JP3981336B2 - Paper transport device - Google Patents

Description

この傾斜角で想定される用紙の最大見掛け幅Ｂ’は、幅方向寸法をＢ、搬送方向寸法をＬとすると、
Ｂ’＝Ｌ×ｓｉｎθ＋Ｂｃｏｓθ
で求まる。
制御手段が、進入してくるスキュー用紙の最大見掛け幅Ｂ’が、受け入れ待機位置（Ｂ＋α）より過大であると判断したとき（Ｓ８）、つまりＢ’＞（Ｂ＋α）のときには、用紙揃えジョガー３８を用紙受け入れ位置より外側に退避させ（Ｂ’＜（Ｂ＋α）となるまで）、斜行用紙の衝突を回避する（Ｓ１０）。
それ以外は通常動作として内側（用紙幅まで）へ移動させ揃え動作を行いスタック動作が完了する（Ｓ９）。しかしながら、用紙Ｐがスキューしてかつ横ズレを起こしている場合が考えられるので、この退避位置は最大退避位置となるホームポジションが望ましく（Ｂ’≪（Ｂ＋α））、また制御の簡素化につながる。また、同時にジャム警告を出してジョブを停止（中断）させる（Ｓ１１、Ｓ１２）。
【０００９】
【発明の効果】
以上説明したように、請求項１によれば、搬送されてくる用紙の位置補正を行うためのガイド部材と、搬送されてくる用紙の斜行状態（スキュー）を検知する検知手段を備え、その検知手段の信号情報に基づいて、ガイド部材の退避動作を行うことによって、不測の事態で発生する過大スキュー紙とガイド部材の衝突による極度のダメージジャムを防止し、ユーザーのジャム紙除去性を大幅向上させるとともに、部品破損の回避も可能となる。
請求項２によれば、少なくとも２つの検知センサ以上の検知手段により、その通過時間より用紙の斜行状態を算出し、その情報を基に、より確実な退避制御が可能となる。
請求項３によれば、ホームポジションとすることで制御の簡素化を図ることができ、それによって、より確実な待機条件となるＢ’≪ Ｂ＋αを十分に満足できる。
【図面の簡単な説明】
【図１】本発明に関わる画像処理装置を示す概略全体図である。
【図２】両面に画像を作像する場合の用紙搬送経路のみを示す概略図である。
【図３】両面ユニットに設けてある、スイッチバック搬送路の構成と用紙揃え機構（位置補正）について説明する概略斜視図である。
【図４】用紙揃えジョガーの動作を説明する概略図である。
【図５】用紙揃えジョガーの動作フローを示すフローチャートである。
【図６】用紙受け入れ位置に進入してくる用紙の過大にスキューを示す概略図である。
【図７】スキュー検知センサを示す概略図である。
【符号の説明】
１ ホームポジションセンサ（基準センサ）
２ 駆動ベルト（ガイド部材駆動手段）
３ 駆動モータ（ガイド部材駆動手段）
３８ ガイド部材（用紙揃えジョガー）
４５ スキュー検知センサ（用紙姿勢検知手段）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet conveying device in an image processing apparatus such as a copying machine, a printer, and a facsimile.
[0002]
[Prior art]
A technology that includes a sensor that detects a skew state of a sheet and controls the driving of a feed roller based on the signal is known (for example, see Patent Document 1), and a sensor that detects a skew state of a sheet. There is also known a technique for performing control printing in which an image is rotated based on the information (see, for example, Patent Document 2).
[Patent Document 1]
Japanese Utility Model Publication No. 2-83737 [Patent Document 2]
Japanese Patent Laid-Open No. 2000-94807
[Problems to be solved by the invention]
In recent years, with the digitalization of copying machines and the rapid spread of printers and the like, improvements in image position accuracy and punch hole position accuracy by a post-processing system are required as issues for improving quality. Particularly for duplex units, the importance of duplex copying, which can reduce paper consumption due to environmental resource problems, is increasing.
In particular, in a paper reversing device (double-sided device), since the conveyance path is longer than normal single-sided copying in order to reverse the paper, it is difficult to prevent paper skew, which causes different front and back copy quality. (Paper misalignment).
2. Description of the Related Art Conventionally, there is a method for correcting a positioning by using a side fence jogger or the like as a means for correcting skew and lateral registration of a sheet reversing device by temporarily storing a sheet in an intermediate tray.
In this method, the side fence interval is set in advance at a position slightly wider than the paper width, and the incoming paper is accepted. When aligning the sheets, the interval is set to the sheet width (the side fence fence is moved), and the aligning operation is performed with respect to the side edges of the sheets.
As a malfunction of this method, there is no problem when the paper enters almost straight, but if the paper enters due to excessive skew for some reason (unexpected situation), it collides with the side fence, Extreme damage jams may occur. This greatly deteriorates the user's ability to remove jammed paper and, in some cases, leads to breakage of parts.
SUMMARY OF THE INVENTION An object of the present invention is to provide a paper transport device in an image processing apparatus that can cope with unexpected situations such as a paper jogger fence collision.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention according to claim 1, a guide member that corrects the position of the sheet by regulating a side edge of the sheet and is movable according to the sheet size, In a paper conveying apparatus comprising a reference sensor for detecting a reference position during operation of the guide member, a driving means for moving the guide member, and a control means for controlling the driving means, the conveying direction of the guide member On the upstream side, there is provided paper orientation detection means for detecting the skew state of the paper entering between the spans of the guide member, and the control unit is configured to detect the paper based on detection information from the paper orientation detection means. When the skew state is determined to be excessive, the drive means is controlled to retract the guide member to the outside of the paper reception standby position.
According to a second aspect of the present invention, in the first aspect, the paper posture detection means is configured by at least two or more detection means provided in a direction substantially orthogonal to the transport direction, and is based on a passage timing difference at the front end of the paper. In this case, the skew amount of the sheet is detected, and the control unit controls the driving unit based on information detected by the sheet attitude detection unit to retract the guide member.
According to a third aspect of the present invention, in the first or second aspect, the retracted position of the guide member is a home position that is an operation reference position.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic overall view showing an image processing apparatus according to the present invention. M is an apparatus for automatically reading a sheet document. The document placed on the document table N is fed to the position of the document reading sensor G by the feeding roller O.
The original passes through the position of the original reading sensor G at a constant speed, and at this time, the image on the front side of the original is read by the original reading sensor G. The read image data is sequentially stored in the image memory after undergoing image processing (various correction, compression, etc.).
The reading unit 20 is a unit for scanning a document placed on the pressure plate. This is composed of a contact glass 6 on which an original is placed and an optical scanning system. The optical scanning system includes an exposure lamp 21, a first mirror 22, a second mirror 25, a third mirror 26, a lens 23, and a CCD image. It consists of a sensor 24 and the like. The document image is read by the CCD image sensor 24, converted into an electrical signal, and processed.
The writing unit 27 includes a laser output unit 28, an imaging lens 29, and a mirror 30, and laser light output from the writing unit 27 is applied to the image forming photoconductor 15.
The procedure for printing an image formed on the photoreceptor is roughly as follows. The sheets stacked on the first tray 8, the second tray 9, and the third tray 10 are fed by the first paper feeding device 11, the second paper feeding device 12, and the third paper feeding device 13, respectively. 14 is conveyed to a position where it contacts the photoconductor 15.
The image data on the memory is written onto the photoconductor 15 by the laser from the writing unit 27 and passes through the developing unit 31 to form a toner image.
The toner image on the photosensitive member 15 is transferred while the sheet is conveyed by the conveying belt 16 at the same speed as the rotation of the photosensitive member 15. Thereafter, the image is fixed in the fixing unit 17 and is discharged to the paper discharge tray 19 by the paper discharge unit 18.
[0006]
FIG. 2 is a schematic diagram showing only the sheet conveyance path when images are formed on both sides. A paper conveyance path when images are formed on both sides will be described with reference to FIGS.
The sheet fed from each of the sheet feeding trays 8 to 10 and imaged is not guided to the sheet discharge tray 19 side by switching the reverse path switching claw 36 (FIG. 2), but is conveyed to the duplex entrance conveyance path 34 and is It is guided to the reversing unit 33 provided in the transport unit 32 and temporarily stored in the switchback transport path 40.
Then, after both sides are aligned by the paper alignment jogger (guide member) 38, it is fed out in the reverse direction (refeeding direction) by the return conveying means 43, guided downward by the reverse paper discharge switching claw 44, and reversed. It is sent to the double-sided intermediate conveyance path 42 provided below.
Then, the intermediate conveying means 39 and the double-sided outlet conveying means 41 connected to a driving source (motor) (not shown) are again sent to the vertical conveying unit 14 to print an image on the back surface and then discharged. Each of the transport means 39 and 41 is provided with a drive shut-off means such as an electromagnetic clutch so that one or more sheets can be packed in the double-sided intermediate transport path 42 and can wait once.
When the paper is reversed and discharged, the paper that has been switched back by the reversing unit 33 as described above is sent by the paper discharge reverse switching claw 44 to the reverse paper discharge transport path 35 without being sent to the double-sided intermediate transport path 42. Return to the paper discharge unit again and discharge out of the main unit.
The paper discharged from the main body is discharged to either the paper discharge tray 19 or the finisher 50 of the main body by a paper discharge destination switching claw 37. The paper discharged to the finisher 50 passes through the punch unit 54 for punch hole processing, and is once stacked on the stack tray 51 for stapling processing. After all the sheets are collected in the stack tray, the sheet bundle is bound by the stapler unit 52 and discharged to the discharge tray 53.
[0007]
FIG. 3 is a schematic perspective view illustrating the configuration of the switchback conveyance path and the sheet alignment mechanism (position correction) provided in the duplex unit. In FIG. 3, the paper alignment jogger 38 is provided so as to be slidable in a direction parallel to the conveyance direction of the paper P and in a vertical direction (a direction orthogonal to the guide rod 46).
The guide rod 46 is driven by the drive belt 2 and the drive motor (drive means) 3. In addition, a home position sensor 1 that detects the home position (reference position during operation) of the paper alignment jogger 38 is provided.
The drive motor 3 is controlled and driven by control means (CPU) (not shown). FIG. 4 is a schematic diagram for explaining the operation of the paper alignment jogger. FIG. 5 is a flowchart showing an operation flow of the paper alignment jogger. When the sheet conveying operation is started (S1), the sheet aligning jogger 38 moves so as to open to the outside (side plate side) of the duplex (reversing) unit 33, and is provided on the sheet aligning jogger 38 on the left side in the drawing. The filler 38a moves until it detects the home position sensor (reference sensor) 1 (S2).
This position is the reference position for the duplex (reversing) unit 33 of the paper alignment jogger 38. Next, when the home position is detected (S3), in order to prepare for receiving the conveyed paper, it moves again to the inside of the duplex (reversing) unit 33 and once to a position (B + α) slightly wider than the paper width B. Wait (S3).
After the conveyed paper is discharged onto the paper alignment jogger 38 (stack portion), which is the paper receiving position (B + α), the paper alignment jogger 38 is moved to the paper width to move the paper to the side edge of the paper. The alignment operation is performed and the stack operation is completed. Then, the sheet is switched back in the re-conveying direction by the return conveying means 43 shown in FIG.
FIG. 6 is a schematic view showing an excessive skew of the paper entering the paper receiving position. However, if the entering paper is excessively skewed or laterally shifted due to unforeseen circumstances, a collision occurs at points A and C as shown in FIG. 6 and extreme damage jam occurs. There is a concern.
This problem can be increased by preliminarily setting the paper receiving position (B + α). However, in order to correct the paper position at a higher speed, α that is the amount of movement of the paper alignment jogger 38 is as small as possible. Is preferable.
[0008]
FIG. 7 is a schematic view showing a skew detection sensor. In the present invention, as shown in FIG. 7, a paper skew detection sensor (paper posture detection means) 45 is provided upstream of the paper alignment jogger 38 (see also FIG. 2). In FIG. 5, two optical elements are provided in a direction substantially perpendicular (orthogonal direction) to the transport direction to detect the passage of paper (S5). If the paper passes through the skew detection sensor 45, the skew amount is obtained from the difference in the passing time of each optical element (S6, S7).
If the span between the sensors is δ [mm], the sheet conveyance speed υ [mm / s], and the difference in passage time is T [s], the inclination angle θ is

Assuming that the maximum apparent width B ′ of the paper assumed at this inclination angle is B in the width direction and L in the transport direction,
B ′ = L × sin θ + B cos θ
It is obtained by
When the control means determines that the maximum apparent width B ′ of the incoming skew paper is larger than the acceptance standby position (B + α) (S8), that is, when B ′> (B + α), the paper alignment jogger 38 Is retracted to the outside of the sheet receiving position (until B ′ <(B + α)), and the skewed sheet collision is avoided (S10).
Otherwise, as a normal operation, the stacking operation is completed by moving inward (to the paper width) and performing an alignment operation (S9). However, since it is conceivable that the paper P is skewed and laterally shifted, the retracted position is preferably the home position that is the maximum retracted position (B ′ << (B + α)), and this leads to simplified control. . At the same time, a jam warning is issued to stop (suspend) the job (S11, S12).
[0009]
【The invention's effect】
As described above, according to the first aspect of the present invention, the guide member for correcting the position of the conveyed paper and the detecting means for detecting the skew state of the conveyed paper are provided, Based on the signal information of the detection means, the guide member is retracted to prevent excessive damage jam due to collision between the excessive skew paper and the guide member, which can occur in unexpected situations, and greatly improve the user's ability to remove jammed paper. It is possible to improve and avoid damage to the parts.
According to the second aspect of the invention, the skew state of the paper is calculated from the passage time by the detection means of at least two detection sensors, and more reliable evacuation control can be performed based on the information.
According to the third aspect, the control can be simplified by setting the home position, whereby B ′ << B + α, which is a more reliable standby condition, can be sufficiently satisfied.
[Brief description of the drawings]
FIG. 1 is a schematic overall view showing an image processing apparatus according to the present invention.
FIG. 2 is a schematic diagram showing only a sheet conveyance path when images are formed on both sides.
FIG. 3 is a schematic perspective view illustrating a configuration of a switchback conveyance path and a sheet alignment mechanism (position correction) provided in the duplex unit.
FIG. 4 is a schematic diagram illustrating the operation of a paper alignment jogger.
FIG. 5 is a flowchart showing an operation flow of a paper alignment jogger.
FIG. 6 is a schematic diagram illustrating an excessive skew of a sheet entering a sheet receiving position.
FIG. 7 is a schematic view showing a skew detection sensor.
[Explanation of symbols]
1 Home position sensor (reference sensor)
2 Drive belt (guide member drive means)
3 Drive motor (guide member drive means)
38 Guide member (paper alignment jogger)
45 Skew detection sensor (paper orientation detection means)

Claims (3)

A guide member that corrects the position of the paper by restricting a side edge of the paper and is movable according to the paper size, a reference sensor that detects a reference position during operation of the guide member, and the guide In a paper conveying apparatus comprising a driving means for moving a member and a control means for controlling the driving means,
On the upstream side in the conveyance direction of the guide member, there is provided a paper posture detection means for detecting the skew state of the paper entering between the spans of the guide member, and the control unit detects from the paper posture detection means. A sheet conveying apparatus that controls the driving unit to retract the guide member to the outside from the sheet receiving standby position when it is determined that the skew state of the sheet is excessive based on the information. . The paper posture detection means is composed of at least two detection means provided in a direction substantially orthogonal to the transport direction, and detects the skew amount of the paper based on the passage timing difference at the front edge of the paper.
2. The paper conveying apparatus according to claim 1, wherein the control means controls the driving means based on information detected by the paper attitude detection means to retract the guide member. 3. A sheet conveying apparatus according to claim 1, wherein the guide member is at a home position where the retracted position is an operation reference position.

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