DE2044514C - Lens system with variable magnification close to the image scale 1 1 - Google Patents

Description

Af ₉ = 1.53933
N ₁₀ = 1.54625

V ₁ = 47.0
K ₈ = 55.5

V ₉ = 48.9
F ₁₀ = 59.7

can be shifted axially in order to achieve these magnification values.

The invention relates to a Linsenswem with changeable Magnification which is continuous within a range close to 1: 1 magnification is changeable. Such a lens system is suitable as a copying lens z. B. in Photokopitrapparaten and photocomposing machines.

In general, photocopiers or photocomposing machines have the required magnification close to the value 1 or elwas above or below this value.

In the case of a large photocomposition machine, for example The magnification can be changed by changing the distance between the original and the copy is changed. However, a complicated mechanism is required to set the template and level or move the plane of the copy perpendicular to the optical axis with a high degree of accuracy. Some photocopying machines have multiple lenses with different focal lengths on a turret or turret, but the magnification can only be changed i, i steps will. Furthermore, the lenses must be arranged with a high degree of accuracy, which requires a high construction effort.

There is already a lens system for photocopiers known, its magnification within a very limited area near 1. between about 0.95 and 1.05 using the depth of field of the lens system is changeable. A major shortcoming here, however, is that the magnification can only be changed in a very limited small area.

There are also relatively simply constructed Phoiokopierapparate known in which one or two reflective mirrors are moved in the optical path while the planes of the original and the copy are kept stationary. In the case of photocopiers, which only have a reflective mirror

.10, the center of the plane of the original or that of the copy is shifted; here it is very difficult to move the large-sized reflective mirror with a high degree of accuracy. In the case of photocopiers with two reflecting mirrors, such a structure cannot practically be used if the angle of view is greater than 4 ° ^C.

The invention is therefore intended to provide an improved lens system, in particular for copiers whose magnification is continuously within a range close to 1: 1 magnification is changeable. which requires less effort to manufacture, has fewer optical defects as a known lens system and in which the two levels of the original and the copy are stationary remain.

According to the invention, this object is achieved with a lens system that has ten lenses symmetrically to a central aperture, the third and fourth lens and the seventh and eighth lens are cemented together. With a focal length range and a relative aperture of 1: 8 between 248 mm and 258 mm, the lens system has the following manufacturing data:

78.65 'I ₁ = 6.58 101.24 d-, = 4..S --21.4 96.68 </, = 3.24 64.89 d _A = 1.48 56.40 Ί> = 12.77 I April 50 2.38

N ₁ = 1.53996

Λ'-, = 1.53172

F ₁ - 59.7

V-, = 48.9

N, = 1.67790 l-'j = 55.5

/ V. = 1.6 ^ 74 V, = 47.0

r ₇ = 44.58 r ₈ = 59.50 r _Q = 95.76 r _I0 = -95.76 r ,, = -59.50 r ,, = -44.58 r, 3 = - 1 50.04 r ₁₄ = - 56.40 r, ₅ = -64.89 r _lb = -96.68 r, ₇ = -101.29 r ₁₈ = -78.65

A ₁ = 4.19 d _s = 10.43 rf, = 8.43 A ₁₀ = 10.43 A _n = 4.19 Aa = 138 A ₁₃ = 12.77 A _-4 = 1.48 Ci ₁₅ = 3.29 J ₁₆ = 4.8-21.4 A ₇ = 6.58

N ₅ = 1.58900 V ₅ = 48.6

N ₆ = 1.58900 V _b = 48.6

N ₇ = 1.62374 V ₁ = 47.0

N ₈ = 1.67790 K ₈ = 55.5

N ₉ = 1.53172

= 48.9

N ₁₀ = 1.53996 K ₁₀ = 59.7

With a relative aperture of 1: 11 and the same focal length range, the lens system has the following Manufacturing data:

r * =

^r 5 =

67.1 75.254 85.9 69.173 53.785 r ₆ = -144.61 r ₇ = 42.326 r ₈ = 59.235 r, = 88.855 r ₁₀ = -88.855 T ₁₁ = -59.259 ra = -42.326 r ₁₃ = 144.61 r ₁₄ = -53.785 r ₁₅ = -69.173 r ₁₆ = -85.9 r ₁₇ = -75.254 r ₁₈ = -67.1

A ₁ = 4.63 d ₂ = 1.71-20.585 d ₃ = 3.45 d ₄ = 2.41 d ₅ = 8.94 4 = 2.63 d ₇ = 2.90 d _s = 5.29 <i, = 6.62 ^ ₁₀ = 5.29 d _u = 2 _.90 d ₁₂ = 2.63 d l3 = 8.94 J ₁₄ = 2.41 d ₁₅ = 3.45

• <Z ₁₆ = 1.71-20.585 d "= 4.36

N ₁ = 1.54625
N ₂ = 1.53993

N ₃ = 1.68641
N ₄ = 1.63306

N ₅ = 1.61725

N ₀ = 1.61725

N ₇ = 1.63306
N ₈ = 1.68641

N ₉ = 1.53933
N ₁₀ = 1.54625

V _x = 59.7 V ₂ = 48.9

V ₃ = 55.5 F ₄ = 47.0

V ₅ = 46.2 F ₆ = 46.2

V ₁ = 47.0 ^ ₈ = 55.5

V ₉ = 48.9 V _w = 59.7

F i g. 1 shows a schematic view of FIG. 2 shows a schematic view of the ob-

refinement of the objective lens according to the invention according to claim 1; underlying principle; Fig. 3 shows a schematic view of the op-

(ο

table system of a photocopier using a variable magnification having lens system according to the invention;

F i g. 4 A and 4 B to F i g. 11 A and 11 B show the curves of the spherical aberration and of the astigmatism of the lens system according to FIG. 2 at Change in magnification from 0.7 to 1.4;

F i g. 12 shows a schematic view of one further objective of the invention;

F i g. 13 shows a schematic view of a further objective of the invention;

14 shows a schematic view of the objective according to claim 2.

First of all, the principle on which the objectives according to the invention are based in connection with FIG. 1 will be explained. When the distance between the original 1 and the image plane 2 is S. the focal length f _{M of} the objective 3 for a given magnification M is given by the following expression:

K4

/ m =

(1 + M) ² "·

When the magnification changed from 1 to 1 / | '2 the focal length changes

= 1 / 4S-

(2)

where /, is the focal length for the magnification M = 1.

From equation (2) it follows that if the focal length / is changed by about 3%, the magnification becomes M = 1 / (/ 2 = 0.7 or ψϊ = 1.4.

It might be considered easy to design a conventional variable magnification lens so that the above condition is satisfied because the change in the focal length f _{M is} small.

However, this does not apply to a copier lens because a desired resolving power over the entire image plane must be maintained at any chosen magnification. namely with one

Minimum distortion and a sufficient aperture to uniformly illuminate the image plane. Such an interpretation is very difficult.

In the copying lens according to the present invention, the lenses are symmetrical to the diaphragm

arranged so that the distortion which is the most difficult error to correct in a Lens with variable magnification represents, can be completely corrected. Because of the symmetrical The coma and the

Color magnifications can be corrected satisfactorily, while spherical aberration, astigmatism and the on-axis chromatic aberration is maximally correctable. The resolving power of more than eight lines per millimeter

can be achieved over the entire image area in the magnification range of approximately 0.7 to 1.4.

F i g. 2 shows the objective with variable magnification according to claim 1. It consists of eight members and ten lenses which are arranged symmetrically to the diaphragm. All the links are menisci, the concave surfaces of which face the diaphragm. The first element L ₁ is a converging lens, the second element L _{2 is} a diverging lens, the third element consists of the lens L ₃ and the lens L ₄ , which are connected to one another.

cemented, the fourth link is a converging lens L ₅ . The fifth to eighth links correspond to the fourth to first links, respectively. The focal lengths of the collecting lens L ₁ and the collecting lens L ₁₀ are between two and five times the total focal length of the

Lens system. These lenses L ₁ . L ₁₀ remain symmetrical with respect to the diaphragm when they are axially displaced, ie the air gaps d ₂ and d _{l0 are} changed. The resulting changes in focal length can be found in the following table:

enlargement

d ₂ = d _ib

Focal length

Distance in the thing space

Distance in the picture space

Total length of the lens system.

0.7 0.8 0.9 1.0 1.1 1.2 1.3 4.8 14.0 19.7 21.4 19.9 16.5 11.8 "> 48.3 "" 53.6 "> 57, O 258 1 257.1 255.1 252.3 553.8 512.6 476.5 447.4 423.9 404.8 389.4 374.2 397.0 421.7 447.4 474.0 502.8 524.6 100.3 118.7 130.1 133.5 130.4 123.7 114.3

1.4
6.3
249.1
377.4
547.6
103.3

The axial distance in the object space is that between the object-side surface of the first lens I ₁ and the original 1, while the axial distance in the image space between the image-side surface of the 10th lens and the image plane 2 lies along the optical axis of the system. For each enlargement, the distance between the original 1 and the image plane 2 was kept at 1028.3 mm (see FIG. 3).

Figures 4A and 4B to HA to HB show the spherical aberration and astigmatism curves for a given magnification. the relative aperture is plotted as the ordinate for the spherical aberration curves, while the height from the center of the template is chosen as the ordinate for the astigmatism curves. The distortion is within 0.1% for each magnification.

The Seidel coefficients of spherical aberration I, coma II, astigmatism III, image curvature IV and the distortion V for a given magnification result from the following Compilation:

Magnification = U 0.7, d ₂ = d _l6 = 4.8 V I. 3.27 111 IV 0.15 1 45.58 -2.15 0.23 1.88 -0.33 2 -11.84 2.47 -0.39 -1.46 0.35 3 13.54 -6.16 0.45 1.51 -0.20 4th -81.29 7.58 -0.46 -2.26 0.21 5 124.86 -1.34 0.46 3.03 -0.07 6th 6.14 0.29 0.05

continuation

7th
8th
9
10
11th
12th
13th
14th
15th
16
17th
18th

- I 73.99

90.50

-6.33

-10.09

104.99

-192.14

4.84

134.79

-88.82

17.17

-15.02

49.76

12.67

1-1

-14.19

11.65

2.27

3.28

3.02
15.30

1.13
- April 8th

6.59
-2.97

2.59
-3.50

0.21

ill

-1.15
1.50

-0.81

-1.06
1.61

-1.21
0.26
0.47

-0.48
0.51

-0.44
0.24

IV

-3.64 2.63

-1.63

-1.63 2.63

- 3.64 0.05 3.03

-2.26 1.51

-1.46 1.88 0.23

-0.39 0.53

-0.88 0.87

-0.52 0.38 0.07

-0.20 0.20

-0.35 0.33

-0.15

_ η ι m

Magnification = 0.8. ά ₂ = d _ib = 14.0

j -

;

i

j -

I.
17th

53.64
14.33
16.58
-96.74
148.26
6.90
- 207.44
108.86
-8.10
- 10.96
119.89
221.25
5.92
155.82
■ 102.47
19.34
-16.41
55.68
13.21

11th

2.34
-2.13

2.87
-7.01

8.61

-1.47

-16.17

-13.36

-2.74

3.74
-14.37

16.98

III

IV

0.10
-0.31

0.49
-0.50

0.50

0.31
-1.26

k64
-0.92
-1.10

1.72
-1.30

0.29

0.51
-0.52

0.54
- 0.34

-14 1 i ι "\ 1 Π

- _. * - »ι - ν / .1 w

0.16 i -0.05

-8.94

7.32

-3.24

2.36

2.03-1.58

1.63 -2.44

3.27

0.06 -3.93

2.84 -1.76 -1.76

2.84 - 3.93

0.06

3.27 _ "> 44

1.63

-1.58

03

0.25

0.09 -0.28

0.37 -0.21

0.21 -0.07 -0.40

0.55 -0.91

0.91 -0.54

0.40

0.07 -0.21

0.21

! -0.36 j 0.27

-0.00

Magnification = 0.9. d ₂ = d _lb = 19.7

14 15 16

17 18

10 1 Il III 181.03 -9.94 0.54 118.80 8.13 -0.55 21.87 -3.53 0.57 -18.37 2.29 -0.28 63.88 -1.71 0.04 14.37 0.08 -0.04

IV

3.50
-2.61

1.75
-1.69

2.18

0.27

-0.22 0.21

-0.37 0.24

-0.05

-0.00

Magnification = 1, d ₂ = d _u , = 21.4

15th

4 5 6 7 8 9 10 11 12 13 14 15 16 17 IS

73.37
- 20.63
24.48
-135.96
207.55
8.74
-292.54
156.03
-12.92
-12.93
156.05
-292.55
8.74
207.56
-135.96
24.49
- 20.63
73.37
16.26

Il

1.56

-2.38

-8.90

10.90

-1.73

- 20.59

17.22

-3.85

3.85

-17.22

20.59

1.73

-10.90

8.90

-3.80

2.38

-1.56

-0.00

III

0.03

-0.27

0.59

-0.58

0.57

0.34
- 1 -11

1.90
-1.14
-1.14

1.90
-1.44

0.34

0.57
-0.58

0.59
-0.27

0.03
-0.03

IV

2.30
-1.78

1 OC
l .11- '

-2.76
3.69
0.06

-4.44
3.21

-1.99

-1.99
3.21

-4.44
0.06
3.69

-2.76
1.85

-1.78
2.30

-0.28

0.04 -0.23 0.37 -0.21 0.22 -0.08 -0.41 0.56 -0.93 0.93 -0.56 0.41 0.08 -0.22 0.21 -0.37 0.23 -0.04 0.00

40

Magnification = 1.1. d ₂ = d _ib = 19.9

I. U Ul IV V 1 63.14 1.69 0.04 2.18 0.05 2 -17.34 -2.19 -0.27 -1.69 -0.24 3 20.36 3.34 0.54 1.75 0.37 4th -115.66 -7.97 -0.54 -2.61 -0.21 5 176.89 9.77 0.53 3.50 0.22 6th 7.80 -1.60 0.33 0.06 -0.08 7th -248.48 -18.40 -1.36 -4.21 -0.41 8th 131.55 15.31 1.78 3.04 0.56 9 -10.38 -3.29 -1.04 -1.89 -0.93 10 -11.94 3.67 -1.13 -1.89 0.93 11th 137.57 -15.83 1.82 3.04 -0.56 12th -256.02 18.82 -1.38 -4.21 0.41 13th 7.27 1.52 0.32 0.06 0.08

IV

86.73 I. 2.06! 0.04 1 2.41 - 24.94 -2.80 -0.31 j -1.87 29.71 4.33 0.63 y 1.94 -161.37 -9.9 I. -0.61 -2.89 245.90 12.20 0.60 ' 3.88 9.87 " -1.87 0.35 0.07 -347.78 -23.09 -1.53 -4.66 186.87 19.42 2.01 3.37 -16.22 -4.51 -1.25 -2.09 -14.10 4.04 -1.15 -2.09 178.71 -18.78 1.97 3.37 -337.55 22.57 -1.51 -4.66 10.60 1.97 0.36 0.07 240.31 -11.99 0.59 3.88 -157.13 9.78 -0.60 -2.89 27.66 -4.09 0.60 1.94 -23.55 2.67 -0.30 -1.87 85.75 -2.04 0.04 2.41 19.47 -0.10 -0.04 0.29

0.05 -0.24

0.37 -0.21

0.22 -0.08 -0.41

0.56 -0.93

0.93 -0.56

0.Oi -0.2:

0.21 -0.3:

0.2 '-O.O:

11th

Magnification = 1.2. J ₂ . ⁼ '''ih ⁼ ' 6.5

101.82:

-29.83 j

35.37;

-188.63 I-

06/11

-407.08

220.11

--19.86

-15.31

202.58

12.63

274.98

- 179.51

30.98

- 26.66

99.06

23.59

3.05

-3.37

4.86

11.03

13.48

- 2.00

25.57

21.60

-5.17

4.21

20.3d

24.51

2.20

April 13

10.63

-4.38

2.08

- 2.99

-0.21

III

0.09

- 0.38 0.66

-0.64 0.63 0.36

- 1.60 2.12 1.34

- 1.16 2.03

-! .56 0.38 0.61

- 0.62 0.62

-0.35 0.09

- 0.06

Magnification = 1.3. r / _: =

119.45

-35.56

41.65

-218.57

332.11

12.35

-472.29

256.77

-23.95

- 16.60

228.44

-436.82

14.8S

312.70

-203.85

34.56

-30.00

113.52

28.81

4.56

-4.12

5.40

-12.11

14.78

-2.14

- 28.09

23.83

-5.85

4.39

-21.83

26.47

2.45

-14.11

11.49

-4.67

3.60

-4.38

0.33

0.P -0.47

0.70 -0.67

0.65

0.37 -1.C.7

2.21 -1.43 -1.16

2.08 - 1.60

0.40

0.63 -0.64

0.63 -0.43

0.16-0.05

IV

2.51 -1.95

2.02

-3.01 4.03 0.07

-4.85 3.51 2.18

-2.18 3.51

-4.85 0.07 4.03

-3.01 2.02 1.95 2.51 0.31

IV

2.60 -2.01

2.09 -3.12

4.17

0.07 - 5.02

3.63

5.02

0.07

4.17 ■:

3.12

2.09

2.01

2.60

0.32

0.07 -0.26

0.37 -0.21

0.21 -0.07 -0.40

- 0.91 0.92

-0.55 0.40 0.08

-0.22 0.21

-0.37 0.26

- 0.07 O.DO

0.10 -0.28

0.36 -0.21

0.21 -0.07 -0.39

0.54 -0.90

0.90 -0.54

0.21 -0.36

0.29-0.10

Magnification = 1.4. d ₂

= d, _ft =

1 Il ill IV V 1 139.51 6.56 0.30 2.67 0.14 ■> -42.07 -5.04 -0.60 -2.07 -0.32 3 48.38 5.94 0.73 2.15 0.35 4th -250.45 -13.17 -0.69 -3.21 -0.20

380.12

13.70

-541.75

295.92

- 28.39
-17.93

255.66

-491.33

17.29

352.52

-229.53

38.30

- 33.44
i 28.58

35.09

111

July 16
-2.28

- 30.60
04/26

- 6.54
4.56

- 23.34
28.41

2.69

-15.17

12.34

-4.95

4.21

- 6.16
-0.42

0.68

0.37
-1.72

2.29
-1.50
-1.16

2.13
-1.64

0.41

0.65
- 0.66

0.64
-0.53

0.29
-0.00

IV

4.30

0.07

-5.17

3.73

- 2.32

- 2.32
3.73

-5.17
0.07
4.30

-3.21
2.15
2.07
2.6 "
0.33

0.21

-0.07

-0.38

0.53

-0.88

0.88

-0.53

0.39

0.07

-0.21

0.20

-0.36

0.32

0.14

0. (X)

In the lens system according to the invention, in which the converging lenses L ₁ and L _{10 are} displaced, the displacement takes place the furthest outward when the magnification is equal to 1. This means that the lens system then has the greatest length. When the magnification is greater or less than 1, both lenses L become ₁ . L _u , moved against the aperture. This means that the length of the lens system and the focal length become smaller. Thus, when a reflecting mirror 4 is inserted into the beam path in order to obtain an upright image. the lens system 3 moves towards the reflecting mirror 4. as at the point 3A in FIG. 3 is illustrated. in order to increase the magnification, but the overall length of the lens system 3 is reduced in the manner described above, so that the lens system 3 is not against the reflective

On the other hand, if the outermost lenses L ₁ and L ₁₀ are diverging lenses, the entire length of the lens system becomes shortest when the magnification is 1. while the length becomes longer when the magnification is greater or less than 1 is so that in the optical system according to Fig. 3, the magnification is greater, the distance between the lens system 3 and the reflecting mirror 4 tends to be too small Magnification range> is reduced.

In the case of the objective described above, the outer lenses, ie the front lens L ₁ and the rear lens L _{10, are} axially displaced symmetrically with respect to the diaphragm, but it goes without saying.

that the lenses L ₂ , L ₉ can be shifted symmetrically with respect to the diaphragm, while the lenses L ₁ and L _{10 are} held stationary, as illustrated in FIG. Optionally, the lenses / -, L ₂ , L ₉ , L ₁₀ can be shifted symmetrically with respect to the diaphragm, as in FIG. 13 is illustrated. In these cases, it is preferable that the diameter of the lenses L ₂ and L _{9 be made} larger. All lenses L ₁ to L ₁₀ are designed so that they are completely symmetrical with respect to the diaphragm

are, however, these lenses can only be almost symmetrical to the aperture.

F i g. 14 shows the objective according to claim 2.

For this purpose 2 sheets of drawings

Claims (3)

Patent claims: 1. Lens system, the magnification of which can be continuously changed in the range of the image scale 1: 1 is ^ characterized by the following production data: Relative opening ί: S, focal length range 248 ... 258 mm r, = 78.65 r ₂ = 101.29 r ₃ = 96.68 r ₄ = 64.89 r ₅ = 56.40 r ₆ = -150.04 r ₇ = 44.58 r ₈ = 59.50 r ₉ = 95.76 r, o = -95.76 r _n = -59.50 r ₁₂ = -44.58 r ₁₃ = 150.04 r ₁₄ = -56.40 r ₁₅ = -64.89 r ₁₆ = -96.68 r ₁₇ = -101.29 r, g = -78.65 d _x = 6.58 d ₂ = 4.8-21.4 d ₃ = 3.29 d _A = 1.48 d ₅ = 12.77 <k = 2.38 d-, = 4.19 d _s = 10.43 dg = 8.43 c /, 0 = 10.43 d _n = 4.19 Ci ₁₂ = 2.38 d _t3 = 12.77 d _u ^ = 1.48 Ci ₁₅ = 3.29 U ₁₆ = 4.8-21.4 c / ₁₇ = 6.58 N ₁ = 1.53996
N ₂ = 1.53172 N ₃ = 1.67790
JV ₄ = 1.62374 N ₅ = 1.58900
N ₆ = 1.58900 N ₇ = 1.62374
N ₈ = 1.67790 N ₉ = 1.53172
N _1n = 1.53996 V ₁ = 59.7 V ₂ = 48.9 K ₃ = 55.5 K ₄ = 47.0 K ₅ = 48.6 K ₆ = 48.6 K ₇ = 47.0 K ₈ = 55.5 K ₉ = 48.9 K ₁₀ = 59.7 2. Modification of the lens system according to claim 1, characterized by the following production data: Relative aperture 1:11, focal length range 248 ... 258 mm r, = 67.1 d _x = 4.63 r ₂ = 75.254 d ₂ = 1.71-20.585 N ₁ = 1.54625 V ₁ = 59.7 ^r i ~ 85.9 d ₃ = 3.45 r ₄ = 69.173 dt, = 2.41 N ₂ = 1.53993 V ₂ = 48.9 ^r 5 = 53.785 d ₅ = 8.94 r _h = -144.61 <4 = 2.63 W ₃ = 1.68641 ^ 3 = 55.5 O r ₇ = 42,326 ii ₇ = 2.90 ^ 4 = 1.63306 V ₄ . = 47.0 'S - 59.235 d _H = 5.29 Λ, = 88.855 Ci ₉ = 6.62 N ₅ = 1.61725 t / 46.2 T ₁ O - - 88,855 4, = 5.29 v _b = 46.2 ^r ll = - 59,259 </ ,, = 2.90 N " = 1.61725 r _u = -42.326 r _a = 144.61 r ₁₄ = -53.735 r _J5 = -69.173 r «, = -85.9 r ₁₇ = -75.254 r ₁₈ = -67.1 d ₁₂ = 2.63
d _n = 8.94 <* »= 2.41 d ₁₅ = 3.45 d _lb = 1.71-20.585 d "= 4.36 3. Lens system according to claim 1 or 2, characterized in that ε? Ϊη magnification range 0.7 ... 1.4 and that the entire Ob- JV ₇ = 1.63306
N ₈ = 1.68641