JPH0826505A - Paper feeder - Google Patents
Paper feederInfo
- Publication number
- JPH0826505A JPH0826505A JP16521894A JP16521894A JPH0826505A JP H0826505 A JPH0826505 A JP H0826505A JP 16521894 A JP16521894 A JP 16521894A JP 16521894 A JP16521894 A JP 16521894A JP H0826505 A JPH0826505 A JP H0826505A
- Authority
- JP
- Japan
- Prior art keywords
- paper
- sheet
- roller
- paper feed
- feeding
- 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.)
- Withdrawn
Links
Landscapes
- Sheets, Magazines, And Separation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、簡単な構造からなる給
紙ロール位置制御機構を備えた給紙装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device having a sheet feeding roll position control mechanism having a simple structure.
【０００２】[0002]
【従来の技術】従来より、多数枚の定形用紙を給紙カセ
ットに収納して用いるプリンタ、複写機等の画像形成装
置（以下、本体装置という）においては、給紙カセット
に収納された用紙を画像形成部へ給紙するために、例え
ば図４(a) に示すように、用紙カセット１の用紙給送方
向前端の本体装置内に、周面が弾性部材からなる給紙ロ
ーラ２及び平面な摩擦面を備えた捌き部材３を配してな
る給紙装置がある。この給紙装置は、給紙ローラ２が時
計回り方向に間歇的に回転して用紙カセット１から用紙
Ｐを取り出し、捌き部材３で一枚毎に分離してガイド４
を介し画像形成部に給送する。用紙カセット１の底板５
は、不図示の付勢部材により下から上方へ加圧されてお
り、これにより底板５上に積載されている用紙Ｐの給送
方向前端が一定圧力で給紙ロール２に圧接されるように
なっている。2. Description of the Related Art Conventionally, in an image forming apparatus (hereinafter referred to as a main body apparatus) such as a printer or a copying machine, which stores a large number of fixed sheets in a sheet feeding cassette, the sheets stored in the sheet feeding cassette are In order to feed the sheet to the image forming unit, as shown in FIG. 4A, for example, as shown in FIG. 4A, a sheet feeding roller 2 having a peripheral surface made of an elastic member and a flat surface are provided in the main body apparatus at the front end of the sheet cassette 1 in the sheet feeding direction. There is a sheet feeding device provided with a separating member 3 having a friction surface. In this paper feeding device, the paper feeding roller 2 intermittently rotates in the clockwise direction to take out the paper P from the paper cassette 1, and the paper separating member 3 separates the paper P one by one and guides it.
The image is fed to the image forming unit via. Bottom plate 5 of paper cassette 1
Is pressed upward from below by an urging member (not shown), so that the front end in the feeding direction of the paper P stacked on the bottom plate 5 is pressed against the paper feed roll 2 at a constant pressure. Has become.
【０００３】ところが、上記円柱形の給紙ローラと捌き
部材からなる給紙装置は、給紙ローラの間歇回転を時間
的に制御すればよく、停止タイミングが多少前後にずれ
ても支障は生じないから回転制御が比較的容易である反
面、動作休止中であっても次の用紙や給紙ローラの弾性
部材が常時捌き部材に圧接しているため用紙や各部材に
不要な歪み癖が形成され、後の印刷動作に悪影響を及ぼ
すという問題を有している。However, in the paper feeding device including the cylindrical paper feeding roller and the separating member, the intermittent rotation of the paper feeding roller may be temporally controlled, and there is no problem even if the stop timing is slightly shifted forward or backward. Since the rotation control is relatively easy, the elastic member of the next paper or the paper feed roller is always in pressure contact with the separating member even when the operation is stopped, so that unnecessary distortion is formed on the paper and each member. However, there is a problem that it adversely affects the subsequent printing operation.
【０００４】この問題を解決するものとして、同図(b)
に示すように、用紙カセット１の給紙方向前端部の両側
に分離爪６を設け、本体装置内の給紙ローラ７を断面が
半月の形状をなすように形成してなる給紙装置がある。
この給紙装置は、給紙ローラ７が上記同様に時計回り方
向に間歇的に回転して用紙カセット１から用紙Ｐを取り
出し、分離爪６で一枚毎に分離して画像形成部に給送す
る。この半月形の給紙ローラと用紙カセットの分離爪か
らなる給紙装置は、捌き部材の配設が不要となって内部
空間を縮小できる利点と、動作休止中に用紙や各部材に
不要な歪み癖を形成することがない利点はあるが、反面
では、給紙ローラの回転タイミングによっては分離爪に
よる用紙の分離がしばしば正しく行われなくなるという
傾向を有している。また、給紙ローラの給紙動作が給紙
途中で終了するため、給紙動作を引き継いだ下流の搬送
手段（不図示）による搬送で用紙の斜行がしばしば発生
するという欠点もあった。As a solution to this problem, FIG.
As shown in FIG. 2, there is a sheet feeding device in which separation claws 6 are provided on both sides of the front end portion of the sheet cassette 1 in the sheet feeding direction, and a sheet feeding roller 7 in the main body device is formed so that the cross section has a half-moon shape. .
In this paper feeding device, the paper feeding roller 7 intermittently rotates clockwise in the same manner as described above to take out the paper P from the paper cassette 1, separate the paper P by the separating claw 6 and feed it to the image forming unit. To do. The paper feeding device including the half-moon-shaped paper feeding roller and the separation claw of the paper cassette does not require the arrangement of the separating member and can reduce the internal space, and the unnecessary distortion of the paper and each member during the operation stop. Although there is an advantage of not forming a habit, on the other hand, there is a tendency that the separation of the paper by the separation claw is often not correctly performed depending on the rotation timing of the paper supply roller. In addition, since the sheet feeding operation of the sheet feeding roller ends during the sheet feeding, there is also a drawback that the sheet is often skewed by the conveyance by the downstream conveying unit (not shown) which succeeds the sheet feeding operation.
【０００５】これらのことから、図５(a) に示すよう
に、上記図４(a),(b) を折衷した形式の給紙装置が考え
られている。同図(b) は、その斜視図であり、同図(c)
は、左に断面図、右に側面図を示している。同図(a) 〜
(c) に示す給紙ローラ８は、図４(b) に示した給紙ロー
ラ同様の半月形弾性部材８−１の両側面に、図４(a) に
示した給紙ローラ同様に捌き部材３に常時当接する回転
部材８−２が配設され、これらが軸８−３によって同軸
に軸支・連結されている。この半月形弾性部材と円形の
回転部材を併設してなる給紙装置も、給紙ローラ８が時
計回り方向に間歇的に回転して用紙カセット１から用紙
Ｐを取り出し、捌き部材３で一枚毎に分離して画像形成
部に給送する。上記の半月形弾性部材は給紙直後には圧
接から離脱し、一方、回転部材は用紙と摩擦部材とに給
紙直後の用紙の重送を充分防止できる程度に軽く当接し
ているだけなので、動作休止中に用紙や摩擦部材に不要
な歪み癖を形成することはない。From these things, as shown in FIG. 5 (a), a paper feeder of the eclectic type shown in FIGS. 4 (a) and 4 (b) has been considered. Figure (b) is a perspective view of the same, and Figure (c).
Shows a sectional view on the left and a side view on the right. Same figure (a) ~
The sheet feeding roller 8 shown in (c) is separated from both side surfaces of the half-moon shaped elastic member 8-1 similar to the sheet feeding roller shown in FIG. 4 (b) in the same manner as the sheet feeding roller shown in FIG. 4 (a). A rotary member 8-2 that is always in contact with the member 3 is provided, and these are coaxially supported and connected by a shaft 8-3. Also in the sheet feeding device in which the half-moon shaped elastic member and the circular rotating member are provided side by side, the sheet feeding roller 8 intermittently rotates in the clockwise direction to take out the sheet P from the sheet cassette 1 and one sheet is separated by the separating member 3. The sheets are separated and fed to the image forming unit. The above-mentioned half-moon shaped elastic member is released from the pressure contact immediately after feeding, while the rotating member is only in light contact with the paper and the friction member so as to sufficiently prevent double feeding of the paper immediately after feeding. No unnecessary distortion is formed on the paper or the friction member during the suspension of operation.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、上記図
５(a) 〜(c) に示した半月形弾性部材と円形の回転部材
を併設してなる給紙装置といえども、連続して次の用紙
送りを正しく行うためには給紙ローラの停止位置を正確
に制御する必要がある。例えば、半月形弾性部材８−１
の底面部（切欠部）が斜めになって図の実線８−１ａで
示すように摩擦部材３の面に正しく対向する位置に停止
するように制御されなければならない。一般には、図６
に示すように、給紙ローラの回転軸８−３への駆動系に
よる駆動伝達を、駆動軸９、クラッチ１０を介して行
い、クラッチ１０の断接によって給紙ローラ８の回転／
停止の制御を行っている。しかし、これだけでは、も
し、同図の矢印Ａで示す時計回り方向に回転し過ぎて、
上記底面部が同図の一方の破線で示す位置までくるよう
なことがあると、給紙動作を引き継いだ下流の搬送手段
（不図示）によって未だ用紙カセット１から後端部が給
紙中である用紙Ｐに、無用の圧接が加わって用紙が斜行
し印字乱れを誘発する。一方、矢印Ｂで示す反時計回り
方向で早めに停止して上記底面部が同図の他方の破線で
示す位置にあると、ガイド４内を上方に反転しながら搬
送される用紙に半月形弾性部材８−１端部が不規則に当
接して、同様に用紙斜行の誘因となる。However, even in the case of the sheet feeding device having the half-moon shaped elastic member and the circular rotating member, which are shown in FIGS. In order to correctly feed the paper, it is necessary to accurately control the stop position of the paper feed roller. For example, the half-moon shaped elastic member 8-1
Must be controlled so that the bottom surface portion (notch portion) becomes slanted and stops at a position that correctly faces the surface of the friction member 3 as shown by the solid line 8-1a in the figure. Generally, FIG.
As shown in FIG. 3, drive transmission to the rotary shaft 8-3 of the paper feed roller is performed by the drive system via the drive shaft 9 and the clutch 10.
The stop is controlled. However, with this alone, if it rotates too much in the clockwise direction indicated by the arrow A in the figure,
If the bottom portion may reach the position shown by the one broken line in the figure, the trailing end portion is still feeding from the sheet cassette 1 by the downstream transporting means (not shown) that has succeeded the sheet feeding operation. Unnecessary pressure contact is applied to a certain sheet P, and the sheet skews and induces print disturbance. On the other hand, if the bottom surface portion is at the position shown by the other broken line in the figure by stopping early in the counterclockwise direction indicated by arrow B, the half-moon shaped elasticity will be applied to the sheet conveyed while reversing upward in the guide 4. The ends of the member 8-1 come into irregular contact with each other, which similarly causes skewing of the sheet.
【０００７】このような、給紙ローラの停止位置を正確
に位置決めするためには、例えば電気的には、パルスモ
ータによる回転制御、電磁リレーによる制動制御等を行
う必要があり、また機械的であれば、回転軸に連動する
変形カム等を用いて、これと係合するレバー等を動作さ
せ、給紙ローラ軸に連結させているギアにラチェット等
を係止させる又は係止を解除するなどのことを行う必要
がある。そして、いずれの場合も駆動伝達機構が複雑に
なるという欠点を有している。In order to accurately position the stop position of the paper feed roller, it is necessary to electrically perform rotation control by a pulse motor, braking control by an electromagnetic relay, etc., and mechanically. If there is, a deforming cam or the like interlocking with the rotating shaft is used to operate a lever or the like that engages with the deforming cam or the like to lock or unlock the ratchet or the like to the gear connected to the paper feeding roller shaft. I need to do that. In any case, there is a drawback that the drive transmission mechanism becomes complicated.
【０００８】本発明の課題は、上記の実情に鑑み、給紙
ロールの簡単な位置制御機構を備えた給紙装置を提供す
ることである。In view of the above situation, an object of the present invention is to provide a sheet feeding device provided with a simple position control mechanism for a sheet feeding roll.
【０００９】[0009]
【課題を解決するための手段】以下に、本発明に係わる
給紙装置の構成を述べる。本発明は、間歇回転可能に軸
支される回転部材と、該回転部材と同軸に設けられ該回
転部材の円周部の径よりも大径の円周の一部を切欠いた
形状を有し、用紙の非給送動作時には上記切欠部を用紙
収納部材上に積載された用紙の最上位用紙と所定間隔を
保ち対向させ、所定のタイミングで回転して上記最上位
用紙に円周部を圧接させることにより上記用紙を下流側
の搬送路へ給送する給紙ローラと、該給紙ローラの軸に
駆動系からの回転駆動力を伝達および非伝達に切り換え
可能であり、上記給紙ローラの非給紙動作時に上記軸を
回転自由とする駆動伝達切換手段と、上記給紙ローラに
より繰り出される用紙を一枚毎に分離する分離機構と、
該分離機構により分離された一枚の用紙を更に下流側の
搬送路へ搬送する搬送手段とを備えた給紙装置を前提と
する。The structure of the sheet feeding device according to the present invention will be described below. The present invention has a rotating member axially rotatably rotatably supported, and a shape in which a part of the circumference that is provided coaxially with the rotating member and has a diameter larger than the diameter of the circumference of the rotating member is cut away. During the non-feeding operation of the paper, the notch is opposed to the topmost paper of the papers stacked on the paper storage member at a predetermined interval, and is rotated at a predetermined timing to press the circumference of the topmost paper into pressure contact. By doing so, it is possible to switch between a paper feed roller for feeding the paper to the downstream conveyance path and a rotational drive force from the drive system to the shaft of the paper feed roller so as to be transmitted or not transmitted. A drive transmission switching means for freely rotating the shaft during a non-paper feeding operation; a separating mechanism for separating the paper fed by the paper feeding roller sheet by sheet;
It is premised on a sheet feeding device provided with a conveying unit that conveys one sheet separated by the separating mechanism to a conveying path further downstream.
【００１０】この発明の給紙装置は、上記給紙ローラの
給送動作時に最初に用紙と当接する該給紙ローラの切欠
部と円周部との境界近傍の該給紙ローラ側部に回転自在
に設けられた小径コロと、該小径コロを上記給紙ローラ
の非給送動作時に上記最上位用紙と当接させて給紙ロー
ラ姿勢を位置決めする位置決め機構とを備えて構成され
る。The sheet feeding device of the present invention is rotated to the side of the sheet feeding roller near the boundary between the notch and the circumference of the sheet feeding roller that first comes into contact with the sheet during the feeding operation of the sheet feeding roller. It is provided with a small-diameter roller that is freely provided and a positioning mechanism that positions the attitude of the paper-feed roller by bringing the small-diameter roller into contact with the uppermost sheet during non-feeding operation of the paper feed roller.
【００１１】上記小径コロは、例えば請求項２記載のよ
うに、上記給紙ローラの給送動作時に最初に用紙と当接
する該給紙ローラの切欠部と円周部との境界近傍に対応
する上記回転部材の側面周辺部に設けるようにしてもよ
い。また、上記位置決め機構は、例えば請求項３記載の
ように、上記小径コロを上記軸の下方に自重で移動させ
るべく重量バランスを設定した機構である。The small-diameter roller corresponds to the vicinity of the boundary between the cutout portion and the circumferential portion of the sheet feeding roller that first comes into contact with the sheet at the time of the sheet feeding operation of the sheet feeding roller. You may make it provide in the peripheral part of the side surface of the said rotation member. Further, the positioning mechanism is a mechanism in which a weight balance is set so as to move the small-diameter roller below the shaft by its own weight, as described in claim 3, for example.
【００１２】[0012]
【作用】この発明の給紙装置は、給紙ローラ又は回転部
材に取り付けられた小径コロを上記軸の下方に自重で移
動させるべく重量バランスを設定した機構により、上記
小径コロが給紙ローラの非給送動作時に最上位用紙と当
接して給紙ローラの姿勢を位置決めする。In the paper feeding device of the present invention, the small diameter roller is attached to the paper feeding roller or the rotating member by a mechanism in which a weight balance is set so as to move the roller below the shaft by its own weight. At the time of the non-feeding operation, the posture of the paper feed roller is positioned by contacting with the topmost paper.
【００１３】[0013]
【実施例】以下、本発明の実施例について図面を参照し
ながら詳述する。図１(a) は、一実施例に係わる給紙機
構の斜視図であり、同図(b) はその正面図である。同図
(a),(b) に示すように、給紙機構１１は、不図示の駆動
系により間歇回転可能な回転軸１２に軸支される回転部
材１３と、この回転部材１３と同軸に設けられ該回転部
材１３の円周部の径よりも大径の円周を有して、その円
周の一部を切欠いた形状をなす給紙ローラ１４と、この
給紙ローラ１４の側部に回転自在に設けられた小径コロ
１５とを備えている。Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1A is a perspective view of a sheet feeding mechanism according to one embodiment, and FIG. 1B is a front view thereof. Same figure
As shown in (a) and (b), the sheet feeding mechanism 11 is provided with a rotating member 13 pivotally supported by a rotating shaft 12 which can be intermittently rotated by a drive system (not shown), and coaxially with the rotating member 13. A paper feed roller 14 having a circumference larger than the diameter of the circumference of the rotating member 13 and having a shape in which a part of the circumference is cut out, and a rotation on the side of the paper feed roller 14. It is provided with a small-diameter roller 15 provided freely.
【００１４】上記給紙ローラ１４は、用紙収納部材であ
る後述する用紙カセット上に積載された用紙の最上位用
紙Ｐに対し、用紙の非給送動作時には上記の切欠部を所
定間隔を保ち対向させ、所定のタイミングで回転して上
記最上位用紙Ｐに円周部を圧接させることにより用紙Ｐ
を下流側の搬送路へ給送する。The sheet feeding roller 14 faces the uppermost sheet P of sheets stacked on a sheet cassette, which will be described later, which is a sheet accommodating member, and keeps the above notches at a predetermined interval during the sheet non-feeding operation. The uppermost sheet P is rotated at a predetermined timing to press the circumferential portion of the sheet P into contact with the sheet P.
Is fed to the downstream transport path.
【００１５】そして、上記小径コロ１５は、給紙ローラ
１４が給送動作時に最初に用紙Ｐと当接する上記切欠部
と円周部との境界近傍において、給紙ローラ１４の側部
に配設されている。The small-diameter roller 15 is disposed on the side of the paper feed roller 14 in the vicinity of the boundary between the notch and the circumferential portion where the paper feed roller 14 first contacts the paper P during the feeding operation. Has been done.
【００１６】この給紙ローラ１４の回転軸１２と駆動系
との間には、例えば図６に示したクラッチ１０のような
駆動伝達切換手段が配設されており、駆動系からの回転
駆動力を、伝達および非伝達と、給紙ローラ１４に間歇
的に加えることができるようになっている。A drive transmission switching means such as the clutch 10 shown in FIG. 6 is disposed between the rotary shaft 12 of the paper feed roller 14 and the drive system, and the rotary drive force from the drive system is provided. Can be intermittently added to the paper feed roller 14 in the transmission and non-transmission.
【００１７】図２は、上記の給紙機構１１を備えたプリ
ンタの断面図である。同図に示すプリンタ１６は、回動
する感光体ドラム１７と、この感光体ドラム１７の感光
面に電荷を付与する帯電器、この電荷を付与された感光
面に露光を行うＬＥＤヘッド、この露光により形成され
た感光面上の静電潜像をトナー像化する現像器、そのト
ナー像を用紙に転写する転写器、この転写後の感光面の
残留トナーを除去するクリーナ等からなる画像形成部１
８を備え、その下流には、上記転写されたトナー像をそ
の用紙に熱定着する発熱ロールと圧着ロールからなる定
着部１９を備えている。そして、底部には着脱自在な用
紙カセット２０を装着している。FIG. 2 is a sectional view of a printer having the above-mentioned paper feed mechanism 11. The printer 16 shown in FIG. 1 includes a rotating photosensitive drum 17, a charger for applying an electric charge to the photosensitive surface of the photosensitive drum 17, an LED head for exposing the photosensitive surface to which the electric charge is applied, and an exposure unit for this exposure. An image forming unit including a developing device for converting the electrostatic latent image formed on the photosensitive surface into a toner image, a transfer device for transferring the toner image onto a sheet, and a cleaner for removing the residual toner on the photosensitive surface after the transfer. 1
8 is provided downstream thereof, and a fixing section 19 including a heat-generating roll for thermally fixing the transferred toner image onto the sheet and a pressure-bonding roll is provided. A removable paper cassette 20 is attached to the bottom.
【００１８】用紙カセット２０の用紙Ｐは、用紙カセッ
ト２０の底板２１により下から上方へ付勢され、給紙時
には給紙機構１１の給紙ローラ１４（図１参照）の円周
部に圧接され、その給紙ローラ１４により最上部から取
り出され、分離機構である摩擦部材２２により一枚毎に
分離され、給紙ガイド２３を通過しながら上方に反転
し、更に下流側の搬送路へ搬送する搬送手段である搬送
ロール対２４により、画像形成部１８に給送される。こ
の画像形成部１８でトナー像を転写された用紙Ｐは、定
着部１９でトナー像を熱定着され、排紙ガイド２５によ
り再び反転して排紙トレー２６上に排出される。The sheet P of the sheet cassette 20 is urged from the bottom to the upper side by the bottom plate 21 of the sheet cassette 20, and is pressed against the circumferential portion of the sheet feeding roller 14 (see FIG. 1) of the sheet feeding mechanism 11 at the time of sheet feeding. The sheet is taken out from the uppermost portion by the sheet feeding roller 14, separated one by one by the friction member 22 which is a separating mechanism, turned upside down while passing through the sheet feeding guide 23, and further conveyed to the conveying path on the downstream side. The sheet is fed to the image forming unit 18 by a pair of conveying rolls 24 that is a conveying unit. The sheet P to which the toner image has been transferred by the image forming section 18 has the toner image thermally fixed by the fixing section 19, is reversed again by the discharge guide 25, and is discharged onto the discharge tray 26.
【００１９】上記給紙機構１１は、上記の給紙動作で、
ほぼ一回弱回転すると、駆動系からの回転駆動伝達をク
ラッチによって解除されて自由回転状態となり、小径コ
ロ１５の自重によって給紙動作時と同方向に更に自由回
転し、上記小径コロ１５が用紙カセット２０の最上位用
紙に当接して給紙ローラ１４を用紙に対し停止させ、こ
れによって、給紙ローラ１４の姿勢を所定の停止位置に
位置決めする。The paper feed mechanism 11 performs the above-mentioned paper feed operation.
When it rotates a little about once, the rotation drive transmission from the drive system is released by the clutch to be in a free rotation state, and the small diameter roller 15 is further rotated freely in the same direction as the paper feeding operation by the weight of the small diameter roller 15. The paper feed roller 14 is brought into contact with the uppermost paper of the cassette 20 and stopped with respect to the paper, whereby the posture of the paper feed roller 14 is positioned at a predetermined stop position.
【００２０】このとき上記給紙ローラ１４による給紙動
作終了後に引き続き給紙動作を引き継いだ搬送ロール対
２４により給紙継続中の用紙Ｐ後端部には、小径コロ１
５が当接していることにより、給紙ローラ１４は用紙Ｐ
面から離脱しており、したがって給紙中の用紙Ｐに強い
押圧が加わることがなく、このため搬送側のトルクが軽
減される。一方、回転部材１３が摩擦部材２２に向けて
適宜な力で当接することにより（図１(a) 参照）、用紙
Ｐ下面に連れ出されている次に給紙されるべき用紙が摩
擦部材２２に押接され、これにより、その用紙の重送が
防止される。At this time, the small-diameter roller 1 is provided at the rear end of the sheet P which is continuously fed by the pair of transport rolls 24 which have succeeded the sheet feeding operation after the sheet feeding operation by the sheet feeding roller 14 is completed.
5 is in contact with the paper feed roller 14, the paper P
Since it is separated from the surface, strong pressure is not applied to the paper P being fed, and therefore the torque on the transport side is reduced. On the other hand, when the rotating member 13 is brought into contact with the friction member 22 with an appropriate force (see FIG. 1 (a)), the next sheet to be fed that has been taken out to the lower surface of the sheet P will be friction member 22. The sheets are pressed against each other, which prevents the sheets from being fed in duplicate.
【００２１】このように本発明によれば、給紙ローラに
対する駆動系からの回転駆動伝達を単にクラッチによっ
て解除して自由回転させるだけで、給紙ローラの姿勢を
最適の停止位置に位置決めすることができる。As described above, according to the present invention, the posture of the paper feed roller can be positioned at the optimum stop position by simply releasing the rotational drive transmission from the drive system to the paper feed roller by the clutch and allowing the paper feed roller to rotate freely. You can
【００２２】尚、本実施例においては、摩擦部材２２に
より用紙を一枚毎に分離する場合を例にとって説明した
が、本発明は、用紙の分離機構が摩擦部材である場合に
限ることなく、分離機構が分離爪である場合にも適用で
きる。In this embodiment, the case where the paper is separated sheet by sheet by the friction member 22 has been described as an example, but the present invention is not limited to the case where the paper separation mechanism is the friction member. It can also be applied when the separating mechanism is a separating claw.
【００２３】これを他の実施例として以下に説明する。
図３(a) は他の実施例に係わる給紙機構の正面図であ
る。同図に示す給紙機構３０は、これも不図示の駆動系
により間歇回転可能な回転軸３１に軸支される回転部材
３２と、この回転部材３２と同軸に設けられ該回転部材
３２の円周部の径よりも大径の円周を有して、その円周
の一部を切欠いた形状をなす給紙ローラ３３と、この給
紙ローラ３３の側面周辺部に設けられた小径コロ３４と
を備えている。この実施例では、回転部材３２も、給紙
ローラ３３と同様に、給紙ローラ３３に対応して、その
円周の一部を切欠いた形状をなしている。そして、小径
コロ３４は、回転部材３２の側面周辺部の上記給紙ロー
ラ３３の切欠部と円周部との境界近傍に対応する位置に
回転自在に配設されている。この、給紙機構３０も、特
には図示しないが、図２に示すプリンタ１６とほぼ同様
の構造をなすプリンタに配設される。ただし、このプリ
ンタは、図２のプリンタ１６とは分離機構が異なる。す
なわち、図２に示した摩擦部材２２が取り除かれ、代わ
りに、用紙カセット２０の給紙方向前端部の両側に分離
爪が設けられる。This will be described below as another embodiment.
FIG. 3A is a front view of a paper feed mechanism according to another embodiment. The sheet feeding mechanism 30 shown in the figure has a rotating member 32 axially supported by a rotating shaft 31 which can be intermittently rotated by a drive system (not shown), and a circle of the rotating member 32 which is provided coaxially with the rotating member 32. A paper feed roller 33 having a circumference having a diameter larger than that of the circumference and having a shape in which a part of the circumference is cut out, and a small-diameter roller 34 provided around the side surface of the paper feed roller 33. It has and. In this embodiment, the rotary member 32 also has a shape in which a part of the circumference of the rotary member 32 is cut out, corresponding to the paper feed roller 33, like the paper feed roller 33. The small-diameter roller 34 is rotatably disposed at a position corresponding to the vicinity of the boundary between the cutout portion and the circumferential portion of the paper feed roller 33 on the peripheral portion of the side surface of the rotating member 32. Although not shown in particular, the paper feed mechanism 30 is also provided in a printer having a structure similar to that of the printer 16 shown in FIG. However, this printer is different in the separating mechanism from the printer 16 of FIG. That is, the friction member 22 shown in FIG. 2 is removed, and instead, separation claws are provided on both sides of the front end portion of the sheet cassette 20 in the sheet feeding direction.
【００２４】図３(b) は、その分離爪３５が配設された
用紙カセット２０と、この用紙カセット２０に積載され
た用紙Ｐと、この用紙Ｐ面に対向して配設される上記給
紙機構３０のみを取り出して示した斜視図である。In FIG. 3B, the paper cassette 20 in which the separation claw 35 is arranged, the paper P stacked in the paper cassette 20, and the above-mentioned paper feeding unit arranged facing the paper P surface. It is a perspective view which took out and showed only the paper mechanism 30.
【００２５】そして、同図(c) には、それらの側面図を
模式的に示している。尚、同図にはプリンタ本体の給紙
ガイド下部３６も示している。同図(a) 〜(c) に示すよ
うに、上記小径コロ３４は、給紙ローラ３３が給送動作
を行うとき最初に用紙Ｐと当接する上記切欠部と円周部
との境界近傍に対応する回転部材３２の側面周辺位置に
配設されている。Then, FIG. 6 (c) schematically shows a side view thereof. The drawing also shows the lower portion 36 of the paper feed guide of the printer body. As shown in FIGS. 8A to 8C, the small-diameter roller 34 is located near the boundary between the cutout portion and the circumferential portion that first come into contact with the paper P when the paper feeding roller 33 performs the feeding operation. The rotary member 32 is disposed at a peripheral position of the side surface of the corresponding rotary member 32.
【００２６】この場合も、上記給紙ローラ３３は、用紙
カセット２０上に積載された用紙Ｐの最上位用紙に対
し、用紙の非給送動作時には上記切欠部を所定間隔を保
って対向させ、所定のタイミングで回転して最上位用紙
に円周部を圧接させてその用紙Ｐを下流側の搬送路へ給
送する。このとき分離爪３５、３５が、最上位用紙一枚
のみを分離する。In this case as well, the paper feed roller 33 makes the cutout portion face the uppermost paper sheet P stacked on the paper cassette 20 at a predetermined interval during the non-feeding operation of the paper sheet. The peripheral portion is pressed against the uppermost sheet by rotating at a predetermined timing, and the sheet P is fed to the conveying path on the downstream side. At this time, the separation claws 35, 35 separate only the topmost sheet.
【００２７】この給紙機構３０も、上記給紙動作で、ほ
ぼ一回弱回転した後、駆動系からの回転駆動伝達をクラ
ッチ等によって解除され、小径コロ３４の自重によって
給紙動作時と同方向に更に自由回転し、上記小径コロ３
４が用紙カセット２０の最上位用紙に当接し、これによ
って、給紙ローラ３３を用紙Ｐ面に当接させることな
く、給紙ローラ３３の用紙に対する姿勢を所定の停止位
置で位置決めする。The paper feed mechanism 30 also rotates slightly once in the paper feed operation described above, and then the rotational drive transmission from the drive system is released by a clutch or the like, and due to the weight of the small diameter roller 34, the same as in the paper feed operation. Rotate further in the direction, and the above small diameter roller 3
4 makes contact with the uppermost sheet of the sheet cassette 20, whereby the attitude of the sheet feeding roller 33 with respect to the sheet is positioned at a predetermined stop position without bringing the sheet feeding roller 33 into contact with the sheet P surface.
【００２８】この場合も、上記給紙ローラ３３による給
紙動作終了後、給紙動作を引き継いだ搬送ロール対２４
により給紙継続中の用紙Ｐ後端部には、上記のように小
径コロ３４が左右に別れて適宜な力で当接していること
により、給送中の用紙Ｐの斜行を予防することができ
る。In this case as well, after the sheet feeding operation by the sheet feeding roller 33 is completed, the pair of transport rolls 24 which have succeeded the sheet feeding operation.
As a result, the small-diameter rollers 34 are separated from the right and left and abut with an appropriate force on the rear end portion of the paper P during continuous feeding, so that the skew of the paper P during feeding is prevented. You can
【００２９】[0029]
【発明の効果】以上詳細に説明したように、本発明によ
れば、給紙ローラに対する駆動系からの回転駆動伝達を
単にクラッチによって解除して自由回転させるだけで、
小径コロが自重により用紙面に当接し、給紙ローラの姿
勢を所定の基準停止位置に位置決めすることができる。
これにより、給紙ローラが基準停止位置より回転し過ぎ
ることも或いは回転不足になることもなく、したがっ
て、給紙動作継続中である用紙面に無用の押圧を加えて
その搬送に悪影響を与えることがない。また、給紙ロー
ラが基準停止位置に正しく停止するので、次の用紙の給
紙動作が正しいタイミングで行われ、したがって、印字
不良等の発生が低減する。そして、極めて簡単な構造の
給紙機構で給紙ローラを基準停止位置に位置決めできる
ので、電気的な駆動制御や制動制御による駆動系の複雑
な断接制御または機械的なカム、レバー、ラチェット等
による駆動系の複雑な断接制御が不要になり、したがっ
て、部品点数が減少して製品コストが低減し、配設空間
が縮小して装置が小型化する。また、構造が簡単である
ため工場の組み立て作業能率が向上し、使用中の故障率
が低下する。As described above in detail, according to the present invention, the rotational drive transmission from the drive system to the paper feed roller is simply released by the clutch to be freely rotated.
The small-diameter roller contacts the sheet surface by its own weight, and the attitude of the sheet feeding roller can be positioned at a predetermined reference stop position.
As a result, the paper feed roller does not rotate too much or becomes insufficiently rotated from the reference stop position, and therefore, unnecessary press is applied to the paper surface during the paper feed operation, which adversely affects the conveyance. There is no. Further, since the paper feed roller is properly stopped at the reference stop position, the paper feeding operation of the next paper is performed at the correct timing, and therefore the occurrence of printing defects and the like is reduced. Moreover, since the paper feed roller can be positioned at the reference stop position by the paper feed mechanism having an extremely simple structure, complicated connection / disconnection control of the drive system by electric drive control or braking control or mechanical cams, levers, ratchets, etc. Therefore, the complicated connection / disconnection control of the drive system is not required. Therefore, the number of parts is reduced, the product cost is reduced, the installation space is reduced, and the device is downsized. In addition, the simple structure improves the efficiency of assembly work in the factory and reduces the failure rate during use.
【図１】(a) は一実施例に係わる給紙機構の斜視図、
(b) はその正面図である。FIG. 1A is a perspective view of a sheet feeding mechanism according to an embodiment,
(b) is a front view thereof.
【図２】図１の給紙機構を備えたプリンタの断面図であ
る。FIG. 2 is a cross-sectional view of a printer including the paper feed mechanism of FIG.
【図３】(a) は他の実施例に係わる給紙機構の正面図、
(b) は分離爪の配設された用紙カセットとの配置関係を
示す斜視図、(c) はその側面図である。FIG. 3A is a front view of a sheet feeding mechanism according to another embodiment,
(b) is a perspective view showing a positional relationship with a paper cassette in which separation claws are arranged, and (c) is a side view thereof.
【図４】(a),(b) は従来の給紙装置の例をそれぞれ示す
斜視図である。4A and 4B are perspective views respectively showing an example of a conventional sheet feeding device.
【図５】(a) は従来の改良型給紙装置の側断面図、(b)
はその斜視図、(c) はその正面から見た断面図及び側面
図である。FIG. 5 (a) is a side sectional view of a conventional improved paper feeder, and FIG.
Is a perspective view thereof, and (c) is a sectional view and a side view seen from the front.
【図６】駆動伝達を断接するクラッチを説明する図であ
る。FIG. 6 is a diagram illustrating a clutch that connects and disconnects drive transmission.
１ 用紙カセット ２ 給紙ローラ ３ 捌き部材 ４ ガイド ５ 底板 ６ 分離爪 ７、８ 給紙ローラ ８−１ 半月形弾性部材 ８−２ 回転部材 ８−３ 軸 １０ クラッチ １１、３０ 給紙機構 １２、３１ 回転軸 １３、３２ 回転部材 １４、３３ 給紙ローラ １５、３４ 小径コロ １６ プリンタ １７ 感光体ドラム １８ 画像形成部 １９ 定着部 ２０ 用紙カセット ２１ 底板 ２２ 摩擦部材 ２３ 給紙ガイド ２４ 搬送ロール対 ２５ 排紙ガイド ２６ 排紙トレー Ｐ 用紙 DESCRIPTION OF SYMBOLS 1 Paper cassette 2 Paper feed roller 3 Separation member 4 Guide 5 Bottom plate 6 Separation claw 7, 8 Paper feed roller 8-1 Half moon elastic member 8-2 Rotating member 8-3 Shaft 10 Clutch 11, 30 Paper feed mechanism 12, 31 Rotating shaft 13, 32 Rotating member 14, 33 Paper feeding roller 15, 34 Small diameter roller 16 Printer 17 Photoreceptor drum 18 Image forming unit 19 Fixing unit 20 Paper cassette 21 Bottom plate 22 Friction member 23 Paper feed guide 24 Conveying roll pair 25 Paper ejection Guide 26 Output tray P Paper
Claims (3)
りも大径の円周の一部を切欠いた形状を有し、用紙の非
給送動作時には前記切欠部を用紙収納部材上に積載され
た用紙の最上位用紙と所定間隔を保ち対向させ、所定の
タイミングで回転して前記最上位用紙に円周部を圧接さ
せることにより前記用紙を下流側の搬送路へ給送する給
紙ローラと、 該給紙ローラの軸に駆動系からの回転駆動力を伝達およ
び非伝達に切り換え可能であり、前記給紙ローラの非給
紙動作時に前記軸を回転自由とする駆動伝達切換手段
と、 前記給紙ローラにより繰り出される用紙を一枚毎に分離
する分離機構と、 該分離機構により分離された一枚の用紙を更に下流側の
搬送路へ搬送する搬送手段と、 を備えた給紙装置において、 前記給紙ローラの給送動作時に最初に用紙と当接する該
給紙ローラの切欠部と円周部との境界近傍の該給紙ロー
ラ側部に回転自在に設けられた小径コロと、 該小径コロを前記給紙ローラの非給送動作時に前記最上
位用紙と当接させて給紙ローラの姿勢を位置決めする位
置決め機構と、 を備えたことを特徴とする給紙装置。1. A rotating member axially rotatably supported by rotation, and a shape which is provided coaxially with the rotating member and has a part of a circumference having a diameter larger than a diameter of a circumference of the rotating member is cut out. However, during the non-feeding operation of the paper, the cutout portion is made to face the uppermost paper of the sheets stacked on the paper storage member at a predetermined interval and is rotated at a predetermined timing so that the circumferential portion is formed on the uppermost paper. A sheet feeding roller that feeds the sheet to a downstream conveying path by pressing it, and a rotational driving force from a drive system can be switched between transmitted and non-transmitted to the shaft of the sheet feeding roller. Drive transmission switching means for freely rotating the shaft during the non-paper feeding operation, a separating mechanism for separating the paper fed by the paper feeding roller sheet by sheet, and one sheet separated by the separating mechanism. Transporting means for transporting to a further downstream transport path, In the paper feeding device, a small diameter rotatably provided on the side of the paper feeding roller near the boundary between the cutout portion and the circumferential portion of the paper feeding roller that first comes into contact with the paper during the feeding operation of the paper feeding roller. A sheet feeding device comprising: a roller; and a positioning mechanism that positions the orientation of the sheet feeding roller by bringing the small-diameter roller into contact with the uppermost sheet when the sheet feeding roller is not feeding.
動作時に最初に用紙と当接する該給紙ローラの切欠部と
円周部との境界近傍に対応する前記回転部材の側面周辺
部に設けられることを特徴とする請求項１記載の給紙装
置。2. The small-diameter roller corresponds to a peripheral portion of a side surface of the rotating member corresponding to a vicinity of a boundary between a cutout portion and a circumferential portion of the paper feed roller that first comes into contact with a sheet during a feeding operation of the paper feed roller. The sheet feeding device according to claim 1, wherein the sheet feeding device is provided in the.
記軸の下方に自重で移動させるべく重量バランスを設定
した機構であることを特徴とする請求項１又は２記載の
給紙装置。3. The sheet feeding device according to claim 1, wherein the positioning mechanism is a mechanism in which a weight balance is set so as to move the small diameter roller below the shaft by its own weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16521894A JPH0826505A (en) | 1994-07-18 | 1994-07-18 | Paper feeder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16521894A JPH0826505A (en) | 1994-07-18 | 1994-07-18 | Paper feeder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0826505A true JPH0826505A (en) | 1996-01-30 |
Family
ID=15808099
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16521894A Withdrawn JPH0826505A (en) | 1994-07-18 | 1994-07-18 | Paper feeder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0826505A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007062933A (en) * | 2005-08-31 | 2007-03-15 | Ricoh Co Ltd | Paper feeding device and image forming device |
| JP2008087938A (en) * | 2006-10-04 | 2008-04-17 | Fuji Xerox Co Ltd | Sheet feeder and image forming apparatus |
| US7597323B2 (en) | 2006-07-28 | 2009-10-06 | Sharp Kabushiki Kaisha | Paper feeder and image forming apparatus |
-
1994
- 1994-07-18 JP JP16521894A patent/JPH0826505A/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007062933A (en) * | 2005-08-31 | 2007-03-15 | Ricoh Co Ltd | Paper feeding device and image forming device |
| US7597323B2 (en) | 2006-07-28 | 2009-10-06 | Sharp Kabushiki Kaisha | Paper feeder and image forming apparatus |
| JP2008087938A (en) * | 2006-10-04 | 2008-04-17 | Fuji Xerox Co Ltd | Sheet feeder and image forming apparatus |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20011002 |