【０００１】[0001]
【産業上の利用分野】本発明は弾性体で形成された給紙
ローラーと、保持手段に保持された用紙を所定の加圧力
で給紙ローラーに圧接させる加圧手段を具え、給紙ロー
ラーにより繰り出された用紙を１枚ずつの用紙に分離し
て下流に搬送する給紙装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a paper feed roller formed of an elastic body, and pressurizing means for pressing the paper held by the holding means against the paper feed roller with a predetermined pressing force. The present invention relates to a sheet feeding device that separates fed-out sheets into individual sheets and conveys the sheets downstream.
【０００２】[0002]
【従来の技術】複写機等の画像記録装置においては、所
定の大きさに裁断された用紙を多数枚収納した給紙カセ
ットから１枚ずつ用紙を繰り出して画像記録部に送る給
紙装置を備えている。給紙装置は重ねて繰り出された複
数枚の用紙を１枚ずつに分離する分離機構を有してい
る。例えば、給紙ローラーに当接する高摩擦係数の分離
パッドに繰り出された用紙の先端を突き当てて、用紙の
弾性および用紙間の摩擦係数と用紙・給紙ローラー、用
紙・分離パッド間の摩擦係数の差を利用して分離する方
式や、所定量以上の負荷に対して空転する負荷制限機構
を有した逆転ローラーとこれに接して正転する給紙ロー
ラーにより繰り出された重送紙を分離する方式が知られ
ている。2. Description of the Related Art An image recording apparatus such as a copying machine is provided with a sheet feeding device which feeds out a sheet from a sheet feeding cassette containing a large number of sheets cut into a predetermined size and feeds the sheet to an image recording section. ing. The sheet feeding device has a separating mechanism that separates a plurality of sheets that are stacked and fed out one by one. For example, by hitting the leading edge of the delivered paper against a separation pad with a high friction coefficient that abuts the paper feed roller, the elasticity of the paper and the friction coefficient between the paper and the friction coefficient between the paper and the paper feed roller and the paper and separation pad The method of separating by utilizing the difference of the above, or the reverse feeding roller having a load limiting mechanism that idles against a load of a predetermined amount or more, and the feeding roller that rotates forward in contact with this, separates the fed multi-fed paper. The scheme is known.
【０００３】[0003]
【発明が解決しようとする課題】ところが、前者の分離
方式においては分離パッドに突き当った用紙の先端が座
屈して隅部に「用紙折れ」が形成されたり、用紙・分離
パッド間の摩擦が大き過ぎて空送りとなる「不送り」が
発生することがあった。また、後者の分離方式において
は複雑な構造の負荷制限機構を有するため、給紙装置が
高価なものになってしまう。本発明は従来技術における
かかる問題点を解消しようとするものであり、「用紙折
れ」や「不送り」を生じることの無い安価な給紙装置を
提供することを目的とする。In the former separation method, however, the leading edge of the paper that hits the separation pad buckles and "paper folds" are formed in the corners, or the friction between the paper and the separation pad is reduced. In some cases, there was a “non-feed” that was too large and was a blank feed. Further, in the latter separation method, since the load limiting mechanism having a complicated structure is provided, the sheet feeding device becomes expensive. The present invention is intended to solve such a problem in the prior art, and an object thereof is to provide an inexpensive paper feeding device that does not cause "paper folding" or "non-feeding".
【０００４】[0004]
【課題を解決するための手段】本発明は上記課題を解決
するために、給紙ローラーは伸縮性に乏しい弾性体で形
成され、軸方向に沿った中央部が中実の中実部と、その
両側に外周が肉薄部で区画されることにより内部に中空
部が形成され、自然状態において中実部の径より大きな
径を有した大径部からなり、保持手段を付勢して、保持
手段に保持された用紙を所定の加圧力で給紙ローラーに
圧接させる加圧手段からの加圧力を受けることにより、
大径部は中空部内の空気圧に抗して肉薄部が内部に没入
し得るようにしたものである。According to the present invention, in order to solve the above-mentioned problems, a paper feed roller is formed of an elastic body having poor elasticity, and a central portion along the axial direction is a solid solid portion. A hollow part is formed inside by dividing the outer circumference on both sides with a thin part, and consists of a large-diameter part having a diameter larger than the diameter of the solid part in the natural state. By receiving the pressure from the pressurizing means that presses the paper held by the means to the paper feed roller with a predetermined pressure,
The large-diameter portion is configured such that the thin-walled portion can be immersed therein against the air pressure in the hollow portion.
【０００５】[0005]
【作用】給紙動作が開始されると、加圧手段は保持手段
を付勢して、保持手段に保持された用紙を所定の加圧力
で給紙ローラーに圧接させる。大径部は加圧手段からの
加圧力を受けることにより、中空部内の空気圧に抗して
肉薄部が内部に没入し、回転する給紙ローラーの大径部
と中実部が接する用紙を異なる搬送速度で搬送する。こ
れにより、搬送される用紙の中央部を競り上げるような
応力が生じ、１枚目の用紙と２枚目の用紙が分離され
る。When the paper feeding operation is started, the pressing means urges the holding means to press the paper held by the holding means against the paper feeding roller with a predetermined pressing force. The large-diameter portion receives the pressure from the pressurizing means, so that the thin-walled portion is recessed inside against the air pressure in the hollow portion, and the large-diameter portion of the rotating sheet feeding roller and the solid portion contact different sheets. Transport at the transport speed. As a result, a stress is generated such that the central portion of the conveyed sheet is tended up, and the first sheet and the second sheet are separated.
【０００６】[0006]
【実施例】以下、図面を参照して本発明の一実施例を詳
細に説明する。図１、図２および図３は本実施例に係る
給紙ローラーを示したものであって、それぞれ給紙状態
における給紙ローラー軸方向の断面図、側面図および待
機状態における給紙ローラー軸方向の断面図である。給
紙ローラー２は軸１に固設され、待機状態（非接触状
態）において図３に示すように、軸方向の両側部に中空
部３ａ，３ｂを有した大径部２ａ，２ｂと中実で小径の
小径部２ｃとから成っており、伸縮性に乏しい弾性ゴム
で形成されている。大径部２ａ，２ｂの径φＤは小径部
２ｃの径φｄより５〜２０％大きな値とするのが良い。
大径部２ａ，２ｂの外周部は肉薄部になっていて、肉薄
部の厚みおよび中空部３ａ，３ｂ内の空気圧は大径部２
ａ，２ｂが加圧力を受けると、加圧部が中空部３ａ，３
ｂ内の空気圧に抗して凹み変形し得るように調整されて
いる。給紙状態においては図１および図２に示すよう
に、用紙Ｐ束を搭載した紙支持板５が押し上げられ、給
紙ローラー２にその上の最上の用紙Ｐが所定の圧接力Ｆ
で圧接する。この圧接によって、給紙ローラー２の大径
部２ａ，２ｂが最上の用紙Ｐに当接する部分が上述のよ
うに凹み変形し、さらに、最上の用紙Ｐが小径部２ｃに
も接触するようになる。制御部の給紙開始信号によって
給紙ローラー２が回転し始めると、給紙ローラー２に接
触する最上の用紙Ｐが給紙ローラー２との摩擦力により
搬送方向に送り出されるが、この時、大径部２ａ，２ｂ
の径φＤと小径部２ｃの径φｄが異なるので、それに応
じて大径部２ａ，２ｂと小径部２ｃが最上の用紙Ｐと接
する位置での周回速度が異なる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1, FIG. 2 and FIG. 3 show a sheet feeding roller according to the present embodiment, which are a sectional view in a sheet feeding roller axial direction in a sheet feeding state, a side view, and a sheet feeding roller axial direction in a standby state, respectively. FIG. The paper feed roller 2 is fixed to the shaft 1, and in a standby state (non-contact state), as shown in FIG. 3, large diameter portions 2a and 2b having hollow portions 3a and 3b on both axial sides and a solid portion. And a small diameter portion 2c having a small diameter, and is formed of elastic rubber having poor elasticity. The diameter φD of the large diameter portions 2a and 2b is preferably set to a value 5 to 20% larger than the diameter φd of the small diameter portion 2c.
The outer peripheral portions of the large diameter portions 2a and 2b are thin portions, and the thickness of the thin portions and the air pressure in the hollow portions 3a and 3b are large diameter portions 2
When a and 2b are subjected to pressure, the pressurizing part is moved to the hollow parts 3a and 3b.
It is adjusted so that it can be deformed in a concave manner against the air pressure in b. In the paper feed state, as shown in FIGS. 1 and 2, the paper support plate 5 on which the bundle of paper P is mounted is pushed up, and the uppermost paper P on the paper feed roller 2 has a predetermined pressing force F.
Press with. By this pressure contact, the portions where the large diameter portions 2a and 2b of the paper feed roller 2 contact the uppermost sheet P are concavely deformed as described above, and the uppermost sheet P also comes into contact with the small diameter portion 2c. . When the paper feed roller 2 starts to rotate in response to the paper feed start signal from the control unit, the uppermost paper P contacting the paper feed roller 2 is sent out in the conveyance direction due to the frictional force with the paper feed roller 2. Diameter parts 2a, 2b
Since the diameter φD and the diameter φd of the small diameter portion 2c are different, the orbiting speed at the position where the large diameter portions 2a and 2b and the small diameter portion 2c are in contact with the uppermost sheet P is different accordingly.
【０００７】図４は給紙状態における給紙ローラー２の
用紙搬送状態を示したものであり、（ａ）は斜視図、
（ｂ）は平面図である。（ｂ）に示す実線矢印は給紙ロ
ーラー２が最上の用紙Ｐと接する位置での周回速度をベ
クトル表示したものである。このように、給紙ローラー
２が最上の用紙Ｐと接する位置での周回速度は大径部２
ａ，２ｂと小径部２ｃで異なるので、給紙ローラー２に
当接する最上の用紙Ｐは給紙ローラー２との接触位置に
よって異なる速度で搬送される。この搬送速度の違いに
より、最上の用紙Ｐは大径部２ａ，２ｂが接する位置で
その間、即ち、小径部２ｃ側に押し付ける応力（図で破
線で示す）を受ける。給紙ローラー２によって送り出さ
れた用紙Ｐは大径部２ａ，２ｂが接する位置の間の下流
側で給紙ローラー２から受ける応力により中央部が競り
上がる。用紙Ｐの紙厚が厚い、あるいは、こしが強く、
用紙Ｐ間の摩擦力が小さい場合は、最上の用紙Ｐを競り
上げようとする両側部から中央部に向かう応力が最上の
用紙Ｐと２枚目の用紙Ｐ間の摩擦力に打ち勝って、最上
の用紙Ｐのみの中央部を競り上がらせる。これによっ
て、最上の用紙Ｐと２枚目の用紙Ｐが分離され、最上の
用紙Ｐのみが下流に搬送される。FIG. 4 shows a sheet conveying state of the sheet feeding roller 2 in the sheet feeding state. FIG. 4A is a perspective view,
(B) is a plan view. The solid arrow shown in (b) is a vector display of the orbital speed at the position where the paper feed roller 2 contacts the uppermost paper P. Thus, the orbiting speed at the position where the paper feed roller 2 contacts the uppermost paper P is the large diameter portion 2
Since a and 2b differ from the small-diameter portion 2c, the uppermost sheet P that abuts the paper feed roller 2 is transported at different speeds depending on the contact position with the paper feed roller 2. Due to this difference in transport speed, the uppermost sheet P receives a stress (indicated by a broken line in the figure) that is pressed against the large diameter portions 2a and 2b between them, that is, on the small diameter portion 2c side. The central portion of the paper P sent out by the paper feed roller 2 goes up due to the stress received from the paper feed roller 2 on the downstream side between the positions where the large diameter portions 2a and 2b contact each other. The paper P is thick or strong,
When the frictional force between the sheets P is small, the stress directed from the both sides toward the center of the uppermost sheet P to overcome the frictional force between the uppermost sheet P and the second sheet P, Bid up the central portion of only the paper P. As a result, the uppermost sheet P and the second sheet P are separated, and only the uppermost sheet P is conveyed downstream.
【０００８】図５は給紙ローラー２の下流側に重なって
送り出された用紙Ｐの状態を示したものであり、（ａ）
は送り出し直後、（ｂ）はやや時間が経過した後の状態
を示している。図５（ａ）に示すように、たまたま最上
の用紙Ｐ1と共に２枚目の用紙Ｐ2が重送された場合で
も、これらの用紙Ｐ1，Ｐ2の後続部分において、上述
の中央部を競り上がらせる応力が加え続けられるから、
やがて、これらの用紙Ｐ1，Ｐ2間の摩擦力が最上の用
紙Ｐ1を競り上げようとする応力と２枚目の用紙Ｐ2の
復元力ｆに耐えきれずに、（ｂ）に示すように、最上の
用紙Ｐ1と２枚目の用紙Ｐ2が分離される。分離された
最上の用紙Ｐ1はそのまま下流に搬送され続け、その後
端部が給紙ローラー２位置あたりに到達する頃には先端
部はその復元力により平坦状態に戻る。このように、本
実施例においては用紙Ｐの分離は給紙ローラー２の軸１
方向に沿った搬送速度の相違を利用して行うようになっ
ているので、給紙される用紙Ｐに紙折れが生じることが
なく、確実に給紙することができる。図６は本実施例の
変形例に係る待機状態における給紙ローラー軸方向の部
分断面図である。本変形例においては給紙ローラー２の
大径部２ａ，２ｂの側端部が軸１と接する位置に軸１に
摺接し、図示しない移動機構によって軸１方向の位置が
変えられる径可変筒４（ａ，ｂ）が設けられている。図
に示すように、移動機構によって径可変筒４（ａ，ｂ）
を内または外側に移動させた後、固定することにより、
大径部２ａ，２ｂの径φＤを変えることができる。用紙
Ｐの厚さが厚い時、または、大きな曲げ弾性を有してい
る時は径可変筒４（ａ，ｂ）を外側に移動させて径φＤ
を小さくし、用紙Ｐの厚さが薄い時、または、小さな曲
げ弾性を有している時は径可変筒４（ａ，ｂ）を内側に
移動させて径φＤを大きくすることにより、用紙Ｐの中
央部を競り上がらせる応力を最適な値に設定できる。FIG. 5 shows the state of the paper P that is fed out on the downstream side of the paper feed roller 2 in a superposed manner.
Shows the state immediately after the delivery, and (b) shows the state after a little time has passed. As shown in FIG. 5A, even if the uppermost sheet P1 happens to be double-fed together with the second sheet P2 , the above-mentioned central portion is removed in the subsequent portions of these sheets P1 and P2. The stress that keeps up the auction will continue to be applied,
Eventually, the frictional force between these sheets P1 and P2 cannot withstand the stress of trying to bid up the uppermost sheet P1 and the restoring force f of thesecond sheet P2 , as shown in (b). Thus, the uppermost sheet P1 and the second sheet P2 are separated. The separated uppermost sheet P1 continues to be conveyed downstream as it is, and when the rear end reaches the position around the feed roller 2, the front end returns to a flat state due to the restoring force. Thus, in this embodiment, the separation of the paper P is performed by the shaft 1 of the paper feed roller 2.
Since it is performed by utilizing the difference in the conveyance speeds along the direction, the paper P to be fed is not folded and the paper can be reliably fed. FIG. 6 is a partial cross-sectional view in the axial direction of the paper feed roller in a standby state according to a modified example of this embodiment. In the present modification, the variable diameter cylinder 4 in which the side ends of the large diameter portions 2a and 2b of the paper feed roller 2 are slidably contacted with the shaft 1 at positions where they are in contact with the shaft 1 and the position in the axial direction can be changed by a moving mechanism (not shown) (A, b) are provided. As shown in the figure, the variable diameter cylinder 4 (a, b) is moved by the moving mechanism.
After moving in or out, by fixing,
The diameter φD of the large diameter portions 2a and 2b can be changed. When the paper P has a large thickness or has a large bending elasticity, the variable diameter cylinder 4 (a, b) is moved to the outside and the diameter φD is changed.
When the thickness of the paper P is small, or when the paper P has a small bending elasticity, the diameter variable cylinder 4 (a, b) is moved inward to increase the diameter φD. It is possible to set the stress that makes the center part of the bid up to an optimum value.
【０００９】[0009]
【発明の効果】以上説明したように請求項１記載の発明
によれば、伸縮性に乏しい弾性体で形成された給紙ロー
ラーは軸方向に沿った中央部が中実の中実部と、その両
側に外周が肉薄部で区画されることにより内部に中空部
が形成され、自然状態において中実部の径より大きな径
を有した大径部からなり、大径部は加圧力を受けること
により、中空部内の空気圧に抗して肉薄部が内部に没入
し得るようにしたので、簡単、かつ、安価な構成で給紙
動作時の「用紙折れ」や「不送り」の発生を防止でき
る。請求項２記載の発明によれば、大径部は自然状態に
おいて軸方向に沿った断面における中央部が最大径で、
中央部から離れるに従って径が小さくなるような形状と
したので、用紙の分離動作を効率良く行うことができ
る。請求項３記載の発明によれば、大径部の軸方向に沿
った両端部と軸との固定位置を変えることにより、大径
部の径を変化させるようにしたので、厚さや曲げ弾性の
大きさが異なる用紙に対しても最適な分離能力を発揮で
きる。As described above, according to the first aspect of the present invention, the paper feed roller formed of the elastic material having poor stretchability has a solid central portion along the axial direction at a solid portion. A hollow part is formed inside by dividing the outer circumference on both sides with a thin part, and it consists of a large diameter part having a diameter larger than the diameter of the solid part in the natural state, and the large diameter part receives a pressing force. As a result, the thin portion can be sunk into the inside against the air pressure in the hollow portion, so it is possible to prevent the occurrence of "paper folding" and "non-feeding" during the paper feeding operation with a simple and inexpensive structure. . According to the invention described in claim 2, in the natural state, the large diameter portion has the maximum diameter in the central portion in the cross section along the axial direction,
Since the diameter is reduced as the distance from the central portion increases, it is possible to efficiently perform the sheet separating operation. According to the invention described in claim 3, since the diameter of the large diameter portion is changed by changing the fixing positions of the shaft and the both ends along the axial direction of the large diameter portion, Optimal separation performance can be achieved even for paper of different sizes.
【図１】本発明の実施例に係る給紙状態における給紙ロ
ーラーの軸方向の断面図FIG. 1 is an axial cross-sectional view of a paper feed roller in a paper feed state according to an embodiment of the present invention.
【図２】給紙状態における給紙ローラーの側面図FIG. 2 is a side view of the paper feed roller in a paper feed state.
【図３】待機状態における給紙ローラーの軸方向の断面
図FIG. 3 is a sectional view in the axial direction of the paper feed roller in a standby state.
【図４】給紙状態における給紙ローラーの用紙搬送状態
を示す斜視図および平面図FIG. 4 is a perspective view and a plan view showing a sheet conveyance state of a sheet feed roller in a sheet feed state.
【図５】給紙ローラーの下流側に重なって送り出された
用紙の状態を示す斜視図FIG. 5 is a perspective view showing a state of sheets that are sent out in an overlapping manner on the downstream side of a sheet feed roller.
【図６】実施例の変形例に係る待機状態における給紙ロ
ーラーの軸方向の部分断面図FIG. 6 is a partial cross-sectional view in the axial direction of a paper feed roller in a standby state according to a modified example of the embodiment.
１ 軸 ２ 給紙ローラー ２ａ，２ｂ 大径部 ２ｃ 小径部 ３ａ，３ｂ 中空部 ４（ａ，ｂ） 径可変筒 ５ 紙支持板 1 axis 2 paper feed rollers 2a, 2b large diameter part 2c small diameter part 3a, 3b hollow part 4 (a, b) variable diameter tube 5 paper support plate
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5127271AJPH06340343A (en) | 1993-05-28 | 1993-05-28 | Paper feeder |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5127271AJPH06340343A (en) | 1993-05-28 | 1993-05-28 | Paper feeder |
| Publication Number | Publication Date |
|---|---|
| JPH06340343Atrue JPH06340343A (en) | 1994-12-13 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5127271APendingJPH06340343A (en) | 1993-05-28 | 1993-05-28 | Paper feeder |
| Country | Link |
|---|---|
| JP (1) | JPH06340343A (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003054775A (en)* | 2001-08-08 | 2003-02-26 | Ricoh Co Ltd | Sheet conveying device and image forming device |
| KR20030067312A (en)* | 2002-02-08 | 2003-08-14 | 삼성전자주식회사 | Paper feeding apparatus for printing device |
| US6769679B2 (en) | 2002-04-10 | 2004-08-03 | Canon Kabushiki Kaisha | Roller, sheet feed apparatus, and image forming apparatus |
| US6962333B2 (en)* | 2002-03-20 | 2005-11-08 | Omron Corporation | Roller and sheet delivery unit |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003054775A (en)* | 2001-08-08 | 2003-02-26 | Ricoh Co Ltd | Sheet conveying device and image forming device |
| KR20030067312A (en)* | 2002-02-08 | 2003-08-14 | 삼성전자주식회사 | Paper feeding apparatus for printing device |
| US6962333B2 (en)* | 2002-03-20 | 2005-11-08 | Omron Corporation | Roller and sheet delivery unit |
| US6769679B2 (en) | 2002-04-10 | 2004-08-03 | Canon Kabushiki Kaisha | Roller, sheet feed apparatus, and image forming apparatus |
| Publication | Publication Date | Title |
|---|---|---|
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