DE3633032A1 - SEVEN-LENS LIGHT-EFFECTIVE LENS WITH CORRECTION COMPENSATION - Google Patents

Description

The invention can be used for imaging on CCD receivers, television recording tubes or footage in a wide range of magnifications be applied.

Lenses for the application, which are characterized by a resolution distinguish the picture elements with a sufficiently good contrast, are known.

DD-WP 1 46 860, DE-AS 21 63 431, US-PS 39 84 155 and US-PS 40 99 843 describe seven-lens, six-membered modified Gaussian Lenses that are optimized for a magnification, however not the required over the entire range of the image scale Possess image quality.

When running these lenses in small focal lengths the air gap between the second and third lens for the Lens frame unfavorable.

US-PS 41 01 203 describes a seven-lens, five-link modified Gaussian lens, with the refractive and expensive glasses be used.

To be even over the entire area of the magnification There are various ways to achieve high image quality the correction compensation for seven-lens modified Gauss lenses known. DE-OS 31 03 012 describes a solution where the lens spacing in the aperture space for correction compensation as the object distance becomes smaller, but the has other disadvantages.

US-PS 44 64 023 and 44 66 710 describe lenses in which for Correction compensation of the lens distance in the aperture space and the Distance of the sixth and seventh lenses can be changed, they but do not have the required light intensity, as well the solution according to US-PS 38 15 974.  

The aim of the invention is a lens for the use mentioned purpose in which no extremely high-index glasses are used will.

The invention has for its object to provide a lens which has a relative aperture of 1: 1.4 for a picture angle of approx. 35 ° evenly corrected for the entire image field is and for a magnification range from 1 / ∞ to approx. -1/4 only have an insignificant reduction in image quality should.

This task is solved by a seven-lens, bright lens Correction compensation according to the invention in that the lens is composed of five optical links, the first one collecting meniscus, the second a cemented dispersing Meniscus, the third a cemented collecting meniscus, the fourth is a converging lens and the fifth is a converging lens.

When focusing from long to short object focal lengths the first four lens members together by a larger amount than the fifth are shifted relative to the image plane. Between the aperture diaphragm is arranged in the second and third optical element.

The lens according to the invention points to an imaging scale range from 1 / ∞ to -1/10 up to an angle of view of approx. 35 ° good contrast and high resolution when the following equations of conditions are observed are:

n ₁ ≦ λτ 1.66 (1)
ν ₁ ≦ λτ 50 (2)
n ₂ ≦ λτ 1.66 (3)
ν ₂ ≦ λτ 50 (4)
n ₂ - n ₃ ≦ λτ 0.05 (5)
ν ₃ ≦ λτ 50 (6)
n ₄ ≦ λτ 1.70 (7)
ν ₄ ≦ ωτ 30 (8)
n ₅ ≦ λτ 1.66 (9)
ν ₅ ≦ λτ 50 (10)
n ₆ ≦ λτ 1.66 (11)
ν ₆ ≦ λτ 50 (12)

Because of these condition equations need in the optical system no extremely high refractive index glasses are used.

The area of the picture scale in which a good contrast is available, can be expanded to approx. -1/4 by focusing from long to short object distance the air gap between the fourth and fifth lens member is enlarged. This increase in the air gap causes compensation when focusing with a conventional fixed lens Imaging errors in the field curvature and astigmatism.

The invention will be explained in more detail with reference to the following drawings will.

Show it

Fig. 1, the lens sectional view schematically

Fig. 2, the longitudinal deviation spherochromatic without Range Correction for different imaging scales,

Fig. 3, the longitudinal deviation with spherochromatic Range Correction for two magnifications,

Fig. 4 shows the longitudinal aberration of the sagittal and meridional scales without correction compensation for four imaging scales and

Fig. 5, the longitudinal aberration as shown in FIG. 4 Range Correction for two magnifications.

In Fig. 1 along the optical axis 0-0 'are a first lens member G ₁ from a collecting meniscus lens L ₁ , a second lens member G ₂ from a cemented diffusing meniscus of the lenses L ₂ , L ₃ , an aperture diaphragm B , a third lens member G ₃ from a cemented collecting meniscus of the lenses L ₄ , L ₅ , a fourth lens member G ₄ from a collecting lens L ₆ and a fifth lens member from a collecting lens L ₇ , wherein the lens members G ₁ to G _{4 are moved} together by a larger amount than the lens member G ₅ relative to the image plane BE .

The lenses are characterized n _e and ν _e by its parameters radius r _i, thickness d _j, while the air spaces are designated by l _k.

Claims (4)

1. Seven-lens bright lens with correction compensation, which contains seven lenses and is of the modified Gauss type, characterized in that the lens is characterized by the following design data. 2. Lens according to claim 1, characterized in that the first four lens members together along the optical axis are displaceable that the fifth lens element independently is displaceable that the first four lens members together by a larger amount than the fifth lens element relative be moved to the image plane. 3. Lens according to claim 1 and 2, characterized in that for the change in the distance between the fourth and fifth lens element depending on the image scale, the relationship applies: β l ₄ 1 / ∞0.0040 -1 / 200.0052 -1 / 100.0403 -1 / 40.2711 4. Lens according to claim 1 to 3, characterized in that the radii, thicknesses and air gaps can be varied within ± 10%, n _e within ± 0.05 and ν _e within ± 5.