JPH05193790A - Image forming device - Google Patents
Image forming deviceInfo
- Publication number
- JPH05193790A JPH05193790A JP4007646A JP764692A JPH05193790A JP H05193790 A JPH05193790 A JP H05193790A JP 4007646 A JP4007646 A JP 4007646A JP 764692 A JP764692 A JP 764692A JP H05193790 A JPH05193790 A JP H05193790A
- Authority
- JP
- Japan
- Prior art keywords
- recording paper
- time
- leading edge
- difference
- registration roller
- 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.)
- Granted
Links
Landscapes
- Conveyance By Endless Belt Conveyors (AREA)
- Registering Or Overturning Sheets (AREA)
- Paper Feeding For Electrophotography (AREA)
- Delivering By Means Of Belts And Rollers (AREA)
- Separation, Sorting, Adjustment, Or Bending Of Sheets To Be Conveyed (AREA)
- Replacement Of Web Rolls (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はレーザプリンタ、ファク
シミリ、複写機等の画像形成装置、特に画像形成装置の
記録紙の先端レジスト補正に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a laser printer, a facsimile, a copying machine, etc., and more particularly to correction of the leading edge registration of recording paper of the image forming apparatus.
【０００２】[0002]
【従来の技術】レーザプリンタ等の従来の画像形成装置
においては、給紙装置から給送される記録紙はレジスト
ローラに突き当てられ一旦停止しスキュー補正の後画像
担持体にタイミングを合わせてレジストローラをスター
トして記録紙の転写部への搬送が開始される。記録紙が
レジストローラに突き当たるとき、用紙の種類により、
レジストローラへの喰い込み量に変化を生じる。例えば
レーザプリンタに使用される用紙は５２kgの薄紙から１
３５kgの厚紙まで多様性がある。薄い紙はレジストロー
ラに対する喰い込み量が０であるのに対し、厚紙では腰
の強さ故に２〜３mmまでの喰い込みを生じることにな
る。このように喰い込み量が違う状態でレジストローラ
のスタートタイミングが一定であると、記録紙の種類に
よって画像担持体の転写位置に到達する記録紙の先端の
タイミングにずれを生じ、先端印字位置にずれを生じる
ことになる。今まではこのずれはそのまま許容するより
仕方がなかったが、このずれを解消し、紙質に関係なく
印字位置を一定させた画像形成装置が従来求められてい
た。2. Description of the Related Art In a conventional image forming apparatus such as a laser printer, a recording sheet fed from a sheet feeding unit is abutted against a registration roller and temporarily stopped, and after skew correction, the recording sheet is registered in timing with an image carrier. The rollers are started, and the conveyance of the recording paper to the transfer portion is started. When the recording paper hits the registration roller, depending on the paper type,
A change occurs in the amount of bite into the registration roller. For example, the paper used for laser printer is 1 from 52kg thin paper.
There is variety up to 35 kg of cardboard. In the case of thin paper, the amount of bite into the registration roller is 0, whereas in thick paper, the bite is up to 2 to 3 mm due to the strength of the waist. If the start timing of the registration roller is constant when the amount of bite is different as described above, the timing of the leading edge of the recording paper that reaches the transfer position of the image carrier may be deviated depending on the type of recording paper, and it may be misaligned to the printing position of the leading edge. Will occur. Until now, it was unavoidable to allow this deviation as it was, but there has been a demand for an image forming apparatus that eliminates this deviation and makes the printing position constant regardless of the paper quality.
【０００３】[0003]
【発明が解決しようとする課題】本発明は、上記の従来
の問題点を解消し、需要者の要求を満足するため、簡単
な安価な装置で紙質に関係なく記録紙の印字開始位置が
一定している画像形成装置を提供することを課題として
いる。SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and satisfies the demands of consumers. Therefore, the printing start position of the recording paper is constant regardless of the paper quality with a simple and inexpensive device. It is an object of the present invention to provide an image forming apparatus that operates.
【０００４】[0004]
【課題を解決するための手段】本発明は、上記の課題
を、給紙装置より給送され画像担持体の画像に対してタ
イミングをとってレジストローラにより搬送される記録
紙に前記画像担持体の画像を転写部により転写し、定着
装置により定着して排出する画像形成装置において、前
記レジストローラより給紙方向下流側に記録紙先端検出
手段を設け、予め定めた時点より前記記録紙先端検出手
段による先端検出までの時間を計測し、計測された時間
と予め設定されている時間との差を算出し、算出した差
に応じて前記レジストローラのスタート時間を調整する
ことを特徴とする画像形成装置により解決した。SUMMARY OF THE INVENTION According to the present invention, there is provided the above-mentioned object for a recording sheet fed from a sheet feeding device and conveyed by a registration roller at a timing relative to an image on the image bearing body. In the image forming apparatus in which the image of the above is transferred by the transfer unit, fixed by the fixing device and discharged, the recording paper leading edge detecting means is provided on the downstream side of the registration roller in the sheet feeding direction, and the recording paper leading edge is detected from a predetermined time. An image characterized in that the time until the leading edge is detected by the means is measured, the difference between the measured time and the preset time is calculated, and the start time of the registration roller is adjusted according to the calculated difference. It was solved by the forming device.
【０００５】[0005]
【作用】本発明により、レジストローラより給紙方向下
流側に設けた記録紙先端検出手段、例えば排紙センサ等
のジャム検知センサとして兼用されるセンサにより記録
紙の先端を検出し、予め定めた時点、例えば給紙コロ駆
動開始時点からの時間を計測し、計測された時間と予め
設定されている時間との差を算出し、算出した差に応じ
てレジストローラのスタート時間を調整する。レジスト
ローラへの喰い込み量の相違により記録紙先端検出手段
による検出時間に差が生じるので、その差を標準となる
時間を基準として算出し、レジストローラの駆動開始時
間をその差に応じて調整し、どのような場合にも記録紙
の先端が画像担持体の転写位置には所定のタイミングで
到達することを可能にする。According to the present invention, the leading edge of the recording sheet is detected by the recording sheet leading edge detecting means provided on the downstream side of the registration roller in the sheet feeding direction, for example, a sensor which is also used as a jam detecting sensor such as a sheet discharge sensor and is determined in advance. At the time, for example, the time from the start of driving the paper feed roller is measured, the difference between the measured time and the preset time is calculated, and the start time of the registration roller is adjusted according to the calculated difference. Since the detection time of the recording paper leading edge detection means varies due to the difference in the amount of bite into the registration roller, the difference is calculated with reference to the standard time and the drive start time of the registration roller is adjusted according to the difference. In any case, however, the leading edge of the recording paper can reach the transfer position of the image carrier at a predetermined timing.
【０００６】[0006]
【実施例】本発明の詳細を図に示す実施例に基づいて説
明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on the embodiments shown in the drawings.
【０００７】図１において、画像形成装置の一例として
両面記録可能なレーザプリンタ１では画像担持体２、例
えばＯＰＣベルトに帯電器３により帯電後光書き込み装
置４により画像信号に基づくレーザビームを投射して画
像の静電潜像を形成する。潜像は現像装置５により現像
されて顕像化される。In FIG. 1, a laser printer 1 capable of recording on both sides as an example of an image forming apparatus projects a laser beam based on an image signal by a post-charging optical writing device 4 on an image carrier 2, for example, an OPC belt by a charger 3. Form an electrostatic latent image of the image. The latent image is developed by the developing device 5 and visualized.
【０００８】給紙装置６、例えば給紙カセットから給紙
コロ７により給送される記録紙は搬送路８によりレジス
トローラ対９に搬送される。A recording sheet fed from a sheet feeding device 6, for example, a sheet feeding cassette by a sheet feeding roller 7 is conveyed to a registration roller pair 9 by a conveying path 8.
【０００９】レジストローラ対９の近くの上流側にはレ
ジストセンサ１０が配置され、記録紙の先端検出が行わ
れる。A registration sensor 10 is arranged on the upstream side near the registration roller pair 9 to detect the leading edge of the recording paper.
【００１０】レジストローラ対９により画像担持体２の
書き込みとタイミングを合わせて記録紙は給送され、転
写部１１の作用により画像担持体２、例えば感光ベルト
から顕像が転写され、定着装置１２を通る間に定着さ
れ、レジストローラ対９の下流側に配置された先端検知
センサ１３、例えばジャム検知センサの一例としての排
紙センサと兼用されるセンサを通過し、排紙ローラ１４
により排紙トレイに排紙される。先端検知センサ１３は
排紙センサのようなジャム検出のために一般に設けられ
るセンサと兼用するのではなく、なジャム検出センサと
は別に専用に設けることもできる。The recording paper is fed by the registration roller pair 9 at the same timing as the writing on the image carrier 2, and the image is transferred from the image carrier 2, for example, the photosensitive belt by the action of the transfer unit 11, and the fixing device 12 is provided. Passing through a leading edge detection sensor 13 disposed on the downstream side of the registration roller pair 9, for example, a sensor that also serves as a paper discharge sensor as an example of a jam detection sensor, and the paper discharge roller 14
Is discharged to the discharge tray. The leading edge detection sensor 13 does not also serve as a sensor that is generally provided for jam detection, such as a paper discharge sensor, but may be provided separately from the jam detection sensor.
【００１１】記録紙の表裏両面に画像を記録する場合に
は排紙トレイに至る排紙路から分岐される戻し路１６に
より両面給紙装置１７に一旦収納され、反転ローラ１８
により表裏を反転してレジストローラ対９に両面給紙路
１９を通って搬送されるように構成することができる。When recording images on both the front and back sides of the recording paper, the paper is temporarily stored in the double-sided paper feeding device 17 by the return path 16 branched from the paper discharge path to the paper discharge tray, and the reversing roller 18 is provided.
Thus, it is possible to reverse the front and back and to convey to the registration roller pair 9 through the double-sided paper feed path 19.
【００１２】画像形成の動作を図２に示すタイムチャー
トを基に説明する。The image forming operation will be described with reference to the time chart shown in FIG.
【００１３】給紙クラッチが入って給紙コロ７が作動
し、記録紙は給紙装置６より搬送され、記録紙はレジス
トセンサ１０により検知されて後レジストローラ対９に
当接する。記録紙の先端が停止しているレジストローラ
対９に当接して後尚所定時間給送コロ７の送りにより記
録紙にたるみが与えられ、スキュー補正が行なわれる。
記録紙にたるみが出来て後給紙クラッチはＯＦＦとなり
給紙コロが停止される。即ち給紙コロ７による給紙開始
後レジストセンサ１０が記録紙の先端を検出するまでの
時間をｔa とすると、その時間をｔa の経過後更に時間
ｔb だけ、すなわちレジストセンサ１０からレジストロ
ーラ９までの距離の搬送時間とスキュー補正時間に対応
する時間とを加えた時間だけ遅れて給紙コロ７が停止さ
れる。The paper feed clutch is engaged to operate the paper feed roller 7, the recording paper is conveyed from the paper feed device 6, and the recording paper is detected by the registration sensor 10 and abuts on the rear registration roller pair 9. The leading edge of the recording paper comes into contact with the stopped registration roller pair 9, and the slack is given to the recording paper by feeding the feeding roller 7 for a predetermined time, and skew correction is performed.
After the recording paper becomes slack, the rear paper feed clutch is turned off and the paper feed roller is stopped. That is, when the time until the registration sensor 10 detects the leading edge of the recording paper after the start of paper feeding by the paper feeding roller 7 is t a , the time is a further time t b after the elapse of t a , that is, the registration sensor 10 performs registration. The paper feed roller 7 is stopped after a delay of a time obtained by adding a transportation time of a distance to the roller 9 and a time corresponding to the skew correction time.
【００１４】記録紙をレジストローラ対９から転写部１
１まで搬送する時間と感光ベルト２に対する光書き込み
から転写部１１に至るまでの時間の違いにより一般に光
書き込みはレジストセンサ１０が記録紙の先端を検知す
る前に開始するようにしてある。すなわち給紙コロ７の
給紙開始後時間ｔ1 に光書き込み装置４による光書き込
みを開始する。The recording sheet is transferred from the registration roller pair 9 to the transfer section 1
Generally, the optical writing is started before the registration sensor 10 detects the leading edge of the recording paper due to the difference between the time for transporting to 1 and the time from the optical writing to the photosensitive belt 2 to the transfer section 11. That is, the optical writing by the optical writing device 4 is started at time t 1 after the feeding of the sheet feeding roller 7 is started.
【００１５】光書き込みは光書き込み装置４内の図示し
ないポリゴンモータの回転によりポリゴンミラーがレー
ザ光を記録紙上に送り方向に対し横方向（水平方向）
に、記録紙の幅に相当するエリアにわたって光走査す
る。The optical writing is performed by rotating a polygon motor (not shown) in the optical writing device 4 so that the polygon mirror laterally (horizontally) with respect to the feeding direction of the laser beam onto the recording paper.
First, the optical scanning is performed over an area corresponding to the width of the recording paper.
【００１６】レジストローラ９は感光体ベルト２の画像
に対してタイミングを合わせてスタートし記録紙の搬送
を開始する。給紙コロ７の停止後時間ｔc 経過時にレジ
ストローラ９が駆動を開始され、その時点が図２に示す
ように給紙コロ７の給送開始より時間ｔ2 に対応するこ
とになる。光書き込み時間を基準にすると、レジストロ
ーラ９のスタート時点までの時間をｔd とする。この時
間ｔd は光書き込み時ｔ1 から感光ベルト２の光書き込
み部が転写部に達する時間ｔ3 に至る時間間隔と、レジ
ストローラ９のスタート時間ｔ2 から記録紙が転写部に
達する時間ｔ3 に至る時間間隔との差に相当する。The registration roller 9 starts at the same timing as the image on the photosensitive belt 2 to start the conveyance of the recording paper. The registration roller 9 starts to be driven when a time t c elapses after the paper feed roller 7 is stopped, and that time corresponds to time t 2 from the start of feeding the paper feed roller 7 as shown in FIG. Based on the optical writing time, the time until the start of the registration roller 9 is t d . This time t d is a time interval from the optical writing time t 1 to the time t 3 at which the optical writing portion of the photosensitive belt 2 reaches the transfer portion, and the time t from the start time t 2 of the registration roller 9 to the recording portion at the recording paper. It corresponds to the difference from the time interval up to 3 .
【００１７】感光体ベルト２への光書き込み位置及び記
録紙が転写部１１に達する時間ｔ3 は一定であるが、レ
ジストローラ９のスタート時間ｔ2 、即ち上記の給紙コ
ロ７の停止後レジストローラスタート迄の時間ｔc 及び
光書き込み時間を基準にしてレジストローラ９のスター
ト時点までの時間ｔd には用紙のレジストローラ９との
関係でばらつきを生じ、変化する。例えば時間ｔc は±
Δｔc の時間変動を伴う。The optical writing position on the photoconductor belt 2 and the time t 3 for the recording paper to reach the transfer portion 11 are constant, but the start time t 2 of the registration roller 9, that is, the registration after the feeding roller 7 is stopped. The time t c until the roller starts and the time t d until the start time of the registration roller 9 based on the optical writing time are varied due to the relation with the registration roller 9 of the sheet and change. For example, the time t c is ±
Accompanying time variation of Δt c .
【００１８】転写された記録紙は定着装置１２により定
着され、先端検出センサ１０、例えば排紙センサにより
先端を検出される。その検出時点迄の給紙コロ７による
給紙開始からの時間をｔ4 とすると、時間ｔ4 は記録搬
送の過程の障害により変化する可能性があり、更に搬送
過程に障害がなくても、停止時のレジストローラ９にた
いする記録紙先端の喰い込み量が記録紙のこわさ、つま
り腰の強さにより変化することに伴う変化±Δｔ4 があ
る。The transferred recording paper is fixed by the fixing device 12, and the front end is detected by the front end detection sensor 10, for example, the paper ejection sensor. Assuming that the time from the start of paper feeding by the paper feeding roller 7 until the detection time point is t 4 , the time t 4 may change due to an obstacle in the process of recording and conveying, and even if there is no obstacle in the conveying process, There is a change ± Δt 4 due to the amount of biting of the leading edge of the recording paper against the registration roller 9 when stopped due to the stiffness of the recording paper, that is, the strength of the waist.
【００１９】感光ベルト２への光書き込みは給紙コロ７
のスタートから一定時間ｔ1 後に行われ、転写部に到達
する時間ｔ3 も一定である。しかるにレジストローラ９
に対する記録紙の喰い込み量にばらつきがあると、レジ
ストローラ９のスタート時間ｔ2 が一定であれば記録紙
の先端が転写部に達する時間は変化する。つまり記録紙
は先端レジスト量を補正する必要がある。Optical writing on the photosensitive belt 2 is performed by a paper feeding roller 7.
It is performed after a constant time t 1 from the start of the above, and the time t 3 to reach the transfer portion is also constant. However, the registration roller 9
If there is a variation in the amount of biting of the recording paper with respect to, if the start time t 2 of the registration roller 9 is constant, the time for the leading edge of the recording paper to reach the transfer portion changes. That is, it is necessary to correct the leading edge resist amount of the recording paper.
【００２０】レジストローラ９への喰い込み量が多いと
きは、記録紙は先端検出サンセ１３、例えば排紙センサ
による基準検出時間ｔ4 に対して検出時間が早くなり、
偏差時間−Δｔ4 だけ検出時間にずれを生じる。逆に喰
い込み量が少ないときは検出が遅くなり、基準検出時間
ｔ4 に対して偏差時間＋Δｔ4 だけずれを生じる。この
偏差時間±Δｔ4 を補正するために、すなわち先端レジ
スト補正のために、レジストローラ９のスタート時間を
調整する。例えば先端検出センサ１３による検出時間が
早いときはレジストローラ９のスタート時間を偏差時間
Δｔ4 だけ遅らし（すなわち＋Δｔ4 ）、逆に遅く検出
するときは偏差時間Δｔ4 だけ早める（すなわち−Δｔ
4 ）。When the amount of biting into the registration roller 9 is large, the recording paper has a shorter detection time than the reference detection time t 4 by the leading edge detection sensor 13, for example, the paper discharge sensor,
A deviation occurs in the detection time by the deviation time −Δt 4 . On the contrary, when the bite amount is small, the detection becomes slow, and the deviation is caused by the deviation time + Δt 4 with respect to the reference detection time t 4 . In order to correct this deviation time ± Δt 4 , that is, in order to correct the leading edge registration, the start time of the registration roller 9 is adjusted. For example, when fast detection time by the tip detecting sensor 13 Okurashi the start time of the registration rollers 9 by the deviation time Delta] t 4 (i.e. + Δt 4), when detecting slow reverse hasten only deviation Time Delta] t 4 (i.e. -Δt
4 ).
【００２１】記録紙先端検出手段１３は排紙センサと兼
用する例を示したが他のセンサと兼用するように変える
こともできるし、更に単独で所望位置に配置することも
できる。The recording paper leading edge detecting means 13 has been shown as an example in which it is also used as a paper discharge sensor, but it may be changed so as to be used also as another sensor, or may be independently arranged at a desired position.
【００２２】給紙装置６より給紙される記録紙の表面に
感光体ベルト２より画像を転写し、定着して後両面給紙
装置１７に一旦収容し、反転ローラ１８により表裏を反
転してレジストローラ９に給送して記録紙の裏面に画像
を転写し、定着する両面画像形成の場合には、記録紙は
一度画像形成されると、定着装置１２を通過することに
より水分を蒸発し、記録紙の腰の強さに変化を生じた
り、カールを生じたりする。このため記録紙が停止して
いるレジストローラ９に突き当たる場合に生じる喰い込
み量は表面画像形成時と裏面画像形成時では微妙に変化
する。したがって記録紙の表面と裏面では画像形成位置
に変化を生じることになる。この表裏面の画像位置ずれ
を補正するために記録紙の表面と裏面では別々に上記の
先端レジスト補正作業を行う。An image is transferred from the photosensitive belt 2 onto the surface of the recording paper fed from the paper feeding device 6, fixed, and then once accommodated in the rear double-sided paper feeding device 17, and the front and back sides are reversed by the reversing roller 18. In the case of double-sided image formation in which an image is transferred to the registration roller 9 to transfer the image to the back surface of the recording paper and then fixed, once the recording paper is imaged, the recording paper passes through the fixing device 12 to evaporate moisture. , The waist strength of the recording paper may change or curl may occur. For this reason, the amount of biting that occurs when the recording paper hits the stopped registration roller 9 slightly changes between the front surface image formation and the back surface image formation. Therefore, the image forming position changes on the front surface and the back surface of the recording paper. In order to correct the image positional deviation on the front and back surfaces, the above-mentioned front end registration correction work is separately performed on the front surface and the back surface of the recording paper.
【００２３】先端レジスト補正は記録紙の給紙の最初に
１回行ない、その後は補正した先端レジスト量により給
紙を行って複数枚の画像形成をすることも可能である
し、複数枚の画像形成時には、所定の枚数毎に先端レジ
スト量を算出して平均的な先端レジスト量を出してその
平均レジスト量を補正するようにしてもよい。The leading edge registration correction may be performed once at the beginning of feeding the recording paper, and thereafter, the feeding may be performed according to the corrected leading edge registration amount to form a plurality of images. At the time of formation, the leading edge resist amount may be calculated for each predetermined number of sheets, and an average leading edge resist amount may be obtained to correct the average resist amount.
【００２４】上記の用紙の先端を検出するのに対し、図
４に示すように記録紙２０にマーク２１を付し、先端検
出手段１３をマーク検出手段に変形して、前記マーク２
１を検出することにより上記と同様にして先端レジスト
補正を行うことができる。このマーク２１を付する方法
は記録紙の先端が直線状でなく凹凸を有するような場合
に検出を正確にする効果がある。In contrast to detecting the leading edge of the above-mentioned sheet, a mark 21 is attached to the recording sheet 20 as shown in FIG. 4, the leading edge detecting means 13 is transformed into the mark detecting means, and the mark 2
By detecting 1, the front end resist correction can be performed in the same manner as above. The method of attaching the mark 21 has an effect of making the detection accurate when the leading end of the recording paper is not linear but has irregularities.
【００２５】画像形成装置の制御装置を図５に示すよう
に形成し、先端レジスト補正量を読み書き可能で不揮発
性のストアＥ2 ＰＲＯＭに記憶させると、プリンタの電
源がＯＦＦした場合にも引き続いて補正を正確に行うこ
とができる。両面画像形成の場合も同様である。図５に
おいては信号処理はＣＰＵ内蔵のＡＳｉＣで行われる。When the control unit of the image forming apparatus is formed as shown in FIG. 5 and the leading edge resist correction amount is stored in the readable / writable and non-volatile store E 2 PROM, it continues even when the power of the printer is turned off. The correction can be performed accurately. The same applies to double-sided image formation. In FIG. 5, signal processing is performed by ASiC with a built-in CPU.
【００２６】給紙装置からレジストローラ９に至る搬送
路における用紙と搬送ローラとの間のスリップ等により
記録紙がレジストローラ９に到達するまでの時間のばら
つきはレジストセンサ１０の記録紙先端検出後のレジス
トローラ９のスタートする時間ｔ2 が変化されることに
より吸収されることができる。After the detection of the leading edge of the recording paper by the registration sensor 10, the time variation until the recording paper reaches the registration roller 9 due to a slip between the paper and the conveyance roller in the conveyance path from the paper feeding device to the registration roller 9 is detected. It can be absorbed by changing the start time t 2 of the registration roller 9 of FIG.
【００２７】変形例として、記録紙先端検出手段１３は
記録紙先端検出と同時にマーク検出手段、例えばライン
マークを読み取り可能な手段として形成し、予め設定さ
れている情報に基づいて感光体ベルト２により最初に給
紙される記録紙にマークを記録し、先端検出手段１３、
例えば排紙センサにより記録紙の先端とマークとを検出
する方法も可能である。図３に示すタイムチャートに示
すように作動し、時間ｔ1 、ｔ2 、ｔ3 、ｔ4 、ｔa 、
ｔb 、ｔc 、ｔd は夫々図２に示す例と同様の時間を示
す。記録紙先端検出手段１３により記録紙先端を検出し
た時間ｔ4 から記録されたマーク、例えばラインマーク
２１を記録紙先端検出手段１３により検出する迄の時間
ｔe を計測し、その計測時間ｔe を予め設定した基準時
間と比較し、その差Δｔe を演算し、その差Δｔe に応
じてレジストローラスタート時間ｔ2 を補正する方法も
可能である。マークを記録するタイミングは予め設定さ
れているので、記録紙の喰い込み量が変化すると、その
変化量だけ、記録紙の先端からマーク迄の距離が変化す
る。この変化をレジストローラスタート時間ｔ2 を調整
して補正し、どの種の記録紙でも、所定の位置に画像形
成を可能にする。上記の例と同様にこの例も両面画像形
成に適応できる。As a modified example, the recording paper leading edge detecting means 13 is formed as a mark detecting means, for example, a means capable of reading a line mark at the same time as the recording paper leading edge detection, and the photosensitive belt 2 is made to operate based on preset information. A mark is recorded on the recording paper fed first, and the leading edge detecting means 13,
For example, a method of detecting the leading edge of the recording paper and the mark with a paper discharge sensor is also possible. It operates as shown in the time chart of FIG. 3 and operates at times t 1 , t 2 , t 3 , t 4 , t a ,
Each of t b , t c , and t d indicates the same time as in the example shown in FIG. The time t e from the time t 4 when the recording paper leading edge detecting means 13 detects the recording paper leading edge to the time when the recorded mark, for example, the line mark 21 is detected by the recording paper leading edge detecting means 13 is measured, and the measured time t e Can be compared with a preset reference time, the difference Δt e can be calculated, and the registration roller start time t 2 can be corrected according to the difference Δt e . Since the mark recording timing is set in advance, when the biting amount of the recording paper changes, the distance from the leading edge of the recording paper to the mark changes by the amount of change. This change is corrected by adjusting the registration roller start time t 2 so that an image can be formed at a predetermined position on any kind of recording paper. Like the above example, this example is also applicable to double-sided image formation.
【００２８】この補正情報を図６の制御装置のＥ2 ＰＲ
ＯＭに記憶することによりパワーオフ後にもテスト印字
の補正情報を維持することができ、予めテスト記録紙に
より先端レジスト量の補正量を算出すればその後の記録
紙の先端レジスト補正はパワーオフ後でも継続して実施
することが可能である。前記の差Δｔe は両面画像形成
の場合の表面と裏面に対し共に測定し、表面、裏面共に
夫々個別に先端レジスト補正すると表裏両面に正確に画
像形成が可能になる。This correction information is used as the E 2 PR for the control device of FIG.
By storing in the OM, the correction information of the test print can be maintained even after the power is turned off. If the correction amount of the leading edge resist amount is calculated by the test recording paper in advance, the leading edge registration correction of the recording paper can be performed even after the power is turned off. It can be continued. In the case of double-sided image formation, the difference Δt e is measured both on the front surface and the back surface, and when the front end resist correction is performed on both the front surface and the back surface individually, it is possible to accurately form the image on the front and back surfaces.
【００２９】[0029]
【発明の効果】本発明により、紙先端検出手段に記録紙
先端が到達する時間の差に応じてレジストローラのスタ
ート時間を調整して、常に正確に記録紙の所定位置に画
像を形成することが可能になり、しかも記録紙の種類に
関係なく所定位置に画像形成が可能になった 先端検出手段を従来使われる排紙センサと兼用すること
になり特別の機械部品を追加すことがなく、安価な費用
で画像形成位置に正確な画像形成装置が得られた。According to the present invention, the start time of the registration roller is adjusted according to the difference in the time when the leading edge of the recording sheet reaches the sheet leading edge detecting means, so that an image is always accurately formed at a predetermined position on the recording sheet. In addition, the leading edge detection means that can form an image at a predetermined position regardless of the type of recording paper can also be used as a paper ejection sensor that has been used conventionally, without adding special mechanical parts. An accurate image forming apparatus can be obtained at an image forming position at a low cost.
【００３０】本発明により、画面画像形成の場合には表
裏両面夫々に適当した補正をするのでより良好な結果が
得られた。According to the present invention, in the case of screen image formation, appropriate correction is made on both the front and back sides, so that better results are obtained.
【００３１】記録紙先端の代わりにマークを検出するよ
うにすれば記録紙の先端形状が一定しない記録紙につい
ても正確な位置に画像形成可能になった。By detecting the mark instead of the leading edge of the recording sheet, it is possible to form an image at an accurate position even on a recording sheet having a non-uniform leading edge.
【００３２】本発明により、記録紙に画像担持体により
所定のタイミングでマークを記録し、そのマークの記録
紙先端よりの距離の変化を計測し、その変化量によりレ
ジストローラのスタート時間を調整して常に正確に記録
紙の所定位置に画像を形成することが可能になる。画面
画像形成の場合には表裏両面夫々に適当した補正をする
のでより良好な結果が得られた。According to the present invention, a mark is recorded on a recording paper by an image carrier at a predetermined timing, a change in the distance of the mark from the front end of the recording paper is measured, and the start time of the registration roller is adjusted by the change amount. Therefore, it becomes possible to always form an image at a predetermined position on the recording paper accurately. In the case of screen image formation, better results were obtained because appropriate corrections were made on both the front and back sides.
【図１】本発明に係る画像形成装置の全体概略図であ
る。FIG. 1 is an overall schematic diagram of an image forming apparatus according to the present invention.
【図２】作動タイムチャートである。FIG. 2 is an operation time chart.
【図３】別の例の作動タイムチャートである。FIG. 3 is an operation time chart of another example.
【図４】記録紙にマークを付した例の平面図である。FIG. 4 is a plan view of an example in which a mark is attached to a recording sheet.
【図５】制御装置のブロック図である。FIG. 5 is a block diagram of a control device.
１ 画像形成装置 ２ 画像担持体 ４ 光書き込み装置 ６ 給紙装置 ９ レジストローラ １０ レジストセンサ １１ 転写部 １２ 定着装置 １３ 先端検出手段 DESCRIPTION OF SYMBOLS 1 Image forming device 2 Image carrier 4 Optical writing device 6 Paper feeding device 9 Registration roller 10 Registration sensor 11 Transfer unit 12 Fixing device 13 Tip detection means
Claims (7)
に対してタイミングをとってレジストローラにより搬送
される記録紙に前記画像担持体の画像を転写部により転
写し、定着装置により定着して排出する画像形成装置に
おいて、 前記レジストローラより給紙方向下流側に記録紙先端検
出手段を設け、予め定めた時点より前記記録紙先端検出
手段による先端検出までの時間を計測し、計測された時
間と予め設定されている時間との差を算出し、算出した
差に応じて前記レジストローラのスタート時間を調整す
ることを特徴とする画像形成装置。1. An image of the image carrier is transferred by a transfer unit onto a recording paper fed from a paper feeding device and conveyed by registration rollers at a timing relative to the image of the image carrier, and is fixed by a fixing device. In the image forming apparatus that ejects the recording paper, the recording paper leading edge detecting means is provided on the downstream side of the registration roller in the sheet feeding direction, and the time from the predetermined time to the leading edge detection by the recording paper leading edge detecting means is measured and measured. The image forming apparatus is characterized by calculating a difference between a preset time and a preset time, and adjusting the start time of the registration roller according to the calculated difference.
ラより下流側に配置されたジャム検知手段と兼用され、
該先端検出手段による検知信号に基づいてジャム処理と
レジストローラのスタート時間調整を行うことを特徴と
する請求項１に記載の画像形成装置。2. The recording paper leading edge detecting means is also used as a jam detecting means arranged downstream of the registration roller,
The image forming apparatus according to claim 1, wherein the jam processing and the registration roller start time adjustment are performed based on a detection signal from the leading edge detection unit.
路と、該戻し路により搬送される記録紙を収容し、表裏
反転給送する両面給紙装置と、該両面給紙装置よりレジ
ストローラに反転した記録紙を搬送する両面搬送路とを
設け、 記録紙の表面と裏面について夫々前記先端検出信号によ
り時間を計測し、夫々基準時間との差を算出し、その差
に応じて表面と裏面について夫々レジストローラの時間
を調整することを特徴とする請求項１又は２に記載の画
像形成装置。3. A return path branched from a paper discharge path after the fixing device, a double-sided paper feeding apparatus for accommodating and feeding the recording paper conveyed by the return path, and a double-sided paper feeding apparatus. A double-sided conveyance path for conveying the reversed recording paper to the registration roller is provided, the time is measured by the leading edge detection signal for each of the front surface and the back surface of the recording paper, and the difference from the reference time is calculated respectively, and the difference is calculated according to the difference. The image forming apparatus according to claim 1, wherein the time of the registration rollers is adjusted for the front surface and the back surface, respectively.
紙を給送し、前記先端検出手段をマーク検出手段として
形成し、前記マークの検出時間を測定し予め設定された
基準時間との差を算出することを特徴とする請求項１〜
３のいずれか１つに記載の画像形成装置4. A recording paper to which a mark indicating the leading edge line is previously attached is fed, the leading edge detecting means is formed as mark detecting means, and the detection time of the mark is measured to obtain a reference time which is set in advance. A difference is calculated, Claim 1 characterized by the above-mentioned.
The image forming apparatus according to any one of 3 above.
に対してタイミングをとってレジストローラにより搬送
される記録紙に前記画像担持体の画像を転写部により転
写し、定着装置により定着して排出する画像形成装置に
おいて、 前記レジストローラより給紙方向下流側に記録紙先端検
出兼マーク検出手段を設け、前記画像担持体により所定
のタイミングで記録紙にマークを形成し、前記記録紙先
端検出兼マーク検出手段により記録紙の先端及びとマー
クを検出し、先端検出からマーク検出迄の時間を測定
し、その時間の予め設定した基準時間との差を算出し、
その差だけレジストローラのスタート時間を調整するこ
とを特徴とする画像形成装置。5. The image of the image carrier is transferred to a recording sheet fed by a sheet feeding device and conveyed by registration rollers at a timing relative to the image of the image carrier, and is fixed by a fixing device. In the image forming apparatus that ejects the recording paper, the recording paper front end detection / mark detection means is provided on the downstream side of the registration roller in the paper feeding direction, and the image carrier forms a mark on the recording paper at a predetermined timing. The leading edge detection and mark detecting means detects the leading edge and the mark of the recording paper, measures the time from the leading edge detection to the mark detection, and calculates the difference between the time and a preset reference time,
An image forming apparatus characterized in that the start time of the registration roller is adjusted by the difference.
路と、該戻し路により搬送される記録紙を収容し、表裏
反転給送する両面給紙装置と、該両面給紙装置よりレジ
ストローラに反転した記録紙を搬送する両面搬送路とを
設け、 記録紙の表面と裏面についてそれぞれ画像担持体により
マークを記録し、表裏それぞれについて先端検出からマ
ーク検出までの時間と基準時間との差よりレジストロー
ラのスタート時間を調整することを特徴とする請求項５
に記載の画像形成装置。6. A return path branched from a paper discharge path after the fixing device, a double-sided paper feeding apparatus for accommodating and feeding the recording paper conveyed by the return path, and a double-sided paper feeding apparatus. The registration roller is provided with a double-sided conveyance path for conveying the reversed recording paper, and marks are recorded by the image carrier on the front and back sides of the recording paper. The start time of the registration roller is adjusted based on the difference.
The image forming apparatus according to item 1.
時間調整量を読み書き可能な不揮発性メモリに記憶させ
ることを特徴とする請求項１〜６のいずれか１つに記載
の画像形成装置。7. The image forming apparatus according to claim 1, wherein a start / start time adjustment amount of the registration roller is stored in a readable / writable nonvolatile memory.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00764692A JP3147962B2 (en) | 1992-01-20 | 1992-01-20 | Image forming device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00764692A JP3147962B2 (en) | 1992-01-20 | 1992-01-20 | Image forming device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05193790A true JPH05193790A (en) | 1993-08-03 |
| JP3147962B2 JP3147962B2 (en) | 2001-03-19 |
Family
ID=11671592
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP00764692A Expired - Fee Related JP3147962B2 (en) | 1992-01-20 | 1992-01-20 | Image forming device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3147962B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008036825A (en) * | 2006-08-01 | 2008-02-21 | Olympus Corp | Image recorder, ink pre-ejection method by the same, and program |
| US8107873B2 (en) | 2006-06-02 | 2012-01-31 | Sharp Kabushiki Kaisha | Image forming apparatus conveying sheets based on previously conveyed sheets |
| US8135290B2 (en) | 2008-06-10 | 2012-03-13 | Canon Kabushiki Kaisha | Image forming apparatus |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4421835B2 (en) | 2003-03-28 | 2010-02-24 | ブラザー工業株式会社 | Image forming apparatus |
| JP6004297B1 (en) * | 2015-11-06 | 2016-10-05 | 吉則 早川 | Multiplication and division abacus |
-
1992
- 1992-01-20 JP JP00764692A patent/JP3147962B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8107873B2 (en) | 2006-06-02 | 2012-01-31 | Sharp Kabushiki Kaisha | Image forming apparatus conveying sheets based on previously conveyed sheets |
| JP2008036825A (en) * | 2006-08-01 | 2008-02-21 | Olympus Corp | Image recorder, ink pre-ejection method by the same, and program |
| US8135290B2 (en) | 2008-06-10 | 2012-03-13 | Canon Kabushiki Kaisha | Image forming apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3147962B2 (en) | 2001-03-19 |
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