JP5106141B2 - Image forming apparatus and image forming apparatus cleaning method - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine and a printer having a function of forming an image on a recording material such as a sheet, for example, by an electrophotographic method, and a method for cleaning the image forming apparatus.

  In a known electrophotographic image forming apparatus including a step of transferring a developer image (toner image) formed on the surface of a photosensitive drum as an image carrier to a recording material such as paper, the image forming apparatus configured as follows It has been put into practical use. First, a recording material is passed through a transfer portion formed at a contact portion between a photosensitive drum and a transfer member such as a transfer roller that is pressed against the photosensitive drum, and a transfer voltage is applied to the transfer member in accordance with this timing. The toner image on the surface of the photosensitive drum is transferred to the recording material by the action of an electric field formed by the applied transfer voltage.

  As a color image forming apparatus, a configuration in which a plurality of image carriers are arranged in a line, toner images are sequentially formed on each image carrier, and the toner images are transferred directly to a recording material or via an intermediate transfer member. Is common.

  Also, with the recent diversification of printer demand, there is a growing demand for marginless printing, particularly in color image forming apparatuses. In order to simplify the work of cutting the margin after printing on a slightly larger recording material in the past, the marginless printing does not create a margin margin around the recording material in advance. ) To perform image printing.

  An example of an electrophotographic full-color image forming apparatus compatible with marginless printing will be briefly described with reference to FIG.

  The image forming apparatus includes four color image forming units (image forming stations 110) 110a, 110b, 110c, and 110d of yellow (Y), magenta (M), cyan (C), and black (K). Each station has a photosensitive drum 111 (111a to 111d) as an image carrier.

  The image forming operation will be described below. In the following description, one of the image forming stations 110a, 110b, 110c, and 110d will be described, and yellow (Y), magenta (M), cyan (C), and black (K ) Representing a) is omitted.

  First, the surface of the photosensitive drum 111 at each station is uniformly charged by the primary charging roller 112. The laser exposure unit 113 performs image exposure for color separation of the document, and forms an electrostatic latent image corresponding to the color separation of the document on the surface of the photosensitive drum 111. Developed using As a result, a toner image of each color is formed on the surface of the photosensitive drum 111.

  The toner images of the respective colors on the photosensitive drum 111 are sequentially superimposed on the intermediate transfer belt 101 by a primary transfer roller 115 as a transfer unit to which a primary transfer voltage is applied from a power source 116 that applies a primary transfer voltage of a primary transfer power source. Primary transcription. Incidentally, the transfer residual toner adhering to the surface of the photosensitive drum 111 after the transfer is removed by the drum cleaner 117, and is used for the next image formation.

  Thereafter, the four color toner images on the intermediate transfer belt 101 are collectively collected by the secondary transfer roller 102 to which the secondary transfer voltage is applied from the secondary transfer power source 121 to the recording material P conveyed to the intermediate transfer belt 101. Secondarily transferred. Then, the recording material P for which the secondary transfer has been completed is conveyed to the fixing device 103 and is pressed and heated by the fixing roller 130 and the pressure roller 131, and the four color toners are melted and mixed and fixed on the recording material P. A full color image is formed on the recording material P.

  On the other hand, the residual toner remaining on the surface of the intermediate transfer belt 101 that has finished the secondary transfer is removed by the belt cleaner 104.

  As shown in FIG. 4, when printing without margins on the recording material P in the image forming apparatus, a mask area E for determining a printing area for the recording material P is set more than the recording material P by the amount of the additional area B. It is also a big area. The added area B has predetermined lengths ET, EB, EL, and ER for the front end, rear end, left end, and right end of the recording material P, respectively.

  Then, an image including the part of the added area is formed on the photosensitive drum, and this is transferred to the recording material P to achieve marginless printing.

  By performing image formation by such a method, it is possible to always perform good marginless printing on the recording material P even if the following variations occur. That is, when the recording material P passes through the secondary transfer nip portion, the conveyance direction (process direction of the image forming apparatus) relating to the relative positional relationship between the image on the intermediate transfer belt 101 and the recording material P and the direction (image). Variation in the scanning direction of the forming apparatus). Further, it is a variation in the process direction and the scanning direction with respect to the recording material P dimension.

  In addition, a part of the toner in the added area outside the recording material P during the secondary transfer adheres to the secondary transfer roller 102. Since the adhered toner can cause the backside of the recording material P to be stained, it is removed by the secondary transfer roller cleaner 122 that is in contact with the secondary transfer roller 102.

  As shown in FIG. 5, on the recording material P that has been subjected to the secondary transfer process in the secondary transfer portion, toner is not only present on the surface but also on a part of the paper surface Pa on the four sides surrounding the end portion. t is transferred. When the recording material P enters the fixing device 103, the toner ta on the paper core surface remains unfixed at the fixing nip portion and is offset on the surfaces of the fixing roller 130 and the pressure roller 131. appear. When the offset toner adheres to the surface of each roller, the recording material P is stained on the front and back surfaces. Therefore, cleaning rollers 132 and 133 are brought into contact with the surfaces of the fixing roller 130 and the pressure roller 131, respectively, and the toner attached to the surfaces of both the rollers is collected.

  However, if the fixing device configured as described above is used and the marginless printing operation is continued, the toner adhesion amount on each cleaning roller increases, and the toner on the cleaning roller flows backward to the fixing roller and the pressure roller, thereby recording. There is a concern that the problem of causing soiling of the material may occur.

In response to this, the following cleaning control method is disclosed (for example, see Patent Document 1). After a predetermined number of printing operations, the fixing device is idly rotated with the temperature controlled, the toner on the cleaning roller is intentionally made to flow backward to the fixing / pressure roller, and further the cleaning material is fed to the fixing nip portion. It is transported and passed. In this way, the toner adhering to the cleaning roller is collected again.
JP 2003-57985 A JP 2005-196096 A

  However, when the cleaning control method is applied to an image forming apparatus capable of performing marginless printing, there is a concern that the following problems may occur.

  In other words, when printing without margins using a recording material of a certain size, the area width in the scanning direction where the toner adheres on each cleaning roller is wider than the width of the recording material that has passed through. It may become. This is because the toner adhering to the surface of the cleaning roller is crushed and spread in the scanning direction by the action of the pressure in the cleaning nip formed by each cleaning roller and the fixing roller or pressure roller.

  On the other hand, when the recording material is conveyed in the fixing device during the marginless printing operation or when the cleaning material is conveyed in the fixing device during the cleaning control, the fixing device and the recording material or the cleaning material Variations in the scanning direction may occur in the relative positional relationship between the two.

  Even if a cleaning material having the same width as the recording material on which printing without margins is performed in this situation and the cleaning control is performed, a part of the toner adhering to the cleaning roller may not be recovered again. Even if it can, all the toner may not be collected again.

  This is a problem peculiar to marginless printing in which the toner remaining in the fixing device causes the recording material to become dirty in the subsequent printing operation.

  When marginless printing is performed with a recording material having the maximum sheet width of the apparatus, the area width in the scanning direction to which the paper dust toner adheres on each cleaning roller is larger than the maximum sheet passing width.

  Therefore, even when the cleaning control disclosed in Patent Document 1 described above is performed using a recording material having the maximum sheet passing width as the cleaning material, the offset toner that has flowed back and adhered to the fixing / pressure roller is completely recovered. There is concern that it cannot be done.

  Therefore, the maximum width of the recording material that can be printed without margins should be set narrower than the maximum paper width of the device, and the width of the cleaning material that can be passed through and the cleaning roller width should be wider than the maximum recording material width that can be printed without margins. good.

  However, for example, as disclosed in Patent Document 2, when the cleaning roller width is set longer than the maximum sheet width of the apparatus, the following problems are concerned.

  That is, it is conceivable that the toner attached on the cleaning roller spreads outside the maximum sheet width of the apparatus. In this state, if the toner on the cleaning roller is caused to flow back to the fixing / pressurizing roller and collected on the cleaning material, the toner outside the maximum paper width of the device is passed even if the cleaning material having the maximum paper width of the device is passed. Remains on the fixing / pressure roller.

  There is no means for removing the toner adhering outside the maximum sheet width of the fixing / pressure roller in this way. Therefore, there is a concern that these toners may enter the paper passing area to contaminate the recording material, or the fixing / pressing roller may be damaged when the apparatus is started in a state where the toner is fixed on the roller. Is done.

  In addition, when printing with margins or when cleaning during jam recovery is performed using a cleaning roller, there is a concern that the amount of toner that can be accumulated on the cleaning roller will quickly exceed the amount of toner that will cause a cleaning failure. .

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to satisfactorily perform cleaning control of a fixing unit and prevent contamination of a recording material in an image forming apparatus capable of performing marginless printing. And

In order to achieve the above object, the present invention provides:
Image forming means for forming an unfixed toner image on a recording material ;
A rotating member that forms a fixing nip portion; and a fixing unit that fixes a non-fixed toner image on the recording material while sandwiching and conveying the recording material at the fixing nip portion, and a cleaning member that contacts the rotating member .
Anda no-margin image formation mode for forming an image on the entire area of the serial Rokuzai, in an image forming apparatus that can perform, and the margin image formation mode for forming an image, leaving a margin on the edge portion of the recording material,
Wherein the width of the recording material of the maximum width that can be used in no-margin image formation mode W1, and the width of the recording material of the maximum width that can be used in the the margin image formation mode W2, WCP the width of the cleaning member, that, W1 <characterized by having a relationship of WCP <W2.

  According to the present invention, in an image forming apparatus capable of performing marginless printing, it is possible to satisfactorily control the cleaning of the fixing unit and prevent the recording material from being stained.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.

  FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus A according to Embodiment 1 of the present invention. FIG. 2 is a schematic diagram illustrating a connection state between the image forming apparatus A and the image transmission apparatus.

  The recording material that can be used in the image forming apparatus according to the present embodiment is up to A3 Nobi size of 320 mm wide × 450 mm long. The process speed is 117 mm / second. A printing speed of A4 horizontal feed can be 24 sheets / minute.

  As shown in FIG. 2, the image forming apparatus A of the present embodiment is connected to a personal computer 91 as an image transmission apparatus via a cable 92. The image data is transmitted from the personal computer 91 to the image forming apparatus A via the cable 92.

  The image forming apparatus A has a function of performing image formation on the recording material P by a marginless printing mode for performing printing without margins and a printing mode with margins for performing printing with ordinary margins. I have. Here, the marginless printing mode constitutes a first image forming mode in which an image is formed on the entire area of the recording material. The printing mode with a margin constitutes a second image forming mode in which an image is formed while leaving a margin at the end of the recording material.

<Configuration and operation of image forming apparatus>
The image forming apparatus A according to the present embodiment is configured as a four-drum, intermediate transfer type full-color printer.

  As shown in FIG. 1, the image forming apparatus A includes four color image forming units (image forming stations 10) 10a, 10b, and 10c of yellow (Y), magenta (M), cyan (C), and black (K). , 10d. Further, the image forming apparatus includes a transfer device including the intermediate transfer belt 1 as an intermediate transfer member, and a fixing device 3 as a fixing unit. Here, the image forming stations 10a to 10d and the transfer device constitute an image forming unit.

  Each of the image forming stations 10a, 10b, 10c, and 10d is configured as an image forming unit, and photosensitive drums (drum-shaped electrophotographic photosensitive members) 11a, 11b, 11c, and 11d as image bearing members are installed to be rotatable in the direction of the arrows. Has been.

  On the outer peripheral surfaces of the photosensitive drums 11a, 11b, 11c, and 11d, primary charging rollers 12a, 12b, 12c, and 12d for uniformly charging the photosensitive drum surfaces are disposed. Then, laser exposure units 13a, 13b, 13c, and 13d for exposing the surface of the photosensitive drum charged by the primary charging roller to laser light modulated in accordance with the image signal are exposed to the photosensitive drum with respect to the primary charging roller. It arrange | positions in the rotation direction downstream.

  Further, developing units 14a, 14b, 14c, and 14d are disposed downstream of the laser exposure unit in the rotation direction of the photosensitive drum. The developing units 14a, 14b, 14c, and 14d use the corresponding colors of yellow, magenta, cyan, and black toner (developer) for the electrostatic latent images of the respective colors on the surface of the photosensitive drum formed by laser exposure. develop.

Primary transfer rollers 15a, 15b, 1 that form primary transfer portions together with the photosensitive drums at positions (transfer positions) between which the photosensitive drums 11a, 11b, 11c, 11d sandwich the intermediate transfer belt 1.
5c and 15d are installed facing each other. Primary transfer power supplies 16a, 16b, 16c, and 16d are connected to the primary transfer rollers 15a, 15b, 15c, and 15d as primary transfer power supplies, and variable primary transfer voltages Vy, Vm, Vc, and Vk are applied to the primary transfer rollers 15a, 15b, 15c, and 15d, respectively. .

  The intermediate transfer belt 1 is stretched and installed on three rollers, a driving roller 1a, a tension roller 1b, and a secondary transfer counter roller 1c. The intermediate transfer belt 1 passes through the image forming stations 10a to 10d and passes through the photosensitive drums 11a to 11d. Is placed in contact. The intermediate transfer belt 1 is rotationally driven in the direction of the arrow shown in FIG. 1 by a driving roller 1a.

  Drum cleaners 17a, 17b, 17c, and 17d are installed downstream of the primary transfer rollers 15a, 15b, 15c, and 15d of the photosensitive drums 11a, 11b, 11c, and 11d. A belt cleaner 4 is disposed on the surface of the intermediate transfer belt 1.

  The image forming operation of the image forming apparatus configured as described above will be described using the yellow image forming station 10a as an example.

  The photosensitive drum 11a of the yellow station 10a has a photoconductive layer on the surface of an aluminum cylinder. Then, the following operation is performed in the process of rotating in the direction of the arrow shown in FIG. The surface is uniformly negatively charged by the primary charging roller 12a (charging potential = −600V), and then image exposure is performed by the laser exposure device 13a (surface potential after exposure = −200V), and the document is placed on the surface of the photosensitive drum 11a. An electrostatic latent image corresponding to the yellow image component is formed. This latent image is developed using negatively charged yellow toner by the developing device 14a, and the latent image is visualized as a yellow toner image (developer image).

  The obtained yellow toner image is primarily transferred onto the intermediate transfer belt 1 by applying a primary transfer voltage from the primary transfer power supply 16a to the primary transfer roller 15a. After the transfer, the transfer residual toner adhering to the surface of the photosensitive drum 11a is removed by the drum cleaner 17a, and used for the next image formation.

  The above image forming operation is performed at a predetermined timing in each of the image forming stations 10a to 10d, and the toner images on the photosensitive drums 11a to 11d are sequentially superposed on the intermediate transfer belt 1 at the respective primary transfer portions to perform primary transfer. To do.

  In the full color mode, the toner images are sequentially transferred to the intermediate transfer belt 1 in the order of yellow, magenta, cyan, and black. In the single color or 2-3 color mode, the toner images of the necessary colors are as described above. Transcribed in the same order. Thereafter, the four-color toner images on the intermediate transfer belt 1 are transferred to the secondary transfer roller 2 that is grounded with the intermediate transfer belt 1 sandwiched between the intermediate transfer belt 1 and the intermediate transfer belt 1 as shown in FIG. It is moved to a secondary transfer portion (secondary transfer nip portion) constituted by contacting the transfer counter roller 1c.

  Then, a secondary transfer voltage is applied to the secondary transfer roller 2 from the secondary transfer power source 21 onto the recording material P supplied at a predetermined timing by the feeding roller 9, so that the secondary transfer is collectively performed. .

  The recording material P on which the unfixed toner image that has passed through the secondary transfer portion is placed is conveyed to the fixing device 3 and is composed of a fixing roller 30 as a heating member and a pressure roller 31 as a pressure member. By being nipped and conveyed at the nip portion, it is heated and pressurized to form a permanently fixed image. Further, the recording material P discharged from the fixing device 3 is discharged to a discharge tray 8 outside the device. The fixing roller 30 and the pressure roller 31 are rotatably provided in the fixing device 3.

  FIG. 3 is a schematic perspective view showing a recording material cassette 5 as recording material holding means. Hereinafter, the recording material cassette 5 will be described with reference to FIG.

  The recording material P includes a photosensitive material drum 11a to 11d, an intermediate transfer belt 1, a fixing roller 30, a pressure roller 31, and cleaning rollers 32 and 33 in a longitudinal direction by a pair of longitudinal position regulating plates 52 in the recording material cassette 5. The centers (centers in the scanning direction) are aligned and accumulated.

  As a result, the recording material P conveyed from the recording material cassette 5 is aligned with the photosensitive drums 11a to 11d, the intermediate transfer belt 1, the fixing roller 30, the pressure roller 31, and the cleaning rollers 32 and 33 in the longitudinal center. In this state, it is inserted into the secondary transfer portion and the fixing nip portion.

  That is, the image forming apparatus of this embodiment has a so-called central reference configuration. The recording material P taken out from the recording material cassette 5 by the pickup roller pair 51 is transferred at a predetermined timing synchronized with the toner image on the intermediate transfer belt 1 by the conveying roller 61 of the feeding device 6 and the feeding roller 9. It is inserted into the next transfer section. Here, in this embodiment, the pickup roller pair 51, the conveying roller 61 of the feeding device 6, and the feeding roller 9 constitute a conveying means for conveying the cleaning material in the discharge cleaning mode described later. Yes.

  FIG. 4 is a diagram showing a region to be added to the recording material P. FIG. 5 is a diagram illustrating a state where paper dust toner is attached. FIG. 6 is a diagram illustrating offset toner on the surfaces of the fixing roller 30 and the pressure roller 31.

  When performing printing without margins on the recording material P in this image forming apparatus, a mask area E that determines a printing area in the recording material P when performing printing with ordinary margins, as shown in FIG. The area B is larger than the recording material P by the added area B. Here, in the present embodiment, the additional region B has a width of 2 mm for each of the front end ET, the rear end EB, the left end EL, and the right end ER of the recording material P as shown in FIG.

  Then, an image including the image portion of the added area B is formed on the photosensitive drum, and this is transferred onto the recording material P via the intermediate transfer belt 1 to obtain a marginless print image.

  Note that a part of the toner in the added area outside the recording material P during the secondary transfer adheres to the secondary transfer roller 2. The adhered toner is removed by the secondary transfer roller cleaner 22 in contact with the secondary transfer roller 2.

  On the other hand, on the recording material P that has been subjected to the secondary transfer process in the secondary transfer portion, as shown in FIG. 5, not only the surface but also a paper sheet that is a cut surface portion of the surrounding four sides surrounding the end portion. The toner t is also transferred to a part of the surface Pa. When the recording material P enters the fixing device 3, as shown in FIG. 6, the toner ta on the paper surface remains unfixed at the fixing nip portion, and the fixing roller 30 and the pressure roller 31 are not fixed. There is a concern that an offset phenomenon occurs on the surface. When the offset toner adheres to the surface of each roller, the recording material P is stained on the front and back surfaces.

  Here, FIG. 7 shows an example of a fixing device in the present embodiment.

  In order to prevent the above-described recording material contamination, the fixing roller 30 and the pressure roller 31 of the fixing device of this embodiment can be selectively brought into contact with and separated from the fixing and pressure rollers, respectively. The cleaning rollers 32 and 33 as collection means are rotatably provided. The configuration of the fixing device and the contact / separation mechanism of the cleaning rollers 32 and 33 will be described later.

  When these cleaning rollers come into contact with the fixing / pressure roller, the toner adhering to the surface of the fixing / pressure roller is collected on the cleaning rollers 32 and 33. This operation is hereinafter referred to as a fixing / pressure roller cleaning operation.

  In this way, a full-color image without margins on which toner images of four colors are transferred and fixed is obtained on the recording material P.

<Detailed description of fixing device>
Here, the configuration of the fixing device according to the present embodiment will be described in detail with reference to FIG.

  The fixing roller 30 is provided with a 2 mm thick silicone rubber elastic layer having heat resistance and low hardness on an iron core bar having an outer diameter of 46 mm and a thickness of 2 mm, and further a PFA resin layer having a thickness of 50 μm is provided thereon. The interior is heated by a heater 94.

  The temperature of the fixing roller 30 is controlled by a known control method as follows so that the surface temperature becomes a predetermined temperature (for example, about 180 ° C.). That is, the surface temperature of the fixing roller 30 is detected by a temperature detection element (not shown) provided for the fixing roller 30, and the temperature control circuit operates the heater intermittently.

  On the other hand, the pressure roller 31 that rotates in pressure contact with the fixing roller 30 is provided with a 2 mm thick silicone rubber elastic layer having heat resistance and low hardness on an iron core bar having an outer diameter of 44 mm and a thickness of 2 mm. It has a structure in which a PFA resin layer having a thickness of 50 μm is provided thereon. However, there is no heater inside. The pressure roller 31 is brought into contact with the fixing roller 30 with a pressure of 980 N by springs 81 provided at both ends.

  The cleaning rollers 32 and 33 are aluminum metal rollers and have an outer diameter of 10 mm. In addition, contact / separation with respect to the fixing roller 30 and the pressure roller 31 can be selected. The applied pressure at the time of contact is 19.6 N.

  The cleaning roller of this embodiment contacts the fixing / pressure roller only during the fixing / pressure roller cleaning operation and the discharge cleaning operation (discharge cleaning mode). Here, fixing and pressure roller cleaning refers to the collection of paper dust adhering to the fixing and pressure roller by performing marginless printing during the printing operation (image forming operation) in the marginless printing mode. To do. The discharge cleaning means that the toner accumulated on the cleaning roller is caused to flow backward on the fixing / pressure roller and collected and removed by a cleaning material. These cleaning operations are controlled and executed by a printer controller as a control means, and a detailed description of the cleaning operation will be described later.

  FIG. 8 is a view for explaining the shape of the cleaning roller 32.

  As shown in FIG. 8, rotation shaft portions 32 c are provided at both ends of the cleaning roller 32, and are rotatably supported by a bearing (not shown) provided in the fixing device. The effective length WCP of the roller excluding the rotation shafts at both ends (the width WCP of the portion where the cleaning roller 32 contacts the fixing roller 30) is 305 mm. The cleaning roller 33 is exactly the same as the cleaning roller 32.

<Fixing and pressure roller cleaning mechanism>
Here, the fixing / pressure roller cleaning mechanism of the cleaning rollers 32 and 33 and the operation thereof in the image forming apparatus of this embodiment will be described with reference to FIG.

  The cleaning roller 32 has a function of cleaning and collecting offset toner and the like attached to the outer peripheral surface (surface) of the fixing roller 30. Here, a solid aluminum roller is used as the cleaning roller 32. The same applies to the cleaning roller 33.

  When the center line average roughness of the surfaces of the cleaning rollers 32 and 33 in the present embodiment is Ra (c), it is set to satisfy 0.20 <Ra (c) ≦ 0.50 μm. On the other hand, when the center line average roughness of the surface of the fixing roller 10 is Ra (s), it is set to satisfy 0.05 <Ra (s) ≦ 0.20 μm.

  The surface roughness Ra (s) of the fixing roller 10 is set to the above value so that the toner on the recording material is not offset to the fixing roller during fixing. Further, the surface roughness Ra (c) of the cleaning rollers 32 and 33 is set to the above value so as to satisfy the relationship Ra (s) <Ra (c) and to ensure good cleaning properties.

  The cleaning roller 32 arranged in parallel with the fixing roller 30 is rotatably held at one end of the first link arm 70. The first link arm 70 is rotatably supported on the frame 84 by the first arm shaft 76, and is urged against the fixing roller 30 with a predetermined pressure by the first spring 82. The cleaning roller 32 is pressed against the surface of the fixing roller 30 by this urging force.

  The cleaning roller 33 disposed in parallel with the pressure roller 31 is rotatably held at one end of the second link arm 71. The second link arm 71 is rotatably supported on the pressure frame 79 by the second arm shaft 77 and is urged against the pressure roller 31 by a second spring 83 with a predetermined pressure. The cleaning roller 33 is pressed against the surface of the pressure roller 31 by this urging force.

  A pin 78 is formed at the other end of the second link arm 71 so as to be in contact with the cleaning separation cam 74 fixedly held by the cam shaft 72. Further, a contact portion 85 is formed at the other end of the first link arm 70 so as to contact the pin 78.

  Here, FIG. 9 shows an enlarged cross-sectional view around the cleaning cam.

  The cleaning separation cam 74 has two large-diameter portions 74 a that contact the outer peripheral surface of the pin 78 and push the pin 78 down, and two small-diameter portions 74 b that do not contact the pin 78, as cam surfaces on the outer peripheral surface.

  In a cleaning roller abutting / separating mechanism including a first link arm 70 having a cleaning roller 32, a second link arm 71 having a cleaning roller 33, and a cleaning separation cam 74 provided on the cam shaft 72, the cam shaft 72 Rotates clockwise. Then, the pin 78 is pushed down by the large-diameter portion 74 a of the cleaning separation cam 74 and rotates the second link arm 71 about the second arm shaft 77 in the clockwise direction. As a result, the cleaning roller 33 is separated from the surface of the pressure roller 31.

  At the same time, the pin 78 contacts the contact portion 85 of the first link arm 70 to rotate the first link arm 70 counterclockwise about the first arm shaft 76. As a result, the cleaning roller 32 is separated from the surface of the fixing roller 30.

Note that reference numeral 73 in FIG. 9 denotes a pressure release cam that controls contact and separation between the fixing roller 30 and the pressure roller 31. The pressure release cam 73 has an elliptical shape, and is fixed to the cam shaft 72 so as to be coaxial with the cleaning separation cam 74. When the cam shaft 72 rotates clockwise and the large diameter portion of the pressure release cam 73 pushes down the pressure release roller 75 provided on the pressure frame 79, the fixing roller 30 and the pressure roller 31 are separated.

  FIG. 10 is a diagram for explaining a contact and separation state of each roller in the fixing device of this embodiment.

  By fixing the pressure release cam 73 and the cleaning separation cam 74 to the cam shaft 72 as shown in FIG. 9, in the apparatus of this embodiment, the contact / separation of the fixing / pressure roller and the contact / separation of the cleaning roller are related. Three states of state I to state III shown in FIG. 10 can be selected.

In the present embodiment, the cleaning rollers 32 and 33 are brought into contact with the fixing roller 30 and the pressure roller 31, respectively, only when printing without margins is performed (state I).
The offset toner on the fixing roller 30 and the pressure roller 31 is cleaned.

After printing without margins, the cleaning rollers 32 and 33 are separated from the fixing roller 30 and the pressure roller 31 again (state III). When printing with margins, printing is performed in status II.

<Regulation of recording material size and cleaning roller length>
FIG. 11 is a diagram showing the relationship between the size of the recording material P and the length (width) of the cleaning roller 32.

  In the image forming apparatus of the present embodiment, the size of the recording material set in the recording material cassette 5 is detected by a known detection means.

  Here, in the following description, when the recording material is conveyed in the image forming apparatus, the size in the scanning direction (direction perpendicular to the recording material conveyance direction (width direction)) is the “width” of the recording material, and the process direction The size in (recording material conveyance direction) is the “length” of the recording material. In this case, the width of the recording material that can be set in the image forming apparatus is in the range of 100 mm to 320 mm, and the length is in the range of 148 mm to 450 mm.

  In the image forming apparatus of the present embodiment, when the user transmits image data from the personal computer 91, it is possible to set whether to perform the printing operation in the marginless printing mode or the printing operation in the margining mode. When the marginless printing mode is used, a final image printed on the entire surface of the recording material P is obtained. When the margining printing mode is used, the leading edge and trailing edge of the recording material P are obtained. A final image in which a margin of 5 mm width is formed at the left end and the right end is obtained.

  Here, in this image forming apparatus, the maximum width W1 of the recording material that can be operated in the marginless printing mode is 297 mm (corresponding to the width at the time of A4 size lateral feeding or A3 size recording material passing). In contrast, since the effective length WCP of the cleaning rollers 32 and 33 is 305 mm as described above, the paper toner offset on the surfaces of the fixing roller 30 and the pressure roller 31 can be reliably collected.

  On the other hand, the maximum width W2 of the recording material that can be operated in the margin printing mode (maximum recording material width that can be passed through the image forming apparatus of the present embodiment) corresponds to the width when passing through the recording material of A3 size. ).

As the cleaning material used in the image forming apparatus according to the present embodiment when the above-described discharge cleaning control is performed, a white paper A3 Novi size having a width WCL of 320 mm (= the maximum recording material width W2 operable in the print mode with a margin). Use plain paper. This cleaning is set in the recording material cassette 5, and the paper dust toner discharged from the cleaning roller to the fixing / pressurizing roller can be reliably collected by using this cleaning.

These can be expressed simply as shown in FIG.
W1 <WCP <W2
WCL = W2
These two relationships are satisfied in the image forming apparatus of this embodiment.

  Here, the reason why the effective length WCP of the cleaning rollers 32 and 33 is set smaller than the maximum recording material width W2 will be described.

  Consider a case where the effective length WCP of the cleaning rollers 32 and 33 is longer than 320 mm (= W2).

  In this case, the paper dust toner adhering to the cleaning roller during marginless printing may spread outside the maximum recording material width W2.

  Even if the toner that spreads outside the maximum recording material width W2 on the cleaning roller is caused to flow back to the fixing / pressurizing roller by the above-described discharge cleaning control and is collected by the cleaning material, the following may be caused. That is, even when a cleaning material having the maximum recording material width W2 of the apparatus is passed, toner outside the maximum recording material width W2 of the apparatus remains on the fixing / pressure roller.

  There is no means for removing the toner adhering outside the maximum recording material width of the fixing / pressure roller in this way. Therefore, there is a concern that these toners may enter the paper passing area to contaminate the recording material, or the fixing / pressing roller may be damaged when the apparatus is started in a state where the toner is fixed on the roller. Is done.

  Therefore, in the image forming apparatus of this embodiment, the effective length WCP of the cleaning rollers 32 and 33 is set so as not to exceed the maximum recording material width W2.

  In the present embodiment, the setting contrary to the above-described relationship cannot be performed by the user on the personal computer 91. That is, when the width of the recording material set in the recording material cassette 5 is 297 mm or less, image data can be transmitted regardless of whether the printing mode without margins or the printing mode with margins is specified. However, when the width of the recording material set in the recording material cassette 5 is larger than 297 mm, the image data can only be transmitted by specifying the printing mode with margin.

<Fixing and pressure roller cleaning control for marginless printing>
Here, fixing and pressure roller cleaning control at the time of marginless printing in the image forming apparatus of the present embodiment will be described.

  FIG. 12 is a diagram illustrating an operation flowchart for printing without margins.

  When a print request is received from the personal computer 91, it is determined whether or not marginless printing is designated (S1). If marginless printing is designated, the recording material size W is a size that allows printing without margins (W ≦ 297 mm). (S2). If it is determined that no margin printing is designated, a margin printing operation is executed (S15).

If the recording material size is a size that allows printing without margins, the marginless printing operation is started, and if the recording material size is inappropriate, an error is determined (S16).

  When the marginless printing operation is started, the cleaning rollers 32 and 33 are first brought into contact with the fixing / pressure roller (S3, the state transition from the state III to the state I described above), and the fixing device is driven to rotate and the print temperature. Key is started (S4). Thereafter, the recording material is fed from the cassette (S6), the recording material on which the toner image without margin is formed is passed through the fixing device, and a permanent image without margin is obtained (S7, S8).

  In the image forming apparatus of this embodiment, the number of pages on which marginless printing has been performed is counted by a marginless printing page number counter of a printer controller provided in the image forming apparatus (S5). As the recording medium, a memory (RAM, rewritable ROM, etc.) in the printer controller is used. At the start of the marginless printing operation, the value N of the marginless printing page number counter is confirmed, and the number n of pages for which marginless printing has been performed is added to this value N.

  In the marginless print counter addition value n determination process (S9) in the flowchart shown in FIG. 12, the addition value n is determined as follows.

  FIG. 13 shows a flowchart of the marginless print counter addition value n determination process.

  Here, the automatically detected length L of the recording material in the cassette 5 is confirmed (S21), and compared with the A4 size (transverse feed) length 210 mm (S22). If the length of the recording material is A4 size or less, the added value n is set to 1 (S23), and if the recording material is longer than the A4 size, the added value n is set to 2 (S24).

  The reason why the counter addition value is changed according to the length L of the recording material is that the paper dust toner on the left and right of the recording material always adheres to the same longitudinal position on the cleaning roller (unless the recording material size is changed). If the length of the recording material is long, the amount of toner adhering to the same longitudinal position on the cleaning roller is increased, and the deterioration of the cleaning property is promoted. Therefore, a large addition value is set for a long recording material.

  When the addition value n is determined in this way, the value obtained by adding the addition value n is updated as the value N of the new marginless print page number counter (S10).

  Thereafter, if double-sided printing is specified (Yes in S13), the recording material is reversed by a known method using an automatic double-side mechanism (not shown), and then fed again to print on the back surface of the recording material (S14). .

  If double-sided printing is not designated (No in S13) and no new print request has been received (No in S17), a print end process (post-rotation temperature adjustment, rotation stop) is performed, and the cleaning roller is separated (S18). ~ 20).

  If a new print request has been received (Yes in S17), the printing operation is continued.

  In the present embodiment, when a print request for printing with margins is received before the end of printing without margins, printing with margins is performed with the cleaning roller in contact (counted to the value N of the page number counter without margins). .

  In this embodiment, the processing is performed in this way in order to omit the transition time from marginless printing to printing with margins. However, printing with margins may be started after completion of marginless printing.

<Discharge cleaning control (discharge cleaning mode)>
In the marginless printing operation, if the value N of the marginless printing page number counter exceeds 1k (1000) pages (Yes in S11), a message prompting execution of ejection cleaning is displayed (S12).

  On the personal computer 91, a single sheet of plain A3 size paper (width 320 mm × length 450 mm) as a cleaning material is set in the recording material cassette 5 and the personal computer is operated to start discharge control. Message is displayed. When the user follows this message, a discharge execution request is sent to the image forming apparatus, and a sequence for recovering the toner on the cleaning roller onto the cleaning material starts.

  FIG. 14 is a diagram illustrating an operation flowchart of the discharge cleaning control.

  When the ejection cleaning execution request is received, it is confirmed whether the recording material size of the recording material cassette 5 is A3 nobi size (width 320 mm × length 450 mm) (S31, 32). Here, the control means for executing S31 and the sensor for detecting the size of the recording material in the recording material cassette 5 constitute detection means, and the control means for executing S32 constitutes judgment means.

  If the recording material size is the above size, ejection cleaning control is started (becomes executable).

  An error occurs if the recording material size is incompatible. Then, a message is displayed again to set a sheet of plain A3 paper (width: 320 mm x length: 450 mm) as a cleaning material in the recording material cassette 5 and to perform a personal computer operation for discharging and starting cleaning control. It is displayed (S44).

  When the discharge cleaning control is started, the cleaning rollers 32 and 33 are first brought into contact with the fixing roller 30 and the pressure roller 31 (S33), and then fixed at a control temperature (predetermined temperature state) 180 ° C. The idle rotation of the apparatus is performed for 60 seconds (S34 to 37). At this time, the toner on the cleaning roller is discharged onto the fixing / pressure roller according to the following principle. Here, the control means for executing S33 to S37 constitutes a moving means.

  By causing the cleaning rollers 32 and 33 to contact the fixing roller 30 and the pressure roller 31 to perform idle rotation, the cleaning rollers 32 and 33 are heated to substantially the same temperature as the fixing roller and the pressure roller, respectively.

  Here, attention is paid to the cleaning roller 32 and the fixing roller 30.

When printing without margins,
Fixing roller temperature> cleaning roller temperature, and
Fixing roller surface roughness Ra (s) <Cleaning roller surface roughness Ra (c)
Therefore, the offset toner on the fixing roller is collected on the cleaning roller.

However, when the idle rotation is performed, as described above,
The fixing roller temperature is equal to the cleaning roller temperature. Further, since the surface of the cleaning roller 32 has no coating layer and remains a metal, the thermal conductivity to the toner is higher than that of the fixing roller.

For these reasons, the toner viscosity on the fixing roller 30 side is higher than that on the cleaning roller 32 side at the contact portion between the fixing roller 30 and the cleaning roller 32. Therefore, the toner tends to adhere to the surface of the fixing roller. The same phenomenon occurs between the cleaning roller 33 and the pressure roller 31.

  In this embodiment, the toner accumulated on the cleaning rollers 32 and 33 due to the above phenomenon can be discharged to the fixing roller 30 and the pressure roller 31.

  The idle rotation time of the fixing device is counted by a timer, and when the count value TR reaches 60 sec, a recording material as a cleaning material is fed from the recording material cassette 5 (S38). In this way, the toner discharged onto the fixing / pressure roller as described above is collected on the cleaning material.

  When the cleaning material is discharged from the apparatus (S39), the printing end process (post-rotation temperature adjustment, rotation stop) is performed, and the cleaning roller is separated (S40, 41).

  When the above operation is completed, the value N of the blank page number counter is reset (N = 0) (S42), and a message notifying the end of the discharge cleaning is displayed (S43).

  By periodically performing such discharge cleaning, a good cleaning property can be ensured over a long period without providing a mechanism for collecting the toner adhering to the cleaning roller.

<Cleaning when JAM occurs>
The fixing device cleaning (jam processing cleaning mode) when a recording material jam (paper jam) occurs during the image forming operation of the image forming apparatus of this embodiment will be described.

  When a jam occurs, the image forming apparatus stops urgently, and the user removes the jammed paper and the residual paper in the apparatus and performs jam processing. After the jam processing, a large amount of offset toner adheres to the fixing roller and the pressure roller.

  In this embodiment, when the offset toner is removed, the offset toner is not collected on the cleaning rollers 32 and 33 but is directly collected on the cleaning material by passing the cleaning material.

  This is because when the offset toner at the time of jam is collected on the cleaning roller, the toner on the cleaning roller immediately exceeds the accumulation limit amount, and the toner is fixed and flows backward onto the pressure roller during printing without margins. This is because of concern.

  Therefore, at the time of jam recovery in this embodiment, by collecting the offset toner directly on the cleaning material as described above, the frequency of performing the above-described discharge cleaning can be reduced, and usability can be improved. .

Assuming that the width of the recording material at the time of jam occurrence is W, and the width of the cleaning material is WCL as described above, if a jam occurs during printing without margins (in the jam processing cleaning mode),
W <WCL
This recording material is used as a cleaning material.

In the present embodiment, on the personal computer 91 as a notification means,
W <WCL
A message prompting the user to use a recording material satisfying the condition as a cleaning material is displayed.

  In this embodiment, plain paper of A3 size (width 320 mm × length 450 mm) set in the recording material cassette 5 is used as a cleaning material.

  In this way, all of the toner fixed from the jammed paper and offset to the pressure roller can be reliably collected, including paper dust toner adhered by marginless printing.

On the other hand, if a jam occurs during printing with margins,
W ≦ WCL
That is, the recording material may be used as a cleaning material.

  In this embodiment, the same size paper (W = WCL) as when a jam occurs is used as the cleaning material. Accordingly, the recording material set in the recording material cassette selected at the time of printing may be passed as a cleaning material as it is.

As described above, in this embodiment, the relationship between the maximum recording material width W1 that can be operated in the marginless printing mode, the maximum recording material width W2 that can be operated in the printing mode with margins, and the effective length WCP of the cleaning roller. W1 <WCP <W2
It is said. Further, only when printing without margins is performed, fixing by the cleaning roller and pressure roller cleaning are performed.

  Accordingly, the paper toner attached to the fixing and pressure roller by the marginless printing operation can be reliably collected by the cleaning roller.

  By adopting such a configuration and operation, it is possible to provide an image forming apparatus that can maintain good cleaning performance for a long period of time.

  In this embodiment, the fixing roller and the pressure roller are cleaned by the cleaning roller only at the time of printing without margins, and the toner adhering to the fixing and pressure roller when a jam occurs is directly collected by the cleaning material. Therefore, the life of the cleaning means can be extended, and the recording material can be reliably prevented from being contaminated for a long period of time.

  In addition, the width of the cleaning material used for cleaning when a jam occurs is selected according to the printing mode (with or without margins) and the recording material width at the time of printing. Can be prevented.

In the present embodiment, the cleaning material width WCL used during the discharge cleaning control is
WCL = W2
However, the present invention is not limited to this. The cleaning material width WCL is the maximum width of the recording material that can be operated in the marginless printing mode in order to obtain the effect of collecting the paper toner attached to the pressure roller by the marginless printing operation with the cleaning roller. It may be larger than W1. In this case, in S32 of the discharge cleaning control shown in FIG.
W1 <WCL
When it is determined that the above is satisfied, the discharge cleaning control may be executed. In addition, since the cleaning material larger than the width W2 does not normally enter the recording material cassette, there is no need to set the upper limit of the cleaning material width WCL. However, when the cleaning material larger than the width W2 enters the recording material cassette. In consideration of the above, an upper limit of the width WCL may be set. In this case, in S32 of the discharge cleaning control shown in FIG.
W1 <WCL ≦ W2
When it is determined that the above is satisfied, the discharge cleaning control may be executed.

  The image forming apparatus according to the second embodiment of the present invention has the configuration shown in FIG. 1 as with the image forming apparatus according to the first embodiment. Further, the operation and components of the image forming apparatus are the same as those of the image forming apparatus of the first embodiment.

  The feature of this embodiment is that the recording material used as the cleaning material at the time of performing the ejection cleaning control is not necessarily the maximum width recording material that can be used in the printing mode with margins of the image forming apparatus as in the first embodiment. Is a point. That is, in this embodiment, the recording material used as the cleaning material when performing the discharge cleaning control is changed according to the usage history of the recording material on which the printing operation has been performed in the marginless printing mode of the image forming apparatus. It is characterized by.

  Also in the image forming apparatus of the present embodiment, the maximum width of the recording material that can be operated in the marginless printing mode is 297 mm (corresponding to the width at the time of A4 size lateral feeding or A3 size recording material passing). In addition, the maximum width of the recording material that can be operated in the margin printing mode is 320 mm (corresponding to the width when the A3 Nobi size recording material is passed).

  In the image forming apparatus of this embodiment, the number of pages on which marginless printing has been performed is counted by the same method as in Embodiment 1 by the printer controller in the image forming apparatus, and the recording used at that time is used. The maximum width W1m of the material is stored. Here, the printer controller constitutes a recording material width storage unit.

  When printing without margins is performed using a recording material of A4 size or less, it is counted as one page, and when printing is performed using a recording material of A4 size or more and A3 size or less, it is counted as two pages.

  When the number of marginless print pages counted in this way reaches 1k pages in total, the following message is displayed on the personal computer 91. That is, as a cleaning material in the recording material cassette 5, a sheet of plain white paper whose width WCL is wider than the maximum width recording material used during printing without margins is set, and discharge cleaning control is started. This message prompts the user to perform a personal computer operation.

  Table 1 below shows the relationship between the maximum width of the recording material used during marginless printing and the type of recording material displayed as a message as the recording material to be used as the cleaning material.

  When the user follows this message, a sequence for recollecting the toner on the cleaning roller onto the cleaning material is activated.

  FIG. 15 is a diagram illustrating an operation flowchart of the discharge cleaning control in this embodiment.

When the ejection cleaning execution request is received, the recording material size W of the recording material cassette 5 is compared with the maximum width W1m of the recording material on which marginless printing has been performed (S51 to 53). At this time,
W1m <W
If so (Yes in S53), the discharge cleaning control is started.

If the recording material size is incompatible, an error occurs and the width of the recording material cassette 5 as a cleaning material is W1m <W.
A message is displayed again to perform a personal computer operation for setting one sheet of plain white paper and starting discharge control (S54). The subsequent control is the same as in the first embodiment.

As described above, in the image forming apparatus of this embodiment,
W1m <WCL
The relationship is established.

Therefore, in this embodiment, even in the following cases, the cleaning control is performed using the cleaning material wider than the maximum width recording material used during the marginless printing, so that the cleaning roller is placed on the cleaning roller. All the adhered toner can be reliably recovered again. It continues the printing operation without margin using a recording material having a width capable of printing without margin, and the width of the adhesion area on the cleaning roller of the toner collected by each cleaning roller is the pressure of the pressure in the cleaning nip. This is a case where it has expanded with respect to the width of the recording material.

  Also, even if the following variation occurs during the marginless printing operation, as long as the above setting is satisfied, all the toner adhering to the cleaning roller can be reliably recovered by the cleaning control. . This is a variation (positional deviation) in the scanning direction that occurs in a relative positional relationship with the fixing device when the recording material is conveyed in the fixing device. Further, this is a variation (positional deviation) in the scanning direction that occurs in the relative positional relationship with the fixing device when the cleaning material is conveyed through the fixing device during the cleaning control using the cleaning material. It is also a variation in width that occurs in the dimensions of the recording material that performs printing without margins and the cleaning material that performs cleaning control.

  In addition, the selection range of the type of cleaning material used when performing the cleaning control is expanded, and the burden on the user when preparing the cleaning material is reduced.

As described above, in this embodiment, the width of the recording material to be used and the width of the cleaning material is set to W1 m, which is the maximum recording material width that has been used in the marginless printing mode, and the cleaning material used in the cleaning control. If the width of is WCL,
W1m <WCL
Is set. That is, the cleaning material width WCL is determined in accordance with the recording material width used during marginless printing, and is a width capable of collecting all the toner on the cleaning roller.

  As a result, the recording material having the maximum width that can be used in the printing mode with margins of the image forming apparatus is used as a cleaning material, and the toner adhered to the cleaning roller is reliably recovered again by the discharge cleaning control. Can prevent dirt.

Note that the image forming apparatus according to the present embodiment also has the same configuration as the image forming apparatus according to the first embodiment. That is, the relationship between the maximum recording material width W1 operable in the marginless printing mode, the maximum recording material width W2 operable in the marginal printing mode, and the effective length WCP of the cleaning roller is as follows.
W1 <WCP <W2
It is. Furthermore, fixing and cleaning with a pressure roller are performed only when printing without margins is performed.

  Therefore, as in the first embodiment, it is possible to provide an image forming apparatus that can maintain good cleaning properties for a long period of time.

  FIG. 16 is a schematic sectional view showing an image forming apparatus according to Embodiment 3 of the present invention.

  The image forming apparatus A ′ according to the present embodiment has the same configuration as the image forming apparatus A according to the first embodiment except that a plurality of recording material cassettes described in the first embodiment are provided. The description is abbreviate | omitted and the description is abbreviate | omitted.

  The image forming apparatus A 'according to the present exemplary embodiment includes a recording material cassette 5α, a recording material cassette 5β, and a recording material cassette 5γ in addition to the recording material cassette 5 as recording material holding means. The configuration of each recording material cassette is the same as the configuration shown in FIG.

  The longitudinal center of the recording material P is aligned with the photosensitive drums 11a to 11d, the intermediate transfer belt 1, the fixing roller 30, the pressure roller 31, and the cleaning rollers 32 and 33 by a pair of longitudinal position regulating plates in each recording material cassette. Accumulated. As a result, the recording material P taken out from each recording material cassette is stored in the state where the longitudinal centers thereof are aligned with the photosensitive drums 11a to 11d, the intermediate transfer belt 1, the fixing roller 30, the pressure roller 31, and the cleaning rollers 32 and 33. It is inserted into the next transfer portion and the fixing nip portion. That is, the image forming apparatus of the present embodiment also has a central reference configuration.

  The recording material P taken out from each recording material cassette by the pick-up roller pair 51, 51α, 51β, 51γ attached to each recording material cassette is fed with the conveying rollers 61, 61α, 61β, 61γ of the feeding device 6 and the feeding roller. 9 is inserted into the secondary transfer portion at a predetermined timing. The predetermined timing is a timing synchronized with the toner image on the intermediate transfer belt 1.

  Here, characteristics of the image forming apparatus according to the present embodiment will be described.

  In the image forming apparatus of this embodiment, a mechanism (not shown) (mechanical or optical) as a detection means for automatically determining the size (width) of the recording material set in each recording material cassette Is provided.

  The size information obtained by the above mechanism is stored by a printer controller in the image forming apparatus. For any recording material cassette, the width of the recording material that can be set is in the range of 100 mm to 320 mm, and the length is in the range of 148 mm to 450 mm.

  When transmitting image data from the personal computer 91, it is possible to specify a recording material (recording material cassette) to be used and a print mode with no margin or with a margin. In this image forming apparatus, Such a decision is made. That is, the printer controller determines which print mode can be specified for each recording material cassette based on the recording material size information set in each recording material cassette. Here, the determination of which print mode can be specified means that whether or not a printing operation is possible in the marginless printing mode and whether or not a printing operation is possible in the marginless printing mode are determined. The printer controller also constitutes a recording material width storage unit and a determination unit.

  In the first embodiment, when the discharge cleaning control is performed, the user sets a cleaning material of a predetermined size in the recording material cassette, and then starts the personal computer operation on the personal computer 91 to start the cleaning control. Was configured. On the other hand, in the image forming apparatus of this embodiment, a recording material set in a certain recording material cassette is automatically selected as a cleaning material used at the time of discharge cleaning control, and is automatically selected at the start of control. Used for.

  An example is described below.

  In Table 2, the recording material cassette 5 is set with A3 size recording material, the recording material cassette 5α is set with A4 lateral feed size, the cassette 5β is set with A3 full bleed size, and the cassette 5γ is set with A3 novi size recording material. Indicates. Here, the width of the recording material of A3 size is 297 mm, the width of the recording material of A4 lateral feed size is 297 mm, the width of the recording material of A3 full bleed size is 312 mm, and the recording material of A3 nobi size is 320 mm wide × 450 mm long. is there.

  In this case, when the user designates the recording material cassette 5 and the recording material cassette 5α on the personal computer 91 and transmits the image data, it is possible to designate either the printing with margin or the printing without margin. On the other hand, when image data is transmitted by specifying the recording material cassette 5β and the recording material cassette 5γ, it is not possible to specify the printing mode without margins, and it is possible to specify only the printing mode with margins.

  Here, when the printing operation is continued while using the recording material set in each recording material cassette in an arbitrary distribution, the number of pages on which marginless printing is performed by the printer controller is counted as in the first embodiment. The execution timing of the discharge cleaning control is determined.

  At this time, the recording material set in the recording material cassette 5β or the recording material cassette 5γ can be used as the cleaning material, but in this example, the recording material set in the recording material cassette 5γ is automatically conveyed and used. Is done.

  That is, in this example, as in the above-described embodiment, the user sets the cleaning material in the recording material cassette and does not perform the personal computer operation for starting the cleaning control. The recording material is automatically conveyed as a cleaning material. Then, discharge cleaning control is performed.

  The operations other than automatically selecting the recording material cassette in which the recording material used as the cleaning material is set as described above are the same as those in the above-described embodiment.

  In Table 3, the recording material cassette 5 is set to LETTER lateral feed size, the recording material cassette 5α is set to A4 horizontal feed size, the cassette 5β is set to A4 vertical feed size, and the cassette 5γ is set to B4 size recording material. Shows the case. Here, the width of the LETTER lateral feed size recording material is 279 mm, the width of the A4 lateral feed size recording material is 297 mm, the width of the A4 vertical feed size recording material is 210 mm, and the width of the B4 size recording material is 257 mm. .

  In this case, when the user designates the recording material cassette 5, the recording material cassette 5β, and the recording material cassette 5γ on the personal computer 91 and transmits the image data, any mode of printing with margins or printing without margins can be designated. is there. On the other hand, when the image data is transmitted by designating the recording material cassette 5α, it is impossible to designate the printing mode without margins, and it is possible to designate only the printing mode with margins.

  In this case, when the printing operation is continued while using the recording material set in each recording material cassette in an arbitrary distribution, the recording material set in the recording material cassette 5α is automatically set at a predetermined timing. It is transported and cleaning control is performed.

In any of the above cases, the relationship between the recording material used and the width of the cleaning material satisfies the following relationship. That is, the width of the largest recording material used in the marginless printing mode is W1t, the width of the largest recording material used in the printing mode with margins is W2t, and the width of the cleaning material used in the cleaning control is WCLt. ,
W1t <W2t = WCLt
Meet.

  Therefore, even if the printing operation is continued while using the recording material set in each recording material cassette in an arbitrary distribution, the following control is performed to perform good cleaning, and the recording material becomes dirty. Can be prevented. That is, in this case, a recording material as a cleaning material is automatically conveyed from a predetermined recording material cassette at a predetermined timing and cleaning control is performed, so that good cleaning can be performed and contamination of the recording material can be prevented. It can be done.

  Further, the troublesomeness that the user has to set the cleaning material in the recording material cassette when performing the cleaning control is also eliminated.

  As described above, the image forming apparatus of this embodiment has a plurality of recording material cassettes. Based on the width information of the recording material set in each recording material cassette, whether or not the printing operation in the marginless printing mode is possible using the recording material set in each recording material cassette, there is a margin. It is possible to determine whether or not the printing operation in the printing mode is possible.

Then, when the ejection cleaning control is performed, a recording material cassette in which a recording material to be used automatically is set is determined. That is, a recording material cassette that is determined not to be capable of printing in the marginless printing mode and is allowed to perform the printing operation in the marginal printing mode is determined, and when there are a plurality of recording material cassettes, The recording material cassette that holds the maximum width recording material is determined.

  As a result, the toner adhering to the cleaning roller can be reliably recovered again and the recording material can be prevented from being stained. Furthermore, it is possible to eliminate the inconvenience that the user has to set the cleaning material in the recording material cassette when performing the discharge cleaning control, and the convenience of the user when using the image forming apparatus can be improved.

Note that the image forming apparatus according to the present embodiment also has the same configuration as the image forming apparatus according to the first embodiment. That is, the relationship between the maximum recording material width W1 operable in the marginless printing mode, the maximum recording material width W2 operable in the marginal printing mode, and the effective length WCP of the cleaning roller is as follows.
W1 <WCP <W2
It is. Furthermore, fixing with a cleaning roller and pressure roller cleaning are performed only when marginless printing is performed.

  Therefore, as in the first embodiment, it is possible to provide an image forming apparatus that can maintain good cleaning properties for a long period of time.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to Embodiment 1. FIG. 1 is a schematic diagram illustrating a connection state between an image forming apparatus and an image transmission apparatus according to Embodiment 1. FIG. FIG. 3 is a schematic perspective view illustrating a recording material cassette of Example 1. In Example 1, it is a figure which shows the addition area | region with respect to a recording material. In Example 1, it is a figure which shows the adhesion state of paper dust toner. 4 is a diagram illustrating offset toner on the surfaces of a fixing roller and a pressure roller in Embodiment 1. FIG. 1 illustrates an example of a fixing device according to a first exemplary embodiment. In Example 1, it is a figure for demonstrating the shape of a cleaning roller. In Example 1, the expanded sectional view of a cleaning cam periphery is shown. FIG. 4 is a diagram for explaining a contact and separation state of each roller in the fixing device according to the first exemplary embodiment. 6 is a diagram illustrating a relationship between the size of a recording material and the length (width) of a cleaning roller in Embodiment 1. FIG. FIG. 9 is a diagram illustrating an operation flowchart when printing without margins in the first embodiment. FIG. 10 is a diagram illustrating a flowchart of a marginless print counter addition value n determination process in the first embodiment. FIG. 6 is a diagram illustrating an operation flowchart of discharge cleaning control in the first embodiment. FIG. 10 is a diagram illustrating an operation flowchart of discharge cleaning control in the second embodiment. 6 is a schematic cross-sectional view illustrating an image forming apparatus according to Embodiment 3. FIG. It is a schematic sectional drawing which shows the conventional image forming apparatus.

Explanation of symbols

3 Fixing device 10 Image forming station 11 Photosensitive drum 30 Fixing roller 31 Pressure roller 32, 33 Cleaning roller P Recording material

Claims (4)

Image forming means for forming an unfixed toner image on a recording material ;
A rotating member that forms a fixing nip portion; and a fixing unit that fixes a non-fixed toner image on the recording material while sandwiching and conveying the recording material at the fixing nip portion, and a cleaning member that contacts the rotating member .
Anda no-margin image formation mode for forming an image on the entire area of the serial Rokuzai, in an image forming apparatus that can perform, and the margin image formation mode for forming an image, leaving a margin on the edge portion of the recording material,
Wherein the width of the recording material of the maximum width that can be used in no-margin image formation mode W1, and the width of the recording material of the maximum width that can be used in the the margin image formation mode W2, WCP the width of the cleaning member, that, W1 An image forming apparatus having a relationship of <WCP <W2. The apparatus is capable of executing a cleaning mode in which the toner adhered to the cleaning member is moved to the rotating body and the cleaning sheet is collected by passing the cleaning sheet through the fixing nip portion, and the cleaning mode collects the toner. 2. The image forming apparatus according to claim 1 , wherein WCL = W2 is set, where WCL is a width of the cleaning sheet used in the above. The apparatus is capable of executing a cleaning mode in which the toner adhered to the cleaning member is moved to the rotating body and the cleaning sheet is collected by passing the cleaning sheet through the fixing nip portion, and the cleaning mode collects the toner. If the width of the cleaning sheet used in W is WCL and the width of the maximum width of the recording material used in the marginless image forming mode before execution of the cleaning mode is W1m, the cleaning sheet is used in the cleaning mode within the range of WCL> W1m. The image forming apparatus according to claim 1 , wherein a cleaning sheet is selected . The apparatus can execute a cleaning mode in which the toner attached to the cleaning member is moved to the rotating body and the cleaning sheet is passed through the fixing nip portion to collect the toner with the cleaning sheet. Among the recorded recording materials, the recording material having the maximum width is set as the cleaning sheet used in the cleaning mode, and the recording material having the maximum width that can be set in the marginless image forming mode is set in the cleaning mode.
2. The image forming apparatus according to claim 1 , wherein the recording material is limited to a recording material having a width smaller than that of the cleaning sheet to be used .

Images