Binocular telescope

Abstract

To provide a binocular telescope which realizes high resolution, significantly reduces the overall length, and is convenient. [Solution] The binocular telescope includes a first biconvex objective lens having positive refractive power, a second meniscus objective lens having negative refractive power, a third meniscus objective lens having positive refractive power, a fourth meniscus objective lens having negative refractive power, a half pentaprism, a roof prism, a first biconcave eyepiece lens having negative refractive power, a second biconvex eyepiece lens having positive refractive power, a third biconvex eyepiece lens having positive refractive power, a fourth meniscus eyepiece lens having negative refractive power, and a fifth meniscus eyepiece lens having positive refractive power, which are arranged in order from the object side to the observation side along the optical axis direction, and when adjusting the focus, the fourth objective lens moves back and forth along the optical axis direction.

Description

[Technical field]

[0001] The present invention relates to the field of optical lenses, and in particular to binocular telescopes. [Background technology]

[0002] Binocular telescopes are used to magnify distant objects through an optical system to the human eye, making details more clearly visible, and their application range includes outdoor activity observation, game viewing, concert viewing, etc. At present, the optical systems of traditional binocular telescopes achieve different effects due to different design concepts, and traditional binocular telescopes have the disadvantages of low resolution and poor user experience. Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, the technical problem to be solved by the present invention is to provide a binocular telescope by overcoming the shortcomings of low resolution and poor user experience existing in the binocular telescope in the prior art. [Means for solving the problem]

[0004] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0005] A binocular telescope including an objective lens group, a Pechan prism group, and an eyepiece lens group, which are arranged in this order from an object side to an observation side along an optical axis direction, the objective lens group includes a first objective lens of a biconvex type having positive refractive power, a second objective lens of a meniscus type having negative refractive power, a third objective lens of a meniscus type having positive refractive power, and a fourth objective lens of a meniscus type having negative refractive power, which are arranged in this order from the object side to the observation side along the optical axis direction; the Pechan prism group includes a half pentaprism and a roof prism, which are disposed in this order from the object side to the observation side along the optical axis direction, The eyepiece lens group includes a first biconcave eyepiece lens having negative refractive power, a second biconvex eyepiece lens having positive refractive power, a third biconvex eyepiece lens having positive refractive power, a fourth meniscus eyepiece lens having negative refractive power, and a fifth meniscus eyepiece lens having positive refractive power, which are arranged in order from the object side to the observation side along the optical axis direction.

[0006] Furthermore, the contacting sides of the first objective lens and the second objective lens are cemented to each other, the contacting sides of the first eyepiece lens and the second eyepiece lens are cemented to each other, and the contacting sides of the third eyepiece lens and the fourth eyepiece lens are cemented to each other.

[0007] Furthermore, the fourth objective lens is installed so as to be movable along the optical axis direction, and focusing between infinity and 3 meters can be achieved by moving the fourth objective lens back and forth along the optical axis direction.

[0008] Furthermore, the magnification of the binoculars is 10x.

[0009] Furthermore, the exit pupil diameter range of the binocular telescope is 3.5 mm to 4.5 mm.

[0010] Furthermore, the exit pupil distance range of the binocular telescope is 15 mm to 18 mm.

[0011] Furthermore, the viewing angle range of the binocular telescope is 6° to 6.5°.

[0012] Furthermore, the aperture range of the first objective lens is 30 mm to 50 mm.

[0013] Furthermore, the overall length of the optical system of said binocular telescope shall not exceed 130 mm. Effect of the Invention

[0014] The technical solution of the present invention has the following advantages: In terms of performance, the binocular telescope can achieve high resolution in the center of the field of view and in the wide field of view, and can provide clear images; it also uses multiple sets of cemented lenses and low-dispersion glass to greatly reduce chromatic aberration; and it uses a combination of half pentaprisms and roof prisms to greatly shorten the overall length of the binocular telescope, making it more convenient. [Brief description of the drawings]

[0015] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces drawings that need to be used in the embodiments of the present invention or the prior art description. It is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings based on these drawings without exerting creative efforts. [Figure 1] 2 is a schematic diagram of the optical system of the binocular telescope according to the embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The following clearly and completely describes the technical solution of the present invention in conjunction with the drawings, and it is obvious that the described embodiments are only some of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained based on the embodiments of the present invention without the creative efforts of those skilled in the art are all within the scope of protection of the present invention.

[0017] In the description of the present invention, it should be explained that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are orientations or positional relationships shown based on the drawings, and are only for facilitating and simplifying the description of the present invention, and do not indicate or imply that the devices or elements mentioned have a specific orientation and must be configured and operated in a specific orientation, and should not be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

[0018] An embodiment of the present invention provides a binocular telescope for magnifying distant objects through an optical system to the human eye for clearer observation of fine details.

[0019] Referring to FIG. 1, the optical system of this binocular telescope includes an objective lens group 1, a Pechan prism group 2, an objective lens real image surface 3, and an eyepiece lens group 4, which are arranged in this order from the object side to the observation side along the optical axis direction. The objective lens group 1 includes a first objective lens L11 of a biconvex type having a positive refractive power, a second objective lens L12 of a meniscus type having a negative refractive power, a third objective lens L13 of a meniscus type having a positive refractive power, and a fourth objective lens L14 of a meniscus type having a negative refractive power. The fourth objective lens L14 is installed so as to be movable along the optical axis direction, and focusing between infinity and 3 meters is achieved by moving the fourth objective lens L14 back and forth along the optical axis direction.

[0020] The Pechan prism group 2 includes 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 inverts the image formed when light rays from a distant object pass through the objective lens group 1, and forms the image on the objective lens real image plane 3.

[0021] The eyepiece group 4 includes a first eyepiece lens L41 having a negative refractive power and a biconcave type eyepiece lens L42 having a positive refractive power and a biconvex type eyepiece lens L43 having a positive refractive power and a fourth eyepiece lens L44 having a negative refractive power and a fifth eyepiece lens L45 having a positive refractive power. The eyepiece group 4 is for magnifying the objective lens real image surface 3, and ultimately, the human eye sees an object with a magnification of 10 times.

[0022] Here, the contact sides of the first objective lens L11 and the second objective lens L12 are cemented together, the contact sides of the first eyepiece lens L41 and the second eyepiece lens L42 are cemented together, and the contact sides of the third eyepiece lens L43 and the fourth eyepiece lens L44 are cemented together. The cementing of positive and negative lenses can greatly improve the problem of chromatic aberration in the telescope, and at the same time, shorten the overall length of the entire optical system after the lenses are cemented together.

[0023] Here, the field of view angle range of the binocular telescope is 6°~6.5°, the exit pupil diameter range of the binocular telescope is 3.5mm~4.5mm, and the exit pupil distance range of the binocular telescope is 15mm~17mm, and the relatively long exit pupil distance facilitates use by different people.

[0024] The aperture range of the first objective lens L11 is 30mm to 50mm, and the total length of the optical system of the binocular telescope does not exceed 130mm. The small volume of the binocular telescope embodies convenience in use.

[0025] In Table 1 below, the actual parameters of each lens in this example that meet the above characteristics are listed.

[0026] [Table 1]

[0027] The changes in the air spacing parameters of the binoculars are shown in Table 2 below.

[0028] [Table 2]

[0029] Here, D(5) is the central air spacing in the optical axis direction between the third objective lens L13 and the fourth objective lens L14, and D(7) is the central air spacing in the optical axis direction between the fourth objective lens L14 and the Pechan prism group 2.

[0030] To summarise, such a binocular telescope has the following advantages:

[0031] First, in terms of performance, this binocular telescope achieves high resolution in the center and wide field of view, and uses multiple sets of cemented lenses and low-dispersion glass to significantly reduce chromatic aberration. Secondly, it has the advantages of being compact in overall structure, small in volume and light in weight; Thirdly, by adopting a prism combination of a half pentaprism and a roof prism, the overall length of the binocular telescope is significantly shortened, making it even more convenient.

[0032] Obviously, the above embodiment is merely an example for clarity of explanation, and is not intended to limit the embodiments. Those skilled in the art can make other different types of changes or variations based on the above description. It is not necessary and cannot be possible to cover all the embodiments here. And the obvious changes or variations derived thereby still fall within the scope of protection of the present invention. [Explanation of symbols]

[0033] 1, objective lens group, L1I, first objective lens, L12, second objective lens, L13, third objective lens, L14, fourth objective lens, 2, Pechan prism group, L2I, half pentaprism, L22, roof prism, 3, objective lens real image surface, 4, eyepiece lens group, L4I, first eyepiece lens, L42, second eyepiece lens, L43, third eyepiece lens, L44, fourth eyepiece lens, L45, fifth eyepiece lens.

Claims

1. A binocular telescope including an objective lens group (1), a Pechan prism group (2), and an eyepiece lens group (4) that are arranged in this order from an object side to an observation side along an optical axis direction, The objective lens group (1) includes a first objective lens (L11) of a biconvex type having positive refractive power, a second objective lens (L12) of a meniscus type having negative refractive power, a third objective lens (L13) of a meniscus type having positive refractive power, and a fourth objective lens (L14) of a meniscus type having negative refractive power, which are arranged in this order from the object side to the observation side along the optical axis direction, The Pechan prism group (2) includes a half pentaprism (L21) and a roof prism (L22) that are arranged in this order from the object side to the observation side along the optical axis direction, The binocular telescope is characterized in that the eyepiece lens group (3) includes, arranged in order from the object side to the observation side along the optical axis direction, a first biconcave eyepiece lens (L41) having negative refractive power, a second biconvex eyepiece lens (L42) having positive refractive power, a third biconvex eyepiece lens (L43) having positive refractive power, a fourth meniscus eyepiece lens (L44) having negative refractive power, and a fifth meniscus eyepiece lens (L45) having positive refractive power.

2. The binocular telescope of claim 1, characterized in that the contacting sides of the first objective lens (L11) and the second objective lens (L12) are cemented to each other, the contacting sides of the first eyepiece lens (L41) and the second eyepiece lens (L42) are cemented to each other, and the contacting sides of the third eyepiece lens (L43) and the fourth eyepiece lens (L44) are cemented to each other.

3. The binocular telescope according to claim 1, characterized in that the fourth objective lens (L14) is installed so as to be movable along the optical axis direction, and focusing between infinity and 3 meters is achieved by moving the fourth objective lens (L14) back and forth along the optical axis direction.

4. 2. The binocular telescope of claim 1, wherein the magnification of the binocular telescope is 10x.

5. 2. The binocular telescope according to claim 1, wherein the exit pupil diameter range of the binocular telescope is 3.5 mm to 4.5 mm.

6. 2. The binocular telescope of claim 1, wherein the binocular telescope has an exit pupil distance range of 15 mm to 18 mm.

7. 2. The binocular telescope according to claim 1, wherein the viewing angle range of the binocular telescope is 6° to 6.5°.

8. 2. The binocular telescope according to claim 1, wherein the aperture range of the first objective lens (L11) is 30 mm to 50 mm.

9. 2. The binocular telescope of claim 1, wherein the overall length of the optical system of the binocular telescope does not exceed 130 mm.

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