binoculars

Abstract

Binoculars characterized in that they comprise an objective group (1), a Pechan prism group (2) and an eyepiece group (4) which are arranged successively along the direction of the optical axis from the object side to the observation side; wherein the objective group (1) comprises a first lens of a biconvex type objective (L11) with a positive optical focal length, a second lens of a meniscus type objective (L12) with a negative optical focal length, a third lens of a meniscus type objective (L13) with a positive optical focal length and a fourth lens of a meniscus type objective (L14) with a negative optical focal length, which are arranged successively along the direction of the optical axis from the object side to the observation side; wherein the Pechan prism group (2) comprises a semi-pentaprism (L21) and a roof prism (L22) arranged successively along the direction of the optical axis from the object side to the observation side; wherein the eyepiece group (4) comprises a first lens of an eyepiece (L41) of the biconcave type with negative optical focal length, a second lens of an eyepiece (L42) of the biconvex type with positive optical focal length, a third lens of an eyepiece (L43) of the biconvex type with positive optical focal length, a fourth lens of an eyepiece (L44) of the meniscus type with negative optical focal length and a fifth lens of an eyepiece (L45) of the meniscus type with positive optical focal length, arranged successively along the direction of an optical axis from the object side to the observation side.

Description

Technical area

[0001] The present utility model relates to the technical field of optical lenses and in particular to binoculars. Background technology

[0002] Binoculars are used to magnify distant objects through the optical system closer to the human eye, thus making detailed observation clearer. They can be used for observing outdoor activities, watching games, watching concerts, etc. The optical systems of current binoculars achieve different effects due to different design concepts. Existing binoculars have shortcomings such as low resolution and a poor user experience. Content of the utility model

[0003] Therefore, the technical problem to be solved by the present utility model is to overcome the shortcomings of low resolution and poor user experience of existing binoculars and thereby provide a pair of binoculars.

[0004] In order to solve the above-mentioned technical problems, the technical solution of the present utility model is as follows: A binocular comprising an objective lens group, a Pechan prism group, and an eyepiece group provided sequentially along the optical axis direction from the object side to the observation side; wherein the lens group comprises a first lens of a biconvex type lens with a positive optical focal length, a second lens of a meniscus type lens with a negative optical focal length, a third lens of a meniscus type lens with a positive optical focal length, and a fourth lens of a meniscus type lens with a negative optical focal length, which are provided sequentially along the optical axis direction from the object side to the observation side; wherein the Pechan prism group comprises a half-pentaprism and a roof prism arranged sequentially along the optical axis direction from the object side to the observation side; wherein the eyepiece group comprises a first lens of a biconcave type eyepiece with a negative optical focal length, a second lens of a biconvex type eyepiece with a positive optical focal length, a third lens of a biconvex type eyepiece with a positive optical focal length, a fourth lens of a meniscus type eyepiece with a negative optical focal length, and a fifth lens of a meniscus type eyepiece with a positive optical focal length, which are arranged sequentially along the direction of an optical axis from the object side to the observation side.

[0005] Furthermore, the first lens of the objective and the second lens of the objective are cemented at the sides where they meet, the first lens of the eyepiece and the second lens of the eyepiece are cemented at the sides where they meet, and the third lens of the eyepiece and the fourth lens of the eyepiece are cemented at the sides where they meet.

[0006] Furthermore, the fourth lens of the objective is arranged to be movable along the direction of the optical axis, and the focusing is achieved from infinity to 3 meters by moving the fourth lens of the objective back and forth along the direction of the optical axis.

[0007] Furthermore, the magnification rate of the binoculars is 10x.

[0008] Furthermore, the exit pupil diameter of the binoculars is in the range of 3.5 mm to 4.5 mm.

[0009] Furthermore, the exit pupil distance of the binoculars is in the range of 15 mm to 18 mm.

[0010] Furthermore, the viewing angle of the binoculars is in the range of 6° to 6.5°.

[0011] Furthermore, the aperture of the first lens of the objective is in the range of 30 mm to 50 mm.

[0012] Furthermore, the total length of the optical system of the binoculars does not exceed 130 mm.

[0013] The technical solution of the present utility model offers the following advantages: In terms of performance, the binoculars achieve high resolution in the center of the field of view and a wide field of view, enabling clear imaging. At the same time, multiple sets of cemented lenses and low-dispersion lenses are used to significantly reduce chromatic aberration. Furthermore, the prism combination of a half-pentaprism and a roof prism significantly shortens the overall length of the binoculars, making them more comfortable to use. Brief description of the drawings

[0014] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present utility model, the accompanying drawings are briefly presented below. These drawings must be used in describing the specific embodiments or prior art. It is obvious that the accompanying drawings in the following description represent some of the embodiments of the present utility model, and that other drawings can be obtained based on the accompanying drawings for general technical personnel in the field, provided they do not perform creative work. Fig. 1 is an optical structure diagram of the optical system of the binoculars in an embodiment of the present utility model.

[0015] In the figures: 1. Objective lens group; L11. first lens of the objective lens; L12. second lens of the objective lens; L13. third lens of the objective lens; L14. fourth lens of the objective lens; 2. Pechan prism group; L21. half-pentaprism; L22. roof prism; 3. real image surface of the objective lens; 4. Eyepiece group; L41. first lens of the eyepiece; L42. second lens of the eyepiece; L43. third lens of the eyepiece; L44. fourth lens of the eyepiece; L45. fifth lens of the eyepiece. Description of the preferred embodiments

[0016] The technical solutions of the present utility model are described clearly and completely below in conjunction with the accompanying drawings. Obviously, the description of the embodiments represents only a portion of the embodiments of the present utility model and not all of them. Starting from the embodiments of the present utility model, all other embodiments that a person skilled in the art can produce without creative effort fall within the scope of protection of the present utility model.

[0017] When describing the embodiment of the present utility model, it is necessary to point out that an azimuth or positional relationship related to terms such as "central," "top," "bottom," "left," "right," "vertical," "horizontal," "inside," "outside," and the like, has the azimuth or positional relationship based on the drawing. They are intended to facilitate and simplify the description of the present utility model, rather than indicating or implying that the said device or component must have a specific orientation, be constructed, and operate in a specific orientation. Therefore, they should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and "third" are used only for discriminatory purposes and should not be understood to indicate a relative meaning.

[0018] Embodiments of the present utility model provide binoculars designed to magnify distant objects into the human eye after passing through an optical system, thus making detailed observation clearer.

[0019] As in Fig. 1, a binocular comprises an objective lens group 1, a Pechan prism group 2, a real image surface of the objective lens 3, and an eyepiece group 4, which are provided sequentially along the direction of the optical axis from the object side to the observation side.

[0020] Lens group 1 includes a first lens of a biconvex lens type L11 with a positive optical focal length, a second lens of a meniscus lens type L12 with a negative optical focal length, a third lens of a meniscus lens type L13 with a positive optical focal length, and a fourth lens of a meniscus lens type L14 with a negative optical focal length, which are arranged sequentially along the optical axis direction from the object side to the observation side. The fourth lens of the lens type L14 is movably arranged along the optical axis direction, and focusing is achieved from infinity to 3 meters by reciprocating the fourth lens of the lens type L14 along the optical axis direction.

[0021] Pechan prism group 2 comprises a half-pentaprism L21 and a roof prism L22. This Pechan prism group 2 significantly shortens the overall optical length of the entire optical system and allows the image formed by the light from a distant object to pass through lens group 1, be inverted, and imaged onto the real image surface of lens 3.

[0022] The eyepiece group 4 includes a first lens of a biconcave type eyepiece L41 with a negative optical focal length, a second lens of a biconvex type eyepiece L42 with a positive optical focal length, a third lens of a biconvex type eyepiece L43 with a positive optical focal length, a fourth lens of a meniscus type eyepiece L44 with a negative optical focal length, and a fifth lens of a meniscus type eyepiece L45 with a positive optical focal length, which are arranged sequentially along the direction of an optical axis from the object side to the observation side. The eyepiece group 4 is designed to magnify the actual image area of ​​the objective lens 3, so that the human eye can ultimately see objects with a magnification of 10x.

[0023] The first lens of objective lens L11 and the second lens of objective lens L12 are cemented at the sides where they meet, the first lens of eyepiece L41 and the second lens of eyepiece L42 are cemented at the sides where they meet, and the third lens of eyepiece L43 and the fourth lens of eyepiece L44 are cemented at the sides where they meet. Cementing the positive and negative lenses can significantly improve the problem of chromatic aberration in binoculars. At the same time, the overall length of the entire optical system is shortened after cementing the lenses.

[0024] The binoculars' angle of view ranges from 6° to 6.5°, their exit pupil diameter ranges from 3.5 mm to 4.5 mm, and their exit pupil distance ranges from 15 mm to 17 mm. The longer exit pupil distance makes them easier to use for different groups of people.

[0025] The aperture of the first lens of the L11 objective lens ranges from 30 mm to 50 mm, and the total length of the binoculars' optical system does not exceed 130 mm. The binoculars' small size reflects their comfortable handling.

[0026] Table 1 below lists the actual parameters of each lens of this embodiment that correspond to the above characteristics: Table 1 lens Serial number Y-radius (mm) Thickness (mm) refractive index Abbe number First lens of the lens 1 113,732 7,092 1,484 83,580 Second lens of the lens 2 -75,473 1,361 1,792 28,553 3 -563,816 2,922 Third lens of the lens 4 47,187 3,940 1,639 53,611 5 121,585 D(5) Fourth lens of the lens 6 53,628 0,957 1,518 67,100 7 27,657 D(7) Pechan prism group / / / / / 8 10,021 First lens of the eyepiece 9 -16,329 1,257 1,838 38,880 Second lens of the eyepiece 10 29,123 8,522 1,819 37,248 11 -15,537 1,447 Third lens of the eyepiece 12 56,325 6,495 1,524 55,380 Fourth lens of the eyepiece 13 -17,732 0,747 1,865 18,567 14 -28,383 0,134 Fifth lens of the eyepiece 15 10,507 4,532 1,704 42,518 16 53,379 16,625

[0027] The changes in the air gap parameters of the binoculars are shown in Table 2 below: Table 2 Object distance Infinite 3 meters D(5) 40,15 43,11 D(7) 10,75 7,79

[0028] Where D(5) is the central air gap between the third lens of objective L13 and the fourth lens of objective L14 in the direction of the optical axis; and D(7) is the central air gap between the fourth lens of objective L14 and the Pechan prism group 2 in the direction of the optical axis.

[0029] In summary, these binoculars offer the following advantages: Firstly, in terms of performance, this binocular achieves high resolution in the center of the field of view and in the wide field of view, and uses multiple groups of cemented lenses and low dispersion glass to significantly reduce chromatic aberration; Secondly, the overall structure is compact and has the advantages of small size and light weight. Thirdly, the prism combination of half-pentaprism and roof prism significantly shortens the overall length of the binoculars and makes them more comfortable.

[0030] Of course, the above-mentioned embodiments serve only as examples for clear explanation and are not intended to limit the embodiments. Other forms of changes or modifications are also possible for general technical personnel in this field based on the above description. An exhaustive list of all embodiments is neither necessary nor possible. The obvious changes or modifications derived therefrom remain within the scope of protection of the present utility model.

Claims

[1] Binoculars, characterized by that it comprises an objective lens group (1), a Pechan prism group (2) and an eyepiece group (4) which are provided successively along the direction of the optical axis from the object side to the observation side; wherein the lens group (1) comprises a first lens of a biconvex type lens (L11) with a positive optical focal length, a second lens of a meniscus type lens (L12) with a negative optical focal length, a third lens of a meniscus type lens (L13) with a positive optical focal length, and a fourth lens of a meniscus type lens (L14) with a negative optical focal length, which are provided sequentially along the direction of the optical axis from the object side to the observation side; wherein the Pechan prism group (2) comprises a half-pentaprism (L21) and a roof prism (L22) arranged sequentially along the direction of the optical axis from the object side to the observation side; wherein the eyepiece group (4) comprises a first lens of a biconcave type eyepiece (L41) with a negative optical focal length, a second lens of a biconvex type eyepiece (L42) with a positive optical focal length, a third lens of a biconvex type eyepiece (L43) with a positive optical focal length, a fourth lens of a meniscus type eyepiece (L44) with a negative optical focal length, and a fifth lens of a meniscus type eyepiece (L45) with a positive optical focal length, which are arranged sequentially along the direction of an optical axis from the object side to the observation side. [2] Binoculars according to claim 1, characterized bythat the first lens of the objective (L11) and the second lens of the objective (L12) are cemented at the sides where they meet; the first lens of the eyepiece (L41) and the second lens of the eyepiece (L42) are cemented at the sides where they meet; the third lens of the eyepiece (L43) and the fourth lens of the eyepiece (L44) are cemented at the sides where they meet. [3] Binoculars according to claim 1, characterized by that the fourth lens of the objective (L14) is arranged to be movable along the direction of the optical axis and the focusing from infinity to 3 meters is achieved by moving the fourth lens of the objective (L14) back and forth along the direction of the optical axis. [4] Binoculars according to claim 1, characterized by that the magnification rate of the binoculars is 10x. [5] Binoculars according to claim 1, wherein the exit pupil diameter of the binoculars is in the range of 3.5 mm to 4.5 mm. [6] Binoculars according to claim 1, characterized by that the exit pupil distance of the binoculars is in the range of 15 mm to 18 mm. [7] Binoculars according to claim 1, characterized by that the viewing angle of the binoculars is in the range of 6° to 6.5°. [8] Binoculars according to claim 1, characterized by that the aperture of the first lens of the objective (L11) is in the range of 30 mm to 50 mm. [9] Binoculars according to claim 1, wherein the total length of the optical system of the binoculars does not exceed 130 mm.

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