DE300544C - - Google Patents

Description

IMPERIAL

j. 9 - << ■

PATENT OFFICE.

PATENT LETTERING

Vr 300544 CLASS 42 h. GROUP

CARL ZEISS company in JENA.

Eyepiece. Patented in the German Empire on July 4, 1914.

The invention relates to eyepieces, which consist of two Lens groups are composed whose mutual distance is less than a quarter of the Total focal length of the eyepiece is one of these groups also through a simple lens can be embodied. In particular, it concerns eyepieces, their lens groups one only consists of limbs cemented together (unless it is only

ίο is formed by a single lens) while in the case of the other lens group, unless their members are also all together are cemented, at most one non-cemented pair of surfaces occurs, namely one whose Refractive power (the sum of the refractive powers of the two surfaces) no more than one fifth the total refractive power of the eyepiece, so that such a pair of surfaces as a cemented surface can apply equivalently. Such eyepieces have become known several times, however, they have the disadvantage that they either fail for a larger field of view are sufficiently free from distortion and astigmatism or as a result of strong curvatures are too expensive to manufacture. With the new eyepiece, these disadvantages are avoided, and this is done by adhering to them The following conditions are achieved: First, the focal length of the lens group on the eye side is one third to two thirds of the focal length of the other group, secondly, the radius of curvature of each group is the Area facing the other group.

no greater than two-thirds of the radius of the outer surface, and third, the strongest returns dispersive cement surface, or the strongest equivalent surface pair the hollow side of both surfaces or that of the more curved of them towards the eye.

If you lay out the strongest dispersing putty surface or the strongest equivalent surface pair, into the lens group facing away from the eye, one obtains the particular advantage that the angles of incidence of the main rays on this surface, or this pair of surfaces, do not become too large and yet sufficient overcorrective action to remove distortion and astigmatism present is. If this surface is in the lens group on the eye side, then there is at most one these advantages can be achieved. Under certain circumstances, it may also be sufficient to add just one to the eyepiece to give a single putty surface or an equivalent pair of surfaces.

As exemplary embodiments of the new eyepiece, four arrangements are shown in the drawing. The front focal plane is indicated by a field stop A in all examples. The first three examples each have a simple, ^ß o plano-convex lens as the lens group on the eye side; the side facing away from the eye lens group consists of the first example (Fig. 1) consists of three lenses, two of which are cemented together, the second example (Fig. 2) also consists of three lenses that are, however, cemented ⁶ S all together while

in the third example (FIG. 3) this group contains only two lenses cemented to one another. In the fourth example (FIG. 4), both lens groups are each formed by a cemented pair of lenses. The radii, distances and thicknesses of the four examples are compiled below, all based on a total focal length 100 of the eyepiece. The types of glass used are each indicated by the refraction exponent % o for the line Ό of the solar spectrum.

i. Example (Fig. 1).

Radii: distances and thicknesses:

r ¹ = oo
r ² = - 177

l ~ 39

f ³ = m ^x = IO d ^l = 51 yi _ (i ² - 9 rf ² = i 18th Γ ⁵ = <2 ³ = 30th <2 ³ = 9 _r e _ Wed ² = 10 Wed == 34 _y 7 ₌ rf ⁴ = 23 rf ⁴ = 10 23 lens III IV Myj = 1.510 ! .573 .2). Radii: distances and thicknesses rl = : OO r ² = = - 520.3 y'i _ · - 4- 72 _r 4 _ - - 97> 3 yf> _{= z} = + 89 J-6 ₌ ; , OO : 282.4 = + 79.8. - - 104.2 - -f 88.5 : 'OO Glass types: : I II 1.516 1.648 2nd example (Fig

Glass types:

Lens: I II III IV

nn = 1.516 1.648 1.516 1.573

3rd example (Fig. 3).

Radii: Step II de and thick v ^x - - 1652.3 I, 5i ⁶ I. = 62 r ² = + 71-8 d ^l = 9 r ³ = - 97.1 d ^z = 34 r * = .-- \ - 88 m - 10 r ⁵ ■ == 00 d * = 23 Glass types: Lens: I. III «Ss = 1.648 1 , 573

4th example (Fig. 4).

Radii: Dist II ands and thicknesses: yl = ■ + 659.9 ' 1.516 I = 53.1 yl = + 78.4 d ¹ =. 8.9 y3 - - 114.5 d * == 44.3 yi = + 99. ¹ ■ m = 10.6 y5 = _ 119.8 d ^s = 35.4 r « r = - 294.2 d ^l = 8 Glass types: ^ ir ise: I. III IV ■ ü = 1.648 1.516 1.573

Claims (3)

Patent-to sayings: 1. Eyepiece, consisting of two lens groups (one of which can also be embodied by a simple lens) whose mutual distance is less than a quarter is the total focal length of the eyepiece, one of which has all the links together are cemented and with their others, unless their members are also all are cemented to one another, at most a non-cemented pair of surfaces occurs, and one whose refractive power is no more than a fifth of the total refractive power of the Eyepiece is characterized by the following conditions: 1. the focal length of the group on the eye side is one third to two thirds of the focal length of the other group, 2. In each group the curvature radius of the surface is that of the other Group facing, not greater than two thirds of the radius of the outer surface, and 3. the strongest dispersing putty surface, or the strongest dispersing equivalent Face pair reverses the hollow side of both faces or that of the stronger curved from them to the eye. 2. Eyepiece according to claim i, characterized in that that the strongest dispersing putty surface, or the strongest dispersing equivalent pair of surfaces is contained in the group facing away from the eye. 3. Eyepiece according to claim 2, characterized in that one group consists of a single lens and the other group contains only a single cemented surface or an equivalent pair of surfaces. 1 sheet of drawings.