JP4591834B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image forming apparatus using the same.

  In an automatic document feeder (ADF) that feeds a document to an image reading unit of an image reading apparatus used in an image forming apparatus such as a facsimile, a copying machine, or a scanner, an upper sheet feeding guide that forms an upper conveyance path of the sheet feeding unit A sheet feed cover that is an exterior of the sheet feed unit, and a sheet feed inlet lower guide that is a lower conveyance path of the sheet feed inlet unit, and the sheet feed cover and the sheet feed upper guide are opened to open the sheet feed unit. In most cases, the conveyance path can be exposed. This is to ensure operability during jam processing and maintenance. In many cases, a reversal conveyance path for reversing a double-sided document and reading the back surface is provided further below the lower conveyance surface of the sheet feeding unit entrance.

  In the apparatus having such a configuration, when the document is conveyed from the document stacking unit to the sheet feeding unit, when the document is conveyed from the reversing path to the sheet feeding unit, the leading end of the document is positioned on the sheet feeding upper guide. After entering the transport surface at a relatively high angle, it is transferred to the pull-out driven roller pair. If the delivery of the leading edge of the document is not smooth, the leading edge of the document hits the antinode of the roller before entering the nip of the pull-out driven roller, and the impact sound may increase.

Conventionally, the structure of attaching an elastic member (flexible member) immediately upstream of a roller is not widely regulated and is generally widely used. Therefore, as far as the inventors of the present application know, this There is no appropriate and direct prior art on the subject.
Japanese Patent No. 3609257

  In the automatic document feeder, what is described as the prior art in Patent Document 1 is that a reverse roller 73 is conventionally provided by attaching an elastic member 75 (flexible member) between a guide member 74 and a reverse roller 73. However, it is intended to prevent damage to the original when it is transported from the original stacking unit to the paper supply unit. There is no description of measures.

  Accordingly, the present invention provides an apparatus for reducing the impact sound when a document is conveyed from a reversing path to a sheet feeding unit in the above-described configuration that can improve operability during jam processing and maintenance. It is intended.

An image reading apparatus according to a first aspect of the present invention is an image reading apparatus provided with an automatic document feeding device that feeds a document to an image reading unit,
A feeding path for conveying a document fed from the document table via a pair of pull-out rollers;
A reversing path for returning the original, which is conveyed through the feeding path and whose surface is read, to the position upstream of the pair of pull-out rollers in the feeding path in the conveying direction,
A first paper feed guide that forms the feeding path and intersects a transport direction of a document transported from the reverse path;
A delivery shape portion provided in the first paper feed guide and guiding a leading edge of the document to a nip portion of the pull-out roller pair ;
A driven roller of the pull-out roller pair is held by the first paper feed guide,
A paper feed cover that is an exterior of the paper feed unit;
The paper feed cover and the first paper feed guide can be opened;
During the opening a driven roller of the pair of pullout rollers is characterized Rukoto such as application of pressure to the other roller which forms the pull-out roller pair can be released.

Those according to the second aspect, characterized in that an image reading apparatus according to claim 1, wherein the sheet feed cover and the first paper guide may be opened at the time when a jam treatment or maintenance And

Which according to the claim 3 is the image reading apparatus according to claim 1 or 2, and wherein the tear Rukoto formed integrally with said first sheet feeding guide and the delivery-shaped portion as a resin To do.

According to a fourth aspect of the present invention, in the image reading apparatus according to the first or second aspect , the delivery shape portion is formed of a separate member from the first paper feed guide.

Those pertaining to the fifth aspect, in any one of the image reading apparatus of claims 1 4, the width of the transfer-shaped portion, that Do is made larger than the width of the roller portion of the driven roller of the pair of pullout rollers It is characterized by that.

Those according to the sixth aspect, in any one of the image reading apparatus of claims 1 4, the width of the transfer-shaped section, that is formed by the following width of the roller portion of the driven roller of the pair of pullout rollers Features.

Those according to the claim 7, in any one of the image reading apparatus of claims 1 6, the member forming the transfer-shaped portion and said transparent member der Rukoto.

Those according to the claim 8, in any of the image reading apparatus of claims 1 6, characterized in that the member forming the transfer-shaped portion is non-transparent member.

According to the ninth aspect of the present invention, in the image reading apparatus according to any one of the first to eighth aspects, the delivery shape portion is formed of a flexible member that is a separate member from the first paper feed guide. It is characterized by that.

Those according to the claim 10, in images reader according to claim 9,
Said flexible member to form a transfer-shaped portion allows the user easily characterized Oh isosamples attached by inaccessible the first paper guide at least one place or more surfaces in double-sided adhesive tape.

According to the eleventh aspect of the present invention, in the image reading apparatus of the ninth or tenth aspect,
Mounting of the flexible member forming the transfer-shaped portion, the front Symbol first paper guide is characterized Rukoto by the at least one place or more fixing screws.

According to claim 12 of the present invention, in the image reading apparatus of claim 9 or 10 ,
It said flexible member to form a transfer-shaped portion allows the user easily mounted in inaccessible the paper sheet guide least one place or more fixing screws to the surface Oh characterized Rukoto.

The image forming apparatus according to the claim 13, characterized by using any of the image reading apparatus of claim 1 1 2.

The image forming apparatus of the present invention has a transfer shape portion that smoothly transfers the document from the first paper feed guide to the driven roller of the pull-out roller pair, so that an impact sound when the document is conveyed from the reverse path is provided. Can be relaxed. Further, since the delivery member can be brought close enough to the pull-out driven roller whose pressure is released when the paper feed cover is opened, it is possible to more effectively reduce the impact sound.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  The present invention relates to an automatic document feeder (ADF) that feeds a document to an image reading unit of an image reading device such as a facsimile, a copying machine, or a scanner. In this specification, as a representative example, a case of a sheet-through type ADF mounted on a copying machine is taken up, and a basic configuration, operation, action, and an embodiment of the present invention will be described.

A basic configuration, operation, and action will be described based on a cross-sectional view (FIG. 1), a block diagram (FIG. 2), and flowcharts (FIGS. 3 to 7) of the apparatus of the present embodiment.

  The original bundle 0 to be read is set on the original table 1 with the original surface facing upward and the front end of the original abutting 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 document bundle 0 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 forward and the stop claw 2 is lowered by the claw home position sensor 34. Retreat in the direction (solid line state in the figure) (step s1: in the flowchart, hereinafter, simply referred to as step 1 etc.). 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 hold the document bundle 0 from above (step s2). Further, an outline of 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 (at least a sensor arrangement that can determine whether the document size is vertical or horizontal is necessary). Then, a rough determination of the document size is performed by a combination with the document width detection result described later (step 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 feeds several (ideally one) documents on the document table 1. The paper is fed to an original separation unit constituted by a belt 5 and a reverse roller 4. The paper feed belt 5 is driven in the paper feed direction by the forward rotation of the paper feed motor 102, and the reverse roller 4 is driven to rotate in the reverse direction to the paper feed, separating the uppermost document and the original document below it, Only a document 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 (step 4). 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 where the pull-out roller 6 is formed with a certain amount of bending. At this point, the pickup motor 101 is reversed to retract the pickup roller 3 from the upper surface of the document, and the document is fed only by the conveying force of the paper feed belt 5 (step 5). 7 can enter the nip 7 and correct the bending (skew) of the document that occurs during separation feeding.

  The pull-out roller 6 has a skew correction function and is a roller for transporting the skew-corrected document to the reading entrance roller 8 after separation, and is driven by the reverse rotation of the paper feed motor 102. 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.

  Then, a bundle of documents stacked on the document table 1 in the main body control unit 111 by a combination of the length information acquired from the detection results of the document length detection sensors 20 to 22 on the document table 1 and the width information. Send zero size 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 paper gap with the previous document by this high-speed conveyance (step 6).

  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 by Y mm than the distance from the reading entrance sensor 26 to the reading entrance roller 8, the leading edge of the document is placed at the nip portion of the stopped reading entrance roller 8. At the end, the document stops with a certain amount of deflection, 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 (step 7).

  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 conveying speed corresponding to the reading magnification (step 8). When the leading edge of the original is detected by the registration sensor 27, the pulse count of the reading motor 103 is started, and a gate signal indicating an effective image area in the sub-scanning direction is sent to the main body controller 111 at the timing when the leading edge of the original reaches the reading portion. Send out (step 9). This gate signal is normally sent until the trailing edge of the document leaves the reading section (step 11). 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 (step 12).

  In the case of a double-sided document, 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 at the time of front side scanning reaches the discharge roller 12 and is driven by the reading motor 103. The paper is conveyed in the B direction by the discharged paper roller 12 and the lower driven roller 13 and the reverse roller 16 and the driven roller 17 driven by the reverse motor 104 (step 13). 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 turned on in the drawing. Returning to the position of the solid line, the reverse roller 16 is reversely rotated by the reverse rotation drive of the reverse motor 104 after a predetermined pulse, 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 102 is reversely rotated (rotated in the direction in which the pull-out roller 6 is driven) at a high speed after a predetermined pulse (step 14).

  The switched-back original is conveyed by the paper discharge roller 12 and the upper driven roller 18 in the direction of the arrow C in the figure, and in the same way as on one side, it passes through the pull-out roller 6 and the reading inlet roller 8 and reads the reading inlet roller nip. Pause at. In order to perform skew correction by abutting the leading end of the document against the reading entrance roller nip portion even when reading the back side, it is necessary to stop the driving of the reading motor 103 before the leading end of the document reaches the reading entrance roller 8. The reading motor 103 stops driving when the leading edge of the document is detected by the reading inlet sensor 26 (step 16). The document whose registration is stopped for reading the back side is conveyed to the reading position 28 at a conveyance speed corresponding to the designated magnification after receiving the reading start signal in the same manner as the front side reading. When the reading of the back side is completed, the same reversing operation for page alignment is performed again, and the sheet is discharged onto the sheet discharge tray 14 by the sheet discharge roller 13. At the time of reversing operation for page alignment, it is not necessary to convey at a speed corresponding to the reading magnification. It prevents jumping out during discharge and shortens the processing time (step 15).

  In the following, embodiments of the present invention in the above-described apparatus will be described. FIG. 8 shows a conventional configuration having no delivery shape shown for comparison. Unlike the case where the leading edge of the document conveyed from the reversing path to the sheet feeding unit enters the sheet feeding upper guide 52, unlike the case where the document is conveyed from the document stacking unit to the sheet feeding unit 52, Incident light is transferred to the pull-out driven roller 7.

  FIG. 9 shows an example in which the delivery shape portion 53 is formed integrally with the paper feed upper guide 52. When formed by integral molding, the number of parts does not increase and the configuration is simple.

  Further, the example of FIG. 10 is an example in which the delivery shape is a member different from the paper feed upper guide 52 and is formed of the flexible member 54. When the delivery shape is a different member from the paper feed guide 52, when a new delivery shape is provided or changed, it is not necessary to modify the paper feed guide 52, which is a large resin part.

  FIG. 11 shows an example in which the delivery shape is formed integrally with the paper feed upper guide 52 and the width of the delivery shape is larger than the width of the roller portion of the pull-out driven roller 7. If the width of the delivery shape is larger than the width of the roller portion of the pull-out driven roller 7, the delivery action can be reliably obtained.

  FIG. 12 shows an example in which the delivery shape is formed of a flexible member 54 that is a separate member from the paper feed upper guide 52, and the width of the delivery shape is equal to or less than the width of the roller portion of the pull-out driven roller 7. As an effect of the transfer, it is not always necessary to transfer the entire roller width, it is sufficient to transfer a partial range of the roller width, and it is well balanced to be near the center of the roller width.

  In FIG. 13, the delivery shape is formed by a flexible member 54 that is a separate member from the paper feed upper guide 52, and the means for attaching the flexible member 54 to the paper feed upper guide 52 includes a double-sided adhesive tape 55 on the transport surface, It is attached with a double-sided adhesive tape 55 on a surface different from the transport surface, and a fixing screw 56 inside the paper feed cover 51 on the side opposite to the transport surface.

  As a method for attaching the flexible member to the paper conveyance guides, it is common to attach a flat flexible member to the conveyance surface of the flat paper conveyance guide with a double-sided adhesive tape. However, in this case, the adhesive force of the double-sided adhesive tape weakens over time, and depending on the configuration of the machine, as shown in FIG. 14, the paper feed cover 51 and the paper feed upper guide 52 may be opened during jam processing or maintenance. Since this is a part that can be easily accessed by the user, there is a case where the user touches the flexible member to cause an unintentional dropout, which blocks the paper conveyance path and causes a jam.

  In this regard, multiple attachment points with double-sided adhesive tape are provided, screws that require a screwdriver to remove the attachment means, and attachment points with double-sided adhesive tape or screws are in places where users cannot easily access them. By doing so, it is possible to prevent unintentional dropping of the flexible member.

  As described above, according to the present invention, since there is a transfer shape portion that smoothly transfers the document from the paper feed upper guide to the pull-out driven roller, the impact sound generated when the document is conveyed from the reverse path to the paper feed portion. The transfer shape portion can be formed by integral molding with the resin feed guide and the configuration can be simplified without increasing the number of parts.

  Further, if the delivery shape portion is formed of a separate member from the resin-made paper feed upper guide, it is not necessary to modify the paper feed upper guide, which is a large resin part, when changing the delivery shape portion. If the delivery shape portion is formed of a flexible member that is a separate member from the resin feed upper guide, the delivery member can be brought close enough to the pull-out driven roller whose pressure is released when the feed cover is opened. If the delivery shape portion is formed of a flexible member that is a separate member from the resin-made upper paper feed guide, the delivery member can be brought close enough to the pull-out driven roller whose pressure is released when the paper feed cover is opened.

  Furthermore, if the width of the delivery shape portion is made larger than the width of the roller portion of the pull-out driven roller, the theoretical delivery effect can be reliably obtained. On the other hand, when the width is equal to or less than the width of the roller portion of the pull-out driven roller, an optimal state can be obtained in which the balance between the delivery effect and the cost is optimal.

  In addition, if the color of the flexible member forming the delivery shape portion is transparent, it can be immediately noticed and cleaned when dust accumulates on the back of the flexible member. On the contrary, if it is opaque, the aesthetic appearance will not be impaired if dust accumulates on the back of the flexible member.

  Note that if the flexible member that forms the delivery shape is attached to the paper feed guide with at least one surface that cannot be easily accessed by the user using double-sided adhesive tape, the user will be mistaken. Thus, the flexible member is not easily removed. Further, if the flexible member forming the delivery shape portion is attached to the paper feed guide with at least one fixing screw, the user will not easily remove the flexible member by mistake.

  In addition, if the flexible member forming the delivery shape portion is attached to the paper feed guide by at least one surface that cannot be easily accessed by the user with the fixing screw, the flexible member Is not easily removed. In addition, the flexible member that forms the delivery shape part can be attached to the paper feed guide with at least one surface that cannot be easily accessed by the user with fixing screws. The flexible member is not easily removed.

1 is a schematic cross-sectional view of an image reading unit of an image forming apparatus that is an example of an embodiment of the present invention. Block diagram showing the configuration Flow chart showing the operation Flow chart showing the operation Flow chart showing the operation Flow chart showing the operation Flow chart showing the operation Conventional configuration diagram without a delivery shape for comparison Diagram of an example in which the delivery shape is formed integrally with the paper feed upper guide Figure delivery shape in a separate member from the feeding paper guide, and is formed of a flexible member Example Figure delivery shape is formed by integrally molding a sheet paper guide, and the width of the delivery shape is greater than the width of the roller portion of the pull-out driven low la examples FIG. 6 is a diagram illustrating an example in which the delivery shape is formed of a flexible member that is a separate member from the paper feed upper guide, and the width of the delivery shape is equal to or less than the width of the roller portion of the pull-out driven roller. Diagram of an example in which the delivery shape is formed of a flexible member that is a separate member from the paper feed upper guide and is attached with a double-sided adhesive tape and a fixing screw The figure which shows the attachment method to the paper conveyance guides of a flexible member

0 Document bundle 1 Document table 2 Stop claw 3 Pickup roller 4 Reverse roller 5 Paper feed belt 6 Pull-out roller 7 Pull-out driven roller 8 Reading inlet roller 10 Reading outlet roller 12 Paper discharge roller 13 Lower driven roller 14 Paper discharge tray 15 Switching claw 16 Reverse roller 17 Follow roller 18 Upper follow roller 19 Document set sensor 20-22 Document length detection sensor 24 Abutment sensor 25 Document width sensor 26 Reading entrance sensor 27 Registration sensor 28 Reading position 29 Reading exit sensor 31 Document setting filler 33 Pickup home Position sensor 34 Claw home position sensor 51 Paper feed cover 52 Paper feed upper guide 53 Delivery shape part 54 Flexible member 55 Double-sided adhesive tape 56 Fixing screw 101 Calling motor 102 Paper feed motor 103 Read motor 104 Reverse motor 105 Reverse solenoid 107 Interface means 111 Main body control unit

Claims (13)

An image reading apparatus provided with an automatic document feeder for feeding an original to an image reading unit,
A feeding path for conveying a document fed from the document table via a pair of pull-out rollers;
A reversing path for returning the original, which has been conveyed through the feeding path and whose surface has been read, to a position upstream of the pair of pull-out rollers in the feeding path in the conveying direction, and
A first paper feed guide that forms the feeding path and intersects a transport direction of a document transported from the reversing path;
A delivery shape portion provided in the first paper feed guide and guiding a leading edge of a document to a nip portion of the pull-out roller pair ;
A driven roller of the pull-out roller pair is held by the first paper feed guide,
A paper feed cover that is an exterior of the paper feed unit;
The paper feed cover and the first paper feed guide can be opened;
The image reading apparatus when the open driven roller of the pull-out roller pair, wherein Rukoto such as application of pressure to the other roller which forms the pull-out roller pair can be released. The image reading apparatus according to claim 1 ,
Wherein the front Symbol feeder cover the first paper guide to an image reading apparatus according to claim capable der Rukoto be opened during the jam processing or during maintenance. The image reading apparatus according to claim 1 , wherein
Image reading apparatus according to claim Thea Rukoto formed integrally with said first sheet feeding guide and the delivery-shaped portion as a resin. The image reading apparatus according to claim 1 or 2 ,
The image reading apparatus according to claim 1 , wherein the delivery shape portion is formed of a member different from the first paper feed guide. In any of the image reading apparatus of claims 1 4,
The delivery width of the shaped portion, the pull-out roller pair image reading apparatus according to claim Rukoto such made larger than the width of the roller portion of the driven roller. In any of the image reading apparatus of claims 1 4,
Wherein the width of the transfer-shaped portion, the image reading apparatus characterized by comprising not more than the width of the roller portion of the driven roller of the pull-out roller pair. In any of the image reading apparatus of claims 1 to 6,
Image reading apparatus member forming the transfer-shaped portion and said transparent member der Rukoto. In any of the image reading apparatus of claims 1 to 6,
Image reading apparatus characterized by the member forming the transfer-shaped portion is non-transparent member. The image reading apparatus according to any one of claims 1 to 8 ,
The image reading apparatus , wherein the delivery shape portion is formed of a flexible member different from the first paper feed guide . In images reader according to claim 9,
Said flexible member to form a transfer-shaped portion allows the user easy access to hard to image reading and said Oh isosamples attached by the first paper guide of at least one place or more surfaces in double-sided adhesive tape apparatus. The image reading device according to claim 9 or 10,
Said flexible member to form a transfer-shaped portion, attached to the previous SL first paper guide to an image reading apparatus according to claim Rukoto by the at least one place or more fixing screws. The image reading device according to claim 9 or 10 ,
It said flexible member to form a transfer-shaped portion includes an image reading apparatus according to the user easy access to hard to the paper sheet guide, wherein the Oh isosamples attached at least one place or more surfaces to the fixing screw. An image forming apparatus characterized by using any one of the image reading apparatus of claims 1 1 2.