CN111103677A

CN111103677A - High-definition zoom lens and security camera device

Info

Publication number: CN111103677A
Application number: CN202010017929.0A
Authority: CN
Inventors: 张平华; 张思慎; 厉冰川; 盛亚茗; 尚洁阳; 张�杰
Original assignee: Jiaxing Zhongrun Optical Technology Co Ltd
Current assignee: Jiaxing Zhongrun Optical Technology Co Ltd
Priority date: 2020-01-08
Filing date: 2020-01-08
Publication date: 2020-05-05

Abstract

The invention discloses a high-definition zoom lens and a security camera device, and relates to the technical field of optics. The invention comprises the following components in sequence from the object plane side to the image plane side: the lens comprises a first fixed lens group with positive focal power, a zoom lens group with negative focal power, a diaphragm, a second fixed lens group with positive focal power, a focusing lens group with negative focal power and a third fixed lens group with positive focal power; the moving amount of the zoom lens group satisfies the following conditional expression: Δ B1/TTL ∈ (0.15, 0.35); wherein: Δ B1 is a relative displacement of the variable power lens group at a wide-angle end position and a telephoto end position, and TTL is a total length of the high-definition zoom lens; the focusing lens group moves along the direction of the optical axis and is used for compensating the moving variable-magnification lens group. The variation range of the relative displacement of the zoom lens group is larger, namely the zooming range of the high-definition zoom lens is larger, and the application range of the high-definition zoom lens is wider.

Description

High-definition zoom lens and security camera device

Technical Field

The invention relates to the technical field of optics, in particular to a high-definition zoom lens and a security camera device.

Background

In order to respond to the development action plan of the national ultra-high-definition video industry, the security industry will also comprehensively enter the ultra-high-definition era in the future according to the general technical route of '4K first and 8K' first. Under the background, the traditional security lens is vacant in the high-end high-magnification zooming field.

In the case of satisfying a large zoom ratio, a conventional security lens often cannot achieve a true 4K resolution for various reasons, such as a telephoto end diffraction limit, a lens group structure, and the like, and a current true 4K resolution product often remains in a small-magnification field.

Disclosure of Invention

The invention solves the technical problems in the prior art, and provides the high-definition zoom lens and the security camera device, wherein the variation range of the relative displacement of the zoom lens group is larger, namely the zoom range of the high-definition zoom lens is larger, and the application range of the high-definition zoom lens is wider.

The technical scheme provided by the invention is as follows:

a high-definition zoom lens comprises the following components in sequence from an object plane side to an image plane side: the lens comprises a first fixed lens group with positive focal power, a zoom lens group with negative focal power, a diaphragm, a second fixed lens group with positive focal power, a focusing lens group with negative focal power and a third fixed lens group with positive focal power; the moving amount of the zoom lens group satisfies the following conditional expression: Δ B1/TTL ∈ (0.15, 0.35); wherein: Δ B1 is a relative displacement of the variable power lens group at a wide-angle end position and a telephoto end position, and TTL is a total length of the high-definition zoom lens; the focusing lens group moves along the direction of the optical axis and is used for compensating the moving variable-magnification lens group.

Preferably, the amount of movement of the focusing lens group satisfies the following conditional expression: Δ B2/. DELTA.B 1 ∈ (0.15, 0.4); wherein: Δ B2 is the relative displacement between the focusing lens group at the end closer to the object plane side and the end closer to the image plane side.

Preferably, the number of lenses in the second fixed lens group is greater than the number of lenses in the first fixed lens group and the number of lenses in the third fixed lens group.

Preferably, a difference between the number of lenses in the first fixed lens group and the number of lenses in the third fixed lens group is less than or equal to 2.

Preferably, the number of lenses in the focusing lens group is less than or equal to the number of lenses in the third fixed lens group; and/or the mass of the focusing lens group is less than the mass of the third fixed lens group.

Preferably, at least one cemented lens is included in three groups of the first fixed lens group, the second fixed lens group and the third fixed lens group.

Preferably, at most one aspheric lens is present in the second fixed lens group.

Preferably, the third fixed lens group includes at least, from the object plane side to the image plane side: a lens of positive power and a lens of negative power.

Preferably, the first fixed lens group includes at least: two lenses with positive focal power and one lens with negative focal power.

One of the objectives of the present invention is to provide a security camera device, which includes a high-definition zoom lens.

Compared with the prior art, the high-definition zoom lens and the security camera device provided by the invention have the following beneficial effects:

1. the definition of the zoom lens is improved through the five-group structure with positive, negative, positive and negative focal powers; meanwhile, the zoom lens group has a large moving range, the high-definition zoom lens has high imaging quality and stable performance; and the variation range of the relative displacement of the zoom lens group is also larger, namely the zooming range of the high-definition zoom lens is larger, and the application range of the high-definition zoom lens is wider.

2. The moving amount of the focusing lens group is small, so that the performances of the rest lens groups are stable, the whole volume of the high-definition zoom lens can be reduced, and the miniaturization of the lens is realized.

3. Through the setting of two positive lenses and a negative lens, each lens need not to select unusual focal power parameter and can form the positive focal power of first fixed lens crowd, therefore, the radius of curvature of each lens can increase, the processing of the interior camera lens of first fixed lens crowd has been made things convenient for, the processing cost of first fixed lens crowd has also been reduced, the radius of curvature of first fixed lens crowd is great simultaneously, the thickness of each lens has also been reduced, then the thickness of first fixed lens crowd has been reduced, be favorable to realizing the miniaturization of camera lens.

Drawings

The above features, technical features, advantages and implementation manners of the high-definition zoom lens and the security imaging device will be further described in the following detailed description of preferred embodiments with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a high-definition zoom lens according to the present invention;

FIG. 2 is a coma aberration diagram of the telephoto state of the high-definition zoom lens according to the present invention;

FIG. 3 is an aberration diagram of the high-definition zoom lens in the telephoto state according to the present invention;

FIG. 4 is a coma diagram of the wide angle state of the high-definition zoom lens according to the present invention;

FIG. 5 is various aberration diagrams of a high-definition zoom lens in a wide-angle state according to the present invention;

FIG. 6 is a schematic structural diagram of another high-definition zoom lens according to the present invention;

FIG. 7 is a coma diagram of the telescopic state of another high-definition zoom lens according to the present invention;

FIG. 8 is a diagram showing various aberrations of another high-definition zoom lens according to the present invention in a telephoto state;

FIG. 9 is a coma diagram of the wide angle state of another high-definition zoom lens according to the present invention;

FIG. 10 is various aberration diagrams of another high definition zoom lens of the present invention in a wide angle state;

FIG. 11 is a schematic structural diagram of a high-definition zoom lens according to yet another embodiment of the present invention;

FIG. 12 is a coma diagram showing the telephoto state of the high definition zoom lens according to the present invention;

FIG. 13 is a diagram showing various aberrations of a high definition zoom lens according to the present invention in a telephoto state;

FIG. 14 is a coma diagram of the wide angle state of the high definition zoom lens according to the present invention;

FIG. 15 is a diagram showing various aberrations of a high-definition zoom lens according to the present invention in a wide-angle state.

The reference numbers illustrate: g1, a first fixed lens group; g2, variable power lens group; STP and a diaphragm; g3, a second fixed lens group; g4, a focusing lens group; g5, a third fixed lens group; g6, auxiliary components.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

For the sake of simplicity, only the parts relevant to the invention are schematically shown in the drawings, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

The first embodiment is as follows: as shown in fig. 1, a high-definition zoom lens includes, in order from an object plane side to an image plane side:

a first fixed lens group G1 of positive power, a variable power lens group G2 of negative power, a diaphragm STP, a second fixed lens group G3 of positive power, a focusing lens group G4 of negative power, and a third fixed lens group G5 of positive power;

the moving amount of the magnification-varying lens group G2 satisfies the following conditional expression:

ΔB1/TTL∈(0.15，0.35)……(1)；

wherein: Δ B1 is the relative displacement of the variable power lens group G2 at the wide-angle end position and the telephoto end position, and TTL is the total length of the high-definition zoom lens.

The focusing lens group G4 is moved in the optical axis direction for compensating for the moved variable magnification lens group G2.

In the embodiment, the definition of the zoom lens is improved by the five-group structure with the focal power being positive, negative, positive and negative respectively; meanwhile, the zoom lens group G2 has a large moving range, so that the high-definition zoom lens has high imaging quality and stable performance; the variation range of the relative displacement of the zoom lens group G2 is also large, that is, the zoom range of the high-definition zoom lens is large, and the application range of the high-definition zoom lens is wide.

Specifically, the amount of movement of the focus lens group G4 satisfies the following conditional expression:

ΔB2/ΔB1∈(0.15，0.4)……(2)；

wherein: Δ B2 is the relative displacement between the end of the focusing lens group G4 located closer to the object plane side and the end located closer to the image plane side.

Since the amount of movement of the focusing lens group G4 is small, the performance of the remaining lens groups is stable, and the entire size of the high-definition zoom lens can be reduced, thereby achieving miniaturization of the lens.

Preferably, at least one cemented lens is included in three groups of the first fixed lens group G1, the second fixed lens group G3, and the third fixed lens group G5; in this embodiment, the arrangement of the cemented lens is advantageous for achieving miniaturization of the lens, and at the same time, correction of chromatic aberration and spherical aberration of imaging can be facilitated.

At most one aspheric lens exists in the second fixed lens group G3; specifically, for a lens with a simpler light path, a single aspheric lens in the original lens group can be directly replaced by two or three aspheric lenses, so that the processing cost of the lens is reduced; for the lens with a complex light path, a better light adjusting effect can still be kept by reserving an aspheric lens, and the processing cost of the second fixed group is lower.

The spherical lens replaces an aspheric lens in the original lens group, the same technical effect is achieved, the processing cost of the second fixed lens group G3 is effectively reduced, and the production benefit of the lens is increased.

According to a modification of the above embodiment, in the present embodiment, the third fixed lens group G5 includes at least, from the object plane side to the image plane side: a lens of positive power and a lens of negative power.

The positive power lens of the third fixed lens group G5 can be close to the negative power focusing lens group G4, and the chromatic aberration and spherical aberration correction can be performed on the light of the focusing lens group G4, while the negative power lens of the third fixed lens group G5 can be arranged on the side close to the image plane side, and the chromatic aberration and spherical aberration correction can be performed on the light again; and the focusing lens group G4, the positive focal power lens and the negative focal power lens form a positive and negative structure, so that the imaging chromatic aberration and spherical aberration performance are good.

According to a modification of the above embodiment, in the present embodiment, the first fixed lens group G1 includes at least: two lenses with positive focal power and one lens with negative focal power.

In this embodiment, through the setting of two positive lenses and a negative lens, each lens need not to select unusual focal power parameter and can form the positive focal power of first fixed lens crowd G1, therefore, the radius of curvature of each lens can increase, the processing of the interior camera lens of first fixed lens crowd G1 has been made things convenient for, the processing cost of first fixed lens crowd G1 has also been reduced, simultaneously the radius of curvature of first fixed lens crowd G1 is great, the thickness of each lens has also been reduced, then the thickness of first fixed lens crowd G1 has been reduced, be favorable to realizing the miniaturization of camera lens.

Specifically, in the present embodiment, the total optical length TTL of the high-definition zoom lens is 60 to 100mm, FNO is 1.2 to 1.8, and the field angle FOV is 8 to 60 degrees; the zoom ratio is five times, and preferably, the focal length F is 10-50 mm.

Example two: as shown in fig. 1, the present embodiment is different from the first embodiment in the number relationship of lenses in each lens group.

In the first embodiment, the number of lenses in the second fixed lens group G3 is greater than the number of lenses in the first fixed lens group G1 and the number of lenses in the third fixed lens group G5.

When the number of lenses in the second fixed lens group G3 is large, the volume of the second fixed lens group G3 is correspondingly increased, and the overall center of gravity of the lens can be located in the second fixed lens group G3, so that the stability of the lens is increased; meanwhile, the second fixed lens group G3 can adjust parameters at the wide-angle end and the telephoto end at the same time, and the adjustment efficiency is high, so that the design difficulty of the rest lens groups is reduced and the design cost of the lens is reduced by increasing the number of the second fixed lens groups G3.

Preferably, the difference between the number of lenses in the first fixed lens group G1 and the number of lenses in the third fixed lens group G5 is less than or equal to 2.

In the embodiment, by reducing the number of lenses in the first fixed lens group G1 and the number of lenses in the third fixed lens group G5, the possibility of shifting the center of gravity of the lens is reduced, and the stability of the lens is increased; meanwhile, the lens groups with the similar number can jointly correct chromatic aberration and spherical aberration of imaging, and design difficulty of the lens is reduced.

Preferably, the number of lenses within the focusing lens group G4 is less than or equal to the number of lenses within the third fixed lens group G5; and/or the mass of the focusing lens group G4 is smaller than that of the third fixed lens group G5.

When the number and/or the mass of the focusing lens group G4 are/is small, the possibility of the change of the overall gravity center of the lens is reduced, and the stability of the lens is improved.

Example three: as shown in fig. 1, a high-definition zoom lens includes, in order from an object plane side to an image plane side:

a first fixed lens group G1 with positive focal power, a variable power lens group G2 with negative focal power, a diaphragm STP, a second fixed lens group G3 with positive focal power, a focusing lens group G4 with negative focal power, a third fixed lens group G5 with positive focal power and an auxiliary component G6.

The first fixed lens group G1 includes: a first lens L1 having a negative power, a second lens L2 having a positive power, a third lens L3 having a positive power; the first lens L1 and the second lens L2 are cemented.

The variable power lens group G2 includes: a fourth lens L4 having a negative power, a fifth lens L5 having a negative power, a sixth lens L6 having a positive power, a seventh lens L7 having a negative power; the fifth lens L5 is cemented with the sixth lens L6.

The second fixed lens group G3 includes: an eighth lens L8 having positive power, a ninth lens L9 having positive power, a tenth lens L10 having negative power, an eleventh lens L11 having positive power, a twelfth lens L12 having negative power, a thirteenth lens L13 having positive power, a fourteenth lens L14 having negative power, a fifteenth lens L15 having positive power; the tenth lens L10 is cemented with the eleventh lens L11, and the fourteenth lens L14 is cemented with the fifteenth lens L15.

The focusing lens group G4 is a sixteenth lens L16 of negative power.

The third fixed lens group G5 is a seventeenth lens L17 of positive refractive power.

The auxiliary member G6 is a cover glass L18.

Table 1 shows basic lens data of the high-definition zoom lens of the present embodiment, table 2 shows variable parameters in table 1, and table 3 shows aspherical surface coefficients.

The plane number column indicates the plane number when the number is increased one by one toward the image side with the plane on the object side being the 1 st plane; the surface type column shows the surface type of a certain lens; the radius of curvature of a lens is shown in the column of radius of curvature, positive radius of curvature indicates that the surface is curved in the object side direction, and negative radius of curvature indicates that the surface is curved in the image side direction; the surface spacing on the optical axis of each surface from the surface adjacent to its image side is shown in the center thickness column; the refractive index of a certain lens is shown in the refractive index column; the abbe number of a certain lens is shown in the abbe number column.

In table 2, the WIDE column indicates specific numerical values of the respective variable parameters when the high-definition zoom lens is in the WIDE-angle end state, and the TELE column indicates specific numerical values of the respective variable parameters when the high-definition zoom lens is in the telephoto end state.

In Table 3, K is the conic coefficient and e is the scientific count number, e.g., e-005 means 10-5.

[ TABLE 1 ]

[ TABLE 2 ]

	WIDE	TELE
			D1
	1	20
			D2	20.9	1.9
D3	0.54	7.1
			D4	8.0	1.44

[ TABLE 3 ]

	14	15
			Conic constant (K)	-1.19856632	-112.89286764
Coefficient of 4 th order (A)	-5.67e-007	1.06e-005
			Coefficient of order 6 (B)	1.15e-007	6.81e-008
Coefficient of order 8 (C)	-5.68e-010	7.59e-010
			Coefficient of order 10 (D)	3.75e-012	-8.75e-012

In the embodiment, the high-definition zoom lens has a focal length F of 10 to 50mm, an FNO of 1.5 to 1.7, an angle of view FOV of 10 to 50 degrees, and a TTL of 90 mm.

ΔB1＝19mm，ΔB2＝6.56mm，ΔB1/TTL＝0.21，ΔB2/ΔB1＝0.35。

As shown in fig. 2 and 4, the three RGB axial chromatic aberrations of the lens are well corrected at each zoom position, so that clear imaging can be achieved, and infrared imaging can be achieved when the chromatic aberration of the infrared band is within an acceptable range; the imaging clarity is always ensured in the zooming process.

As shown in fig. 3 and fig. 5, in the present embodiment, the magnification chromatic aberration and the coma aberration of the RGB three colors are well corrected, so that the imaging picture does not have an obvious purple fringed red edge or a phenomenon that the picture blurs, and the requirement of the ultrahigh image quality is satisfied.

Example four: as shown in fig. 6, a high-definition zoom lens includes, in order from an object plane side to an image plane side:

The second fixed lens group G3 includes: an eighth lens L8 having positive power, a ninth lens L9 having positive power, a tenth lens L10 having negative power, an eleventh lens L11 having positive power, a twelfth lens L12 having negative power, a thirteenth lens L13 having positive power, a fourteenth lens L14 having positive power; the tenth lens L10 is cemented with the eleventh lens L11.

The focusing lens group G4 is a fifteenth lens L15 of negative power.

The third fixed lens group G5 includes: a sixteenth lens L16 of positive power, a seventeenth lens L17 of negative power.

The auxiliary member G6 is a cover glass L18.

Table 4 shows basic lens data of the high-definition zoom lens of the present embodiment, table 5 shows variable parameters in table 4, and table 6 shows aspheric coefficients.

In table 5, the WIDE column indicates specific numerical values of the respective variable parameters when the high-definition zoom lens is in the WIDE-angle end state, and the TELE column indicates specific numerical values of the respective variable parameters when the high-definition zoom lens is in the telephoto end state.

In Table 6, K is the conic coefficient and e is the scientific count number, e.g., e-005 means 10-5.

[ TABLE 4 ]

[ TABLE 5 ]

	WIDE	TELE
			D1	0.7	14.8
D2	15.2	1.1
			D3	0.6	4.15
D4	6.89	3.34

[ TABLE 6 ]

In the embodiment, the high-definition zoom lens has a focal length F of 10 to 50mm, an FNO of 1.4 to 1.6, an angle of view FOV of 8 to 50 degrees, and a TTL of 80 mm.

ΔB1＝14.1mm，ΔB2＝3.55mm，ΔB1/TTL＝0.18，ΔB2/ΔB1＝0.25。

As shown in fig. 7 to 10, the three RGB axial chromatic aberrations of the lens are well corrected at each zoom position, so that clear imaging can be achieved, and infrared imaging can be achieved when the chromatic aberration of the infrared band is within an acceptable range. The imaging clarity is always ensured in the zooming process. Fig. 3 is a spherical aberration diagram of three zoom positions, and as shown in the figure, the present embodiment performs a better correction on the magnification chromatic aberration and the coma aberration of RGB three colors, so that the imaging picture does not have an obvious purple fringed red edge or a phenomenon that the picture blurs, and the requirement of ultrahigh image quality is satisfied.

As shown in fig. 7 and 9, the three RGB axial chromatic aberrations of the lens are well corrected at each zoom position, so that clear imaging can be achieved, and infrared imaging can be achieved when the chromatic aberration of the infrared band is within an acceptable range; the imaging clarity is always ensured in the zooming process.

As shown in fig. 8 and 10, in the present embodiment, the magnification chromatic aberration and the coma of the RGB three colors are well corrected, so that the imaging picture does not have an obvious purple fringed red edge or a phenomenon that the picture blurs, and the requirement of the ultrahigh image quality is satisfied.

The axial chromatic aberration of RGB three colors has better convergence, and the definition of the picture is better improved. And meanwhile, the F number of the lens is increased, so that the lens performs better under the low-light condition.

Example five: as shown in fig. 11, a high-definition zoom lens includes, in order from an object plane side to an image plane side:

The second fixed lens group G3 includes: an eighth lens L8 having positive power, a ninth lens L9 having positive power, a tenth lens L10 having negative power, an eleventh lens L11 having positive power, a twelfth lens L12 having negative power, a thirteenth lens L13 having positive power; the tenth lens L10 is cemented with the eleventh lens L11, and the twelfth lens L12 is cemented with the thirteenth lens L13.

The focusing lens group G4 is a fourteenth lens L14 of negative power.

The third fixed lens group G5 includes: a fifteenth lens L15 having a positive power, a sixteenth lens L16 having a positive power, and a seventeenth lens L17 having a negative power.

The auxiliary component G6 includes: filter 18 and cover glass L19.

Table 7 shows basic lens data of the high-definition zoom lens of this embodiment, table 8 shows variable parameters in table 7, and table 9 shows aspherical surface coefficients.

In table 8, the WIDE column indicates specific numerical values of the respective variable parameters when the high-definition zoom lens is in the WIDE-angle end state, and the TELE column indicates specific numerical values of the respective variable parameters when the high-definition zoom lens is in the telephoto end state.

In Table 9, K is the conic coefficient and e is the scientific count number, e.g., e-005 means 10-5.

[ TABLE 7 ]

[ TABLE 8 ]

	WIDE	TELE
			D1	0.2	20.85
D2	21.26	0.61
			D3	0.8	4.51
D4	6.51	2.8

[ TABLE 9 ]

In the embodiment, the high-definition zoom lens has a focal length F of 10 to 50mm, an FNO of 1.2 to 1.5, an angle of view FOV of 8 to 49 degrees, and a TTL of 71 mm.

ΔB1＝20.65mm，ΔB2＝3.71mm，ΔB1/TTL＝0.29，ΔB2/ΔB1＝0.18。

As shown in fig. 12 and 14, the three RGB axial chromatic aberrations of the lens are well corrected at each zoom position, so that clear imaging can be achieved, and infrared imaging can be achieved when the chromatic aberration of the infrared band is within an acceptable range; the imaging clarity is always ensured in the zooming process.

As shown in fig. 13 and fig. 15, in the present embodiment, the magnification chromatic aberration and the coma aberration of the RGB three colors are well corrected, so that the imaging picture does not have an obvious purple fringed red edge or a phenomenon that the picture blurs, and the requirement of the ultrahigh image quality is satisfied.

The spherical aberration convergence condition is better, and the definition of the picture is better improved. And meanwhile, the F number of the lens is increased, so that the lens performs better under the low-light condition.

Example six: a high-definition zoom lens described in any one of the embodiments is mounted on the security camera device.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A high definition zoom lens, its characterized in that:

the device sequentially comprises the following components from the object plane side to the image plane side:

the lens comprises a first fixed lens group with positive focal power, a zoom lens group with negative focal power, a diaphragm, a second fixed lens group with positive focal power, a focusing lens group with negative focal power and a third fixed lens group with positive focal power;

the moving amount of the zoom lens group satisfies the following conditional expression:

ΔB1/TTL∈（0 .15，0 .35）；

wherein: Δ B1 is a relative displacement of the variable power lens group at a wide-angle end position and a telephoto end position, and TTL is a total length of the high-definition zoom lens;

the focusing lens group moves along the direction of the optical axis and is used for compensating the moving variable-magnification lens group.

2. The high-definition zoom lens according to claim 1, wherein:

the moving amount of the focusing lens group satisfies the following conditional expression:

ΔB2/ΔB1∈（0.15，0.4）；

wherein: Δ B2 is the relative displacement between the focusing lens group at the end closer to the object plane side and the end closer to the image plane side.

3. The high-definition zoom lens according to claim 1, wherein:

the number of lenses in the second fixed lens group is greater than the number of lenses in the first fixed lens group and the number of lenses in the third fixed lens group.

4. The high-definition zoom lens according to claim 3, wherein:

the difference between the number of lenses in the first fixed lens group and the number of lenses in the third fixed lens group is less than or equal to 2.

5. The high-definition zoom lens according to claim 3, wherein:

the number of lenses in the focusing lens group is less than or equal to the number of lenses in the third fixed lens group;

and/or

The mass of the focusing lens group is smaller than that of the third fixed lens group.

6. The high-definition zoom lens according to claim 1, wherein:

the three groups of the first fixed lens group, the second fixed lens group and the third fixed lens group at least comprise a cemented lens.

7. The high-definition zoom lens according to claim 1, wherein:

and at most one aspheric lens exists in the second fixed lens group.

8. The high-definition zoom lens according to claim 1, wherein:

the third fixed lens group includes at least, from the object plane side to the image plane side: a lens of positive power and a lens of negative power.

9. The high-definition zoom lens according to claim 1, wherein:

the first fixed lens group includes at least: two lenses with positive focal power and one lens with negative focal power.

10. The utility model provides a security protection camera device which characterized in that: the security camera device comprises the high-definition zoom lens as claimed in any one of claims 1 to 9.