CN108490582B - Imaging lens and image acquisition device having the same - Google Patents

Abstract

The invention discloses an imaging lens, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, wherein the first lens has positive refractive power, the second lens has negative refractive power, the fifth lens has negative refractive power, the object side surface of the fifth lens is of a concave structure, and the image side surface of the fifth lens is of a convex structure; the sixth lens element with positive refractive power has a convex object-side surface at paraxial region, at least one inflection point on the object-side surface, and a convex image-side surface; the seventh lens element with negative refractive power has a concave object-side surface and a concave image-side surface at a paraxial region, and the image-side surface has at least one inflection point on an off-axis region; by combining the surface shape structure of each lens of the seven-lens type imaging lens and the optimization range of the optical parameters, the imaging lens can effectively shorten the total length of the imaging lens and improve the visual angle of the lens under the condition of maintaining high imaging quality, and has high resolution brought by high pixels.

Description

Imaging lens and image acquisition device having the same

technical field

The present invention relates to the technical field of imaging devices, and in particular, to an imaging lens and an image acquisition device having the imaging lens.

Background technique

With the rapid development of electronic technology in recent years, portable and portable electronic devices have been rapidly popularized. The popularity of mobile and portable electronic devices has led to the vigorous development of modules such as imaging lenses and various sensors. At the same time, the application of imaging lenses has been more and more widely used. For example, the highly popular smartphones, tablet computers, driving recorders, and action cameras all use imaging lenses. While bringing great convenience to life, people's requirements for mobile electronic equipment terminals are also getting higher and higher. The existing intelligent portable electronic equipment is not only used to shoot long-range shots, but also used to shoot portraits, close-up shots, etc., which is very important for imaging lenses. The resolution, aperture, field of view, etc. put forward higher requirements.

At present, most of the mainstream imaging lenses adopt a five-lens or six-lens lens design. Although this structure can be made light and thin, it is difficult to improve the pixel and imaging quality on this basis. In addition, because the current seven-element imaging lens has a large distance on the optical axis from the object side of the first lens to the imaging surface, it is not conducive to the thinning of mobile phones and digital cameras.

In view of this, there is currently a need for an imaging lens with a short overall length, a large field of view, and good imaging quality. Therefore, how to produce an imaging lens that meets the needs of consumer electronic products, with good imaging quality, excellent field of view, large aperture, and short lens length, has long been an eager pursuit in the art.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an imaging lens, which is used to adapt to each electronic imaging module device, by means of the optimization range of the surface structure and optical parameters of each lens of the seven-lens imaging lens proposed by the present invention. Combined, the imaging lens can effectively shorten the overall length of the imaging lens and improve the lens angle of view while maintaining high image quality. The portable device is used, such as a mobile phone, a PDA, a computer, a camera, a driving recorder or a camera, etc. The invention also provides an image acquisition device.

For this purpose, the present invention adopts the following technical solutions:

An 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 in sequence from the object side to the image side, and each lens has a lens facing the object side. And an object side surface that allows the imaging light to pass through and an image side surface that faces the image side and allows the imaging light to pass;

The first lens has a positive refractive power, and the object side surface is a convex structure;

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

the third lens has refractive power;

the fourth lens has refractive power;

The fifth lens has a negative refractive power, its object side is a concave structure, and its image side is a convex structure;

The sixth lens has a positive refractive power, the object side surface is a convex structure at the near optical axis, and the object side surface has at least one curve inflection point, and its image side surface is a convex surface structure;

The seventh lens has a negative refractive power, the object side surface and the image side surface are both concave structures at the near optical axis, and the image side surface has at least one curve inflection point at the off-axis;

The imaging lens satisfies the following relationship:

1.0<f/f16;

25.0<|f3|/CT3<35.0;

2.0<(CT4+CT5+CT6)/(AG45+AG56)<8.0;

Wherein, f is the focal length of the imaging lens, f16 is the combined focal length of the first lens to the sixth lens, f3 is the focal length of the third lens, and CT3 is the center thickness of the third lens on the optical axis , CT4 is the central thickness of the fourth lens on the optical axis, CT5 is the central thickness of the fifth lens on the optical axis, CT6 is the central thickness of the sixth lens on the optical axis, and AG45 is the central thickness of the sixth lens on the optical axis The air distance between the fourth lens and the fifth lens on the optical axis, AG56 is the air distance between the fifth lens and the sixth lens on the optical axis.

Optionally, the object side of the third lens has a convex structure at the near optical axis, and the image side of the third lens has a convex structure.

Optionally, the following relationship is also satisfied: -2.0<R61/R62<-0.5, where R61 is the radius of curvature of the object-side surface of the sixth lens, and R62 is the radius of curvature of the image-side surface of the sixth lens.

Optionally, the following relationship is also satisfied: 1.0<f15/f16<2.0, where f15 is the combined focal length of the first lens to the fifth lens.

Optionally, the following relationship is also satisfied: 0.8<f26/f36<2.0, where f26 is the combined focal length of the second lens to the sixth lens, and f36 is the combined focal length of the third lens to the sixth lens.

Optionally, the following relationship is also satisfied: 10<(f+f6)(f+f7)<30, where f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

Optionally, the following relationship is also satisfied: 0.4<LCT14/LCT26<1.0, where LCT14 is the distance on the optical axis from the object side of the first lens to the image side of the fourth lens, and LCT26 is the object side of the second lens. The distance from the side to the image side of the sixth lens on the optical axis.

Optionally, the following relational formula is also satisfied: 1.4<CT6/ET6<2.2, where ET6 is the edge thickness of the sixth lens.

Optionally, the object side of the third lens is a concave structure, and its image side is a convex structure, and the following relationship is also satisfied:

0.4<CT3/ET3<0.8, where ET3 is the edge thickness of the third lens.

Optionally, the following relationship is also satisfied: 1.0<(R41+R42)/(R41-R42)<1.6, where R41 is the radius of curvature of the object-side surface of the fourth lens, and R42 is the image of the fourth lens The radius of curvature of the side surface.

Optionally, the following relationship is also satisfied: -5.50<(f/R51+f/R52)<-4.0, where R51 is the radius of curvature of the object-side surface of the fifth lens, and R52 is the image of the fifth lens The radius of curvature of the side surface.

An image acquisition device includes the imaging lens described above.

Optionally, the image acquisition device is a mobile phone, a PDA, a computer, a camera, a driving recorder or a camera.

Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

The imaging lens provided by the embodiment of the present invention is a seven-lens type, and the surface structure of each lens is combined with the optimized range of optical parameters, which can effectively shorten the overall length of the imaging lens and improve the Its lens angle of view has high resolution brought by high pixels, so it can be used for small or thin portable devices that need to be equipped with high imaging quality equipment.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1 is a schematic diagram of an imaging lens according to Embodiment 1 of the present invention.

FIG. 2 is a diagram of astigmatism and distortion of an imaging lens provided in the first embodiment.

FIG. 3 is a spherical aberration diagram of an imaging lens provided in the first embodiment.

FIG. 4 is a schematic diagram of an imaging lens according to Embodiment 2 of the present invention.

FIG. 5 is a diagram of astigmatism and distortion of an imaging lens provided in the second embodiment.

FIG. 6 is a spherical aberration diagram of an imaging lens provided in the second embodiment.

FIG. 7 is a schematic diagram of an imaging lens according to Embodiment 3 of the present invention.

FIG. 8 is a diagram of astigmatism and distortion of an imaging lens provided in the third embodiment.

FIG. 9 is a spherical aberration diagram of an imaging lens provided in the third embodiment.

FIG. 10 is a schematic diagram of an imaging lens according to Embodiment 4 of the present invention.

FIG. 11 is a diagram of astigmatism and distortion of an imaging lens provided in the fourth embodiment.

FIG. 12 is a spherical aberration diagram of an imaging lens provided in the fourth embodiment.

Illustration description:

The first lens 10; the second lens 20; the third lens 30; the fourth lens 40; the fifth lens 50; the sixth lens 60; the seventh lens 70; the infrared filter 80;

Detailed ways

In order to make the purpose, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the following The described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

For the convenience of description, first define the contents of the following symbols:

f: the focal length of the imaging lens;

f3: the focal length of the third lens;

f6: the focal length of the sixth lens;

f7: the focal length of the seventh lens;

f15: the combined focal length of the first lens to the fifth lens;

f16: the combined focal length of the first lens to the sixth lens;

f26: the combined focal length of the second lens to the sixth lens;

f36: the combined focal length of the third lens to the sixth lens;

R41: the radius of curvature of the object-side surface of the fourth lens;

R42: The curvature radius of the image side surface of the fourth lens;

R51: the radius of curvature of the object-side surface of the fifth lens;

R52: The curvature radius of the image side surface of the fifth lens;

R61: the radius of curvature of the object-side surface of the sixth lens;

R62: The curvature radius of the image-side surface of the sixth lens;

CT3: the central thickness of the third lens on the optical axis;

CT4: the center thickness of the fourth lens on the optical axis;

CT5: the central thickness of the fifth lens on the optical axis;

CT6: the central thickness of the sixth lens on the optical axis;

ET3: the edge thickness of the third lens;

ET6: the edge thickness of the sixth lens;

AG45: the air distance between the fourth lens and the fifth lens on the optical axis;

AG56: the air distance between the fifth lens and the sixth lens on the optical axis;

LCT14: the distance on the optical axis from the object side of the first lens to the image side of the fourth lens;

LCT26: The distance on the optical axis from the object side of the second lens to the image side of the sixth lens.

An embodiment of the present invention provides an imaging lens, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens in sequence from the object side to the image side, each lens Both have 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 a positive refractive power, and the object side surface is a convex structure;

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

the third lens has refractive power;

the fourth lens has refractive power;

The fifth lens has a negative refractive power, its object side is a concave structure, and its image side is a convex structure;

The sixth lens has a positive refractive power, the object side surface is a convex structure at the near optical axis, and the object side surface has at least one curve inflection point, and its image side surface is a convex surface structure;

The seventh lens has a negative refractive power, the object side surface and the image side surface are both concave structures at the near optical axis, and the image side surface has at least one curve inflection point at the off-axis.

The imaging lens satisfies the following relationship:

1.0<f/f16;

25.0<|f3|/CT3<35.0;

2.0<(CT4+CT5+CT6)/(AG45+AG56)<8.0.

The above-mentioned imaging lens, through the first lens with positive refractive power, can condense the light of large viewing angle entering the imaging lens, and suppress the spherical aberration generated by the first lens through the second lens with meniscus shape with negative refractive power, Make sure that the aberration of this segment is not too large. Through the concave structure on the side of the object and the convex structure on the image side, the fifth lens with a meniscus-shaped negative refractive power pulls the light up. The center part of the light is focused by the sixth lens whose center thickness is greater than the edge thickness, and both the object side and the image side have a biconvex structure, and guide the edge part of the light to ensure the image height, so that the image surface curvature and distortion are well corrected. The seventh lens closest to the image side of the imaging lens has a double-concave structure at the near optical axis, and the edge thickness is greater than the center thickness, which plays a role in suppressing the refraction angle of off-axis light to a small extent, avoiding excessive incident light angle of the main light. Too large can cause the light not to focus on the photosensitive area, resulting in darkening or discoloration of the image.

Further, the imaging lens satisfies the relationship: 1.0<f/f16, which is used to limit the ratio range between the focal length of the imaging lens and the combined focal length of the first lens to the sixth lens, which is beneficial to the optical optimization of the entire lens group, and at the same time make the structure compact. At the same time, the imaging lens also satisfies the relation: 25.0<|f3|/CT3<35.0, and this condition is used to limit the ratio range between the focal length of the third lens and the central thickness of the third lens. When the ratio exceeds the upper limit of 35.0, it means that the focal length value of the third lens is too large and the center thickness is too small. At this time, the sensitivity of the third lens is poor and the process forming conditions are poor. When the ratio is lower than the lower limit of 25.0, it means that the focal length of the third lens is too small and the center thickness is too thick, which is also not conducive to process molding and the overall sensitivity optimization of the imaging lens.

Further, the imaging lens satisfies the relationship: 2.0<(CT4+CT5+CT6)/(AG45+AG56)<8.0, which can effectively make the fourth lens, the fifth lens and the sixth lens in the second half cooperate in structure It is more compact, so that the total length of the imaging lens is shortened and the miniaturization of the imaging lens is ensured.

Further, the sixth lens satisfies the relationship: -2.0<R61/R62<-0.5, which ensures the biconvex structure shape of the object side and the image side of the sixth lens at the near optical axis, which is beneficial to the correction of aberrations such as astigmatic distortion , and the shape of the lens is easier to form in the process. When R61/R62 exceeds this range, the shape of the lens tends to become more curved, which makes it difficult to form, and the incident light angle will be too large, which will affect the image quality.

Further, the relationship between the combined focal length f15 of the first lens to the fifth lens and the combined focal length f16 of the first lens to the sixth lens satisfies the relationship: 1.0<f15/f16<2.0, by setting the range of the combined focal length, the combined focal length is guaranteed to be combined. The focal length will not be too large or too small to affect the image quality.

Preferably, the imaging lens also satisfies the following relationship: 0.8<f26/f36<2.0.

Further, the relationship between the focal length of the imaging lens, the focal length of the sixth lens and the focal length of the seventh lens satisfies the relationship: 10<(f+f6)(f+f7)<30, by adjusting the focal length relationship between the two lenses , to ensure a reasonable configuration of the focal length with the imaging lens, and to control the aberration effect caused by the amount of light deflection when the TTL is reduced, improving the imaging quality.

Further, the distance LCT14 from the object side of the first lens to the image side of the fourth lens on the optical axis and the distance LCT26 from the object side of the second lens to the image side of the sixth lens on the optical axis satisfy the relationship: 0.4<LCT14/LCT26< 1.0, so that the distance between different lenses can be better controlled, which is more convenient in structural design.

Further, the central thickness and the edge thickness of the sixth lens satisfy the relational formula: 1.4<CT6/ET6<2.2. At the same time, the object side of the third lens is a concave structure, and its image side is a convex structure. The center thickness and edge thickness of the third lens satisfy the relationship: 0.4<CT3/ET3<0.8. By controlling the ratio of the thickness of different parts of the lens, the lens can be Satisfy better molding conditions and reduce production costs.

Further, the radius of curvature of the object side and the image side of the fourth lens satisfies the relationship: 1.0<(R41+R42)/(R41-R42)<1.6, which can effectively control the shape of the fourth lens and is conducive to the formation of the fourth lens. And avoid forming defects and stress due to the excessively large surface curvature radius of the fourth lens, and at the same time obtain the ability to balance part of the field curvature.

Preferably, the imaging lens also satisfies the following relationship: -5.50<(f/R51+f/R52)<-4.0.

The imaging lens provided by the embodiment of the present invention is a seven-lens type, which is used to adapt to each electronic imaging module device. It can effectively shorten the length of the imaging lens and improve the angle of view of the lens while maintaining high image quality. Such as mobile phones, PDAs, computers, cameras, driving recorders or cameras, etc.

Furthermore, when the aperture number of the imaging lens is Fno=2.0, it has the advantage of large aperture, which ensures sufficient light input, which can effectively improve the sensitivity and ensure better image quality.

The imaging lens adopts the structure of seven aspherical lenses. Its suitable surface shape and higher-order aspherical coefficient can effectively correct various aberrations such as field curvature, astigmatism, and chromatic aberration of magnification. At the same time, the imaging lens has an excellent thickness-to-thickness ratio, good sensitivity, improved process yield and reduced production cost.

The aspheric curve equation of each lens is expressed as follows:

Among them, X is the point on the aspheric surface whose distance from the optical axis is Y, and its relative height to the tangent plane tangent to the vertex on the optical axis of the aspheric surface; R is the radius of curvature; Y is the perpendicularity of the point on the aspheric curve to the optical axis distance; k is the cone coefficient; A _i is the i-th order aspheric coefficient.

Preferably, the lens material of the imaging lens is made of plastic material, and the plastic material has the characteristics of precision molding to realize mass production, which can greatly reduce the processing cost of the imaging lens, thereby greatly reducing the manufacturing cost of the imaging lens, which is convenient for large-scale production. promotion.

An embodiment of the present invention further provides an image acquisition device, including the imaging lens applied with the above. The image capturing device may be various mobile terminals, photographing devices, etc., such as mobile phones, PDAs, computers, cameras, driving recorders or cameras.

The technical solutions of the present invention will be further described below with reference to the accompanying drawings and through specific embodiments.

The following are four specific embodiments.

Example 1

Referring to FIG. 1 , the imaging lens provided in this embodiment includes a first lens 10 , a second lens 20 , a third lens 30 , a fourth lens 40 , a fifth lens 50 , and a sixth lens 60 in order from the object side to the image side , the seventh lens 70, the infrared filter 80 and the imaging surface 90, each lens has an object side facing the object side and passing the imaging light and an image side facing the image side and allowing the imaging light to pass;

The first lens 10 has a positive refractive power, and its object side surface is a convex structure;

The second lens 20 has a negative refractive power, the object side is a convex structure, and its image side is a concave structure;

the third lens 30 has refractive power;

The fourth lens 40 has refractive power;

The fifth lens 50 has a negative refractive power, and its object side is a concave structure, and its image side is a convex structure;

The sixth lens 60 has a positive refractive power, the object side surface is a convex surface structure at the near optical axis, and the object side surface has at least one curve inflection point, and its image side surface is a convex surface structure;

The seventh lens 70 has a negative refractive power, the object side surface and the image side surface are both concave structures at the near optical axis, and the image side surface has at least one curve inflection point at off-axis;

The imaging lens satisfies the following relationship:

1.0<f/f16;

25.0<|f3|/CT3<35.0;

2.0<(CT4+CT5+CT6)/(AG45+AG56)<8.0.

It should be noted that, in the four specific embodiments in this application, the convex structure on the object side of the lens means that the object side of the lens is cut at any point on the surface, and the surface is always on the right side of the cut surface, and its curvature radius is On the contrary, the side of the object is a concave structure, and its curvature radius is negative; the image side is a convex structure, which means that the side of the lens is cut at any point on the surface, and the surface is always on the left side of the cut surface. The radius of curvature is negative, and vice versa. It is a concave structure, and its radius of curvature is positive; if the surface is cut through any point on the object side or the image side of the lens, and the surface has both the left part of the cut surface and the right part of the cut surface, the surface has a curve inflection point. At this time, the above rules still apply to the judgment of the concavo-convexity on the object side and the image side at the near optical axis.

The structural parameters of each lens are shown in Table 1.

The imaging lens has a focal length of f=4.84mm, an aperture number of Fno=2.00, and a field of view angle of FOV=78.0°. The units of curvature radius, thickness, and focal length in Table 1 are all mm. Surfaces 0-18 in Table 1 represent the surfaces from the object side to the image side in order.

The aspheric coefficients of each lens in this embodiment are specifically shown in Table 2, and A2-A16 represent the 2-16th order aspheric coefficients of the lens surface, respectively.

The values of the relational expressions in this embodiment are shown in Table 3.

Astigmatism and distortion field curves and spherical aberration curves of the imaging lens of this embodiment are shown in FIG. 2 and FIG. 3 , respectively.

The wavelengths of the astigmatism and distortion field graphs are 555 nm, and the wavelengths of the spherical aberration graphs are 0.470 μm, 0.510 μm, 0.555 μm, 0.610 μm and 0.650 μm, respectively.

Embodiment 2

Referring to FIG. 4 , the imaging lens provided in this embodiment includes a first lens 10 , a second lens 20 , a third lens 30 , a fourth lens 40 , a fifth lens 50 , and a sixth lens 60 in order from the object side to the image side , the seventh lens 70, the infrared filter 80 and the imaging surface 90, each lens has an object side facing the object side and passing the imaging light and an image side facing the image side and allowing the imaging light to pass;

The first lens 10 has a positive refractive power, and its object side surface is a convex structure;

The second lens 20 has a negative refractive power, the object side is a convex structure, and its image side is a concave structure;

the third lens 30 has refractive power;

The fourth lens 40 has refractive power;

The fifth lens 50 has a negative refractive power, and its object side is a concave structure, and its image side is a convex structure;

The sixth lens 60 has a positive refractive power, the object side surface is a convex surface structure at the near optical axis, and the object side surface has at least one curve inflection point, and its image side surface is a convex surface structure;

The seventh lens 70 has a negative refractive power, the object side surface and the image side surface are both concave structures at the near optical axis, and the image side surface has at least one curve inflection point at off-axis;

The imaging lens satisfies the following relationship:

1.0<f/f16;

25.0<|f3|/CT3<35.0;

2.0<(CT4+CT5+CT6)/(AG45+AG56)<8.0.

The structural parameters of each lens are shown in Table 4.

The imaging lens has a focal length of f=4.72mm, an aperture number of Fno=2.00, and a field of view angle of FOV=78.0°. The units of curvature radius, thickness, and focal length in Table 4 are all mm. Surfaces 0-18 in Table 4 represent the surfaces from the object side to the image side in order.

The aspheric coefficients of each lens in this embodiment are specifically shown in Table 5, and A2-A16 represent the 2-16th order aspheric coefficients of the lens surface, respectively.

The values of the relational expressions in this embodiment are shown in Table 6.

The astigmatism and distortion field curves and spherical aberration curves of the imaging lens of this embodiment are shown in FIG. 5 and FIG. 6 , respectively.

The wavelengths of the astigmatism and distortion field graphs are 555 nm, and the wavelengths of the spherical aberration graphs are 0.470 μm, 0.510 μm, 0.555 μm, 0.610 μm and 0.650 μm, respectively.

Embodiment 3

Referring to FIG. 7 , the imaging lens provided by this embodiment includes a first lens 10 , a second lens 20 , a third lens 30 , a fourth lens 40 , a fifth lens 50 , and a sixth lens 60 in order from the object side to the image side , the seventh lens 70, the infrared filter 80 and the imaging surface 90, each lens has an object side facing the object side and passing the imaging light and an image side facing the image side and allowing the imaging light to pass;

The first lens 10 has a positive refractive power, and its object side surface is a convex structure;

The second lens 20 has a negative refractive power, the object side is a convex structure, and its image side is a concave structure;

the third lens 30 has refractive power;

The fourth lens 40 has refractive power;

The fifth lens 50 has a negative refractive power, and its object side is a concave structure, and its image side is a convex structure;

The sixth lens 60 has a positive refractive power, the object side surface is a convex surface structure at the near optical axis, and the object side surface has at least one curve inflection point, and its image side surface is a convex surface structure;

The seventh lens 70 has a negative refractive power, the object side surface and the image side surface are both concave structures at the near optical axis, and the image side surface has at least one curve inflection point at off-axis;

The imaging lens satisfies the following relationship:

1.0<f/f16;

25.0<|f3|/CT3<35.0;

2.0<(CT4+CT5+CT6)/(AG45+AG56)<8.0.

The structural parameters of each lens are shown in Table 7.

The imaging lens has a focal length of f=4.78mm, an aperture number of Fno=2.00, and a field of view angle of FOV=78.0°. The units of curvature radius, thickness, and focal length in Table 7 are all mm. Surfaces 0-18 in Table 7 represent the surfaces from the object side to the image side in order.

The aspheric coefficients of each lens in this embodiment are specifically shown in Table 8, and A2-A16 represent the 2-16th order aspheric coefficients of the lens surface, respectively.

The values of the relational expressions in this embodiment are shown in Table 9.

The astigmatism and distortion field curves and spherical aberration curves of the imaging lens of this embodiment are shown in FIG. 8 and FIG. 9 , respectively.

The wavelengths of the astigmatism and distortion field graphs are 555 nm, and the wavelengths of the spherical aberration graphs are 0.470 μm, 0.510 μm, 0.555 μm, 0.610 μm and 0.650 μm, respectively.

Embodiment 4

Referring to FIG. 10 , the imaging lens provided in this embodiment includes a first lens 10 , a second lens 20 , a third lens 30 , a fourth lens 40 , a fifth lens 50 , and a sixth lens 60 in order from the object side to the image side , the seventh lens 70, the infrared filter 80 and the imaging surface 90, each lens has an object side facing the object side and passing the imaging light and an image side facing the image side and allowing the imaging light to pass;

The first lens 10 has a positive refractive power, and its object side surface is a convex structure;

The second lens 20 has a negative refractive power, the object side is a convex structure, and its image side is a concave structure;

the third lens 30 has refractive power;

The fourth lens 40 has refractive power;

The fifth lens 50 has a negative refractive power, and its object side is a concave structure, and its image side is a convex structure;

The sixth lens 60 has a positive refractive power, the object side surface is a convex surface structure at the near optical axis, and the object side surface has at least one curve inflection point, and its image side surface is a convex surface structure;

The seventh lens 70 has a negative refractive power, the object side surface and the image side surface are both concave structures at the near optical axis, and the image side surface has at least one curve inflection point at off-axis;

The imaging lens satisfies the following relationship:

1.0<f/f16;

25.0<|f3|/CT3<35.0;

2.0<(CT4+CT5+CT6)/(AG45+AG56)<8.0.

The structural parameters of each lens are shown in Table 10.

Its imaging lens has a focal length of f=4.69mm, an aperture number of Fno=2.04, and a field of view angle of FOV=81.8°. The units of curvature radius, thickness, and focal length in Table 10 are all mm. Surfaces 0-18 in Table 10 represent the surfaces from the object side to the image side in order.

The aspheric coefficients of the lenses in this embodiment are shown in Table 11. A2-A16 represent the 2nd-16th order aspheric coefficients of the lens surface, respectively.

The values of the relational expressions in this embodiment are shown in Table 12.

It should be noted that the difference between this embodiment and the first three embodiments is that the object side of the third lens 30 is convex at the near optical axis, the image side is convex, and the second lens 20 and the fifth lens 50 are made of high refractive index materials .

The astigmatism, distortion field curves and spherical aberration curves of the imaging lens of this embodiment are shown in FIG. 11 and FIG. 12 , respectively.

The wavelengths of the astigmatism and distortion field graphs are 555 nm, and the wavelengths of the spherical aberration graphs are 0.470 μm, 0.510 μm, 0.555 μm, 0.610 μm and 0.650 μm, respectively.

Therefore, the imaging lens provided by the embodiment of the present invention is a seven-lens type, which is used for adapting to each electronic imaging module device. The surface structure of each lens of the seven-lens type imaging lens is consistent with the optimized range of optical parameters. Combined, it can effectively shorten the length of the system and improve the viewing angle of the lens while maintaining high image quality. Such as mobile phones, PDAs, computers, cameras, driving recorders or cameras, etc.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: The technical solutions described in the embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the present invention.

Claims (12)

1. An imaging lens is characterized by comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from an object side to an image side in sequence, wherein each lens is provided with an object side surface facing to the object side and allowing imaging light rays to pass through and an image side surface facing to the image side and allowing the imaging light rays to pass through;

the first lens element with positive refractive power has a convex object-side surface;

the second lens element with negative refractive power has a convex object-side surface and a concave image-side surface;

the third lens element with refractive power;

the fourth lens element with refractive power;

the fifth lens element with negative refractive power has a concave object-side surface and a convex image-side surface;

the sixth lens element with positive refractive power has a convex object-side surface at paraxial region, at least one inflection point on the object-side surface, and a convex image-side surface;

the seventh lens element with negative refractive power has a concave object-side surface and a concave image-side surface at a paraxial region, and the image-side surface has at least one inflection point on an off-axis region;

the imaging lens satisfies the following relational expression:

1.0<f/f16；

27.0≤|f3|/CT3<35.0；

2.0<(CT4+CT5+CT6)/(AG45+AG56)<8.0；

wherein f is a focal length of the imaging lens, f16 is a combined focal length of the first lens to the sixth lens, f3 is a focal length of the third lens, CT3 is a central thickness of the third lens on an optical axis, CT4 is a central thickness of the fourth lens on the optical axis, CT5 is a central thickness of the fifth lens on the optical axis, CT6 is a central thickness of the sixth lens on the optical axis, AG45 is an air space between the fourth lens and the fifth lens on the optical axis, and AG56 is an air space between the fifth lens and the sixth lens on the optical axis.

2. The imaging lens assembly of claim 1, wherein the third lens element has a convex object-side surface at a paraxial region and a convex image-side surface.

3. An imaging lens according to claim 1, characterized in that the following relation is also satisfied: -2.0< R61/R62< -0.5, wherein R61 is a radius of curvature of the object-side surface of the sixth lens, and R62 is a radius of curvature of the image-side surface of the sixth lens.

4. An imaging lens according to claim 1, characterized in that the following relation is also satisfied: 1.0< f15/f16<2.0, wherein f15 is a combined focal length of the first to fifth lenses.

5. An imaging lens according to claim 1, characterized in that the following relation is also satisfied: 0.8< f26/f36<2.0, where f26 is the combined focal length of the second to sixth lenses and f36 is the combined focal length of the third to sixth lenses.

6. An imaging lens according to claim 1, characterized in that the following relation is also satisfied: 10< (f + f6) (f + f7) <30, wherein f6 is the focal length of the sixth lens and f7 is the focal length of the seventh lens.

7. An imaging lens according to claim 1, characterized in that the following relation is also satisfied: 0.4< LCT14/LCT26<1.0, where LCT14 is the distance on the optical axis from the object-side surface of the first lens to the image-side surface of the fourth lens and LCT26 is the distance on the optical axis from the object-side surface of the second lens to the image-side surface of the sixth lens.

8. An imaging lens according to claim 1, characterized in that the following relation is also satisfied: 1.4< CT6/ET6<2.2, wherein ET6 is the edge thickness of the sixth lens.

9. The imaging lens assembly as claimed in claim 1, wherein the object-side surface of the third lens element has a concave structure, the image-side surface of the third lens element has a convex structure, and further satisfies the following relation: 0.4< CT3/ET3<0.8, wherein ET3 is the edge thickness of the third lens.

10. An imaging lens according to claim 9, characterized in that the following relation is also satisfied: 1.0< (R41+ R42)/(R41-R42) <1.6, wherein R41 is a radius of curvature of the object-side surface of the fourth lens, and R42 is a radius of curvature of the image-side surface of the fourth lens.

11. An imaging lens according to claim 1, characterized in that the following relation is also satisfied: -5.50< (f/R51+ f/R52) < -4.0, wherein R51 is a radius of curvature of the object-side surface of the fifth lens, and R52 is a radius of curvature of the image-side surface of the fifth lens.

12. An image pickup apparatus characterized by comprising the imaging lens according to any one of claims 1 to 11.

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