Small-size telescope optical system

Abstract

The utility model discloses a small-size telescope optical system, which is characterized in that an objective lens first lens, an objective lens second lens, a Porro first prism, a Porro second prism, an eyepiece first lens, an eyepiece second lens and an eyepiece third lens are sequentially arranged from an object side to an image side along the direction of an optical axis, the first objective lens and the second objective lens form a cemented lens, the first objective lens is a biconvex lens, the second objective lens is a concave-convex lens, the concave surface faces the object side, the first eyepiece lens is a biconvex lens, the second eyepiece lens and the third eyepiece lens form a cemented lens, the second eyepiece lens is a biconvex lens, and the third eyepiece lens is a concave-convex lens. The third lens of the eyepiece is a concave-convex lens, the concave surface faces the object side, and the size is small.

Description

Technical Field

[0001] The utility model relates to the technical field of telescope manufacturing, in particular to a small-volume telescope optical system. Background Art

[0002] Paul telescope is a relatively mature telescope with good imaging quality and stable optical axis. With the continuous development of consumers' personalized needs, small and exquisite telescopes are becoming more and more popular. In order to meet the design requirements, the optical systems of current telescopes are very long, which greatly increases the size of the telescope. Utility Model Content

[0003] The purpose of the present invention is to provide a small-volume telescope optical system to solve the problems raised in the above-mentioned background technology.

[0004] In order to solve the above technical problems, the utility model provides the following technical solutions: a small-volume telescope optical system, characterized in that: an objective lens first lens, an objective lens second lens, a Porro prism first, a Porro prism second, an eyepiece lens first lens, an eyepiece lens second lens, and an eyepiece lens third lens are arranged in sequence along the optical axis from the object side to the image side, the objective lens first lens and the objective lens second lens forming a cemented lens, the objective lens first lens is a biconvex lens, and the objective lens second lens is a concave-convex lens with the concave surface facing the object side;

[0005] The first lens of the eyepiece is a biconvex lens, the second lens of the eyepiece and the third lens of the eyepiece form a cemented lens, the second lens of the eyepiece is a biconvex lens, and the third lens of the eyepiece is a concave-convex lens with the concave surface facing the object side.

[0006] As an optimal technical solution, the center thickness of the first lens of the objective lens along the optical axis is 9.3 mm, the center thickness of the second lens of the objective lens is 3.5 mm, the distance between the second lens of the objective lens and the first Porro prism is 106.73 mm, the distance between the second Porro prism and the first lens of the eyepiece is 48.5 mm, the center thickness of the first lens of the eyepiece is 5.2 mm, the center thickness of the second lens of the eyepiece is 7.8 mm, and the center thickness of the third lens of the eyepiece is 1.7 mm.

[0007] As a preferred technical solution, the object side of the first lens of the objective lens is coated with a magnesium fluoride film, and the image side of the second lens of the objective lens is coated with a magnesium fluoride film.

[0008] As an optimal technical solution, the object side and image side of the first lens of the eyepiece are both coated with magnesium fluoride film, the object side of the second lens of the eyepiece is coated with magnesium fluoride film, and the image side of the third lens of the eyepiece is coated with magnesium fluoride film.

[0009] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0010] The optical system of the present application can have a magnification of 7 times and a field of view angle of 6.4 degrees. The first lens of the objective lens and the second lens of the objective lens constitute the front group of the objective lens, and the focal length of the front group of the objective lens is 195.93 mm. The first lens of the eyepiece, the second lens of the eyepiece, and the third lens of the eyepiece constitute the eyepiece group, and the focal length of the eyepiece group is 28.49 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0012] Figure 1 It is a schematic diagram of the optical system of the present utility model. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0014] like Figure 1 As shown, the utility model provides the following technical solution: a small-volume telescope optical system, characterized in that: an objective lens first lens 1, an objective lens second lens 2, a Porro first prism 3, a Porro second prism 4, an eyepiece first lens 5, an eyepiece second lens 6, and an eyepiece third lens 7 are sequentially arranged along the optical axis from the object side to the image side, the objective lens first lens 1 and the objective lens second lens 2 forming a cemented lens, the objective lens first lens 1 being a biconvex lens, the objective lens second lens 2 being a concave-convex lens, with the concave surface facing the object side;

[0015] The first eyepiece lens 5 is a biconvex lens, the second eyepiece lens 6 and the third eyepiece lens 7 form a cemented lens, the second eyepiece lens 6 is a biconvex lens, and the third eyepiece lens 7 is a concave-convex lens with the concave surface facing the object side.

[0016] As an optimal technical solution, the center thickness of the first lens 1 of the objective lens along the optical axis is 9.3 mm, the center thickness of the second lens 2 of the objective lens is 3.5 mm, the distance between the second lens 2 of the objective lens and the first Polo prism 3 is 106.73 mm, the distance between the second Polo prism 4 and the first lens 5 of the eyepiece is 48.5 mm, the center thickness of the first lens 5 of the eyepiece is 5.2 mm, the center thickness of the second lens 6 of the eyepiece is 7.8 mm, and the center thickness of the third lens 7 of the eyepiece is 1.7 mm.

[0017] As an optimal technical solution, the object side of the first lens 1 of the objective lens is coated with a magnesium fluoride film, the image side of the second lens 2 of the objective lens is coated with a magnesium fluoride film, the object side and image side of the first lens 5 of the eyepiece are both coated with a magnesium fluoride film, the object side of the second lens 6 of the eyepiece is coated with a magnesium fluoride film, and the image side of the third lens 7 of the eyepiece is coated with a magnesium fluoride film.

[0018] The optical system can have a magnification of 7 times and a field of view of 6.4 degrees. The first lens and the second lens of the objective lens constitute the front group of the objective lens. The focal length of the front group of the objective lens is 195.93mm. The first lens, the second lens and the third lens of the eyepiece constitute the eyepiece group. The focal length of the eyepiece group is 28.49mm, the effective object diameter is 48.6mm, the exit pupil diameter is 7mm, the eye point distance is 19.6mm, and the shortest focusing distance is 8m.

[0019] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A small telescope optical system, characterized by: The first objective lens (1), the second objective lens (2), the first Paul prism (3), the second Paul prism (4), the first eyepiece lens (5), the second eyepiece lens (6), and the third eyepiece lens (7) are sequentially arranged along the optical axis from the object side to the image side. The first objective lens (1) and the second objective lens (2) form a cemented lens. The first objective lens (1) is a biconvex lens, and the second objective lens (2) is a concave-convex lens, with the concave surface facing the object side. The first eyepiece lens (5) is a biconvex lens, the second eyepiece lens (6) and the third eyepiece lens (7) form a cemented lens, the second eyepiece lens (6) is a biconvex lens, and the third eyepiece lens (7) is a concave-convex lens, with the concave surface facing the object side.

2. The small telescope optical system according to claim 1, characterized in that: Along the optical axis, the center thickness of the first lens (1) of the objective lens is 9.3 mm, the center thickness of the second lens (2) of the objective lens is 3.5 mm, the distance between the second lens (2) of the objective lens and the first Paul prism (3) is 106.73 mm, the distance between the second Paul prism (4) and the first lens (5) of the eyepiece is 48.5 mm, the center thickness of the first lens (5) of the eyepiece is 5.2 mm, the center thickness of the second lens (6) of the eyepiece is 7.8 mm, and the center thickness of the third lens (7) of the eyepiece is 1.7 mm.

3. The small telescope optical system according to claim 1, characterized in that: The object side of the first lens (1) of the objective lens is coated with a magnesium fluoride film, and the image side of the second lens (2) of the objective lens is coated with a magnesium fluoride film.

4. The small telescope optical system according to claim 1, characterized in that: The object side and image side of the first eyepiece lens (5) are both coated with magnesium fluoride film, the object side of the second eyepiece lens (6) is coated with magnesium fluoride film, and the image side of the third eyepiece lens (7) is coated with magnesium fluoride film.

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