CN105739068A - Wide-angle lens - Google Patents

Abstract

The invention provides a wide-angle lens, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged from an object side to an image side along an optical axis; the first lens is a meniscus lens with negative focal power, and the concave surface of the first lens faces the image side; the second lens is a biconvex thin lens with positive focal power; the third lens is a meniscus lens with negative focal power, and the concave surface of the third lens faces the image side; the fourth lens is a biconvex thick lens with positive focal power; the fifth lens is a double concave thin lens with negative focal power; the sixth lens is a meniscus thin lens having positive refractive power, and a concave surface thereof faces the image side. The optical lens is applied to the mobile phone, the view field angle reaches the wide-angle requirement, and the image quality from the center to the edge is greatly kept. When the wide-angle lens is applied to a mobile phone for taking a picture, the imaging angle is 96 degrees, and the imaging angle of the mobile phone is only about 70 degrees.

Description

Wide-angle lens

technical field

The invention relates to the technical field of lenses, in particular to a wide-angle lens.

Background technique

Wide-angle lenses have the characteristics of short focal length, wide viewing angle and deep depth of field. They are more suitable for taking photos of larger scenes, such as buildings and landscapes. With the continuous development of technology, electronic products (such as mobile phones, tablet computers, etc.) already have imaging devices, but their focal lengths are fixed, so they cannot meet the needs of shooting different scenes. For this reason, it is usually necessary to attach a wide-angle lens to an electronic product to reduce the focal length of the mobile phone camera lens itself. At this time, the mobile phone and the additional lens are equivalent to a micro-single wide-angle lens, which can take suitable pictures in scenes such as landscapes. photo.

However, the existing wide-angle lenses usually have the defects that the angle of view does not meet the wide-angle requirements, and the image quality at the edge of the camera is too poor. For this reason, in the prior art, the resolution of the wide-angle lens is generally improved by increasing the number of lenses. For example, Chinese patent CN105158878A discloses an eight-lens ultra-wide-angle lens, which includes a lens barrel and a first lens, a second lens, a third lens, a fourth lens, The fifth lens, the sixth lens, the seventh lens and the eighth lens, and the first lens, the second lens, the third lens and the fifth lens are spherical lenses with negative refractive power; the fourth lens, the sixth lens The lens, the seventh lens and the eighth lens are spherical lenses with positive refractive power.

However, the above-mentioned design method of increasing the number of lenses makes the volume of the lens larger and cannot achieve miniaturization of the lens. Therefore, how to provide a small wide-angle lens with a field of view that meets the wide-angle requirement and has good imaging quality at the edge of the camera has become a technical problem that needs to be solved urgently.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing wide-angle lens that the angle of view cannot meet the wide-angle requirement and the image quality at the edge of the camera is too poor.

For this reason, the present invention provides a kind of wide-angle lens, comprises first lens, second lens, third lens, fourth lens, fifth lens and the sixth lens that arrange in order from object side to image side along optical axis; One lens is a meniscus lens with negative power, and its concave surface is towards the image side; the second lens is a biconvex thin lens with positive power; the third lens has a curved lens with negative power. Moon-shaped lens, and its concave surface is towards the image side; the fourth lens is a biconvex thick lens with positive power; the fifth lens is a biconcave thin lens with negative power; the sixth The lens is a thin meniscus lens with positive power, and its concave surface faces the image side.

Preferably, the wide-angle lens satisfies the following conditional formula:

-0.95<f _1-2 /f<-0.7;

0.48<f _3-6 /f<0.73;

-1.60< _f1-2 / _f3-6 <-1.0;

-0.8< _f1-3 / _f4-6 <-0.55;

-0.9< _f3-4 / _f5-6 <-0.65;

Wherein, f is the effective focal length of the wide-angle lens, f _1-2 is the combined focal length of the first lens and the second lens, f _3-6 is the third lens, the fourth lens, the The combined focal length of the fifth lens and the sixth lens, f _1-3 is the combined focal length of the first lens, the second lens and the third lens, and f _3-4 is the combined focal length of the third lens and the third lens The combined focal length of the fourth lens, f _5-6 is the combined focal length of the fifth lens and the sixth lens, f _4-6 is the combined focal length of the fourth lens, the fifth lens and the sixth lens The combined focal length between lenses.

Preferably, the wide-angle lens satisfies the following conditional formula:

-0.85<f _1-2 /f<-0.80;

0.58<f _3-6 /f<0.63;

-1.50< _f1-2 / _f3-6 <-1.10;

-0.70< _f1-3 / _f4-6 <-0.65;

-0.80<f _3-4 /f _5-6 <-0.75.

Preferably, the wide-angle lens also satisfies: TTL<24.0mm, wherein TTL is the distance from the object side to the imaging surface of the first lens along the optical axis direction.

Preferably, the outer diameters of the first lens to the sixth lens decrease successively.

Preferably, the outer diameter of the first lens is less than 25mm, and the total length of the wide-angle lens is less than 24mm.

Preferably, 1.68<Nd<1.86, 40<Vd<63, Nd is the d-light refractive index of the first lens, and Vd is the Abbe number of the first lens.

Preferably, the first lens, the second lens, the third lens, the fifth lens and the sixth lens are thin lenses, and the fourth lens is a thick lens.

Preferably, the materials of the first lens to the sixth lens are all optical glass, and the first lens to the sixth lens are all spherical lenses.

Preferably, the wide-angle lens is an additional lens of the mobile phone, and the wide-angle lens is installed above the camera of the mobile phone.

The technical solution of the present invention has the following advantages:

The wide-angle lens provided by the present invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the optical axis from the object side to the image side, and adopts negative, positive, Negative, positive, negative, positive optical system structure, and through multiple structures to control the imaging effect under different object distances to achieve the best results at the same time, so that the optical lens can be applied to mobile phones to meet the wide-angle requirements, but the maximum distortion is 2% Within, and the picture quality from the center to the edge maintains a very large advantage. The first lens, the third lens, and the fifth lens have negative refractive power, which provides a structural basis for the realization of a super large field of view. The second lens, the fourth lens, and the sixth lens have positive refractive power, making the image of the optical system The main square moves forward, so that the length of the system is shortened. The optical lens can be used on Iphone6, Iphone6Plus, Iphone6s, Iphone6sPlus, Xiaomi Note, Huawei and other mobile phones. Moreover, when the wide-angle lens is used to take pictures on a mobile phone, the imaging angle is 96 degrees, while the imaging angle of the mobile phone itself is only about 70 degrees. At the same distance, it can shoot a larger range and the maximum distortion is within 2%.

The wide-angle lens provided by the present invention limits the focal power distribution of the wide-angle lens, so that it not only has high imaging quality at a long distance but also keeps image quality at a short distance such as 0.25m compared to other products on the market.

In the wide-angle lens provided by the present invention, the outer diameter of the first lens is less than 25mm, and the total length of the wide-angle lens is less than 24mm, so that the volume is really small.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

FIG. 1 is a schematic structural view of a wide-angle lens provided in an embodiment of the present invention;

FIG. 2 is a field curvature diagram of a wide-angle lens provided in an embodiment of the present invention;

FIG. 3 is a distortion diagram of a wide-angle lens provided in an embodiment of the present invention;

FIG. 4 is a lateral chromatic aberration diagram of the wide-angle lens provided in the embodiment of the present invention.

detailed description

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, or in a specific orientation. construction and operation, therefore, should not be construed as limiting the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance. In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

This embodiment provides a wide-angle lens, as shown in Figure 1, comprising a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, and a first lens arranged in sequence along the optical axis from the object side to the image side. Five lenses 5 and the sixth lens 6; the first lens 1 is a meniscus lens with negative refractive power, and its concave surface faces the image side; the second lens 2 is a biconvex thin lens with positive refractive power; The third lens 3 has a meniscus lens with negative refractive power, and its concave surface is towards the image side; the fourth lens 4 is a biconvex thick lens with positive refractive power; the fifth lens 5 has A biconcave thin lens with negative refractive power; the sixth lens 6 is a meniscus thin lens with positive refractive power, and its concave surface faces the image side.

The wide-angle lens provided by this embodiment includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the optical axis from the object side to the image side, and adopts negative and positive lenses. , negative, positive, negative, positive optical system structure, and through multiple structures to control the imaging effect at different object distances to achieve the best results at the same time, so that the optical lens can be applied to mobile phones to meet the wide-angle requirements, but the maximum distortion is 2 %, and the picture quality from the center to the edge maintains a very large advantage. The optical lens can be used on Iphone6, Iphone6Plus, Iphone6s, Iphone6sPlus, Xiaomi Note, Huawei and other mobile phones. Moreover, when the wide-angle lens is used to take pictures on a mobile phone, the imaging angle is 96 degrees, while the imaging angle of the mobile phone itself is only about 70 degrees. At the same distance, it can shoot a larger range and the maximum distortion is within 2%.

The first lens 1 is a meniscus lens with negative refractive power, which has the functions of reducing distortion and adjusting light rays in a large field of view. The first lens 1, the third lens 3, and the fifth lens 5 have negative refractive power, thereby providing a structural basis for the realization of a super large field of view, and the second lens 2, fourth lens 4, and sixth lens 6 have positive refractive power. , so that the image plane of the optical system is mainly moved forward, so that the length of the system is shortened.

As a preferred embodiment, the wide-angle lens satisfies the following conditional formula:

-0.95<f _1-2 /f<-0.7;

0.48<f _3-6 /f<0.73;

-1.60< _f1-2 / _f3-6 <-1.0;

-0.8< _f1-3 / _f4-6 <-0.55;

-0.9< _f3-4 / _f5-6 <-0.65;

Wherein, f is the effective focal length of the wide-angle lens, f _1-2 is the combined focal length of the first lens 1 and the second lens 2, f _3-6 is the third lens 3, the fourth lens 4. The combined focal length of the fifth lens 5 and the sixth lens 6, f _1-3 is the combined focal length of the first lens 1, the second lens 2 and the third lens 3, f _{3 -4} is the combined focal length of the third lens 3 and the fourth lens 4, f _5-6 is the combined focal length of the fifth lens 5 and the sixth lens 6, and f _4-6 is the combined focal length of the first lens 5 and the sixth lens 6. The combined focal length between the four lenses 4 , the fifth lens 5 and the sixth lens 6 .

By limiting the focal power distribution of the wide-angle lens, compared with other products on the market, not only the long-distance imaging quality is high, but also the image quality is not degraded at a short distance such as 0.25m. Moreover, since the first lens to the third lens have negative refractive power as a whole, the fourth lens to the sixth lens have positive refractive power as a whole, and the ratio meets the requirements: -0.8<f _1-3 /f _4-6 <- 0.55, thereby increasing the field of view angle of the wide-angle lens.

As a further preferred embodiment, the wide-angle lens satisfies the following conditional formula:

-0.85<f _1-2 /f<-0.80;

0.58<f _3-6 /f<0.63;

-1.50< _f1-2 / _f3-6 <-1.10;

-0.70< _f1-3 / _f4-6 <-0.65;

-0.80<f _3-4 /f _5-6 <-0.75.

It should be noted that the focal power distribution of the wide-angle lens provided by the present invention is not limited to the above-mentioned preferred example, it can adopt any common setting parameters in the prior art, and those skilled in the art can set it according to the performance needs of the wide-angle lens Certainly.

As a preferred embodiment, the wide-angle lens also satisfies: TTL<24.0mm, wherein TTL is the distance from the object side of the first lens 1 to the imaging plane along the optical axis.

As a preferred implementation manner, the outer diameters of the first lens 1 to the sixth lens 6 decrease successively. More preferably, the outer diameter of the first lens 1 is less than 25mm, and the total length of the wide-angle lens is less than 24mm.

The above-mentioned wide-angle lens has the characteristics of small size by limiting the size of each lens.

As a further preferred embodiment, 1.68<Nd<1.86, 40<Vd<63, Nd is the d-light refractive index of the first lens 1 , and Vd is the Abbe number of the first lens 1 .

As a preferred embodiment, the first lens 1, the second lens 2, the third lens 3, the fifth lens 5 and the sixth lens 6 are thin lenses, and the fourth lens 4 For thick lenses.

The above arrangement can reduce the angle of refraction variation of light rays between the lenses, and control imaging distortion.

As a preferred embodiment, the materials of the first lens 1 to the sixth lens 6 are all optical glass, and the first lens 1 to the sixth lens 6 are all spherical lenses.

It should be noted that the material of each lens is not limited to the above preferred examples.

As a preferred embodiment, the wide-angle lens is an additional lens of the mobile phone, and the wide-angle lens is installed above the camera of the mobile phone.

The present invention also tests the performance parameters of the wide-angle lens provided by an embodiment, wherein f _1-2 =-708.6mm, f _3-6 =530.8mm, f _1-3 =-14.3mm, f _3-4 = 33.2 mm, f _4-6 = 21 mm, f _5-6 = -42.4 mm, f = 864 mm. The test results are shown in Figure 2, Figure 3 and Figure 4.

It can be seen from Figure 2 that the field curvature in the meridian (corresponding to T in Figure 2) direction and sagittal (corresponding to S in Figure 2) direction produced by the wide-angle lens to the light is between -0.035㎜ and 0.035㎜. It can be seen from Figure 3 that the maximum distortion of the wide-angle lens is within 2%. It can be seen from Figure 4 that the lateral aberration value produced by the wide-angle lens for light with different wavelengths is between several microns.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in different forms can also be made. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. a kind of wide-angle lens is characterized in that, comprises the first lens (1), the second lens (2), the 3rd lens (3), the 4th lens (4) that are configured sequentially along the optical axis from the object side to the image side ), the fifth lens (5) and the sixth lens (6); the first lens (1) is a meniscus lens with negative power, and its concave surface faces the image side; the second lens (2) is A biconvex thin lens with positive refractive power; the third lens (3) has a meniscus lens with negative refractive power, and its concave surface is facing the image side; the fourth lens (4) is a lens with positive refractive power biconvex thick lens; the fifth lens (5) is a biconcave thin lens with negative power; the sixth lens (6) is a meniscus thin lens with positive power, and The concave surface faces the image side. 2. wide-angle lens according to claim 1, is characterized in that, described wide-angle lens satisfies the following conditional formula: -0.95<f _1-2 /f<-0.7; 0.48<f _3-6 /f<0.73; -1.60< _f1-2 / _f3-6 <-1.0; -0.8< _f1-3 / _f4-6 <-0.55; -0.9< _f3-4 / _f5-6 <-0.65; Wherein, f is the effective focal length of the wide-angle lens, f _1-2 is the combined focal length of the first lens (1) and the second lens (2), and f _3-6 is the third lens (3) , the combined focal length of the fourth lens (4), the fifth lens (5) and the sixth lens (6), f _1-3 is the first lens (1), the second lens (2) and the combined focal length of the third lens (3), f _3-4 is the combined focal length of the third lens (3) and the fourth lens (4), and f _5-6 is the combined focal length of the first lens (3) The combined focal length of the fifth lens (5) and the sixth lens (6), where f _4-6 is one of the fourth lens (4), the fifth lens (5) and the sixth lens (6) combined focal length. 3. wide-angle lens according to claim 2, is characterized in that, described wide-angle lens satisfies the following conditional formula: -0.85<f _1-2 /f<-0.80; 0.58<f _3-6 /f<0.63; -1.50< _f1-2 / _f3-6 <-1.10; -0.70< _f1-3 / _f4-6 <-0.65; -0.80<f _3-4 /f _5-6 <-0.75. 4. The wide-angle lens according to any one of claims 1 to 3, characterized in that, the wide-angle lens also satisfies: TTL<24.0mm, wherein TTL is from the object side surface of the first lens (1) along the optical axis direction to The distance between the imaging planes. 5. The wide-angle lens according to any one of claims 1 to 3, characterized in that, the outer diameters of the first lens (1) to the sixth lens (6) decrease successively. 6. The wide-angle lens according to claim 5, characterized in that, the outer diameter of the first lens (1) is less than 25mm, and the total length of the wide-angle lens is less than 24mm. 7. The wide-angle lens according to claim 5, characterized in that, 1.68<Nd<1.86, 40<Vd<63, Nd is the d light refractive index of the first lens (1), Vd is the first lens The Abbe number of (1). 8. The wide-angle lens according to any one of claims 1 to 3, characterized in that, the first lens (1), the second lens (2), the third lens (3), the The fifth lens (5) and the sixth lens (6) are thin lenses, and the fourth lens (4) is a thick lens. 9. The wide-angle lens according to any one of claims 1 to 3, wherein the materials of the first lens (1) to the sixth lens (6) are optical glass, and the first lens (1) to the sixth lens (6) are all spherical lenses. 10. The wide-angle lens according to any one of claims 1 to 3, wherein the wide-angle lens is an additional lens of a mobile phone, and the wide-angle lens is installed above the camera of the mobile phone.