JP2008290810A - Double-feeding detection device and image forming device - Google Patents

Double-feeding detection device and image forming device Download PDF

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JP2008290810A
JP2008290810A JP2007135837A JP2007135837A JP2008290810A JP 2008290810 A JP2008290810 A JP 2008290810A JP 2007135837 A JP2007135837 A JP 2007135837A JP 2007135837 A JP2007135837 A JP 2007135837A JP 2008290810 A JP2008290810 A JP 2008290810A
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information
sheet
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detection device
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JP4898553B2 (en
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Masataka Shimooosako
正孝 下大迫
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Ricoh Co Ltd
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Ricoh Co Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-feeding detection device detecting double feeding to convey sheets in an overlapped state of a plurality of sheets, capable of detecting continuous double feeding and improving the reliability and performance of the double feeding detection, and to provide an image forming device provided with the double-feeding detection device. <P>SOLUTION: This double-feeding detection device is provided with a sheet information storage means, recorded with an initial value of sheet information related to the sheets 20 stored in a paper feeding part 2 and recorded with update of the sheet information; a sheet information detection means provided with a light-emitting part 81 and a light-receiving part 82 to detect the transmission states of the sheets 20 under conveyance in a conveying path A and detect the sheet information, based on the transmission states; and a control means for making it decide whether it is double feeding, by comparing the sheet information on the first sheet detected by the sheet information detection means and the initial value, and making the sheet information storage means update and record the sheet information detected by the sheet information detection means and making the sheet information as a compared value for the next double feeding decision, when it is decided as not being double feeding, as the decision result. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、用紙が複数枚重なった状態で搬送される重送か否かを検知させる重送検知装置と、その重送検知装置を備えた電子写真方式の画像形成装置に関する。   The present invention relates to a double feed detection device that detects whether or not multiple sheets are conveyed in a state where a plurality of sheets are overlapped, and an electrophotographic image forming apparatus including the double feed detection device.

近年の画像形成装置（複写機、プリンタ等）は、高速化、高画質化に伴って印刷業界に用いられるようになっているが、この印刷業界のみならず、オフィスでのビジネス文章印刷においてもジャム等によるダウンタイム低減防止は重要な課題となっている。とりわけ、大量印刷時に、用紙が複数枚重なった状態で搬送される所謂重送による未印刷用紙の混入は、チェック作業を含め多大な損害となることから、従来、重送の検知を行う装置が提案されている。
この重送の検知を行う装置（重送検知装置）としては、例えば、給紙ユニットから給紙された用紙が１枚づつ分離されたか否か、つまり重送されているか否かを検出するための重送検出センサをレジストローラ手前の搬送路近傍に設け、一枚の用紙の先端と後端の通過を検出し、検出した各時間から正常な用紙通過時間と比較して、あるいは時間を用紙の搬送路方向の長さに換算した上で用紙１枚の搬送路方向の長さと比較して、重送が発生しているか否かを検知している。
また、他の技術手段として、用紙が搬送ローラ対を通過する際に用紙の厚みを測定、あるいは、光透過率測定によって用紙の厚みを測定し、１枚の用紙の厚みより大きいと判断した場合に重送が発生したと検知、判定するものが挙げられる（例えば特許文献１参照）。
このように、いくつかの重送検知の技術手段が挙げられるが、用紙の通過時間、または、用紙の長さに基づいて重送検知を行う技術手段は、重送を起こしている複数枚の用紙が搬送方向にある程度ずれていることが前提であるため、複数枚の用紙が完全に重なっている場合は、重送検知ができない。
一方、光透過率測定に基づいて重送検出を行う手段は、複数枚の用紙が位置ずれなく完全に重なっていても検知が可能であり好適なものである。従来の光透過率測定に基づく重送検知の方法は、光透過率測定によって測定した用紙の厚さと、先に搬送された用紙（先行紙）の厚さとを比較して重送か否かを検知していた。したがって、１枚目の用紙は、比較対象となる基準の「厚さ」がないことから、重送か否かを検知することができなかった。
もっとも、給紙トレイが複数ある場合、異なるタイプの用紙がセットされる場合があることから、給紙トレイを切替えた際の１枚目の用紙に対し、切替え前の用紙を比較対象としたら誤検知となる場合があり、むしろ、１枚目の用紙は重送か否かを検知しない構成になっていた。
特開２００５−１５１６６公報（第５頁、図１） In recent years, image forming apparatuses (copiers, printers, etc.) have been used in the printing industry along with higher speed and higher image quality, but not only in this printing industry but also in business text printing in offices. Prevention of downtime reduction due to jams is an important issue. In particular, in the case of mass printing, mixing of unprinted paper due to so-called multi-feed that is transported in a state where a plurality of sheets are overlapped causes great damage including check work. Proposed.
As an apparatus (multifeed detection apparatus) for detecting this double feed, for example, it is detected whether or not the sheets fed from the paper feed unit are separated one by one, that is, whether or not multiple feeds are being performed. A double feed detection sensor is installed in the vicinity of the conveyance path in front of the registration rollers to detect the passage of the leading edge and trailing edge of a sheet of paper, and compare the detected time with the normal paper passage time or the time for the paper. Is converted into the length in the transport path direction and compared with the length in the transport path direction of one sheet of paper, it is detected whether or not double feeding has occurred.
Also, as another technical means, when the thickness of the paper is measured when the paper passes through the pair of conveyance rollers, or the thickness of the paper is measured by measuring the light transmittance, and it is determined that it is larger than the thickness of one paper. One that detects and determines that double feed has occurred (see, for example, Patent Document 1).
In this way, there are several technical means for detecting double feed. The technical means for detecting double feed based on the passage time of the paper or the length of the paper includes a plurality of sheets causing double feed. Since it is premised that the sheets are deviated to some extent in the transport direction, double feed detection cannot be performed when a plurality of sheets are completely overlapped.
On the other hand, a means for performing double feed detection based on light transmittance measurement is preferable because it can detect even when a plurality of sheets are completely overlapped without being displaced. The conventional method of detecting double feed based on light transmittance measurement compares the thickness of the paper measured by the light transmittance measurement with the thickness of the paper transported first (preceding paper) to determine whether or not double feed is performed. It was detected. Therefore, since the first sheet does not have a reference “thickness” to be compared, it has not been possible to detect whether or not it is a double feed.
Of course, if there are multiple paper feed trays, different types of paper may be set. Therefore, if the paper before switching is compared with the first paper when the paper feed tray is switched, it will be incorrect. In some cases, the first sheet is not detected as to whether or not it is a double feed.
Japanese Patent Laying-Open No. 2005-15166 (5th page, FIG. 1)

上記した不具合は、異なるタイプの用紙か同じタイプの用紙かを問わず、複数の給紙トレイから用紙を給紙させて大量印刷を行う場合に発生するが、しかしながら、上記したように、給紙トレイを切替えた際の１枚目の用紙について重送か否かを検知していないことには問題があり、さらなる改良の余地があった。
そこで本発明は、このような状況に鑑みてなされたものであり、上記問題点を解決できる重送検知装置、画像形成装置を提供することを目的とする。 The above-mentioned problems occur when large-scale printing is performed by feeding paper from a plurality of paper feed trays, regardless of whether they are different types or the same type. However, as described above, There is a problem in not detecting whether or not the first sheet is double-fed when the tray is switched, and there is room for further improvement.
Accordingly, the present invention has been made in view of such a situation, and an object thereof is to provide a double feed detection device and an image forming apparatus that can solve the above-described problems.

上記技術課題を達成するために、本発明にかかる重送検知装置、画像形成装置は、下記の技術的手段を講じた。
すなわち、請求項１にかかる重送検知装置は、用紙収納手段から搬送路に搬送される用紙が複数枚重なった状態で搬送される重送か否かを検知、判定する重送検知装置であって、前記用紙収納手段に収納される前記用紙と関連付けられた用紙情報の初期値が記憶されると共に前記用紙情報の更新内容が記憶される用紙情報記憶手段と、前記搬送路に設けられ、搬送中の前記用紙の透過状態を検出してその透過状態に基づいた前記用紙情報を検知する用紙情報検知手段と、該用紙情報検知手段で検知された１枚目の前記用紙情報と、前記用紙情報の初期値とを比較させて重送か否かを判断すると共に、重送でないと判断した場合に、前記用紙情報検知手段で検知された前記用紙情報を前記用紙情報記憶手段に更新記憶させて次の重送判断の被比較値とする制御手段と、を備えたことを特徴とする。
請求項２にかかる重送検知装置は、請求項１において、前記用紙収納手段は、前記用紙の送り出しを切り替え可能に複数設けられると共に、夫々の前記用紙収納手段から搬送される夫々の前記用紙は前記搬送路に搬送可能に構成され、前記用紙情報記憶手段は、夫々の前記用紙収納手段毎に収納される用紙毎に関連づけられた前記初期値が記憶され、前記制御手段は、前記用紙収納手段を切り替える度に、切り替えられた前記用紙と関連付けた前記初期値を用いて１枚目の前記用紙情報との比較をさせて重送か否かを判断することを特徴とする。 In order to achieve the above technical problem, a multifeed detection device and an image forming apparatus according to the present invention employ the following technical means.
That is, the multifeed detection device according to claim 1 is a multifeed detection device that detects and determines whether or not the multifeed is transported in a state where a plurality of sheets transported from the paper storage means to the transport path is overlapped. An initial value of the paper information associated with the paper stored in the paper storage means, and a paper information storage means for storing the updated contents of the paper information; A paper information detecting means for detecting a paper transmission state of the paper and detecting the paper information based on the paper transmission state; the paper information of the first sheet detected by the paper information detection means; and the paper information Is compared with the initial value to determine whether or not it is a double feed, and when it is determined that it is not a double feed, the paper information detected by the paper information detection means is updated and stored in the paper information storage means. Next double feed judgment ratio Characterized by comprising a control means for a value, a.
According to a second aspect of the present invention, there is provided the multifeed detection device according to the first aspect, wherein the plurality of paper storage units are provided so as to be able to switch delivery of the papers, and each of the papers conveyed from the respective paper storage units is The sheet information storage means is configured to be capable of being conveyed to the conveyance path, the initial value associated with each sheet stored for each of the sheet storage means is stored, and the control means includes the sheet storage means Each time is switched, the initial value associated with the switched sheet is used to compare with the first sheet information to determine whether or not to double feed.

請求項３にかかる重送検知装置は、請求項２において、前記用紙情報検知手段は、発光部と受光部とが前記搬送路を挟んで対向するように配設されると共に、前記用紙の種類毎に前記発光部の発光量を関連付けて、複数設けられた前記用紙収納手段の切り替えに対応して前記発光部の発光量を調整可能に構成されていることを特徴とする。
請求項４にかかる重送検知装置は、請求項３において、前記用紙情報検知手段は、前記発光量の調整を入力可能に構成されていることを特徴とする。
請求項５にかかる重送検知装置は、請求項２乃至４の何れか一項において、夫々の前記用紙収納手段と関連付けられ、前記用紙を選択させる用紙情報設定手段を備えたことを特徴とする。
請求項６にかかる重送検知装置は、請求項１乃至５の何れか一項において、前記制御手段は、前記用紙情報検知手段により検知された１枚目の前記用紙の前記用紙情報と前記初期値とが著しく異なる場合、前記用紙収納手段と前記用紙とを関連付けに間違いがないかを報知させる報知手段を備えたことを特徴とする。
請求項７にかかる重送検知装置は、請求項３乃至５の何れか一項において、前記制御手段は、初期値としての前記用紙情報が、前記用紙情報検知手段により検知された１枚目の前記用紙の前記用紙情報と著しく異なる場合、前記発光部の発光量を替えて再度重送か否かを判断させることを特徴とする。 According to a third aspect of the present invention, there is provided the double feed detection device according to the second aspect, wherein the paper information detection means is disposed so that the light emitting portion and the light receiving portion face each other with the conveyance path interposed therebetween, and the type of the paper The light emission amount of the light emitting unit is associated with each other, and the light emission amount of the light emitting unit can be adjusted in response to switching of the plurality of paper storage means provided.
According to a fourth aspect of the present invention, in the multifeed detection device according to the third aspect, the paper information detection means is configured to be able to input the adjustment of the light emission amount.
According to a fifth aspect of the present invention, there is provided a multifeed detection apparatus according to any one of the second to fourth aspects, further comprising a sheet information setting unit that is associated with each of the sheet storage units and that selects the sheet. .
According to a sixth aspect of the present invention, in the multifeed detection device according to any one of the first to fifth aspects, the control unit includes the sheet information of the first sheet detected by the sheet information detection unit and the initial value. When the value is remarkably different, there is provided an informing means for informing whether there is an error in associating the paper storage means and the paper.
According to a seventh aspect of the present invention, in the multifeed detection device according to any one of the third to fifth aspects, the control unit is configured to detect the first sheet in which the sheet information as an initial value is detected by the sheet information detection unit. When the paper information of the paper is significantly different from the paper information, the light emission amount of the light emitting unit is changed and it is determined whether or not double feeding is performed again.

請求項８にかかる重送検知装置は、請求項１乃至７の何れか一項において、初期値としての前記用紙情報は、前記用紙の誘電率に基づいていることを特徴とする。
請求項９にかかる重送検知装置は、請求項１乃至８の何れか一項において、前記用紙収納手段に設けられ、該用紙収納手段に収納された前記用紙の誘電率を検出させる第２用紙情報検出手段を備え、前記制御手段は、前記第２用紙情報検出手段で検出された前記誘電率に基づいて前記用紙種類の検知及び前記初期値を導出させて前記用紙情報記憶手段に記憶させることを特徴とする。
請求項１０にかかる重送検知装置は、請求項１乃至９の何れか一項において、前記用紙情報検知手段は、ジャム信号を出力するジャム検知手段を兼ねており、前記用紙情報検知手段が所定時間に前記用紙を検出しないとき、前記制御手段は、ジャム信号が出力されたこととみなすことを特徴とする。
請求項１１にかかる画像形成装置は、請求項１乃至１０の何れか一項に記載の重送検知装置と電子写真方式の画像形成手段とを備えたことを特徴とする。 According to an eighth aspect of the present invention, in the multifeed detection device according to any one of the first to seventh aspects, the paper information as an initial value is based on a dielectric constant of the paper.
According to a ninth aspect of the present invention, there is provided the double feed detection device according to any one of the first to eighth aspects, wherein the second paper is provided in the paper storage means and detects a dielectric constant of the paper stored in the paper storage means. An information detection unit, and the control unit detects the paper type and derives the initial value based on the dielectric constant detected by the second sheet information detection unit, and stores the detected value in the sheet information storage unit. It is characterized by.
According to a tenth aspect of the present invention, in the multifeed detection device according to any one of the first to ninth aspects, the paper information detection means also serves as a jam detection means for outputting a jam signal, and the paper information detection means is a predetermined value. When the paper is not detected in time, the control means considers that a jam signal has been output.
An image forming apparatus according to an eleventh aspect includes the double-feed detection apparatus according to any one of the first to tenth aspects and an electrophotographic image forming unit.

本発明によれば、搬送路に設けた用紙情報検知手段が、搬送中の、１枚目の用紙の透過状態を検出して、その透過状態に基づいた用紙情報を検知し、この用紙情報と、用紙情報記憶手段に記憶している用紙情報の初期値とを制御手段が比較して重送か否かを判断するから、重送検知の性能を向上させることができる。
また、制御手段は、その判断の結果が重送でないとした場合に、用紙情報検知手段で検知した用紙情報を用紙情報記憶手段に記憶して、次の用紙情報の被比較値とし、後から搬送してきた用紙の用紙情報と比較するから、上記した初期値のような理論値に基づいた用紙情報ではなく、実測値に基づいた用紙情報となり、重送検知の信頼性を向上させることができる。
また、用紙収納手段を複数設けた場合、用紙情報記憶手段は、夫々の用紙収納手段毎に収納された用紙の用紙情報の初期値を記憶し、制御手段は、用紙収納手段を切り替えても対応した初期値と、用紙情報検知手段の検出による切り替え後の１枚目の用紙情報とを比較するから、異なるタイプの用紙か同じタイプの用紙かを問わず、連続的に重送検知を行うことができる。
また、複数段階の異なる発光量による発光が可能な発光部と受光部とを備えて用紙情報検知手段を構成し、用紙収納手段に応じて発光部の発光量を選択可能に制御手段を構成したから、透過率のレンジが著しく違う用紙（例えば普通紙とＯＨＰフィルム）にも容易に対応することができる。
また、用紙収納手段に収納した用紙の誘電率を検出する第２用紙情報検出手段を設けて、その第２用紙情報検出手段で実際に収納された用紙の誘電率を検出し、その誘電率から導出した初期値と、その用紙とを関連付けするから、重送検知自体の精度を高めることができる。 According to the present invention, the paper information detection means provided in the transport path detects the transmission state of the first sheet being transported, detects the paper information based on the transmission state, and detects the paper information and Since the control means compares the initial value of the paper information stored in the paper information storage means and determines whether or not the double feed is made, the performance of double feed detection can be improved.
In addition, if the determination result is not double feeding, the control means stores the paper information detected by the paper information detection means in the paper information storage means to be a value to be compared for the next paper information. Since it is compared with the paper information of the conveyed paper, it becomes paper information based on actual measurement values instead of paper information based on theoretical values such as the above-mentioned initial values, and the reliability of double feed detection can be improved. .
Further, when a plurality of paper storage means are provided, the paper information storage means stores the initial value of the paper information of the paper stored for each paper storage means, and the control means can cope with switching of the paper storage means. Since the initial value is compared with the first paper information after the switching by the detection of the paper information detection means, it is possible to detect double feed continuously regardless of whether the paper is a different type or the same type. Can do.
In addition, a paper information detection unit is configured by including a light emitting unit and a light receiving unit that can emit light at different levels of light emission, and a control unit is configured so that the light emission amount of the light emitting unit can be selected according to the paper storage unit. Therefore, it is possible to easily cope with paper (for example, plain paper and OHP film) having a significantly different transmittance range.
Further, a second paper information detecting means for detecting the dielectric constant of the paper stored in the paper storage means is provided, and the dielectric constant of the paper actually stored by the second paper information detecting means is detected. Since the derived initial value is associated with the paper, the accuracy of double feed detection itself can be improved.

以下、図面を参照して、本発明の実施形態を詳細に説明する。
図１は、本実施の形態にかかる重送検知装置を備えた電子写真方式の画像形成装置の概略構成図である。まず、画像形成装置の概略を説明する。
本実施の形態にかかる画像形成装置は、図１に示すように、その中央に画像形成部１が配置され、この画像形成部１のすぐ下方に給紙部２（用紙収納手段）が配置されている。給紙部２は複数具備され、それぞれに給紙トレイ２１を備えている。画像形成部１の上方は、原稿を読取る読取部３が配設されている。画像形成部１の左側には排紙収納部４が設けられ、画像形成された用紙２０が排紙収納される。
画像形成部１には作像部６が配置され、ドラム状をした感光体６１の周囲には、表面に帯電処理を行う帯電部６２、画像情報を表面にレーザー光で照射する露光部７、表面に露光されて形成された静電潜像を可視化する現像部６３、及び感光体６１の残留するトナーを除去回収するクリーニング部６４が配置されている。
また、感光体６１上に形成されたトナー像を用紙２０に転写する転写部５１、トナー像を得た用紙上のトナーを、一対のローラ間を通過して熱と圧力を加えることによってトナー像を定着処理する定着部５２がそれぞれ配置されている。定着部５２を通過した用紙は排紙ローラ５３により排紙収納部４に排紙される。両面印刷時は、分岐部９１にて分岐され、反転両面部９で用紙２０が反転されてレジストローラ２３まで搬送し、レジストローラ２３で用紙２０のスキューが補正され、裏面画像形成動作に至る。
給紙部２においては、給紙トレイ２１に未使用の用紙２０が収容されており、回動可能に支持された底板２４が最上の用紙２０をピックアップローラ２５が当接可能な位置まで上昇する。給紙ローラ２６の回転により、最上の用紙２０は給紙トレイ２１から送り出され、レジストローラ２３へと搬送される。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an electrophotographic image forming apparatus including a double feed detection device according to the present embodiment. First, an outline of the image forming apparatus will be described.
As shown in FIG. 1, the image forming apparatus according to the present embodiment has an image forming unit 1 disposed at the center thereof, and a sheet feeding unit 2 (paper storage unit) disposed immediately below the image forming unit 1. ing. A plurality of paper feed units 2 are provided, each having a paper feed tray 21. Above the image forming unit 1, a reading unit 3 for reading a document is disposed. A paper discharge storage unit 4 is provided on the left side of the image forming unit 1, and a sheet 20 on which an image is formed is discharged and stored.
An image forming unit 6 is disposed in the image forming unit 1. Around the drum-shaped photoconductor 61, a charging unit 62 that performs charging processing on the surface, an exposure unit 7 that irradiates image information with laser light on the surface, A developing unit 63 that visualizes the electrostatic latent image formed by exposure on the surface and a cleaning unit 64 that removes and collects toner remaining on the photoreceptor 61 are disposed.
In addition, the transfer unit 51 that transfers the toner image formed on the photoconductor 61 to the paper 20, the toner on the paper from which the toner image was obtained passes between a pair of rollers, and heat and pressure are applied to the toner image. A fixing unit 52 for fixing the image is disposed. The sheet that has passed through the fixing unit 52 is discharged to the discharge storage unit 4 by the discharge roller 53. At the time of double-sided printing, the paper is branched by the branching unit 91, the paper 20 is reversed by the reversing double-sided part 9, and conveyed to the registration roller 23, the skew of the paper 20 is corrected by the registration roller 23, and the back side image forming operation is performed.
In the paper feed unit 2, unused paper 20 is stored in the paper feed tray 21, and the bottom plate 24 that is rotatably supported raises the uppermost paper 20 to a position where the pickup roller 25 can abut. . With the rotation of the paper feed roller 26, the uppermost paper 20 is sent out from the paper feed tray 21 and conveyed to the registration roller 23.

レジストローラ２３は用紙２０の搬送を一時止め、感光体６１表面のトナー像と用紙２０の先端との位置関係が所定の位置になるよう、タイミングをとって回転が開始するよう制御される。
読取部３では、コンタクトガラス３１上に載置される原稿の読取り走査を行うために、原稿照明用光源とミラーよりなる読取走行体３２、３３が往復移動する。この読取走行体３２、３３により走査された画像情報は、レンズ３４の後方に設置されているＣＣＤ３５に画像信号として読込まれる。
この読込まれた画像信号は、画像処理部（図示せず）によってデジタル化され画像処理される。画像形成部１では、画像処理部によって処理された画像信号に基づいて、露光部７内のレーザダイオードＬＤ（図示せず）の発光により感光体６１の表面に静電潜像が形成される。ＬＤからの光信号は、公知のポリゴンミラーやレンズを介して感光体６１に至る。読取部３の上方には、原稿を自動的に搬送する自動原稿搬送装置１００が取り付けられるようになっている。 The registration roller 23 is controlled to start rotation at a timing so that the conveyance of the paper 20 is temporarily stopped and the positional relationship between the toner image on the surface of the photosensitive member 61 and the leading edge of the paper 20 becomes a predetermined position.
In the reading unit 3, in order to read and scan a document placed on the contact glass 31, the reading traveling bodies 32 and 33 including a document illumination light source and a mirror reciprocate. The image information scanned by the reading traveling bodies 32 and 33 is read as an image signal into the CCD 35 installed behind the lens 34.
The read image signal is digitized and image processed by an image processor (not shown). In the image forming unit 1, an electrostatic latent image is formed on the surface of the photoreceptor 61 by light emission of a laser diode LD (not shown) in the exposure unit 7 based on the image signal processed by the image processing unit. The optical signal from the LD reaches the photosensitive member 61 via a known polygon mirror or lens. An automatic document feeder 100 that automatically feeds a document is attached above the reading unit 3.

本実施の形態の画像形成装置は、上記したように原稿を読取りデジタル化して用紙に複写する、いわゆるデジタルコピー機としての機能の他に、原稿の画像情報を遠隔地と授受するファックスの機能や、コンピュータが扱う画像情報を用紙上に印刷するいわゆるプリンタの機能を有する多機能になっている。コピー機としての設定は、オペレータが任意に設定可能な操作部（図示せず）で行う。また、どの機能によって形成された画像もすべて排紙収納部４に排出される。
また、本実施の形態の画像形成装置は、給紙部２の自動切り替え機能を備えており、各給紙部２に同じ種類の用紙をセットし、その旨を設定しておくことで、給紙中の給紙部２の用紙２０が無くなり次第、次の給紙部２に切り替わるようになっている。
分岐爪９１にて分岐され反転両面部９を経由して、用紙を反転させ反転排紙ローラ５４を経由して排紙ローラ５３から排出された場合、排紙収納部４にスタックされた用紙は画像面が下面になった状態であり、コピー、ファクシミリ、プリンタで扱う原稿の処理順が１ページから行われて印刷されても、排紙収納部４から取り出したときに１ページ目が最上になっており、改めてページを揃えるなどの作業から開放される。 As described above, the image forming apparatus according to the present embodiment reads a document, digitizes it, and copies it on a sheet of paper. This is a multi-function having a so-called printer function for printing image information handled by a computer on paper. Setting as a copier is performed by an operation unit (not shown) that can be arbitrarily set by an operator. In addition, all images formed by any function are discharged to the paper discharge storage unit 4.
Further, the image forming apparatus of the present embodiment has an automatic switching function of the paper feed unit 2, and the same type of paper is set in each paper feed unit 2, and the fact is set accordingly. As soon as the paper 20 in the paper feed unit 2 in the paper runs out, the paper feed unit 2 is switched to the next.
When the paper is branched by the branching claw 91 and reversed via the reverse double-sided portion 9 and discharged from the paper discharge roller 53 via the reverse paper discharge roller 54, the paper stacked in the paper discharge storage portion 4 is The image side is the bottom side, and even if the document, which is handled by copying, facsimile, and printer, is processed from the first page, the first page is the top when it is taken out from the paper discharge storage unit 4 It is freed from work such as aligning pages again.

次に、本発明の要部である重送検知装置について詳述する。
（実施の形態１）
実施の形態１にかかる重送検知装置は、搬送路Ａに搬送される用紙２０が複数枚重なった状態で搬送される重送か否かを検知させるのに好適なものが例示されており、用紙情報記憶手段と、用紙情報検知手段と、用紙情報設定手段と、制御手段とを備えて構成される。なお、搬送路Ａとは、複数設けられた給紙部２（用紙収納手段）から排紙収納部４に至る用紙２０の行程部分とのことをいう。さらにこの搬送路Ａは、適宜設けたガイド材ａ１や回転駆動可能なローラ対などで構成されている。
用紙情報記憶手段は、後述する用紙情報検知手段によって検知された１枚目の用紙情報に対して重送か否かを判断させる用紙情報の初期値（閾値の初期値）が記録されていると共に、その用紙情報を情報更新可能なメモリを備えて構成されている。
なお、この「１枚目」とは、通常の画像形成をする度（スタートボタンを操作する度）の１枚目であり、画像形成装置の電源を入れた直後の画像形成時、給紙部２に用紙２０を補充した直後の画像形成時も含むものである。
この用紙情報の初期値は、普通紙、第二原図用紙、ＯＨＰフィルム等の用紙の種類によって異なる用紙夫々の誘電率に基づいた各用紙の数値情報であり、夫々の用紙２０と関連付けられている。
なお、本実施の形態では、用紙の誘電率に基づいて用紙情報の初期値としているが、用紙の透過率（透光率）等、用紙夫々の固有の情報であれば特に限定されない。 Next, the double feed detection device which is the main part of the present invention will be described in detail.
(Embodiment 1)
The multifeed detection device according to the first exemplary embodiment is exemplified by a device suitable for detecting whether or not a multifeed is transported in a state where a plurality of sheets 20 transported in the transport path A are overlapped, A sheet information storage unit, a sheet information detection unit, a sheet information setting unit, and a control unit are provided. The transport path A refers to a travel portion of the paper 20 from the plurality of paper supply units 2 (paper storage means) to the paper discharge storage unit 4. Further, the transport path A is configured by a guide material a1 provided as appropriate, a pair of rollers that can be rotationally driven, and the like.
The paper information storage means stores an initial value (initial value of the threshold value) of paper information for determining whether or not the first paper information detected by the paper information detection means described later is double-fed. , A memory capable of updating the paper information is provided.
The “first sheet” is the first sheet each time a normal image is formed (when the start button is operated), and the sheet feeding unit is used when an image is formed immediately after the image forming apparatus is turned on. 2 includes the time of image formation immediately after the paper 20 is replenished.
The initial value of the sheet information is numerical information of each sheet based on the dielectric constant of each sheet that differs depending on the sheet type, such as plain paper, second original sheet, and OHP film, and is associated with each sheet 20. .
In the present embodiment, the initial value of the paper information is set based on the dielectric constant of the paper. However, the information is not particularly limited as long as the information is unique to each paper such as the paper transmittance (light transmittance).

用紙情報検知手段は、図２に示すように、給紙部２から排紙収納部４に至る搬送路Ａのうち、給紙ローラ２６とレジストローラ２３とを結ぶ区間の搬送路Ａを形成させる一対のガイド材ａ１の中途部が開口され、その開口部ａ２に、搬送路Ａを挟んで発光部８１と受光部８２とが対向配置された透過型の光センサを備えて構成される。
本実施の形態では、用紙２０への作像開始以前に重送を検知できた方が好ましいことから、用紙情報検知手段を給紙ローラ２６とレジストローラ２３との間に配設している。また、この用紙情報検知手段は、給紙ローラ２６やレジストローラ２３、あるいはその間に設けた搬送ローラ２７等の近傍に配設することが、搬送される用紙の挙動が小さく、計測に誤差が生じにくいことから好ましいものである。
このように設けられた用紙情報検知手段は、搬送中の用紙２０自体（用紙通過の有無）の検出と同時に、そのとき透過状態によって変化する受光部８２の受光量に対応した数値情報からなる用紙情報を後述する制御手段に送信するようになっている。 As shown in FIG. 2, the sheet information detection unit forms a conveyance path A in a section connecting the sheet feeding roller 26 and the registration roller 23 in the conveyance path A from the sheet feeding unit 2 to the sheet discharge storage unit 4. A midway portion of the pair of guide materials a1 is opened, and a transmissive optical sensor in which a light emitting portion 81 and a light receiving portion 82 are disposed to face each other with the conveyance path A interposed therebetween is configured.
In the present embodiment, it is preferable that double feed can be detected before the start of image formation on the paper 20, and therefore, paper information detection means is disposed between the paper feed roller 26 and the registration roller 23. Further, if the paper information detection means is arranged in the vicinity of the paper feed roller 26, the registration roller 23, or the transport roller 27 provided therebetween, the behavior of the transported paper is small, and an error occurs in measurement. It is preferable because it is difficult.
The sheet information detecting means provided in this way simultaneously detects the sheet 20 being conveyed (whether or not the sheet has passed), and simultaneously forms a sheet of numerical information corresponding to the amount of light received by the light receiving unit 82 that changes depending on the transmission state. Information is transmitted to the control means described later.

また、発光部８１の発光量であるが、例えば、透過率の低い用紙を基準にして発光量を決定してしまうと、透過率の高い用紙では発光量が強すぎて測定可能範囲を超えてしまい、その逆に、透過率の高い用紙を基準にして発光量を決定してしまうと、透過率の低い用紙では発光量が弱すぎてしまい、測定に誤差が生じやすいなどの不具合が発生してしまう恐れがある。
そこで、普通紙、第二原図用紙、ＯＨＰフィルム等の透過率の著しく異なる各被計測物を、一つの透過型の光センサでもって精度よく計測させるために、発光部８１を、複数の給紙部２の中から給紙させる給紙部２に応じて、予め段階的に設定された発光量で発光させるようになっている。
例えば、上記の用紙で言えば、透過率の良い順として、ＯＨＰフィルム、第二原図用紙、普通紙となり、発光量は、ＯＨＰフィルムを小の発光量とし、第二原図用紙を中の発光量とし、普通紙を大の発光量とする。なお、この発光量を段階的にするのは、センサの特性・性能によるため、必ずしも必要ではない。
この段階的な発光量は、使用者（オペレータ）の意思でもって設定を替えるものではなく、後述する用紙情報設定手段によって入力された「用紙種類選択」によって装置側が自動的に切り替えるようになっている。 In addition, the light emission amount of the light emitting unit 81, for example, if the light emission amount is determined based on a sheet with low transmittance, the light emission amount is too strong for a sheet with high transmittance and exceeds the measurable range. On the other hand, if the amount of light emission is determined based on a sheet with a high transmittance, the amount of light emission is too weak for a sheet with a low transmittance, causing problems such as measurement errors. There is a risk that.
Therefore, in order to accurately measure each object to be measured such as plain paper, second original drawing paper, OHP film, and the like with a single transmission type optical sensor, the light emitting unit 81 is provided with a plurality of paper feeds. Light is emitted with a light emission amount set in a stepwise manner in accordance with the paper feeding unit 2 that feeds paper from the unit 2.
For example, in the case of the above paper, the OHP film, the second original paper, and the plain paper are in order of good transmittance. The light emission amount is a small light emission amount for the OHP film, and the light emission amount for the second original paper is medium. And plain paper with a large light emission amount. Note that it is not always necessary to make the amount of light emitted stepwise because of the characteristics and performance of the sensor.
This stepwise light emission amount is not changed by the intention of the user (operator), but is automatically switched by the apparatus side by “paper type selection” input by a paper information setting means described later. Yes.

ここで、第二原図用紙の発光量を基準にした（「１」とした）普通紙とＯＨＰフィルムの発光量の倍率と、各用紙の透過率％（１枚時、２枚時）との関係を表１に示す。２枚用紙が重なった状態（重送）では、普通紙、第二原図用紙とも透過率は約半分となることがわかっている。ＯＨＰフィルムは透過率が著しく高いため、その差は僅かになっている。
［表１］

Figure 2008290810
さらに、この発光量は、情報に対応して微調整が可能になっている。すなわち、上記した例では、普通紙、第二原図用紙、ＯＨＰフィルム等、代表的な用紙種類で、かつ、標準的な用紙を基準にした初期値（閾値）のみなので、使用者がこれらから外れる用紙を用いた場合、重送か否かの検知精度が低下してしまう恐れがある。
そこで、後述する用紙情報設定手段を、例えば、標準的な厚さの用紙より薄手または厚手を用いた場合、「薄紙」「厚紙」選択ボタンや、用紙の厚さが標準より「＋」または「−」など直感的な入力操作が可能なボタンを備えて構成し、これに対応して発光量を微調整可能にして、標準的な用紙を基準にした初期値（閾値）を利用できるようにしている。なお、本実施の形態では、図３に示すように、「薄紙」「厚紙」選択ボタンを例示している。
また、この用紙情報検知手段は、給紙部２での給紙動作の際、例えば、ピックアップローラや給紙ローラ等に用紙が絡まってジャムが発生したか否かを検出させるジャム検知手段を兼ねている。すなわち、給紙部２の給紙動作が始まってから所定時間内に用紙が発光部８１と受光部８２との間を通過（遮光）しなかったとき、当然のことながら遮光をしなかった情報が制御手段に入力される。すなわち、この用紙情報検知手段はジャム信号を出力させるジャム検知手段にもなっている。 Here, the magnification of the light emission amount of the plain paper and the OHP film based on the light emission amount of the second original drawing paper (referred to as “1”) and the transmittance% of each paper (at the time of 1 sheet and 2 sheets) The relationship is shown in Table 1. When two sheets are overlapped (double feeding), it is known that the transmittance of both the plain paper and the second original drawing paper is about half. Since the OHP film has a very high transmittance, the difference is small.
[Table 1]
Figure 2008290810
Further, the light emission amount can be finely adjusted in accordance with the information. That is, in the above-described example, only the initial value (threshold value) based on a standard paper type and a standard paper type such as plain paper, second original drawing paper, OHP film, and the like is excluded from the user. When paper is used, there is a risk that the accuracy of detecting whether or not double feeding will be reduced.
Therefore, when the paper information setting means to be described later is thinner or thicker than the standard thickness paper, for example, a “thin paper” or “thick paper” selection button or a paper thickness of “+” or “ It is configured with buttons that allow intuitive input operations such as “-”, and the amount of light emission can be finely adjusted accordingly, so that the initial value (threshold value) based on standard paper can be used. ing. In this embodiment, as shown in FIG. 3, “thin paper” and “thick paper” selection buttons are exemplified.
The paper information detection means also functions as a jam detection means for detecting whether or not a jam has occurred due to a paper entangled with a pickup roller, a paper feed roller, or the like during a paper feeding operation in the paper feeding unit 2. ing. In other words, when the paper does not pass between the light emitting part 81 and the light receiving part 82 within a predetermined time after the paper feeding operation of the paper feeding part 2 starts, the information that is not light-shielded naturally. Is input to the control means. That is, the paper information detection means is also a jam detection means for outputting a jam signal.

用紙情報設定手段は、タッチ入力可能な液晶パネルとテンキー等で構成された画像形成装置（本体）の入力表示部８３を利用しており、その液晶パネルに「用紙種類選択」や上記した発光量の微調整の入力を行うボタン等が表示され、夫々の給紙部２と関連付けられている。この「用紙種類選択」自体は、使用者が画像形成をする用紙の種類を選択するもので、画像形成装置の標準的な機能の一つであるが、実施の形態１では、この「用紙種類選択」による用紙の選択と同時に、用紙と関連付けされた用紙情報の初期値や、発光部８１の発光量（各用紙の標準的な発光量）が決定されるようになっている。
また、この用紙情報設定手段は、「用紙種類選択」機能を実現させるため、予め各給紙部２と各種類の用紙２０とを関連付けさせるための入力ができるようになっている。すなわち、「用紙種類選択」を選択入力することで、選択された「用紙」に対応した給紙部２が選択されるようになっている。
例えば、最上段の給紙部２と、２段目の給紙部２を普通紙とし、３段目の給紙部２を第二原図用紙とし、最下段の給紙部２をＯＨＰフィルムと選択入力したり、全ての給紙部２を普通紙と選択入力したり等、使用者の使用態様に応じて適宜、各給紙部２と用紙種類とを関連付けできるようになっている。この設定は、通常、予め行っておくもので、必要なときのみ呼び出して設定変更するようになっている。
制御手段は、用紙情報記憶手段と、用紙情報検知手段と、用紙情報設定手段と、画像形成装置（本体）を統括制御させて、各構成部を動作させるもので、その詳細は、以下の動作説明で行うものとする。 The paper information setting means uses an input display unit 83 of an image forming apparatus (main body) configured by a liquid crystal panel capable of touch input and a numeric keypad. The liquid crystal panel displays “paper type selection” and the light emission amount described above. A button for inputting the fine adjustment is displayed and associated with each sheet feeding unit 2. This “paper type selection” itself is one in which the user selects the type of paper on which an image is to be formed. This is one of the standard functions of the image forming apparatus. Simultaneously with the selection of the paper by “select”, the initial value of the paper information associated with the paper and the light emission amount of the light emitting unit 81 (standard light emission amount of each paper) are determined.
Further, the paper information setting means can input in advance to associate each paper feed unit 2 with each type of paper 20 in order to realize the “paper type selection” function. That is, by selecting and inputting “paper type selection”, the paper feeding unit 2 corresponding to the selected “paper” is selected.
For example, the uppermost sheet feeder 2, the second sheet feeder 2 are plain paper, the third sheet feeder 2 is a second original drawing sheet, and the lowermost sheet feeder 2 is an OHP film. Each paper feed unit 2 can be associated with a paper type as appropriate according to the user's usage, such as selection input or selection input of all paper feed units 2 as plain paper. This setting is normally performed in advance, and is called only when necessary to change the setting.
The control unit is configured to control the sheet information storage unit, the sheet information detection unit, the sheet information setting unit, and the image forming apparatus (main body) to operate each component, and details thereof are as follows. It shall be done in the explanation.

以上のように構成された実施の形態１にかかる重送検知装置を備えた画像形成装置の一連の動作を説明する。なお、各給紙部２と各種類の用紙２０との関連付けは予め設定されているものとし、また、画像形成を行う原稿等はセットされているものとする。
まず、図３に示すように、画像形成装置（本体）の入力表示部８３に表示した「用紙種類選択」に従って、画像形成を行う用紙２０を選択入力する。この用紙の選択入力によって、関連づけした給紙部２が選択される。例えば、「第二原図用紙」を選択することで、関連づけした給紙部２、例えば最上段の給紙部２が選択される。
なお、同じ「第二原図用紙」でも紙厚が厚いタイプや薄いタイプがある。その場合、「薄紙」「厚紙」選択ボタンを押動して発光部８１の発光量の微調整を行う。
次いで、画像形成装置の入力表示部８３を構成するテンキーボタンで画像形成枚数を入力し、「スタート」ボタンを押動することにより、原稿の読取り、潜像の形成等が開始する。これと略同時に、例えば最上段の給紙部２が用紙２０（第二原図用紙）を搬送路Ａに送り出す。 A series of operations of the image forming apparatus including the double feed detection device according to the first embodiment configured as described above will be described. Assume that the association between each paper feed unit 2 and each type of paper 20 is set in advance, and a document or the like for image formation is set.
First, as shown in FIG. 3, according to “paper type selection” displayed on the input display unit 83 of the image forming apparatus (main body), the paper 20 on which image formation is selected is input. By this paper selection input, the associated paper feed unit 2 is selected. For example, by selecting “second original drawing sheet”, the associated sheet feeding unit 2, for example, the uppermost sheet feeding unit 2 is selected.
Note that the same “second original drawing paper” includes a thick paper type and a thin paper type. In this case, the “thin paper” and “thick paper” selection buttons are pressed to finely adjust the light emission amount of the light emitting unit 81.
Next, the number of images to be formed is input using the numeric key buttons constituting the input display unit 83 of the image forming apparatus, and the “start” button is pushed to start reading a document, forming a latent image, and the like. At substantially the same time, for example, the uppermost paper feed unit 2 sends the paper 20 (second original drawing paper) to the transport path A.

この給紙部２による用紙２０の送り出しを基点に、所定時間に達するまでタイムカウントを始めると同時に、発光部８１が用紙に応じた所定の発光量でもって発光して検出可能な状態に移行する。
この所定時間内に発光部８１と受光部８２との間を用紙２０が通過して発光部８１の発光を遮光（透過状態が変化）した時点で制御手段はジャムの発生なしとの判断をすると同時に、制御手段は、遮光時の受光部８２の受光量に対応した数値情報からなる用紙情報を得る。なお、所定時間内に発光部８１と受光部８２との間を用紙２０が通過しない場合、ジャムが発生したとしてその旨を画像形成装置（本体）の入力表示部８３に表示して装置を停止する。
制御手段は、ジャムの発生なしとの判断をしたら、用紙と関連付けした用紙情報の初期値（閾値の初期値）と、用紙情報検知手段による１枚目の用紙情報とを比較する。用紙情報検知手段による１枚目の用紙情報が初期値としての用紙情報に達していない場合は、「重送なし」と判断し、用紙情報検知手段による用紙情報が初期値としての用紙情報に達している場合、または超えている場合は、「重送あり」と判断して、その旨を画像形成装置（本体）の入力表示部８３に表示すると同時に、装置を停止する。この場合、排紙収納部４に用紙２０が排紙した直後装置を停止しても良い。 Starting from the feeding of the paper 20 by the paper feeding unit 2, time counting is started until a predetermined time is reached, and at the same time, the light emitting unit 81 emits light with a predetermined light emission amount corresponding to the paper and shifts to a detectable state. .
If the paper 20 passes between the light emitting unit 81 and the light receiving unit 82 within the predetermined time and the light emission of the light emitting unit 81 is blocked (transmission state is changed), the control means determines that no jam occurs. At the same time, the control means obtains paper information consisting of numerical information corresponding to the amount of light received by the light receiving unit 82 when light is blocked. If the paper 20 does not pass between the light emitting unit 81 and the light receiving unit 82 within a predetermined time, the fact that a jam has occurred is displayed on the input display unit 83 of the image forming apparatus (main body) and the apparatus is stopped. To do.
When the control unit determines that the jam does not occur, the control unit compares the initial value of the sheet information associated with the sheet (the initial value of the threshold value) with the first sheet information by the sheet information detection unit. If the first paper information by the paper information detection means has not reached the initial paper information, it is determined that there is no double feed, and the paper information by the paper information detection means has reached the initial paper information. If it is, or exceeds it, it is determined that “double feed is present”, and a message to that effect is displayed on the input display unit 83 of the image forming apparatus (main body), and at the same time the apparatus is stopped. In this case, the apparatus may be stopped immediately after the paper 20 is discharged to the paper discharge storage unit 4.

また制御手段が「重送なし」と判断した場合は、用紙情報検知手段によって得られた用紙情報を新たな閾値として用紙情報記憶手段に記録・更新し、一般的な電子写真方式の画像形成行程を続行する。なお、新たに更新する用紙情報は、用紙情報の初期値（閾値の初期値）に対して上書きするのではなく、用紙情報記憶手段の新たなメモリ領域に記録する。
また、入力設定した画像形成枚数が一枚である場合、用紙情報検知手段によって得られた用紙情報を新たな閾値としての更新を行わず処理を終了する。
複写枚数が複数枚の場合、１枚目の画像形成が終了（またはその直前）すると、給紙部２が２枚目の用紙２０（第二原図用紙）を搬送路Ａに送り出し、上記と同じく、制御手段によるジャムの発生の判断、２枚目の用紙情報と１枚目の用紙情報とを比較して重送の有無の判断を行う。この一連の動作は、画像形成枚数が終了するまで行う。なお、２枚目以降は、ｎ枚目の用紙情報とｎ−１枚目の用紙情報とを比較して重送の有無の判断を行う。
仮に、２段目の給紙部２も第二原図用紙に設定しておき、最上段の給紙部２の用紙がなくなった場合は、２段目の給紙部２に自動的に切り替わるが、このとき、用紙情報検知手段によって得られた切り替わり後の一枚目の用紙情報と、２段目の給紙部２にセットした用紙の用紙情報の初期値（閾値の初期値）とを比較する。
もちろん、２段目の給紙部２に第二原図用紙やＯＨＰフィルム等の用紙をセットしていた場合も、当然のことながら、用紙情報検知手段によって得られた一枚目の用紙情報と、２段目の給紙部２にセットした用紙の用紙情報の初期値（閾値の初期値）とを比較する。さらに連続して画像形成をする場合は、用紙情報検知手段によって得られた用紙情報を新たな閾値として用紙情報記憶手段に記録・更新する。 If the control means determines that “no double feed”, the paper information obtained by the paper information detection means is recorded / updated in the paper information storage means as a new threshold value, and a general electrophotographic image forming process is performed. To continue. Note that the newly updated paper information is recorded in a new memory area of the paper information storage means rather than overwriting the initial value (initial value of the threshold value) of the paper information.
When the number of image formations that has been input is set to one, the processing ends without updating the paper information obtained by the paper information detection means as a new threshold value.
When the number of copies is plural, when the first image formation is completed (or immediately before), the paper feeding unit 2 sends the second sheet 20 (second original sheet) to the transport path A, and the same as above. Then, the determination of the occurrence of jam by the control means is performed to compare the second sheet information and the first sheet information to determine the presence or absence of double feeding. This series of operations is performed until the number of image formations is completed. For the second and subsequent sheets, the n-th sheet information is compared with the (n-1) -th sheet information to determine the presence or absence of double feeding.
If the second-stage sheet feeding unit 2 is also set as the second original drawing sheet and the uppermost sheet feeding unit 2 runs out of paper, it automatically switches to the second-stage sheet feeding unit 2. At this time, the first sheet information after switching obtained by the sheet information detecting means is compared with the initial value (initial value of the threshold value) of the sheet information of the sheet set in the second-stage sheet feeding unit 2. To do.
Of course, even when paper such as a second original drawing paper or an OHP film is set in the second-stage paper feeding unit 2, it is natural that the first paper information obtained by the paper information detection means, The initial value (initial value of the threshold value) of the paper information of the paper set in the second-stage paper feeding unit 2 is compared. Further, when image formation is continuously performed, the sheet information obtained by the sheet information detection unit is recorded / updated in the sheet information storage unit as a new threshold value.

また、用紙情報の初期値（閾値の初期値）と、用紙情報検知手段による１枚目の用紙情報との比較の際、用紙情報の初期値と、用紙情報検知手段により検知された１枚目の用紙の用紙情報とが著しく異なる場合、図４に示すように、各給紙部２と各種類の用紙２０とを関連付けに間違いがないかを画像形成装置（本体）の入力表示部８３に表示して装置を停止する。
例えば、普通紙用として設定した給紙部２に、使用者が誤ってＯＨＰフィルムをセットしていた場合等、用紙の種類に応じて発光量を段階的に自動調整していても、用紙情報の初期値と、用紙情報検知手段により検知された１枚目の用紙の用紙情報とが、想定範囲を超えた差が生じることから、使用者による設定ミス、あるいは使用者による用紙セットミス等が推察でき、使用者に確認を促すメッセージを表示する。
他の例としては、用紙情報の初期値と、用紙情報検知手段により検知された１枚目の用紙の用紙情報とが著しく異なったら、発光部８１の発光量を他の用紙種類に関連付けた発光量に替えて再度重送か否かを判断することが挙げられる。この場合、各給紙部２と各種類の用紙２０との関連付けに間違いがあったか否かをも同時に判断することになり、画像形成装置（本体）の入力表示部８３に、給紙部にセットした用紙種類の確認を促すメッセージを表示する。
このような一連の制御を、所望の枚数の複写が終了するまで行う。そして、再度、画像形成を行う際（スタートボタンを押動する際）は、用紙と関連付けした用紙情報の初期値（閾値の初期値）と、用紙情報検知手段による１枚目の用紙情報とを比較する。
このように実施の形態１にかかる重送検知装置を備えた画像形成装置は、搬送路Ａに設けた用紙情報検知手段が、搬送中の、１枚目の用紙の透過状態を検出して、その透過状態に基づいた用紙情報を検知し、この用紙情報と、用紙情報記憶手段に記録している用紙情報の初期値とを制御手段が比較して重送か否かを判断するから、重送検知の性能を向上させることができる。 In addition, when comparing the initial value of the paper information (the initial value of the threshold value) with the first paper information by the paper information detection unit, the initial value of the paper information and the first sheet detected by the paper information detection unit If the paper information of the paper is significantly different, as shown in FIG. 4, the input display unit 83 of the image forming apparatus (main body) indicates whether there is an error in associating each paper feed unit 2 with each type of paper 20. Display and stop the device.
For example, even if the user has accidentally set an OHP film in the paper feeding unit 2 set for plain paper, the paper information can be adjusted even if the light emission amount is automatically adjusted stepwise according to the type of paper. Since the difference between the initial value and the sheet information of the first sheet detected by the sheet information detection means exceeds the expected range, a setting error by the user or a sheet setting error by the user A message that can be inferred and prompts the user to confirm is displayed.
As another example, when the initial value of the sheet information and the sheet information of the first sheet detected by the sheet information detection unit are significantly different, the light emission amount of the light emitting unit 81 is associated with another sheet type. For example, it is determined whether or not double feeding is performed again instead of the amount. In this case, whether or not there is an error in the association between each paper feed unit 2 and each type of paper 20 is determined at the same time, and is set in the input display unit 83 of the image forming apparatus (main body) in the paper feed unit. Displays a message prompting you to confirm the paper type you have selected.
Such a series of control is performed until a desired number of copies are completed. When image formation is performed again (when the start button is pressed), the initial value of the sheet information associated with the sheet (the initial value of the threshold value) and the first sheet information by the sheet information detection unit are displayed. Compare.
As described above, in the image forming apparatus including the double feed detection device according to the first embodiment, the sheet information detection unit provided in the conveyance path A detects the transmission state of the first sheet being conveyed, Paper information based on the transmission state is detected, and the control means compares the paper information with the initial value of the paper information recorded in the paper information storage means to determine whether or not double feeding is performed. The feed detection performance can be improved.

また、制御手段は、その判断の結果が重送でないとした場合に、用紙情報検知手段で検知した用紙情報を用紙情報記憶手段に記憶して次の用紙情報の被比較値とし、後から搬送してきた用紙の用紙情報と比較するから、上記した初期値のような理論値に基づいた用紙情報ではなく、実測値に基づいた用紙情報となり、重送検知の信頼性を向上させることができる。
また、用紙収納手段を複数設けた場合、用紙情報記憶手段は、夫々の用紙収納手段毎に収納された用紙の用紙情報の初期値を記憶し、制御手段は、用紙収納手段を切り替えても対応した初期値と、用紙情報検知手段の検出による切り替え後の１枚目の用紙情報とを比較するから、異なるタイプの用紙か同じタイプの用紙かを問わず、連続的に重送検知を行うことができる。
また、複数段階の異なる発光量による発光が可能な発光部８１と受光部８２とを備えて用紙情報検知手段を構成し、用紙収納手段に応じて発光部８１の発光量を選択可能に制御するように構成したから、透過率のレンジが著しく違う用紙（例えば普通紙とＯＨＰフィルム）にも容易に対応することができる。 In addition, if the result of the determination is not double feeding, the control means stores the paper information detected by the paper information detection means in the paper information storage means as the comparison value of the next paper information, and carries it later. Since it is compared with the sheet information of the sheet that has been printed, the sheet information is based on the actual measurement value instead of the sheet information based on the theoretical value such as the above-described initial value, and the reliability of double feed detection can be improved.
Further, when a plurality of paper storage means are provided, the paper information storage means stores the initial value of the paper information of the paper stored for each paper storage means, and the control means can cope with switching of the paper storage means. Since the initial value is compared with the first paper information after the switching by the detection of the paper information detection means, it is possible to detect double feed continuously regardless of whether the paper is a different type or the same type. Can do.
In addition, a paper information detection unit is configured by including a light emitting unit 81 and a light receiving unit 82 that can emit light at different levels of light emission, and the light emission amount of the light emitting unit 81 is controlled to be selectable according to the paper storage unit. Since it is configured as described above, it is possible to easily cope with paper (for example, plain paper and OHP film) having a significantly different transmittance range.

（実施の形態２）
実施の形態１では、初期値が用紙情報記憶手段に既に記憶されていることを前提にした例であるが、この実施の形態２にかかる重送検知装置は、給紙部２に設けた第２用紙情報検出手段が、画像形成をする度（スタートボタンを操作する度）や、画像形成装置の電源を入れた直後、給紙部２に用紙２０を補充した直後などの際に、給紙トレイ２１に収納した用紙２０の誘電率を検出し、制御手段が、その誘電率から初期値を導出して、その都度、用紙情報記憶手段に記録する例である。
すなわち、実施の形態１では、用紙情報の初期値と用紙とが予め関連付けられており、各給紙部２と各種類の用紙２０とを関連付けるための入力を行うことで、「用紙種類選択」による用紙２０の選択と同時に、用紙２０と関連付けされた用紙情報の初期値や、発光部８１の発光量（各用紙の標準的な発光量）が決定されるようになっているが、実施の形態２では、「用紙種類選択」機能を実現させるために、各給紙部２と各種類の用紙２０とを関連付けるための入力を予め行い、画像形成をする度（スタートボタンを操作する度）や、画像形成装置の電源を入れた直後、給紙部２に用紙２０を補充した直後などの際に、給紙トレイ２１に収納した用紙２０の誘電率を、図２に示すように、給紙トレイ２１に設けた誘電率検出センサ８４（第２用紙情報検出手段）で検出し、制御手段が、その誘電率から初期値を導出し、その初期値と用紙（給紙部２）とを関連付けるようになっており、その他の構成、動作は、実施の形態１と同じでるため、詳細な説明は省略する。
この実施の形態２にかかる重送検知装置によれば、給紙トレイ２１に収納した用紙２０の誘電率を誘電率検出センサ８４が検出し、その誘電率から導出した初期値と、その給紙トレイ２１に収納した用紙（給紙部２）とを直接関連付けるから、重送検知自体の精度を高めることができる。
以上、本実施の形態を説明したが、上述した実施の形態は、本発明の好適な実施の形態の一例を示すものであり、本発明はそれに限定されるものではなく、その要旨を逸脱しない範囲内において、種々変形実施が可能である。 (Embodiment 2)
The first embodiment is an example on the assumption that the initial value is already stored in the paper information storage unit. However, the double feed detection device according to the second embodiment is provided in the paper feed unit 2. 2 When the sheet information detection unit performs image formation (every time the start button is operated), immediately after the image forming apparatus is turned on, or immediately after the sheet 20 is replenished to the sheet feeding unit 2, In this example, the dielectric constant of the paper 20 stored in the tray 21 is detected, and the control means derives an initial value from the dielectric constant and records it in the paper information storage means each time.
That is, in the first embodiment, the initial value of the paper information and the paper are associated in advance, and “paper type selection” is performed by performing input for associating each paper feed unit 2 with each type of paper 20. At the same time as the selection of the paper 20 by, the initial value of the paper information associated with the paper 20 and the light emission amount of the light emitting unit 81 (standard light emission amount of each paper) are determined. In the second embodiment, in order to realize the “paper type selection” function, an input for associating each paper feed unit 2 with each type of paper 20 is performed in advance and image formation is performed (every time the start button is operated). When the image forming apparatus is turned on, or immediately after the paper 20 is replenished to the paper feed unit 2, the dielectric constant of the paper 20 stored in the paper feed tray 21 is supplied as shown in FIG. Dielectric constant detection sensor 84 (first) provided on the paper tray 21 Paper information detection means), and the control means derives an initial value from the dielectric constant, and associates the initial value with the paper (paper feed unit 2). Since it is the same as Embodiment 1, detailed description is abbreviate | omitted.
According to the double feed detection device according to the second embodiment, the dielectric constant detection sensor 84 detects the dielectric constant of the paper 20 stored in the paper feed tray 21, and the initial value derived from the dielectric constant and the paper feed. Since the paper (paper feed unit 2) stored in the tray 21 is directly associated, the accuracy of double feed detection itself can be improved.
Although the present embodiment has been described above, the above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto and does not depart from the gist thereof. Various modifications can be made within the range.

本実施の形態にかかる重送検知装置を備えた画像形成装置の概略構成図である。1 is a schematic configuration diagram of an image forming apparatus including a double feed detection device according to an embodiment. 用紙情報検知手段の配設を示した模式図である。FIG. 5 is a schematic diagram showing the arrangement of paper information detection means. 用紙情報設定手段の表示例を示した模式図である。FIG. 6 is a schematic diagram illustrating a display example of a paper information setting unit. 用紙情報設定手段の表示例を示した模式図である。FIG. 6 is a schematic diagram illustrating a display example of a paper information setting unit.

符号の説明Explanation of symbols

Ａ…搬送路 ａ１…ガイド材 ａ２…開口部 ２…給紙部 ２０…用紙 ８１…発光部 ８２…受光部 ８３…入力表示部 A ... Conveying path a1 ... Guide material a2 ... Opening part 2 ... Paper feeding part 20 ... Paper 81 ... Light emitting part 82 ... Light receiving part 83 ... Input display part

Claims (11)

用紙収納手段から搬送路に搬送される用紙が複数枚重なった状態で搬送される重送か否かを検知、判定する重送検知装置であって、
前記用紙収納手段に収納される前記用紙と関連付けられた用紙情報の初期値が記憶されると共に前記用紙情報の更新内容が記憶される用紙情報記憶手段と、
前記搬送路に設けられ、搬送中の前記用紙の透過状態を検出してその透過状態に基づいた前記用紙情報を検知する用紙情報検知手段と、
該用紙情報検知手段で検知された１枚目の前記用紙情報と、前記用紙情報の初期値とを比較させて重送か否かを判断すると共に、重送でないと判断した場合に、前記用紙情報検知手段で検知された前記用紙情報を前記用紙情報記憶手段に更新記憶させて次の重送判断の被比較値とする制御手段と、
を備えたことを特徴とする重送検知装置。 A multi-feed detection device that detects and determines whether or not a multi-feed is transported in a state where a plurality of sheets of paper are transported from a paper storage means to a transport path,
Paper information storage means for storing an initial value of paper information associated with the paper stored in the paper storage means and storing the updated contents of the paper information;
Paper information detection means provided in the transport path for detecting the transmission state of the paper being transported and detecting the paper information based on the transmission state;
When the paper information of the first sheet detected by the paper information detection means is compared with the initial value of the paper information to determine whether or not it is double feed, the paper information Control means for updating and storing the paper information detected by the information detection means in the paper information storage means to be a comparison value for the next double feed determination;
A double feed detection device comprising: 前記用紙収納手段は、前記用紙の送り出しを切り替え可能に複数設けられると共に、夫々の前記用紙収納手段から搬送される夫々の前記用紙は前記搬送路に搬送可能に構成され、
前記用紙情報記憶手段は、夫々の前記用紙収納手段毎に収納される用紙毎に関連づけられた前記初期値が記憶され、
前記制御手段は、前記用紙収納手段を切り替える度に、切り替えられた前記用紙と関連付けた前記初期値を用いて１枚目の前記用紙情報との比較をさせて重送か否かを判断することを特徴とする請求項１記載の重送検知装置。 A plurality of the paper storage means are provided so as to be able to switch the delivery of the paper, and each of the paper transported from each of the paper storage means is configured to be transportable to the transport path,
The paper information storage means stores the initial value associated with each paper stored in each of the paper storage means,
Whenever the paper storage means is switched, the control means makes a comparison with the paper information of the first sheet by using the initial value associated with the switched paper and determines whether or not double feeding. The multifeed detection device according to claim 1. 前記用紙情報検知手段は、発光部と受光部とが前記搬送路を挟んで対向するように配設されると共に、前記用紙の種類毎に前記発光部の発光量を関連付けて、複数設けられた前記用紙収納手段の切り替えに対応して前記発光部の発光量を調整可能に構成されていることを特徴とする請求項２記載の重送検知装置。   A plurality of the paper information detection means are provided so that the light emitting unit and the light receiving unit are opposed to each other with the conveyance path interposed therebetween, and the light emission amount of the light emitting unit is associated with each paper type. 3. The multifeed detection device according to claim 2, wherein the light emission amount of the light emitting unit is adjustable in accordance with switching of the paper storage means. 前記用紙情報検知手段は、前記発光量の調整を入力可能に構成されていることを特徴とする請求項３記載の重送検知装置。   4. The double feed detection device according to claim 3, wherein the paper information detection means is configured to be able to input the adjustment of the light emission amount. 夫々の前記用紙収納手段と関連付けられ、前記用紙を選択させる用紙情報設定手段を備えたことを特徴とする請求項２乃至４の何れか一項に記載の重送検知装置。   5. The multifeed detection device according to claim 2, further comprising a sheet information setting unit that is associated with each of the sheet storage units and that selects the sheet. 前記制御手段は、前記用紙情報検知手段により検知された１枚目の前記用紙の前記用紙情報と前記初期値とが著しく異なる場合、前記用紙収納手段と前記用紙とを関連付けに間違いがないかを報知させる報知手段を備えたことを特徴とする請求項１乃至５の何れか一項に記載の重送検知装置。   If the paper information of the first sheet detected by the paper information detection means is significantly different from the initial value, the control means determines whether there is an error in associating the paper storage means with the paper. The multifeed detection device according to claim 1, further comprising a notification unit that performs notification. 前記制御手段は、初期値としての前記用紙情報が、前記用紙情報検知手段により検知された１枚目の前記用紙の前記用紙情報と著しく異なる場合、前記発光部の発光量を替えて再度重送か否かを判断することを特徴とする請求項３乃至５の何れか一項に記載の重送検知装置。   When the paper information as an initial value is significantly different from the paper information of the first paper detected by the paper information detection means, the control means changes the light emission amount of the light emitting unit and double-feeds again. 6. The multifeed detection device according to claim 3, wherein the multifeed detection device determines whether or not. 初期値としての前記用紙情報は、前記用紙の誘電率に基づいていることを特徴とする請求項１乃至７の何れか一項に記載の重送検知装置。   The multi-feed detection apparatus according to claim 1, wherein the sheet information as an initial value is based on a dielectric constant of the sheet. 前記用紙収納手段に設けられ、該用紙収納手段に収納された前記用紙の誘電率を検出する第２用紙情報検出手段を備え、
前記制御手段は、前記第２用紙情報検出手段で検出された前記誘電率に基づいて前記初期値を導出させて前記用紙情報記憶手段に記憶させることを特徴とする請求項１乃至８の何れか一項に記載の重送検知装置。 A second paper information detecting means provided in the paper storage means for detecting a dielectric constant of the paper stored in the paper storage means;
9. The control unit according to claim 1, wherein the control unit derives the initial value based on the dielectric constant detected by the second sheet information detection unit and stores the initial value in the sheet information storage unit. The double feed detection device according to one item. 前記用紙情報検知手段は、ジャム信号を出力するジャム検知手段を兼ねており、前記用紙情報検知手段が所定時間に前記用紙を検出しないとき、前記制御手段は、ジャム信号が出力されたこととみなすことを特徴とする請求項１乃至９の何れか一項に記載の重送検知装置。   The paper information detection means also serves as a jam detection means for outputting a jam signal. When the paper information detection means does not detect the paper at a predetermined time, the control means considers that a jam signal has been output. The multifeed detection device according to any one of claims 1 to 9, wherein 請求項１乃至１０の何れか一項に記載の重送検知装置と電子写真方式の画像形成手段とを備えたことを特徴とする画像形成装置。   An image forming apparatus comprising: the double feed detection device according to claim 1; and an electrophotographic image forming unit.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015129823A (en) * 2014-01-07 2015-07-16 コニカミノルタ株式会社 Damage amount determination apparatus, image forming apparatus, damage amount determination program, and damage amount determination method
US9085428B2 (en) 2012-12-25 2015-07-21 Ricoh Company, Ltd. Multi-feed judging device, image forming apparatus, multi-feed judging method and multi-feed judging program
US9723165B1 (en) 2016-01-22 2017-08-01 S-Printing Solution Co., Ltd. Image forming apparatus

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07215537A (en) * 1994-02-07 1995-08-15 Ricoh Co Ltd Document double feed detecting device mounted on automatic document conveyor
JPH09113230A (en) * 1995-10-13 1997-05-02 Kofu Nippon Denki Kk Device for regulating generated light quantity of medium detecting sensor of printer
JP2001124514A (en) * 1999-10-25 2001-05-11 Ricoh Co Ltd Optical sensor and image former
JP2006321215A (en) * 2005-01-07 2006-11-30 Ricoh Co Ltd Medium discrimination device, image forming apparatus, program, and recording medium
JP2007021779A (en) * 2005-07-12 2007-02-01 Canon Inc Image forming apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07215537A (en) * 1994-02-07 1995-08-15 Ricoh Co Ltd Document double feed detecting device mounted on automatic document conveyor
JPH09113230A (en) * 1995-10-13 1997-05-02 Kofu Nippon Denki Kk Device for regulating generated light quantity of medium detecting sensor of printer
JP2001124514A (en) * 1999-10-25 2001-05-11 Ricoh Co Ltd Optical sensor and image former
JP2006321215A (en) * 2005-01-07 2006-11-30 Ricoh Co Ltd Medium discrimination device, image forming apparatus, program, and recording medium
JP2007021779A (en) * 2005-07-12 2007-02-01 Canon Inc Image forming apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9085428B2 (en) 2012-12-25 2015-07-21 Ricoh Company, Ltd. Multi-feed judging device, image forming apparatus, multi-feed judging method and multi-feed judging program
JP2015129823A (en) * 2014-01-07 2015-07-16 コニカミノルタ株式会社 Damage amount determination apparatus, image forming apparatus, damage amount determination program, and damage amount determination method
US9568876B2 (en) 2014-01-07 2017-02-14 Konica Minolta, Inc. Damage amount determination device, image forming device, computer-readable recording medium storing damage amount determination program, and damage amount determination method
US9723165B1 (en) 2016-01-22 2017-08-01 S-Printing Solution Co., Ltd. Image forming apparatus

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