JP3911872B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording material storing means for storing a recording material, an image forming means for forming an image on the recording material, and conveying the recording material along a conveying path from the recording material storing means to the image forming means. conveying means for relates to an image forming equipment having a.
[0002]
[Prior art]
A recording material storage means for storing the recording material; an image forming means for forming an image on the recording material; and a transport means for transporting the recording material from the recording material storage means to the image forming means along a transport path. imaging equipment that is a copying machine, widely used printers, and the like facsimile. Among such image forming apparatuses, for example, an image forming apparatus that forms an image by an electrophotographic method forms an electrostatic latent image on a photoreceptor by image exposure, and develops the latent image with a developer so that the visible image is visible. The toner image is transferred onto a recording material conveyed by a conveying unit, and is heated and fixed to form an image.
[0003]
In such an image forming apparatus, in general, in order to synchronize the recording material conveyed by the conveying unit with the timing of image formation by the image forming unit, a resist that temporarily stops the recording material in the vicinity of the image forming unit. It has a roller. The recording material is once abutted against the registration roller to stop the recording material, and the recording material conveyance and the image formation are synchronized with each other. Further, the registration roller is configured so that the bending of the leading end of the recording material can be corrected by forming a loop in the recording material after the recording material is temporarily stopped.
[0004]
As described above, the registration roller disposed in front of the image forming unit matches the timing of the recording material and image formation, and corrects the bending of the leading end of the recording material to be conveyed, thereby correcting the recording material on the recording material. An image is formed at an accurate position.
[0005]
[Problems to be solved by the invention]
By the way, in recent years, an increase in the number of copies per unit time (improvement in productivity) has been demanded in smaller image forming apparatuses, and the speed has been increased. For this reason, attempts have been made to improve each part of the image forming apparatus and more strictly control the paper conveyance. However, there are problems such as an increase in the cost of the image forming apparatus and a decrease in reliability due to complicated control. Not improved.
[0006]
In other words, if the speed of the image forming apparatus is increased, the conveyance timing may be misaligned or the paper may be bent due to causes such as an increase in frictional resistance between the recording material and the conveyance guide and an increase in slippage between the recording material and the conveyance roller. It will be bigger than before. In addition, due to the correspondence to various types of recording materials, the image forming means and the recording materials are required due to the need to provide a large number of recording material storage means and the deviation of the conveyance timing due to the difference of the recording material types and the variation of paper bending. It has become necessary to increase the distance between the storage means. For this reason, even if an attempt is made to set the timing of image formation with a registration roller arranged in the vicinity of the image forming means, there is a large deviation in the conveyance timing in the conveyance path before the recording material reaches the registration roller. If there is a variation, the timing cannot be kept, causing problems such as a paper jam due to a delay in the conveyance of the recording material. Also, even in the case of paper bending, since a large paper bending occurs in the conveyance path before the recording material reaches the registration roller, correction is not performed by correcting the paper bending in the registration roller arranged in the vicinity of the image forming unit. I can't finish it. This bending of the paper becomes more noticeable as the conveying path becomes longer.
[0007]
The inventors of the present application have examined in detail the causes of this paper bending and conveyance timing deviation. As a result, when the recording material is taken out from the recording material storage means, the position where the first paper bending occurs is determined between the recording materials. The paper is bent due to the frictional force, and the second generation position is the conveyance path, and the friction between the recording material and the conveyance guide becomes significant particularly at the curve position where the conveyance direction is changed. It has been found that enlargement of the image and a delay in the conveyance timing occur. When the above transport timing deviation or paper skew occurs, in addition to the decrease in productivity due to recording paper transport delay, paper jams occur due to collisions between recording materials, or between recording materials and transport rollers or transport guides. This leads to a fatal problem of stopping the image forming apparatus.
[0008]
Therefore, in the present invention, it is possible to suppress a variation in conveyance, or to suppress the bending of the recording material, to satisfactorily form an image at an accurate position on the recording material, and to easily handle a paper jam, and It is an object of the present invention to provide an image forming apparatus that can perform surely.
[0009]
[Means for Solving the Problems]
The above problem can be solved by the following configuration.
[0010]
(1) Recording material storage means for storing the recording material, image forming means for forming an image on the recording material, and transport means for transporting the recording material from the recording material storage means to the image forming means along a transport path In an image forming apparatus having
The conveying means has a first abutting means for abutting the recording material conveyed from the recording material storage means and re-conveying after stopping at least the tip of the recording material,
Wherein a recording material housing means, said first abutment means is unitized, an image forming apparatus, wherein the integrally, is capable drawn out to the image forming apparatus this.
[0011]
According to such a configuration, even when the paper is jammed, the unit can be pulled out while the paper is jammed, and the paper jam can be easily and reliably processed.
[0012]
(2) A plurality of the recording material storage means are provided, the first abutting means is provided corresponding to each of the plurality of recording material storage means, each of the plurality of recording material storage means, and the plurality of the recording material storage means The image forming apparatus according to (1), wherein each of the first abutting means provided corresponding to each of the recording material storing means is unitized .
[0013]
With such a configuration, it is possible to suppress the conveyance variation at the position where the variation in the conveyance is most likely to occur, and even when the paper is jammed, the paper can be pulled out while being jammed. The paper jam can be easily and reliably processed.
[0014]
(3) A plurality of first transport paths through which the recording material is sent out from the recording material storage means, an intermediate transport path through which the recording material sent out through the first transport path is transported, and transported through the intermediate transport path A recording material to be conveyed to the image forming unit, and a second conveyance path.
The image forming apparatus according to (2 ), wherein the first abutting unit is provided on the first conveyance path .
[0015]
According to such a configuration, the first conveyance path is most likely to cause variations in conveyance, but since variations in conveyance on the first conveyance path can be suppressed, it is easy to accurately take the timing in the subsequent stage, and in the second conveyance path. since configured to abut, because the timing of the image forming even wear exactly ensured, it is good image formation.
[0016]
(4) The second abutting means for abutting the recording material reconveyed after being abutted by the first abutting means is provided on the second conveying path. Image forming apparatus.
[0017]
With this configuration, the recording material conveyed by the conveying unit is abutted a plurality of times by a plurality of abutting units, and the variation in conveyance can be greatly reduced, so that a good image can be obtained at an accurate position on the recording material. Formation can be performed. In particular, even when the speed is increased, variations in conveyance can be suppressed, so that productivity can be improved.
[0018]
(5) The second abutting means is a common abutting means against which a recording material re-fed after being abutted by each of the plurality of first abutting means is abutted ( The image forming apparatus according to 4).
[0019]
With this configuration, the second abutting means can be shared, and the number of parts can be reduced and the cost can be reduced.
[0020]
(6) When the recording material is abutted against the first abutting means on the upstream side of the first abutting means with respect to the conveyance direction of the recording material and at least the leading end of the recording material is stopped, the recording material The image forming apparatus according to any one of (1) to (5), further comprising: a loop forming unit that forms a loop .
[0021]
With such a configuration, it is possible to correct not only the conveyance variation but also the bending of the recording material, and it is possible to satisfactorily form an image at an accurate position.
[0022]
(7) The image forming apparatus according to (6), further comprising a loop forming guide for forming a recording material loop between the loop forming unit and the first abutting unit.
[0023]
With this configuration, the loop can be formed with an appropriate shape, and the bending can be reliably corrected.
[0024]
(8) for conveying the that Symbol Rokuzai housing means to house the recording medium, an image forming unit for forming an image on a recording material, the recording material to the image forming means along a conveyance path from the recording material housing means An image forming apparatus having a conveying unit;
The conveying means includes first bending correction means for correcting the bending of the recording material conveyed from the recording material storage means,
The image forming apparatus according to claim 1, wherein the recording material storage unit and the first bend correction unit are unitized and can be integrally pulled out from the image forming apparatus.
[0025]
With such a configuration, even when the paper is jammed, the paper can be pulled out while being jammed, and the paper jam can be easily and reliably processed.
[0026]
(9) A plurality of the recording material storage units are provided, and the first bending correction unit is provided corresponding to each of the plurality of recording material storage units, and each of the plurality of recording material storage units, (8) The image forming apparatus according to (8) , wherein each of the first bending correction units provided corresponding to each of the recording material storage units is unitized .
[0027]
With this configuration, it is possible to correct the bending of the recording material at a position where the bending of the recording material is most likely to occur, and even when the paper is jammed, the paper can be pulled out while being jammed. Thus, the paper jam can be easily and reliably processed.
[0028]
(10) A plurality of first transport paths through which the recording material is sent out from the recording material storage means, an intermediate transport path through which the recording material sent through the first transport path is transported, and transport through the intermediate transport path And a second transport path through which the recorded material is transported to the image forming means,
The image forming apparatus according to (9), wherein the first bend correction unit is provided on the first conveyance path .
[0029]
With such a configuration, any recording material sent out from a plurality of recording material storage means can correct the bending multiple times and greatly reduce the bending of the recording material, so that the accurate position on the recording material can be reduced. Excellent image formation can be performed.
[0030]
(11) The image forming apparatus according to any one of (8) to (10), wherein the first bend correction unit is provided in the vicinity of the recording material storage unit .
[0031]
With this configuration, it is possible to suppress the bending of the recording material that is likely to occur during feeding.
[0032]
(12) The image formation according to (10), characterized in that second bending correction means for correcting the bending of the recording material whose bending has been corrected by the first bending correction means is provided on the second conveyance path. apparatus.
[0033]
According to such a configuration, the recording material conveyed by the conveying means is bent a plurality of times by a plurality of bending correcting means, and the bending of the recording material accompanying the conveyance can be greatly reduced. Even so, good image formation can be performed at an accurate position on the recording material. Further, although the recording material is most likely to be bent in the first conveyance path, such a configuration can suppress the bending of the recording material on the first conveyance path and can correct the bending in the initial stage. Further, since the amount of bending is reduced and the bending is further corrected in the second conveyance path, it can be made to coincide with the position of image formation by the image forming means, so that good image formation can be achieved. .
[0034]
(13) The image forming apparatus according to (12), wherein the second bend correcting unit is provided in the vicinity of the image forming unit.
[0035]
With this configuration, it is possible to match the position of image formation by the image forming means, and good image formation can be performed.
[0036]
(14) The second bend correcting means is a common bend correcting means for correcting the bend of the recording material whose bend is corrected by each of the plurality of first bend correcting means (12) or The image forming apparatus according to (13) .
[0037]
With this configuration, the second bend correcting means can be shared, and the number of parts can be reduced and the cost can be reduced.
[0038]
(15) The first bend correcting unit includes a loop forming unit that forms a loop of the recording material, and a first abutting unit that abuts the leading end of the recording material on the downstream side in the recording material conveyance direction with respect to the loop forming unit. (8) The image forming apparatus as described in any one of (8) to (12) .
[0039]
With such a configuration, it is possible to correct the bending with a simple configuration, to suppress not only the bending of the recording material but also the conveyance variation, and it is possible to form a favorable image at an accurate position.
[0040]
(16) The first bending correcting means includes a loop forming guide for forming a loop of the recording material between the loop forming means and the first abutting means. The image forming apparatus described.
[0041]
With this configuration, the loop can be formed with an appropriate shape, and the bending can be reliably corrected.
[0042]
(17) The image forming apparatus according to any one of (8) to (16), wherein the first bending correction unit is a pre-registration roller configured by a pair of rollers .
[0043]
With such a configuration, reliable transport timing can be taken, and an image can be formed at a more accurate position.
[0044]
(18) The image forming apparatus according to (2) or (9), wherein the plurality of recording material storage units are arranged in a multi-stage below the image forming apparatus.
[0045]
(19) At least a part of the intermediate transport path is shared in order to transport the recording material sent out through the plurality of first transport paths, according to (3) or (10) An image forming apparatus is preferable.
[0072]
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.
[0073]
The copying machine of the present embodiment is provided with an automatic document feeder 1 at the top of the copying machine main body, and an image reading device 2, an image forming means 3, a recording paper storage means 4, a conveying means 5, and a copying machine main body. The paper discharge / refeed means 6 is provided.
[0074]
The automatic document feeder 1 is an apparatus that is provided on the upper part of the copying machine main body, 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.
[0075]
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.
[0076]
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. In the present embodiment, the document conveying unit 13 conveys the document while reading the image of the document. However, the document conveyed by the document conveying unit 13 is stopped on the platen glass. You may comprise so that an image may be read by.
[0077]
The image reading device 2 is a means for reading an image of a document and obtaining image data, and is provided at an upper portion in 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 V mirror unit 24 in which a second mirror 241 and a third mirror 242 that reflect light are integrated, and an imaging unit that forms an image on a CCD 26 (to be described later) on reflected light from a document on the slit 21 or the platen glass 22. An imaging lens 25 and a linear CCD which is an image reading means for obtaining image information by photoelectrically converting a light image formed by the imaging lens 25 It has a 6.
[0078]
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 V mirror unit 24 move to the left in FIG. 1, and the first mirror unit 23 is slit. 21 is located below. 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 CCD 26 via 25. In the CCD, incident light is photoelectrically converted to read an image of a document in the main scanning direction (in the direction perpendicular to the paper surface in FIG. 1). On the other hand, the document is moved in the sub-scanning direction by the document conveying means 13, so The entire image can be read. The image information read by the CCD 26 is appropriately subjected to image processing and provided to a laser writing system 33 described later.
[0079]
When the document is placed directly on the platen glass 22, the first mirror unit 23 and the V mirror unit 24 are moved along the platen glass in the right direction in FIG. Can be read.
[0080]
The image forming unit 3 is a unit that forms an image on a recording sheet that is a recording material 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 photosensitive drum 31 that is an image carrier having a photoconductive photosensitive layer and carrying a toner image, a charger 32 that uniformly charges the photosensitive drum 31, and image information read by the CCD 26. Based on this, 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 the photosensitive member A transfer device 35 for transferring the toner image carried on the drum 31 onto a separately conveyed recording paper, a separator 36 for separating the recording paper on which the toner image has been transferred from the photosensitive drum 31, and after being transferred. 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.
[0081]
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 device 34, and a toner image based on image information read by the 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.
[0082]
In the present embodiment, a pre-drum transport roller 39 for transporting the recording paper fed from the registration roller 56 is provided in the vicinity of the photoconductive drum 31 between the photoconductive drum 31 and the registration roller 56. This contributes to an increase in recording paper conveyance. 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 conveying roller (no symbol) and a belt (no symbol) are provided for conveyance.
[0083]
The recording paper storage means 4 is a recording material 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 materials stored in these recording paper storage means 4A to 4C, there are various media such as OHT in addition to recording paper such as plain paper and recycled paper.
[0084]
The conveying unit 5 is a conveying unit that conveys the recording material from the recording paper storage unit 4 to the image forming unit 3, and conveys 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. It is configured to be able to. The specific configuration and operation of the transport unit 5 will be described in detail later.
[0085]
The paper discharge / refeed unit 6 is a unit for discharging or refeeding the recording paper on which the image is formed by the image forming unit 3 on the recording paper conveyed by the conveyance unit 5. The paper discharge / refeed means 5 includes a fixing discharge roller 61 for discharging the recording paper on which the toner image is fixed from the fixing means 38, and a case where the recording paper discharged by the fixing discharge roller 61 is discharged to the outside as it is. Switching means 62 for switching the conveyance path when discharging after reversing the front and back, or when re-feeding to form an image on the back side, a discharge roller 63 for discharging recording paper to the outside of the apparatus, and a side surface of the copying machine A paper discharge tray 64 on which recording paper discharged by a paper discharge roller 63 is stacked, a reversing unit 65 for reversing the front and back of the re-fed recording paper, and a recording paper reversed by the reversing unit 65 is formed into an image. Refeeding means 66 for refeeding to the means 3 is provided.
[0086]
When the image-formed recording paper is discharged as it is, that is, with the image-formed surface facing upward, the switching means 62 is positioned at the position indicated by the chain line in FIG. As a result, the sheet is discharged to a discharge tray 64 outside the apparatus. Further, when paper is discharged with the front and back sides of the recording paper on which the image is formed being discharged, that is, when the paper on which the image is formed is discharged downward, the switching means 62 is positioned at the position indicated by the solid line in FIG. The recording paper conveyed by the 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 discharges the recording paper outside the apparatus. It is discharged to the 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 the sheet is conveyed to re-feeding means 66. The recording paper conveyed to the re-feeding means 66 joins the conveying path between a loop forming roller 55 described later and an intermediate conveying roller 541 described later, and in the same manner as the paper feeding from the recording paper storage means 4, It is conveyed to the forming means 3.
[0087]
Next, with regard to the configuration and operation of the transport unit 5 applied in the present embodiment, FIG. 2 is a schematic enlarged view of the recording paper transport path by the transport unit 5, and the operation in the vicinity of the recording paper storage unit will be described. Description will be made based on FIG. 3 which is a schematic diagram and FIG. 4 which is a perspective view of the first unit in a state where the first unit is pulled out.
[0088]
First, the recording paper conveyance path by the conveyance means 5 will be described. The conveyance of the recording paper by the conveyance means 5 is performed along a 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 material and a second conveying path c for conveying the recording material conveyed via 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.
[0089]
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 in which at least one part is 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 a transport path shared by the recording paper transport from each of the recording paper storage units 4A to 4C.
[0090]
Next, each structure (means) of the conveying means 5 will be described.
[0091]
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. Pre-registration rollers 53 as first abutting means, a plurality of intermediate conveyance rollers 541 to 543 as intermediate conveyance means for conveying the recording paper conveyed by the pre-registration rollers 53, and conveyance of the recording paper conveyed by the intermediate conveyance rollers Is conveyed by the loop forming roller 55 as the second loop forming means and the loop forming roller 55 The recording paper and a registration roller 56 is a second abutment means for resuming the transport after being butted once.
[0092]
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.
[0093]
Further, the pickup roller 51, the separating unit 52 including the separating conveyance roller 521 and the separating retard roller 522, and the pre-registration roller 53 have the same functions corresponding to the recording paper storage units 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.
[0094]
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, the pickup roller 51 is located on the first transport path a and is placed in the recording paper storage means 4. It is possible to abut on the uppermost recording paper among a plurality of stored recording papers, be driven by a driving means (not shown), rotate in the direction of the arrow, and send out 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.
[0095]
The separating unit 52 is a unit that separates the recording sheets fed by the pickup roller 51 one by one, and is provided on 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.
[0096]
In the present embodiment, the pickup roller 51 that feeds the recording material stored in the recording paper storage unit 4 and the separation unit 52 that separates the recording material 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 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.
[0097]
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 constituted by 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 its 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.
[0098]
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 this embodiment, the width of the pre-registration roller (the length in the direction perpendicular to the recording paper conveyance direction) is set at the center in the direction orthogonal to the recording paper conveyance direction as shown in FIG. A wider roller than the pickup roller 51, the separation conveying roller 521, and the separation retard roller 522 provided (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). It is possible to correct bends and to prevent variations in conveyance.
[0099]
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 is formed to guide 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.
[0100]
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.
[0101]
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 applied, the first abutting means may be a shutter or a stopper capable of blocking the conveyance path, for example, without using a roller pair.
[0102]
Intermediate conveyance rollers 541 to 543 are intermediate conveyance means for conveying 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, conveying the recording paper from the third recording paper storage unit 4C.
[0103]
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 on the second transport path c so as to be rotatable in a direction indicated by an arrow by a driving unit (not shown). 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.
[0104]
The registration roller 56 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 manner, once the recording paper is abutted against the registration roller 56, 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 33 can be synchronized. This facilitates image formation on the recording paper at an accurate position.
[0105]
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. Loops can be formed in the paper to correct the 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 582 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 582. It is functioning as.
[0106]
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.
[0107]
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.
[0108]
Next, the operation of transporting the recording paper by the transport unit 5 will be described with reference to FIGS. 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.
[0109]
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 indicated by the arrow in FIG. . As a result, the uppermost recording paper (indicated by a thick line in FIG. 3) among the plurality of recording papers stored in the first recording paper storage means 4A is sent out, and the separation means 52A (separation conveying roller 521A) is sent out. Are separated and conveyed one by one by the tolling retard roller 522A). Then, the recording paper separated and conveyed by the separating means 52A hits the non-rotating pre-registration roller 53A (FIG. 3B). 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.
[0110]
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 paper whose leading edge is stopped by the pre-registration roller 53A is further conveyed by the separation means 52A, so that a loop is formed between the pre-registration roller 53A and the separation means 52A as shown in FIG. It is formed. 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. In particular, in recent years when various types of recording paper such as plain paper and recycled paper are used, the feeding (separation and separation) from the recording paper storage means 4 is bent due to slippage between the recording paper and a roller. In spite of being the most unstable state in which it is likely to occur, the bending can be corrected at an early stage, and adverse effects on the later can be eliminated. Further, in the present embodiment, since the paper bending is corrected on the front side (upstream side in the transport direction) of the curve position where the transport direction is changed from the first transport path a to the intermediate transport path b, the curve accompanies the curve. The occurrence of bending can be suppressed as much as possible, and eventually the occurrence of a paper jam can be prevented.
[0111]
The feeding, separation and loop formation of the recording paper from the first recording paper storage means 4A are performed at a predetermined interval. If there is a preceding recording paper, the preceding recording paper is pre-registered. This is not the case when the sheet is conveyed by the roller 53A. However, if the recording paper to be transported by feeding, separation, and loop formation does not overlap the preceding recording paper, feeding may be performed.
[0112]
When an appropriate loop is formed on the recording paper, the conveyance by the separating unit 52A is stopped, and the preregistration roller 53A, the intermediate conveyance roller 541, and the loop forming roller 55 are controlled based on the preregistration restart signal from the control unit. Rotation starts. Therefore, the recording paper that has stopped by hitting the pre-registration roller 52A is conveyed at an accurate timing as the rotation starts based on the pre-registration restart signal. In particular, for the same reason as described above, it is possible to take an accurate timing even when the paper feeding from the recording paper storage means 4 is in an unstable state in which the variation in the conveyance timing is the largest. The timing can be performed at an early stage, and the influence on the later can be eliminated. At this time, the separation conveying roller 521 rotates following the recording sheet conveyed by the pre-registration roller 53A, while the separation retarding roller 522 performs recording other than the recording sheet conveyed by the operation of the torque limiter. It acts so that the paper is not conveyed.
[0113]
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.
[0114]
The recording paper conveyed by the pre-registration roller 53A is conveyed by the intermediate conveyance roller 541 on the intermediate conveyance path b (FIG. 3D), 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. Accordingly, the recording paper whose leading edge is stopped by the registration roller 56 is further conveyed by the loop forming roller 55 to form a loop between the registration roller 56 and the loop forming roller 55 as in FIG. Is done. 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.
[0115]
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.
[0116]
Incidentally, in the present embodiment, as shown in FIG. 4, the sheet feeding means 4, the pickup roller 51, the separating means 52, the pre-registration roller 53, and the upper and lower guides 571 and 572 are unitized as a unit 7. That is, the unit 7 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 unit 7 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.
[0117]
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 functions are provided, the unit 7 is provided corresponding to each of the recording paper storage means 4A to 4C (as shown in the figure, provided as the first unit 7A to the third unit 7C). The first unit 7A to the third unit 7C are provided so as to be independently drawn out from the copying machine.
[0118]
In the present embodiment, the pre-registration roller 53 and the first loop formation means (separation means 52), the registration roller 56 and the loop formation roller 55 are provided on the conveyance path from each recording paper storage means 4A to 4C. Needless to say, three or more may be provided. In particular, when the recording paper is transported from the second recording paper storage unit 4B or the third recording paper storage unit 4C where the distance of the transport path is long, a shift in the transport timing and a bending of the paper occur as the distance increases. Therefore, a better effect can be expected by providing it on the intermediate conveyance path b.
[0119]
【The invention's effect】
As described above in detail, according to the present invention, an image forming apparatus capable of suppressing a variation in conveyance or suppressing a bending of a recording material and forming an image at an accurate position on the recording material. In addition, the recording material conveying method or paper jam handling can be easily and reliably performed.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a copying machine.
FIG. 2 is a schematic enlarged view of a recording paper conveyance path by a conveyance unit.
FIG. 3 is a schematic diagram for explaining the operation in the vicinity of the recording paper storage means.
FIG. 4 is a perspective view of a state in which the first unit is pulled out.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Automatic document feeder 2 Image reading device 3 Image formation means 4 Recording paper storage means 5 Conveyance means 6 Paper discharge / refeed means 7A-7C Unit 51 Pickup roller 52 Separation means 53 Preregistration roller 55 Loop formation roller 56 Registration roller

Claims (19)

A recording material storing means for storing the recording material; an image forming means for forming an image on the recording material; and a conveying means for conveying the recording material from the recording material storing means to the image forming means along a conveying path. In the image forming apparatus,
The conveying means has a first abutting means for abutting the recording material conveyed from the recording material storage means and re-conveying after stopping at least the tip of the recording material,
Wherein a recording material housing means, said first abutment means is unitized, an image forming apparatus, wherein the integrally, is capable drawn out to the image forming apparatus this. A plurality of the recording material storage means are provided, and the first abutting means is provided corresponding to each of the plurality of recording material storage means, and each of the plurality of recording material storage means and the plurality of recording material storages are provided. The image forming apparatus according to claim 1, wherein each of the first abutting units provided corresponding to each of the units is unitized . A plurality of first transport paths through which the recording material is sent out from the recording material storage means, an intermediate transport path through which the recording material sent through the first transport path is transported, and a recording transported through the intermediate transport path A second conveyance path through which the material is conveyed to the image forming unit,
The image forming apparatus according to claim 2 , wherein the first abutting unit is provided on the first conveyance path . The image forming apparatus according to claim 3, wherein a second abutting unit that abuts the recording material reconveyed after being abutted by the first abutting unit is provided on the second conveying path. apparatus. 5. The second abutting unit is a common abutting unit that abuts a recording material that has been re-fed after being abutted by each of the plurality of first abutting units. The image forming apparatus described. When the recording material is abutted against the first abutting means on the upstream side of the first abutting means with respect to the recording material conveyance direction and at least the leading end of the recording material is stopped, a recording material loop is formed. 6. The image forming apparatus according to claim 1, further comprising a loop forming unit for forming the image forming apparatus. The image forming apparatus according to claim 6, further comprising: a loop forming guide for forming a recording material loop between the loop forming unit and the first abutting unit. And to that Symbol Rokuzai housing means housing a recording material, an image forming unit for forming an image on a recording material, conveying means for conveying the recording material to the image forming means along a conveyance path from the recording material housing means In an image forming apparatus having
The conveying means includes first bending correction means for correcting the bending of the recording material conveyed from the recording material storage means,
The image forming apparatus according to claim 1, wherein the recording material storage unit and the first bend correction unit are unitized and can be integrally pulled out from the image forming apparatus. A plurality of the recording material storage means, and corresponding to each of the plurality of recording material storage means, provided with the first bending correction means, and each of the plurality of recording material storage means and the plurality of recording materials; 9. The image forming apparatus according to claim 8 , wherein each of the first bending correcting means provided corresponding to each of the storage means is unitized . A plurality of first transport paths through which the recording material is sent out from the recording material storage means, an intermediate transport path through which the recording material sent through the first transport path is transported, and a recording transported through the intermediate transport path A second conveyance path through which the material is conveyed to the image forming unit,
The image forming apparatus according to claim 9, wherein the first bending correction unit is provided on the first conveyance path . 11. The image forming apparatus according to claim 8, wherein the first bend correction unit is provided in the vicinity of the recording material storage unit . The music of the recording material whose curvature is corrected by the first bending correction means The image forming apparatus according to claim 10, further comprising a second bend correcting unit that corrects the skew on the second transport path. The image forming apparatus according to claim 12, wherein the second bend correcting unit is provided in the vicinity of the image forming unit. 14. The second bend correcting means is a common bend correcting means for correcting a bend of a recording material whose bend is corrected by each of the plurality of first bend correcting means. the image forming apparatus according to. The first bend correcting unit includes a loop forming unit that forms a loop of the recording material, and a first abutting unit that abuts the leading end of the recording material on the downstream side in the recording material conveyance direction with respect to the loop forming unit. The image forming apparatus according to claim 8, wherein the image forming apparatus is an image forming apparatus. 16. The image according to claim 15 , wherein the first bend correcting unit includes a loop forming guide for forming a loop of the recording material between the loop forming unit and the first abutting unit. Forming equipment. 17. The image forming apparatus according to claim 8, wherein the first bend correcting unit is a pre-registration roller configured by a pair of rollers . The image forming apparatus according to claim 2, wherein the plurality of recording material storage units are arranged in a multi-stage below the image forming apparatus. 11. The image forming apparatus according to claim 3, wherein at least a part of the intermediate transport path is shared in order to transport the recording material sent through the plurality of first transport paths. .

Images