JP2007070055A - Automatic document feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic document feeder having a conveying path of a stage structure which is capable of easily taking out a jammed paper even when jam occurs in a paper discharge path or a switch-back path. <P>SOLUTION: The automatic document feeder is mounted on an image forming device, and has a switch-back path for inverting face and back sides of an original between a paper feed path for separating a stacked original bundle one by one and feeding the originals on the image reading position, and a paper discharge path for discharging the original after passing the reading position. The three kinds of paths form a stage structure in the order of the paper feed path, the switch-back path and the paper discharge path from the top side. Jam treatment can be performed in a similar procedure irrespective of the jamming position by opening a guide of the switch-back path upwardly from the paper feed path for performing the jam treatment of the paper discharge path. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automatic document feeder mounted on an image reading apparatus or an image forming apparatus.

2. Description of the Related Art In an automatic document feeder having a double-sided document reading mechanism, an automatic document feeder having a reversing unit for reversing a document in the conveyance path of the device has become widespread. Such an apparatus uses a mechanism for opening a document conveyance path in order to remove a jammed document (see Patent Document 1).

In Patent Document 2, a plurality of document trays, a document discharge tray disposed below the document tray, a base frame, and a plurality of document conveyance paths that curve in a U shape from the document tray to the document discharge tray are provided. A conveying means that conveys the document using a conveying roller and a guide, and an upper portion on which at least one of the conveying roller or the guide that is rotatably attached to the base frame and disposed in the upper area of the document conveying path is mounted. A frame, and an intermediate frame mounted with at least one of the transport roller or the guide disposed in an intermediate region surrounded by the document transport path and rotatably mounted about the one rotation axis. And opening the upstream side of the document conveyance path by rotating the upper frame, and downstream of the document conveyance path by rotating the intermediate frame. There it is disclosed to open.

In Patent Document 3, the document reversing placement unit is formed by narrowing the width direction orthogonal to the longitudinal direction as the document reversing placing unit moves away from the document feeding mechanism side along the longitudinal direction which is a predetermined direction. It is disclosed that even when a jam occurs with the document feeding mechanism, the document reversing placement unit itself does not get in the way and the jam processing can be easily performed.

JP-A-6-72589 JP 2004-99240 A Japanese Patent Laid-Open No. 2004-256200

However, in an automatic document feeder that has a floor path, if a jam occurs in the paper discharge path or switchback path, the jammed paper is hidden under the reversing guide or paper discharge guide. Even with such a structure, it is difficult to handle jam.
In such a case, the automatic document feeder may be lifted up and jammed from the platen. However, a mechanism that can lift and open the platen is required as well as a mechanism for opening the platen. There is a problem that becomes.
Further, since the opening fulcrum of the reversing guide and the paper discharge guide are opposite, the opening operation direction is different, and since the area of the opening is small, there is a problem that it is difficult to open the paper discharge guide in the same way. .
In addition, if a handle is provided to open the document, the document may be caught when the document is conveyed.

Therefore, the present invention has been made in view of the above problems, and by enabling jam processing from above, it is possible to perform jam processing in the same procedure regardless of the position of the jam. It is an object of the present invention to provide an automatic document feeder that can be simplified.

The features of the present invention, which is a means for solving the above problems, are listed below.
The present invention is provided between a paper feed path which is mounted on an image forming apparatus and separates a stacked bundle of documents one by one and feeds them to an image reading position, and a paper discharge path which discharges a document after passing through the reading position. In addition, the automatic document feeder is provided with a switchback path for reversing the front and back of the document, and the three-type path path has a floor structure from the top in the order of the paper feed path, the switchback path, and the paper discharge path. , The paper discharge path jam processing is performed by opening the switchback path guide upward from the paper feed path.
Furthermore, the present invention is characterized in that, in the automatic document feeder according to the first aspect, the paper discharge guide plate is opened upward by pressing it from above.
Further, the present invention is characterized in that a part of the handle is provided so that the end of the paper discharge guide can be easily pushed.

  According to the present invention, by performing the above-described means for solving the problem, it is possible to perform the jam processing from the upper side, so that the jam processing can be performed in the same procedure regardless of the position of the jam. An automatic document feeder can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

The present embodiment relates to a read original processing apparatus (hereinafter referred to as ADF) used in an apparatus for reading an image while conveying the read original to a fixed reading unit and conveying it at a predetermined speed. The basic configuration, operation, and action will be described with reference to FIGS. Here, FIG. 1 is a diagram showing a cross section of the automatic document feeder in the present embodiment. FIG. 2 is a system block diagram showing the configuration of the automatic document feeder in the present embodiment. FIG. 3 is a diagram showing a flowchart of sheet feeding control of the automatic document feeder in the present embodiment. FIG. 4 is a diagram illustrating a flowchart of movement control to the reading unit of the automatic document feeder according to the present embodiment. FIG. 5 is a diagram showing a flowchart of the reading control of the automatic document feeder in the present embodiment. FIG. 6 is a diagram showing a flowchart of the reversal control of the automatic document feeder in the present embodiment. FIG. 7 is a view showing a flowchart of back side reading control of the automatic document feeder in the present embodiment. FIG. 8 is a diagram illustrating the opening of the paper feed cover, the reverse guide, and the paper discharge guide of the automatic document feeder according to the present embodiment. FIG. 9 is a view showing fulcrums of the paper discharge guide and the reversing guide of the automatic document feeder in the present embodiment. FIG. 10 is a cross-sectional view showing a method for opening the paper discharge guide of the automatic document feeder in this embodiment. FIG. 11 is a perspective view showing a method for opening the paper discharge guide of the automatic document feeder in the present embodiment.

The document bundle P to be read is set on the document table 1 with the document surface facing upward and the document tip set against the stop claw 2 (the state at the time of setting is indicated by a two-dot chain line). The document set filler 31 changes the angle from the broken line state shown in FIG. 1 to the solid line state, and the document set sensor 19 detects the document set. Further, the width direction of the document bundle P is positioned in a direction perpendicular to the conveyance direction by a side fence (not shown).

When a print key is pressed from a main body operation unit (not shown) and a document feed signal is transmitted from the main body control unit to the ADF control unit, the calling motor 101 is driven to rotate forward and the nail home position sensor 34 lowers the set nail 2. direction
(Refer to S1 in FIG. 3). Subsequently, the calling motor 101 is driven in the reverse direction, and the pickup home position sensor 33 lowers the pickup roller 3 so as to press the document bundle P from above (see S2 in FIG. 3). In addition, the length of the document in the conveyance direction is determined by the document length detection sensors 20 to 22 provided on the sheet feeding document table surface, and the document size is roughly determined by a combination with the document width detection result described later. [See S3 in FIG. 3].

The pickup roller 3 is driven to rotate in the direction in which the uppermost document is conveyed to the sheet feeding port by the normal rotation of the sheet feeding motor 102, and several sheets (ideally one sheet) on the document table 1 are fed to the sheet feeding belt. 5 and the reverse roller 4 are fed to a document separation unit. The paper feeding belt 5 is driven in the paper feeding direction by the forward rotation of the paper feeding motor, and the reverse roller 4 is driven to rotate in the reverse direction to the paper feeding to separate the uppermost original from the original underneath, and the uppermost original. Only the paper can be fed. The document separated into one sheet by the action of the sheet feeding belt 5 and the reverse roller 4 is further fed by the sheet feeding belt 5, and the document is fed by a predetermined amount from the time when the leading edge is detected by the abutting sensor 24 to feed the document. The forward rotation drive 102 is stopped [see S4 in FIG. 3]. At this time, by making the above-mentioned predetermined amount larger than the distance from the abutting sensor 24 to the pull-out roller 6, the document is stopped in a state in which the pull-out roller 6 is formed with a certain amount of bending. At this time, by rotating the calling motor 101 in the reverse direction, the pickup roller 3 is retracted from the upper surface of the original and the original is fed only by the conveying force of the paper feed belt 5 [see S5 in FIG. In addition, it is possible to correct the bending (skew) of the original that has entered the nip of the driven roller 7 and has been separated and fed.

The pull-out roller 6 has the skew correction function and is a roller for conveying the skew-corrected document to the reading entrance roller 8 after separation, and is driven by the reverse rotation of the paper feed motor. At this time (when the paper feed motor reverses), the pull-out roller 7 is driven, but the pickup roller 3 and the paper feed belt 5 are not driven by the action of a one-way clutch (not shown).

A plurality of document width sensors 25 are arranged in the depth direction, and acquire information in the width direction orthogonal to the transport direction of the document transported by the pull-out roller 6. The length information acquired from the detection results of the length sensors 20 to 22 on the original table and the size information of the original bundle loaded on the original table are transmitted to the main body control unit 111 by a combination of the width information. . The exact length of the document in the conveyance direction is calculated by counting the number of motor driving pulses for the distance conveyed while the leading edge and the trailing edge of the document are detected by the abutment sensor 24. When the document is conveyed to the reading entrance roller 8 by driving the pull-out roller 6, the document conveying speed is set to a high speed and the processing time for feeding the document to the reading unit is shortened. In this document, productivity can be improved by shortening the sheet gap with the previous document by this high-speed conveyance [see S6 in FIG. 3].

When the leading edge of the document is detected by the reading entrance sensor 26, deceleration starts before the leading edge of the document enters the reading entrance roller 8. Here, when the paper feed motor 102 is stopped so that the conveyance distance is longer than the distance from the reading entrance sensor 26 to the reading entrance roller 8 by a predetermined amount, the leading edge of the document is placed at the nip portion of the stopped reading entrance roller 8. The document is stopped in a state where a certain amount of deflection is formed, and the skew generated when the document is conveyed by the pull-out roller 6 can be corrected. When the original is temporarily stopped (resist stop) at the nip portion of the reading entrance roller 8, a registration stop signal is transmitted to the main body control unit 111 via the interface means 107 (see S7 in FIG. 4).

Subsequently, when a reading start signal is received from the main body control unit 111, the document reading operation starts. The reading motor 103 is driven to rotate forward to drive the reading inlet roller 8 and the reading outlet roller 10 at a conveyance speed corresponding to the reading magnification (see S8 in FIG. 5). When the leading edge of the document is detected by the registration sensor 27, the pulse count of the reading motor is started. At the timing when the leading edge of the document reaches the reading unit, a gate signal indicating an effective image area in the sub-scanning direction is sent to the main body control unit. [Refer to S9 in FIG. 5]. The gate signal is normally sent until the trailing edge of the document exits the reading unit [see S11 in FIG. 5]. The document that has passed through the reading unit is conveyed by the reading exit roller 10 and the paper discharge roller 12 (direction A) and discharged to the paper discharge tray 14 [see S12 in FIG. 5].

In the case of a double-sided document, during surface reading, the switching claw 15 is switched to the position indicated by a two-dot chain line by turning on the reverse solenoid 105 before the leading end of the document that has passed through the reading unit reaches the paper discharge roller 12 and is driven by the reading motor 103. The sheet is conveyed in the B direction by the discharged paper roller 12 and the lower driven roller 13 and the reversing roller 16 and the driven roller 17 driven by the reversing motor 104 [see S13 in FIG. 6]. When the trailing edge of the document conveyed in the B direction passes through the paper discharge roller 12 (after a predetermined pulse after the reading exit sensor 29 detects the trailing edge of the document), the reverse solenoid 105 is turned off and the switching claw 15 is shown by a solid line. Then, after a predetermined pulse, the reverse roller 16 is reversely rotated by the reverse rotation drive of the reverse motor 104, and the document is switched back in the C direction. At this time, the driving direction of the reading motor 103 is the same direction and the driving direction of the reversing motor 104 is the reverse direction, and the reversing motor 104 and the reading motor 103 are driven at a high speed in order to shorten the processing time. When the document starts to switch back, the paper feed motor is reversely rotated (rotated in the direction of driving the pull-out roller) at a high speed after a predetermined pulse [see S14 in FIG. 6].

The switched-back document is conveyed in the direction C by the paper discharge roller 12 and the upper driven roller 18, and is temporarily stopped at the reading inlet roller nip portion for reading the back side through the pull-out roller 6 and the reading inlet roller 8 as in the case of one side. . In order to perform skew correction by abutting the leading edge of the document on the reading entrance roller nip even when reading the back side, it is necessary to stop the driving of the reading motor before the leading end of the document reaches the reading entrance roller. Stops driving when the leading edge of the document is detected by the reading entrance sensor 26 (see S16 in FIG. 7). The original whose registration has been stopped for reading the back side is conveyed to the reading position at a conveyance speed corresponding to the designated magnification after receiving the reading start signal as in the case of reading the front side. When the reading of the back surface is completed, the same reversing operation for page alignment is performed again, and the paper is discharged onto the paper discharge tray 14 by the paper discharge roller 13. During the reversing operation for page alignment, it is not necessary to transport at a speed corresponding to the scanning magnification. Therefore, the document is discharged by passing the scanning position while maintaining high-speed transport and decelerating when the trailing edge of the document is detected by the reading exit sensor. The projecting time is prevented and the processing time is shortened [see S15 in FIG. 7].

In the present invention, the reversing guide 44 and the paper discharge guide 43 have a fulcrum at the position shown in FIG. 9, and can be opened in the direction of double door opening as shown in FIG. This is because if they are opened in the same direction, they interfere with each other and the opening area cannot be increased. In the case of this double door configuration, in order to open the paper discharge guide 43, it is necessary to put a hand near the fulcrum of the reversing guide 44 and open it by hooking.
However, the vicinity of the fulcrum of the reversing guide 44 is narrow and difficult to insert. In addition, when a lever or the like is provided on the reversing guide so that it can be easily put on, there is a risk that the document will be caught on the lever.
Therefore, by providing a lever on the upper surface on the fulcrum side of the reversing guide so as not to affect the conveying surface and pushing the lever to open the reversing guide 44, the reversing guide 44 can be easily opened.

As a method of jam processing, when a jam occurs on the paper discharge guide, only the reverse guide is opened in the direction of FIG.

When a jam occurs on the lower side of the paper discharge guide, the paper feed cover is opened in the direction of FIG. 8, and the reversing guide 44 is opened in the direction of FIG. At this time, the reverse guide is provided with a click so as to stop at the position shown in FIG. Next, when pressed in the D direction in FIG. 10, the paper discharge guide 43 is opened in the E direction around the fulcrum of the paper discharge guide 43 to perform jam processing. FIG. 11 shows the position of the handle designed so that the end of the paper discharge guide can be easily pushed.

It is a figure which shows the cross section of the automatic document feeder in this Embodiment. 1 is a system block diagram showing a configuration of an automatic document feeder in the present embodiment. FIG. 4 is a diagram illustrating a flowchart of sheet feeding control of the automatic document feeder according to the present embodiment. It is a figure which shows the flowchart of the movement control to the reading part of the automatic document feeder in this Embodiment. It is a figure which shows the flowchart of reading control of the automatic document feeder in this Embodiment. It is a figure which shows the flowchart of the inversion control of the automatic document feeder in this Embodiment. It is a figure which shows the flowchart of back surface reading control of the automatic document feeder in this Embodiment. FIG. 4 is a diagram illustrating opening of a paper feed cover, a reversing guide, and a paper discharge guide of the automatic document feeder in the present embodiment. FIG. 4 is a diagram showing fulcrums of a paper discharge guide and a reversing guide of the automatic document feeder in the present embodiment. FIG. 6 is a cross-sectional view illustrating a method for opening a paper discharge guide of the automatic document feeder in the present embodiment. FIG. 5 is a perspective view showing a method for opening a paper discharge guide of the automatic document feeder in the present embodiment.

Explanation of symbols

P Document bundle 1 Document table 43 Paper discharge guide 44 Reverse guide 50 Paper feed path 60 Paper discharge path 70 Switchback path

Claims (3)

A switchback path that reverses the front and back of the original between a paper feed path that separates the stacked original bundle one by one and feeds it to the image reading position and a paper discharge path that discharges the original after passing the reading position. In the automatic document feeder in which the above three-type path path has a floor structure in the order of the paper feed path, the switchback path, and the paper discharge path from the top, An automatic document feeder, wherein the switchback path guide is opened upward. 2. The automatic document feeder according to claim 1, wherein the automatic document feeder is opened upward by pressing the paper discharge guide plate from above. 3. The automatic document feeder according to claim 1, wherein a part of the handle is provided so that the end of the paper discharge guide can be easily pushed.

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