DE3039734C2 - Galilean telescope - Google Patents

Description

in the / ", the image-side focal length of the lens.
Γ the magnification of the optical

Systems, and

/? _v denotes the size of the radius of curvature of the anterior refractive surface of the scattering concentric meniscus (3).

2. Telescope according to claim 1, characterized.

- That the cemented surfaces (7) of the lenses (4 and 5) of the scattering concentric meniscus (3) Phm surfaces are.

3. Telescope according to claim I. characterized.

that the cemented surfaces (7) of the lenses (4 and 5) of the scattering concentric meniscus (3) are spherical surfaces, an equal one Have radius of curvature and with their concave sides of the exit pupil (6) of the optical system are facing.

The invention relates to Galileo telescopes according to the preamble of claim I.

The invention can be used in the manufacture of opera glasses and telescope glasses.

In the creation of low magnification optical devices, and particularly those that are intended for people with impaired visual acuity, the problem lies in the simultaneous guarantee a relatively large angle of the field of view and a sufficient image quality, d. H. one good sharpness, clarity of the image, which should be free from color defects, and the like. Currently in such optical systems used ensure a field of view

at an angle that is usually no greater than 17 °. aside from that they are mostly heavy and unwieldy to use. The invention has the purpose that To make use of the optical devices with small magnification more convenient and the characteristic values to improve the telescopic optical systems used in these facilities.

From SU-ES 1 75 270 an optical Gaiilean telescope system is known which contains two members, which are arranged one behind the other on the optical axis of this system in the direction of the beam path are. In this optical telescope system the first limb represents a collecting meniscus, in which the anterior convex refractive surface is that of the one to be viewed Object, or in other words, the entrance pupil of this system is facing. elliptical and the rear concave crushing surface spherical = 5t. Here the collecting meniscus is designed as a lens, which is cemented together from two glasses. whose refractive indices differ greatly from one another.

3 »The second link of the optical telescope system represents a concentrated scattering meniscus, in which the anterior convex refractive surface and the posterior concave refractive surface are spherical. Both menisci of this optical system are with their concave surfaces the eye of the observer, or in other words, the exit pupil of the optical Facing the system. Such an optical system ensures, in addition to a certain magnification the correction of astigmatism over the whole Facial field.

But this well-known Galilean optical telescope system has only one that is not sufficiently large Field of view ', vinkcl. Both / um System belonging optical members represent relatively thick lenses with a large diameter. What the correction the aberration is required. thereby the optical device in which this optical system is used comes, has relatively large dimensions and mass, what the handling of this device

5Ii difficult.

In addition, complicates the spherical shape of the anterior convex lens of the first lens Link to a certain extent the manufacturing technology for the ^ c lens, thereby mass production

«5 of the optical devices in which the described optical Fcrnrohrsystcni is used, complicates and becomes more expensive because of the conventional processing machinery to manufacture such a lens cannot be used.

wi Furthermore, SU-ES 2 01 716 is another optical one Gaiileisches telescope system known, which contains three optical members, which on the optical axis of this Systems are arranged one behind the other in the beam path direction. In this optical telescope system

Λ5 star represents the first link a single collecting Meniscus, the wide limb a collecting meniscus in the form of an I.insc. the; ws two glasses with different refractive indices;: mmeneekittct

is, and the third link is a scattering concentric Meniscus, which is separated from the second limb by an air gap. Form here the first and second elements represent the objective of the optical system, and the third element represents the eyepiece of the optical system. All three members of this optical system have spherical refractive surfaces and have their concave side facing the exit pupil of this system. The correction of the field and the chromatic aberration in such a telescope system is made in the object.

Although this is the product of size with this well-known Galilean optical telescope system the field of view angle (which is equal to 24 °) and the value of the visible magnification is greater than at the telescope system described above, are used in this system to correct the above-mentioned Aberration errors and for correcting the spherical aberration of the axial and the oblique Light bundle relatively thick glasses with large refractive indices are used, which give a sufficient must have a large diameter and a.-is this Reason are relatively heavy. As a result, the mass and dimensions of the optical Device in which this system is used, but as large as the device in which the system described above is used.

Also, in this optical system, the air gap is between the second and third Link too small to allow the eyepiece to focus on the observer's eye.

The invention is based on the object of creating a Galilean telescope in which the system belonging lenses have a relatively simple shape and a relatively low mass and ensure a relatively large field of view angle with sufficient image quality.

This object is achieved by the characterizing features of claim 1.

Thanks to the fact that in the optical Galilean telescope system according to the invention the scattering concentric meniscus, which functions as the ocular of the system, is designed in the form of a lens cemented together from two glasses with the aforementioned characteristics, the correction of the image distortion caused by the chromatic aberration takes place in this system Eyepiece. This made it possible for "the glasses of the meniscus to choose glasses with small refractive indices, ie lighter glasses, and thus to make all menisci <ks optical system thinner and with smaller radii.

In one de. "Embodiments of the invention Gaulean telescope system, the cemented surfaces of the lenses of the concentric meniscus are flat surfaces represent.

Such a form of the cemented surface simplifies the manufacturing technology of the lens of the diffusing one concentric meniscus.

In another embodiment of the Galilean optical telescope system according to the invention the cemented surfaces of the glasses of the scattering concentric meniscus represent spherical surfaces, have the same radius of curvature and, with their concavities of the exit pupil, are this optical Facing the system.

Such a shape of the putty surfaces makes the correction the more chromatic. Aberration is simpler in the present system, which is more detailed below is received.

The invention is explained in more detail, for example, with the aid of the drawing. It shows

1 shows a schematic representation of a Galileo vision Telescope in cross section;

F i g. 2 shows a schematic representation of another embodiment for a Galilean telescope at of which the cemented surfaces of the lenses of the diffusing concentric meniscus are spherical, in cross section;

ίο Fig. 3 in a diagram the dependency of the Size of the spherical longitudinal aberration from the height of the exit pupil of the optical shown Systems;

Fig. 4 in a characteristic curve the dependence of the meridional and the sagittal curvature of the field of view as a function of the angle of the field of view of the displayed optical system;

F i g. 5 shows in a diagram the dependence of the spherical transverse aberration on the height of the exit pupil at the maximum field of view angle for the illustrated optical system;

FIG. 6 shows the dependence on FIG. 5 tu * a field of view angle, which is smaller than the maximum angle; and

F i g. 7 shows the dependence on FIG. 5 for the field of vision angle zero.

Looking at FIG. 1 it can be seen that the illustrated Galilean telescopic optical system, which is used in an opera glasses of small format, contains three optical members which are arranged one behind the other on the optical axis of the system in the direction of the beam path of the axial light beam A and the oblique light beam B. The first member represents a relatively thin single convergent meniscus 1, which has a relatively small ratio between its thickness on the optical axis and the diameter, which is not greater than '/' °. The second link also represents a relatively thin single collecting meniscus 2, which however has a slightly larger ratio between thickness and diameter, since its diameter is slightly smaller (approx. 10%) than the diameter of the single collecting meniscus 1, which is due to the beam path of the oblique light beam B is conditioned. Here, the individual jarring menisci 1 and 2 are made of glasses with the same refractive indices and the same dispersion. The third link represents a scattering concentric meniscus 3, which is designed as a composite lens, which is made up of two thinner lenses 4 and 5 made of glasses that have a different dispersion but practically the same refractive indices, which ensures the correction of the chromatic aberration will. In each of the three menisci 1, 2 and 3 the front convex and the rear concave refractive surface represent spherical surfaces, and all three menisci have their concave sides facing the exit pupil 6 of the optical system, in which, w: ~ the drawing shows the eye of the observer lies.

The individual converging menisci 1 and 2, which are closely matched to one another with an air gap of not more than 0.1 mm, form the objective of the optical system shown, which has a positive focal length. In JEC * m ^r de individual collected menisci. 1 and 2, the radius of the rear refractive surface is greater than the radius of the front refractive surface. Here, the radii of the front crushing surface are

of each of the menisci 1 and 2 are chosen in such a way that that each of these refractive surfaces has an optical effect which is greater than the entire optical Action of the meniscus to which it belongs, and for this reason the anterior refractive surfaces are this Menisci are the optically effective refractive surfaces. The radii of the posterior refractive surfaces of each of the individual collecting menisci 1 and 2 are chosen so that these refractive surfaces are the correction surfaces represent. The combination of menisci 1 and 2 in the objective of the optical system shown guarantees the correction of astigmatism and coma in this lens and maintains a palpable negative spherical aberration upright that is required to compensate for the positive spherical aberration in the eyepiece of the system.

The scattering concentric meniscus 3 serves as the eyepiece of the optical telescope system shown.

III UCIM UIL * l ^

are cemented, which have the same shape and represent flat surfaces, with an eccentricity of 20% must not exceed, the difference in the refractive indices of the glasses of lenses 4 and 5 does not exceed 0.05 and the difference in dispersion must not be less than 20. Here the lens 5. is closer to the Ausirittspupiiie 6 of the optical system, the The dispersion is considerably smaller than in the case of the lens 4, which is further away from the Alistrittpupil 6.

The diffusing concentric meniscus 3 is separated from the single converging meniscus 2 through one Air gap 8 separated, the size of which, d. H. the distance between the posterior refractive surface of the meniscus 2 and the anterior refractive surface of the meniscus 3. on the optical axis through that given below Formula is set:

In this formula denote:

i /, the size of the air gap on the optical axis.

/ Ί the focal length of the lens of the optical Systems.

/ the magnification provided by the optical system it is, and

R, the magnitude of the radius of curvature of the anterior refractive surface of the scattering concentric meniscus.

The above relationship is based on the following circumstances. On the one hand, in the optical telescope system shown, the optical effect of the objective, which is composed of the individual collecting menisci 1 and 2, and the optical effect of the eyepiece. that the scattering concentric meniscus 3 is shown, chosen such that the ratio of the focal length of the lens / 'to the focal length of the eyepiece. which can be denoted by f \ , which is equal to the magnification Γ. which the optical system ensures:

Γ = / '■: /':
It follows from this:

(D

(2)

On the other hand, the difference between the stated focal lengths of the sum of the size R _{x of} the radius of the front refractive surface of the scattering concentric meniscus 3 and the size d of the air gap 8 between this meniscus 3 and the individual collecting meniscus 2 must be equal. ie it must apply:

It follows from this:

ι «After substituting the right part of the equation (2) In equation (4) and a corresponding simplification, the above formula results:

Ice must be noted that it is desirable. that the size of the air gap 8 is here 'S' ^ fcchend '-icr

is chosen, in which A. a proportionality factor represents, which represents the range of focusing of the eyepiece in diopters and usually not less than 3 is chosen.

The choice of the size of the Lufi / wipe space entsprecher i the above-derived equations (5) and (6) allows it. in a sufficiently wide ι.

jo area to change the convergence of the light beam emerging from the eyepiece, i.e. she gives the opportunity the optical system au. '"to focus the eye of the observer.

In the embodiment shown in FIG the cemented surfaces 7 of the lenses 4 and 5 of the diffusing concentric meniscus 3 spherical surfaces, them have the same radius of curvature and are with their concave sides of the exit pupil of the optical Facing the system. This is where the size

the radii of the cemented surfaces 7 selected such that it is larger than the size of the radii of the front and the posterior refractive surfaces of the scattering concentric meniscus 3.

The Galilean telescope system shown works as follows:

The parallel light rays of the axial light bundle A and the light rays of the oblique bundle B, which come from the object to be viewed, which is at infinity, enter the objective

of the optical system by falling onto the front refractive surface of the collecting individual MenisLas 1 of the objective. In the lens, these light bundles are bundled by the collecting individual menisci 1 and 2 in the rear focal plane and generate the image of the object to be viewed in this plane. When the axial bundle A and the oblique bundle B pass through the objective, the menisci 1 and 2 correct the distortions in the image caused by aberrations, including

ω astigmatism and coma are caused. Stay here completely preserve the image distortion caused by the chromatic aberration, and the the image distortions caused by spherical aberration are partially retained.

~ From the objective the axial light bundle A and the oblique light bundle B reach the eyepiece, ie to the scattering concentric meniscus 3. Since this meniscus 3 is at a certain distance on the

optical axis of the meniscus 2 of the objective, the rear focal plane of the objective coincides with the front focal plane of the eyepiece, and for this reason the light bundles A and B incident on the meniscus 3 from this meniscus 3 are practically parallel hit the eye of the observer, whose center of rotation coincides with the center point of the exit pupil of the optical system.

Since a diffusing concentric meniscus 3 is used as the eyepiece in the optical system shown this eyepiece introduces positive spherical aberration into the system. but completely is offset by the negative spherical aberration introduced by the lens. As for the chromatic aberration introduced into the optical system by the lens, it is also fully compensated in the eyepiece because the meniscus 3 is designed in the form of a lens which is cemented together from glasses that have different dispersions and the same refractive indices exhibit.

When focusing the optical system according to the characteristics of the observer's eyes is required, this is done by changing the size of the air gap 8 Adjustment of the scattering concentric meniscus 3 on the optical axis in one or the other Direction. The maximum change in this size can be approx. 6 mm.

The function of the optical system according to the in F i g. 2 is the variant embodiment illustrated practically identical to the function of the system according to Fig. 1. But the training with spherical Putty surfaces 7 for the lenses 4 and 5 of the scattering concentric meniscus 3 has certain advantages, although with a flat design of these cemented surfaces 7 more lenses on a processing machine for the meniscus 3 can be produced. One of the advantages is that this embodiment the achievement of a predetermined range for the correction of chromatic aberration in a allows smaller difference in the dispersion of the glasses for lenses 4 and 5. This fact has important ones practical importance as it is often difficult to choose among the existing types of optical glasses with the desired difference in dispersion and with the same refractive indices.

The illustrated Galilean optical telescope system can have the following main dimensions and parameters for the links belonging to the system are built:

Radius of curvature of the
front crushing surface
of the meniscus 1
Radius of curvature of the
rear breaking surface
of the meniscus 1
Radius of curvature of the
front crushing surface
of the meniscus 2
Radius of curvature of the
rear breaking surface
of the meniscus 2
Radius of curvature of the
front crushing surface
of the meniscus 3

- radius of curvature of the
Cemented surface 7 of the lenses

4 and 5 of the meniscus 3 /? ₆ =

- radius of curvature of the
rear breaking surface

of the meniscus 3 R ₁ -

- Thickness of the meniscus 1
on the optical

Axis (J ₁ =

ίο - thickness of the meniscus 2
on the optical
Axis el =

- Meniscus 1 and meniscus 2 are made of optimal

Shem glass and

of the same brand, refractive index of this glass brand "
Size of the air gap

: o room 8

- Thickness of the front
Lens 4 of meniscus 3
on the optical
axis

- Refractive index of the glass
the lens 4

- Thickness of the rear
Lens 5 of meniscus 3
on the optical

jo axis i / ₅ =

- Refractive index of the glass

of the lens 5 n _Dl =

- dispersion of the glass

of the lens 4 ν =

Dispersion of the glass

of the lens 5 ν =

100.0 mm

7.015 mm

4.0 mm

4.0 mm

d _x = </,

1.613 mm Ί 3. mm

3.6 mm 1.7424

4.49 mm

1.7398
50.4
28.16

The Galücischc optical telescope system with the The following main dimensions and optical characteristics of the elements belonging to the system have been given Characteristic values

enlargement
Field of view angle

Γ = 2.1 times
2 (0 = 30 ".

45

Λ, = 50.93 mm

R ₂ = 105.2 mm

R, = 34.51 mm

= 67.92 mm

R _x = R ₅ = 15.101 mm The image quality that is achieved with the aid of the Galilean optical telescope system with the specified parameters is illustrated in the diagrams shown in FIGS. 3, 4, 5, 6 and 7.
The diagram of FIG. 3 shows a characteristic curve H which shows the dependence of the size of the spherical longitudinal aberration of the optical system shown for an object which is at infinity on the optical axis of the system on the height of the exit pupil of the system, wherein on the ordinate the values of the size aS _"d of the longitudinal spherical aberration in diopters and on the abscissa the values of the height h of the exit pupil in mm are plotted. in consideration of the characteristic curve H is seen that with the increase in the height of the exit pupil, the longitudinal spherical aberration grows gradually, the size of the spherical longitudinal aberration not exceeding 0.5 diopters at the edge of the exit pupil with a value for the height h of this pupil equal to 2.5 mm.

4 shows a characteristic curve K which shows the dependence of the curvature of the image ir. The meridional plane on the size of the field of view angle of the optical system for the case

that the object to be viewed lies outside the optical axis of the system (see also Fig. 1), as well as a characteristic curve M, which represents the dependence of the curvature in the sagittal plane on the size of the field angle of this system under the same conditions. Here, the values of the values Z ₁ and Z _{3 are} plotted over the ordinate axis, which accordingly characterize the field curvature in the meridional plane and the field curvature in the sagittal plane in diopters, and the values of the field of view angle 2ω in degrees over the abscissa axis. When looking at the characteristics K and M , it can be seen that as the angle of the field of view increases, the curvature of the field in the meridional and sagittal planes gradually increases. From these diagrams it can also be seen that the astigmatism of the optical system, which is determined by the difference between the meridional and sagittal field curvature, has a small size, which is approximately equal to 1.5 diopters, which is particularly beneficial in observation devices.

In Fig. 5 a characteristic curve P is shown, which shows the dependence of the size of the spherical transverse aberration of the optical Galilean telescope system on the height of the exit pupil of the system under the condition that the size of the field of view angle is maximum and is 30 *, the object to be viewed lies outside the optical axis of the system and the rays of the oblique light bundle B (see also FIG. 1) run in the meridional section of the system. Here, the values of the quantity Δ is on the ordinate σ of the spherical aberration in transverse angular minutes plotted and on the abscissa the values of the height h of the exit pupil of the system in mm. When considering the characteristic curve P it can be seen that the optical system shown is coma-free and the spherical transverse aberration has a low value over the entire height of the exit pupil.

6 shows a characteristic curve Γ which shows the dependence of the size of the spherical transverse aberration of the optical system shown on the height of the exit pupil of the system at a field of view angle of 20. Here, too, the values of the magnitude Δ σ of the spherical transverse aberration are plotted in angular minutes on the ordinate and the values of the height h of the exit pupil of the system in mm are plotted on the abscissa.

7 shows a characteristic curve X which shows the dependence of the size of the spherical transverse aberration of the optical system shown on the height of the outward pupil of the system at a field angle of zero when the object to be viewed lies on the optical axis of the system. Again above the ordinate axis are the

Values of the magnitude Δ σ of the spherical transverse aberration are plotted in angular minutes and the values of the height h of the exit pupil of the system in mm are plotted on the abscissa axis.

When looking at the characteristics Γ and X it is evident

lent that it also for these cases in the illustrated optical Galilean telescope system is no coma and the spherical transverse aberration is small.

The Galilean optical telescope system according to the invention has over known optical

Systems of the same provision have the following advantages:

First, the construction of the optical system of the present invention provides that shown above wider angle of face when sufficient

: o Image quality of the object to be viewed.

Second, in constructing the optical system of the present invention, optical members are made smaller geometric dimensions and smaller masses are used. This makes it possible to change the dimensions of the optical devices in which such an optical system is used, for example Opera glasses, at least by 15-20% and the dimensions of these devices by at least two times the optical characteristics of the devices remain unchanged or get better.

Third, the fact that in the invention optical system a thinner first and a thinner second member are used, the Achieving a greater distance from the exit

pupil of the system up to the third limb, which in turn increases the radii of the The fracture surfaces of this member and sornii allow simplification of its manufacturing technology on the one hand and on the other hand comfortable working conditions for

Observer results because when using the optical device the observer's eyes are far away from the Eyepiece are removed and the eyelashes are not touching the eyepiece mount.

Finally, one of the convenience for the user of the device is the possibility of focusing the optical device in a sufficiently wide range, namely from -3 diopters to +3 diopters.
All of this together makes it possible. to make the apparatus using the Galilean telescopic optical system of the present invention cheaper and more convenient for the user.

For this purpose 2 sheets of drawings

Claims (1)

Patent claims: 1. Gaiilean telescope with three optical sections, the first of which is a single section collecting meniscus, the second link a collecting meniscus and the third link a scattering one is concentric meniscus, the third limb from the second limb through an air gap separated, the first and the second member the objective and the third member the eyepiece of the telescope and all three members of the exit pupil of the telescope with their concave Side facing, characterized. ~ that the second member is designed in the form of a single collecting meniscus (2), - That the scattering concentric meniscus (3) in the third member is cemented together Lens is made up of two lenses (4 and 5) whose Putty surfaces (7) have the same shape and their glasses have practically the same refractive indices but different dispersion the glass on the optical axis closer to the exit pupil (6) the lens (5) arranged in the optical system has a considerably smaller dispersion, than the glass that lies further from the exit pupil (6) of the optical system Lens (4). and - That the size d _{x of} the air gap (8) on the opti. ^r ~ hen A-: hse. which separates the third link from the second link is determined by the following formula: