JPH04348334A - Method for correcting zoom variable power optical system - Google Patents
Method for correcting zoom variable power optical systemInfo
- Publication number
- JPH04348334A JPH04348334A JP4675491A JP4675491A JPH04348334A JP H04348334 A JPH04348334 A JP H04348334A JP 4675491 A JP4675491 A JP 4675491A JP 4675491 A JP4675491 A JP 4675491A JP H04348334 A JPH04348334 A JP H04348334A
- Authority
- JP
- Japan
- Prior art keywords
- magnification
- projection lens
- optical path
- path length
- focal length
- 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
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- 230000003287 optical effect Effects 0.000 title claims abstract description 55
- 238000000034 method Methods 0.000 title claims abstract description 16
- 230000008859 change Effects 0.000 claims description 11
- 238000003384 imaging method Methods 0.000 claims description 7
- 230000004075 alteration Effects 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 5
- 239000011521 glass Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 239000013256 coordination polymer Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 108091008695 photoreceptors Proteins 0.000 description 1
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Landscapes
- Lens Barrels (AREA)
- Variable Magnification In Projection-Type Copying Machines (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は複写機等の走査型ズーム
変倍光学系の投影レンズの焦点距離にばらつきがある場
合に、各変倍時の結像における公称倍率と実際倍率とを
一致させるための精度向上に必要な投影レンズとミラー
等光路長可変手段との移動位置の補正に関する。[Industrial Application Field] The present invention is capable of matching the nominal magnification and actual magnification in image formation during each magnification change when there are variations in the focal length of the projection lens of a scanning zoom variable magnification optical system such as a copying machine. The present invention relates to correction of the movement position of a projection lens and optical path length variable means such as a mirror, which is necessary to improve accuracy.
【０００２】0002
【従来の技術】複写機等の走査型ズーム変倍光学系にお
いては第３図に示すように原稿台ガラス１に臨ませた光
源２と複数のミラー３，４，５，６及び投影レンズ７を
用いて該原稿台ガラス１上の原稿画面１０を感光体ドラ
ム８等の像担持体に結像して画像を形成する。そして、
前記光源２と第１ミラー３は一体となり第１走行台を形
成し、前記第２ミラー４及び第３ミラー５とは一体とな
り第２走行台を形成して前記原稿台ガラス１に平行な同
一方向に走行して原稿画面１０をスキャンしている。こ
のような走査型ズーム変倍光学系の画像倍率を変更する
には該定倍率に対応して前記投影レンズ７を矢印Ａ方向
に位置調整して焦点調節を行うと共に前記第２走行台即
ち前記第２、第３ミラー４，５を移動する前パス方式ま
たは最終ミラーである前記第４ミラー６を移動する後パ
ス方式の何れかによってミラー位置を移動し前記原稿画
面１０から前記感光体ドラム８に至る全光路長を変更す
るようにしてある。なお、上述した従来の技術に関連し
て公開特許公報昭６１−５６３３５号及び公開実用新案
公報昭５７−３９０５７号が知られている。前者の特開
昭６１−５６３３５号は可変倍露光装置における変倍時
の光路長変化を後パス方式によってミラーを移動し調節
する光路長可変手段に関する。また後者の実開昭５７−
３９０５７号は可変倍露光装置における変倍時の光路長
変化を前パス方式によってミラーを移動し調節する光路
長可変手段とその駆動方法に関するものである。2. Description of the Related Art In a scanning type zoom variable magnification optical system of a copying machine, etc., as shown in FIG. An image is formed by forming an image of the original screen 10 on the original table glass 1 on an image carrier such as the photosensitive drum 8 using the image forming apparatus. and,
The light source 2 and the first mirror 3 are integrally formed to form a first traveling table, and the second mirror 4 and the third mirror 5 are integrally formed to form a second traveling table. The document screen 10 is scanned by traveling in the direction shown in FIG. To change the image magnification of such a scanning zoom variable magnification optical system, focus adjustment is performed by adjusting the position of the projection lens 7 in the direction of arrow A in accordance with the constant magnification, and the second traveling table, that is, the The mirror position is moved from the original screen 10 to the photosensitive drum 8 by either a front pass method in which the second and third mirrors 4 and 5 are moved or a back pass method in which the fourth mirror 6, which is the final mirror, is moved. The total optical path length leading to is changed. Incidentally, in connection with the above-mentioned conventional technology, Japanese Patent Publication No. 56335/1982 and Publication of Utility Model No. 39057/1987 are known. The former Japanese Patent Application Laid-Open No. 61-56335 relates to a variable optical path length means for adjusting optical path length changes during zooming in a variable magnification exposure apparatus by moving a mirror using a back pass method. Also, the latter Utsukai 1977-
No. 39057 relates to a variable optical path length means and a driving method thereof, which adjust optical path length changes during zooming in a variable magnification exposure apparatus by moving a mirror using a front pass method.
【０００３】0003
【発明が解決しようとする課題】しかしながら、ズーム
変倍光学系に用いられる投影レンズの焦点距離はその製
作誤差などによって標準焦点距離に対し通常±１％前後
の範囲で許容誤差が設けられていて個々にばらつきをも
っている。[Problem to be Solved by the Invention] However, the focal length of a projection lens used in a zoom variable magnification optical system has a tolerance of about ±1% from the standard focal length due to manufacturing errors. There are individual variations.
【０００４】従って、標準焦点距離の投影レンズに対し
ホームポジションである公称等倍位置での実際の画像倍
率が異りまた任意の変倍時に該レンズと同じ移動量であ
れば必然的にその実際の画像倍率も公称倍率と相異する
。例えば焦点距離２００ｍｍの投影レンズでは±２ｍｍ
前後の範囲で誤差を有し等倍位置を基点として２倍の拡
大倍率の移動量は約１００ｍｍ±１ｍｍ、また０．５倍
の縮小倍率の移動量は約２００ｍｍ±２ｍｍが計算値で
ある。そしてこの計算値を引用した２倍の拡大倍率側で
±１ｍｍの移動量誤差をもつ場合の実際の画像倍率は１
．９９倍或は２．０１倍となる。従来、拡大倍率が１．
５倍以下の普及型の複写機などではこのような１％前後
の倍率誤差はあまり問題とはならなかった。しかし解像
度が要求されかつ高倍率を備えたグレードの高い複写機
等にあってはユーザ側は等倍の画像倍率精度は勿論のこ
と最大倍率側（例えば２倍）及び縮小倍率側（例えば０
．５倍）での画像評価は出来上り画像を精測するなど極
めて厳しく評価し上述のような誤差量をもった画像倍率
のものは不可とされている。Therefore, the actual image magnification at the nominal equal magnification position, which is the home position, is different from that of a projection lens with a standard focal length, and if the amount of movement is the same as that of the lens when changing the magnification, the actual image magnification will necessarily be different. The image magnification of is also different from the nominal magnification. For example, for a projection lens with a focal length of 200mm, ±2mm
There is an error in the front and rear ranges, and the calculated value is that the amount of movement for a 2x magnification is about 100 mm±1 mm, and the amount of movement for a 0.5x reduction is about 200 mm±2 mm, with the same magnification position as the base point. Then, when there is a movement amount error of ±1 mm on the 2x magnification side that quoted this calculated value, the actual image magnification is 1
．． It becomes 99 times or 2.01 times. Conventionally, the magnification is 1.
Such a magnification error of around 1% did not pose much of a problem in popular copying machines with a magnification of 5 times or less. However, in the case of high-grade copying machines that require high resolution and have high magnification, the user must not only maintain the same image magnification accuracy, but also the maximum magnification (e.g., 2x) and reduction magnification (e.g., 0x).
．． Image evaluation at a magnification of 5 times (5 times) is extremely strict, such as by carefully measuring the finished image, and image magnifications with the above-mentioned error amount are not allowed.
【０００５】従って、このような問題点はグレードの高
い複写機等の性能上重大な欠点とされているので製造過
程で使用される投影レンズの焦点距離に応じてその画像
倍率をできるだけ公称設定倍率に近づけるようにいちい
ち解像度や画像倍率をチェックしながら反複して調整し
ているため熟練を要する作業であるし多くの労力と工数
がかけられている。しかし、自ずからこの調整作業にも
限界があって解像度或は画像倍率の何れかが満足されな
いことがある。本発明はこのような問題点を解決して投
影レンズの焦点距離がばらついていても容易にしかも正
確に公称設定倍率と一致する画像倍率と高解像度の結像
とを得ることのできるズーム変倍光学系の補正方法の提
供を課題目的とする。Therefore, since such a problem is considered to be a serious drawback in terms of the performance of high-grade copying machines, etc., the image magnification should be adjusted to the nominal setting magnification as much as possible according to the focal length of the projection lens used in the manufacturing process. Because the resolution and image magnification are checked and adjusted repeatedly in order to get close to the actual image size, it is a process that requires skill and requires a lot of effort and man-hours. However, this adjustment work naturally has its limits, and either the resolution or the image magnification may not be satisfied. The present invention solves these problems and provides a variable zoom magnification that can easily and accurately obtain an image magnification that matches the nominally set magnification and high-resolution imaging even if the focal length of the projection lens varies. The purpose of this project is to provide a correction method for optical systems.
【０００６】[0006]
【課題を解決するための手段】この目的は原稿画面を投
影レンズと光路長可変手段とによって投影して各倍率の
画像を結像する走査型ズーム変倍方法において、所定可
変倍率内の任意の少なくとも１つの公称設定倍率の決め
られた光路長の中で前記投影レンズ及び／又は光路長可
変手段を移動して、該投影レンズが合焦した位置の実際
の画像倍率を測定し、該倍率値から
１／ｆ＝１／ａ＋１／ｂ ｍ＝ｂ／ａＵ＝（
２＋ｍ＋１／ｍ）ｆ＋Ｈ＋δｍ
によって該投影レンズの真の焦点距離を算出し、該焦点
距離と各公称倍率とから上式でＵ及びａ，ｂを計算して
該投影レンズ及び該光路長可変手段の各補正位置を決め
各変倍時に各公称の設定倍率と等しい実際の画像倍率が
得られるように該投影レンズ及び該光路長可変手段の移
動位置を補正したことを特徴とするズーム変倍光学系の
補正方法によって達成される。[Means for Solving the Problems] This object is to provide a scanning zoom magnification method in which an image of each magnification is formed by projecting the original screen using a projection lens and an optical path length variable means. moving the projection lens and/or the optical path length variable means within a determined optical path length of at least one nominally set magnification, measuring the actual image magnification at the position where the projection lens is focused; From 1/f=1/a+1/b m=b/aU=(
2+m+1/m)f+H+δm Calculate the true focal length of the projection lens, and calculate U, a, and b from the focal length and each nominal magnification using the above formula to determine each of the projection lens and the optical path length variable means. A zoom variable magnification optical system, characterized in that a correction position is determined and the moving position of the projection lens and the optical path length variable means are corrected so that an actual image magnification equal to each nominal set magnification is obtained at each magnification change. This is accomplished by a correction method.
【０００７】
但し ｆ：投影レンズの焦点距離 ｍ：倍率ａ
：原稿画面から投影レンズ第１主点までの距離ｂ：投影
レンズ第２主点から結像面までの距離Ｈ：投影レンズの
主点間距離
δｍ：投影レンズの収差
Ｕ：原稿画面から結像面までの全光路長[0007] However, f: focal length of the projection lens m: magnification a
: Distance from the original screen to the first principal point of the projection lens b: Distance from the second principal point of the projection lens to the imaging plane H: Distance between principal points of the projection lens δm: Aberration of the projection lens U: Image formation from the original screen Total optical path length to surface
【０００８】[0008]
【実施例】本発明の１実施例を第１図（ａ）（ｂ）のズ
ーム変倍光学系の構成を示す概要図と第２図の焦点距離
誤差をもつ投影レンズの移動量補正を示す図表とを用い
て説明する。しかし、本発明は本実施例に限定されるも
のではない。また、従来のものと同一機能のものは同一
記号をもって表わす。[Example] An embodiment of the present invention is shown in Fig. 1 (a) and (b), which are schematic diagrams showing the configuration of a zoom variable magnification optical system, and Fig. 2, which shows correction of the amount of movement of a projection lens having a focal length error. This will be explained using diagrams. However, the present invention is not limited to this example. Also, those with the same functions as conventional ones are indicated by the same symbols.
【０００９】前述したように投影レンズの焦点距離は許
容誤差範囲内で個々にばらついていて変倍時に標準焦点
距離の移動量をそのまヽ適用すると当然のことながら移
動された位置での画像倍率に誤差ができる。As mentioned above, the focal length of the projection lens varies individually within the tolerance range, and if the amount of movement of the standard focal length is applied as is when changing the magnification, the image magnification at the moved position will naturally change. Errors may occur.
【００１０】第２図はこれらを補正するため拡大倍率側
を例に等倍位置０を基点とし標準焦点距離Ｆｏに対して
その補正の考え方を示した図表である。即ち、その補正
は前記標準焦点距離Ｆｏの最大倍率（例えば２倍）の移
動量を横軸で表わしたＤに対しそれより短い焦点距離Ｆ
ｓの場合前記Ｆｏと同じ移動量Ｄであっては当然該Ｆｏ
の画像倍率に対して小さいので一致した画像倍率とする
ために横軸で表わしたｄｓの移動量を前記移動量Ｄに付
加して補正すればよい。また長い焦点距離ＦＬの場合は
、前記Ｆｓの場合とは逆に図に示すようにｄＬの移動量
を前記移動量Ｄから減少させることによってその実際の
画像倍率は前記Ｆｏの倍率、即ち公称設定倍率と一致す
る。FIG. 2 is a diagram illustrating the concept of correction for the standard focal length Fo using the same magnification position 0 as an example on the magnification side in order to correct these. That is, the correction is made by adjusting the focal length F, which is shorter than D, where the horizontal axis represents the amount of movement of the maximum magnification (for example, 2 times) of the standard focal length Fo.
In the case of s, if the amount of movement D is the same as Fo, then the Fo
Since the image magnification is small compared to the image magnification, the amount of movement ds expressed on the horizontal axis may be added to the amount of movement D for correction in order to match the image magnification. In addition, in the case of a long focal length FL, contrary to the case of Fs, by decreasing the movement amount of dL from the movement amount D as shown in the figure, the actual image magnification can be changed to the magnification of Fo, that is, the nominal setting. Match the magnification.
【００１１】そして、等倍から拡大側及び縮小側の任意
の倍率位置についてもこの考え方に基いて補正される。[0011] Further, arbitrary magnification positions from the same magnification to the enlargement side and reduction side are also corrected based on this concept.
【００１２】そこで本発明は第１図（ａ）に示すように
先ず使用される投影レンズ７の真の焦点距離の値を得る
ために例えば、ホームポジションである等倍位置におい
て（ａ）全光路長を一定とした中で該投影レンズ７を第
１ステッピングモータ９によって光軸上矢印Ａ方向前後
に微動させて合焦位置を選定する。又は他の手段として
（ｂ）該投影レンズ７を固定し、一体となっている第４
ミラー６と第５ミラー６ａとからなる光路長可変手段６
０を光路長可変用の第２ステッピングモータ９ａによっ
て該レンズ７の光軸上矢印Ａ方向前後に微動させて該レ
ンズ７の合焦位置を選定する。また場合によっては、も
う一つの手段として、（ｃ）投影レンズ７と前記光路長
可変手段の両方を光軸上矢印Ａ方向前後に微動させて、
該投影レンズ７の合焦位置を選定する。そして合焦した
位置で例えば、ＣＣＤ又は目視による調整治具（図示せ
ず）を用いてそのときの実際の画像倍率ｍを測定する。
そして測定された実際の画像倍率ｍとそのときの全光路
長Ｕとを用いて
１／ｆ＝１／ａ＋１／ｂ ｍ＝ｂ／ａＵ＝（
２＋ｍ＋１／ｍ）ｆ＋Ｈ＋δｍ
の関係式から前記投影レンズ７の真の焦点距離ｆを求め
る。Therefore, in order to obtain the true focal length value of the projection lens 7 used as shown in FIG. While the length is kept constant, the projection lens 7 is slightly moved back and forth in the direction of arrow A on the optical axis by the first stepping motor 9 to select a focal position. or as another means (b) fixing the projection lens 7 and providing an integral fourth lens;
Optical path length variable means 6 consisting of mirror 6 and fifth mirror 6a
The focusing position of the lens 7 is selected by slightly moving the lens 7 back and forth in the direction of arrow A on the optical axis using a second stepping motor 9a for varying the optical path length. In some cases, as another means, (c) slightly move both the projection lens 7 and the optical path length variable means back and forth in the direction of arrow A on the optical axis,
The focal position of the projection lens 7 is selected. Then, at the focused position, the actual image magnification m at that time is measured using, for example, a CCD or a visual adjustment jig (not shown). Then, using the measured actual image magnification m and the total optical path length U at that time, 1/f=1/a+1/b m=b/aU=(
The true focal length f of the projection lens 7 is determined from the relational expression: 2+m+1/m)f+H+δm.
【００１３】
但し ｆ：投影レンズの焦点距離 ｍ：倍率
ａ：原稿画面から投影レンズ第１主点までの距離ｂ：投
影レンズ第２主点から結像面までの距離Ｈ：投影レンズ
の主点間距離
δｍ：投影レンズの収差
Ｕ：原稿画面から結像面までの全光路長そして、その後
、真の焦点距離及び任意の設定倍率により上式からＵと
ａ，ｂを求め、該投影レンズ７及び光路長可変手段６０
の補正位置即ち、移動量を決定する。そして、あらかじ
め前記調整治具と複写機内に内蔵するＣＰＵ１１とをリ
ンクさせかつ個々の前記投影レンズ７のもつ前記真の焦
点距離、例えば前述のＦｓ，ＦＬのそれぞれに対応し前
述のように補正された移動量が計算されるようにしてあ
るので該調整治具のテンキーに求められた真の焦点距離
を打ち込むことによって補正された等倍位置と共に各変
倍時の設定倍率毎に補正された投影レンズ７及び光路長
可変手段６０の移動量が直ちに算出され同時に前記ＣＰ
Ｕ１１にインプットされる。そして、ステッピングモー
タの１パルスによる移動量は決められているので前述の
ようにして記憶された前記ＣＰＵ１１の制御する補正す
べきパルス数の印加に従って投影レンズ駆動用の第１ス
テッピングモータ９が駆動され等倍位置を補正してホー
ムポジションを決める。そして、各変倍時には前記ＣＰ
Ｕ１１の補正された移動量のパルス印加により第１図（
ａ）に示すように前記第１ステッピングモータ９と連動
する前記投影レンズ７を移動し同時に光路長可変用の第
２ステッピングモータ９ａも駆動して光路長可変手段６
０を構成する第４ミラー６及び第５ミラー６ａとが一体
となってレンズの移動方向と平行に移動することによっ
て全光路長を変化して所要の実際の画像倍率と公称設定
倍率とを一致させる。where f: focal length of the projection lens m: magnification a: distance from the original screen to the first principal point of the projection lens b: distance from the second principal point of the projection lens to the imaging plane H: principal point of the projection lens Distance δm: Aberration of the projection lens U: Total optical path length from the original screen to the imaging plane. Then, calculate U, a, and b from the above equation using the true focal length and an arbitrary setting magnification, and calculate the projection lens 7. and optical path length variable means 60
The corrected position, that is, the amount of movement is determined. Then, the adjustment jig and the CPU 11 built in the copying machine are linked in advance, and the true focal lengths of the individual projection lenses 7, for example, the above-mentioned Fs and FL, are corrected as described above. Since the amount of movement is calculated, by entering the obtained true focal length into the numeric keypad of the adjustment jig, the corrected same-magnification position and the corrected projection for each set magnification at each zooming are obtained. The amount of movement of the lens 7 and the optical path length variable means 60 is immediately calculated, and at the same time the CP
Input to U11. Since the amount of movement of the stepping motor by one pulse is determined, the first stepping motor 9 for driving the projection lens is driven in accordance with the application of the number of pulses to be corrected and controlled by the CPU 11 stored as described above. Correct the same magnification position and determine the home position. Then, at each magnification change, the CP
Figure 1 (
As shown in a), the projection lens 7 interlocked with the first stepping motor 9 is moved, and at the same time, the second stepping motor 9a for varying the optical path length is also driven to change the optical path length variable means 6.
The fourth mirror 6 and the fifth mirror 6a constituting 0 are moved together in parallel to the lens movement direction to change the total optical path length and match the required actual image magnification with the nominally set magnification. let
【００１４】そして、原稿台ガラス１に臨ませた光源２
によって照射された原稿画面１０は第１、第２、第３ミ
ラー３、４、５によって投影され矢印で示す方向に前記
投影レンズ７及び光路長可変手段である前記第４ミラー
６及び前記第５ミラー６ａを経て最終段の固定された第
６ミラー６ｂ面に入光し反射されて感光体ドラム８面上
に所要の倍率による投影画像が結像される。[0014] Then, a light source 2 facing the document table glass 1
The document screen 10 illuminated by The light passes through the mirror 6a, enters the surface of the sixth mirror 6b fixed at the final stage, is reflected, and forms a projected image at a required magnification on the surface of the photoreceptor drum 8.
【００１５】このようにして極めて解像度のよい結像と
公称設定倍率に等しい所要の画像倍率とが得られる。前
述した光路長可変手段の例はいわゆる、後パス方式によ
ってその光路長を変化調節して所要の公称倍率に等しい
実際の画像倍率が得られるようにしている。一方、第１
図（ｂ）に示すように前記投影レンズ７からの投影画像
を前記感光体ドラム８に入光させる最終段である第４ミ
ラー６の位置は固定し、前述した第２走行台を構成する
第２ミラー４及び第３ミラー５とを一体に投影レンズの
移動方向と平行に前記ＣＰＵ１１の制御する光路長可変
用の第２ステッピングモータ９ｂによって移動して各変
倍時の光路長を変化調節する前パス方式による光路長可
変手段を用いて所要の画像倍率を得ることが可能である
。In this way, very high resolution imaging and the required image magnification equal to the nominally set magnification are obtained. The above-mentioned examples of variable optical path length means vary the optical path length in a so-called back-pass manner so as to obtain an actual image magnification equal to the desired nominal magnification. On the other hand, the first
As shown in Figure (b), the position of the fourth mirror 6, which is the final stage for making the projected image from the projection lens 7 enter the photosensitive drum 8, is fixed, and The second mirror 4 and the third mirror 5 are integrally moved parallel to the moving direction of the projection lens by a second stepping motor 9b for variable optical path length controlled by the CPU 11 to change and adjust the optical path length at each magnification change. It is possible to obtain a desired image magnification using a variable optical path length means based on the front pass method.
【００１６】従って、各変倍時に第１図（ａ）に示す後
パス方式または第１図（ｂ）の前パス方式の何れの光路
長可変手段を用いてもさしつかえない。Therefore, at each magnification change, it is possible to use either the rear pass method shown in FIG. 1(a) or the front pass method shown in FIG. 1(b).
【００１７】なお、合焦位置における実際倍率測定によ
る焦点距離の算出は、任意の１つの設定倍率位置での実
際倍率測定で充分であるが、それ以上の任意の設定倍率
位置での実際倍率の測定を行って各投影レンズ及び光路
長可変手段の補正位置の補間をし合うことも良策である
。Note that for calculation of the focal length by measuring the actual magnification at the in-focus position, it is sufficient to measure the actual magnification at any one set magnification position; It is also a good idea to perform measurements and interpolate the correction positions of each projection lens and optical path length variable means.
【００１８】[0018]
【発明の効果】本発明によって複写機等のズーム変倍光
学系に用いる投影レンズの焦点距離にばらつきがあって
も容易に光学系の組立調整ができると共に、等倍や変倍
時に極めて解像度のよい結像と公称設定倍率に等しい実
際の画像倍率とが得られるようになった。Effects of the Invention According to the present invention, even if there are variations in the focal length of the projection lens used in the zoom magnification optical system of a copying machine, it is possible to easily assemble and adjust the optical system, and it is possible to easily assemble and adjust the optical system, and it is possible to achieve extremely high resolution when magnifying at the same magnification or changing magnification. Good imaging and an actual image magnification equal to the nominally set magnification are now obtained.
第１図（ａ），（ｂ）は本発明の１実施例によるズーム
変倍光学系の構成を示す概要図。
第２図は焦点距離誤差をもつ投影レンズの移動量補正を
示す図表。
第３図はズーム変倍光学系の原理図。FIGS. 1(a) and 1(b) are schematic diagrams showing the configuration of a zoom variable power optical system according to an embodiment of the present invention. FIG. 2 is a chart showing compensation for the amount of movement of a projection lens that has a focal length error. Figure 3 is a diagram of the principle of the variable zoom optical system.
１・・・原稿台ガラス ２・・・光源３・・
・第１ミラー ４・・・第２ミラー５・
・・第３ミラー ６・・・第４ミラー６
ａ・・・第５ミラー ６ｂ・・・第６ミラー
７・・・投影レンズ ８・・・感光体ド
ラム９・・・第１ステッピングモータ1... Original table glass 2... Light source 3...
・First mirror 4...Second mirror 5・
...Third mirror 6...Fourth mirror 6
a...Fifth mirror 6b...Sixth mirror 7...Projection lens 8...Photosensitive drum 9...First stepping motor
Claims (1)
段とによって投影して各倍率の画像を結像する走査型ズ
ーム変倍方法において、所定可変倍率内の任意の少なく
とも１つの公称設定倍率の決められた光路長の中で前記
投影レンズ及び／又は光路長可変手段を移動して、該投
影レンズが合焦した位置の実際の画像倍率を測定し、該
倍率値から １／ｆ＝１／ａ＋１／ｂ ｍ＝ｂ／ａＵ＝（
２＋ｍ＋１／ｍ）ｆ＋Ｈ＋δｍ によって該投影レンズの真の焦点距離を算出し、該焦点
距離と各公称倍率とから上式でＵ及びａ，ｂを計算して
該投影レンズ及び該光路長可変手段の各補正位置を決め
各変倍時に各公称設定倍率と等しい実際の画像倍率が得
られるように該投影レンズ及び該光路長可変手段の移動
位置を補正したことを特徴とするズーム変倍光学系の補
正方法。 但し ｆ：投影レンズの焦点距離 ｍ：倍率ａ
：原稿画面から投影レンズ第１主点までの距離ｂ：投影
レンズ第２主点から結像面までの距離Ｈ：投影レンズの
主点間距離 δｍ：投影レンズの収差 Ｕ：原稿画面から結像面までの全光路長1. A scanning zoom magnification method in which an image of each magnification is formed by projecting a document screen by a projection lens and an optical path length variable means, wherein at least one nominally set magnification within a predetermined variable magnification is Move the projection lens and/or the optical path length variable means within the determined optical path length, measure the actual image magnification at the position where the projection lens focuses, and calculate 1/f=1/ from the magnification value. a+1/b m=b/aU=(
2+m+1/m)f+H+δm Calculate the true focal length of the projection lens, and calculate U, a, and b from the focal length and each nominal magnification using the above formula to determine each of the projection lens and the optical path length variable means. Correction of a zoom magnification optical system, characterized in that a correction position is determined and the moving positions of the projection lens and the optical path length variable means are corrected so that an actual image magnification equal to each nominally set magnification is obtained at each magnification change. Method. However, f: focal length of the projection lens m: magnification a
: Distance from the original screen to the first principal point of the projection lens b: Distance from the second principal point of the projection lens to the imaging plane H: Distance between principal points of the projection lens δm: Aberration of the projection lens U: Image formation from the original screen Total optical path length to surface
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4675491A JPH04348334A (en) | 1990-06-05 | 1991-03-12 | Method for correcting zoom variable power optical system |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14662390 | 1990-06-05 | ||
| JP14662290 | 1990-06-05 | ||
| JP2-146622 | 1990-06-05 | ||
| JP2-146623 | 1990-06-05 | ||
| JP4675491A JPH04348334A (en) | 1990-06-05 | 1991-03-12 | Method for correcting zoom variable power optical system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04348334A true JPH04348334A (en) | 1992-12-03 |
Family
ID=27292732
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4675491A Pending JPH04348334A (en) | 1990-06-05 | 1991-03-12 | Method for correcting zoom variable power optical system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04348334A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5809381A (en) * | 1996-01-06 | 1998-09-15 | Canon Kabushiki Kaisha | Image-forming apparatus and magnification correction method using the same |
| US5880766A (en) * | 1996-01-17 | 1999-03-09 | Fuji Xerox Co., Ltd. | Apparatus for correcting positional deviation of light source emitting light beams in image recording apparatus |
-
1991
- 1991-03-12 JP JP4675491A patent/JPH04348334A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5809381A (en) * | 1996-01-06 | 1998-09-15 | Canon Kabushiki Kaisha | Image-forming apparatus and magnification correction method using the same |
| US5880766A (en) * | 1996-01-17 | 1999-03-09 | Fuji Xerox Co., Ltd. | Apparatus for correcting positional deviation of light source emitting light beams in image recording apparatus |
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