TWI595260B - Lens assembly - Google Patents

Description

Imaging lens

The present invention relates to an imaging lens.

Digital cameras and mobile phones are constantly moving toward high-definition and lightweight, making the demand for miniaturization and high-resolution imaging lenses increasing. Most of the imaging lenses consisting of five lenses use a low Abbe number lens and four high Abbe number lenses, combined with a front aperture to achieve imaging lens miniaturization and improvement. The purpose of resolution. However, there are still improvements that still need to be improved, and an imaging lens with another architecture is needed to meet today's needs.

In view of this, the main object of the present invention is to provide an imaging lens whose lens length is short, but still has good optical performance, and the lens resolution can also meet the requirements.

The imaging lens of the present invention sequentially includes a first lens, a second lens, an aperture, a third lens, a fourth lens and a fifth lens from the object side to the image side along the optical axis. The first lens is a lenticular lens having a positive refractive power. The second lens has a convex-concave lens having a negative refractive power, and the convex surface of the second lens faces the object side concave surface toward the image side. The third lens has a convex-concave lens having a negative refractive power, and the convex surface of the third lens faces the object side concave surface toward the image side. The fourth lens has a positive refractive power of the meniscus lens, and the concave surface of the fourth lens faces the image side convex surface toward the image side. The fifth lens is a biconcave lens having a negative refractive power. The imaging lens satisfies the following condition: 1.10 < D _L1 / D _ST <10.90; wherein D _L1 is the effective diameter of the first lens, and D _ST is the effective diameter of the aperture.

The imaging lens satisfies the following condition: 1.10<D _L1 /D _L2 <1.35; wherein D _L1 is the effective diameter of the first lens, and D _L2 is the effective diameter of the second lens.

The Abbe Number of the first lens, the fourth lens, and the fifth lens is greater than the Abbe Number of the second lens and the third lens.

The imaging lens satisfies the following conditions: Vd ₁ >40, Vd ₂ <40, Vd ₃ <40, Vd ₄ >40, Vd ₅ >40; wherein Vd ₁ is the Abbe Number of the first lens, Vd ₂ is the Abbe Number of the second lens, Vd ₃ is the Abbe Number of the third lens, Vd ₄ is the Abbe Number of the fourth lens, and Vd ₅ is the fifth lens Abbe Number.

Wherein the first lens, the third lens and the fourth lens satisfy the following condition: -1.3<f/f ₃ +f/f ₄ -f/f ₁ <−0.1; wherein f is an effective focal length of the imaging lens, and f ₁ is The effective focal length of the first lens, f ₃ is the effective focal length of the third lens, and f ₄ is the effective focal length of the fourth lens.

The third lens and the fourth lens satisfy the following condition: -54.97<Vd ₄ -Vd ₃ <43.61; wherein Vd ₃ is the Abbe number of the third lens, and Vd ₄ is the Abbe number of the fourth lens (Abbe Number).

The imaging lens satisfies the following condition: 0.6<SL/TTL<0.87; wherein SL is the distance from the aperture to an imaging plane on the optical axis, and TTL is the distance from the object side of the first lens to the imaging plane on the optical axis.

The fourth lens is made of a glass material.

The first lens, the second lens, the third lens and the fifth lens are made of a plastic material.

The aperture includes a light aperture, and the diameter of the aperture can be changed to change the effective diameter of the aperture.

The imaging lens satisfies the following conditions: 1.4 F 13; where F is the aperture value (F-number) of the imaging lens.

The above described objects, features, and advantages of the invention will be apparent from the description and appended claims

1, 2, 3 ‧ ‧ imaging lens

L11, L21, L31‧‧‧ first lens

L12, L22, L32‧‧‧ second lens

L13, L23, L33‧‧‧ third lens

L14, L24, L34‧‧‧ fourth lens

L15, L25, L35‧‧‧ fifth lens

ST1, ST2, ST3‧‧ ‧ aperture

OF1, OF2, OF3‧‧‧ Filters

IMA1, IMA2, IMA3‧‧‧ imaging surface

OA1, OA2, OA3‧‧‧ optical axis

S11, S12, S13, S14, S15, S16, S17‧‧

S18, S19, S110, S111, S112, S113‧‧‧

S21, S22, S23, S24, S25, S26, S27‧‧

S28, S29, S210, S211, S212, S213‧‧‧

S31, S32, S33, S34, S35, S36, S37‧‧

S38, S39, S310, S311, S312, S313‧‧

1 is a schematic view showing a lens configuration and an optical path of a first embodiment of an imaging lens according to the present invention.

Fig. 2A is a field curvature diagram of the imaging lens of Fig. 1.

Fig. 2B is a distortion diagram of the imaging lens of Fig. 1.

Fig. 2C is a diagram of the modulation conversion function of the imaging lens of Fig. 1.

Fig. 3 is a schematic view showing a lens configuration and an optical path of a second embodiment of the imaging lens according to the present invention.

Fig. 4A is a field curvature diagram of the imaging lens of Fig. 3.

Fig. 4B is a distortion diagram of the imaging lens of Fig. 3.

Figure 4C is a diagram of the modulation transfer function of the imaging lens of Figure 3.

Fig. 5 is a view showing a lens configuration and an optical path of a third embodiment of the imaging lens according to the present invention.

Fig. 6A is a field curvature diagram of the imaging lens of Fig. 5.

Fig. 6B is a distortion diagram of the imaging lens of Fig. 5.

Fig. 6C is a diagram of the modulation conversion function of the imaging lens of Fig. 5.

Please refer to FIG. 1. FIG. 1 is a schematic view showing a lens configuration and an optical path of a first embodiment of an imaging lens according to the present invention. The imaging lens 1 sequentially includes a first lens L11, a second lens L12, an aperture ST1, a third lens L13, a fourth lens L14, and a fifth lens L15 from the object side to the image side along the optical axis OA1. And a filter OF1. At the time of imaging, the light from the object side is finally imaged on an image plane IMA1. The first lens L11 has a positive refractive power made of a plastic material, and the object side surface S11 has a convex image side surface S12 as a convex surface, and the object side surface S11 and the image side surface S12 are aspherical surfaces. The second lens L12 has a negative refractive power made of a plastic material, and the object side surface S13 has a convex image side surface S14 which is a concave surface, and the object side surface S13 and the image side surface S14 are aspherical surfaces. The third lens L13 has a negative refractive power made of a plastic material, and the object side surface S16 has a convex image side surface S17 which is a concave surface, and the object side surface S16 and the image side surface S17 are both aspherical surfaces. The fourth lens L14 has a positive refractive power made of a glass material, and the object side surface S18 has a concave image side surface S19 which is a convex surface, and the object side surface S18 and the image side surface S19 are aspherical surfaces. The fifth lens L15 has a negative refractive power made of a plastic material, and the object side surface S110 has a concave image side surface S111 which is a concave surface, and the object side surface S110 and the image side surface S111 are aspherical surfaces. Both the object side surface S112 and the image side surface S113 of the filter OF1 are flat. In the first embodiment, the Abbe coefficients of the first lens L11, the fourth lens L14, and the fifth lens L15 are larger than the Abbe coefficients of the second lens L12 and the third lens L13.

In addition, in order to maintain good optical performance of the imaging lens of the present invention, the imaging lens 1 of the first embodiment is required to satisfy the following eleven conditions:

1.10<D1 _L11 /D1 _ST1 <10.90 (1)

1.10<D1 _L11 /D1 _L12 <1.35 (2)

Vd1 ₁ >40 (3)

Vd1 ₂ <40 (4)

Vd1 ₃ <40 (5)

Vd1 ₄ >40 (6)

Vd1 ₅ >40 (7)

-1.3<f1/f1 ₃ +f1/f1 ₄ -f1/f1 ₁ <-0.1 (8)

-54.97<Vd1 ₄ -Vd1 ₃ <43.61 (9)

0.6<SL1/TTL1<0.87 (10)

Wherein D1 _L11 is the effective diameter of the first lens L11, D1 _L12 is the effective diameter of the second lens L12, D1 _ST1 is the effective diameter of the aperture ST1, and the effective diameter D1 _L11 of the first lens L11 is from the first lens L11 One edge passes through the linear length from the center point of the first lens L11 to the other edge, and the effective diameter D1 _L12 of the second lens L12 means from one edge of the second lens L12 through the center point of the second lens L12 to the other edge The linear length of the aperture ST1 and the effective diameter D1 _ST1 of the aperture ST1 refer to the diameter of a light aperture of the aperture ST1. Vd1 ₁ is the Abbe Number of the first lens L11, Vd1 ₂ is the Abbe Number of the second lens L12, and Vd1 ₃ is the Abbe Number of the third lens L13, Vd1 ₄ The Abbe Number of the fourth lens L14, Vd1 ₅ is the Abbe Number of the fifth lens L15, f1 is the effective focal length of the imaging lens 1, and f1 ₁ is the effective focal length of the first lens L11. F1 ₃ is the effective focal length of the third lens L13, f1 ₄ is the effective focal length of the fourth lens L14, SL1 is the distance from the aperture ST1 to the imaging plane IMA1 on the optical axis OA1, and TTL1 is the object side S11 of the first lens L11 to the imaging The distance of the face IMA1 on the optical axis OA1.

With the design of the above lens and aperture ST1, the imaging lens 1 can effectively shorten the total length of the lens, effectively correct aberrations, and improve lens resolution.

Table 1 is a table of related parameters of the lenses of the imaging lens 1 in Fig. 1. Table 1 shows that the effective focal length of the imaging lens 1 of the first embodiment is equal to 4.914 mm, the aperture value is equal to 1.6, and the total length of the lens is equal to 5.515 mm. Equal to 120°, the effective diameter of the first lens L11 is equal to 2.68 mm, the effective diameter of the second lens L12 is equal to 2.030 mm, and the effective diameter of the aperture ST1 is equal to 1.998 mm.

The aspherical surface depression z 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 +Eh ¹² +Fh ¹⁴ +Gh ¹⁶

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

Table 2 is a table of related parameters of the aspherical surface of each lens in Table 1, where k is a conical coefficient (Conic Constant) and A~G is an aspherical coefficient.

The imaging lens 1 of the first embodiment has an effective diameter D1 _{L11 of} the first lens L11 = 2.68 mm, an effective diameter D1 _{L12 of the} second lens _L12 = 2.030 mm, and an effective diameter D1 _{ST1 of the} aperture _ST1 = 1.998 mm, the first lens The Abbe Number of V11 is Vd1 ₁ = 56.1, the Abbe Number of the second lens L12 is Vd1 ₂ = 21.5, and the Abbe Number of the third lens L13 is Vd1 ₃ = 21.5, and the fourth The Abbe Number of the lens L14 is Vd1 ₄ = 40.3, the Abbe Number of the fifth lens L15 is Vd1 ₅ = 56.1, the effective focal length of the imaging lens 1 is f1 = 4.914 mm, and the effective focal length of the first lens L11 F1 ₁ =3.0183 mm, the effective focal length f1 _{3 of the} third lens L13 is -13.9211 mm, the effective focal length of the fourth lens L14 is f1 ₄ =3.9326 mm, and the distance from the aperture ST1 to the imaging plane IMA1 on the optical axis OA1 is SL1=3.778 mm The distance from the object side surface S11 of the first lens L11 to the imaging surface IMA1 on the optical axis OA1 is TTL1=5.515 mm, and D1 _L11 /D1 _ST1 =1.34, D1 _L11 /D1 _L12 =1.32, Vd1 ₁ =56.1 can be obtained from the above data. , Vd1 ₂ = 21.5, Vd1 ₃ = 21.5, Vd1 ₄ = 40.3, Vd1 ₅ = 56.1, f1/f1 ₃ + f1/f1 _{4 -} f1/f1 ₁ = -0.7314, Vd1 _{4 -} Vd1 ₃ = 18.8, SL1/TTL1 =0 .685 and F1=1.6 can satisfy the requirements of the above conditions (1) to (11).

In addition, the optical performance of the imaging lens 1 of the first embodiment can also be achieved, which can be seen from the 2A to 2C drawings. 2A is a Field Curvature diagram of the imaging lens 1 of the first embodiment. Fig. 2B is a distortion diagram of the imaging lens 1 of the first embodiment. 2C is a modulation transfer function diagram of the imaging lens 1 of the first embodiment.

As can be seen from FIG. 2A, the imaging lens 1 of the first embodiment has a field of the Tangential direction and the Sagittal direction of the light having a wavelength of 0.435 μm, 0.555 μm, and 0.650 μm, which is between -0.16. Between mm and 0.06 mm. As can be seen from FIG. 2B, the imaging lens 1 of the first embodiment has a distortion of between 0.0% and 1.4% for light having a wavelength of 0.435 μm, 0.555 μm, and 0.650 μm. As can be seen from FIG. 2C, the imaging lens 1 of the first embodiment has a wavelength range of 0.435 μm to 0.650 μm in the direction of the Tangential direction and the Sagittal direction, respectively, and the field of view height is 0.000. Mm, 0.6864mm, 1.3728mm, 2.4024mm, 3.4320mm, the spatial frequency is between 0lp/mm and 446lp/mm, and the modulation transfer function value is between 0.0 and 1.0. It can be seen that the field curvature and distortion of the imaging lens 1 of the first embodiment can be effectively corrected, and the lens resolution can also meet the requirements, thereby obtaining better optical performance.

In the above first embodiment, when the effective diameter of the aperture ST1 is changed to be 2.340 mm, 1.458 mm, 0.954 mm, and 0.246 mm, the aperture values of the imaging lens 1 are changed to 1.4, 2.4, 3.4, and 13, respectively. The relative value of D1 _L11 /D1 _ST1 is equal to 2.68/0.246=10.894, and the minimum value is equal to 2.68/2.348=1.141, which can meet the requirements of the above condition (1), and can control imaging by changing the effective diameter of the aperture ST1. The amount of light entering the lens 1 changes the illumination of the imaging surface IMA1. On the other hand, changing the effective diameter of the aperture ST1 can control the depth of field. When the effective diameter of the aperture ST1 is larger, the depth of field is shallower, and the smaller the effective diameter of the aperture ST1, the deeper the depth of field.

Please refer to FIG. 3, which is a schematic diagram of a lens configuration and an optical path of a second embodiment of an imaging lens according to the present invention. The imaging lens 2 sequentially includes a first lens L21, a second lens L22, an aperture ST2, a third lens L23, a fourth lens L24, and a fifth lens L25 from the object side to the image side along the optical axis OA2. And a filter OF2. At the time of imaging, the light from the object side is finally imaged on an image plane IMA2. The first lens L21 has a positive refractive power made of a plastic material, and the object side surface S21 has a convex image side surface S22 as a convex surface, and the object side surface S21 and the image side surface S22 are aspherical surfaces. The second lens L22 has a negative refractive power made of a plastic material, and the object side surface S23 has a convex surface side surface S24 which is a concave surface, and the object side surface S23 and the image side surface S24 are aspherical surfaces. The third lens L23 has a negative refractive power made of a plastic material, and the object side surface S26 has a convex image side surface S27 which is a concave surface, and the object side surface S26 and the image side surface S27 are both aspherical surfaces. The fourth lens L24 has a positive refractive power made of a glass material, and the object side surface S28 has a concave image side surface S29 as a convex surface, and the object side surface S28 and the image side surface S29 are aspherical surfaces. The fifth lens L25 has a negative refractive power made of a plastic material, and the object side surface S210 has a concave image side surface S211 as a concave surface, and the object side surface S210 and the image side surface S211 are aspherical surfaces. Both the object side surface S212 and the image side surface S213 of the filter OF2 are flat. in In the second embodiment, the Abbe coefficients of the first lens L21, the fourth lens L24, and the fifth lens L25 are larger than the Abbe coefficients of the second lens L22 and the third lens L23.

In addition, in order to maintain good optical performance of the imaging lens of the present invention, the imaging lens 2 of the second embodiment is required to satisfy the following eleven conditions:

1.10<D2 _L21 /D2 _ST2 <10.90 (12)

1.10<D2 _L21 /D2 _L22 <1.35 (13)

Vd2 ₁ >40 (14)

Vd2 ₂ <40 (15)

Vd2 ₃ <40 (16)

Vd2 ₄ >40 (17)

Vd2 ₅ >40 (18)

-1.3<f2/f2 ₃ +f2/f2 ₄ -f2/f2 ₁ <-0.1 (19)

-54.97<Vd2 ₄ -Vd2 ₃ <43.61 (20)

0.6<SL2/TTL2<0.87 (21)

Wherein D2 _L21 is the effective diameter of the first lens L21, D2 _L22 is the effective diameter of the second lens L22, D2 _ST2 is the effective diameter of the aperture ST2, and the effective diameter D2 _L21 of the first lens L21 is from the first lens L21 One edge passes through the linear length from the center point of the first lens L21 to the other edge, and the effective diameter D2 _L22 of the second lens L22 means from one edge of the second lens L22 through the center point of the second lens L22 to the other edge The linear length of the aperture ST2 and the effective diameter D2 _ST2 of the aperture ST2 refer to the diameter of a light aperture of the aperture ST2. Vd2 ₁ is the Abbe Number of the first lens L21, Vd2 ₂ is the Abbe Number of the second lens L22, and Vd2 ₃ is the Abbe Number of the third lens L23, Vd2 ₄ It is the Abbe Number of the fourth lens L24, Vd2 ₅ is the Abbe Number of the fifth lens L25, f2 is the effective focal length of the imaging lens 2, and f2 ₁ is the effective focal length of the first lens L21. F2 ₃ is the effective focal length of the third lens L23, f2 ₄ is the effective focal length of the fourth lens L24, SL2 is the distance from the aperture ST2 to the imaging plane IMA2 on the optical axis OA2, and TTL2 is the object side S21 of the first lens L21 to imaging The distance of the face IMA2 on the optical axis OA2.

The design of the lens and the aperture ST2 described above enables the imaging lens 2 to effectively shorten the total length of the lens, effectively correct aberrations, and improve lens resolution.

Table 3 is a table of related parameters of the lenses of the imaging lens 2 in FIG. 3, and Table 3 shows that the effective focal length of the imaging lens 2 of the second embodiment is equal to 4.837 mm, the aperture value is equal to 1.6, the total length of the lens is equal to 5.493 mm, and the viewing angle is Equal to 120°, the effective diameter of the first lens L21 is equal to 2.74 mm, the effective diameter of the second lens L22 is equal to 2.314 mm, and the effective diameter of the aperture ST2 is equal to 2.052 mm.

The aspherical surface depression z 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 +Eh ¹² +Fh ¹⁴ +Gh ¹⁶

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

Table 4 is the relevant parameter table of the aspherical surface of each lens in Table 3, where k It is a conical coefficient (Conic Constant) and A~G is an aspheric coefficient.

The imaging lens 2 of the second embodiment has an effective diameter D2 _{L21 of} the first lens L21 = 2.74 mm, an effective diameter D2 _{L22 of the} second lens _L22 = 2.314 mm, and an effective diameter D2 _{ST2 of the} aperture _ST2 = 2.052 mm of the first lens L21 Abbe Number Vd2 ₁ = 56.1, Abbe Number of the second lens L22 Vd2 ₂ = 21.5, Abbe Number of the third lens L23 Vd2 ₃ = 35, fourth lens The Abbe Number of L24 is Vd2 ₄ = 50, the Abbe Number of the fifth lens L25 is Vd2 ₅ = 56.1, the effective focal length of the imaging lens 2 is f2 = 4.837 mm, and the effective focal length f2 of the first lens L21 ₁ = 3.0152 mm, the effective focal length of the third lens L23 is f2 ₃ = -14.3156 mm, the effective focal length of the fourth lens L24 is f2 ₄ = 3.9271 mm, and the distance from the aperture ST2 to the imaging plane IMA2 on the optical axis OA2 is SL2 = 3.997 mm. The distance from the object side surface S21 of the first lens L21 to the imaging surface IMA2 on the optical axis OA2 is TTL2=5.493 mm, and D2 _L21 /D2 _ST2 =1.34, D2 _L21 /D2 _L22 =1.18, Vd2 ₁ =56.1, can be obtained from the above data. Vd2 ₂ = 21.5, Vd2 ₃ = 35, Vd2 ₄ = 50, Vd2 ₅ = 56.1, f2 / f2 ₃ + f2 / f2 _{4 -} f2 / f2 ₁ = -0.71, Vd2 _{4 -} Vd2 ₃ = 15, SL2 / TTL2 = 0.709, F2=1.6 It can meet the requirements of the above conditions (12) to (22).

In addition, the optical performance of the imaging lens 2 of the second embodiment can also be achieved, which can be seen from Figs. 4A to 4C. Fig. 4A is a field curvature diagram of the imaging lens 2 of the second embodiment. Fig. 4B is a distortion diagram of the imaging lens 2 of the second embodiment. 4C is a modulation transfer function diagram of the imaging lens 2 of the second embodiment.

As can be seen from FIG. 4A, the imaging lens 2 of the second embodiment has a meridional direction and a sagittal direction field curvature of -0.020 for light having a wavelength of 0.470 μm, 0.555 μm, and 0.650 μm. Between mm and 0.035 mm. As can be seen from Fig. 4B, the imaging lens 2 of the second embodiment has a distortion of between 0.0% and 0.6% for light having a wavelength of 0.470 μm, 0.555 μm, and 0.650 μm. As can be seen from FIG. 4C, the imaging mirror of the second embodiment The first two pairs of light having a wavelength range of 0.470 μm to 0.650 μm are respectively in the direction of the tangential direction and the Sagittal direction, and the field of view heights are 0.000 mm, 0.6864 mm, 1.3728 mm, 2.4024 mm, and 3.4320 mm, respectively. The spatial frequency is between 0 lp/mm and 446 lp/mm, and the modulation transfer function value is between 0.0 and 1.0. It can be seen that the field curvature and distortion of the imaging lens 2 of the second embodiment can be effectively corrected, and the lens resolution can also meet the requirements, thereby obtaining better optical performance.

In the second embodiment described above, when the effective diameter of the aperture ST2 is changed to be 2.222 mm, 1.41 mm, 0.98 mm, and 0.252 mm, the aperture values of the imaging lens 2 are changed to 1.4, 2.4, 3.4, and 13, respectively. The relative value of D2 _L21 /D2 _ST2 is equal to 2.74/0.252=10.873, and the minimum value is equal to 2.74/2.222=1.233, which can meet the requirements of the above condition (12). By changing the effective diameter of the aperture ST2, the imaging can be controlled. The amount of light entering the lens 2 causes the illumination of the imaging surface IMA2 to change. On the other hand, changing the effective diameter of the aperture ST2 can control the depth of field. When the effective diameter of the aperture ST2 is larger, the depth of field is shallower, and the smaller the effective diameter of the aperture ST2, the deeper the depth of field.

Please refer to FIG. 5, which is a schematic diagram of a lens configuration and an optical path of a third embodiment of an imaging lens according to the present invention. The imaging lens 3 sequentially includes a first lens L31, a second lens L32, an aperture ST3, a third lens L33, a fourth lens L34, and a fifth lens L35 from the object side to the image side along the optical axis OA3. And a filter OF3. At the time of imaging, the light from the object side is finally imaged on an image plane IMA3. The first lens L31 has a positive refractive power made of a plastic material, and the object side surface S31 has a convex image side surface S32 as a convex surface, and the object side surface S31 and the image side surface S32 are aspherical surfaces. The second lens L32 has a negative refractive power made of a plastic material, and the object side surface S33 has a convex image side surface S34 as a concave surface, and the object side surface S33 and the image side surface S34 are aspherical surfaces. The third lens L33 has a negative refractive power made of a plastic material, and the object side surface S36 is a convex image side surface S37. For the concave surface, both the object side surface S36 and the image side surface S37 are aspherical surfaces. The fourth lens L34 has a positive refractive power made of a glass material, and the object side surface S38 has a concave image side surface S39 as a convex surface, and the object side surface S38 and the image side surface S39 are aspherical surfaces. The fifth lens L35 has a negative refractive power made of a plastic material, and the object side surface S310 has a concave image side surface S311 as a concave surface, and the object side surface S310 and the image side surface S311 are aspherical surfaces. Both the object side surface S312 and the image side surface S313 of the filter OF3 are flat. In the third embodiment, the Abbe coefficients of the first lens L31, the fourth lens L34, and the fifth lens L35 are larger than the Abbe coefficients of the second lens L32 and the third lens L33.

In addition, in order to maintain good optical performance of the imaging lens of the present invention, the imaging lens 3 of the third embodiment is required to satisfy the following eleven conditions:

1.10<D3 _L31 /D3 _ST3 <10.90 (23)

1.10<D3 _L31 /D3 _L32 <1.35 (24)

Vd3 ₁ >40 (25)

Vd3 ₂ <40 (26)

Vd3 ₃ <40 (27)

Vd3 ₄ >40 (28)

Vd3 ₅ >40 (29)

-1.3<f3/f3 ₃ +f3/f3 ₄ -f3/f3 ₁ <-0.1 (30)

-54.97<Vd3 ₄ -Vd3 ₃ <43.61 (31)

0.6<SL3/TTL3<0.87 (32)

Wherein D3 _L31 is the effective diameter of the first lens L31, D3 _L32 is the effective diameter of the second lens L32, D3 _ST3 is the effective diameter of the aperture ST3, and the effective diameter D3 _L31 of the first lens L31 is from the first lens L31. One edge passes through the linear length from the center point of the first lens L31 to the other edge, and the effective diameter D3 _L32 of the second lens L32 means from one edge of the second lens L32 through the center point of the second lens L32 to the other edge The length of the straight line, and the effective diameter D3 _ST3 of the aperture ST3 refers to the diameter of a light hole of the aperture ST3. Vd3 ₁ is the Abbe Number of the first lens L31, Vd3 ₂ is the Abbe Number of the second lens L32, and Vd3 ₃ is the Abbe Number of the third lens L33, Vd3 ₄ It is the Abbe Number of the fourth lens L34, Vd3 ₅ is the Abbe Number of the fifth lens L35, f3 is the effective focal length of the imaging lens 3, and f3 ₁ is the effective focal length of the first lens L31. F3 ₃ is the effective focal length of the third lens L33, f3 ₄ is the effective focal length of the fourth lens L34, SL3 is the distance from the aperture ST3 to the imaging plane IMA3 on the optical axis OA3, and TTL3 is the object side S31 of the first lens L31 to imaging The distance of the face LMA3 on the optical axis OA3.

The design of the lens and the aperture ST3 described above enables the imaging lens 3 to effectively shorten the total length of the lens, effectively correct aberrations, and improve lens resolution.

Table 5 is a table of related parameters of the lenses of the imaging lens 3 in FIG. 5. Table 5 shows that the effective focal length of the imaging lens 3 of the third embodiment is equal to 4.885 mm, the aperture value is equal to 1.6, and the total length of the lens is 5.494 mm. Equal to 120°, the effective diameter of the first lens L31 is equal to 2.59 mm, the effective diameter of the second lens L32 is equal to 2.268 mm, and the effective diameter of the aperture ST3 is equal to 2.084 mm.

The aspherical surface depression z 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 +Eh ¹² +Fh ¹⁴ +Gh ¹⁶

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

Table 6 is the relevant parameter table of the aspherical surface of each lens in Table 5, where k is the conic coefficient (Conic Constant) and A~G is the aspherical coefficient.

The imaging lens 3 of the third embodiment has an effective diameter D3 _{L31 of} the first lens L31 = 2.59 mm, an effective diameter D3 _{L32 of the} second lens _L32 = 2.268 mm, and an effective diameter D3 _{ST3 of the} aperture _ST3 = 2.084 mm, the first lens The Abbe Number of L31 is Vd3 ₁ = 56.1, the Abbe Number of the second lens L32 is Vd3 ₂ = 21.5, and the Abbe Number of the third lens L33 is Vd3 ₃ = 21.5, and the fourth The Abbe Number of the lens L34 is Vd3 ₄ = 60, the Abbe Number of the fifth lens L35 is Vd3 ₅ = 56.1, the effective focal length of the imaging lens 3 is f3 = 4.885 mm, and the effective focal length of the first lens L31 F3 ₁ = 3.017 mm, effective focal length f3 _{3 of the} third lens L33 = -14.362 mm, effective focal length f3 _{4 of the} fourth lens L34 = 3.913 mm, distance from the aperture ST3 to the imaging plane IMA3 on the optical axis OA3 SL3 = 3.911 mm The distance from the object side surface S31 of the first lens L31 to the imaging surface IMA3 on the optical axis OA3 is TTL3=5.494 mm, and D3 _L31 /D3 _ST3 =1.24, D3 _L31 /D3 _L32 =1.14, Vd3 ₁ =56.1 can be obtained from the above data. , Vd3 ₂ = 21.5, Vd3 ₃ = 21.5, Vd3 ₄ = 60, Vd3 ₅ = 56.1, f3 / f3 ₃ + f3 / f3 _{4 -} f3 / f3 ₁ = -0.7111, Vd3 _{4 -} Vd3 ₃ = 38.5, SL3 / TTL3 =0.711, F 3 = 1.6 can meet the requirements of the above conditions (23) to (33).

Further, the optical performance of the imaging lens 3 of the third embodiment can also be achieved, which can be seen from Figs. 6A to 6C. Fig. 6A is a field curvature diagram of the imaging lens 3 of the third embodiment. Fig. 6B is a distortion diagram of the imaging lens 3 of the third embodiment. FIG. 6C is a modulation conversion of the imaging lens 3 of the third embodiment. Modulation Transfer Function diagram.

As can be seen from FIG. 6A, the imaging lens 3 of the third embodiment has a field of the Tangential direction and the sagittal direction of the light having a wavelength of 0.470 μm, 0.555 μm, and 0.650 μm between -0.04. Between mm and 0.06 mm. As can be seen from Fig. 6B, the distortion of the imaging lens 3 of the third embodiment for light having a wavelength of 0.470 μm, 0.555 μm, and 0.650 μm is between -0.2% and 0.4%. As can be seen from Fig. 6C, the imaging lens 3 of the third embodiment has a wavelength range of 0.470 μm to 0.650 μm in the direction of the Tangential direction and the Sagittal direction, respectively, and the field of view height is 0.000. Mm, 0.6864mm, 1.3728mm, 2.4024mm, 3.4320mm, the spatial frequency is between 0lp/rmm and 446lp/mm, and the modulation transfer function value is between 0.0 and 1.0. It can be seen that the field curvature and distortion of the imaging lens 3 of the third embodiment can be effectively corrected, and the lens resolution can also meet the requirements, thereby obtaining better optical performance.

In the third embodiment described above, when the effective diameter of the aperture ST3 is changed to be 2.258 mm, 1.344 mm, 0.996 mm, and 0.256 mm, the aperture values of the imaging lens 3 are changed to 1.4, 2.4, 3.4, and 13, respectively. The relative value of D3 _L31 /D3 _ST3 is equal to 2.59/0.256=10.117, and the minimum value is equal to 2.59/2.258=1.147, which can meet the requirements of the above condition (23). By changing the effective diameter of the aperture ST1, the imaging can be controlled. The amount of light entering the lens 1 changes the illumination of the imaging surface IMA1. On the other hand, changing the effective diameter of the aperture ST1 can control the depth of field. When the effective diameter of the aperture ST1 is larger, the depth of field is shallower, and the smaller the effective diameter of the aperture ST1, the deeper the depth of field.

1‧‧‧ imaging lens

L11‧‧‧ first lens

L12‧‧‧ second lens

L13‧‧‧ third lens

L14‧‧‧4th lens

L15‧‧‧ fifth lens

ST1‧‧‧ aperture

OF1‧‧‧Filter

OA1‧‧‧ optical axis

IMA1‧‧‧ imaging surface

S11, S12, S13, S14, S15‧‧

S16, S17, S18, S19, S110‧‧‧

S111, S112, S113‧‧‧

Claims (11)

An imaging lens includes, in order from the object side to the image side along the optical axis, a first lens having a positive refractive power and a second lens having a negative refractive power, wherein the second lens has a negative refractive power. The convex surface of the second lens faces the object side concave surface toward the image side; an aperture; a third lens, wherein the third lens has a convex-concave lens having a negative refractive power, and the convex surface of the third lens faces the object side concave surface toward the image side a fourth lens, the fourth lens having a positive refractive power, a concave surface of the fourth lens facing the object side convex surface toward the image side; and a fifth lens having a negative refractive power of the double concave lens; Wherein the imaging lens satisfies the following condition: 1.10<D _L1 /D _ST <10.90 wherein D _{L1 is} the effective diameter of the first lens, and D _ST is the effective diameter of the aperture. The imaging lens of claim 1, wherein the imaging lens satisfies the following condition: 1.10<D _L1 /D _L2 <1.35 wherein D _L1 is an effective diameter of the first lens, and D _{L2 is} the second lens Effective diameter. The imaging lens of claim 1, wherein an Abbe Number of the first lens, the fourth lens, and the fifth lens is greater than an Abbe number of the second lens and the third lens (Abbe Number). The imaging lens of claim 1, wherein the imaging lens satisfies the following condition: Vd ₁ >40 Vd ₂ <40 Vd ₃ <40 Vd ₄ >40 Vd ₅ >40, wherein Vd _{1 is} the first lens Abbe Number, Vd _{2 is} the Abbe Number of the second lens, Vd _{3 is} the Abbe Number of the third lens, and Vd _{4 is} the fourth lens Abbe Number, Vd _{5 is} the Abbe Number of the fifth lens. The imaging lens of claim 1, wherein the first lens, the third lens, and the fourth lens satisfy the following condition: -1.3 < f / f ₃ + f / f ₄ - f / f ₁ < -0.1 where f is the effective focal length of the imaging lens, f _{1 is} the effective focal length of the first lens, f _{3 is} the effective focal length of the third lens, and f _{4 is} the effective focal length of the fourth lens. The imaging lens of claim 1, wherein the third lens and the fourth lens satisfy the following condition: -54.97 < Vd ₄ - Vd ₃ < 43.61 wherein Vd _{3 is} the Abbe coefficient of the third lens (Abbe Number), Vd _{4 is} the Abbe Number of the fourth lens. The imaging lens of claim 1, wherein the imaging lens satisfies the following condition: 0.6 <SL/TTL<0.87, wherein SL is the distance from the aperture to an imaging surface on the optical axis, and the TTL is the first The distance from the side of a lens to the imaging surface on the optical axis. The imaging lens of claim 1, wherein the fourth lens is made of a glass material. The imaging lens of claim 1, wherein the first lens, the second lens, the third lens, and the fifth lens are made of a plastic material. The imaging lens of claim 1, wherein the aperture comprises a light aperture, the diameter of the aperture being sized to vary the effective diameter of the aperture. The imaging lens of claim 10, wherein the imaging lens satisfies the following conditions: 1.4 F 13 where F is the aperture value (F-number) of the imaging lens.