Feeding device, image reading device and image forming device

Abstract

To provide a feeding device capable of excellently correcting a skew of a small-sized sheet.SOLUTION: A feeding device includes: a document placement tray as a placement part on which a document as a sheet is placed; side fences 23 as a pair of regulation members that regulate a position in the width direction of the document placed on the document placement tray; a pickup roller 24 as a feeding member that contacts and feeds the document placed on the document placement tray; and pull-out roller pairs 28 disposed on the downstream side of the pickup roller 24 in the conveyance direction of the sheet and serving as a skew correction member that abuts a tip end of the document to correct a skew. In addition, regulation fences 50 as a pair of second regulation members that contact end parts in the width direction of a small-sized document such as a business card and regulate a position in the width direction of the small-sized document are provided between the pickup roller 24 and the pair of pull-out rollers 28.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a feeding device, an image reading device, and an image forming apparatus. [Background technology]

[0002] Conventionally, a feeding device is known that includes a loading section on which a sheet is placed, a pair of regulating members that regulate the widthwise position of the sheet placed on the loading section, a feeding member that contacts the sheet placed on the loading section and feeds it, and a skew correction member that is positioned downstream of the feeding member in the sheet transport direction and abuts against the leading edge of the sheet to correct the skew.

[0003] Patent document 1 describes a feeding device that includes a pair of registration rollers as skew correction members that abut against the leading edge of the document, correcting the skew of the document, upstream in the document transport direction from a reading unit that reads an image of the document sheet. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are cases where the skew correction of small size sheets is insufficient. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a feeding device comprising a loading section on which sheets are placed, a pair of regulating members which regulate the widthwise position of the sheets placed on the loading section, a feeding member which abuts against the sheets placed on the loading section and feeds them, and a skew correction member which is arranged downstream in the sheet conveying direction from the feeding member and abuts against the leading edge of the sheet to correct the skew, wherein a pair of second regulating members which abut against the widthwise ends of small-size sheets to regulate the widthwise position of the small-size sheets are provided between the feeding member and the skew correction member. Effect of the Invention

[0006] According to the present invention, the skew of a small size sheet can be corrected satisfactorily. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing an image forming apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged view showing the main configuration of the ADF. [Diagram 3] FIG. 2 is a schematic plan view of a document placement tray according to the embodiment. [Figure 4] 2 is a plan view showing a state in which a stack of small-sized documents is set on the document placement tray in the embodiment. FIG. [Diagram 5] FIG. 4 is a schematic plan view showing how a small-sized original is fed. [Figure 6] 5A and 5B are diagrams for explaining skew correction of a small size document using a restriction fence. [Figure 7] FIG. 4 is a schematic diagram showing how a large-sized original is transported. [Figure 8] 5A and 5B are diagrams illustrating the positional relationship between a lower paper feed guide member and a restriction fence. [Figure 9] FIG. [Figure 10] 6A to 6C are diagrams for explaining the behavior of the pressing member when a large-sized original is transported. [Figure 11] 13A and 13B are diagrams illustrating modified examples of the restriction fence. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The best mode for carrying out the present invention will be described below with reference to the drawings. Note that a person skilled in the art can easily modify and alter the present invention within the scope of the claims to create other embodiments, and these modifications and alterations are included in the scope of the claims. The following description is an example of the best mode for carrying out the present invention, and does not limit the scope of the claims.

[0009] FIG. 1 is a perspective view showing an image forming apparatus 1 of the present embodiment. The image forming device 1 shown in FIG. 1 combines the functions of a copier, printer, facsimile machine, scanner, etc., and can record and output full-color images or monochrome images on recording paper or in a specified data format based on input data such as scanned image data.

[0010] The image forming apparatus 1 includes a paper feed section 5, an image forming section 6, and an image reading device 2. The image reading device 2 includes a scanner section 4 and an ADF 3 which is an automatic document feeder.

[0011] The paper feed unit 5 includes, for example, multiple paper feed cassettes each storing cut-shaped recording paper, and multiple sets of paper feed rollers that pick up and feed recording paper from any of the paper feed cassettes. The paper feed unit also has a paper feed path that includes various rollers that transport the recording paper fed from any of the paper feed rollers to a predetermined image forming position in the image forming unit 6.

[0012] The image forming section 6 includes, for example, an exposure unit, multiple photosensitive drums, a developing device that uses toner of four colors, cyan (C), magenta (M), yellow (Y) and black (K), an intermediate transfer section, a secondary transfer section and a fixing section.

[0013] Based on the read image read by the image reading device 2, the image forming unit 6 exposes the photosensitive drums of each color with the exposure unit to form an electrostatic latent image on each photosensitive drum, and develops the latent image on each photosensitive drum by supplying toner to the latent image on each photosensitive drum with the developing unit of each color of the developing device. The image forming unit 6 also primarily transfers the toner images on the photosensitive drums of each color to the intermediate transfer belt of the intermediate transfer unit, and then secondarily transfers them onto the recording paper in the secondary transfer unit. The toner image secondarily transferred onto the recording paper is fixed by the fixing unit by applying heat and pressure to the toner image on the recording paper, thereby obtaining a color image. Furthermore, the image forming unit 6 is capable of forming an external output image such as an image file or data that can be output to the outside, based on the image read by the scanner unit 4 or a second image reading unit described later. Instead of the image forming unit 6 of the electrophotographic type as described above, an image forming unit adopting another recording method such as an inkjet method may be used.

[0014] Next, ADF3 will be described. FIG. 2 is an enlarged diagram showing the main configuration of the ADF 3. As shown in FIG. The ADF 3 separates documents one by one from a stack of documents loaded on a document loading tray 21 serving as a loading section, carries the documents into a document transport path 22, and transports the documents along the document transport path 22. During the transport, the documents are arranged so that they gradually come partially in contact with the upper surface of the DF contact glass 14 from the upstream portion in the transport direction.

[0015] A pair of side fences 23, which are movable in the width direction and serve as regulating members for positioning the document, i.e., the document sheets set in the ADF 3, in the document width direction perpendicular to the paper feed direction, are attached to the document placement tray 21. These side fences 23 can move toward and away from each other so that the centers of the document placement tray 21 and the document in the width direction coincide with each other.

[0016] The ADF 3 includes a call roller 24 as a feeding member that calls up the document set on the document placement tray 21 in the feeding direction, and a pair of separation rollers 25 as a separation mechanism that separates the multiple documents fed by the call roller 24 into one document.

[0017] The separation roller pair 25 is composed of a transport roller 25a and a reverse roller 25b facing the transport roller 25a. A driving force is transmitted from a paper feed motor to the transport roller 25a and the reverse roller 25b, and the transport roller 25a is driven to rotate clockwise in FIG. 2 (the direction in which the document is transported). The driving force of the paper feed motor is transmitted to the reverse roller 25b via a torque limiter, and the reverse roller 25b is driven to rotate in the same direction as the rotation direction of the transport roller 25a (clockwise in the figure) by the driving force of the paper feed motor.

[0018] When the reverse roller 25b is in direct contact with the conveying roller 25a or in contact with the conveying roller 25a via only one document (when only one document S is sandwiched in the separation nip), the force of the reverse roller 25b rotating with the conveying roller 25a is greater than the torque set by the torque limiter. Therefore, the reverse roller 25b rotates with the conveying roller 25a or the document. That is, the reverse roller 25b rotates counterclockwise in FIG. 2.

[0019] On the other hand, when two or more documents are sandwiched in the separation nip, the accompanying rotation force becomes lower than the set torque of the torque limiter, and the driving force of the feed motor is transmitted to the reverse roller 25b, which is rotated in the opposite direction to the accompanying rotation direction. By rotating the reverse roller 25b in the opposite direction to the accompanying rotation direction, a moving force in the opposite direction to the feed direction is applied by the reverse roller 25b to the documents other than the top document among the documents transported to the separation nip. As a result, the excess documents are pushed back, and only the top document is separated from the multiple documents, preventing double feeding.

[0020] The document separated into one sheet by the separation roller pair 25 is conveyed by the conveying roller 25a, and the leading edge of the document abuts against the pull-out roller pair 28, which serves as a skew correction member and whose rotation is stopped.

[0021] The feed motor that is driven at this time is driven for a predetermined time from the detection of the leading edge of the document by the abutment sensor 72, and then stopped. This causes the document to be fed a predetermined distance from the position detected by the abutment sensor 72. As a result, the transport of the document by the transport roller 25a stops with the document pressed against the pull-out roller pair 28 with a predetermined amount of deflection.

[0022] When the leading edge detection sensor 71, which detects the leading edge of the document immediately after it leaves the separation roller pair 25, detects the leading edge of the document and conveys the document a predetermined distance, the call roller 24 retreats from the top surface of the document, and the document is conveyed only by the conveying force of the conveying roller 25a. As a result, the leading edge of the document enters the nip formed by the upper and lower rollers of the pull-out roller pair 28, and the leading edge of the document is aligned (skew correction).

[0023] As described above, the pull-out roller pair 28 has a skew correction function and is a roller pair for transporting the skew-corrected original to the intermediate roller pair 29 .

[0024] The document S sent out by the pull-out roller pair 28 is transported by an intermediate roller pair 29 and a reading entrance roller pair 30 so as to pass over the DF contact glass 14. Then, the scanner unit 4 reads the image on the surface of the document at the appropriate time.

[0025] A pair of reading exit rollers 32 for conveying the document, the front side of which has already been read, to a back side image reading module 35 side is provided downstream of the DF contact glass 14 in the document conveying direction.

[0026] When reading of the back side image of the document is required, the back side image is read by a back side image reading module 35 consisting of a contact type image sensor for reading the back side. A second reading exit roller pair 36 is provided downstream of the back side image reading module 35 in the document conveying direction, and a paper discharge roller pair 37 is provided further downstream. After reading, the document is discharged to a paper discharge tray 39 by the paper discharge roller pair 37.

[0027] In this embodiment, a pair of regulating fences 50 serving as second regulating members for regulating the width direction of a small-sized document are provided between the separation roller pair 25 and the pull-out roller pair 28. The ADF 3 of this embodiment also includes a pressing member 60 for pressing down the document before the regulating fences 50 to prevent the document from floating.

[0028] FIG. 3 is a schematic plan view of the document placement tray 21 in this embodiment. FIG. 4 is a plan view showing a state in which a document stack P of small-sized documents, i.e., sheets whose sheet width size is smaller than a predetermined size, is set on the document loading tray 21 in this embodiment (a state in which the side fence alignment work has been completed).

[0029] 3 and 4, a pair of side fences 23 are provided on the document placement tray 21 as regulating members that respectively come into contact with one side and the other side of the document stack P in the width direction. These two side fences 23 are configured to be movable in the document width direction in conjunction with each other so that the distance between each side fence 23 and the center position in the document width direction is always constant.

[0030] When the document stack P is set on the document placement tray 21, the document stack P is placed between the two side fences 23, and then the two side fences 23 are moved along the document width direction until the document stack P is sandwiched between the two side fences 23 from the width direction. In this way, the width direction position of the document stack P is regulated by the two side fences 23.

[0031] The document placement tray 21 is provided with a guide groove 123 that guides the side fence 23 to move in the document width direction. As shown in Figures 3 and 4, the guide groove 123 extends in the document width direction and opens onto the document placement tray 21. A guide pin provided in the lower part of the side fence 23 fits into the guide groove 123, thereby allowing the side fence 23 to move in the document width direction along the guide groove 123.

[0032] Furthermore, four side fence width sensors 116a to 116d are arranged along the guide groove 123 on the document placement tray 21. The side fence width sensors 116a to 116d are configured with optical sensors, and detect the document width direction position of the side fence 23 by detecting a filler 124 attached to a guide pin of the side fence 23. There is no particular limit to the number of side fence width sensors 116a to 116d, and there may be one or two or more.

[0033] In this embodiment, each of the side fence width sensors 116a to 116d turns on when it detects the filler 124 of the side fence 23, and the detection result is sent to the control unit. The control unit detects the document width direction position of the side fence 23 depending on which of the four side fence width sensors 116a to 116d is on. Then, the control unit detects the size of the document set in the document placement tray 21 from the detected side fence position.

[0034] 4, when a small-sized original is set on the original placement tray 21, the innermost side fence width sensor 116a in the width direction detects the filler 124 of the side fence 23 and turns on. When the innermost side fence width sensor 116a is on, the control unit determines that a small-sized original is set on the original placement tray 21.

[0035] Alternatively, a plurality of document length sensors, each of which is an optical sensor, may be arranged at a predetermined interval in the document transport direction on the document placement tray 21, and the document size may be detected based on the detection results of the document length sensors and the side fence width sensors 116a to 116d. Alternatively, the document size may be detected based only on the detection results of the plurality of document length sensors.

[0036] FIG. 5 is a schematic plan view showing how a small-sized original is fed. 5, the conveying path length L1 from the separation roller pair 25 to the pull-out roller pair 28 is shorter than the length in the conveying direction of the smallest size sheet that can be conveyed by the ADF 3. This allows the conveying roller 25a to convey the document until the leading edge of the smallest size document that can be conveyed by the ADF 3 hits the pull-out roller pair 28.

[0037] The transport path length L2 from the call roller 24 to the pair of pull-out rollers 28 is longer than the length in the transport direction of the smallest size document that can be transported by the ADF 3. Therefore, the call roller 24 is configured to rise before the rear end of the smallest size document passes through the call roller 24. Specifically, as described above, when the leading edge detection sensor 71, which detects the leading edge of the document immediately after it passes through the pair of separation rollers 25, detects the leading edge of the document and transports the document a predetermined amount, the call roller 24 is raised and withdrawn from the top surface of the document. The predetermined amount is a transport amount that is shorter than the length in the transport direction of the smallest size document. This allows the call roller 24 to withdraw from the top surface of the document before the trailing edge of the smallest size document passes through the call roller 24.

[0038] Furthermore, the length L0 in the transport direction of a small-sized document such as a business card size document is shorter than the length Lp of the transport path from the downstream end of the side fence 23 in the transport direction to the pair of pull-out rollers 28. Therefore, the rear end of the small-sized document passes through the side fence 23 before the leading end reaches the pair of pull-out rollers 28, and the document is transported for a predetermined period of time without being restricted in the width direction by the side fence 23. In this way, by being fed without being restricted by the side fence 23, the small-sized document may be significantly skewed, as shown by the solid line in the figure.

[0039] As described above, the document is pressed against the pair of pull-out rollers 28 with a predetermined amount of deflection, and the skew of the document is corrected. However, if the amount of skew is large, the amount of deflection must be increased in order to properly correct the skew of the document. However, since the length L0 in the conveying direction of a small-sized document is short, if the amount of deflection is increased, the trailing end of the document will pass through the separation nip of the pair of separation rollers 25 before the desired amount of deflection is reached. In addition, in the case of small-sized documents such as business cards that are stiff and difficult to bend, it is difficult to increase the amount of deflection. Therefore, when the amount of skew is large, skew remains when the skew is corrected by the pair of pull-out rollers 28, and there is a risk that the skew correction will be insufficient.

[0040] In contrast, in this embodiment, a pair of regulating fences 50 are provided between the pair of separation rollers 25 and the pair of pull-out rollers 28, and the pair of regulating fences 50 are used to correct the skew of small-sized documents.

[0041] FIG. 6 is a diagram for explaining skew correction of a small-sized document by the regulating fence 50. As shown in FIG. 6, the pair of regulating fences 50 are provided so as to be movable within a predetermined range in the width direction. Similar to the side fences 23, the pair of regulating fences 50 are configured so as to be movable in the width direction in conjunction with each other so that the distance between each regulating fence 50 and the center position of the document in the width direction is always constant.

[0042] An operator sets a stack of small-sized originals and manually moves the side fences in the width direction to abut against the widthwise ends of the stack of small-sized originals on the document placement tray 21, thereby restricting the stack of small-sized originals in the width direction. When the operator presses the start button on the operation display unit 130 (see FIG. 1) of the image forming apparatus 1, the control unit detects the size of the originals based on the detection results of the side fence width sensors 116a to 116d. At this time, the pair of restriction fences 50 are waiting at a home position outside the widthwise ends of the small-sized originals, as shown by the solid lines in the figure.

[0043] When the document set on document placement tray 21 is a small-sized document, the mode is switched to small-sized document transport mode. In small-sized document transport mode, the document is transported a predetermined distance after the leading edge of the document is detected by leading edge detection sensor 71, and transport of the document is temporarily stopped just before the leading edge of the document reaches pair of pull-out rollers 28. This causes transport of the document to be temporarily stopped with the leading edge of the document positioned near the downstream end of the regulating fence in the transport direction. In addition, in small-sized document transport mode, the transport speed may be slower than in normal document transport mode to prevent skew from occurring.

[0044] In the configuration shown in Fig. 6, the rear end of the small-sized original passes through the call roller 24 before the small-sized original is temporarily stopped, so the call roller 24 is raised before the temporary stop to move away from the top surface of the original. However, it is preferable to raise the call roller 24 to move away from the top surface of the original simultaneously with or after the original transport is stopped. In this way, the small-sized original can be held by the pair of separation rollers 25 and pressed against the original placement tray 21 by the call roller 24 until the transport of the original is temporarily stopped. As a result, the small-sized original is transported while being held at two points in the transport direction, and skew of the small-sized original after the rear end passes through the side fence is suppressed.

[0045] When the call roller 24 is in a retracted position away from the top surface of the document, the drive means moves the regulating fence 50 inward in the width direction, and the regulating fence 50 abuts against the width direction end of the small-sized document that is temporarily stopped. This causes the skew of the small-sized document to be corrected by the regulating fence 50. At this time, the call roller 24 has retracted from the top surface of the document, and the small-sized document is held only by the pair of separation rollers 25. Therefore, the small-sized document rotates more easily than when the call roller 24 is in contact with it, and the skew can be properly corrected by the regulating fence 50.

[0046] Also, transport of the small-sized original is temporarily stopped just before the leading edge of the original reaches the pair of pull-out rollers 28, and the small-sized original is skewed in a state where the leading edge of the small-sized original is located near the downstream end of the regulating fence 50 in the transport direction. As a result, the entire area of ​​the regulating fence 50 in the transport direction abuts against the width direction end of the small-sized original, and skew correction is performed, making it possible to satisfactorily correct the skew of the small-sized original. Also, compared to when the leading edge of the original abuts against the pair of pull-out rollers 28, the original is easier to rotate, and skew correction can be satisfactorily performed by the regulating fence 50. Also, the regulating fence 50 may be reciprocated in the width direction a number of times to abut against the width direction edge of the document a number of times, thereby performing skew correction by the regulating fence a number of times.

[0047] Also, the conveying roller 25a of the separation roller pair may be configured to be movable toward and away from the reverse roller 25b, so that the conveying roller 25a is moved away from the reverse roller 25b during skew correction by the regulating fence 50. This makes it easier for small-sized documents to rotate during skew correction by the regulating fence 50, and allows for even better skew correction by the regulating fence 50.

[0048] After the skew correction, the transport of the small-sized original is resumed with the restriction fence 50 abutting against the widthwise end of the small-sized original. Then, the leading edge of the original is abutted against the stopped pull-out roller pair 28, and the leading edge of the original is caused to enter the nip portion of the pull-out roller pair 28. At this time, the small-sized original may be bent to perform skew correction by the pull-out roller pair 28. Also, the user may be allowed to select whether or not to perform skew correction by the pull-out roller pair 28.

[0049] If the user selects to perform skew correction by the pull-out roller pair 28 by operating the operation display unit 130 (see FIG. 1), the small-sized original is transported by the transport roller 25a even after the leading edge of the original hits the stopped pull-out roller pair 28. This causes the small-sized original to bend between the separation roller pair 25 and the pull-out roller pair, and skew correction is performed. This makes it possible to more reliably suppress skew of the small-sized original.

[0050] After the skew correction by the pull-out roller pair 28, the feed motor is rotated in the reverse direction to stop the rotation of the transport roller 25a, and the pull-out roller pair 28 is rotated to transport the small-sized original toward the intermediate roller pair 29. The rear end of the original is detected by the abutment sensor 72, and when it is detected that the rear end of the original has passed through the regulating fence 50, the regulating fence 50 is moved to the home position.

[0051] On the other hand, if the user has selected not to perform skew correction by the pull-out roller pair 28, when the leading edge of the document hits the stopped pull-out roller pair 28, the paper feed motor is rotated in reverse to transport the small-sized document toward the intermediate roller pair 29. This makes it possible to prevent the generation of tensioning noises that may occur when the document is released from its slack, thereby reducing the noise level of the device. It also makes it possible to prevent a decrease in productivity.

[0052] In this embodiment, the small-sized original after skew correction by the restriction fence 50 is conveyed while being restricted in the width direction by the restriction fence 50. The original conveying distance from the downstream end of the restriction fence 50 in the original conveying direction to the pull-out roller pair 28 is shorter than the conveying direction length L0 of the small-sized original (see FIG. 5). Therefore, in a state where the small-sized original is restricted in the width direction by the restriction fence 50, it is possible to enter the pull-out roller pair 28, and it is possible to suppress the occurrence of skew after skew correction.

[0053] Furthermore, in the case of the following configuration, the pair of pullout rollers 28 may be rotationally driven at the time when transport of the original document is resumed after skew correction, and the original document may be transported as is without abutting the leading edge of the original document against the stopped pair of pullout rollers 28. That is, in this case, for example, the pair of pullout rollers 28 may be rotationally driven by a separate drive motor, or the drive of the pair of pullout rollers 28 may be performed independently of the drive of the transport roller 25a of the separation roller pair or the call roller.

[0054] FIG. 7 is a schematic diagram showing the state of conveyance of an original other than a small-sized original (hereinafter, referred to as a large-sized original Pw). The upper surface of the restriction fence 50 serves as a guide surface 51 for guiding the large-sized document Pw. The guide surface 51 has a first guide portion 51a and a second guide portion 51b.

[0055] The first guide portion 51a has an inclined surface that is positioned upward as it approaches the downstream in the document transport direction, so that a large-sized document can smoothly ride up onto the regulating fence 50.

[0056] The second guide portion 51b connected to the downstream end of the first guide portion in the document transport direction guides the leading edge of the document to the nip between the pair of pull-out rollers 28, and is shaped to fit along the upper guide member 22a facing the regulating fence 50. Specifically, it is an inclined surface that is positioned lower as it approaches the downstream in the document transport direction.

[0057] The gap S1 between the second guide portion 51b and the upper guide member 22a narrows toward the downstream side in the conveying direction, so that the leading edge of the large-sized document can be smoothly guided to the nip between the pair of pull-out rollers . The gap S2 between the first guide portion 51a and the upper guide member 22a is widened to ensure a space for the document to bend when the document is skew-corrected by the pull-out roller pair 28. This allows the pull-out roller pair 28 to perform good skew correction.

[0058] The leading edge of the large size document is guided by the first guide portion 51a of the regulating fence 50, and after climbing up onto the regulating fence 50, is guided by the upper guide member 22a and the second guide portion 51b toward the nip of the pull-out roller pair.

[0059] 7, immediately after the leading edge of the large-sized document hits the stopped pull-out roller pair 28, the area between the separation roller pair 25 for the large-sized document and the pull-out roller pair 28 is aligned with the guide surface 51 of the regulating fence. When the large-sized document is subsequently fed by the conveying force of the conveying roller 25a of the separation roller pair, the area between the separation roller pair 25 for the large-sized document and the pull-out roller pair 28 is bent upward to follow the upper guide member 22a.

[0060] In this embodiment, since the gap S2 between the first guide portion 51a and the upper guide member 22a is wide, a desired amount of deflection can be ensured and the pull-out roller pair 28 can satisfactorily correct the skew of a large-sized document.

[0061] In addition, the guide surface 51 of the regulating fence 50 has a generally mountain-like shape that inclines upward from the upstream side in the conveying direction and then inclines downward. Therefore, the area between the separation roller pair 25 for large-sized documents and the pull-out roller pair 28 is easily bent upward, and the area between the separation roller pair 25 for large-sized documents and the pull-out roller pair 28 can be smoothly aligned with the upper guide member 22a. This allows the pull-out roller pair 28 to effectively correct the skew of the large-sized documents.

[0062] When the large-sized document is also skew-corrected by the restriction fence 50, it is necessary to retract the restriction fence 50 to the outside in the width direction. Also, when there is no guide surface for guiding the large-sized document on the restriction fence 50, it is necessary to retract the restriction fence 50 to the outside in the width direction. In this way, in the case of a configuration in which it is necessary to retract the restriction fence 50 to the outside in the width direction of the large-sized document when feeding the large-sized document, it becomes necessary to move the restriction fence 50 to the outside in the width direction of the large-sized document by the drive motor before starting to feed the large-sized document. As a result, since the feeding of the large-sized document starts after the restriction fence 50 is retracted to the outside in the width direction of the large-sized document, productivity decreases. Also, power consumption occurs in order to move the restriction fence 50 to the outside in the width direction of the large-sized document by the drive motor.

[0063] In contrast, in this embodiment, for large-sized documents, the pull-out roller pair 28 performs skew correction, and the regulating fence 50 is provided with a guide surface for guiding the large-sized document. This eliminates the need to retract the regulating fence 50 to the outside in the width direction of the large-sized document when transporting the large-sized document. This makes it possible to shorten the widthwise movement range of the regulating fence 50, and simplify the device structure. In addition, it is no longer necessary to retract the regulating fence 50 to the outside in the width direction of the large-sized document by the drive motor before starting transport of the large-sized document, and transport can be started immediately after the large-sized document is set, thereby suppressing a decrease in productivity. In addition, it is possible to reduce power consumption.

[0064] 8, guide surface 22b1 of lower sheet-feed guide member 22b in front of regulating fence 50 is positioned above lower end X1 of first guide portion 51a of regulating fence 50. This makes it possible to prevent the leading edge of the large-sized document guided by guide surface 22b1 of lower sheet-feed guide member 22b from slipping under regulating fence 50, and allows the document to be smoothly handed over to first guide portion 51a.

[0065] When the rear end of a small-sized document is skewed significantly after passing through the side fence, the leading edge of the small-sized document may run onto the regulating fence 50. In particular, when the leading edge of a small-sized document is curled and the widthwise end of the leading edge of the document is slightly raised, the leading edge of the small-sized document is likely to run onto the regulating fence when the document is skewed significantly. In addition, the regulating fence 50 is mountain-shaped, and the upstream side of the first guide portion 51a in the transport direction is low in height, so that the leading edge of the document is likely to run onto the first guide portion 51a. For this reason, in this embodiment, a pressing member 60 is provided to prevent the document from floating.

[0066] FIG. 9 is a schematic diagram of the pressing member 60. As shown in FIG. The pressing member 60 is rotatably supported on the shaft of the conveying roller 25a of the separation roller pair 25, and the width W10 of the pressing member 60 is narrower than the width W4 of the small-sized document shown in Fig. 5. In this embodiment, the pressing member prevents the small-sized document from floating near the upstream end of the regulating fence.

[0067] By pressing down the document with the pressing member 60, it is possible to suppress the lifting up of a small-sized document when the document is significantly skewed and the leading edge of the document abuts against the restriction fence from the width direction. This makes it possible to suppress the leading edge of the document from riding up onto the restriction fence, and allows the small-sized document to be transported between the restriction fences. In addition, when the restriction fence is brought into contact with the width direction end of the small-sized document to perform skew correction, the pressing member can suppress the lifting up of the center of the small-sized document. This makes it possible to satisfactorily correct the skew of the small-sized document with the restriction fence.

[0068] The height of the restriction fence is low, and by pressing down the vicinity of the upstream end of the restriction fence, where the leading edge of a small-sized document is likely to climb up, with the pressing member, it is possible to effectively prevent the small-sized document from climbing up onto the restriction fence.

[0069] On the other hand, the large-sized original Pw is guided by the first guide portion 51a of the regulating fence 50 and forced to float up (ride on the regulating fence). At this time, the pressing member 60 rotates clockwise in FIG. 10 against the pressing force (its own weight) of the pressing member 60 due to the stiffness of the original, and assumes the position shown by the dashed line in the figure. In this embodiment, the document is pressed down by the weight of the pressing member 60, but the document may be pressed down by the biasing force of a biasing member such as a torsion spring.

[0070] In addition, the width W10 (see FIG. 9) of the tip (contact portion with the document) of the pressing member 60 in this embodiment is narrower than the width W4 of the small-sized document shown in FIG. 5, and only the center portion of the small-sized document in the width direction is pressed by the pressing member 60. This makes it possible to suppress the occurrence of skew compared to pressing both ends of the small-sized document in the width direction with the pressing member 60, and the small-sized document can be transported well between the regulating fences. On the other hand, pressing both ends of the small-sized document in the width direction with the pressing member 60 has the advantage of suppressing the tip of the small-sized document from climbing up onto the regulating fence 50 compared to pressing only the center portion of the small-sized document in the width direction with the pressing member 60.

[0071] 11, the pressing member 60 may be extended further upstream in the document transport direction than in the embodiment, and the leading edge of the small-sized document may be restricted in the width direction by a pair of restriction fences 50 before the trailing edge of the small-sized document passes through the side fences 23. As a result, the small-sized document is transported while being restricted in the width direction by the restriction fences 50 even after the trailing edge of the small-sized document passes through the side fences, and the small-sized document can be prevented from being significantly skewed. As a result, the skew can be effectively corrected by the pair of pull-out rollers 28 even with a small amount of bending.

[0072] 11 has a tapered portion 52 that is positioned inward in the width direction toward the upstream side in the document transport direction on the downstream side of the document transport direction. This allows the leading edge of a small-sized document to be guided between the pair of restriction fences 50 by the tapered portion 52.

[0073] Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the spirit of the present invention described in the claims unless otherwise specifically limited in the above description. For example, the present invention can be applied to the paper feed unit 5 of the image forming apparatus 1 and the manual paper feed unit.

[0074] The above description is merely an example, and each of the following aspects provides unique effects. (Aspect 1) In a feeding device having a loading section such as an original loading tray 21 on which sheets such as originals are placed, a regulating member such as a pair of side fences 23 that regulates the widthwise position of the sheet placed on the loading section, a feeding member such as a call roller 24 that contacts and feeds the sheet placed on the loading section, and a skew correction member such as a pair of pull-out rollers 28 that is arranged downstream in the sheet transport direction from the feeding member and abuts against the leading edge of the sheet to correct the skew, a second regulating member such as a pair of regulating fences 50 that contacts the widthwise end of the sheet to regulate the widthwise position of the sheet is provided between the feeding member and the skew correction member, and when a size detection means detects a small size sheet, the pair of second regulating members regulate the widthwise position of the small size sheet. In the case of a small-sized sheet such as a business card-sized sheet, the trailing edge of the sheet passes through a regulating member such as the side fence 23 before the leading edge of the sheet reaches a skew correction member such as the pair of pull-out rollers 28, and the sheet is fed without being regulated by the regulating member for a certain period of time until the leading edge of the sheet reaches the skew correction member. In this way, the sheet may become significantly skewed by being fed without being regulated by the regulating member. Skew correction by the skew correction member is performed by bending the sheet by a predetermined amount after the leading edge of the sheet abuts against the skew correction member. By increasing the amount of bending of the sheet at this time, the skew correction member can perform skew correction even when the amount of skew is large. However, since small-sized sheets are short in the sheet conveying direction, if the amount of bending of the sheet is increased, the trailing end of the sheet will pass through the conveying member in front of the skew correction member before the desired amount of bending is reached. As a result, with small-sized sheets, the amount of bending of the sheet cannot be increased, and skew remains when the skew correction member is used for skew correction, which may result in insufficient skew correction. In contrast, in the first embodiment, the skew of the small size sheet can be corrected by moving a pair of second regulating members such as the regulating fences 50 provided between the feeding member and the skew correction member in the width direction to abut against the width direction end of the small size sheet. This allows the skew of the small size sheet, which is fed without being regulated by the regulating members and becomes significantly skewed, to be corrected well for a certain period of time until the leading edge of the sheet reaches the skew correction member. 11, it is also possible to prevent the small size sheet from being significantly skewed by restricting the leading edge of the small size sheet in the width direction with the second restricting member before the trailing edge of the small size sheet passes through the restricting member. Therefore, the skew of the small size sheet can be satisfactorily corrected by the skew correction member with a small amount of bending.

[0075] (Aspect 2) In the first embodiment, the length L0 of the small size sheet in the conveying direction is shorter than the sheet conveying path length Lp from the downstream end of a regulating member such as the side fence 23 in the conveying direction to a skew correction member such as the pair of pullout rollers 28. According to this, as described in the embodiment, the leading edge of the sheet is fed without being regulated by the regulating member for a certain period until it reaches the skew correction member, and the sheet may be significantly skewed. By regulating the sheet with the second regulating member, it is possible to effectively correct the skew of the sheet having such a conveying length.

[0076] (Aspect 3) In aspect 1 or 2, a size detection means (e.g., composed of a control unit and side fence width sensors 116a-116d) is provided to detect the size of a sheet placed on a placement section such as the document placement tray 21, and a second regulating member such as a pair of regulating fences 50 is arranged to be movable in the width direction, and when the size detection means detects a small size sheet, sheet transport is temporarily halted before the leading edge of the small size sheet reaches a skew correction member such as a pair of pull-out rollers 28, and the pair of second regulating members are moved in the width direction to abut against the widthwise end of the small size sheet. According to this, as described in the embodiment, the skew of the small size sheet can be corrected by the second regulating member such as the regulating fence 50.

[0077] (Aspect 4) In the third aspect, the user can select whether or not to perform skew correction using the skew correction member for small-sized sheets such as small-sized originals. According to this, as described in the embodiment, by selecting not to perform skew correction by the skew correction member for small size sheets, the noise of the sheet leading edge hitting the sheet during or after skew correction by the skew correction member and the tension sound of the sheet when the flexure is released are not generated, so that the noise of the device can be reduced and a decrease in productivity can be suppressed. On the other hand, by selecting to perform skew correction by the skew correction member for small size sheets, it is possible to further suppress skew of small size sheets.

[0078] (Aspect 5) In any of the first to fourth aspects, the second regulating member such as the pair of regulating fences 50 has a guide surface 51 for guiding sheets other than small-sized sheets such as large-sized originals. As a result, as described in the embodiment, when transporting sheets other than small-sized sheets such as large-sized originals, it is no longer necessary to move the second regulating member such as the regulating fence 50 to a position where it is retracted outside the widthwise end of the sheet, thereby suppressing a decrease in productivity and an increase in power consumption.

[0079] (Aspect 6) In the fifth aspect, the guide surface 51 of the second regulating member such as a pair of regulating fences 50 is When the leading edge of the sheet contacts a skew correction member such as a pair of pull-out rollers, the sheet is guided so as to be curved toward a guide member such as the upper guide member 22a that faces the pair of second regulating members. This allows the sheet to be easily deflected toward the guide member such as the upper guide member 22a when performing skew correction with the skew correction member. This allows the deflected sheet to be smoothly guided to the guide member such as the upper guide member 22a, allowing the skew correction member to perform satisfactory skew correction.

[0080] (Aspect 7) In any of aspects 1 to 6, a pressure member 60 is provided to prevent small-sized sheets from floating while moving between a second regulating member such as a regulating fence 50, and the contact portion of the pressure member 60 with the sheet is movable in a direction perpendicular to the sheet surface. According to this, as described in the embodiment, when a small-size sheet moves between a second regulating member such as a regulating fence 50 and is significantly skewed, the leading edge of the small-size sheet can be effectively prevented from riding over the regulating member. On the other hand, in the case of sheets other than small-sized sheets, such as large-sized documents, the contact portion of the pressing member 60 with the sheet moves vertically to the sheet surface in response to the lift caused by the guide of the guide surface of the second restricting member, so that sheets other than small-sized sheets can be well guided by the guide surface 51 of the second restricting member.

[0081] (Aspect 8) In the seventh embodiment, the pressing member 60 contacts the central portion of the sheet in the width direction. According to this, when the pressing member 60 contacts both ends of the small-sized document in the width direction, skew is likely to occur due to a difference in the pressing force of the pressing member 60 between one end and the other end, or a misalignment in the contact position. However, by making the pressing member 60 contact the center portion in the width direction, it is possible to suppress the occurrence of skew caused by the pressing member, compared to when the pressing member 60 contacts both ends of the small-sized document in the width direction.

[0082] (Aspect 9) In an image reading device including a feeding section and an image reading section that reads an image on a document sheet fed from the feeding section, the feeding device according to any one of the embodiments 1 to 8 was used as the feeding section. This allows the skew of small-sized documents such as business cards to be corrected satisfactorily.

[0083] (Aspect 10) In the ninth aspect, the pair of second regulating members such as the regulating fences 50 are disposed upstream in the sheet conveying direction from the image reading position by the image reading unit. According to this, the small-sized original document whose skew has been corrected by the pair of second regulating members such as the regulating fences 50 can be transported to the image reading position, and the image of the small-sized original document can be read satisfactorily.

[0084] (Aspect 11) In an image forming apparatus including a feeding section and an image forming section for forming an image on a sheet fed from the feeding section, the feeding device according to any one of the embodiments 1 to 8 was used as the feeding section. This allows the skew of small size sheets to be corrected satisfactorily. [Explanation of symbols]

[0085] 1: Image forming device 2: Image reader 3: ADF 4: Scanner section 5:Paper feed section 6: Image forming section 14:DF contact glass 21: Document tray 22: Document transport path 22a: Upper guide member 22b: Paper feed lower guide member 22b1: Guide surface 23: Side fence 24: Call roller 25: Separation roller pair 25a: Transport roller 25b: Reverse roller 28:Pull-out roller pair 29: Intermediate roller pair 30: Reading entrance roller pair 32: Reading exit roller pair 35: Backside image reading module 36: Second reading exit roller pair 37: Paper discharge roller pair 39: Paper output tray 50: Restriction fence 51: Guide surface 51a: First guide part 51b: Second guide part 52: Tapered section 60: Clamping member 71: Tip detection sensor 72: Stop sensor 116a: Side fence width sensor 116b: Side fence width sensor 116c: Side fence width sensor 116d: Side fence width sensor 123: Guide groove 124: Filler 130: Operation display section [Prior art documents] [Patent documents]

[0086] [Patent Document 1] JP 2003-81445 A

Claims

1. a placement section on which a sheet is placed; a pair of regulating members that regulate a widthwise position of the sheet placed on the placement portion; a feeding member that contacts and feeds the sheet placed on the sheet placement section; a skew correction member disposed downstream of the feeding member in a sheet conveying direction and configured to abut against a leading edge of the sheet to perform skew correction, A feeding device characterized in that a pair of second regulating members that abut against the widthwise ends of a small-size sheet and regulate the widthwise position of the small-size sheet are provided between the feeding member and the skew correction member.

2. 2. The feeding device according to claim 1, a length of the small size sheet in the transport direction is shorter than a length of a sheet transport path from a downstream end of the regulating member in the transport direction to the skew correction member.

3. 2. The feeding device according to claim 1, a size detection unit that detects the size of the sheet placed on the placement unit, The pair of second stop members are provided to be movable in the width direction, A feeding device characterized in that, when the size detection means detects the small size sheet, sheet transport is temporarily stopped before the leading edge of the small size sheet reaches the skew correction member, and a pair of the second regulating members are moved in the width direction to abut against the width direction end of the small size sheet.

4. The feeding device according to claim 3, a skew correction member for correcting the skew of the small size sheet;

5. 2. The feeding device according to claim 1, The feeding device according to the present invention is characterized in that the pair of second regulating members have guide surfaces for guiding sheets other than the small size sheets.

6. 6. The feeding device according to claim 5, A feeding device characterized in that the guide surfaces of a pair of the second stop members guide the sheet so that when the leading edge of the sheet abuts the skew correction member, the sheet curves toward the guide member that faces the pair of the second stop members.

7. 6. The feeding device according to claim 5, a pressing member for pressing the small size sheet against floating while the small size sheet is moving between the second stop members; A feeding device, characterized in that a contact portion of the pressing member with the sheet is movable in a direction perpendicular to a sheet surface.

8. 8. The feeding device according to claim 7, The sheet feeding device, wherein the pressing member contacts a central portion of the sheet in a width direction.

9. A feeding section; an image reading unit that reads an image on the original sheet fed from the feeding unit, 2. An image reading apparatus, comprising: the feeding device according to claim 1 as said feeding section.

10. 10. The image reading apparatus according to claim 9, The image reading device according to claim 1, wherein the pair of second stop members are disposed upstream of an image reading position of the image reading unit in a transport direction of the document sheet.

11. A feeding section; an image forming apparatus including an image forming unit that forms an image on the sheet fed from the feeding unit, 2. An image forming apparatus, comprising: the feeding device according to claim 1 as said feeding section.

Images