CN114355582B - Wide-angle lens - Google Patents

Abstract

The invention discloses a wide-angle lens, which comprises the following components in sequence from an object side to an imaging surface along an optical axis: a first lens having a negative optical power, an object side surface of the first lens being concave at a paraxial region; a second lens having an optical power; a diaphragm; a third lens having optical power; the fourth lens is provided with positive focal power, and the object side surface and the image side surface of the fourth lens are convex surfaces; a fifth lens having a negative optical power, an image-side surface of the fifth lens being concave at a paraxial region and having at least one inflection point. The wide-angle lens has the advantages of large visual angle, small f-theta distortion and light weight, and can meet the use requirements of miniaturized electronic equipment.

Description

Wide-angle lens

technical field

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

Background technique

In recent years, with the rise of the VR industry, major brands have gradually upgraded and improved the VR helmet equipment. The equipment is combined with user experience and is guided by comfort and convenience. Some high-end VR products have a see-through function, which allows users to experience VR. At the same time, you can directly see the external scene without taking off the helmet. The perspective function needs to simulate the observation range of the human eye through the lens, and transmit the external scene to the human eye through the photosensitive element. The lens needs to have a large field of view, Features such as small distortion and miniaturization can meet the requirements of accurately restoring external scenes and reducing the weight of VR helmets.

Traditional ultra-wide-angle lenses for non-mobile phones mostly use seven-piece and eight-piece glass spherical lens structures. This kind of lens has high cost, large volume, increased weight, and aberrations such as distortion and spherical aberration cannot be well corrected. Applied to VR devices.

SUMMARY OF THE INVENTION

Therefore, the purpose of the present invention is to provide a wide-angle lens, which has the advantages of large viewing angle, small f-θ distortion, and lightness and thinness, and can meet the use requirements of miniaturized electronic devices.

The embodiments of the present invention implement the above-mentioned objects through the following technical solutions.

The invention provides a wide-angle lens, which sequentially includes from the object side to the imaging plane along the optical axis: a first lens with negative refractive power, the object side of the first lens is concave at the near optical axis; The second lens; diaphragm; the third lens with refractive power; the fourth lens with positive refractive power, the object side and the image side of the fourth lens are convex; the fifth lens with negative refractive power , the image side of the fifth lens is concave at the near optical axis and has at least one inflection point; wherein, the wide-angle lens includes at least one aspherical lens; the wide-angle lens satisfies the following conditional formula: -6<f12/f <-0.5; wherein, f12 represents the combined focal length of the first lens and the second lens, and f represents the effective focal length of the wide-angle lens.

Compared with the prior art, the wide-angle lens provided by the present invention adopts five aspherical lenses with specific focal powers, through the matching of specific surface shapes and reasonable power distribution, and at the same time by reasonably distributing the first lens and the second lens. The combined optical power of the lens, coupled with the use of aspherical lenses to properly correct off-axis aberrations, enables the lens to have a large viewing angle while reducing f-θ distortion aberrations. At the same time, the use of plastic materials effectively reduces the weight of the system. It better satisfies the demand for light, thin and low-cost use of portable electronic devices.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

1 is a schematic structural diagram of a wide-angle lens according to a first embodiment of the present invention;

Fig. 2 is the f-θ distortion curve diagram of the wide-angle lens of the first embodiment of the present invention;

3 is a field curvature diagram of the wide-angle lens according to the first embodiment of the present invention;

4 is a vertical-axis chromatic aberration curve diagram of the wide-angle lens according to the first embodiment of the present invention;

5 is a schematic structural diagram of a wide-angle lens according to a second embodiment of the present invention;

Fig. 6 is the f-θ distortion curve diagram of the wide-angle lens of the second embodiment of the present invention;

7 is a field curvature diagram of a wide-angle lens according to a second embodiment of the present invention;

8 is a vertical-axis chromatic aberration curve diagram of a wide-angle lens according to a second embodiment of the present invention;

9 is a schematic structural diagram of a wide-angle lens according to a third embodiment of the present invention;

10 is an f-θ distortion curve diagram of the wide-angle lens according to the third embodiment of the present invention;

11 is a field curvature diagram of a wide-angle lens according to a third embodiment of the present invention;

12 is a vertical-axis chromatic aberration curve diagram of a wide-angle lens according to a third embodiment of the present invention;

13 is a schematic structural diagram of a wide-angle lens according to a fourth embodiment of the present invention;

14 is an f-θ distortion curve diagram of the wide-angle lens according to the fourth embodiment of the present invention;

15 is a field curvature diagram of a wide-angle lens according to a fourth embodiment of the present invention;

FIG. 16 is a vertical-axis chromatic aberration curve diagram of the wide-angle lens according to the fourth embodiment of the present invention.

Detailed ways

In order to make the objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the invention are presented in the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. Throughout the specification, the same reference numerals refer to the same elements.

The present invention provides a wide-angle lens, which includes a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens and a filter in sequence from the object side to the imaging plane along the optical axis.

Wherein, the first lens has negative refractive power, and the object side surface of the first lens is concave at the near optical axis;

the second lens has optical power;

The third lens has optical power;

The fourth lens has positive refractive power, and both the object side and the image side of the fourth lens are convex;

The fifth lens has negative refractive power, and the image side surface of the fifth lens is concave at the near optical axis and has at least one inflection point;

Wherein, the wide-angle lens includes at least one aspherical lens.

The wide-angle lens of the invention adopts a combination of five-piece aspherical lenses, and through the matching of specific surface shapes and reasonable power distribution, the wide-angle lens has the advantages of large viewing angle, small f-θ distortion, and lightness and thinness.

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

-6<f12/f<-0.5; (1)

Wherein, f12 represents the combined focal length of the first lens and the second lens, and f represents the effective focal length of the wide-angle lens. Satisfying the above conditional formula (1), reasonably control the combined lens of the first lens and the second lens to be a negative lens, which helps to obtain a longer system back focal length in the case of a large wide angle and a short focal length, and avoids insufficient back focus. The camera cannot be designed or the lens interferes with the chip components, resulting in the inability to image.

In some embodiments, the second lens has negative refractive power, the image side of the second lens is concave; the third lens has positive refractive power, the object side and the image side of the third lens are convex; the image side of the first lens is convex; The side surface is concave, and the object side surface of the fifth lens is convex at the near optical axis.

In some embodiments, the second lens has positive refractive power, the object side of the second lens is concave, and the image side of the second lens is convex; the third lens has negative refractive power, and the image side of the third lens is at low beam The axis is concave; the image side of the first lens is convex at the near optical axis, and the object side of the fifth lens is concave.

Each lens in the wide-angle lens is matched with different surface shapes, all of which can make it have good imaging quality.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

-10<f12/f34<-1; (2)

Wherein, f12 represents the combined focal length of the first lens and the second lens, and f34 represents the combined focal length of the third lens and the fourth lens. Satisfying the above conditional formula (2), the positive spherical aberration generated by the negative lens group combined with the first and second lenses can be offset by the negative spherical aberration generated by the positive lens group combined with the third and fourth lenses, while correcting the off-axis distortion image of the system Poor, and finally achieve a better balance effect, effectively improve the image quality.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

2.5<TTL/f<3.5; (3)

2<TTL/IH<3; (4)

Wherein, TTL represents the total optical length of the wide-angle lens, IH represents the image height corresponding to the half-angle of view of the wide-angle lens, and f represents the effective focal length of the wide-angle lens. Satisfying the above conditional expressions (3) and (4) can better achieve the balance between the miniaturization of the wide-angle lens and the high pixel count.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

-2%<(IH-f×θ)/(f×θ)<1%; (5)

Wherein, θ represents the half-angle of view of the wide-angle lens, IH represents the image height corresponding to the half-angle of view of the wide-angle lens, and f represents the effective focal length of the wide-angle lens. Satisfying the above conditional formula (5), the f-θ distortion of the system can be controlled within ±2%, so that the field angle of the system and the image height tend to have a linear relationship, which is beneficial to the image algorithm to correct the distortion in the later application of the whole machine, so that the The image size after distortion correction is more original and natural.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

0.16<BEL/TTL<0.3; (6)

Wherein, BEL represents the distance between the image side surface of the fifth lens and the imaging surface on the optical axis, and TTL represents the total optical length of the wide-angle lens. Satisfying the above conditional formula (6) can make the lens have a longer system back focal length, so as to avoid the lack of back focus resulting in the failure of the opto-mechanical design or the interference between the lens and the chip components, resulting in inability to image.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

0.5<SD32/SD11<0.7; (7)

Among them, SD11 represents the effective aperture of the object side of the first lens, and SD32 represents the effective aperture of the image side of the third lens. Satisfying the above conditional formula (7) can make the effective aperture of the third lens smaller than the effective aperture of the first lens, maintain the miniaturization of the system, and help to correct the coma and field curvature of the off-axis field of view, and improve the imaging quality.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

0.5<f4/f<1; (8)

-2<R41/R42<-0.3; (9)

Wherein, f4 represents the focal length of the fourth lens, f represents the effective focal length of the wide-angle lens, R41 represents the radius of curvature of the object side of the fourth lens, and R42 represents the radius of curvature of the image side of the fourth lens. Satisfying the above conditional expressions (8) and (9), the focal length and surface shape of the fourth lens can be reasonably controlled, so that the surface shape is a more uniform biconvex shape, which is conducive to correcting aberrations and improving the resolution quality of the wide-angle lens. .

In some embodiments, the wide-angle lens satisfies the following conditional formula:

-6<f1/f<-1; (10)

-2<f5/f<-0.3;(11)

Wherein, f1 represents the focal length of the first lens, f5 represents the focal length of the fifth lens, and f represents the effective focal length of the wide-angle lens. Satisfying the above conditional formulas (10) and (11), by reasonably setting the focal length ratio of the first lens and the fifth lens, so that they assume the main negative refractive power in the system, the aberration can be better corrected, and the overall imaging can be improved. quality.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

0.9<(CT2+CT3)/(ET2+ET3)<1.5; (12)

Wherein, CT2 represents the thickness of the second lens on the optical axis, CT3 represents the thickness of the third lens on the optical axis, ET2 represents the edge thickness of the second lens, and ET3 represents the edge thickness of the third lens. Satisfying the above conditional formula (12) can ensure that the thickness ratio of the second lens and the third lens is uniform, which is conducive to the production and molding of the lens; at the same time, it can prevent the edge of the lens from being too curved, and reduce the difference in the incidence angle of light in different areas of the pupil, Reduce system sensitivity.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

0.7<SD21/SD12<1; (13)

Among them, SD12 represents the effective aperture of the image side of the first lens, and SD21 represents the effective aperture of the object side of the second lens. Satisfying the above conditional formula (13) can make the light deflection tend to be slow, and at the same time reduce the size of the head, which can achieve the effect of maintaining the miniaturization of the head of the system and reducing the sensitivity of the system.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

3<CT4/AC45<11; (14)

Wherein, CT4 represents the thickness of the fourth lens on the optical axis, and AC45 represents the air gap between the fourth lens and the fifth lens on the optical axis. Satisfying the above conditional formula (14), by controlling the ratio of the center thickness of the fourth lens to the air space between the fourth lens and the fifth lens on the optical axis, it is beneficial to reduce the space ratio of the fourth lens and ensure that the production process is The assembly stability of the lens and the miniaturization of the wide-angle lens make it easier to meet the size requirements of the terminal.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

0.3<CT1/CT2<1.4; (15)

Wherein, CT1 represents the thickness of the first lens on the optical axis, and CT2 represents the thickness of the second lens on the optical axis. Satisfying the above conditional formula (15), by limiting the ratio of the center thickness of the first and second lenses, the aberration of the wide-angle lens can be effectively corrected while ensuring the processing feasibility of the wide-angle lens.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

-10<SAG21/SAG31<-1; (16)

Among them, SAG21 represents the edge sag of the object side of the second lens, and SAG31 represents the edge sag of the object side of the third lens. Satisfying the above conditional formula (16), by reasonably matching the object side profile of the second lens and the third lens, it is beneficial to correct the aberration of the off-axis field of view and the central field of view, and improve the imaging quality of the wide-angle lens.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

-3<(R11+R12)/(R11-R12)<0.6; (17)

Wherein, R11 represents the curvature radius of the object side surface of the first lens, and R12 represents the curvature radius of the image side surface of the first lens. Satisfying the above conditional formula (17), by reasonably setting the surface shape of the first lens, it is beneficial to reduce the f-θ distortion of the system, and at the same time, the sensitivity of the field curvature of the first lens can be reduced, so that the first lens can be manufactured during production. The field curvature distribution is more concentrated.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

-0.5<(R21-R22)/(R21+R22)<2; (18)

Among them, R21 represents the curvature radius of the object side surface of the second lens, and R22 represents the curvature radius of the image side surface of the second lens. Satisfying the above conditional expression (18), by adjusting the surface shape of the second lens at the near optical axis, the shape change of the second lens can be slowed down, the sensitivity of the system can be reduced, the formability of the lens can be improved, and the manufacturing yield can be improved.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

0.5<(SAG11+SAG12)/CT1<2.5; (19)

Wherein, SAG11 represents the edge sag of the object side of the first lens, SAG12 represents the edge sag of the image side of the first lens, and CT1 represents the thickness of the first lens on the optical axis. Satisfying the above conditional formula (19), by reasonably limiting the surface shape of the first lens, the processing difficulty of the lens is reduced on the premise of ensuring the bending force of the lens to light; if the lower limit is exceeded, the bending ability of the first lens to light is insufficient , the total length of the lens will be longer; if it exceeds the upper limit, the edge sag of the first lens will be too large, which will make the lens processing difficult.

In some embodiments, the wide-angle lens satisfies the following conditional formula:

0.05<ET3/TTL<0.2; (20)

Among them, ET3 represents the edge thickness of the third lens, and TTL represents the optical total length of the wide-angle lens. Satisfying the above conditional expression (20) ensures that the third lens has sufficient edge thickness, which can avoid the problem of lens edge cracking caused by the thin edge thickness of the lens during the molding process and the equipment manipulator clamping the lens during the assembly process.

As an embodiment, an all-plastic lens can be used, or a glass-plastic mixed and matched lens can be used, both of which can achieve good imaging effects; in this application, in order to better reduce the size, weight and cost of the lens, five lenses are used. The combination of plastic lenses, through the combination of specific surface shapes and reasonable power distribution, enables the wide-angle lens to have a large viewing angle while reducing f-θ distortion aberration, effectively reducing the weight of the system and providing more cost-effective optical performance products , and better meet the needs of portable electronic devices for thinning and wide-angle use.

The present invention will be further described below with a plurality of embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the wide-angle lens are different. For details, please refer to the parameter table of each embodiment. The following examples are only preferred embodiments of the present invention, but the embodiments of the present invention are not only limited by the following examples, and any other changes, substitutions, combinations or simplifications that do not deviate from the innovations of the present invention, All should be regarded as equivalent replacement modes, and all are included in the protection scope of the present invention.

In each embodiment of the present invention, when the lens adopts an aspheric lens, the surface shape of the aspheric lens satisfies the following equation:

Among them, z is the distance vector height of the aspheric surface from the vertex of the aspheric surface when the height is h along the optical axis, c is the paraxial curvature of the surface, k is the quadratic surface coefficient, and A _2i is the aspheric surface of order 2i face coefficient.

first embodiment

Please refer to FIG. 1 , which is a schematic structural diagram of the wide-angle lens 100 provided in the first embodiment of the present invention. The wide-angle lens 100 includes in sequence from the object side to the imaging surface S13 along the optical axis: a first lens L1, a second lens L2, a light Stop ST, third lens L3, fourth lens L4, fifth lens L5 and filter G1.

Wherein, the first lens L1 has negative refractive power, the object side S1 of the first lens is concave at the near optical axis, and the image side S2 of the first lens is concave;

The second lens L2 has negative refractive power, the object side S3 of the second lens is convex at the near optical axis, and the image side S4 of the second lens is concave;

The third lens L3 has positive refractive power, the object side S5 of the third lens is convex, and the image side S6 of the third lens is convex;

The fourth lens L4 has positive refractive power, and both the object side S7 and the image side S8 of the fourth lens are convex;

The fifth lens L5 has negative refractive power, the object side S9 of the fifth lens is convex at the near optical axis, and the image side S10 of the fifth lens is concave at the near optical axis;

The object side of the filter G1 is S11, and the image side is S12.

The first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 and the fifth lens L5 are all plastic aspherical lenses.

Specifically, the design parameters of each lens of the wide-angle lens 100 provided in this embodiment are shown in Table 1.

Table 1

Table 2 shows the surface shape coefficients of each aspherical surface of the wide-angle lens 100 in this embodiment.

Table 2

Please refer to FIG. 2 , FIG. 3 and FIG. 4 , which are respectively the f-θ distortion graph, the field curvature graph, and the vertical-axis chromatic aberration graph of the wide-angle lens 100 . It can be seen from Fig. 2 that the optical distortion is controlled within ±1%, indicating that the distortion of the wide-angle lens 100 is well corrected; it can be seen from Fig. 3 that the field curvature is controlled within ±0.07mm, indicating that the wide-angle lens 100 has a good correction of the field curvature. ; It can be seen from Fig. 4 that the vertical chromatic aberration at different wavelengths is controlled within ±2 microns, indicating that the vertical chromatic aberration of the wide-angle lens 100 is well corrected; from Fig. 2, Fig. 3, Fig. 4 can be seen that the image of the wide-angle lens 100 The difference is well balanced and has good optical imaging quality.

Second Embodiment

As shown in FIG. 5 , which is a schematic structural diagram of the wide-angle lens 200 provided in this embodiment, the wide-angle lens 200 of this embodiment is substantially the same as the above-mentioned first embodiment, and the main differences are: the object side S3 of the second lens is concave, and The curvature radius, aspheric coefficient, thickness, and material of each lens surface are different.

Specifically, the design parameters of the wide-angle lens 200 provided in this embodiment are shown in Table 3.

table 3

Table 4 shows the surface shape coefficients of each aspherical surface of the wide-angle lens 200 in this embodiment.

Table 4

Please refer to FIG. 6 , FIG. 7 and FIG. 8 , which show the f-θ distortion curve, the field curvature curve, and the vertical-axis chromatic aberration curve of the wide-angle lens 200 respectively. It can be seen from FIG. 6 that the optical distortion is controlled at ±1.5%. It can be seen that the distortion of the wide-angle lens 200 is well corrected; it can be seen from FIG. 7 that the paraxial field curvature is controlled within ±0.07mm, which shows that the field curvature of the wide-angle lens 200 is well corrected; it can be seen from FIG. 8 that at different wavelengths The vertical chromatic aberration of the wide-angle lens 200 is controlled within ±2 microns, which means that the vertical chromatic aberration of the wide-angle lens 200 is well corrected; it can be seen from Figure 6, Figure 7 and Figure 8 that the wide-angle lens 200 has a well-balanced aberration and good optical imaging. quality.

Third Embodiment

As shown in FIG. 9 , which is a schematic structural diagram of the wide-angle lens 300 provided in this embodiment, the wide-angle lens 300 in this embodiment sequentially includes: a first lens L1 , a second lens L2 , a diaphragm ST, The third lens L3, the fourth lens L4, the fifth lens L5 and the filter G1.

The first lens L1 has negative refractive power, the object side S1 of the first lens is concave at the near optical axis, and the image side S2 of the first lens is convex at the near optical axis;

The second lens L2 has positive refractive power, the object side S3 of the second lens is concave, and the image side S4 of the second lens is convex;

The third lens L3 has negative refractive power, the object side S5 of the third lens is convex, and the image side S6 of the third lens is concave at the near optical axis;

The fourth lens L4 has positive refractive power, and both the object side S7 and the image side S8 of the fourth lens are convex;

The fifth lens L5 has negative refractive power, the object side S9 of the fifth lens is concave, and the image side S10 of the fifth lens is concave at the near optical axis;

The first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 and the fifth lens L5 are all plastic aspherical lenses.

Specifically, the design parameters of the wide-angle lens 300 provided in this embodiment are shown in Table 5.

table 5

Table 6 shows the surface shape coefficients of each aspherical surface of the wide-angle lens 300 in this embodiment.

Table 6

Please refer to FIG. 10 , FIG. 11 and FIG. 12 , which show the f-θ distortion curve, field curvature curve, and vertical-axis chromatic aberration curve of the wide-angle lens 300 respectively. It can be seen from FIG. 10 that the optical distortion is controlled at ±2% It shows that the distortion of the wide-angle lens 300 is well corrected; it can be seen from Figure 11 that the field curvature is controlled within ±0.07mm, which means that the field curvature of the wide-angle lens 300 is well corrected; it can be seen from Figure 12 that the vertical axis at different wavelengths The chromatic aberration is controlled within ±2 microns, indicating that the vertical axis chromatic aberration of the wide-angle lens 300 is well corrected; it can be seen from Figures 10, 11 and 12 that the wide-angle lens 300 has a well-balanced aberration and good optical imaging quality.

Fourth Embodiment

As shown in FIG. 13 , which is a schematic structural diagram of a wide-angle lens 400 provided in this embodiment, the wide-angle lens 400 in this embodiment is substantially the same as the wide-angle lens 300 provided in the third embodiment above, except that the object side S5 of the third lens is It is concave at the near optical axis, and the curvature radius, aspheric coefficient, thickness and material of each lens surface are different.

Specifically, the design parameters of the wide-angle lens 400 provided in this embodiment are shown in Table 7.

Table 7

In this embodiment, the aspherical parameters of each lens in the wide-angle lens 400 are shown in Table 8.

Table 8

Please refer to FIG. 14, FIG. 15 and FIG. 16, which show the f-θ distortion curve, the field curvature curve, and the vertical-axis chromatic aberration curve of the wide-angle lens 400, respectively. It can be seen from FIG. 14 that the optical distortion is controlled at ±2% It shows that the distortion of the wide-angle lens 400 is well corrected; it can be seen from Figure 15 that the paraxial field curvature is controlled within ±0.05mm, which means that the field curvature of the wide-angle lens 400 is well corrected; it can be seen from Figure 16 that at different wavelengths The vertical chromatic aberration of the wide-angle lens 400 is controlled within ±2 microns, which means that the vertical chromatic aberration of the wide-angle lens 400 is well corrected; from Figure 14, Figure 15, and Figure 16, it can be seen that the wide-angle lens 400 has a well-balanced aberration and good optical imaging. quality.

Please refer to Table 9, which shows the optical characteristics corresponding to the wide-angle lenses provided in the above four embodiments, including the field of view 2θ of the wide-angle lens, the total optical length TTL, the image height IH corresponding to the half field of view, the effective focal length f, and Correlation values corresponding to each of the preceding conditional expressions.

Table 9

It can be seen from the f-θ distortion graph, field curvature graph and vertical axis chromatic aberration graph of the above embodiments that the f-θ distortion value of the wide-angle lens in each embodiment is within ±2%, and the field curvature value is within ±2%. Within ±0.1 mm and vertical axis chromatic aberration within ±2 microns, it indicates that the lens provided by the embodiment of the present invention has the advantages of large viewing angle, small f-θ distortion, miniaturization, etc., and also has good resolution.

To sum up, the wide-angle lens provided by the present invention adopts five aspherical lenses with specific refractive powers, and through the combination of specific surface shapes and reasonable refractive power distribution, the wide-angle lens has a large viewing angle and reduces f-θ distortion at the same time. Aberration, the use of plastic lenses effectively reduces the weight of the system, provides more cost-effective optical performance products, and better meets the needs of lightweight and wide-angle portable electronic devices.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as limiting the scope of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims (9)

1. A wide-angle lens, comprising five lenses in sequence from an object side to an image plane along an optical axis:

a first lens having a negative optical power, an object side surface of the first lens being concave at a paraxial region;

a second lens having an optical power;

a diaphragm;

a third lens having optical power;

the fourth lens is provided with positive focal power, and the object side surface and the image side surface of the fourth lens are convex surfaces;

a fifth lens having a negative optical power, an image-side surface of the fifth lens being concave at a paraxial region and having at least one inflection point;

the wide-angle lens at least comprises an aspheric lens;

the wide-angle lens meets the following conditional expression:

-6<f12/f<-0.5；

-2%<(IH-f×θ)/(f×θ)<1%；

where f12 denotes a combined focal length of the first lens and the second lens, f denotes an effective focal length of the wide-angle lens, θ denotes a half field angle of the wide-angle lens, and IH denotes an image height corresponding to the half field angle of the wide-angle lens.

2. The wide-angle lens of claim 1, wherein the second lens has a negative optical power, and an image-side surface of the second lens is concave; the third lens has positive focal power, and both the object-side surface and the image-side surface of the third lens are convex surfaces; the image side surface of the first lens element is concave, and the object side surface of the fifth lens element is convex at a paraxial region.

3. The wide-angle lens of claim 1, wherein the second lens has a positive optical power, the second lens has a concave object-side surface, and the second lens has a convex image-side surface; the third lens has a negative optical power, the image side surface of the third lens being concave at the paraxial region; the image side surface of the first lens element is convex at a paraxial region, and the object side surface of the fifth lens element is concave.

4. The wide-angle lens of any one of claims 1 to 3, wherein the wide-angle lens satisfies the following conditional expression:

-10<f12/f34<-1；

wherein f34 represents a combined focal length of the third lens and the fourth lens.

5. The wide-angle lens of any one of claims 1 to 3, wherein the wide-angle lens satisfies the following conditional expression:

2.5<TTL/f<3.5；

2<TTL/IH<3；

wherein, TTL represents the optical total length of the wide-angle lens, and IH represents the image height corresponding to the half field angle of the wide-angle lens.

6. The wide-angle lens of any one of claims 1 to 3, wherein the wide-angle lens satisfies the following conditional expression:

0.16<BEL/TTL<0.3；

the BEL represents the distance between the image side surface of the fifth lens and an imaging surface on an optical axis, and the TTL represents the total optical length of the wide-angle lens.

7. The wide-angle lens of any one of claims 1 to 3, wherein the wide-angle lens satisfies the following conditional expression:

0.5<SD32/SD11<0.7；

wherein SD11 represents an effective aperture of the object side surface of the first lens, and SD32 represents an effective aperture of the image side surface of the third lens.

8. The wide-angle lens of any one of claims 1 to 3, wherein the wide-angle lens satisfies the following conditional expression:

0.5<f4/f<1；

-2<R41/R42<-0.3；

where f4 denotes a focal length of the fourth lens, R41 denotes a radius of curvature of an object side surface of the fourth lens, and R42 denotes a radius of curvature of an image side surface of the fourth lens.

9. The wide-angle lens of any one of claims 1 to 3, wherein the wide-angle lens satisfies the following conditional expression:

-6<f1/f<-1；

-2<f5/f<-0.3；

wherein f1 denotes a focal length of the first lens, and f5 denotes a focal length of the fifth lens.

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