JP2009276386A

JP2009276386A - Relay optical system

Info

Publication number: JP2009276386A
Application number: JP2008124825A
Authority: JP
Inventors: Kokichi Kenno; 孝吉研野
Original assignee: Olympus Corp
Current assignee: Olympus Corp
Priority date: 2008-05-12
Filing date: 2008-05-12
Publication date: 2009-11-26

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small relay optical system which projects a wide field of view, using a simple constitution. <P>SOLUTION: The relay optical system 1 is rotationally symmetric, with respect to the rotational axis and images an object on a physical surface, formed from a flat face onto an image surface formed from a flat surface. The relay optical system 1 includes a front group Gf, a stop S and a back group Gb, in this order starting from the object side. The front group Gf has a front group first reflecting face 22, whose convex face is oriented on the side of the physical surface 3, and a front-group second reflecting face 23. The back group Gb has a rear-group first reflecting face 32, whose convex face is oriented on the side of the image surface 5, and a rear-group second reflecting face 33, and also has a first optical path A for imaging an object around the center axis 2 onto the image surface 5, around the center axis 2 through the front group first and second reflecting faces 22 and 23 and back group first and second reflecting faces 32 and 33, and a second optical path B for imaging an object near the center axis 2 onto the image surface 5 near the center axis 2. The system satisfies the conditional formula (1): 0.8<βt/βr<1.2, where βt is the magnification factor for the first optical path and βr is magnification factor for the second optical path. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は光学系に関し、簡単な構成で物像間距離が短いリレー光学系に関する。 The present invention relates to an optical system, and relates to a relay optical system having a simple configuration and a short distance between object images.

一般に、反射光学系を用いることにより、光路が折り畳まれるため光学系を小型にすることが可能である。特に、望遠鏡等の焦点距離が長く、画角が小さい光学系に対して古くから使われている手段である。しかし、像高を広く取りつつ、物像間距離（全長）の短い光学系は、光路が干渉するため不可能であった。また、凹面鏡を用いたリレー光学系として、特許文献１の光学系が提案されている。
特開２００７−１０５４９号公報 Generally, by using a reflection optical system, the optical path can be folded, so that the optical system can be reduced in size. In particular, it is a means that has been used for a long time for an optical system having a long focal length and a small angle of view, such as a telescope. However, an optical system with a short image-to-object distance (full length) while taking a wide image height is impossible because the optical path interferes. Moreover, the optical system of patent document 1 is proposed as a relay optical system using a concave mirror.
JP 2007-10549 A

しかしながら、小型で広画角なリレー光学系はなかった。 However, there is no small and wide field of view relay optical system.

本発明は、従来技術のこのような状況に鑑みてなされたものであり、その目的は、小型で簡単な構成で広い視野を投影できるリレー光学系を提供することである。 The present invention has been made in view of such a situation in the prior art, and an object thereof is to provide a relay optical system capable of projecting a wide field of view with a small and simple configuration.

上記目的を達成する本発明のリレー光学系は、中心軸に対して回転対称で、平面からなる物体面上の物体を、平面からなる像面上に結像するリレー光学系において、物体側から順に、前群と、開口と、後群と、を備え、前記前群は、物体側に凹面を向けた前群第１反射面と、前群第２反射面とを有し、前記後群は、像面側に凹面を向けた後群第１反射面と、後群第２反射面とを有し、中心軸周辺部分の物体を、前記前群第１反射面、前記前群第２反射面、前記後群第１反射面及び前記後群第２反射面を経て、像面の中心軸周辺部分に結像する第１光路と、中心軸近傍の物体を像面の中心軸近傍に結像する第２光路と、を有し、
以下の条件式（１）を満足することを特徴とする。
０．８＜βｔ／βｒ＜１．２・・・（１）
ただし、βｔは第１光路の倍率、
βｒは第２光路の倍率、
である。 A relay optical system according to the present invention that achieves the above object is a relay optical system that is rotationally symmetric with respect to a central axis and forms an object on a plane object surface on a plane image surface. In order, the front group includes an opening and a rear group, and the front group includes a front group first reflecting surface having a concave surface facing the object side, and a front group second reflecting surface, and the rear group Has a rear group first reflecting surface with a concave surface facing the image surface side, and a rear group second reflecting surface, and an object around a central axis is represented by the front group first reflecting surface and the front group second reflecting surface. A first optical path that forms an image on the periphery of the center axis of the image plane through the reflection surface, the rear group first reflection surface, and the rear group second reflection surface, and an object near the center axis in the vicinity of the center axis of the image plane A second optical path for imaging,
The following conditional expression (1) is satisfied.
0.8 <βt / βr <1.2 (1)
Where βt is the magnification of the first optical path,
βr is the magnification of the second optical path,
It is.

また、前記前群は、前記物体面近傍の前群第１透過面と、前記前群第１透過面より像面側に配置され、物体面側に凹面を向けた前群第１反射面と、前記前群第１反射面より像面と反対側に配置され、物体面側に凹面を向けた前群第２反射面と、前記前群第２反射面より像面側の前記中心軸上に配置された前群第２透過面と、からなる前群透明媒体を有し、前記後群は、前記開口近傍の前記中心軸上に配置された後群第１透過面と、前記後群第１透過面より像面側に配置され、像面側に凹面を向けた後群第１反射面と、前記後群第１反射面より像面と反対側に配置され、像面側に凹面を向けた後群第２反射面と、前記後群第２反射面より像面側に配置された後群第２透過面と、からなる後群透明媒体を有することを特徴とする。 The front group includes a front group first transmission surface in the vicinity of the object surface, a front group first reflection surface that is disposed closer to the image surface side than the front group first transmission surface and has a concave surface facing the object surface side. A front group second reflecting surface disposed on the opposite side of the image plane from the front group first reflecting surface and having a concave surface facing the object plane; and the central axis on the image plane side from the front group second reflecting surface And a rear group first transmission surface disposed on the central axis in the vicinity of the opening, and the rear group. A rear group first reflecting surface disposed on the image plane side from the first transmission surface and having a concave surface directed toward the image plane side, and disposed on a side opposite to the image plane from the rear group first reflecting surface, and is concave on the image plane side. And a rear group second transparent surface disposed on the image plane side with respect to the rear group second reflective surface, and a rear group transparent medium.

また、前記前群透明媒体及び前記後群透明媒体に入射する光束は、順光線追跡の順に、前記前群第１透過面を経て前記前群透明媒体内に入り、前記前群第１反射面で像面と反対側に反射され、前記前群第２反射面で像面側に反射され、前記前群第２透過面を経て前記前群透明媒体から像面側に外へ出る略Ｚ字状の光路と、前記開口を通り、前記後群第１透
過面を経て前記後群透明媒体内に入り、前記後群第１反射面で像面と反対側に反射され、前記後群第２反射面で像面側に反射され、前記後群第２透過面を経て前記後群透明媒体から像面側に外へ出る略Ｚ字状の光路と、からなる前記第１光路を構成し、前記第１光路の少なくとも前記前群第１反射面と前記前群第２反射面の間、及び、少なくとも前記後群第１反射面と前記後群第２反射面の間は、前記中心軸に対して片側のみで構成され、前記第１光路は、前記開口で前記中心軸に対して交差し、中間像が結像されることなく、前記物体面上の物体を前記中心軸と反対側で前記像面に結像することを特徴とする。 The light beams incident on the front group transparent medium and the rear group transparent medium enter the front group transparent medium through the front group first transmission surface in the order of forward ray tracing, and the front group first reflection surface. Is reflected to the opposite side of the image plane, reflected to the image plane side by the front group second reflecting surface, and exits from the front group transparent medium to the image plane side through the front group second transmitting surface. And passes through the opening, enters the rear group transparent medium through the rear group first transmission surface, is reflected by the rear group first reflection surface to the side opposite to the image plane, A substantially Z-shaped optical path that is reflected by the reflecting surface toward the image surface side and exits from the rear group transparent medium to the image surface side through the rear group second transmission surface, and constitutes the first optical path. At least the front group first reflecting surface and the front group second reflecting surface of the first optical path, and at least the rear group first reflecting surface and the rear group second reflecting surface. The first optical path intersects the central axis at the opening, and an object on the object plane is formed without forming an intermediate image. An image is formed on the image plane on the side opposite to the central axis.

また、前記前群第１透過面は、前記前群第２反射面に隣接して配置され、前記後群第１反射面は、前記後群第２透過面に隣接して配置される、ことを特徴とする。 The front group first transmission surface is disposed adjacent to the front group second reflection surface, and the rear group first reflection surface is disposed adjacent to the rear group second transmission surface. It is characterized by.

また、前記前群第１透過面と前記前群第２反射面は、同一位置同一形状からなり、前記後群第１反射面と前記後群第２透過面は、同一位置同一形状からなることを特徴とする。 Further, the front group first transmission surface and the front group second reflection surface have the same shape at the same position, and the rear group first reflection surface and the rear group second transmission surface have the same shape at the same position. It is characterized by.

また、前記前群第１反射面は、前記前群第２透過面に隣接して配置され、前記後群第１透過面は、前記後群第２反射面に隣接して配置される、ことを特徴とする。 The front group first reflecting surface is disposed adjacent to the front group second transmitting surface, and the rear group first transmitting surface is disposed adjacent to the rear group second reflecting surface. It is characterized by.

また、前記前群第１反射面と前記前群第２透過面は、同一位置同一形状からなり、前記後群第１透過面と前記後群第２反射面は、同一位置同一形状からなることを特徴とする。 Further, the front group first reflecting surface and the front group second transmitting surface have the same shape at the same position, and the rear group first transmitting surface and the rear group second reflecting surface have the same shape at the same position. It is characterized by.

また、前記前群透明媒体は、前記物体面側の前記中心軸上に配置された前群第３透過面を有し、前記後群透明媒体は、前記像面側の前記中心軸上に配置された後群第３透過面を有することを特徴とする。 The front group transparent medium includes a front group third transmission surface disposed on the central axis on the object plane side, and the rear group transparent medium is disposed on the central axis on the image plane side. The rear group third transmission surface is provided.

また、前記前群透明媒体及び前記後群透明媒体に入射する光束は、順光線追跡の順に、前記前群第３透過面を経て前記前群透明媒体内に入り、前記前群第２透過面を経て前記前群透明媒体から像面側に外へ出て、前記開口を通り、前記後群第１透過面を経て前記後群透明媒体内に入り、前記後群第３透過面を経て前記後群透明媒体から像面側に外へ出る前記第２光路を構成することを特徴とする。 The light beams incident on the front group transparent medium and the rear group transparent medium enter the front group transparent medium through the front group third transmission surface in the order of forward ray tracing, and the front group second transmission surface. Through the front group transparent medium to the image surface side, through the opening, through the rear group first transmission surface and into the rear group transparent medium, and through the rear group third transmission surface The second optical path that exits from the rear group transparent medium to the image plane side is configured.

また、前記前群第３透過面は、前記前群第１透過面に隣接して配置され、前記後群第３透過面は、前記後群第２透過面に隣接して配置される、ことを特徴とする。 The front group third transmission surface is disposed adjacent to the front group first transmission surface, and the rear group third transmission surface is disposed adjacent to the rear group second transmission surface. It is characterized by.

また、前記前群透明媒体及び前記後群透明媒体に入射する光束は、順光線追跡の順に、前記前群第３透過面を経て前記前群透明媒体内に入り、前記前群第２透過面を経て前記前群透明媒体から像面側に外へ出る光路と、前記開口を通り、前記後群第１透過面を経て前記後群後群透明媒体内に入り、前記後群第１反射面で像面と反対側に反射され、前記後群第２反射面で像面側に反射され、前記後群第２透過面を経て前記後群透明媒体から像面側に外へ出る略Ｚ字状の光路と、からなる前記第３光路と、前記前群第１透過面を経て前記前群前群透明媒体内に入り、前記前群第１反射面で像面と反対側に反射され、前記前群第２反射面で像面側に反射され、前記前群第２透過面を経て前記前群透明媒体から像面側に外へ出る略Ｚ字状の光路と、前記開口を通り、前記後群第１透過面を経て前記後群透明媒体内に入り、前記後群第３透過面を経て前記後群透明媒体から像面側に外へ出る光路と、からなる第４光路と、を有することを特徴とする。 The light beams incident on the front group transparent medium and the rear group transparent medium enter the front group transparent medium through the front group third transmission surface in the order of forward ray tracing, and the front group second transmission surface. An optical path that exits from the front group transparent medium to the image surface side through the opening, enters the rear group rear group transparent medium through the rear group first transmission surface, and the rear group first reflection surface. Is substantially reflected by the rear group second reflecting surface, reflected by the rear group second reflecting surface, and exits from the rear group transparent medium to the image surface side through the rear group second transmitting surface. And enters the front group front group transparent medium through the front group first transmission surface and reflected by the front group first reflection surface to the opposite side to the image plane, A substantially Z-shaped optical path reflected by the front group second reflecting surface toward the image surface side and going out from the front group transparent medium to the image surface side through the front group second transmitting surface; An optical path that passes through the aperture, enters the rear group transparent medium through the rear group first transmission surface, and exits from the rear group transparent medium to the image plane side through the rear group third transmission surface. And four optical paths.

また、以下の条件式（２）を満足することを特徴とする。
０．９＜βｔｒ／βｒｔ＜１．１・・・（２）
ただし、βｔｒは第３光路の投影倍率、
βｒｔは第４光路の投影倍率、
である。 Moreover, the following conditional expression (2) is satisfied.
0.9 <βtr / βrt <1.1 (2)
Where βtr is the projection magnification of the third optical path,
βrt is the projection magnification of the fourth optical path,
It is.

また、前記前群透明媒体及び前記後群透明媒体の屈折率は、１．６以上であることを特徴とする。 The refractive index of the front group transparent medium and the rear group transparent medium is 1.6 or more.

また、以下の条件式（３）を満足することを特徴とする。
１．０＜Ｄ／（２×Ｉmax）＜１．８・・・（３）
ただし、Ｉmaxは最大像高、
Ｄは透明媒体の外径、
である。 Moreover, the following conditional expression (3) is satisfied.
1.0 <D / (2 × Imax) <1.8 (3)
Where Imax is the maximum image height,
D is the outer diameter of the transparent medium,
It is.

また、以下の条件式（４）を満足することを特徴とする。
１．２＜Ｌ／（２×Ｉmax）＜２．０・・・（４）
ただし、Ｉmaxは最大像高、
Ｌは物体面から像面までの距離、
である。 Moreover, the following conditional expression (4) is satisfied.
1.2 <L / (2 × Imax) <2.0 (4)
Where Imax is the maximum image height,
L is the distance from the object plane to the image plane,
It is.

また、以下の条件式（５）及び条件式（６）を満足することを特徴とする。
１．０＜Ｆｒ１／Ｆｒ２＜１．８・・・（５）
１．０＜Ｒｒ２／Ｒｒ１＜１．８・・・（６）
ただし、Ｆｒ１は前群第１反射面の曲率、
Ｆｒ１は前群第２反射面の曲率、
Ｒｒ１は後群第１反射面の曲率、
Ｒｒ２は後群第２反射面の曲率、
である。 Further, the following conditional expression (5) and conditional expression (6) are satisfied.
1.0 <Fr1 / Fr2 <1.8 (5)
1.0 <Rr2 / Rr1 <1.8 (6)
Where Fr1 is the curvature of the first reflecting surface of the front group,
Fr1 is the curvature of the second reflecting surface of the front group,
Rr1 is the curvature of the first reflecting surface of the rear group,
Rr2 is the curvature of the rear second reflective surface,
It is.

以上の本発明の光学系においては、簡単な構成により、短い物像間距離で、広い観察視野を確保するリレー光学系を得ることができる。 In the above optical system of the present invention, a relay optical system that secures a wide observation field with a short distance between object images can be obtained with a simple configuration.

以下、実施例に基づいて本発明の光学系について説明する。 The optical system of the present invention will be described below based on examples.

図１は、実施例１のリレー光学系１の中心軸（回転対称軸）２に沿ってとった断面図である。 FIG. 1 is a cross-sectional view taken along the central axis (rotation symmetry axis) 2 of the relay optical system 1 of the first embodiment.

実施例１のリレー光学系１は、中心軸２に対して回転対称で、平面からなる物体面３上の物体を、平面からなる像面５上に結像するリレー光学系１において、物体側から順に、前群Ｇｆと、開口Ｓと、後群Ｇｂと、を備え、前群Ｇｆは、物体側に凹面を向けた前群第１反射面２２と、前群第２反射面２３とを有し、後群Ｇｂは、像側に凹面を向けた後群第１反射面３２と、後群第２反射面３３とを有し、中心軸２周辺部分の物体を、前群第１反射面２２、前群第２反射面２３、後群第１反射面３２及び後群第２反射面３３を経て、像面５の中心軸周辺部分に結像する第１光路Ａと、中心軸２近傍の物体を像面５の中心軸２近傍に結像する第２光路Ｂと、を有し、
以下の条件式（１）を満足することが重要である。
０．８＜βｔ／βｒ＜１．２・・・（１）
ただし、βｔは第１光路の倍率、
βｒは第２光路の倍率、
である。 The relay optical system 1 according to the first embodiment is rotationally symmetric with respect to a central axis 2, and in the relay optical system 1 that forms an object on a plane object plane 3 on a plane image plane 5, the object side The front group Gf includes, in order, a front group Gf, an opening S, and a rear group Gb. The front group Gf includes a front group first reflecting surface 22 with a concave surface facing the object side, and a front group second reflecting surface 23. The rear group Gb includes a rear group first reflecting surface 32 having a concave surface directed toward the image side, and a rear group second reflecting surface 33, and an object in the vicinity of the central axis 2 is subjected to front group first reflection. A first optical path A that forms an image on the periphery of the central axis of the image plane 5 through the surface 22, the front group second reflecting surface 23, the rear group first reflecting surface 32, and the rear group second reflecting surface 33; A second optical path B for imaging a nearby object in the vicinity of the central axis 2 of the image plane 5,
It is important to satisfy the following conditional expression (1).
0.8 <βt / βr <1.2 (1)
Where βt is the magnification of the first optical path,
βr is the magnification of the second optical path,
It is.

反射光路からなる第１光路Ａを用いることによりリレー光学系１を小型にすることが可
能となるが、反射面で光路が遮蔽される為、中心付近の物体を結像することが不可能となってしまう。そこで、本発明は中心付近を別な透過光路からなる第２光路Ｂを形成することにより、広い視野を短い物像間距離で連続的にリレーすることを可能にしたものである。 Although the relay optical system 1 can be reduced in size by using the first optical path A composed of the reflected optical path, it is impossible to image an object near the center because the optical path is shielded by the reflecting surface. turn into. Therefore, the present invention makes it possible to continuously relay a wide field of view with a short distance between object images by forming a second optical path B composed of another transmission optical path near the center.

また、前群第１反射面２２と前群第２反射面２３は物体面３側に凹面を向け、後群第１反射面３２と後群第２反射面３３は像面５側に凹面を向けていることが重要である。この配置により物体側から光路順に、前群Ｇｆでは正−負、後群Ｇｂでは負−正のパワー配置になり、所謂レトロフォーカス構成にすることが可能となり、焦点距離を短くして、広画角な結像が可能となったものである。 The front group first reflecting surface 22 and the front group second reflecting surface 23 have a concave surface facing the object surface 3, and the rear group first reflecting surface 32 and the rear group second reflecting surface 33 have a concave surface on the image surface 5 side. It is important to point. With this arrangement, the front group Gf has a positive-negative power arrangement and the rear group Gb has a negative-positive power arrangement in order of the optical path from the object side. Angular imaging is now possible.

また、この配置によりリレー光学系１の主点を前群Ｇｆでは物体面３側、後群Ｇｂでは像面５側に配置することが可能となり、Ｆバックを取ることが可能となる。 Also, with this arrangement, the principal point of the relay optical system 1 can be arranged on the object plane 3 side in the front group Gf and on the image plane 5 side in the rear group Gb, and F-back can be taken.

２つの光路Ａ，Ｂにより一つの物体像をリレーして像を形成するとき、条件式（１）を満足するように構成することにより、２つの光路Ａ，Ｂの映像を滑らかに繋げることが可能となる。 When an image is formed by relaying one object image through the two optical paths A and B, it is possible to smoothly connect the images of the two optical paths A and B by configuring so as to satisfy the conditional expression (1). It becomes possible.

さらに、
０．９＜βｔ／βｒ＜１．１・・・（１’）
なる条件式を満足することが好ましい。 further,
0.9 <βt / βr <1.1 (1 ′)
It is preferable to satisfy the following conditional expression:

また、像高と物体高は本発明では主光線高を用いているが、スポットダイヤグラムの重心を用いても良い。 In the present invention, the principal ray height is used for the image height and the object height, but the center of gravity of the spot diagram may be used.

さらに、
０．９５＜βｔ／βｒ＜１．０５・・・（１’’）
なる条件式を満足することがより好ましい。 further,
0.95 <βt / βr <1.05 (1 ″)
It is more preferable that the following conditional expression is satisfied.

また、前群Ｇｆは、物体面３近傍の前群第１透過面２１と、前群第１透過面２１より像面５側に配置され、物体面３側に凹面を向けた前群第１反射面２２と、前群第１反射面２２より像面５と反対側に配置され、物体面３側に凹面を向けた前群第２反射面２３と、前群第２反射面２３より像面５側の中心軸２上に配置された前群第２透過面２４と、からなる前群透明媒体Ｌｆを有し、後群Ｇｂは、開口Ｓ近傍の中心軸２上に配置された後群第１透過面３１と、後群第１透過面３１より像面５側に配置され、像面５側に凹面を向けた後群第１反射面３２と、後群第１反射面３２より像面５と反対側に配置され、像面５側に凹面を向けた後群第２反射面３３と、後群第２反射面３３より像面５側に配置された後群第２透過面３４と、からなる後群透明媒体Ｌｂを有することが重要である。 The front group Gf is a front group first transmission surface 21 in the vicinity of the object plane 3 and the front group first transmission surface 21 that is disposed closer to the image plane 5 than the front group first transmission surface 21 and has a concave surface facing the object plane 3 side. Reflecting surface 22, front group second reflecting surface 23 disposed on the opposite side of image surface 5 from front group first reflecting surface 22, with the concave surface facing object surface 3, and image from front group second reflecting surface 23. A front group transparent medium Lf including a front group second transmission surface 24 disposed on the central axis 2 on the surface 5 side, and the rear group Gb is disposed on the central axis 2 near the opening S From the group first transmission surface 31, the rear group first reflection surface 32 disposed on the image plane 5 side of the rear group first transmission surface 31, with the concave surface facing the image surface 5 side, and the rear group first reflection surface 32. Rear group second reflecting surface 33 disposed on the side opposite to image surface 5 and having a concave surface facing image surface 5, and rear group second transmitting surface disposed on image surface 5 side from rear group second reflecting surface 33 34 and the rear group It is important to have a bright medium Lb.

開口Ｓを挟んで、前群Ｇｆと後群Ｇｂに正のパワーを有する光学系を配置することにより、主光線頃角を小さくすることが可能となり、両テレセントリックな光学系にすることが可能となる。前群Ｇｆ及び後群Ｇｂ共に、透過面―反射面―反射面―透過面の構成にすることにより、反射面を内部反射面で構成することが可能となり、組立が容易になると同時に媒質の屈折率により、反射面で発生する収差を少なくすることが可能となる。 By arranging an optical system having positive power in the front group Gf and the rear group Gb across the aperture S, it becomes possible to reduce the angle of the chief ray and to make it a bi-telecentric optical system. Become. By configuring the front group Gf and the rear group Gb to be a transmission surface-reflection surface-reflection surface-transmission surface, the reflection surface can be configured as an internal reflection surface, which facilitates assembly and at the same time refracts the medium. Depending on the ratio, it is possible to reduce the aberration generated on the reflecting surface.

また、前群透明媒体Ｌｆ及び後群透明媒体Ｌｂに入射する光束は、順光線追跡の順に、前群第１透過面２１を経て前群透明媒体Ｌｆ内に入り、前群第１反射面２２で像面５と反対側に反射され、前群第２反射面２３で像面５側に反射され、前群第２透過面２４を経て前群透明媒体Ｌｆから像面５側に外へ出る略Ｚ字状の光路と、開口Ｓを通り、後群第１透過面３１を経て後群透明媒体Ｌｂ内に入り、後群第１反射面３２で像面５と反対側に反射
され、後群第２反射面３３で像面５側に反射され、後群第２透過面３４を経て後群透明媒体Ｌｂから像面５側に外へ出る略Ｚ字状の光路と、からなる第１光路Ａを構成し、第１光路Ａの少なくとも前群第１反射面２２と前群第２反射面２３の間、及び、少なくとも後群第１反射面３２と後群第２反射面３３の間は、中心軸２に対して片側のみで構成され、第１光路Ａは、開口Ｓで中心軸２に対して交差し、中間像が結像されることなく、物体面３上の物体を中心軸２と反対側で像面５に結像することが重要である。 The light beams incident on the front group transparent medium Lf and the rear group transparent medium Lb enter the front group transparent medium Lf through the front group first transmission surface 21 in the order of forward ray tracing, and enter the front group first reflection surface 22. Is reflected to the side opposite to the image plane 5, reflected to the image plane 5 side by the front group second reflecting surface 23, and exits from the front group transparent medium Lf to the image plane 5 side through the front group second transmitting surface 24. It passes through the substantially Z-shaped optical path and the opening S, enters the rear group transparent medium Lb through the rear group first transmission surface 31, is reflected by the rear group first reflection surface 32 on the side opposite to the image plane 5, and A substantially Z-shaped optical path which is reflected by the group second reflecting surface 33 toward the image surface 5 side and exits from the rear group transparent medium Lb to the image surface 5 side through the rear group second transmitting surface 34. An optical path A is configured, and at least between the front group first reflecting surface 22 and the front group second reflecting surface 23 in the first optical path A, and at least the rear group first reflecting surface 32 and the rear group second reflecting. 33 is configured only on one side with respect to the central axis 2, and the first optical path A intersects the central axis 2 at the opening S, and an intermediate image is not formed on the object plane 3. It is important to image the object on the image plane 5 on the side opposite to the central axis 2.

Ｚ字光路をとることにより、各面での反射角を小さくすることが可能となり、収差の発生を少なくすることが可能となる。また、光路的に近い前群第２反射面２３と後群第１反射面３２は、入射する光束が比較的低い（光軸に近い）所で反射面に当り反射されるため、反射面に強い負のパワーを持たせても、収差の発生を少なくすることが可能となる。 By taking the Z-shaped optical path, it is possible to reduce the reflection angle on each surface and reduce the occurrence of aberrations. In addition, the front group second reflecting surface 23 and the rear group first reflecting surface 32 that are close to each other in the optical path are reflected on the reflecting surface at a relatively low incident light beam (close to the optical axis). Even with strong negative power, the occurrence of aberration can be reduced.

また、中心軸２と光路が交差することは、少なくともサジタル断面で中間結像をすることを意味し、光路長が長くなってしまい、光学系の大型化を招いてしまう。 Further, the intersection of the central axis 2 and the optical path means that an intermediate image is formed at least in a sagittal section, and the optical path length becomes long, leading to an increase in the size of the optical system.

さらに、光路途中で結像させると、光学系の外径を小さくすることが可能であるが、中間像を形成すると光学系の全長が長く（光軸方向）なってしまい、光学系を小型にすることが不可能になってしまう。 Furthermore, if the image is formed in the middle of the optical path, the outer diameter of the optical system can be reduced. However, if the intermediate image is formed, the total length of the optical system becomes long (in the optical axis direction), and the optical system becomes smaller. It becomes impossible to do.

また、前群第１透過面２１は、前群第２反射面２３に隣接して配置され、後群第１反射面３２は、後群第２透過面３４に隣接して配置される、ことが重要である。 The front group first transmission surface 21 is disposed adjacent to the front group second reflection surface 23, and the rear group first reflection surface 32 is disposed adjacent to the rear group second transmission surface 34. is important.

このように配置することにより、反射光路と透過光路の光線の干渉を小さくすることが可能となる。 By arranging in this way, it becomes possible to reduce the interference of light rays in the reflected light path and the transmitted light path.

また、前群第１透過面２１と前群第２反射面２３は、同一位置同一形状からなり、後群第１反射面３２と後群第２透過面３４は、同一位置同一形状からなることが重要である。 Further, the front group first transmission surface 21 and the front group second reflection surface 23 have the same shape at the same position, and the rear group first reflection surface 32 and the rear group second transmission surface 34 have the same shape at the same position. is important.

このように配置することにより、前群第１透過面２１と前群第２反射面２３の使用領域及び後群第１反射面３２と後群第２透過面３４の使用領域をオーバーラップさせることが可能となり、より広画角な結像が可能となる。また、製作が容易になり、低コスト化が可能となる。 By arranging in this way, the use area of the front group first transmission surface 21 and the front group second reflection surface 23 and the use area of the rear group first reflection surface 32 and the rear group second transmission surface 34 are overlapped. Image formation with a wider field angle becomes possible. Further, the manufacturing becomes easy and the cost can be reduced.

また、前群第１反射面２２は、前群第２透過面２４に隣接して配置され、後群第１透過面３１は、後群第２反射面３３に隣接して配置される、ことを特徴とする。 Further, the front group first reflection surface 22 is disposed adjacent to the front group second transmission surface 24, and the rear group first transmission surface 31 is disposed adjacent to the rear group second reflection surface 33. It is characterized by.

また、前群第１反射面２２と前群第２透過面２４は、同一位置同一形状からなり、後群第１透過面３１と後群第２反射面３３は、同一位置同一形状からなることを特徴とする。 Further, the front group first reflecting surface 22 and the front group second transmitting surface 24 have the same shape at the same position, and the rear group first transmitting surface 31 and the rear group second reflecting surface 33 have the same shape at the same position. It is characterized by.

このように配置することにより、製作が容易になり、低コスト化が可能となる。 By arranging in this way, the manufacturing becomes easy and the cost can be reduced.

また、前群透明媒体Ｌｆは、物体面３側の中心軸２上に配置された前群第３透過面２５を有し、後群透明媒体Ｌｂは、像面５側の中心軸２上に配置された後群第３透過面３５を有することが重要である。 The front group transparent medium Lf has a front group third transmission surface 25 arranged on the central axis 2 on the object plane 3 side, and the rear group transparent medium Lb is on the central axis 2 on the image plane 5 side. It is important to have the rear group third transmission surface 35 arranged.

前群第３透過面２５及び後群第３透過面３５を配置することにより、両光路Ａ，Ｂの像を滑らかに連続させることが可能となる。 By disposing the front group third transmission surface 25 and the rear group third transmission surface 35, the images of both optical paths A and B can be smoothly continued.

また、前群透明媒体Ｌｆ及び後群透明媒体Ｌｂに入射する光束は、順光線追跡の順に、前群第３透過面２５を経て前群透明媒体Ｌｆ内に入り、前群第２透過面２４を経て前群透明媒体Ｌｆから像面５側に外へ出て、開口Ｓを通り、後群第１透過面３１を経て後群透明媒体Ｌｂ内に入り、後群第３透過面３５を経て後群透明媒体Ｌｂから像面５側に外へ出る第２光路Ｂを構成することが重要である。 The light beams incident on the front group transparent medium Lf and the rear group transparent medium Lb enter the front group transparent medium Lf via the front group third transmission surface 25 in the order of forward ray tracing, and enter the front group second transmission surface 24. After passing through the front group transparent medium Lf to the image surface 5 side, passes through the opening S, passes through the rear group first transmission surface 31, enters the rear group transparent medium Lb, and passes through the rear group third transmission surface 35. It is important to configure the second optical path B that exits from the rear group transparent medium Lb to the image plane 5 side.

中心付近から広画角で連続な結像が可能となる。 Continuous imaging with a wide angle of view from near the center is possible.

また、前群第３透過面２５は、前群第１透過面２１に隣接して配置され、後群第３透過面３５は、後群第２透過面３４に隣接して配置される、ことが重要である。 The front group third transmission surface 25 is disposed adjacent to the front group first transmission surface 21, and the rear group third transmission surface 35 is disposed adjacent to the rear group second transmission surface 34. is important.

前群第３透過面２５を前群第１透過面２１に隣接して配置し、後群第３透過面３５を後群第２透過面３４に隣接して配置することにより、第２光路Ｂと第１光路Ａの干渉を最小にすることが可能となり、両光路Ａ，Ｂの像をさらに滑らかに連続させることが可能となる。 By arranging the front group third transmission surface 25 adjacent to the front group first transmission surface 21 and the rear group third transmission surface 35 adjacent to the rear group second transmission surface 34, the second optical path B Thus, the interference between the first optical path A and the first optical path A can be minimized, and the images of both the optical paths A and B can be more smoothly continued.

また、前群透明媒体Ｌｆ及び後群透明媒体Ｌｂに入射する光束は、順光線追跡の順に、前群第３透過面２５を経て前群透明媒体Ｌｆ内に入り、前群第２透過面２４を経て前群透明媒体Ｌｆから像面５側に外へ出る光路と、開口Ｓを通り、後群第１透過面３１を経て後群後群透明媒体Ｌｂ内に入り、後群第１反射面３２で像面５と反対側に反射され、後群第２反射面３３で像面５側に反射され、後群第２透過面３４を経て後群透明媒体Ｌｂから像面５側に外へ出る略Ｚ字状の光路と、からなる前記第３光路Ｃと、前群第１透過面２１を経て前群前群透明媒体Ｌｆ内に入り、前群第１反射面２２で像面５と反対側に反射され、前群第２反射面２３で像面５側に反射され、前群第２透過面２４を経て前群透明媒体Ｌｆから像面５側に外へ出る略Ｚ字状の光路と、開口Ｓを通り、後群第１透過面３１を経て後群透明媒体Ｌｂ内に入り、後群第３透過面３５を経て後群透明媒体Ｌｂから像面５側に外へ出る光路と、からなる第４光路Ｄと、を有することが重要である。 The light beams incident on the front group transparent medium Lf and the rear group transparent medium Lb enter the front group transparent medium Lf via the front group third transmission surface 25 in the order of forward ray tracing, and enter the front group second transmission surface 24. And the light path exiting from the front group transparent medium Lf to the image plane 5 side, the aperture S, the rear group first transmission surface 31, the rear group rear group transparent medium Lb, and the rear group first reflection surface. 32 is reflected to the side opposite to the image surface 5, reflected to the image surface 5 side by the rear group second reflecting surface 33, and then passes from the rear group transparent medium Lb to the image surface 5 side through the rear group second transmitting surface 34. A substantially Z-shaped optical path that exits and enters the front group front group transparent medium Lf via the front group first transmission surface 21 and the front group first reflection surface 22 and the image plane 5. Reflected to the opposite side, reflected to the image surface 5 side by the front group second reflecting surface 23, and exits from the front group transparent medium Lf to the image surface 5 side through the front group second transmitting surface 24. And enters the rear group transparent medium Lb through the rear group first transmission surface 31 and exits from the rear group transparent medium Lb to the image plane 5 side through the rear group third transmission surface 35. It is important to have a fourth optical path D consisting of an optical path.

光路が中心軸２を交差する切り替え部としての開口Ｓを介して、透過光路と反射光路を通過する第３光路Ｃ及び第４光路Ｄを有するように光学系を構成することにより、光軸から物体高が増すにつれて、透過光路、光路切り替え部、反射光路と滑らかに光路が変化することにより連続した像を形成することが可能となる。 By configuring the optical system so that the optical path has a third optical path C and a fourth optical path D that pass through the transmitted optical path and the reflected optical path via the opening S as a switching portion where the optical path intersects the central axis 2, As the object height increases, a continuous image can be formed by smoothly changing the optical path from the transmitted optical path, the optical path switching unit, and the reflected optical path.

また、以下の条件式（２）を満足することが重要である。
０．９＜βｔｒ／βｒｔ＜１．１・・・（２）
ただし、βｔｒは第３光路の投影倍率、
βｒｔは第４光路の投影倍率、
である。 Moreover, it is important to satisfy the following conditional expression (2).
0.9 <βtr / βrt <1.1 (2)
Where βtr is the projection magnification of the third optical path,
βrt is the projection magnification of the fourth optical path,
It is.

第３光路Ｃ及び第４光路Ｄの映像をより滑らかにつなげることが可能となる。 It becomes possible to connect the images of the third optical path C and the fourth optical path D more smoothly.

さらに、
０．９３＜βｔｒ／βｒｔ＜１．０５・・・（２’）
なる条件式を満足することが好ましい。 further,
0.93 <βtr / βrt <1.05 (2 ′)
It is preferable to satisfy the following conditional expression:

さらに、
０．９８＜βｔｒ／βｒｔ＜１．０３・・・（２’’）
なる条件式を満足することがより好ましい。 further,
0.98 <βtr / βrt <1.03 (2 ″)
It is more preferable that the following conditional expression is satisfied.

また、前群透明媒体Ｌｆ及び後群透明媒体Ｌｂの屈折率は、１．６以上であることが重要である。 Further, it is important that the refractive indexes of the front group transparent medium Lf and the rear group transparent medium Lb are 1.6 or more.

前群第２反射面２３及び後群第１反射面３２での臨界角を小さくすることが可能となり、前群第２反射面２３及び後群第１反射面３２での反射コーティングを行う領域が小さく出来る。これにより、第２光路Ｂの画角を小さくすることが可能となり。第２光路Ｂで発生しやすい像面湾曲の収差を小さく抑えることが可能となる。さらに好ましく、屈折率は１．７以上であることが望ましい。 It is possible to reduce the critical angle at the front group second reflecting surface 23 and the rear group first reflecting surface 32, and there is an area for performing reflective coating on the front group second reflecting surface 23 and the rear group first reflecting surface 32. Can be small. As a result, the angle of view of the second optical path B can be reduced. It is possible to suppress aberrations in field curvature that are likely to occur in the second optical path B. More preferably, the refractive index is 1.7 or more.

また、以下の条件式（３）を満足することが重要である。
１．０＜Ｄ／（２×Ｉmax）＜１．８・・・（３）
ただし、Ｉmaxは最大像高、
Ｄは光学系の外径、
である。 Moreover, it is important to satisfy the following conditional expression (3).
1.0 <D / (2 × Imax) <1.8 (3)
Where Imax is the maximum image height,
D is the outer diameter of the optical system,
It is.

条件式（３）の下限の１．０を下回ると、反射光路における反射面において臨界角を超える角度で光線を入射させることができなくなるので、透過光路の物体高を高くする必要があり、収差発生が多く、鮮明な映像を得ることできなくなる。条件式（３）の上限の１．８を上回ると、光学系１の外径が大きくなりすぎ光学系１が大型し、小型の光学系を得ることができない。 If the lower limit of 1.0 of the conditional expression (3) is not reached, it becomes impossible to make a light beam incident at an angle exceeding the critical angle on the reflecting surface in the reflected light path, so it is necessary to increase the object height of the transmitted light path, and aberrations. There are many occurrences, and it becomes impossible to obtain clear images. When the upper limit of 1.8 of conditional expression (3) is exceeded, the outer diameter of the optical system 1 becomes too large, the optical system 1 becomes large, and a small optical system cannot be obtained.

また、以下の条件式（４）を満足することが重要である。
１．２＜Ｌ／（２×Ｉmax）＜２．０・・・（４）
ただし、Ｉmaxは最大像高、
Ｌは開口から像面までの距離、
である。 Moreover, it is important to satisfy the following conditional expression (4).
1.2 <L / (2 × Imax) <2.0 (4)
Where Imax is the maximum image height,
L is the distance from the aperture to the image plane,
It is.

条件式（４）は、像高に対する光学系全長を規定するものである。条件式（４）の下限の１．２を下回ると、最も物体側又は像面側の透過面の負のパワーが強くなりすぎ、視野周辺の収差発生が大きくなり鮮明な映像を得られなくなる。条件式（４）の上限の２．０を上回ると、光学系全長が長くなってしまい、光学系が光軸方向に大型化してしまう。 Conditional expression (4) defines the total length of the optical system with respect to the image height. If the lower limit of 1.2 of the conditional expression (4) is not reached, the negative power of the transmission surface closest to the object side or the image surface side becomes too strong, and aberrations in the periphery of the field of view increase and a clear image cannot be obtained. If the upper limit of 2.0 of conditional expression (4) is exceeded, the total length of the optical system becomes long, and the optical system becomes large in the optical axis direction.

また、以下の条件式（５）及び条件式（６）を満足することが重要である。
１．０＜Ｆｒ１／Ｆｒ２＜１．８・・・（５）
１．０＜Ｒｒ２／Ｒｒ１＜１．８・・・（６）
ただし、Ｆｒ１は前群第１反射面の曲率、
Ｆｒ１は前群第２反射面の曲率、
Ｒｒ１は後群第１反射面の曲率、
Ｒｒ２は後群第２反射面の曲率、
である。 Moreover, it is important to satisfy the following conditional expressions (5) and (6).
1.0 <Fr1 / Fr2 <1.8 (5)
1.0 <Rr2 / Rr1 <1.8 (6)
Where Fr1 is the curvature of the first reflecting surface of the front group,
Fr1 is the curvature of the second reflecting surface of the front group,
Rr1 is the curvature of the first reflecting surface of the rear group,
Rr2 is the curvature of the rear second reflective surface,
It is.

条件式（５）及び条件式（６）は、二つの反射面のパワーの比を規定しているものである。条件式（５）及び条件式（６）の下限の１．０を下回ると、正のパワーを有する反射面の曲率半径が小さくなり、正のパワーを有する反射面の正のパワーに比べて、負のパワーを有する反射面の負のパワーが大きくなり光学系の全長を短くすることが出来ない。条件式（５）及び条件式（６）の上限の１．８を上回ると、負のパワーを有する反射面の曲率が小さくなり正のパワーを有する反射面の正のパワーが大きくなりすぎ、物体側に凸の像面湾曲が大きく発生する。 Conditional expression (5) and conditional expression (6) define the ratio of the power of the two reflecting surfaces. When the lower limit of 1.0 of the conditional expression (5) and the conditional expression (6) is below 1.0, the radius of curvature of the reflecting surface having a positive power becomes smaller, compared to the positive power of the reflecting surface having a positive power, The negative power of the reflecting surface having negative power is increased, and the total length of the optical system cannot be shortened. If the upper limit of 1.8 of conditional expression (5) and conditional expression (6) is exceeded, the curvature of the reflecting surface having negative power becomes small and the positive power of the reflecting surface having positive power becomes too large, and the object A large curvature of field on the side occurs.

以下に、本発明の光学系の実施例１及び実施例２を説明する。これら光学系の構成パラ
メータは後記する。 Examples 1 and 2 of the optical system according to the present invention will be described below. The configuration parameters of these optical systems will be described later.

また、各実施例の光学系を構成する光学作用面の中、特定の面とそれに続く面が共軸光学系を構成する場合には面間隔が与えられており、その他、面の曲率半径、媒質の屈折率、アッベ数が慣用法に従って与えられている。 Further, among the optical action surfaces constituting the optical system of each embodiment, when a specific surface and a subsequent surface constitute a coaxial optical system, a surface interval is given, in addition, the curvature radius of the surface, The refractive index and Abbe number of the medium are given according to conventional methods.

また、後記の構成パラメータ中にデータの記載されていない非球面に関する項は０である。屈折率、アッベ数については、ｄ線（波長５８７．５６ｎｍ）に対するものを表記してある。長さの単位はｍｍである。 In addition, a term relating to an aspheric surface for which no data is described in the constituent parameters described later is zero. About a refractive index and an Abbe number, the thing with respect to d line (wavelength 587.56nm) is described. The unit of length is mm.

なお、非球面は、以下の定義式で与えられる回転対称非球面である。
Ｚ＝（Ｙ²／Ｒ）／［１＋｛１−（１＋ｋ）Ｙ²／Ｒ²｝^{1 /2}］
＋ａＹ⁴＋ｂＹ⁶＋ｃＹ⁸＋ｄＹ¹⁰＋・・・
・・・（ａ）
ただし、Ｚを中心軸とし、Ｙを中心軸と垂直な方向にとる。ここで、Ｒは近軸曲率半径、ｋは円錐定数、ａ、ｂ、ｃ、ｄ、…はそれぞれ４次、６次、８次、１０次の非球面係数である。この定義式のＺ軸が回転対称非球面の軸となる。 The aspheric surface is a rotationally symmetric aspheric surface given by the following definition.
^{Z = (Y 2 / R)} / [1+ {1- (1 + k) Y 2 / R 2} 1/2]
+ AY ⁴ + bY ⁶ + cY ⁸ + dY ¹⁰ +...
... (a)
However, Z is the central axis, and Y is the direction perpendicular to the central axis. Here, R is a paraxial radius of curvature, k is a conic constant, a, b, c, d,... Are fourth-order, sixth-order, eighth-order, and tenth-order aspherical coefficients, respectively. The Z axis of this defining formula is the axis of a rotationally symmetric aspherical surface.

実施例１のリレー光学系１の中心軸２に沿ってとった断面図を図１、第３光路Ｃ及び第４光路Ｄを示す図を図２に示す。また、この実施例の光学系の第１光路Ａの横収差図を図３、第２光路Ｂの横収差図を図４に示す。 FIG. 1 shows a cross-sectional view taken along the central axis 2 of the relay optical system 1 of Example 1, and FIG. 2 shows a diagram showing the third optical path C and the fourth optical path D. FIG. 3 shows a lateral aberration diagram of the first optical path A and FIG. 4 shows a lateral aberration diagram of the second optical path B of the optical system of this example.

リレー光学系１は、中心軸２に同軸に配置された開口Ｓを有する遮光部材Ｓ１と、この開口Ｓの物体面３側に配置された前群Ｇｆと、開口Ｓの像面５側に配置された後群Ｇｂと、からなり、前群Ｇｆは、前群カバーガラスＣｆと、前群透明媒体Ｌｆと、後群Ｇｂは、後群透明媒体Ｌｂと、後群カバーガラスＣｂとからなる。 The relay optical system 1 includes a light shielding member S1 having an opening S arranged coaxially with a central axis 2, a front group Gf arranged on the object plane 3 side of the opening S, and an image plane 5 side of the opening S. The rear group Gb includes the front group cover glass Cf, the front group transparent medium Lf, and the rear group Gb includes the rear group transparent medium Lb and the rear group cover glass Cb.

前群カバーガラスＣｆは、中心軸２の周りで回転対称な屈折率が１より大きい平行平板からなり、前群カバーガラス第１透過面１１と、前群カバーガラス第１透過面１１に対して像側に形成される前群カバーガラス第２透過面１２とを有する。 The front group cover glass Cf is composed of parallel flat plates having a rotational symmetry around the central axis 2 and a refractive index larger than 1. The front group cover glass first transmission surface 11 and the front group cover glass first transmission surface 11 And a front group cover glass second transmission surface 12 formed on the image side.

前群透明媒体Ｌｆは、中心軸２の周りで回転対称であり、屈折率が１より大きく、中心軸２周辺部分で負のパワーをもつ非球面からなる前群第１透過面としての前群透明媒体第１透過面２１と、前群透明媒体第１透過面２１に対して像面５側に形成され、一部を反射コーティング４ａされ、正のパワーをもつ非球面からなる第１反射面としての前群透明媒体第１反射面２２と、前群透明媒体第１反射面２２に対して像面５と反対側に配置され、反射コーティング４ｂされ、負のパワーをもつ非球面からなる第２反射面としての前群透明媒体第２反射面２３と、前群透明媒体第２反射面２３より像面５側に配置され、正のパワーをもつ非球面からなり、前群透明媒体第１反射面２２と同一位置同一形状からなる第２透過面としての前群透明媒体第２透過面２４を有する。また、前群透明媒体第２透過面２４に対して像面５と反対側に形成され、正のパワーをもつ球面からなる第３透過面としての前群透明媒体第３透過面２５をさらに有する。 The front group transparent medium Lf is rotationally symmetric around the central axis 2 and has a refractive index larger than 1 and a front group as a front group first transmission surface made of an aspheric surface having a negative power around the central axis 2. The first transparent surface of the transparent medium and the first reflective surface which is formed on the image surface 5 side with respect to the first transparent surface of the front group transparent medium 21 and is partially coated with a reflective coating 4a and having an aspherical surface having a positive power. The first transparent surface of the front group transparent medium 22 and the first transparent surface 22 of the front group transparent medium are disposed on the opposite side of the image surface 5 with respect to the first reflective surface 22 of the front group, are coated with a reflective coating 4b, and are made of an aspherical surface having negative power. The front transparent medium second reflective surface 23 as two reflective surfaces and an aspherical surface having a positive power disposed on the image surface 5 side from the front transparent medium second reflective surface 23, The front transparent medium as the second transmission surface having the same shape and the same position as the reflection surface 22 Having second transmitting surface 24. Further, the front transparent medium third transmission surface 25 is formed on the side opposite to the image plane 5 with respect to the front transparent medium second transmission surface 24 and is a third transmission surface made of a spherical surface having a positive power. .

後群透明媒体Ｌｂは、中心軸２の周りで回転対称であり、屈折率が１より大きく、中心軸２部分で正のパワーをもつ非球面からなる後群第１透過面としての後群透明媒体第１透過面３１と、後群透明媒体第１透過面３１に対して像面５側に形成され、一部を反射コーティング４ｃされ、負のパワーをもつ非球面からなる第１反射面としての後群透明媒体第１反射面３２と、後群透明媒体第１反射面３２に対して像面５と反対側に配置され、反射コーティング４ｄされ、正のパワーをもつ非球面からなり、後群透明媒体第１透過面３１と同一位置同一形状からなる第２反射面としての前群透明媒体第２反射面３３と、後群透
明媒体第２反射面３３より像面５側に配置され、正のパワーをもつ非球面からなる第２透過面としての後群透明媒体第２透過面３４を有する。また、後群透明媒体第１透過面３１に対して像面５側に形成され、正のパワーをもつ球面からなる第３透過面としての後群透明媒体第３透過面３５をさらに有する。 The rear group transparent medium Lb is rotationally symmetric about the central axis 2 and has a refractive index larger than 1 and a rear group transparent as a rear group first transmission surface made of an aspheric surface having a positive power at the central axis 2 portion. The first transmission surface 31 and the rear transparent medium first transmission surface 31 are formed on the image surface 5 side, part of which is a reflective coating 4c, and a first reflection surface made of an aspheric surface having negative power. Rear group transparent medium first reflecting surface 32, and rear group transparent medium first reflecting surface 32 which is disposed on the opposite side of the image surface 5 from the rear surface transparent medium first reflecting surface 32. The front transparent medium second reflective surface 33 as a second reflective surface having the same position and the same shape as the first transparent surface 31 of the transparent medium, and the image surface 5 side from the rear transparent medium second reflective surface 33, Rear group transparent medium second as second transmission surface made of aspherical surface having positive power Having an over surface 34. Further, it further has a rear group transparent medium third transmission surface 35 as a third transmission surface which is formed on the image plane 5 side with respect to the rear group transparent medium first transmission surface 31 and is a spherical surface having a positive power.

後群カバーガラスＣｂは、中心軸２の周りで回転対称な屈折率が１より大きい平行平板からなり、後群カバーガラス第１透過面４１と、後群カバーガラス第１透過面４１に対して像側に形成される後群カバーガラス第２透過面４２とを有する。 The rear group cover glass Cb is composed of parallel flat plates having a refractive index that is rotationally symmetric around the central axis 2 and greater than 1. The rear group cover glass first transmission surface 41 and the rear group cover glass first transmission surface 41 And a rear group cover glass second transmission surface 42 formed on the image side.

リレー光学系１は、第１光路Ａ及び第２光路Ｂを形成する。 The relay optical system 1 forms a first optical path A and a second optical path B.

第１光路Ａにおいて、リレー光学系１の物体面３から入射する光束は、前群カバーガラスＣｆの前群カバーガラス第１透過面１１と前群カバーガラス第２透過面１２を経て、前群透明媒体Ｌｆ内に入る。 In the first optical path A, the light beam incident from the object surface 3 of the relay optical system 1 passes through the front group cover glass first transmission surface 11 and the front group cover glass second transmission surface 12 of the front group cover glass Cf, and passes through the front group cover glass Cf. It enters into the transparent medium Lf.

前群透明媒体Ｌｆでは、前群透明媒体第１透過面２１を経て入り、反射コーティング４ａにより、前群透明媒体第１反射面２２で像面５と反対側に反射され、前群透明媒体第２反射面２３で、一部が反射コーティング４ｂ、一部が全反射により像面５側に反射され、前群透明媒体第２透過面２４を経て前群透明媒体Ｌｆから外に出る略Ｚ字状の光路を有する。 In the front group transparent medium Lf, the light enters through the front group transparent medium first transmission surface 21 and is reflected by the reflective coating 4a on the front group transparent medium first reflection surface 22 on the side opposite to the image plane 5, Two reflective surfaces 23, part of which is reflective coating 4b, part of which is reflected to the image surface 5 side by total reflection, and passes through the front transparent medium second transmission surface 24 and then exits from the front transparent medium Lf. Shaped optical path.

その後、前群透明媒体Ｌｆの像面５側で中心軸２に同軸に配置された開口Ｓを経て後群透明媒体Ｌｂ内に入る。後群透明媒体Ｌｂでは、後群透明媒体第１透過面３１を経て入り、一部が反射コーティング４ｃ、一部が全反射により、後群透明媒体第１反射面３２で像面５と反対側に反射され、後群透明媒体第２反射面３３で反射コーティング４ｄにより像面５側に反射され、後群透明媒体第２透過面３４を経て後群透明媒体Ｌｂから外に出る略Ｚ字状の光路を有する。 Thereafter, the light enters the rear group transparent medium Lb through an opening S arranged coaxially with the central axis 2 on the image plane 5 side of the front group transparent medium Lf. In the rear group transparent medium Lb, it enters through the rear group transparent medium first transmission surface 31, partly by the reflective coating 4 c and partly by total reflection, the rear group transparent medium first reflection surface 32 opposite to the image surface 5. Is reflected by the second transparent surface 33 of the rear group transparent medium, reflected to the image surface 5 side by the reflective coating 4d, and then exits from the rear group transparent medium Lb through the second transparent surface of the rear group transparent medium 34. It has a light path.

その後、後群カバーガラスＣｂの後群カバーガラス第１透過面４１と後群カバーガラス第２透過面４２を経て、像面５の中心軸２から外れた半径方向の所定位置に円環状に結像する。 After that, it passes through the rear group cover glass first transmission surface 41 and the rear group cover glass second transmission surface 42 of the rear group cover glass Cb, and is circularly connected to a predetermined radial position away from the central axis 2 of the image plane 5. Image.

また、第２光路Ｂにおいて、リレー光学系１の物体面３から入射する光束は、前群カバーガラスＣｆの前群カバーガラス第１透過面１１と前群カバーガラス第２透過面１２を経て、前群カバーガラスＣｆから外に出て、前群透明媒体Ｌｆ内に入る。前群透明媒体Ｌｆでは前群透明媒体第３透過面２５から前群透明媒体Ｌｆに入り、前群透明媒体第２透過面２４を経て前群透明媒体Ｌｆから外に出る。 In the second optical path B, the light beam incident from the object plane 3 of the relay optical system 1 passes through the front group cover glass first transmission surface 11 and the front group cover glass second transmission surface 12 of the front group cover glass Cf, It exits from the front group cover glass Cf and enters the front group transparent medium Lf. The front group transparent medium Lf enters the front group transparent medium Lf from the front group transparent medium third transmission surface 25, and exits from the front group transparent medium Lf through the front group transparent medium second transmission surface 24.

その後、前群透明媒体Ｌｆの像面５側で中心軸２に同軸に配置された開口Ｓを経て後群透明媒体Ｌｂ内に入る。後群透明媒体Ｌｂでは、後群透明媒体第１透過面３１を経て入り、後群第３透過面３５を経て後群透明媒体Ｌｂから外に出て、後群カバーガラスＣｂ内に入る。後群カバーガラスＣｂの後群第１透過面４１と後群第２透過面４２を経て、後群カバーガラスＣｂから外に出て、像面５の中心軸２上に結像する。 Thereafter, the light enters the rear group transparent medium Lb through an opening S arranged coaxially with the central axis 2 on the image plane 5 side of the front group transparent medium Lf. In the rear group transparent medium Lb, it enters through the rear group transparent medium first transmission surface 31, exits from the rear group transparent medium Lb through the rear group third transmission surface 35, and enters the rear group cover glass Cb. After passing through the rear group first transmission surface 41 and the rear group second transmission surface 42 of the rear group cover glass Cb, the light exits from the rear group cover glass Cb and forms an image on the central axis 2 of the image plane 5.

図２は、第３光路及び第４光路を示す図である。 FIG. 2 is a diagram illustrating the third optical path and the fourth optical path.

中心主光線が前群透明媒体第１透過面２１と前群透明媒体第３透過面２５の境界付近を通る第３光路Ｃについては、リレー光学系１の物体面３から入射する光束は、前群カバーガラスＣｆの前群カバーガラス第１透過面１１と前群カバーガラス第２透過面１２を経て、前群カバーガラスＣｆから外に出て、前群透明媒体Ｌｆ内に入る。前群透明媒体Ｌｆで
は前群透明媒体第３透過面２５から前群透明媒体Ｌｆに入り、前群透明媒体第２透過面２４を経て前群透明媒体Ｌｆから外に出る。 For the third optical path C in which the central principal ray passes near the boundary between the front transparent medium first transmission surface 21 and the front transparent medium third transmission surface 25, the light beam incident from the object plane 3 of the relay optical system 1 is Through the front group cover glass first transmission surface 11 and the front group cover glass second transmission surface 12 of the group cover glass Cf, the group cover glass Cf exits from the front group cover glass Cf and enters the front group transparent medium Lf. The front group transparent medium Lf enters the front group transparent medium Lf from the front group transparent medium third transmission surface 25, and exits from the front group transparent medium Lf through the front group transparent medium second transmission surface 24.

また、中心主光線が後群透明媒体第２透過面３４と後群透明媒体第３透過面３５の境界付近を通る第４光路Ｄについては、リレー光学系１の物体面３から入射する光束は、前群カバーガラスＣｆの前群カバーガラス第１透過面１１と前群カバーガラス第２透過面１２を経て、前群カバーガラスＣｆから外に出て、前群透明媒体Ｌｆ内に入る。 Further, regarding the fourth optical path D in which the central principal ray passes near the boundary between the rear group transparent medium second transmission surface 34 and the rear group transparent medium third transmission surface 35, the light beam incident from the object plane 3 of the relay optical system 1 is Through the front group cover glass first transmission surface 11 and the front group cover glass second transmission surface 12 of the front group cover glass Cf, they exit out of the front group cover glass Cf and enter the front group transparent medium Lf.

その後、前群透明媒体Ｌｆの像面５側で中心軸２に同軸に配置された開口Ｓを経て後群透明媒体Ｌｂ内に入る。後群透明媒体Ｌｂでは、後群透明媒体第１透過面３１を経て入り、後群第３透過面３５を経て後群透明媒体Ｌｂ１から外に出て、後群カバーガラスＣｂ内に入る。後群カバーガラスＣｂの後群第１透過面４１と後群第２透過面４２を経て、後群カバーガラスＣｂから外に出て、像面５の中心軸２から外れた半径方向の所定位置に円環状に結像する。 Thereafter, the light enters the rear group transparent medium Lb through an opening S arranged coaxially with the central axis 2 on the image plane 5 side of the front group transparent medium Lf. In the rear group transparent medium Lb, it enters through the rear group transparent medium first transmission surface 31, exits from the rear group transparent medium Lb1 through the rear group third transmission surface 35, and enters the rear group cover glass Cb. A predetermined position in the radial direction that exits from the rear group cover glass Cb through the rear group first transmission surface 41 and the rear group second transmission surface 42 of the rear group cover glass Cb and deviates from the central axis 2 of the image plane 5. An image is formed in an annular shape.

この実施例１の仕様は、
第１光路Ａ
物体高 φ1.333〜2.000
倍率 1.00
瞳径 φ0.22mm
第２光路Ｂ
物体高〜φ1.333
倍率 1.00
瞳径 φ0.22mm
である。 The specification of this Example 1 is
First optical path A
Object height φ1.333〜2.000
Magnification 1.00
Pupil diameter φ0.22mm
Second optical path B
Object height ~ φ1.333
Magnification 1.00
Pupil diameter φ0.22mm
It is.

実施例２のリレー光学系１の中心軸２に沿ってとった断面図を図５、第３光路Ｃ及び第４光路Ｄを示す図を図６に示す。また、この実施例の光学系の第１光路Ａの横収差図を図７、第２光路Ｂの横収差図を図８に示す。 FIG. 5 shows a cross-sectional view taken along the central axis 2 of the relay optical system 1 of Example 2, and FIG. 6 shows a diagram showing the third optical path C and the fourth optical path D. Further, FIG. 7 shows a lateral aberration diagram of the first optical path A and FIG. 8 shows a lateral aberration diagram of the second optical path B of the optical system of this example.

リレー光学系１は、中心軸２に同軸に配置された開口Ｓを有する遮光部材Ｓ１と、この開口Ｓの物体面３側に配置された前群Ｇｆと、開口Ｓの像面５側に配置された後群Ｇｂと、からなり、前群Ｇｆは、前群カバーガラスＣｆと、前群透明媒体Ｌｆと、後群Ｇｂは、
後群透明媒体Ｌｂと、後群カバーガラスＣｂとからなる。 The relay optical system 1 includes a light shielding member S1 having an opening S arranged coaxially with a central axis 2, a front group Gf arranged on the object plane 3 side of the opening S, and an image plane 5 side of the opening S. The rear group Gb includes the front group Gf, the front group cover glass Cf, the front group transparent medium Lf, and the rear group Gb.
It consists of a rear group transparent medium Lb and a rear group cover glass Cb.

後群透明媒体Ｌｂは、中心軸２の周りで回転対称であり、屈折率が１より大きく、中心軸２部分で正のパワーをもつ非球面からなる後群第１透過面としての後群透明媒体第１透過面３１と、後群透明媒体第１透過面３１に対して像面５側に形成され、一部を反射コーティング４ｃされ、負のパワーをもつ非球面からなる第１反射面としての後群透明媒体第１反射面３２と、後群透明媒体第１反射面３２に対して像面５と反対側に配置され、反射コーティング４ｄされ、正のパワーをもつ非球面からなり、後群透明媒体第１透過面３１と同一位置同一形状からなる第２反射面としての前群透明媒体第２反射面３３と、後群透明媒体第２反射面３３より像面５側に配置され、正のパワーをもつ非球面からなる第２透過面としての後群透明媒体第２透過面３４を有する。また、後群透明媒体第１透過面３１に対して像面５側に形成され、正のパワーをもつ球面からなる第３透過面としての後群透明媒体第３透過面３５をさらに有する。 The rear group transparent medium Lb is rotationally symmetric about the central axis 2 and has a refractive index larger than 1 and a rear group transparent as a rear group first transmission surface made of an aspheric surface having a positive power at the central axis 2 portion. The first transmission surface 31 and the rear transparent medium first transmission surface 31 are formed on the image surface 5 side, part of which is a reflective coating 4c, and a first reflection surface made of an aspheric surface having negative power. A rear group transparent medium first reflecting surface 32, and a rear group transparent medium first reflecting surface 32 which is disposed on the opposite side to the image plane 5, is coated with a reflective coating 4d, and is composed of an aspherical surface having a positive power. The front transparent medium second reflective surface 33 as a second reflective surface having the same position and the same shape as the first transparent surface 31 of the transparent medium, and the image surface 5 side from the rear transparent medium second reflective surface 33, Rear group transparent medium second as second transmission surface made of aspherical surface having positive power Having an over surface 34. Further, it further has a rear group transparent medium third transmission surface 35 as a third transmission surface which is formed on the image plane 5 side with respect to the rear group transparent medium first transmission surface 31 and is a spherical surface having a positive power.

前群透明媒体Ｌｆでは、前群透明媒体第１透過面２１を経て入り、反射コーティング４ａにより、前群透明媒体第１反射面２２で像面５と反対側に反射され、前群透明媒体第２反射面２３で、一部が反射コーティング４ｂ、一部が全反射により像面５側に反射され、前群透明媒体第２透過面２４を経て前群透明媒体Ｌｆから外に出る略Ｚ字状の光路を有する。 The front group transparent medium Lf enters through the front group transparent medium first transmission surface 21 and is reflected by the reflective coating 4a on the front group transparent medium first reflection surface 22 on the side opposite to the image plane 5, Two reflective surfaces 23, part of which is reflective coating 4b, part of which is reflected to the image surface 5 side by total reflection, and passes through the front transparent medium second transmission surface 24 and then exits from the front transparent medium Lf. Shaped optical path.

その後、前群透明媒体Ｌｆの像面５側で中心軸２に同軸に配置された開口Ｓを経て後群透明媒体Ｌｂ内に入る。後群透明媒体Ｌｂでは、後群透明媒体第１透過面３１を経て入り、一部が反射コーティング４ｃ、一部が全反射により、後群透明媒体第１反射面３２で像面５と反対側に反射され、後群透明媒体第２反射面３３で反射コーティング４ｄにより像
面５側に反射され、後群透明媒体第２透過面３４を経て後群透明媒体Ｌｂから外に出る略Ｚ字状の光路を有する。 Thereafter, the light enters the rear group transparent medium Lb through an opening S arranged coaxially with the central axis 2 on the image plane 5 side of the front group transparent medium Lf. In the rear group transparent medium Lb, it enters through the rear group transparent medium first transmission surface 31, partly by the reflective coating 4 c and partly by total reflection, the rear group transparent medium first reflection surface 32 opposite to the image surface 5. Is reflected to the image surface 5 side by the reflective coating 4d on the rear group transparent medium second reflecting surface 33, and passes through the rear group transparent medium second transmitting surface 34 and exits from the rear group transparent medium Lb. It has a light path.

図６は、第３光路及び第４光路を示す図である。 FIG. 6 is a diagram illustrating the third optical path and the fourth optical path.

中心主光線が前群透明媒体第１透過面２１と前群透明媒体第３透過面２５の境界付近を通る第３光路Ｃについては、リレー光学系１の物体面３から入射する光束は、前群カバーガラスＣｆの前群カバーガラス第１透過面１１と前群カバーガラス第２透過面１２を経て、前群カバーガラスＣｆから外に出て、前群透明媒体Ｌｆ内に入る。前群透明媒体Ｌｆでは前群透明媒体第３透過面２５から前群透明媒体Ｌｆに入り、前群透明媒体第２透過面２４を経て前群透明媒体Ｌｆから外に出る。 For the third optical path C in which the central principal ray passes near the boundary between the front transparent medium first transmission surface 21 and the front transparent medium third transmission surface 25, the light beam incident from the object plane 3 of the relay optical system 1 is Through the front group cover glass first transmission surface 11 and the front group cover glass second transmission surface 12 of the group cover glass Cf, the group cover glass Cf exits from the front group cover glass Cf and enters the front group transparent medium Lf. The front group transparent medium Lf enters the front group transparent medium Lf from the front group transparent medium third transmission surface 25, and exits from the front group transparent medium Lf through the front group transparent medium second transmission surface 24.

その後、前群透明媒体Ｌｆの像面５側で中心軸２に同軸に配置された開口Ｓを経て後群透明媒体Ｌｂ内に入る。後群透明媒体Ｌｂでは、後群透明媒体第１透過面３１を経て入り、一部が反射コーティング４ｃ、一部が全反射により、後群透明媒体第１反射面３２で像面５と反対側に反射され、後群透明媒体第２反射面３３で反射コーティング４ｄにより像面５側に反射され、後群透明媒体第２透過面３４を経て後群透明媒体Ｌｂから外に出る略Ｚ字状の光路を有する。 Thereafter, the light enters the rear group transparent medium Lb through an opening S arranged coaxially with the central axis 2 on the image plane 5 side of the front group transparent medium Lf. In the rear group transparent medium Lb, it enters through the rear group transparent medium first transmission surface 31, partly by the reflective coating 4 c and partly by total reflection, the rear group transparent medium first reflection surface 32 opposite to the image surface 5 Is reflected to the image surface 5 side by the reflective coating 4d on the rear group transparent medium second reflecting surface 33, and passes through the rear group transparent medium second transmitting surface 34 and exits from the rear group transparent medium Lb. It has a light path.

実施例２のリレー光学系１は、物体面３側と像面５側を逆に用いることにより、１／２倍の縮小光学系として使用することができる。 The relay optical system 1 of Example 2 can be used as a 1/2 times reduction optical system by using the object plane 3 side and the image plane 5 side in reverse.

この実施例２の仕様は、
第１光路Ａ
物体高 φ0.666〜1.000
倍率 2.00
瞳径 φ0.22mm
第２光路Ｂ
物体高〜φ0.666
倍率 2.00
瞳径 φ0.22mm
である。 The specification of Example 2 is
First optical path A
Object height φ0.666〜1.000
Magnification 2.00
Pupil diameter φ0.22mm
Second optical path B
Object height ~ φ0.666
Magnification 2.00
Pupil diameter φ0.22mm
It is.

なお、実施例１及び実施例２の前群カバーガラスＣｆ及び後群カバーガラスＣｂは、撮像素子保護用のものであり、なくてもよい。さらに、前群透明媒体Ｌｆの物体面３側、後群透明媒体Ｌｂの像面５側にレンズ等の光学素子を付加してもよい。 In addition, the front group cover glass Cf and the rear group cover glass Cb of Example 1 and Example 2 are for image pick-up element protection, and do not need to be. Further, an optical element such as a lens may be added to the object surface 3 side of the front group transparent medium Lf and the image surface 5 side of the rear group transparent medium Lb.

また、最大像高をＩmax（mm）、リレー光学系１の外径をＤ（mm）、物体面から像面ま
での距離Ｌ（mm）、第１反射面２２の曲率をＲ１、第２反射面２３の曲率をＲ２とするとき、
実施例１実施例２
I max 1.00 1.00
Ｄ 3.00 3.20
Ｌ 3.43 2.95
Ｄ／（２×Ｉmax） 1.50 1.60
Ｌ／（２×Ｉmax） 1.71 1.47
Ｆｒ１ -1.83 -1.05
Ｆｒ２ -1.54 -0.77
Ｆｒ１／Ｆｒ２ 1.19 1.36
Ｒｒ１ 1.54 1.47
Ｒｒ２ 1.83 2.06
Ｒｒ２／Ｒｒ１ 1.19 1.40
である。 Further, the maximum image height is Imax (mm), the outer diameter of the relay optical system 1 is D (mm), the distance L (mm) from the object surface to the image surface, the curvature of the first reflecting surface 22 is R1, and the second reflection. When the curvature of the surface 23 is R2,
Example 1 Example 2
I max 1.00 1.00
D 3.00 3.20
L 3.43 2.95
D / (2 x Imax) 1.50 1.60
L / (2 x Imax) 1.71 1.47
Fr1 -1.83 -1.05
Fr2 -1.54 -0.77
Fr1 / Fr2 1.19 1.36
Rr1 1.54 1.47
Rr2 1.83 2.06
Rr2 / Rr1 1.19 1.40
It is.

以下に、上記実施例１及び２の構成パラメータを示す。なお、以下の表中の “ＲＥ”
は反射面を示す。
The configuration parameters of Examples 1 and 2 are shown below. “RE” in the table below
Indicates a reflective surface.

実施例１
第１光路
面番号曲率半径面間隔偏心屈折率アッベ数
物体面 ∞ 0.100
1 ∞ 0.200 1.5163 64.1
2 ∞ 0.567
4 非球面[1] 0.798 1.8348 42.7
5（ＲＥ）非球面[2] -0.798 1.8348 42.7
6（ＲＥ）非球面[1] 0.798 1.8348 42.7
7 非球面[2] 0.050
3 ∞（絞り） 0.050
4 非球面[3] 0.798 1.8348 42.7
5（ＲＥ）非球面[4] -0.798 1.8348 42.7
6（ＲＥ）非球面[3] 0.798 1.8348 42.7
7 非球面[4] 0.567
8 ∞ 0.200 1.5163 64.1
9 ∞ 0.100
像面 ∞
非球面[1]
曲率半径 -1.540
k 1.1917E+000
a 4.9138E-002
非球面[2]
曲率半径 -1.827
k 2.2806E-001
a 4.6733E-003
非球面[3]
曲率半径 1.827
k 2.2806E-001
a -4.6733E-003
非球面[4]
曲率半径 1.540
k 1.1917E+000
a -4.9138E-002

第２光路
面番号曲率半径面間隔偏心屈折率アッベ数
物体面 ∞ 0.100
1 ∞ 0.200 1.5163 64.1
2 ∞ 0.549
5 1.28 0.817 1.8348 42.7
4 非球面[2] 0.050
3 ∞（絞り） 0.050
4 非球面[3] 0.817 1.8348 42.7
5 -1.28 0.549
6 ∞ 0.200 1.5163 64.1
7 ∞ 0.100
像面 ∞
非球面[2]
曲率半径 -1.827
k 2.2806E-001
a 4.6733E-003
非球面[3]
曲率半径 1.827
k 2.2806E-001
a -4.6733E-003
Example 1
1st optical path surface number of curvature radius Surface spacing Eccentricity Refractive index Abbe number Object surface ∞ 0.100
1 ∞ 0.200 1.5163 64.1
2 ∞ 0.567
4 Aspherical surface [1] 0.798 1.8348 42.7
5 (RE) aspherical surface [2] -0.798 1.8348 42.7
6 (RE) Aspherical surface [1] 0.798 1.8348 42.7
7 Aspherical surface [2] 0.050
3 ∞ (Aperture) 0.050
4 Aspherical surface [3] 0.798 1.8348 42.7
5 (RE) aspherical surface [4] -0.798 1.8348 42.7
6 (RE) Aspherical surface [3] 0.798 1.8348 42.7
7 Aspherical [4] 0.567
8 ∞ 0.200 1.5163 64.1
9 ∞ 0.100
Image plane ∞
Aspherical [1]
Radius of curvature -1.540
k 1.1917E + 000
a 4.9138E-002
Aspherical [2]
Radius of curvature -1.827
k 2.2806E-001
a 4.6733E-003
Aspherical [3]
Curvature radius 1.827
k 2.2806E-001
a -4.6733E-003
Aspherical [4]
Curvature radius 1.540
k 1.1917E + 000
a -4.9138E-002

Second optical path number Curvature radius Surface spacing Eccentricity Refractive index Abbe number Object surface ∞ 0.100
1 ∞ 0.200 1.5163 64.1
2 ∞ 0.549
5 1.28 0.817 1.8348 42.7
4 Aspherical [2] 0.050
3 ∞ (Aperture) 0.050
4 Aspherical surface [3] 0.817 1.8348 42.7
5 -1.28 0.549
6 ∞ 0.200 1.5163 64.1
7 ∞ 0.100
Image plane ∞
Aspherical [2]
Radius of curvature -1.827
k 2.2806E-001
a 4.6733E-003
Aspherical [3]
Curvature radius 1.827
k 2.2806E-001
a -4.6733E-003

実施例２
第１光路
面番号曲率半径面間隔偏心屈折率アッベ数
物体面 ∞ 0.110
1 ∞ 0.220 1.5163 64.1
2 ∞ 0.224
4 非球面[1] 0.516 1.8348 42.7
5（ＲＥ）非球面[2] -0.516 1.8348 42.7
6（ＲＥ）非球面[1] 0.516 1.8348 42.7
7 非球面[2] 0.050
3 ∞（絞り） 0.050
4 非球面[3] 1.078 1.8348 42.7
5（ＲＥ）非球面[4] -1.078 1.8348 42.7
6（ＲＥ）非球面[3] 1.078 1.8348 42.7
7 非球面[4] 0.366
8 ∞ 0.220 1.5163 64.1
9 ∞ 0.110
像面 ∞
非球面[1]
曲率半径 -0.773
k 5.5392E-001
a 9.2898E-001
非球面[2]
曲率半径 -1.049
k -5.3553E-002
a 2.0502E-002
非球面[3]
曲率半径 2.058
k 1.0005E-001
a -6.5276E-003
非球面[4]
曲率半径 1.465
k 1.0247E+000
a -2.1419E-001

第２光路
面番号曲率半径面間隔偏心屈折率アッベ数
物体面 ∞ 0.110
1 ∞ 0.220 1.5163 64.1
2 ∞ 0.209
5 0.562 0.532 1.8348 42.7
4 非球面[2] 0.050
3 ∞（絞り） 0.050
4 非球面[3] 1.099 1.8348 42.7
5 -2.281 0.345
6 ∞ 0.220 1.5163 64.1
7 ∞ 0.110
像面 ∞
非球面[2]
曲率半径 -1.049
k -5.3553E-002
a 2.0502E-002
非球面[3]
曲率半径 2.058
k 1.0005E-001
a -6.5276E-003
Example 2
1st optical path number Curvature radius Surface spacing Eccentricity Refractive index Abbe number Object surface ∞ 0.110
1 ∞ 0.220 1.5163 64.1
2 ∞ 0.224
4 Aspherical surface [1] 0.516 1.8348 42.7
5 (RE) aspherical surface [2] -0.516 1.8348 42.7
6 (RE) Aspherical surface [1] 0.516 1.8348 42.7
7 Aspherical surface [2] 0.050
3 ∞ (Aperture) 0.050
4 Aspherical surface [3] 1.078 1.8348 42.7
5 (RE) aspherical surface [4] -1.078 1.8348 42.7
6 (RE) Aspherical surface [3] 1.078 1.8348 42.7
7 Aspherical [4] 0.366
8 ∞ 0.220 1.5163 64.1
9 ∞ 0.110
Image plane ∞
Aspherical [1]
Radius of curvature -0.773
k 5.5392E-001
a 9.2898E-001
Aspherical [2]
Radius of curvature -1.049
k -5.3553E-002
a 2.0502E-002
Aspherical [3]
Curvature radius 2.058
k 1.0005E-001
a -6.5276E-003
Aspherical [4]
Curvature radius 1.465
k 1.0247E + 000
a -2.1419E-001

Second optical path number Curvature radius Surface spacing Eccentricity Refractive index Abbe number Object surface ∞ 0.110
1 ∞ 0.220 1.5163 64.1
2 ∞ 0.209
5 0.562 0.532 1.8348 42.7
4 Aspherical [2] 0.050
3 ∞ (Aperture) 0.050
4 Aspherical surface [3] 1.099 1.8348 42.7
5 -2.281 0.345
6 ∞ 0.220 1.5163 64.1
7 ∞ 0.110
Image plane ∞
Aspherical [2]
Radius of curvature -1.049
k -5.3553E-002
a 2.0502E-002
Aspherical [3]
Curvature radius 2.058
k 1.0005E-001
a -6.5276E-003

本発明の実施例１の光学系の中心軸に沿ってとった断面図である。It is sectional drawing taken along the central axis of the optical system of Example 1 of this invention. 本発明の実施例１の第３光路及び第４光路を示す図である。It is a figure which shows the 3rd optical path and Example 4 of Example 1 of this invention. 実施例１の光学系の第１光路の横収差図を示す図である。6 is a lateral aberration diagram of the first optical path of the optical system of Example 1. FIG. 実施例１の光学系の第２光路の横収差図を示す図である。6 is a lateral aberration diagram of the second optical path of the optical system of Example 1. FIG. 本発明の実施例２の光学系の中心軸に沿ってとった断面図である。It is sectional drawing taken along the central axis of the optical system of Example 2 of this invention. 本発明の実施例２の第３光路及び第４光路を示す図である。It is a figure which shows the 3rd optical path and Example 4 of Example 2 of this invention. 実施例２の光学系の第１光路の横収差図を示す図である。FIG. 10 is a transverse aberration diagram for the first optical path of the optical system according to Example 2. 実施例２の光学系の第２光路の横収差図を示す図である。6 is a lateral aberration diagram of the second optical path of the optical system of Example 2. FIG.

Explanation of symbols

１…光学系
２…中心軸
３…物体面
５…像面
Ａ…第１光路
Ｂ…第２光路
Ｃ…第３光路
Ｄ…第４光路
Ｇｆ…前群
Ｇｂ…後群
Ｓ…開口
Ｌｆ…前群透明媒体
Ｌｂ…後群透明媒体
２１…前群透明媒体第１透過面（前群第１透過面）
２２…前群透明媒体第１反射面（前群第１反射面）
２３…前群透明媒体第２反射面（前群第２反射面）
２４…前群透明媒体第２透過面（前群第２透過面）
２５…前群透明媒体第３透過面（前群第３透過面）
３１…後群透明媒体第１透過面（後群第１透過面）
３２…後群透明媒体第１反射面（後群第１反射面）
３３…後群透明媒体第２反射面（後群第２反射面）
３４…後群透明媒体第２透過面（後群第２透過面）
３５…後群透明媒体第３透過面（後群第３透過面） DESCRIPTION OF SYMBOLS 1 ... Optical system 2 ... Center axis 3 ... Object surface 5 ... Image plane A ... 1st optical path B ... 2nd optical path C ... 3rd optical path D ... 4th optical path Gf ... Front group Gb ... Rear group S ... Opening Lf ... Front Group transparent medium Lb ... Rear group transparent medium 21 ... Front group transparent medium first transmission surface (front group first transmission surface)
22. Front group transparent medium first reflecting surface (front group first reflecting surface)
23: Front group transparent medium second reflecting surface (front group second reflecting surface)
24: Front group transparent medium second transmission surface (front group second transmission surface)
25: Front group transparent medium third transmission surface (front group third transmission surface)
31 ... Rear group transparent medium first transmission surface (back group first transmission surface)
32. Rear group transparent medium first reflecting surface (rear group first reflecting surface)
33 ... Rear group transparent medium second reflecting surface (rear group second reflecting surface)
34: Rear group transparent medium second transmission surface (rear group second transmission surface)
35: Rear group transparent medium third transmission surface (back group third transmission surface)

Claims

In a relay optical system that forms an object on a plane object surface that is rotationally symmetric with respect to the central axis on a plane image plane.
In order from the object side, a front group, an opening, and a rear group are provided,
The front group includes a front group first reflecting surface with a concave surface facing the object side, and a front group second reflecting surface;
The rear group includes a rear group first reflecting surface with a concave surface facing the image surface side, and a rear group second reflecting surface,
An object around the central axis passes through the front group first reflecting surface, the front group second reflecting surface, the rear group first reflecting surface, and the rear group second reflecting surface to the portion around the central axis of the image plane. A first optical path for imaging;
A second optical path for imaging an object near the central axis in the vicinity of the central axis of the image plane;
Have
A relay optical system characterized by satisfying the following conditional expression (1).
0.8 <βt / βr <1.2 (1)
Where βt is the magnification of the first optical path,
βr is the magnification of the second optical path,
It is.

The front group includes a front group first transmission surface in the vicinity of the object surface, a front group first reflection surface that is disposed closer to the image plane side than the front group first transmission surface, and has a concave surface facing the object surface side, Arranged on the opposite side of the image plane from the front group first reflecting surface, with the front group second reflecting surface having a concave surface facing the object plane side, and on the central axis on the image plane side from the front group second reflecting surface A front group transparent medium comprising: a front group second transmission surface formed;
The rear group includes a rear group first transmission surface disposed on the central axis in the vicinity of the opening, and a rear group having a concave surface facing the image plane side, disposed closer to the image plane side than the rear group first transmission surface. A first reflecting surface, a rear group second reflecting surface disposed on the opposite side of the image surface from the rear group first reflecting surface, and having a concave surface facing the image surface side; and an image surface side from the rear group second reflecting surface The relay optical system according to claim 1, further comprising: a rear group transparent medium including a rear group second transmission surface disposed on the rear group.

The light beams incident on the front group transparent medium and the rear group transparent medium are in the order of forward ray tracing,
It enters the front group transparent medium through the front group first transmission surface, is reflected on the opposite side to the image surface by the front group first reflection surface, is reflected on the image surface side by the front group second reflection surface, A substantially Z-shaped optical path that exits from the front group transparent medium to the image plane side through the front group second transmission surface;
It passes through the opening, passes through the rear group first transmission surface, enters the rear group transparent medium, is reflected by the rear group first reflection surface to the side opposite to the image plane, and is image plane by the rear group second reflection surface. A substantially Z-shaped optical path that is reflected to the side and exits from the rear group transparent medium to the image side through the rear group second transmission surface;
Comprising the first optical path comprising:
The center axis is at least between the first group first reflecting surface and the front group second reflecting surface and at least between the rear group first reflecting surface and the rear group second reflecting surface of the first optical path. Consists of only one side,
The first optical path intersects the central axis at the opening, and forms an object on the object plane on the image plane opposite to the central axis without forming an intermediate image. The relay optical system according to claim 2.

The front group first transmission surface is disposed adjacent to the front group second reflection surface,
The rear group first reflection surface is disposed adjacent to the rear group second transmission surface,
The relay optical system according to claim 2 or claim 3, wherein

The front group first transmission surface and the front group second reflection surface have the same shape at the same position, and the rear group first reflection surface and the rear group second transmission surface have the same shape at the same position. The relay optical system according to any one of claims 2 to 4.

The front group first reflective surface is disposed adjacent to the front group second transmission surface,
The rear group first transmission surface is disposed adjacent to the rear group second reflection surface,
The relay optical system according to any one of claims 2 to 5, wherein the relay optical system according to any one of claims 2 to 5 is provided.

The front group first reflection surface and the front group second transmission surface have the same shape at the same position, and the rear group first transmission surface and the rear group second reflection surface have the same shape at the same position. The relay optical system according to any one of claims 2 to 6.

The front group transparent medium has a front group third transmission surface disposed on the central axis on the object plane side,
The relay optical system according to any one of claims 2 to 7, wherein the rear group transparent medium includes a rear group third transmission surface disposed on the central axis on the image plane side. system.

The light beams incident on the front group transparent medium and the rear group transparent medium are in the order of forward ray tracing,
It enters the front group transparent medium through the front group third transmission surface, exits from the front group transparent medium to the image surface side through the front group second transmission surface, passes through the opening, and passes through the rear group. The second optical path is configured to enter the rear group transparent medium through the first transmission surface, and to exit to the image surface side from the rear group transparent medium through the rear group third transmission surface. Item 9. The relay optical system according to Item 8.

The front group third transmission surface is disposed adjacent to the front group first transmission surface,
The rear group third transmission surface is disposed adjacent to the rear group second transmission surface,
The relay optical system according to claim 8 or 9, wherein

The light beams incident on the front group transparent medium and the rear group transparent medium are in the order of forward ray tracing,
An optical path that enters the front group transparent medium through the front group third transmission surface, exits to the image surface side from the front group transparent medium through the front group second transmission surface, passes through the opening, and passes the rear. Enter the rear group rear group transparent medium through the group first transmission surface, reflected by the rear group first reflection surface to the side opposite to the image plane, reflected by the rear group second reflection surface to the image plane side, A third optical path comprising a substantially Z-shaped optical path exiting from the rear group transparent medium to the image plane side through the rear group second transmission surface;
The light enters the front group front group transparent medium through the front group first transmission surface, is reflected by the front group first reflection surface to the side opposite to the image surface, and is reflected by the front group second reflection surface to the image surface side. A substantially Z-shaped optical path exiting from the front group transparent medium to the image plane side through the front group second transmission surface, and the opening, passing through the opening, and passing through the rear group first transmission surface. A fourth optical path comprising: an optical path that enters the medium and exits from the rear group transparent medium to the image plane side through the rear group third transmission surface;
The relay optical system according to claim 8, wherein the relay optical system includes:

The relay optical system according to claim 11, wherein the following conditional expression (2) is satisfied.
0.9 <βtr / βrt <1.1 (2)
Where βtr is the projection magnification of the third optical path,
βrt is the projection magnification of the fourth optical path,
It is.

13. The relay optical system according to claim 1, wherein the refractive index of the front group transparent medium and the rear group transparent medium is 1.6 or more.

The relay optical system according to claim 1, wherein the following conditional expression (3) is satisfied.
1.0 <D / (2 × Imax) <1.8 (3)
Where Imax is the maximum image height,
D is the outer diameter of the transparent medium,
It is.

The relay optical system according to claim 1, wherein the following conditional expression (4) is satisfied.
1.2 <L / (2 × Imax) <2.0 (4)
Where Imax is the maximum image height,
L is the distance from the object plane to the image plane,
It is.

The relay optical system according to claim 1, wherein the following conditional expression (5) and conditional expression (6) are satisfied.
1.0 <Fr1 / Fr2 <1.8 (5)
1.0 <Rr2 / Rr1 <1.8 (6)
Where Fr1 is the curvature of the first reflecting surface of the front group,
Fr1 is the curvature of the second reflecting surface of the front group,
Rr1 is the curvature of the first reflecting surface of the rear group,
Rr2 is the curvature of the rear second reflective surface,
It is.