CN105607234B - Fisheye lens - Google Patents

Abstract

The invention belongs to the technical field of lenses, and particularly relates to an ultra-high-definition fisheye lens which comprises 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 which are sequentially arranged from an object space to an image space, wherein the first lens is a convex-concave negative focal power lens, the second lens is a plano-concave negative focal power lens, the third lens is a convex-concave negative focal power lens, the fourth lens is a convex-plano-positive focal power lens, the fifth lens is a plano-convex positive focal power lens, the sixth lens is a double-concave negative focal power lens, the seventh lens is a double-convex positive focal power lens, the eighth lens is a double-convex positive focal power lens, and the ninth lens is a double-convex positive focal power lens. Compared with the prior art, the invention can improve the imaging quality of the lens and reduce the volume, and has the day and night in-focus function, namely, infrared light can be imaged clearly without focusing under the condition that visible light is imaged clearly, so that the invention can completely meet the requirement of 4K and has good market prospect.

Description

a fisheye lens

technical field

The invention belongs to the technical field of lenses, in particular to an ultra-high-definition fisheye lens.

Background technique

Fisheye lenses usually have a field of view of more than 180°, so they are widely used in panoramic surveillance systems.

The fisheye lens needs to introduce a lot of barrel distortion due to its large angle characteristics. For ordinary lenses, the distortion has a small impact on the imaging clarity. However, the distortion of the fisheye lens is close to -100%. The image at the edge of the field is greatly compressed, resulting in reduced edge corner resolution and blurred edges after the picture is unfolded. Therefore, the design of the fisheye lens needs to strictly control the distortion to improve the angular resolution of the peripheral field of view. Generally, the focal length/image height of the fisheye lens is <0.35 to ensure a better peripheral angular resolution.

At present, the general fisheye lens has between 2 million and 5 million pixels, the total optical length is more than 30mm, and the aperture is around F2.2. With the rise of the 4K concept, people require the lens to develop in the direction of smaller size, higher pixel and better image quality.

Obviously, the traditional fisheye lens can no longer meet the requirements of 4K, so it is necessary to develop a fisheye lens with small pixels that can meet the requirements of 4K.

The present invention aims to provide an ultra-high-definition fisheye lens, which adopts 9 pieces of glass lenses, the field of view reaches 190°, the total optical length is less than 27mm, the maximum aperture reaches F1.6, the visible light resolution reaches 12 million pixels, and the infrared resolution The rate reaches more than 800 million pixels, which can fully meet the requirements of 4K and has a good market prospect.

Contents of the invention

The object of the present invention is to: address the deficiencies of the prior art, and provide an ultra-high-definition fisheye lens, which uses 9 glass lenses, the field of view reaches 190°, the total optical length is less than 27mm, and its maximum aperture reaches F1.6. The visible light resolution reaches 12 million pixels, and the infrared resolution reaches more than 8 million pixels, which can fully meet the requirements of 4K and has a good market prospect.

In order to achieve the above object, the present invention adopts following technical scheme:

An ultra-high-definition fisheye lens, 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 The ninth lens, the first lens is a convex-concave negative power lens, the second lens is a plano-concave negative power lens, the third lens is a convex-concave negative power lens, and the fourth lens is Convex planar positive refractive power lens, the fifth lens is a plano-convex positive refractive power lens, the sixth lens is a biconcave negative refractive power lens, the seventh lens is a biconvex positive refractive power lens, and the sixth lens The eight lenses are biconvex positive diopter lenses, and the ninth lens is a biconvex positive diopter lens; the first surface (near the surface of the first lens) of the second lens is set to a plane, so that the first lens and the second lens The two lenses form a form of plane positioning, which greatly improves the stability of assembly and improves the assembly yield of the lens.

The ratio of the focal lengths of the first lens to the ninth lens to the focal length of the entire lens satisfies the following conditions:

6<|f1/f|<8.5;

2<|f2/f|<4;

6<|f3/f|<8.5;

3.2<|f4/f|<5.3;

11<|f5/f|<16;

1.5<|f6/f|<3;

2.01<|f7/f|<3.98;

7.1<|f8/f|<9.6;

3.9<|f9/f|<6.2;

Wherein, f is the focal length of the entire lens; f1 to f9 are the focal lengths of the first lens to the ninth lens, respectively.

As an improvement of the ultra-high-definition fisheye lens of the present invention, the focal length and refractive index of the first lens to the ninth lens meet the following conditions:

-15.14≤f1≤-10.22 1.65≤n1≤1.9 -6.51≤f2≤-3.92 1.65≤n2≤1.9 -13.65≤f3≤-9.22 1.65≤n3≤1.9 5.41≤f4≤7.85 1.7≤n4≤1.96 18.62≤f5≤24.32 1.4≤n5≤1.6 -4.35≤f6≤-2.51 1.65≤n6≤1.9 3.12≤f7≤5.33 1.55≤n7≤1.75 11.01≤f8≤14.23 1.4≤n8≤1.6 6.54≤f9≤9.12 1.55≤n9≤1.75

In the above table, "f" is the focal length, "n" is the refractive index, and the sign "-" indicates that the direction is negative;

Wherein, f1 to f9 respectively correspond to focal lengths of the first to ninth lenses; n1 to n9 respectively correspond to refractive indices of the first to ninth lenses.

As an improvement of the ultra-high-definition fisheye lens of the present invention, the first lens and the second lens are directly mounted in close contact, and the second lens and the third lens are tightly fitted through a spacer.

As an improvement of the ultra-high-definition fisheye lens of the present invention, the third lens and the fourth lens are tightly fitted through a spacer, the fourth lens and the fifth lens are tightly fitted through a spacer, and the first The fifth lens is tightly fitted with the sixth lens through a spacer, the seventh lens is tightly fitted with the eighth lens through a spacer, and the eighth lens is tightly fitted with the ninth lens through a spacer.

As an improvement of the ultra-high-definition fisheye lens of the present invention, the sixth lens and the seventh lens are glued together by optical glue.

As an improvement of the ultra-high-definition fisheye lens of the present invention, the ratio D/R of the semi-diameter of the side of the first lens close to the second lens to the spherical radius is 0.81, which avoids the difficulty of most fisheye lenses. The appearance of close to hemisphere or super hemisphere greatly improves the processability of the lens.

As an improvement to the ultra-high-definition fisheye lens of the present invention, an aperture is provided between the fifth lens and the sixth lens.

Compared with the prior art, the present invention adopts 9 pieces of glass lenses, the field of view reaches 190°, the total optical length is less than 27mm, the focal length/image height is 0.33, and the large aperture is realized through reasonable use of glass combination, and its maximum aperture reaches F1.6, The imaging quality is good, the visible light resolution reaches 12 million pixels, and the infrared can reach more than 8 million pixels without refocusing. Even in the low light at night, it can realize clear and bright monitoring pictures, and it has temperature compensation Function, that is, it can be used in the environment of -30 ~ +80 ℃ without running out of focus.

In a word, the present invention can improve the imaging quality of the lens, reduce the volume, and the present invention has the function of co-focusing day and night, that is, it can form a clear image of infrared light without focusing when visible light forms a clear image, so the present invention is completely It can meet the requirements of 4K and has a good market prospect.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is an optical path diagram of the present invention.

detailed description

The present invention and its beneficial effects will be further described in detail below in conjunction with specific examples, however, the specific embodiments of the present invention are not limited thereto.

As shown in Figures 1 and 2, an ultra-high-definition fisheye lens provided by the present invention includes a first lens 1, a second lens 2, a third lens 3, and a fourth lens 4 arranged in sequence from the object side to the image side , the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8 and the ninth lens 9, the first lens 1 is a convex-concave negative power lens, and the second lens 2 is a plano-concave negative power lens , the third lens 3 is a convex-concave negative power lens, the fourth lens 4 is a convex plane positive power lens, the fifth lens 5 is a plano-convex positive power lens, and the sixth lens 6 is a double-concave negative power lens, The seventh lens 7 is a double-convex positive power lens, the eighth lens 8 is a double-convex positive power lens, and the ninth lens 9 is a double-convex positive power lens; The surface of the lens) is set as a plane, so that the first lens 1 and the second lens 2 form a form of positioning with a plane, thereby greatly improving the stability of assembly and improving the assembly yield of the lens. In the present invention, the first lens 1 to the ninth lens 9 are all glass spherical lenses.

The ratio of the focal length of the first lens 1 to the ninth lens 9 to the focal length of the entire lens satisfies the following conditions:

6<|f1/f|<8.5;

2<|f2/f|<4;

6<|f3/f|<8.5;

3.2<|f4/f|<5.3;

11<|f5/f|<16;

1.5<|f6/f|<3;

2.01<|f7/f|<3.98;

7.1<|f8/f|<9.6;

3.9<|f9/f|<6.2;

Wherein, f is the focal length of the entire lens; f1 to f9 are the focal lengths of the first lens to the ninth lens respectively.

Wherein, the focal length and refractive index of the first lens 1 to the ninth lens 9 satisfy the following conditions:

-15.14≤f1≤-10.22 1.65≤n1≤1.9 -6.51≤f2≤-3.92 1.65≤n2≤1.9 -13.65≤f3≤-9.22 1.65≤n3≤1.9 5.41≤f4≤7.85 1.7≤n4≤1.96 18.62≤f5≤24.32 1.4≤n5≤1.6 -4.35≤f6≤-2.51 1.65≤n6≤1.9 3.12≤f7≤5.33 1.55≤n7≤1.75 11.01≤f8≤14.23 1.4≤n8≤1.6 6.54≤f9≤9.12 1.55≤n9≤1.75

In the above table, "f" is the focal length, "n" is the refractive index, and the sign "-" indicates that the direction is negative;

Wherein, f1 to f9 correspond to the focal lengths of the first lens 1 to the ninth lens 9 respectively; n1 to n9 correspond to the refractive indices of the first lens 1 to the ninth lens 9 respectively.

The first lens 1 and the second lens 2 are directly assembled closely, and the second lens 2 and the third lens 3 are tightly fitted through a spacer.

The third lens 3 and the fourth lens 4 are tightly fitted by a spacer, the fourth lens 4 and the fifth lens 5 are tightly fitted by a spacer, the fifth lens 5 and the sixth lens 6 are tightly fitted by a spacer, and the seventh lens 7 and the fifth lens are tightly fitted by a spacer. The eighth lens 8 is tightly fitted through a spacer, and the eighth lens 8 and the ninth lens 9 are tightly fitted through a spacer.

The sixth lens 6 and the seventh lens 7 are bonded by optical glue.

A stop is provided between the fifth lens 5 and the sixth lens 6 .

The ratio D/R of the semi-diameter of the side of the first lens 1 close to the second lens 2 to the radius of the spherical surface is 0.81, which avoids the situation of approaching a hemisphere or a super-hemisphere that most fisheye lenses tend to have, and greatly improves the performance of the lens. machinability.

In short, the present invention adopts 9 pieces of glass lenses, the field of view reaches 190°, the total optical length is less than 27mm, the focal length/image height is 0.33, and the large aperture is realized by rationally using the glass combination. The maximum aperture reaches F1.6, and the imaging quality is good. Visible light resolution reaches 12 million pixels, and the infrared can reach more than 8 million pixels without refocusing. It can realize clear and bright monitoring images even in low light at night. At the same time, it has a temperature compensation function, that is, in It can be used in the environment of -30～+80℃ without running out of focus.

In a word, the present invention can improve the imaging quality of the lens, reduce the volume, and the present invention has the function of co-focusing day and night, that is, it can form a clear image of infrared light without focusing when visible light forms a clear image, so the present invention is completely It can meet the requirements of 4K and has a good market prospect.

Example 1

The surface shape, radius of curvature, lens thickness, lens spacing and lens refractive index of the nine lenses of the lens in total meet the following conditions:

Table 1: Physical parameters of the nine lenses.

In the above table, "R" is the radius of curvature, "-" indicates that the direction is negative, and "PL" indicates a plane. If the serial number of the same surface in the above table has both refractive index data n and data D, the data D indicates the lens axis The thickness at the center line, if the serial number of the same plane only has data D but no refractive index data n, the data D represents the distance from the lens to the next lens plane.

According to the disclosure and teaching of the above specification, those skilled in the art to which the present invention pertains can also make appropriate changes and modifications to the above embodiment. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims (7)

1. A kind of 1. fish eye lens, it is characterised in that：Including be arranged in order from the object side to the image side the first lens, the second lens, Three lens, the 4th lens, the 5th lens, the 6th lens, the 7th lens, the 8th lens and the 9th lens, first lens are Convex-concave negative-power lenses, second lens are plano-concave negative-power lenses, and the 3rd lens are that convex-concave negative power is saturating Mirror, the 4th lens are convex flat positive power lens, and the 5th lens are plano-convex positive power lens, the 6th lens For concave-concave negative-power lenses, the 7th lens are biconvex positive power lens, and the 8th lens are biconvex positive light coke Lens, the 9th lens are biconvex positive power lens；

   The ratio of first lens to the focal length and the focal length of whole camera lens of the 9th lens meets following condition：

   6<|f1/f|<8.5；

   2<|f2/f|<4；

   6<|f3/f|<8.5；

   3.2<|f4/f|<5.3；

   11<|f5/f|<16；

   1.5<|f6/f|<3；

   2.01<|f7/f|<3.98；

   7.1<|f8/f|<9.6；

   3.9<|f9/f|<6.2；

   Wherein, f is the focal length of whole camera lens；F1 to f9 is focal length of first lens to the 9th lens respectively.
2. 2. fish eye lens according to claim 1, it is characterised in that：First lens to the 9th lens Jiao Meet following condition away from, refractive index：

   -15.14≤f1≤-10.22 1.65≤n1≤1.9 -6.51≤f2≤-3.92 1.65≤n2≤1.9 -13.65≤f3≤-9.22 1.65≤n3≤1.9 5.41≤f4≤7.85 1.7≤n4≤1.96 18.62≤f5≤24.32 1.4≤n5≤1.6 -4.35≤f6≤-2.51 1.65≤n6≤1.9 3.12≤f7≤5.33 1.55≤n7≤1.75 11.01≤f8≤14.23 1.4≤n8≤1.6 6.54≤f9≤9.12 1.55≤n9≤1.75

   In upper table, " f " is focal length, and " n " is refractive index, and "-" number represents that direction is negative；

   Wherein, f1 to f9 corresponds respectively to the first lens to the focal length of the 9th lens；N1 to n9 corresponds respectively to the first lens extremely The refractive index of 9th lens.
3. 3. fish eye lens according to claim 1, it is characterised in that：First lens and second lens are directly tight By assembling, second lens and the 3rd lens pass through spacer ring close-fitting.
4. 4. fish eye lens according to claim 3, it is characterised in that：3rd lens and the 4th lens by every Close-fitting is enclosed, the 4th lens and the 5th lens are passed through by spacer ring close-fitting, the 5th lens and the 6th lens Spacer ring close-fitting, the 7th lens and the 8th lens are led to by spacer ring close-fitting, the 8th lens and the 9th lens Cross spacer ring close-fitting.
5. 5. fish eye lens according to claim 1, it is characterised in that：6th lens and the 7th lens pass through light Learn glue bond.
6. 6. fish eye lens according to claim 1, it is characterised in that：Close second lens of first lens Half bore and the ratio D/R of spherical radius simultaneously is 0.81.
7. 7. fish eye lens according to claim 1, it is characterised in that：Set between 5th lens and the 6th lens It is equipped with diaphragm.