JP3788084B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus that forms an image on recording paper, and more particularly to an improvement in a mechanism for jamming processing in the case where the recording paper is jammed in the image forming apparatus.
[0002]
[Prior art]
In a double-sided image forming apparatus capable of forming images on both front and back sides of a recording sheet, the recording sheet is usually sent to the image forming unit of the apparatus to form an image on one side of the recording sheet, and then the recording sheet is formed again. The image is formed on both sides of the recording paper by sending it to the means and forming an image on the other side.
[0003]
In the double-sided image forming apparatus, as described above, the part for sending the recording paper to the image forming means again can be taken out from the main body of the image forming apparatus as a unit, and the recording paper jam processing in or near the unit can be performed. It is comprised so that it may be easy to do.
[0004]
In the conventional copying machine, the unit bottom plate forming the recording paper passage in the unit is held in a closed position by the force of a spring, and when the unit is taken out from the copying machine main body, the force of the spring is reduced. The path of the recording paper can be opened by opening the unit bottom plate against this. Since such a jam handling mechanism only requires a simple operation of opening the unit bottom plate, it is much simpler than the conventional one requiring a troublesome operation of removing a fastener such as a screw. It has become a thing.
[0005]
Also, in the conventional image forming apparatus, the jamming mechanism immediately upstream of the transfer position in the recording paper transport path for transporting the recording paper to the transfer position can release the nip of the transport roller provided immediately upstream of the transfer position. There are some that have been made, and others that can be rotated manually.
[0006]
[Problems to be solved by the invention]
By the way, in the double-sided image forming apparatus, a roller for transporting the recording paper is provided on the unit bottom plate that forms the passage of the recording paper, and the transportability of the recording paper in the unit is the spring. Affected by. If the spring force is weak, there is a problem in that the conveying force of the conveying roller that feeds the recording paper is weakened. Further, if the spring force is increased in order to increase the conveying force, the operability of the unit bottom plate is reduced, and the configuration of the unit and the force of the spring are required to satisfy such conflicting conditions at the same time. Subtle adjustments are required.
[0007]
In addition, the jam handling mechanism for the jam of the recording paper immediately upstream of the transfer position does not release the jammed portion of the recording paper, so that the jammed recording paper is not easily taken out and is insufficient. Met.
[0008]
An object of the present invention is to solve the problems of the related art relating to such jam processing.
[0009]
[Means for Solving the Problems]
  The object of the present invention is as follows.
  (1) In an image forming apparatus capable of forming an image on the other side of the recording paper in the image forming means again after forming an image on one side of the recording paper in the image forming means,
  A re-feeding unit that transports the recording paper to the image forming unit again is detachably provided to the image forming apparatus main body,
  The image forming apparatus main body is provided with a restoring means,
  The refeeding means is provided with a releasable recording paper path forming means for forming a recording paper path and a locking means for locking the opening of the recording paper path forming means,
  When the re-feeding unit is taken out from the main body of the image forming apparatus, the recording paper path forming unit releases the locking unit to release the recording paper path. ,
  When the refeeding means is mounted on the image forming apparatus main body, the recording paper path forming means is driven by the restoring means to form the recording paper path, and the recording paper path is set by the locking means. An image forming apparatus characterized in that the recording paper path forming means is locked at a position where the recording paper is formed.,
InThis is achieved.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention in which the present invention is applied to an electrophotographic copying machine as an image forming apparatus will be described with reference to the drawings. First, the overall configuration and schematic process of the copying machine will be described with reference to FIG. 1 which is a schematic sectional view of the copying machine.
[0011]
The copying machine according to the present embodiment is provided with an automatic document feeder 1 at the upper part of the copying machine main body A, and an image reading device 2, an image forming means 3, a recording paper storage means 4, and a conveying means 5 in the copying machine main body. have.
[0012]
The automatic document feeder 1 is an apparatus that is provided on the upper part of the copying machine main body A, feeds documents one by one, conveys them to the image reading position, and discharges the document after image reading. The automatic document feeder 1 includes a document placing table 11 for placing a document, a document separating unit 12 for separating a document placed on the document placing table 11, and a document transport for transporting a document separated by the document separating unit 12. Means 13, document discharge means 14 for discharging the document conveyed by document transfer means 13, document discharge table 15 for receiving and placing the document discharged by document discharge means 14, and both sides of the document There is a document reversing means 16 for reversing the front and back of the document when reading the image.
[0013]
A plurality of documents placed on the document placing table 11 are separated by the document separating means 12 and conveyed one by one. The document separated and transported by the document separating unit 12 is transported by the document transporting unit 13, and the image of the document is read through the slit 21 by the image reading device 2 provided below. The document from which the image has been read is discharged onto the document discharge table 15 by the document discharge unit 14. By the way, when reading images on both sides of an original, the original on which the image has been read is reversed by the original reversing means 16 and conveyed again by the original conveying means 13, and is slit by the image reading means. Through 21, the image on the back side of the document is read. Then, the original on which the image on the back side has been read is discharged onto the original discharge table 15 by the original discharge means 14. Such a process is repeated for the number of documents placed on the document placing table 11, and an image of the document is read.
[0014]
Further, the automatic document feeder 1 is configured to be integrally retractable, and the document is directly placed on the platen glass 22 by raising the automatic document feeder 1 and opening the platen glass 22. It is configured to be able to. As described above, in the present embodiment, the image is read by the reading method for reading the image of the original while the original is conveyed by the original conveying means 13 and the reading method for reading the image after the original is stopped on the platen glass 22. Reading can be performed.
[0015]
The image reading device 2 is a means for reading an image of a document and obtaining image data, and is provided at the upper part of the copying machine main body. The image reading device 2 is provided with a slit 21 which is a slit-shaped opening for reading an image of a document conveyed by the document conveying means 13 of the automatic document feeder 1 and for directly placing (statically) the document. From the first mirror unit 23 and the first mirror 232, in which a platen glass 22 serving as a document table, a lamp 231 serving as a light source for irradiating the document, and a first mirror 232 reflecting reflected light from the document are integrated. A second mirror unit 24 that integrates a second mirror 241 that reflects light and a third mirror 242 and an image that forms an image of reflected light from a document on the slit 21 or the platen glass 22 on a line CCD 26 described later. An imaging lens 25 as a means, and a line C as an image reading means for obtaining image information by photoelectrically converting a light image formed by the imaging lens 25 It has a D26.
[0016]
When the document fed by the automatic document feeder 1 is read by the image reading device 2, the first mirror unit 23 and the second mirror unit 24 are positioned at the left end position shown in FIG. 23 is located below the slit 21. Then, the original conveyed on the slit 21 by the original conveying means 13 is irradiated with light by the lamp 231, and the light reflected from the original is a first mirror 232, a second mirror 241, a third mirror 242, an imaging lens. Then, the light enters the line CCD 26 through 25. In the line CCD 26, incident light is photoelectrically converted to read an image of a document.
[0017]
When the original is directly placed on the platen glass 22, the first mirror unit 23 and the second mirror unit 24 are moved along the platen glass 22 in the right direction in FIG. Read the image.
[0018]
The image forming unit 3 is a unit that forms an image on a recording sheet conveyed at a predetermined process speed based on the image data obtained by the image reading unit 2. The image forming means 3 of the present embodiment forms an image using an electrophotographic process. The image forming means 3 includes a photoconductive drum 31 that is an image carrier having a photoconductive photosensitive layer and carrying a toner image, a charger 32 that uniformly charges the photoconductive drum 31, and image information read by the line CCD 26. Based on the above, the laser writing system 33 which is an exposure means for exposing the photosensitive drum 31 to form a latent image, the developing device 34 for developing the latent image on the photosensitive drum 31 to form a toner image, and photosensitive A transfer device 35 for transferring the toner image carried on the photosensitive drum 31 onto the recording paper being conveyed; a separator 36 for separating the recording paper on which the toner image has been transferred from the photosensitive drum 31; A cleaning unit 37 for removing toner remaining on the photosensitive drum 31 and a fixing unit 38 for fixing the toner image on the recording paper are provided. Around the photosensitive drum 31, a charger 32, a laser writing system 33, a developing device 34, a transfer device 35, a separator 36, and a cleaning means 37 are arranged.
[0019]
The photosensitive drum 31 is rotated in a direction indicated by an arrow by a driving unit (not shown), and exposure is started in synchronization with the uniform charging by the charger 32 and the leading edge of a recording sheet fed from a registration roller 56 described later. A latent image is formed by the laser writing system 33 and developed by the developing unit 34, and a toner image based on the image information read by the line CCD 26 is formed. The formed toner image is transferred onto a recording paper separately conveyed by the transfer device 35. The recording paper on which the toner image has been transferred is separated from the photosensitive drum 31 by the separator 36 and conveyed to the fixing means 38, where the toner image is fixed on the recording paper by heating and pressing. On the other hand, the photosensitive drum 31 on which the toner image has been transferred onto the recording paper continues to rotate, and the toner remaining on the photosensitive drum 31 is removed by the cleaning means 37 and is used for the next image formation.
[0020]
In the present embodiment, a conveyance roller 39 for conveying the recording paper fed from the registration roller 56 is provided in the vicinity of the photosensitive drum 31 between the photosensitive drum 31 and the registration roller 56, and the recording paper This contributes to an increase in the conveyance power. Further, between the separator 36 and the fixing unit 38, in order to convey the recording paper separated by the separator 36, the lower surface side of the recording paper (the side opposite to the image-formed side) is supported. A conveyance belt 391 for conveyance is provided.
[0021]
The recording paper storage means 4 is a recording paper storage means for storing a plurality of recording papers in a stacked state. In the present embodiment, the recording paper storage means 4 includes a plurality of recording paper storage means 4, that is, a first recording paper storage means 4 A, a second recording paper storage means 4 B, and a third recording paper storage means 4 C. These recording paper storage means 4 A -4C are arranged in multiple stages below the image forming means 3. As recording paper stored in these recording paper storage means 4A to 4C, there are various recording media such as OHT in addition to recording paper such as plain paper and recycled paper.
[0022]
The transport unit 5 is a transport unit that transports the recording paper from the recording paper storage unit 4 to the image forming unit 3, and transports the recording paper stored in each of the recording paper storage units 4 </ b> A to 4 </ b> C to the image forming unit 3. The recording paper supply means 4X is configured so as to be able to do so.
[0023]
Next, the conveying means 5 will be described in detail with reference to FIG. The conveyance of the recording paper by the conveying means 5 is performed along a recording paper conveyance path (no code). That is, the recording paper stored in each of the recording paper storage means 4A to 4C passes through the first transport path a and the first transport path a for feeding the recording paper from the recording paper storage means 4, as shown in FIG. Conveying along a conveying path having an intermediate conveying path b for conveying the fed recording paper and a second conveying path c for conveying the recording paper conveyed through the intermediate conveying path b to the image forming means 3 It is conveyed by means 5. The first conveyance path a is a conveyance path from the recording paper storage unit 4 to the pre-registration roller 53, and is a conveyance path in the right direction (substantially horizontal direction) in FIG. The intermediate conveyance path b is a conveyance path from the pre-registration roller 53 to the loop forming roller 55, and is a conveyance path in the vertical upward direction in FIG. The second conveyance path c is a conveyance path from the loop forming roller 55 to the transfer device 35, and is a conveyance path in the left direction in FIG.
[0024]
The recording paper is conveyed in the order of the first conveyance path a, the intermediate conveyance path b, and the second conveyance path c. In the present embodiment, the first transport path a is provided in each of the recording paper storage units 4A to 4C. Further, the intermediate conveyance path b is a conveyance path that is at least partially shared, that is, in the middle of the intermediate conveyance path b of the recording paper from the third recording paper storage means 4C, from the second recording paper storage means 4B. This recording paper is a conveyance path that is shared by the recording paper from the first recording paper storage means 4A. The second transport path c is configured so that the recording paper from each of the recording paper storage units 4A to 4C can be transported to the image forming unit 3.
[0025]
Next, each structure (means) of the conveying means 5 will be described.
[0026]
The conveying means 5 is disposed above the recording paper storage means 4 and includes a pickup roller 51 which is a delivery means for sending out the recording paper stored in the recording paper storage means 4, and the recording paper sent out by the pickup roller 51 one by one. Separating means 52 (also serving as a first loop forming means) consisting of a separating conveying roller 521 and a separating retard roller 522 for separation, and once the recording paper separated by the separating means 52 is abutted, the conveyance is resumed. A pre-registration roller 53 as a first abutting means, a plurality of intermediate conveyance rollers 541 to 543 as intermediate conveyance rollers for conveying the recording paper conveyed by the pre-registration roller 53, and a recording paper conveyed by the intermediate conveyance roller Is conveyed by a loop forming roller 55 and a loop forming roller 55 as second loop forming means. Recording paper has a resist roller 56 and the transport roller 39 is a second abutment means for resuming the conveyance after abuts once.
[0027]
The first bend correcting means is composed of a pre-registration roller 53 as a first abutting means and a separating means 52 as a first loop forming means, and forms a loop on the conveyed recording paper to bend the paper. It is a means to correct. Furthermore, it is preferable that the first bending correction means includes a loop formation guide 572 described later. The second bend correcting means is composed of a registration roller 56 as a second abutting means and a loop forming roller 55 as a second loop forming means, and forms a loop on the recording paper to be conveyed to bend the paper. It is a means to correct. Furthermore, it is preferable that the second bending correction means includes a loop formation guide 581 described later.
[0028]
Further, the pickup roller 51, the separating means 52 comprising the separating conveyance roller 521 and the separating retard roller 522, and the pre-registration roller 53 have the same functions corresponding to the respective recording paper storage means 4A to 4C (this book) In the embodiment, the same structure is provided), and in the figure, the symbols A to C are added after the respective symbols, but the symbols A to C are not added for the sake of explanation. In this case, the same can be said for all of them.
[0029]
The pickup roller 51 is a delivery unit that is disposed above the recording paper storage unit 4 and that feeds out the recording paper stored in the recording paper storage unit 4. The pickup roller 51 is provided so as to be movable up and down by a driving means (not shown in FIG. 2). When the pickup roller 51 is moved to the lower position, it is positioned on the first transport path a and is stored in the recording paper storage means 4. It is possible to abut on the uppermost recording paper among the plurality of recording papers, and be driven by a driving means (not shown) to rotate in the direction of the arrow, and to feed the uppermost recording paper. Further, when the pickup roller 51 is moved to the upper position, it is a position separated from the recording paper. The recording paper storage means 4 is pushed up by means such as a bottom plate (not shown) so that the upper positions of a plurality of stored recording papers are always the same position.
[0030]
The separating unit 52 is a unit that separates the recording sheets fed by the pickup roller 51 one by one, and is provided in the first transport path a. In the present embodiment, a separation conveying roller 521 and a separation retard roller 522 are provided. The separation conveying roller 521 is a roller that is in contact with the upper surface of the recording paper to be conveyed and is rotated in a direction indicated by an arrow by a driving unit (not shown), and is recorded on a pre-registration roller 53 adjacent to the downstream side in the recording paper conveying direction. A roller for transporting paper. The separation retard roller 522 is a roller in which a torque limiter is incorporated, and is a roller that cooperates with the separation conveyance roller 521 to separate the recording sheets fed by the pickup roller 51 one by one. As will be described later, the separating unit 52 also serves as a first loop forming unit that constitutes a first bending correcting unit for correcting the bending of the recording paper.
[0031]
In the present embodiment, the pickup roller 51 that feeds the recording paper stored in the recording paper storage means 4 and the separation means 52 that separates the recording paper one by one are provided with separate functions. It may be a sending means. For example, a belt can be suspended between the pickup roller 51 and the separation conveying roller 521, and the separation retard roller 522 can be brought into contact with the belt, thereby providing a feeding unit that functions integrally. In this case, as will be described later, this sending means also serves as a first loop forming means that constitutes a first bending correcting means for correcting the bending of the recording paper.
[0032]
The pre-registration roller 53 is a first abutting unit that once abuts the recording paper separated by the separating unit 52 and resumes conveyance, and is a so-called registration roller. The pre-registration roller 53 is composed of a pair of opposed rollers, and is provided on the first transport path a so as to be rotatable in a direction indicated by an arrow by a driving unit (not shown). The pre-registration roller 53 stops rotating when the recording paper is transported by the separating means 52. For this reason, the transported recording paper once hits the pre-registration roller 53 and the leading end stops. I'm damned. Thereafter, the rotation of the pre-registration roller 53 is started, and the recording paper is conveyed again by the pre-registration roller 53. In this manner, once the recording paper is abutted against the pre-registration roller 53, the timing of the leading edge of the recording paper can be accurately taken, and variations in conveyance can be suppressed.
[0033]
In the present embodiment, the recording paper is transported by the separating means 52 even after the leading edge of the recording paper hits the pre-registration roller 53, whereby the recording with the leading edge stopped. Loops can be formed in the paper to correct the paper bending. In the present embodiment, the width of the pre-registration roller 53 (the length in the direction orthogonal to the recording paper conveyance direction) is set to the pickup roller 51 provided at the center in the direction orthogonal to the recording paper conveyance direction. , A roller wider than the separation conveying roller 521 and the separation retarding roller 522 (preferably, the recording paper of a standard size has a width substantially equal to the width direction of the maximum size capable of forming an image). By configuring, it is possible to reliably correct the bend and to suppress variations in conveyance.
[0034]
Further, in this embodiment, in order to surely perform this loop formation, the upper guide 571 and the lower guide 572 are used as guide members for guiding the conveyance of the recording paper between the separating means 52 and the pre-registration roller 53. Is provided. In this embodiment, the lower guide 572 has a cross-sectional shape (when viewed as shown in FIGS. 1 and 2) and is formed in an inverted mountain shape, and a loop that guides the recording paper in a loop shape along the lower guide 572 It functions as a guide. It is preferable to provide this loop formation guide as a bending correction means.
[0035]
As described above, in this embodiment, the leading edge of the recording paper is abutted against the pre-registration roller 53 whose rotation has been stopped, and the conveyance of the recording paper by the separating means 52 is continued, thereby forming a loop on the recording paper. Thus, it is configured to surely correct the bending of the paper.
[0036]
In the present embodiment, the pre-registration roller 53 serves as a configuration in which the first abutting means that abuts the recording paper and a part of the first bend correcting means that corrects the bending of the recording paper are used as the number of parts. However, each function may be provided separately. In this case, when only the recording paper is abutted, the first abutting means may be a shutter, a stopper, or the like that can block the conveyance path, without using a pair of rollers.
[0037]
The intermediate conveyance rollers 541 to 543 are intermediate conveyance rollers that convey the recording paper conveyed by the pre-registration roller 53. The intermediate transport rollers 541 to 543 are provided on the intermediate transport path b. In the present embodiment, each of the intermediate transport rollers 541 to 543 is composed of a pair of opposed rollers, and is rotated in the direction of the arrow by a driving unit (not shown). The intermediate conveyance roller 541 is a roller for conveying the recording paper conveyed by the pre-registration rollers 53A to 53C, that is, conveying the recording paper from the first recording paper storage means 4A to the third recording paper storage means 4C. The intermediate conveyance roller 542 is a roller for conveying the recording paper conveyed by the pre-registration rollers 53B and 53C, that is, conveying the recording paper from the second recording paper storage means 4B and the third recording paper storage means 4C. The intermediate conveyance roller 543 is a roller for conveying the recording paper conveyed by the pre-registration roller 53C, that is, for conveying the recording paper from the third recording paper storage unit 4C.
[0038]
The loop forming roller 55 is means for transporting the recording paper transported by the intermediate transport roller 541. The loop forming roller 55 is composed of a pair of opposed rollers, and is provided at one end of the movable frame body 551 where one loop forming roller 55 is opened. And it is provided on the 2nd conveyance path c so that rotation in the direction of an arrow is possible by the drive means which is not illustrated. As will be described later, the loop forming roller 55 also serves as second loop forming means constituting second bending correcting means for correcting the bending of the recording paper.
[0039]
The registration roller 56 serving as a synchronous conveyance unit is a second abutting unit that once abuts the recording paper conveyed by the loop forming roller 55 and restarts the conveyance. The registration roller 56 includes a pair of opposed rollers, and is provided on the second conveyance path c so as to be rotatable in a direction indicated by an arrow by a driving unit (not shown). The registration roller 56 stops rotating when the recording paper is conveyed by the loop forming roller 55. For this reason, the conveyed recording paper once abuts against the registration roller 56 and stops its leading end. It is done. Thereafter, the rotation of the registration roller 56 is started, and the recording paper is conveyed again by the registration roller 56. Then, in synchronism with the recording paper fed from the registration roller 56, the latent image formation by the laser writing system 33 is started, and the recording paper and the toner image on the photosensitive drum 31 are synchronized. In this way, the recording paper is once abutted against the registration roller 56 and then conveyed again, whereby the timing of the leading edge of the recording paper can be accurately taken, variation in conveyance can be suppressed, and the laser writing system can be suppressed. 33 can be easily synchronized, and an image can be formed at an accurate position on the recording paper.
[0040]
In the present embodiment, the recording paper is continuously conveyed by the loop forming roller 55 even after the leading edge of the recording paper abuts against the registration roller 56, whereby the leading edge is stopped. A paper loop can be formed to correct paper bending. Further, in this embodiment, in order to surely perform this loop formation, the upper guide 581 and the lower guide 582 are used as guide members for guiding the conveyance of the recording paper between the loop forming roller 55 and the registration roller 56. Is provided. In the present embodiment, the upper guide 581 is formed in a mountain shape with a cross-sectional shape (when viewed as shown in FIGS. 1 and 2), and a loop forming guide that guides the recording paper in a loop shape along the upper guide 581. It is functioning as. A pair of transport rollers 39 is provided on the downstream side of the upper guide 581 and the lower guide 582, and a light source L (L 1) that is a means for detecting the transport state of the recording paper between the transport roller 39 and the registration roller 56. The detection member S (S1) is provided.
[0041]
In the present embodiment, the registration roller 56 is used as a configuration in which the second abutting means that abuts the recording paper and a part of the second bend correcting means that corrects the bending of the recording paper are used as the number of parts. Although reduced, each function may be provided separately. In this case, in the case where only the recording paper is applied, the first abutting means may be a shutter or a stopper that can block the conveyance path, for example, without using a roller pair.
[0042]
The recording paper stored in the first recording paper storage means 4A by the transport means 5 having such a configuration (means) is a pickup roller 51A, a separation means 52A, a pre-registration roller 53A, an intermediate transport roller 541, and a loop forming roller. 55 and the registration roller 56 to the image forming unit 3. Similarly, the recording paper stored in the second recording paper storage unit 4B is imaged by the pickup roller 51B, the separation unit 52B, the pre-registration roller 53B, the intermediate conveyance rollers 542 and 541, the loop forming roller 55, and the registration roller 56. The recording paper transported to the forming means 3 and stored in the third recording paper storage means 4C includes a pickup roller 51C, a separating means 52C, a pre-registration roller 53C, intermediate transport rollers 543, 542, 541, a loop forming roller 55, And it is conveyed to the image forming means 3 by the registration roller 56.
[0043]
The present embodiment has a drawer unit 6 as shown in FIG. 3, and the drawer unit 6 has a refeeding unit that inverts the recording paper having an image formed on one side thereof and conveys it again to the image forming unit 3. The paper unit, a part of the transport unit 5, the fixing unit 38, and the paper discharge unit are mounted, and can be pulled out from the main body of the image forming apparatus as shown in FIGS. That is, the drawer unit 6 includes the refeeding unit, the fixing unit 38, and the paper discharge unit. However, only the refeeding unit may be mounted.
[0044]
As described later, the drawer unit 6 is configured to re-feed the recording paper on which the image is formed by the image forming unit 3 onto the recording paper transported by the transport unit 5. And a fixing discharge roller 61 that discharges the recording paper on which the toner image is fixed from the fixing means 38, and the recording paper discharged by the fixing discharge roller 61 is discharged to the outside of the apparatus as it is and is discharged after being turned upside down. Or switching means 62 for switching the conveyance path when re-feeding to form an image on the back side, reversing means 65 for reversing the front and back of the re-fed recording paper, and recording reversed by reversing means 65 A paper refeeding path 66 for refeeding the paper to the image forming unit 3 is provided.
[0045]
When the image-formed recording paper is discharged as it is, that is, with the image-formed side facing up, the switching means 62 is positioned at the position indicated by the one-dot chain line in FIGS. The recording paper is discharged by a paper roller 63 to a paper discharge tray 64 outside the apparatus. Further, when paper is discharged with the front and back sides of the image-formed recording paper turned over, that is, with the image-formed surface facing down, the switching means 62 is positioned at the position indicated by the solid line in FIGS. The recording paper conveyed by the fixing discharge roller 61 is once conveyed in the direction of the reversing means 65, and after the recording paper passes through the switching means 62, the conveying direction is reversed and the paper discharge roller 63 removes the recording paper. Are discharged to the paper discharge tray 64. On the other hand, when an image is formed on the back side of the recording paper, the switching unit 62 is positioned at a position indicated by a solid line in FIG. 1, and the recording paper conveyed by the fixing discharge roller 61 is conveyed in the direction of the reversing unit 65 and reversed. By switching back by means 65, the front and back are reversed and conveyed to the refeed path 66. The recording paper transported to the refeed path 66 joins the transport path between a loop forming roller 55 described later and an intermediate transport roller 541 described later, and in the same manner as the paper feed from the recording paper storage means 4, It is conveyed to the forming means 3.
[0046]
Next, in the drawer unit 6 in the present embodiment, a processing mechanism when the recording paper transported from the transport unit 5 has a transport failure will be described.
[0047]
FIG. 3 is an enlarged sectional view showing the drawer unit 6. FIG. 4 is a plan view of the drawer unit 6. FIG. 5 is an enlarged cross-sectional view showing only the sheet feeding / conveying portion of the drawer unit 6. 6A is a sectional view showing a state in which the drawer unit 6 is pulled out from the copying machine main body A, and FIG. 6B is a side view in which a part of the drawer unit 6 is opened downward.
[0048]
Hereinafter, the configuration will be described mainly based on FIGS.
[0049]
As shown in FIG. 3, the recording paper on which the toner image formed on the photosensitive drum 31 is transferred by the transfer device 35 is separated from the photosensitive drum 31 by the separator 36, and then the recording paper is transferred to the fixing unit 38. A conveying member 391 for conveying is provided. As a means for conveying the recording paper fixed by the fixing means 38 to the reversing means 65 without discharging it to the paper discharge section 621, a switching means 62 and a pair of conveying rollers 57 are provided.
[0050]
The re-feeding means guide members 81, 82 slidably provided on the fixed frames A 1, A 2 (shown in FIG. 4) fixed to the copying machine main body A are connected to the support frames 6 A, 6 B constituting the drawer unit 6. Both ends are supported and fixed, and the drawer unit 6 can be pulled out from the copying machine main body A to the front side of the drawing. A drawer unit bottom plate 80 (shown in FIG. 6) is provided at a lower position of the drawer unit 6 so as to open the refeed path 66 of the drawer unit 6 with one end rotatably supported on the drawer unit 6. Yes. Conveying rollers 70 and 71 are provided on the drawer unit 6 side, and conveying rollers 701 and 711 are provided on the drawer unit bottom plate 80 side so as to be paired with the conveying rollers 70 and 71 and 701 and 711, respectively. A reversing means 65 for switching back the recording paper conveyed by the pair of conveying rollers 70 and 701, 71 and 711 is provided in the drawer unit 6, and the reversing means 65 includes a pair of conveying rollers 651 that can be rotated left and right and a switchback. A recording paper guide section 77 for guiding the recording paper to be provided is provided.
[0051]
Furthermore, in order to transport the switched back recording paper to the refeed path 66, transport rollers 72, 73, 74, 75 are provided on the drawer unit 6 side, and transport rollers 72, 73, 74 are provided on the drawer unit bottom plate 80 side. , 75 and a pair of conveying rollers 721, 731, 741, 751 are provided. In order to transport the recording paper fed in the refeed path 66 to the transfer position again, a pair of transport rollers 76, the loop forming roller 55, the registration roller 56, and the transport roller 39 are provided on the drawer unit 6 side. ing.
[0052]
Further, a movable guide member 551 that opens the loop forming roller 55 and a plurality of sheets arranged in a direction perpendicular to the recording paper conveyance direction in order to detect the recording paper that is provided downstream of the registration roller 56 and detected. In addition to the light source L and the light receiving element S, a registration roller 56 and a movable guide member 561 that opens between the pair of transport rollers 39 are provided. The light source L is provided to the movable guide member 561, and the light receiving element S is provided to the light receiving element S. The support frames 6A and 6B are provided respectively. A sensor composed of a plurality of light sources L and a plurality of light receiving elements S detects the leading edge of the recording paper to be conveyed, and detects the conveyance timing, inclination, and deviation of the recording paper from the detection result.
[0053]
Next, referring to FIG. 6, the structure for pulling out the drawer unit 6 from the copying machine main body A will be described.
[0054]
Guide members 81A and 82A for guiding the drawer unit guide members 81 and 82 are fixed to the fixed frames A1 and A2 constituting the copying machine main body A, and the drawer unit guide members 81 and 82 support the drawer unit 6. Both ends of the frames 6A and 6B are supported. Further, positioning members 6C, 6D, 6E, and 6F are provided on the support frames 6A and 6B or the fixed frames A1 and A2, and the drawer unit 6 is installed at a predetermined position of the copying machine main body A. The supporting frame bodies 6A and 6B are provided with locking means 83. The locking means 83 is locked to the fixed frame body A1, and the drawer unit 6 is maintained in the holding state with the copying machine main body A. The pulling unit 6 can be pulled out from the copying machine main body A in the direction of the arrow X by releasing the locking state of the locking means 83 with the operation lever 84.
[0055]
The operation lever 85 is provided on the drawer unit bottom plate 80 so as to be rotatable in the direction of arrow Z. When the drawer unit 6 is mounted on the image forming apparatus main body, the right end (in FIG. 6) of the drawer unit bottom plate 80 is shown in FIG. 6A by the locking claws 86A and 86B that can rotate together with the operation lever 85. As indicated by the solid line, the frame is locked to the frame of the drawer unit 6.
[0056]
Next, a state where the drawer unit 6 is pulled out from the copying machine main body A and the drawer unit bottom plate 80 is opened will be described with reference to FIGS.
[0057]
As shown in FIG. 6A, when the drawer unit bottom plate 80 is accommodated in the copying machine main body A, the operation lever 85 is integrated with the fixing pins 862 and 863 provided on the support frames 6A and 6B. The pulling unit bottom plate 80 is coupled to the pulling unit 6 (right end) at its tip (right end). In this way, the refeed path 66 is formed by the drawer unit bottom plate 80.
[0058]
The drawer unit 6 can be moved out in the direction of the arrow X and pulled out from the copying machine main body A as shown by a one-dot chain line in FIG. Then, by rotating the operation lever 85 as indicated by the arrow Z, the engagement between the fixing pins 862 and 863 and the locking claws 86A and 86B can be released. With this disengagement, the drawer unit bottom plate 80 rotates as indicated by the arrow Y, the refeed path 66 is opened, and the jammed recording paper can be taken out.
[0059]
As shown in FIGS. 4 and 6B, one end of a wire 88 is attached to the drawer unit bottom plate 80, and the other end of the wire is connected to one end of a coil spring 87. The other end of the coil spring 87 is fixed to the frame of the drawer unit 6. The coil spring 87 reduces the impact when the right end portion of the drawer unit bottom plate 80 is dropped.
[0060]
The operation lever 85 is urged in a direction opposite to the arrow Z by a spring (not shown), and when the right end portion of the operation lever 85 is dropped by the operation of the operation lever 85 and is separated from the operator's hand, The operating lever 85 returns to its original position by the force, and the state shown in FIG.
[0061]
When the drawer unit 6 is moved in the direction opposite to the arrow X and returned to the position of the solid line from the one-dot chain line position in FIG. 80 is pushed up by rollers 911, 912 provided on the auxiliary guide member 91 and rollers 921 provided on the auxiliary guide member 92, and automatically moves to the position indicated by the solid line in FIG. Return to the position to form. The right end portion of the drawer unit bottom plate 80 is locked to the frame of the drawer unit 6 by the action of the locking claws 86A and 86B and the fixing pins 862 and 863. The rollers 911, 912, and 921 are rotatably attached. However, the rollers 911, 912, and 921 are made of a highly slippery material so that the drawer unit bottom plate 80 is returned to the sliding unit without touching the drawer unit bottom plate 80 without rotating. It may be.
[0062]
Next, the operation of conveying the recording paper by the conveying means 5 will be described with reference to FIG.
[0063]
As described above, since the recording paper stored in any of the recording paper storage means 4A to 4C is transported in the same manner, the recording stored in the first recording paper storage means 4A is used here. The paper conveyance will be described.
[0064]
When a paper feed start signal is received from a control means (not shown), first, the pickup roller 51A is moved to the lower position, and then the pickup roller 51A and the separation conveying roller 521 are rotated in the direction of the arrow. As a result, the uppermost recording paper among the plurality of recording papers stored in the first recording paper storage means 4A is sent out and separated one by one by the separation means 52A (the separation conveying roller 521A and the separation retard roller 522A). Are transported. Then, the recording paper separated and conveyed by the separating means 52A hits the pre-registration roller 53A that is not rotating. When the recording paper is conveyed by the separating means 52A, the rotation of the pickup roller 51A is stopped and the pickup roller 51A is moved to the upper position.
[0065]
Even after the recording paper hits the pre-registration roller 53A, the conveyance of the recording paper by the separating means 52A is continued. Accordingly, the recording sheet whose leading edge is stopped by the pre-registration roller 53A is further conveyed by the separation unit 52A, thereby forming a loop between the pre-registration roller 53A and the separation unit 52A. At this time, the formed loop is surely formed in an appropriate shape by the upper and lower guides 571 and 572, and a sufficient loop can be formed, so that the bending of the paper can be reliably corrected.
[0066]
Here, the pre-registration restart signal is not limited to this when there is a preceding recording sheet or when the preceding recording sheet is conveyed by the loop forming roller 55 or the intermediate conveying roller 541. However, when the recording paper to be re-transported from the pre-registration roller 53A does not overlap the preceding recording paper, the re-transport may be started.
[0067]
The recording sheet conveyed by the pre-registration roller 53A is conveyed by the intermediate conveyance roller 541 on the intermediate conveyance path b, and further conveyed by the loop forming roller 55. The recording paper conveyed by the loop forming roller 55 abuts against the registration roller 56 that is not rotating. Even after the recording paper hits the registration roller 56, the conveyance of the recording paper by the loop forming roller 55 is continued. Therefore, the recording paper whose leading edge is stopped by the registration roller 56 is further conveyed by the loop forming roller 55, so that a loop is formed between the registration roller 56 and the loop forming roller 55. At this time, the formed loop is surely formed in an appropriate shape by the upper and lower guides 581 and 582, and a sufficient loop can be formed, and the conveyance between the pre-registration roller 53A and the registration roller 56 is performed. This makes it possible to reliably correct the bending of the paper caused by the above.
[0068]
When an appropriate loop is formed on the recording paper, the conveyance by the loop forming roller 55 is stopped, and the rotation of the registration roller 56 is started based on the registration restart signal from the control means. The rotational peripheral speed of the registration roller 56 is the same as the process speed at which image formation by the image forming unit 3 is performed. Therefore, the recording paper that has stopped by hitting the registration roller 56 is conveyed at an accurate timing as the rotation starts based on the registration restart signal. At this time, the loop forming roller 55 is driven to rotate in synchronization with the registration roller 56.
[0069]
Incidentally, in the present embodiment, the recording paper supply means 4X comprising the recording paper storage means 4, the pickup roller 51, the separation means 52, the pre-registration roller 53, and the upper and lower guides 571 and 572 shown in FIGS. The recording paper supply means 4X is provided on the front surface of the copying machine so that it can be pulled out integrally. Therefore, when there is no recording paper in the recording paper storage means 4, the recording paper supply means 4X can be pulled out and the recording paper can be replenished. Furthermore, when various types of recording paper are used, paper jams are likely to occur in the vicinity of feeding and separation. Therefore, when only the recording paper storage means 4 is provided so that it can be pulled out, the jammed paper is held between rollers. The processing becomes complicated at the time of pulling out, but by making it a unit as in this embodiment, it can be pulled out while being pinched by the roller, making it easy to handle paper jams and It can be done reliably.
[0070]
The pick-up roller 51, the separating means 52 including the separating conveyance roller 521 and the separating retard roller 522, the pre-registration roller 53, and the upper and lower guides 571 and 572 are the same corresponding to each of the recording paper storage means 4A to 4C. Since those having a function are provided, the recording paper supply means 4X is provided corresponding to each of the recording paper storage means 4A to 4C (as shown in the figure, the first recording paper supply means 4AX to the third recording paper Each of the first recording paper supply means 4AX to the third recording paper supply means 4CX is provided so that it can be pulled out independently from the copying machine.
[0071]
In this way, the recording sheets conveyed from the respective recording sheet storage means 4A to 4C are sequentially conveyed between the photosensitive drum 31 and the transfer unit 35 by the loop forming roller 55, the registration roller 56, and the conveying roller 39, and the toner image is transferred. After the transferred recording sheet is separated from the photosensitive drum 31 by the separator 36, the recording sheet is conveyed to the fixing unit 38 by the conveying unit 391. After the conveyance, in the case of single-sided recording, the switching means 62 is moved to the alternate long and short dash line position and discharged to the external discharge tray 64 via the discharge portion 621.
[0072]
When performing double-sided recording, as shown in FIG. 3, the recording paper fixed by the fixing unit 38 is not discharged to the paper discharge unit 621, and the recording paper is re-fed to the drawer unit 6 by the solid line position switching unit 62. Then, a pair of transport rollers 70, 701, 71, 711 and a transport roller 651 are transported to the recording paper guide unit 7 via the transport roller 57, and the transport roller 651 sandwiching the rear end of the recording paper is switched back. Next, a pair of transport rollers 72, 721, 73, 731, 74, 741, 75, and 751 feed the paper to the paper refeed section 66, and the transport roller 76 again feeds the loop forming roller 55, the registration roller 56, and the transport. The sheet is conveyed between the photosensitive drum 31 and the transfer unit 35 by a roller 39 and recorded on both sides by recording the back side of the recording sheet, separated by the separator 36, fixed by the fixing unit 38, and discharged from the outside. 64 to discharge.
[0073]
In the present embodiment, by operating the operation lever 84, it is possible to guide by the re-feeding means guide members 81 and 82 and to pull out the drawer unit 6 from the copying machine main body A to the outside of the apparatus.
[0074]
A recording paper guide member 90 is provided that guides the recording paper conveyed by the pair of conveying rollers 76 and is openable. The recording paper guide member 90 is always sucked and fixed in the direction of the recording paper conveyance path by a suction member 901 such as a magnet. Next, one end of an openable movable guide member 551 is provided on the downstream side of the recording paper guide member 90 by a support shaft 552 so as to be rotatable along the recording paper conveyance path of the support frames 6A and 6B. One end of the pair of loop forming rollers 55 is provided at the distal end of the movable guide member 551, and the other loop forming roller 55 is provided on the support frame bodies 6A and 6B so that the loop forming roller 55 is provided. It is formed in a pair of states. Further, the movable guide member 551 is constantly urged in the closing direction by the urging member 553 provided on the support shaft 552 so that the pair of loop forming rollers 55 are brought into contact with each other with a constant pressure. Further, an opening handle 554 is formed at the tip of the movable guide member 551, and the movable guide member 551 is opened against the urging member 553 as shown by a one-dot chain line so that the pair of loop forming rollers 55 can be separated. is doing.
[0075]
Further, the movable guide member 561 provided on the downstream side of the movable guide member 551 and having the light source L (L1) facing the light receiving element S (S1) is indicated by an alternate long and short dash line with the positions of the pair of transport rollers 56 as support shafts. As shown in the figure, it is provided so that it can be opened, and one of the conveying rollers 39 and a handle 563 are provided at the other end. By opening the movable guide members 551 and 561 in this way, it is possible to easily eliminate the jam of the recording paper in the upstream portion of the transfer device 35.
[0076]
The process of eliminating the jam at the upstream portion of the transfer unit 35 has been difficult in the past because this portion is very narrow. However, such a problem has been solved by the jam eliminating mechanism as described above.
[0077]
The movable guide members 551 and 561 are configured to rotate about an axis to open the recording paper supply path. For example, the movable guide members 551 and 561 are placed on a frame to form and lift the recording paper supply path. It is also possible to adopt other configurations such as opening by the
[0078]
The jam handling operation is as follows. The operation lever 84 shown in FIG. 4 releases the engagement state of the engagement means 83 and the drawer unit 6 is guided from the copying machine main body A by the drawer unit guide members 81 and 82 and pulled out in the direction indicated by the white arrow. The recording paper in a jam state at the position of the forming roller 55 is opened against the urging member 553 by the release handle 554, and the movable guide member 551 is opened to release the pressure contact state of the loop forming roller 55. Can be removed. When the release handle 554 is released, the movable guide member 551 is automatically returned to the original position by the biasing member 553.
[0079]
Further, as shown in FIG. 5, the recording paper jammed between the registration roller 56 and the conveyance roller 39 opens the movable guide member 561 together with the light source L (L1) with the handle 563 to release the pressure contact state of the conveyance roller 39. The recording paper can be easily removed.
[0080]
Further, when a jam occurs in the refeed path 66, the pressing operation member 85 is pressed to release the locking claws 86A and 86B from the fixing pins 862 and 863 as shown in FIG. Is opened downward so that the transport rollers 701, 711, 721, 731, 741, and 751 provided on the drawer unit bottom plate 80 are separated from the transport rollers 70, 71, 72, 73, 74, and 75, and the lower recording paper. It is possible to open the entire conveyance path, and it is possible to remove the recording paper in the jammed state.
[0081]
When all the jams are completed and the drawer unit 6 is returned into the copying machine main body A by using the operation lever 84 or the like, the drawer unit bottom plate 80 is guided and pushed back by the drawer unit guide members 81 and 82 and is in an open state. Since the transport rollers 701, 711, 721, 731, 741, and 751 are again brought into contact with the transport rollers 70, 71, 72, 73, 74, and 75 with a predetermined pressure contact force, smooth recording paper transport can be performed.
[0082]
The correspondence between the constituent elements of the present invention described in the claims and the constituent parts of the above-described embodiment is as follows. However, the present invention is not limited to the above-described embodiment, and can be changed and modified within the scope described in the claims.
[0083]
Image forming means: Image forming means 3
Refeeding means ... drawer unit 6
Image forming apparatus main body: a portion of the image forming apparatus excluding the drawer unit 6
Restoring means: rollers 911, 912, 921
Recording paper path ... re-feed path 66
Recording paper path forming means: drawer unit bottom plate 80
Locking means ... locking claws 86A, 86B
Mitigation means: coil spring 87
Image carrier ... photosensitive drum 31
Transfer means: Transfer device 35
Synchronous conveying means: Registration roller 56
Guide means: movable guide member 561
Supply path guide means—movable guide member 551
[0084]
【The invention's effect】
As described above in detail, according to the present invention, the operation of jamming to take out the recording paper jammed in the refeeding unit is facilitated, and the refeeding unit is attached to the image forming main body. The recording paper path in the refeeding means is automatically restored, stable recording paper transportability in the refeeding means is ensured, and paper jams in the refeeding means are reduced.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a digital copying machine according to an embodiment of the present invention.
FIG. 2 is a diagram schematically illustrating an enlarged recording paper conveyance path.
FIG. 3 is an enlarged sectional view showing a drawer unit.
FIG. 4 is a plan view of the drawer unit.
FIG. 5 is an enlarged cross-sectional view showing a part of the drawer unit.
FIG. 6 is a side view of the drawer unit.
[Explanation of symbols]
1 Automatic document feeder
2 Image reader
3 Image forming means
4 Recording paper storage means
4X recording paper supply means
5 Transport means
6 drawer unit
52 Separation means
53 Pre-registration roller
55 Loop forming roller
56 Registration Roller
551, 561 Movable guide member
70, 71, 72, 73, 74, 75, 76, 701, 711, 721, 731, 741, 751 Conveying rollers
911, 912, 921 roller
66 Refeed path
80 Drawer unit bottom plate
86A, 86B Claw
87 Coil spring
31 Photosensitive drum
35 Transfer machine

Claims (2)

In the image forming apparatus capable of forming an image on the other side of the recording paper in the image forming unit again after forming an image on one side of the recording paper in the image forming unit,
A re-feeding unit that transports the recording paper to the image forming unit again is detachably attached to the image forming apparatus main body,
The image forming apparatus main body is provided with a restoring means,
The refeeding means is provided with a releasable recording paper path forming means for forming a recording paper path and a locking means for locking the opening of the recording paper path forming means,
When the re-feeding unit is taken out from the main body of the image forming apparatus, the recording paper path forming unit can release the locking unit, thereby opening the recording paper path. ,
When the re-feeding means is mounted on the image forming apparatus main body, the recording paper path forming means is driven by the restoring means to form the recording paper path, and the recording paper path is set by the locking means. An image forming apparatus, wherein the recording paper path forming means is locked at a position where the recording paper is formed. The recording paper path forming means is configured to be operated by gravity to open the recording paper path,
The image forming apparatus according to claim 1, wherein the refeeding unit is provided with a mitigating unit that prevents abrupt operation of the recording paper path forming unit.

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