CN109116512B

CN109116512B - Six-piece wide-angle lens group

Info

Publication number: CN109116512B
Application number: CN201710493727.1A
Authority: CN
Inventors: 赖淑姿
Original assignee: Xinju Technology Co ltd
Current assignee: Xinju Technology Co ltd
Priority date: 2017-06-26
Filing date: 2017-06-26
Publication date: 2020-11-17
Anticipated expiration: 2037-06-26
Also published as: CN109116512A

Abstract

The invention is a six-piece wide-angle lens set, in order from an object side to an image side comprising: a first lens element with negative refractive power; a second lens element with positive refractive power; an aperture; a third lens element with positive refractive power; a fourth lens element with negative refractive power; a fifth lens element with positive refractive power; a sixth lens element with negative refractive power. Therefore, the present invention provides a six-piece wide-angle lens assembly with improved angle, high resolution, short lens length, and small distortion.

Description

Six-piece wide-angle lens group

Technical Field

The invention relates to a six-piece wide-angle lens group, in particular to a miniaturized six-piece wide-angle lens group applied to electronic products.

Background

With the rise of electronic products with a photographing function, the demand of optical systems is increasing. In order to obtain a wide shooting range in shooting, the angle of view of the lens is required to meet certain requirements, and thus the requirements for the shooting angle and the image quality of the lens are becoming stricter. In general, the field angle (FOV) of the lens is designed to be 50 to 60 degrees, and if the field angle exceeds the designed angle, not only is the aberration large, but also the design of the lens is complicated. It is known that US 8335043 and US 8576497 use 2 lens groups, 5-6 lens groups to achieve the purpose of large angle, but the distortion (distortion) is too large, and US 8593737, US 8576497 and US 8395853 can achieve the purpose of large angle, but the Total Length (TL) of the lens group is too long.

Therefore, how to develop a miniaturized six-piece wide-angle lens set, which has the effects of larger angle of view and reducing aberration in addition to being capable of being configured in electronic products such as a lens used in a digital camera, a lens used in a web camera, or a mobile phone lens, so as to reduce the complexity of lens design, is the motivation for the development of the present invention.

Disclosure of Invention

The present invention provides a six-piece wide-angle lens assembly, and more particularly, to a six-piece wide-angle lens assembly with improved view angle, high resolution, short lens length, and small distortion.

Therefore, in order to achieve the above object, the present invention provides a six-piece wide-angle lens assembly, in order from an object side to an image side: a first lens element with negative refractive power having an object-side surface being convex at a paraxial region and an image-side surface being concave at a paraxial region, at least one of the object-side surface and the image-side surface being aspheric; a second lens element with positive refractive power having an object-side surface being concave at a paraxial region thereof and an image-side surface being convex at a paraxial region thereof, wherein at least one of the object-side surface and the image-side surface thereof is aspheric; an aperture; a third lens element with positive refractive power having an object-side surface being convex at a paraxial region thereof and an image-side surface being convex at a paraxial region thereof, wherein at least one of the object-side surface and the image-side surface is aspheric; a fourth lens element with negative refractive power having an object-side surface being convex at a paraxial region and an image-side surface being concave at a paraxial region, at least one of the object-side surface and the image-side surface being aspheric; a fifth lens element with positive refractive power having an object-side surface being convex at a paraxial region and an image-side surface being convex at a paraxial region, at least one of the object-side surface and the image-side surface being aspheric; the sixth lens element with negative refractive power has an object-side surface being concave at a paraxial region thereof and an image-side surface being concave at a paraxial region thereof, at least one of the object-side surface and the image-side surface thereof being aspheric, and at least one of the object-side surface and the image-side surface thereof having at least one inflection point.

Preferably, the focal length of the first lens is f1, the focal length of the second lens is f2, and the following conditions are satisfied: -0.1< f1/f2< -0.005. Therefore, the refractive power configuration of the first lens element and the second lens element is suitable, which is beneficial to obtaining a wide field angle and reducing excessive increase of system aberration.

Preferably, the focal length of the second lens is f2, the focal length of the third lens is f3, and the following conditions are satisfied: 25< f2/f3< 180. Therefore, the refractive power of the third lens element can be effectively distributed, and the refractive power of the third lens element is not too large, thereby facilitating the reduction of system sensitivity and the reduction of aberration.

Preferably, the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the following conditions are satisfied: -0.6< f3/f4< -0.25. Therefore, the configuration of the refractive power can be effectively balanced to enhance and correct the aberration of the six-piece wide-angle lens set.

Preferably, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, and the following conditions are satisfied: -1.9< f4/f5< -1.3. Therefore, the chromatic aberration of the image lens assembly can be balanced, and the imaging quality is improved.

Preferably, the focal length of the fifth lens element is f5, the focal length of the sixth lens element is f6, and the following conditions are satisfied: -1.3< f5/f6< -0.8. Therefore, the refractive power configuration of the rear group lens system is balanced, and the reduction of the system sensitivity and the correction of the high-order aberration are facilitated.

Preferably, the focal length of the first lens is f1, the focal length of the third lens is f3, and the following conditions are satisfied: -2.3< f1/f3< -1.7. Therefore, the refractive power of the first lens element is effectively distributed, and the sensitivity of the six-lens wide-angle lens assembly is reduced.

Preferably, the focal length of the second lens is f2, the focal length of the fourth lens is f4, and the following conditions are satisfied: -70< f2/f4< -15. Therefore, the large visual angle and the large aperture characteristic of the six-piece imaging lens group are favorably improved, the sensitivity of the six-piece imaging lens group can be reduced, the manufacture of each lens is favorably realized, and the production yield is improved.

Preferably, the focal length of the third lens is f3, the focal length of the fifth lens is f5, and the following conditions are satisfied: f3/f5 is more than 0.5 and less than 0.9. Therefore, the large visual angle and the large aperture characteristic of the six-piece imaging lens group are favorably improved, the sensitivity of the six-piece imaging lens group can be reduced, the manufacture of each lens is favorably realized, and the production yield is improved.

Preferably, the focal length of the fourth lens element is f4, the focal length of the sixth lens element is f6, and the following conditions are satisfied: f4/f6 is more than 1.5 and less than 2.0. Therefore, the sensitivity of the lens group of the camera system can be reduced, and the total length of the lens group can be effectively shortened.

Preferably, the focal length of the first lens element is f1, the combined focal length of the second and third lens elements is f23, and the following conditions are satisfied: -2.4< f1/f23< -1.65. By proper configuration of the refractive power, the spherical aberration and astigmatism can be reduced.

Preferably, a combined focal length of the second lens element and the third lens element is f23, a combined focal length of the fourth lens element and the fifth lens element is f45, and the following conditions are satisfied: f23/f45 is more than 0.15 and less than 0.6. When f23/f45 satisfies the above relation, the resolution capability of the six-piece wide-angle lens set can be significantly improved while having a large drawing angle, a high drawing number and a low lens height, whereas if the resolution capability exceeds the data value range of the above optical formula, the performance and resolution capability of the six-piece wide-angle lens set are low, and the yield is insufficient.

Preferably, a focal length of the fourth lens element is f45, a focal length of the sixth lens element is f6, and the following conditions are satisfied: -2.6< f45/f6< -1.4. When f45/f6 satisfies the above relation, the resolution capability of the six-piece wide-angle lens set can be significantly improved while having a large drawing angle, a high drawing number and a low lens height, whereas if the resolution capability exceeds the data value range of the above optical formula, the performance and resolution capability of the six-piece wide-angle lens set are low, and the yield is insufficient.

Preferably, a combined focal length of the first lens element and the second lens element is f12, a combined focal length of the third lens element and the fourth lens element is f34, and the following conditions are satisfied: -1.7< f12/f34< -1.1. When f12/f34 satisfies the above relation, the resolution capability of the six-piece wide-angle lens set can be significantly improved while having a large drawing angle, a high drawing number and a low lens height, whereas if the resolution capability exceeds the data value range of the above optical formula, the performance and resolution capability of the six-piece wide-angle lens set are low, and the yield is insufficient.

Preferably, a combined focal length of the third lens element and the fourth lens element is f34, a combined focal length of the fifth lens element and the sixth lens element is f56, and the following conditions are satisfied: -1.6< f34/f56< -0.65. When f34/f56 satisfies the above relation, the resolution capability of the six-piece wide-angle lens set can be significantly improved while having a large drawing angle, a high drawing number and a low lens height, whereas if the resolution capability exceeds the data value range of the above optical formula, the performance and resolution capability of the six-piece wide-angle lens set are low, and the yield is insufficient.

Preferably, the focal length of the first lens element is f1, the combined focal length of the second lens element, the third lens element and the fourth lens element is f234, and the following conditions are satisfied: -1.8< f1/f234< -1.0. By proper configuration of the refractive power, the spherical aberration and astigmatism can be reduced.

Preferably, a combined focal length of the second lens element, the third lens element and the fourth lens element is f234, and a combined focal length of the fifth lens element and the sixth lens element is f56, and the following conditions are satisfied: -1.6< f234/f56< -0.6. By proper configuration of the refractive power, the spherical aberration and astigmatism can be reduced.

Preferably, a focal length of the first lens element, the second lens element and the third lens element is f123, a focal length of the fourth lens element is f4, and the following conditions are satisfied: -0.65< f123/f4< -0.35. By proper configuration of the refractive power, the spherical aberration and astigmatism can be reduced.

Preferably, a combined focal length of the first lens element, the second lens element and the third lens element is f123, and a combined focal length of the fourth lens element and the fifth lens element is f45, and the following conditions are satisfied: f123/f45 is more than 0.2 and less than 0.75. When f123/f45 satisfies the above relation, the resolution capability of the six-piece wide-angle lens set can be significantly improved while having a large drawing angle, a high drawing number and a low lens height, whereas if the resolution capability exceeds the data value range of the above optical formula, the performance and resolution capability of the six-piece wide-angle lens set are low, and the yield is insufficient.

Preferably, a combined focal length of the first lens element, the second lens element and the third lens element is f123, and a combined focal length of the fourth lens element, the fifth lens element and the sixth lens element is f456, and the following conditions are satisfied: f123/f456 is more than 1.0 and less than 1.55. When f123/f456 satisfies the above relation, the resolution capability of the six-piece wide-angle lens group can be significantly improved while having a large drawing angle, a high drawing number, and a low lens height, whereas if the resolution capability exceeds the data value range of the optical formula, the performance and resolution capability of the six-piece wide-angle lens group are low, and the yield is insufficient.

Preferably, a combined focal length of the first lens element and the second lens element is f12, and a combined focal length of the third lens element, the fourth lens element, the fifth lens element and the sixth lens element is f3456, and the following conditions are satisfied: -2.7< f12/f3456< -1.95. When f12/f3456 satisfies the above relation, the resolution capability of the six-piece wide-angle lens set can be significantly improved while having a large drawing angle, a high drawing number and a low lens height, whereas if the resolution capability exceeds the data value range of the above optical formula, the performance and resolution capability of the six-piece wide-angle lens set are low, and the yield is insufficient.

Preferably, the third lens has an abbe number of V3, the fourth lens has an abbe number of V4, and the following conditions are satisfied: 30< V3-V4< 42. Therefore, the chromatic aberration of the six-piece wide-angle lens group can be corrected.

Preferably, the fifth lens has an abbe number of V5, the sixth lens has an abbe number of V6, and the following conditions are satisfied: 30< V5-V6< 42. Therefore, the chromatic aberration of the six-piece wide-angle lens group can be corrected.

Preferably, the overall focal length of the six-piece wide-angle lens assembly is f, the distance between the object-side surface of the first lens element and the image plane on the optical axis is TL, and the following conditions are satisfied: f/TL is more than 0.25 and less than 0.6. Therefore, the six-piece wide-angle lens set can be mounted on a light and thin electronic product, and is favorable for obtaining a wide field angle (field angle) and maintaining the miniaturization of the six-piece wide-angle lens set.

To achieve the above objects, the present invention provides a technique, means and other effects, which are described in detail below with reference to the accompanying drawings.

Drawings

FIG. 1A is a schematic view of a six-piece wide-angle lens set according to a first embodiment of the invention.

Fig. 1B is a graph illustrating the field curvature and distortion aberration curves of the six-piece wide-angle lens assembly of the first embodiment in order from left to right.

FIG. 2A is a schematic view of a six-piece wide-angle lens assembly according to a second embodiment of the present invention.

FIG. 2B is a graph showing the field curvature and distortion aberration curves of the six-piece wide-angle lens assembly of the second embodiment in order from left to right.

FIG. 3A is a schematic view of a six-piece wide-angle lens set according to a third embodiment of the present invention.

FIG. 3B is a graph showing the field curvature and distortion aberration curves of the six-piece wide-angle lens assembly of the third embodiment in order from left to right.

The reference numbers in the figures illustrate:

100. 200 and 300: aperture

110. 210, 310: first lens

111. 211, 311: object side surface

112. 212, 312: surface of image side

120. 220, 320: second lens

121. 221, 321: object side surface

122. 222, 322: surface of image side

130. 230, 330: third lens

131. 231, 331: object side surface

132. 232, 332: surface of image side

140. 240, 340: fourth lens

141. 241, 341: object side surface

142. 242, 342: surface of image side

150. 250, 350: fifth lens element

151. 251, 351: object side surface

152. 252, 352: surface of image side

160. 260, 360: sixth lens element

161. 261, 361: object side surface

162. 262, 362: surface of image side

170. 270, 370: infrared filtering component

180. 280, 380: image plane

190. 290, 390: optical axis

f: focal length of six-piece wide-angle lens group

Fno: aperture value of six-piece wide-angle lens group

FOV: maximum field angle in six-piece wide-angle lens group

f 1: focal length of the first lens

f 2: focal length of the second lens

f 3: focal length of the third lens

f 4: focal length of the fourth lens

f 5: focal length of fifth lens

f 6: focal length of sixth lens

f 12: the combined focal length of the first lens and the second lens

f 23: the combined focal length of the second lens and the third lens

f 34: the combined focal length of the third lens and the fourth lens

f 45: the combined focal length of the fourth lens and the fifth lens

f 56: the combined focal length of the fifth lens and the sixth lens

f 123: the combined focal length of the first lens, the second lens and the third lens

f 234: the combined focal length of the second lens, the third lens and the fourth lens

f 456: the combined focal length of the fourth lens, the fifth lens and the sixth lens

f 3456: the combined focal length of the third lens, the fourth lens, the fifth lens and the sixth lens

V3: abbe number of third lens

V4: abbe number of fourth lens

V5: abbe number of fifth lens

V6: abbe number of sixth lens

TL: distance between the object side surface of the first lens element and the image plane on the optical axis

Detailed Description

< first embodiment >

Referring to fig. 1A and fig. 1B, fig. 1A is a schematic diagram of a six-piece wide-angle lens assembly according to a first embodiment of the invention, and fig. 1B is a graph of field curvature and distortion aberration of the six-piece wide-angle lens assembly of the first embodiment in order from left to right. In fig. 1A, the six-piece wide-angle lens assembly includes an aperture stop 100 and an optical assembly including, in order from an object side to an image side, a first lens element 110, a second lens element 120, a third lens element 130, a fourth lens element 140, a fifth lens element 150, a sixth lens element 160, an ir-cut filter element 170 and an image plane 180, wherein six lens elements in the six-piece wide-angle lens assembly have refractive power. The stop 100 is disposed between the object-side surface 121 of the second lens element 120 and the image-side surface 132 of the third lens element 130.

The first lens element 110 with negative refractive power has an object-side surface 111 being convex at a paraxial region 190 and an image-side surface 112 being concave at a paraxial region 190, and the object-side surface 111 and the image-side surface 112 are aspheric.

The second lens element 120 with positive refractive power has an object-side surface 121 being concave in a paraxial region 190 and an image-side surface 122 being convex in a paraxial region 190, and is made of plastic material, wherein the object-side surface 121 and the image-side surface 122 are aspheric.

The third lens element 130 with positive refractive power has an object-side surface 131 being convex at a paraxial region 190 and an image-side surface 132 being convex at a paraxial region 190, wherein the third lens element 130 is made of plastic material, and both the object-side surface 131 and the image-side surface 132 are aspheric.

The fourth lens element 140 with negative refractive power has an object-side surface 141 being convex at a paraxial region 190 and an image-side surface 142 being concave at a paraxial region 190, and the object-side surface 141 and the image-side surface 142 are aspheric.

The fifth lens element 150 with positive refractive power has an object-side surface 151 being convex at a paraxial region 190 and an image-side surface 152 being convex at a paraxial region 190, wherein the fifth lens element 150 is made of plastic material, and both the object-side surface 151 and the image-side surface 152 are aspheric.

The sixth lens element 160 with negative refractive power is made of plastic material, and has an object-side surface 161 being concave at a paraxial region 190 and an image-side surface 162 being concave at a paraxial region 190, wherein the object-side surface 161 and the image-side surface 162 are aspheric, and at least one of the object-side surface 161 and the image-side surface 162 has at least one inflection point.

The ir-cut filter assembly 170 is made of glass, and is disposed between the sixth lens element 160 and the image plane 180 without affecting the focal length of the six-piece wide-angle lens assembly.

The curve equation of the aspherical surface of each lens described above is as follows:

wherein z is a position value referenced to the surface vertex at a position of height h along the optical axis 190; c is a curvature of the lens surface near the optical axis 190 and is an inverse of a curvature radius (R) (c is 1/R), R is a curvature radius of the lens surface near the optical axis 190, h is a perpendicular distance of the lens surface from the optical axis 190, k is a conic coefficient (conic constant), and A, B, C, D, E, G, … … are high order aspheric coefficients.

In the six-piece wide-angle lens group of the first embodiment, the focal length of the six-piece wide-angle lens group is f, the aperture value (f-number) of the six-piece wide-angle lens group is Fno, and the maximum field of view of the six-piece wide-angle lens group is FOV, which are as follows: 1.902 (millimeters); fno 2.2; and FOV 140 (degrees).

In the sixth wide-angle lens group of the first embodiment, the focal length of the first lens element 110 is f1, and the focal length of the second lens element 120 is f2, and the following conditions are satisfied: f1/f2 is-0.05.

In the sixth wide-angle lens group of the first embodiment, the focal length of the second lens element 120 is f2, and the focal length of the third lens element 130 is f3, and the following conditions are satisfied: 38.64 for f2/f 3.

In the sixth wide-angle lens group of the first embodiment, the focal length of the third lens element 130 is f3, the focal length of the fourth lens element 140 is f4, and the following conditions are satisfied: f3/f4 is-0.47.

In the sixth wide-angle lens group of the first embodiment, the focal length of the fourth lens element 140 is f4, the focal length of the fifth lens element 150 is f5, and the following conditions are satisfied: f4/f5 is-1.47.

In the sixth wide-angle lens group of the first embodiment, the focal length of the fifth lens element 150 is f5, the focal length of the sixth lens element 160 is f6, and the following conditions are satisfied: f5/f6 is-1.17.

In the sixth wide-angle lens group of the first embodiment, the focal length of the first lens element 110 is f1, the focal length of the third lens element 130 is f3, and the following conditions are satisfied: f1/f3 is-1.87.

In the sixth wide-angle lens group of the first embodiment, the focal length of the second lens element 120 is f2, and the focal length of the fourth lens element 140 is f4, and the following conditions are satisfied: f2/f4 is-18.16.

In the sixth wide-angle lens group of the first embodiment, the focal length of the third lens element 130 is f3, the focal length of the fifth lens element 150 is f5, and the following conditions are satisfied: f3/f5 is 0.69.

In the sixth wide-angle lens group of the first embodiment, the focal length of the fourth lens element 140 is f4, the focal length of the sixth lens element 160 is f6, and the following conditions are satisfied: f4/f6 is 1.71.

In the sixth embodiment of the present invention, the focal length of the first lens element 110 is f1, and the combined focal length of the second lens element 120 and the third lens element 130 is f23, and the following conditions are satisfied: f1/f23 is-1.93.

In the sixth embodiment of the present invention, the combined focal length of the second lens element 120 and the third lens element 130 is f23, and the combined focal length of the fourth lens element 140 and the fifth lens element 150 is f45, and the following conditions are satisfied: f23/f45 is 0.33.

In the sixth embodiment of the present invention, the combined focal length of the fourth lens element 140 and the fifth lens element 150 is f45, the focal length of the sixth lens element 160 is f6, and the following conditions are satisfied: f45/f6 is-2.37.

In the sixth wide-angle lens assembly of the first embodiment, the combined focal length of the first lens element 110 and the second lens element 120 is f12, and the combined focal length of the third lens element 130 and the fourth lens element 140 is f34, and the following conditions are satisfied: f12/f34 is-1.33.

In the sixth wide-angle lens assembly of the first embodiment, the combined focal length of the third lens element 130 and the fourth lens element 140 is f34, and the combined focal length of the fifth lens element 150 and the sixth lens element 160 is f56, and the following conditions are satisfied: f34/f56 is-1.42.

In the sixth wide-angle lens assembly of the first embodiment, the focal length of the first lens element 110 is f1, and the combined focal length of the second lens element 120, the third lens element 130 and the fourth lens element 140 is f234, and the following conditions are satisfied: f1/f234 is-1.29.

In the sixth embodiment of the present invention, the combined focal length of the second lens element 120, the third lens element 130 and the fourth lens element 140 is f234, and the combined focal length of the fifth lens element 150 and the sixth lens element 160 is f56, and the following conditions are satisfied: f234/f56 is-1.36.

In the sixth lens element of the first embodiment, the combined focal length of the first lens element 110, the second lens element 120 and the third lens element 130 is f123, and the focal length of the fourth lens element 140 is f4, and the following conditions are satisfied: f123/f4 is-0.54.

In the sixth embodiment of the present invention, the combined focal length of the first lens element 110, the second lens element 120 and the third lens element 130 is f123, and the combined focal length of the fourth lens element 140 and the fifth lens element 150 is f45, and the following conditions are satisfied: f123/f45 is 0.39.

In the sixth lens element of the first embodiment, a combined focal length of the first lens element 110, the second lens element 120 and the third lens element 130 is f123, and a combined focal length of the fourth lens element 140, the fifth lens element 150 and the sixth lens element 160 is f456, and the following conditions are satisfied: f123/f456 equals 1.20.

In the sixth wide-angle lens assembly of the first embodiment, the combined focal length of the first lens element 110 and the second lens element 120 is f12, and the combined focal length of the third lens element 130, the fourth lens element 140, the fifth lens element 150 and the sixth lens element 160 is f3456, and the following conditions are satisfied: f12/f 3456-2.26.

In the sixth wide-angle lens group of the first embodiment, the third lens 130 has an abbe number of V3, and the fourth lens 140 has an abbe number of V4, and the following conditions are satisfied: V3-V4 ═ 34.6.

In the sixth wide-angle lens group of the first embodiment, the abbe number of the fifth lens element 150 is V5, the abbe number of the sixth lens element 160 is V6, and the following conditions are satisfied: V5-V6 ═ 34.6.

In the first embodiment of the six-piece wide angle lens assembly, the overall focal length of the six-piece wide angle lens assembly is f, the distance from the object-side surface 111 of the first lens element 110 to the image plane 180 on the optical axis 190 is TL, and the following conditions are satisfied: f/TL is 0.40.

Further, refer to the following Table 1 and Table 2.

Table 1 shows the detailed structural data of the first embodiment of fig. 1A, wherein the units of the radius of curvature, the thickness and the focal length are mm, and surfaces 0-17 sequentially represent the surfaces from the object side to the image side. Table 2 shows aspheric data in the first embodiment, where k denotes a cone coefficient in the aspheric curve equation, and A, B, C, D, E, F … … denotes a higher-order aspheric coefficient. In addition, the following tables of the embodiments correspond to the schematic diagrams of the embodiments and the field curvature and distortion aberration curves, and the definitions of the data in the tables are the same as those in tables 1 and 2 of the first embodiment, which are not repeated herein.

< second embodiment >

Referring to fig. 2A and fig. 2B, fig. 2A is a schematic diagram of a six-piece wide-angle lens assembly according to a second embodiment of the invention, and fig. 2B is a graph of field curvature and distortion aberration of the six-piece wide-angle lens assembly of the second embodiment in order from left to right. In fig. 2A, the six-piece wide-angle lens assembly includes an aperture stop 200 and an optical assembly including, in order from an object side to an image side, a first lens element 210, a second lens element 220, a third lens element 230, a fourth lens element 240, a fifth lens element 250, a sixth lens element 260, an ir-cut filter 270, and an image plane 280, wherein six lens elements in the six-piece wide-angle lens assembly have refractive power. The stop 200 is disposed between an object-side surface 221 of the second lens element 220 and an image-side surface 232 of the third lens element 230.

The first lens element 210 with negative refractive power has an object-side surface 211 being convex at a paraxial region 290 and an image-side surface 212 being concave at a paraxial region 290, and the object-side surface 211 and the image-side surface 212 are aspheric.

The second lens element 220 with positive refractive power has an object-side surface 221 being concave at a paraxial region 290 thereof and an image-side surface 222 being convex at a paraxial region 290 thereof, wherein the object-side surface 221 and the image-side surface 222 are aspheric.

The third lens element 230 with positive refractive power has an object-side surface 231 being convex at a paraxial region 290 and an image-side surface 232 being convex at a paraxial region 290, and is made of plastic material, wherein the object-side surface 231 and the image-side surface 232 are aspheric.

The fourth lens element 240 with negative refractive power has an object-side surface 241 being convex at a paraxial region 290 and an image-side surface 242 being concave at a paraxial region 290, and the object-side surface 241 and the image-side surface 242 are aspheric.

The fifth lens element 250 with positive refractive power has an object-side surface 251 being convex at a paraxial region 290 and an image-side surface 252 being convex at a paraxial region 290, wherein the object-side surface 251 and the image-side surface 252 are aspheric.

The sixth lens element 260 with negative refractive power has an object-side surface 261 being concave at a paraxial region 290 thereof and an image-side surface 262 being concave at a paraxial region 290 thereof, wherein the object-side surface 261 and the image-side surface 262 are aspheric, and at least one of the object-side surface 261 and the image-side surface 262 has at least one inflection point.

The ir-cut filter 270 is made of glass, and is disposed between the sixth lens element 260 and the image plane 280 without affecting the focal length of the six-piece wide-angle lens set.

Further, the following Table 3 and Table 4 are referred to.

In the second embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.

The following data can be derived from tables 3 and 4:

< third embodiment >

Referring to fig. 3A and fig. 3B, fig. 3A is a schematic diagram of a six-piece wide-angle lens assembly according to a third embodiment of the invention, and fig. 3B is a graph of field curvature and distortion aberration of the six-piece wide-angle lens assembly of the third embodiment in order from left to right. In fig. 3A, the six-piece wide-angle lens assembly includes an aperture stop 300 and an optical assembly including, in order from an object side to an image side, a first lens element 310, a second lens element 320, a third lens element 330, a fourth lens element 340, a fifth lens element 350, a sixth lens element 360 and an image plane 380, wherein six lens elements have refractive power. The stop 300 is disposed between the object-side surface 321 of the second lens element 320 and the image-side surface 332 of the third lens element 330.

The first lens element 310 with negative refractive power has an object-side surface 311 being convex at a paraxial region 390, and an image-side surface 312 being concave at a paraxial region 390, wherein the object-side surface 311 and the image-side surface 312 are aspheric.

The second lens element 320 with positive refractive power has an object-side surface 321 being concave at a paraxial region 390 thereof and an image-side surface 322 being convex at a paraxial region 390 thereof, and the object-side surface 321 and the image-side surface 322 are aspheric.

The third lens element 330 with positive refractive power has an object-side surface 331 being convex at a paraxial region 390 and an image-side surface 332 being convex at a paraxial region 390, and the object-side surface 331 and the image-side surface 332 are aspheric.

The fourth lens element 340 with negative refractive power has an object-side surface 341 being convex at a paraxial region 390, and an image-side surface 342 being concave at a paraxial region 390, wherein the object-side surface 341 and the image-side surface 342 are aspheric.

The fifth lens element 350 with positive refractive power has an object-side surface 351 being convex at a paraxial region 390 and an image-side surface 352 being convex at a paraxial region 390, and the object-side surface 351 and the image-side surface 352 are aspheric.

The sixth lens element 360 with negative refractive power has an object-side surface 361 being concave at a paraxial region 390 thereof and an image-side surface 362 being concave at a paraxial region 390 thereof, wherein the object-side surface 361 and the image-side surface 362 are aspheric, and the object-side surface 361 and the image-side surface 362 have at least one inflection point.

The ir-cut filter 370 is made of glass, and is disposed between the sixth lens element 360 and the image plane 380 without affecting the focal length of the six-piece wide-angle lens set.

Further, the following Table 5 and Table 6 were referred to.

In the third embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.

The following data can be derived from tables 5 and 6:

in the six-piece wide-angle lens group provided by the invention, the material of the lens can be plastic or glass, when the material of the lens is plastic, the production cost can be effectively reduced, and when the material of the lens is glass, the degree of freedom of the configuration of the refractive power of the six-piece wide-angle lens group can be increased. In addition, the object-side surface and the image-side surface of the lenses in the six-piece wide-angle lens group can be aspheric surfaces, the aspheric surfaces can be easily made into shapes other than spherical surfaces, more control variables are obtained for reducing the aberration, and the number of the lenses is further reduced, so that the total length of the six-piece wide-angle lens group can be effectively reduced.

In the six-lens wide-angle lens assembly provided by the invention, for a lens with refractive power, if the lens surface is convex and the position of the convex surface is not defined, the lens surface is convex at a paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at the paraxial region.

The six-piece wide-angle lens group provided by the invention can be applied to an optical system for moving focusing according to the requirements, has the characteristics of excellent aberration correction and good imaging quality, and can be applied to electronic image systems such as 3D (three-dimensional) image acquisition, digital cameras, mobile devices, digital drawing boards or vehicle photography and the like in many aspects.

In summary, the above embodiments and drawings are only preferred embodiments of the present invention, and the scope of the present invention should not be limited thereby, and all equivalent changes and modifications made in the claims of the present invention should be covered by the claims of the present invention.

Claims

1. A six-lens wide-angle lens assembly, in order from an object side to an image side comprising:

a first lens element with negative refractive power having an object-side surface being convex at a paraxial region and an image-side surface being concave at a paraxial region, at least one of the object-side surface and the image-side surface being aspheric;

a second lens element with positive refractive power having an object-side surface being concave at a paraxial region thereof and an image-side surface being convex at a paraxial region thereof, wherein at least one of the object-side surface and the image-side surface thereof is aspheric;

an aperture;

a third lens element with positive refractive power having an object-side surface being convex at a paraxial region thereof and an image-side surface being convex at a paraxial region thereof, wherein at least one of the object-side surface and the image-side surface is aspheric;

a fourth lens element with negative refractive power having an object-side surface being convex at a paraxial region and an image-side surface being concave at a paraxial region, at least one of the object-side surface and the image-side surface being aspheric;

a fifth lens element with positive refractive power having an object-side surface being convex at a paraxial region and an image-side surface being convex at a paraxial region, at least one of the object-side surface and the image-side surface being aspheric;

a sixth lens element with negative refractive power having an object-side surface being concave at a paraxial region thereof and an image-side surface being concave at a paraxial region thereof, at least one of the object-side surface and the image-side surface being aspheric, and at least one of the object-side surface and the image-side surface having at least one inflection point;

the focal length of the second lens is f2, the focal length of the third lens is f3, and the following conditions are satisfied: 25< f2/f3< 180.

2. The six-piece wide-angle lens assembly of claim 1, wherein the first lens element has a focal length of f1 and the second lens element has a focal length of f2, wherein the following conditions are satisfied: -0.1< f1/f2< -0.005.

3. The six-piece wide-angle lens assembly of claim 1, wherein the third lens element has a focal length of f3 and the fourth lens element has a focal length of f4, wherein the following conditions are satisfied: -0.6< f3/f4< -0.25.

The six-piece wide angle lens assembly of claim 1, wherein the focal length of the fourth lens element is f4, the focal length of the fifth lens element is f5, and the following conditions are satisfied: -1.9< f4/f5< -1.3.

5. The six-piece wide-angle lens assembly of claim 1, wherein the fifth lens element has a focal length of f5, and the sixth lens element has a focal length of f6, wherein the following conditions are satisfied: -1.3< f5/f6< -0.8.

6. The six-piece wide-angle lens assembly of claim 1, wherein the first lens element has a focal length of f1 and the third lens element has a focal length of f3, wherein the following conditions are satisfied: -2.3< f1/f3< -1.7.

7. The six-piece wide-angle lens assembly of claim 1, wherein the second lens element has a focal length of f2 and the fourth lens element has a focal length of f4, wherein the following conditions are satisfied: -70< f2/f4< -15.

8. The six-piece wide-angle lens assembly of claim 1, wherein the third lens element has a focal length of f3 and the fifth lens element has a focal length of f5, wherein the following conditions are satisfied: 0.5< f3/f5< 0.9.

9. The six-piece wide-angle lens assembly of claim 1, wherein the focal length of the fourth lens element is f4, the focal length of the sixth lens element is f6, and the following conditions are satisfied: 1.5< f4/f6< 2.0.

10. The six-piece wide-angle lens assembly of claim 1, wherein the first lens element has a focal length of f1, and the combined focal length of the second and third lens elements is f23, wherein the following conditions are satisfied: -2.4< f1/f23< -1.65.

11. The six-piece wide-angle lens assembly of claim 1, wherein the combined focal length of the second and third lenses is f23, and the combined focal length of the fourth and fifth lenses is f45, wherein the following conditions are satisfied: 0.15< f23/f45< 0.6.

12. The six-piece wide-angle lens assembly of claim 1, wherein the combined focal length of the fourth lens element and the fifth lens element is f45, the focal length of the sixth lens element is f6, and the following conditions are satisfied: -2.6< f45/f6< -1.4.

13. The six-piece wide-angle lens assembly of claim 1, wherein the combined focal length of the first and second lenses is f12, and the combined focal length of the third and fourth lenses is f34, wherein the following conditions are satisfied: -1.7< f12/f34< -1.1.

14. The six-piece wide-angle lens assembly of claim 1, wherein the combined focal length of the third lens element and the fourth lens element is f34, and the combined focal length of the fifth lens element and the sixth lens element is f56, wherein the following conditions are satisfied: -1.6< f34/f56< -0.65.

15. The six-piece wide angle lens assembly of claim 1, wherein the first lens element has a focal length f1, and the combined focal length of the second, third and fourth lens elements is f234, wherein the following conditions are satisfied: -1.8< f1/f234< -1.0.

16. The six-piece wide angle lens assembly of claim 1, wherein the combined focal length of the second lens element, the third lens element and the fourth lens element is f234, and the combined focal length of the fifth lens element and the sixth lens element is f56, wherein the following conditions are satisfied: -1.6< f234/f56< -0.6.

17. The six-piece wide-angle lens assembly of claim 1, wherein the combined focal length of the first lens element, the second lens element and the third lens element is f123, and the focal length of the fourth lens element is f4, and the following conditions are satisfied: -0.65< f123/f4< -0.35.

18. The six-piece wide angle lens assembly of claim 1, wherein the combined focal length of the first lens element, the second lens element and the third lens element is f123, and the combined focal length of the fourth lens element and the fifth lens element is f45, wherein the following conditions are satisfied: 0.2< f123/f45< 0.75.

19. The six-piece wide angle lens assembly of claim 1, wherein the combined focal length of the first, second and third lenses is f123, and the combined focal length of the fourth, fifth and sixth lenses is f456, and wherein the following conditions are satisfied: 1.0< f123/f456< 1.55.

20. The six-piece wide angle lens assembly of claim 1, wherein the combined focal length of the first lens element and the second lens element is f12, and the combined focal length of the third lens element, the fourth lens element, the fifth lens element and the sixth lens element is f3456, wherein the following conditions are satisfied: -2.7< f12/f3456< -1.95.

21. The six-piece wide-angle lens set of claim 1, wherein the third lens element has an abbe number of V3 and the fourth lens element has an abbe number of V4, wherein the following conditions are satisfied: 30< V3-V4< 42.

22. The six-piece wide-angle lens set of claim 1, wherein the fifth lens element has an abbe number of V5, and the sixth lens element has an abbe number of V6, wherein the following conditions are satisfied: 30< V5-V6< 42.

23. The six-piece wide angle lens assembly of claim 1, wherein the overall focal length of the six-piece wide angle lens assembly is f, the distance from the object-side surface of the first lens element to the image plane is TL, and the following conditions are satisfied: 0.25< f/TL < 0.6.