JPH0818718B2 - Paper feeding device of image forming apparatus - Google Patents
Paper feeding device of image forming apparatusInfo
- Publication number
- JPH0818718B2 JPH0818718B2 JP62262262A JP26226287A JPH0818718B2 JP H0818718 B2 JPH0818718 B2 JP H0818718B2 JP 62262262 A JP62262262 A JP 62262262A JP 26226287 A JP26226287 A JP 26226287A JP H0818718 B2 JPH0818718 B2 JP H0818718B2
- Authority
- JP
- Japan
- Prior art keywords
- paper
- roller
- feeding
- sheet
- double feed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、静電写真複写機やプリンターなどの画像形
成装置に装備される給紙装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a sheet feeding device provided in an image forming apparatus such as an electrostatographic copying machine or a printer.
上記画像形成装置における給紙装置として、クラッチ
を介して給紙方向に駆動回転自在な搬送ローラと、駆動
手段により反給紙方向にのみ駆動回転自在な重送防止用
ローラとの対（重送防止手段）を、給紙部の下流側に配
置して、前記給紙部から用紙が二枚重ねの状態で前記重
送防止手段に送り込まれた際に、前記搬送ローラ側の用
紙のみを給紙させるように構成する一方、前記重送防止
用ローラを、重送防止とは無関係に時々、または重送防
止に関連させて、反給紙方向に回転させて、当該重送防
止用ローラの前記搬送ローラに対するニップ面の偏摩耗
を抑止させることで、重送防止の機能を長期にわたって
良好に維持させるようにしたものがある。As a sheet feeding device in the above-mentioned image forming apparatus, a pair of a conveying roller that is driven and rotatable in a sheet feeding direction via a clutch and a double feed prevention roller that is driven and rotatable only in a direction opposite to the sheet feeding direction by a driving unit (double feeding) (Prevention means) is arranged on the downstream side of the paper feed section so that when the two sheets of paper are fed from the paper feed section to the double feed prevention means, only the paper on the conveyance roller side is fed. On the other hand, the double-feeding prevention roller is rotated in the direction opposite to the sheet feeding direction regardless of the double-feeding prevention sometimes or in association with the double-feeding prevention to convey the double-feeding prevention roller. There is a structure in which uneven feeding of the nip surface with respect to the roller is suppressed so that the function of preventing double feeding is favorably maintained for a long period of time.
そして更に、前記給紙部から排紙部にわたる給紙経路
途中にジャム検出手段を設けて、該ジャム検出手段から
の情報を基にして前記給紙部から排紙部に至る給紙駆動
系を駆動停止させるようにし、ジャムの発生原因となっ
た用紙を給紙経路から取り除かせるようにしている。Further, a jam detecting unit is provided in the middle of the paper feeding path from the paper feeding unit to the paper discharging unit, and a paper feeding drive system from the paper feeding unit to the paper discharging unit is provided based on the information from the jam detecting unit. The drive is stopped so that the paper causing the jam can be removed from the paper feeding path.
上記のジャム検出手段は、前記給紙部の直下流箇所や
転写部の近傍、その他定着部や排紙部の近傍などに配設
され、かつ一般に、ジャムが発生した際にそのジャムの
発生箇所をランプの点灯などで表示するようにしてい
る。The above-mentioned jam detecting means is disposed immediately downstream of the paper feeding unit, near the transfer unit, and near the fixing unit and the paper discharging unit, and generally, when a jam occurs, the place where the jam occurs. Is displayed by turning on the lamp.
而して、例えば定着部近傍のジャム検出手段がジャム
の発生を検出した場合、そのジャム表示に基づいて定着
部近傍でジャムした用紙が搬送経路から取り除かれるの
であるが、その際、前記搬送ローラと重送防止用ローラ
との間に用紙が噛み込まれていると、その用紙も取り除
いておく必要がある。Thus, for example, when the jam detection unit near the fixing unit detects the occurrence of a jam, the jammed paper near the fixing unit is removed from the conveyance path based on the jam display. If a sheet is caught between the double feed prevention roller and the sheet, it is necessary to remove the sheet as well.
しかし、この用紙には前記重送防止手段での摩擦力が
加わっていることから、当該用紙を重送防止手段から取
り除くことが非常に困難である。However, it is very difficult to remove the sheet from the double feed prevention means because the sheet is subjected to the frictional force of the double feed prevention means.
本発明は、上記の実情に鑑みて成されたものであっ
て、本来備える重送防止のための構成を有効に利用した
コスト的に安価で且つ極めて合理的な改良によって、上
記従来の欠点を解消することを目的としている。The present invention has been made in view of the above circumstances, and is a cost-effective and extremely rational improvement that effectively utilizes a configuration for preventing double-feeding that is originally provided. The purpose is to eliminate it.
上記の目的を達成するために本発明は、クラッチを介
して給紙方向に駆動回転自在な搬送ローラと、駆動手段
により反給紙方向にのみ駆動回転自在な重送防止用ロー
ラとの対を、給紙部の下流側に配置すると共に、前記給
紙部から排紙部にわたる搬送経路途中に配置したジャム
検出手段からの情報を基にして、前記クラッチを切ると
共に、前記搬送ローラを停止させ、さらに前記駆動手段
により重送防止用ローラを反給紙方向に回転させる制御
手段を設け、更に、前記搬送ローラと重送防止用ローラ
との対の直上流側の給紙経路部に前記搬送ローラと重送
防止用ローラ間で用紙が噛み込まれていることを検知す
る用紙検知手段を設け、ジャム発生時に前記用紙検知手
段が用紙を検知すると前記制御手段により前記重送防止
用ローラを反給紙方向に回転させる点に特徴がある。In order to achieve the above-mentioned object, the present invention provides a pair of a conveying roller which is rotatable in a sheet feeding direction via a clutch and a double feed preventing roller which is rotatable by a driving means only in a non-sheet feeding direction. , Based on the information from the jam detecting means arranged on the downstream side of the paper feeding unit and on the way of the conveying path from the paper feeding unit to the paper discharging unit, the clutch is disengaged and the conveying roller is stopped. Further, a control means for rotating the double feed prevention roller in the anti-feeding direction by the driving means is provided, and further, the conveyance is performed to a sheet feeding path portion on the upstream side of the pair of the conveyance roller and the double feed prevention roller. A paper detection unit that detects that the paper is caught between the roller and the double-feed prevention roller is provided. When the paper detection unit detects the paper when a jam occurs, the control unit reverses the double-feed prevention roller. Paper feeding method It is characterized in that rotate to.
上記の特徴構成によれば、給紙部から排紙部にわたる
搬送経路途中においてジャムが発生すると、前記重送防
止用ローラが反給紙方向に回転することで、該重送防止
用ローラと搬送ローラとの間に噛み込まれた用紙が自動
的に給紙部に戻される。特に、本発明では、搬送ローラ
と重送防止用ローラとの対の直上流側の給紙経路部に前
述したような用紙検知手段を設けているので、給紙経路
途中でジャムが発生し且つそのとき前記搬送ローラと重
送防止用ローラ間に用紙が噛み込まれていると、前記重
送防止用ローラの反給紙方向への回転により、前記用紙
検知手段が用紙を検出しなくなるまで、前記噛み込まれ
ている用紙をカセットケースに向けて反給紙方向に戻す
ことができる。According to the above characteristic configuration, when a jam occurs in the middle of the conveyance path from the paper feed unit to the paper discharge unit, the double feed prevention roller rotates in the direction opposite to the paper feed direction, and the double feed prevention roller and the conveyance The paper bitten between the rollers is automatically returned to the paper feed unit. Particularly, in the present invention, since the above-described paper detection means is provided in the paper feed path portion on the upstream side of the pair of the conveyance roller and the double feed prevention roller, a jam occurs in the middle of the paper feed path and At this time, if the paper is caught between the transport roller and the double feed prevention roller, the paper is not detected by the paper detection means due to the rotation of the double feed prevention roller in the direction opposite to the paper feed direction. The jammed paper can be returned toward the cassette case in the opposite paper feed direction.
以下、本発明の実施例を図面に基づいて説明すると、
第２図は画像形成装置の一例である片面複写と両面複写
の選択が可能な静電写真複写機の概略を示し、原稿の自
動給紙装置１を備えた原稿押え２を複写機本体３の上部
に設けると共に、該複写機本体３に感光体４を横架し、
かつ当該感光体４のまわりに、帯電装置５、現像装置
６、転写装置７、用紙分離装置８、クリーニング装置９
を、その順に感光体４の回転方向に配置すると共に、前
記複写機本体３の上部空間に光学系移動式の露光装置10
を配置し、さらに、手差し部11またはカセットケース12
内の用紙を前記転写装置７に搬送する給紙搬送装置13
と、転写・分離後の用紙を定着装置14に搬送する排紙搬
送装置15、および、定着後の用紙をトレイ16に排出する
排紙ローラ対17を設けてある。Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 2 shows an outline of an electrostatographic copying machine which is an example of an image forming apparatus and is capable of selecting one-sided copying and two-sided copying. The document holder 2 provided with an automatic document feeder 1 is attached to the copying machine main body 3. In addition to being provided on the upper part, the photoconductor 4 is horizontally mounted on the copying machine main body 3,
In addition, around the photoconductor 4, the charging device 5, the developing device 6, the transfer device 7, the paper separating device 8, and the cleaning device 9 are provided.
Are arranged in that order in the rotation direction of the photoconductor 4 and an optical system movable exposure apparatus 10 is provided in the upper space of the copying machine main body 3.
And insert the manual feed part 11 or cassette case 12
Paper feeding / conveying device 13 for conveying the paper inside to the transfer device 7.
Further, there are provided a sheet discharging and conveying device 15 that conveys the sheet after transfer and separation to the fixing device 14, and a pair of sheet discharging rollers 17 that discharges the sheet after fixing to the tray 16.
そして、前記複写機本体３の下部空間に、片面複写済
みの用紙をストックして再給紙するための再給紙装置18
を設けると共に、前記定着後の用紙を選択的に上記再給
紙装置18に排紙するスイッチバック機構19を前記定着装
置14と排紙ローラ対17との間に配置し、更に、前記再給
紙装置18に収容された片面複写後の用紙を前記給紙搬送
装置13に合流給紙する搬送装置20を設けてある。Then, in the lower space of the copying machine body 3, a sheet re-feeding device 18 for stocking and re-feeding sheets of which one side has been copied.
In addition, a switchback mechanism 19 for selectively discharging the fixed paper to the re-feeding device 18 is provided between the fixing device 14 and the discharge roller pair 17, and the re-feeding device is further provided. A conveying device 20 is provided which merges and feeds the single-sided copied sheets accommodated in the paper device 18 to the paper feeding and conveying device 13.
一方、前記カセットケース12の配置部の下方に、大容
量の用紙を収容し得るエレベーター式の大容量カセット
ケース21を設け、かつ、該大容量カセットケース21から
の用紙を前記搬送装置20に合流給紙させるための重送防
止機能を有する給紙装置22を設けて成る。On the other hand, an elevator-type large-capacity cassette case 21 capable of accommodating a large-capacity sheet is provided below the arrangement part of the cassette case 12, and the sheets from the large-capacity cassette case 21 are merged with the conveying device 20. A sheet feeding device 22 having a double feed preventing function for feeding sheets is provided.
そして更に、前記給紙装置22の給紙ローラ25による給
紙部から前記排紙ローラ対17による排紙部にわたる搬送
経路の途中、具体的には前記給紙装置22の直下流側と転
写装置７ならびに定着装置14の直上流側の夫々に、給紙
経路でのジャムを検出するジャム検出手段Ｓ…を設けて
いる。第３図を参照して、該ジャム検出手段Ｓにより導
出された紙詰まり信号は制御信号Ｂに入り、制御手段Ｂ
は前記クラッチＣをOFFさせると共に、給紙搬送装置1
3、排紙搬送装置15、合流給紙用のの搬送装置20、及
び、ストック給紙搬送装置27の駆動を停止するよう制御
する。Further, further, in the middle of the conveying path from the sheet feeding section by the sheet feeding roller 25 of the sheet feeding apparatus 22 to the sheet discharging section by the sheet discharging roller pair 17, specifically, immediately downstream of the sheet feeding apparatus 22 and the transfer apparatus. 7 and jam detecting means S for detecting a jam in the sheet feeding path are provided on the upstream side of the fixing device 14 and the fixing device 14, respectively. Referring to FIG. 3, the paper jam signal derived by the jam detecting means S enters the control signal B, and the control means B
Turns off the clutch C and feeds the paper feeding device 1
3, control is performed so as to stop driving of the sheet discharging and conveying device 15, the conveying device 20 for combined sheet feeding, and the stock sheet feeding and conveying device 27.
次に、前記大容量カセットケース21は、第１図に示す
ように、例えば2500枚と言ったオーダーの用紙を収容し
得る乗載板28を駆動昇降自在にケース本体29に設けると
共に、最上位の用紙の前端肩部に作用する分離爪（特に
なくてもよい。）30を設けて成り、そして、この大容量
カセットケース21に対する給紙装置22は、前記ケース本
体29に架設された所定範囲にわたって上下移動自在な支
軸31に設けられた給紙ローラ25と、該給紙ローラ25によ
って給紙され、前記分離爪30で分離しきれなかった用紙
を、さらに分離して前記給紙搬送装置13に給紙する重送
防止手段32から成る。Next, as shown in FIG. 1, the large-capacity cassette case 21 is provided with a loading plate 28 capable of accommodating sheets of the order of 2500 sheets, for example, on the case main body 29 so as to be able to drive up and down. Separation claws 30 (which do not need to be provided) that act on the front end shoulders of the sheets are provided, and the sheet feeding device 22 for the large-capacity cassette case 21 has a predetermined range installed on the case body 29. A paper feed roller 25 provided on a support shaft 31 that can move up and down, and paper fed by the paper feed roller 25 and not completely separated by the separation claw 30 is further separated to the paper feed and conveyance device. It comprises a multi-feed preventing means 32 for feeding the paper to 13.
前記重送防止手段32の詳しくは、第４図及び第５図に
も示すように、給紙用のガイド板（第１図参照）33の上
下に一対の上部軸34と下部軸35を配設すると共に、前記
上部軸34に伝達ギヤ36と搬送ローラ37,37を所定間隔で
設け、かつ、該上部軸34に動力断続用のクラッチＣを介
在させる。一方、大径と小径のローラ部分を交互に一体
成型して成る重送防止用ローラ38は、ジグザグの給紙経
路が形成されるように、前記大径のローラ部分間に前記
搬送ローラ37,37を入り込ませるようにして前記下部軸3
5に設けられている。また該重送防止用ローラ38を反給
紙方向に所定角度回転させるローラ回転機構39を前記下
部軸35に連設し、かつ、前記搬送ローラ37,37の摩擦抵
抗を重送防止用ローラ38の摩擦抵抗よりも大に、また、
該重送防止用ローラ38の摩擦抵抗を用紙どうしの摩擦抵
抗よりも大に設定してある。For details of the double feed preventing means 32, as shown in FIGS. 4 and 5, a pair of an upper shaft 34 and a lower shaft 35 are arranged above and below a paper feed guide plate 33 (see FIG. 1). At the same time, a transmission gear 36 and conveying rollers 37, 37 are provided on the upper shaft 34 at predetermined intervals, and a clutch C for power connection / disconnection is interposed on the upper shaft 34. On the other hand, the double feed prevention roller 38 formed by alternately molding large-diameter and small-diameter roller parts integrally forms the conveyance roller 37 between the large-diameter roller parts so that a zigzag sheet feeding path is formed. 37 so that the lower shaft 3
It is provided in 5. Further, a roller rotation mechanism 39 for rotating the double feed preventing roller 38 in a direction opposite to the sheet feeding direction by a predetermined angle is connected to the lower shaft 35, and the friction resistance of the conveying rollers 37, 37 is prevented from increasing. Greater than the friction resistance of
The frictional resistance of the double feed preventing roller 38 is set to be larger than the frictional resistance between the sheets.
そして、前記給紙ローラ25,25の支軸31にギヤ40を設
けると共に、該ギヤ40と前記伝動ギヤ36とにわたってエ
ンドレスチェーン41を巻回してあって、給紙信号を入力
して前記クラッチＣが動力伝動状態に切り換えられるこ
とによって、前記搬送ローラ37,37と給紙ローラ25とが
一体になって給紙方向に駆動回転され、かつ、該給紙ロ
ーラ25によって用紙が二枚重ねの状態で前記搬送ローラ
37,37と重送防止用ローラ38との間に送りこまれた際
に、上記摩擦抵抗の差及びローラ37,38のジグザグ形状
の配置を基にして前記搬送ローラ37,37側の用紙のみを
給紙させるように構成されている。A gear 40 is provided on the support shaft 31 of the paper feed rollers 25, 25, and an endless chain 41 is wound around the gear 40 and the transmission gear 36 to input a paper feed signal to the clutch C. Is switched to a power transmission state, the conveying rollers 37, 37 and the sheet feeding roller 25 are integrally driven and rotated in the sheet feeding direction, and the sheet feeding roller 25 allows the sheets to be stacked in a two-sheet state. Conveyor roller
When fed between the rollers 37, 37 and the double feed prevention roller 38, only the paper on the side of the rollers 37, 37 is conveyed based on the difference in friction resistance and the zigzag arrangement of the rollers 37, 38. It is configured to feed paper.
一方、前記重送防止用ローラ38を反給紙方向に回転さ
せるためのローラ回転機構39は次のように構成されてい
る。即ち、駆動手段の一例のソレノイド42を前記ケース
本体29に連設のブラケット43に設けると共に、前記下部
軸35の一端側に一方向駆動伝達手段44を介して被動部材
45を連設し、かつ、前記下部軸35と平行な軸46を介して
ベルクランク47を前記ブラケット43に回動自在に枢着す
ると共に、該ベルクランク47の水平アーム部分47aの長
孔ａに、ピンｂを介して前記ソレノイド42のスピンドル
ｆを連係させ、かつ、前記ベルクランク47の縦アーム部
分47bの長孔ｄに、ピンｅを介して前記被動部材45を連
係させて成る。On the other hand, the roller rotation mechanism 39 for rotating the double feed prevention roller 38 in the direction opposite to the sheet feeding direction is configured as follows. That is, the solenoid 42, which is an example of driving means, is provided on the bracket 43 that is continuous with the case body 29, and the driven member is provided on one end side of the lower shaft 35 via the one-way drive transmission means 44.
The bell crank 47 is rotatably pivotally attached to the bracket 43 through a shaft 46 parallel to the lower shaft 35, and a long hole a of a horizontal arm portion 47a of the bell crank 47 is provided. In addition, the spindle f of the solenoid 42 is linked with the pin b, and the driven member 45 is linked with the elongated hole d of the vertical arm portion 47b of the bell crank 47 with the pin e.
尚、前記ソレノイド42には、例えば前記大容量カセッ
トケース21から用紙を給紙するモードを選択したとき
に、該ソレノイド42を所定時間だけ励磁（ON）させる信
号が入力されるように構成されている。The solenoid 42 is configured so that, for example, when a mode for feeding a sheet from the large capacity cassette case 21 is selected, a signal for exciting (ON) the solenoid 42 for a predetermined time is input. There is.
而して、該ソレノイド42がONされると前記スピンドル
ｆがソレノイドケース内に後退する方向に駆動（第６図
に示す状態から第７図に示す状態）され、このスピンド
ルｆの直線運動が前記ベルクランク47の揺動運動に変換
されて、これに連動して前記重送防止用ローラ38が反給
紙方向に所定角度だけ回転され、前記搬送ローラ37,37
に対する該重送防止用ローラ38のニップ面が変更される
結果、該重送防止用ローラ38による重送防止の機能が良
好に維持されるのである。When the solenoid 42 is turned on, the spindle f is driven in the direction of retracting into the solenoid case (from the state shown in FIG. 6 to the state shown in FIG. 7), and the linear movement of the spindle f is The oscillating motion of the bell crank 47 is converted, and in conjunction with this, the double feed preventing roller 38 is rotated by a predetermined angle in the direction opposite to the sheet feeding direction, and the conveying rollers 37, 37
As a result of the change in the nip surface of the double feed prevention roller 38 with respect to the above, the double feed prevention function of the double feed prevention roller 38 is favorably maintained.
そして、前記ON信号を入力して所定時間を経過すると
前記ソレノイド42がOFF（消磁）され、前記被動部材45
が元の姿勢に復帰操作（第７図に示す状態から第６図に
示す状態）されるのであるが、前記下部軸35と前記被動
部材45との間に一方向駆動伝達手段44が設けられている
ので、前記被動部材45が元の姿勢に復帰操作されても前
記重送防止用ローラ38は回転することがなく、即ち、大
容量カセットケース21からの給紙モードがとられるたび
に、前記重送防止用ローラ38が反給紙方向に所定角度だ
け回転されるようになっている。Then, when a predetermined time elapses after the ON signal is input, the solenoid 42 is turned off (demagnetized), and the driven member 45
Is returned to the original posture (from the state shown in FIG. 7 to the state shown in FIG. 6). One-way drive transmission means 44 is provided between the lower shaft 35 and the driven member 45. Therefore, even if the driven member 45 is operated to return to the original posture, the double feed prevention roller 38 does not rotate, that is, every time the paper feed mode from the large capacity cassette case 21 is taken, The double feed prevention roller 38 is adapted to be rotated in the opposite paper feed direction by a predetermined angle.
上記構成の給紙装置22において、前記重送防止手段32
の直上流側の給紙経路部分にセンサー（用紙検知手段）
S1を設けてある。このセンサーS1は、搬送ローラ37,37
と重送防止用ローラ38間で用紙が噛み込まれていること
を検知するためのものであり、つまり、前記重送防止手
段32における紙詰まり状態が、前記ソレノイド42の作動
により解消されるに至ったことを検知する。In the paper feeding device 22 having the above-mentioned configuration, the double feeding preventing means 32
Sensor (paper detection means) in the paper feed path part immediately upstream of the
S 1 is provided. This sensor S 1 is
It is for detecting that the sheet is caught between the double feed prevention roller 38 and the double feed prevention roller 38, that is, the paper jam state in the double feed prevention means 32 is eliminated by the operation of the solenoid 42. Detect that it has arrived.
すなわち、給紙経路途中でジャムが発生し且つそのと
き前記重送防止手段32に用紙が噛み込まれていると、前
記制御手段Ｂによって前記給紙駆動系（13,15,20）と前
記ストック給紙駆動系（27）を駆動停止させると同時
に、第４図ならびに第6,7図に示すように、制御手段Ｂ
によって前記クラッチＣを切り且つ前記ソレノイド42の
ON,OFFを繰り返し行わせて前記重送防止用ローラ38を反
給紙方向に間欠回転させ、この重送防止用ローラ38の回
転により、前記用紙を介して前記駆動系が断たれた前記
搬送ローラ37,37と給紙ローラ25とを反給紙方向に回転
させて、前記センサーS1が用紙を検出しなくなるまで、
前記重送防止手段32に噛み込まれている用紙を前記大容
量カセットケース21に向けて反給紙方向に戻すように構
成してある。要するに、本発明によると、ジャム発生時
に、用紙検知手段S1が用紙を検知した場合のみ、重送防
止用ローラ38を反給紙方向へ回転させることができ、且
つ用紙検知手段S1がOFFされ、噛み込まれた用紙がカセ
ットケース側へ確実に戻された時点で、重送防止用ロー
ラ38を停止させることができるので、不要な動作を省略
することが可能である。つまり、用紙検知手段S1を設け
ることにより、ジャムしている用紙とは別で、ジャム発
生時に搬送ローラ37と重送防止用ローラ38間で噛み込ま
れている用紙（重送されている用紙、または、ジャムし
ている用紙以後に通常給紙されている途中にある用紙）
をカセット側へ送り返してやることで、ジャム処理後、
複写動作を再開した時に、用紙を噛み込んだまま給紙さ
れて再びジャムが発生するのを防止できる。That is, when a jam occurs in the middle of the paper feed path and the paper is caught in the double feed prevention means 32 at that time, the control means B causes the paper feed drive system (13, 15, 20) and the stock. At the same time as stopping the driving of the paper feed drive system (27), as shown in FIGS.
The clutch C is disengaged by the solenoid 42
The ON / OFF operation is repeatedly performed to intermittently rotate the double feed prevention roller 38 in the opposite paper feed direction, and the rotation of the double feed prevention roller 38 causes the conveyance system in which the drive system is cut off via the sheet. Rotate the rollers 37, 37 and the paper feed roller 25 in the opposite paper feed direction until the sensor S 1 no longer detects the paper.
The sheet caught in the double feed preventing means 32 is configured to be returned in the direction opposite to the sheet feeding direction toward the large capacity cassette case 21. In short, according to the present invention, the double feed preventing roller 38 can be rotated in the direction opposite to the sheet feeding direction only when the sheet detecting means S 1 detects the sheet at the time of the jam, and the sheet detecting means S 1 is turned off. Since the double feed prevention roller 38 can be stopped at the time when the jammed paper is reliably returned to the cassette case side, it is possible to omit an unnecessary operation. In other words, by providing the sheet detecting means S 1 , the sheet jammed between the conveyance roller 37 and the double feed preventing roller 38 at the time of the occurrence of the jam (the sheet that has been double fed is separated from the jammed sheet. , Or paper that is being fed normally after the jammed paper)
By sending back to the cassette side, after jam processing,
When the copying operation is resumed, it is possible to prevent the paper from being jammed and jammed again.
尚、上記制御手段Ｂによる用紙の戻し搬送の形態は一
例であって、例えば、前記重送防止手段32の直上流側に
用紙先端を検出するセンサーを設けると共に、該センサ
ーが用紙先端を検出したことの情報を基にして作動する
パルス発信器を設け、かつ、前記用紙先端が前記重送防
止手段32に最も近いジャム検出手段Ｓを通過したことの
検出結果によって前記パルス発信器をリセットさせるよ
うにし、もって、ジャム発生時における用紙の前記重送
防止手段32による用紙噛み込み長さをパルス数を基に検
出させるようにして、その長さに対応させて必要量だけ
前記重送防止用ローラ38を反給紙方向に回転させる形態
や、あるいは、用紙の搬送方向の長さと、前記ソレノイ
ド42が１回ON,OFFした際の重送防止用ローラ38の反給紙
方向への回転周長を基にして、前記重送防止手段32に噛
み込まれている用紙の噛み込み長さの如何にかかわら
ず、前記重送防止用ローラ38を反給紙方向に回転させる
形態などに変形可能である。Note that the form of the return and conveyance of the paper by the control means B is an example, and for example, a sensor for detecting the front end of the paper is provided immediately upstream of the double feed prevention means 32, and the sensor detects the front end of the paper. A pulse oscillator that operates based on this information is provided, and the pulse oscillator is reset according to the detection result that the leading edge of the sheet has passed the jam detecting unit S closest to the double feed preventing unit 32. Therefore, the length of the sheet jamming of the sheet by the double feed preventing means 32 at the time of jam occurrence is detected based on the number of pulses, and the double feed preventing roller is provided in a required amount corresponding to the length. The form in which 38 is rotated in the reverse paper feed direction, or the length in the paper conveyance direction, and the rotation perimeter of the double feed prevention roller 38 in the reverse paper feed direction when the solenoid 42 is turned on and off once Based on The regardless of double feed preventing means 32 to the chewing crowded with which bite length of the paper how is deformable like the form of rotating the prevention roller 38 the double feed in a counter sheet feeding direction.
また、前記重送防止用ローラ38を所定角度回動させる
ための駆動手段としてソレノイド42を例示したが、これ
をモータなどに変更でき、かつ上記の実施例では、大容
量カセットケース21の給紙装置22を対象にして説明した
が、両面複写のための再給紙用の給紙装置18や、手差し
部11あるいはカセットケース12における給紙装置を実施
対象にすることができ、その他、複写機に限らずプリン
ターやファクシミリなど各種の画像形成装置における給
紙装置を本発明の実施対象にすることができる。Further, the solenoid 42 is illustrated as a drive means for rotating the double feed preventing roller 38 by a predetermined angle, but this may be changed to a motor or the like, and in the above embodiment, the large capacity cassette case 21 is fed with paper. Although the description has been made for the device 22, the paper feeding device 18 for re-paper feeding for double-sided copying, and the paper feeding device in the manual feed section 11 or the cassette case 12 can be implemented. However, the present invention can be applied to paper feeding devices in various image forming apparatuses such as printers and facsimiles.
以上説明したように本発明による画像形成装置の給紙
装置は、当該給紙装置が本来備えるところの重送防止の
ための構成を有効に利用した合理的な改良によって、重
送防止手段に噛み込まれた用紙を自動的に給紙部に戻す
ように成されたものであって、従来の専用モータによる
構成に比べてコスト的に安価に用紙の自動排除を達成で
きるに至ったのである。特に、前記搬送ローラと重送防
止用ローラとの対の直上流側の給紙経路部に、前記搬送
ローラと重送防止用ローラ間で用紙が噛み込まれている
ことを検知する用紙検知手段を設けているので、給紙経
路途中でジャムが発生し且つそのとき前記搬送ローラと
重送防止用ローラ間に用紙が噛み込まれていると、前記
重送防止用ローラの反給紙方向への回転により、用紙検
知手段が用紙を検出しなくなるまで、前記噛み込まれて
いる用紙をカセットケースに向けて反給紙方向に戻し、
よって、用紙の噛み込みの解除を確実に行える利点を有
する。As described above, the sheet feeding device of the image forming apparatus according to the present invention is engaged with the double feeding preventing means by a rational improvement that effectively utilizes the structure for preventing the double feeding which the sheet feeding device originally has. It is configured to automatically return the inserted paper to the paper feed section, and it has been possible to achieve automatic paper removal at a lower cost than the conventional dedicated motor configuration. In particular, a sheet detection unit that detects that a sheet is caught between the conveyance roller and the double feed prevention roller in the sheet feeding path portion on the upstream side of the pair of the conveyance roller and the double feed prevention roller. Therefore, if a jam occurs in the middle of the sheet feeding path and the sheet is caught between the conveying roller and the double feed prevention roller at that time, the double feed prevention roller moves in the direction opposite to the sheet feeding direction. By the rotation of the, until the paper detection means no longer detects the paper, return the jammed paper in the direction opposite to the paper feed direction toward the cassette case,
Therefore, there is an advantage that the jamming of the paper can be surely released.
第１図は給紙装置の詳細図、第２図は画像形成装置の一
例の静電写真複写機の概略縦断側面図、第３図はブロッ
ク図、第４図は給紙装置の斜視図、第５図は給紙装置の
展開図、第６図及び第７図は重送防止用ローラの反給紙
方向への回転と共に用紙の戻し状態を示す説明図であ
る。 37……搬送ローラ、38……重送防止用ローラ、42……駆
動手段（ソレノイド）、Ｂ……制御手段、Ｃ……クラッ
チ、Ｓ……ジャム検出手段、S1……用紙検知手段。1 is a detailed view of a sheet feeding device, FIG. 2 is a schematic vertical sectional side view of an electrostatographic copying machine as an example of an image forming apparatus, FIG. 3 is a block diagram, and FIG. 4 is a perspective view of the sheet feeding device. FIG. 5 is a development view of the sheet feeding device, and FIGS. 6 and 7 are explanatory views showing a state of returning the sheet as the double feed preventing roller rotates in the direction opposite to the sheet feeding direction. 37 ...... conveying roller, 38 ...... double feed prevention roller, 42 ...... driving means (solenoid), B ...... control unit, C ...... clutch, S ...... jam detecting means, S 1 ...... sheet detection means.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭58−11437（ＪＰ，Ａ) 特開 昭59−102731（ＪＰ，Ａ) 実開 昭59−159652（ＪＰ，Ｕ) ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-11437 (JP, A) JP-A-59-102731 (JP, A) Practical use Sho-59-159652 (JP, U)
Claims (1)
な搬送ローラと、駆動手段により反給紙方向にのみ駆動
回転自在な重送防止用ローラとの対を、給紙部の下流側
に配置すると共に、前記給紙部から排紙部にわたる搬送
経路途中に配置したジャム検出手段からの情報を基にし
て、前記クラッチを切ると共に、前記搬送ローラを停止
させ、さらに前記駆動手段により重送防止用ローラを反
給紙方向に回転させる制御手段を設け、しかも、前記搬
送ローラと重送防止用ローラとの対の直上流側の給紙経
路部に前記搬送ローラと重送防止用ローラ間で用紙が噛
み込まれていることを検知する用紙検知手段を設け、ジ
ャム発生時に前記用紙検知手段が用紙を検知すると前記
制御手段により前記重送防止用ローラを反給紙方向に回
転させることを特徴とする画像形成装置の給紙装置。1. A downstream side of a sheet feeding unit, which comprises a pair of a conveyance roller that is rotatable in a sheet feeding direction via a clutch and a double feed preventing roller that is driven and rotatable only in an opposite sheet feeding direction by a driving unit. In addition, the clutch is disengaged and the conveying roller is stopped based on information from the jam detecting means arranged in the middle of the conveying path extending from the paper feeding portion to the paper discharging portion, and further the driving means is used to A control means for rotating the feeding prevention roller in the direction opposite to the sheet feeding direction is provided, and further, the feeding roller and the feeding prevention roller are provided in the feeding path portion immediately upstream of the pair of the feeding roller and the feeding prevention roller. Paper detecting means is provided for detecting that the paper is caught between the sheets, and when the paper detecting means detects the paper when a jam occurs, the control means rotates the double feed preventing roller in the counter paper feeding direction. Special Sheet feeding device of an image forming apparatus according to.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62262262A JPH0818718B2 (en) | 1987-10-17 | 1987-10-17 | Paper feeding device of image forming apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62262262A JPH0818718B2 (en) | 1987-10-17 | 1987-10-17 | Paper feeding device of image forming apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01104538A JPH01104538A (en) | 1989-04-21 |
| JPH0818718B2 true JPH0818718B2 (en) | 1996-02-28 |
Family
ID=17373337
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62262262A Expired - Fee Related JPH0818718B2 (en) | 1987-10-17 | 1987-10-17 | Paper feeding device of image forming apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0818718B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4017531B2 (en) * | 2003-01-17 | 2007-12-05 | 株式会社リコー | Image forming apparatus |
| WO2011007406A1 (en) * | 2009-07-13 | 2011-01-20 | キヤノン株式会社 | Sheet feed device and image forming device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5811437A (en) * | 1981-07-08 | 1983-01-22 | Ricoh Co Ltd | Paper feeder |
| JPS59159652U (en) * | 1983-04-09 | 1984-10-26 | 株式会社リコー | Copy machine paper feed device |
-
1987
- 1987-10-17 JP JP62262262A patent/JPH0818718B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01104538A (en) | 1989-04-21 |
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