+D12+D2)≦D23; and one of the fourth lenses The maximum length of an effective diameter of the side surface projected to an optical axis to the intersection of the object side surface of the fourth lens and the optical axis is Δ7, the thickness of the fourth lens is D4, and | δ7/D4 | ≧2. The optical lens of claim 1 or 2, wherein the optical lens satisfies at least one of the following conditions: the third lens is a meniscus lens, the fourth lens has a negative refracting power and the fourth lens is a concave lens. The optical lens of claim 1 or 2, wherein the first lens has a focal length F1, the second lens has a focal length F2, and 0.1 <| F1/F2 | < 0.5. The optical lens of claim 1 or 2, wherein F12 is an integrated focal length of the first lens and the second lens, and F34 is an integrated focal length of the third lens and the fourth lens, and D23 is from the The distance from the image side of the first lens to the object side of the fourth lens, and -0.12 < 1/(F12 + F34 - D23) < 0. The optical lens of claim 1 or 2, wherein the image side surface of the fourth lens has an inflection point, and the shortest distance from the inflection point of the fourth lens to an optical axis is a A distance h8, the shortest distance from one of the outer diameters of the fourth lens to the optical axis is a second distance H8, and |h8/H8|<0.4. The optical lens of claim 1 or 2, wherein the image side surface of the fourth lens has an inflection point, and the intersection of the image side surface of the fourth lens and an optical axis to the inflection point projection The position to the optical axis has an extension length δ8, and the fourth lens has a thickness D4 along the optical axis, and | δ8/D4 | < 0.22. The optical lens of claim 1 or 2, wherein the optical lens satisfies at least one of: the second lens has a negative refracting power, the third lens has a positive refracting power, and the fourth lens has a negative Diopters. The optical lens of claim 1 or 2, wherein the optical lens satisfies at least one of the following conditions: at least one of the first lens, the second lens, the third lens, and the fourth lens An aspherical lens or a free-form lens, and/or at least one of the first lens, the second lens, the third lens, and the fourth lens are plastic lenses. The optical lens according to claim 1 or 2, wherein the optical lens satisfies at least one of the following conditions: an object side surface of the first lens is a convex surface facing the object side, and an object side surface of the second lens The concave surface facing the image side, and the object side surface of the third lens are concave surfaces facing the image side.