JP2006194975A - Zoom lens and imaging apparatus using the same - Google Patents
Zoom lens and imaging apparatus using the same Download PDFInfo
- Publication number
- JP2006194975A JP2006194975A JP2005003992A JP2005003992A JP2006194975A JP 2006194975 A JP2006194975 A JP 2006194975A JP 2005003992 A JP2005003992 A JP 2005003992A JP 2005003992 A JP2005003992 A JP 2005003992A JP 2006194975 A JP2006194975 A JP 2006194975A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- lens group
- positive
- zoom
- object side
- 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
Links
Images
Landscapes
- Lenses (AREA)
- Structure And Mechanism Of Cameras (AREA)
Abstract
Description
本発明は、ズームレンズ及びそれを用いた撮像装置に関し、特に、ズームレンズ等の光学系部分の工夫により沈胴時の奥行き方向の薄型化を実現したデジタルカメラやビデオカメラ等の電子撮像装置に適したズームレンズとその撮像装置に関するものである。 The present invention relates to a zoom lens and an image pickup apparatus using the same, and particularly suitable for electronic image pickup apparatuses such as a digital camera and a video camera that are thinned in the depth direction when retracted by devising an optical system part such as a zoom lens. The present invention relates to a zoom lens and its imaging device.
近年、銀塩35mmフィルムカメラに代わる次世代カメラとして、デジタルカメラが注目されている。さらに、それは業務用高機能タイプからポータブルな普及タイプまで幅広い範囲でいくつものカテゴリーを有するようになってきている。 In recent years, digital cameras have attracted attention as next-generation cameras that can replace silver salt 35 mm film cameras. Furthermore, it has come to have a number of categories in a wide range from a high-function type for business use to a portable popular type.
後記する本発明においては、特にポータブルな普及タイプのカテゴリーに注目し、高画質を確保しながら奥行きの薄いビデオカメラ、デジタルカメラを実現する技術を提供することを狙っている。カメラの奥行き方向を薄くするのに最大のネックとなっているのは、光学系、特にズームレンズ系の最も物体側の面から撮像面までの厚みである。最近では、撮影時に光学系をカメラボディ内からせり出し、携帯時に光学系をカメラボディ内に収納するいわゆる沈胴式鏡筒を採用することが主流になっている。 In the present invention to be described later, focusing on the category of portable popular types, it is aimed to provide a technology for realizing a video camera and a digital camera with a small depth while ensuring high image quality. The biggest bottleneck in reducing the depth direction of the camera is the thickness from the most object-side surface to the imaging surface of the optical system, particularly the zoom lens system. Recently, it has become a mainstream to employ a so-called collapsible lens barrel that projects an optical system from the camera body during shooting and stores the optical system in the camera body when carried.
薄型化小型化を実現するには、撮像素子を小さくすればよいが、同じ画素数とするためには画素ピッチを小さくする必要があり、感度不足を光学系でカバーしなければならない。回折の影響も然りである。したがって、F値の明るい光学系が必要となる。 In order to achieve a reduction in thickness and size, the image sensor can be made smaller. However, in order to obtain the same number of pixels, it is necessary to reduce the pixel pitch, and the lack of sensitivity must be covered by the optical system. The same is true for diffraction. Therefore, an optical system with a bright F value is required.
F値が明るく、ズーム比が3倍程度と大きく、画角が広い、比較的コンパクトなズームレンズの例として、特許文献1、特許文献2、特許文献3、特許文献4、特許文献5に開示されたものがある。 Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5 disclose examples of relatively compact zoom lenses having a bright F value, a large zoom ratio of about 3 times, and a wide angle of view. There is something that was done.
しかしながら、これらのズームレンズは、ズームレンズを構成する各群の光軸上肉厚が厚いため、沈胴したとしても鏡筒の厚み方向寸法が十分に薄くならず、カメラが十分に小型化できないという問題があった。
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、沈胴時の厚みを小さくしつつも、光学性能とのバランスを確保したズームレンズ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 of the present invention is to provide a zoom lens that ensures a balance with optical performance while reducing the thickness when retracted.
さらには、F値が2. 8程度と明るく、ズーム比が3倍程度と大きく、広角端での画角が60°程度と広角な、結像性能が高いズームレンズとしながらも、構成枚数が少なく、光学系を構成する各レンズ群の軸上厚さが薄く、鏡筒の沈胴時のサイズのコンパクト化を実現できるズームレンズを提供することを目的とするものである。 Furthermore, the zoom lens has a high F value of about 2.8, a zoom ratio of about 3 times, a wide angle of view of about 60 ° at the wide-angle end, and a high imaging performance. Accordingly, it is an object of the present invention to provide a zoom lens that can reduce the size when the lens barrel is retracted, and the axial thickness of each lens group constituting the optical system is small.
上記目的を達成する本発明のズームレンズは、物体側より像側へ順に、負の屈折力の第1レンズ群、正の屈折力の第2レンズ群、正の屈折力の第3レンズ群を有し、各群の間隔を変化させて広角端から望遠端への変倍を行うズームレンズにおいて、
前記第1レンズ群は、物体側より順に、1枚の負レンズと1枚の正レンズの2枚で構成され、
前記第2レンズ群は、2枚の正レンズと1枚の負レンズを有し、
前記第3レンズ群は、1枚の正レンズで構成され、
以下の条件式を満足することを特徴とするものである。
The zoom lens of the present invention that achieves the above object includes, in order from the object side to the image side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. In a zoom lens that performs zooming from the wide-angle end to the telephoto end by changing the interval of each group,
The first lens group is composed of two negative lenses and one positive lens in order from the object side.
The second lens group has two positive lenses and one negative lens,
The third lens group is composed of one positive lens,
The following conditional expression is satisfied.
(1) (Σd1 +Σd2 +Σd3 )/ft <0.64
ただし、Σd1 :第1レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
Σd2 :第2レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
Σd3 :第3レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
ft :望遠端でのズームレンズ全系の焦点距離、
である。
(1) (Σd 1 + Σd 2 + Σd 3) / f t <0.64
Where Σd 1 is the thickness on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side of the first lens group,
Σd 2 : thickness on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the second lens group,
Σd 3 : Thickness on the optical axis from the most object side lens surface to the most image side lens surface of the third lens group,
f t : focal length of the entire zoom lens system at the telephoto end,
It is.
以下において、本発明において上記構成をとる理由と作用を説明する。 Below, the reason and effect | action which take the said structure in this invention are demonstrated.
電子撮像素子に適したズームレンズとして、負の第1レンズ群、正の第2レンズ群、正の第3レンズ群からなる3群構成のズームレンズが知られている。本発明でもこのような3群構成を採用している。このような構成にすることで、テレセントリック性が良くなり、CCD等の撮像素子に効率的に光線を入射させることができる。また、バックフォーカスを長くとることができるため、光学的ローパスフィルタや赤外線カットフィルタといった部材を配置するスペースが確保できる。 As a zoom lens suitable for an electronic imaging device, a zoom lens having a three-group configuration including a negative first lens group, a positive second lens group, and a positive third lens group is known. The present invention also employs such a three-group configuration. With such a configuration, telecentricity is improved, and light can be efficiently incident on an image pickup device such as a CCD. Further, since the back focus can be long, a space for arranging members such as an optical low-pass filter and an infrared cut filter can be secured.
第1レンズ群は、物体側より順に、1枚の負レンズ、1枚の正レンズの2枚の構成としている。最少の構成で第1レンズ群内で発生する収差を抑えることができるため、全長や沈胴長が必要以上に大きくならずにすむ利点がある。 The first lens group has two negative lens elements and one positive lens in order from the object side. Since the aberration generated in the first lens group can be suppressed with the minimum configuration, there is an advantage that the total length and the retractable length do not need to be increased more than necessary.
第2レンズ群は、2枚の正レンズと1枚の負レンズを有する構成としている。このような構成にすると、第2レンズ群内で発生する球面収差、コマ収差、非点収差を補正することが可能となる。 The second lens group has two positive lenses and one negative lens. With such a configuration, it is possible to correct spherical aberration, coma aberration, and astigmatism occurring in the second lens group.
第3レンズ群は、1枚の正レンズの構成としている。1枚のみの構成でも、射出瞳を適切な距離に配置させる作用と、実用的なレベルの収差補正は可能であり、必要十分な構成である。 The third lens group has a configuration of one positive lens. Even with the configuration of only one sheet, the operation of arranging the exit pupil at an appropriate distance and the practical level of aberration correction are possible, and this is a necessary and sufficient configuration.
さらに、このとき、次の条件式を満たすようにするのがよい。 At this time, it is preferable to satisfy the following conditional expression.
(1) (Σd1 +Σd2 +Σd3 )/ft <0.64
ただし、Σd1 :第1レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
Σd2 :第2レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
Σd3 :第3レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
ft :望遠端でのズームレンズ全系の焦点距離、
である。
(1) (Σd 1 + Σd 2 + Σd 3) / f t <0.64
Where Σd 1 is the thickness on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side of the first lens group,
Σd 2 : thickness on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the second lens group,
Σd 3 : Thickness on the optical axis from the most object side lens surface to the most image side lens surface of the third lens group,
f t : focal length of the entire zoom lens system at the telephoto end,
It is.
この条件式(1)の上限の0.64を越えると、ズームレンズを構成する各レンズ群の光軸上肉厚が厚くなりすぎ、鏡筒を沈胴したときにカメラを十分に小型化することができなくなる。 If the upper limit of 0.64 in conditional expression (1) is exceeded, the thickness on the optical axis of each lens group constituting the zoom lens becomes too thick, and the camera can be sufficiently miniaturized when the lens barrel is retracted. Can not be.
なお、この条件式(1)に下限値を設けて、
0.30<(Σd1 +Σd2 +Σd3 )/ft <0.64
としてもよい。
In addition, a lower limit value is provided for this conditional expression (1),
0.30 <(Σd 1 + Σd 2 + Σd 3) / f t <0.64
It is good.
この下限の0.30を越えると、ズームレンズを構成する各レンズの軸上肉厚や縁肉が小さくなりすぎ、加工が難しくなってコストアップしたり、加工が不可能になったりする。 If this lower limit of 0.30 is exceeded, the on-axis thickness and rim thickness of each lens constituting the zoom lens become too small, making processing difficult and increasing costs, or making processing impossible.
さらに、以下のようにすると、さらによい。 Further, the following is better.
(1)’ 0.42<(Σd1 +Σd2 +Σd3 )/ft <0.60
さらには、以下を満足すると、なおよい。
(1)” 0.53<(Σd1 +Σd2 +Σd3 )/ft <0.56
条件式(1)を満たしてズームレンズを小型化すると、光学系を構成する各レンズのパワーが強くなるため、収差補正が難しくなって高い光学性能を満たすことが難しくなるし、レンズ部品の製造誤差や組み立て誤差による影響を受けやすくなり、光学性能の劣化が生じる懸念もある。本発明の後記の実施例では、以下のように光学系に様々な工夫を施すことで、高い光学性能を維持することに成功している。
(1) '0.42 <(Σd 1 + Σd 2 + Σd 3) / f t <0.60
Furthermore, it is even better if the following is satisfied.
(1) "0.53 <(Σd 1 + Σd 2 + Σd 3) / f t <0.56
If the zoom lens is miniaturized by satisfying conditional expression (1), the power of each lens constituting the optical system becomes strong, so that it becomes difficult to correct aberrations and satisfy high optical performance, and manufacture of lens components. There is also a concern that the optical performance is likely to be deteriorated because of being easily affected by errors and assembly errors. In the following examples of the present invention, high optical performance has been successfully maintained by applying various devices to the optical system as described below.
なお、広角端から望遠端への変倍時には、第1レンズ群は像側に凸の軌跡を描いて移動し、第2レンズ群は物体側へのみ移動するように構成することが好ましい。それにより、射出瞳距離を適切に保ちながら、全長をコンパクトにすることができる。 In zooming from the wide-angle end to the telephoto end, it is preferable that the first lens unit moves along a locus convex toward the image side, and the second lens unit moves only toward the object side. Thereby, the total length can be made compact while keeping the exit pupil distance appropriately.
第3レンズ群は、第2レンズ群とは異なる量で移動するようにすると、テレセントリック性の調整がしやすくなるので、より好ましい。 It is more preferable to move the third lens group by an amount different from that of the second lens group because the telecentricity can be easily adjusted.
また、第3レンズ群は固定としてもよく、その場合は、レンズ群の移動機構を簡略にできる。 Further, the third lens group may be fixed. In this case, the moving mechanism of the lens group can be simplified.
また、第1レンズ群と第2レンズ群の屈折力の比は、次の条件式を満たすようにすることが好ましい。 Moreover, it is preferable that the ratio of the refractive powers of the first lens group and the second lens group satisfy the following conditional expression.
(2) −1.6<f1 /f2 <−1.1
ただし、f1 :第1レンズ群の焦点距離、
f2 :第2レンズ群の焦点距離、
である。
(2) −1.6 <f 1 / f 2 <−1.1
Where f 1 is the focal length of the first lens group,
f 2 : focal length of the second lens group,
It is.
条件式(2)の上限の−1.1を越えて第2レンズ群のパワーが強くなると、テレセントリック性の確保が難しくなり、撮影画面の隅での明るさのかげり(シェーディング)が発生しやすくなる。下限の−1.6を越えて第2レンズ群のパワーが弱くなると、第2レンズ群の変倍作用が小さくなってレンズ移動量が増加し、レンズ系全体が大きくなる。 If the power of the second lens unit exceeds the upper limit of -1.1 in conditional expression (2), it will be difficult to ensure telecentricity, and shading will likely occur at the corners of the shooting screen. Become. When the power of the second lens group becomes weaker beyond the lower limit of −1.6, the zooming action of the second lens group is reduced, the lens movement amount is increased, and the entire lens system is enlarged.
以下のようにすると、さらによい。 The following is even better.
(2)’ −1.5<f1 /f2 <−1.2
さらには、以下を満足すると、なおよい。
(2) ′ −1.5 <f 1 / f 2 <−1.2
Furthermore, it is even better if the following is satisfied.
(2)” −1.4<f1 /f2 <−1.3
第1レンズ群内の負レンズと正レンズの焦点距離について、以下の条件式を満たすようにすることが好ましい。
(2) "-1.4 <f 1 / f 2 <-1.3
It is preferable to satisfy the following conditional expression for the focal length of the negative lens and the positive lens in the first lens group.
(3) 0.25<|f11/f12|<0.60
ただし、f11:第1レンズ群の負レンズの焦点距離、
f12:第1レンズ群の正レンズの焦点距離、
である。
(3) 0.25 <| f 11 / f 12 | <0.60
Where f 11 is the focal length of the negative lens of the first lens group,
f 12 : focal length of the positive lens of the first lens group,
It is.
条件式(3)の上限の0.60を越えると、負レンズのパワーが弱くなりすぎるため、第1レンズ群の前側主点を像側に出し難くなり、入射瞳が深くなりがちで、前玉径が大型化しやすくなる。下限の0.25を越えると、負レンズのパワーが強くなりすぎ、軸外の非点収差、歪曲収差、倍率色収差の補正が困難になる。 If the upper limit of 0.60 to conditional expression (3) is exceeded, the power of the negative lens will be too weak, making it difficult to bring the front principal point of the first lens group to the image side, and the entrance pupil will tend to be deep. The ball diameter is easy to increase. If the lower limit of 0.25 is exceeded, the power of the negative lens becomes too strong, making it difficult to correct off-axis astigmatism, distortion, and lateral chromatic aberration.
以下のようにすると、さらによい。 The following is even better.
(3)’ 0.35<|f11/f12|<0.56
さらには、以下を満足すると、なおよい。
(3) ′ 0.35 <| f 11 / f 12 | <0.56
Furthermore, it is even better if the following is satisfied.
(3)” 0.45<|f11/f12|<0.52
また、第1レンズ群の負レンズは、像面側に凹面を向けた形状とし、像面側の凹面に非球面を配置するとよい。この面を非球面とすると、軸外の非点収差、歪曲収差補正に効果的である。
(3) "0.45 <| f 11 / f 12 | <0.52
In addition, the negative lens of the first lens group may have a shape with a concave surface facing the image surface side, and an aspheric surface may be disposed on the concave surface on the image surface side. If this surface is an aspherical surface, it is effective for correcting off-axis astigmatism and distortion.
第1レンズ群の正レンズの形状については、次の条件式を満足することが好ましい。 As for the shape of the positive lens in the first lens group, it is preferable that the following conditional expression is satisfied.
(4) −0.6<SF12<−0.1
ただし、SF12=(R11−R12)/(R11+R12)で定義され、
R11:第1レンズ群の正レンズの物体側面の近軸曲率半径、
R12:第1レンズ群の正レンズの像側面の近軸曲率半径,
である。
(4) −0.6 <SF 12 <−0.1
Provided that SF 12 = (R 11 −R 12 ) / (R 11 + R 12 )
R 11 : Paraxial radius of curvature of the object side surface of the positive lens in the first lens group,
R 12 : Paraxial radius of curvature of the image side surface of the positive lens in the first lens group,
It is.
条件式(4)の下限の−0.6を越えると、レンズ面の面精度に製造誤差が生じたときに結像性能への影響が大きくなるため、要求される面精度が厳しくなり、加工が難しくなったり歩留まりが悪くなってコストアップしたりする。上限の−0.1を越えると、正レンズのパワーが足りなくなり、軸外の非点収差、歪曲収差の補正が不足になる。 If the lower limit of -0.6 of conditional expression (4) is exceeded, the manufacturing performance of the lens surface will have a greater effect on the imaging performance. It becomes difficult or the yield gets worse and the cost increases. When the upper limit of −0.1 is exceeded, the power of the positive lens becomes insufficient, and correction of off-axis astigmatism and distortion becomes insufficient.
以下のようにすると、さらによい。 The following is even better.
(4)’ −0.54<SF12<−0.23
さらには、以下を満足すると、なおよい。
(4) ′ −0.54 <SF 12 <−0.23
Furthermore, it is even better if the following is satisfied.
(4)” −0.48<SF12<−0.36
第2レンズ群のレンズ構成は、物体側から順に、正レンズ、正レンズと負レンズの接合レンズの3枚からなる構成を採用することが好ましい。このような構成にすると、第2レンズ群の前側主点位置を物体側に出すことができるので、変倍時の第2レンズ群の移動量を少なくすることができる。そのため、沈胴時の鏡筒のコンパクト化に貢献する。さらに接合レンズを配置することで、軸上色収差、倍率色収差を補正できる。
(4) ”− 0.48 <SF 12 <−0.36
As the lens configuration of the second lens group, it is preferable to employ a configuration including three lenses of a positive lens and a cemented lens of a positive lens and a negative lens in order from the object side. With such a configuration, the front principal point position of the second lens group can be brought out to the object side, so that the amount of movement of the second lens group during zooming can be reduced. Therefore, it contributes to downsizing of the lens barrel when retracted. Further, by arranging a cemented lens, axial chromatic aberration and lateral chromatic aberration can be corrected.
さらに、第2レンズ群を構成するレンズのパワー配置について、次の条件式を満たすことが好ましい。 Furthermore, it is preferable that the following conditional expression is satisfied for the power arrangement of the lenses constituting the second lens group.
(5) −0.90<f21/f23<−0.15
ただし、f21:第2レンズ群の最も物体側の正レンズの焦点距離、
f23:第2レンズ群の接合レンズの焦点距離、
である。
(5) −0.90 <f 21 / f 23 <−0.15
Where f 21 is the focal length of the positive lens closest to the object side in the second lens group,
f 23 : focal length of the cemented lens of the second lens group,
It is.
条件式(5)の上限の−0.15を越えると、第2レンズ群の主点が物体側に寄るために全長を短くする作用があるが、非点収差の補正が困難となる。下限の−0.90を越えると、第2レンズ群の主点が像側寄りとなって第2レンズ群の倍率が高くならないため、第1レンズ群や第2レンズ群の移動量が大きくなったりして、鏡筒が大型化しやすくなってしまう。 If the upper limit of -0.15 in conditional expression (5) is exceeded, the principal point of the second lens group is closer to the object side, so that the total length is shortened, but it is difficult to correct astigmatism. If the lower limit of −0.90 is exceeded, the principal point of the second lens group is closer to the image side, and the magnification of the second lens group does not increase, so the amount of movement of the first lens group and the second lens group increases. In other words, the lens barrel is likely to increase in size.
以下のようにすると、さらによい。 The following is even better.
(5)’ −0.66<f21/f23<−0.23
さらには、以下を満足すると、なおよい。
(5) ′ −0.66 <f 21 / f 23 <−0.23
Furthermore, it is even better if the following is satisfied.
(5)” −0.42<f21/f23<−0.32
第2レンズ群内の接合レンズにおいて、接合される正レンズは両凸形状として、接合面を像面側に凸の形状とすることが好ましい。縁肉を確保するためには、接合レンズ中の正レンズをメニスカス形状の正レンズとし、接合面を物体側に凸の形状にする方が有利である。しかしながら、接合レンズの肉厚の製造誤差による像面湾曲の発生が起こりやすくなってしまう。光学性能確保の点では、この正レンズは接合面を像面側に凸形状とした両凸形状とするのが好ましい。
(5) ”− 0.42 <f 21 / f 23 <−0.32
In the cemented lens in the second lens group, it is preferable that the positive lens to be cemented has a biconvex shape, and the cemented surface has a convex shape on the image plane side. In order to secure the rim, it is advantageous that the positive lens in the cemented lens is a meniscus-shaped positive lens and the cemented surface is convex on the object side. However, field curvature is likely to occur due to manufacturing errors in the thickness of the cemented lens. In terms of ensuring optical performance, it is preferable that the positive lens has a biconvex shape in which the cemented surface is convex toward the image surface side.
また、第2レンズ群中の接合面の曲率半径について、以下の条件式を満足することが好ましい。 Further, it is preferable that the following conditional expression is satisfied with respect to the radius of curvature of the cemented surface in the second lens group.
(6) 1.0<f23/Rcem <6.0
ただし、f23:第2レンズ群の接合レンズの焦点距離、
Rcem :第2レンズ群の接合レンズにおける接合面の近軸曲率半径、
である。
(6) 1.0 <f 23 / R cem <6.0
Where f 23 is the focal length of the cemented lens of the second lens group,
R cem : Paraxial curvature radius of the cemented surface in the cemented lens of the second lens group,
It is.
条件式(6)の下限の1.0を越えると、軸上色収差、倍率色収差が補正不足になりやすい。上限の6.0を越えると、接合レンズ中の正レンズの縁肉確保の関係上、光軸上での厚みが増大し好ましくない。 When the lower limit of 1.0 to conditional expression (6) is exceeded, axial chromatic aberration and lateral chromatic aberration tend to be undercorrected. Exceeding the upper limit of 6.0 is not preferable because the thickness on the optical axis increases in view of securing the edge thickness of the positive lens in the cemented lens.
以下のようにすると、さらによい。 The following is even better.
(6)’ 2.0<f23/Rcem <5.1
さらには、以下を満足すると、なおよい。
(6) '2.0 <f 23 / R cem <5.1
Furthermore, it is even better if the following is satisfied.
(6)” 3.10<f23/Rcem <4.30
接合される正レンズの屈折率は1.75以上の硝材を用いることが好ましい。このような硝材を用いると、レンズ面の曲率を大きくすることなく所望の屈折力が得られるので、収差発生量を最小限に抑えることができる。
(6) "3.10 <f 23 / R cem <4.30
It is preferable to use a glass material having a refractive index of 1.75 or more to be joined. When such a glass material is used, a desired refractive power can be obtained without increasing the curvature of the lens surface, so that the amount of aberration generated can be minimized.
また、表裏面の曲率半径は符号のみ異なり絶対値は等しいようにするのが望ましい。組み立て時に表裏判別をする手間が省けるため、組み立て性が良くなり、また、表裏の組み込み間違いがなくなり、歩留まりの向上やコストダウンにつながる。 Further, it is desirable that the curvature radii of the front and back surfaces are different from each other only in sign and have the same absolute value. This eliminates the trouble of discriminating the front and back during assembly, which improves assembly and eliminates the mistake of mounting the front and back, leading to improved yields and reduced costs.
第2レンズ群は主に変倍を担う群であり、全変倍域に亘って良好な光学性能を得るためには、第2レンズ群内で発生する諸収差をできるだけ小さくしたほうがよい。そのためには、第2レンズ群内に2面以上の非球面を配置することが望ましい。 The second lens group is a group mainly responsible for zooming. In order to obtain good optical performance over the entire zooming range, it is preferable to reduce various aberrations generated in the second lens group as much as possible. For this purpose, it is desirable to arrange two or more aspheric surfaces in the second lens group.
特に、本発明の後記の実施例に示すように、最も物体側の正レンズを両面非球面レンズとすることが好ましい。異なるレンズにそれぞれ非球面を配置すると、レンズ枠への組み込み誤差でレンズ同士の相対偏心が生じたときに光学性能の劣化が大きくなりやすくなるため、両面非球面とすることでこの問題を回避している。この正レンズの物体側面上では、CCD等の撮像素子の光軸上に結像する光束が広がって通過するので、非球面としたときに球面収差補正に効果がある。その正レンズの像側面の非球面はコマ収差や非点収差補正に効果がある。 In particular, it is preferable that the most object-side positive lens is a double-sided aspheric lens, as shown in the examples below. If the aspheric surfaces are arranged on different lenses, the optical performance is likely to deteriorate when the lenses are decentered due to errors in the lens frame. ing. On the object side surface of the positive lens, the light beam that forms an image on the optical axis of an image pickup device such as a CCD spreads and passes through. The aspherical surface on the image side of the positive lens is effective in correcting coma and astigmatism.
また、第2レンズ群の最も物体側の正レンズのレンズ形状が以下の条件式を満足する非球面レンズとするとよい。 The positive lens closest to the object side in the second lens group may be an aspheric lens that satisfies the following conditional expression.
(7) −5.0<SF21<−1.0
ただし、SF12=(R21−R22)/(R21+R22)で定義され、
R21:第2レンズ群の最も物体側の正レンズの物体側面の近軸曲率半径、
R22:第2レンズ群の最も物体側の正レンズの像側面の近軸曲率半径、
である。
(7) −5.0 <SF 21 <−1.0
However, SF 12 = (R 21 −R 22 ) / (R 21 + R 22 )
R 21 : Paraxial radius of curvature of the object side surface of the positive lens closest to the object side in the second lens group,
R 22 : Paraxial curvature radius of the image side surface of the positive lens closest to the object side in the second lens group,
It is.
条件式(7)の上限の−1.0を越えると、非球面によるコマ収差、非点収差の補正が不足しやすくなり、全変倍域で良好な光学性能を確保するのが困難になる。下限の−5.0を越えると、収差補正に対する非球面による寄与が過剰になる傾向があり、非球面に加工誤差が生じたときに光学性能が大きく劣化しやすい。結果として、非球面の要求加工精度が厳しくなるため歩留まりが悪化したりコストが高くなったりする。 If the upper limit of -1.0 of conditional expression (7) is exceeded, correction of coma and astigmatism due to an aspheric surface is likely to be insufficient, and it becomes difficult to ensure good optical performance in the entire zoom range. . If the lower limit of −5.0 is exceeded, the contribution of the aspheric surface to the aberration correction tends to be excessive, and the optical performance tends to be greatly deteriorated when a processing error occurs in the aspheric surface. As a result, the required processing accuracy of the aspherical surface becomes severe, so that the yield is deteriorated and the cost is increased.
以下のようにすると、さらによい。 The following is even better.
(7)’ −3.7<SF21<−1.2
さらには、以下を満足すると、なおよい。
(7) ′ − 3.7 <SF 21 <−1.2
Furthermore, it is even better if the following is satisfied.
(7)” −2.4<SF21<−1.5
本発明の後記の実施例に示すように、第3レンズ群は1枚の正レンズのみからなる構成とすることが好ましい。本発明の構成の負、正、正タイプのズームレンズでの第3レンズ群の役割は、主に軸外の光線を屈折させることでCCD面等の受光面への光線の入射角を適切な角度範囲になるようコントロールし、受光面上に効率的に光線を入射させることである。この目的のためには、1枚の正レンズのみで十分である。また、第3レンズ群は通過する軸外光線高が高くなる場所でもあるので、軸外の非点収差や歪曲収差補正の役割を担わせることもできるが、1枚のレンズのみでも実用的な収差レベルの補正は可能である。したがって、1枚の正レンズのみで必要十分であり、レンズ枚数を増やして必要以上にレンズ系の軸上厚さが厚くなってしまうのを回避することが好ましい。
(7) "-2.4 <SF 21 <-1.5
As will be described later in the embodiments of the present invention, it is preferable that the third lens group is composed of only one positive lens. The role of the third lens group in the negative, positive, and positive type zoom lenses of the configuration of the present invention is to appropriately refract off-axis light rays so that the incident angle of light rays on a light receiving surface such as a CCD surface is appropriate. It is to control the angle range so that the light beam is efficiently incident on the light receiving surface. For this purpose, only one positive lens is sufficient. Further, since the third lens group is also a place where the height of the off-axis ray passing therethrough is high, it can also play a role of correcting off-axis astigmatism and distortion, but even with only one lens, it is practical. Correction of the aberration level is possible. Therefore, it is necessary and sufficient to use only one positive lens, and it is preferable to increase the number of lenses to avoid the on-axis thickness of the lens system becoming larger than necessary.
また、第3レンズ群を移動させることでフォーカシングを行うことが好ましい。第1レンズ群でフォーカシングしてもよいのだが、第3レンズ群で行う方がレンズ重量が軽量なため、フォーカシング用モータにかかる負荷が少なくできる。さらに、第3レンズ群の移動でフォーカシングを行う場合、フォーカシング時に全長が変化せず、鏡枠内部に駆動モータを配置できるため、鏡枠のコンパクト化に有利である。 Further, it is preferable to perform focusing by moving the third lens group. Focusing may be performed with the first lens group, but since the lens weight is lighter when performing with the third lens group, the load on the focusing motor can be reduced. Further, when focusing is performed by moving the third lens group, the overall length does not change during focusing, and the drive motor can be arranged inside the lens frame, which is advantageous for making the lens frame compact.
また、この第3レンズ群は軸外の非点収差や歪曲収差の補正に適した場所である。積極的に収差補正の役割を与えるために、このレンズに非球面を配置することが好ましい。その際、次の条件式を満足することが好ましい。 The third lens group is a place suitable for correcting off-axis astigmatism and distortion. In order to positively give a role of aberration correction, it is preferable to arrange an aspherical surface on this lens. In that case, it is preferable to satisfy the following conditional expression.
(8) 0.001<|asp31/fw |<0.02
ただし、asp31:第3レンズ群に配置された非球面の有効径での非球面偏倚量であり、非球面偏倚量は、非球面の面頂を面頂とし、曲率半径を非球面の近軸曲率半径とした球面から非球面までの光軸方向での距離であり、
fw :広角端でのズームレンズ全系の焦点距離、
である。
(8) 0.001 <| asp31 / f w | <0.02
Where asp31 is an aspherical deviation amount at the effective diameter of the aspherical surface disposed in the third lens group, and the aspherical deviation amount has the aspherical surface apex as the apex and the radius of curvature is the aspherical paraxial axis. It is the distance in the optical axis direction from the spherical surface to the aspherical surface as the radius of curvature,
f w : focal length of the entire zoom lens system at the wide-angle end,
It is.
条件式(8)の上限の0.02を越えると、非点収差補正に対する第3レンズ群の非球面の寄与が大きくなりすぎ、無限遠物点合焦時に非点収差が良好に補正されていても、第3レンズ群を移動させて至近物点にフォーカシングしたときに非点収差の変動が大きくなり、軸外の光学性能が劣化しやすくなる。下限の0.001を越えると、軸外の非点収差、歪曲収差の補正が足りなくなる。 When the upper limit of 0.02 to conditional expression (8) is exceeded, the contribution of the aspherical surface of the third lens group to the astigmatism correction becomes too great, and astigmatism is corrected well when focusing on an object point at infinity. However, when the third lens unit is moved and focused on the closest object point, the fluctuation of astigmatism increases, and the off-axis optical performance tends to deteriorate. If the lower limit of 0.001 is exceeded, off-axis astigmatism and distortion will not be corrected.
以下のようにすると、さらによい。 The following is even better.
(8)’ 0.002<|asp31/fw |<0.013
さらには、以下を満足すると、なおよい。
(8) '0.002 <| asp31 / f w | <0.013
Furthermore, it is even better if the following is satisfied.
(8)” 0.003<|asp31/fw |<0.005
また、第3レンズ群の正レンズの形状が、以下の条件式を満たすことが好ましい。
(8) "0.003 <| asp31 / f w | <0.005
Moreover, it is preferable that the shape of the positive lens of the third lens group satisfies the following conditional expression.
(9) −8.0<SF31<0.0
ただし、SF31=(R31−R32)/(R31+R32)で定義され、
R31:第3レンズ群の正レンズの物体側面の近軸曲率半径、
R32:第3レンズ群の正レンズの像側面の近軸曲率半径、
である。
(9) −8.0 <SF 31 <0.0
However, SF 31 = (R 31 −R 32 ) / (R 31 + R 32 )
R 31 : Paraxial radius of curvature of the object side surface of the positive lens in the third lens group,
R 32 : Paraxial radius of curvature of the image side surface of the positive lens in the third lens group,
It is.
条件式(9)の下限の−8.0を越えると、第3レンズ群の正レンズとそれよりも像側に配置される光学的ローパスフィルタやCCD等のカバーガラス等との間に生じる反射光によって、ゴーストやスポットフレアが発生しやすくなり、著しく光学性能を劣化させる。上限の0.0を越えると、レンズの縁肉厚確保のために軸上肉厚を大きくしなければならなくなる。 When the lower limit of −8.0 of conditional expression (9) is exceeded, reflection occurs between the positive lens of the third lens group and an optical low-pass filter or a cover glass such as a CCD disposed on the image side of the third lens group. Light tends to cause ghosts and spot flare, which significantly deteriorates optical performance. When the upper limit of 0.0 is exceeded, it is necessary to increase the axial thickness in order to secure the lens edge thickness.
以下のようにすると、さらによい。 The following is even better.
(9)’ −5.2<SF31<−0.6
さらには、以下を満足すると、なおよい。
(9) ′ −5.2 <SF 31 <−0.6
Furthermore, it is even better if the following is satisfied.
(9)” −2.4<SF31<−1.2
開口絞りを配置する位置は、第1レンズ群と第2レンズ群の間に配置することが好ましい。こうすると、入射瞳位置を浅くできるため前玉径が小さくでき、結果として光軸上のレンズ肉厚を薄くできる。そのため、厚さ方向のコンパクト化に貢献する。また、射出瞳位置を結像位置から遠くできるので、CCD等の撮像素子に射出する光線角度を小さくでき、画面隅でのシェーディングの発生を防ぐことができる。また、開口絞りを変倍時に第2レンズ群と一体で移動する構成とすることが好ましい。それにより、機構を単純にできる。しかも、沈胴時のデッドスペースが発生し難く、広角端と望遠端のF値差も小さくできる。
(9) "-2.4 <SF 31 <-1.2
The position at which the aperture stop is disposed is preferably disposed between the first lens group and the second lens group. In this way, the entrance pupil position can be made shallow, so that the front lens diameter can be reduced, and as a result, the lens thickness on the optical axis can be reduced. Therefore, it contributes to downsizing in the thickness direction. In addition, since the exit pupil position can be set far from the image formation position, the angle of the light beam emitted to the image sensor such as a CCD can be reduced, and the occurrence of shading at the corners of the screen can be prevented. Further, it is preferable that the aperture stop is moved integrally with the second lens group at the time of zooming. Thereby, the mechanism can be simplified. In addition, a dead space at the time of retracting hardly occurs, and the F value difference between the wide-angle end and the telephoto end can be reduced.
また、物体側から順に、負の屈折力の第1レンズ群、正の屈折力の第2レンズ群、正の屈折力の第3レンズ群からなる3群ズームレンズとして構成すると、沈胴時の小型化と光学性能の確保に有利となる。 Further, in order from the object side, when the zoom lens is configured as a three-unit zoom lens including a first lens unit having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, the compact size when the lens barrel is retracted. This is advantageous for achieving high performance and ensuring optical performance.
さらには、本発明のズームレンズは、テレセントリック性とコンパクト化に有利であるので、ズームレンズと、その像側に配され、そのズームレンズにより形成される像を電気信号に変換する撮像素子とを備えた撮像装置として構成すれば、小型な撮像装置とすることができる。 Furthermore, since the zoom lens of the present invention is advantageous for telecentricity and compactness, a zoom lens and an image sensor that is arranged on the image side and converts an image formed by the zoom lens into an electrical signal are provided. When configured as an imaging device provided, a small imaging device can be obtained.
また、本発明の何れかのズームレンズ、若しくは、撮像装置において、第1レンズ群が以下の条件式(10)、(11)を満足するとよい。 In any zoom lens or imaging apparatus of the present invention, it is preferable that the first lens group satisfies the following conditional expressions (10) and (11).
(10) 1.6800<nd1<2.3000
(11) 1.7000<nd2<2.3000
ただし、nd1:前記第1レンズ群内の負レンズの屈折率、
nd2:前記第1レンズ群内の正レンズの屈折率、
である。
(10) 1.6800 <n d1 <2.3000
(11) 1.7000 <n d2 <2.3000
Where n d1 is the refractive index of the negative lens in the first lens group,
n d2 : refractive index of the positive lens in the first lens group,
It is.
さらには、以下の条件(12)、(13)、(14)、(15)の何れか1つを満足することがより好ましい。 Furthermore, it is more preferable to satisfy any one of the following conditions (12), (13), (14), and (15).
(12) 30.0<νd2<50.0
(13) 0.0<nd2−nd1<0.5
(14) 16.0<νd1−νd2<50.0
(15) 0.10<Σd1 /ft <0.50
ただし、νd2:前記第1レンズ群内の正レンズのアッベ数、
νd1:前記第1レンズ群内の負レンズのアッベ数、
nd1:前記第1レンズ群内の負レンズの屈折率、
nd2:前記第1レンズ群内の正レンズの屈折率、
Σd1 :前記第1レンズ群の最も物体側の面から最も像側の面までの軸上厚み、 ft :望遠端でのズームレンズ全系の焦点距離、
である。
(12) 30.0 <ν d2 <50.0
(13) 0.0 <n d2 −n d1 <0.5
(14) 16.0 <ν d1 −ν d2 <50.0
(15) 0.10 <Σd 1 / f t <0.50
Where ν d2 is the Abbe number of the positive lens in the first lens group,
ν d1 : Abbe number of the negative lens in the first lens group,
n d1 : refractive index of the negative lens in the first lens group,
n d2 : refractive index of the positive lens in the first lens group,
[Sigma] d 1: axial thickness from a most object side surface of the first lens group to the surface of the most image side, f t: the focal length of the zoom lens system in the telephoto end,
It is.
条件(10)、(11)は、第1レンズ群内の収差補正を実現し、全変倍域で良好な光学性能を確保する上で好ましい条件である。 Conditions (10) and (11) are preferable conditions for realizing aberration correction in the first lens group and ensuring good optical performance in the entire zoom range.
条件式(10)、(11)についての作用を次に説明する。 The operation of conditional expressions (10) and (11) will be described next.
ズームレンズの沈胴状態での寸法を薄くするためには、第1レンズ群の厚みを薄くすることが必要である。そのため、本発明では、第1レンズ群の構成枚数を少なくし、かつ、各レンズの軸上肉厚をできる限り薄くして、各レンズ群の軸上間隔をできる限り小さくすることが好ましい。一方、そうすると、第1レンズ群内で発生する諸収差の補正、特に、軸上色収差、倍率色収差の補正が難しくなってくる。 In order to reduce the size of the zoom lens in the retracted state, it is necessary to reduce the thickness of the first lens group. For this reason, in the present invention, it is preferable to reduce the number of constituent lenses of the first lens group and to reduce the axial thickness of each lens as much as possible and to reduce the axial distance between the lens groups as much as possible. On the other hand, it becomes difficult to correct various aberrations occurring in the first lens group, particularly to correct axial chromatic aberration and lateral chromatic aberration.
そのため、第1レンズ群の負レンズ、正レンズの2枚のみの構成としたとき、これらのレンズについて、条件(10)、(11)を同時に満足する構成とすることが好ましい。 For this reason, when only the negative lens and the positive lens in the first lens group are configured, it is preferable that these lenses satisfy the conditions (10) and (11) at the same time.
条件式(10)の下限の1.6800及び条件式(11)の下限の1.7000を越えると、各レンズが所望の屈折力を得るためにはレンズ面の曲率を大きくしなければならなくなり、収差の発生が大きくなってしまう。特に軸外のコマ収差や非点収差が補正し切れずに、撮影画像の軸外での解像力が不足してしまう。それらの条件式の上限の2.3000を越えると、硝材の入手性や量産性が悪くなり、コストが高くなる。 When the lower limit of 1.6800 of conditional expression (10) and 1.7000 of the lower limit of conditional expression (11) are exceeded, the curvature of the lens surface must be increased for each lens to obtain a desired refractive power. As a result, the generation of aberrations becomes large. In particular, the off-axis coma and astigmatism cannot be completely corrected, and the resolution of the captured image off-axis is insufficient. If the upper limit of 2.3,000 of these conditional expressions is exceeded, the availability and mass productivity of the glass material will deteriorate, and the cost will increase.
条件式(12)の下限の30.0を越えると、硝材の異常分散性が大きくなりやすく、軸上色収差及び倍率色収差の2次スペクトルの補正が難しくなるため、撮影画像に色にじみが発生しやすくなる。又は、色収差の2次スペクトル補正のためにズームレンズを構成するレンズ枚数を増やさなくてはならなくなり、コストが高くなったりズームレンズのコンパクト化ができなくなったりする。条件式(12)の上限の50.0を越えると、正レンズの色分散が小さくなりすぎ、負レンズで発生する色収差を打ち消すことができなくなるため、色収差補正が不完全になる。 Exceeding the lower limit of 30.0 of conditional expression (12), anomalous dispersion of the glass material tends to increase, and correction of the secondary spectrum of longitudinal chromatic aberration and lateral chromatic aberration becomes difficult, resulting in color blur in the photographed image. It becomes easy. Alternatively, it is necessary to increase the number of lenses constituting the zoom lens for correcting the secondary spectrum of chromatic aberration, which increases the cost and makes it impossible to make the zoom lens compact. If the upper limit of 50.0 in conditional expression (12) is exceeded, the chromatic dispersion of the positive lens becomes too small, and the chromatic aberration that occurs in the negative lens cannot be canceled out, resulting in incomplete chromatic aberration correction.
第1レンズ群内の負レンズL11を通過する軸外光線の高さは、正レンズL12での光線高よりも高いところを通るため、負レンズL11で発生する収差量が正レンズL12でキャンセルされる収差量よりも大きくなりやすく、残存しやすい。特に、非点収差、歪曲収差、倍率色収差等の軸外主光線の収差が残存しやすい。これは撮影画角が広角になる程顕著であり、問題になる。ズームレンズの広角化を実現するためには、負レンズL11で発生する軸外収差を正レンズL12で打ち消すことが必要となり、そのためには条件式(13)を満足するのがよい。条件式(13)の下限の0.0を越えると、負レンズL11で発生する軸外の非点収差、歪曲収差、倍率色収差を正レンズL12で補正することができなくなり、画面の周辺部まで良好な画像を得ることができなくなる。その上限の0.5を越えると、条件式(10)及び(11)と両立させられる硝材の組み合わせが限定されてしまい、入手性や量産性の悪い硝材を用いなくてはならず、現実的ではない。 Since the height of the off-axis light beam passing through the negative lens L 11 in the first lens group passes higher than the light beam height at the positive lens L 12 , the amount of aberration generated in the negative lens L 11 is positive lens L 11. It tends to be larger than the amount of aberration canceled at 12 , and tends to remain. In particular, aberrations of off-axis principal rays such as astigmatism, distortion, and lateral chromatic aberration tend to remain. This becomes more conspicuous as the shooting angle of view becomes wider and becomes a problem. To realize the wide angle of the zoom lens becomes necessary to cancel the off-axis aberration occurring in the negative lens L 11 in the positive lens L 12, it may satisfy the conditional expression for the (13). If the lower limit of 0.0 in conditional expression (13) is exceeded, off-axis astigmatism, distortion, and lateral chromatic aberration that occur in the negative lens L 11 cannot be corrected by the positive lens L 12 , and the periphery of the screen It becomes impossible to obtain a good image up to the portion. If the upper limit of 0.5 is exceeded, combinations of glass materials compatible with conditional expressions (10) and (11) are limited, and glass materials with poor availability and mass productivity must be used. is not.
さらに、各々の条件式(10)、(11)、(12)、(13)の何れか、又は、その複数にて、次の条件式を満足するとさらによい。 Furthermore, it is further preferable that the following conditional expression is satisfied in any one or a plurality of conditional expressions (10), (11), (12), (13).
(10)’ 1.7000<nd1<1.9000
(11)’ 1.8000<nd2<2.0000
(12)’ 30.5<νd2<46.0
(13)’ 0.05<nd2−nd1<0.45
さらには、以下を満足するとなおよい。
(10) '1.7000 <n d1 <1.9000
(11) ′ 1.8000 <n d2 <2.0000
(12) '30.5 <ν d2 <46.0
(13) ′ 0.05 <n d2 −n d1 <0.45
Furthermore, it is more preferable that the following is satisfied.
(10)” 1.7200<nd1<1.8500
(11)” 1.8500<nd2<1.9500
(12)” 31.0<νd2<42.0
(13)” 0.1<nd2−nd1<0.3
なお、広角端から望遠端への変倍時には、第1レンズ群は像側に凸の軌跡を描いて移動し、第2レンズ群は物体側へのみ移動するように構成することが好ましい。それにより、射出瞳距離を適切に保ちながら、全長をコンパクトにすることができる。
(10) "1.7200 <n d1 <1.8500
(11) "1.8500 <n d2 <1.9500
(12) "31.0 <ν d2 <42.0
(13) "0.1 <n d2 -n d1 <0.3
In zooming from the wide-angle end to the telephoto end, it is preferable that the first lens unit moves along a locus convex toward the image side, and the second lens unit moves only toward the object side. Thereby, the total length can be made compact while keeping the exit pupil distance appropriately.
硝材に関して、さらに次の条件式を満足するとよい。 Regarding the glass material, the following conditional expression should be satisfied.
(14) 16.0<νd1−νd2<50.0
ただし、νd1:前記第1レンズ群内の負レンズのアッベ数、
である。
(14) 16.0 <ν d1 −ν d2 <50.0
Where ν d1 is the Abbe number of the negative lens in the first lens group,
It is.
条件式(14)の下限の16.0を越えると、第1レンズ群内での色収差の打ち消しが不十分になりやすい。その上限の50.0を越えると、条件式(10)及び(11)と両立させられる硝材の組み合わせが限定されてしまい、入手性や量産性の悪い硝材を用いなくてはならず、現実的ではない。 When the lower limit of 16.0 in conditional expression (14) is exceeded, chromatic aberration cancellation in the first lens group tends to be insufficient. If the upper limit of 50.0 is exceeded, combinations of glass materials compatible with conditional expressions (10) and (11) are limited, and glass materials with poor availability and mass productivity must be used. is not.
以下のようにすると、さらによい。 The following is even better.
(14)’ 16.8<νd1−νd2<41.0
さらには、以下を満足すると、なおよい。
(14) ′ 16.8 <ν d1 −ν d2 <41.0
Furthermore, it is even better if the following is satisfied.
(14)” 17.6<νd1−νd2<32.0
本発明のズームレンズを採用するには、以下の条件式を満足するのがよい。
(14) ”17.6 <ν d1 −ν d2 <32.0
In order to employ the zoom lens of the present invention, it is preferable to satisfy the following conditional expression.
(15) 0.10<Σd1 /ft <0.50
ただし、Σd1 :前記第1レンズ群の最も物体側の面から最も像側の面までの軸上厚み、 ft :望遠端でのズームレンズ全系の焦点距離、
である。
(15) 0.10 <Σd 1 / f t <0.50
However, [Sigma] d 1: axial thickness from a most object side surface of the first lens group to the surface of the most image side, f t: the focal length of the zoom lens system in the telephoto end,
It is.
条件式(15)の下限の0.10を越えると、第1レンズ群を構成するレンズの縁肉厚や軸上肉厚が十分に確保できなくなり加工が難しくなり、したがってコストアップするため安価なズームレンズが提供できなくなる。又は、加工が不可能になる。その上限の0.50を越えると、本発明の構成を採用しなくとも、良好な収差補正を行える。 Exceeding the lower limit of 0.10 of conditional expression (15), the edge thickness and the axial thickness of the lenses constituting the first lens group cannot be sufficiently secured, making the processing difficult, and thus increasing the cost and thus making it inexpensive. A zoom lens cannot be provided. Or processing becomes impossible. If the upper limit of 0.50 is exceeded, good aberration correction can be performed without employing the configuration of the present invention.
以下のようにすると、さらによい。 The following is even better.
(15)’ 0.16<Σd1 /ft <0.38
さらには、以下を満足すると、なおよい。
(15) '0.16 <Σd 1 / f t <0.38
Furthermore, it is even better if the following is satisfied.
(15)” 0.22<Σd1 /ft <0.25
なお、上述した構成要件を種々組み合わせて構成してもよい。
(15) "0.22 <Σd 1 / f t <0.25
In addition, you may comprise combining the component requirements mentioned above variously.
また、上位概念の条件式に対して、下位概念の条件式の下限値のみ若しくは上限値のみを限定するようにしてもよい。 Further, only the lower limit value or only the upper limit value of the lower-level concept conditional expression may be limited to the higher-level concept conditional expression.
以上の本発明によると、沈胴時の厚みを小さくしつつも、光学性能とのバランスを確保したズームレンズが得られる。 According to the present invention as described above, it is possible to obtain a zoom lens that ensures a balance with optical performance while reducing the thickness when retracted.
また、F値が2. 8程度と明るく、ズーム比が3倍程度と大きく、広角端での画角が60°程度と広角な、結像性能が高いズームレンズでありながらも、構成枚数が少なく、光学系を構成する各レンズ群の軸上厚さが薄く、鏡筒の沈胴時のサイズのコンパクト化を実現できるズームレンズを得ることができる。 In addition, the zoom lens has a high F value of about 2.8, a zoom ratio of about 3 times, a wide angle of about 60 ° at the wide angle end, and a high imaging performance. Therefore, it is possible to obtain a zoom lens that can reduce the size when the lens barrel is retracted, and the axial thickness of each lens group constituting the optical system is small.
以下、本発明のズームレンズの実施例1〜4について説明する。実施例1の無限遠物点合焦時の広角端(a)、中間状態(b)、望遠端(c)のレンズ断面図を図1に示す。なお、実施例2〜4の構成は実施例1と同様であるので、同様のレンズ断面図は省く。図1中、第1レンズ群はG1、開口絞りはS、第2レンズ群はG2、第3レンズ群はG3、赤外光、紫外光を制限する波長域制限コートを施したローパスフィルタを構成する平行平板はF、電子撮像素子のカバーガラスの平行平板はC、像面はIで示してある。なお、カバーガラスCの表面に波長域制限用の多層膜を施してもよい。また、そのカバーガラスCにローパスフィルタ作用を持たせるようにしてもよい。 Examples 1 to 4 of the zoom lens according to the present invention will be described below. FIG. 1 shows lens cross sections of the wide-angle end (a), the intermediate state (b), and the telephoto end (c) when focusing on an object point at infinity according to the first embodiment. In addition, since the structure of Examples 2-4 is the same as that of Example 1, the same lens sectional drawing is abbreviate | omitted. In FIG. 1, the first lens group is G1, the aperture stop is S, the second lens group is G2, the third lens group is G3, and a low-pass filter is provided with a wavelength range limiting coat that limits infrared light and ultraviolet light. The parallel flat plate is indicated by F, the parallel flat plate of the cover glass of the electronic image sensor is indicated by C, and the image plane is indicated by I. In addition, you may give the multilayer film for a wavelength range restriction | limiting to the surface of the cover glass C. FIG. Further, the cover glass C may have a low-pass filter action.
実施例1〜4のズームレンズは、図1に示すように、物体側から順に、負の屈折力の第1レンズ群G1と、開口絞りSと、正屈折力の第2レンズ群G2と、正屈折力の第3レンズ群G3とから構成されており、広角端から望遠端への変倍をする際に、第1レンズ群G1は、像面側に凸の軌跡で移動し、望遠端では中間状態の位置より物体側であって広角端の位置より若干像側に位置し、開口絞りSと第2レンズ群G2は一体に物体側へ単調に移動し、第3レンズ群G3は、物体側に凸の軌跡で移動し、望遠端では広角端の位置より若干像側に位置する。 As shown in FIG. 1, the zoom lenses of Examples 1 to 4 include, in order from the object side, a first lens group G1 having a negative refractive power, an aperture stop S, and a second lens group G2 having a positive refractive power, The third lens group G3 has a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves along a locus that is convex toward the image plane side. Then, it is located on the object side with respect to the position of the intermediate state and slightly on the image side with respect to the position of the wide-angle end, the aperture stop S and the second lens group G2 move monotonously to the object side, and the third lens group G3 is It moves along a locus that is convex toward the object side, and is slightly closer to the image side at the telephoto end than at the wide-angle end.
物体側から順に、第1レンズ群G1は、物体側に凸面を向けた負メニスカスレンズと、物体側に凸面を向けた正メニスカスレンズとからなり、第2レンズ群G2は、両凸正レンズと、両凸正レンズと両凹負レンズの2枚接合レンズとからなり、第3レンズ群G3は両凸正レンズ1枚からなる。 In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side, and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconvex positive lens and The third lens group G3 is composed of one biconvex positive lens and a biconvex positive lens and a biconcave negative lens.
非球面は、第1レンズ群G1の負メニスカスレンズの像側の面、第2レンズ群G2の単レンズの両凸正レンズの両側の面、第3レンズ群G3の単レンズの両凸正レンズの像側の面の4面に用いている。 The aspherical surfaces are the image side surface of the negative meniscus lens of the first lens group G1, the surfaces on both sides of the biconvex positive lens of the single lens of the second lens group G2, and the biconvex positive lens of the single lens of the third lens group G3. Are used on four surfaces on the image side.
実施例1〜4では、第3レンズ群G3を光軸方向に移動させてフォーカシングを行っている。 In Examples 1 to 4, focusing is performed by moving the third lens group G3 in the optical axis direction.
なお、実施例1〜4全てで、第1レンズ群G1のみ、第2レンズ群G2のみ、あるいは、ズームレンズ全系の移動によってフォーカシングを行うように構成してもよい。 In all the first to fourth embodiments, focusing may be performed by moving only the first lens group G1, only the second lens group G2, or the entire zoom lens system.
以下に、上記各実施例の数値データを示すが、記号は上記の外、fは全系焦点距離、FNOはFナンバー、2ωは画角、WEは広角端、STは中間状態、TEは望遠端、r1 、r2 …は各レンズ面の曲率半径、d1 、d2 …は各レンズ面間の間隔、nd1、nd2…は各レンズのd線の屈折率、νd1、νd2…は各レンズのアッベ数である。なお、非球面形状は、xを光の進行方向を正とした光軸とし、yを光軸と直交する方向にとると、下記の式にて表される。 Hereinafter, numerical data of each embodiment described above, but the symbols are outside the above, f is the focal length, F NO is the F-number, 2 [omega is field angle, WE denotes a wide angle end, ST intermediate state, TE is The telephoto end, r 1 , r 2 ... Is the radius of curvature of each lens surface, d 1 , d 2 ... Are the distances between the lens surfaces, n d1 , n d2 are the refractive index of the d-line of each lens, ν d1 , ν d2 ... is the Abbe number of each lens. The aspherical shape is represented by the following formula, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.
x=(y2 /r)/[1+{1−(K+1)(y/r)2 }1/2 ]
+A4 y4 +A6 y6 +A8 y8 +A10y10
ただし、rは近軸曲率半径、Kは円錐係数、A4 、A6 、A8 、A10はそれぞれ4次、6次、8次、10次の非球面係数である。
x = (y 2 / r) / [1+ {1- (K + 1) (y / r) 2 } 1/2 ]
+ A 4 y 4 + A 6 y 6 + A 8 y 8 + A 10 y 10
Here, r is a paraxial radius of curvature, K is a conical coefficient, and A 4 , A 6 , A 8 , and A 10 are fourth-order, sixth-order, eighth-order, and tenth-order aspherical coefficients, respectively.
実施例1
r1 = 486.879 d1 = 1.20 nd1 =1.74330 νd1 =49.33
r2 = 6.572 (非球面) d2 = 1.84
r3 = 11.096 d3 = 2.64 nd2 =1.90366 νd2 =31.31
r4 = 29.983 d4 = (可変)
r5 = ∞(絞り) d5 = 0.20
r6 = 9.565 (非球面) d6 = 2.40 nd3 =1.58313 νd3 =59.46
r7 = -32.947 (非球面) d7 = 0.10
r8 = 10.752 d8 = 2.31 nd4 =1.77250 νd4 =49.60
r9 = -10.752 d9 = 0.70 nd5 =1.64769 νd5 =33.79
r10= 5.145 d10= (可変)
r11= 15.888 d11= 1.74 nd6 =1.58313 νd6 =59.46
r12= -92.317 (非球面) d12= (可変)
r13= ∞ d13= 0.86 nd7 =1.54771 νd7 =62.84
r14= ∞ d14= 0.50
r15= ∞ d15= 0.50 nd8 =1.51633 νd8 =64.14
r16= ∞ d16= 0.43
r17= ∞(像面)
非球面係数
第2面
K = -0.639
A4 = -2.98759×10-5
A6 = 3.27427×10-6
A8 = -1.20087×10-7
A10= 1.35884×10-9
第6面
K = 0.000
A4 = -2.50030×10-4
A6 = -5.47642×10-6
A8 = -2.75670×10-7
A10= 7.44525×10-10
第7面
K = 0.000
A4 = 1.00025×10-5
A6 = -4.46990×10-6
A8 = -2.98489×10-7
A10= 5.19077×10-9
第12面
K = 0.000
A4 = 9.29735×10-5
A6 = -3.43799×10-6
A8 = 5.61229×10-8
A10= 0
ズームデータ(∞)
WE ST TE
f (mm) 8.160 12.898 23.519
FNO 2.78 3.37 5.00
2ω (°) 60.6 39.1 21.5
d4 18.95 8.79 2.56
d10 8.51 12.48 24.73
d12 3.93 4.69 3.27 。
Example 1
r 1 = 486.879 d 1 = 1.20 n d1 = 1.74330 ν d1 = 49.33
r 2 = 6.572 (aspherical surface) d 2 = 1.84
r 3 = 11.096 d 3 = 2.64 n d2 = 1.90366 ν d2 = 31.31
r 4 = 29.983 d 4 = (variable)
r 5 = ∞ (aperture) d 5 = 0.20
r 6 = 9.565 (aspherical surface) d 6 = 2.40 n d3 = 1.58313 ν d3 = 59.46
r 7 = -32.947 (aspherical surface) d 7 = 0.10
r 8 = 10.752 d 8 = 2.31 n d4 = 1.77250 ν d4 = 49.60
r 9 = -10.752 d 9 = 0.70 n d5 = 1.64769 ν d5 = 33.79
r 10 = 5.145 d 10 = (variable)
r 11 = 15.888 d 11 = 1.74 n d6 = 1.58313 ν d6 = 59.46
r 12 = -92.317 (aspherical surface) d 12 = (variable)
r 13 = ∞ d 13 = 0.86 n d7 = 1.54771 ν d7 = 62.84
r 14 = ∞ d 14 = 0.50
r 15 = ∞ d 15 = 0.50 n d8 = 1.51633 ν d8 = 64.14
r 16 = ∞ d 16 = 0.43
r 17 = ∞ (image plane)
Aspheric coefficient 2nd surface K = -0.639
A 4 = -2.98759 × 10 -5
A 6 = 3.27427 × 10 -6
A 8 = -1.20087 × 10 -7
A 10 = 1.35884 × 10 -9
6th surface K = 0.000
A 4 = -2.50030 × 10 -4
A 6 = -5.47642 × 10 -6
A 8 = -2.75670 × 10 -7
A 10 = 7.44525 × 10 -10
Surface 7 K = 0.000
A 4 = 1.00025 × 10 -5
A 6 = -4.46990 × 10 -6
A 8 = -2.98489 × 10 -7
A 10 = 5.19077 × 10 -9
Surface 12 K = 0.000
A 4 = 9.29735 × 10 -5
A 6 = -3.43799 × 10 -6
A 8 = 5.61229 × 10 -8
A 10 = 0
Zoom data (∞)
WE ST TE
f (mm) 8.160 12.898 23.519
F NO 2.78 3.37 5.00
2ω (°) 60.6 39.1 21.5
d 4 18.95 8.79 2.56
d 10 8.51 12.48 24.73
d 12 3.93 4.69 3.27.
実施例2
r1 = 294.078 d1 = 1.20 nd1 =1.74330 νd1 =49.33
r2 = 6.502 (非球面) d2 = 1.80
r3 = 10.826 d3 = 2.57 nd2 =1.90366 νd2 =31.31
r4 = 27.909 d4 = (可変)
r5 = ∞(絞り) d5 = 0.19
r6 = 9.136 (非球面) d6 = 2.18 nd3 =1.58313 νd3 =59.46
r7 = -39.275 (非球面) d7 = 0.10
r8 = 10.822 d8 = 2.50 nd4 =1.77250 νd4 =49.60
r9 = -9.099 d9 = 0.70 nd5 =1.64769 νd5 =33.79
r10= 5.101 d10= (可変)
r11= 15.878 d11= 1.67 nd6 =1.58313 νd6 =59.46
r12= -85.491 (非球面) d12= (可変)
r13= ∞ d13= 0.86 nd7 =1.54771 νd7 =62.84
r14= ∞ d14= 0.50
r15= ∞ d15= 0.50 nd8 =1.51633 νd8 =64.14
r16= ∞ d16= 0.42
r17= ∞(像面)
非球面係数
第2面
K = -0.596
A4 = -2.94826×10-5
A6 = 2.52126×10-6
A8 = -9.55661×10-8
A10= 1.01269×10-9
第6面
K = -5.804
A4 = 7.57126×10-4
A6 = -2.09226×10-5
A8 = 6.30687×10-7
A10= -1.52351×10-9
第7面
K = 0.000
A4 = 1.12664×10-4
A6 = 5.88091×10-6
A8 = -2.73515×10-7
A10= 2.10480×10-8
第12面
K = 0.000
A4 = 8.66591×10-5
A6 = -2.64058×10-6
A8 = 4.05681×10-8
A10= 0
ズームデータ(∞)
WE ST TE
f (mm) 8.160 12.848 23.520
FNO 2.79 3.36 4.99
2ω (°) 60.6 39.2 21.5
d4 18.23 8.47 2.18
d10 8.33 12.15 23.83
d12 3.64 4.36 3.26 。
Example 2
r 1 = 294.078 d 1 = 1.20 n d1 = 1.74330 ν d1 = 49.33
r 2 = 6.502 (aspherical surface) d 2 = 1.80
r 3 = 10.826 d 3 = 2.57 n d2 = 1.90366 ν d2 = 31.31
r 4 = 27.909 d 4 = (variable)
r 5 = ∞ (aperture) d 5 = 0.19
r 6 = 9.136 (aspherical surface) d 6 = 2.18 n d3 = 1.58313 ν d3 = 59.46
r 7 = -39.275 (aspherical surface) d 7 = 0.10
r 8 = 10.822 d 8 = 2.50 n d4 = 1.77250 ν d4 = 49.60
r 9 = -9.099 d 9 = 0.70 n d5 = 1.64769 ν d5 = 33.79
r 10 = 5.101 d 10 = (variable)
r 11 = 15.878 d 11 = 1.67 n d6 = 1.58313 ν d6 = 59.46
r 12 = -85.491 (aspherical surface) d 12 = (variable)
r 13 = ∞ d 13 = 0.86 n d7 = 1.54771 ν d7 = 62.84
r 14 = ∞ d 14 = 0.50
r 15 = ∞ d 15 = 0.50 n d8 = 1.51633 ν d8 = 64.14
r 16 = ∞ d 16 = 0.42
r 17 = ∞ (image plane)
Aspheric coefficient 2nd surface K = -0.596
A 4 = -2.94826 × 10 -5
A 6 = 2.52126 × 10 -6
A 8 = -9.55661 × 10 -8
A 10 = 1.01269 × 10 -9
6th page K = -5.804
A 4 = 7.57126 × 10 -4
A 6 = -2.09226 × 10 -5
A 8 = 6.30687 × 10 -7
A 10 = -1.52351 × 10 -9
Surface 7 K = 0.000
A 4 = 1.12664 × 10 -4
A 6 = 5.88091 × 10 -6
A 8 = -2.73515 × 10 -7
A 10 = 2.10480 × 10 -8
Surface 12 K = 0.000
A 4 = 8.66591 × 10 -5
A 6 = -2.64058 × 10 -6
A 8 = 4.05681 × 10 -8
A 10 = 0
Zoom data (∞)
WE ST TE
f (mm) 8.160 12.848 23.520
F NO 2.79 3.36 4.99
2ω (°) 60.6 39.2 21.5
d 4 18.23 8.47 2.18
d 10 8.33 12.15 23.83
d 12 3.64 4.36 3.26.
実施例3
r1 = 486.879 d1 = 1.20 nd1 =1.76802 νd1 =49.24
r2 = 6.645 (非球面) d2 = 1.84
r3 = 11.096 d3 = 2.64 nd2 =1.90366 νd2 =31.31
r4 = 29.983 d4 = (可変)
r5 = ∞(絞り) d5 = 0.20
r6 = 9.545 (非球面) d6 = 2.40 nd3 =1.58313 νd3 =59.46
r7 = -27.157 (非球面) d7 = 0.10
r8 = 11.231 d8 = 2.31 nd4 =1.77250 νd4 =49.60
r9 = -10.413 d9 = 0.70 nd5 =1.64769 νd5 =33.79
r10= 5.145 d10= (可変)
r11= 18.541 d11= 1.74 nd6 =1.58313 νd6 =59.46
r12= -48.356 (非球面) d12= (可変)
r13= ∞ d13= 0.86 nd7 =1.54771 νd7 =62.84
r14= ∞ d14= 0.50
r15= ∞ d15= 0.50 nd8 =1.51633 νd8 =64.14
r16= ∞ d16= 0.43
r17= ∞(像面)
非球面係数
第2面
K = -0.640
A4 = -1.93128×10-5
A6 = 3.09412×10-6
A8 = -1.14942×10-7
A10= 1.33472×10-9
第6面
K = 0.000
A4 = -3.03396×10-4
A6 = -8.09623×10-6
A8 = -2.93773×10-7
A10= -5.59229×10-9
第7面
K = 0.000
A4 = -2.34522×10-5
A6 = -7.40484×10-6
A8 = -3.02179×10-7
A10= -2.62318×10-10
第12面
K = 0.000
A4 = 9.38135×10-5
A6 = -2.59439×10-6
A8 = 4.06888×10-8
A10= 0
ズームデータ(∞)
WE ST TE
f (mm) 8.160 12.898 23.517
FNO 2.80 3.40 4.99
2ω (°) 60.6 38.9 21.5
d4 18.86 9.05 2.59
d10 9.32 13.42 25.08
d12 3.39 4.08 3.32 。
Example 3
r 1 = 486.879 d 1 = 1.20 n d1 = 1.76802 ν d1 = 49.24
r 2 = 6.645 (aspherical surface) d 2 = 1.84
r 3 = 11.096 d 3 = 2.64 n d2 = 1.90366 ν d2 = 31.31
r 4 = 29.983 d 4 = (variable)
r 5 = ∞ (aperture) d 5 = 0.20
r 6 = 9.545 (aspherical surface) d 6 = 2.40 n d3 = 1.58313 ν d3 = 59.46
r 7 = -27.157 (aspherical surface) d 7 = 0.10
r 8 = 11.231 d 8 = 2.31 n d4 = 1.77250 ν d4 = 49.60
r 9 = -10.413 d 9 = 0.70 n d5 = 1.64769 ν d5 = 33.79
r 10 = 5.145 d 10 = (variable)
r 11 = 18.541 d 11 = 1.74 n d6 = 1.58313 ν d6 = 59.46
r 12 = -48.356 (aspherical surface) d 12 = (variable)
r 13 = ∞ d 13 = 0.86 n d7 = 1.54771 ν d7 = 62.84
r 14 = ∞ d 14 = 0.50
r 15 = ∞ d 15 = 0.50 n d8 = 1.51633 ν d8 = 64.14
r 16 = ∞ d 16 = 0.43
r 17 = ∞ (image plane)
Aspheric coefficient 2nd surface K = -0.640
A 4 = -1.93128 × 10 -5
A 6 = 3.09412 × 10 -6
A 8 = -1.14942 × 10 -7
A 10 = 1.33472 × 10 -9
6th surface K = 0.000
A 4 = -3.03396 × 10 -4
A 6 = -8.09623 × 10 -6
A 8 = -2.93773 × 10 -7
A 10 = -5.59229 × 10 -9
Surface 7 K = 0.000
A 4 = -2.34522 × 10 -5
A 6 = -7.40484 × 10 -6
A 8 = -3.02179 × 10 -7
A 10 = -2.62318 × 10 -10
Surface 12 K = 0.000
A 4 = 9.38135 × 10 -5
A 6 = -2.59439 × 10 -6
A 8 = 4.06888 × 10 -8
A 10 = 0
Zoom data (∞)
WE ST TE
f (mm) 8.160 12.898 23.517
F NO 2.80 3.40 4.99
2ω (°) 60.6 38.9 21.5
d 4 18.86 9.05 2.59
d 10 9.32 13.42 25.08
d 12 3.39 4.08 3.32.
実施例4
r1 = 318.320 d1 = 1.20 nd1 =1.76802 νd1 =49.24
r2 = 6.577 (非球面) d2 = 1.82
r3 = 11.349 d3 = 2.42 nd2 =2.08200 νd2 =30.40
r4 = 25.614 d4 = (可変)
r5 = ∞(絞り) d5 = 0.20
r6 = 9.567 (非球面) d6 = 2.40 nd3 =1.58313 νd3 =59.46
r7 = -24.132 (非球面) d7 = 0.10
r8 = 12.907 d8 = 2.31 nd4 =1.77250 νd4 =49.60
r9 = -8.977 d9 = 0.70 nd5 =1.64769 νd5 =33.79
r10= 5.412 d10= (可変)
r11= 15.888 d11= 1.74 nd6 =1.58313 νd6 =59.46
r12= -94.482 (非球面) d12= (可変)
r13= ∞ d13= 0.86 nd7 =1.54771 νd7 =62.84
r14= ∞ d14= 0.50
r15= ∞ d15= 0.50 nd8 =1.51633 νd8 =64.14
r16= ∞ d16= 0.43
r17= ∞(像面)
非球面係数
第2面
K = -0.629
A4 = -3.38899×10-5
A6 = 3.12452×10-6
A8 = -1.21401×10-7
A10= 1.36173×10-9
第6面
K = 0.000
A4 = -3.78307×10-4
A6 = -8.54823×10-6
A8 = -3.26150×10-7
A10= -1.05875×10-8
第7面
K = 0.000
A4 = -5.94059×10-5
A6 = -8.00131×10-6
A8 = -2.99719×10-7
A10= -4.82349×10-9
第12面
K = 0.000
A4 = 8.69257×10-5
A6 = -2.84130×10-6
A8 = 4.77586×10-8
A10= 0
ズームデータ(∞)
WE ST TE
f (mm) 8.160 12.899 23.519
FNO 2.80 3.39 5.04
2ω (°) 60.6 39.1 21.5
d4 18.94 8.85 2.66
d10 8.40 12.43 24.75
d12 4.07 4.79 3.32 。
Example 4
r 1 = 318.320 d 1 = 1.20 n d1 = 1.76802 ν d1 = 49.24
r 2 = 6.577 (aspherical surface) d 2 = 1.82
r 3 = 11.349 d 3 = 2.42 n d2 = 2.08200 ν d2 = 30.40
r 4 = 25.614 d 4 = (variable)
r 5 = ∞ (aperture) d 5 = 0.20
r 6 = 9.567 (aspherical surface) d 6 = 2.40 n d3 = 1.58313 ν d3 = 59.46
r 7 = -24.132 (aspherical surface) d 7 = 0.10
r 8 = 12.907 d 8 = 2.31 n d4 = 1.77250 ν d4 = 49.60
r 9 = -8.977 d 9 = 0.70 n d5 = 1.64769 ν d5 = 33.79
r 10 = 5.412 d 10 = (variable)
r 11 = 15.888 d 11 = 1.74 n d6 = 1.58313 ν d6 = 59.46
r 12 = -94.482 (aspherical surface) d 12 = (variable)
r 13 = ∞ d 13 = 0.86 n d7 = 1.54771 ν d7 = 62.84
r 14 = ∞ d 14 = 0.50
r 15 = ∞ d 15 = 0.50 n d8 = 1.51633 ν d8 = 64.14
r 16 = ∞ d 16 = 0.43
r 17 = ∞ (image plane)
Aspheric coefficient 2nd surface K = -0.629
A 4 = -3.38899 × 10 -5
A 6 = 3.12452 × 10 -6
A 8 = -1.21401 × 10 -7
A 10 = 1.36173 × 10 -9
6th surface K = 0.000
A 4 = -3.78307 × 10 -4
A 6 = -8.54823 × 10 -6
A 8 = -3.26150 × 10 -7
A 10 = -1.05875 × 10 -8
Surface 7 K = 0.000
A 4 = -5.94059 × 10 -5
A 6 = -8.00131 × 10 -6
A 8 = -2.99719 × 10 -7
A 10 = -4.82349 × 10 -9
Surface 12 K = 0.000
A 4 = 8.69257 × 10 -5
A 6 = -2.84130 × 10 -6
A 8 = 4.77586 × 10 -8
A 10 = 0
Zoom data (∞)
WE ST TE
f (mm) 8.160 12.899 23.519
F NO 2.80 3.39 5.04
2ω (°) 60.6 39.1 21.5
d 4 18.94 8.85 2.66
d 10 8.40 12.43 24.75
d 12 4.07 4.79 3.32.
以上の実施例1〜4の無限遠物点合焦時の収差図をそれぞれ図2〜図5に示す。これらの収差図において、(a)は広角端、(b)は中間状態、(c)は望遠端における球面収差、非点収差、歪曲収差、倍率色収差を示す。各図中、“FIY”は最大像高を示す。
Aberration diagrams at the time of focusing on an object point at infinity in Examples 1 to 4 are shown in FIGS. In these aberration diagrams, (a) is a wide-angle end, (b) is an intermediate state, and (c) is spherical aberration, astigmatism, distortion, and lateral chromatic aberration at a telephoto end. In each figure, “FIY” indicates the maximum image height.
次に、上記各実施例における画角、条件式(1)〜(9)の値を示す。 Next, the angle of view and the values of conditional expressions (1) to (9) in each of the above embodiments are shown.
条件式 実施例1 実施例2 実施例3 実施例4
(1) 0.550 0.540 0.550 0.540
(2) -1.353 -1.383 -1.312 -1.356
(3) -0.491 -0.491 -0.479 -0.506
(4) -0.460 -0.441 -0.460 -0.386
(5) -0.355 -0.336 -0.350 -0.410
(6) 3.404 4.231 3.514 3.279
(7) -1.818 -1.606 -2.084 -2.314
(8) 0.00344 0.00377 0.00447 0.00376
(9) -1.416 -1.456 -2.244 -1.404
(10) 1.74330 1.74330 1.76802 1.76802
(11) 1.90366 1.90366 1.90366 2.08200
(12) 31.310 31.310 31.310 30.400
(13) 0.160 0.160 0.136 0.314
(14) 18.020 18.020 17.930 18.840
(15) 0.242 0.237 0.242 0.231
。
Conditional Example Example 1 Example 2 Example 3 Example 4
(1) 0.550 0.540 0.550 0.540
(2) -1.353 -1.383 -1.312 -1.356
(3) -0.491 -0.491 -0.479 -0.506
(4) -0.460 -0.441 -0.460 -0.386
(5) -0.355 -0.336 -0.350 -0.410
(6) 3.404 4.231 3.514 3.279
(7) -1.818 -1.606 -2.084 -2.314
(8) 0.00344 0.00377 0.00447 0.00376
(9) -1.416 -1.456 -2.244 -1.404
(10) 1.74330 1.74330 1.76802 1.76802
(11) 1.90366 1.90366 1.90366 2.08200
(12) 31.310 31.310 31.310 30.400
(13) 0.160 0.160 0.136 0.314
(14) 18.020 18.020 17.930 18.840
(15) 0.242 0.237 0.242 0.231
.
図6〜図8は、以上のようなズームレンズを撮影光学系41に組み込んだ本発明によるデジタルカメラの構成の概念図を示す。図6はデジタルカメラ40の外観を示す前方斜視図、図7は同後方正面図、図8はデジタルカメラ40の構成を示す模式的な断面図である。ただし、図6と図8においては、撮影光学系41の非沈胴時を示している。デジタルカメラ40は、この例の場合、撮影用光路42を有する撮影光学系41、ファインダー用光路44を有するファインダー光学系43、シャッターボタン45、フラッシュ46、液晶表示モニター47、焦点距離変更ボタン61、設定変更スイッチ62等を含み、撮影光学系41の沈胴時には、カバー60をスライドすることにより、撮影光学系41とファインダー光学系43とフラッシュ46はそのカバー60で覆われる。そして、カバー60を開いてカメラ40を撮影状態に設定すると、撮影光学系41は図8の非沈胴状態になり、カメラ40の上部に配置されたシャッターボタン45を押圧すると、それに連動して撮影光学系41、例えば実施例1のズームレンズを通して撮影が行われる。撮影光学系41によって形成された物体像が、波長域制限コートを施したローパスフィルタFとカバーガラスCを介してCCD49の撮像面上に形成される。このCCD49で受光された物体像は、処理手段51を介し、電子画像としてカメラ背面に設けられた液晶表示モニター47に表示される。また、この処理手段51には記録手段52が接続され、撮影された電子画像を記録することもできる。なお、この記録手段52は処理手段51と別体に設けてもよいし、フロッピーディスクやメモリーカード、MO等により電子的に記録書込を行うように構成してもよい。また、CCD49に代わって銀塩フィルムを配置した銀塩カメラとして構成してもよい。
6 to 8 are conceptual diagrams of the configuration of the digital camera according to the present invention in which the zoom lens as described above is incorporated in the photographing optical system 41. FIG. 6 is a front perspective view showing the external appearance of the digital camera 40, FIG. 7 is a rear front view thereof, and FIG. 8 is a schematic cross-sectional view showing the configuration of the digital camera 40. However, FIGS. 6 and 8 show a state in which the photographing optical system 41 is not retracted. In this example, the digital camera 40 includes a photographing optical system 41 having a photographing optical path 42, a finder optical system 43 having a finder optical path 44, a shutter button 45, a flash 46, a liquid crystal display monitor 47, a focal length change button 61, When the photographing optical system 41 is retracted, including the setting change switch 62, the photographing optical system 41, the finder optical system 43, and the flash 46 are covered with the cover 60 by sliding the cover 60. When the cover 60 is opened and the camera 40 is set to the photographing state, the photographing optical system 41 enters the non-collapsed state shown in FIG. Photographing is performed through the optical system 41, for example, the zoom lens of the first embodiment. An object image formed by the photographic optical system 41 is formed on the imaging surface of the
さらに、ファインダー用光路44上にはファインダー用対物光学系53が配置してある。ファインダー用対物光学系53は、複数のレンズ群(図の場合は3群)と2つのプリズムからなり、撮影光学系41のズームレンズに連動して焦点距離が変化するズーム光学系からなり、このファインダー用対物光学系53によって形成された物体像は、像正立部材である正立プリズム55の視野枠57上に形成される。この正立プリズム55の後方には、正立正像にされた像を観察者眼球Eに導く接眼光学系59が配置されている。なお、接眼光学系59の射出側にカバー部材50が配置されている。 Further, a finder objective optical system 53 is disposed on the finder optical path 44. The finder objective optical system 53 includes a plurality of lens groups (three groups in the figure) and two prisms, and includes a zoom optical system whose focal length changes in conjunction with the zoom lens of the photographing optical system 41. The object image formed by the finder objective optical system 53 is formed on the field frame 57 of the erecting prism 55 that is an image erecting member. Behind the erecting prism 55, an eyepiece optical system 59 for guiding the erect image to the observer eyeball E is disposed. A cover member 50 is disposed on the exit side of the eyepiece optical system 59.
このように構成されたデジタルカメラ40は、撮影光学系41が 本発明により、沈胴時に厚みを極めて薄く、高変倍で全変倍域で結像性能を極めて安定的であるので、高性能・小型化・広角化が実現できる。 The digital camera 40 configured in this manner has the imaging optical system 41 that is extremely thin when retracted according to the present invention, and has a high zoom ratio and extremely stable imaging performance in the entire zoom range. Miniaturization and wide angle can be realized.
G1…第1レンズ群
G2…第2レンズ群
G3…第3レンズ群
S…開口絞り
F…ローパスフィルタ
C…カバーガラス
I…像面
E…観察者眼球
40…デジタルカメラ
41…撮影光学系
42…撮影用光路
43…ファインダー光学系
44…ファインダー用光路
45…シャッターボタン
46…フラッシュ
47…液晶表示モニター
49…CCD
50…カバー部材
51…処理手段
52…記録手段
53…ファインダー用対物光学系
55…正立プリズム
57…視野枠
59…接眼光学系
60…カバー
61…焦点距離変更ボタン
62…設定変更スイッチ
G1 ... 1st lens group G2 ... 2nd lens group G3 ... 3rd lens group S ... Aperture stop F ... Low pass filter C ... Cover glass I ... Image plane E ... Observer eyeball 40 ... Digital camera 41 ... Shooting optical system 42 ... Optical path for photographing 43 ... finder optical system 44 ... optical path for finder 45 ... shutter button 46 ... flash 47 ... liquid crystal display monitor 49 ... CCD
DESCRIPTION OF SYMBOLS 50 ... Cover member 51 ... Processing means 52 ... Recording means 53 ... Viewfinder objective optical system 55 ... Erect prism 57 ... Field frame 59 ... Eyepiece optical system 60 ... Cover 61 ... Focal length change button 62 ... Setting change switch
Claims (12)
前記第1レンズ群は、物体側より順に、1枚の負レンズと1枚の正レンズの2枚で構成され、
前記第2レンズ群は、2枚の正レンズと1枚の負レンズを有し、
前記第3レンズ群は、1枚の正レンズで構成され、
以下の条件式を満足することを特徴とするズームレンズ。
(1) (Σd1 +Σd2 +Σd3 )/ft <0.64
ただし、Σd1 :第1レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
Σd2 :第2レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
Σd3 :第3レンズ群の最も物体側のレンズ面から最も像側のレンズ面までの光 軸上の厚さ、
ft :望遠端でのズームレンズ全系の焦点距離、
である。 In order from the object side to the image side, there are a first lens unit having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. In zoom lenses that perform zooming from the end to the telephoto end,
The first lens group is composed of two negative lenses and one positive lens in order from the object side.
The second lens group has two positive lenses and one negative lens,
The third lens group is composed of one positive lens,
A zoom lens satisfying the following conditional expression:
(1) (Σd 1 + Σd 2 + Σd 3) / f t <0.64
Where Σd 1 is the thickness on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side of the first lens group,
Σd 2 : thickness on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side in the second lens group,
Σd 3 : Thickness on the optical axis from the most object side lens surface to the most image side lens surface of the third lens group,
f t : focal length of the entire zoom lens system at the telephoto end,
It is.
(2) −1.6<f1 /f2 <−1.1
ただし、f1 :第1レンズ群の焦点距離、
f2 :第2レンズ群の焦点距離、
である。 The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
(2) −1.6 <f 1 / f 2 <−1.1
Where f 1 is the focal length of the first lens group,
f 2 : focal length of the second lens group,
It is.
(3) 0.25<|f11/f12|<0.60
ただし、f11:第1レンズ群の負レンズの焦点距離、
f12:第1レンズ群の正レンズの焦点距離、
である。 The zoom lens according to claim 1, wherein the first lens group satisfies the following conditional expression.
(3) 0.25 <| f 11 / f 12 | <0.60
Where f 11 is the focal length of the negative lens of the first lens group,
f 12 : focal length of the positive lens of the first lens group,
It is.
(4) −0.6<SF12<−0.1
ただし、SF12=(R11−R12)/(R11+R12)で定義され、
R11:第1レンズ群の正レンズの物体側面の近軸曲率半径、
R12:第1レンズ群の正レンズの像側面の近軸曲率半径,
である。 The zoom lens according to any one of claims 1 to 3, wherein the following conditional expression is satisfied.
(4) −0.6 <SF 12 <−0.1
Provided that SF 12 = (R 11 −R 12 ) / (R 11 + R 12 )
R 11 : Paraxial radius of curvature of the object side surface of the positive lens in the first lens group,
R 12 : Paraxial radius of curvature of the image side surface of the positive lens in the first lens group,
It is.
(5) −0.90<f21/f23<−0.15
ただし、f21:第2レンズ群の最も物体側の正レンズの焦点距離、
f23:第2レンズ群の接合レンズの焦点距離、
である。 The zoom lens according to claim 5, wherein the second lens group satisfies the following conditional expression.
(5) −0.90 <f 21 / f 23 <−0.15
Where f 21 is the focal length of the positive lens closest to the object side in the second lens group,
f 23 : focal length of the cemented lens of the second lens group,
It is.
(6) 1.0<f23/Rcem <6.0
ただし、f23:第2レンズ群の接合レンズの焦点距離、
Rcem :第2レンズ群の接合レンズにおける接合面の近軸曲率半径、
である。 The zoom lens according to claim 5 or 6, wherein the following conditional expression is satisfied.
(6) 1.0 <f 23 / R cem <6.0
Where f 23 is the focal length of the cemented lens of the second lens group,
R cem : Paraxial curvature radius of the cemented surface in the cemented lens of the second lens group,
It is.
(7) −5.0<SF21<−1.0
ただし、SF12=(R21−R22)/(R21+R22)で定義され、
R21:第2レンズ群の最も物体側の正レンズの物体側面の近軸曲率半径、
R22:第2レンズ群の最も物体側の正レンズの像側面の近軸曲率半径、
である。 The zoom lens according to any one of claims 5 to 7, wherein a positive lens closest to the object side in the second lens group is an aspherical lens that satisfies the following conditional expression.
(7) −5.0 <SF 21 <−1.0
However, SF 12 = (R 21 −R 22 ) / (R 21 + R 22 )
R 21 : Paraxial radius of curvature of the object side surface of the positive lens closest to the object side in the second lens group,
R 22 : Paraxial curvature radius of the image side surface of the positive lens closest to the object side in the second lens group,
It is.
(8) 0.001<|asp31/fw |<0.02
ただし、asp31:第3レンズ群に配置された非球面の有効径での非球面偏倚量であり、非球面偏倚量は、非球面の面頂を面頂とし、曲率半径を非球面の近軸曲率半径とした球面から非球面までの光軸方向での距離であり、
fw :広角端でのズームレンズ全系の焦点距離、
である。 9. The zoom lens according to claim 1, wherein the third lens group has an aspherical surface that satisfies the following conditional expression. 10.
(8) 0.001 <| asp31 / f w | <0.02
Where asp31 is an aspherical deviation amount at the effective diameter of the aspherical surface disposed in the third lens group, and the aspherical deviation amount has the aspherical surface apex as the apex and the radius of curvature is the aspherical paraxial axis. It is the distance in the optical axis direction from the spherical surface to the aspherical surface as the radius of curvature,
f w : focal length of the entire zoom lens system at the wide-angle end,
It is.
(9) −8.0<SF31<0.0
ただし、SF31=(R31−R32)/(R31+R32)で定義され、
R31:第3レンズ群の正レンズの物体側面の近軸曲率半径、
R32:第3レンズ群の正レンズの像側面の近軸曲率半径、
である。 The zoom lens according to any one of claims 1 to 9, wherein the positive lens of the third lens group satisfies the following condition.
(9) −8.0 <SF 31 <0.0
However, SF 31 = (R 31 −R 32 ) / (R 31 + R 32 )
R 31 : Paraxial radius of curvature of the object side surface of the positive lens in the third lens group,
R 32 : Paraxial radius of curvature of the image side surface of the positive lens in the third lens group,
It is.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2005003992A JP2006194975A (en) | 2005-01-11 | 2005-01-11 | Zoom lens and imaging apparatus using the same |
US11/322,564 US7277233B2 (en) | 2005-01-11 | 2006-01-03 | Zoom lens and imaging system incorporating it |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2005003992A JP2006194975A (en) | 2005-01-11 | 2005-01-11 | Zoom lens and imaging apparatus using the same |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2006194975A true JP2006194975A (en) | 2006-07-27 |
JP2006194975A5 JP2006194975A5 (en) | 2007-12-20 |
Family
ID=36801125
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2005003992A Pending JP2006194975A (en) | 2005-01-11 | 2005-01-11 | Zoom lens and imaging apparatus using the same |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2006194975A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007272216A (en) * | 2006-03-09 | 2007-10-18 | Matsushita Electric Ind Co Ltd | Zoom lens system, imaging device and camera |
JP2007272215A (en) * | 2006-03-09 | 2007-10-18 | Matsushita Electric Ind Co Ltd | Zoom lens system, imaging device and camera |
US7663809B2 (en) | 2008-02-04 | 2010-02-16 | Samsung Digital Imaging Co., Ltd. | Compact zoom lens |
JP2010039014A (en) * | 2008-08-01 | 2010-02-18 | Nikon Corp | Zoom lens, imaging apparatus and variable-magnification method |
US7830616B2 (en) | 2008-10-02 | 2010-11-09 | Nikon Corporation | Zoom lens, optical apparatus and manufacturing method |
US8023199B2 (en) | 2008-10-10 | 2011-09-20 | Olympus Imaging Corp. | Zoom lens and image pickup apparatus equipped with same |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002277740A (en) * | 2001-03-19 | 2002-09-25 | Asahi Optical Co Ltd | Zoom lens system |
JP2004061675A (en) * | 2002-07-26 | 2004-02-26 | Canon Inc | Zoom lens |
JP2004333767A (en) * | 2003-05-06 | 2004-11-25 | Canon Inc | Zoom lens and optical equipment having the same |
JP2006078581A (en) * | 2004-09-07 | 2006-03-23 | Sony Corp | Zoom lens and imaging device |
JP2006139187A (en) * | 2004-11-15 | 2006-06-01 | Canon Inc | Zoom lens |
JP2006178242A (en) * | 2004-12-24 | 2006-07-06 | Nidec Copal Corp | Zoom lens |
-
2005
- 2005-01-11 JP JP2005003992A patent/JP2006194975A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002277740A (en) * | 2001-03-19 | 2002-09-25 | Asahi Optical Co Ltd | Zoom lens system |
JP2004061675A (en) * | 2002-07-26 | 2004-02-26 | Canon Inc | Zoom lens |
JP2004333767A (en) * | 2003-05-06 | 2004-11-25 | Canon Inc | Zoom lens and optical equipment having the same |
JP2006078581A (en) * | 2004-09-07 | 2006-03-23 | Sony Corp | Zoom lens and imaging device |
JP2006139187A (en) * | 2004-11-15 | 2006-06-01 | Canon Inc | Zoom lens |
JP2006178242A (en) * | 2004-12-24 | 2006-07-06 | Nidec Copal Corp | Zoom lens |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007272216A (en) * | 2006-03-09 | 2007-10-18 | Matsushita Electric Ind Co Ltd | Zoom lens system, imaging device and camera |
JP2007272215A (en) * | 2006-03-09 | 2007-10-18 | Matsushita Electric Ind Co Ltd | Zoom lens system, imaging device and camera |
US7663809B2 (en) | 2008-02-04 | 2010-02-16 | Samsung Digital Imaging Co., Ltd. | Compact zoom lens |
JP2010039014A (en) * | 2008-08-01 | 2010-02-18 | Nikon Corp | Zoom lens, imaging apparatus and variable-magnification method |
US7830616B2 (en) | 2008-10-02 | 2010-11-09 | Nikon Corporation | Zoom lens, optical apparatus and manufacturing method |
US8023199B2 (en) | 2008-10-10 | 2011-09-20 | Olympus Imaging Corp. | Zoom lens and image pickup apparatus equipped with same |
US8390938B2 (en) | 2008-10-10 | 2013-03-05 | Olympus Imaging Corp. | Zoom lens and image pickup apparatus equipped with same |
US8582211B2 (en) | 2008-10-10 | 2013-11-12 | Olympus Imaging Corp. | Zoom lens and image pickup apparatus equipped with same |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4840909B2 (en) | Zoom lens and image pickup apparatus including the same | |
JP4900924B2 (en) | Zoom lens and electronic imaging apparatus using the same | |
JP4859186B2 (en) | Zoom lens and image pickup apparatus including the same | |
JP4900923B2 (en) | Zoom lens and electronic imaging apparatus using the same | |
JP4901270B2 (en) | Zoom lens | |
JP4909089B2 (en) | Zoom lens and imaging apparatus having the same | |
JP2007327991A (en) | Zoom lens and imaging apparatus with the same | |
JP2007328178A (en) | Zoom lens and electronic imaging apparatus with the same | |
JP4906439B2 (en) | Zoom lens and electronic imaging apparatus using the same | |
JP4911679B2 (en) | Zoom lens and image pickup apparatus including the same | |
JP4690052B2 (en) | Zoom lens and imaging apparatus using the same | |
JP2006301154A (en) | Zoom lens and electronic imaging apparatus using the same | |
JP2006220715A (en) | Zoom lens and imaging apparatus using the same | |
US7277233B2 (en) | Zoom lens and imaging system incorporating it | |
JP2006308649A (en) | Imaging apparatus | |
JP4605698B2 (en) | Zoom lens and image pickup apparatus equipped with the same | |
JP4873937B2 (en) | Three-group zoom lens and image pickup apparatus including the same | |
JP5186034B2 (en) | Zoom lens and image pickup apparatus including the same | |
JP2006194975A (en) | Zoom lens and imaging apparatus using the same | |
JP4489398B2 (en) | Zoom lens and electronic imaging apparatus using the same | |
JP4884054B2 (en) | Zoom lens | |
JP4947992B2 (en) | Zoom lens and imaging apparatus using the same | |
JP2006343534A (en) | Zoom lens and electronic imaging apparatus using the same | |
JP4605699B2 (en) | Zoom lens and image pickup apparatus equipped with the same | |
JP2006337419A (en) | Imaging apparatus |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A711 | Notification of change in applicant |
Effective date: 20061222 Free format text: JAPANESE INTERMEDIATE CODE: A711 |
|
A521 | Written amendment |
Effective date: 20061222 Free format text: JAPANESE INTERMEDIATE CODE: A821 |
|
A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20071031 |
|
A621 | Written request for application examination |
Effective date: 20071031 Free format text: JAPANESE INTERMEDIATE CODE: A621 |
|
A977 | Report on retrieval |
Effective date: 20100929 Free format text: JAPANESE INTERMEDIATE CODE: A971007 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20101006 |
|
A02 | Decision of refusal |
Effective date: 20110309 Free format text: JAPANESE INTERMEDIATE CODE: A02 |