A zoom radiation-resistant lens

Abstract

The present invention discloses a zoom radiation-resistant lens. Through the cooperative action of a first fixed group, a zoom group, a second fixed group, and a focusing group, when the zoom group moves along the optical axis towards the object side and the focusing group moves along the optical axis towards the image side, zooming from the telephoto end to the wide-angle end is achieved. When the zoom group moves along the optical axis towards the image side and the focusing group moves along the optical axis towards the object side, zooming from the wide-angle end to the telephoto end is achieved. Thus, the moving groups for zooming between the telephoto end and the wide-angle end are the zoom group and the focusing group, reducing the number of moving groups, simplifying the structure of the zoom lens, and lowering the manufacturing difficulty and production cost.

Description

Technical Field

[0001] The present invention relates to the field of optical elements, and particularly to a zoom radiation-resistant lens. Background Art

[0002] Most of the known zoom lenses are composed of multiple components such as a first fixed group with positive diopter, a second moving group with negative diopter, a third moving group with negative diopter, a fourth moving group with positive diopter, and a fifth fixed group with positive diopter that does not move. Although the above structure realizes high performance, including a zoom function of more than 3 times, it has the disadvantages of too many moving groups, overly complex structure, high manufacturing difficulty, and high cost. Summary of the Invention

[0003] The main object of the present invention is to propose a zoom radiation-resistant lens, aiming to solve the problems in the prior art that in order to achieve a zoom function of more than 3 times, there are disadvantages such as too many lens moving groups, overly complex structure, high manufacturing difficulty, and high cost.

[0004] To achieve the above object, the zoom radiation-resistant lens proposed by the present invention includes:

[0005] It includes a housing and a plurality of lens groups installed in the inner cavity of the housing and arranged in sequence. An optical axis is formed in the housing corresponding to between the plurality of lens groups. Among them, the plurality of lens groups sequentially include from the object side to the image side:

[0006] A first fixed group with positive optical power, and the position of the first fixed group is fixed;

[0007] A variable magnification group with negative optical power, and the variable magnification group has a moving stroke close to the object side or the image side;

[0008] A second fixed group with positive optical power, and the position of the second fixed group is fixed; and,

[0009] A focusing group with positive optical power, and the focusing group has a moving stroke close to the object side or the image side;

[0010] Among them, when the variable magnification group moves along the optical axis towards the object side and the focusing group moves along the optical axis towards the image side, the change from the telephoto end to the wide-angle end is realized. When the variable magnification group moves along the optical axis towards the image side and the focusing group moves along the optical axis towards the object side, the change from the wide-angle end to the telephoto end is realized.

[0011] Optionally, the effective focal length of the zoom radiation-resistant lens is 15 - 75 mm.

[0012] Optionally, the zoom radiation-resistant lens further includes a diaphragm disposed between the variable magnification group and the second fixed group, and the position of the diaphragm is fixed.

[0013] Optionally, the numerical aperture of the zoom radiation-resistant lens is 1.65.

[0014] Optionally, the lens materials of the first fixed group, the zoom group, the second fixed group, and the focusing group are all radiation-resistant optical glass.

[0015] Optionally, the first fixed group includes:

[0016] The first lens, which is a crescent-shaped negative lens with its convex surface facing the object side, has a refractive index of Nd, where 1.7 < Nd < 1.9, and a dispersion coefficient of Vd, where 20 < Vd < 30;

[0017] The second lens, which is a biconvex positive lens, has a refractive index of Nd, where 1.5 < Nd < 1.65, and a dispersion coefficient of Vd, where 60 < Vd < 65;

[0018] The third lens, which is a crescent-shaped positive lens with its convex surface facing the object side, has a refractive index of Nd, where 1.5 < Nd < 1.65, and a dispersion coefficient of Vd, where 60 < Vd < 65.

[0019] Optionally, the zoom group includes:

[0020] The fourth lens, which is a crescent-shaped negative lens with its convex surface facing the object side, has a refractive index of Nd, where 1.5 < Nd < 1.65, and a dispersion coefficient of Vd, where 60 < Vd < 65;

[0021] The fifth lens, which is a biconcave negative lens, has a refractive index of Nd, where 1.5 < Nd < 1.65, and a dispersion coefficient of Vd, where 60 < Vd < 65;

[0022] The sixth lens, which is a crescent-shaped positive lens with its convex surface facing the object side, has a refractive index of Nd, where 1.7 < Nd < 1.9, and a dispersion coefficient of Vd, where 20 < Vd < 30.

[0023] Optionally, the second fixed group includes:

[0024] The seventh lens, which is a crescent-shaped negative lens with its convex surface facing the object side, has a refractive index of Nd, where 1.7 < Nd < 1.9, and a dispersion coefficient of Vd, where 20 < Vd < 30;

[0025] The eighth lens, which is a biconvex positive lens, has a refractive index of Nd, where 1.5 < Nd < 1.65, and a dispersion coefficient of Nd, where 60 < Vd < 65;

[0026] The ninth lens, which is a crescent-shaped positive lens with its convex surface facing the object side, has a refractive index of Nd, where 1.5 < Nd < 1.65, and a dispersion coefficient of Vd, where 60 < Vd < 65.

[0027] Optionally, the focusing group includes:

[0028] The tenth lens is a biconvex positive lens with a refractive index of Nd, where 1.5 < Nd < 1.65, and an Abbe number of Vd, where 60 < Vd < 65;

[0029] The eleventh lens is a biconvex positive lens with a refractive index of Nd, where 1.5 < Nd < 1.65, and an Abbe number of Vd, where 60 < Vd < 65;

[0030] The twelfth lens is a biconcave negative lens with a refractive index of Nd, where 1.7 < Nd < 1.9, and an Abbe number of Vd, where 20 < Vd < 30.

[0031] Optionally, the zoom radiation-resistant lens further includes a protection window, which is disposed on the object side of the first fixed group and is installed in the inner cavity of the housing.

[0032] In the technical solution provided by the present invention, through the combined action of the first fixed group, the variable magnification group, the second fixed group, and the focusing group, when the variable magnification group moves along the optical axis toward the object side and the focusing group moves along the optical axis toward the image side, the variable magnification from the wide-angle end to the telephoto end is achieved. When the variable magnification group moves along the optical axis toward the image side and the focusing group moves along the optical axis toward the object side, the variable magnification from the telephoto end to the wide-angle end is achieved. Thus, the moving groups for variable magnification between the telephoto end and the wide-angle end are the variable magnification group and the focusing group, reducing the number of moving groups, simplifying the structure of the zoom lens, and reducing the manufacturing difficulty and production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0034] Figure 1 It is a schematic structural diagram of an embodiment of the zoom radiation-resistant lens provided by the present invention;

[0035] Figure 2 For Figure 1 the schematic structural diagram of the zoom radiation-resistant lens at the telephoto end in

[0036] Figure 3 For Figure 1 the schematic structural diagram of the zoom radiation-resistant lens at the wide-angle end in

[0037] Figure 4 For Figure 1 the schematic structural diagram of the zoom radiation-resistant lens at the intermediate end in

[0038] Description of the reference numerals in the drawings:

[0039]

[0040] The realization of the object of the present invention, its functional features and advantages will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0042] It should be noted that if there are directional indications (such as up, down, left, right, front, back,...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0043] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0044] Most known zoom lenses are composed of multiple components such as a first fixed group with a positive diopter, a second moving group with a negative diopter, a third moving group with a negative diopter, a fourth moving group with a positive diopter, and a fifth fixed positive diopter moving group. Although the above structure realizes high performance, including a zoom function of more than 3 times, it has disadvantages such as too many moving groups, overly complex structure, high manufacturing difficulty, and high cost.

[0045] The present invention provides a zoom radiation-resistant lens, wherein, Figures 1 to 4 It is a schematic structural diagram of an embodiment of the zoom lens provided by the present invention.

[0046] Please refer to Figures 1 to 3 , the zoom radiation-resistant lens includes a housing and a plurality of lens groups mounted in the inner cavity of the housing and arranged in sequence. A optical axis is formed in the housing corresponding to between the plurality of lens groups. Among them, the plurality of lens groups sequentially include a first fixed group 1, a zoom group 2, a second fixed group 3, and a focusing group 4 from the object side to the image side. The first fixed group 1 has a positive optical power, the position of the first fixed group 1 is fixed, the zoom group 2 has a negative optical power, the zoom group 2 has a moving stroke close to the object side or the image side, the second fixed group 3 has a positive optical power, the position of the second fixed group 3 is fixed, the focusing group 4 has a positive optical power, the focusing group 4 has a moving stroke close to the object side or the image side. When the zoom group 2 moves along the optical axis towards the object side and the focusing group 4 moves along the optical axis towards the image side, zooming from the wide-angle end to the telephoto end is achieved. When the zoom group 2 moves along the optical axis towards the image side and the focusing group 4 moves along the optical axis towards the object side, zooming from the telephoto end to the wide-angle end is achieved.

[0047] In the technical solution provided by the present invention, through the cooperative action of the first fixed group 1, the zoom group 2, the second fixed group 3, and the focusing group 4, when the zoom group 2 moves along the optical axis towards the object side and the focusing group 4 moves along the optical axis towards the image side, zooming from the wide-angle end to the telephoto end is achieved. When the zoom group 2 moves along the optical axis towards the image side and the focusing group 4 moves along the optical axis towards the object side, zooming from the telephoto end to the wide-angle end is achieved. Thus, the moving groups for zooming between the telephoto end and the wide-angle end are the zoom group 2 and the focusing group 4, reducing the number of moving groups, simplifying the structure of the zoom lens, and reducing the manufacturing difficulty and production cost.

[0048] It should be noted that the wide-angle end is the state with the shortest focal length of the zoom radiation-resistant lens, and the telephoto end is the state with the longest focal length of the zoom radiation-resistant lens.

[0049] Specifically, the effective focal length of the lens is 15 - 75 mm. That is, when the effective focal length of the lens is 15 mm, the lens is in the wide-angle end state. When the lens is 75 mm, the lens is in the telephoto end state. When the lens is in the middle end state, the effective focal length is 30 mm.

[0050] Specifically, the zoom radiation-resistant lens further includes a diaphragm 5 disposed between the zoom group 2 and the second fixed group 3. The position of the diaphragm 5 is fixed. With such a setting, the size of the zoom lens can be reduced, and it is beneficial to balance aberrations, and the imaging effect is good.

[0051] Specifically, in the embodiment of the present application, during the process of zooming between the telephoto end and the wide-angle end, the numerical aperture of the zoom lens is 1.65.

[0052] In the embodiments of the present application, the lens materials of the first fixed group 1, the zoom group 2, the second fixed group 3, and the focusing group 4 are all radiation-resistant optical glasses. Such a setting can improve the service life of the zoom lens in a high-radiation environment.

[0053] It should be noted that specifically, the radiation-resistant optical glass can be three kinds of radiation-resistant optical glass materials: K709, SF6G05, and BK7G18. In other embodiments, other radiation-resistant optical glasses can also be selected, and the present application does not limit this.

[0054] Specifically, the first fixed group 1 includes a first lens 11, a second lens 12, and a third lens 13. The first lens 11 is a crescent-shaped negative lens with its convex surface facing the object side. Its refractive index is Nd, and 1.7 < Nd < 1.9, and its dispersion coefficient is Vd, and 20 < Vd < 30. The second lens 12 is a biconvex positive lens with its refractive index being Nd, and 1.5 < Nd < 1.65, and its dispersion coefficient is Vd, 50 < Vd < 65. The third lens 13 is a crescent-shaped positive lens with its convex surface facing the object side. Its refractive index is Nd, and 1.5 < Nd < 1.65, and its dispersion coefficient is Vd, and 60 < Vd < 65.

[0055] It should be noted that the first lens 11, the second lens 12, and the third lens 13 can all withstand the above radiation dose.

[0056] Specifically, the zoom group 2 includes a fourth lens 21, a fifth lens 22, and a sixth lens 23. The fourth lens 21 is a crescent-shaped negative lens with its convex surface facing the object side. Its refractive index is Nd, and 1.5 < Nd < 1.65, and its dispersion coefficient is Vd, and 60 < Vd < 65. The fifth lens 22 is a biconcave negative lens with its refractive index being Nd, 1.5 < Nd < 1.65, and its dispersion coefficient is Vd, and 60 < Vd < 65. The sixth lens 23 is a crescent-shaped positive lens with its convex surface facing the object side. Its refractive index is Nd, and 1.7 < Nd < 1.9, and its dispersion coefficient is Vd, and 20 < Vd < 30.

[0057] It should be noted that the fourth lens 21, the fifth lens 22, and the sixth lens 23 can all withstand the above radiation dose.

[0058] Specifically, the second fixed group 3 includes a seventh lens 31, an eighth lens 32, and a ninth lens 33. The seventh lens 31 is a crescent-shaped negative lens with its convex surface facing the object side. Its refractive index is Nd, and 1.7 < Nd < 1.9. Its dispersion coefficient is Vd, and 20 < Vd < 30. The eighth lens 32 is a biconvex positive lens with its refractive index being Nd, and 1.5 < Nd < 1.65. Its dispersion coefficient is Vd, and 60 < Vd < 65. The ninth lens 33 is a crescent-shaped positive lens with its convex surface facing the object side. Its refractive index is Nd, and 1.5 < Nd < 1.65. Its dispersion coefficient is Vd, and 60 < Vd < 65.

[0059] It should be noted that the seventh lens 31, the eighth lens 32, and the ninth lens 33 can all withstand the above radiation dose.

[0060] Specifically, the focusing group 4 includes a tenth lens 41, an eleventh lens 42, and a twelfth lens 43. The tenth lens 41 is a biconvex positive lens with its refractive index being Nd, and 1.5 < Nd < 1.65. Its dispersion coefficient is Vd, and 60 < Vd < 65. The eleventh lens 42 is a biconvex positive lens with its refractive index being Nd, and 1.5 < Nd < 1.65. Its dispersion coefficient is Vd, and 50 < Vd < 65. The twelfth lens 43 is a biconcave negative lens with its refractive index being Nd, and 1.7 < Nd < 1.9. Its dispersion coefficient is Vd, and 20 < Vd < 30.

[0061] It should be noted that the tenth lens 41, the eleventh lens 42, and the twelfth lens 43 can all withstand the above radiation dose.

[0062] Referring to Figure 4 , the zoom radiation-resistant lens further includes a protection window. The protection window is disposed on the first fixed group 1 near the object side and is installed in the inner cavity of the housing. The protection window protects the multiple lens groups to prevent the lens groups from being exposed, thereby affecting the service life of the zoom lens.

[0063] It should be noted that the protection window includes a window piece 61. The window piece 61 can withstand the above radiation dose, and the refractive index of the window piece 61 is Nd, and 1.5 < Nd < 1.65. The dispersion coefficient of the window piece 61 is Vd, and 50 < Vd < 65.

[0064] Table 1 shows the basic parameter table of the zoom radiation-resistant lens in the embodiment of the present application. Among them, the units of the radius of curvature and the thickness are both millimeters (mm).

[0065] Table 1:

[0066]

[0067] In this example, by changing the spacing distance A on the optical axis between the third lens 13 and the fourth lens 21 (i.e., the spacing distance on the optical axis from the image side of the third lens 13 to the object side of the fourth lens 21), the spacing distance B on the optical axis between the sixth lens 23 and the diaphragm 5 (i.e., the spacing distance on the optical axis from the image side of the sixth lens 23 to the object side of the diaphragm 5), the spacing distance C on the optical axis between the ninth lens 33 and the tenth lens 41 (i.e., the spacing distance on the optical axis from the image side of the ninth lens 33 to the object side of the tenth lens 41), and the spacing distance D on the optical axis between the twelfth lens 43 and the image side (i.e., the spacing distance on the optical axis from the image side of the twelfth lens 43 to the object side of the image side), the zoom radiation-resistant lens is switched from the telephoto end to the wide-angle end or from the wide-angle end to the telephoto end.

[0068] Table 2 shows the specific parameter values of A, B, C, and D corresponding to between the third lens 13 and the fourth lens 21, the sixth lens 23 and the diaphragm 5, the ninth lens 33 and the tenth lens 41, and the twelfth lens 43 and the image side when switching from the telephoto end to the wide-angle end or from the wide-angle end to the telephoto end in the above embodiments. Among them, the units of A, B, C, and D are all millimeters (mm).

[0069] Table 2:

[0070]

[0071] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A zoom radiation-resistant lens, characterized in that, It includes a housing and a plurality of lens groups installed in the inner cavity of the housing and arranged in sequence. A optical axis is formed in the housing corresponding to the plurality of lens groups. Among them, the plurality of lens groups are successively composed of the following lenses from the object side to the image side: The first fixed group, having a positive focal power, and the position of the first fixed group is fixed; The zoom group, having a negative focal power, and the zoom group has a moving stroke close to the object side or the image side; The second fixed group, having a positive focal power, and the position of the second fixed group is fixed; and, The focusing group, having a positive focal power, and the focusing group has a moving stroke close to the object side or the image side; Among them, when the zoom group moves along the optical axis toward the object side and the focusing group moves along the optical axis toward the image side, zooming from the wide-angle end to the telephoto end is achieved. When the zoom group moves along the optical axis toward the image side and the focusing group moves along the optical axis toward the object side, zooming from the telephoto end to the wide-angle end is achieved; The first fixed group includes: The first lens, which is a crescent-shaped negative lens with its convex surface facing the object side; The second lens, which is a biconvex positive lens; The third lens, which is a crescent-shaped positive lens with its convex surface facing the object side; The zoom group includes: The fourth lens, which is a crescent-shaped negative lens with its convex surface facing the object side; The fifth lens, which is a biconcave negative lens; The sixth lens, which is a crescent-shaped positive lens with its convex surface facing the object side; The second fixed group includes: The seventh lens, which is a crescent-shaped negative lens with its convex surface facing the object side; The eighth lens, which is a biconvex positive lens; The ninth lens, which is a crescent-shaped positive lens with its convex surface facing the object side; The focusing group includes: The tenth lens, which is a biconvex positive lens; The eleventh lens, which is a biconvex positive lens; The twelfth lens, which is a biconcave negative lens.

2. The zoom radiation-resistant lens according to claim 1, wherein The effective focal length of the lens is 15 - 75 mm.

3. The zoom radiation-resistant lens according to claim 1, wherein, The zoom radiation-resistant lens further includes a diaphragm disposed between the zoom group and the second fixed group, and the position of the diaphragm is fixed.

4. The zoom radiation-resistant lens according to claim 1, wherein The numerical aperture of the zoom radiation-resistant lens is 1.

65.

5. The zoom radiation-resistant lens according to claim 1, wherein The lens materials of the first fixed group, the zoom group, the second fixed group and the focusing group are all radiation-resistant optical glass.

6. The zoom radiation-resistant lens according to claim 1, characterized in that, The refractive index of the first lens is Nd, and 1.7 < Nd < 1.9, and the dispersion coefficient is Vd, and 20 < Vd < 30; The refractive index of the second lens is Nd, and 1.5 < Nd < 1.65, and the dispersion coefficient is Vd, 60 < Vd < 65; The convex surface of the third lens faces the object side, its refractive index is Nd, and 1.5 < Nd < 1.65, and the dispersion coefficient is Vd, and 60 < Vd < 65.

7. The zoom radiation-resistant lens according to claim 1, wherein, The refractive index of the fourth lens is Nd, and 1.5 < Nd < 1.65, and the dispersion coefficient is Vd, and 60 < Vd < 65; The refractive index of the fifth lens is Nd, 1.5 < Nd < 1.65, and the dispersion coefficient is Vd, and 60 < Vd < 65; The refractive index of the sixth lens is Nd, and 1.7 < Nd < 1.9, and the dispersion coefficient is Vd, and 20 < Vd < 30.

8. The zoom radiation-resistant lens according to claim 1, wherein The refractive index of the seventh lens is Nd, and 1.7 < Nd < 1.9, and the dispersion coefficient is Vd, and 20 < Vd < 30; The refractive index of the eighth lens is Nd, and 1.5 < Nd < 1.65, and the dispersion coefficient is Nd, and 60 < Vd < 65; The refractive index of the ninth lens is Nd, and 1.5 < Nd < 1.65, the dispersion coefficient is Vd, and 60 < Vd < 65.

9. The zoom radiation-resistant lens according to claim 1, wherein, The refractive index of the tenth lens is Nd, and 1.5 < Nd < 1.65, the dispersion coefficient is Vd, and 60 < Vd < 65; The refractive index of the eleventh lens is Nd, and 1.5 < Nd < 1.65, the dispersion coefficient is Vd, and 60 < Vd < 65; The refractive index of the twelfth lens is Nd, and 1.7 < Nd < 1.9, the dispersion coefficient is Vd, and 20 < Vd < 30.

10. The zoom radiation-resistant lens according to claim 1, wherein The zoom radiation-resistant lens further includes a protection window, which is arranged on the first fixed group close to the object side and installed in the inner cavity of the housing.

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