JP2011090346A - Front converter lens - Google Patents

Front converter lens Download PDF

Info

Publication number
JP2011090346A
JP2011090346A JP2011026350A JP2011026350A JP2011090346A JP 2011090346 A JP2011090346 A JP 2011090346A JP 2011026350 A JP2011026350 A JP 2011026350A JP 2011026350 A JP2011026350 A JP 2011026350A JP 2011090346 A JP2011090346 A JP 2011090346A
Authority
JP
Japan
Prior art keywords
lens
positive
object side
group
positive lens
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.)
Granted
Application number
JP2011026350A
Other languages
Japanese (ja)
Other versions
JP5075257B2 (en
Inventor
Nobuyuki Miyazawa
伸幸 宮沢
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 JP2011026350A priority Critical patent/JP5075257B2/en
Publication of JP2011090346A publication Critical patent/JP2011090346A/en
Application granted granted Critical
Publication of JP5075257B2 publication Critical patent/JP5075257B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Lenses (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-weight converter lens that is composed of relatively fewer lenses, while achieving high afocal magnification ratio at low cost. <P>SOLUTION: The front converter lens C is composed of a front group L1 with a positive refractive power and a back group L2 with a negative refractive power, and is attachable to a front of a main lens system M. The front group L1 has at least two positive lens and all of the lens are arranged with a certain interval, and the back group L2 is composed of the positive lens and negative lens. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明はデジタルスチルカメラ、ビデオカメラ、銀塩写真用カメラ等の撮影レンズ(主レンズ系)の前方(物体側)に装着してレンズ系全体の焦点距離を変位させるコンバータレンズに関するものである。   The present invention relates to a converter lens that is mounted in front (object side) of a photographic lens (main lens system) such as a digital still camera, a video camera, or a silver halide photographic camera to displace the focal length of the entire lens system.

従来、撮影レンズの前方に装着し全系の焦点距離を長焦点距離側に変化させるフロント方式のテレコンバータレンズ(テレコンバータ)が例えば特許文献1で提案されている。   Conventionally, for example, Patent Document 1 proposes a front-type teleconverter lens (teleconverter) that is mounted in front of a photographing lens and changes the focal length of the entire system to the long focal length side.

テレコンバータは多くの場合、正の屈折力の前群と負の屈折力の後群の2つのレンズ群を両レンズ群の焦点距離の和だけ主点間隔を隔てて配置し、全系としてアフォーカル系を構成している。従って最も簡単なレンズ系としては特許文献1のように正レンズと負レンズを1枚づつ配置した構成とすることができる。しかしながら高い光学性能を得るためには、収差補正上、2枚のレンズのみの構成では困難である。   In many cases, a teleconverter has two lens groups, a front group having a positive refractive power and a rear group having a negative refractive power, arranged with a principal point interval that is the sum of the focal lengths of both lens groups. Consists of a focal system. Therefore, as the simplest lens system, a configuration in which one positive lens and one negative lens are arranged as in Patent Document 1 can be used. However, in order to obtain high optical performance, it is difficult to correct aberrations by using only two lenses.

レンズ枚数を増やし収差補正したテレコンバータとして、特許文献2、特許文献3が知られている。   Patent Documents 2 and 3 are known as teleconverters in which the number of lenses is increased and aberrations are corrected.

特開昭55−32046号公報JP 55-32046 A 特開平4−191717号公報JP-A-4-191717 特開平6−289289号公報JP-A-6-289289

特許文献2に開示されたテレコンバータは、アフォーカル倍率が増大したときに1枚のレンズのみで構成された前群では諸収差の補正が困難となる問題を、前群を2枚の正メニスカスレンズにし、各レンズの屈折力を弱くすることで収差補正を図っている。但し、後群は負レンズ1枚のみで構成されており、色収差の補正が不十分である。   The teleconverter disclosed in Patent Document 2 has a problem that it is difficult to correct various aberrations in the front group composed of only one lens when the afocal magnification is increased, and the front group includes two positive meniscuses. Aberrations are corrected by reducing the refractive power of each lens. However, the rear group is composed of only one negative lens, and correction of chromatic aberration is insufficient.

また、特許文献3に開示されたテレコンバータは、前群を低分散ガラスで形成した1枚の正レンズのみの構成として色収差の劣化を防いでいるが、アフォーカル倍率が1.3倍以下と低い。   In addition, the teleconverter disclosed in Patent Document 3 prevents deterioration of chromatic aberration by using only one positive lens in which the front group is made of low dispersion glass, but the afocal magnification is 1.3 times or less. Low.

しかし、これらの補正のために径の大きい前群の枚数を増やしすぎると重量及びコストの増加に大きな影響を及ぼす。   However, if the number of the front group having a large diameter is excessively increased for these corrections, the weight and cost are greatly increased.

本発明は上述した従来例を鑑みなされたもので、高いアフォーカル倍率を実現しつつ、比較的構成レンズ枚数が少なく、安価で軽量なコンバータレンズを提供することを目的とする。   The present invention has been made in view of the above-described conventional example. An object of the present invention is to provide an inexpensive and lightweight converter lens having a relatively small number of constituent lenses while realizing a high afocal magnification.

上記目的を達成するため、本発明は、正の屈折力の前群と、その後方に配置された負の屈折力の後群とから構成され、主レンズ系の前方に着脱可能なフロントコンバータレンズであって、前群が2枚の正レンズを有すると共に、全てのレンズが間隔を隔てて(接合レンズがない)配置され、後群は正レンズと負レンズを有することを特徴としている。   In order to achieve the above-mentioned object, the present invention comprises a front group having a positive refractive power and a rear group having a negative refractive power disposed behind the front group, and is detachable in front of the main lens system. The front group has two positive lenses, all the lenses are arranged at intervals (no cemented lens), and the rear group has a positive lens and a negative lens.

本発明によれば、高いアフォーカル倍率を実現しつつ、比較的構成レンズ枚数が少なく、安価で軽量なコンバータレンズが実現できる。   According to the present invention, it is possible to realize an inexpensive and lightweight converter lens with a relatively small number of constituent lenses while realizing a high afocal magnification.

実施例1のテレコンバータと主レンズ系のレンズ断面図である。2 is a lens cross-sectional view of a teleconverter and a main lens system of Example 1. FIG. 実施例1のテレコンバータを装着した系の諸収差図である。FIG. 6 is a diagram illustrating various aberrations of the system in which the teleconverter of Example 1 is mounted. 実施例2のテレコンバータと主レンズ系のレンズ断面図である。6 is a lens cross-sectional view of a teleconverter and a main lens system of Example 2. FIG. 実施例2のテレコンバータを装着した系の諸収差図である。FIG. 7 is a diagram illustrating all aberrations of the system to which the teleconverter of Example 2 is mounted. 実施例3のテレコンバータと主レンズ系のレンズ断面図である。6 is a lens cross-sectional view of a teleconverter and a main lens system of Example 3. FIG. 実施例3のテレコンバータを装着した系の諸収差図である。FIG. 10 is a diagram illustrating all aberrations of the system to which the teleconverter of Example 3 is mounted. 主レンズ系のみの諸収差図である。It is an aberration diagram of only the main lens system. ビデオカメラの要部概略図である。It is a principal part schematic diagram of a video camera.

以下に図面を用いて本発明のコンバータレンズの実施例について説明する。本実施例で開示するコンバータレンズは、カメラの撮影レンズの前方に装着してレンズ系全体の焦点距離を長い方に変位させるテレコンバータである。   Embodiments of the converter lens of the present invention will be described below with reference to the drawings. The converter lens disclosed in the present embodiment is a teleconverter that is mounted in front of a photographing lens of a camera and displaces the focal length of the entire lens system in the longer direction.

図1,3,5はそれぞれ数値実施例1〜3のテレコンバータを撮影レンズ(主レンズ系)の物体側(前方)に装着したときのレンズ断面図を示す。   1, 3, and 5 are lens cross-sectional views when the teleconverters of Numerical Examples 1 to 3 are mounted on the object side (front) of the photographing lens (main lens system), respectively.

図2,4,6はそれぞれ数値実施例1〜3のテレコンバータを主レンズ系に装着した状態での諸収差図であり、各数値実施例は共通の主レンズ系を用いている。図7は主レンズ系単独での諸収差図である。   2, 4 and 6 are graphs showing various aberrations in the state where the teleconverters of Numerical Examples 1 to 3 are mounted on the main lens system. Each of the numerical examples uses a common main lens system. FIG. 7 is a diagram showing various aberrations of the main lens system alone.

各レンズ断面図において、左方が物体側(前方)で、右方が像側(後方)である。Cはテレコンバータ、Mは撮影レンズである。テレコンバータCは、物体側より順に、正の屈折力の前群L1と負の屈折力の後群L2とから構成されている。撮影レンズMにおいて、SPは開口絞り、Pは光学的ローパスフィルター、赤外カットフィルター、カバーガラス等の光路中に存在する平行平板に対応して設計上設けたガラスブロック、IはCCDセンサやCMOSセンサ等の固体撮像素子(光電変換素子)の感光面が位置する像面である。   In each lens cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). C is a teleconverter, and M is a taking lens. The teleconverter C includes, in order from the object side, a front group L1 having a positive refractive power and a rear group L2 having a negative refractive power. In the taking lens M, SP is an aperture stop, P is an optical low-pass filter, an infrared cut filter, a glass block designed to correspond to a parallel plate existing in an optical path such as a cover glass, and I is a CCD sensor or CMOS. It is an image surface on which a photosensitive surface of a solid-state imaging device (photoelectric conversion device) such as a sensor is located.

各収差図において、c,d,f,gは各々c線、d線、f線及びg線、ΔM、ΔSはメリジオナル像面、サジタル像面を表している。   In each aberration diagram, c, d, f, and g represent c-line, d-line, f-line, and g-line, respectively, and ΔM and ΔS represent a meridional image surface and a sagittal image surface.

本実施例のテレコンバータCは、前群L1と後群L2の主点間隔を前群L1と後群L2の焦点距離の和に略等しくしており、これにより全体として略アフォーカル系を構成している。   In the teleconverter C of the present embodiment, the principal point interval between the front group L1 and the rear group L2 is substantially equal to the sum of the focal lengths of the front group L1 and the rear group L2, thereby forming a substantially afocal system as a whole. is doing.

そして、前群L1に2枚の正レンズを配置することにより、主に球面収差、非点収差を良好に補正している。また、後群L2に正レンズと負レンズを配置することにより、前群L1で発生した色収差を効果的に打ち消している。   Then, by arranging two positive lenses in the front group L1, mainly spherical aberration and astigmatism are corrected favorably. Further, by arranging a positive lens and a negative lens in the rear group L2, chromatic aberration generated in the front group L1 is effectively canceled.

本実施例のテレコンバータCは、更に良好な収差補正を行うために、最も物体側に配置された正レンズの像側の面を凸形状としている。最も物体側に配置された正レンズの像側の面が凹形状であると、この正レンズは所望の屈折力を保つために物体側の面の曲率半径をより小さくする必要があり、画角の小さな望遠端においては、軸外入射光線とこの最も物体側に配置された正レンズの物体側の面とのなす角度が急になる。その結果、倍率色収差が大きくなってしまい、後群L2での補正が困難となる。このため、本実施例では、最も物体側に配置された正レンズの像側の面を凸形状とし、倍率色収差の発生を後群L2で補正可能な程度に抑制している。   In the teleconverter C of the present embodiment, in order to perform better aberration correction, the image side surface of the positive lens disposed closest to the object side has a convex shape. If the image side surface of the positive lens located closest to the object side has a concave shape, this positive lens needs to have a smaller radius of curvature of the object side surface in order to maintain the desired refractive power. At a small telephoto end, the angle formed between the off-axis incident light beam and the object side surface of the positive lens disposed closest to the object side becomes steep. As a result, the chromatic aberration of magnification becomes large and correction in the rear group L2 becomes difficult. For this reason, in the present embodiment, the image side surface of the positive lens disposed closest to the object side is convex, and the occurrence of lateral chromatic aberration is suppressed to a level that can be corrected by the rear group L2.

また、有効径の大きなレンズである最も物体側に配置された正レンズは諸収差の発生量が大きいため、最も物体側に配置された正レンズには曲率半径を大きくし(屈折力を小さくし)諸収差の発生を軽減することが望まれる。このため、本実施例では、最も物体側に配置された正レンズの像側の面の曲率半径をRI、前群の最も像側に配置された正レンズの物体側の面の曲率半径をROするとき、
|RI|>|RO| …(1)
なる条件を満足するように設定している。
更に、
5<| RI / RO | …(2)
なる条件を満足することが更に好ましく、本実施例のテレコンバータはこの条件を満足している。また、最も物体側に配置された正レンズの物体側の面が凸形状であれば、正の屈折力を保ったまま|RI|を大きくすることが可能となる。
更に、本実施例のテレコンバータは前群L1の焦点距離と後群L2の焦点距離をそれぞれfP,fNとするとき、
1.5<|fP/fN|<3.0 …(3)
なる条件を満足している。
In addition, since the positive lens placed on the most object side, which has a large effective diameter, generates a large amount of various aberrations, the positive lens placed on the most object side has a larger radius of curvature (reducing the refractive power). It is desirable to reduce the occurrence of various aberrations. For this reason, in this embodiment, the radius of curvature of the image side surface of the positive lens disposed closest to the object side is RI, and the radius of curvature of the object side surface of the positive lens disposed closest to the image side of the front group is RO. and when,
| RI | >> | RO | (1)
Is set to satisfy the following conditions.
Furthermore,
5 <| RI / RO | (2)
It is more preferable that the above condition is satisfied, and the teleconverter of this embodiment satisfies this condition. If the object side surface of the positive lens arranged closest to the object side is convex, | RI | can be increased while maintaining positive refractive power.
Further, in the teleconverter of this embodiment, when the focal length of the front group L1 and the focal length of the rear group L2 are fP and fN,
1.5 <| fP / fN | <3.0 (3)
Is satisfied.

条件式(3)はテレコンバータのアフォーカル倍率を規定する式である。条件式(3)の上限値を超えると、前群L1で発生する色収差が大きくなりすぎるため、後群L2のみの補正では不十分となり画質の劣化が大きくなってしまう。条件式(3)の下限値を超えると、前群L1での諸収差の発生量が少なくなるため、本実施例で提案するようなレンズ構成の必要性が低くなってしまう。条件式(3)の範囲は、
1.6<|fP/fN|<2.6 …(3a)
とするとなお良い。
Conditional expression (3) defines the afocal magnification of the teleconverter. If the upper limit value of conditional expression (3) is exceeded, the chromatic aberration generated in the front group L1 becomes too large, so that correction of only the rear group L2 is insufficient and image quality deteriorates greatly. If the lower limit of conditional expression (3) is exceeded, the amount of various aberrations generated in the front group L1 decreases, and the necessity of the lens configuration proposed in the present embodiment becomes low. The range of conditional expression (3) is
1.6 <| fP / fN | <2.6 (3a)
And even better.

次に数値実施例1〜3の数値データを示す。各数値実施例においてRiは物体側より順に第i番目の面(第i面)の曲率半径、Diは第i面と第(i+1)面との間の間隔、Niとνiはそれぞれd線を基準とした光学部材の屈折率、アッベ数を示す。主レンズ系(撮影レンズM)の数値データも合わせて示す。主レンズ系の数値データにおいて、最も像側の2つの平面は前述したように設計上設けたガラスブロックGBを構成する面である。そして、fは焦点距離、FnoはFナンバー、ωは半画角である。   Next, numerical data of numerical examples 1 to 3 are shown. In each numerical example, Ri is the radius of curvature of the i-th surface (i-th surface) in order from the object side, Di is the distance between the i-th surface and the (i + 1) -th surface, and Ni and νi are d-lines, respectively. The refractive index and Abbe number of the optical member used as a reference are shown. Numerical data of the main lens system (photographing lens M) is also shown. In the numerical data of the main lens system, the two planes closest to the image side are the surfaces constituting the glass block GB provided by design as described above. F is a focal length, Fno is an F number, and ω is a half angle of view.

非球面形状は光軸方向にX軸、光軸と垂直方向にH軸、光の進行方向を正としRを近軸曲率半径、kを円錐定数、B,C,D,E,Fを各々非球面係数としたとき   The aspherical shape is the X axis in the optical axis direction, the H axis in the direction perpendicular to the optical axis, the light traveling direction is positive, R is the paraxial radius of curvature, k is the conic constant, and B, C, D, E, and F are respectively Aspheric coefficient

Figure 2011090346
Figure 2011090346

なる式で表している。なお「e±Z」は「×10±Z」を意味する。 It is expressed by the following formula. “E ± Z” means “× 10 ± Z ”.

また前述の各条件式と数値実施例の関係を表1に示す。
(数値実施例1)
1.64倍
R 1 = 50.964 D 1 = 9.00 N 1 = 1.487490 ν1 = 70.2
R 2 = -224.857 D 2 = 0.30
R 3 = 37.531 D 3 = 4.00 N 2 = 1.487490 ν2 = 70.2
R 4 = 54.080 D 4 = 15.00
R 5 = -243.690 D 5 = 2.00 N 3 = 1.846660 ν3 = 23.9
R 6 = -100.901 D 6 = 1.50 N 4 = 1.834000 ν4 = 37.2
R 7 = 36.891 D 7 = 3.80

(数値実施例2)
1.98倍
R 1 = 47.743 D 1 = 14.64 N 1 = 1.496999 ν 1 = 81.5
R 2 = -6539.459 D 2 = 0.98
R 3 = 39.131 D 3 = 5.62 N 2 = 1.496999 ν 2 = 81.5
R 4 = 65.714 D 4 = 18.33
R 5 = 829.088 D 5 = 3.01 N 3 = 2.003300 ν 3 = 28.3
R 6 = 21.205 D 6 = 4.92
R 7 = 26.029 D 7 = 4.01 N 4 = 1.922860 ν 4 = 18.9
R 8 = 40.003 D 8 = 3.80

(数値実施例3)
2.51倍
R 1 = 86.372 D 1 = 16.47 N 1 = 1.433870 ν1 = 95.1
R 2 = -361.663 D 2 = 10.00
R 3 = 52.557 D 3 = 8.28 N 2 = 1.433870 ν2 = 95.1
R 4 = 113.013 D 4 = 36.10
R 5 = -181.942 D 5 = 4.19 N 3 = 1.922860 ν3 = 18.9
R 6 = -57.843 D 6 = 3.48 N 4 = 2.003300 ν4 = 28.3
R 7 = 52.764 D 7 = 3.80

(主レンズ系)
f = 46.728
R 1 = 45.439 D 1 = 1.05 N 1 = 1.846660 ν1 = 23.9
R 2 = 21.972 D 2 = 4.42 N 2 = 1.603112 ν2 = 60.6
R 3 = -175.910 D 3 = 0.17
R 4 = 18.527 D 4 = 2.68 N 3 = 1.772499 ν3 = 49.6
R 5 = 49.994 D 5 = 15.72
R 6 = 40.310 D 6 = 0.60 N 4 = 1.846660 ν4 = 23.9
R 7 = 6.119 D 7 = 2.00
R 8 = -15.571 D 8 = 0.60 N 5 = 1.772499 ν5 = 49.6
R 9 = 15.571 D 9 = 1.70
R10 = 14.649 D10 = 2.27 N 6 = 1.846660 ν6 = 23.9
R11 = -11.573 D11 = 0.07
R12 = -10.432 D12 = 0.60 N 7 = 1.772499 ν7 = 49.6
R13 = 49.276 D13 = 0.65
R14 = 9.009 D14 = 2.13 N 8 = 1.693500 ν8 = 53.2
R15 = 146.263 D15 = 1.25
R16 = ∞(絞り) D16 = 2.62
R17 = 17.860 D17 = 0.60 N 9 = 1.846660 ν9 = 23.9
R18 = 7.660 D18 = 0.45
R19 = 14.925 D19 = 1.34 N10 = 1.603112 ν10 = 60.6
R20 = -247.566 D20 = 5.54
R21 = 11.668 D21 = 2.74 N11 = 1.712995 ν11 = 53.9
R22 = -9.023 D22 = 0.50 N12 = 1.846660 ν12 = 23.9
R23 = -46.321 D23 = 3.32
R24 = ∞ D24 = 2.40 N13 = 1.516330 ν13 = 64.1
R25 = ∞

R14(非球面)
K=-1.86050e-01
B=-1.18491e-04 C=-6.43582e-07 D=6.57163e-11 E=-1.34365e-12
Table 1 shows the relationship between the above-described conditional expressions and numerical examples.
(Numerical example 1)
1.64 times
R 1 = 50.964 D 1 = 9.00 N 1 = 1.487490 ν1 = 70.2
R 2 = -224.857 D 2 = 0.30
R 3 = 37.531 D 3 = 4.00 N 2 = 1.487490 ν2 = 70.2
R 4 = 54.080 D 4 = 15.00
R 5 = -243.690 D 5 = 2.00 N 3 = 1.846660 ν3 = 23.9
R 6 = -100.901 D 6 = 1.50 N 4 = 1.834000 ν4 = 37.2
R 7 = 36.891 D 7 = 3.80

(Numerical example 2)
1.98 times
R 1 = 47.743 D 1 = 14.64 N 1 = 1.496999 ν 1 = 81.5
R 2 = -6539.459 D 2 = 0.98
R 3 = 39.131 D 3 = 5.62 N 2 = 1.496999 ν 2 = 81.5
R 4 = 65.714 D 4 = 18.33
R 5 = 829.088 D 5 = 3.01 N 3 = 2.003300 ν 3 = 28.3
R 6 = 21.205 D 6 = 4.92
R 7 = 26.029 D 7 = 4.01 N 4 = 1.922860 ν 4 = 18.9
R 8 = 40.003 D 8 = 3.80

(Numerical Example 3)
2.51 times
R 1 = 86.372 D 1 = 16.47 N 1 = 1.433870 ν1 = 95.1
R 2 = -361.663 D 2 = 10.00
R 3 = 52.557 D 3 = 8.28 N 2 = 1.433870 ν2 = 95.1
R 4 = 113.013 D 4 = 36.10
R 5 = -181.942 D 5 = 4.19 N 3 = 1.922860 ν3 = 18.9
R 6 = -57.843 D 6 = 3.48 N 4 = 2.003300 ν4 = 28.3
R 7 = 52.764 D 7 = 3.80

(Main lens system)
f = 46.728
R 1 = 45.439 D 1 = 1.05 N 1 = 1.846660 ν1 = 23.9
R 2 = 21.972 D 2 = 4.42 N 2 = 1.603112 ν2 = 60.6
R 3 = -175.910 D 3 = 0.17
R 4 = 18.527 D 4 = 2.68 N 3 = 1.772499 ν3 = 49.6
R 5 = 49.994 D 5 = 15.72
R 6 = 40.310 D 6 = 0.60 N 4 = 1.846660 ν4 = 23.9
R 7 = 6.119 D 7 = 2.00
R 8 = -15.571 D 8 = 0.60 N 5 = 1.772499 ν5 = 49.6
R 9 = 15.571 D 9 = 1.70
R10 = 14.649 D10 = 2.27 N 6 = 1.846660 ν6 = 23.9
R11 = -11.573 D11 = 0.07
R12 = -10.432 D12 = 0.60 N 7 = 1.772499 ν7 = 49.6
R13 = 49.276 D13 = 0.65
R14 = 9.009 D14 = 2.13 N 8 = 1.693500 ν8 = 53.2
R15 = 146.263 D15 = 1.25
R16 = ∞ (aperture) D16 = 2.62
R17 = 17.860 D17 = 0.60 N 9 = 1.846660 ν9 = 23.9
R18 = 7.660 D18 = 0.45
R19 = 14.925 D19 = 1.34 N10 = 1.603112 ν10 = 60.6
R20 = -247.566 D20 = 5.54
R21 = 11.668 D21 = 2.74 N11 = 1.712995 ν11 = 53.9
R22 = -9.023 D22 = 0.50 N12 = 1.846660 ν12 = 23.9
R23 = -46.321 D23 = 3.32
R24 = ∞ D24 = 2.40 N13 = 1.516330 ν13 = 64.1
R25 = ∞

R14 (Aspherical)
K = -1.86050e-01
B = -1.18491e-04 C = -6.43582e-07 D = 6.57163e-11 E = -1.34365e-12

Figure 2011090346
Figure 2011090346

次に本発明のコンバータレンズを撮影光学系の前方に装着可能な撮像装置の実施例について図8を用いて説明する。   Next, an embodiment of an imaging apparatus capable of mounting the converter lens of the present invention in front of the photographing optical system will be described with reference to FIG.

図8において、10はビデオカメラ本体、11は撮影光学系、12は撮影光学系11によって形成された被写体像を受光するCCDセンサやCMOSセンサ等の固体撮像素子(光電変換素子)、13は撮像素子12よって光電変換された被写体像に対応する情報を記録するメモリ、14は不図示の表示素子に表示された被写体像を観察するためのファインダー、15は本発明のコンバータレンズである。上記表示素子は液晶パネル等によって構成され、撮像素子12上に形成された被写体像が表示される。   In FIG. 8, 10 is a video camera body, 11 is a photographic optical system, 12 is a solid-state image sensor (photoelectric conversion element) such as a CCD sensor or a CMOS sensor that receives a subject image formed by the photographic optical system 11, and 13 is an image sensor. A memory for recording information corresponding to the subject image photoelectrically converted by the element 12, 14 a viewfinder for observing the subject image displayed on a display element (not shown), and 15 a converter lens of the present invention. The display element is constituted by a liquid crystal panel or the like, and a subject image formed on the image sensor 12 is displayed.

本発明のコンバータレンズを、このようなビデオカメラ等の撮像装置の撮影光学系の前方に着脱可能に構成することにより、光学系全体の焦点距離を変位させることが可能になる。   By configuring the converter lens of the present invention so as to be detachable in front of the photographing optical system of such an imaging apparatus such as a video camera, the focal length of the entire optical system can be displaced.

C テレコンバータ
M 撮影レンズ(主レンズ系)
L1 前群
L2 後群
SP 開口絞り
P ガラスブロック
I 像面
d d線
g g線
c c線
f f線
ΔM d線メリディオナル
ΔS d線サジタル
C Teleconverter M Photography lens (main lens system)
L1 front group L2 rear group SP aperture stop P glass block I image plane d d line g g line c c line f f line ΔM d line meridional ΔS d line sagittal

Claims (6)

正の屈折力の前群と、その後方に配置された負の屈折力の後群とから構成され、主レンズ系の前方に着脱可能なフロントコンバータレンズであって、前記前群は2枚の正レンズを有すると共に、全てのレンズが間隔を隔てて配置され、前記後群は正レンズと負レンズを有することを特徴とするフロントコンバータレンズ。   A front converter lens composed of a front group having a positive refractive power and a rear group having a negative refractive power disposed behind the front group, and is detachable in front of the main lens system. A front converter lens having a positive lens, wherein all the lenses are spaced apart, and the rear group includes a positive lens and a negative lens. 最も物体側に配置された正レンズの像側の面が凸形状であることを特徴とする請求項1記載のフロントコンバータレンズ。   2. The front converter lens according to claim 1, wherein the image side surface of the positive lens disposed closest to the object side has a convex shape. 最も物体側に配置された正レンズの像側の面の曲率半径をRI、前群の最も像側に配置された正レンズの物体側の面の曲率半径をROとするとき、
|RI|>|RO|
なる条件を満足することを特徴とする請求項1又は2記載のフロントコンバータレンズ。
When the radius of curvature of the image side surface of the positive lens disposed closest to the object side is RI, and the radius of curvature of the object side surface of the positive lens disposed closest to the image side of the front group is RO,
| RI | > | RO |
The front converter lens according to claim 1, wherein the following condition is satisfied.
最も物体側に配置された正レンズの像側の面の曲率半径をRI、前群の最も像側に配置された正レンズの物体側の面の曲率半径をROとするとき、
5<|RI/RO|
なる条件を満足することを特徴とする請求項1〜3いずれかに記載のフロントコンバータレンズ。
When the radius of curvature of the image side surface of the positive lens disposed closest to the object side is RI, and the radius of curvature of the object side surface of the positive lens disposed closest to the image side of the front group is RO,
5 <| RI / RO |
The front converter lens according to claim 1, wherein the following condition is satisfied.
最も物体側に配置された正レンズの物体側の面が凸形状であることを特徴とする請求項1〜4いずれかに記載のフロントコンバータレンズ。   The front converter lens according to claim 1, wherein the object side surface of the positive lens arranged closest to the object side has a convex shape. 前記前群の焦点距離と前記後群の焦点距離をそれぞれfP,fNとするとき、
1.5<|fP/fN|<3.0
なる条件を満足することを特徴とする請求項1〜5いずれかに記載のフロントコンバータレンズ。
When the focal length of the front group and the focal length of the rear group are fP and fN, respectively,
1.5 <| fP / fN | <3.0
The front converter lens according to claim 1, wherein the following condition is satisfied.
JP2011026350A 2011-02-09 2011-02-09 Front converter lens Expired - Fee Related JP5075257B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2011026350A JP5075257B2 (en) 2011-02-09 2011-02-09 Front converter lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2011026350A JP5075257B2 (en) 2011-02-09 2011-02-09 Front converter lens

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP2004151980A Division JP5013663B2 (en) 2004-05-21 2004-05-21 Front converter lens

Publications (2)

Publication Number Publication Date
JP2011090346A true JP2011090346A (en) 2011-05-06
JP5075257B2 JP5075257B2 (en) 2012-11-21

Family

ID=44108583

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2011026350A Expired - Fee Related JP5075257B2 (en) 2011-02-09 2011-02-09 Front converter lens

Country Status (1)

Country Link
JP (1) JP5075257B2 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5316628A (en) * 1976-07-30 1978-02-15 Olympus Optical Co Ltd Attachment lens for close-up picture
JPS5776513A (en) * 1980-09-02 1982-05-13 Minnesota Mining & Mfg Auxiliary lens
JP2000292696A (en) * 1999-04-12 2000-10-20 Enplas Corp Image pickup device and attachment lens
JP2000292695A (en) * 1999-04-12 2000-10-20 Enplas Corp Attachment lens
JP2003156685A (en) * 2001-11-19 2003-05-30 Canon Inc Telephoto side converter lens

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5316628A (en) * 1976-07-30 1978-02-15 Olympus Optical Co Ltd Attachment lens for close-up picture
JPS5776513A (en) * 1980-09-02 1982-05-13 Minnesota Mining & Mfg Auxiliary lens
JP2000292696A (en) * 1999-04-12 2000-10-20 Enplas Corp Image pickup device and attachment lens
JP2000292695A (en) * 1999-04-12 2000-10-20 Enplas Corp Attachment lens
JP2003156685A (en) * 2001-11-19 2003-05-30 Canon Inc Telephoto side converter lens

Also Published As

Publication number Publication date
JP5075257B2 (en) 2012-11-21

Similar Documents

Publication Publication Date Title
JP4794912B2 (en) Zoom lens and imaging apparatus having the same
US7773311B2 (en) Zoom lens and image pickup apparatus including the same
JP5006575B2 (en) Zoom lens and imaging apparatus using the same
US7864445B2 (en) Zoom lens and image pickup apparatus including the same
JP4829586B2 (en) Zoom lens and imaging apparatus having the same
JP5053750B2 (en) Zoom lens and imaging apparatus having the same
US7170689B2 (en) Front converter lens
US7715112B2 (en) Zoom lens system and image pickup apparatus including the same
JP4695912B2 (en) Zoom lens and imaging apparatus having the same
JP6181017B2 (en) Zoom lens and imaging device
JP4898399B2 (en) Optical system and imaging apparatus having the same
JP2007322635A (en) Zoom lens and imaging apparatus having the same
JP2010044225A (en) Zoom lens system, optical equipment having same, and variable magnification method using same
JP6150302B2 (en) Zoom lens and imaging device
JP6164894B2 (en) Zoom lens and imaging apparatus having the same
JP6278700B2 (en) Zoom lens and imaging apparatus having the same
JP2007256602A (en) Fish-eye attachment
JP2014202806A5 (en)
JP6355331B2 (en) Zoom lens and image pickup apparatus using the same
JP4865218B2 (en) Zoom lens and imaging apparatus having the same
JP2015179189A (en) Zoom lens and image capturing device having the same
JP5682715B2 (en) Zoom lens system and optical apparatus provided with the zoom lens system
JP5372205B2 (en) Zoom lens and imaging apparatus using the same
JP5574796B2 (en) Zoom lens and imaging apparatus having the same
JP5075257B2 (en) Front converter lens

Legal Events

Date Code Title Description
A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20110311

A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20110311

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20120821

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120824

R151 Written notification of patent or utility model registration

Ref document number: 5075257

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150831

Year of fee payment: 3

LAPS Cancellation because of no payment of annual fees