JPS633285B2 - - Google Patents
Info
- Publication number
- JPS633285B2 JPS633285B2 JP58049633A JP4963383A JPS633285B2 JP S633285 B2 JPS633285 B2 JP S633285B2 JP 58049633 A JP58049633 A JP 58049633A JP 4963383 A JP4963383 A JP 4963383A JP S633285 B2 JPS633285 B2 JP S633285B2
- Authority
- JP
- Japan
- Prior art keywords
- lens
- group
- front group
- positive
- negative
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000003287 optical effect Effects 0.000 claims description 8
- 239000011521 glass Substances 0.000 claims description 6
- 239000006185 dispersion Substances 0.000 claims description 3
- 239000000853 adhesive Substances 0.000 claims 1
- 230000001070 adhesive effect Effects 0.000 claims 1
- 230000004075 alteration Effects 0.000 description 23
- 206010073261 Ovarian theca cell tumour Diseases 0.000 description 4
- 208000001644 thecoma Diseases 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 206010010071 Coma Diseases 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/02—Telephoto objectives, i.e. systems of the type + - in which the distance from the front vertex to the image plane is less than the equivalent focal length
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Description
本発明は同軸型光波測距儀対物レンズに関する
ものである。
従来、セオドライト対物レンズとして、正の屈
折力を有する前群と負の屈折力を有する後群とか
らなる望遠タイプのレンズがあり、後群レンズを
光軸に沿つて移動させる事により無限遠から近距
離までのピント合わせを行うことを特徴としてい
た。また、後群レンズの移動による収差変動、組
立誤差、加工誤差による性能の劣化を少なくする
ため、後群レンズは正、負レンズを接着した１群
２枚構成が一般的であつた。
ところで、従来のセオドライト対物レンズに測
距機能を付加し、光波測距儀とするための手段と
して、セオドライト対物レンズの前群を赤外光発
光及び受光のためのコリメーターとして利用し、
後群は従来通りセオドライトのピント合わせのた
めの可動レンズとする方法が考えられるが、この
方法では、前群の焦点位置即ち光軸上に発光部、
受光部が来る事になり不都合を生じる。しかし、
この不都合は、前群と後群の間に赤外光と可視光
を分離するための手段を設け、前群の赤外光の焦
点位置を光軸外に導くことで解決できる。
さて、この様なセオドライトと一体となつた同
軸型光波測距儀対物レンズでは、前群は赤外光の
ためのコリメーターとして収差が補正されていな
ければならず、かつ、可視光ではセオドライトの
前群として、移動可能な後群との収差のバランス
を保ち全体として収差が補正されていなければな
らない。ところが、前群を赤外光のためのコリメ
ーターとして色収差を補正した場合、可視光は短
波長側で大きく補正過剰となり、後群で補正でき
なくなるため、セオドライトとしての機能が劣化
するという欠点があつた。また前群と後群の間に
赤外光と可視光を分離するための手段を設ける事
により、後群の移動のためのスペースがなくなる
という欠点があつた。従つて、これらの欠点を無
くすために、前群で一度結像させた後、リレーレ
ンズにより像を伝達し、リレーレンズ内に可動レ
ンズを設けピント合わせを行うという手段が考え
られるが、このような手段では、光学系が複雑と
なり、機能的にも従来のセオドライトには及ばな
かつた。
本発明は、前群のレンズに使用されるガラスに
適当なものを選び、かつ適当な条件を設定する事
により、従来のセオドライトの特長を保ちなが
ら、光波測距儀としての機能は勿論、セオドライ
トとしての機能も十分果たし得る同軸型光波測距
儀対物レンズを提供するものである。
本発明による対物レンズは、正の屈折力を有す
る前群、負の屈折力を有する後群、前記前群と後
群の間に配した赤外光と可視光を分離するための
ダイクロイツクプリズム及び後群後方に配した正
立プリズムからなる光学系で、前群は正単レンズ
及び正・負レンズの接着レンズからなる２群３枚
の構成であり、後群は負・正レンズの接着レンズ
からなる１群２枚の構成であつて、次の諸条件を
満足することを特徴とする光波測距儀対物レンズ
である。
(1) f1,2,3＜0.45f
(2) νd1＋νd2−νd3＞75
(3) θ1＋θ2＜0.0037（νd1＋νd2）＋1.22
(4) ｜r2｜＞｜r1｜、r1＞０、r2＜０
但し、ｆは全系の焦点距離、f1,2,3は前群の合成
焦点距離、νdi（ｉ＝１、２、３）は第ｉ番目のガ
ラス（レンズ）のｄ線のアツベ数、θj（ｊ＝１、
２）はｃ線の屈折率nc、Ｆ線の屈折率nF及び波長
1014nmの光線の屈折率n1014を用いてθ＝
nc−n1014／nF−ncと定義される第ｊ番目のガラス（レ
ン
ズ）の赤外域の部分分散比、ri（ｉ＝１、２）は
第ｉ番目の面の曲率半径を表わす。
次に各条件について説明する。
条件(1)は、レンズ系の大きさを決めるためのも
ので、前群に大きな正の屈折力を持たせて望遠比
を小さくしようとするものである。即ち、条件(1)
の右辺を越えて前群の焦点距離が長くなると、コ
ンパクトな光波測距儀を得ることができない。
条件(2)は前群の色収差を適度に補正過剰とする
ものである。望遠タイプのレンズの色収差の補正
の方法としては、前群で補正過剰とし後群で補正
不足として全系の補正を行うのが一般的である。
しかるに、条件(2)からはずれて色収差の補正を行
う場合には、各レンズの屈折力が大となり、色収
差以外の収差が大きくなるか、または倍率の色収
差が大きくなり好ましくない。
条件(3)は、前群で赤外光の色補正をした時に、
前群の可視光の色収差を少なくするためのもので
ある。即ち、赤外光の部分分散比θjが右辺を越え
て大きくなると、赤外光の色収差の補正をした場
合の可視光の色収差は短波長側で大きく補正過剰
となり、後群でこれを補正することが困難となる
ものある。
条件(4)は前群、後群を通じてコマ収差をとるた
めの条件である。後群は、負の屈折力を持ち、か
つダイクロイツクプリズムの後方に位置するた
め、後群に入射する光線の入射高が低くなり、負
の屈折力が大となるために、後群で球面収差を補
正した場合には後群の第１面（実施例のr8）によ
るコマ収差が残つてしまう。従つて、このコマ収
差は前群で補正する必要があり、前群の正単レン
ズでの光線の屈折角を大きなものとしてコマ収差
を補正するものである。即ち、条件(4)において｜
r2｜が｜r1｜より小さくなつた場合には、前群で
のコマ収差が後群のコマ収差が後群のコマ収差の
補正に必要な量以上に大きくなり、全系として前
群のコマ収差が残つてしまうので好ましくない。
以下、本発明による実施例をあげる。
ここで、ri（ｉ＝１、２、３、…）は第ｉ番目
の面の曲率半径、di（ｉ＝１、２、３、…）は第
ｉ番目の面と第（ｉ＋１）番目の面の間隔、nj、
νj（ｊ＝１、２、３…）は第ｊ番目のガラスのｄ
線の屈折率及びｄ線のアツベ数を示す。
実施例 １
The present invention relates to a coaxial optical rangefinder objective lens. Conventionally, there is a telephoto type lens as a theodolite objective lens, which consists of a front group with positive refractive power and a rear group with negative refractive power. It was characterized by the ability to focus up to a distance. Furthermore, in order to reduce performance deterioration due to aberration fluctuations due to movement of the rear lens group, assembly errors, and processing errors, the rear lens group generally has a two-lens configuration in which a positive lens and a negative lens are bonded to each other. By the way, as a means of adding a distance measurement function to a conventional theodolite objective lens and making it a light wave rangefinder, the front group of the theodolite objective lens is used as a collimator for emitting and receiving infrared light.
One possible method is to use a movable lens for focusing the theodolite in the rear group as in the past, but in this method, a light emitting part is placed at the focal position of the front group, that is, on the optical axis.
The light-receiving part will come closer, causing an inconvenience. but,
This inconvenience can be solved by providing means for separating infrared light and visible light between the front group and the rear group, and guiding the focal position of the infrared light of the front group off the optical axis. Now, in such a coaxial optical rangefinder objective lens that is integrated with a theodolite, the front group must be used as a collimator for infrared light to correct aberrations, and for visible light, the theodolite's aberrations must be corrected. The front group must balance aberrations with the movable rear group and correct aberrations as a whole. However, if the front group is used as a collimator for infrared light to correct chromatic aberration, visible light will be greatly overcorrected on the short wavelength side, and the rear group will not be able to correct it, resulting in a deterioration in the function of the theodolite. It was hot. Furthermore, by providing a means for separating infrared light and visible light between the front group and the rear group, there is a drawback that there is no space for movement of the rear group. Therefore, in order to eliminate these drawbacks, it is conceivable to form an image once in the front group, then transmit the image through a relay lens, and then set a movable lens inside the relay lens to perform focusing. However, the optical system was complicated, and it was not as functional as a conventional theodolite. By selecting an appropriate glass for the front group lens and setting appropriate conditions, the present invention maintains the features of conventional theodolites, while also functioning as a light wave rangefinder. The object of the present invention is to provide an objective lens for a coaxial light wave rangefinder that can also function as a coaxial optical rangefinder. The objective lens according to the present invention includes a front group having a positive refractive power, a rear group having a negative refractive power, and a dichroic prism arranged between the front group and the rear group for separating infrared light and visible light. The optical system consists of an erecting prism placed at the rear of the rear group.The front group consists of two groups of three elements, each consisting of a positive single lens and a positive/negative lens bonded together, and the rear group consists of a negative/positive lens bonded together. This is an objective lens for a light wave rangefinder, which has a configuration of two lenses in a group, and is characterized by satisfying the following conditions. (1) f 1,2,3 ＜0.45f (2) νd 1 +νd 2 −νd 3 ＞75 (3) θ 1 +θ 2 ＜0.0037(νd 1 +νd 2 )+1.22 (4) ｜r 2 ｜＞ |r 1 |, r 1 > 0, r 2 < 0 However, f is the focal length of the entire system, f 1,2,3 is the combined focal length of the front group, and νd i (i=1, 2, 3) is The d-line Atsube number of the i-th glass (lens), θ j (j=1,
2) is the refractive index n c of the c-line, the refractive index n F of the F-line, and the wavelength
Using the refractive index n 1014 of a ray of 1014 nm, θ=
The infrared partial dispersion ratio of the j-th glass (lens) is defined as n c −n 1014 /n F −n c , and r i (i=1, 2) is the radius of curvature of the i-th surface. represent. Next, each condition will be explained. Condition (1) is for determining the size of the lens system, and is intended to provide a large positive refractive power to the front group to reduce the telephoto ratio. That is, condition (1)
If the focal length of the front group becomes longer than the right side of , it is impossible to obtain a compact light wave rangefinder. Condition (2) is such that the chromatic aberration of the front group is appropriately overcorrected. A common method for correcting chromatic aberration in a telephoto lens is to correct the entire system by overcorrecting in the front group and undercorrecting in the rear group.
However, if chromatic aberration is corrected deviating from condition (2), the refractive power of each lens becomes large, and aberrations other than chromatic aberration become large, or chromatic aberration of magnification becomes large, which is not preferable. Condition (3) is when the front group performs color correction for infrared light.
This is to reduce the chromatic aberration of visible light in the front group. In other words, when the partial dispersion ratio θ j of infrared light increases beyond the right side, the chromatic aberration of visible light when correcting the chromatic aberration of infrared light becomes greatly overcorrected on the short wavelength side, and this is corrected in the rear group. There are some things that are difficult to do. Condition (4) is a condition for eliminating comatic aberration through the front and rear groups. The rear group has negative refractive power and is located behind the dichroic prism, so the incident height of the light rays that enter the rear group is low, and the negative refractive power is large, so the rear group has a spherical surface. When aberrations are corrected, coma aberration due to the first surface of the rear group (r 8 in the embodiment) remains. Therefore, it is necessary to correct this coma aberration in the front group, and the coma aberration is corrected by increasing the refraction angle of the light beam at the positive single lens in the front group. That is, in condition (4) |
When r 2 | becomes smaller than | r 1 |, the coma in the front group becomes larger than the amount necessary to correct the coma in the rear group, and as a whole system, the front group This is not preferable because the coma aberration remains. Examples according to the present invention will be given below. Here, r i (i=1, 2, 3,...) is the radius of curvature of the i-th surface, and d i (i=1, 2, 3,...) is the radius of curvature of the i-th surface and (i+1) Spacing between the th planes, n j ,
ν j (j=1, 2, 3...) is d of the jth glass
The line refractive index and the d-line Abbe number are shown. Example 1
【表】【table】
【表】 実施例 ２【table】 Example 2
【表】 実施例 ３【table】 Example 3
第１図は本発明の実施例１のレンズ断面図、第
２図は本発明の実施例１の収差図、第３図は本発
明の実施例２のレンズ断面図、第４図は本発明の
実施例２の収差図、第５図は本発明の実施例３の
レンズ断面図、第６図は本発明の実施例３の収差
図。
FIG. 1 is a cross-sectional view of a lens according to Example 1 of the present invention, FIG. 2 is an aberration diagram of Example 1 of the present invention, FIG. 3 is a cross-sectional view of a lens according to Example 2 of the present invention, and FIG. 4 is a cross-sectional view of a lens according to Example 2 of the present invention. FIG. 5 is a cross-sectional view of a lens according to Example 3 of the present invention, and FIG. 6 is an aberration diagram of Example 3 of the present invention.
Claims (1)
る後群、前記前群と後群の間に配した赤外光と可
視光を分離するためのダイクロイツクプリズム及
び後群後方に配した正立プリズムからなる光学系
で、前群は正単レンズ及び正・負レンズの接着レ
ンズからなる２群３枚の構成であり、後群は負・
正レンズの接着レンズからなる１群２枚の構成で
あつて、次の諸条件を満足することを特徴とする
光波測距儀対物レンズ。 (1) f1,2,3＜0.45f (2) νd1＋νd2−νd3＞75 (3) θ1＋θ2＜0.0037（νd1＋νd2）＋1.22 (4) ｜r2｜＞｜r1｜、r1＞０、r2＜０ 但し、ｆは全系の焦点距離、f1,2,3は前群の合成
焦点距離、νdi（ｉ＝１、２、３）は第ｉ番目のガ
ラス（レンズ）のｄ線のアツベ数、θj（ｊ＝１、
２）はｃ線の屈折率nc、Ｆ線の屈折率nF及び波長
1014nmの光線の屈折率n1014を用いてθ＝
nc−n1014／nF−ncと定義される第ｊ番目のガラス（レ
ン ズ）の赤外域の部分分散比、ri（ｉ＝１、２）は
第ｉ番目の面の曲率半径を表わす。[Claims] 1. A front group having a positive refractive power, a rear group having a negative refractive power, and a dichroic prism arranged between the front group and the rear group for separating infrared light and visible light. The optical system consists of an erecting prism placed at the rear of the rear group.The front group has a configuration of three elements in two groups consisting of a positive single lens and a bonded lens with positive and negative lenses, and the rear group has a negative and negative lens.
An objective lens for a light wave rangefinder, which has a configuration of two lenses in a group consisting of a positive adhesive lens and satisfies the following conditions. (1) f 1,2,3 ＜0.45f (2) νd 1 +νd 2 −νd 3 ＞75 (3) θ 1 +θ 2 ＜0.0037(νd 1 +νd 2 )+1.22 (4) ｜r 2 ｜＞ |r 1 |, r 1 > 0, r 2 < 0 However, f is the focal length of the entire system, f 1,2,3 is the combined focal length of the front group, and νd i (i=1, 2, 3) is The d-line Atsube number of the i-th glass (lens), θ j (j=1,
2) is the refractive index n c of the c-line, the refractive index n F of the F-line, and the wavelength
Using the refractive index n 1014 of a ray of 1014 nm, θ=
The infrared partial dispersion ratio of the j-th glass (lens) is defined as n c −n 1014 /n F −n c , and r i (i=1, 2) is the radius of curvature of the i-th surface. represent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4963383A JPS59174811A (en) | 1983-03-24 | 1983-03-24 | Objective lens of light wave range finder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4963383A JPS59174811A (en) | 1983-03-24 | 1983-03-24 | Objective lens of light wave range finder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59174811A JPS59174811A (en) | 1984-10-03 |
| JPS633285B2 true JPS633285B2 (en) | 1988-01-22 |
Family
ID=12836615
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4963383A Granted JPS59174811A (en) | 1983-03-24 | 1983-03-24 | Objective lens of light wave range finder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59174811A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53129061A (en) * | 1977-04-18 | 1978-11-10 | Asahi Optical Co Ltd | Inner focusing analactic telescope objective lens |
| JPS5786771A (en) * | 1980-11-20 | 1982-05-29 | Tokyo Optical Co Ltd | Light wave range finder with collimating telescope |
-
1983
- 1983-03-24 JP JP4963383A patent/JPS59174811A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53129061A (en) * | 1977-04-18 | 1978-11-10 | Asahi Optical Co Ltd | Inner focusing analactic telescope objective lens |
| JPS5786771A (en) * | 1980-11-20 | 1982-05-29 | Tokyo Optical Co Ltd | Light wave range finder with collimating telescope |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59174811A (en) | 1984-10-03 |
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