JP5213388B2 - Image forming apparatus - Google Patents

Description

  The present invention provides a permanent image on a transfer material by transferring a developer image (toner image) formed on an image carrier, for example, by an electrophotographic method to a transfer material, and then fixing the image. And the like.

  There is 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 onto a transfer material such as paper as a transfer medium. Further, as a color image forming apparatus, a plurality of image carriers are arranged in a line, and a toner image is sequentially formed on each image carrier, and the toner image is transferred to a transfer material directly or via an intermediate transfer member. The configuration is common.

  Also, with the recent diversification of printer demand, there is a growing demand for marginless printing, particularly in color image forming apparatuses. Conventionally, a large transfer material is used, and the margin is cut after printing. In order to simplify the cutting operation, there is an increasing need for so-called marginless printing in which a margin margin is not previously formed around the transfer material, and image printing is performed on the entire transfer material.

  However, if 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, causing a problem that the transfer material is soiled. Sometimes.

  On the other hand, some employ the following cleaning control method. After performing a certain number of printing operations, the fixing device is rotated idly with the temperature controlled, and the cleaning paper is transported to the fixing nip portion and passed therethrough to recollect the toner adhering to the cleaning roller. (For example, refer to Patent Document 1).

JP2003-57985A

  However, when the cleaning control method is applied to an image forming apparatus capable of performing marginless printing, the following problems occur. In other words, when printing without margins using a transfer material of a certain size, the width of the area in the scanning direction where the toner adheres on each cleaning roller is larger than the width of the transferred transfer material. It becomes. 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 transfer material is transported in the fixing device during the marginless printing operation, or when the cleaning paper is transported in the fixing device during the cleaning control, the fixing device and the transfer material or the cleaning paper Variations in the scanning direction may occur in the relative positional relationship between the two.

  In such a situation, if cleaning control is performed by passing a transfer material on which marginless printing has been performed and a cleaning paper having the same width, a part of the toner adhering to the cleaning roller is recovered again. I can. However, all toner cannot be collected again. In this case, the toner remaining in the fixing device causes the transfer material to become dirty in the subsequent printing operation.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to satisfactorily perform fixing control of a fixing device in an electrophotographic image forming apparatus capable of performing marginless printing to prevent transfer material from being stained.

In order to achieve the above object, a typical configuration according to the present invention includes an image forming unit that forms a toner image on a sheet fed from a sheet stacking unit, and heating while conveying the sheet on which the toner image is formed at a nip unit. A fixing unit that fixes the toner image on the sheet, and a cleaning unit that collects toner adhering to the fixing unit and cleans the fixing unit, and forcibly fixes the toner collected by the cleaning unit to the fixing unit. An image forming apparatus capable of executing a toner recovery mode in which the toner recovery sheet is transported to the nip portion and then the toner of the fixing unit is attached to the toner recovery sheet and recovered The image forming unit can form a toner image without a border and a toner image with a border on the sheet, and the maximum width of the sheet that can form a toner image without a border is There is a restriction that the toner collection sheet is smaller than the maximum width of a sheet capable of forming a toner image with a margin, and the toner recovery sheet is a toner having a margin larger than the maximum width of the sheet capable of forming a marginless toner image. It is a sheet capable of forming an image, and is fed from the sheet stacking unit .

  Since the present invention has the above-described configuration, in an electrophotographic image forming apparatus capable of performing marginless printing, it is possible to satisfactorily control the fixing device to prevent the transfer material from being stained.

[First Embodiment]
Hereinafter, an image forming apparatus according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an image forming apparatus 100 according to the first embodiment, and FIG. 2 is a view showing a connection between the image forming apparatus and an image transmitting apparatus.

[About schematic configuration of image forming apparatus]
An electrophotographic full-color image forming apparatus compatible with marginless printing will be described with reference to FIGS. 1 and 2. Here, marginless printing refers to an image forming method in an image forming mode in which an image is formed over the entire area of the transfer material. Accordingly, in the following description, an image forming mode for forming an image over the entire area of the transfer material is referred to as a marginless printing mode. An image forming mode in which an image is formed in a region excluding the predetermined region of the transfer material is referred to as a margin printing mode.

  In the image forming apparatus of the present embodiment, the maximum size of the transfer material that can be used is SRA3 (width 320 mm × length 450 mm). 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 100 according to the present embodiment is connected to a personal computer 101 as an image transmitting apparatus via a cable 102. The image data is transmitted from the personal computer 101 to the image forming apparatus 100 via the cable 102.

  The image forming apparatus 100 performs, on the transfer material P, a marginless printing mode which is a first image forming mode for performing printing without margins, and a second image forming for performing printing with ordinary margins. It has a function to perform image formation by a printing mode with margins which is a mode. Here, the margin is a predetermined area set in advance in the transfer material. For this reason, an image forming mode in which an image is formed in an area excluding a predetermined area of the transfer material is referred to as a margin printing mode. The image forming apparatus has a function of performing image formation according to each image forming mode.

[Configuration and operation of image forming apparatus]
As an image forming apparatus of this embodiment, as shown in FIG. 1, a four-drum, intermediate transfer type full-color printer will be used. This image forming apparatus has four color image forming means (image forming stations 10) 10a to 10d of yellow (Y), magenta (M), cyan (C), and black (K), and further, as an intermediate transfer member. A transfer device including the intermediate transfer belt 1 and a fixing device (fixing means) 3.

  Each of the image forming stations 10a to 10d is unitized as an image forming unit, and a photosensitive drum 11 (drum electrophotographic photosensitive member) 11a to 11d, which is an image carrier, is installed to be rotatable in the direction of the arrow. Primary charging rollers 12a to 12d for uniformly charging the surfaces of the photosensitive drums are disposed on the outer peripheral surfaces of the photosensitive drums 11a to 11d, respectively. Laser exposure devices 13a to 13d that expose the surface of the photosensitive drum with laser light modulated in accordance with the image signal are disposed on the downstream side of the primary charging roller 12 in the rotational direction of the photosensitive drum. Further, on the downstream side of the laser exposure unit 13, development is performed by developing the electrostatic latent images of the respective colors on the surface of the photosensitive drum formed by laser exposure using toners of corresponding colors of yellow, magenta, cyan, and black. Containers 14a-14d are arranged.

  Primary transfer rollers 15a to 15d that form a primary transfer portion together with the photosensitive drum are disposed opposite to each other (transfer position) between the photosensitive drums 11a to 11d with the intermediate transfer belt 1 interposed therebetween. Primary transfer power sources 16a to 16d are connected to the primary transfer rollers 15a to 15d as primary transfer power sources, and variable primary transfer voltages Vy, Vm, Vc, and Vk are applied to the primary transfer rollers 15a to 15d, respectively.

  The intermediate transfer belt 1 is stretched and installed on three rollers, that is, a driving roller 1a, a tension roller 1b, and a secondary transfer counter roller 1c. 11d is placed in contact. The intermediate transfer belt 1 is driven to rotate in the direction of the arrow in the figure by a driving roller 1a. Drum cleaners 17a to 17d are installed downstream of the primary transfer rollers 15a to 15d of the photosensitive drums 11a to 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 formed on the surface of an aluminum cylinder, and the surface is uniformly negatively charged (charged potential) by the primary charging roller 12a in the process of rotating in the direction of the arrow. = −600V). Next, image exposure is performed by the laser exposure device 13a (surface potential after exposure = −200 V), and an electrostatic latent image corresponding to the yellow image component of the document is formed on the surface of the photosensitive drum 11a. This electrostatic latent image is developed using negatively charged yellow toner by the developing device 14a, and the electrostatic latent image is visualized as a yellow toner image.

  The obtained yellow toner image is primarily transferred onto the intermediate transfer bell 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 overlapped on the intermediate transfer belt 1 in the respective primary transfer portions to be primary. Transcript. 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 secondary images in which the secondary transfer roller (transfer means) 2 is grounded with the intermediate transfer belt 1 interposed therebetween as the intermediate transfer belt 1 rotates in the arrow direction. It is moved to the secondary transfer portion in contact with the transfer counter roller 1c. A secondary transfer voltage is applied from the secondary transfer power source 21 to the secondary transfer roller 2 on the transfer material P supplied thereto at a predetermined timing by the feeding roller 9. As a result, the toner images are secondarily transferred onto the transfer material P all at once. The transfer material P on which the unfixed toner image that has passed through the secondary transfer nip is placed is conveyed to the fixing device 3 and is heated and pressurized to form a permanent fixed image. Further, the transfer material P discharged from the fixing device 3 is discharged to a discharge tray 8 outside the device.

  The transfer material cassette 5 will be described with reference to FIG. FIG. 3 is a perspective view of the transfer material cassette 5.

  As shown in FIG. 3, the transfer material P is accumulated by aligning each rotary body and the longitudinal center (center in the scanning direction) by a pair of longitudinal position regulating plates 52 in the transfer material cassette 5. The rotating bodies are the photosensitive drums 11a to 11d, the intermediate transfer belt 1, the fixing roller 30, the pressure roller 31, and the cleaning rollers (collecting means) 32 and 33.

  As a result, the transfer material P taken out from the transfer material cassette 5 is aligned with the longitudinal centers of 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 this state, it is inserted into the secondary transfer nip portion and the fixing nip portion. That is, the image forming apparatus according to the present embodiment has a so-called central reference configuration. The transfer material P taken out from the transfer 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 transport roller 61 of the feeding device 6 and the feeding roller 9. It is inserted into the next transfer section.

  Here, a region to be added to the transfer material P will be described. FIG. 4 is a diagram showing a region where the transfer material P is applied.

  When printing without margins on the transfer material P in this image forming apparatus, as shown in FIG. 4, the mask area E that determines the print area in the transfer material P is large when printing with normal margins is performed. Become. More specifically, the transfer material P is larger than the transfer material P by the amount of the additional region B having a width of 2 mm for each of the front end portion, the rear end portion, the left end portion, and the right end portion. Thus, by forming an image including the image portion of the added region B on the photosensitive drum, the image transferred onto the transfer material P via the intermediate transfer belt 1 becomes a marginless print image. .

  Note that a part of the toner in the added area outside the transfer 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 that is in contact with the secondary transfer roller 2.

  On the other hand, on the transfer material P that has finished the secondary transfer process in the secondary transfer portion, not only the surface but also a part of the paper surface that is the cut surface portion of the four sides surrounding the end portion shown in FIG. Also, the toner is transferred. FIG. 5 is a perspective view showing a state where paper dust toner is attached.

  When the transfer material P enters the fixing device 3, as shown in FIG. 6, the toner on the surface of the paper remains unfixed at the fixing nip, and on the surfaces of the fixing roller 30 and the pressure roller 31. The phenomenon of offsetting occurs. FIG. 6 shows a state where the toner is offset.

  When the offset toner adheres to the surface of each roller, the transfer material P becomes dirty on the front and back surfaces. Here, the fixing roller 30 and the pressure roller 31 are in contact with cleaning rollers 32 and 33, respectively, and using these, toner adhering to the surfaces of both rollers is collected.

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

[Components of image forming apparatus]
In this embodiment, a negatively chargeable OPC drum having a diameter of 30.6 mm is used as the photosensitive drum 11 (11a to 11d). Further, a charging voltage in which an AC component is superimposed on a DC component is applied to the primary charging roller 12 (12a to 12d), and the surface of the photosensitive drum 11 is uniformly charged to about −600 V regardless of the environment. The laser exposure unit 13 (13a to 13d) includes a near-infrared laser diode having a wavelength of 760 nm and a polygon mirror that scans the photosensitive drum 11 with laser light. By using the laser exposure device 13, the surface potential of the photosensitive drum 11 is lowered to −200 V at the exposure portion, and an electrostatic latent image having this as an image portion is formed.

  The developing unit 14 (14a to 14d) is a developing type developing unit using non-magnetic toner (non-magnetic one-component developer). As the non-magnetic toner, a polymerized toner having a particle size of 6 μm having a core / shell structure containing wax was used. This non-magnetic toner is coated and carried on the surface of the developing sleeve by a coating roller. The toner layer thickness is regulated by an elastic blade as the developing sleeve rotates. Thereafter, the toner on the developing sleeve is transported to a developing unit facing the photosensitive drum 11, and electrostatic on the photosensitive drum 11 (11a to 11d) is generated by a developing voltage in which an AC component is superimposed on a DC component applied to the developing sleeve. Adhere to the exposed part of the latent image. Thus, the electrostatic latent image is reversely developed.

The primary transfer roller 15 (15a to 15d) is formed by covering an 8 mm diameter cored bar with an EPDM conductive rubber layer in the longitudinal direction so as to have a diameter of 16 mm. Each cored bar is connected to the primary transfer power supply 16 (16a to 16d) via a power supply spring. The roller hardness of the primary transfer roller 15 is 35 ° in Asker C, and its resistance value is 1 × 10 ⁶ Ω.

The secondary transfer roller 2 is a roller having an outer diameter of 22.1 mm constituted by an aluminum cored bar having a diameter of 14.0 mm, a silicon rubber layer having a thickness of 4 mm, and a fluororesin layer having a surface thickness of 100 μm. The roller resistance value is set to 1 × 10 ⁸ Ω by adjusting the resistance of silicon rubber and fluororesin. The hardness of the secondary transfer roller 55 is 45 ° (ASKER-C). The secondary transfer roller 2 also has a metal core connected to a secondary transfer power source 21 of a high-voltage power source via a power supply spring.

  A urethane rubber blade is used as the secondary transfer roller cleaner 4.

  The driving roller 1a, the tension roller 1b, and the secondary transfer counter roller 1c are all made of a conductive roller made of aluminum having a diameter of 32 mm, and the cored bar portion is grounded via a power supply spring.

The intermediate transfer belt 1 is a single-layer seamless endless belt made of polyimide resin, the resistance of which is adjusted by carbon dispersion, and has a thickness of 75 μm and a peripheral length of 1115 mm. In accordance with JIS-K6911, in order to obtain good contact between the electrode and the surface of the belt, conductive rubber is used as the electrode, and the volume resistivity ρv of the intermediate transfer belt is measured using an Rvanto R8340 ultrahigh resistance meter. The surface resistivity ρs is measured. Thereby, a value of ρv = 5 × 10 ⁸ Ωcm is obtained when 100 V is applied for 10 seconds.

  The tension of the intermediate transfer belt 1 stretched around the three rollers 1a, 1b, 1c is 6 kgf. The distance between the driving roller 1a and the tension roller 1b is 500 mm. The primary transfer unit composed of the photosensitive drum 11 (11a to 11d) and the primary transfer roller 15 (15a to 15d) of each image forming station 10 (10a to 10d) is an intermediate transfer belt 1 between the rollers 1a and 1b. Arranged at even intervals on top. Each primary transfer roller 15 is brought into contact with the back surface of the intermediate transfer belt 1 with a pressure of 8.5 N by springs provided at both ends.

  The fixing roller 30 is provided with a 2 mm thick silicon 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. In addition, the inside is heated by a heater. The surface temperature of the fixing roller 30 is detected by a temperature detection element in contact with the fixing roller 30, and the temperature control circuit intermittently operates the heater so that the surface temperature becomes a predetermined temperature (for example, It is controlled to be about 180 ° C.).

  On the other hand, the pressure roller 31 that rotates in pressure contact with the fixing roller 30 is provided with a silicon rubber elastic layer having a heat resistance and a low hardness of 2 mm on an iron core 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 in contact with the fixing roller 30 with a pressure of 980 N by springs provided at both ends.

  The cleaning rollers 32 and 33 are metal rollers made of aluminum pipe. The pipe thickness is 2 mm and the outer diameter is 10 mm. Further, they are in contact with the fixing roller 30 and the pressure roller 31 with a pressure of 19.6 N, respectively.

[About cleaning control]
Here, the cleaning control of the cleaning rollers 32 and 33 in the image forming apparatus of the present embodiment will be described. The cleaning control is performed when the personal computer 101 issues a cleaning mode command. The image forming apparatus has a function of executing the cleaning mode.

  In the image forming apparatus of this embodiment, the number of pages on which marginless printing has been performed is counted by a printer controller (not shown) included in the image forming apparatus. The number of normally printed pages with margins is not counted. As the recording medium, a memory (RAM, rewritable ROM, etc.) in the printer controller is used. When printing without margins is performed using a transfer material of A4 size or smaller, it is counted as one page, and when printing is performed using a transfer material of A4 size or larger and A3 size or smaller, it is counted as two pages. However, when double-sided printing is performed on the same paper, when printing without margins is performed using a transfer material of A4 size or less, it is performed using a transfer material of 2 pages, A4 size or more and A3 size or less. Is counted as 4 pages.

  When the number of marginless print pages counted in this way reaches 1000 pages in total, a message is displayed on the personal computer 101. Specifically, first, a message is displayed to set one sheet of blank SRA3 size plain paper as a cleaning material (cleaning paper) in the transfer material cassette 5. Next, a message is displayed to perform a personal computer operation for starting the cleaning control.

  When the user follows this message, the sequence for recollecting the toner on the cleaning roller onto the cleaning paper is activated. In the image forming apparatus of this embodiment, first, idling is performed for 60 seconds in a heater control state at 180 ° C. during the printing operation. Thereby, the toner on each cleaning roller is forced to flow back onto the fixing roller and the pressure roller.

  In this manner, as much toner as possible on each cleaning roller that may cause image smearing due to backflow in the subsequent printing operation is caused to flow back to the surface of the fixing roller and the pressure roller as much as possible. Thereafter, the cleaning paper is automatically conveyed from the transfer material cassette 5 to the fixing nip and passed therethrough. Thus, the toner is collected again on the cleaning paper.

[Printable transfer material size]
In the image forming apparatus of the present embodiment, the user can set the size information of the transfer material set in the transfer material cassette 5 on the personal computer 101. When the transfer material is transported through the image forming apparatus, if the size in the scanning direction is the “width” of the transfer material and the size in the process direction is the “length” of the transfer material, transfer that can be set by this image forming apparatus The material has a width of 100 mm to 320 mm and a length of 148 mm to 450 mm. In the image forming apparatus according to the present embodiment, when the user transmits image data from the personal computer 101, it is possible to set whether to perform a printing operation in the marginless printing mode or a printing operation in the margining mode. When the marginless printing mode is used, a final image is obtained that is printed on the entire surface of the transfer material P. When the margin printing mode is used, the leading edge and trailing edge of the transfer material P are used. 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 transfer material that can be operated in the marginless printing mode is 312 mm (corresponding to the width when the A3 full bleed size transfer material is passed). The maximum width W2 of the transfer material that can be operated in the margin printing mode is set to 320 mm (corresponding to the width when the SRA3 size transfer material is passed). User can not do above. That is, when the width of the transfer material set in the transfer material cassette 5 is 312 mm or less, image data can be transmitted by specifying either the marginless print mode or the margin print mode. On the other hand, when the width of the transfer material set in the transfer material cassette 5 is larger than 312 mm, the image data can be transmitted only by specifying the print mode with margin.

  Further, as described above, in the present image forming apparatus, the cleaning paper that is set and used in the transfer material cassette 5 at the time of cleaning control is a plain white SRA3 size paper having a width WCL of 320 mm.

As described above, in the image forming apparatus of the present embodiment, as shown in FIG.
W1 <W2 = WCL
The relationship becomes true. Here, W1 is the maximum width of the transfer material operable in the marginless printing mode, W2 is the maximum width of the transfer material operable in the marginless printing mode, and WCL is the cleaning material used. The width of the paper. FIG. 7 shows the relationship between W1 and WCL.

  Therefore, in the image forming apparatus of the present embodiment, cleaning control is performed using a cleaning paper having a width of 320 mm. As a result, when the printing operation without a margin is continued using a transfer material having a maximum width of 312 mm capable of printing without a margin, the toner adhered on the cleaning roller can be reliably recovered. This is because the width of the adhesion area on the cleaning roller of the toner collected by each cleaning roller is larger than the width of the transfer material due to the action of the pressure in the cleaning nip during printing without margins. This is because it is wider than the width of the adhesion region.

  Further, during a printing operation without a margin using the transfer material, there may be a variation (position shift) in the scanning direction in the relative positional relationship with the fixing device when the transfer material is conveyed in the fixing device. . Also in this case, the width of the adhesion area on the cleaning roller of the toner collected by each cleaning roller is expanded with respect to the width of the transfer material. However, by performing cleaning control using the cleaning paper, similarly, the toner attached on the cleaning roller can be reliably recovered again.

  On the other hand, during the cleaning control using the cleaning paper, there may be a variation in the scanning direction (positional deviation) in the relative positional relationship with the fixing device when the cleaning paper is conveyed in the fixing device. . In this case, the area in the scanning direction in which the toner can be collected again by the cleaning paper changes, but as long as the above setting is satisfied, the cleaning control ensures that all the toner adhering to the cleaning roller is collected again. can do.

  Further, there may be width variations in the dimensions of the transfer material that performs marginless printing and the cleaning paper that performs cleaning control. This is because as long as the above setting is satisfied, the toner attached on the cleaning roller can be reliably recovered by the cleaning control.

  As described above, in the image forming apparatus according to this embodiment, the relationship between the transfer material used and the width of the cleaning paper is as follows. That is, the width of the maximum transfer material usable in the marginless printing mode is W1, the width of the maximum transfer material usable in the margin printing mode is W2, and the width of the cleaning paper used in the cleaning control is WCL. , W1 <W2 = WCL. For this reason, the toner attached on the cleaning roller can be reliably recovered by the cleaning control, and the transfer material can be prevented from being stained.

  In the image forming apparatus according to the present exemplary embodiment, the maximum width W2 of the transfer material that can be used in the margin printing mode and the width WCL of the cleaning paper used in the cleaning control have the same width (W2 = WCL), but is not limited to this. For example, even if W2 = WCL, if the WCL and the width W1 of the maximum transfer material that can be used in the marginless printing mode satisfy the relationship of W1 <WCL, the toner attached on the cleaning roller by the cleaning control is removed. Recovering can be ensured and contamination of the transfer material can be prevented.

However, assuming the action of pressure in the cleaning nip and other variations that may actually occur,
WCL-W1 ≧ 8mm
It is desirable that

  There are mainly three other variations. First, there is a variation in the main scanning direction of a relative positional relationship with the fixing device when the transfer material is conveyed in the fixing device. Next, there is a variation in the scanning direction of the relative positional relationship with the fixing device when the cleaning paper is conveyed in the fixing device. Finally, there is a variation in the width of the dimensions of the transfer material and the cleaning paper.

[Second Embodiment]
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 image forming apparatus according to the present embodiment is characterized by a transfer material used as cleaning paper when cleaning control is performed. In the above-described embodiment, the transfer material having the maximum width that can be used in the print mode with margins of the image forming apparatus is used. This is characterized in that the size of the transfer material is changed according to the usage history of.

  Also in the image forming apparatus of this embodiment, the maximum width of the transfer material that can be operated in the marginless printing mode is 312 mm (corresponding to the width when the A3 full bleed size transfer material is passed). The maximum width of the transfer material that can be operated in the print mode with margin is 320 mm (corresponding to the width when the SRA3 size transfer material is passed).

  The image forming apparatus according to the present exemplary embodiment includes a counting unit that counts the number of pages, and a transfer material use history storage unit that stores the width of the transfer material operated in the image forming mode. As a result, the number of pages on which marginless printing has been performed is counted by a printer controller (not shown) included in the image forming apparatus, and the maximum width W1m of the transfer material used at that time is stored.

  For example, when printing without margins is performed using a transfer material of A4 size or smaller, it is counted as one page, and when it is performed using a transfer material of A4 size or larger and A3 size or smaller, it is counted as two pages. However, when double-sided printing is performed on the same paper, when printing without margins is performed using a transfer material of A4 size or less, it is performed using a transfer material of 2 pages, A4 size or more and A3 size or less. Is counted as 4 pages.

  When the number of marginless print pages counted in this way reaches 1000 pages in total, a message is displayed on the personal computer 101 to perform a personal computer operation for starting the cleaning control. For example, the message is set as a cleaning paper in the transfer material cassette 5, and a sheet of plain white paper whose width WCLm is wider than the maximum width transfer material used during printing without margins is set and cleaning control is performed. A message to start is displayed.

  FIG. 8 is a chart showing the relationship between the width of the transfer material used during printing and the width of the transfer material of the cleaning paper. FIG. 8 is used to illustrate the relationship between the width of the maximum transfer material used during marginless printing and the type of transfer material displayed as a message as the transfer material to be used as the cleaning paper.

  When the user follows this message, the sequence for recollecting the toner on the cleaning roller onto the cleaning paper is activated. In the image forming apparatus of this embodiment, first, idling is performed for 60 seconds in a heater control state at 180 ° C. during the printing operation. Thereby, the toner on each cleaning roller is forced to flow back onto the fixing roller and the pressure roller. In this way, as much of the toner adhering to each cleaning roller that may cause image contamination due to backflow in the subsequent printing operation is caused to flow back to the surface of the fixing roller and pressure roller as much as possible. Thereafter, the cleaning paper is automatically conveyed from the inside of the transfer material cassette 5 to the fixing nip and passed therethrough, whereby the toner is collected on the cleaning paper.

As described above, in the image forming apparatus of the present embodiment,
W1m <WCLm
The relationship becomes true. Here, W1m is the maximum width of the transfer material used when marginless printing is performed, and WCLm is the width of the cleaning paper.

  In the image forming apparatus of the present embodiment, cleaning control is performed using a cleaning paper wider than the transfer material of the maximum width used during marginless printing, so that all toner adhering to the cleaning roller can be reliably recycled. It can be recovered. Even if the width of the adhesion area on the cleaning roller of the toner collected by each cleaning roller is larger than the width of the transfer material, the width of the cleaning paper is larger than the width of the toner adhesion area. Because it is wider.

  Further, according to the cleaning control of the present embodiment, during the marginless printing operation, the variation in the scanning direction (positional deviation) occurs in the relative positional relationship with the fixing device when the transfer material is conveyed in the fixing device. Even in this case, it is possible to reliably recover all the toner adhering to the cleaning roller.

In addition, during cleaning control using the cleaning paper, all toners are detected even if a variation (positional deviation) in the scanning direction occurs in the relative positional relationship with the fixing device when the cleaning paper is conveyed in the fixing device. Can be recovered again. Furthermore, even if there is a variation in the width of the transfer material that performs marginless printing or the size of the cleaning paper that performs cleaning control, all the toner can be collected again.

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

  As described above, the image forming apparatus according to the present embodiment has the following configuration. That is, the relationship between the width of the transfer material used and the cleaning paper is W1m, where W1m is the maximum width of the transfer material having a history of use in the marginless printing mode, and WCLm is the width of the cleaning paper used in the cleaning control. <WCLm. For this reason, the transfer material having the maximum width that can be used in the margin printing mode of the image forming apparatus may not be used as the cleaning paper. Thus, the toner attached on the cleaning roller can be reliably recovered by the cleaning control, and the transfer material can be efficiently prevented from being contaminated.

[Third Embodiment]
The image forming apparatus according to the third embodiment of the present invention has the configuration shown in FIG. FIG. 9 is a cross-sectional view of an image forming apparatus 200 used in the third embodiment.

  The image forming apparatus has the same configuration as that of the image forming apparatus 100 of the first embodiment, except that a plurality of transfer material cassettes described in the first embodiment are held.

  As shown in FIG. 9, the image forming apparatus 200 according to the present embodiment includes a transfer material cassette 5A, a transfer material cassette 5B, and a transfer material cassette 5C in addition to the transfer material cassette 5. The structure of each transfer material cassette is the same as the structure shown in FIG. The transfer material P is aligned with the longitudinal center of 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 transfer material cassette. Has been accumulated.

  Thus, the transfer material P taken out from each transfer material cassette is in a 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 secondary transfer nip portion and the fixing nip portion. That is, the image forming apparatus of this embodiment also has a central reference configuration. The transfer material P is taken out from each transfer material cassette by a pair of pickup rollers 51, 51A, 51B, 51C attached to each transfer material cassette. The transfer material P is inserted into the secondary transfer portion at a predetermined timing synchronized with the toner image on the intermediate transfer belt 1 by the transport rollers 61, 61A, 61B, 61C of the feeding device 6 and the feeding roller 9. The

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

  In the image forming apparatus of the present embodiment, the user can set the size information of the transfer material set in each of the transfer material cassettes 5, 5A, 5B, 5C on the personal computer 101. The size information is stored in a printer controller (not shown) attached to the image forming apparatus. In any transfer material cassette, the width of the transfer 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. Further, when transmitting image data from the personal computer 101, it is possible to specify a transfer material (transfer material cassette) to be used and a print mode with no margin or with a margin. However, in this image forming apparatus, it is determined which print mode can be designated for each transfer material cassette based on the transfer material size information set in each transfer material cassette stored in the printer controller.

  In the first embodiment, when the cleaning control is performed, the user sets a cleaning paper of a predetermined size in the transfer material cassette, and then starts the personal computer operation on the personal computer 101 to start the cleaning control. The configuration was However, in the image forming apparatus of the present embodiment, a transfer material set in a certain transfer material cassette is automatically selected as a cleaning paper used at the time of control, and is automatically used at the start of control. .

  An example of this embodiment will be described below. 10, FIG. 11 and FIG. 12 are tables showing the size of the transfer material in the transfer material cassette in the third embodiment.

  An example where transfer materials of various sizes are set in the transfer material cassette as shown in FIG. 10 will be described. In the example of FIG. 10, A3 size (width 297 mm) is set in the transfer material cassette 5, and A4 lateral feed size (width 297 mm) is set in the transfer material cassette 5A. Further, a transfer material of A3 full bleed size (width 312 mm) is set in the cassette 5B, and an SRA3 size (width 320 mm) is set in the cassette 5C.

  In this case, when the user designates the transfer material cassette 5, the transfer material cassette 5A, and the transfer material cassette 5B on the personal computer 101 and transmits the image data, it is possible to specify any mode of printing with margins or printing without margins. is there. On the other hand, when image data is transmitted by designating the transfer material cassette 5C, it is not possible to designate the printing mode without margins, and it is possible to designate only the printing mode with margins.

  Here, when the printing operation is continued while using the transfer material set in each transfer material cassette in an arbitrary distribution, the image forming apparatus is the same as that in the first embodiment. That is, the number of pages on which marginless printing has been performed by the printer controller is counted, and the execution timing of the cleaning control is determined. However, in this embodiment, the transfer material set in the transfer material cassette 5C is automatically conveyed and used as the cleaning paper in this embodiment. That is, in this embodiment, the transfer material set in the transfer material cassette 5C is automatically conveyed as cleaning paper, and cleaning control is performed. Therefore, as in the above-described embodiment, the user does not have to perform a personal computer operation for setting the cleaning paper in the transfer material cassette and starting the cleaning control.

  In the example of FIG. 11, the transfer material cassette 5 is set with an A3 size (width 297 mm), and the transfer material cassette 5A is set with an A4 lateral feed size (width 297 mm). Further, a transfer material of A3 full bleed size (width 312 mm) is set in the cassette 5B, and a transfer material of B4 size (width 257 mm) is set in the cassette 5C.

  In this case, when the user designates the transfer material cassette 5, the transfer material cassette 5A, and the transfer material cassette 5C on the personal computer 101 and transmits the image data, it is possible to specify either the printing mode with margins or the printing mode without margins. is there. On the other hand, when image data is transmitted by designating the transfer material cassette 5B, it is not possible to specify the print mode without margins, and it is possible to specify only the print mode with margins.

  When the printing operation is continued while using the transfer material set in each transfer material cassette in an arbitrary distribution, the transfer material set in the transfer material cassette 5B is automatically conveyed and cleaning control at a predetermined timing. Is implemented.

In any of the above cases,
W1t <W2t = WCLt
Meet. Here, W1t is the width of the maximum transfer material used in the marginless printing mode, and the relationship between the width of the transfer material used and the cleaning paper is W2t, and W2t is the maximum used in the printing mode with margins. This is the width of the transfer material. WCLt is the width of the cleaning paper used in the cleaning control.

  Therefore, in this embodiment, even if the printing operation is continued while using the transfer material set in each transfer material cassette in an arbitrary distribution, the cleaning paper is automatically conveyed from the predetermined transfer material cassette at a predetermined timing. Cleaning control is performed. Thereby, good cleaning can be performed and contamination of the transfer material can be prevented. Further, the troublesomeness that the user has to set the cleaning paper in the transfer material cassette when performing the cleaning control is also eliminated.

  In the example of FIG. 12, the transfer material cassette 5 and the transfer material cassette 5B are set with A3 size (width 297 mm), and the transfer material cassette 5A and the transfer material cassette 5C are set with A4 lateral feed size (width 297 mm). Is done.

  In this case, even if the user designates any of the transfer material cassette 5, the transfer material cassette 5A, the transfer material cassette 5B, and the transfer material cassette 5C on the personal computer 101 and transmits the image data, the no margin printing mode is not designated. Is possible. In this case, only the print mode with margins can be specified.

  In such a case, the transfer material cassette is not specified until the user removes the transfer material from a transfer material cassette and sets a transfer material that is narrower than the transfer material in another transfer material cassette. When sending data, it is possible to specify the print mode without margins. For this purpose, for example, the user changes the direction of the A4 lateral feed (width 297 mm) set in the transfer material cassette 5A or the transfer material cassette 5C to A4 vertical feed (width 210 mm) and transfers the same in the same transfer material cassette. It may be set again.

  As described above, the image forming apparatus according to the present embodiment has a configuration including a transfer material cassette as a plurality of transfer material holding units that hold a transfer material before a transfer operation. Then, based on the information on the transfer material width stored in the transfer material holding state storage means, it is determined whether or not image formation is possible in the marginless printing mode and the margining printing mode.

  In this case, based on the width information of the transfer material set in each transfer material cassette, using the transfer material set in each transfer material cassette, whether or not the printing operation in the marginless print mode is possible, It is determined whether or not the printing operation in the printing mode with margins is possible. Further, a transfer material cassette in which a transfer material that is automatically used when cleaning control is performed is determined. For this reason, the toner attached on the cleaning roller can be reliably recovered by the cleaning control, and the transfer material can be prevented from being stained. At the same time, the troublesomeness that the user has to set the cleaning paper in the transfer material cassette during the cleaning control is eliminated. For this reason, the convenience of the user when using the image forming apparatus can be enhanced.

  In the image forming apparatus according to the present embodiment, the size of the transfer material set in the plurality of transfer material cassettes is input by the user on the personal computer. However, the present invention is not limited to this. In some cases, the image forming apparatus itself includes a mechanical or optical mechanism for automatically determining the size of the transfer material set in each transfer material cassette. Even in such a case, using the determination result, it is possible to use the transfer material set in each transfer material cassette to determine whether or not the printing operation in the marginless printing mode is possible. It is determined whether a printing operation is possible. Further, since the transfer material cassette in which the transfer material used automatically when cleaning control is performed is determined, the same effect can be obtained.

1 is a cross-sectional view illustrating an image forming apparatus 100 according to a first embodiment. FIG. 3 is a diagram illustrating a connection between the image forming apparatus 100 and an image transmission apparatus. The perspective view of the transfer material cassette 5. FIG. FIG. 6 is a diagram illustrating a region where a transfer material P is applied. The perspective view which shows the adhesion state of a paper dust toner. FIG. 6 is a perspective view illustrating a state where toner is offset. The figure which shows the relationship between W1 and WCL. FIG. 6 is a chart showing a relationship between the width of a transfer material used during printing and the width of a transfer material of cleaning paper in the second embodiment. Sectional drawing of the image forming apparatus 200 used for 3rd Embodiment. The chart which shows the size of the transfer material in a transfer material cassette in a 3rd embodiment. The chart which shows the size of the transfer material in a transfer material cassette in a 3rd embodiment. The chart which shows the size of the transfer material in a transfer material cassette in a 3rd embodiment.

Explanation of symbols

B ... Addition area, P ... Transfer material, 1 ... Intermediate transfer belt, 1a ... Drive roller, 1b ... Tension roller, 1c ... Secondary transfer counter roller, 2 ... Secondary transfer roller, 3 ... Fixer, 4 ... Belt Cleaner, 5 ... transfer material cassette, 6 ... feed device, 8 ... discharge tray, 9 ... feed roller, 10 ... image forming station, 11 ... photosensitive drum, 12 ... primary charging roller, 13 ... laser exposure device, 14 ... Developer 15 ... Primary transfer roller 16 ... Primary transfer power source 17 ... Drum cleaner 21 ... Secondary transfer power source 22 ... Secondary transfer roller cleaner 30 ... Fixing roller 31 ... Pressure roller 32 ... Cleaning Roller, 33 ... Cleaning roller, 51 ... Pickup roller pair, 52 ... Longitudinal position regulating plate, 61 ... Conveyance roller, 100 ... Image forming device, 101 ... Personal computer, 102 ... Cable, 200 ... Image forming device

Claims (4)

An image forming unit that forms a toner image on a sheet fed from a sheet stacking unit, a fixing unit that fixes the toner image on the sheet by heating the sheet on which the toner image has been formed while being conveyed in the nip unit, and adheres to the fixing unit A cleaning unit that collects the collected toner and cleans the fixing unit, and after the toner collected by the cleaning unit is forcibly moved to the fixing unit, a sheet for collecting the toner is collected at the nip unit. In an image forming apparatus capable of executing a toner recovery mode in which the toner of the fixing unit is conveyed and attached to the toner recovery sheet and recovered.
The image forming unit can form a toner image without a border and a toner image with a border on a sheet, and the maximum width of a sheet capable of forming a toner image without a border is a toner image with a border. There is a restriction that it is smaller than the maximum width of the sheet that can be formed,
The toner collecting sheet is a sheet that is capable of forming a marginal toner image having a width larger than the maximum width of a sheet capable of forming a marginless toner image, and is fed from the sheet stacking unit. An image forming apparatus . The sheet stacking unit is capable of stacking a plurality of sheets of different sizes for each size, and has sheet information storage means for acquiring and storing information on the size of the sheets stacked on the sheet stacking unit. The image forming apparatus according to claim 1, wherein it is determined whether or not a borderless toner image can be formed on a sheet designated by a user based on information in the sheet information storage unit . The image forming apparatus according to claim 2, wherein the size of the toner collection sheet is determined based on information in the sheet information storage unit when the toner collection mode is executed . The fixing unit includes a fixing roller and a pressure roller that forms the nip portion together with the fixing roller, and the cleaning unit includes a first cleaning roller that contacts the fixing roller, and the pressure roller. The image forming apparatus according to claim 1, further comprising a second cleaning roller that abuts the first cleaning roller .