CN115524833A - Optical imaging lens - Google Patents

Abstract

The present disclosure relates to the field of imaging lenses, and more particularly, to an optical imaging lens, which includes a first lens element to a ninth lens element along an optical axis in sequence from an object side to an image side; the first lens, the second lens, the third lens and the fourth lens respectively comprise an object side surface which faces the object side and enables the imaging light to pass through and an image side surface which faces the image side and enables the imaging light to pass through; the first lens has a negative optical power, the second lens has a negative optical power, the third lens has a negative optical power, the fourth lens has a positive optical power, the fifth lens has a positive optical power, the sixth lens has a negative optical power, the seventh lens has a positive optical power, the eighth lens has a positive optical power, the ninth lens has a positive optical power, and the following conditions are satisfied: 1.4<(f _{Front side} /f _{Rear end} )<2.1; the spherical lens and the non-spherical lens are matched for use, so that the imaging quality is good.

Description

An optical imaging lens

technical field

This patent relates to the field of imaging lenses, in particular to an optical imaging lens.

Background technique

With the development of wireless technology, the application of wireless transmission technology is more and more accepted by all walks of life. As a special method of use, wireless image transmission is gradually favored by the majority of users and widely used in work and life. Video conferencing also plays an important role in work. Existing video conferencing lenses use too many lenses to correct aberrations, resulting in high overall cost of the lens; large lens distortion and small imaging range lead to poor imaging quality of the lens, which cannot meet the requirements of high-definition imaging.

Contents of the invention

In order to overcome the deficiencies of the prior art, the present invention provides an optical imaging lens, which can solve technical problems such as high cost caused by too many lenses, large lens distortion, and poor imaging quality caused by small imaging range.

In order to solve the above technical problems, the present invention provides the following technical solutions:

An optical imaging lens is characterized in that it comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, The eighth lens and the ninth lens; the first lens to the ninth lens each include an object side facing the object side and allowing the imaging light to pass through, and an image side facing the image side and allowing the imaging light to pass through;

The first lens has negative refractive power, the object side is convex, and the image side is concave;

The second lens has negative refractive power, the object side is convex, and the image side is concave;

The third lens has negative refractive power, the object side is convex, and the image side is concave;

The fourth lens has positive refractive power, the object side is convex, and the image side is flat or concave;

The fifth lens has positive refractive power, the object side is convex, and the image side is convex;

The sixth lens has negative refractive power, the object side is concave, and the image side is concave;

The seventh lens has positive refractive power, the object side is convex, and the image side is convex;

The eighth lens has positive refractive power, the object side is convex, and the image side is convex;

The ninth lens has positive refractive power, the object side is convex, and the image side is convex;

And meet the following conditions:

1.4<(f _before /f _after )<2.1;

The first lens to the fourth lens are the front group, the fifth lens to the ninth lens are the rear group, the f _front is the focal length of the front group lens, and the f _rear is the focal length of the rear group lens.

Further, the following conditional formula is met, 0.7< _{│f 4} /ffront│<1.2, and f ₄ is the focal length of the fourth lens.

Further, the following conditional formula is met, 6mm<CT ₄ , where CT ₄ is the lens thickness of the fourth lens along the optical axis.

Further, the following conditional formula is met, TTL/(f*IMH*(1-DIS))<2.5, the f is the focal length of the lens, the TTL is the total optical length of the lens, and the IMH is the half-image height of the lens, The DIS is the optical distortion of the lens.

Further, meet the following conditional formula, 1.6<nd1<1.8, 1.5<nd2<1.7, 1.5<nd3<1.6, 1.8<nd4, 1.5<nd5<1.7, 1.6<nd6<1.7, 1.5<nd7<1.6, 1.5< nd8<1.7 and 1.6<nd9<1.7, the nd1 to nd9 are the refractive indices of the first lens to the ninth lens respectively.

Further, in line with the series of conditional formulas, 50<vd1<65, 60<vd2<70, 50<vd3<60, vd4<30, 50<vd5<60, vd6<30, 50<vd7<60, 50<vd8< 60 and 50<vd9<70, the vd1 to vd9 are the Abbe coefficients of the first lens to the ninth lens respectively.

Further, the following conditions are met, 19<f ₁ <23, 13<f ₂ <14, 7<f ₃ <8, 8.5<f ₄ <9.5, 5<f ₅ <7, 4<f ₆ <5, 5<f ₇ <6, 4<f ₈ <27, and 20<f ₉ <30, where f ₁ to f ₉ are the focal lengths of the first lens to the ninth lens, respectively.

Further, the following conditions are met, 7.5<(f ₁ /f)<9, 2<(f 2 /f)< _{3, 2.5<(f 3 /f)<4.5} , 2<(f ₄ /f)< 3. 2<(f 5 /f)< _{3, 2.5<(f 6 /f)<3.5} , 1.5<(f ₇ /f)<3, 2<(f ₈ /f)<10 and 2<(f ₉ /f)<4, the f ₁ to f ₉ are the focal lengths of the first lens to the ninth lens, respectively.

Further, the third lens, the fifth lens, the sixth lens and the seventh lens are all plastic aspheric lenses, and the first lens, the second lens, the fourth lens, the eighth lens and the ninth lens are all Glass spherical lens.

Further, the following conditional formula is met, 2.49mm<f<2.51mm, where f is the focal length of the lens.

The beneficial effects of the present invention are:

This solution adopts a nine-piece structure, in which spherical lenses and aspheric lenses are used together, so that when the spatial frequency of the optical imaging system reaches 125lp/mm, the MTF of the full viewing angle is greater than 0.41, which has a good imaging effect and can be used with 1/ The 1.8" sensor can achieve 4K imaging resolution and meet the high-definition needs of users. At the same time, the distortion is controlled within 17%, ensuring that the imaging screen is displayed normally, reducing the phenomenon of graphic distortion, and the imaging quality is good.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore do not It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is an optical path diagram of the optical imaging lens described in Embodiment 1 of the present invention;

Fig. 2 is the MTF curve diagram of the optical imaging lens described in Embodiment 1 of the present invention;

Fig. 3 is a defocus curve diagram of the optical imaging lens described in Embodiment 1 of the present invention;

Fig. 4 is a lateral chromatic aberration curve diagram of the optical imaging lens described in Embodiment 1 of the present invention;

Fig. 5 is a graph of longitudinal chromatic aberration of the optical imaging lens according to Embodiment 1 of the present invention;

Fig. 6 is a field curvature and distortion diagram of the optical imaging lens described in Embodiment 1 of the present invention;

FIG. 7 is an optical path diagram of the optical imaging lens described in Embodiment 2 of the present invention;

FIG. 8 is an MTF curve diagram of the optical imaging lens described in Embodiment 2 of the present invention;

Fig. 9 is a defocus curve diagram of the optical imaging lens described in Embodiment 2 of the present invention;

Fig. 10 is a lateral chromatic aberration curve diagram of the optical imaging lens described in Embodiment 2 of the present invention;

Fig. 11 is a graph of longitudinal chromatic aberration of the optical imaging lens described in Embodiment 2 of the present invention;

Fig. 12 is a field curvature and distortion diagram of the optical imaging lens described in Embodiment 2 of the present invention;

Fig. 13 is an optical path diagram of the optical imaging lens described in Embodiment 3 of the present invention;

FIG. 14 is an MTF curve diagram of the optical imaging lens described in Embodiment 3 of the present invention;

Fig. 15 is a defocus curve diagram of the optical imaging lens described in Embodiment 3 of the present invention;

Fig. 16 is a lateral chromatic aberration curve diagram of the optical imaging lens described in Embodiment 3 of the present invention;

Fig. 17 is a graph of longitudinal chromatic aberration of the optical imaging lens described in Embodiment 3 of the present invention;

Fig. 18 is a diagram of field curvature and distortion of the optical imaging lens described in Embodiment 3 of the present invention.

Description of main component symbols

1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 8. Eighth lens; 9. Ninth lens; 10, diaphragm; 11, protective sheet; 12, imaging surface.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is some embodiments of the present invention, but not all of them. Based on the implementation manners in the present invention, all other implementation manners obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the implementation manners in the present invention, all other implementation manners obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

1-18, the present invention provides an optical imaging lens, which includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, and a fifth lens along an optical axis from the object side to the image side. Lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, and the ninth lens 9; the first lens 1 to the ninth lens 9 each include an object side facing the object side and allowing the imaging light to pass through and an object side facing the image. The image side and the image side through which the imaging light passes; also includes a diaphragm 10 , and the diaphragm 10 is arranged between the fourth lens 4 and the fifth lens 5 .

The first lens 1 has negative refractive power, the object side is convex, and the image side is concave;

The second lens 2 has negative refractive power, the object side is convex, and the image side is concave;

The third lens 3 has negative refractive power, the object side is convex, and the image side is concave;

The fourth lens 4 has positive refractive power, the object side is convex, and the image side is plane or concave;

The fifth lens 5 has positive refractive power, the object side is convex, and the image side is convex;

The sixth lens 6 has negative refractive power, the object side is concave, and the image side is concave;

The seventh lens 7 has positive refractive power, the object side is convex, and the image side is convex;

The eighth lens 8 has positive refractive power, the object side is convex, and the image side is convex;

The ninth lens 9 has positive refractive power, the object side is convex, and the image side is convex;

The image sides of the first lens 1 , the second lens 2 and the third lens 3 are all curved toward the direction of the diaphragm 10 , which is beneficial for the conditional expression of the lens to achieve a low distortion imaging effect at a large angle. The third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are plastic aspheric lenses, the first lens 1, the second lens 2, the fourth lens 4, the eighth lens 8 and the ninth lens 9 All are glass spherical lenses. Adding multiple pieces of plastic aspheric lenses to the glass spherical lens can better optimize the optical structure, which is beneficial to better achieve the design value in the design process of the optical imaging lens.

Preferably, the following conditional formula is met: 1.4<(f _front /f _rear )<2.1; the first lens 1 to the fourth lens 4 are the front group, the fifth lens 5 to the ninth lens 9 are the rear group, and f _front is the front The focal length of the group lens, _after f is the focal length of the rear group lens, controlling the front group lens and the rear group lens to satisfy the above formula can better allocate the focal power ratio between the front group lens and the rear group lens, and then better Control the imaging effect of the optical imaging lens.

Preferably, the following conditional formula is met, 6mm<CT ₄ , CT ₄ is the lens thickness of the fourth lens 4 along the optical axis, increasing the thickness of the fourth lens 4 can better correct the distortion caused by the correction of the first three lenses The aberrations brought about, so as to more effectively control the aberrations of the front group lens.

Preferably, the following conditional formula is met: 0.7<│f ₄ /f _Front │<1.2, f ₄ is the focal length of the fourth lens 4, while increasing the thickness of the fourth lens 4, the difference between the fourth lens 4 and the front group lens Controlling the focal length ratio between them can better correct the focal power of the front group lens and improve the aberration correction capability of the optical imaging lens.

Preferably, the following conditional formula is met: TTL/(f*IMH*(1-DIS))<2.5, f is the focal length of the lens, TTL is the total optical length of the lens, and IMH is the half-image height of the lens, that is, the maximum image formed by the lens Half of the height; DIS is the optical distortion of the lens, and the optical imaging lens is controlled to meet the above formula. The optical imaging lens can better control the total optical length under the premise of low distortion, and has a smaller volume, which is conducive to the assembly of the lens.

Preferably, the following conditions are met: 2.49mm<f<2.51mm, HFOV≥120°, TTL≤30mm, HFOV is the maximum field of view range that can be captured by the horizontal field of view of the optical imaging lens, and the shooting range is large, so that the image plane can Accommodates larger frames. The field of view and total optical length of the lens are controlled to meet the characteristics of a large field of view and a small overall size.

Preferably, the following conditions are met: 1.6<nd1<1.8, 1.5<nd2<1.7, 1.5<nd3<1.6, 1.8<nd4, 1.5<nd5<1.7, 1.6<nd6<1.7, 1.5<nd7<1.6, 1.5< nd8<1.7 and 1.6<nd<1.7, nd1 to nd9 are the refractive indices of the first lens 1 to the ninth lens 9 respectively.

Preferably, a series of conditional formulas are met: 50<vd1<65, 60<vd2<70, 50<vd3<60, vd4<30, 50<vd5<60, vd6<30, 50<vd7<60, 50<vd8< 60 and 50<vd9<70, where vd1 to vd9 are the Abbe coefficients of the first lens 1 to the ninth lens 9 respectively.

Preferably, the following conditions are met: 19<f ₁ <23, 13<f ₂ <14, 7<f ₃ <8, 8.5<f ₄ <9.5, 5<f ₅ <7, 4<f ₆ <5, 5<f ₇ <6, 4<f ₈ <27 and 20<f ₉ <30, f ₁ to f ₉ are the focal lengths of the first lens 1 to the ninth lens 9 respectively.

Preferably, the following conditions are met, 7.5<(f ₁ /f)<9, 2<(f 2 /f)< _{3, 2.5<(f 3 /f)<4.5} , 2<(f ₄ /f)< 3. 2<(f 5 /f)< _{3, 2.5<(f 6 /f)<3.5} , 1.5<(f ₇ /f)<3, 2<(f ₈ /f)<10 and 2<(f ₉ /f)<4.

The optical imaging lens of the present invention will be described in detail below with specific embodiments.

Embodiment one

Please refer to accompanying drawing 1-6, the present invention provides a kind of optical imaging lens, comprises first lens 1 to ninth lens 9 successively along an optical axis from object side to image side; First lens 1 to ninth lens 9 comprises respectively An object side facing the object side and allowing the imaging light to pass through, and an image side facing the image side and allowing the imaging light to pass through; it also includes a diaphragm 10 , and the diaphragm 10 is arranged between the fourth lens 4 and the fifth lens 5 .

The first lens 1 has negative refractive power, the object side is convex, and the image side is concave;

The second lens 2 has negative refractive power, the object side is convex, and the image side is concave;

The third lens 3 has negative refractive power, the object side is convex, and the image side is concave;

The fourth lens 4 has a positive refractive power, the object side is a convex surface, and the image side is a plane;

The fifth lens 5 has positive refractive power, the object side is convex, and the image side is convex;

The sixth lens 6 has negative refractive power, the object side is concave, and the image side is concave;

The seventh lens 7 has positive refractive power, the object side is convex, and the image side is convex;

The eighth lens 8 has positive refractive power, the object side is convex, and the image side is convex;

The ninth lens 9 has positive refractive power, the object side is convex, and the image side is convex;

The detailed optical data of this embodiment are shown in Table 1.

The detailed optical data of table 1 embodiment one

In this specific embodiment, the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are all plastic aspheric lenses, and the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens Please refer to the following table 2 for the detailed description of the aspheric surface of 7:

Table 2: Aspheric Coefficients

The focal length of the optical imaging lens described in this embodiment is 2.50mm, the TTL is 30mm, and F#=2.4.

In this specific embodiment, please refer to the accompanying drawing 1 for the optical path diagram of the optical imaging lens. Please refer to the accompanying drawing 2 for the MTF curves of the optical imaging lens disclosed in this embodiment with different focal lengths in the visible light 435nm-650nm band. It can be seen from the figure that the spatial frequency of the optical imaging lens described in this embodiment reaches 125lp/mm When the full viewing angle MTF is greater than 0.41, it has a good imaging effect. It can be matched with a 1/1.8" sensor to achieve 4K imaging clarity and meet the user's high-definition use requirements. The optical imaging lens disclosed in this embodiment is used in For the defocus curves in the 435nm-650nm band of visible light, please refer to attached drawing 3. Different curves represent the defocus curves in the meridian direction and sagittal direction in different fields of view. It can be seen from attached drawing 3 that almost all the peak values of the curves are All near the zero offset vertical axis, the defocus characteristics of the optical imaging lens are relatively excellent at this time, and a larger effective focal depth range can be obtained. The optical imaging lens disclosed in this embodiment has a lateral Please refer to the accompanying drawing 4 for the chromatic aberration curve. It can be seen from the accompanying drawing 4 that the maximum lateral chromatic aberration of the optical imaging lens working in the visible light band is 18 μm; the longitudinal chromatic aberration of the optical imaging lens disclosed in this embodiment under the visible light 435nm-650nm band Please refer to the accompanying drawing 5 for the curve, as can be seen from the accompanying drawing 5, the maximum longitudinal chromatic aberration of the optical imaging lens working in the visible light band is 0.04mm, and the lateral chromatic aberration and longitudinal chromatic aberration of this optical lens are preferably corrected. For the field curvature distortion curve of the disclosed optical imaging lens in the visible light 435nm-650nm band, please refer to the accompanying drawing 6. From the accompanying drawing 6, it can be seen that the optical distortion of the optical imaging lens is less than 17%, the imaging quality is good, and the difficulty of later correction is reduced.

Embodiment two

Please refer to accompanying drawings 7-12, the present invention provides a kind of optical imaging lens, comprises first lens 1 to ninth lens 9 sequentially along an optical axis from object side to image side; First lens 1 to ninth lens 9 includes respectively An object side facing the object side and allowing the imaging light to pass through, and an image side facing the image side and allowing the imaging light to pass through; it also includes a diaphragm 10 , and the diaphragm 10 is arranged between the fourth lens 4 and the fifth lens 5 .

The first lens 1 has negative refractive power, the object side is convex, and the image side is concave;

The second lens 2 has negative refractive power, the object side is convex, and the image side is concave;

The third lens 3 has negative refractive power, the object side is convex, and the image side is concave;

The fourth lens 4 has positive refractive power, the object side is convex, and the image side is concave;

The fifth lens 5 has positive refractive power, the object side is convex, and the image side is convex;

The sixth lens 6 has negative refractive power, the object side is concave, and the image side is concave;

The seventh lens 7 has positive refractive power, the object side is convex, and the image side is convex;

The eighth lens 8 has positive refractive power, the object side is convex, and the image side is convex;

The ninth lens 9 has positive refractive power, the object side is convex, and the image side is convex;

The detailed optical data of this embodiment is shown in Table 3.

The detailed optical data of table 3 embodiment one

In this specific embodiment, the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are all plastic aspheric lenses, and the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens Please refer to the following table 4 for the detailed description of the aspheric surface of 7:

Table 4: Aspheric Coefficients

The focal length of the optical imaging lens described in this embodiment is 2.50mm, the TTL is 30mm, and F#=2.4.

In this specific embodiment, please refer to the accompanying drawing 7 for the optical path diagram of the optical imaging lens. Please refer to the accompanying drawing 8 for the MTF curves of the optical imaging lens disclosed in this embodiment with different focal lengths in the visible light 435nm-650nm band. It can be seen from the figure that the spatial frequency of the optical imaging lens described in this embodiment reaches 125lp/mm When the full viewing angle MTF is greater than 0.40, it has a good imaging effect. It can be matched with a 1/1.8 "sensor to achieve 4K imaging definition and meet the user's high-definition use requirements. The optical imaging lens disclosed in this embodiment is used in For the defocus curves in the 435nm-650nm band of visible light, please refer to attached drawing 9. Different curves represent the defocus curves in the meridian direction and sagittal direction in different fields of view. It can be seen from attached drawing 9 that almost all the peak values of the curves are All near the zero offset vertical axis, the defocus characteristics of the optical imaging lens are relatively excellent at this time, and a larger effective focal depth range can be obtained. The optical imaging lens disclosed in this embodiment has a lateral Please refer to the accompanying drawing 10 for the chromatic aberration curve. It can be seen from the accompanying drawing 10 that the maximum lateral chromatic aberration of the optical imaging lens working in the visible light band is 18.2 μm; Please refer to the accompanying drawing 11 for the chromatic aberration curve. It can be seen from the accompanying drawing 11 that the maximum longitudinal chromatic aberration of the optical imaging lens working in the visible light band is 0.04 mm, and the lateral chromatic aberration and longitudinal chromatic aberration of this optical lens are well corrected. This embodiment For the field curvature distortion curve of the disclosed optical imaging lens in the visible light 435nm-650nm band, please refer to the accompanying drawing 12. From the accompanying drawing 12, it can be seen that the optical distortion of the optical imaging lens is less than 16.5%, the imaging quality is good, and the difficulty of later correction is reduced.

Embodiment three

Please refer to accompanying drawings 13-18, the present invention provides a kind of optical imaging lens, comprises first lens 1 to ninth lens 9 sequentially along an optical axis from object side to image side; First lens 1 to ninth lens 9 includes respectively An object side facing the object side and allowing the imaging light to pass through, and an image side facing the image side and allowing the imaging light to pass through; it also includes a diaphragm 10 , and the diaphragm 10 is arranged between the fourth lens 4 and the fifth lens 5 .

The first lens 1 has negative refractive power, the object side is convex, and the image side is concave;

The second lens 2 has negative refractive power, the object side is convex, and the image side is concave;

The third lens 3 has negative refractive power, the object side is convex, and the image side is concave;

The fourth lens 4 has positive refractive power, the object side is convex, and the image side is concave;

The fifth lens 5 has positive refractive power, the object side is convex, and the image side is convex;

The sixth lens 6 has negative refractive power, the object side is concave, and the image side is concave;

The seventh lens 7 has positive refractive power, the object side is convex, and the image side is convex;

The eighth lens 8 has positive refractive power, the object side is convex, and the image side is convex;

The ninth lens 9 has positive refractive power, the object side is convex, and the image side is convex;

The detailed optical data of this embodiment is shown in Table 5.

The detailed optical data of table 5 embodiment one

In this specific embodiment, the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens 7 are all plastic aspheric lenses, and the third lens 3, the fifth lens 5, the sixth lens 6 and the seventh lens Please refer to the following table 6 for the detailed description of the aspheric surface of 7:

Table 6: Aspherical Coefficients

The focal length of the optical imaging lens described in this embodiment is 2.497 mm, the TTL is 30 mm, and F#=2.4.

In this specific embodiment, please refer to FIG. 13 for the optical path diagram of the optical imaging lens. For the MTF curves of the optical imaging lens disclosed in this embodiment with different focal lengths in the visible light 435nm-650nm band, please refer to accompanying drawing 14, it can be seen from the figure that the optical imaging lens described in this embodiment reaches a spatial frequency of 125lp/mm When the full viewing angle MTF is greater than 0.40, it has a good imaging effect. It can be matched with a 1/1.8 "sensor to achieve 4K imaging definition and meet the user's high-definition use requirements. The optical imaging lens disclosed in this embodiment is used in For the defocus curves in the 435nm-650nm band of visible light, please refer to Figure 15. Different curves represent the defocus curves in the meridional and sagittal directions in different fields of view. It can be seen from Figure 15 that almost all curves have peak values All near the zero offset vertical axis, the defocus characteristics of the optical imaging lens are relatively excellent at this time, and a larger effective focal depth range can be obtained. The optical imaging lens disclosed in this embodiment has a lateral Please refer to the accompanying drawing 16 for the chromatic aberration curve. It can be seen from the accompanying drawing 16 that the maximum lateral chromatic aberration of the optical imaging lens working in the visible light band is 18 μm; the longitudinal chromatic aberration of the optical imaging lens disclosed in this embodiment under the visible light 435nm-650nm band Please refer to the accompanying drawing 17 for the curve, as can be seen from the accompanying drawing 17, the maximum longitudinal chromatic aberration of the optical imaging lens working in the visible light band is 0.04mm, and the lateral chromatic aberration and longitudinal chromatic aberration of the optical lens are well corrected. For the field curvature distortion curve of the disclosed optical imaging lens in the visible light 435nm-650nm band, please refer to the accompanying drawing 18. From the accompanying drawing 18, it can be seen that the optical distortion of the optical imaging lens is less than 17%, which ensures that the imaging screen is displayed normally and reduces the phenomenon of graphic distortion , the image quality is good, and the difficulty of post-correction is reduced.

Table 7 is the numerical value of relevant important parameter of three embodiments of the present invention:

Table 7: Relevant important parameters of each embodiment

Conditional Example 1 Example 2 Example 3 0.7&lt;│f₄/f_before│&lt;1.2 0.7935 1.1689 1.1673 6&lt;CT₄ 6.904 6.325 6.976 EFL 2.7659 2.7653 2.7606 1.4&lt;(f_before/f_after)&lt;2.1 2.012 1.478 1.506 TTL/(f*IMH*(1-DIS))<2.5 2.335 2.332 2.338

In the present invention, unless otherwise clearly specified and limited, a first feature being "on" or "under" a second feature may include direct contact between the first and second features, and may also include the first and second features Not in direct contact but through another characteristic contact between them. Moreover, "above", "above" and "above" the first feature on the second feature include that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. "Below", "beneath" and "under" the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above-mentioned embodiments, and those described in the above-mentioned embodiments and description are only preferred examples of the present invention, and are not intended to limit the present invention, without departing from the spirit and scope of the present invention. Under the premise, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (10)

1. An optical imaging lens is characterized by comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens in sequence from an object side to an image side along an optical axis; the first lens element to the ninth lens element each include an object-side surface facing the object side and allowing the imaging light to pass therethrough, and an image-side surface facing the image side and allowing the imaging light to pass therethrough;

the first lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface;

the second lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface;

the third lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface;

the fourth lens has positive focal power, the object side surface is a convex surface, and the image side surface is a plane or a concave surface;

the fifth lens has positive focal power, the object side surface is a convex surface, and the image side surface is a convex surface;

the sixth lens has negative focal power, the object side surface is a concave surface, and the image side surface is a concave surface;

the seventh lens has positive focal power, the object side surface is a convex surface, and the image side surface is a convex surface;

the eighth lens has positive focal power, the object side surface is a convex surface, and the image side surface is a convex surface;

the ninth lens has positive focal power, the object side surface is a convex surface, and the image side surface is a convex surface;

and the following conditional expressions are satisfied:

1.4<(f _{front side} /f _{Rear end} )<2.1；

The first to fourth lenses are front groups, the fifth to ninth lenses are rear groups, and f _{Front side} Is the focal length of the front group lens, said f _{Rear end} The focal length of the rear group lens.

2. The optical imaging lens according to claim 1, characterized in that: satisfies the following conditional formula, 0.7<│f ₄ /f _{Front side} │<1.2, said f ₄ Is the focal length of the fourth lens.

3. The optical imaging lens of claim 1, characterized in that: according to the following conditional formula, 6mm<CT ₄ The CT ₄ Is the thickness of the fourth lens along the optical axis.

4. The optical imaging lens according to claim 1, characterized in that: according to the following conditional expression, TTL/(f IMH (1-DIS)) <2.5, wherein f is the focal length of the lens, TTL is the optical total length of the lens, IMH is the half-image height of the lens, and DIS is the optical distortion of the lens.

5. The optical imaging lens of claim 1, characterized in that: the following conditional expressions are satisfied, 1.6-nd 1-or 1.8-or 1.5-or-nd 2-or-quarter 1.7-or 1.5-or-quarter 3-or-1.6-or 1.8-or-quarter 4-or 1.5-or-quarter 5-or-quarter 1.7-or 1.6-or-quarter 1.7-or 1.5-or-quarter 1.6-or-quarter 8-or-quarter 1.7-or 1.6-or-quarter 9-or-quarter 1.7-or-quarter, and nd1 to nd9 are refractive indices of first to ninth lenses, respectively.

6. The optical imaging lens of claim 1, characterized in that: in accordance with a series of conditional expressions, 50-t & lt 1 & gt, 65, 60-t & lt 2 & gt, 50-t & lt 3 & gt, v & lt 4 & lt 30, 50-t & lt 5 & gt, v & lt 6 & lt 30, 50-t & lt 7 & lt 60, 50-t & lt 8 & gt, 60 and 50-t 9 & lt 70 & gt are provided, and the v & lt 1 & gt to the v & lt 9 & gt are respectively abbe coefficients of first to ninth lenses.

7. The optical imaging lens according to claim 1, characterized in that: satisfies the following conditional formula 19<f ₁ <23、13<f ₂ <14、7<f ₃ <8、8.5<f ₄ <9.5、5<f ₅ <7、4<f ₆ <5、5<f ₇ <6、4<f ₈ <27 and 20<f ₉ <30, said f ₁ To f ₉ The focal lengths of the first lens to the ninth lens are respectively.

8. The optical imaging lens according to claim 1, characterized in that: satisfies the following conditional formula, 7.5<(f ₁ /f)<9、2<(f ₂ /f)<3、2.5<(f ₃ /f)<4.5、2<(f ₄ /f)<3、2<(f ₅ /f)<3、2.5<(f ₆ /f)<3.5、1.5<(f ₇ /f)<3、2<(f ₈ /f)<10 and 2<(f ₉ /f)<4, said f ₁ To f ₉ The focal lengths of the first lens to the ninth lens are respectively, and f is the focal length of the lens.

9. The optical imaging lens according to claim 1, characterized in that: the third lens, the fifth lens, the sixth lens and the seventh lens are all plastic aspheric lenses, and the first lens, the second lens, the fourth lens, the eighth lens and the ninth lens are all glass spherical lenses.

10. The optical imaging lens according to claim 1, characterized in that: the following conditional expression is met, 2.49mm and f are woven together for 2.51mm, and f is the focal length of the lens.

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