JP2012236670A5

JP2012236670A5 -

Info

Publication number: JP2012236670A5
Application number: JP2011106155A
Authority: JP
Filing date: 2011-05-11
Publication date: 2014-06-26
Anticipated expiration: 2031-05-11

Description

ところで、記録シートの後端がローラ対を通過する際に記録シートの搬送精度が低下する原因の一つとして、上記のローラ対による後端はじき以外に、搬送ローラのたわみの存在がわかってきた。具体的には、記録シートが上流側と下流側とに配置された２つの搬送ローラにより搬送されている際に、これら２つの搬送ローラの速度差によって記録シートを介してこれらに引っ張り力もしくは反発力が発生する。この力によって発生した搬送ローラの搬送方向へのたわみは、ローラ対によるニップから記録シートの後端が抜けると解放され、これによって搬送ローラの復元量だけ記録シートが動いてしまう。 By the way, as one of the causes that the recording sheet conveyance accuracy decreases when the trailing edge of the recording sheet passes through the roller pair, it has been found that there is a deflection of the conveying roller in addition to the trailing edge repelling by the roller pair. . Specifically, when the recording sheet is conveyed by two conveying rollers arranged on the upstream side and the downstream side, a tensile force or repulsion is exerted on the recording sheet via the recording sheet due to a difference in speed between the two conveying rollers. Force is generated. Deflection of the conveying direction of the conveying rollers generated by this force is released and the trailing edge of the recording sheet from the nip by Russia over roller pair exits, thereby resulting in moving only the recording sheet recovery amount of the conveying roller.

本発明に係るシート搬送装置は、第１の搬送ローラと、前記第１の搬送ローラに付勢される第１の従動部材と、前記第１の搬送ローラに対してシートの搬送方向の下流側に配置された第２の搬送ローラと、前記第２の搬送ローラに付勢される第２の従動部材と、を有するシート搬送装置であって、前記第１および第２の搬送ローラのうち、少なくとも剛性の低い搬送ローラの側に設けられ、当該搬送ローラとこれに対応する従動部材との間に作用する圧接力を変更可能な圧接力変更機構と、シートが前記第１の搬送ローラおよび前記第１の従動部材にニップされ且つ前記第２の搬送ローラおよび前記第２の従動部材にニップされている状態から、当該シートの後端が前記第１の搬送ローラおよび前記第１の従動部材によるニップを抜ける前に、前記圧接力変更機構によって前記圧接力を変更させる制御手段と、を有することを特徴とする。 A sheet conveying apparatus according to the present invention, a first conveying roller, before Symbol a first driven member which is biased to the first conveying row La, the sheet conveying direction relative to the previous SL first conveying roller transportation of a second transportation roller arranged downstream, said second follower member is biased to the second conveying rows La, a sheet conveying apparatus having the first and second of roller, provided on the side of the lower conveying roller having at least rigid, and can change the pressure contact force changing mechanism the pressure contact force acting between the driven member corresponding thereto and the conveying roller, wherein the sheet over preparative second from the state of being two-up to the first conveying roller and the first is two-up to the driven member and the second conveying roller and the second driven member, the end after the equivalent 該Shi over preparative previous before it leaves the nip by the serial first conveying roller and the first driven member And having a control means for changing the pressing force by the pressing force changing mechanism.

次に、本実施形態に係る記録時の制御フローを説明する。図６は本発明の第１実施形態における制御動作のフローチャートである。図７は本発明の第１実施形態における各制御動作状態の搬送機構要素の状態を示した図である。記録命令が下されると、まず給紙部１によって給紙動作が行われる（５０１）。給紙された記録シートＰの先端部がエッジセンサによって検出されると、搬送モータが回転し搬送ローラ３が回転を始める（本実施形態では排紙ローラ４も同時に回転を始める）。記録シートＰの先端部が搬送ローラ３とピンチローラ５のニップ部に到達すると、所定のレジ取り動作が行われ、記録部１まで記録シートＰの先端部が搬送され画像記録作業が開始される。まず記録部１が搬送方向と直交する方向に走査することで記録動作が行われる（５０２）。その後、画像記録の終了判定（５０３）が行われる。画像記録が終了している場合（５０３にてＹＥＳ）は、記録シートＰの後端部が搬送ローラのニップ部を既に通過しているものと判定し、処理を終了する。他方、画像記録が終了していない場合（５０３にてＮＯ）は、後端部のニップ部の抜け判定（５０４）が行われる。ここでは、記録シートＰの後端がエッジセンサによって検出されたか否かによって、次回の紙送り動作で記録シートＰの後端が搬送ローラ３とピンチローラ５のニップ部を抜けるか否かが判定される。記録シートＰの後端がエッジセンサによって検出されていない場合（５０４にてＮＯ）、次回の紙送り動作では記録シートＰの後端部が搬送ローラのニップ部に到達しないので、搬送ローラ３による紙送り動作が行われる（５０５）。画像記録作業は、記録部１による記録動作（５０３）と、搬送ローラ３（もしくは搬送ローラ３と排紙ローラ４）による紙送り動作（５０５）を繰り返すことで実行される。記録シートＰの後端がエッジセンサによって検出され、次回の紙送り動作で記録シートＰの後端が搬送ローラ３とピンチローラ５のニップ部を抜けることが検知されると（５０４にてＹＥＳ）、圧接解除動作に移行する。 Next, a control flow during recording according to the present embodiment will be described. FIG. 6 is a flowchart of the control operation in the first embodiment of the present invention. FIG. 7 is a diagram showing the state of the transport mechanism element in each control operation state according to the first embodiment of the present invention. When a recording command is issued, a paper feeding operation is first performed by the paper feeding unit 1 (501). When the leading edge of the fed recording sheet P is detected by the edge sensor, the transport motor rotates and the transport roller 3 starts rotating (in the present embodiment, the paper discharge roller 4 also starts rotating simultaneously). When the leading end portion of the recording sheet P reaches the nip portion between the conveying roller 3 and the pinch roller 5, a predetermined registration operation is performed, and the leading end portion of the recording sheet P is conveyed to the recording portion 1 to start image recording work. . First, the recording operation is performed by the recording unit 1 scanning in a direction orthogonal to the transport direction (502). Thereafter, the end of image recording (503) is determined . If the image recording has been completed (YES in 503), it is determined that the trailing edge of the recording sheet P has already passed through the nip portion of the conveying roller, and the process is terminated. On the other hand, if the image recording has not been completed (NO in 503), the determination of nip removal at the rear end (504) is performed. Here, it is determined whether or not the trailing edge of the recording sheet P passes through the nip portion of the conveying roller 3 and the pinch roller 5 in the next paper feeding operation depending on whether or not the trailing edge of the recording sheet P is detected by the edge sensor. Is done. When the trailing edge of the recording sheet P is not detected by the edge sensor (NO in 504), the rear end of the recording sheet P in the next paper feed operation is INO reaches Shinano the nip portion of the conveying roller, the conveying roller 3 is performed (505). Image recording operation, the recording operation by the recording unit 1 (503), Ru is performed by repeating a conveying roller 3 (or the conveying roller 3 and the paper discharge roller 4) paper transporting operation by (505). The rear end of the record sheet P is thus detected in the edge sensor, at the trailing edge of the recording sheet P at the next paper feed operation is detected that leaves the nip of the conveying roller 3 and the pinch roller 5 (504 YES ), move to pressure release operation.

Claims

A first conveying roller, before Symbol a first driven member which is biased to the first conveying row La, before Symbol second disposed on the downstream side in the conveying direction of the sheet relative to the first conveying roller a of the conveying roller, a sheet conveying apparatus having a second driven member is energized, the said second conveying rows La,
Of the first and second transport rollers, a pressure contact force changing mechanism that is provided on the side of the transport roller having low rigidity and that can change the pressure contact force that acts between the transport roller and the corresponding driven member. and,
From a state where sheet over bets are two-up to the first conveying roller and the first is two-up to the driven member and the second conveying roller and the second driven member, the sheet over preparative before end that passes through the nip by the previous SL first conveying roller and the first driven member after the sheet, characterized in that it and a control means for changing the pressing force by the pressing force adjusting mechanism Conveying device.

The second conveying roller to the first conveying roller has a low have rigidity,
A first pressing force changing mechanism for changing the contact pressure between the first driven member and the first conveying roller,
Further comprising a second pressing force changing mechanism for changing the contact pressure between the second driven member and the second conveying roller,
Wherein, prior to before the rear end of carboxymethyl over bets is exiting the nip by the first conveying roller and the first driven member, the second pressing force changing mechanism to thus the second conveying roller reducing the pressure contact force between the second driven member and, thereafter, the pressure contact force between the first pressing force adjusting mechanism therefore the first conveying roller and the first driven member The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is decreased .

Wherein, prior to the stop state of carboxymethyl over preparative sheet conveying apparatus according to claim 1 or 2, characterized in that to reduce the pressure contact force.

Before Kitoma stop state, according to claim 3, the rear end of the front alkoxy over preparative is characterized in that it is a stopped state immediately before exiting the nip by the first transport roller and the first driven member Sheet conveying device.

The conveying speed of the first conveying roller, a sheet conveying apparatus according to any one of claims 1 to 4, characterized in that different from the conveying speed of the second conveying roller.

A recording unit that records an image on sheet over preparative, first conveying roller and a front Symbol first driven member which is biased to the first conveying row La, before Symbol first conveying roller for conveying the sheet a recording apparatus for chromatic and second transportation roller arranged downstream in the transport direction of the sheet, and a second driven member which is biased to the second conveying rows La, against,
Of the first and second transport rollers, a pressure contact force changing mechanism that is provided on the side of the transport roller having low rigidity and that can change the pressure contact force that acts between the transport roller and the corresponding driven member. When,
From a state where sheet over bets are two-up to the first conveying roller and the first is two-up to the driven member and the second conveying roller and the second driven member, the sheet over preparative before end that passes through the nip by the previous SL first conveying roller and the first driven member after the recording, characterized in that it and a control means for changing the pressing force by the pressing force adjusting mechanism apparatus.