A high-pixel telephoto lens

Abstract

A high-pixel telephoto lens of the present invention has six lenses arranged from the object side to the image side. The first lens has a positive refractive power, and the object side surface is convex; the second lens has a positive refractive power, the object side surface is convex, and the image side surface is concave; the third lens has a negative refractive power, the object side surface is convex, and the image side surface is concave; the fourth lens has a negative refractive power, the object side surface is concave, and the image side surface is concave; the fifth lens has a negative refractive power; all surfaces of the six lenses are aspherical surfaces, satisfying the following conditions: TTL / F < 0.6, where TTL is the total optical length of the optical system of the high-pixel telephoto lens, and F is the focal length of the optical system; 0.25 < T34 / TTL < 0.5, where T34 is the air gap on the optical axis between the third lens and the fourth lens; 0 < |F4 / F| < 0.3, where F4 is the focal length of the fourth lens. This high-pixel telephoto lens is a telephoto optical imaging lens with a long focal length and good imaging quality, and is applicable to portable electronic products.

Description

Technical Field

[0001] The invention belongs to the technical field of optical imaging lenses and relates to a high-pixel telephoto lens. Background Art

[0002] With the popularity of portable electronic products such as smartphones and the continuous upgrading of hardware of electrically coupled devices or complementary metal oxide semiconductor image sensors in lenses, the concept of dual-camera has been proposed in the camera function, that is, a method of combining two optical lenses with image processing algorithms to achieve zoom. In the dual-camera lens, one of the telephoto lenses has the characteristics of large magnification and small depth of field, which is conducive to blurring the background of the image, thereby obtaining a better shooting effect. At the same time, in order to match larger chips to pursue higher resolution, there is an urgent need for a telephoto optical imaging lens that can be applied to portable electronic products, has a long focal length and good imaging quality. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a high-pixel telephoto lens, a telescopic optical imaging lens with a long focal length and good imaging quality.

[0004] A high-pixel telephoto lens of the present invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the optical axis from the object side to the image side.

[0005] The first lens has positive refractive power, and its object side surface is convex; the second lens has positive refractive power, its object side surface is convex, and its image side surface is concave; the third lens has negative refractive power, its object side surface is convex, and its image side surface is concave; the fourth lens has negative refractive power, its object side surface is concave, and its image side surface is concave; the fifth lens has negative refractive power; a stop is also provided in front of the first lens, and all surfaces of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are aspherical and plastic lenses, and meet the following conditions:

[0006] TTL / F<0.6

[0007] Wherein, TTL is the total optical length of the optical system of the high-pixel telephoto lens; F is the focal length of the optical system;

[0008] 0.25 <T34 / TTL<0.5

[0009] Wherein, T34 is the air space between the third lens and the fourth lens on the optical axis;

[0010] 0<∣F4 / F∣<0.3

[0011] Wherein, F4 is the focal length of the fourth lens.

[0012] In the high-pixel telephoto lens of the present invention, the optical system of the high-pixel telephoto lens also satisfies the following conditions:

[0013] TTL / IH<4.2

[0014] Here, IH is the half image height.

[0015] In the high-pixel telephoto lens of the present invention, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all made of even-order aspherical plastic lenses, and the aspherical coefficient satisfies the following equation:

[0016]

[0017] Among them, Z is the aspheric surface vector height, c is the aspheric surface paraxial curvature, y is the lens aperture, k is the cone coefficient, A4 is the 4th aspheric surface coefficient, A6 is the 6th aspheric surface coefficient, A8 is the 8th aspheric surface coefficient, A10 is the 10th aspheric surface coefficient, A12 is the 12th aspheric surface coefficient, A14 is the 14th aspheric surface coefficient, A16 is the 16th aspheric surface coefficient, A18 is the 18th aspheric surface coefficient, and A20 is the 20th aspheric surface coefficient.

[0018] Compared with the existing lens, the high-pixel telephoto lens of the present invention has a longer focal length and a better telephoto effect if the total length is the same; if the focal length is the same, the lens of the present invention has a shorter total length and is more compact. The high-pixel telephoto lens is a telephoto optical imaging lens with a long focal length and good imaging quality, and can be applied to portable electronic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a two-dimensional diagram of the optical system of a high-pixel telephoto lens embodiment 1 of the present invention;

[0020] Figure 2 is an astigmatism curve diagram of the optical system of Example 1;

[0021] Figure 3 is an optical distortion curve diagram of the optical system of Example 1;

[0022] Figure 4 is a relative illumination curve diagram of the optical system of Example 1;

[0023] Figure 5 is a two-dimensional diagram of the optical system of a high-pixel telephoto lens embodiment 2 of the present invention;

[0024] Figure 6 is an astigmatism curve diagram of the optical system of Example 2;

[0025] Figure 7 is an optical distortion curve diagram of the optical system of Example 2;

[0026] Figure 8 It is a relative illumination curve diagram of the optical system of Example 2. DETAILED DESCRIPTION

[0027] A high-pixel telephoto lens of the present invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the optical axis from the object side to the image side.

[0028] The first lens has positive refractive power, and its object side surface is convex; the second lens has positive refractive power, its object side surface is convex, and its image side surface is concave; the third lens has negative refractive power, its object side surface is convex, and its image side surface is concave; the fourth lens has negative refractive power, its object side surface is concave, and its image side surface is concave; the fifth lens has negative refractive power; a stop is also provided in front of the first lens, and all surfaces of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are aspherical and plastic lenses, and meet the following conditions:

[0029] Condition one:

[0030] TTL / F<0.6

[0031] Among them, TTL is the total optical length of the optical system of the high-pixel telephoto lens; F is the focal length of the optical system. Meeting this condition is conducive to controlling the total length of the optical system to be less than the effective focal length of the optical imaging system, which can ensure the miniaturization of the optical system structure and meet the characteristics of the telephoto lens with large imaging magnification and small depth of field under long focal length.

[0032] Condition two:

[0033] 0.25 <T34 / TTL<0.5

[0034] Wherein, T34 is the air spacing between the third lens and the fourth lens on the optical axis. This condition is used to control the air spacing between the third lens and the fourth lens, so as to increase the effective focal length of the entire optical system.

[0035] Condition three:

[0036] 0<∣F4 / F∣<0.3

[0037] Wherein, F4 is the focal length of the fourth lens. Meeting this condition is conducive to ensuring the telephoto characteristics of the lens, making the field of view of the lens small while the effective focal length large.

[0038] In the high-pixel telephoto lens of the present invention, the optical system of the high-pixel telephoto lens also satisfies the following conditions:

[0039] TTL / IH<4.2

[0040] Here, IH is the half image height.

[0041] In the high-pixel telephoto lens of the present invention, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all made of even-order aspherical plastic lenses, and the aspherical coefficient satisfies the following equation:

[0042]

[0043] Among them, Z is the aspheric surface vector height, c is the aspheric surface paraxial curvature, y is the lens aperture, k is the cone coefficient, A4 is the 4th aspheric surface coefficient, A6 is the 6th aspheric surface coefficient, A8 is the 8th aspheric surface coefficient, A10 is the 10th aspheric surface coefficient, A12 is the 12th aspheric surface coefficient, A14 is the 14th aspheric surface coefficient, A16 is the 16th aspheric surface coefficient, A18 is the 18th aspheric surface coefficient, and A20 is the 20th aspheric surface coefficient.

[0044] Example 1

[0045] In this embodiment, the fifth lens has negative refractive power, the object-side surface is concave and the image-side surface is convex; the sixth lens has negative refractive power, the object-side surface is convex and the image-side surface is concave.

[0046] The design parameters of the lens are shown in Table 1 and Table 2:

[0047] Table 1:

[0048]

[0049]

[0050] Table 2:

[0051]

[0052] The corresponding parameters in this embodiment are shown in Table 3:

[0053] Table 3:

[0054] FOV 18° TTL 12.2 F 20.6 F4 3.0966 TTL / F 0.592 T34 / TTL 0.33 ∣F4 / F∣ 0.15 TTL / IH 4.107

[0055] See also Figure 1 The shapes of the lenses in this optical system are relatively symmetrical, which is convenient for molding and production, and the lens spacing is reasonable, which is convenient for later structural design;

[0056] See also Figure 2 , the astigmatism of the optical system shown is controlled within the range of ±0.05.

[0057] See also Figure 3 , the optical distortion curve of the optical system is shown, and the distortion percentage is controlled at about ±1%.

[0058] See also Figure 4 The relative illumination curve of the optical system shown in the figure can comprehensively reflect the imaging quality of the system. The smoother the curve shape and the higher the height relative to the X-axis, the better the imaging quality of the system. This lens has a higher definition.

[0059] Example 2

[0060] In this embodiment, in addition to the claims, the fifth lens has negative refractive power, the object side surface is convex and the image side surface is concave; the sixth lens has positive refractive power, the object side surface is concave and the image side surface is convex.

[0061] The design parameters of the lens are shown in Table 4 and Table 5:

[0062] Table 4:

[0063]

[0064]

[0065] Table 5:

[0066]

[0067] The corresponding parameters in this embodiment are shown in Table 6:

[0068] Table 6:

[0069]

[0070]

[0071] See also Figure 5 The shapes of the lenses in this optical system are relatively symmetrical, which is convenient for molding and production, and the lens spacing is reasonable, which is convenient for later structural design;

[0072] See also Figure 6 , the astigmatism of the optical system shown is controlled within the range of ±0.05.

[0073] See also Figure 7 , the optical distortion curve of the optical system shown in FIG. 1 , the distortion percentage is controlled within the range of 2%.

[0074] See also Figure 8 The relative illumination curve of the optical system shown in the figure can comprehensively reflect the imaging quality of the system. The smoother the curve shape and the higher the height relative to the X-axis, the better the imaging quality of the system. This lens has a higher definition.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the concept of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-pixel telephoto lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the optical axis from the object side to the image side, characterized in that: The first lens has positive refractive power, and its object side surface is convex; the second lens has positive refractive power, its object side surface is convex, and its image side surface is concave; the third lens has negative refractive power, its object side surface is convex, and its image side surface is concave; the fourth lens has negative refractive power, its object side surface is concave, and its image side surface is concave; the fifth lens has negative refractive power; a stop is also provided in front of the first lens, and all surfaces of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are aspherical and plastic lenses, and meet the following conditions: TTL / F<0.6 TTL / IH<4.2 0.25 <T34 / TTL<0.5 0<∣F4 / F∣<0.3 Wherein, TTL is the total optical length of the optical system of the high-pixel telephoto lens; F is the focal length of the optical system; IH is the half-image height; T34 is the air interval between the third lens and the fourth lens on the optical axis; F4 is the focal length of the fourth lens; The first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all made of even-order aspheric plastic lenses, and the aspheric coefficients satisfy the following equation: Among them, Z is the aspheric surface vector height, c is the aspheric surface paraxial curvature, y is the lens aperture, k is the cone coefficient, A4 is the 4th aspheric surface coefficient, A6 is the 6th aspheric surface coefficient, A8 is the 8th aspheric surface coefficient, A10 is the 10th aspheric surface coefficient, A12 is the 12th aspheric surface coefficient, A14 is the 14th aspheric surface coefficient, A16 is the 16th aspheric surface coefficient, A18 is the 18th aspheric surface coefficient, and A20 is the 20th aspheric surface coefficient.

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