RU2229150C1 - Eyepiece - Google Patents

Abstract

FIELD: optical equipment. SUBSTANCE: Eyepiece comprises three components. First component includes biconcave and biconvex lenses placed in path of ray, second component is single biconvex lens, third component incorporates two lenses cemented together and comprises biconvex lens and negative meniscus facing image with convexity. Relations specified in formula of invention are implemented in proposed eyepiece. EFFECT: enhanced adaptability of eyepiece to manufacture with preservation of high quality of image. 2 cl, 1 dwg, 2 tbl

Description

The present invention relates to optical instrumentation and can be used in various telescopic systems and microscopes.

Known eyepiece [1], consisting along the rays of the first positive component glued from a biconcave and biconvex lenses, the second component is a biconvex lens and the third component is a positive meniscus, facing concavity to the image space. The eyepiece has a small field of view in the image space 2W = 34.2 degrees and low manufacturability, because all the radii of the optical surfaces are different, which requires the use of a test glass and a processing tool on each optical surface. In addition, the use of STK9 glass of the lanthanum glass group, which is several times more expensive than ordinary glass grades, makes the eyepiece more expensive.

The closest analogue to the claimed technical solution is the eyepiece [2], consisting along the rays of a two-lens component glued from a biconcave and biconvex lens, a single biconvex lens and a two-lens component glued from a biconvex lens and a negative meniscus convex to the space the relations are:

R ₂ = | R ₃ |,

R ₄ = | R ₅ |,

n ₁ = n ₅ ,

n ₂ = n ₃ = n ₄ ,

where R ₂ is the radius of the second optical surface;

r ₃ is the radius of the third optical surface;

R ₄ is the radius of the fourth optical surface;

R ₅ is the radius of the fifth optical surface;

n ₁ is the refractive index of the material of the first lens along the rays for λ = 0.5893 μm;

n ₂ is the refractive index of the material of the second lens along the rays for λ = 0.5893 μm;

n ₃ is the refractive index of the material of the third lens along the rays for λ = 0.5893 μm;

n ₄ is the refractive index of the material of the fourth lens along the rays for λ = 0.5893 μm;

n ₅ is the refractive index of the material of the fifth lens along the rays for λ = 0.5893 μm;

λ is the wavelength.

This eyepiece has low manufacturability, because there are only two equal radii of the optical surfaces and therefore the use of different tools and test glasses is required.

The task of the invention is the creation of an eyepiece with high adaptability with high image quality.

The technical result is an increase in the manufacturability of the eyepiece while maintaining high image quality, with an angular field in the image space of up to 60 degrees when removing the exit pupil of 12 mm.

This is achieved by the fact that in the eyepiece, which contains three components, of which the first component along the rays is a two-lens bonded, consisting of a biconcave and biconvex lenses, the second component is a biconvex single lens, and the third component is a two-lens glued, consisting of a biconvex lens and a negative meniscus, convex to the image, and there are relations:

R ₂ = | R ₃ |,

R ₄ = | R ₅ |,

n ₁ = n ₅ ,

n ₂ = n ₃ = n ₄ ,

in contrast to the known, there are relations:

R ₂ = R ₆ = | R ₇ |,

1.6 <n ₁ = n ₅ <1.618,

8 <f '/ d ₁ = d ₇ ) <10,

d ₁ = d ₇ ,

where R ₆ is the radius of the sixth optical surface;

R ₇ is the radius of the seventh optical surface;

f ’is the focal length of the entire eyepiece;

d ₁ - the thickness of the first lens along the rays;

d ₇ - the thickness of the fifth lens along the rays;

In addition, it is possible to fulfill the ratio:

d ₂ = d ₆ ,

where d ₂ is the thickness of the second lens along the rays;

d ₆ - the thickness of the fourth lens along the rays.

The drawing shows an optical diagram of the eyepiece.

The eyepiece consists of a biconcave lens 1 glued to a biconvex lens 2; then a biconvex lens 3 is located, then a biconvex lens 4 glued with a negative meniscus 5, convex to the image.

The eyepiece works as follows.

In front of part 1 is the plane of objects, which is depicted by the eyepiece at infinity and is viewed by the eye of the observer located behind the lens 5.

Two variants of the invention are calculated, the structural data of which are given in tables 1 and 2.

The first version of the eyepiece has the following characteristics:

Focal Length f ’16.56 mm

Exit pupil diameter 4 mm

Angular field in the image space 60 degrees

12 mm exit pupil removal

The eyepiece has aberrations for λ = 0.5893 μm:

0.14 mm longitudinal spherical aberration

3.64 mm meridional image curvature

Sagittal image curvature 0.306 mm

Distortion at an angular field of 46 degrees 6.6%

The following ratios are observed:

n ₁ = n ₅ = 1.6169;

f '/ (d ₁ = d ₇ ) = 9.2

The second option has the design data shown in table 2.

The calculated eyepiece has the following characteristics:

Focal Length f ’16.56 mm

Exit pupil diameter 4 mm

Angular field in the image space 60 degrees

12 mm exit pupil removal

The eyepiece has aberrations for λ = 0.5893 μm:

0.14 mm longitudinal spherical aberration

3.57 mm meridional image curvature

Sagittal image curvature 0.344 mm

Distortion at an angular field of 46 degrees 6.4%

The following ratios are observed:

n ₁ = n ₅ = 1.6169;

f '/ (d ₁ = d ₇ ) = 9.2

Thus, as a result of the proposed solution, a technical result is obtained: a more technologically advanced eyepiece with a high image quality, with an angular field in the image space of up to 60 degrees when removing the exit pupil of 12 mm, is created.

Sources of information

1. Patent of Russia RU N2042971 C1, G 02 B 25/00; publ. 1995 year

2. Turygin I.A. Applied Optics, book 2, M .: Mechanical Engineering, 1966, p. 427.

Claims (2)

1. An eyepiece containing three components, of which the first component along the rays is glued two-lens, consisting of a biconcave and biconvex lenses, the second component is a biconvex single lens, and the third component is a two-lens glued, consisting of a biconvex lens and a negative meniscus convex to the image , moreover, the relations R ₂ = | R ₃ |, R ₄ = | R ₅ |, n ₁ = n ₅ , n ₂ = n ₃ = n ₄ , where R ₂ is the radius of the second optical surface; R ₃ is the radius of the third optical surface; R ₄ is the radius of the fourth optical surface; R ₅ is the radius of the fifth optical surface; n ₁ is the refractive index of the material of the first lens along the rays for λ = 0.5893 μm; n ₂ is the refractive index of the material of the second lens along the rays for λ = 0.5893 μm; n ₃ is the refractive index of the material of the third lens along the rays for λ = 0.5893 μm; n ₄ is the refractive index of the fourth lens material along the rays for λ = 0.5893 μm; n ₅ is the refractive index of the material of the fifth lens along the rays for λ = 0.5893 μm; λ is the wavelength characterized in that the following relationships hold: R ₂ = R ₆ = | R ₇ |, 1.6 <n ₁ = n ₅ <1.618, 8 <f / (d ₁ = d ₇ ) <10, d ₁ = d ₇ , where R ₆ is the radius of the sixth optical surface; R ₇ is the radius of the seventh optical surface; f is the focal length of the entire eyepiece; d ₁ - the thickness of the first lens along the rays; d ₇ - the thickness of the fifth lens along the rays. 2. The eyepiece according to claim 1, characterized in that the ratio is: d ₂ = d ₆ , where d ₂ is the thickness of the second lens along the rays; d ₆ - the thickness of the fourth lens along the rays.