# US 4,398,809 A · High speed catadioptric system

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- Number: US 4,398,809 A
- Document ID: US4398809A
- Status: Granted
- Kind: A
- Application number: 06/280,244
- Filed: 1981-07-06
- Granted: 1983-08-16
- Earliest claimed: 1980-08-16
- Inventors: Ludvik Canzek
- Web page: https://patentgrep.com/patent/US4398809A

## CPC

- G02B 17/0856: {comprising a refractive element with a reflective surface, the reflection taking place inside the element, e.g. Mangin mirrors}
- G02B 17/0808: {on-axis systems with at least one of the mirrors having a central aperture}
- G02B 17/0852: {having a field corrector only}
- G02B 17/0884: {having a pupil corrector}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

This invention provides a high speed catadioptric system of F/1.2. The lens system comprises, in accordance with the advance of the light rays, a front lens, a main mirror lens, a counter mirror surfaced to the central portion of the front lens, and a field lens system. The field lens system is composed of the unsilvered central portion of the main mirror lens and additional lenses immediately adjacent to the main mirror lens at its object- and image side. The same glass is used for the front lens and the main mirror lens. This glass is light, cheap and rather resistant to chemical attack. Three preferred embodiments present a rather high state of correction for the wavelength range from 400 nm to 1000 nm, providing a high contrast image with good detectability of poor-contrast objects. Such lens systems, in spite of their good performance, are of rather simple construction bringing about a lower price of manufacture than known systems. The new lenses are useful also for systems used at low light level employing image intensifier tubes of the 1st, 2nd and 3rd generation.

## Claims

### Claim 1

A high speed catadioptric system comprising in the order of the transmission of a regular light ray:
a first single positive lens (L.sub.1);
a main mirror lens (M.sub.1) with an unsilvered central portion;
a counter mirror (M.sub.2);
a convergent lens system (L.sub.2);
a lens (L.sub.3) consisting of the unsilvered central portion of the main mirror (M.sub.1) and
a divergent lens system (L.sub.4), wherein:
the system consisting of said convergent lens system (L.sub.2), said lens (L.sub.3) and said divergent lens system (L.sub.4) is of positive refractive power, and
said first single positive lens (L.sub.1) and said main mirror lens (M.sub.1) consist of the same type of glass.

### Claim 2 (depends on 1)

A high speed catadioptric system according to claim 1, wherein, the entrance pupil diameter EPD and the distance d.sub.2 between said first single positive lens (L.sub.1) and said main mirror lens (M.sub.1) fulfill the following condition:
d.sub.2 <0.55 EPD.

### Claim 3

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.558 s' = 9.722 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 258.418 d.sub.1 = 6 1.54814 45.8 r.sub.2 = -2818.489 d.sub.2 = 43 M.sub.1 r.sub.3 = -140.076 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -220.868 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 38 L.sub.2 r.sub.7 = 39.963 d.sub.7 = 5 1.46450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.84666 23.8 r.sub.10 = -333.333 ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance.

### Claim 4

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.834 s' = 9.855 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 252.742 d.sub.1 = 6 1.54814 45.8 r.sub.2 = -3615.329 d.sub.2 = 43 M.sub.1 r.sub.3 = -140.131 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -222.158 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 38 L.sub.2 r.sub.7 = 40.895 d.sub.7 = 5 1.48450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.59551 39.2 r.sub.10 = - 513.875 ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance.

### Claim 5

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system containing three optical members (L.sub.1 ; L.sub.2,L.sub.3, L.sub.4 ; L.sub.5) and composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.723 s' = 0 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 251.458 d.sub.1 = 7 1.54814 45.8 r.sub.2 = -16077.170 d.sub.2 = 44 M.sub.1 r.sub.3 = -148.447 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -231.310 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 39 L.sub.2 r.sub.7 = 40.614 d.sub.7 = 5 1.48450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.84666 23.8 r.sub.10 = -310.907 d.sub.10 = 6.025 L.sub.5 r.sub.11 = .infin. d.sub.11 = 5.6 1.48748 70.4 r.sub.12 = .infin. ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance and L.sub.5 is a plane plate.

### Claim 6

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, a field lens system (L.sub.2, L.sub.3, L.sub.4) with at least one lens (L.sub.4) immediately adjacent to said central portion (L.sub.3) of the main mirror lens (M.sub.1) on the image side, the component (L.sub.4) on the image side being divergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.558 s' = 9.722 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 258.418 d.sub.1 = 6 1.54814 45.8 r.sub.2 = -2818.489 d.sub.2 = 43 M.sub.1 r.sub.3 = -140.076 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -220.868 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 38 L.sub.2 r.sub.7 = 39.963 d.sub.7 = 5 1.46450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.84666 23.8 r.sub.10 = -333.333 ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance.

### Claim 7

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, a field lens system (L.sub.2, L.sub.3, L.sub.4) with at least one lens (L.sub.4) immediately adjacent to said central portion (L.sub.3) of the main mirror lens (M.sub.1) on the image side, the component (L.sub.4) on the image side being divergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.834 s' = 9.855 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 252.742 d.sub.1 = 6 1.54814 45.8 r.sub.2 = -3615.329 d.sub.2 = 43 M.sub.1 r.sub.3 = -140.131 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -222.158 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 38 L.sub.2 r.sub.7 = 40.895 d.sub.7 = 5 1.48450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.59551 39.2 r.sub.10 = - 513.875 ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance.

### Claim 8

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, a field lens system (L.sub.2, L.sub.3, L.sub.4) with at least one lens (L.sub.4) immediately adjacent to said central portion (L.sub.3) of the main mirror lens (M.sub.1) on the image side, the component (L.sub.4) on the image side being divergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.723 s' = 0 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 251.458 d.sub.1 = 7 1.54814 45.8 r.sub.2 = -16077.170 d.sub.2 = 44 M.sub.1 r.sub.3 = -148.447 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -231.310 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 39 L.sub.2 r.sub.7 = 40.614 d.sub.7 = 5 1.48450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.84666 23.8 r.sub.10 = -310.907 d.sub.10 = 6.025 L.sub.5 r.sub.11 = .infin. d.sub.11 = 5.6 1.48748 70.4 r.sub.12 = .infin. ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance and L.sub.5 is a plane plate.

### Claim 9

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, a field lens system (L.sub.2, L.sub.3, L.sub.4) with at least one lens (L.sub.2) immediately adjacent to said central portion (L.sub.3) of the main mirror lens (M.sub.1) on the object side, the component (L.sub.2) on the object side being convergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.558 s' = 9.722 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 258.418 d.sub.1 = 6 1.54814 45.8 r.sub.2 = -2818.489 d.sub.2 = 43 M.sub.1 r.sub.3 = -140.076 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -220.868 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 38 L.sub.2 r.sub.7 = 39.963 d.sub.7 = 5 1.46450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.84666 23.8 r.sub.10 = -333.333 ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance.

### Claim 10

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, a field lens system (L.sub.2, L.sub.3, L.sub.4) with at least one lens (L.sub.2) immediately adjacent to said central portion (L.sub.3) of the main mirror lens (M.sub.1) on the object side, the component (L.sub.2) on the object side being convergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.834 s' = 9.855 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 252.742 d.sub.1 = 6 1.54814 45.8 r.sub.2 = -3615.329 d.sub.2 = 43 M.sub.1 r.sub.3 = -140.131 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -222.158 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 38 L.sub.2 r.sub.7 = 40.895 d.sub.7 = 5 1.48450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.59551 39.2 r.sub.10 = - 513.875 ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance.

### Claim 11

A high speed catadioptric system with a first single front lens (L.sub.1), a main mirror lens (M.sub.1) with an unsilvered central portion (L.sub.3), a counter mirror (M.sub.2) and a field lens system (L.sub.2, L.sub.3, L.sub.4), comprising a field lens system containing three optical members (L.sub.1 ; L.sub.2,L.sub.3,L.sub.4 ; L.sub.5) and composed of the dioptrically effective central portion (L.sub.3) of the main mirror lens and lenses (L.sub.2, L.sub.4) immediately adjacent to said central portion (L.sub.3) on the object side and on the image side, the field lens system being convergent, a field lens system (L.sub.2, L.sub.3, L.sub.4) with at least one lens (L.sub.2) immediately adjacent to said central portion (L.sub.3) of the main mirror lens (M.sub.1) on the object side, the component (L.sub.2) on the object side being convergent, wherein the elements of the system referred to have the following numerical values:
______________________________________ F = 1:1.2 f = 99.723 s' = 0 Radius Thickness n.sub.d v.sub.d ______________________________________ L.sub.1 r.sub.1 = 251.458 d.sub.1 = 7 1.54814 45.8 r.sub.2 = -16077.170 d.sub.2 = 44 M.sub.1 r.sub.3 = -148.447 d.sub.3 = 8 1.54814 45.8 r.sub.4 = -231.310 d.sub.4 = d.sub.3 1.54814 45.8 r.sub.5 = r.sub.3 d.sub.5 = d.sub.2 M.sub.2 r.sub.6 = r.sub.2 d.sub.6 = 39 L.sub.2 r.sub.7 = 40.614 d.sub.7 = 5 1.48450 67.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 L.sub.3 r.sub.8 = r.sub.3 d.sub.8 = d.sub.3 1.54814 45.8 r.sub.9 = r.sub.4 L.sub.4 r.sub.9 = r.sub.4 d.sub.9 = 2 1.84666 23.8 r.sub.10 = -310.907 d.sub.10 = 6.025 L.sub.5 r.sub.11 = .infin. d.sub.11 = 5.6 1.48748 70.4 r.sub.12 = .infin. ______________________________________
where F is the speed of the system, f is the focal length of the system, s' is the back focal distance and L.sub.5 is a plane plate.