JPH0943508A - Hybrid lens - Google Patents
Hybrid lensInfo
- Publication number
- JPH0943508A JPH0943508A JP21245495A JP21245495A JPH0943508A JP H0943508 A JPH0943508 A JP H0943508A JP 21245495 A JP21245495 A JP 21245495A JP 21245495 A JP21245495 A JP 21245495A JP H0943508 A JPH0943508 A JP H0943508A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- lens group
- plastic material
- negative
- positive
- 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.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はファクシミリ、イメ
ージスキャナ等の原稿読取りに用いられるハイブリッド
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 a hybrid lens used for reading a document such as a facsimile or an image scanner.
【０００２】[0002]
【従来の技術】近年ファクシミリ、イメージスキャナ等
原稿読取装置の高速化、読取高密度化の要求により、レ
ンズには益々明るさ、高解像力が求められている。2. Description of the Related Art In recent years, due to the demand for higher speed and higher reading density of original reading devices such as facsimiles and image scanners, the lenses are required to have higher brightness and higher resolution.
【０００３】斯かる用途のレンズで、例えば読取密度４
００dpi 、読取幅が半画角２０°程度のレンズとして
は、特開昭５６−９５２０６号の様な４群６枚構成の所
謂ガラスタイプレンズ、又は特開平２−２１６１１５号
の様な５群７枚構成の様にレンズ枚数を増やしたものが
知られている。又、レンズの材料をプラスチックとし、
レンズを非球面化したプラスチックモールドレンズとす
ることが知られている。A lens having such a purpose, for example, a reading density of 4
As a lens having a scanning width of 00 dpi and a reading width of about 20 °, a so-called glass type lens having a structure of 4 groups and 6 elements as in JP-A-56-95206 or a group of 5 groups as in JP-A-2-216115. It is known that the number of lenses is increased like a single lens structure. Also, the lens material is plastic,
It is known that the lens is an aspherical plastic molded lens.
【０００４】[0004]
【発明が解決しようとする課題】上記した従来のレンズ
に於いて、前者のガウスタイプのレンズではレンズ枚数
を増し、更にガラス材の屈折率を高くしたりしていたの
で、高価なものとなっていた。又、後者のプラスチック
モールドレンズとした場合、温度変化により、屈折率が
大幅に変化する為、バックフォーカスが変化したり、解
像度を劣化させてしまうという問題がある。Among the conventional lenses described above, the former Gauss type lens requires an increased number of lenses and a higher refractive index of the glass material, which makes it expensive. Was there. Further, when the latter plastic molded lens is used, there is a problem that the back focus is changed and the resolution is deteriorated because the refractive index is largely changed due to the temperature change.
【０００５】本発明は斯かる実情に鑑み、明るく、高解
像度で而も低コストのハイブリッドレンズを提供しよう
とするものである。In view of the above situation, the present invention aims to provide a bright, high-resolution and extremely low-cost hybrid lens.
【０００６】[0006]
【課題を解決するための手段】本発明は、正のレンズ群
と負のレンズ群を有するハイブリッドレンズに於いて、
少なくとも正のレンズ群の一部にプラスチック材を使用
し、前記プラスチック材の正のレンズ群の温度変化に起
因するバックフォーカスの変化を相殺する様、負のレン
ズ群の少なくとも一部をプラスチック材としたものであ
り、又物体側から順に物体面に凸面を向けた両凸でプラ
スチック材料より成る正の第１レンズ群と、両凹でプラ
スチック材料より成る負の第２レンズ群と、単体レンズ
又は接合レンズから成る両凸の第３レンズ群と、物体側
に強い屈折面を有し像面側に凸面を向けたメニスカス状
でプラスチック材料より成る負の第４レンズ群とを有
し、第１レンズ群の少なくとも１つの面が非球面形状で
あり、又第４レンズ群の少なくとも１つの面が非球面形
状から成るレンズであって、且下記の条件を満足するも
のである。 （１） ０．６５＜ｆ1 ／ｆ＜ ０．９５ （２） −１．１ ＜ｆ4 ／ｆ＜−０．８ （３） −０．００５＜ｆ12／ｆ＜ ０．００２ （４） ５０ ＜ ν1 ＜ ６０ 但し ｆ ：全系の焦点距離 ｆ1 ：正第１レンズ群の焦点距離 ｆ4 ：負第４レンズ群の焦点距離 ｆ12：正第１レンズ群と負第２レンズ群の合成焦点距離 ν1 ：正第１レンズ群のアッベ数 である。DISCLOSURE OF THE INVENTION The present invention provides a hybrid lens having a positive lens group and a negative lens group,
A plastic material is used for at least a part of the positive lens group, and at least a part of the negative lens group is made of a plastic material so as to cancel the change in back focus caused by the temperature change of the positive lens group of the plastic material. In addition, a biconvex positive first lens unit made of a plastic material with a convex surface facing the object surface in order from the object side, a biconcave negative second lens unit made of a plastic material, and a single lens or A biconvex third lens unit consisting of a cemented lens, and a negative meniscus fourth lens unit consisting of a plastic material with a strong refracting surface facing the object side and a convex surface facing the image side, A lens in which at least one surface of the lens group has an aspherical shape and at least one surface of the fourth lens group has an aspherical shape, and the following conditions are satisfied. (1) 0.65 <f1 / f <0.95 (2) -1.1 <f4 / f <-0.8 (3) -0.005 <f12 / f <0.002 (4) 50 < ν1 <60 where f: focal length of the whole system f1: positive focal length of the first lens group f4: negative focal length of the fourth lens group f12: combined focal length of the positive first lens group and negative second lens group ν1: It is the Abbe number of the positive first lens group.
【０００７】而して、プラスチック材を使用することで
温度変化による屈折率の変化が生じ、バックフォーカス
が変化し、解像力が劣化するが、負の第２レンズ群、負
の第４レンズ群をプラスチック材料で形成することで、
温度によるバックフォーカスの変化を相殺する。Thus, when a plastic material is used, the refractive index changes due to temperature changes, the back focus changes, and the resolution deteriorates, but the negative second lens group and the negative fourth lens group are used. By forming with a plastic material,
Cancels back focus changes due to temperature.
【０００８】[0008]
【発明の実施の形態】以下、図面を参照しつつ本発明の
実施の形態を説明する。Embodiments of the present invention will be described below with reference to the drawings.
【０００９】物体側から順に物体面に凸面を向けた両凸
でプラスチック材料から成る正の第１レンズ群１、両凹
でプラスチック材料から成る負の第２レンズ群２、単体
又は接合レンズから成る両凸の第３レンズ群３、物体側
に強い屈折面を有し、像面側に凸面を向けたメニスカス
状でプラスチック材料から成る負の第４レンズ群４とを
順次配置し、前記第１レンズ群１の少なくとも１つの面
が非球面形状であり、又第４レンズ群４の少なくとも１
つの面が非球面形状とする。It is composed of a biconvex positive first lens group 1 made of a plastic material and a biconcave negative negative lens group 2 made of a plastic material, and a single lens or a cemented lens. A biconvex third lens unit 3 and a negative meniscus fourth lens unit 4 having a strong refracting surface on the object side and having a convex surface facing the image side are sequentially arranged, and the first lens unit At least one surface of the lens group 1 has an aspherical shape, and at least one surface of the fourth lens group 4
Two surfaces are aspherical.
【００１０】又、全系の焦点距離をｆ、第１レンズ群１
の焦点距離をｆ1 、第４レンズ群４の焦点距離をｆ4 、
第１レンズ群１と第２レンズ群２の合成焦点距離をｆ1
2、第１レンズ群１のアッベ数をν1 とし、前記第１レ
ンズ群１、第２レンズ群２、第３レンズ群３、第４レン
ズ群４を下記条件式（１）〜（４）を満たす様作成す
る。Further, the focal length of the entire system is f, and the first lens group 1
, The focal length of the fourth lens group 4 is f4,
The combined focal length of the first lens group 1 and the second lens group 2 is f1.
2, the Abbe number of the first lens group 1 is ν1, and the first lens group 1, the second lens group 2, the third lens group 3 and the fourth lens group 4 are expressed by the following conditional expressions (1) to (4). Create to meet.
【００１１】 （１） ０．６５＜ｆ1 ／ｆ＜ ０．９５ （２） −１．１ ＜ｆ4 ／ｆ＜−０．８ （３） −０．００５＜ｆ12／ｆ＜ ０．００２ （４） ５０ ＜ ν1 ＜ ６０ 本発明は前群が正のパワーで、最も像側に近いレンズが
負のパワーのレンズが配置された所謂望遠タイプのレン
ズである。(1) 0.65 <f1 / f <0.95 (2) -1.1 <f4 / f <-0.8 (3) -0.005 <f12 / f <0.002 (4 ) 50 <ν1 <60 The present invention is a so-called telephoto type lens in which a lens having a positive power in the front group and a lens having a negative power in the lens closest to the image side is arranged.
【００１２】上記構成でＦナンバーを明るくする為に
は、各レンズ面の周辺部での屈折力が強くなり球面収差
が増大しない様に、前群の屈折率を高くし、曲率がきつ
くならない様にすれば良い。本発明では正の第１レンズ
群１をプラスチックレンズとした。一般にプラスチック
材料の屈折率は１．５５以下と低い為に、明るくすると
曲率がきつくなり球面収差やコマ収差が悪化する。然し
本発明では、上記プラスチックレンズの第１レンズ群１
の１面を非球面化することにより、収差を良好に補正し
ている。In order to make the F-number bright with the above construction, the refractive index of the front lens group is increased and the curvature is not tight so that the peripheral power of each lens surface does not increase and spherical aberration does not increase. You can do it. In the present invention, the positive first lens group 1 is a plastic lens. Generally, since the refractive index of plastic materials is as low as 1.55 or less, when it is bright, the curvature becomes tight and the spherical aberration and the coma become worse. However, in the present invention, the first lens group 1 of the above plastic lens is used.
Aberration is favorably corrected by making one of the surfaces aspheric.
【００１３】プラスチック材料を使用すると温度変化に
よる屈折率の変化によりバックフォーカスが変化し、解
像力が劣化してしまう。然し本発明では、負の第２レン
ズ群２と負の第４レンズ群４をプラスチック材料で形成
することによって温度によるバックフォーカスの変化を
相殺する構成とした。When a plastic material is used, the back focus changes due to the change in the refractive index due to the temperature change, and the resolution deteriorates. However, in the present invention, the negative second lens group 2 and the negative fourth lens group 4 are made of a plastic material to cancel the back focus change due to temperature.
【００１４】前記条件式（１）の上限を越えると温度変
化による第１レンズ群１の変化を第２レンズ群２で相殺
することが困難となる。又焦点距離が長くなる為、正の
第１レンズ群１での色収差が増大し、全体で色収差が補
正不足となり、解像力が劣化する。逆に下限を越えると
パワーが強くなる為、非点収差が増大し最大画角での性
能を良好に保てなくなる。When the upper limit of the conditional expression (1) is exceeded, it becomes difficult for the second lens group 2 to cancel the change of the first lens group 1 due to the temperature change. Further, since the focal length becomes long, the chromatic aberration in the positive first lens group 1 increases, the chromatic aberration is undercorrected as a whole, and the resolving power deteriorates. On the contrary, when the value goes below the lower limit, the power becomes strong, so that the astigmatism increases and the performance at the maximum angle of view cannot be kept good.
【００１５】条件式（２）の上限を越え、負の第４レン
ズ群４のパワーが強くなると、正の歪曲収差が大きくな
り逆に下限を越えて第４レンズ群４のパワーを弱くする
と、像面湾曲収差が補正不足となり解像力が低下する。
又レンズ全長も長くなりレンズが大きくなってしまうの
でコスト面や使い勝手の点から好ましくない。When the upper limit of conditional expression (2) is exceeded and the power of the negative fourth lens unit 4 becomes strong, the positive distortion becomes large, and conversely, when the lower limit is exceeded and the power of the fourth lens unit 4 becomes weak, The field curvature aberration is insufficiently corrected and the resolving power is reduced.
Further, the total lens length becomes long and the lens becomes large, which is not preferable in terms of cost and usability.
【００１６】条件式（３）は温度補償の為の条件であ
り、この範囲を越えると、第１、第２レンズ群１、２の
温度変化に対する焦点距離等の変化が大きくなる為、第
４レンズ群４のパワーを変えても温度補償ができなくな
る。Conditional expression (3) is a condition for temperature compensation. If it exceeds this range, the focal length and the like of the first and second lens units 1 and 2 change greatly with temperature, so that the fourth condition. Even if the power of the lens group 4 is changed, temperature compensation cannot be performed.
【００１７】条件式（４）は色収差を補正する為の条件
である。本発明は、第１、第２レンズ群１、２にプラス
チック材料を使用しているが、負の第２レンズ群２に使
用できるプラスチック材料はν＝約３０と限られている
ので、この範囲の上限を越えると色収差補正過剰とな
り、逆に下限を越えると色収差補正不足となり解像力が
劣化する。Conditional expression (4) is a condition for correcting chromatic aberration. In the present invention, the plastic material is used for the first and second lens groups 1 and 2. However, the plastic material that can be used for the negative second lens group 2 is limited to ν = about 30, so this range If the upper limit of the above is exceeded, chromatic aberration is overcorrected, and if the lower limit is exceeded, the chromatic aberration is undercorrected and the resolution is deteriorated.
【００１８】尚、図１では第１レンズ群１、第２レンズ
群２、第３レンズ群３、第４レンズ群４を模式的に単一
のレンズで表したが、各レンズ群は単体又は複数のレン
ズを接合した接合レンズであってもよい。更に、本発明
は写真用、ＣＣＤカメラ等の撮影レンズとして使用する
ことも勿論可能である。In FIG. 1, the first lens group 1, the second lens group 2, the third lens group 3, and the fourth lens group 4 are schematically represented by a single lens, but each lens group is a single lens or a single lens. It may be a cemented lens in which a plurality of lenses are cemented. Furthermore, the present invention can of course be used as a taking lens for photography, CCD cameras and the like.
【００１９】[0019]
【実施例】次に本発明の実施例を示す。表中のｒは曲率
半径、ｄは面間隔、ｎは屈折率、νはアッベ数、ｆはレ
ンズ全系の焦点距離、ＦＮはＦナンバー、ｍは倍率を示
す。尚、非球面を表わす式は、 Ｘ＝Ｙ2 （１／ｒ）／［１＋｛１−（１＋ｋ）Ｙ2 （１
／ｒ）2 ｝1/2 ］＋Ｃ２Ｙ4 ＋Ｃ４Ｙ6 ＋Ｃ６Ｙ8 ＋Ｃ
８Ｙ10 という式で表わされ、ｋ、Ｃ２、Ｃ４、Ｃ６、Ｃ８の実
施例に示す。EXAMPLES Examples of the present invention will be described below. In the table, r is the radius of curvature, d is the surface spacing, n is the refractive index, ν is the Abbe number, f is the focal length of the entire lens system, FN is the F number, and m is the magnification. The expression representing the aspherical surface is expressed by X = Y 2 (1 / r) / [1+ {1- (1 + k) Y 2 (1
/ R) 2 } 1/2 ] + C2Y 4 + C4Y 6 + C6Y 8 + C
It is represented by the formula 8Y 10 and is shown in the examples of k, C2, C4, C6 and C8.
【００２０】＜第１実施例＞ ｆ＝４０．０ ＦＮ＝４．０ ｍ＝０．１１<First Embodiment> f = 40.0 FN = 4.0 m = 0.11
【００２１】[0021]
【表１】 [Table 1]
【００２２】非球面係数 １面 ｋ＝ ０．２０４７ Ｃ２＝−０．１７８７Ｅ−４ Ｃ４＝−０．１２１６Ｅ−６ Ｃ６＝ ０．５３２５Ｅ−８ Ｃ８＝−０．５６０９Ｅ−１１ ７面 ｋ＝−０．５９７１ Ｃ２＝ ０．７２４５Ｅ−５ Ｃ４＝−０．１１９７Ｅ−７ Ｃ６＝−０．２６０８Ｅ−９ Ｃ８＝−０．３３２５Ｅ−１３ ｆ1 ／ｆ ＝ ０．７５３ ｆ4 ／ｆ ＝−０．９４０ １ ／ｆ12＝ ０．００１１ ν1 ＝５８．０ 第１実施例に対応するハイブリッドレンズの収差図を図
２に示す。Aspheric coefficient 1 surface k = 0.2047 C2 = -0.1787E-4 C4 = -0.1216E-6 C6 = 0.5325E-8 C8 = -0.5609E-11 7 surface k = -0 .5971 C2 = 0.7245E-5 C4 = -0.1197E-7 C6 = -0.2608E-9 C8 = -0.3325E-13 f1 / f = 0.753 f4 / f = -0.9401 / f12 = 0.0011 ν1 = 58.0 An aberration diagram of the hybrid lens corresponding to the first example is shown in FIG.
【００２３】＜第２実施例＞ ｆ＝４０．０ ＦＮ＝４．０ ｍ＝０．１１<Second Embodiment> f = 40.0 FN = 4.0 m = 0.11
【００２４】[0024]
【表２】 [Table 2]
【００２５】非球面係数 １面 ｋ＝ ０．２０２５ Ｃ２＝−０．１７９２Ｅ−４ Ｃ４＝−０．１５０６Ｅ−６ Ｃ６＝ ０．７１６２Ｅ−９ Ｃ８＝−０．１０７２Ｅ−１０ ７面 ｋ＝−０．５４８１ Ｃ２＝ ０．６１６２Ｅ−５ Ｃ４＝ ０．３０４１Ｅ−８ Ｃ６＝−０．２７８３Ｅ−９ Ｃ８＝−０．６２９０Ｅ−１２ ｆ1 ／ｆ ＝ ０．９０４ ｆ4 ／ｆ ＝−１．００２ １ ／ｆ12＝−０．００３９ ν1 ＝５８．０ 第２実施例に対応するハイブリッドレンズの収差図を図
３に示す。Aspheric coefficient 1 surface k = 0.2025 C2 = -0.1792E-4 C4 = -0.1506E-6 C6 = 0.7162E-9 C8 = -0.1072E-10 7 surface k = -0 .5481 C2 = 0.6162E-5 C4 = 0.3041E-8 C6 = -0.2783E-9 C8 = -0.6290E-12 f1 / f = 0.904 f4 / f = -1.0021 / f12 = -0.0039 ν1 = 58.0 An aberration diagram of the hybrid lens corresponding to the second example is shown in FIG.
【００２６】＜第３実施例＞ ｆ＝４０．０ ＦＮ＝４．０ ｍ＝０．１１<Third Embodiment> f = 40.0 FN = 4.0 m = 0.11
【００２７】[0027]
【表３】 [Table 3]
【００２８】非球面係数 １面 ｋ＝ ０．３１１６ Ｃ２＝−０．１８３７Ｅ−４ Ｃ４＝−０．５１２０Ｅ−７ Ｃ６＝−０．６１２９Ｅ−９ Ｃ８＝ ０．２８９７Ｅ−１１ ７面 ｋ＝−０．５６９１ Ｃ２＝−０．２３０５Ｅ−５ Ｃ４＝−０．８８１９Ｅ−８ Ｃ６＝−０．３２６６Ｅ−９ Ｃ８＝−０．２０３６Ｅ−１２ ｆ1 ／ｆ ＝ ０．７５３ ｆ4 ／ｆ ＝−１．０６９ １ ／ｆ12＝−０．００１７ ν1 ＝５６．３ 第３実施例に対応するハイブリッドレンズの収差図を図
４に示す。Aspheric coefficient 1 surface k = 0.3116 C2 = -0.1837E-4 C4 = -0.5120E-7 C6 = -0.6129E-9 C8 = 0.2897E-11 7 surface k = -0 .5691 C2 = -0.2305E-5 C4 = -0.8819E-8 C6 = -0.3266E-9 C8 = -0.2036E-12 f1 / f = 0.753 f4 / f = -1.0691 /F12=-0.0017 ν1 = 56.3 An aberration diagram of the hybrid lens corresponding to the third example is shown in FIG.
【００２９】＜第４実施例＞ ｆ＝４０．０ ＦＮ＝４．０ ｍ＝０．１１<Fourth Embodiment> f = 40.0 FN = 4.0 m = 0.11
【００３０】[0030]
【表４】 [Table 4]
【００３１】非球面係数 １面 ｋ＝ ０．１５６６ Ｃ２＝−０．１９３０Ｅ−４ Ｃ４＝−０．６５７３Ｅ−７ Ｃ６＝−０．５９９３Ｅ−９ Ｃ８＝ ０．１３４１Ｅ−１１ ８面 ｋ＝−０．６０１１ Ｃ２＝−０．１４７４Ｅ−４ Ｃ４＝ ０．１００４Ｅ−７ Ｃ６＝−０．８０５５Ｅ−９ Ｃ８＝ ０．２３７８Ｅ−１１ ｆ1 ／ｆ ＝ ０．８５４ ｆ4 ／ｆ ＝−０．９３６ １ ／ｆ12＝−０．０００９ ν1 ＝５８．０ 第４実施例に対応するハイブリッドレンズの収差図を図
５に示す。Aspherical coefficient 1 surface k = 0.1566 C2 = -0.1930E-4 C4 = -0.6573E-7 C6 = -0.5993E-9 C8 = 0.1341E-11 8 surface k = -0 .6011 C2 = -0.1474E-4 C4 = 0.1004E-7 C6 = -0.8055E-9 C8 = 0.2378E-11 f1 / f = 0.854 f4 / f = -0.9361 / f12 = -0.0009 ν1 = 58.0 An aberration diagram of the hybrid lens corresponding to the fourth example is shown in FIG.
【００３２】[0032]
【発明の効果】以上述べた如く本発明によれば、各レン
ズのパワー等を適切に設定することで、Ｆナンバーが４
程度と明るく、半画角が２０°程度で構成レンズの大部
分にプラスチック材料を使用しているにもかかわらず温
度変化の影響を受けにくく、諸収差が良好に補正された
高解像力で且コストダウンを図った読取用レンズを得る
ことができる。As described above, according to the present invention, by appropriately setting the power of each lens, the F number is 4
It is bright and has a half angle of view of about 20 °, and although it uses a plastic material for most of the constituent lenses, it is not easily affected by temperature changes, and it has high resolution with good correction of various aberrations and cost. It is possible to obtain a down reading lens.
【図１】本発明の実施の形態に係るハイブリッドレンズ
の断面図である。FIG. 1 is a sectional view of a hybrid lens according to an embodiment of the present invention.
【図２】本発明の第１実施例のレンズの収差図である。FIG. 2 is an aberration diagram of a lens of Example 1 of the present invention.
【図３】同前第２実施例のレンズの収差図である。FIG. 3 is an aberration diagram of a lens of Example 2 of the same.
【図４】同前第３実施例のレンズの収差図である。FIG. 4 is an aberration diagram of a lens according to Example 3 of the same.
【図５】同前第４実施例のレンズの収差図である。FIG. 5 is an aberration diagram of a lens of Example 4 of the same.
１ 第１レンズ群 ２ 第２レンズ群 ３ 第３レンズ群 ４ 第４レンズ群 1 1st lens group 2 2nd lens group 3 3rd lens group 4 4th lens group
Claims (2)
イブリッドレンズに於いて、少なくとも正のレンズ群の
一部にプラスチック材を使用し、前記プラスチック材の
正のレンズ群の温度変化に起因するバックフォーカスの
変化を相殺する様、負のレンズ群の少なくとも一部をプ
ラスチック材としたことを特徴とするハイブリッドレン
ズ。1. A hybrid lens having a positive lens group and a negative lens group, wherein a plastic material is used for at least a part of the positive lens group, and the plastic material is caused by a temperature change of the positive lens group. A hybrid lens in which at least a part of the negative lens group is made of a plastic material so as to cancel the change in back focus.
凸でプラスチック材料より成る正の第１レンズ群と、両
凹でプラスチック材料より成る負の第２レンズ群と、単
体レンズ又は接合レンズから成る両凸の第３レンズ群
と、物体側に強い屈折面を有し像面側に凸面を向けたメ
ニスカス状でプラスチック材料より成る負の第４レンズ
群とを有し、第１レンズ群の少なくとも１つの面が非球
面形状であり、又第４レンズ群の少なくとも１つの面が
非球面形状から成るレンズであって、且下記の条件を満
足することを特徴とするプラスチックハイブリッドレン
ズ。 （１） ０．６５＜ｆ1 ／ｆ＜ ０．９５ （２） −１．１ ＜ｆ4 ／ｆ＜−０．８ （３） −０．００５＜ｆ12／ｆ＜ ０．００２ （４） ５０ ＜ ν1 ＜ ６０ 但し ｆ ：全系の焦点距離 ｆ1 ：正第１レンズ群の焦点距離 ｆ4 ：負第４レンズ群の焦点距離 ｆ12：正第１レンズ群と負第２レンズ群の合成焦点距離 ν1 ：正第１レンズ群のアッベ数 である。2. A biconvex positive first lens unit made of a plastic material and a biconcave negative second lens unit made of a plastic material with a convex surface facing the object surface in order from the object side, and a single lens or a cemented lens. A biconvex third lens unit consisting of a lens, and a negative meniscus fourth lens unit made of a plastic material having a strong refracting surface on the object side and a convex surface facing the image side, and the first lens A plastic hybrid lens, wherein at least one surface of the group has an aspherical shape, and at least one surface of the fourth lens group has an aspherical shape, and the following conditions are satisfied. (1) 0.65 <f1 / f <0.95 (2) -1.1 <f4 / f <-0.8 (3) -0.005 <f12 / f <0.002 (4) 50 < ν1 <60 where f: focal length of the whole system f1: positive focal length of the first lens group f4: negative focal length of the fourth lens group f12: combined focal length of the positive first lens group and negative second lens group ν1: It is the Abbe number of the positive first lens group.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21245495A JPH0943508A (en) | 1995-07-28 | 1995-07-28 | Hybrid lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21245495A JPH0943508A (en) | 1995-07-28 | 1995-07-28 | Hybrid lens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0943508A true JPH0943508A (en) | 1997-02-14 |
Family
ID=16622898
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21245495A Pending JPH0943508A (en) | 1995-07-28 | 1995-07-28 | Hybrid lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0943508A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0997759A2 (en) * | 1998-10-02 | 2000-05-03 | Canon Kabushiki Kaisha | Imaging lens and image reading apparatus using it |
| JP2005351972A (en) * | 2004-06-08 | 2005-12-22 | Konica Minolta Business Technologies Inc | Reading lens |
| JP2007219529A (en) * | 2007-02-26 | 2007-08-30 | Ricoh Co Ltd | Original reading lens/original reading lens unit/original reading module/original reading method/original reader/image information processing device |
| CN100346189C (en) * | 2004-10-28 | 2007-10-31 | 索尼株式会社 | Image pickup lens |
| EP2037306A1 (en) * | 2007-09-12 | 2009-03-18 | Fujinon Corporation | Imaging lens and imaging apparatus |
| US7589899B2 (en) | 2006-06-23 | 2009-09-15 | Mitutoyo Corporation | Lens optical system and photoelectric encoder |
| US7889442B2 (en) | 2007-09-12 | 2011-02-15 | Fujinon Corporation | Imaging lens and imaging apparatus |
| US8054565B2 (en) | 2006-06-26 | 2011-11-08 | Mitutoyo Corporation | Lens optical system and photoelectric encoder |
| WO2013074290A1 (en) * | 2011-11-17 | 2013-05-23 | Symbol Technologies, Inc. | Apparatus for and method of imaging targets with wide angle, athermalized, achromatic, hybrid imaging lens assembly |
| CN105425375A (en) * | 2016-01-13 | 2016-03-23 | 广西奥顺仪器有限公司 | Imaging apparatus for operation microscope |
| CN108292026A (en) * | 2015-10-22 | 2018-07-17 | 赫普塔冈微光有限公司 | Luminescence component |
-
1995
- 1995-07-28 JP JP21245495A patent/JPH0943508A/en active Pending
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0997759A2 (en) * | 1998-10-02 | 2000-05-03 | Canon Kabushiki Kaisha | Imaging lens and image reading apparatus using it |
| EP0997759A3 (en) * | 1998-10-02 | 2002-03-20 | Canon Kabushiki Kaisha | Imaging lens and image reading apparatus using it |
| US6507444B2 (en) | 1998-10-02 | 2003-01-14 | Canon Kabushiki Kaisha | Imaging lens and image reading apparatus using it |
| JP2005351972A (en) * | 2004-06-08 | 2005-12-22 | Konica Minolta Business Technologies Inc | Reading lens |
| CN100346189C (en) * | 2004-10-28 | 2007-10-31 | 索尼株式会社 | Image pickup lens |
| US7589899B2 (en) | 2006-06-23 | 2009-09-15 | Mitutoyo Corporation | Lens optical system and photoelectric encoder |
| US8054565B2 (en) | 2006-06-26 | 2011-11-08 | Mitutoyo Corporation | Lens optical system and photoelectric encoder |
| JP2007219529A (en) * | 2007-02-26 | 2007-08-30 | Ricoh Co Ltd | Original reading lens/original reading lens unit/original reading module/original reading method/original reader/image information processing device |
| US7787196B2 (en) | 2007-09-12 | 2010-08-31 | Fujinon Corporation | Imaging lens and imaging apparatus |
| US7889442B2 (en) | 2007-09-12 | 2011-02-15 | Fujinon Corporation | Imaging lens and imaging apparatus |
| EP2037306A1 (en) * | 2007-09-12 | 2009-03-18 | Fujinon Corporation | Imaging lens and imaging apparatus |
| WO2013074290A1 (en) * | 2011-11-17 | 2013-05-23 | Symbol Technologies, Inc. | Apparatus for and method of imaging targets with wide angle, athermalized, achromatic, hybrid imaging lens assembly |
| US8624985B2 (en) | 2011-11-17 | 2014-01-07 | Symbol Technologies, Inc. | Apparatus for and method of imaging targets with wide angle, athermalized, achromatic, hybrid imaging lens assembly |
| CN108292026A (en) * | 2015-10-22 | 2018-07-17 | 赫普塔冈微光有限公司 | Luminescence component |
| CN108292026B (en) * | 2015-10-22 | 2021-11-26 | 赫普塔冈微光有限公司 | Athermal optical assembly |
| CN105425375A (en) * | 2016-01-13 | 2016-03-23 | 广西奥顺仪器有限公司 | Imaging apparatus for operation microscope |
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