JP2011133808A - Paper feeding device, image forming apparatus and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent roughness on a surface of a fixing section without any deterioration in productivity and without enlarging an apparatus. <P>SOLUTION: A paper feeding device includes: a storage section for storing recording paper; a suction conveying section for sucking the recording paper stored in the storing section and conveying in a suction state; and a section for varying position in a conveyance orthogonal direction of the recording paper in the suction conveying section, wherein the section for varying the position in conveyance orthogonal direction varies the position in conveyance orthogonal direction of the recording paper during suction or conveyance in the suction conveying section. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention includes a paper feeding device used in an image forming apparatus such as a copying machine, a printer, a facsimile machine, a printing machine, and a multifunction machine, an image forming apparatus provided with the paper feeding device, and a paper feeding device and an image forming apparatus. The present invention relates to an image forming system, and more particularly to a technique for preventing the surface of a fixing roller from being roughened when a recording sheet used for image formation is sucked and fed.

  In an electrophotographic image forming apparatus, a toner image is formed on an image bearing member of a rotating photosensitive drum or photosensitive belt, and the formed toner image is directly or indirectly transferred onto a recording paper and further fixed. An image is formed.

In this image formation, the toner image electrostatically transferred onto the recording paper is fixed on the recording paper in a stable state by heat and pressure from the fixing roller.
By the way, image formation (fixing) is repeated with recording paper of the same size, and the end of the recording paper comes into contact with the same part of the fixing roller surface, so that the fixing roller surface is scratched or the fixing roller surface is scraped. May occur. This causes a problem that the life of the fixing roller is shortened.

  In addition, if you continue to use a fusing roller with such scratches or shavings, when using recording paper that is wider than the scratches or shavings, unevenness in fixing occurs at the flawed or scratched parts of the fixing roller. However, there is a problem that the image deteriorates. That is, this phenomenon becomes prominent when a recording paper having a size larger than the recording paper is used after the fixing roller is scratched or scraped by repeatedly using a certain size of the transfer paper.

Further, such scratches and scrapes are problems that may occur not only on the fixing roller but also on the photoconductor.
Various proposals have been made in the following patent documents in order to prevent such flaws and scratches (hereinafter referred to as “roughness”) on the surface of the fixing roller.

JP 2008-298925 A JP 2006-317881 A JP 2008-225276 A JP 2007-34068 A Japanese Patent Application Laid-Open No. 07-13450

  In the above-mentioned Patent Document 1, a technique has been proposed in which the end portion is thinned by sandwiching the end portion of the recording paper on the upstream side of the fixing device. As a result, the extent to which the edge of the recording paper pinched and thinned damages the surface of the fixing roller is improved.

In the above-mentioned Patent Document 2, an abrasive that polishes the surface of the fixing belt is provided to deal with surface roughness.
In the above Patent Document 3, a concave portion for reducing the pressing force is provided on the surface of the fixing roller or the fixing belt.

In the above-mentioned Patent Document 4, in fixing the configuration of the upper belt and the lower roller, a contact member of the belt is arranged and the surface roughness is made larger than the surface roughness of the upper belt.
In the above Patent Documents 1-4, a method of thinning or polishing the scratch is used, and it does not fundamentally solve the occurrence of scratches or scraping on the fixing roller.

  Therefore, a configuration in which the fixing roller itself is swung in the fixing roller axial direction (sub-scanning direction) is also conceivable. However, it is necessary to configure the fixing roller to be larger than the original size in the sub-scanning direction because of the allowance for rocking. In addition, since the fixing roller is heavy and large, there is a problem that a swing mechanism becomes large. Note that the fixing roller is made to cover the maximum size of the recording paper, but since the circumference is further increased to swing it, the size of the entire apparatus may be affected. is assumed.

  Therefore, in Patent Document 5 described above, the recording paper is moved in the sub-scanning direction in order to equalize the heat of the fixing roller. However, the effect of dispersing the scratches on the fixing roller can also be obtained using this. That is, in Patent Document 5, since the position of the scratch on the fixing roller is dispersed by shifting the position of the recording paper in the sub-scanning direction, it seems effective at first glance.

  However, in Patent Document 5, as shown in the flowchart of FIG. 13, after the preceding recording paper is fed and conveyed by the paper feed roller (steps S01 and S02 in FIG. 13) and comes out of the paper feed cassette (step in FIG. 13). S03), the paper feed cassette is moved in the sub-scanning direction (step S04 in FIG. 13) in a very short time until the next recording paper starts to be driven by the paper feed roller (step S01 in FIG. 13). It is necessary to perform positioning (steps S05 and S06 in FIG. 13).

  For this reason, a low-speed image forming apparatus can cope with this, but a high-speed image forming apparatus does not have much time margin (steps S02 to S05 in FIG. 13) for moving the paper feed cassette in the sub-scanning direction. Is getting harder. It is also expected that the paper feed timing will be delayed and the productivity of image formation will be reduced by taking the movement time of the paper feed cassette.

  The present invention has been made in order to solve the above-described problem, and is capable of effectively preventing roughening of the fixing unit surface without reducing productivity and without increasing the size of the apparatus. An object is to provide an apparatus, an image forming apparatus, and an image forming system.

  The present invention relates to a storage unit that stores recording paper, a suction transport unit that sucks and transports the recording paper stored in the storage unit in a suction state, and changes the position in the conveyance orthogonal direction of the recording paper in the suction transport unit. A conveyance orthogonal direction position changing unit that changes the conveyance orthogonal direction position of the recording paper during the suction or the conveyance by the suction conveyance unit. Is a sheet feeding device.

  Here, the conveyance orthogonal direction position change unit changes the conveyance orthogonal direction position of the recording paper by changing the conveyance orthogonal direction position of the storage unit during the suction or the conveyance in the suction conveyance unit. It is characterized by.

  Here, the conveyance orthogonal direction position changing unit includes guide means for guiding the recording sheet to change the conveyance orthogonal direction position in a path sucked from the storage unit toward the suction conveyance unit. Features.

  Here, the conveyance orthogonal direction position change unit changes the conveyance speed in the adsorption conveyance unit according to the difference in the conveyance orthogonal direction position during the suction or the conveyance in the adsorption conveyance unit. Further, the position of the recording paper in the conveyance orthogonal direction is changed.

  According to another aspect of the invention, there is provided an image forming apparatus comprising: the paper feeding device according to any one of the above; and an image forming unit that forms an image on recording paper fed from the paper feeding device. Device. Here, the image forming unit forms an image in an image area of the recording paper in accordance with a difference in the transport orthogonal direction position of the recording paper.

  According to another aspect of the present invention, there is provided an image forming system comprising: an image forming apparatus that forms an image on a recording sheet; a paper feeding device that conveys the recording sheet to the image forming apparatus; and a control unit that controls each unit. The sheet feeding device includes: a storage unit that stores recording paper; a suction transport unit that sucks and transports the recording paper stored in the storage unit in a suction state; and a conveyance orthogonal direction of the recording paper in the suction transport unit A conveyance orthogonal direction position changing unit that changes a position, and the control unit changes the conveyance orthogonal direction position of the recording paper during the suction or the conveyance in the suction conveyance unit. An image forming system that controls a position changing unit.

  Here, the conveyance orthogonal direction position change unit changes the conveyance orthogonal direction position of the recording paper by changing the conveyance orthogonal direction position of the storage unit during the suction or the conveyance in the suction conveyance unit. It is characterized by.

  Here, the conveyance orthogonal direction position changing unit includes guide means for guiding the recording sheet to change the conveyance orthogonal direction position in a path sucked from the storage unit toward the suction conveyance unit. Features.

  Here, the conveyance orthogonal direction position change unit changes the conveyance speed in the adsorption conveyance unit according to the difference in the conveyance orthogonal direction position during the suction or the conveyance in the adsorption conveyance unit. Further, the position of the recording paper in the conveyance orthogonal direction is changed.

  Here, the image forming unit forms an image in an image area of the recording paper in accordance with a difference in the transport orthogonal direction position of the recording paper.

  In the present invention, when the recording paper stored in the storage unit is sucked by the suction transport unit and transported in the suction state, the suction transport unit is changed by the transport orthogonal direction position change unit that changes the transport orthogonal direction position of the recording paper. The position of the recording paper in the direction perpendicular to the conveyance direction is changed during suction or conveyance.

  By changing the position of the recording paper P in the direction perpendicular to the conveyance direction, the surface of the fixing roller diffuses roughness such as scratches or scrapes at the end of the recording paper so that it does not concentrate on a specific position. Will be suppressed. Further, by changing the position of the recording paper P in the conveyance orthogonal direction, the heat of the fixing roller can be used widely and evenly.

  In this case, it is only necessary to change the position of the recording paper in the conveyance orthogonal direction during the suction or separation operation of the recording paper in the suction conveyance section or during the suction conveyance of the recording paper, and the position change needs to be performed at a specific short timing. Therefore, productivity of image formation is not reduced.

  In addition, since it is only necessary to change the position in the conveyance orthogonal direction of the recording paper at the time of suction or conveyance in the suction conveyance unit, the size of the fixing unit surface can be reduced without increasing the size of the apparatus as compared with the case of moving the fixing roller itself. It becomes possible to effectively prevent roughening.

It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a flowchart which shows the structure of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a block diagram which shows operation | movement of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a flowchart which shows the operation | movement in a conventional apparatus.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings.
〔Constitution〕
Here, the configuration of the image forming system 300 of the first embodiment will be described in detail based on FIG. 1 (block diagram) and FIG. 2 (cross-sectional configuration diagram).

  The image forming system of this embodiment can be applied to various systems. Here, an image forming apparatus as a multifunction peripheral (MFP) having functions of a scanner, a copier, a printer, and a facsimile machine is used. The description will be continued with a specific example of a system connected to a paper feeder.

Here, descriptions of general portions that are known as image forming apparatuses and paper feeding apparatuses and are not directly related to the characteristic configuration, operation, and control of this embodiment are omitted.
In FIG. 1, the image forming apparatus 100 according to the present embodiment and a paper feeding apparatus 200 that feeds recording paper to the image forming apparatus 100 are connected to form an image forming system 300. Show.

  An image forming apparatus 100 according to the present embodiment includes a control unit 101 as an overall control unit that controls each unit, a ROM (Read Only Memory) 102 in which various data and programs are stored, and a RAM (Random Access) in which programs and the like are expanded. Memory) 103, an operation display unit 105 that displays an operation input state, an image processing unit 110 that performs image processing on the image data, and an image forming unit 130 that forms an image using the image processed image data. It is configured.

  Further, the paper feeding device 200 includes a control unit 201 that controls each part of the paper feeding device, a paper suction detection sensor 211 that detects the suction state of the recording paper in the suction conveyance unit 260, and a conveyance state of the recording paper in the suction conveyance unit 260. A feed sensor 212 for detecting, a paper height detection sensor 213 for detecting the stacking height so that the height of the recording paper bundle stacked on the paper feed tray can be maintained at the optimum height for performing the above-mentioned suction, A grip sensor 214 for grip detection provided in a grip part that pulls out a housing part that can be inserted into and removed from the main body of the apparatus 200, and a paper remaining amount sensor 215 that detects the presence or absence or the remaining amount of recording paper P on the paper feed tray The suction unit 264 sucks the recording paper and the side blower 240 that generates a side wind that promotes the second and subsequent drops, and the second sheet of recording paper sucked up to prevent double feeding of the recording paper A wind blower 250 that sends down winds to separate and drop, a suction unit 264 that sucks and sucks the recording paper loaded on the tray by air pressure, and transports and feeds the recording paper sucked by the suction unit 264 When the recording paper P accommodated in the suction conveyance unit 260 including the conveyance unit 263 is sucked by the suction conveyance unit 260 and conveyed in the adsorption state, the conveyance orthogonal position of the recording paper P is set. A conveyance orthogonal direction position changing unit 280 to be changed is provided.

  As will be described later, the side air blowing unit 240 functions as a side part regulating member in conjunction with the conveyance orthogonal direction position changing unit, and the side wind strength differs between the right and left air volumes and wind speeds. It may be possible.

FIG. 2 is a cross-sectional configuration diagram schematically illustrating the overall configuration of the image forming apparatus 100 to which the paper feeding device 200 is connected.
Here, the image reading device SC that reads an image of a document, an automatic document feeder DF that automatically sends a document to the image reading device SC, an image forming unit 130 that forms an image on recording paper, and a paper feeding device 200 are roughly divided here. The sheet feeding device 200 ′ is built in the image forming apparatus 100.

  The image forming unit 130 shown in FIG. 2 includes a photoconductor 1 as an image carrier, a charging unit 2, an exposure device 3, a developing device 4, a transfer unit 5, a cleaning unit 6, and a fixing device 7. Configured.

The recording paper transport unit that transports the recording paper in the image forming apparatus 100 includes a second paper feed unit 12, a paper discharge unit 14, a transport path switching unit 15, a circulation refeed unit 16, a reverse paper discharge unit 17, and the like. Has been.
The document d placed on the document table of the automatic document feeder DF is transported by the paper feed unit, and an image on one or both sides of the document d is exposed by the optical system of the image reading device SC and read by the image sensor CCD. . The analog signal photoelectrically converted by the image sensor CCD is subjected to analog processing, A / D conversion, shade ink correction, image compression processing, and the like in the image processing unit 110, and then sent to the exposure device 3.

The image forming unit 130 performs a series of processes such as charging, exposure, development, transfer, separation, and cleaning in the case of electrophotographic image formation.
In the image forming unit 130, the surface of the photoreceptor 1 is charged by the charging unit 2, an electrostatic latent image is formed by laser light irradiation from the exposure device 3, and the electrostatic latent image is visualized by the developing device 4. It becomes a toner image. Next, the recording paper P stored in the paper feeding device 200 or the paper feeding device 200 ′ is fed and conveyed. The recording paper P is conveyed in synchronism with the toner image by the second paper feeding unit 12 composed of registration rollers. Thereafter, the recording paper P is fixed by the fixing device 7 after the toner image is transferred by the transfer unit 5.

  The recording paper P after fixing is discharged out of the apparatus by the paper discharge unit 14. On the other hand, the toner remaining on the photosensitive member 1 is removed by the cleaning unit 6. In the case of double-sided copying, the recording paper P on which the image is formed on the first surface is sent to the circulation refeed unit 16 and reversed, and after the image is formed again on the second surface in the image forming unit, the paper discharge unit 14 is discharged out of the image forming apparatus. In the case of reverse paper discharge, the recording paper P branched from the normal paper discharge path is switched back and upside down in the reverse paper discharge unit 17 and then discharged out of the image forming apparatus by the paper discharge unit 14.

  The sheet feeding device 200 according to the present embodiment is configured separately from the image forming apparatus 100 and is connected to the image forming apparatus 100. Further, the sheet feeding device 200 ′ of the present embodiment is connected to the image forming unit 130 inside the image forming apparatus 100.

  The sheet feeding device 200 or 200 ′ includes a storage unit 230, a side air blowing unit 240, a front air blowing unit 250, a suction conveyance unit 260, and the like, stores a large amount of recording paper P, and stores the recording paper in the image forming unit 130. P is transported while sucking one sheet at a time.

[Suction transfer operation]
FIG. 3 is a perspective view showing an internal configuration in the vicinity of the accommodating portion 230 that is a main portion of the paper feeding device 200 of the present embodiment.

  As shown in FIG. 3, the storage unit 230 includes a paper feed tray 231, a leading edge regulating member 232 that regulates the leading edge of the recording paper, and a trailing edge regulating member 233 that regulates the trailing edge of the recording paper. A side part regulating member 241 that regulates the side part of the recording paper is disposed in a side air blowing part 240 described later.

  In FIG. 1, as the sheet feeding device 200, the accommodation unit 230 is configured in three vertical stages. Further, in FIG. 1, as the sheet feeding device 200 ′ built in the image forming apparatus 100, the accommodation unit 230 is configured in two vertical stages.

  In these drawings, the stacked recording papers P are placed on a paper feed tray 231 and accommodated by a mechanism (not shown) so as to be moved up and down. The side regulating member 241 is movable in the recording paper width direction, and the both side positions of the recording paper P are regulated by lightly pressing on both sides of the recording paper P in accordance with the recording paper width of the stacked recording paper P. To do.

  The side regulating member 241 has a step at the top, the upstream surface 241a in the feeding direction of the recording paper P is high, and the downstream surface 241b is low. Although not shown, a support member that supports the upper end of the side regulating member 241 is attached to the upstream surface 241a. The downstream surface 241b overlaps a suction conveyance unit 260, which will be described later, on the recording paper conveyance direction (arrow X direction in FIG. 3).

  As will be described later, the position of the recording paper P in the conveyance orthogonal direction (Y direction in FIG. 3) can be changed during the suction of the recording paper in the suction conveyance unit 260 or the conveyance of the recording paper. Yes. This configuration and operation will be described in detail with reference to another drawing.

  The leading edge regulating member 232 regulates the leading edge position of the recording paper P in the conveyance direction. The rear end regulating member 233 is movable in the conveyance direction of the recording paper P, and regulates the rear end position in the conveyance direction of the recording paper P.

  Further, in order to maintain the optimum height of the recording paper bundle loaded on the paper feed tray 231 to blow air and to blow the recording paper P, the control unit 201 includes a height detection sensor. Based on the detection result 213, a lifting motor (not shown) is driven to perform control to raise the recording paper P on the paper feed tray 231.

  Further, a suction conveyance unit 260 is disposed in the vicinity of the leading end of the recording paper P in the feeding direction (X direction). The suction conveyance unit 260 has a suction belt 263 </ b> B that functions as a conveyance unit 263 by rotating around a large roller 261 and two small rollers 262 connected to a driving source. A large number of small-diameter through holes are formed in the suction belt 263B. An adsorbing portion 264 that functions as an adsorbing portion is disposed inside the adsorbing belt 263B, and the recording paper P is conveyed while being adsorbed by an attractive force via the adsorbing belt 263B, and the recording paper P is fed to the paper feed roller 265. To send.

  Further, as shown in FIG. 3, a side air blower 240 that blows air on the upper side of the recording paper P stacked in the paper feeding tray 231 from the side perpendicular to the conveyance direction of the recording paper P is provided with the paper feeding tray 231. Arranged on both sides. The side air blower 240 has a blower fan 242 that blows air onto the upper part of the recording paper P from the air blowing ports 244 on both sides orthogonal to the withdrawal direction of the recording paper P. The air blowing port 244 is disposed on the downstream surface 241b of the side regulating member 241 so as to at least partially overlap the suction conveyance unit 260 in the recording paper conveyance direction (arrow X).

  Since the side air blowing unit 240 is attached in the side portion regulating member 241, even when the size of the recording paper P is changed, the side air blowing unit 240 is also changed by moving the side portion regulating member 241. You can move. In this embodiment, the side blower 240 is provided on both sides of the recording paper P, but it may be provided on only one side.

  The side air blowing unit 240 is driven, air is blown from the air blowing port 244 to the lower part of the suction conveyance unit 260, and air is blown to several sheets on the upper side of the stacked recording sheets P. Air is blown from one end of the recording paper P through the recording paper toward the other end. As a result, the top several sheets of recording paper P are separated one by one. The suction conveyance unit 260 sucks only the uppermost recording paper P from the recording paper P thus separated.

  Further, the suction detection sensor PS1 disposed in the vicinity of the suction surface of the suction belt 263B detects that the uppermost surface of the recording paper P is sucked by the suction belt 263B. The suction belt 263B starts to rotate and starts conveying the recording paper P. A feed sensor PS2 disposed in the vicinity of the suction belt 263B on the downstream side in the recording sheet conveyance direction of the sheet feeding tray 231 detects passage of the recording sheet P to be fed.

  A front air blower 250 is fixed to the housing 230 near the tip of the suction belt 263B on the downstream side of the paper feed tray 231 in the recording paper conveyance direction. The front blowing unit 250 is configured by a blowing fan 251 and the like. Note that the front blowing unit 250 may be configured to be attached to the storage unit 230 so as to blow air to the leading end portion of the recording paper bundle through a duct. The blowing fan 251 of the front blowing unit 250 is attached with the blowing port 253 facing upward. The air blown upward is changed in direction by the guide plate 252, blown obliquely upward from the blower opening 253, and blown to the vicinity of the suction belt 263 </ b> B of the suction conveyance unit 260. Driving of the front blowing unit 250 is controlled according to the type of the recording paper P. In other words, OHP film, trace recording paper, coated paper with a smooth surface, recording paper subjected to processing such as perforation and streaking, and recording with offset powder applied to recording paper. Blow air between the papers to ensure separation.

  When the suction belt 263B continues to rotate while sucking the recording paper P, the uppermost recording paper P in the recording paper bundle advances in the direction of the arrow X in FIG. It is sent to 130.

  As shown in FIG. 3, the air inlet of the side air blowing unit 240 is shielded by a shielding member 245 and can be opened and closed. That is, the shielding member 245 formed of a plate-like shutter is pivotally supported by the shaft 246 and opened and closed by the solenoid SOL. The control means controls the shielding member 245 so as to be openable and closable so as to switch the air blowing by the side air blowing unit 240 between on (blowing) and off (stop).

  FIG. 4 is a cross-sectional view showing a process of adsorbing and conveying recording paper by the side blower 240 and the front blower 250. Here, FIG. 4A shows the adsorption process of the recording paper. Due to the side blower V1 blown up by the side blower 240 (the white arrow in the figure), a small number of recording sheets P in the upper layer of the stack of recording sheets stacked on the paper feed tray 231 resists the weight of the recording sheet. And is sucked by the intake air V3 (open arrow in the figure) due to the negative pressure of the suction belt 263B. The front air blower V2 (the white arrow in the figure) blown up by the front air blower 250 blows the vicinity of the front bottom of the suction belt 263B.

  FIG. 4B shows a recording paper separation process. When a small number of upper layers of the recording paper bundle are adsorbed by the adsorbing belt 263B, the shielding member 245 shields the air inlet of the side air blowing unit 240 and stops air blowing. Then, the air blown only by the front blower 250 passes between the uppermost recording paper P1 and the lower recording paper P2. The uppermost recording paper P1 is adsorbed by the intake air V3 of the adsorbing and conveying unit 260, and is separated from the recording paper P of the recording paper bundle excluding the uppermost recording paper P1. The recording paper P2 below the separated uppermost recording paper P1 descends in the direction of the arrow due to its own weight and is accommodated on the recording paper P.

  In this way, by repeating the air blowing of the side air blowing unit 240 and the front air blowing unit 250, the floating of the several recording papers P2 above the recording paper bundle spreads over almost the entire surface of the air blowing ports 244 and 253, and between each recording paper The gaps are almost the same. And air passes through this gap. As a result, the separation of the recording paper P1 is improved and the recording paper P1 is easily fed out.

[Configuration of the Characteristic Part of the Present Embodiment (1)]
FIG. 5 shows the configuration of the paper feed tray 231 near the storage unit 230, the side air blowing unit 240, and the suction conveyance unit 260 so that the recording paper conveyance direction (arrow X) is in the direction perpendicular to the paper surface (front or back). It is explanatory drawing shown.

  Here, the paper feed tray 231 includes a paper feed tray movable portion 231b that is movable in the Y direction on the paper feed tray base portion 231a whose position is fixed with respect to other parts of the image forming apparatus. Has been.

The paper feed tray movable unit 231b is configured to suck the recording paper P by the suction conveyance unit 260 by the driving unit 281 constituting the conveyance orthogonal direction position change unit 280 and convey the recording paper P in the adsorption state. It is comprised so that a conveyance orthogonal direction position may be changed. Here, FIGS. 5 (a), (b), (c), and (d) show three stages of position change in the Y direction. However, the position may be changed step by step or continuously. May be. Further, the continuous position change may be a smooth continuous position change, or may be a multi-step fine step-like position change.
The drive unit 281 can be driven or swung in the Y direction using various drive means such as a screw rod and nut driven by a motor, a voice coil motor, an ultrasonic motor, a solenoid, and a giant magnetostrictive element. is there. Note that the amplitude of the position change by driving or swinging at this time is to prevent the roughness generated on the surface of the fixing roller by the end of the recording paper, and may be about several mm to several tens of mm.

  Here, an example of a two-stage configuration using a paper feed tray movable portion 231b movable in the Y direction on a paper feed tray base portion 231a whose position is fixed with respect to other parts of the image forming apparatus is shown. However, the configuration may be such that the paper feed tray base portion 231a moves on the fixing member of the image forming apparatus.

[Configuration of the Characteristic Part of the Present Embodiment (2)]
FIG. 6 shows the configuration of the paper feed tray 231 in the vicinity of the storage unit 230, the side air blowing unit 240, and the suction conveyance unit 260 so that the recording paper conveyance direction (arrow X) is perpendicular to the paper surface (front or back). It is explanatory drawing shown.

  Here, the vicinity of the upper end portion serving as the side portion regulating member 241 and the side air blowing portion 240 constitutes the conveyance orthogonal direction position changing portion 280 so that the restriction position (the restriction direction toward the suction direction) can be varied in the Y direction. It is configured as a variable side regulating member 282. By using the variable side portion regulating member 282 as a guide means, the recording paper P is sucked by the suction conveyance unit 260 and is conveyed in the suction state, so that the position in the conveyance orthogonal direction of the recording paper P is changed. Has been. Here, FIGS. 6A, 6B, 6C, and 6D show three stages of Y-direction recording sheet position change (change in the inclination of the variable side portion regulating member 282). It may be a simple change in inclination, or an inclination change for continuous Y-direction position change.

  The variable side portion regulating member 282 can be changed in inclination so as to be driven or oscillated in the Y direction by using various driving means. Note that the amplitude of the change in the position of the recording paper P due to driving or swinging at this time is to prevent roughening on the surface of the fixing roller due to the end of the recording paper, and may be about several mm to several tens of mm.

[Explanation of operation of characteristic part of this embodiment]
Hereinafter, operations of the sheet feeding device 200 and the image forming apparatus 100 will be described with reference to the flowchart in FIG. 7 and the flowchart in FIG. 8.

  Here, for simplification of explanation, transmission / reception of signals between the control unit 101 and the control unit 201 may be omitted, but the control unit 201 controls each unit of the sheet feeding device in response to an instruction from the control unit 101. It shall be. As will be described later, the control of this embodiment can be performed by any one of the control units.

  First, when there is an instruction for image formation output from the operation display unit 105 or an external PC (not shown) (YES in step S101 in FIG. 7), the control unit 101 that has received this instruction, based on the instructed image data. In order to form an image, the image processing unit 110 and the image forming unit 130 are controlled.

  Here, the control unit 101 controls each unit in the image forming unit 130 to execute charging, exposure, development, conveyance, transfer, and fixing (step S102 in FIG. 7). Further, the control unit 201 that has received an instruction from the control unit 101 controls each unit in the paper feeding apparatus 200 to perform paper feeding accompanied by suction conveyance (step S102 in FIG. 7). At this time, as an initial state, the processing is started with the function of preventing the surface roughness of the fixing roller off.

  When image formation is to be continued (YES in step S103 in FIG. 7), the control unit 101 confirms whether or not the fixing roller surface roughening prevention function is on (step S104 in FIG. 7). If there is (NO in step S104 in FIG. 7), the process returns to step S102 and the image forming process (steps S102 to S104) is repeated until the image formation is completed (step S103 in FIG. 7).

  If the fixing roller surface roughening prevention function is OFF (YES in step S104 in FIG. 7), the control unit 101 counts the number of sheets passing through the fixing roller for each recording paper size (in FIG. 7). Step S105). If there is a possibility that a plurality of fixing devices are provided and the number of sheets to be passed does not match, this counting is performed independently for each fixing device.

  If the number of sheets of recording paper of any size has not reached a predetermined number by image formation (NO in step S106 in FIG. 7), the process returns to step S102 until image formation is completed (FIG. 7 in step S103), the above image forming process (steps S102 to S106) is repeated.

  Here, the predetermined number means that the image forming is repeated with the recording paper of that size, the end of the recording paper comes into contact with the same portion of the fixing roller surface, the fixing roller surface is scratched, The number of sheets is determined in advance as the number of sheets on which the phenomenon that the surface of the fixing roller is scraped is likely to occur or slightly less than the number of sheets on which such a phenomenon is likely to occur.

  If the number of sheets of recording paper of any size has reached a predetermined number as a result of image formation (YES in step S106 in FIG. 7), control is performed to turn on the fixing roller surface roughening prevention function. The unit 101 gives an instruction to the control unit 201 (step S107 in FIG. 7).

  When the control unit 201 receives an instruction from the control unit 101 and turns on the fixing roller surface roughening prevention function, the control unit 201 sucks the recording paper P by the suction transport unit 260 and transports the recording paper P in the suction state. As shown in FIGS. 6A to 6D, or as shown in FIGS. 6A to 6D, the conveyance orthogonal direction position changing unit 280 controls to change the conveyance orthogonal direction position of the recording paper P. By changing the position in the direction perpendicular to the conveyance direction of the recording paper P, roughness such as scratches or scraping due to the end of the recording paper is diffused on the surface of the fixing roller so that it does not concentrate on a specific position. Note that the amplitude of the position change (swing) at this time is to diffuse and prevent the roughness generated on the surface of the fixing roller by the end of the recording paper, and is several times during the fixing of several tens to several hundreds of sheets. Oscillation is controlled in a cycle that moves from mm to about 10 mm.

  Then, after the fixing roller surface roughening prevention function is turned on as described above, the control unit 101 returns to step S102 and completes the image formation (step S103 in FIG. 7). Repeat step S104).

  When there is an instruction to end the image formation output from the operation display unit 105 or an external PC (not shown) (NO in step S103 in FIG. 7), or when the image formation output of the instructed image data is completed (in FIG. 7). In step S103, the control unit 101 performs control so as to stop the respective units of the image processing unit 110 and the image forming unit 130 (step S108 in FIG. 7), and ends the processing.

  As described above, it is possible to effectively prevent the fixing roller surface from being roughened by operating the fixing roller surface roughening preventing function when a predetermined number of images having the same size as the recording paper have been formed. It becomes possible.

  For the recording paper P fed from the paper feeding device 200, the position and orientation of the recording paper are determined by the detection result of a recording paper position detection sensor (not shown) provided at any position of the image forming unit 130. Is detected. Then, a toner image is formed on the photoreceptor 1 according to the control of the control unit 101 according to the position and orientation of the recording paper, and within the image area of the recording paper according to the difference in the conveyance orthogonal direction position of the recording paper P. The image is transferred properly. Therefore, even if the fixing roller surface roughening prevention function is turned on and the position of the recording paper P is changed during paper feeding and conveyance, the image does not shift on the recording paper P.

  Hereinafter, with reference to FIG. 8, as a function of preventing the fixing roller surface from being roughened according to the present embodiment, the control of the conveyance orthogonal direction position change unit 280 to change the conveyance sheet orthogonal direction position of the recording paper P (Step S <b> 107 in FIG. 7) explain.

  The control unit 201 that has received an instruction from the control unit 101 operates the drive unit 281 (see FIG. 5) or the variable side portion regulating member 282 (see FIG. 6) when the fixing roller surface roughening prevention function is turned on. . As a result, the sheet feed tray movable portion 231b or the movable side portion regulating member 282 driven by the drive portion 281 swings the recording paper P in the conveyance orthogonal direction with the above-described predetermined amplitude (in FIG. 8). Step S201).

  Then, the controller 201 sucks the first sheet of recording paper P stored in the paper feed cassette 231 by the suction transport unit 260 and separates the second and subsequent sheets of recording paper P from each other. The intake air of 260, the side wind from the side air blowing unit 240, and the front air blowing from the front air blowing unit 250 are controlled (step S202 in FIG. 8).

Then, the control unit 201 controls to transport the uppermost recording paper P sucked by the suction belt 263 in a predetermined transport direction (step S203 in FIG. 8).
During this transport, the recording paper on the paper feed cassette 231 to be sucked and transported next is the drive unit 281 (see FIGS. 5B to 5D) or the variable side regulating member 282 (FIG. 6B). ) To (d)), the position control in the transport orthogonal direction is performed toward the position to be transported next.

  In this way, the suction / separation (step S202 in FIG. 8) and the suction conveyance (step S203 in FIG. 8) are fed while the conveyance orthogonal direction position change (step S201 in FIG. 8) is executed. The next recording sheet P on the cassette 231 is repeatedly executed until image formation is completed (steps S204 and S205 in FIG. 8).

  In the case of this embodiment, the recording paper conveyance orthogonal position may be changed during the suction or separation operation of the recording paper P in the suction conveyance unit 260 or during the adsorption conveyance of the recording paper, as in the conventional example. Since it is not necessary to change the position at a specific short timing, productivity of image formation is not reduced.

  By changing the position of the recording paper P in the direction perpendicular to the conveyance direction, the surface of the fixing roller diffuses roughness such as scratches or scrapes at the end of the recording paper so that it does not concentrate on a specific position. Will be suppressed.

  In addition, since the position in the conveyance orthogonal direction of the recording paper P at the time of suction or conveyance in the suction conveyance unit 260 may be changed, the fixing unit is not increased in size as compared with the case where the fixing roller itself is moved. Surface roughness can be effectively prevented.

[Other Configurations of Characteristic Part of this Embodiment (1)]
In FIG. 6, the variable side restricting member 282 is used as a guide means for changing the position in the conveyance orthogonal direction, but the present invention is not limited to this.

  For example, in addition to the variable side restricting member 282, it is possible to positively use the side wind from the side air blower 240 for changing the position in the conveyance orthogonal direction as the guide means. In this case, the control unit 201 controls the blower fan 242 of the side blower unit 240 so as to send a side wind stronger than the opposite direction toward the side where the conveyance orthogonal direction position is changed.

  In FIG. 9, the state of controlling the amount or speed of the side wind from the side blower 240 is schematically shown by the thickness of the gray arrow. A thicker gray arrow indicates a strong side wind. Thereby, in addition to the variable side part restricting member 282, the side air blowing part 240 also operates in conjunction with the guide means. As a result, the position change in the conveyance orthogonal direction operates smoothly and stably.

[Other Configurations of Characteristic Part of this Embodiment (2)]
In the above-described embodiment, the case where the conveyance orthogonal direction position change is performed as the conveyance orthogonal direction position change unit 280 when the recording paper P is sucked by the suction conveyance unit 260 has been described, but is not limited thereto. .

  For example, in addition to the specific example of the above embodiment or instead of the specific example of the above embodiment, the following method is possible. Here, as shown in FIG. 10, the suction belt 263 is configured by being divided into a plurality of pieces in the conveyance orthogonal direction (Y direction in the figure).

  In the specific example of FIG. 10A, three suction belts 263a to 263c are illustrated. While the recording paper P is being sucked and transported using such a plurality of suction belts 263a to 263c, the transport speed is changed according to the difference in the transport orthogonal direction position. In FIG. 10B, the control unit 201 controls the suction belt 263a at one end to be higher than the normal transport speed, controls the suction belt 263b at the center to be equal to the normal transport speed, The suction belt 263c is controlled to be lower than the normal transport speed.

  As a result, the recording paper P is generally conveyed at a normal conveyance speed, but is inclined such that the side end on the high speed side advances and the side end on the low speed side is delayed. As a result, the portion where the side edge of the recording paper P is in contact with the surface of the fixing roller is widened, so that roughness such as scratches or scraping due to the edge of the recording paper is diffused on the surface of the fixing roller and is not concentrated on a specific position. Thus, the occurrence of scratches and scrapes is suppressed.

  In addition, although the three examples of the suction belts 263a to 263c are shown, it can be realized with at least two. Further, even in the state of FIG. 10B alone, the portion where the side edge of the recording paper P is in contact with the surface of the fixing roller is widened, but the high speed side and the low speed side are alternately switched, or the high speed side and the low speed side. By using the control to widen or shrink the speed difference of the recording paper, the inclination of the recording paper P changes, and the surface of the fixing roller is further diffused to identify scratches and scrapes caused by the recording paper edge. Do not concentrate on the position of.

  In FIGS. 10A and 10B, the speed difference between the suction belts 263a to 263c is used. In addition to this, as shown in FIG. 10C, the recording paper P via the suction belt 263B is used. It is also desirable to transport with a difference in suction force.

  Here, the manner in which the suction force is controlled is schematically indicated by the thickness of the gray arrow. A thicker gray arrow indicates a strong suction force. In this case, the suction belt 263c on the low speed side has a strong suction force and the brake is applied. As a result, the recording paper P is tilted to a state where the high-speed side end is advanced and the low-speed side end is delayed while the recording paper P is conveyed at a normal conveyance speed as a whole. Accordingly, roughness such as scratches and scrapes at the end of the recording paper is diffused on the surface of the fixing roller so that it is not concentrated at a specific position, and the occurrence of scratches and scrapes is suppressed.

[Other configurations of sheet feeding device, image forming apparatus, and image forming system (1)]
In the above embodiment, the control unit 101 is provided in the image forming apparatus 100 and the control unit 201 is provided on the paper feeding device 200 side. However, the present invention is not limited to this.

  For example, a control unit that exists in one of the image forming apparatus 100 and the paper feeding apparatus 200 may control both the image forming apparatus 100 and the paper feeding apparatus 200. In the example illustrated in FIG. 11, the control unit 101 ′ exists on the image forming apparatus 100 side and is configured to control both the image forming apparatus 100 and the paper feeding apparatus 200.

[Other configurations of sheet feeding device, image forming apparatus, and image forming system (2)]
Also, as shown in FIG. 12, a control unit 401 exists in a terminal device 400 connected to at least one of the image forming apparatus 100 and the paper feeding device 200 via a network, a control signal line, and the like. However, the configuration may be such that the control of the embodiment described above is executed. At this time, the control unit 101 and the control unit 201 may or may not exist. In any case, it is realized at least by the control unit 401 controlling the above-described embodiment.

[Other configuration of sheet feeding device, image forming apparatus, and image forming system (3)]
In the above-described embodiment, the description has been made assuming that the recording paper P is adsorbed by the suction conveyance unit by the suction force of air. However, the present invention is not limited to this, and good results can be obtained by applying the above-described embodiment even to an adsorption conveyance unit using various suction forces other than air suction such as static electricity or magnetism.

[Other Configurations of Paper Feeding Device, Image Forming Device, and Image Forming System (4)]
Note that the sheet feeding device of the present embodiment is a sheet feeding device 200 ′ provided inside the image forming apparatus 100 even if it is a large capacity sheet feeding device 200 connected to the outside of the image forming apparatus 100. There may be.

[Other configuration of sheet feeding device, image forming apparatus, and image forming system (5)]
In the above embodiment, the recording paper is sucked and conveyed from the paper feeding device 200 to the image forming apparatus 100 to suppress the surface of the fixing roller in the image forming apparatus 100 from being roughened or scraped. It is not limited to.

  That is, a deterrent effect can be obtained even when the end of the recording paper P is roughened or scraped on the surface of a surface other than the fixing roller, such as a photosensitive drum or a photosensitive belt. Similarly, it is configured as a paper feeding device or a paper feeding system that sucks and conveys recording paper or sheets to various devices other than the image forming device, and suppresses roughening or scraping on a rotating body in the various devices. Is also possible.

100 Image forming apparatus 101 Control unit 102 ROM
103 RAM
105 Operation Display Unit 110 Image Processing Unit 130 Image Forming Unit 200 Paper Feeding Device 201 Control Unit 240 Side Blower Unit 250 Front Blower Unit 260 Adsorption Transport Unit 280 Conveyance Orthogonal Direction Position Change Unit

Claims (11)

A storage section for storing recording paper;
A suction transport unit that sucks and transports the recording paper stored in the storage unit in a suction state;
A conveyance orthogonal direction position change unit that changes a conveyance orthogonal direction position of the recording paper in the suction conveyance unit;
With
The conveyance orthogonal direction position change unit changes the conveyance orthogonal direction position of the recording paper during the suction or the conveyance in the suction conveyance unit.
A paper feeder characterized by that. The conveyance orthogonal direction position change unit changes the conveyance orthogonal direction position of the recording paper by changing the conveyance orthogonal direction position of the storage unit during the suction or the conveyance in the suction conveyance unit.
The paper feeding device according to claim 1. The conveyance orthogonal direction position change unit includes a guide unit that guides the recording sheet to change the conveyance orthogonal direction position of the recording paper in a path sucked from the storage unit toward the suction conveyance unit.
The paper feeding device according to claim 1. The conveyance orthogonal direction position change unit changes the conveyance speed in the adsorption conveyance unit according to a difference in the conveyance orthogonal direction position during the suction or the conveyance in the suction conveyance unit, thereby changing the recording speed. Change the paper transport orthogonal direction position,
The paper feeding device according to claim 1. A sheet feeding device according to any one of claims 1 to 4,
An image forming unit that forms an image on recording paper fed from the paper feeding device;
An image forming apparatus comprising: The image forming unit forms an image in an image area of the recording paper according to a difference in the transport orthogonal direction position of the recording paper;
The image forming apparatus according to claim 5. An image forming apparatus for forming an image on recording paper;
A paper feeding device that conveys the recording paper to the image forming apparatus;
A control unit for controlling each unit;
An image forming system comprising:
The paper feeder is
A storage section for storing recording paper;
A suction transport unit that sucks and transports the recording paper stored in the storage unit in a suction state;
A conveyance orthogonal direction position change unit that changes a conveyance orthogonal direction position of the recording paper in the suction conveyance unit,
The controller is
Controlling the conveyance orthogonal direction position changing unit to change the conveyance orthogonal direction position of the recording paper during the suction or conveyance in the suction conveyance unit;
An image forming system. The conveyance orthogonal direction position changing unit is
Changing the conveyance orthogonal direction position of the recording paper by changing the conveyance orthogonal direction position of the storage unit during the suction or the conveyance in the suction conveyance unit;
The image forming system according to claim 7. The conveyance orthogonal direction position changing unit is
A guide means for guiding the recording paper in a direction orthogonal to the conveyance direction in a path sucked from the storage unit toward the suction conveyance unit;
The image forming system according to claim 7. The conveyance orthogonal direction position changing unit is
During the suction or transport in the suction transport unit, the transport orthogonal direction position of the recording paper is changed by changing the transport speed in the suction transport unit according to the difference in the transport orthogonal direction position. ,
The image forming system according to claim 7. The image forming unit includes:
Forming an image in an image area of the recording paper according to a difference in the conveyance orthogonal position of the recording paper;
The image forming system according to any one of claims 7 to 10.