【０００１】[0001]
【発明の属する技術分野】本発明は原稿読取用レンズに
関し、特に明るいＦＮｏ（Ｆナンバー）であり、周辺画
角まで１００％の開口率を維持しながら、且つ各種収差
がバランスよく補正され、高解像力を有する、例えばデ
ジタル複写機やイメージスキャナ等のデジタル読取機器
に好適な原稿読取用レンズに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an original reading lens, particularly a bright FNo (F number), which maintains a 100% aperture ratio up to a peripheral angle of view, corrects various aberrations in a well-balanced manner, and has a high performance. The present invention relates to a document reading lens having a resolving power and suitable for a digital reading device such as a digital copying machine or an image scanner.
【０００２】[0002]
【従来の技術】一般にデジタル複写機やイメージスキャ
ナ等のデジタル読取機器では照明装置により照明された
原稿を、原稿読取用レンズにより順次原稿面をスキャン
していき、１次元固体撮像素子（ＣＣＤ）面上に順次縮
小結像させて、該原稿の画像情報をデジタルデータとし
て読み取り、電気的に処理できる信号に変換している。2. Description of the Related Art In general, in a digital reading device such as a digital copying machine or an image scanner, a document illuminated by an illumination device is sequentially scanned on a document surface by a document reading lens, and a one-dimensional solid-state imaging device (CCD) surface. The image information of the original is read as digital data and converted into a signal that can be electrically processed.
【０００３】この場合に装置全体の性能から要求される
原稿読取用レンズの特性としては、まず読取速度を向上
するために単位時間当りのＣＣＤ（ラインセンサー）へ
の十分な光量を確保できることである。In this case, a characteristic of the original reading lens required from the performance of the entire apparatus is that a sufficient amount of light to a CCD (line sensor) per unit time can be secured in order to improve the reading speed. .
【０００４】読取速度が高速になればその分、単位時間
あたりにＣＣＤが受光できる光量が減少するため、照明
系の光量をアップするか、もしくは十分な光量を確保で
きる光学系の設定が必要となる。As the reading speed increases, the amount of light that can be received by the CCD per unit time decreases accordingly. Therefore, it is necessary to increase the amount of light in the illumination system or set an optical system capable of securing a sufficient amount of light. Become.
【０００５】しかしながら照明系の光量アップは照明装
置を大型化させ、また電気的にも必要な電力が増大する
ためコストアップにもつながり好ましくない。However, an increase in the amount of light in the illumination system undesirably leads to an increase in the size of the illumination device and an increase in electric power required, which leads to an increase in cost.
【０００６】そのため原稿読取用レンズを広開口にし、
つまりＦＮｏを明るいものとし、ＣＣＤ面上に到達する
光量を高い効率で送り込むことが要求される。For this reason, the original reading lens has a wide opening,
That is, it is required to make the FNo bright and to send the light amount reaching the CCD surface with high efficiency.
【０００７】また装置全体の小型化の点からは全光路長
を短くして必要な容積を減少させることが必要になる。
同じ原稿サイズでレンズが短い距離で結像するというこ
とは広い画角を要求されるということである。Further, from the viewpoint of miniaturization of the entire apparatus, it is necessary to shorten the total optical path length to reduce the required volume.
The fact that the lens forms an image at a short distance with the same original size means that a wide angle of view is required.
【０００８】更に近年４５０ｄｐｉや６００ｄｐｉ等の
高解像度で高品質なデジタル画像情報を得ることが要求
されている。物体（読取原稿）側の周辺領域においても
十分な光量を確保するため開口率は全域１００％とし、
光量の違いによる像の劣化を極力防ぐことが必要であ
り、また基本的な収差そのものも十分に除去されている
ことが必要とされる。In recent years, there has been a demand for obtaining high-resolution and high-quality digital image information such as 450 dpi and 600 dpi. The aperture ratio is set to 100% for the entire area in order to secure a sufficient amount of light even in the peripheral area on the object (read original) side.
It is necessary to prevent image deterioration due to the difference in light amount as much as possible, and it is necessary that basic aberrations themselves are sufficiently removed.
【０００９】また色収差についてもカラー画像読取りに
適応できるためにはもちろん、白黒画像においても像の
にじみ、フレア防止の観点からも十分に除去されている
ことが必要である。Further, in order to be applicable to color image reading, it is necessary for chromatic aberration to be sufficiently removed from a black-and-white image from the viewpoint of preventing image bleeding and flare.
【００１０】従来、原稿読取用レンズとしてガウスタイ
プを採用したものが、例えば特開平6-342120号公報で提
案されている。同公報の原稿読取用レンズは第１レンズ
乃至第６レンズより成る４群６枚構成より成っている。
同公報ではＦＮｏが４以下の大口径の読取用レンズを開
示している。Conventionally, a lens employing a Gauss type as a document reading lens has been proposed in, for example, Japanese Patent Application Laid-Open No. 6-342120. The document reading lens disclosed in the publication has a four-group, six-lens configuration including a first lens to a sixth lens.
This publication discloses a large-diameter reading lens having an FNo of 4 or less.
【００１１】[0011]
【発明が解決しようとする課題】本発明は４群６枚構成
のガウスタイプの原稿読取用レンズの各レンズ群のレン
ズ構成を適切に設定することにより、明るいＦＮｏであ
り、周辺画角まで１００％の開口率を維持しながら、且
つ各種収差がバランスよく補正され、高解像力を有す
る、例えばデジタル複写機やイメージスキャナ等のデジ
タル読取機器に好適な原稿読取用レンズの提供を目的と
する。SUMMARY OF THE INVENTION The present invention provides a bright FNo by setting the lens configuration of each lens group of a Gaussian type original reading lens having six elements in four groups, to achieve a bright FNo. An object of the present invention is to provide a document reading lens having a high resolving power, which is suitable for digital reading devices such as a digital copying machine and an image scanner, while maintaining a high aperture ratio while maintaining various% aberrations.
【００１２】[0012]
【課題を解決するための手段】請求項１の発明の原稿読
取用レンズは、物体側から順に物体側に凸面を向けたメ
ニスカス状の正の第１レンズを有する第１群、正の第２
レンズと負の第３レンズとを貼り合わせた負の第２３レ
ンズを有する第２群、絞り、負の第４レンズと正の第５
レンズとを貼り合わせた負の第４５レンズを有する第３
群、そして像面側に凸面を向けたメニスカス状の正の第
６レンズを有する第４群の４つのレンズ群を有し、 P1=(dG2+dG3)/(d1+d10) P2=(n1+n2+n5+n6)/4-(n3+n4)/2 P3=(f1/f)/n1+(f6/f)/n6 P4=((f1/f12)×(d3+d4))/((f4/f34)×(d7+d8)) P5=(ν1+ν2+ν5+ν6)/4-(ν3+ν4)/2 とする各パラメータを設定したとき、 1.3 < P1 < 1.9 ‥‥‥（１） 0.02 < P2 < 0.04 ‥‥‥（２） 1.1 < P3 < 1.3 ‥‥‥（３） 0.9 < P4 < 2.1 ‥‥‥（４） 15 < P5 < 20 ‥‥‥（５） 但し、 ｆ ：全系の焦点距離 f1 ：第１レンズの焦点距離 f4 ：第４レンズの焦点距離 f6 ：第６レンズの焦点距離 f12 ：第１群と第２群の合成の焦点距離 f34 ：第３群と第４群の合成の焦点距離 dG2 ：第２群のレンズ厚 dG3 ：第３群のレンズ厚 di ：物体側から順に第ｉ番目のレンズ厚又は空気間隔
（但し、絞りも１面として数える。） ni ：物体側から順に第ｉ番目のレンズの材質の屈折率 νi ：物体側から順に第ｉ番目のレンズのアッベ数 なる条件を満足することを特徴としている。According to a first aspect of the present invention, there is provided a document reading lens comprising: a first group having a meniscus-shaped positive first lens having a convex surface facing the object side in order from the object side;
A second group having a negative twenty-third lens in which a lens and a negative third lens are bonded, an aperture, a negative fourth lens and a positive fifth lens
A third lens having a negative 45th lens bonded to a lens
Group, and a fourth lens group having a meniscus-shaped positive sixth lens with the convex surface facing the image side, and P1 = (dG2 + dG3) / (d1 + d10) P2 = (n1 + n2 + n5 + n6) / 4- (n3 + n4) / 2 P3 = (f1 / f) / n1 + (f6 / f) / n6 P4 = ((f1 / f12) × (d3 + d4)) / ( (f4 / f34) × (d7 + d8)) P5 = (ν1 + ν2 + ν5 + ν6) / 4- (ν3 + ν4) / 2 When setting each parameter, 1.3 <P1 <1.9 ‥‥‥ (1) 0.02 <P2 <0.04 (2) 1.1 <P3 <1.3 (3) 0.9 <P4 <2.1 (4) 15 <P5 <20 (5) where f : Focal length of the entire system f1: focal length of the first lens f4: focal length of the fourth lens f6: focal length of the sixth lens f12: focal length of the combination of the first and second groups f34: third and fourth groups The combined focal length of the fourth group dG2: the lens thickness of the second group dG3: the lens thickness of the third group di: the i-th lens thickness or air spacing in order from the object side (however, the aperture is also counted as one surface). ni: i-th order from the object side Refractive index of the lens material .nu.i: is characterized by satisfying the Abbe number becomes conditions of the i-th lens from the object side.
【００１３】請求項２の発明は請求項１の発明において P6=(r5+r7)/(d5+d6) P7=(r3-r9)/(d3+d4+d5+d6+d7+d8) とする各パラメータを設定したとき、 -0.1 < P6 < 0.1 ‥‥‥（６） 1.0 < P7 < 1.3 ‥‥‥（７） 但し、 ri ：物体側から順に第ｉ番目のレンズ面の曲率半径
（但し、絞りも１面として数える。） なる条件を満足することを特徴としている。The invention of claim 2 is the invention of claim 1, wherein P6 = (r5 + r7) / (d5 + d6) P7 = (r3-r9) / (d3 + d4 + d5 + d6 + d7 + d8) When each parameter is set, -0.1 <P6 <0.1 (6) 1.0 <P7 <1.3 (7) where ri is the radius of curvature of the i-th lens surface in order from the object side (however, The aperture is also counted as one surface.) The following condition is satisfied.
【００１４】[0014]
【発明の実施の形態】図１、図２、図３は各々本発明の
後述する数値実施例１、２、３のレンズ断面図、図４、
図５、図６は各々本発明の後述する数値実施例１、２、
３の諸収差図（球面収差、非点収差、歪曲収差）、図
７、図８、図９は各々本発明の後述する数値実施例１、
２、３の縦収差図である。1, 2, and 3 are lens sectional views of Numerical Examples 1, 2, and 3 of the present invention, respectively, and FIGS.
5 and 6 show Numerical Examples 1 and 2 of the present invention, respectively.
3, 8 and 9 show various aberration diagrams (spherical aberration, astigmatism, distortion) of Numerical Example 1 of the present invention,
It is a 2 and 3 longitudinal aberration figure.
【００１５】図１、図２、図３において原稿読取用レン
ズは物体側（読取画像が設けられている側）から順に物
体側に凸面を向けたメニスカス状の正の第１レンズ１を
有する第１群Ｇ１、正の第２レンズ２と負の第３レンズ
３とを貼り合わせた負の第２３レンズ２３を有する第２
群Ｇ２、絞りＳＰ、負の第４レンズ４と正の第５レンズ
５とを貼り合わせた負の第４５レンズ４５を有する第３
群Ｇ３、そして像面側（例えばＣＣＤが設けられている
側）に凸面を向けたメニスカス状の正の第６レンズ６を
有する第４群Ｇ４の４つのレンズ群を有している。In FIGS. 1, 2 and 3, the original reading lens has a meniscus-shaped positive first lens 1 whose convex surface faces the object side in order from the object side (the side on which the read image is provided). A first group G1, a second group including a negative twenty-third lens 23 in which a positive second lens 2 and a negative third lens 3 are bonded to each other;
A third group including a group G2, a diaphragm SP, and a negative 45th lens 45 in which a negative fourth lens 4 and a positive fifth lens 5 are bonded to each other;
It has four lens groups, a group G3 and a fourth group G4 having a meniscus-shaped positive sixth lens 6 with the convex surface facing the image plane side (for example, the side where the CCD is provided).
【００１６】本実施形態では原稿読取用レンズを図１、
図２、図３に示すように所定形状の４群６枚のガウスタ
イプのレンズより構成すると共に前述の各条件式（１）
〜（５）の如く設定することにより、明るいＦＮｏであ
り、周辺画角まで１００％の開口率を維持しながら、且
つ各種収差がバランスよく補正され、高解像力を有する
原稿読取用レンズを得ている。In this embodiment, the original reading lens is shown in FIG.
As shown in FIGS. 2 and 3, the lens is composed of six groups of six Gaussian lenses having a predetermined shape, and the above-mentioned conditional expressions (1)
By setting as in (5), it is possible to obtain a document reading lens which is a bright FNo, has a 100% aperture ratio up to the peripheral angle of view, has various aberrations corrected in a well-balanced manner, and has a high resolution. I have.
【００１７】本実施形態では第１レンズ１を物体側に凸
面を向けたメニスカス状の正レンズより構成し、第６レ
ンズ６を像面側に凸面を向けたメニスカス状の正レンズ
より構成することにより、原稿読取用レンズ全体の小型
化を図っている。In this embodiment, the first lens 1 is composed of a meniscus positive lens having a convex surface facing the object side, and the sixth lens 6 is composed of a meniscus positive lens having a convex surface facing the image surface. As a result, the size of the entire document reading lens is reduced.
【００１８】次に各条件式（１）〜（５）の技術的意味
について説明する。Next, the technical meaning of each of the conditional expressions (1) to (5) will be described.
【００１９】条件式（１）はパワー配分を定める上で全
系の光路長から主点間隔を定めるための条件であり、条
件式（１）の上限値を超えると主に倍率の色収差が増大
し良くない。また条件式（１）の下限値を越えると主に
色収差や非点収差が増大するので良くない。Conditional expression (1) is a condition for determining the principal point interval from the optical path length of the entire system in determining the power distribution. If the upper limit of conditional expression (1) is exceeded, chromatic aberration of magnification mainly increases. Not good. If the lower limit of conditional expression (1) is exceeded, chromatic aberration and astigmatism will mainly increase, which is not good.
【００２０】条件式（２）は各レンズの材質の屈折率の
選択を定めるための条件であり、条件式（２）の上限値
を越えると像面湾曲が増大し良くない。また条件式
（２）の下限値を越えると主として非点収差の補正が困
難となるので良くない。Conditional expression (2) is a condition for determining the selection of the refractive index of the material of each lens. If the upper limit of conditional expression (2) is exceeded, the curvature of field increases, which is not good. If the lower limit of conditional expression (2) is exceeded, correction of astigmatism becomes difficult mainly, which is not good.
【００２１】条件式（３）は正の第１群Ｇ１と第４群Ｇ
４でのパワーの分担を定めるための条件であり、条件式
（３）の範囲を逸脱すると主として球面収差の補正、及
び像面湾曲収差の補正が困難となるので良くない。Conditional expression (3) shows that the first lens unit G1 and the fourth lens unit G
This is a condition for determining the power allotment in Condition 4, and if it is out of the range of the conditional expression (3), it is difficult to correct mainly the spherical aberration and the field curvature aberration, which is not good.
【００２２】条件式（４）は絞りＳＰの前後のパワー配
分を定めるための条件であり、条件式（４）の範囲を逸
脱すると主としてコマ収差、歪曲収差の補正が困難とな
るので良くない。Conditional expression (4) is a condition for determining the power distribution before and after the aperture stop SP. If the value deviates from the range of conditional expression (4), it becomes difficult to correct mainly coma and distortion, which is not good.
【００２３】条件式（５）は分散の選択を定めるための
条件であり、条件式（５）の上限値を越えると色収差が
補正過剰となり良くない。また条件式（５）の下限値を
越えると色収差が補正不足となるので良くない。Conditional expression (5) is a condition for determining the choice of dispersion. If the upper limit of conditional expression (5) is exceeded, chromatic aberration will be overcorrected, which is not good. If the lower limit of conditional expression (5) is exceeded, chromatic aberration will be insufficiently corrected, which is not good.
【００２４】尚、本発明において更に収差補正上、好ま
しくは P6=(r5+r7)/(d5+d6) P7=(r3-r9)/(d3+d4+d5+d6+d7+d8) とする各パラメータを設定したとき、 -0.1 < P6 < 0.1 ‥‥‥（６） 1.0 < P7 < 1.3 ‥‥‥（７） 但し、 ri ：物体側から順に第ｉ番目のレンズ面の曲率半径
（但し、絞りも１面として数える。） を満足させるのが良い。In the present invention, in order to further correct aberrations, preferably, P6 = (r5 + r7) / (d5 + d6) P7 = (r3-r9) / (d3 + d4 + d5 + d6 + d7 + d8) When each parameter is set, -0.1 <P6 <0.1 (6) 1.0 <P7 <1.3 (7) where ri is the radius of curvature of the i-th lens surface in order from the object side (however, , And the aperture is counted as one surface.)
【００２５】条件式（６）は上記条件式（２）、（３）
と合わせて考慮することで主として球面収差の補正と、
コマ収差の補正に有効なための条件である。条件式
（６）の範囲を逸脱すると解像力が著しく劣化するので
良くない。Conditional expression (6) is equivalent to conditional expressions (2) and (3).
By mainly considering the correction of spherical aberration,
This is a condition that is effective for correcting coma aberration. Deviating from the range of the conditional expression (6) is not preferable because the resolving power is remarkably deteriorated.
【００２６】条件式（７）は主として原稿読取用レンズ
を小型化しつつ、像面湾曲収差を補正するために必要な
条件であり、条件式（７）の範囲を逸脱するとその効果
が薄れるので良くない。条件式（６）及び条件式（７）
を満足させることにより、全系の補正バランスと収差補
正に有利な形状、配分を与えることができる。Conditional expression (7) is a condition necessary for correcting the field curvature aberration while reducing the size of the original reading lens. If the value is out of the range of conditional expression (7), the effect is diminished. Absent. Conditional expression (6) and conditional expression (7)
Is satisfied, it is possible to provide a shape and distribution advantageous for the correction balance and aberration correction of the entire system.
【００２７】次に本発明の数値実施例１〜３を示す。数
値実施例においてｒｉは物体側より順に第ｉ番目のレン
ズ面の曲率半径、ｄｉは物体側より第ｉ番目のレンズ厚
及び空気間隔、ｎｉとνｉは各々物体側より順に第ｉ番
目のレンズのｄ線におけるガラスの屈折率とアッベ数で
ある。ｆｄはｄ線における焦点距離、ＦＮｏは物体距離
無限時のＦナンバー、Ｙは原稿側の物体高、ｍは結像倍
率を表している。また前述の各条件式と数値実施例にお
ける諸数値との関係を表−１に示す。Next, Numerical Examples 1 to 3 of the present invention will be described. In the numerical examples, ri is the radius of curvature of the i-th lens surface in order from the object side, di is the i-th lens thickness and air space from the object side, and ni and νi are the i-th lens surfaces in order from the object side. The refractive index and Abbe number of glass at d-line. fd is the focal length at the d-line, FNo is the F-number when the object distance is infinite, Y is the object height on the document side, and m is the imaging magnification. Table 1 shows the relationship between the above-described conditional expressions and various numerical values in the numerical examples.
【００２８】 ［数値実施例１］ fd =50.98mm m =0.11102 FNo 3.8 Y =150mm r 1= 26.6843 d 1= 3.8 n1= 1.6228 ν 1= 57.05 r 2= 87.2769 d 2= 0.74 r 3= 15.3923 d 3= 5.23 n2= 1.63854 ν2= 55.38 r 4= 58.3850 d 4= 1.39 n3= 1.6398 ν3= 34.46 r 5= 11.0869 d 5= 6.11 r 6= 絞り面 d 6= 8.58 r 7= -12.2774 d 7= 1.24 n4= 1.6668 ν4= 33.05 r 8= -264.6 d 8= 4.93 n5= 1.6779 ν5= 55.34 r 9= -18.157 d 9= 0.39 r10= -560.8268 d10= 3.48 n6= 1.8061 ν6= 40.92 r11= -33.4298 ［数値実施例２］ fd =50.95mm m =0.11102 FNo 3.8 Y =150mm r 1= 25.7427 d 1= 4.0 n1= 1.6228 ν1= 57.05 r 2= 80.936 d 2= 0.34 r 3= 15.8989 d 3= 5.2 n2= 1.63854 ν2= 55.38 r 4= 48.9122 d 4= 1.4 n3= 1.6398 ν3= 34.46 r 5= 11.116 d 5= 6.3 r 6= 絞り面 d 6= 8.57 r 7= -12.3034 d 7= 1.2 n4= 1.6668 ν4= 33.05 r 8= -250.0 d 8= 5.0 n5= 1.67000 ν5= 57.33 r 9= -17.5478 d 9= 0.23 r10= -419.5012 d10= 3.5 n6= 1.8061 ν6= 40.92 r11= -33.1216 ［数値実施例３］ fd =49.32mm m =0.11102 FNo 3.8 Y =150mm r 1= 28.9081 d 1= 4.0 n1= 1.6228 ν1= 57.05 r 2= 95.1107 d 2= 1.91 r 3= 15.9129 d 3= 6.0 n2= 1.651 ν2= 56.16 r 4= 127.4637 d 4= 1.54 n3= 1.63980 ν3= 34.46 r 5= 11.4334 d 5= 4.58 r 6= 絞り面 d 6= 9.20 r 7= -10.5045 d 7= 1.0 n4= 1.6668 ν4= 33.05 r 8= -64.0863 d 8= 3.97 n5= 1.64 ν5= 60.07 r 9= -14.9899 d 9= 0.2 r10=-1884.9453 d10= 5.0 n6= 1.8061 ν6= 40.92 r11= -30.1395Numerical Example 1 fd = 50.98 mm m = 0.11102 FNo 3.8 Y = 150 mm r 1 = 26.6843 d 1 = 3.8 n1 = 1.6228 ν 1 = 57.05 r 2 = 87.2769 d 2 = 0.74 r 3 = 15.3923 d 3 = 5.23 n2 = 1.63854 ν2 = 55.38 r 4 = 58.3850 d 4 = 1.39 n3 = 1.6398 ν3 = 34.46 r 5 = 11.0869 d 5 = 6.11 r 6 = Aperture d 6 = 8.58 r 7 = -12.2774 d 7 = 1.24 n4 = 1.6668 ν4 = 33.05 r 8 = -264.6 d 8 = 4.93 n5 = 1.6779 ν5 = 55.34 r 9 = -18.157 d 9 = 0.39 r10 = -560.8268 d10 = 3.48 n6 = 1.8061 ν6 = 40.92 r11 = -33.4298 [Numerical Example 2] Fd = 50.95mm m = 0.11102 FNo 3.8 Y = 150mm r 1 = 25.7427 d 1 = 4.0 n1 = 1.6228 ν1 = 57.05 r 2 = 80.936 d 2 = 0.34 r 3 = 15.8989 d 3 = 5.2 n2 = 1.63854 ν2 = 55.38 r 4 = 48.9122 d 4 = 1.4 n3 = 1.6398 ν3 = 34.46 r 5 = 11.116 d 5 = 6.3 r 6 = Aperture d 6 = 8.57 r 7 = -12.3034 d 7 = 1.2 n4 = 1.6668 ν4 = 33.05 r 8 = -250.0 d 8 = 5.0 n5 = 1.67000 ν5 = 57.33 r 9 = -17.5478 d 9 = 0.23 r10 = -419.5012 d10 = 3.5 n6 = 1.8061 ν6 = 40.92 r11 = -33.1216 [Numerical example 3] fd = 49.32mm m = 0.11102 FNo 3.8 Y = 150mm r 1 = 28.9081 d 1 = 4.0 n1 = 1.62 28 ν1 = 57.05 r 2 = 95.1107 d 2 = 1.91 r 3 = 15.9129 d 3 = 6.0 n2 = 1.651 ν2 = 56.16 r 4 = 127.4637 d 4 = 1.54 n3 = 1.63980 ν3 = 34.46 r 5 = 11.4334 d 5 = 4.58 r 6 = Drawing surface d 6 = 9.20 r 7 = -10.5045 d 7 = 1.0 n4 = 1.6668 ν4 = 33.05 r 8 = -64.0863 d 8 = 3.97 n5 = 1.64 ν5 = 60.07 r 9 = -14.9899 d 9 = 0.2 r10 = -1884.9453 d10 = 5.0 n6 = 1.8061 ν6 = 40.92 r11 = -30.1395
【００２９】[0029]
【表１】[Table 1]
【００３０】[0030]
【発明の効果】本発明によれば前述の如く４群６枚構成
のガウスタイプの原稿読取用レンズの各レンズ群のレン
ズ構成を適切に設定することにより、明るいＦＮｏであ
り、周辺画角まで１００％の開口率を維持しながら、且
つ各種収差がバランスよく補正され、高解像力を有す
る、例えばデジタル複写機やイメージスキャナ等のデジ
タル読取機器に好適な原稿読取用レンズを達成すること
ができる。According to the present invention, as described above, by appropriately setting the lens configuration of each lens group of a Gaussian type document reading lens having four groups and six elements, it is possible to obtain a bright FNo. It is possible to achieve a document reading lens having a high resolution and suitable for digital reading equipment such as a digital copying machine and an image scanner, while maintaining an aperture ratio of 100% and correcting various aberrations in a well-balanced manner.
【図１】 本発明の数値実施例１のレンズ断面図FIG. 1 is a sectional view of a lens according to a numerical example 1 of the present invention.
【図２】 本発明の数値実施例２のレンズ断面図FIG. 2 is a sectional view of a lens according to a numerical example 2 of the present invention.
【図３】 本発明の数値実施例３のレンズ断面図FIG. 3 is a sectional view of a lens according to a numerical example 3 of the present invention.
【図４】 本発明の数値実施例１の諸収差図FIG. 4 is a diagram showing various aberrations of Numerical Example 1 of the present invention.
【図５】 本発明の数値実施例２の諸収差図FIG. 5 is a diagram showing various aberrations of Numerical Example 2 of the present invention.
【図６】 本発明の数値実施例３の諸収差図FIG. 6 is a diagram illustrating various aberrations of a numerical example 3 of the present invention.
【図７】 本発明の数値実施例１の縦収差図FIG. 7 is a longitudinal aberration diagram according to Numerical Embodiment 1 of the present invention.
【図８】 本発明の数値実施例２の縦収差図FIG. 8 is a longitudinal aberration diagram of Numerical Example 2 of the present invention.
【図９】 本発明の数値実施例３の縦収差図FIG. 9 is a longitudinal aberration diagram according to Numerical Example 3 of the present invention.
Ｇ１ 第１群 Ｇ２ 第２群 Ｇ３ 第３群 Ｇ４ 第４群 ＳＰ 絞り １ 第１レンズ ２ 第２レンズ ３ 第３レンズ ４ 第４レンズ ５ 第５レンズ ６ 第６レンズ ２３ 第２３レンズ ４５ 第４５レンズ G1 First group G2 Second group G3 Third group G4 Fourth group SP Aperture 1 First lens 2 Second lens 3 Third lens 4 Fourth lens 5 Fifth lens 6 Sixth lens 23 23rd lens 45 45th lens
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18372899AJP2001013407A (en) | 1999-06-29 | 1999-06-29 | Document reading lens |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18372899AJP2001013407A (en) | 1999-06-29 | 1999-06-29 | Document reading lens |
| Publication Number | Publication Date |
|---|---|
| JP2001013407Atrue JP2001013407A (en) | 2001-01-19 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18372899APendingJP2001013407A (en) | 1999-06-29 | 1999-06-29 | Document reading lens |
| Country | Link |
|---|---|
| JP (1) | JP2001013407A (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110133826A (en)* | 2018-02-08 | 2019-08-16 | 奥林巴斯株式会社 | Information acquisition device |
| CN117572607A (en)* | 2024-01-16 | 2024-02-20 | 苏州高视半导体技术有限公司 | Cylindrical lens with negative distortion and broadband and microscopic optical system |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110133826A (en)* | 2018-02-08 | 2019-08-16 | 奥林巴斯株式会社 | Information acquisition device |
| CN110133826B (en)* | 2018-02-08 | 2022-04-01 | 奥林巴斯株式会社 | Information acquisition device |
| CN117572607A (en)* | 2024-01-16 | 2024-02-20 | 苏州高视半导体技术有限公司 | Cylindrical lens with negative distortion and broadband and microscopic optical system |
| CN117572607B (en)* | 2024-01-16 | 2024-03-29 | 苏州高视半导体技术有限公司 | Cylindrical lens with negative distortion and broadband and microscopic optical system |
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