JP2008105791A - Image formation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image formation device capable of facilitating jam treatment and replacement of a sheet feeding roller. <P>SOLUTION: A separating part 20A is constituted of the sheet feeding roller 12 and a separating member 20. Additionally, a sheet carrying route R through which sheets separated by the separating part 20A pass is formed, a sheet carrying guide 13 free to move to a sheet carrying position forming the sheet carrying route R and to an opening position to open the sheet carrying route on the downstream side in the sheet feeding direction of a sheet loading part 11 and this carrying guide 13 is moved to the opening position by a moving part. Thereafter, the separating member 20 is provided on the upstream side in the sheet feeding direction of the sheet carrying guide 13, and the moving direction of the sheet carrying guide 13 by the moving part in opening the sheet carrying route R is made to a direction free to separate the separating member 20 from the sheet feeding roller 12 and to replace the sheet carrying roller 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus in which a sheet conveying path is provided on the downstream side in the sheet feeding direction of a sheet stacking portion so as to be opened and closed.

  Conventionally, in image forming apparatuses such as printers and facsimiles, in addition to a sheet feeding unit that feeds a standard size sheet stored in a paper feeding cassette, a so-called manual feeding unit that transports an irregular size sheet or the like There is something with.

  As such a manual feed unit, for example, a sheet feed / separation mechanism such as a sheet feed roller and a separation pad appears by opening a manual feed tray provided in the image forming apparatus main body so as to be openable and closable. Yes. When manual feeding is performed, the user sets a sheet on the manual sheet feeding tray, and then feeds the sheet to the image forming unit by the sheet feeding roller. When you are finished using the manual feed tray, you can close it to reduce the area occupied by the printer, or keep it open if it does not get in the way or if you frequently use the manual feed tray. But you can.

  Incidentally, in recent years, printers have been required to be downsized, in particular, to reduce the height of the main body. In the case of a desktop printer, it is also required to discharge and stack discharged sheets toward the front side of the printer body.

  For this reason, the paper feed / separation mechanism of the paper feed cassette is disposed on the back side of the printer main body, which is difficult to access from the front side of the printer main body. In addition, the paper feed / separation mechanism of the manual feed unit is also often arranged on the back side of the printer main body and at the same or close vertical position as the paper feed / separation mechanism of the paper feed cassette. .

  Here, when the sheet feeding / separating mechanism of the manual feeding unit is arranged as described above, the sheet conveyance path arranged on the downstream side of the manual sheet feeding tray may be positioned above the cassette sheet feeding mechanism. In this case, when the jam of the sheet is processed, particularly when the sheet stays in the middle of the sheet conveyance path, it is necessary to open the sheet conveyance path in order to take out the jammed sheet.

  At both ends in the width direction orthogonal to the sheet conveying direction of the sheet conveying guide constituting the sheet conveying path, there are a rotation shaft necessary for opening the sheet conveying path and a lock mechanism for locking the sheet conveying guide to the home position. Each is provided.

  When jamming is performed, the lock by the lock mechanism is released, the sheet conveyance guide is rotated in the direction to open the sheet conveyance path with the rotation axis as a fulcrum, and then the sheet conveyance path is opened. The sheet in the road is removed. After that, the printer can be used again by returning the sheet conveyance guide to the original position.

  By the way, when the sheet conveying path is released in this way, a sheet feeding / separating mechanism such as a sheet feeding roller and a separation pad is disposed on the front side of the printer main body, so when a jam occurs, the sheet conveying path is only opened. In this case, it is not possible to secure a sufficient opening space for a hand.

  Therefore, conventionally, as a manual feeding unit, a conveyance belt located on the upper surface of the paper feed cassette and provided to be exposed on the upper surface of the cassette cover and a conveyance belt attached to the main body and rotated in contact with the conveyance roller. There is a configuration in which the is provided. In the manual feeding unit having such a configuration, when a jam occurs, the paper feed cassette is pulled out together with the paper feed cassette to open the paper feed path, thereby facilitating the jam processing (see Patent Document 1). ).

  In addition, as another manual feeding unit, a sheet conveyance path opening unit in which either a conveyance roller for conveying a sheet or a separation member is integrally incorporated is provided, and when the sheet conveyance path is opened, the sheet conveyance is performed. There is one in which the road opening unit is opened (see Patent Document 2).

Japanese Patent Laid-Open No. 06-16253 Japanese Patent Laid-Open No. 02-151169

  However, in such a conventional image forming apparatus, there is a case where the paper feed / separation mechanism of the manual feed portion is located at a position recessed from the front of the printer main body, which is not easily accessible. In this case, it is difficult to secure a minimum required opening space when processing a jam sheet or when maintaining functional parts such as a sheet feeding roller and a separation pad.

  Here, when the separation mechanism includes a sheet feeding roller and a separation member such as a separation pad that contacts the sheet feeding roller, the separation member is attached so that a predetermined pressure is always applied to the sheet feeding roller. It is energized. For this reason, when it is attempted to remove the sheet feeding roller in maintenance or the like, it becomes necessary to detach other parts including a separation pad in order to secure a space necessary for detaching the roller.

  However, when removing other parts including the separation pad and the like for replacement of the sheet feeding roller in this way, if the minimum required opening space cannot be secured, work is troublesome.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus in which jam processing and replacement of a sheet feeding roller can be easily performed.

  The present invention provides an image forming apparatus including a sheet feeding unit that feeds sheets stacked on a sheet stacking unit, wherein the sheet feeding unit is replaceably attached to an image forming apparatus main body, and the sheet stacking unit A sheet feeding roller that feeds the sheets stacked on the sheet, a separation member that is in pressure contact with the sheet feeding roller and forms a separation unit that separates the sheets fed by the sheet feeding roller, and the sheet stacking A sheet conveyance position that is provided downstream of the sheet feeding direction and through which the sheet separated by the separation unit passes, and a sheet conveyance position that forms the sheet conveyance path, and an opening that opens the sheet conveyance path A sheet transport guide that is movable to a position, and the separation member is provided upstream of the sheet transport guide in the sheet feeding direction, and the sheet transport path is opened when the sheet transport path is opened. The movement direction of the conveying guide, in which the separating member, wherein said spaced apart from the sheet feeding roller, and to a direction becomes possible replacement of the sheet feeding roller.

  According to the present invention, the movement direction of the sheet conveying guide when opening the sheet conveying path is set to a direction in which the separation member is separated from the sheet feeding roller and the sheet feeding roller can be replaced, Jam handling and maintenance become easy.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a color laser beam printer which is an example of an image forming apparatus according to a first embodiment of the present invention. 1 is a color laser beam printer, 50 is a color laser beam printer main body ( Hereinafter, the printer body).

  The color laser beam printer 1 includes an image forming unit 1A for forming an image, a sheet feeding unit 1B, a manual feeding unit 1C, a fixing roller pair 8 and the like.

  Here, the image forming unit 1A includes stations 61 to 64 that are four image forming units arranged in parallel for four colors of magenta (M), yellow (Y), cyan (C), and black (Bk). ing. The image forming unit 1A includes a scanner unit (not shown), an intermediate transfer belt 5 that is an endless intermediate transfer member that runs in the direction of the arrow, and the like. Each of the stations 61 to 64 includes a photosensitive drum 61a to 64a that is rotatably arranged, a primary charger (not shown), a developer that stores toners of magenta, yellow, cyan, and black, a cleaning unit, and the like. I have.

  The photosensitive drums 61a to 64a are rotated in a clockwise direction according to an image forming operation by a drive motor (not shown), and an electrostatic latent image is formed on the surface by exposure by a scanner unit (not shown). It has come to be.

  On the other hand, the intermediate transfer belt 5 is in contact with the photosensitive drums 61a to 64a of the stations 61 to 64 arranged in series above and is stretched by the driving roller 5a and the tension roller 5b to counterclockwise when forming a color image. Rotate around. By this rotation, the color toner images formed on the photosensitive drums 61a to 64a are transferred.

  Further, a primary transfer roller (not shown) is brought into contact with the intermediate transfer belt 5 at the time of image formation, and each color toner image formed on the photosensitive drums 61a to 64a by the primary transfer roller is formed on the intermediate transfer belt 5. The images are transferred sequentially. Further, each color toner image on the intermediate transfer belt 5 is transferred to the sheet when the sheet (not shown) is nipped and conveyed by the secondary transfer unit constituted by the secondary transfer roller 7 and the drive roller 5a. It has become.

  The fixing roller pair 8 fixes the transferred toner image on the sheet, and includes a fixing roller 8a for heating the sheet and a pressure roller 8b for pressing the sheet against the fixing roller 8a. . The sheet holding the transferred toner image is conveyed by the fixing roller 8a and the pressure roller 8b, and the toner image is fixed on the surface by applying heat and pressure when passing through the fixing roller pair 8. The

  The sheet feeding unit 1B includes another sheet feeding cassette (sheet stacking unit) 2 that is detachably attached to the printer main body 50 that is the main body of the image forming apparatus, and sheet feeding that feeds the sheets stored in the sheet feeding cassette 2 A roller (another sheet feeding roller) 3 is provided. Further, a separation roller 3 a that is another separation member that separates the sheet fed by the sheet feeding roller 3 together with the sheet feeding roller 3 is provided.

  The manual feed unit 1 </ b> C is stacked on the manual feed tray 11, which is a sheet stacking unit provided on the side wall surface on the front side of the printer main body 50 with the rotation shaft 11 a serving as a fulcrum, and the manual feed tray 11. A sheet feeding roller 12 for feeding the sheet is provided.

  The manual feeding unit 1C is in pressure contact with the sheet feeding roller 12, is located above the separation pad 20 constituting the separation unit 20A, and the sheet feeding cassette 2, and includes a pair of conveying rollers 14 and 15. An intermediate conveyance guide 13 that is a conveyance guide is provided. The separation pad 20 is integrally provided at the upstream end portion of the intermediate conveyance guide 13.

  The intermediate conveyance guide 13 forms a sheet conveyance path R through which the sheet separated by the separation unit 20A passes. The intermediate conveyance guide 13 is provided with a lower guide surface 13a and a lower guide surface 13a (not shown) provided opposite to the lower guide surface 13a. And an upper guide surface. Further, a pair of conveying rollers 14 and 15 are provided on the lower guide surface 13a and the upper guide surface (not shown).

  In this embodiment, the separation pad 20 is provided upstream of the intermediate conveyance guide 13 in the sheet feeding direction. When the intermediate conveyance guide 13 is lowered as described later, the separation pad 20 is moved to the sheet feeding roller. 12 is separated.

  In FIG. 1, reference numeral 16 denotes a leading edge detection sensor that detects the leading edge of the manual sheet fed by the sheet feeding roller 12. Then, based on the sheet leading edge detection signal from the leading edge detection sensor 16, the control unit (not shown), when the leading edge of the sheet reaches the position indicated by the reference numeral 17 that can be fed by the sheet feeding roller 3, the conveying roller pair 14. , 15 is stopped. Accordingly, when the sheet feeding roller 3 is rotated thereafter, the manual sheet is fed by the sheet feeding roller 3.

  Next, an image forming operation of the color laser beam printer 1 configured as described above will be described.

  When forming a color image on a sheet, first, the photosensitive drums 61a to 64a are charged, and then the scanner unit applies the photosensitive drums 61a to 64a to the photosensitive drums 61a to 64a based on image signals of respective color components transmitted from a controller (not shown). Exposure. Thereby, an electrostatic latent image is formed on the surface of the photosensitive drum.

  Next, the electrostatic latent image is developed with magenta, yellow, cyan, and black toners to form a toner image on the photosensitive drum. Then, when the toner image arrives at a transfer portion where the photosensitive drums 61a to 64a and the intermediate transfer belt 5 come into contact with the rotation of the photosensitive drums 61a to 64a, the primary transfer bias is applied by the primary transfer roller. Apply. As a result, the toner image on the photosensitive drum is primarily transferred to the intermediate transfer belt 5 rotating in the counterclockwise direction.

  Here, the toner image is sequentially transferred onto the intermediate transfer belt in the order of magenta, yellow, cyan, and black with the rotation of the intermediate transfer belt 5, thereby forming a color visible image on the intermediate transfer belt.

  On the other hand, for example, when a mode in which an image is formed on a sheet stored in the paper feed cassette 2 is selected, the paper feed cassette 2 is used at a predetermined sequence control timing in parallel with such a color visible image forming operation. The sheet is fed from the sheet feeding roller 3. Then, the sheets separated into one sheet by the separation roller 3 a that contacts the sheet feeding roller 3 are conveyed to the registration roller 4 in a stopped state, and the skew is corrected by the registration roller 4.

  Thereafter, the registration roller 4 starts to rotate in accordance with the color image formed on the intermediate transfer belt. As a result, the temporarily stopped sheet is supplied to a secondary transfer portion constituted by the secondary transfer roller 7 and the drive roller 5a, and a color visible image is transferred by a transfer bias applied to the secondary transfer roller 7.

  After the color visible image is transferred in this way, the sheet is conveyed from the secondary transfer portion to the fixing roller pair 8 and heated and pressed by the fixing roller pair 8 to fix the color visible image. . Further, the sheet on which the toner image is fixed is thereafter discharged onto the discharge tray 10 by the discharge roller pair 9.

  On the other hand, when the manual feed mode is selected by the manual feed unit 1C, the manual feed tray 11 is first opened in the d1 direction, and the manual sheet is first set on the manual feed tray 11. Thereafter, the manual sheet is separated and fed one by one by the sheet feeding roller 12 and the separation pad 20, and is conveyed toward the sheet feeding roller 3 on the intermediate conveyance guide 13 by the conveyance roller pair 14 and 15. .

  Next, when the leading edge detection sensor 16 detects the sheet leading edge position, the control unit stops the manual sheet at a position where the sheet leading edge position can be fed by the sheet feeding roller 3 based on the detection signal. . Thereafter, the sheet is fed again by rotating the sheet feeding roller 3. The subsequent operation is the same as the operation from the feeding cassette 2 described above, and the sheet is discharged to the discharge tray 10.

  Here, when the sheet fed by the manual feeding unit 1C is conveyed by the sheet feeding roller 3 as in this embodiment, the sheet feeding roller is used when the sheet is fed from the manual feeding unit 1C. 12 and the separation pad 20 are formed. Thereafter, the sheet passes through another separation unit 3A constituted by the sheet feeding roller 3 and the separation roller 3a of the sheet feeding unit 1B.

  That is, when the sheet is fed by the manual feeding unit 1C, the sheet passes through the two separation units 20A and 3A. With this configuration, even when multiple feeding occurs in the manual feeding unit 1C, the sheets are separated and fed one by one by the sheet feeding unit 1B, thereby preventing double feeding. Can do.

  In FIG. 1, reference numeral 19 denotes a guide portion provided on the side surface of the printer main body, and 18 denotes a link member constituting a link portion provided on the printer main body 50 so as to be rotatable about a shaft 18a. The intermediate conveyance guide 13 is usually a sheet shown in FIG. 1 by a moving unit including a guide unit 19, a link member 18, and an operation lever (not shown) that rotates the link member 18. The sheet is held at the sheet conveying position above the sheet feeding cassette 2 that forms the conveying path R.

  On the other hand, when the link member 18 is rotated downward by operating an operation lever (not shown), the intermediate conveyance guide 13 is lowered to the open position of the lower end of the printer body as shown in FIG. Therefore, for example, when a jam occurs in the intermediate conveyance guide 13 and the sheet feeding unit 1B, after the paper cassette 2 is pulled out, the operation lever is operated to lower the intermediate conveyance guide 13 to the open position. .

  Next, a jam process when a jam occurs in the intermediate conveyance guide 13 and the sheet feeding unit 1B will be described.

  When a jam occurs, first, as shown in FIG. 2, the feeding cassette 2 is pulled out in the d2 direction and removed from the printer main body 50, and then the manual feed tray 11 is closed. By closing the manual paper feed tray 11 in this manner, the side of the printer main body 50 can be widened, and the front opening 50A for inserting a hand from the d3 direction can be secured more widely.

  Next, an operation lever (not shown) is operated to rotate the link member 18 downward to move the intermediate transport guide 13 to the open position. Here, as described above, the separation pad 20 that constitutes the separation unit 20 </ b> A together with the sheet feeding roller 12 is provided and held in the intermediate conveyance guide 13.

  Therefore, when the intermediate conveyance guide 13 is moved downward in this way during the jam processing, the separation pad 20 is separated from the sheet feeding roller 12 together with the intermediate conveyance guide 13. As a result, a larger front opening 50A on the front surface of the printer body can be secured.

  Thus, by moving the intermediate conveyance guide 13 to the open position, it becomes possible to secure a larger front opening 50A, and as a result, it is possible to easily remove the jammed sheet S from the d3 direction. Can do.

  Furthermore, according to the present embodiment, the moving direction of the intermediate conveyance guide 13 is set to a direction in which the sheet feeding roller 12 can be detached and attached as indicated by an arrow L in FIG. 20 can be separated greatly. Accordingly, access to the sheet feeding roller 12 is facilitated, and maintenance such as replacement of the sheet feeding roller 12 is improved.

  That is, as in this embodiment, the separation pad 20 is separated from the sheet feeding roller 12 and the sheet feeding roller 12 can be replaced in the direction of movement of the intermediate conveyance guide 13 when the sheet conveying path is opened. By adopting a proper direction, jam handling and maintenance become easy.

  Next, a second embodiment of the present invention will be described.

  FIG. 3 is an enlarged schematic diagram of a main part of the image forming apparatus according to the present embodiment. In FIG. 3, the same reference numerals as those shown in FIGS. 1 and 2 indicate the same or corresponding parts.

  In FIG. 3, reference numeral 21 denotes a link that constitutes a moving unit that moves the intermediate conveying guide 13 to a sheet conveying position above the sheet feeding cassette 2 or an open position shown in FIG. Part.

  The link portion 21 includes a first link member 22 and a second link member 23. Note that one end of the first link member 22 is rotatably provided on the printer main body 50 about the first rotation shaft 22a. Further, one end of the second link member 23 is connected to the rotating end of the first link member 22 by the connecting portion 23a, and the other end is connected to the intermediate transport guide 13 and the rotary coupling portion 13a.

  In general, the intermediate conveyance guide 13 is held at the sheet conveyance position via a guide portion (not shown) (see FIG. 1) provided on the side surface of the printer main body, and the first link member 22 and the second link member 23. Yes.

  FIG. 4 is a diagram illustrating a state in which the intermediate conveyance guide 13 is lowered to the open position for jam processing or replacement of the sheet feeding roller 12 by operating the operation unit.

  Since the separation pad 20 that constitutes the separation portion of the manual feed portion 1C is provided via the biasing spring 20a at the upstream end of the intermediate conveyance guide 13, when the intermediate conveyance guide 13 is lowered to the open position, The separation pad 20 is separated from the sheet feeding roller 12. Accordingly, when the intermediate conveyance guide 13 is moved to the open position, a large front opening 50A of the printer main body 50 can be secured, and the separation pad 20 can be separated from the sheet feeding roller 12.

  By the way, if the intermediate conveyance guide 13 is supported by the two link members 22 and 23 as in the present embodiment, a larger opening space is ensured when the intermediate conveyance guide 13 is lowered to the open position. It becomes possible. Accordingly, access to the sheet feeding roller 12 is facilitated, and maintenance such as replacement of the sheet feeding roller 12 is improved.

  In the present embodiment, as shown in FIG. 4, when the intermediate conveyance guide 13 is in the open position, a straight line connecting the first rotation shaft 22 a and the rotation coupling portion 13 a provided in the intermediate conveyance guide 13 is used. Also, the second connecting portion 23a is disposed above.

  For this reason, when the intermediate conveyance guide 13 is lifted from the open position to the sheet conveyance position, it can be avoided that the first link member 22 and the second link member 23 interfere with each other on the trajectory. . Thereby, the intermediate conveyance guide 13 can be set smoothly at the sheet conveyance position.

1 is a diagram showing a schematic configuration of a color laser beam printer which is an example of an image forming apparatus according to a first embodiment of the present invention. The figure which shows a state when the intermediate conveyance guide in the said color laser printer is lowered | hung to the open position. FIG. 4 is an enlarged schematic view of a main part of an image forming apparatus according to a second embodiment of the present invention. FIG. 4 is a diagram illustrating a state when an intermediate conveyance guide is lowered to an open position in the image forming apparatus.

Explanation of symbols

1 Color Laser Beam Printer 1A Image Forming Unit 1B Sheet Feeding Unit 1C Manual Feeding Unit 2 Paper Feed Cassette 3 Sheet Feeding Roller 3a Separating Roller 3A Other Separating Unit 11 Manual Feeding Tray 12 Sheet Feeding Roller 13 Intermediate Conveyance Guide 13a Lower guide surfaces 14 and 15 Conveying roller pair 18 Link member 19 Guide portion 20 Separation pad 20A Separation portion 21 Link portion 22 First link member 23 Second link member 50 Color laser beam printer main body 50A Front opening R Sheet conveyance path

Claims (8)

In an image forming apparatus provided with a sheet feeding unit for feeding sheets stacked on a sheet stacking unit,
The sheet feeding unit is
A sheet feeding roller that is replaceably attached to the image forming apparatus main body and feeds the sheets stacked on the sheet stacking unit;
A separating member that is in pressure contact with the sheet feeding roller and constitutes a separating unit that separates the sheet fed by the sheet feeding roller;
A sheet conveyance position that is provided downstream of the sheet stacking unit in the sheet feeding direction and through which the sheet separated by the separation unit passes, and that forms the sheet conveyance path, and the sheet conveyance path A sheet conveyance guide that is movable to an open position to be opened,
The separation member is provided upstream of the sheet conveyance guide in the sheet feeding direction, and the separation member is separated from the sheet feeding roller in a moving direction of the sheet conveyance guide when the sheet conveyance path is opened; and An image forming apparatus characterized in that the sheet feeding roller can be replaced. A guide unit provided in the image forming apparatus main body for guiding one end of the sheet conveying guide, and provided in the image forming apparatus main body and connected to the other end of the sheet conveying guide, and the sheet conveying guide is connected to the sheet conveying A link part for moving to a position to be held in a position, or a position to be the open position,
The image forming apparatus according to claim 1, wherein the link part moves the sheet conveyance guide to the open position or the sheet conveyance position while guiding one end of the sheet to the guide part.   3. The image according to claim 2, wherein the link unit is configured by a link member having one end rotatably provided in the image forming apparatus main body and the other end connected to the other end of the sheet conveyance guide. Forming equipment.   The link portion includes a first link member having one end rotatably provided on the image forming apparatus main body, one end connected to a rotation end of the first link member, and the other end other than the sheet conveyance guide. The image forming apparatus according to claim 2, further comprising a second link member connected to the end.   The image forming apparatus according to claim 1, wherein another separation unit is provided on the downstream side of the sheet conveyance guide in the sheet conveyance direction. Another sheet stacking unit provided below the sheet conveyance guide and detachably attached to the image forming apparatus main body;
Another sheet feeding roller provided downstream of the sheet conveyance guide in the sheet feeding direction and feeding the sheets stacked on the other sheet stacking unit,
6. The image forming apparatus according to claim 5, wherein the other separation unit is brought into pressure contact with the other sheet feeding roller.   The image forming apparatus according to claim 1, wherein the sheet conveyance guide includes a guide surface provided to face the roller, and a pair of rollers is provided on the guide surface.   The image forming apparatus according to claim 1, wherein the separation member is disposed at an upstream end portion of the sheet conveyance guide.

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