TWI556004B - Lens assembly - Google Patents

Description

Imaging lens

The present invention relates to an imaging lens.

The continuous development of digital cameras and hands to high-definition and lightweight, so that the demand for miniaturization and high-resolution lens modules has increased. The lens module consisting of the conventional six-lens lens is still not perfect, and there is still much room for improvement. Another lens module with a new architecture is needed to meet the needs of today's miniaturization and high resolution.

In view of this, the main object of the present invention is to provide an imaging lens which has a short total lens length and a large viewing angle, 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, a third lens, a fourth lens, a fifth lens and a sixth lens from the object side to the image side along the optical axis. The first lens has a negative refractive power and includes a concave surface that faces the image side. The second lens is a lenticular lens having a positive refractive power. The third lens has a negative refractive power and includes a concave surface that faces the object side. The fourth lens is a lenticular lens having a positive refractive power. The fifth lens has a positive refractive power of the meniscus lens, the concave surface of the fifth lens faces the object side, and the convex surface faces the image side. The sixth lens has a negative refractive power and includes a convex surface that faces the object side.

The first lens may further include a convex surface facing the object side, and the third lens may further include a concave surface facing the image side, and the sixth lens may further include a concave surface facing the image side.

The imaging lens satisfies the following conditions: 0.4 f/TTL 0.5; where f is the effective focal length of the imaging lens, and TTL is the distance from the object side of the first lens to the imaging plane on the optical axis.

The first lens and the sixth lens satisfy the following conditions: 2 f ₁ /f ₆ 5; wherein f ₁ is the effective focal length of the first lens, and f ₆ is the effective focal length of the sixth lens.

Wherein the second lens satisfies the following conditions: -3 (R ₂₁ -R ₂₂ )/(R ₂₁ +R ₂₂ ) -1; wherein R ₂₁ is the radius of curvature of the object side surface of the second lens, and R ₂₂ is the radius of curvature of the image side surface of the second lens.

The third lens satisfies the following conditions: 2 (R ₃₁ -R ₃₂ )/(R ₃₁ +R ₃₂ ) 5; wherein R ₃₁ is a radius of curvature of an object side surface of the third lens, and R ₃₂ is a radius of curvature of an image side surface of the third lens.

The fourth lens satisfies the following conditions: 2 (R ₄₁ -R ₄₂ )/(R ₄₁ +R ₄₂ ) 20; wherein R ₄₁ is a radius of curvature of an object side surface of the fourth lens, and R ₄₂ is a curvature radius of an image side surface of the fourth lens.

The fifth lens satisfies the following conditions: 0.1 (R ₅₁ -R ₅₂ )/(R ₅₁ +R ₅₂ ) 1; wherein R ₅₁ is a radius of curvature of an object side surface of the fifth lens, and R ₅₂ is a radius of curvature of an image side surface of the fifth lens.

Wherein the first lens satisfies the following condition: 2.19<|f ₁ /f|<2.74; wherein f ₁ is an effective focal length of the first lens, and f is an effective focal length of the imaging lens.

Wherein the second lens satisfies the following condition: 0.53<|f ₂ /f|<1.03; wherein f ₂ is an effective focal length of the second lens, and f is an effective focal length of the imaging lens.

The third lens satisfies the following condition: 0.72<|f ₃ /f|<1.37; wherein f ₃ is the effective focal length of the third lens, and f is the effective focal length of the imaging lens.

The fourth lens satisfies the following condition: 0.54<|f ₄ /f|<1.19; wherein f4 is the effective focal length of the fourth lens, and f is the effective focal length of the imaging lens.

The imaging lens satisfies the following condition: 5.15<|TTL/BFL|<5.65; wherein TTL is the distance from the object side of the first lens to an imaging surface on the optical axis, and the BFL is the image side of the sixth lens to the imaging surface. The distance on the optical axis. .

The imaging lens of the present invention may further include an aperture disposed between the first lens and the third lens.

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

1, 2, 3, 4 ‧ ‧ imaging lens

L11, L21, L31, L41‧‧‧ first lens

L12, L22, L32, L42‧‧‧ second lens

L13, L23, L33, L43‧‧‧ third lens

L14, L24, L34, L44‧‧‧ fourth lens

L15, L25, L35, L45‧‧‧ fifth lens

L16, L26, L36, L46‧‧‧ sixth lens

ST1, ST2, ST3, ST4‧‧ ‧ aperture

OF1, OF2, OF3, OF4‧‧‧ Filters

IMA1, IMA2, IMA3, IMA4‧‧‧ imaging surface

OA1, OA2, OA3, OA4‧‧‧ optical axis

S11, S12, S13, S14, S15, S16, S17‧‧

S18, S19, S110, S111, S112, S113‧‧‧

S114, S115‧‧‧ face

S21, S22, S23, S24, S25, S26, S27‧‧

S28, S29, S210, S211, S212, S213‧‧‧

S214, S215‧‧‧

S31, S32, S33, S34, S35, S36, S37‧‧

S38, S39, S310, S311, S312, S313‧‧

S314, S315‧‧‧

S41, S42, S43, S44, S45, S46, S47‧‧

S48, S49, S410, S411, S412, S413‧‧

S414, S415‧‧‧

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 longitudinal spherical aberration diagram of the imaging lens of Fig. 1.

Fig. 2B is an astigmatic field curvature diagram of the imaging lens of Fig. 1.

Fig. 2C is a distortion diagram 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 longitudinal spherical aberration diagram of the imaging lens of Fig. 3.

Fig. 4B is an astigmatic field curvature diagram of the imaging lens of Fig. 3.

Fig. 4C is a distortion diagram of the imaging lens of Fig. 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 longitudinal spherical aberration diagram of the imaging lens of Fig. 5.

Fig. 6B is an astigmatic field curvature diagram of the imaging lens of Fig. 5.

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

Fig. 7 is a schematic view showing the lens configuration of a fourth embodiment of the imaging lens according to the present invention.

Fig. 8A is a longitudinal aberration diagram of the imaging lens of Fig. 7.

Fig. 8B is a field curvature diagram of the imaging lens of Fig. 7.

Fig. 8C is a distortion diagram of the imaging lens of Fig. 7.

Fig. 8D is a lateral chromatic aberration diagram of the imaging lens of Fig. 7.

Fig. 8E is a modulation transfer function diagram of the imaging lens of Fig. 7.

Fig. 8F is a diagram showing the defocus modulation conversion function of the imaging lens of Fig. 7.

Fig. 8G is a comparison diagram of the imaging lens of Fig. 7.

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. At the time of imaging, the light from the object side is finally imaged on an image plane IMA1. 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. a sixth lens L16 and a filter OF1. The first lens L11 is a convex-concave lens having a negative refractive power made of a plastic material, the object side surface S11 is a convex surface, the image side surface S12 is a concave surface, and the object side surface S11 and the image side surface S12 are both aspherical surfaces. The second lens L12 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S13 and the image side surface S14 are aspherical surfaces. The third lens L13 is a biconcave lens having a negative refractive power made of a plastic material, and both the object side surface S16 and the image side surface S17 are aspherical surfaces. The fourth lens L14 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S18 and the image side surface S19 are aspherical surfaces. The fifth lens L15 is a meniscus lens having a positive refractive power made of a plastic material, and the object side surface S110 is a concave surface, the image side surface S111 is a convex surface, and the object side surface S110 and the image side surface S111 are aspherical surfaces. The sixth lens L16 is a convex-concave lens having a negative refractive power made of a plastic material, and the object side surface S112 is a convex surface, like the side surface S113 is a concave surface, and both the object side surface S112 and the image side surface S113 are aspherical surfaces. The filter OF1 has a flat surface S114 and an image side surface S115.

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 six conditions:

Wherein, f1 is the effective focal length of the imaging lens 1, TTL1 object side surface of the first lens L11 is a distance of S11 to the image plane on the optical axis OA1 of IMA1, f1 is the effective focal _{length. 1} of a first lens L11, f1 is the sixth _{lens. 6} The effective focal length of L16, R1 ₂₁ is the radius of curvature of the object side surface S13 of the second lens L12, R1 ₂₂ is the radius of curvature of the image side surface S14 of the second lens L12, and R1 ₃₁ is the radius of curvature of the object side surface S16 of the third lens L13. R1 ₃₂ is the radius of curvature of the image side surface S17 of the third lens L13, R1 ₄₁ is the radius of curvature of the object side surface S18 of the fourth lens L14, R1 ₄₂ is the radius of curvature of the image side surface S19 of the fourth lens L14, and R1 ₅₁ is the fifth radius. The radius of curvature of the object side surface S110 of the lens L15, and R1 ₅₂ is the radius of curvature of the image side surface S111 of the fifth lens L15.

The design of the lens and the aperture ST1 described above enables the imaging lens 1 to effectively shorten the total length of the lens, improve the viewing angle, 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 1.7974 mm, the aperture value is equal to 2.4, the viewing angle is equal to 80°, and the total length of the lens Equal to 4.198mm.

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 focal length f1=1.7974 mm, a distance TTL1=4.198 mm from the object side surface S11 of the first lens L11 to the imaging plane IMA1 on the optical axis OA1, and an effective focal length f1 _{1 of the} first lens L11. -3.35650 mm, the effective focal length of the sixth lens L16 is f1 ₆ = -1.27358 mm, the radius of curvature of the object side surface S13 of the second lens L12 is R1 ₂₁ = 1.02552 mm, and the radius of curvature of the image side surface S14 of the second lens L12 is R1 ₂₂ = - 4.00000mm, the radius of curvature R1 ₃₁ = -4.000000mm of the object side surface S16 of the third lens L13, the curvature radius R1 ₃₂ of the image side surface S17 of the third lens L13 = 1.75063 mm, and the radius of curvature R1 of the object side surface S18 of the fourth lens L14 ₄₁ =2.37557 mm, the curvature radius R1 ₄₂ of the image side surface S19 of the fourth lens L14 is -1.63906 mm, the radius of curvature R1 ₅₁ of the object side surface S110 of the fifth lens L15 is -1.41888 mm, and the image side surface S111 of the fifth lens L15 The radius of curvature R1 ₅₂ = -0.52700 mm. From the above data, we can obtain f1/TTL1=0.4282, f1 ₁ /f1 ₆ =2.6355, (R1 ₂₁ -R1 ₂₂ )/(R1 ₂₁ +R1 ₂₂ )=-1.6895, (R1 ₃₁ -R1 ₃₂ )/(R1 ₃₁ + R1 ₃₂ )=2.5566, (R1 ₄₁ -R1 ₄₂ )/(R1 ₄₁ +R1 ₄₂ )=5.4509, (R1 ₅₁ -R1 ₅₂ )/(R1 ₅₁ +R1 ₅₂ )=0.4583, all satisfying the above condition (1) To the requirements of condition (6).

In addition, the optical performance of the imaging lens 1 of the first embodiment can also meet the requirements. This can be seen from Figures 2A through 2C. Fig. 2A is a longitudinal Spherical Aberration diagram of the imaging lens 1 of the first embodiment. Fig. 2B is an astigmatic field curve diagram of the imaging lens 1 of the first embodiment. Fig. 2C is a distortion 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 wavelength of Light rays of 470.0000 nm, 555.0000 nm, and 650.0000 nm produce a longitudinal spherical difference of between -0.0050 mm and 0.0100 mm. As can be seen from FIG. 2B, the imaging lens 1 of the first embodiment has an astigmatic field curvature of -0.010 mm to 0.010 mm in the direction of the tangential direction and the Sagittal direction for the light having a wavelength of 555.0000 nm. between. As can be seen from Fig. 2C, the imaging lens 1 of the first embodiment produces a distortion of between -0.2% and 2.1% for light having a wavelength of 555.0000 nm. It is apparent that the longitudinal spherical aberration, the astigmatic field curvature, and the distortion of the imaging lens 1 of the first embodiment can be effectively corrected, thereby obtaining better optical performance.

Please refer to FIG. 3, which is a second embodiment of the imaging lens according to the present invention. A schematic diagram of the lens configuration and optical path of the embodiment. At the time of imaging, the light from the object side is finally imaged on an image plane IMA2. 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. a sixth lens L26 and a filter OF2. The first lens L21 is a convex-concave lens having a negative refractive power made of a plastic material, the object side surface S11 is a convex surface, the image side surface S12 is a concave surface, and the object side surface S11 and the image side surface S12 are both aspherical surfaces. The second lens L22 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S23 and the image side surface S24 are aspherical surfaces. The third lens L23 is a biconcave lens having a negative refractive power made of a plastic material, and its object side S26 Both the image side surface S27 are aspherical surfaces. The fourth lens L24 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S28 and the image side surface S29 are aspherical surfaces. The fifth lens L25 is a meniscus lens having a positive refractive power made of a plastic material, the object side surface S210 is a concave surface, the image side surface S211 is a convex surface, and the object side surface S210 and the image side surface S211 are both aspherical surfaces. The sixth lens L26 is a convex-concave lens having a negative refractive power made of a plastic material, the object side surface S212 is a convex surface, the image side surface S213 is a concave surface, and the object side surface S212 and the image side surface S213 are both aspherical surfaces. The filter side OF2 has a flat side surface S214 and an image side surface S215.

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 six conditions:

Wherein, f2 is the effective focal length of the imaging lens 2 of, TTL2 object side surface of the first lens L21 of the distance to the image plane IMA2 S21 on the optical axis OA2, _{f2. 1} is the effective focal length of the first lens L21, _{f2. 6} of the sixth lens The effective focal length of L26, R2 ₂₁ is the radius of curvature of the object side surface S23 of the second lens L22, R2 ₂₂ is the radius of curvature of the image side surface S24 of the second lens L22, and R2 ₃₁ is the radius of curvature of the object side surface S26 of the third lens L23. R2 ₃₂ is the radius of curvature of the image side surface S27 of the third lens L23, R2 ₄₁ is the radius of curvature of the object side surface S28 of the fourth lens L24, R2 ₄₂ is the radius of curvature of the image side surface S29 of the fourth lens L24, and R2 ₅₁ is the fifth radius. The radius of curvature of the object side surface S210 of the lens L25, and R2 ₅₂ is the radius of curvature of the image side surface S211 of the fifth lens L25.

Using the above lens and aperture ST2 design, the imaging lens 2 can be effectively Shorten the total length of the lens, improve the viewing angle, effectively correct aberrations, and improve lens resolution.

Table 3 is the relevant parameter table of each lens of the imaging lens 2 in FIG. 3, Table 3 The data shows that the effective focal length of the imaging lens 2 of the second embodiment is equal to 1.7409 mm, the aperture value is equal to 2.2, the viewing angle is equal to 81.8°, and the total length of the lens is equal to 4.177 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 is the conical coefficient (Conic Constant) and A~G is the aspherical coefficient.

The imaging lens 2 of the second embodiment has an effective focal length f2=1.7409 mm, a distance TTL2=4.177 mm from the object side surface S21 of the first lens L21 to the imaging plane IMA2 on the optical axis OA2, and an effective focal length f2 _{1 of the} first lens L21. -3.02095mm, sixth lens effective focal length f2 ₆ = -1.23124mm L26, the radius of curvature of the second side surface S23 of the lens L22 was R2 ₂₁ = 1.06990mm, a second lens L22 of the side surface S24 of the curvature radius R2 ₂₂ = - 3.50000 mm, the radius of curvature R2 ₃₁ of the object side S26 of the third lens L23 is -3.50000 mm, the radius of curvature R2 ₃₂ of the image side surface S27 of the third lens L23 is 1.96810 mm, and the radius of curvature R2 of the object side surface S28 of the fourth lens L24 ₄₁ = 2.46034 mm, the curvature radius R2 ₄₂ of the image side surface S29 of the fourth lens L24 is -1.35300 mm, the radius of curvature R2 ₅₁ of the object side surface S210 of the fifth lens L25 is -1.40995 mm, and the image side surface S211 of the fifth lens L25 The radius of curvature R2 ₅₂ = -0.52088 mm. From the above data, we can get f2/TTL2=0.4168, f2 ₁ /f2 ₆ =2.4536, (R2 ₂₁ -R2 ₂₂ )/(R2 ₂₁ +R2 ₂₂ )=-1.8805, (R2 ₃₁ -R2 ₃₂ )/(R2 ₃₁ + R2 ₃₂ )=3.5695, (R2 ₄₁ -R2 ₄₂ )/(R2 ₄₁ +R2 ₄₂ )=3.4437, (R2 ₅₁ -R2 ₅₂ )/(R2 ₅₁ +R2 ₅₂ )=0.4605, all satisfy the above conditions (7) To the requirements of condition (12).

In addition, the optical performance of the imaging lens 2 of the second embodiment can also meet the requirements. This can be seen from Figures 4A through 4C. Fig. 4A is a longitudinal Spherical Aberration diagram of the imaging lens 2 of the second embodiment. Fig. 4B is an astigmatic field curve diagram of the imaging lens 2 of the second embodiment. Fig. 4C is a distortion 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 wavelength of Light rays of 470.0000 nm, 555.0000 nm, and 650.0000 nm produce a longitudinal spherical difference of between -0.0050 mm and 0.0100 mm. As can be seen from FIG. 4B, the imaging lens 2 of the second embodiment has an astigmatic field curvature of -0.020 mm to 0.020 mm in the direction of the tangential direction and the sagittal direction for the light having a wavelength of 555.0000 nm. between. As can be seen from Fig. 4C, the imaging lens 2 of the second embodiment produces a distortion of between -2.1% and 2.1% for light having a wavelength of 555.0000 nm. It is apparent that the longitudinal spherical aberration, the astigmatic field curvature, and the distortion of the imaging lens 2 of the second embodiment can be effectively corrected, thereby obtaining better optical performance.

Please refer to FIG. 5, which is a third embodiment of the imaging lens according to the present invention. A schematic diagram of the lens configuration and optical path of the embodiment. At the time of imaging, the light from the object side is finally imaged on an image plane IMA3. 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. A sixth lens L36 and a filter OF3. The first lens L31 is a convex-concave lens having a negative refractive power made of a plastic material, the object side surface S31 being a convex surface, the image side surface S32 being a concave surface, and the object side surface S31 and the image side surface S32 being aspherical surfaces. The second lens L32 is a lenticular lens The positive refractive power is made of a plastic material, and both the object side surface S33 and the image side surface S34 are aspherical surfaces. The third lens L33 is a biconcave lens having a negative refractive power made of a plastic material, and both the object side surface S36 and the image side surface S37 are aspherical surfaces. The fourth lens L34 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S38 and the image side surface S39 are aspherical surfaces. The fifth lens L35 is a meniscus lens having a positive refractive power made of a plastic material, and the object side surface S310 is a concave surface, the image side surface S311 is a convex surface, and the object side surface S310 and the image side surface S311 are both aspherical surfaces. The sixth lens L36 is a convex-concave lens having a negative refractive power made of a plastic material, the object side surface S312 being a convex surface, the image side surface S313 being a concave surface, and the object side surface S312 and the image side surface S313 being aspherical surfaces. The filter OF3 has a flat surface S314 and an image side surface S315.

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 six conditions:

Where f3 is the effective focal length of the imaging lens 3, TTL3 is the distance from the object side S31 of the first lens L31 to the imaging plane IMA3 on the optical axis OA3, f3 ₁ is the effective focal length of the first lens L31, and f3 ₆ is the sixth lens The effective focal length of L36, R3 ₂₁ is the radius of curvature of the object side surface S33 of the second lens L32, R3 ₂₂ is the radius of curvature of the image side surface S34 of the second lens L32, and R3 ₃₁ is the radius of curvature of the object side surface S36 of the third lens L33. R3 ₃₂ is the radius of curvature of the image side surface S37 of the third lens L33, R3 ₄₁ is the radius of curvature of the object side surface S38 of the fourth lens L34, R3 ₄₂ is the radius of curvature of the image side surface S39 of the fourth lens L34, and R3 ₅₁ is the fifth radius. The radius of curvature of the object side surface S310 of the lens L35, and R3 ₅₂ is the radius of curvature of the image side surface S311 of the fifth lens L35.

With the design of the above lens and aperture ST3, the imaging lens 3 can effectively shorten the total length of the lens, improve the viewing angle, 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 1.7971 mm, the aperture value is equal to 2.4, the viewing angle is equal to 80°, and the total length of the lens Equal to 4.104mm.

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

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 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 focal length f3=1.7971 mm, a distance TTL3=4.104 mm from the object side surface S31 of the first lens L31 to the imaging plane IMA3 on the optical axis OA3, and an effective focal length f3 _{1 of the} first lens L31. -4.81271mm, the effective focal length of the sixth lens ₆ = _-1.28548mm f3 L36, the radius of curvature of the second side surface S33 of the lens L32 of the object R3 ₂₁ = 1.34072mm, a second lens L32 of the side surface S34 of the curvature radius R3 ₂₂ = - 4.00000mm, the radius of curvature of the object side surface S36 of the third lens L33 is R3 ₃₁ = -4.000000 mm, the radius of curvature of the image side surface S37 of the third lens L33 is R3 ₃₂ = 2.61394 mm, and the radius of curvature R3 of the object side surface S38 of the fourth lens L34 ₄₁ = 2.95016 mm, the curvature radius R3 ₄₂ of the image side surface S39 of the fourth lens L34 is -2.62791 mm, the radius of curvature R3 ₅₁ of the object side surface S310 of the fifth lens L35 is -3.305116 mm, and the image side surface S311 of the fifth lens L35 The radius of curvature R3 ₅₂ = -0.53635 mm. From the above data, we can obtain f3/TTL3=0.4379, f3 ₁ /f3 ₆ =3.7439, (R3 ₂₁ -R3 ₂₂ )/(R3 ₂₁ +R3 ₂₂ )=-2.0083, (R3 ₃₁ -R3 ₃₂ )/(R3 ₃₁ + R3 ₃₂ )=4.7718, (R3 ₄₁ -R3 ₄₂ )/(R3 ₄₁ +R3 ₄₂ )=17.3101, (R3 ₅₁ -R3 ₅₂ )/(R3 ₅₁ +R3 ₅₂ )=0.7208, all satisfying the above condition (12) To the requirements of condition (18).

In addition, the optical performance of the imaging lens 3 of the third embodiment can also meet the requirements. This can be seen from Figures 6A through 6C. Fig. 6A is a longitudinal Spherical Aberration diagram of the imaging lens 3 of the third embodiment. Fig. 6B is an astigmatism field curve diagram of the imaging lens 3 of the third embodiment. Fig. 6C is a distortion diagram of the imaging lens 3 of the third embodiment.

As can be seen from FIG. 6A, the imaging lens 3 of the third embodiment has a wavelength of Light rays of 470.0000 nm, 555.0000 nm, and 650.0000 nm produce a longitudinal spherical difference of between -0.0050 mm and 0.0120 mm. As can be seen from FIG. 6B, the imaging lens 3 of the third embodiment has an astigmatic field curvature of -0.022 mm to 0.017 mm in the direction of the tangential direction and the Sagittal direction for the light having a wavelength of 555.0000 nm. between. As can be seen from Fig. 6C, the imaging lens 3 of the third embodiment has a distortion of between 0.0% and 2.1% for light having a wavelength of 555.0000 nm. It is apparent that the longitudinal spherical aberration, the astigmatic field curvature, and the distortion of the imaging lens 3 of the third embodiment can be effectively corrected, thereby obtaining better optical performance.

Please refer to FIG. 7 , which is a fourth embodiment of the imaging lens according to the present invention. Schematic diagram of the lens configuration of the embodiment. At the time of imaging, the light from the object side is finally imaged on an image plane IMA4. The imaging lens 4 sequentially includes a first lens L41, an aperture ST4, a second lens L42, a third lens L43, a fourth lens L44, and a fifth lens L45 from the object side to the image side along the optical axis OA4. a sixth lens L46 and a filter OF4. The first lens L41 is a convex-concave lens The negative refractive power is made of a glass material, and the object side surface S41 is a convex surface, the image side surface S42 is a concave surface, and the object side surface S41 and the image side surface S42 are both aspherical surfaces. The second lens L42 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S44 and the image side surface S45 are aspherical surfaces. The third lens L43 is a biconcave lens having a negative refractive power made of a plastic material, and both the object side surface S46 and the image side surface S47 are aspherical surfaces. The fourth lens L44 is a lenticular lens having a positive refractive power made of a plastic material, and both the object side surface S48 and the image side surface S49 are aspherical surfaces. The fifth lens L45 is a meniscus lens having a positive refractive power made of a plastic material, and the object side surface S410 is a concave surface, the image side surface S411 is a convex surface, and the object side surface S410 and the image side surface S411 are both aspherical surfaces. The sixth lens L46 is a convex-concave lens having a negative refractive power made of a plastic material, the object side surface S412 is a convex surface, the image side surface S413 is a concave surface, and the object side surface S412 and the image side surface S413 are both aspherical surfaces. The filter OF4 has a flat surface S414 and an image side surface S415.

In addition, in order to maintain good optical performance of the imaging lens of the present invention, the imaging lens 4 of the fourth embodiment is required to satisfy the following five conditions: 2.19 <|f4 ₁ /f4|<2.74 (19)

0.53<|f4 ₂ /f4|<1.03 (20)

0.72<|f4 ₃ /f4|<1.37 (21)

0.54<|f4 ₄ /f4|<1.19 (22)

5.15<|TTL4/BFL4|<5.65 (23)

Where f4 is the effective focal length of the imaging lens 4, f4 ₁ is the effective focal length of the first lens L41, f4 ₂ is the effective focal length of the second lens L42, f4 ₃ is the effective focal length of the third lens L43, and f4 ₄ is the fourth lens The effective focal length of L44, TTL4 is the distance from the object side S41 of the first lens L41 to the imaging plane IMA4 on the optical axis OA4, and BFL4 is the distance from the image side S413 of the sixth lens L46 to the imaging plane IMA4 on the optical axis OA4.

The imaging lens 4 can be effectively utilized by the design of the lens and the aperture ST4 described above. Shorten the total length of the lens, improve the viewing angle, effectively correct aberrations, and improve lens resolution.

Table 7 is a table of related parameters of the lenses of the imaging lens 4 in Fig. 7. Table 7 shows that the effective focal length of the imaging lens 4 of the fourth embodiment is equal to 11.019 mm, the aperture value is equal to 2.4, and the total length of the lens is equal to 18.324 mm.

The aspherical surface depression z of each lens in Table 7 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 8 is a table of related parameters of the aspherical surfaces of the respective lenses in Table 7, where k is a conical coefficient (Conic Constant) and A to G are aspherical coefficients.

The imaging lens 4 of the fourth embodiment has an effective focal length f4=11.019 mm, an effective focal length f4 _{1 of the} first lens L41 = -27.092 mm, and an effective focal length f4 _{2 of the} second lens L42 = 8.622 mm, and an effective focal length of the third lens L43 F4 ₃ = -11.482 mm, the effective focal length of the fourth lens L44 is f4 ₄ = 9.522 mm, the distance from the object side S41 of the first lens L41 to the imaging plane IMA4 on the optical axis OA4 is TTL4 = 18.324 mm, and the image of the sixth lens L46 The distance from the side S413 to the imaging plane IMA4 on the optical axis OA4 is BFL4 = 3.392 mm. From the above data, we can get |f4 ₁ /f4|=2.459, |f4 ₂ /f4|=0.782, |f4 ₃ /f4|=1.042, |f4 ₄ /f4|=0.864, |TTL4/BFL4|=5.402, both It can meet the requirements of the above conditions (19) to (23).

In addition, the optical performance of the imaging lens 4 of the fourth embodiment can also be achieved, which can be seen from the 8A to 8G drawings. Figure 8A shows the imaging lens 4 of the fourth embodiment. Longitudinal Aberration diagram. Fig. 8B is a field curvature diagram of the imaging lens 4 of the fourth embodiment. Fig. 8C is a distortion diagram of the imaging lens 4 of the fourth embodiment. Fig. 8D is a lateral color difference diagram of the imaging lens 4 of the fourth embodiment. Fig. 8E is a modulation transfer function diagram of the imaging lens 4 of the fourth embodiment. Fig. 8F is a diagram showing a Through Focus Modulation Transfer Function of the imaging lens 4 of the fourth embodiment. Fig. 8G is a diagram showing a Relative Illumination of the imaging lens 4 of the fourth embodiment.

As can be seen from FIG. 8A, the imaging lens 4 of the fourth embodiment has a wavelength of Light of 470.0000 nm, 555.0000 nm, and 650.0000 nm produces a longitudinal aberration value between -0.01 mm and 0.04 mm. As can be seen from FIG. 8B, the imaging lens 4 of the fourth embodiment has a field curvature of -70 in the direction of the tangential direction and the sagittal direction for the light having a wavelength of 470.0000 nm, 555.0000 nm, and 650.0000 nm. Between mm and 0.07mm. As can be seen from Fig. 8C, the imaging lens 4 of the fourth embodiment has a distortion of between -0.2% and 5.2% for light having wavelengths of 470.0000 nm, 555.0000 nm, and 650.0000 nm. As can be seen from FIG. 8D, the imaging lens 4 of the fourth embodiment produces a lateral color difference value of -1.5 μm to 3.5 μm for different wavelengths of the light having wavelengths of 470.0000 nm, 555.0000 nm, and 650.0000 nm. between. As can be seen from FIG. 8E, the imaging lens 4 of the fourth embodiment has a field of view with a wavelength range of 470.0000 nm to 650.0000 nm in the direction of the tangential direction and the Sagittal direction, respectively, and the field of view height is 0.0000, respectively. Mm, 1.8870mm, 3.7740mm, 4.7175mm, 6.6045mm, 8.4915mm, 9.4350mm, the spatial frequency is between 0lp/mm and 135lp/mm, and the modulation transfer function value is between 0.26 and 1.0. As can be seen from FIG. 8F, the imaging lens 4 of the fourth embodiment has a wavelength range of 470.0000 nm to 650.0000 nm, respectively in the Tangential direction and the sagittal direction. (Sagittal) direction and field of view height are 0.0000mm, 1.8870mm, 3.7740mm, 4.7175mm, 6.6045mm, 8.4915mm, 9.4350mm, and the spatial frequency is equal to 135lp/mm, when the focus shift is between -0.016mm and 0.014 The value of the modulation transfer function between mm is greater than 0.2. As can be seen from Fig. 8G, the imaging lens 4 of the fourth embodiment has a contrast angle of between 0.26 and 1.0 for a light having a wavelength of 555.0000 nm between 0 mm and 9.435 mm in the Y field of view. It can be seen that the longitudinal aberration, field curvature, distortion, and lateral chromatic aberration of the imaging lens 4 of the fourth embodiment can be effectively corrected, and the lens resolution, depth of focus, and phase contrast can also satisfy the requirements, thereby obtaining better optical performance.

Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention, and it is possible to make some modifications without departing from the spirit and scope of the invention. And the scope of the present invention is defined by the scope of the appended claims.

1‧‧‧ imaging lens

L11‧‧‧ first lens

L12‧‧‧ second lens

L13‧‧‧ third lens

L14‧‧‧4th lens

L15‧‧‧ fifth lens

L16‧‧‧ sixth lens

ST1‧‧‧ aperture

OF1‧‧‧Filter

OA1‧‧‧ optical axis

IMA1‧‧‧ imaging surface

S11, S12, S13, S14, S15‧‧

S16, S17, S18, S19, S110‧‧‧

S111, S112, S113, S114, S115‧‧‧

Claims (14)

An imaging lens includes, in order from the object side to the image side along the optical axis, a first lens having a negative refractive power, the first lens including a concave surface facing the image side, and a second lens The second lens is a lenticular lens having a positive refractive power; a third lens having a negative refractive power, the third lens includes a concave surface facing the object side; and a fourth lens, the fourth lens is The lenticular lens has a positive refractive power; a fifth lens having a positive refractive power, the concave surface of the fifth lens facing the object side convex surface toward the image side; and a sixth lens having a negative The refractive power, the sixth lens includes a convex surface that faces the object side. The imaging lens of claim 1, wherein the first lens further comprises a convex surface facing the object side, the third lens further comprising a concave surface facing the image side, the sixth lens There is further included a concave surface that faces the image side. The imaging lens of claim 2, wherein the imaging lens satisfies the following conditions: Where f is the effective focal length of the imaging lens, and TTL is the distance from the object side of the first lens to an imaging surface on the optical axis. The imaging lens of claim 2, wherein the first lens and the sixth lens satisfy the following conditions: Where f _{1 is} the effective focal length of the first lens and f _{6 is} the effective focal length of the sixth lens. The imaging lens of claim 2, wherein the second lens satisfies the following conditions: Wherein R _{21 is a} radius of curvature of an object side surface of the second lens, and R _{22 is a} radius of curvature of an image side surface of the second lens. The imaging lens of claim 2, wherein the third lens satisfies the following conditions: Wherein R _{31 is a} radius of curvature of an object side surface of the third lens, and R _{32 is a} radius of curvature of an image side surface of the third lens. The imaging lens of claim 2, wherein the fourth lens satisfies the following conditions: Wherein R _{41 is} the radius of curvature of the object side surface of the fourth lens, and R _{42 is} the radius of curvature of the image side surface of the fourth lens. The imaging lens of claim 2, wherein the fifth lens satisfies the following conditions: Where R _{51 is} the radius of curvature of the object side surface of the fifth lens, and R _{52 is} the radius of curvature of the image side surface of the fifth lens. The imaging lens of claim 1, wherein the first lens satisfies the following condition: 2.19<|f ₁ /f|<2.74, wherein f ₁ is an effective focal length of the first lens, and f is the imaging lens Effective focal length. The imaging lens of claim 1, wherein the second lens satisfies the following condition: 0.53<|f ₂ /f|<1.03, wherein f ₂ is an effective focal length of the second lens, and f is the imaging lens Effective focal length. The imaging lens of claim 1, wherein the third lens satisfies the following condition: 0.72<|f ₃ /f|<1.37, wherein f ₃ is an effective focal length of the third lens, and f is the imaging lens Effective focal length. The imaging lens of claim 1, wherein the fourth lens satisfies the following condition: 0.54<|f ₄ /f|<1.19, wherein f ₄ is an effective focal length of the fourth lens, and f is the imaging lens Effective focal length. The imaging lens of claim 1, wherein the imaging lens satisfies the following condition: 5.15 <| TTL / BFL | < 5.65 wherein TTL is the object side of the first lens to an imaging surface on the optical axis The distance between the BFL is the image side of the sixth lens to the imaging surface on the optical axis. The imaging lens of claim 1, further comprising an aperture disposed between the first lens and the third lens.