TWI701457B - Wide-angle lens - Google Patents

Abstract

A wide-angle lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens, all of which are arranged in sequence from an object side to an image side along an optical axis. The first lens is a meniscus lens with negative refractive power and includes a convex surface facing the object side and a concave surface facing the image side. The second lens is a biconcave lens with negative refractive power. The third lens is a biconvex lens with positive refractive power. The fourth lens includes a convex surface facing the object side. The fifth lens is with positive refractive power and includes a convex surface facing the image side. The sixth lens is a biconvex lens with positive refractive power. The seventh lens is a biconcave lens with negative refractive power. The eighth lens is a biconvex lens with positive refractive power.

Description

Wide-angle lens

The invention relates to a wide-angle lens.

The development trend of today’s wide-angle lenses, in addition to the continuous development towards miniaturization and wide viewing angles, with different application requirements, it also needs to have both high resolution and resistance to environmental temperature changes. The conventional wide-angle lenses can no longer meet today’s requirements. Demands require another wide-angle lens with a new architecture to meet the needs of miniaturization, wide viewing angle, high resolution, and resistance to environmental temperature changes.

In view of this, the main purpose of the present invention is to provide a wide-angle lens, which has a short overall lens length, a large viewing angle, and is resistant to environmental temperature changes, but still has good optical performance and the lens resolution can also meet the requirements.

The wide-angle lens of the present invention includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens in order from an object side to an image side along an optical axis. A seventh lens and an eighth lens. The first lens is a meniscus lens with negative refractive power, and the convex surface of the first lens faces the object side and the concave surface faces the image side. The second lens is a biconcave lens with negative refractive power. The third lens is a biconvex lens with positive refractive power. The fourth lens includes a convex surface facing the object side. The fifth lens has positive refractive power and includes a convex surface facing the image side. The sixth lens is a biconvex lens with positive refractive power. The seventh lens is a biconcave lens with negative refractive power. The eighth lens is a biconvex lens with positive refractive power.

The fourth lens and the fifth lens are glued into a cemented lens.

The sixth lens and the seventh lens are glued into a cemented lens.

(R₇₁-R₇₂)/(R₇₁+R₇₂)

-1；其中，R₇₁為第七透鏡之物側面之曲率半徑，R₇₂為第七透鏡之像側面之曲率半徑。 The seventh lens satisfies the following conditions: -110

(R ₇₁ -R ₇₂ )/(R ₇₁ +R ₇₂ )

-1; where R ₇₁ is the curvature radius of the object side surface of the seventh lens, and R ₇₂ is the curvature radius of the image side surface of the seventh lens.

f₄/f

20；其中，f₄為第四透鏡之有效焦距，f為廣角鏡頭之有效焦距。 The fourth lens satisfies the following conditions: -20

f ₄ /f

20; where f ₄ is the effective focal length of the fourth lens, and f is the effective focal length of the wide-angle lens.

f₆₇/f

-5；其中，f₆₇為第六透鏡及第七透鏡膠合成一膠合透鏡之有效焦距，f為廣角鏡頭之有效焦距。 Among them, the sixth lens and the seventh lens meet the following conditions: -30

f ₆₇ /f

-5; Among them, f ₆₇ is the effective focal length of the sixth lens and the seventh lens combined into a cemented lens, and f is the effective focal length of the wide-angle lens.

Vd₄/Nd₄

50；其中，Vd₄為第四透鏡之阿貝係數，Nd₄為第四透鏡之折射率。 The fourth lens satisfies the following conditions; 5

Vd ₄ /Nd ₄

50; where Vd ₄ is the Abbe number of the fourth lens, and Nd ₄ is the refractive index of the fourth lens.

The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are made of glass material.

Wherein, at least one surface of each of the second lens and the eighth lens is an aspheric surface.

The wide-angle lens of the present invention may further include an aperture set between the third lens and the fourth lens.

In order to make the above-mentioned objects, features, and advantages of the present invention more obvious and understandable, the following specifically describes preferred embodiments in conjunction with the accompanying drawings.

1, 2, 3: wide-angle lens

L11, L21, L31: the first lens

L12, L22, L32: second lens

L13, L23, L33: third lens

L14, L24, L34: fourth lens

L15, L25, L35: fifth lens

L16, L26, L36: sixth lens

L17, L27, L37: seventh lens

L18, L28, L38: eighth lens

ST1, ST2, ST3: aperture

OF1, OF2, OF3: filter

IMA1, IMA2, IMA3: imaging surface

OA1, OA2, OA3: Optical axis

S11, S12, S13, S14, S15, S16, S17: surface

S18, S19, S110, S111, S112, S113: surface

S114, S115, S116, S117: surface

S21, S22, S23, S24, S25, S26, S27: surface

S28, S29, S210, S211, S212, S213: surface

S214, S215, S216, S217: surface

S31, S32, S33, S34, S35, S36, S37: surface

S38, S39, S310, S311, S312, S313: surface

S314, S315, S316, S317: surface

FIG. 1 is a schematic diagram of the lens arrangement and optical path of the first embodiment of the wide-angle lens according to the present invention.

Figure 2A is the longitudinal spherical aberration diagram of the wide-angle lens of Figure 1.

Figure 2B is the astigmatic field curve of the wide-angle lens in Figure 1.

Figure 2C is the distortion diagram of the wide-angle lens of Figure 1.

FIG. 3 is a schematic diagram of the lens configuration and optical path of the second embodiment of the wide-angle lens according to the present invention.

Fig. 4A is the longitudinal spherical aberration diagram of the wide-angle lens in Fig. 3.

Figure 4B is the astigmatic field curve of the wide-angle lens in Figure 3.

Figure 4C is the distortion diagram of the wide-angle lens in Figure 3.

FIG. 5 is a schematic diagram of the lens arrangement and optical path of the third embodiment of the wide-angle lens according to the present invention.

Fig. 6A is the longitudinal spherical aberration diagram of the wide-angle lens in Fig. 5.

Figure 6B is the astigmatic field curve of the wide-angle lens in Figure 5.

Figure 6C is the distortion diagram of the wide-angle lens in Figure 5.

Please refer to FIG. 1, which is a schematic diagram of the lens configuration and optical path of the first embodiment of the wide-angle lens according to the present invention. The wide-angle lens 1 includes a first lens L11, a second lens L12, a third lens L13, an aperture ST1, a fourth lens L14, and a fifth lens in order from an object side to an image side along an optical axis OA1. Lens L15, a sixth lens L16, a seventh lens L17, an eighth lens L18 and a filter OF1. When imaging, the light from the object side is finally imaged on an imaging surface IMA1. The first lens L11 is a meniscus lens with negative refractive power and is made of glass. The object side surface S11 is convex, the image side surface S12 is concave, and both the object side surface S11 and the image side surface S12 are spherical surfaces. The second lens L12 is a biconcave lens with negative refractive power and is made of glass. The object side surface S13 is an aspheric surface, and the image side surface S14 is an aspheric surface. The third lens L13 is a double-convex lens with positive refractive power and is made of glass. Its object side S15 is a spherical surface, and the image side The surface S16 is a spherical surface. The fourth lens L14 is a meniscus lens with negative refractive power and is made of glass. The object side surface S18 is convex and the image side surface S19 is concave. Both the object side surface S18 and the image side surface S19 are spherical surfaces. The fifth lens L15 is a biconvex lens with positive refractive power made of glass material, and the object side surface S19 and the image side surface S110 are spherical surfaces. The fourth lens L14 and the fifth lens L15 are cemented into a cemented lens. The sixth lens L16 is a biconvex lens with positive refractive power made of glass material, and the object side surface S111 and the image side surface S112 are both spherical surfaces. The seventh lens L17 is a biconcave lens with negative refractive power made of glass material, and the object side surface S112 and the image side surface S113 are spherical surfaces. The sixth lens L16 and the seventh lens L17 are cemented into a cemented lens. The eighth lens L18 is a biconvex lens with positive refractive power made of glass material, and the object side surface S114 and the image side surface S115 are both aspherical surfaces. The object side surface S116 and the image side surface S117 of the filter OF1 are both flat surfaces.

In addition, in order for the wide-angle lens of the present invention to maintain good optical performance, the wide-angle lens 1 in the first embodiment needs to meet the following four conditions:

Wherein, R1 ₇₁ is the radius of curvature of the side surface S112 of the seventh lens L17 things, R1 ₇₂ is the seventh lens L17 of the image side surface S113 of the radius of curvature, _{f1. 4} is the effective focal length L14 of the fourth lens, f1 is the effective focal length of the wide-angle lens 1 , f1 ₆₇ synthesis effective focal length of a lens of the cemented lens L16 to the sixth and the seventh lens L17 gum, Vd1 ₄ Abbe number of the fourth lens L14 of, Nd1 ₄ is the refractive index of the fourth lens L14.

Using the above-mentioned design of the lens and the aperture ST1, the wide-angle lens 1 can effectively shorten the total length of the lens, increase the angle of view, effectively correct aberrations, increase the resolution of the lens, and reduce the impact of temperature changes on the resolution of the lens.

Table 1 is a table of related parameters of each lens of the wide-angle lens 1 in Figure 1. The data in Table 1 shows that the effective focal length of the wide-angle lens 1 of the first embodiment is equal to 1.8288mm, the aperture value is equal to 2.0, the viewing angle is equal to 174.3°, and the total lens length is equal to 17.625mm.

The concavity z of the aspheric surface of each lens in Table 1 is obtained by the following formula: z=ch ² /{1+[1-(k+1)c ² h ² ] ^1/2 }+Ah ⁴ +Bh ⁶ + Ch ⁸ +Dh ¹⁰

Among them; c: curvature; h: the vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~D: aspherical coefficient.

Table 2 is the relevant parameter table of the aspheric surface of each lens in Table 1, where k is the Conic Constant and A~D are the aspheric coefficients.

In the wide-angle lens 1 of the first embodiment, the seventh lens L17 has a radius of curvature of the object side S112 R1 ₇₁ = -3.32024mm, and the seventh lens L17 has a radius of curvature R1 ₇₂ of the image side S113 = 7.62421mm. The fourth lens L14 is effective The focal length f1 ₄ = -8.6650mm, the effective focal length of the wide-angle lens 1 is f1=1.8288mm, the sixth lens L16 and the seventh lens L17 are glued together to form a cemented lens with the effective focal length f1 ₆₇ =-15.24650mm, the Abbe number of the fourth lens L14 Vd1 ₄ =58.6, the refractive index of the fourth lens L14 is Nd1 ₄ =1.652, from the above data we can get (R1 ₇₁ -R1 ₇₂ )/(R1 ₇₁ +R1 ₇₂ )=-2.543, f1 ₄ /f1=-4.738, f1 ₆₇ /f1=-8.337, Vd1 ₄ /Nd1 ₄ =35.451, all of which can meet the requirements of the above conditions (1) to (4).

In addition, the optical performance of the wide-angle lens 1 of the first embodiment can also meet the requirements, which can be seen from Figures 2A to 2C. FIG. 2A shows the Longitudinal Spherical Aberration (Longitudinal Spherical Aberration) diagram of the wide-angle lens 1 of the first embodiment. Figure 2B shows the Astigmatic Field Curves of the wide-angle lens 1 of the first embodiment. Figure 2C shows a distortion (distortion) diagram of the wide-angle lens 1 of the first embodiment.

It can be seen from Fig. 2A that the longitudinal spherical aberration value of the wide-angle lens 1 of the first embodiment for light with wavelengths of 436.000nm, 546.000nm, and 656.000nm is between -0.02mm and 0.00mm. It can be seen from Figure 2B that the wide-angle lens 1 of the first embodiment has a light beam with a wavelength of 546.000nm, and the astigmatic field curvature in the Tangential direction and the Sagittal direction is between -0.13mm and 0.02mm. . It can be seen from Fig. 2C that the distortion of the wide-angle lens 1 of the first embodiment for light with a wavelength of 546.000 nm is between -100% and 0%. It is obvious that the longitudinal spherical aberration, astigmatic field curvature, and distortion of the wide-angle lens 1 of the first embodiment can be effectively corrected to obtain better optical performance.

Please refer to Figure 3, which is the second example of the wide-angle lens according to the present invention Schematic diagram of the lens configuration and optical path of the embodiment. The wide-angle lens 2 includes a first lens L21, a second lens L22, a third lens L23, an aperture ST2, a fourth lens L24, and a fifth lens in order from an object side to an image side along an optical axis OA2. Lens L25, a sixth lens L26, a seventh lens L27, an eighth lens L28 and a filter OF2. When imaging, the light from the object side is finally imaged on an imaging surface IMA2. The first lens L21 is a meniscus lens with negative refractive power and is made of glass. The object side surface S21 is a convex surface, the image side surface S22 is a concave surface, and both the object side surface S21 and the image side surface S22 are spherical surfaces. The second lens L22 is a biconcave lens with negative refractive power and is made of glass material, the object side surface S23 is an aspheric surface, and the image side surface S24 is an aspheric surface. The third lens L23 is a biconvex lens with positive refractive power made of glass material, the object side surface S25 is a spherical surface, and the image side surface S26 is a spherical surface. The fourth lens L24 is a biconvex lens with positive refractive power made of glass material, and the object side surface S28 and the image side surface S29 are spherical surfaces. The fifth lens L25 is a meniscus lens with positive refractive power made of glass material, and the object side surface S29 and the image side surface S210 are both spherical surfaces. The fourth lens L24 and the fifth lens L25 are cemented into a cemented lens. The sixth lens L26 is a biconvex lens with positive refractive power made of glass material, and the object side surface S211 and the image side surface S212 are both spherical surfaces. The seventh lens L27 is a biconcave lens with negative refractive power made of glass material, and the object side surface S212 and the image side surface S213 are spherical surfaces. The sixth lens L26 and the seventh lens L27 are cemented into a cemented lens. The eighth lens L28 is a biconvex lens with positive refractive power made of glass material, and the object side surface S214 and the image side surface S215 are both aspherical surfaces. The object side S216 and the image side S217 of the filter OF2 are both flat.

In addition, in order for the wide-angle lens of the present invention to maintain good optical performance, the wide-angle lens 2 in the second embodiment needs to meet the following four conditions:

Wherein, R2 ₇₁ is a side radius of curvature of the seventh lens L27 S212 thing, R2 ₇₂ of the seventh lens L27 of the radius of curvature of the image side surface of S213, _{f2. 4} is the effective focal length L24 of the fourth lens, f2 is the effective focal length of the wide angle lens of 2 , f2 ₆₇ synthesis effective focal length of a lens of the cemented lens L26 to the sixth and the seventh lens L27 gum, Vd2 ₄ Abbe number of the fourth lens L24 of, Nd2 ₄ is the refractive index of the fourth lens L24.

Using the above-mentioned design of the lens and the aperture ST2, the wide-angle lens 2 can effectively shorten the total length of the lens, increase the angle of view, effectively correct aberrations, increase the resolution of the lens, and reduce the impact of temperature changes on the resolution of the lens.

Table 3 is a table of relevant parameters of each lens of the wide-angle lens 2 in Figure 3. The data in Table 3 shows that the effective focal length of the wide-angle lens 2 of the second embodiment is equal to 1.8287mm, the aperture value is equal to 2.0, the angle of view is equal to 173.9°, and the total lens length is equal to 18.000mm.

The concavity z of the aspheric surface of each lens in Table 3 is obtained by the following formula: z=ch ² /{1+[1-(k+1)c ² h ² ] ^1/2 }+Ah ⁴ +Bh ⁶ + Ch ⁸ +Dh ¹⁰

Among them: c: curvature; h: the vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~D: aspherical coefficient.

Table 4 is the relevant parameter table of the aspheric surface of each lens in Table 3, where k is the Conic Constant and A~D are the aspheric coefficients.

For the wide-angle lens 2 of the second embodiment, the seventh lens L27 has a radius of curvature of the object side S212 R2 ₇₁ = -3.07642mm, and the seventh lens L27 has a radius of curvature R2 ₇₂ of the image side S213 =4.61793mm. The fourth lens L24 is effective The focal length f2 ₄ =16.2755mm, the effective focal length of the wide-angle lens 2 is f2=1.8287mm, the sixth lens L26 and the seventh lens L27 are glued to form a cemented lens with the effective focal length f2 ₆₇ =-11.84770mm, and the Abbe number Vd2 of the fourth lens L24 ₄ = 23.8, the refractive index of the fourth lens L24 Nd2 ₄ =1.847, from the above data we can get (R2 ₇₁ -R2 ₇₂ )/(R2 ₇₁ +R2 ₇₂ )=-4.991, f2 ₄ /f2=8.900, f2 ₆₇ / f2=-6.479, Vd2 ₄ /Nd2 ₄ =12.876, all of which can meet the requirements of the above conditions (5) to (8).

In addition, the optical performance of the wide-angle lens 2 of the second embodiment can also meet the requirements, which can be seen from Figures 4A to 4C. Fig. 4A shows a longitudinal spherical aberration (Longitudinal Spherical Aberration) diagram of the wide-angle lens 2 of the second embodiment. Figure 4B shows the Astigmatic Field Curves diagram of the wide-angle lens 2 of the second embodiment. FIG. 4C shows a distortion (distortion) diagram of the wide-angle lens 2 of the second embodiment.

It can be seen from Fig. 4A that the wide-angle lens 2 of the second embodiment produces longitudinal spherical aberration values between -0.015mm and 0.008mm for light with wavelengths of 436.000nm, 546.000nm, and 656.000nm. It can be seen from Fig. 4B that the wide-angle lens 2 of the second embodiment has a light beam with a wavelength of 546.000nm, and the astigmatic field curvature in the Tangential direction and the Sagittal direction is between -0.04mm and 0.01mm. . It can be seen from FIG. 4C that the distortion of the wide-angle lens 2 of the second embodiment to light with a wavelength of 546.000 nm is between -100% and 0%. It is obvious that the longitudinal spherical aberration, astigmatic field curvature, and distortion of the wide-angle lens 2 of the second embodiment can be effectively corrected, thereby obtaining better optical performance.

Please refer to FIG. 5, which is a schematic diagram of the lens configuration and optical path of the third embodiment of the wide-angle lens according to the present invention. The wide-angle lens 3 includes a first lens L31, a second lens L32, a third lens L33, an aperture ST3, a fourth lens L34, and a fifth lens in order from an object side to an image side along an optical axis OA3. Lens L35, a sixth lens L36, a seventh lens L37, an eighth lens L38 and a filter OF3. When imaging, the light from the object side is finally imaged on an imaging surface IMA3. The first lens L31 is a meniscus lens with negative refractive power and is made of glass. The object side surface S31 is convex, the image side surface S32 is concave, and both the object side surface S31 and the image side surface S32 are spherical surfaces. The second lens L32 is a biconcave lens with negative refractive power made of glass material, the object side surface S33 is an aspheric surface, and the image side surface S34 is an aspheric surface. The third lens L33 is a biconvex lens with positive refractive power made of glass material, the object side surface S35 is a spherical surface, and the image side surface S36 is a spherical surface. The fourth lens L34 is a meniscus lens with negative refractive power and is made of glass. The object side surface S38 is convex and the image side surface S39 is concave. Both the object side surface S38 and the image side surface S39 are spherical surfaces. The fifth lens L35 is a double-convex lens with positive refractive power made of glass material, and the object side surface S39 and the image side surface S310 are both spherical surfaces. The fourth lens L34 and the fifth lens L35 are cemented into a cemented lens. The sixth lens L36 is a biconvex lens with positive refractive power made of glass material, and the object side surface S311 and the image side surface S312 are both spherical surfaces. The seventh lens L37 is a biconcave lens The object side surface S312 and the image side surface S313 are spherical surfaces. The sixth lens L36 and the seventh lens L37 are cemented into a cemented lens. The eighth lens L38 is a biconvex lens with positive refractive power made of glass material, and the object side surface S314 and the image side surface S315 are both aspherical surfaces. The object side S316 and the image side S317 of the filter OF3 are both flat.

In addition, in order for the wide-angle lens of the present invention to maintain good optical performance, the wide-angle lens 3 in the third embodiment needs to meet the following four conditions:

Among them, R3 ₇₁ is the curvature radius of the object side S312 of the seventh lens L37, R3 ₇₂ is the curvature radius of the image side S313 of the seventh lens L37, f3 ₄ is the effective focal length of the fourth lens L34, f3 is the effective focal length of the wide-angle lens 3 , f3 ₆₇ synthesis effective focal length of a lens of the cemented lens L36 to the sixth and the seventh lens L37 gum, Vd3 ₄ is the Abbe number of the fourth lens L34, Nd3 ₄ is the refractive index of the fourth lens L34.

Using the above-mentioned design of the lens and the aperture ST3, the wide-angle lens 3 can effectively shorten the total length of the lens, increase the angle of view, effectively correct aberrations, increase the resolution of the lens, and reduce the impact of temperature changes on the resolution of the lens.

Table 5 is a table of related parameters of each lens of the wide-angle lens 3 in Figure 5. The data in Table 5 shows that the effective focal length of the wide-angle lens 3 of the third embodiment is equal to 1.8325mm, the aperture value is equal to 2.0, the viewing angle is equal to 174.0°, and the total lens length is equal to 18.000mm.

The concavity z of the aspheric surface of each lens in Table 5 is obtained by the following formula: z=ch ² /{1+[1-(k+1)c ² h ² ] ^1/2 }+Ah ⁴ +Bh ⁶ + Ch ⁸ +Dh ¹⁰

among them: c: curvature; h: the vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~D: aspheric coefficient.

Table 6 is the relevant parameter table of the aspheric surface of each lens in Table 5, where k is the Conic Constant and A~D are the aspheric coefficients.

In the wide-angle lens 3 of the third embodiment, the seventh lens L37 has a radius of curvature of the object side S312 R3 ₇₁ = -4.91214mm, the seventh lens L37 has a radius of curvature R3 ₇₂ of the image side S313 =5.00930mm, and the fourth lens L34 is effective The focal length f3 ₄ = -20.0008mm, the effective focal length of the wide-angle lens 3 is f3=1.8325mm, the sixth lens L36 and the seventh lens L37 are glued together to form a cemented lens with the effective focal length f3 ₆₇ = -47.05990mm, the Abbe number of the fourth lens L34 Vd3 ₄ = 23.8, the refractive index of the fourth lens L34 Nd3 ₄ =1.847, from the above data we can get (R3 ₇₁ -R3 ₇₂ )/(R3 ₇₁ +R3 ₇₂ )=-102.115, f3 ₄ /f3=-10.915, f3 ₆₇ /f3=-25.681, Vd3 ₄ /Nd3 ₄ =12.876, all of which can meet the requirements of the above conditions (9) to (12).

In addition, the optical performance of the wide-angle lens 3 of the third embodiment can also meet the requirements, which can be seen from Figures 6A to 6C. FIG. 6A shows the Longitudinal Spherical Aberration diagram of the wide-angle lens 3 of the third embodiment. FIG. 6B shows the Astigmatic Field Curves diagram of the wide-angle lens 3 of the third embodiment. FIG. 6C shows a distortion (distortion) diagram of the wide-angle lens 3 of the third embodiment.

It can be seen from FIG. 6A that the wide-angle lens 3 of the third embodiment produces longitudinal spherical aberration values between -0.014 mm and 0.007 mm for light with wavelengths of 436.000 nm, 546.000 nm, and 656.000 nm. It can be seen from Fig. 6B that the wide-angle lens 3 of the third embodiment has a light beam with a wavelength of 546.000nm, and the astigmatic field curvature in the Tangential direction and the Sagittal direction is between -0.04mm and 0.01mm. . It can be seen from FIG. 6C that the distortion of the wide-angle lens 3 of the third embodiment to light with a wavelength of 546.000 nm is between -100% and 0%. It is obvious that the longitudinal spherical aberration, astigmatic field curvature, and distortion of the wide-angle lens 3 of the third embodiment can be effectively corrected, thereby obtaining better optical performance.

1: wide-angle lens

L11: first lens

L12: second lens

L13: third lens

L14: Fourth lens

L15: fifth lens

L16: sixth lens

L17: seventh lens

L18: Eighth lens

ST1: Aperture

OF1: filter

OA1: Optical axis

IMA1: imaging surface

S11, S12, S13, S14, S15: surface

S16, S17, S18, S19, S110: surface

S111, S112, S113, S114: surface

S115, S116, S117: surface

Claims (12)

A wide-angle lens, from an object side to an image side along an optical axis, includes: a first lens, the first lens having negative refractive power; a second lens, the second lens includes a concave surface, the concave surface facing the The object side has negative refractive power; a third lens, the third lens has positive refractive power; an aperture; a fourth lens, the fourth lens includes a convex surface, the convex surface facing the object side; a fifth lens, the first lens Five lenses have positive refractive power; a sixth lens, the sixth lens has positive refractive power; a seventh lens, the seventh lens has negative refractive power; and an eighth lens, the eighth lens has positive refractive power. According to the wide-angle lens described in claim 1, wherein the first lens is a meniscus lens with negative refractive power, and the convex surface of the first lens faces the object side and the concave surface faces the image side. The wide-angle lens described in item 1 of the scope of patent application, wherein the second lens is a biconcave lens. In the wide-angle lens described in item 3 of the scope of patent application, at least one of the third lens, the sixth lens and the eighth lens is a biconvex lens. According to the wide-angle lens described in claim 1, wherein the fifth lens includes a convex surface, and the convex surface faces the image side. The wide-angle lens described in item 1 of the scope of patent application, wherein the seventh lens is a biconcave lens. According to the wide-angle lens described in item 5 or 6, wherein the fourth lens and the fifth lens are cemented into a cemented lens or the sixth lens and the seventh lens are cemented into a cemented lens. The wide-angle lens described in item 5 of the scope of patent application, wherein the fourth lens satisfies the following conditions: -20

f ₄ /f

20 where f _{4 is} the effective focal length of the fourth lens, and f is the effective focal length of the wide-angle lens. The wide-angle lens described in item 1 of the scope of patent application, wherein the fourth lens satisfies the following conditions: 5

Vd ₄ /Nd ₄

50 where Vd _{4 is} the Abbe number of the fourth lens, and Nd _{4 is} the refractive index of the fourth lens. The wide-angle lens as described in item 1 of the scope of patent application, wherein the sixth lens and the seventh lens meet the following conditions: -30

f ₆₇ /f

-5 where f _{67 is} the effective focal length of the sixth lens and the seventh lens combined into a cemented lens, and f is the effective focal length of the wide-angle lens. The wide-angle lens described in item 1 of the scope of patent application, wherein the seventh lens satisfies the following conditions: -110

(R ₇₁ -R ₇₂ )/(R ₇₁ +R ₇₂ )

-1 where R _{71 is} the radius of curvature of the object side surface of the seventh lens, and R _{72 is} the radius of curvature of the image side surface of the seventh lens. The wide-angle lens described in the first item of the scope of patent application, wherein at least one of the second lens and the eighth lens is an aspherical surface.

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