JPH06286904A - Paper conveying mechanism for image forming device - Google Patents
Paper conveying mechanism for image forming deviceInfo
- Publication number
- JPH06286904A JPH06286904A JP5073838A JP7383893A JPH06286904A JP H06286904 A JPH06286904 A JP H06286904A JP 5073838 A JP5073838 A JP 5073838A JP 7383893 A JP7383893 A JP 7383893A JP H06286904 A JPH06286904 A JP H06286904A
- Authority
- JP
- Japan
- Prior art keywords
- roller
- paper
- sheet
- rollers
- upstream
- 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.)
- Pending
Links
Landscapes
- Delivering By Means Of Belts And Rollers (AREA)
- Paper Feeding For Electrophotography (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、電子写真方式の複写
機、レーザープリンタ等の画像形成装置における用紙の
搬送を行う用紙搬送機構に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper carrying mechanism for carrying paper in an image forming apparatus such as an electrophotographic copying machine and a laser printer.
【0002】[0002]
【従来の技術】従来の複写機やレーザープリンタ等の画
像形成装置において、用紙搬送時に用紙のたるみを防止
するために、感光体を挟んで配された定着ローラとペー
パーストップローラ(PSローラ)に周速差を持たせ、
定着ローラで用紙を常に引っ張るようにして搬送してい
た。しかしながら、用紙の後端がPSローラから抜ける
と、その瞬間用紙の後端が振動して、その振動が用紙の
前方向へ伝搬して転写装置まで達する。これが原因で、
転写ズレが発生し、画質に悪影響を及ぼすという問題点
があった。2. Description of the Related Art In a conventional image forming apparatus such as a copying machine or a laser printer, a fixing roller and a paper stop roller (PS roller) arranged with a photoconductor interposed therebetween are provided in order to prevent the slack of the paper when the paper is conveyed. Giving a difference in peripheral speed,
The paper was always conveyed while being pulled by the fixing roller. However, when the trailing edge of the sheet comes out of the PS roller, the trailing edge of the sheet vibrates at that moment, and the vibration propagates in the front direction of the sheet and reaches the transfer device. Because of this,
There has been a problem that transfer deviation occurs and the image quality is adversely affected.
【0003】この問題を解決するために、図6の如く、
定着ローラ1とPSローラ2との間の搬送路3中で、特
にPSローラ2側の感光体4および転写装置5付近に、
用紙Yを強制的に転写ケース6側へ押し付ける押圧部材
7(PET材、薄い弾性板やクッション材等)を設け
て、用紙Yの後端がPSローラ2から抜ける時の振動を
抑え、振動が用紙Yの転写装置5側の前方向へ伝搬しな
いようにしていた。In order to solve this problem, as shown in FIG.
In the conveying path 3 between the fixing roller 1 and the PS roller 2, especially near the photoconductor 4 and the transfer device 5 on the PS roller 2 side,
By providing a pressing member 7 (PET material, thin elastic plate, cushion material, etc.) forcibly pressing the paper Y to the transfer case 6 side, the vibration when the trailing edge of the paper Y comes out of the PS roller 2 is suppressed. The sheet Y is prevented from propagating in the forward direction on the transfer device 5 side.
【0004】[0004]
【発明が解決しようとする課題】しかしながら、この従
来の方法では、用紙Yの後端が押圧部材7から抜ける時
に、用紙Yの後端が振動するため、完全に転写ズレを防
止することができなかった。However, in this conventional method, when the trailing edge of the sheet Y comes out of the pressing member 7, the trailing edge of the sheet Y vibrates, so that the transfer deviation can be completely prevented. There wasn't.
【0005】また、押圧部材7をできるだけ転写装置5
の近傍に設ける必要があるので、周囲が狭い転写装置5
付近での組立作業は、非常に作業性が悪く、画像形成装
置としての品質の安定性が悪くなるといった問題があっ
た。Further, the pressing member 7 is provided as much as possible to the transfer device 5.
Since it is necessary to provide it in the vicinity of the
Assembling work in the vicinity has very poor workability, and there is a problem that the stability of the quality of the image forming apparatus deteriorates.
【0006】さらに、用紙Yが定着ローラ1とPSロー
ラ2の間で、常に定着ローラ1側に引っ張られているの
で、用紙YがPSローラ2から抜ける瞬間、その反動で
PSローラ2の駆動力に大きな負荷変動が発生し、この
影響によりPSローラ2の回転ムラが発生する。そし
て、PSローラ2の駆動系統と他の搬送ローラの駆動系
統が同じであるため、他の搬送ローラの駆動にも影響を
与え、他の搬送ローラの回転ムラを誘発し、これが原因
で転写ズレが発生するといった問題があった。Further, since the sheet Y is always pulled toward the fixing roller 1 between the fixing roller 1 and the PS roller 2, at the moment when the sheet Y comes out of the PS roller 2, the driving force of the PS roller 2 is generated by its reaction. In this case, a large load fluctuation occurs, which causes uneven rotation of the PS roller 2. Since the drive system of the PS roller 2 and the drive system of the other transport rollers are the same, it also affects the drive of the other transport rollers and induces rotation unevenness of the other transport rollers, which causes transfer deviation. There was a problem that occurred.
【0007】本発明は、上記に鑑み、搬送中の用紙の振
動を抑えて転写ズレを防止できる画像形成装置の用紙搬
送機構の提供を目的とする。In view of the above, it is an object of the present invention to provide a sheet conveying mechanism of an image forming apparatus capable of suppressing the vibration of the sheet being conveyed and preventing the transfer deviation.
【0008】[0008]
【課題を解決するための手段】本発明請求項1による課
題解決手段は、用紙搬送方向上流側に上下一対の用紙搬
送ローラが配され、下流側に上下一対の用紙搬送ローラ
が配され、前記上流側の用紙搬送ローラおよび前記下流
側の用紙搬送ローラに対してその上下のローラのうちど
ちらか一方のローラを回転駆動させる駆動部36が設け
られ、前記下流側の用紙搬送ローラの周速が前記上流側
の用紙搬送ローラの周速よりも僅か速く設定され、前記
上流側の用紙搬送ローラの回転軸と駆動部36との間
に、ローラの回転方向と同方向にのみ回転駆動する一方
向クラッチ37が介装されたものである。According to a first aspect of the present invention, a pair of upper and lower sheet conveying rollers are arranged on the upstream side in the sheet conveying direction, and a pair of upper and lower sheet conveying rollers are arranged on the downstream side. A drive unit 36 for rotating and driving one of the upper and lower rollers of the upstream side sheet transport roller and the downstream side sheet transport roller is provided, and the peripheral speed of the downstream side sheet transport roller is set. One direction that is set to be slightly higher than the peripheral speed of the upstream paper transport roller and is rotationally driven only between the rotation axis of the upstream paper transport roller and the drive unit 36 in the same direction as the rotation direction of the roller. The clutch 37 is interposed.
【0009】請求項2による課題解決手段は、前記用紙
搬送方向下流側の用紙搬送ローラを定着ローラ31と
し、前記上流側の用紙搬送ローラをPSローラ30とし
たものである。According to a second aspect of the present invention, the sheet conveying roller on the downstream side in the sheet conveying direction is the fixing roller 31, and the sheet conveying roller on the upstream side is the PS roller 30.
【0010】請求項3による課題解決手段は、前記用紙
搬送方向下流側の用紙搬送ローラをPSローラ30と
し、前記上流側の用紙搬送ローラを給紙カセット26か
ら給紙された用紙YをPSローラ30へ送る紙送りロー
ラ32としたものである。According to a third aspect of the present invention, in the means for solving the problem, the paper carrying roller on the downstream side in the paper carrying direction is the PS roller 30, and the paper carrying roller on the upstream side is the PS roller for the paper Y fed from the paper feeding cassette 26. It is a paper feed roller 32 for feeding to 30.
【0011】請求項4による課題解決手段は、前記用紙
搬送方向下流側の用紙搬送ローラを定着ローラ31と
し、前記上流側の用紙搬送ローラをPSローラ30と
し、該PSローラ30の上流側に紙送りローラ32が配
され、該紙送りローラ32も上流側の用紙搬送ローラと
されたものである。According to a fourth aspect of the present invention, there is provided a means for solving the problems, in which the sheet conveying roller on the downstream side in the sheet conveying direction is the fixing roller 31, the sheet conveying roller on the upstream side is the PS roller 30, and the sheet on the upstream side of the PS roller 30. A feed roller 32 is provided, and the paper feed roller 32 is also an upstream side paper feed roller.
【0012】請求項5による課題解決手段は、前記一方
向クラッチ37が前記上下一対の用紙搬送ローラの両
方、あるいはどちらか一方に介装されたものである。According to a fifth aspect of the present invention, the one-way clutch 37 is provided on either or both of the pair of upper and lower sheet conveying rollers.
【0013】[0013]
【作用】上記請求項1による課題解決手段において、用
紙搬送時に用紙搬送上流側の用紙搬送ローラと下流側の
用紙搬送ローラの周速差によって、用紙Yには徐々に大
きな張力が作用する。そして、用紙Yの張力がある程度
大きくなると、上流側の用紙搬送ローラの回転軸と駆動
部36の間に介装された一方向クラッチ37により、上
流側の用紙搬送ローラは駆動部36の駆動力に影響され
ず、下流側の用紙搬送ローラと同じ周速で同方向に回転
して、用紙Yの後端が上流側の用紙搬送ローラからスム
ーズに抜けていく。In the means for solving the problems according to the above-mentioned claim 1, when the sheet is conveyed, a large tension is gradually applied to the sheet Y due to the peripheral speed difference between the sheet conveying roller on the upstream side and the sheet conveying roller on the downstream side. Then, when the tension of the sheet Y becomes large to some extent, the one-way clutch 37 interposed between the rotary shaft of the upstream-side sheet transport roller and the drive unit 36 causes the upstream-side sheet transport roller to drive the driving force of the drive unit 36. Is not affected by the above, the rear end of the sheet Y is smoothly removed from the upstream sheet transport roller by rotating in the same peripheral speed as the downstream sheet transport roller in the same direction.
【0014】請求項2,3,4による課題解決手段にお
いて、用紙搬送時にPSローラ30あるいは紙送りロー
ラ32から用紙Yの後端が抜けるとき、各ローラ30,
32に設けられた一方向クラッチ37がそのショックを
和らげ、各ローラ30,32の駆動力の負荷変動を抑え
る。In the means for solving the problems according to claims 2, 3 and 4, when the trailing edge of the paper Y comes out of the PS roller 30 or the paper feed roller 32 during the paper transport, the rollers 30,
The one-way clutch 37 provided in 32 absorbs the shock and suppresses the load fluctuation of the driving force of each roller 30, 32.
【0015】請求項5による課題解決手段において、用
紙搬送時に用紙Yの張力が大きくなると、上下一対のロ
ーラの両方、あるいはどちらか一方に設けられた一方向
クラッチ37によって、ローラがその回転方向と同方向
に回転され、ローラの回転ムラをなくす。In the means for solving the problem according to the fifth aspect, when the tension of the sheet Y is increased during the sheet conveyance, the roller is rotated in the direction of rotation thereof by the one-way clutch 37 provided on both or one of the pair of upper and lower rollers. It is rotated in the same direction, eliminating uneven rotation of the rollers.
【0016】[0016]
【実施例】図1は本発明の一実施例を示す画像形成装置
の用紙搬送機構の構成図、図2は本実施例のPSローラ
の駆動部を示す断面図、図3は一方向クラッチの作動機
構を示し、(A)はクラッチかみ合い時を示す図、
(B)はクラッチ空転時を示す図、図4はレーザープリ
ンタの全体構成図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a sheet conveying mechanism of an image forming apparatus showing an embodiment of the present invention, FIG. 2 is a sectional view showing a drive portion of a PS roller of the present embodiment, and FIG. 3 is a one-way clutch. The operating mechanism is shown, (A) is a figure which shows the time of clutch engagement,
FIG. 4B is a diagram showing a state in which the clutch is idling, and FIG.
【0017】本実施例のレーザープリンタの全体構成を
図4に基づいて説明する。図4において、20はプリン
タ本体、21は半導体レーザー等の光学系ユニット、2
2は帯電装置、クリーニング装置が一体とされたドラム
カートリッジ、23は感光体、24は現像カートリッ
ジ、25は転写装置、26は給紙カセット、27は給紙
ローラ、28は給紙カセット26内の用紙の有無を検知
する用紙検知器、29は給紙カセット26から給紙され
た用紙をローラによって感光体23へ送ってその後排紙
させる用紙搬送機構である。The overall structure of the laser printer of this embodiment will be described with reference to FIG. In FIG. 4, 20 is a printer main body, 21 is an optical system unit such as a semiconductor laser, and 2
2 is a drum cartridge in which a charging device and a cleaning device are integrated, 23 is a photoconductor, 24 is a developing cartridge, 25 is a transfer device, 26 is a paper feed cassette, 27 is a paper feed roller, and 28 is a paper feed cassette 26. A paper detector 29 for detecting the presence or absence of paper, and a paper transport mechanism 29 for sending the paper fed from the paper feed cassette 26 to the photoconductor 23 by the rollers and then ejecting the paper.
【0018】そして、用紙搬送機構29は、感光体23
に対して用紙搬送方向上流側に上下一対のPSローラ3
0が配され、下流側に上下一対の定着ローラ31が配さ
れている。なお、図4中、32は紙送りローラ、33は
排紙ローラ、34,35は紙通過検知器である。Then, the paper transport mechanism 29 is provided with the photoconductor 23.
A pair of upper and lower PS rollers 3 are provided on the upstream side in the paper transport direction with respect to
0 is arranged, and a pair of upper and lower fixing rollers 31 is arranged on the downstream side. In FIG. 4, 32 is a paper feed roller, 33 is a paper discharge roller, and 34 and 35 are paper passage detectors.
【0019】前記PSローラ30は、プリンタ本体20
に回転自在に軸受されたローラ軸30aと、該ローラ軸
30aに外嵌固定されたローラ体30bとを備え、該ロ
ーラ体30bの表面にはゴム体30cが外嵌固定されて
いる。そして、図1の如く、ローラ軸30aを矢印a方
向に回転させる駆動部36が設けられ、ローラ軸30a
と駆動部36との間に、ローラの回転方向と同方向に回
転駆動する一方向クラッチ37が介装されている。The PS roller 30 is the printer body 20.
A roller shaft 30a rotatably supported on the roller shaft 30a and a roller body 30b externally fitted and fixed to the roller shaft 30a are provided, and a rubber body 30c is externally fitted and fixed to the surface of the roller body 30b. Then, as shown in FIG. 1, a drive unit 36 for rotating the roller shaft 30a in the direction of the arrow a is provided.
A one-way clutch 37 that is rotationally driven in the same direction as the rotation direction of the roller is interposed between the drive unit 36 and the drive unit 36.
【0020】前記定着ローラ31は、プリンタ本体20
に回転自在に軸受され、図示しないモータからの駆動力
によってPSローラ30の周速よりも1〜2%速い周速
で駆動される。The fixing roller 31 is the printer body 20.
Is rotatably supported by the motor and is driven at a peripheral speed that is 1 to 2% faster than the peripheral speed of the PS roller 30 by a driving force from a motor (not shown).
【0021】前記駆動部36は、図2の如く、モータか
らの駆動力により回転されるギア38と、該ギア38と
かみ合ってギア38からの駆動力により回転する駆動ギ
ア39と、該駆動ギア39とかみ合って従動回転する従
動ギア40とからなる。そして、駆動ギア39はPSロ
ーラ30の下側を回転させ、従動ギア40はPSローラ
30の上側を回転させる。As shown in FIG. 2, the drive unit 36 includes a gear 38 rotated by a drive force from a motor, a drive gear 39 engaged with the gear 38 and rotated by a drive force from the gear 38, and the drive gear. It is composed of a driven gear 40 meshed with 39 and driven to rotate. Then, the drive gear 39 rotates the lower side of the PS roller 30, and the driven gear 40 rotates the upper side of the PS roller 30.
【0022】前記一方向クラッチ37は、駆動ギア39
および従動ギア40に内嵌固定されている。そして、図
3(A)の如く、駆動ギア39および従動ギア40が矢
印a方向に回転するとき、クラッチ37の外輪41が同
方向に回転しようとし、ばね42のスプリング作用で、
ころ43は外輪カム面44のかみ合い位置に進み、外輪
カム面44とPSローラ30のローラ軸30aとのくさ
び作用でローラ軸30aを駆動する。The one-way clutch 37 has a drive gear 39.
It is also fitted and fixed to the driven gear 40. Then, as shown in FIG. 3A, when the drive gear 39 and the driven gear 40 rotate in the arrow a direction, the outer ring 41 of the clutch 37 tries to rotate in the same direction, and the spring action of the spring 42 causes
The roller 43 advances to the meshing position of the outer ring cam surface 44, and drives the roller shaft 30a by the wedge action of the outer ring cam surface 44 and the roller shaft 30a of the PS roller 30.
【0023】また、図3(B)の如く、外輪41が停止
しているとき、ローラ軸30aを矢印a方向に回転させ
ると、ころは外輪カム面44のかみ合い位置から離れ、
ローラ軸30aは外輪41に対して空転する。Further, as shown in FIG. 3B, when the outer ring 41 is stopped and the roller shaft 30a is rotated in the direction of arrow a, the roller is separated from the meshing position of the outer ring cam surface 44,
The roller shaft 30a idles with respect to the outer ring 41.
【0024】したがって、各ギア39,40が矢印a方
向に回転し、クラッチ37がかみ合ってPSローラ30
を駆動しているとき、PSローラ30に各ギア39,4
0の駆動力よりも大きな駆動力が同方向に加わると、P
Sローラ30は矢印a方向に各ギア39,40の回転に
先行して回転する。Therefore, the gears 39 and 40 rotate in the direction of arrow a, the clutch 37 is engaged, and the PS roller 30 is engaged.
When driving the PS roller 30, each gear 39, 4
If a driving force larger than 0 is applied in the same direction, P
The S roller 30 rotates in the direction of arrow a prior to the rotation of the gears 39 and 40.
【0025】上記構成において、給紙カセット26から
給紙された用紙Yが、紙送りローラ32からPSローラ
30へと搬送される。ここで、一時停止されてから感光
体23の回転のタイミングに合わせてPSローラ30が
駆動され、感光体23側へと送り込まれる。In the above structure, the paper Y fed from the paper feed cassette 26 is conveyed from the paper feed roller 32 to the PS roller 30. Here, after being temporarily stopped, the PS roller 30 is driven at the timing of the rotation of the photoconductor 23 and is fed to the photoconductor 23 side.
【0026】そして、転写装置25により用紙Yにトナ
ー像が転写された後、用紙Yは定着ローラ31側へと搬
送され、定着ローラ31にかみ込まれる。Then, after the toner image is transferred onto the paper Y by the transfer device 25, the paper Y is conveyed to the fixing roller 31 side and caught in the fixing roller 31.
【0027】このとき、用紙Yの後端がPSローラ30
に残っているので、用紙Yが定着ローラ31にかみ込ま
れていくと、定着ローラ31とPSローラ30の周速差
によって、用紙Yには徐々に大きな張力が作用する。し
かし、用紙Yの張力がある程度大きくなると、PSロー
ラ30のローラ軸30aとギア39,40の間に介装さ
れた一方向クラッチ37の作用により、PSローラ30
はギア38の駆動力で得られる周速よりも早く回転し、
用紙Yの搬送速度と同じ速度で回転し始める。At this time, the trailing edge of the sheet Y is the PS roller 30.
As the sheet Y is bitten into the fixing roller 31, a large tension gradually acts on the sheet Y due to the difference in peripheral speed between the fixing roller 31 and the PS roller 30. However, when the tension of the sheet Y becomes large to some extent, the PS roller 30 is actuated by the action of the one-way clutch 37 interposed between the roller shaft 30a of the PS roller 30 and the gears 39 and 40.
Rotates faster than the peripheral speed obtained by the driving force of the gear 38,
The paper Y starts to rotate at the same speed as the conveyance speed.
【0028】そして、用紙Yの搬送は定着ローラ31の
駆動力に依存することとなり、用紙Yにはたわまない程
度の張力がかかり、両ローラ30,31間をたわむこと
なく搬送され、用紙Yの後端がPSローラ30からスム
ーズに抜けていく。Then, the conveyance of the sheet Y depends on the driving force of the fixing roller 31, and the sheet Y is applied with a tension not to bend, and is conveyed between the rollers 30 and 31 without bending. The rear end of Y smoothly comes out of the PS roller 30.
【0029】その後、用紙Yは定着ローラ31により排
出ローラ33へと送られ、排出ローラ33にて排出され
る。そして、以上の動作が所定枚数回だけ繰り返され
る。After that, the sheet Y is sent to the discharge roller 33 by the fixing roller 31 and discharged by the discharge roller 33. Then, the above operation is repeated a predetermined number of times.
【0030】このように、用紙搬送時に定着ローラ31
とPSローラ30との周速差によって、用紙Yに作用す
る張力が大きくなっても、PSローラ30のローラ軸3
0aとギア39,40の間に介装された一方向クラッチ
37によって、PSローラ30はギア39からの駆動力
に影響されることなく、定着ローラ31と同じ周速で同
方向に回転可能となる。As described above, the fixing roller 31 is used when the sheet is conveyed.
Even if the tension acting on the sheet Y increases due to the difference in peripheral speed between the PS roller 30 and the PS roller 30, the roller shaft 3 of the PS roller 30
The one-way clutch 37 interposed between 0a and the gears 39 and 40 enables the PS roller 30 to rotate in the same direction as the fixing roller 31 at the same peripheral speed without being affected by the driving force from the gear 39. Become.
【0031】したがって、用紙Yにはたわまない程度の
張力がかかり、両ローラ30,31間をたわむことなく
搬送され、用紙Yの後端がPSローラ30からスムーズ
に抜けて振動がなくなるので、転写装置25での転写ズ
レを防止することができ、画質の向上が可能となる。ま
た、PSローラ30の駆動力の負荷変動が抑えられ、P
Sローラ30の回転ムラをなくすことができるので、P
Sローラ30の駆動に連動して駆動される他の用紙搬送
ローラにも悪影響を与えない。Therefore, the tension is applied to the paper Y so that it does not bend, and the paper Y is conveyed between the rollers 30 and 31 without bending, and the rear end of the paper Y is smoothly removed from the PS roller 30 and vibration is eliminated. The transfer deviation in the transfer device 25 can be prevented, and the image quality can be improved. Further, the load fluctuation of the driving force of the PS roller 30 is suppressed, and P
Since the rotation unevenness of the S roller 30 can be eliminated, P
It does not adversely affect other paper transport rollers that are driven in association with the driving of the S roller 30.
【0032】なお、本発明は、上記実施例に限定される
ものではなく、本発明の範囲内で上記実施例に多くの修
正および変更を加え得ることは勿論である。The present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes can be made to the above embodiment within the scope of the present invention.
【0033】例えば、上記実施例では、PSローラ30
に一方向クラッチ37を設けたが、図5のようにPSロ
ーラ30とその上流側の紙送りローラ32に一方向クラ
ッチ37を設けても良い。あるいは紙送りローラ32に
一方向クラッチ37を設けても良い。また、一方向クラ
ッチ37を一対のローラの両方に設けたが、どちらか一
方だけでも良い。For example, in the above embodiment, the PS roller 30
Although the one-way clutch 37 is provided in the above, the one-way clutch 37 may be provided in the PS roller 30 and the paper feed roller 32 on the upstream side thereof as shown in FIG. Alternatively, the paper feed roller 32 may be provided with the one-way clutch 37. Further, although the one-way clutch 37 is provided on both the pair of rollers, only one of them may be provided.
【0034】さらに、上記実施例の定着ローラ31とP
Sローラ30との周速差は、モータからの駆動力をギア
等を介して、各ローラ軸30a,31aの回転速度を変
えていたが、各ローラ軸30a,31aの回転速度を同
一にすると共に、定着ローラ31の直径をPSローラ3
0の直径よりも大きくして周速差を設定しても良い。Further, the fixing roller 31 and P of the above embodiment are used.
As for the peripheral speed difference with the S roller 30, the rotational speeds of the roller shafts 30a and 31a were changed by using the driving force from the motor via gears, but the rotational speeds of the roller shafts 30a and 31a are the same. In addition, the diameter of the fixing roller 31 is set to the PS roller 3
The peripheral speed difference may be set to be larger than the diameter of 0.
【0035】[0035]
【発明の効果】以上の説明から明らかな通り、本発明請
求項1,5によると、用紙から受ける張力によって、上
流側の用紙搬送ローラにその駆動力よりも大きな力がか
かっても、一方向クラッチにより周速を速くし、下流側
の用紙搬送ローラと同じ速度で同方向に回転駆動するの
で、用紙に悪影響を及ぼすことを排除している。As is apparent from the above description, according to claims 1 and 5 of the present invention, even if a force larger than the driving force is applied to the upstream side sheet conveying roller by the tension received from the sheet, it is unidirectional. Since the peripheral speed is increased by the clutch and the downstream side sheet conveying roller is driven to rotate in the same direction at the same speed, the adverse effect on the sheet is eliminated.
【0036】したがって、用紙にはたわまない程度の張
力がかかり、両ローラ間をたわむことなく搬送され、用
紙の後端が上流側の用紙搬送ローラからスムーズに抜け
て振動がなくなるので、転写装置での転写ズレを防止す
ることができ、画質の向上が可能となる。また、上流側
の用紙搬送ローラの駆動力の負荷変動が抑えられ、ロー
ラの回転ムラをなくすことができる。Therefore, tension is applied to the paper so that the paper is not bent, and the paper is conveyed between the rollers without bending, and the trailing edge of the paper is smoothly removed from the paper conveyance roller on the upstream side to eliminate vibration. It is possible to prevent transfer deviation in the apparatus and improve image quality. Further, the load fluctuation of the driving force of the upstream-side sheet conveying roller is suppressed, and the uneven rotation of the roller can be eliminated.
【0037】請求項2,3,4によると、一方クラッチ
をPSローラ、あるいはPSローラと紙送りローラ、ま
たは紙送りローラに設けることにより、用紙が各ローラ
から抜ける時のショックが減少し、各ローラの駆動力の
負荷変動が抑えられるといった優れた効果がある。According to the second, third, and fourth aspects, by providing the one-side clutch on the PS roller, the PS roller and the paper feed roller, or the paper feed roller, the shock when the paper comes out of each roller is reduced, There is an excellent effect that the load fluctuation of the driving force of the roller is suppressed.
【図1】本発明の一実施例を示す画像形成装置の用紙搬
送機構の構成図FIG. 1 is a configuration diagram of a sheet conveying mechanism of an image forming apparatus showing an embodiment of the present invention.
【図2】本実施例のPSローラの駆動部を示す断面図FIG. 2 is a cross-sectional view showing a drive unit of the PS roller of this embodiment.
【図3】(A)は一方向クラッチのクラッチかみ合い時
を示す図、(B)は一方向クラッチのクラッチ空転時を
示す図FIG. 3A is a diagram showing a one-way clutch when the clutch is engaged, and FIG. 3B is a diagram showing a one-way clutch when the clutch is idling.
【図4】レーザープリンタの全体構成図[Fig. 4] Overall configuration of laser printer
【図5】他の実施例を示す画像形成装置の用紙搬送機構
の構成図FIG. 5 is a configuration diagram of a sheet transport mechanism of an image forming apparatus according to another embodiment.
【図6】従来の画像形成装置の用紙搬送機構の構成図FIG. 6 is a configuration diagram of a sheet transport mechanism of a conventional image forming apparatus.
30 PSローラ 31 定着ローラ 32 紙送りローラ 36 駆動部 37 一方向クラッチ 30 PS roller 31 Fixing roller 32 Paper feed roller 36 Drive unit 37 One-way clutch
Claims (5)
送ローラが配され、下流側に上下一対の用紙搬送ローラ
が配され、前記上流側の用紙搬送ローラおよび前記下流
側の用紙搬送ローラに対してその上下のローラのうちど
ちらか一方のローラを回転駆動させる駆動部が設けら
れ、前記下流側の用紙搬送ローラの周速が前記上流側の
用紙搬送ローラの周速よりも僅か速く設定され、前記上
流側の用紙搬送ローラの回転軸と前記駆動部との間に、
ローラの回転方向と同方向にのみ回転駆動する一方向ク
ラッチが介装されたことを特徴とする画像形成装置の用
紙搬送機構。1. A pair of upper and lower sheet conveying rollers is arranged on the upstream side in the sheet conveying direction, and a pair of upper and lower sheet conveying rollers is arranged on the downstream side, and the upstream sheet conveying roller and the downstream sheet conveying roller are arranged. On the other hand, a drive unit for rotating and driving one of the upper and lower rollers is provided, and the peripheral speed of the downstream side paper transport roller is set to be slightly higher than the peripheral speed of the upstream side paper transport roller. , Between the rotary shaft of the upstream side sheet transport roller and the drive unit,
A sheet conveying mechanism for an image forming apparatus, comprising a one-way clutch that is rotationally driven only in the same direction as the roller rotation direction.
機構において、前記用紙搬送方向下流側の用紙搬送ロー
ラを定着ローラとし、前記上流側の用紙搬送ローラをペ
ーパーストップローラとしたことを特徴とする画像形成
装置の用紙搬送機構。2. The sheet transport mechanism of the image forming apparatus according to claim 1, wherein the downstream sheet transport roller in the sheet transport direction is a fixing roller, and the upstream sheet transport roller is a paper stop roller. The paper transport mechanism of the image forming apparatus.
機構において、前記用紙搬送方向下流側の用紙搬送ロー
ラをペーパーストップローラとし、前記上流側の用紙搬
送ローラを給紙カセットから給紙された用紙をペーパー
ストップローラへ送る紙送りローラとしたことを特徴と
する画像形成装置の用紙搬送機構。3. The paper transport mechanism of the image forming apparatus according to claim 1, wherein the paper transport roller downstream of the paper transport direction is a paper stop roller, and the upstream paper transport roller is fed from a paper feed cassette. A paper feed mechanism for an image forming apparatus, which is a paper feed roller that feeds the formed paper to a paper stop roller.
機構において、前記ペーパーストップローラの上流側に
紙送りローラが配され、該紙送りローラが請求項1記載
の上流側の用紙搬送ローラとされたことを特徴とする画
像形成装置の用紙搬送機構。4. The paper transport mechanism of the image forming apparatus according to claim 2, wherein a paper feed roller is arranged upstream of the paper stop roller, and the paper feed roller is the upstream paper transport roller according to claim 1. A sheet conveying mechanism for an image forming apparatus characterized by the above.
上下一対の用紙搬送ローラの両方、あるいはどちらか一
方に介装されたことを特徴とする画像形成装置の用紙搬
送機構。5. The sheet conveying mechanism of an image forming apparatus, wherein the one-way clutch according to claim 1 is interposed between both or one of the pair of upper and lower sheet conveying rollers.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5073838A JPH06286904A (en) | 1993-03-31 | 1993-03-31 | Paper conveying mechanism for image forming device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5073838A JPH06286904A (en) | 1993-03-31 | 1993-03-31 | Paper conveying mechanism for image forming device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH06286904A true JPH06286904A (en) | 1994-10-11 |
Family
ID=13529686
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP5073838A Pending JPH06286904A (en) | 1993-03-31 | 1993-03-31 | Paper conveying mechanism for image forming device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH06286904A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7570914B2 (en) | 2004-10-06 | 2009-08-04 | Samsung Electronics Co., Ltd. | Image forming apparatus and a paper feeding apparatus for the same |
CN101930193A (en) * | 2009-06-25 | 2010-12-29 | 富士施乐株式会社 | Sheet length measuring apparatus, image forming apparatus, and sheet length measuring method |
CN110712418A (en) * | 2019-10-18 | 2020-01-21 | 嘉峪关天源新材料有限责任公司 | Device for correcting deviation of composite plate strip steel |
-
1993
- 1993-03-31 JP JP5073838A patent/JPH06286904A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7570914B2 (en) | 2004-10-06 | 2009-08-04 | Samsung Electronics Co., Ltd. | Image forming apparatus and a paper feeding apparatus for the same |
CN101930193A (en) * | 2009-06-25 | 2010-12-29 | 富士施乐株式会社 | Sheet length measuring apparatus, image forming apparatus, and sheet length measuring method |
US20100329759A1 (en) * | 2009-06-25 | 2010-12-30 | Fuji Xerox Co., Ltd. | Sheet length measuring apparatus, image forming apparatus, and sheet length measuring method |
CN110712418A (en) * | 2019-10-18 | 2020-01-21 | 嘉峪关天源新材料有限责任公司 | Device for correcting deviation of composite plate strip steel |
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