An optical imaging lens

Abstract

The application provides an optical imaging lens, comprising first to seventh lenses arranged in sequence along an optical axis from an object side to an image side, the third lens and the fourth lens being provided with a diaphragm, through reasonable distribution of refractive powers of the lenses, optimization of surface shapes, thicknesses of the lenses and distances between the lenses, the lens can have wide angle and good imaging quality, can satisfy 4K imaging quality, adopts a structure design of glass-plastic mixing, can well reduce lens cost, can well correct lens aberration, and in combination with thermal expansion coefficients of glass materials and plastic materials, the lens has good imaging quality under high and low temperature conditions, and satisfies use under different temperature environments.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, specifically to an optical imaging lens. Background Technology

[0002] Currently, the optical systems on the market have a relatively long distance from the center of the front surface of the first lens to the image plane, requiring a large number of lenses, resulting in excessively high overall lens cost and weight, and limiting their installation and use. In addition, conventional wide-angle lenses have a large angle of incidence, which will produce more severe astigmatism, resulting in poor image quality at the edges of the field of view. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to propose an optical imaging lens that, by rationally allocating the optical power of each lens, optimizing the surface shape, thickness and distance between each lens, enables the lens to have a wide angle and good imaging quality, thereby solving the problems mentioned in the background section above.

[0004] This invention is achieved through the following technical solution:

[0005] An optical imaging lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical axis from the object side to the image side, wherein:

[0006] The object-side surface of the first lens is convex, the image-side surface of the first lens is concave, and the first lens has negative refractive power.

[0007] The object-side surface of the second lens is concave, the image-side surface of the second lens is convex, and the second lens has positive refractive power.

[0008] The object-side surface of the third lens is concave, the image-side surface of the third lens is convex, and the third lens has negative refractive power.

[0009] The object-side surface of the fourth lens is convex, the image-side surface of the fourth lens is convex, and the fourth lens has positive refractive power.

[0010] The object-side surface of the fifth lens is convex near the optical axis, and the image-side surface of the fifth lens is concave near the optical axis. The fifth lens has negative refractive power.

[0011] The object-side surface of the sixth lens is convex near the optical axis, and the image-side surface of the sixth lens is concave near the optical axis. The sixth lens has negative refractive power.

[0012] The object-side surface of the seventh lens is convex, and the image-side surface of the seventh lens near the optical axis is convex. The seventh lens has positive refractive power.

[0013] The beneficial effects of this embodiment are: only seven lenses are needed to form the lens, which reduces the overall cost and weight of the lens, and the image quality is high.

[0014] Furthermore,

[0015] The focal length F1 of the first lens satisfies the following relationship: -7mm≤F1≤-6mm;

[0016] The focal length F2 of the second lens satisfies the following relationship: 15mm≤F2≤18mm;

[0017] The focal length F3 of the third lens satisfies the following relationship: -20mm≤F3≤-15mm;

[0018] The focal length F4 of the fourth lens satisfies the following relationship: 6mm≤F4≤7mm;

[0019] The focal length F5 of the fifth lens satisfies the following relationship: -9mm≤F5≤-6.5mm;

[0020] The focal length F6 of the sixth lens satisfies the following relationship: -130mm≤F6≤-110mm;

[0021] The focal length F7 of the seventh lens satisfies the following relationship: 7mm≤F7≤8mm.

[0022] The beneficial effect of this embodiment is that it further reduces the combined focal length of the first to seventh lenses, making the lens structure more compact.

[0023] Furthermore,

[0024] The absolute value of the ratio of the focal length F1 of the first lens to the overall focal length F of the lens satisfies the following relationship: 2≤(F1 / F)≤2.5;

[0025] The absolute value of the ratio of the focal length F2 of the second lens to the overall focal length F of the lens satisfies the following relationship: 3≤(F2 / F)≤5;

[0026] The absolute value of the ratio of the focal length F3 of the third lens to the overall focal length F of the lens satisfies the following relationship: 3≤(F3 / F)≤5;

[0027] The absolute value of the ratio of the focal length F4 of the fourth lens to the overall focal length F of the lens satisfies the following relationship: 1≤(F4 / F)≤2;

[0028] The absolute value of the ratio of the focal length F5 of the fifth lens to the overall focal length F of the lens satisfies the following relationship: 1≤(F5 / F)≤2;

[0029] The absolute value of the ratio of the focal length F6 of the sixth lens to the overall focal length F of the lens satisfies the following relationship: 25≤(F6 / F)≤32;

[0030] The absolute value of the ratio of the focal length F7 of the seventh lens to the overall focal length F of the lens satisfies the following relationship: 1≤(F7 / F)≤2.

[0031] The beneficial effect of this embodiment is that it further reduces the combined focal length of the first to seventh lenses, making the lens structure more compact.

[0032] Furthermore,

[0033] The lens satisfies the following relationship: BFL / TTL≥0.2, where BFL is the distance from the center of the image side of the seventh lens to the imaging surface on the optical axis, and TTL is the distance from the first lens to the imaging surface on the optical axis.

[0034] The beneficial effect of this embodiment is that satisfying the above formula allows the lens to be miniaturized while having a more reasonable back focus, which is more conducive to lens assembly.

[0035] Furthermore,

[0036] The lens satisfies the following relationship: 1.6≤ET6 / CT6≤1.7, where ET6 is the edge thickness of the sixth lens and CT6 is the center thickness of the sixth lens on the optical axis.

[0037] The beneficial effects of this embodiment are: satisfying the above formula can better control the thickness ratio of the lens, making the lens forming more stable, thereby improving the overall yield of the lens.

[0038] Furthermore,

[0039] The lens satisfies the following relationship: -1.8 ≤ F 56 / F≤-1.6; where F 56 F is the combined focal length of the fifth and sixth lenses, and F is the overall focal length of the lens.

[0040] The beneficial effects of this embodiment are: satisfying the above formula is beneficial to the turning angle of light when it passes through the lens group, thereby reducing the incident angle of light on the imaging surface, improving the light sensitivity of the imaging surface, and thus improving the imaging quality of the lens.

[0041] Furthermore,

[0042] The lens satisfies the following relationship: 0.9 ≤ |F 123 / F 4567 |≤1.1, where F 123 F is the combined focal length of the first to the third lenses.4567 The combined focal length of the fourth to seventh lenses.

[0043] The beneficial effects of this embodiment are: satisfying the above formula can make the optical power of the front and rear groups closer to 1:1, which is conducive to a smoother transition of light between the front and rear groups and can better improve the image quality of the lens.

[0044] Furthermore,

[0045] The lens satisfies the following relationship: TTL≤26mm, where TTL is the distance from the first lens to the imaging surface on the optical axis.

[0046] The beneficial effect of this embodiment is that it makes the lens small in size, thus making it extremely convenient to install, use, or carry.

[0047] Furthermore,

[0048] The first, third, and fourth lenses are made of glass lenses, while the second, fifth, sixth, and seventh lenses are made of plastic aspherical lenses.

[0049] The beneficial effects of this embodiment are as follows: the design using four plastic aspherical lenses and three glass lenses is beneficial for correcting secondary spectral and higher-order aberrations; at the same time, the use of a glass-plastic hybrid structure design can significantly reduce lens costs and effectively correct lens aberrations. Furthermore, the combination of the thermal expansion coefficients of glass and plastic materials ensures that the lens maintains good image quality under both high and low temperature conditions, meeting the requirements for use in various temperature environments.

[0050] Furthermore,

[0051] The lens satisfies the following relationship: 4.1mm≤EFL≤4.2mm, where BFL is the distance on the optical axis from the center of the image side of the seventh lens to the imaging surface.

[0052] The beneficial effects of this embodiment are: it makes the overall field of view of the lens large, the structure compact, and the practicality strong.

[0053] Furthermore, an aperture stop is provided between the third lens and the fourth lens. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the optical imaging lens structure of the present invention.

[0055] Figure 2 This is an MTF curve of the lens in Embodiment 1 of the present invention under visible light 435nm-650nm.

[0056] Figure 3This is a defocus curve of the lens in the visible light range of 435nm-650nm according to an embodiment of the present invention.

[0057] Figure 4 This is a defocus curve of the lens in Embodiment 1 of the present invention under infrared light at 850nm.

[0058] Figure 5 This is a lateral chromatic aberration curve of the lens in an embodiment of the present invention under visible light 435nm-650nm.

[0059] Figure 6 This is a longitudinal chromatic aberration curve of the lens in Embodiment 1 of the present invention under visible light 435nm-650nm.

[0060] Figure 7 The image shows the field curvature and distortion of the lens in the visible light range of 435nm-650nm according to an embodiment of the present invention.

[0061] Figure 8 This is the MTF curve of the lens in Embodiment 2 of the present invention under visible light 435nm-650nm.

[0062] Figure 9 This is a defocus curve of the lens in Embodiment 2 of the present invention in the visible light range of 435nm-650nm.

[0063] Figure 10 This is a defocus curve of the lens in Embodiment 2 of the present invention under infrared light at 850nm.

[0064] Figure 11 This is a lateral chromatic aberration curve of the lens in Embodiment 2 of the present invention under visible light 435nm-650nm.

[0065] Figure 12 This is a longitudinal chromatic difference curve of the lens in Embodiment 2 of the present invention under visible light 435nm-650nm.

[0066] Figure 13 The image shows the field curvature and distortion of the lens in Embodiment 2 of the present invention under visible light (435nm-650nm).

[0067] Figure 14 This is the MTF curve of the lens in Embodiment 3 of the present invention under visible light 435nm-650nm.

[0068] Figure 15 This is a defocus curve of the lens in Embodiment 3 of the present invention in the visible light range of 435nm-650nm.

[0069] Figure 16 This is a defocus curve of the lens in Embodiment 3 of the present invention under infrared light at 850nm.

[0070] Figure 17This is a lateral chromatic aberration curve of the lens in Embodiment 3 of the present invention under visible light 435nm-650nm.

[0071] Figure 18 This is a longitudinal chromatic difference curve of the lens in Embodiment 3 of the present invention under visible light 435nm-650nm.

[0072] Figure 19 The image shows the field curvature and distortion of the lens in the visible light range of 435nm-650nm according to Embodiment 3 of the present invention.

[0073] The above figures include the following reference numerals:

[0074] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 8. Aperture stop; 9. Filter; 10. Imaging plane. Detailed Implementation

[0075] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0076] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0077] refer to Figure 1 As shown, an optical imaging lens includes a first lens 1, a second lens 2, a third lens 3, an aperture stop 8, a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7 arranged sequentially along the optical axis from the object side to the image side. The first lens 1, the second lens 2, and the third lens 3 form the front group of the lens, and the fourth to seventh lenses 7 form the rear group of the lens.

[0078] The object-side surface of the first lens 1 is convex, the image-side surface of the first lens 1 is concave, and the first lens 1 has negative refractive power.

[0079] The object-side surface of the second lens 2 is concave, the image-side surface of the second lens 2 is convex, and the second lens 2 has positive refractive power.

[0080] The object-side surface of the third lens 3 is concave, the image-side surface of the third lens 3 is convex, and the third lens 3 has negative refractive power.

[0081] The object-side surface of the fourth lens 4 is convex, the image-side surface of the fourth lens 4 is convex, and the fourth lens 4 has positive refractive power.

[0082] The object-side surface of the fifth lens 5 is convex near the optical axis, and the image-side surface of the fifth lens 5 is concave near the optical axis. The fifth lens 5 has negative refractive power.

[0083] The object-side surface of the sixth lens 6 is convex near the optical axis, and the image-side surface of the sixth lens 6 is concave near the optical axis. The sixth lens 6 has negative refractive power.

[0084] The object side of the seventh lens 7 is convex, and the image side of the seventh lens 7 is convex near the optical axis. The seventh lens 7 has positive refractive power.

[0085] The beneficial effects of this embodiment are: only seven lenses are needed to form the lens, which reduces the overall cost and weight of the lens, and the image quality is high.

[0086] Furthermore,

[0087] The focal length F1 of the first lens 1 satisfies the following relationship: -7mm≤F1≤-6mm;

[0088] The focal length F2 of the second lens 2 satisfies the following relationship: 15mm≤F2≤18mm;

[0089] The focal length F3 of the third lens 3 satisfies the following relationship: -20mm≤F3≤-15mm;

[0090] The focal length F4 of the fourth lens 4 satisfies the following relationship: 6mm≤F4≤7mm;

[0091] The focal length F5 of the fifth lens 5 satisfies the following relationship: -9mm≤F5≤-6.5mm;

[0092] The focal length F6 of the sixth lens 6 satisfies the following relationship: -130mm≤F6≤-110mm;

[0093] The focal length F7 of the seventh lens 7 satisfies the following relationship: 7mm≤F7≤8mm.

[0094] The beneficial effect of this embodiment is that it further reduces the combined focal length of the first lens 1 to the seventh lens 7, making the lens structure more compact.

[0095] Furthermore,

[0096] The absolute value of the ratio of the focal length F1 of the first lens 1 to the overall focal length F of the lens satisfies the following relationship: 2≤(F1 / F)≤2.5;

[0097] The absolute value of the ratio of the focal length F2 of the second lens 2 to the overall focal length F of the lens satisfies the following relationship: 3≤(F2 / F)≤5;

[0098] The absolute value of the ratio of the focal length F3 of the third lens 3 to the overall focal length F of the lens satisfies the following relationship: 3≤(F3 / F)≤5;

[0099] The absolute value of the ratio of the focal length F4 of the fourth lens 4 to the overall focal length F of the lens satisfies the following relationship: 1≤(F4 / F)≤2;

[0100] The absolute value of the ratio of the focal length F5 of the fifth lens 5 to the overall focal length F of the lens satisfies the following relationship: 1≤(F5 / F)≤2;

[0101] The absolute value of the ratio of the focal length F6 of the sixth lens 6 to the overall focal length F of the lens satisfies the following relationship: 25≤(F6 / F)≤32;

[0102] The absolute value of the ratio of the focal length F7 of the seventh lens 7 to the overall focal length F of the lens satisfies the following relationship: 1≤(F7 / F)≤2.

[0103] The beneficial effect of this embodiment is that it further reduces the combined focal length of the first lens 1 to the seventh lens 7, making the lens structure more compact.

[0104] Furthermore, the lens is preferably such that it satisfies the following relationship: BFL / TTL≥0.2, where BFL is the distance from the center of the image side of the seventh lens 7 to the imaging surface on the optical axis, and TTL is the distance from the first lens 1 to the imaging surface on the optical axis.

[0105] The beneficial effect of this embodiment is that satisfying the above formula allows the lens to be miniaturized while having a more reasonable back focus, which is more conducive to lens assembly.

[0106] Furthermore, the lens is preferably satisfied with the following relationship: 1.6≤ET6 / CT6≤1.7, where ET6 is the edge thickness of the sixth lens 6 and CT6 is the center thickness of the sixth lens 6 on the optical axis.

[0107] The beneficial effects of this embodiment are: satisfying the above formula can better control the thickness ratio of the lens, making the lens forming more stable, thereby improving the overall yield of the lens.

[0108] Furthermore, addressing the issue that currently available wide-angle lenses have large incident angles, resulting in significant astigmatism and poor image quality at the edges of the field of view, this invention solves this problem by setting the lens to satisfy the following relationship. Preferably, the lens satisfies the following relationship: -1.8 ≤ F 56 / F≤-1.6; where F 56 F is the combined focal length of the fifth and sixth lenses 6, and F is the overall focal length of the lens.

[0109] The beneficial effects of this embodiment are: satisfying the above formula is beneficial to the turning angle of light when it passes through the lens group, thereby reducing the incident angle of light on the imaging surface, improving the light sensitivity of the imaging surface, and thus improving the imaging quality of the lens.

[0110] Furthermore,

[0111] The preferred lens satisfies the following relationship: 0.9 ≤ |F 123 / F 4567 |≤1.1, where F 123 F is the combined focal length of the first lens 1 to the third lens 3. 4567 The combined focal length of the fourth lens 4 to the seventh lens 7.

[0112] The beneficial effects of this embodiment are: satisfying the above formula can make the optical power of the front and rear groups closer to 1:1, which is conducive to a smoother transition of light between the front and rear groups and can better improve the image quality of the lens.

[0113] Furthermore, since most wide-angle lenses on the market use multiple glass or cemented lenses to improve resolution and correct chromatic aberration, they suffer from high costs and large size. This invention addresses this deficiency by using glass lenses (first lens 1, third lens 3, and fourth lens 4) and plastic aspherical lenses (second lens 2, fifth lens 5, sixth lens 6, and seventh lens 7) to improve resolution and correct chromatic aberration.

[0114] The beneficial effects of this embodiment are as follows: the design of using four plastic aspherical lenses and three glass lenses is beneficial for correcting secondary spectral and higher-order aberrations; at the same time, the use of a glass-plastic hybrid structure design can not only reduce lens cost, but also correct lens aberrations well. In addition, the combination of the thermal expansion coefficients of glass and plastic materials ensures that the lens has good imaging quality under high and low temperature conditions, meeting the requirements for use in different temperature environments.

[0115] Furthermore,

[0116] The preferred lens satisfies the following relationship: 4.1mm ≤ EFL ≤ 4.2mm;

[0117] With a DFOV between 155° and 161°, the optimal DFOV is 158°. When DFOV is 158°, the lens has a good MTF and good image quality, which can meet the requirements for 4K image quality.

[0118] 2.0 ≤ Fno ≤ 2.4, therefore, the optimal value is Fno = 2.2.

[0119] With a TTL of ≤26mm, the lens is small in size, making it easy to install, use, or carry.

[0120] In the formula, BFL is the distance on the optical axis from the center of the image side of the seventh lens 7 to the imaging surface; TTL is the distance on the optical axis from the first lens 1 to the imaging surface; Fno is the aperture coefficient; and DFOV is the digital field of view.

[0121] The beneficial effects of this embodiment are: it makes the overall field of view of the lens large, the structure compact, and the practicality strong.

[0122] In summary, the present invention has the following beneficial effects: 1. The optical TTL is less than 26mm, and the glass-plastic hybrid 7-element design results in a small overall lens size and convenient installation and use; 2. The DFOV is 158°, the lens MTF is good, and it has good image quality, which can meet the requirements of 4K imaging quality; 3. The 3G4P glass-plastic hybrid structure not only provides good image quality but also reduces the cost of the lens.

[0123] The present invention provides detailed optical data for embodiments one to three, as shown in Table 1-1.

[0124] Detailed optical data in Table 1-1

[0125]

[0126]

[0127]

[0128]

[0129]

[0130] In the table above, each lens contains two surfaces, and the surface with the smaller number in each lens is the surface closer to the object side.

[0131] Among them, the second lens 2, the fifth lens 5, the sixth lens 6, and the seventh lens 7 are made of plastic aspherical lenses. The equation for the surface curve of the aspherical lens is expressed as follows:

[0132]

[0133] In the formula, z represents the aspherical sagitta; c represents the paraxial curvature of the aspherical surface; y represents the lens diameter; k represents the cone coefficient; A4 represents the 4th order aspherical coefficient; A6 represents the 6th order aspherical coefficient; A8 represents the 8th order aspherical coefficient; A10 represents the 10th order aspherical coefficient; A12 represents the 12th order aspherical coefficient; A14 represents the 14th order aspherical coefficient; and A16 represents the 16th order aspherical coefficient. The corresponding aspherical data for Examples 1 to 3 are shown in Tables 1-2.

[0134] Detailed optical data in Table 1-2

[0135]

[0136]

[0137]

[0138] Figure 2 The figure shows the MTF curve of the lens in the visible light range of 435nm-650nm according to Embodiment 1 of the present invention. As can be seen from the figure, the lens has excellent imaging quality and high resolution when the spatial frequency is 125lp / mm.

[0139] Figure 3 The figure shows the defocus curve of the lens in the visible light range of 435nm-650nm according to Embodiment 1 of the present invention. It can be seen from the figure that the defocus curves of the lens in each field of view under visible light are relatively concentrated and the defocus amount is small.

[0140] Figure 4 The figure shows the defocus curve of the lens in Embodiment 1 of the present invention under infrared light at 850nm. It can be seen from the figure that the defocus curves of the lens in each field of view are relatively concentrated under the infrared wavelength of 850nm, and the center defocus is small, indicating good confocality.

[0141] Figure 5 The figure shows the lateral chromatic aberration curve of the lens in the visible light range of 435nm-650nm according to Embodiment 1 of the present invention. It can be seen from the figure that the lens has small chromatic aberration and high color reproduction.

[0142] Figure 6 The figure shows the longitudinal chromatic aberration curve of the lens in the visible light range of 435nm-650nm according to Embodiment 1 of the present invention. It can be seen from the figure that the chromatic aberration on the lens axis is small, the color reproduction is good, the color difference is small, and the blue-purple fringing phenomenon is not obvious.

[0143] Figure 7 The image shows the field curvature and distortion of the lens in the visible light range of 435nm-650nm according to an embodiment of the present invention. The image shows that the field curvature and distortion of the lens at various wavelengths are well controlled, which effectively improves the image quality, ensures normal display of the image, reduces the phenomenon of image distortion, and reduces the difficulty of post-correction.

[0144] Figure 8 The image shows the MTF curve of the lens in Embodiment 2 of the present invention in the visible light range of 435nm-650nm. As can be seen from the figure, the lens has excellent imaging quality and high resolution when the spatial frequency is 125lp / mm.

[0145] Figure 9 The figure shows the defocus curve of the lens in the visible light range of 435nm-650nm according to Embodiment 2 of the present invention. It can be seen from the figure that the defocus curves of the lens in each field of view under visible light are relatively concentrated and the defocus amount is small.

[0146] Figure 10 The figure shows the defocus curve of the lens in Embodiment 2 of the present invention under infrared light at 850nm. It can be seen from the figure that the defocus curves of the lens in each field of view are relatively concentrated under the infrared wavelength of 850nm, and the center defocus is small, indicating good confocality.

[0147] Figure 11 The figure shows the lateral chromatic aberration curve of the lens in Embodiment 2 of the present invention under visible light 435nm-650nm. It can be seen from the figure that the lens has small chromatic aberration and high color reproduction.

[0148] Figure 12 The figure shows the longitudinal chromatic aberration curve of the lens in Embodiment 2 of the present invention under visible light 435nm-650nm. It can be seen from the figure that the chromatic aberration on the lens axis is small, the color reproduction is good, the color difference is small, and the blue-purple fringing phenomenon is not obvious.

[0149] Figure 13 The image shows the field curvature and distortion of the lens in Embodiment 2 of the present invention in the visible light range of 435nm-650nm. As can be seen from the image, the field curvature and distortion of the lens at each wavelength are well controlled, effectively improving the image quality.

[0150] Figure 14 The figure shows the MTF curve of the lens in Embodiment 3 of the present invention in the visible light range of 435nm-650nm. As can be seen from the figure, the lens has excellent imaging quality and high resolution when the spatial frequency is 125lp / mm.

[0151] Figure 15 The figure shows the defocus curve of the lens in the visible light range of 435nm-650nm in Embodiment 3 of the present invention. It can be seen from the figure that the defocus curves of the lens in each field of view under visible light are relatively concentrated and the defocus amount is small.

[0152] Figure 16 The figure shows the defocus curve of the lens in Embodiment 3 of the present invention under infrared light at 850nm. It can be seen from the figure that the defocus curves of the lens in each field of view are relatively concentrated under the infrared wavelength of 850nm, and the center defocus is small, indicating good confocality.

[0153] Figure 17 The figure shows the lateral chromatic aberration curve of the lens in Embodiment 3 of the present invention in the visible light range of 435nm-650nm. It can be seen from the figure that the lens has small chromatic aberration and high color reproduction.

[0154] Figure 18 The figure shows the longitudinal chromatic aberration curve of the lens in Embodiment 3 of the present invention under visible light 435nm-650nm. It can be seen from the figure that the chromatic aberration on the lens axis is small, the color reproduction is good, the color difference is small, and the blue-purple fringing phenomenon is not obvious.

[0155] Figure 19 The image shows the field curvature and distortion of the lens in Embodiment 3 of the present invention in the visible light range of 435nm-650nm. The image shows that the field curvature and distortion of the lens are well controlled at each wavelength, which effectively improves the image quality.

[0156] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. An optical imaging lens, characterized in that: The optical imaging lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical axis from the object side to the image side. The total number of lenses with optical power in the lens is seven, wherein: The object-side surface of the first lens is convex, the image-side surface of the first lens is concave, and the first lens has negative refractive power. The object-side surface of the second lens is concave, the image-side surface of the second lens is convex, and the second lens has positive refractive power. The object-side surface of the third lens is concave, the image-side surface of the third lens is convex, and the third lens has negative refractive power. The object-side surface of the fourth lens is convex, the image-side surface of the fourth lens is convex, and the fourth lens has positive refractive power. The object-side surface of the fifth lens is convex near the optical axis, and the image-side surface of the fifth lens is concave near the optical axis. The fifth lens has negative refractive power. The object-side surface of the sixth lens is convex near the optical axis, and the image-side surface of the sixth lens is concave near the optical axis. The sixth lens has negative refractive power. The object-side surface of the seventh lens is convex, and the image-side surface of the seventh lens near the optical axis is convex. The seventh lens has positive refractive power. The lens satisfies the following relationship: 0.9 ≤ | / |≤1.1, where The combined focal length of the first to the third lenses. The combined focal length of the fourth to seventh lenses.

2. The optical imaging lens according to claim 1, characterized in that: The focal length of the first lens The following relationship must be satisfied: -7mm≤ ≤-6 mm; The focal length of the second lens The following relationship must be satisfied: 15 mm ≤ ≤18 mm; The focal length of the third lens The following relationship must be satisfied: -20 mm ≤ ≤-15 mm; The focal length of the fourth lens The following relationship must be satisfied: 6 mm ≤ ≤7 mm; The focal length of the fifth lens The following relationship must be satisfied: -9 mm ≤ ≤-6.5 mm; The focal length of the sixth lens The following relationship must be satisfied: -130 mm ≤ ≤-110 mm; The focal length of the seventh lens The following relationship must be satisfied: 7 mm ≤ ≤8 mm.

3. An optical imaging lens according to claim 1 or 2, characterized in that: The focal length of the first lens The absolute value of the ratio to the overall focal length F of the lens satisfies the following relationship: 2 ≤ ( / F)≤2.5; The focal length of the second lens The absolute value of the ratio to the overall focal length F of the lens satisfies the following relationship: 3 ≤ ( / F)≤5; The focal length of the third lens The absolute value of the ratio to the overall focal length F of the lens satisfies the following relationship: 3 ≤ ( / F)≤5; The focal length of the fourth lens The absolute value of the ratio to the overall focal length F of the lens satisfies the following relationship: 1 ≤ ( / F)≤2; The focal length of the fifth lens The absolute value of the ratio to the overall focal length F of the lens satisfies the following relationship: 1 ≤ ( / F)≤2; The focal length of the sixth lens The absolute value of the ratio to the overall focal length F of the lens satisfies the following relationship: 25 ≤ ( / F)≤32; The focal length of the seventh lens The absolute value of the ratio to the overall focal length F of the lens satisfies the following relationship: 1 ≤ / F)≤2.

4. An optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: BFL / TTL≥0.2, where BFL is the distance from the center of the image side of the seventh lens to the imaging surface on the optical axis, and TTL is the distance from the first lens to the imaging surface on the optical axis.

5. An optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: 1.6≤ET6 / CT6≤1.7, where ET6 is the edge thickness of the sixth lens and CT6 is the center thickness of the sixth lens on the optical axis.

6. An optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: -1.8 ≤ / F≤-1.6; where, F is the combined focal length of the fifth and sixth lenses, and F is the overall focal length of the lens.

7. An optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: TTL≤26mm, where TTL is the distance from the first lens to the imaging surface on the optical axis.

8. An optical imaging lens according to claim 1, characterized in that: The first, third, and fourth lenses are made of glass lenses, while the second, fifth, sixth, and seventh lenses are made of plastic aspherical lenses.

9. An optical imaging lens according to claim 1, characterized in that: The lens satisfies the following relationship: 4.1mm ≤ EFL ≤ 4.2mm, where BFL is the distance on the optical axis from the center of the image side of the seventh lens to the imaging surface.

10. An optical imaging lens according to claim 1, characterized in that: An aperture stop is provided between the third lens and the fourth lens.

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