JPH0951409A - Method and device for adjusting focus of image reader - Google Patents
Method and device for adjusting focus of image readerInfo
- Publication number
- JPH0951409A JPH0951409A JP7203005A JP20300595A JPH0951409A JP H0951409 A JPH0951409 A JP H0951409A JP 7203005 A JP7203005 A JP 7203005A JP 20300595 A JP20300595 A JP 20300595A JP H0951409 A JPH0951409 A JP H0951409A
- Authority
- JP
- Japan
- Prior art keywords
- focus
- image
- focus measurement
- adjustment
- regression calculation
- Prior art date
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- Facsimile Scanning Arrangements (AREA)
- Focusing (AREA)
- Automatic Focus Adjustment (AREA)
- Facsimile Heads (AREA)
- Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、電荷結合素子（Ｃ
ＣＤ：Charge Coupled Device)等の撮像素子とその撮像
面上に画像を結像させる光学系を有する画像読取装置の
ピント調整方法、及び装置に関し、特に、複数のピント
計測部の調整目標を全て満足する高精度なピント調整を
容易に行えるようにした画像読取装置のピント調整方
法、及び装置に関する。TECHNICAL FIELD The present invention relates to a charge-coupled device (C
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus adjustment method and apparatus for an image reading apparatus having an image pickup device such as a CD (Charge Coupled Device) and an optical system for forming an image on its image pickup surface, and particularly, all adjustment targets of a plurality of focus measurement units The present invention relates to a focus adjustment method and apparatus for an image reading apparatus, which facilitates highly accurate focus adjustment.
【０００２】[0002]
【従来の技術】ディジタル複写機等、画像を読み取る必
要があるものには、ＣＣＤ等の撮像素子と結像レンズを
組み合わせた画像読取装置が広く用いられている。2. Description of the Related Art An image reading apparatus having a combination of an image pickup device such as a CCD and an image forming lens is widely used for a device such as a digital copying machine which needs to read an image.
【０００３】このような画像読取装置では、原稿の画像
が結合レンズを介して撮像素子に正しく結像するよう
に、ピント、結像倍率、及び撮像素子の主走査方向と副
走査方向の位置等の種々の調整を行う必要があり、その
中でもピント調整は重要な調整項目の１つになってい
る。In such an image reading apparatus, the focus, the imaging magnification, the position of the image sensor in the main scanning direction and the sub-scanning direction, etc. are formed so that the image of the document is correctly formed on the image sensor via the coupling lens. It is necessary to make various adjustments, and the focus adjustment is one of the important adjustment items.
【０００４】図１３には、従来の画像読取装置のピント
調整装置が示されている。この画像読取装置のピント調
整装置は、原稿面に相当する位置に配置され、左側、中
央、及び右側の３箇所にピント計測用のマーク（例え
ば、ラダーマーク）１Ａが記された調整用チャート１
と、結像レンズ２を介して結像される調整用チャート１
のマーク１Ａを読み取る撮像素子３と、撮像素子３のＣ
ＣＤから出力される画像信号をＡ／Ｄ変換した後、信号
処理を行う波形処理回路５と、波形処理回路５から出力
されるディジタルの画像信号に基づいて、撮像素子３に
おける調整用チャート１の左側、中央、及び右側のマー
ク１Ａのピント計測値を演算する演算回路６と、撮像素
子３を搭載した基板４の両端をその調整軸Ｙｌ、Ｙｒを
介してピント調整方向（光軸方向）に移動させる移動装
置７と、調整用チャート１に光を照射する照明装置８
と、移動装置７、及び照明装置８を駆動する駆動回路９
と、波形処理回路５、演算回路６、及び駆動回路９を制
御する制御回路１０を備えて構成されている。FIG. 13 shows a focus adjusting device of a conventional image reading apparatus. The focus adjustment device of this image reading apparatus is arranged at a position corresponding to the document surface, and an adjustment chart 1 is provided with marks (for example, ladder marks) 1A for focus measurement at three positions on the left side, the center, and the right side.
And the adjustment chart 1 which is imaged through the imaging lens 2.
Image pickup element 3 for reading the mark 1A of C, and C of the image pickup element 3
After the image signal output from the CD is A / D converted, the waveform processing circuit 5 that performs signal processing, and based on the digital image signal output from the waveform processing circuit 5, the adjustment chart 1 of the image sensor 3 is displayed. The arithmetic circuit 6 for calculating the focus measurement values of the marks 1A on the left side, the center, and the right side, and both ends of the substrate 4 on which the image sensor 3 is mounted are moved in the focus adjustment direction (optical axis direction) via the adjustment axes Yl and Yr. A moving device 7 for moving and an illuminating device 8 for irradiating the adjustment chart 1 with light.
And a drive circuit 9 for driving the moving device 7 and the lighting device 8.
And a control circuit 10 for controlling the waveform processing circuit 5, the arithmetic circuit 6, and the drive circuit 9.
【０００５】以下、ピント調整方法を説明する。まず、
適当な入力装置から制御回路１０に指令を与え、ピント
調整動作を開始させると、調整用チャート１を照明装置
８で照射し、調整用チャート１の左側、中央、及び右側
のマーク１Ａが結像レンズ２を経て撮像素子３の撮像面
上に結像する。この状態で駆動回路９を制御して移動装
置８を駆動させることにより、基板４の調整軸Ｙｌ、Ｙ
ｒを調整して、撮像素子３の両側をピント調整位置の所
定の範囲にわたって移動させ、任意の位置において撮像
素子３のＣＣＤから調整用チャート１のマーク１Ａに応
じた画像信号を波形処理回路５に出力する。波形処理回
路５はその画像信号に所定の信号処理を施した後、それ
を演算回路６に出力する。The focus adjusting method will be described below. First,
When a command is given to the control circuit 10 from an appropriate input device to start the focus adjustment operation, the adjustment chart 1 is illuminated by the illumination device 8, and the marks 1A on the left side, the center, and the right side of the adjustment chart 1 are imaged. An image is formed on the image pickup surface of the image pickup device 3 through the lens 2. In this state, by controlling the drive circuit 9 to drive the moving device 8, the adjustment axes Yl, Y of the substrate 4 are adjusted.
By adjusting r, both sides of the image pickup device 3 are moved over a predetermined range of the focus adjustment position, and the image signal corresponding to the mark 1A of the adjustment chart 1 is sent from the CCD of the image pickup device 3 to the waveform processing circuit 5 at an arbitrary position. Output to. The waveform processing circuit 5 subjects the image signal to predetermined signal processing and then outputs it to the arithmetic circuit 6.
【０００６】演算回路６はこの画像信号の最大値と最小
値に基づいて所定の演算を左側、中央、及び右側のそれ
ぞれについて行って、各ピント計測部のピント計測値を
算出する。そして、撮像素子３の左側、中央、及び右側
のピント計測部のピント計測値が目標値を満足するまで
撮像素子３のピント調整位置を調整軸Ｙｌ、Ｙｒによっ
て調整する。調整が完了すると、撮像素子３をねじ締結
や接着によって固定する。The calculation circuit 6 performs a predetermined calculation for each of the left side, the center, and the right side based on the maximum value and the minimum value of the image signal to calculate the focus measurement value of each focus measurement section. Then, the focus adjustment position of the image sensor 3 is adjusted by the adjustment axes Yl and Yr until the focus measurement values of the left, center, and right focus measurement units of the image sensor 3 satisfy the target values. When the adjustment is completed, the image sensor 3 is fixed by screw fastening or adhesion.
【０００７】[0007]
【発明が解決しようとする課題】しかし、従来の画像読
取装置のピント調整装置によると、左側、及び右側のピ
ントはそれぞれ調整軸Ｙｌ、Ｙｒの位置に依存している
が、厳密には各調整軸の調整が相互に干渉するため、調
整軸の最適調整量の特定が困難になっている。このた
め、調整者の経験と勘に頼って調整するしかなく、調整
に熟練が必要になると共に、調整作業が煩雑になってい
る。However, according to the focus adjusting device of the conventional image reading apparatus, the left and right focus depend on the positions of the adjustment axes Yl and Yr, respectively, but strictly speaking, each adjustment is performed. Since the adjustment of the axes interferes with each other, it is difficult to specify the optimum adjustment amount of the adjustment axis. For this reason, it is necessary to make adjustments based on the experience and intuition of the adjuster, which requires skill in adjustment and the adjustment work is complicated.
【０００８】一方、特開平５−２６０２４７号公報に、
撮像素子で調整用チャートを読み取った時の出力波形か
らピント調整に対応する特徴量を算出し、この特徴量に
基づいてファジィ推論により２つの調整軸の調整量を算
出する方法も提案されているが、ピントが最適となる位
置は、左側、中央、及び右側で異なっているため、複数
のピント計測部で高精度なピント調整が求められる場
合、全てのピント計測値から調整軸Ｙｌ、Ｙｒの調整位
置を決定するのをファジィ推論で行おうとすると、ルー
ル数が莫大になり、調整則の設定に時間がかかる等の不
都合がある。On the other hand, in Japanese Patent Laid-Open No. 5-260247,
A method has also been proposed in which a feature amount corresponding to focus adjustment is calculated from an output waveform when an adjustment chart is read by an image sensor, and fuzzy inference is used to calculate the adjustment amounts of two adjustment axes based on the feature amount. However, the optimum focus position is different on the left side, the center, and the right side. Therefore, when highly accurate focus adjustment is required in a plurality of focus measurement units, the adjustment axes Yl and Yr are calculated from all the focus measurement values. If the fuzzy inference is used to determine the adjustment position, the number of rules becomes enormous and it takes time to set the adjustment rule.
【０００９】従って、本発明の目的は、複数のピント計
測部の調整目標を全て満足する高精度なピント調整を容
易に行うことができる画像読取装置のピント調整方法、
及び装置を提供することである。Therefore, an object of the present invention is to provide a focus adjusting method for an image reading apparatus, which can easily perform highly accurate focus adjustment satisfying all the adjustment targets of a plurality of focus measuring units,
And to provide a device.
【００１０】[0010]
【課題を解決するための手段】本発明は上記問題点に鑑
み、複数のピント計測部の調整目標を全て満足する高精
度なピント調整を容易に行えるようにするため、撮像素
子に複数のピント計測部を設定し、調整用チャートに対
する撮像素子のピント調整方向の位置、或いは撮像素子
の姿勢を変化させ、調整用チャートを撮像素子の複数の
ピント計測部によって読み取らせて複数の画像信号を発
生させ、複数の画像信号にそれぞれ所定の演算処理を施
して複数のピント計測部のピント計測値を算出して、複
数のピント計測部における最適位置をそれぞれ算出し、
複数のピント計測部における最適位置の回帰計算用デー
タをそれぞれ１つ以上生成し、回帰計算用データに基づ
いて回帰計算を行って、撮像素子の位置、或いは姿勢を
算出し、位置、或いは姿勢に応じて撮像素子を調整した
後、調整用チャートを撮像素子の複数のピント計測部に
よって読み取らせて、複数の調整後の画像信号を発生さ
せ、複数の調整後の画像信号にそれぞれ所定の演算処理
を施して複数のピント計測部のピント計測値をそれぞれ
算出すると共にこれらのピント計測値と目標値を比較
し、複数のピント計測部のピント計測値の少なくとも１
つが目標値を満たさなかった場合、前回の回帰計算用デ
ータに対し目標値を満たさなかったピント計測部の回帰
計算用データの数を目標値を満たしたピント計測部に対
して相対的に多くなるように変更し、その回帰計算用デ
ータに基づいて再度回帰計算を行って撮像素子の位置、
或いは姿勢を算出し、この算出した位置、或いは姿勢に
応じて撮像素子を調整するようにした画像読取装置のピ
ント調整方法を提供するものである。In view of the above problems, the present invention provides a plurality of focus points on an image pickup device in order to easily perform highly accurate focus adjustment that satisfies all the adjustment targets of a plurality of focus measurement units. Set the measurement unit, change the position of the image sensor in the focus adjustment direction with respect to the adjustment chart, or change the attitude of the image sensor, and read the adjustment chart with multiple focus measurement units of the image sensor to generate multiple image signals. Then, the plurality of image signals are subjected to predetermined arithmetic processing to calculate the focus measurement values of the plurality of focus measurement units, and the optimum positions in the plurality of focus measurement units are calculated,
One or more pieces of regression calculation data of optimum positions in a plurality of focus measurement units are respectively generated, regression calculation is performed based on the regression calculation data, and the position or orientation of the image sensor is calculated to determine the position or orientation. After adjusting the image sensor accordingly, the adjustment chart is read by a plurality of focus measuring units of the image sensor to generate a plurality of adjusted image signals, and the plurality of adjusted image signals are respectively subjected to predetermined arithmetic processing. The focus measurement values of the plurality of focus measurement units are calculated respectively, and the focus measurement values and the target values are compared, and at least one of the focus measurement values of the plurality of focus measurement units is calculated.
If one does not meet the target value, the number of pieces of regression calculation data of the focus measurement unit that did not meet the target value for the previous regression calculation data becomes relatively larger than that of the focus measurement unit that satisfies the target value. Change, and perform regression calculation again based on the regression calculation data, and position of the image sensor,
Alternatively, the present invention provides a focus adjusting method for an image reading apparatus, which calculates an attitude and adjusts an image sensor according to the calculated position or attitude.
【００１１】また、本発明の画像読取装置のピント調整
装置は、調整用チャートに対する撮像素子のピント調整
方向の位置、或いは撮像素子の姿勢を変化させる調整手
段と、撮像素子に設定された複数のピント計測部から出
力される調整用チャートに応じた画像信号に所定の演算
処理を施してピント計測値を算出することにより、複数
のピント計測部の最適位置を算出する最適位置演算手段
と、複数のピント計測部の最適位置から回帰計算用デー
タをそれぞれ１つ以上生成すると共に、回帰計算用デー
タに基づいて回帰計算を実行して撮像素子の最適位置、
或いは最適姿勢を演算する演算手段と、演算手段によっ
て算出された撮像素子の最適位置、或いは最適姿勢に基
づいて調整手段を制御することにより、撮像素子を最適
位置、或いは最適姿勢へ調整する制御手段を備え、制御
手段は、調整後に撮像素子の複数のピント計測部から発
生する調整用チャートに基づく複数の調整後の画像信号
のピント計測値と目標値を比較して、複数のピント計測
部のピント計測値の少なくとも１つが目標値を満たさな
かった場合、演算手段の前回の回帰計算用データに対し
目標値を満たさなかったピント計測部の回帰計算用デー
タの数を目標値を満たしたピント計測部に対して相対的
に多くなるように変更し、演算手段に変更した回帰計算
用データに基づいて再度、回帰計算を実行させて撮像素
子の最適位置、或いは最適姿勢を演算させ、その最適位
置、或いは最適姿勢に基づいて調整手段を制御すること
により、撮像素子を最適位置、或いは最適姿勢へ調整す
る構成を有している。Further, the focus adjusting device of the image reading apparatus of the present invention comprises adjusting means for changing the position of the image pickup device in the focus adjusting direction with respect to the adjustment chart or the posture of the image pickup device, and a plurality of image pickup devices set in the image pickup device. An optimum position calculating means for calculating the optimum position of the plurality of focus measuring units by performing a predetermined calculation process on the image signal corresponding to the adjustment chart output from the focus measuring unit to calculate the focus measurement value; One or more pieces of regression calculation data are generated from the optimum position of the focus measurement unit of, and the regression calculation is executed based on the regression calculation data to optimize the image sensor position.
Alternatively, the calculating means for calculating the optimum posture, and the controlling means for controlling the adjusting means based on the optimum position or the optimum posture of the image sensor calculated by the calculating means to adjust the image sensor to the optimum position or the optimum posture. The control means compares the focus measurement value and the target value of the plurality of adjusted image signals based on the adjustment chart generated from the plurality of focus measurement units of the image sensor after the adjustment, and controls the plurality of focus measurement units. If at least one of the focus measurement values does not satisfy the target value, the number of pieces of regression calculation data of the focus measuring unit that did not satisfy the target value with respect to the previous regression calculation data of the calculation means satisfies the target value. The regression calculation is executed again on the basis of the regression calculation data changed by the calculation means so that the optimum position of the image sensor, or It causes the computed optimum posture, the optimum position, or by controlling the adjusting means based on the optimum posture, and has an optimum position, or configuration of adjusting to the optimum position of the imaging element.
【００１２】[0012]
【発明の実施の形態】撮像素子の両端の調整軸を調整し
て、撮像素子のピント調整方向の位置、或いは姿勢（位
置、及び姿勢の両者を含む）を変化させると共に調整用
チャートを撮像素子に設定された複数のピント計測部で
読み取って複数の画像信号を発生させる。最適位置演算
手段はこれらの画像信号を入力し、画像信号の最大値と
最小値に基づいて所定の演算を行って、撮像素子の任意
の位置における複数のピント計測部のピント計測値を算
出し、モノクロ画像の場合、ピント計測値が最大となる
位置を最適位置として算出する。また、カラー画像の場
合、ピント計測部のＲ、Ｇ、Ｂのそれぞれピント計測値
が最大となる位置は異なるため、Ｒ、Ｇ、Ｂのピント計
測値をできるだけ均一にする位置を最適位置として算出
する。このようにして算出された複数のピント計測部の
最適位置は演算手段に出力され、ここで最適位置に基づ
く回帰計算用データがそれぞれ少なくとも１つ以上生成
され、更に、この回帰計算用データを用いて最小２乗法
による回帰計算が実行されて、撮像素子の位置、或いは
姿勢を直線式で求められる。そして、この直線式から調
整位置を算出して撮像素子の調整を実行する。調整後に
撮像素子の複数のピント計測部から発生する調整用チャ
ートに基づく複数の調整後の画像信号から最適位置演算
手段が複数のピント計測部のピント計測値を算出し、こ
れを目標値と比較する。その結果、全てのピント計測部
のピント計測値が目標値を満足していれば調整を完了す
る。一方、１つでも目標値を満足しないピント計測部が
あれば、演算手段の前回の回帰計算用データに対し目標
値を満たさなかったピント計測部の回帰計算用データの
数を増加し、演算手段に増加した回帰計算用データに基
づいて再度回帰計算を実行させて、撮像素子の位置、或
いは姿勢を直線式で求めてこの直線式から調整位置を算
出して撮像素子の調整を実行する。BEST MODE FOR CARRYING OUT THE INVENTION By adjusting the adjustment axes at both ends of an image sensor, the position or orientation (including both position and orientation) of the image sensor in the focus adjustment direction is changed, and an adjustment chart is displayed. A plurality of focus measuring units set to 1 are read to generate a plurality of image signals. The optimum position calculating means inputs these image signals, performs a predetermined calculation based on the maximum value and the minimum value of the image signals, and calculates focus measurement values of a plurality of focus measurement units at arbitrary positions of the image sensor. In the case of a monochrome image, the position where the focus measurement value is maximum is calculated as the optimum position. Further, in the case of a color image, the positions where the focus measurement values of R, G, and B of the focus measurement unit are maximum are different, so the position that makes the focus measurement values of R, G, and B as uniform as possible is calculated as the optimum position. To do. The optimum positions of the plurality of focus measuring units calculated in this way are output to the calculating means, where at least one regression calculation data is generated based on the optimum positions, and the regression calculation data is used. Then, the regression calculation by the least-squares method is executed, and the position or orientation of the image pickup device can be obtained by a linear equation. Then, the adjustment position is calculated from this linear equation to adjust the image sensor. After the adjustment, the optimum position calculating means calculates the focus measurement value of the plurality of focus measurement units from the plurality of adjusted image signals based on the adjustment chart generated from the plurality of focus measurement units of the image sensor, and compares this with the target value. To do. As a result, if the focus measurement values of all the focus measurement units satisfy the target value, the adjustment is completed. On the other hand, if there is even one focus measurement unit that does not satisfy the target value, the number of pieces of regression calculation data of the focus measurement unit that did not satisfy the target value with respect to the previous regression calculation data of the calculation unit is increased, and the calculation unit The regression calculation is executed again based on the increased regression calculation data, the position or orientation of the image sensor is obtained by a linear equation, and the adjustment position is calculated from this linear equation to adjust the image sensor.
【００１３】[0013]
【実施例】以下、本発明の画像読取装置のピント調整方
法、及び装置を添付図面を参照しながら詳細に説明す
る。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A focus adjusting method and apparatus for an image reading apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.
【００１４】図１には、本発明の一実施例の画像読取装
置のピント調整装置の構成が示されている。この画像読
取装置のピント調整装置は、原稿面に相当する位置に配
置され、左側、中央、及び右側の３箇所にマーク１Ａが
記された調整用チャート１と、結像レンズ２を介して結
像される調整用チャート１のマーク１Ａを読み取る撮像
素子３と、撮像素子３のＣＣＤから出力される画像信号
（カラー画像の場合、Ｒ、Ｇ、Ｂの画像信号）をそれぞ
れＡ／Ｄ変換した後、信号処理を行う波形処理回路５
と、波形処理回路５から出力されるディジタルの画像信
号に基づいて、撮像素子３の位置、及び姿勢を演算する
演算回路１１と、撮像素子３を搭載した基板４の両端を
その調整軸Ｙｌ、Ｙｒを介してピント調整方向（光軸方
向）に移動させる移動装置７と、調整用チャート１を照
射する照明装置８と、移動装置７、及び照明装置８を駆
動する駆動回路９と、波形処理回路５、演算回路１１、
及び駆動回路９を制御する制御回路１０を備えて構成さ
れている。FIG. 1 shows the structure of a focus adjusting device of an image reading apparatus according to an embodiment of the present invention. The focus adjustment device of this image reading device is arranged at a position corresponding to the document surface, and is connected via an imaging lens 2 to an adjustment chart 1 having marks 1A at three positions on the left side, the center, and the right side. The image sensor 3 for reading the mark 1A of the adjustment chart 1 to be imaged and the image signals (R, G, B image signals in the case of a color image) output from the CCD of the image sensor 3 are A / D converted. After that, the waveform processing circuit 5 that performs signal processing
And a calculation circuit 11 for calculating the position and orientation of the image sensor 3 based on the digital image signal output from the waveform processing circuit 5, and both ends of the substrate 4 on which the image sensor 3 is mounted, the adjustment axes Yl, A moving device 7 that moves in the focus adjustment direction (optical axis direction) via Yr, an illuminating device 8 that illuminates the adjustment chart 1, a moving device 7, and a drive circuit 9 that drives the illuminating device 8, and waveform processing. Circuit 5, arithmetic circuit 11,
And a control circuit 10 for controlling the drive circuit 9.
【００１５】調整用チャート１は、図２に示すように、
複数の黒線群より成るピント調整のためのマーク１Ａを
左側、中央、及び右側の位置に有している。The adjustment chart 1 is, as shown in FIG.
Marks 1A for focus adjustment, which are composed of a plurality of black line groups, are provided at left, center, and right positions.
【００１６】撮像素子３は、図３に示すように、ＣＣＤ
を所定の画素数で一次元的に配置して成るラインセンサ
３Ａを有して構成されている。また、カラー画像を読み
取る撮像素子３は、図４に示すように、Ｒ、Ｇ、Ｂのそ
れぞれ対応した画像を読み取る３本のラインセンサ３
Ａ、３Ｂ、３Ｃを有して構成されている。The image pickup device 3 is a CCD as shown in FIG.
Is arranged in a one-dimensional manner with a predetermined number of pixels. Further, as shown in FIG. 4, the image sensor 3 for reading a color image has three line sensors 3 for reading images corresponding to R, G, and B, respectively.
A, 3B, and 3C are included.
【００１７】演算回路１１は、波形処理回路５から出力
されるディジタルの画像信号に基づいて撮像素子３の左
側、中央、及び右側のピント計測部の最適位置を演算す
る最適位置演算部１２と、撮像素子３の各ピント計測部
の最適位置から撮像素子３の位置、及び姿勢を演算する
位置・姿勢演算部１３より構成されている。The arithmetic circuit 11 calculates the optimum positions of the focus measuring sections on the left side, the center, and the right side of the image sensor 3 based on the digital image signal output from the waveform processing circuit 5, and an optimum position calculating section 12. The image sensor 3 includes a position / orientation calculator 13 that calculates the position and attitude of the image sensor 3 from the optimum position of each focus measurement unit.
【００１８】最適位置演算部１２は、モノクロ画像の場
合、波形処理回路５から入力したディジタルの画像信号
に基づいて撮像素子３の左側、中央、及び右側の３箇所
のピント計測部のピント計測値Ｐを演算する。即ち、波
形処理回路５から入力したディジタルの画像信号が、例
えば、図５に示すような出力波形の場合、その階調値Ｖ
max とＶmin 、つまり、調整用チャート１のマーク１Ａ
の黒、白の出力差に基づいて以下の演算を行ってピント
計測値Ｐを算出し、図６に示すように、ピント計測値Ｐ
が最大となる位置を最適位置とする。 Ｐ＝〔（Ｖmax −Ｖmin ）／（Ｖmax ＋Ｖmin ）〕×１００〔％〕 ──(1) In the case of a monochrome image, the optimum position calculating section 12 is based on the digital image signal inputted from the waveform processing circuit 5, and the focus measurement values of the focus measuring sections at three positions on the left side, the center and the right side of the image pickup device 3 are measured. Calculate P. That is, when the digital image signal input from the waveform processing circuit 5 has an output waveform as shown in FIG.
max and V min , that is, the mark 1A on the adjustment chart 1
The focus measurement value P is calculated by performing the following calculation based on the black and white output difference of the focus measurement value P, as shown in FIG.
The position with the maximum is the optimum position. P = [(V max −V min ) / (V max + V min )] × 100 [%] ── (1)
【００１９】また、カラー画像の場合、波形処理回路５
から入力したＲ、Ｇ、Ｂのディジタルの画像信号に基づ
いて撮像素子３の左側、中央、及び右側の３箇所のピン
ト計測部のＲ、Ｇ、Ｂのそれぞれピント計測値Ｐｒ、Ｐ
ｇ、Ｐｂをそれぞれ上記(1)式に従って演算する。カラ
ー画像の場合、図７に示すように、各ピント計測部の
Ｒ、Ｇ、Ｂのピント計測値が最大となる位置は異なるた
め、Ｒ、Ｇ、Ｂのピント計測値をできるだけ均一にする
位置を最適位置とする。即ち、算出したＲ、Ｇ、Ｂのそ
れぞれのピント計測値Ｐｒ、Ｐｇ、Ｐｂに基づいて以下
の演算を左側、中央、及び右側のそれぞれのピント計測
部について行って評価値Ｆ、つまり、Ｒ、Ｇ、Ｂそれぞ
れのピント計測値Ｐｒ、Ｐｇ、Ｐｂが大きい程、また、
それぞれのピント計測値Ｐｒ、Ｐｇ、Ｐｂの差が小さい
程、大きくなるような値を算出し、図８に示すように、
評価値Ｆが最大となる位置を最適位置とする。 Ｆ＝Ｐｒ＋Ｐｇ＋Ｐｂ −｜Ｐｒ−Ｐｇ｜−｜Ｐｇ−Ｐｂ｜−｜Ｐｂ−Ｐｒ｜ ──(2) In the case of a color image, the waveform processing circuit 5
Focus measurement values Pr, P of R, G, B of three focus measurement units on the left side, the center, and the right side of the image sensor 3 based on the R, G, B digital image signals input from
g and Pb are calculated according to the above equation (1). In the case of a color image, as shown in FIG. 7, the positions where the focus measurement values of R, G, and B of the focus measurement units are maximum are different, and therefore the positions where the focus measurement values of R, G, and B are made as uniform as possible. Is the optimum position. That is, the following calculation is performed on each of the left, center, and right focus measurement units based on the calculated R, G, and B focus measurement values Pr, Pg, and Pb to obtain an evaluation value F, that is, R, The larger the focus measurement values Pr, Pg, and Pb of G and B, respectively,
A value that increases as the difference between the focus measurement values Pr, Pg, and Pb decreases is calculated, and as shown in FIG.
The position where the evaluation value F is the maximum is the optimum position. F = Pr + Pg + Pb- | Pr-Pg |-| Pg-Pb |-| Pb-Pr |-(2)
【００２０】位置・姿勢演算部１３は、最適位置演算部
１２で算出された左側、中央、及び右側のピント計測部
の最適位置から回帰計算用データを生成する。即ち、図
９に示すように、撮像素子３を調整軸Ｙｌ、Ｙｒを介し
てピント調整方向に移動させて、撮像素子３の左側、中
央、及び右側のピント計測部１４Ａ、１４Ｂ、１４Ｃの
最適位置ｐ1 、ｐ2 、ｐ3 を算出すると、図１０に示す
ように、調整軸ＹL と調整軸ＹR の原点を結ぶ直線をｘ
軸、中央のピント計測部１４Ｂを通り光軸に平行な直線
をｙ軸とする座標における各最適位置ｐ1 、ｐ2 、ｐ3
の座標値Ｐ1 、Ｐ2 、Ｐ3 を算出する。つまり、図１０
では、回帰計算用データとしてＰ1 （−ｘ１，ｙ１）、
Ｐ2 （０，ｙ２）、Ｐ3 （ｘ３，ｙ３）を生成する。そ
して、回帰計算用データを生成すると、回帰計算に使用
する回帰計算用データＰ1 、Ｐ2、Ｐ3 の個数を回帰計
算用データ数Ｎ１、Ｎ２、Ｎ３として、それぞれ少なく
とも１つ以上設定する。例えば、Ｎ１＝２、Ｎ２＝１、
Ｎ３＝３と設定した場合、Ｐ1 、Ｐ1 、Ｐ2 、Ｐ3 、Ｐ
3 、Ｐ3 の回帰計算用データが使用される。通常、回帰
計算用初期データ数はＮ１＝１、Ｎ２＝１、Ｎ３＝１と
設定される。このようにして回帰計算用データ数を設定
すると、最小２乗法による回帰計算を実行して撮像素子
３の位置、及び姿勢を直線式で求め、調整軸Ｙｌ、Ｙｒ
のｘ座標値−ｘｌ、ｘｒをその直線式に代入して調整位
置を算出する。また、回帰計算用データ数は、調整を実
行し、１つでも目標値を満足しないピント計測部があれ
ば、変更される。即ち、目標値を満足しないピント計測
部の前回の回帰計算用データ数に加算値ｄＮ１＝２、ｄ
Ｎ２＝２、ｄＮ３＝２が選択的に加算されて再設定され
る。The position / orientation calculation unit 13 generates regression calculation data from the optimum positions of the left, center, and right focus measurement units calculated by the optimum position calculation unit 12. That is, as shown in FIG. 9, the image pickup device 3 is moved in the focus adjustment direction via the adjustment axes Yl and Yr to optimize the focus measurement units 14A, 14B, and 14C on the left side, the center, and the right side of the image pickup device 3. When the positions p 1 , p 2 and p 3 are calculated, a straight line connecting the origins of the adjustment axes Y L and Y R is x as shown in FIG.
Optimal positions p 1 , p 2 , p 3 in the coordinates with the y axis being a straight line passing through the axis and the central focus measuring unit 14B and parallel to the optical axis.
The coordinate values P 1 , P 2 , P 3 are calculated. That is, FIG.
Then, as regression calculation data, P 1 (−x1, y1),
P 2 (0, y2) and P 3 (x3, y3) are generated. After generating a regression calculation data, as a regression calculation data P 1, P 2, P regression calculation data number the number of 3 N1, N2, N3 to be used in the regression calculation, to set at least one or more, respectively. For example, N1 = 2, N2 = 1,
When N3 = 3 is set, P 1 , P 1 , P 2 , P 3 , P
3 and P 3 regression calculation data are used. Normally, the number of initial data for regression calculation is set as N1 = 1, N2 = 1, N3 = 1. When the number of data for regression calculation is set in this way, the regression calculation by the least squares method is executed to obtain the position and orientation of the image sensor 3 by a linear equation, and the adjustment axes Yl, Yr
The x-coordinate value −xl, xr is substituted into the linear equation to calculate the adjustment position. Further, the number of data for regression calculation is changed if adjustment is performed and even one focus measuring unit does not satisfy the target value. That is, the addition value dN1 = 2, d is added to the previous regression calculation data number of the focus measuring unit that does not satisfy the target value.
N2 = 2 and dN3 = 2 are selectively added and reset.
【００２１】以下、本発明の画像読取装置のピント調整
方法を、図１１、及び図１２を参照しながら説明する。
尚、ここではモノクロ画像を読み取る撮像素子の調整を
行う場合について説明する。The focus adjusting method of the image reading apparatus according to the present invention will be described below with reference to FIGS. 11 and 12.
Note that, here, a case will be described in which the image pickup device for reading a monochrome image is adjusted.
【００２２】まず、適当な入力装置から制御回路１０に
指令を与え、ピント調整動作を開始すると、調整用チャ
ート１を照明装置９で照射し、調整用チャート１の左
側、中央、及び右側のマーク１Ａが結像レンズ２を経て
撮像素子３の撮像面上に結像する。この状態で撮像素子
３をピント調整位置の所定の範囲にわたって変化させ、
任意の位置において撮像素子３のラインセンサ３Ａから
調整用チャート１のマーク１Ａに応じた画像信号を波形
出力回路５に出力する。波形処理回路５はこの画像信号
に所定の信号処理を施した後、それを演算回路１１に出
力する。First, when a command is given to the control circuit 10 from an appropriate input device to start the focus adjustment operation, the adjustment chart 1 is illuminated by the illuminating device 9, and the marks on the left side, the center, and the right side of the adjustment chart 1 are illuminated. 1A forms an image on the image pickup surface of the image pickup device 3 through the image formation lens 2. In this state, the image sensor 3 is changed over a predetermined range of the focus adjustment position,
An image signal corresponding to the mark 1A of the adjustment chart 1 is output to the waveform output circuit 5 from the line sensor 3A of the image sensor 3 at an arbitrary position. The waveform processing circuit 5 performs a predetermined signal processing on this image signal, and then outputs it to the arithmetic circuit 11.
【００２３】演算回路１１では、最適位置演算部１２に
おいてこの画像信号の最大値Ｖmaxと最小値Ｖmin に基
づいて上記(1) 式の演算を行って、撮像素子３の任意の
位置における左側、中央、及び右側の３箇所のピント計
測部１４Ａ、１４Ｂ、１４Ｃのピント計測値Ｐを算出
し、ピント計測値Ｐが最大となる位置を最適位置ｐ1 、
ｐ2 、ｐ3 として算出して（図１１のＳ1 ）、この算出
結果を制御回路１０、及び位置・姿勢演算部１３に出力
する。位置・姿勢演算部１３では、最適位置演算部１２
で算出された左側、中央、及び右側のピント計測部１４
Ａ、１４Ｂ、１４Ｃの最適位置ｐ1 、ｐ2 、ｐ3 に基づ
いて回帰計算用データＰ1 、Ｐ2 、Ｐ3 を生成する（図
１１のＳ2 ）。In the calculation circuit 11, the optimum position calculation unit 12 calculates the above formula (1) based on the maximum value V max and the minimum value V min of the image signal, and the left side at any position of the image pickup device 3 is calculated. , The center, and the focus measurement values P of the three focus measurement units 14A, 14B, and 14C on the right side are calculated, and the position where the focus measurement value P is maximum is the optimum position p 1 ,
It is calculated as p 2 and p 3 (S 1 in FIG. 11), and the calculation result is output to the control circuit 10 and the position / orientation calculation unit 13. In the position / orientation calculation unit 13, the optimum position calculation unit 12
The left, center, and right focus measuring units 14 calculated by
Regression calculation data P 1 , P 2 , P 3 are generated based on the optimum positions p 1 , p 2 , p 3 of A, 14B, 14C (S 2 of FIG. 11).
【００２４】回帰計算用データを生成すると、回帰計算
に使用する回帰計算用データＰ1 、Ｐ2 、Ｐ3 の個数、
つまり、回帰計算用データ数Ｎ１、Ｎ２、Ｎ３をＮ１＝
１、Ｎ２＝１、Ｎ３＝１として設定する（図１１の
Ｓ3 ）。この後、回帰計算用データＰ1 、Ｐ2 、Ｐ3 を
用いて最小２乗法による回帰計算を実行して撮像素子３
の位置、及び姿勢を直線式で求め、調整軸Ｙｌ、Ｙｒの
ｘ座標値をその直線式に代入して調整位置を算出する。
制御回路１０はこの調整位置に基づいて駆動回路９を制
御し、移動装置８を駆動させて調整軸Ｙｌ、Ｙｒの調整
を実行する（図１１のＳ4 ）。When the regression calculation data is generated, the number of regression calculation data P 1 , P 2 and P 3 used for the regression calculation,
That is, the regression calculation data numbers N1, N2, and N3 are N1 =
It is set as 1, N2 = 1, N3 = 1 (S 3 in FIG. 11). After that, the regression calculation by the least squares method is executed by using the regression calculation data P 1 , P 2 , and P 3 and the image sensor 3
The position and orientation of is adjusted by a linear equation, and the x coordinate values of the adjustment axes Yl and Yr are substituted into the linear equation to calculate the adjusted position.
The control circuit 10 controls the drive circuit 9 based on this adjustment position to drive the moving device 8 to adjust the adjustment axes Yl and Yr (S 4 in FIG. 11).
【００２５】このとき、撮像素子３のラインセンサ３Ａ
から調整用チャート１のマーク１Ａに応じた画像信号が
波形出力回路５に出力され、波形回路５で所定の信号処
理を施された後、演算回路１１に入力される。演算回路
１１では、最適位置演算部１２においてこの画像信号の
最大値Ｖmax と最小値Ｖmin から撮像素子３の左側、中
央、及び右側の３箇所のピント計測部１４Ａ、１４Ｂ、
１４Ｃのピント計測値Ｐを算出する。この算出結果は制
御回路１０において目標値と比較され（図１１の
Ｓ5 ）、全てのピント計測部１４Ａ、１４Ｂ、１４Ｃの
ピント計測値が目標値を満足していれば調整を完了す
る。一方、１つでも目標値を満足しないピント計測部が
あれば、そのピント計測部の回帰計算用データ数を増加
させ、回帰計算用データ数Ｎ１、Ｎ２、Ｎ３を変更する
（図１１のＳ6 ）。例えば、前回調整時にＮ１＝１、Ｎ
２＝１、Ｎ３＝１であって、左側と右側のピント計測部
が目標値を満足し、中央のピント計測部のみが目標値を
満足しなかった場合、図１２のＳ64においてＳ65に移行
し、回帰計算用データの加算値ｄＮ２＝２が加算され、
回帰計算用データ数をＮ１＝１、Ｎ２＝３、Ｎ３＝１に
変更する。At this time, the line sensor 3A of the image pickup device 3
The image signal corresponding to the mark 1A of the adjustment chart 1 is output from the waveform output circuit 5 to the waveform output circuit 5 and subjected to predetermined signal processing, and then input to the arithmetic circuit 11. In the arithmetic circuit 11, in the optimum position arithmetic unit 12, three focus measuring units 14A, 14B on the left side, the center, and the right side of the image sensor 3 are determined from the maximum value V max and the minimum value V min of the image signal.
The focus measurement value P of 14C is calculated. The calculation result is compared with the target value in the control circuit 10 (S 5 in FIG. 11), and if the focus measurement values of all the focus measuring units 14A, 14B, 14C satisfy the target value, the adjustment is completed. On the other hand, if there is even one focus measurement unit that does not satisfy the target value, the number of regression calculation data in that focus measurement unit is increased and the number N1, N2, N3 of regression calculation data is changed (S 6 in FIG. 11). ). For example, N1 = 1, N during the previous adjustment
A 2 = 1, N3 = 1, if the focus measuring portion of the left and right satisfied the target value, only the center focus measurement unit does not satisfy the target value, the S 65 in S 64 of FIG. 12 Transition, the added value dN2 = 2 of the regression calculation data is added,
The number of data for regression calculation is changed to N1 = 1, N2 = 3, N3 = 1.
【００２６】回帰計算用データ数を変更すると、再び図
１１のＳ4 に戻り、回帰計算用データＰ1 、Ｐ2 、
Ｐ2 、Ｐ2 、Ｐ3 に基づいて最小２乗法による回帰計算
を実行して、撮像素子３の位置、及び姿勢を直線式で求
め、調整軸Ｙｌ、Ｙｒの調整を実行する。この場合、Ｎ
２が大きくなったので、撮像素子３の中央のピント計測
部１４Ｂは前回調整時より中央の最適位置に近づけら
れ、中央のピント計測値が改善される。このようにして
前回調整時に目標に達しなかったピント計測部の回帰計
算用データ数を増加させる回帰計算を調整の都度実行
し、撮像素子３の左側、中央、及び右側のピント計測部
のピント計測値が目標値を満足するように調整する。調
整が完了すると、撮像素子３をねじ締結や接着によって
固定する。When the number of regression calculation data is changed, the process returns to S 4 in FIG. 11 again, and the regression calculation data P 1 , P 2 ,
A regression calculation by the least-squares method is executed based on P 2 , P 2 , and P 3 , the position and orientation of the image sensor 3 are obtained by a linear equation, and the adjustment axes Yl and Yr are adjusted. In this case, N
Since 2 is increased, the central focus measuring unit 14B of the image sensor 3 is brought closer to the central optimum position than in the previous adjustment, and the central focus measurement value is improved. In this way, the regression calculation that increases the number of data for regression calculation of the focus measuring unit that did not reach the target at the time of the previous adjustment is executed every adjustment, and the focus measurement of the focus measuring units on the left side, the center, and the right side of the image sensor 3 is performed. Adjust so that the value satisfies the target value. When the adjustment is completed, the image sensor 3 is fixed by screw fastening or adhesion.
【００２７】以上の実施例において、回帰計算用初期デ
ータ数Ｎ１、Ｎ２、Ｎ３、及び加算値ｄＮ１、ｄＮ２、
ｄＮ３は調整時間が短くなるように適当に設定すれば良
い。In the above embodiment, the initial data numbers N1, N2, N3 for regression calculation and the added values dN1, dN2,
The dN3 may be set appropriately so that the adjustment time becomes short.
【００２８】[0028]
【発明の効果】以上説明した通り、本発明の画像読取装
置のピント調整方法、及び装置によると、調整用チャー
トを撮像素子の複数のピント計測部で読み取らせて複数
の画像信号を出力させ、この画像信号から複数のピント
計測部のピント計測値を算出することにより複数のピン
ト計測部の最適位置を求め、それらの最適位置から回帰
計算用データをそれぞれ１つ以上生成して、回帰計算を
実行することにより撮像素子の位置、或いは姿勢を算出
して、撮像素子をその位置、或いは姿勢に調整し、複数
のピント計測部のピント計測値の少なくとも１つが目標
値に満たさなかった場合、前回の回帰計算用データに対
し目標値を満たさなかったピント計測部の回帰計算用デ
ータの数を増加して再度回帰計算を行い、撮像素子の位
置、或いは姿勢を算出して、撮像素子をその位置、或い
は姿勢に調整するようになっているため、複数のピント
計測部の調整目標を全て満足する高精度なピント調整を
容易に行うことができる。As described above, according to the focus adjusting method and apparatus of the image reading apparatus of the present invention, the adjustment chart is read by the plurality of focus measuring units of the image pickup device to output the plurality of image signals. Optimum positions of the plurality of focus measurement units are obtained by calculating focus measurement values of the plurality of focus measurement units from this image signal, and one or more regression calculation data are generated from each of the optimum positions to perform regression calculation. The position or orientation of the image sensor is calculated by executing the adjustment, and the image sensor is adjusted to the position or orientation, and if at least one of the focus measurement values of the plurality of focus measurement units does not satisfy the target value, The regression calculation data that did not satisfy the target value for the regression calculation data of is increased and the regression calculation is performed again to determine the position or orientation of the image sensor. Out, in its position an imaging element, or for being adapted to adjust the attitude, can be performed to satisfy all adjustment target of the plurality of focus measuring unit highly accurate focus adjustment easily.
【図１】本発明の一実施例を示す説明図。FIG. 1 is an explanatory diagram showing an embodiment of the present invention.
【図２】一実施例に係る調整用チャートを示す説明図。FIG. 2 is an explanatory diagram showing an adjustment chart according to one embodiment.
【図３】一実施例に係る撮像素子を示す説明図。FIG. 3 is an explanatory diagram showing an image sensor according to an embodiment.
【図４】一実施例に係る撮像素子を示す説明図。FIG. 4 is an explanatory diagram showing an image sensor according to an example.
【図５】一実施例に係る波形処理後の画像信号を示す説
明図。FIG. 5 is an explanatory diagram showing an image signal after waveform processing according to an embodiment.
【図６】一実施例に係るピント調整位置とピント計測値
の関係を表すグラフ。FIG. 6 is a graph showing a relationship between a focus adjustment position and a focus measurement value according to an embodiment.
【図７】一実施例に係るピント調整位置とＲ、Ｇ、Ｂの
ピント計測値の関係を表すグラフ。FIG. 7 is a graph showing the relationship between focus adjustment positions and R, G, and B focus measurement values according to an embodiment.
【図８】一実施例に係るピント調整位置と評価値の関係
を表すグラフ。FIG. 8 is a graph showing the relationship between the focus adjustment position and the evaluation value according to the embodiment.
【図９】一実施例に係るピント計測部の最適位置を探索
する状態を示す説明図。FIG. 9 is an explanatory diagram showing a state of searching for an optimum position of the focus measuring unit according to the embodiment.
【図１０】一実施例に係る最適位置の座標値を示す説明
図。FIG. 10 is an explanatory diagram showing coordinate values of an optimum position according to an embodiment.
【図１１】一実施例に係る調整手順を示すフローチャー
ト。FIG. 11 is a flowchart showing an adjustment procedure according to an embodiment.
【図１２】一実施例に係る回帰計算用データの変更手順
を示すフローチャート。FIG. 12 is a flowchart showing a procedure for changing regression calculation data according to an embodiment.
【図１３】従来の画像読取装置のピント調整装置を示す
説明図。FIG. 13 is an explanatory diagram showing a focus adjustment device of a conventional image reading device.
１ 調整用チャート １Ａ マーク ２ 結像レンズ ３ 撮像素子 ３Ａ、３Ｂ、３Ｃ ラインセンサ ４ 基板 ５ 波形処理回路 ６ 演算回路 ７ 移動装置 ８ 照明回路 ９ 駆動回路 １０ 制御回路 １１ 演算回路 １２ 最適位置演算部 １３ 位置・姿勢演算部 １４Ａ、１４Ｂ、１４Ｃ ピント計測部 1 Adjustment Chart 1A Mark 2 Imaging Lens 3 Image Sensor 3A, 3B, 3C Line Sensor 4 Substrate 5 Waveform Processing Circuit 6 Arithmetic Circuit 7 Moving Device 8 Illumination Circuit 9 Driving Circuit 10 Control Circuit 11 Arithmetic Circuit 12 Optimal Position Arithmetic Section 13 Position / orientation calculation unit 14A, 14B, 14C Focus measurement unit
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｇ０３Ｂ 3/00 Ａ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI Technical display location G03B 3/00 A
Claims (2)
像素子の撮像面上に結像させてピント調整を行う画像読
取装置のピント調整方法において、 前記撮像素子に複数のピント計測部を設定し、 前記調整用チャートに対する前記撮像素子のピント調整
方向の位置、或いは前記撮像素子の姿勢を変化させ、 前記調整用チャートを前記撮像素子の前記複数のピント
計測部によって読み取らせて複数の画像信号を発生さ
せ、 前記複数の画像信号にそれぞれ所定の演算処理を施して
前記複数のピント計測部のピント計測値を算出して、前
記複数のピント計測部における最適位置をそれぞれ算出
し、 前記複数のピント計測部における最適位置の回帰計算用
データをそれぞれ１つ以上生成し、 前記回帰計算用データに基づいて回帰計算を行って、前
記撮像素子の位置、或いは姿勢を算出し、 前記位置、或いは姿勢に応じて前記撮像素子を調整した
後、前記調整用チャートを前記撮像素子の前記複数のピ
ント計測部によって読み取らせて、複数の調整後の画像
信号を発生させ、 前記複数の調整後の画像信号にそれぞれ所定の演算処理
を施して前記複数のピント計測部のピント計測値をそれ
ぞれ算出すると共にこれらのピント計測値と目標値を比
較し、 前記複数のピント計測部のピント計測値の少なくとも１
つが前記目標値を満たさなかった場合、前回の回帰計算
用データに対し前記目標値を満たさなかったピント計測
部の回帰計算用データの数を目標値を満たしたピント計
測部に対して相対的に多くなるように変更し、 その回帰計算用データに基づいて再度回帰計算を行って
前記撮像素子の位置、或いは姿勢を算出し、この算出し
た位置、或いは姿勢に応じて前記撮像素子を調整するこ
とを特徴とする画像読取装置のピント調整方法。1. A focus adjusting method for an image reading apparatus, wherein a plurality of focus measuring units are set in the image sensor, in which the adjustment chart is imaged on an image pickup surface of the image sensor through an image forming lens to perform focus adjustment. Then, the position in the focus adjustment direction of the image sensor with respect to the adjustment chart or the attitude of the image sensor is changed, and the adjustment chart is read by the plurality of focus measurement units of the image sensor to obtain a plurality of image signals. Is generated, and the plurality of image signals are subjected to predetermined arithmetic processing to calculate the focus measurement values of the plurality of focus measurement units, and the optimum positions in the plurality of focus measurement units are calculated, respectively, One or more pieces of regression calculation data for the optimum position in the focus measurement unit are generated, and regression calculation is performed based on the regression calculation data, After calculating the position or orientation of the image element and adjusting the image sensor according to the position or orientation, the adjustment chart is read by the plurality of focus measurement units of the image element to perform a plurality of adjustments. The subsequent image signal is generated, and the plurality of adjusted image signals are subjected to predetermined arithmetic processing to calculate the focus measurement values of the plurality of focus measurement units, respectively, and the focus measurement value and the target value are compared. At least 1 of the focus measurement values of the plurality of focus measurement units
If one does not satisfy the target value, the number of pieces of regression calculation data of the focus measurement unit that did not satisfy the target value for the previous regression calculation data is set relatively to the focus measurement unit that satisfies the target value. Change to increase the number, perform regression calculation again based on the regression calculation data, calculate the position or orientation of the image sensor, and adjust the image sensor according to the calculated position or orientation. A method for adjusting the focus of an image reading apparatus characterized by the above.
像素子の撮像面上に結像させてピント調整を行う画像読
取装置のピント調整装置において、 前記調整用チャートに対する前記撮像素子のピント調整
方向の位置、或いは前記撮像素子の姿勢を変化させる調
整手段と、 前記撮像素子に設定された複数のピント計測部から出力
される前記調整用チャートに応じた画像信号に所定の演
算処理を施してピント計測値を算出することにより、前
記複数のピント計測部の最適位置を算出する最適位置演
算手段と、 前記複数のピント計測部の最適位置から回帰計算用デー
タをそれぞれ１つ以上生成すると共に、前記回帰計算用
データに基づいて回帰計算を実行して前記撮像素子の最
適位置、或いは最適姿勢を演算する演算手段と、 前記演算手段によって算出された前記撮像素子の最適位
置、或いは最適姿勢に基づいて前記調整手段を制御する
ことにより、前記撮像素子を前記最適位置、或いは前記
最適姿勢へ調整する制御手段を備え、 前記制御手段は、調整後に前記撮像素子の前記複数のピ
ント計測部から発生する前記調整用チャートに基づく複
数の調整後の画像信号のピント計測値と目標値を比較し
て、前記複数のピント計測部のピント計測値の少なくと
も１つが前記目標値を満たさなかった場合、前記演算手
段の前回の回帰計算用データに対し前記目標値を満たさ
なかったピント計測部の回帰計算用データの数を目標値
を満たしたピント計測部に対して相対的に多くなるよう
に変更し、前記演算手段に変更した回帰計算用データに
基づいて再度、回帰計算を実行させて前記撮像素子の最
適位置、或いは最適姿勢を演算させ、その最適位置、或
いは最適姿勢に基づいて前記調整手段を制御することに
より、前記撮像素子を前記最適位置、或いは前記最適姿
勢へ調整することを特徴とする画像読取装置のピント調
整装置。2. A focus adjustment device for an image reading apparatus, which adjusts a focus by forming an image of an adjustment chart on an image pickup surface of an image pickup element through an imaging lens, the focus adjustment of the image pickup element with respect to the adjustment chart. Adjusting means for changing the position in the direction or the attitude of the image sensor, and a predetermined calculation process for the image signal according to the adjustment chart output from the plurality of focus measuring units set in the image sensor. While calculating one or more regression calculation data from each of the optimum positions of the plurality of focus measurement units by calculating the focus measurement value, an optimum position calculation unit that calculates the optimum positions of the plurality of focus measurement units, and Calculating means for calculating the optimum position or the optimum posture of the image sensor by executing regression calculation based on the regression calculation data; By controlling the adjusting means based on the calculated optimum position or optimum posture of the image pickup device, the image pickup device is provided with control means for adjusting the optimum position or the optimum posture, and the control means is After adjustment, by comparing focus measurement values and target values of a plurality of adjusted image signals based on the adjustment chart generated from the plurality of focus measurement sections of the image sensor, focus measurement values of the plurality of focus measurement sections If at least one of the values does not satisfy the target value, the number of pieces of regression calculation data of the focus measuring unit that did not satisfy the target value with respect to the previous regression calculation data of the calculation means satisfies the target value. The regression calculation is performed again based on the regression calculation data changed by the calculation means, and the maximum number of the image pickup device is changed. Image reading characterized by adjusting the image pickup device to the optimum position or the optimum posture by calculating a position or an optimum posture and controlling the adjusting means based on the optimum position or the optimum posture Focus adjustment device for the device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7203005A JPH0951409A (en) | 1995-08-09 | 1995-08-09 | Method and device for adjusting focus of image reader |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7203005A JPH0951409A (en) | 1995-08-09 | 1995-08-09 | Method and device for adjusting focus of image reader |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0951409A true JPH0951409A (en) | 1997-02-18 |
Family
ID=16466762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7203005A Pending JPH0951409A (en) | 1995-08-09 | 1995-08-09 | Method and device for adjusting focus of image reader |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0951409A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008090209A (en) * | 2006-10-05 | 2008-04-17 | Fuji Xerox Co Ltd | Focal position adjusting method for exposure apparatus |
-
1995
- 1995-08-09 JP JP7203005A patent/JPH0951409A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008090209A (en) * | 2006-10-05 | 2008-04-17 | Fuji Xerox Co Ltd | Focal position adjusting method for exposure apparatus |
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