JPS5934508A - Photographic lens having short overall lens length - Google Patents

Photographic lens having short overall lens length

Info

Publication number
JPS5934508A
JPS5934508A JP57145292A JP14529282A JPS5934508A JP S5934508 A JPS5934508 A JP S5934508A JP 57145292 A JP57145292 A JP 57145292A JP 14529282 A JP14529282 A JP 14529282A JP S5934508 A JPS5934508 A JP S5934508A
Authority
JP
Japan
Prior art keywords
lens
aspherical
refractive power
refracting power
face
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.)
Pending
Application number
JP57145292A
Other languages
Japanese (ja)
Inventor
Yasuhisa Sato
泰久 佐藤
Yasuyuki Yamada
康幸 山田
Hideo Yokota
秀夫 横田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to JP57145292A priority Critical patent/JPS5934508A/en
Publication of JPS5934508A publication Critical patent/JPS5934508A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00Optical objectives specially designed for the purposes specified below
    • G02B13/18Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)

Abstract

PURPOSE:To decrease the number of lenses and to shorten the overall lens length, by disposing the 1st meniscus lens having positive refracting power, the 2nd lens having negative refracting power, the 3rd lens having positive refracting power, and the 4th meniscus lens having negative refracting power, and forming the lens face on the object side of the 3rd lens to an aspherical face. CONSTITUTION:A lens face R5 is made into such an aspherical face by which the positive refracting power is decreased on the periphery of the lens, thereby decreasing the refraction quantity of a lower ray L to L' and correcting satisfactorily comatic aberration. The transverse aberration corrected well of comatic aberration is thus obtd. and the resolving power is considerably improved. If the lens face on the object side of the 3rd lens group is used, the lens shape that makes finishing t an aspherical shape easy is obtd.

Description

【発明の詳細な説明】 本発明はレンズ系のレンズ全長(レンズの第1面から焦
点面まで)の短かいコンパクトな広角の写真レンズに関
するものである。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compact wide-angle photographic lens having a short overall lens length (from the first surface of the lens to the focal plane).

近年、カメラの小型化に伴って、レンズ全長の短かいコ
ンパクトなレンズが要求されるようになっている。特に
レンズ系のレンズ全長を焦点距離の1倍以下にするため
には、レンズ系の前群を正の屈折力、後群を負の屈折力
に構成することが望ましい。こうした屈折力配置は画角
の狭い長焦点レンズに多用されるが、レンズ系のレンズ
全長が短かく、かつ口径比の大きな画角600以上の広
角レンズに適用されている例は少ない。
In recent years, with the miniaturization of cameras, there has been a demand for compact lenses with short overall lens lengths. In particular, in order to make the total lens length of the lens system less than or equal to one time the focal length, it is desirable to configure the front group of the lens system to have positive refractive power and the rear group to have negative refractive power. Such a refractive power arrangement is often used for long focal length lenses with a narrow angle of view, but it is rarely applied to wide-angle lenses with a short overall lens length and a large aperture ratio of 600 or more.

その理由としては、この種の屈折力配置でレンズ全長を
短かぐするに従って、また口径比を大きくするに従って
、更には画角を増やすに従って歪曲収差や非点収差が悪
化し、あるいはコ屈折力配置のレンズ系は周知であるが
、そこに記載されたレンズの画角は46度で、標準レン
ズ程度の画角であり、もし、画角の増加を計る−け1 
: 4.5であり明るいl/レンズは言えない。
The reason for this is that with this type of refractive power arrangement, as the overall length of the lens is shortened, as the aperture ratio is increased, and as the angle of view is increased, distortion and astigmatism worsen; The lens system is well known, but the angle of view of the lens described there is 46 degrees, which is about the same as a standard lens.
: 4.5, so it cannot be said that it is a bright l/lens.

又、特公昭56−50248号公報で提案されているよ
うに非球面を用いず、球面系のレンズのみでレンズを構
成した場合には、画面中間部で像面彎曲のふくらみが大
きく、これを補正しようとするとコマ収差が多く発生す
るという欠点を有し〜ている。コマ収差は解像力を著し
く低下させるため、非常に好ましくない。
In addition, when the lens is constructed from only spherical lenses without using an aspherical surface as proposed in Japanese Patent Publication No. 56-50248, the curvature of field is large in the middle of the screen, and this It has the disadvantage that a large amount of coma aberration occurs if an attempt is made to correct it. Comatic aberration is extremely undesirable because it significantly reduces resolution.

一方、特公昭44〜10831号公報や特開昭56−9
4317号公報で提案されているように最終の負の屈折
力のメニスカス状のレンズ’を非球面化する方法はコマ
収差を除去し解像力を向上させる手段として有効でt;
t、6るが、負の屈折力のメニスカス状のレンズの曲率
半径が極め−ご小さく、極端な場合には半球に近いレン
ズ面を非球面加工しなければ々らない場合がある。この
為、加工・検査がむずかしいという欠点を有している。
On the other hand, Japanese Patent Publication No. 44-10831 and Japanese Unexamined Patent Publication No. 56-9
As proposed in Publication No. 4317, the method of making the final meniscus-shaped lens with negative refractive power aspherical is effective as a means for removing coma aberration and improving resolution.
However, the radius of curvature of a meniscus-shaped lens with negative refractive power is extremely small, and in extreme cases, it may be necessary to process the nearly hemispherical lens surface into an aspherical surface. For this reason, it has the disadvantage of being difficult to process and inspect.

本発明はレンズ枚数が少なく、レンズ全長の短かいコン
パクトな写真レンズを提供することを目的とL1後述す
る実施例はFナンバー1:2.8、画角62度と明るく
、広角の写真レンズを達成している。
The purpose of the present invention is to provide a compact photographic lens with a small number of lenses and a short overall lens length. Achieved.

本発明の目的を達成する為のレンズ構成の特徴は物体側
より順に、物体へ凸面を向けた正の屈折力のメニスカス
状の第ルンズ、両レンズ面が凹面の負の屈折力の第2レ
ンズ、両レンズ面が凸面の正の屈折力の第3レンズ、そ
して物体へ凹面を向けた負の屈折力のメニスカス状の第
4レンズを配置し、M3レンズの物体側のレンズ面を非
球面としたことでおる。このようなレンズ構成において
第3レンズの物体側のレンズ面を非球面化することによ
って画面中間部でのコマ収差の補正を良好に行い、しか
本非球面加工がしやすいレンズ形状とすることができる
The features of the lens configuration for achieving the purpose of the present invention are, in order from the object side, a meniscus-shaped lens with a positive refractive power with a convex surface facing the object, and a second lens with a negative refractive power with both lens surfaces concave. , a third lens with positive refractive power with both convex lens surfaces, and a meniscus-shaped fourth lens with negative refractive power with the concave surface facing the object, and the object-side lens surface of the M3 lens is an aspherical surface. I'm sorry for what I did. In such a lens configuration, by making the object-side lens surface of the third lens aspherical, coma aberration in the middle part of the screen can be well corrected, and the lens shape can be easily processed by aspherical processing. can.

前述したように本発明の如きレンズタイプにおいて、全
てのレンズ面を球面系のみで構成するならば、画面中間
部でコマ収差が多く発生する。これを模式的に描込たの
が第2図である。
As mentioned above, in the lens type of the present invention, if all the lens surfaces are composed of only spherical surfaces, a large amount of comatic aberration will occur in the middle part of the screen. Figure 2 is a schematic depiction of this.

画面中間部に到達する光束の主光線をPl−ト方の光線
をU、下方の光線をLl レンズの球面をR,5,R6
で表現している。このレンズタイプの特徴は下方の光線
りが屈折力が過少となってフィルム面Fの面上で主光線
Pよりも上方に到達することにある。したがって外向性
コマの発性原因と々り第3図Aに示す如く横収差の劣化
となってあられれる。
The principal ray of the light beam reaching the middle part of the screen is Pl, the ray on the upper side is U, the lower ray is Ll, and the spherical surface of the lens is R, 5, R6.
It is expressed as. A feature of this lens type is that the downward light ray has too little refractive power and reaches above the principal ray P on the film surface F. Therefore, the cause of extroverted coma is the deterioration of transverse aberration, as shown in FIG. 3A.

本発明では、レンズ面R5をレンズの周辺で正の屈折力
が減少するような形状にレンズ面R5を非球面化するこ
とによって、下方の光線りの屈折量を減らしてL′とし
、コマ収差を良好に補正している。この結果第3図Bに
示すようにコマ収差のよく補正された横収差が得られ解
像力の大巾な向上が可能となるのである。
In the present invention, by making the lens surface R5 aspherical so that the positive refractive power decreases at the periphery of the lens, the amount of refraction of the downward light ray is reduced to L', thereby eliminating coma aberration. is well corrected. As a result, as shown in FIG. 3B, lateral aberrations with well-corrected comatic aberrations are obtained, making it possible to greatly improve resolving power.

そして本発明では第3レンズ群の物体側のレンズ面に非
球面を用いることKより、非球面形状の加工が容易とな
るレンズ形状とすることがズの物体側のレンズ面を非球
面化した場合、このレンズ面の有効面を見込む角が80
°以上、極端な場合には180°(半球)に近くなり極
めて加工がしにくくなる。本発明によれば同角が20゜
以下程度であり、非球面加工が容易に行なえる。
In addition, in the present invention, since an aspherical surface is used for the object side lens surface of the third lens group, it is preferable to use a lens shape that can be easily processed into an aspherical shape. In this case, the angle looking into the effective surface of this lens surface is 80
degree or more, and in extreme cases it approaches 180 degrees (hemisphere), making it extremely difficult to process. According to the present invention, the same angle is about 20° or less, and aspherical processing can be easily performed.

また、加工精度の検査もより容易にできる。In addition, inspection of machining accuracy can be made easier.

なお、第3レンズ群の非球面レンズを合成樹脂素材で製
造すれば、廉価な写真用レンズを提供することができる
Note that if the aspherical lens of the third lens group is manufactured from a synthetic resin material, an inexpensive photographic lens can be provided.

又、本発明に係る写真レンズにおいてフォーカシングは
、一般に行なわれているレンズ全体を繰り出して行って
も良く、又第4レンズを固定し、第ルンズから第3レン
ズまでを繰り出して行うことも可能である。第ルンズの
み又は第3レンズのみを繰り出して行うことも可能であ
る。
Further, in the photographic lens according to the present invention, focusing may be performed by extending the entire lens as is generally done, or by fixing the fourth lens and extending from the lens to the third lens. be. It is also possible to extend only the third lens or the third lens.

以上のようにレンズ構成を決めれば、レンズ全長の短い
コンパクトでしかも良好に収差補正を行った写貞レンズ
を達成することができる。
By determining the lens configuration as described above, it is possible to achieve a compact photographic lens with a short overall lens length and excellent aberration correction.

次に本発明の実施例を示す。実施例においてRi#−を
物体側より順に第1番目のレンズ面の曲率半径、Diは
物体側より順に第i番目の1/ンズ厚及び空気間隔、N
iとνiは夫々物体側より順に第i番目のレンズのガラ
スの屈折率とアツベ数である。
Next, examples of the present invention will be shown. In the example, Ri#- is the radius of curvature of the first lens surface in order from the object side, Di is the i-th 1/lens thickness and air gap in order from the object side, and N
i and νi are the refractive index and Abbe number of the glass of the i-th lens, respectively, in order from the object side.

非球面形状は光軸方向にY軸、光軸と垂直な方向にY軸
、光の進行方向を正とし、レンズの頂点とY軸の交点を
原点に採り、R米を第3群レンズの物体側の【/ンズ面
の近軸曲率半径、atを非球面偶係数、biを非球面奇
係数としたとき、+bIY8+b2Y5+b3Y7+・
・・・・・・−・なる展開式で表わしている。
The aspherical shape has the Y-axis in the optical axis direction, the Y-axis in the direction perpendicular to the optical axis, and the direction of light propagation as positive.The origin is the intersection of the apex of the lens and the Y-axis, and R is the third group lens The paraxial radius of curvature of the [/lens surface on the object side, at is the even coefficient of the aspherical surface, and bi is the odd coefficient of the aspherical surface, +bIY8+b2Y5+b3Y7+・
It is expressed by the following expansion formula.

数値実施例1゜ F=100   FNO=1 : 2.8  2ω=5
9.31%1=  33.15  D1=10.44 
 N1=1.77250  シ1=49.6R2= 1
02.55  D2= 2.63R3=−125,6(
I  D3= 2.63  N2=1.80518  
ν2=25.4R4=  56.37  D4=7.5
4R5’=  95.48  D5= 5.61  N
5=1.80610  シ3−40.9R6=−90.
67  D6=22.98R7= −21,20D7=
 3.16  N4=1.51633  シ4=64.
IR8= −32,85 非球面係数 4 a、 = 1.893 X 10    b、 = 1
.649 X 10−’a2 = 1.190 X 1
0’   bz = 1.758 X 10−”10 a! =−2,507x 10    bs = 2.
127 x 10−”14 a4 := −7,929X 10    b4 = 
1.046 X 10−”数値実施例2゜ F=100.   FNO=1 : 3.5  2ω=
63.4R1=  34.23  DI=10.53 
 N1=1.77250  シ1=49.6R2二 1
18.16  D2=3.43R3−−116,98D
3= 2.86  N2=1.80518  ν2=2
5.4R4=  55.07  D4=9.09R5本
 59.57  D5=5.64  N5=1.605
62  シ3=43.7R6= −69,04D6=2
2.17R7= −21,36D7= 3.43  N
4=1.51633  ν4褐4.1R8= −37,
63 非球面係数 a、 = 1.697 X 10    b、 = 1
.774 X 10’as = 5.786 X 10
    bz = 1.721 X 10’10 am = 9.483 X 10    b、 = −
1,831X 10”13 a4 = −4,197X 10    b4 = −
2,684X 1O−14a、 == 3.450 X
 10−”
Numerical example 1°F=100 FNO=1: 2.8 2ω=5
9.31%1=33.15 D1=10.44
N1=1.77250 Si1=49.6R2=1
02.55 D2= 2.63R3=-125,6(
ID3=2.63 N2=1.80518
ν2=25.4R4=56.37 D4=7.5
4R5'= 95.48 D5= 5.61 N
5=1.80610 C3-40.9R6=-90.
67 D6=22.98R7= -21,20D7=
3.16 N4=1.51633 C4=64.
IR8= -32,85 Aspheric coefficient 4 a, = 1.893 X 10 b, = 1
.. 649 x 10-'a2 = 1.190 x 1
0' bz = 1.758 x 10-"10 a! = -2,507x 10 bs = 2.
127 x 10-”14 a4 := -7,929X 10 b4 =
1.046 X 10-” Numerical Example 2°F=100. FNO=1: 3.5 2ω=
63.4R1=34.23 DI=10.53
N1=1.77250 Si1=49.6R22 1
18.16 D2=3.43R3--116,98D
3=2.86 N2=1.80518 ν2=2
5.4R4 = 55.07 D4 = 9.09R5 pieces 59.57 D5 = 5.64 N5 = 1.605
62 Shi3=43.7R6=-69,04D6=2
2.17R7=-21,36D7=3.43N
4=1.51633 ν4brown4.1R8= -37,
63 Aspheric coefficient a, = 1.697 x 10 b, = 1
.. 774 x 10'as = 5.786 x 10
bz = 1.721 x 10'10 am = 9.483 x 10 b, = -
1,831X 10"13 a4 = -4,197X 10 b4 = -
2,684X 1O-14a, == 3.450X
10-”

【図面の簡単な説明】 第1図は本発明と同じレンズタイプの光路を示すレンズ
断面図、 第2図は画面中間部に結像す光束の非球面を通過する光
線の説明図、 第3図A、Bは非球面を用いたときのコマ収差の補正を
示す横収差図、 第4図は本発明の数値実施例1のレンズ断面図、第5図
、第6図は各々本発明の数値実施例1.2の諸収差図で
ある。 図中、Rはレンズ面、Dはレンズ面間隔、ΔMはメリデ
イオル像面、ΔSはサジタル像面である。 出願人  キャノン株式会社
[Brief Description of the Drawings] Figure 1 is a cross-sectional view of a lens showing the optical path of the same lens type as the present invention, Figure 2 is an explanatory diagram of a light beam that passes through an aspherical surface of a light beam that forms an image in the middle of the screen, and Figure 3. Figures A and B are lateral aberration diagrams showing the correction of coma aberration when an aspherical surface is used. Figure 4 is a cross-sectional view of the lens of Numerical Example 1 of the present invention. Figures 5 and 6 are each of the lenses of the present invention. FIG. 6 is a diagram of various aberrations of Numerical Example 1.2. In the figure, R is a lens surface, D is a distance between lens surfaces, ΔM is a meridian image surface, and ΔS is a sagittal image surface. Applicant Canon Co., Ltd.

Claims (2)

【特許請求の範囲】[Claims] (1)物体側より順に、物体へ凸面を向けた正の屈折力
のメニスカス状の第ルンズ、両レンズ面が凹面の負の屈
折力の第2レンズ、両レンズ面が凸面の正の屈折力の第
3レンズ、そして物体側へ凹面を向けた負の屈折力のメ
ニスカス状の第4レンズを配置し2、 前記第3レンズの物体側のレンズ面を非球面としたこと
を特徴とするレンズ全長の短い写真レンズ。
(1) In order from the object side: a meniscus-shaped lens with positive refractive power with a convex surface facing the object, a second lens with negative refractive power with both concave lens surfaces, and a positive refractive power with both lens surfaces convex. and a meniscus-shaped fourth lens with a negative refractive power with a concave surface facing the object side, 2, and the object-side lens surface of the third lens is an aspherical lens. A photographic lens with a short overall length.
(2)前記第3レンズの非球面はレンズの周辺部にいく
にしたがい正の屈折力が弱まるような形状となっている
ことを特徴とする特許請求の範囲第1項記載のレンズ全
長の短い写真レンズ。
(2) The aspherical surface of the third lens has a shape such that the positive refractive power becomes weaker toward the periphery of the lens. photographic lens.
JP57145292A 1982-08-20 1982-08-20 Photographic lens having short overall lens length Pending JPS5934508A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP57145292A JPS5934508A (en) 1982-08-20 1982-08-20 Photographic lens having short overall lens length

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57145292A JPS5934508A (en) 1982-08-20 1982-08-20 Photographic lens having short overall lens length

Publications (1)

Publication Number Publication Date
JPS5934508A true JPS5934508A (en) 1984-02-24

Family

ID=15381764

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57145292A Pending JPS5934508A (en) 1982-08-20 1982-08-20 Photographic lens having short overall lens length

Country Status (1)

Country Link
JP (1) JPS5934508A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61110568A (en) * 1984-10-31 1986-05-28 アルカテル・エヌ・ブイ Printer device
US4787721A (en) * 1984-08-18 1988-11-29 Minolta Camera Kabushiki Kaisha Photographic lens system
US6950246B2 (en) 2003-04-23 2005-09-27 Olympus Corporation Imaging optical system and apparatus using the same

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5557709U (en) * 1978-10-17 1980-04-19
JPS5610606U (en) * 1979-07-02 1981-01-29

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5557709U (en) * 1978-10-17 1980-04-19
JPS5610606U (en) * 1979-07-02 1981-01-29

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4787721A (en) * 1984-08-18 1988-11-29 Minolta Camera Kabushiki Kaisha Photographic lens system
JPS61110568A (en) * 1984-10-31 1986-05-28 アルカテル・エヌ・ブイ Printer device
JPH0572266B2 (en) * 1984-10-31 1993-10-08 Alcatel Nv
US6950246B2 (en) 2003-04-23 2005-09-27 Olympus Corporation Imaging optical system and apparatus using the same

Similar Documents

Publication Publication Date Title
JP3769373B2 (en) Bright wide-angle lens
JP3369654B2 (en) Wide-angle lens
JPS6352364B2 (en)
JPH11183796A (en) Image pickup optical system
US4057328A (en) Enlarging lens system
JPS6048013B2 (en) Finder optical system
JPH05224119A (en) Large-diameter intermediate telephoto lens
JPS6040604B2 (en) Gauss type large aperture ratio photographic lens
JPS5833211A (en) Small-sized photographic lens
US4373786A (en) Photographic objective of reduced size
JPS6132653B2 (en)
JPH07168095A (en) Triplet lens
JP2001133684A (en) Photographic lens
JPH07318798A (en) Photographic lens
JP3082997B2 (en) Wide-angle lens
JPS5934508A (en) Photographic lens having short overall lens length
JPH06160706A (en) Wide angle lens
JPH02248910A (en) Fish-eye lens
JP3809270B2 (en) Objective lens
JPH07104180A (en) Wide-angle lens
JPH1096858A (en) Zoom lens
JPH05323184A (en) Photographic lens
JPH06242370A (en) Large aperture lens
JPS6140087B2 (en)
JPH0694992A (en) Photographic lens