CS229291B1 - Optical system of reproduction lens - Google Patents

Abstract

The invention relates to an optical system of a reproduction lens, which is composed of six elements, formed by a scattering meniscus, a connecting lens, a connecting meniscus, a scattering meniscus, a cemented meniscus and a connecting lens. Its design parameters are selected so that the optical system meets the following conditions: The correction condition is optimized for setting the lens to a magnification of β = —0.021.

Description

The invention relates to an optical system of a reproduction lens, composed of six members, formed by a diffusing meniscus, a connecting lens, a connecting meniscus, a diffusing meniscus, a cemented meniscus and a connecting lens.

Current reproduction technology requires imaging systems, in particular, to provide high-resolution contrast imaging and minimal vignetting over a large field of view. These requirements can only be met by technologically demanding optical systems with seven to eight lenses, the optical elements of which are mostly made of special lanthanum glasses. This is reflected in the high production costs and thus in the price of these lenses.

The requirement was therefore to design an optical system for a reproduction lens that would contain a maximum of seven lenses, would be technologically undemanding, and would contain a minimum number of lenses made of lanthanum glasses. The relative aperture of the optical system should be 1 : 3, the field of view 2ω = 42 ⁰ with practically zero geometric vignetting and top image performance.

This task is solved by the subject of the invention, which is an optical system of a reproduction lens composed of six members, formed by a scattering meniscus, a connecting lens, a connecting meniscus, a scattering meniscus, a cemented meniscus and a connecting lens.

The essence of the invention lies in the fact that the optical system meets the following conditions

1. 1.2 F< iFtl <1.8 F, where F^O

2. 0.25 |Fj| <e ₄ <0.4 |F ₄ | _ vdj + vd ₂ + i»d ₃ + ud ₄

4 W- Ri = 247,544 _r2 = 63,325 r ₃ = 132,961 R ₄ = — 151,239 r ₅ = 52,193 r ₆ = 145,813 r ₇ = 1047,866 R ₈ = 42,819 R ₉ = — 124,736 ^R io = 45,053 Rh = — 79,368 ^R 12 = 259,111 R _i3 = — 285,507 R ₄₄ ~ OO ^R 15 = ooo

< 36, d _x = 10.92 θ! = 46.12 d ₂ = 25.70 e ₂ = 0.36 d ₃ = 14.64 e ₃ = 5.43 d ₄ = 6.28 e ₄ = 6.64 d ₅ = 6.78 d ₆ = 24.20 e ₅ = 0.36 d ₇ = 14.35 e ₆ = 82.40 d ₈ = 21.43 where means

F focal length of the optical system

F _t focal length of the first scattering meniscus ej air gap between the first scattering meniscus and the connecting lens pd ₄ Abbe number of the first, scattering meniscus i>d ₂ Abbe number of the second, connecting lens yd ₃ Abbe number of the third, outer meniscus »d ₄ Abbe number of the fourth, scattering meniscus.

The optical system of the reproduction lens solved in this way fully meets the required performance parameters and contains only one or two lenses made of low-cost lanthanum glass.

An exemplary embodiment of the optical system according to the invention is schematically illustrated in the attached drawing, from which it follows that on the optical axis O there are sequentially arranged — a scattering meniscus 1, the second member is a biconvex lens 2, followed by a connecting meniscus 3, a scattering meniscus 4 and a cemented meniscus, which is composed of a scattering meniscus 5 and a biconvex lens 6 cemented to it. This is followed by a separate biconvex lens 7. With regard to its use, this optical system also includes a plane-parallel plate 8. The correction condition is optimized for setting the objective to a magnification of β = —0.021 when using a plane-parallel plate 8.

The following tables show the design parameters of two examples of optical systems according to the invention, and these design parameters are recalculated so that their focal lengths have the value F = 100 mm.

'n _d »d n _d = 1.68893 air in _d = 31.1 n _d = 1.68893 air in _d = 31.1 n _d = 1.70154 air in _d = 41.1 m, = 1.63980 air in _d ~ 34.6 n _d — 1.75520 in _d = 27.5 n _d = 1.69100 air » _d = 54.8 n _d = 1.62041 air in _d = 60.3 n _d = 1.51680 _pd = 64.2

where

F = 100.1 _Ft = -126.57

WITH

Ri = 150,663 _r2 = 63,083 r ₃ = 109,134 R ₄ = — 208,496 r ₅ = 50,353 Re = 104,700 R ₇ = 184,318 Rs - 38,553 Rg = — 72,107 Rio — 54,190 Rn = — 68,220 Rl2 = 140,609 ^R 13 = — 283,134 — OO Rl5 = ooo

d _t = 7.85 e _t = 47.60 d ₂ = 16.45 e ₂ = 0.31 d ₃ = 15.26 ^e 3 ⁼ 5.46 d ₄ = 4.58 e ₄ = 6.28 ds — 6.03 d ₆ = 24.43 θ5 = 0.31 d ₇ = 13.06 e ₆ = 81.73 d ₈ = 18.75

n _d »d n _d = 1.67270 air Vd = 32.2 ,n _d = 1.67270 air in _d — 32.2 n _d — 1.66755 air in _d — 41.9 n _d = 1.63636 air in _d = 35.4 n _d = 1.74077 in _d - 27.7 n _d = 1.65830 Air r _d = 57.1 n _d = 1.65830 air in _d — 57.1 n _d = 1.51680 in _d β 64.2

F = 99.96 F _t = -167.35

In both exemplary embodiments, the deviation of the radii of curvature R1 to _R13 can be up to +10%, the axial thicknesses _dt to _d8 and the air gaps _e4 to _e6 can be up to +10%, the refractive indices _nd up to +2 ^% and the Abbe number _vd up to +2%.

The optical system according to the invention is suitable for lenses intended for reproduction purposes.

Claims (3)

1. 1.2 F< JFJ <1.8 F, with Fi<0, where F denotes the focal length of the optical system Fj denotes the focal length of the first scattering meniscus 1. An optical system of a reproduction lens, consisting of six members, formed by a scattering meniscus, a connecting lens, a connecting meniscus, a scattering meniscus, a cemented meniscus and a connecting lens, characterized in that it satisfies the following relations 2. The optical system according to item 1, characterized in that it has the following parameters Ri — 247,544 _R2 = 63.325 _R3 = 132.961 R ₄ = — 151.239 _R5 = 52.193 _R6 = 145.813 R-? = 1047.866 R _with = Rg = Rio = Ru = — ^R 12 — r ₁₃ = — Rlí = oo R ₁₅ = oo 42,819 124,736 45,053 79,368 259,111 285,507 n _{d dt} = 10.92 n _d = 1.68893 in _d = 31.1 ej = 46.12 air _d2 = 25.70 n _d = 1.68893 in _á = 31.1 _e2 = 0.36 air _d3 = 14.64 n _d = 1.70154 in _d = 41.1 _e3 = 5.43 air _d4 = 6.28 n _d =, 1.63980 in _d = 34.6 _e4 = 6.64 air _d5 = 6.78 n _d = 1.75520 in _d = 27.5 _d6 = 24.20 n _d = 1.69100 » _d = 54.8 _e5 = 0.36 air _d7 = 14.35 n _d = 1.62041 in _d = 60.3 e ₆ = 82.40' air _d8 = 21.43 n _d = 1.51680 in _d = 64.20 whereby the deviation of the radii of curvature Ri to R ₁₃ may be up to + 10%, the axial thicknesses dj to d ₈ and the air gaps e ₃ to e ₆ may be up to + 10%, the refractive indices n _d up to + 2% and the Abbe number v _d up to + 2%. 2. 0.25 jFil <e _:L <0.4 |F ₄ | , where OF THE INVENTION e _t denotes the air gap between the first scattering meniscus and the connecting lens 3 rd ₄ 4~ vd ₂ + vd ₃ + i>d ₄ < where ud _t denotes the Abbe number of the first, scattering meniscus. vd ₂ denotes the Abbe number of the second, converging lens vd ₃ denotes the Abbe number of the third, converging meniscus vd ₄ denotes the Abbe number of the fourth, dispersive meniscus. 3. The optical system according to item 1, characterized in that it has the following parameters Ri = 150,663 _r2 = 63,083 r ₃ = 109,134 Ri = — 208,496 _R5 = 50,353 R ₆ = 104,700 r ₇ = 184,318 Rs = 38,553 Rg = — 72,107 Rio = 54,190 Rn = — 68,220 Rl2 — 140,609 Rl3 = — 283,134 Rj4 = oo R ₁₅ = oo n _d l>d _dt = 7.85 n _d = 1.67270 in _d = 32.2 θ| = 47.60 air in _d = 32.2 _d2 = 16.45 n _d = 1.67270 »d = 41.9 θ2 — 0.31 air !M = 35.4 _d3 = 15.26 n _d = 1.66755 Vd = 27.7 _e3 = 5.46 air in _d = 57.1 _d4 = 4.58 n _d = 1.63636 in _d = 57.1 _e4 = 6.28 air in _d = 64.2 dg = 6.03 n _d = 1.74077 _d6 = 24.43 n _d = 1.65830 es = 0.31 air _d7 = 13.06 n _d = 1.65830 _e6 = 81.73 air _d8 = 18.75 n _d = 1.51680 whereby the deviations of the radii of curvature Ri to R ₁₃ can be up to + 10%, the axial thicknesses di to d ₈ and the air gaps e _t to e ₆ can be up to + 10%, the refractive indices n _d up to + 2% and the Abbe number v _d up to + 2%.