JP2004341080A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus absorbing residual toner on a fixing roll surface by transfer material. <P>SOLUTION: An engine control part, a controller part carrying out instruction of printing action to the engine control part and feeding of image data, an image masking means, a jamming detecting means, detecting jamming of the transfer material, a residual paper detecting means detecting residual paper, an automatic paper ejecting means, ejecting the residual paper inside the device, a printing error notifying means notifying that printing is interrupted and a recovery means, recovering a page in which the control part is interrupted are provided in the image forming apparatus. A fixing roll cleaning means is provided, in which the engine control part uses the first page which is recovered by the recovery means as cleaning paper to clean the soiling of a nip part of a fixing means when printing is interrupted and judgement is made such that there is a possibility of the transfer material being held in the nip part of the fixing means by the residual paper detecting means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as an electrophotographic or electrostatic storage type copying machine or printer.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a fixing device used in an image forming apparatus such as an electrophotographic copying machine or a printer is used to ensure a high fixing property, and to offset a toner to a fixing roller and wrap a transfer material around the fixing roller. In order to prevent this, so-called oil application fixing in which a release oil such as silicone oil is applied to the surface of the fixing roller has been performed. However, in recent years, so-called oilless fixing that does not require oil application has been realized instead of the above-described oil application fixing.
[0003]
The fixing device used for the oilless fixing is to fix the unfixed toner image transferred to the surface of the image forming section by heating and pressing while nipping and conveying between the fixing roller and the pressure roller. These rollers are constituted by providing a rubber layer as an elastic body on the outer peripheral surface of a core metal having a heater as a heating element at the center, and further providing a release layer on the surface of the rubber layer. The release layer is composed of a PFA tube, FEP coat, or the like.
[0004]
As the toner used for oilless fixing, a wax containing wax contained in a resin, which is a main component of the developer, is melted to prevent the toner from adhering to the fixing roller. No means for cleaning residual toner is required (see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2000-131898
[Problems to be solved by the invention]
However, the above-described oilless fixing device has the following problems.
[0006]
That is, although the toner containing wax is used in the resin to prevent the toner from adhering to the fixing roller, printing is performed in a state where the transfer material being fixed is held between the fixing roller and the pressure roller. Is interrupted, for example, when JAM occurs, the jammed toner remains on the fixing roller after the JAM processing. If printing is resumed in this state, image stains or back stains on the transfer material may occur.
[0007]
Further, when the amount of residual toner on the fixing roller is large, hot offset may occur, and there is a risk that the transfer material may be wound around the fixing device due to the adhesive effect of the residual toner.
[0008]
The present invention has been made in view of the above problems, and in an image forming apparatus having a fixing device without a cleaning mechanism, when it is determined that there is a possibility that a transfer material may be held in a nip portion of a fixing unit. Is to forcibly mask the entire image area of the first sheet when printing is resumed, pass untransferred transfer material through the fixing roller, and absorb residual toner on the surface of the fixing roller with the transfer material. The purpose is.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 includes a paper feeding unit for stacking a transfer material, an image forming unit for scanning a modulated laser beam on a photoconductor to carry a latent image, and Developing means for developing the image into a visible image, transfer means for transferring the visible image to a transfer material, and a nip portion between two rotating bodies including a heat source for transferring the transfer material onto which the visible image has been transferred An image forming apparatus having a fixing unit for performing heat fixing while nipping and conveying by an engine control unit that controls the sheet feeding unit, the image forming unit, the developing unit, the transfer unit, and the fixing unit; and communicable with the engine control unit. An image masking means connected to the engine control unit for instructing a printing operation and transmitting image data to the engine control unit, masking the laser beam, and forcibly not carrying a latent image; Paper feeding by the paper feeding means Jam detecting means for detecting a jam of the transferred transfer material, residual paper detecting means for detecting the residual paper in the image forming apparatus, automatic paper discharging means for discharging the residual paper in the apparatus to the outside of the apparatus, and interruption of printing. At this time, when the engine control unit notifies the controller unit that the printing has been interrupted, and when the misprint notifying unit notifies the controller unit that the printing has been interrupted, the controller unit performs the following operations. A recovery unit for recovering the interrupted page, and when the printing is interrupted, when the residual paper detection unit determines that there is a possibility that the transfer material may be held in the nip portion of the fixing unit, the engine A control unit that cleans the first page recovered by the recovery unit to clean the nip portion of the fixing unit; Characterized in that it has a fixing roller cleaning means for use as Gupepa.
[0010]
According to a second aspect of the present invention, in the first aspect of the present invention, the fixing roller cleaning unit is configured such that the engine control unit causes the entire image area of the first page recovered by the recovery unit to be scanned by the image mask unit. Masking is performed so that the untransferred transfer material is controlled to pass through the nip portion of the fixing unit, and when the transfer material is discharged out of the apparatus, the printing is interrupted by the misprint notifying unit in a pseudo manner. And a dummy misprint notifying unit for notifying the controller unit of the fact.
[0011]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the dummy misprint notifying unit is configured such that the first page recovered by the controller unit by the fixing roller cleaning unit is replaced with a cleaning paper by the engine control unit. In this case, a request is made to the controller again for recovery from the page used as the cleaning paper.
[0012]
According to a fourth aspect of the present invention, in the invention of any one of the first to third aspects, when it is determined that there is a possibility that the transfer material may be pinched in the nip portion of the fixing unit when printing is interrupted. If the untransferred transfer material having the same width or a wider width than the transfer material that stains the nip portion of the fixing unit is located upstream of the transfer unit, the fixing roller The operation of the cleaning means is not performed.
[0013]
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, during the operation of the fixing roller cleaning unit or the operation of the automatic sheet discharging unit, the cleaning paper is fixed. A forced fixing roller cleaning unit that notifies the user to set the cleaning paper to a predetermined paper feed port when the paper is wound around the roller, and passes the cleaning paper according to the user's instruction. It is characterized by the following.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a multicolor image forming apparatus according to the present invention will be described with reference to the accompanying drawings. In the embodiment described below, the case of the multicolor image forming apparatus shown in FIG. 1 will be described as an example. However, the present invention is applicable to image forming apparatuses in general, and is not particularly limited to an image forming apparatus using an electrophotographic process.
[0015]
<Embodiment 1>
Referring to FIG. 1, an outline of the overall configuration of a laser printer as a multicolor image forming apparatus according to the present invention will be described.
[0016]
As shown in FIG. 1, the laser printer forms an electrostatic latent image in an image forming unit using image light formed based on an image signal transmitted from a controller (not shown), and develops the electrostatic latent image. The visible image is superimposed and transferred to form a color visible image, the color visible image is transferred to the transfer material 2, and the color visible image on the transfer material 2 is fixed. Photoconductors (5Y, 5M, 5C, 5K) for each station arranged in parallel, injection charging means (7Y, 7M, 7C, 7K) as primary charging means, developing means (8Y, 8M, 8C, 8K), toner cartridge ( 11Y, 11M, 11C, and 11K), an intermediate transfer body 12, a paper feed unit, a transfer unit, and a fixing unit 11.
[0017]
The photoreceptor (5Y, 5M, 5C, 5K), injection charging means (7Y, 7M, 7C, 7K) as primary charging means, and developing means (8Y, 8M, 8C, 8K) are detachable from the main body of the image forming apparatus. Is mounted on a simple process cartridge (22Y, 22M, 22C, 22K).
[0018]
The photosensitive drums (photoreceptors) 5Y, 5M, 5C, and 5K are formed by applying an organic photoconductive layer to an outer periphery of an aluminum cylinder, and rotate by transmitting a driving force of a driving motor (not shown). Rotates the photosensitive drums 5Y, 5M, 5C, 5K counterclockwise in accordance with the image forming operation. Exposure light to the photosensitive drums 5Y, 5M, 5C, and 5K is sent from the scanner units 10Y, 10M, 10C, and 10K, and selectively exposes the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K. It is configured to form an image.
[0019]
As primary charging means, four injection chargers 7Y, 7M, 7C, 7K for charging the yellow (Y), magenta (M), cyan (C), and black (K) photoconductors are provided for each station. With the configuration, each injection charger is provided with a sleeve 7YS, 7MS, 7CS, 7KS.
[0020]
As developing means, four developing units 8Y and 8M for developing yellow (Y), magenta (M), cyan (C), and black (K) for each station in order to visualize the electrostatic latent image. , 8C and 8K, and each developing unit is provided with a sleeve 8YS, 8MS, 8CS and 8CK. The developing units 8Y, 8M, 8C and 8K are detachably mounted.
[0021]
The intermediate transfer body 12 is in contact with the photosensitive drums 5Y, 5M, 5C, and 5K, rotates clockwise during color image formation, and rotates with the rotation of the photosensitive drums 5Y, 5M, 5C, and 5K to be visible. Receive image transfer. The intermediate transfer body 12 simultaneously superimposes and transfers a color visible image onto the intermediate transfer body 12 on the transfer material 2 by the transfer roller 9a, which will be described later, contacting and conveying the transfer material 2 during image formation.
[0022]
The transfer roller 9a is brought into contact with the intermediate transfer body 12 while the color visible image is superimposed and transferred on the intermediate transfer body 12, but separates to the position 9b when the printing process is completed.
[0023]
The fixing unit 13 fixes the transferred color visible image while transporting the transfer material 2. The fixing unit 14 heats the transfer material 2 and pressurizes the transfer material 2 against the fixing roller 14. And a roller 15. The fixing roller 14 and the pressure roller 15 are formed in a hollow shape, and have heaters 16 and 17 therein, respectively. That is, the transfer material 2 holding the color visible image is conveyed by the fixing roller 14 and the pressure roller 15, and the toner is fixed on the surface by applying heat and pressure.
[0024]
After the visible image is fixed, the transfer material 2 is discharged to a discharge unit (not shown) by a discharge roller (not shown), and the image forming operation is completed.
[0025]
The printer uses a lower conveyance sensor A23, an upper conveyance sensor A24, a lower conveyance sensor B25, an upper conveyance sensor B26, a registration sensor 19, a pre-fixing sensor 27, a fixing paper ejection sensor 20, and a paper ejection sensor 28 on the transfer material conveyance path. Manage.
[0026]
The cleaning unit 21 cleans the toner remaining on the photosensitive drums 5Y, 5M, 5C, and 5K and the intermediate transfer body 12, and removes a visible image by the toner formed on the photosensitive drums 5Y, 5M, 5C, and 5K. The waste toner after being transferred to the intermediate transfer member 12 or the waste toner after transferring the four color visible images formed on the intermediate transfer member 9 to the transfer material 2 is stored in a cleaner container.
[0027]
FIG. 2 is a schematic system diagram of an engine unit of the image forming apparatus according to the present embodiment. The engine control unit 211 includes a video interface unit 200 that is an interface unit with a controller unit 212 that controls the engine, a fixing unit 208, a sensor unit 209 for detecting a temperature and humidity sensor and a remaining toner amount, a high-pressure control unit 210, An image processing GA 206 such as γ correction for image data received from the image data 200, an image forming unit 207 for outputting an image such as a laser output or a scanner motor, and a main control CPU 201 for controlling a transfer material transport control CPU 202 of a sub CPU. The transfer material transport control CPU controls a drive unit 203 such as a motor, a clutch, and a fan, a sensor unit 204 for position detection and the like, and a paper feed control 205, respectively.
[0028]
FIG. 3 is a diagram illustrating an interface (video interface unit) between the controller unit 212 and the engine control unit 211 of the image forming apparatus.
[0029]
Reference numeral 301 denotes a serial command signal line for transmitting an instruction command from the controller unit 212 to the engine control unit 211 by serial communication, and 302 denotes a serial status signal line for transmitting status data from the engine control unit 211 to the controller unit 212 by serial communication. is there.
[0030]
Reference numeral 303 denotes a vertical synchronization signal line for transmitting a vertical synchronization signal from the engine control unit 211 to the controller unit 212. Reference numeral 304 denotes a horizontal synchronization signal line for transmitting a horizontal synchronization signal from the engine control unit 211 to the controller unit 212. Reference numeral 305 denotes an image data signal line for transmitting image data from the controller unit 212 to the engine control unit 211.
[0031]
Upon receiving a print start command from the personal computer 306, the controller unit 212 transmits a command for designating a print mode, a paper feed port, a paper discharge port, and the like to the engine control unit 211 via the serial command communication line 301. A print reservation command for confirming these information is transmitted for each page. After transmitting the print reservation command, the controller unit 212 transmits a print command instructing the start of printing. Upon receiving the print command, the engine control unit 211 starts a printing operation based on the information specified by the print reservation command. The controller unit 212 transmits a print command once for one print reservation command.
[0032]
Upon receiving the print command, the engine control unit 211 starts a printing operation in the order of receiving the print reservation command, and sends a vertical synchronization signal (hereinafter, referred to as a “/ TOP signal”) and a horizontal synchronization signal to the controller unit 212, respectively. The signal is output via a signal line 303 and a horizontal synchronization signal line 304. The controller 212 outputs image data to the engine controller 211 via the image data signal line in synchronization with the / TOP signal and the horizontal synchronization signal. The engine control unit 211 emits a laser beam based on the image data information input from the controller unit 212 to form an electrostatic latent image on the photosensitive drums 5Y, 5M, 5C, and 5K. 12 to form a developer image on the intermediate transfer member 12.
[0033]
FIG. 4 is a diagram for explaining operations of the engine control unit 211 and the controller unit 212 during printing. Here, the operation when printing three pages is described.
[0034]
The controller unit 212 transmits a print reservation command managed by the print mode (S401), paper feed port, paper discharge port (S402), and ID for each page to the engine control unit 211 via the serial command signal line 301. (S403).
[0035]
The engine control unit 211 sets the paper feed port, paper discharge port, and print mode for each print reservation command, and validates the last designated print mode, paper feed port, and paper discharge port when each print reservation command is received. To Therefore, when changing the print mode, paper feed port, and paper discharge port for each page, the controller unit 212 must specify these before transmitting each print reservation command. In FIG. 4, it is assumed that the same print mode, paper feed port, and paper discharge port are all specified for the print reservation of three pages.
[0036]
When the preparation for printing is completed, the controller 212 sends a print command to the engine controller 211 (S404). Upon receiving the print command, the engine control unit 211 starts the printing operation in the order of receiving the print reservation command (in the order of ID = 1, ID = 2, ID = 3), and sends a / TOP signal to the controller unit 212 (S405). ) And a horizontal synchronizing signal. The controller 212 outputs image data to the engine controller 211 via the image data signal line in synchronization with the / TOP signal (S405) and a horizontal synchronization signal not shown in FIG. The engine control unit 211 emits a laser beam based on the image data information input from the controller unit 212 to form an electrostatic latent image on the photosensitive drum, and forms a toner image on the intermediate transfer body 12 by the developing unit. A developer image is formed on the transfer body 12.
[0037]
After the engine control unit 211 outputs the / TOP signal, the controller unit 212 transmits a print command for the next page (ID = 2). Upon receiving the print command, the engine control unit 211 outputs a / TOP signal for the second page (ID = 2) at a desired timing after the completion of image formation for the first page (ID = 1) (S407). ). Thereafter, when the printing operation is continued, the above operation is repeated (S408, S409).
[0038]
Here, the jam detecting unit will be described with reference to FIG.
[0039]
The jam is determined based on the timing at which the fed transfer material reaches a sensor disposed on the transfer material transport path. When the fed transfer material has not reached the sensor arranged on the transfer material transport path by a predetermined timing (hereinafter, referred to as “delay jam”), or has not passed the sensor by the predetermined timing. (Hereinafter referred to as “remaining jam”). In addition, when a jam occurs, the position of the jammed paper can be specified by the sensor that detects the jam.
[0040]
FIG. 5A shows a case where the transfer material does not reach the fixing and discharging sensor 20 by a predetermined timing due to a roller slip on the conveyance path, and FIG. This is a case where the sheet does not reach the fixing sheet discharge sensor by a predetermined timing. In either case, it is determined that the developer has not reached the fixing paper discharge sensor by a predetermined timing, and it is determined that a delay jam of the fixing paper discharge sensor has occurred.
[0041]
FIG. 5C shows a case in which the leading end of the transfer material reaches the fixing paper discharge sensor by a predetermined timing, but does not pass through the sensor by the predetermined timing due to slippage of a conveyance roller or the like. In this case, it is determined that the paper jam has occurred in the fixing paper discharge sensor.
[0042]
A recovery process when printing is interrupted will be described with reference to FIGS. Here, particularly, a recovery process when a jam occurs will be described.
[0043]
FIG. 6 is a flowchart from the occurrence of a jam until recovery is performed.
[0044]
After removing the jammed transfer material (non-dischargeable residual paper) by the operator, the engine control unit 211 checks whether there is any dischargeable residual paper on the transfer material transport path (S601, S602, S603). ). If it is determined that there is any remaining paper that can be discharged, automatic paper discharging is performed to discharge the remaining paper outside the image forming apparatus (hereinafter, referred to as “outside the machine”) (S604). In the automatic paper ejection, all the rollers on the transfer material conveyance path are driven for a predetermined time in order to discharge all the remaining paper existing on the transfer material conveyance path to the outside of the apparatus. Thereafter, the engine control unit 211 and the controller unit 212 notify the engine control unit of a print reservation for recovering the page interrupted by the jam (S605).
[0045]
FIG. 7 is a diagram for explaining the operations of the engine control unit 211 and the controller unit 212 from the occurrence of a jam until recovery is performed. Here, during the printing operation of the third page described with reference to FIG. 4, the printing of the first page is completed (the transfer material of ID = 1 has already been ejected outside the machine), and the JAM is performed during the printing of the second page (ID = 2). The case where the error occurs will be described. S400 in FIG. 7 indicates that the same processing as that in S400 in FIG. 4 is being performed, and thus will not be described here.
[0046]
When a jam occurs, the engine control unit 211 notifies the controller unit 212 of a status for notifying that a jam has occurred (hereinafter, referred to as “jam status”) (S701), and the printing is interrupted (normally). A status (hereinafter, referred to as “misprint status”) for notifying that the printing has not been completed is notified (S702).
[0047]
Upon receiving the misprint status from the engine control unit 211, the controller unit 212 transmits a data retransmission confirmation command (S703). Upon receiving the data retransmission confirmation command, the engine control unit 211 returns the misprint detail status as the return status, and notifies the controller unit 212 of which page could not be printed normally (S704).
[0048]
After the operator removes the jammed transfer material, if there is any residual paper that can be discharged into the machine, the engine control unit 211 notifies the controller unit 212 of the fact (hereinafter, the “within remaining paper presence status”). (S705).
[0049]
When the controller unit 212 is notified of the presence of the dischargeable residual sheet from the engine control unit 211, the controller unit 212 issues a command for instructing the engine control unit 211 to start the operation of discharging the residual sheet outside the machine (hereinafter, “ ("Automatic paper ejection command") (S706). When receiving the automatic paper ejection command, the engine control unit 211 executes automatic paper ejection.
[0050]
When the automatic paper ejection is completed, the controller 212 determines a page to be recovered based on the misprint detail status (S704), and transmits a print reservation command to the engine controller 211 again (S707). Here, since a jam occurs during printing of ID = 2, a print reservation of ID = 2 and ID = 3 is transmitted (S707).
[0051]
Thereafter, the controller unit 212 sends out a print command (S708), and the engine control unit 211 outputs a / TOP signal, and performs a print operation in the order of print reservation specified by the controller unit 212, thereby performing normal printing. It is possible to recover a page that could not be recovered.
[0052]
However, when a paper jam occurs, the printing is interrupted while the transfer material being fixed is being held by the fixing device, and when toner remains on the fixing roller, when printing is resumed according to the above-described recovery processing, There is a risk that a fixing device wrapping jam or the like may occur due to image stains, back stains of the transfer material, or adhesiveness of the residual toner.
[0053]
Therefore, in the present embodiment, when the printing operation is interrupted due to the occurrence of a jam or the like and the transfer material may be held in the nip portion of the fixing device, the first page of the recovery page is recovered. The entire image area is masked (without performing image formation), and is used as cleaning paper for cleaning dirt in the nip portion of the fixing device. After the paper is discharged outside the apparatus, the recovery process is performed again.
[0054]
This embodiment will be described with reference to FIGS.
[0055]
FIG. 8 is a flowchart for explaining the present embodiment.
[0056]
When a jam occurs, the engine control unit 211 determines whether the transfer material is held in the nip portion of the fixing device (S801). When the transfer material is not held in the nip portion of the fixing device, the engine control unit 211 and the controller unit 212 perform a normal recovery process (S810).
[0057]
If the transfer material is held between the nips of the fixing device, the operator removes the jammed paper, and then checks whether there is any remaining dischargeable paper on the transfer material conveyance path (S802, S803). If there is a remaining sheet, an automatic sheet discharging process for discharging the remaining sheet out of the image forming apparatus is performed (S804). After that, the controller unit 212 transmits a print reservation command and a print command for the page where printing has been interrupted due to the occurrence of the jam to the engine control unit (S805).
[0058]
Upon receiving the print command (S806), the engine control unit 211 masks the entire image area (without forming an image), and starts the printing operation of the first page resent from the controller unit 212 (S807). . When the transfer material of the first page is discharged outside the machine, the engine control unit 211 notifies the controller unit 212 of a dummy misprint and interrupts the printing operation (S808). At this time, the engine control unit 211 determines that the printing of the first page (ID = 2) used as the cleaning paper and the pages reserved thereafter (ID = 3) could not be printed normally and misprinted. Inform the controller unit 212 in the detailed status.
[0059]
Upon receiving the misprint detailed status, the controller unit 212 restarts (recovers) printing from the misprinted page (ID = 2) again (S809).
[0060]
The operation of the engine control unit 211 and the controller control unit 212 according to the present embodiment will be described with reference to FIG. Here, during the printing operation of the third page described with reference to FIG. 4, the printing of the first page is completed (the transfer material of ID = 1 has already been ejected outside the machine), and the printing of the second page (ID = 2) is being performed. The case where JAM occurs will be described. The operation of S700 in FIG. 9 is the same as the operation of S700 in FIG.
[0061]
When a JAM occurs, the engine control unit 211 notifies the controller unit 211 of the jam status (S901) and the misprint status (S902). When receiving the misprint status from the engine control unit 211, the controller unit 212 transmits a data retransmission confirmation command (S903). The engine control unit 211 notifies the controller 212 of the misprint detail status as the return status (S904).
[0062]
After the operator removes the jammed transfer material, the engine control unit 211 determines whether or not there is any residual paper that can be discharged into the apparatus. Then, the status of remaining paper in the machine is returned (S905).
[0063]
When notified of the presence of the dischargeable residual sheet from the engine control unit 211, the controller unit 212 transmits an automatic discharge command to the engine control unit 211 (S906). When receiving the automatic paper ejection command, the engine control unit 211 executes automatic paper ejection.
[0064]
When the automatic paper discharge is completed, the controller 212 determines a page to be recovered based on the misprint detailed status (S904), and transmits a print reservation command to the engine controller 211 again (S907). Here, the print reservation of ID = 2 and ID = 3 is transmitted to the engine control unit 211 (S907).
[0065]
When the preparation for printing is completed, the controller 212 transmits a print command to the engine controller 211 (S908). When receiving the print command, the engine control unit 211 masks the entire image area of the first page (ID = 2) and starts the printing operation of the first page (ID = 2). And a horizontal synchronization signal is output (S905). At this time, even if a print command for the next page (ID = 3) is transmitted from the controller unit 212, the engine control unit 211 does not output the / TOP signal for (ID = 3) (S911).
[0066]
The engine control unit 211 interrupts the printing operation when the transfer material of the first page (ID = 2) is discharged outside the machine, transmits a dummy misprint to the controller unit 212, and prints the first page. Is notified that printing has not been performed normally (S912, S913, S914).
[0067]
Upon receiving the misprint status from the engine control unit 211, the controller unit 212 transmits a data retransmission confirmation command (S915), determines a page to be recovered from the misprint detail status (S916), which is the return status, and The print reservation command is transmitted to the control unit 211 again (S917).
[0068]
At this time, in the misprint detailed status, the engine control unit 211 determines that the first sheet (ID = 2) used as the cleaning paper and the page reserved thereafter (ID = 3) could not be printed normally. Here, to notify the controller unit, the print reservation of ID = 2 and ID = 3 is transmitted to the engine control unit 211 (S917).
[0069]
The engine control unit 211 performs a print operation in the order of the print reservation command specified by the controller unit 212, thereby recovering a page that could not be normally printed (S918, S919, S920, S921). .
[0070]
As described above, the toner remaining on the fixing roller can be cleaned without adding a new function to the controller unit 211 even if there is no mechanism for cleaning the fixing roller.
[0071]
Further, since the first sheet at the time of recovery is used as the cleaning paper, a transfer material having the same size as the transfer material being fixed and held by the fixing device is used as the cleaning paper (the toner on the fixing roller). Since the transfer material having the same width as the width of the stain is passed), the stain (toner) on the fixing roller can be completely collected.
[0072]
Furthermore, according to the cleaning means of the present embodiment, the toner remaining on the fixing roller is cleaned, so that the operator's hand is not bothered.
[0073]
It should be noted that the present embodiment can be variously modified based on the gist of the present invention, and these are not excluded from the scope of the present invention.
[0074]
<Embodiment 2>
Next, a second embodiment of the present invention will be described.
[0075]
In the first embodiment, when the printing operation is interrupted due to the occurrence of a jam or the like, and when there is a possibility that the transfer material may be held in the nip portion of the fixing device, all the images of the first page after the recovery are recovered. A method of masking an area (without performing image formation), using the paper as a cleaning paper for cleaning dirt in a nip portion of a fixing device, and performing a recovery process again after the paper is discharged out of the apparatus. Stated.
[0076]
Since the object of the present invention is to completely remove the toner adhered by the transfer material during fixing stopped in a state of being held by the fixing device, it is not always necessary to use the cleaning sheet as the first sheet of the recovery. Instead, it is only necessary that the transfer material stopped in the state of being held by the fixing device can be completely removed.
[0077]
Therefore, in the present embodiment, when the transfer material is sandwiched in the nip portion of the fixing device when printing is interrupted, an untransferred transfer material that can be discharged exists in the machine, and the paper width of the transfer material is reduced. When the width of the transfer material is equal to or larger than the width of the transfer material held in the nip portion of the fixing device, the transfer material is used as cleaning paper during automatic paper ejection. In this case, it is possible to completely clean the dirt on the fixing roller at the time of automatic paper discharge, so that the first recovery sheet does not have to be used as a cleaning paper. However, if there is no untransferred residual paper, or even if there is untransferred residual paper, if the width is smaller than the transfer material sandwiched in the fixing device nip, the first embodiment Similarly, the first sheet at the time of recovery is used as cleaning paper.
[0078]
FIG. 10 is a flowchart of the present embodiment.
[0079]
When a jam occurs, the engine control unit 211 determines whether the transfer material is held at the nip portion of the fixing device (S1001). If the transfer material is not held in the nip portion of the fixing device, the engine control unit 211 and the controller unit 212 perform the normal recovery process described with reference to FIG. 6 (S1010).
[0080]
If the transfer material is held in the nip of the fixing device, after the jammed paper is removed by the operator, it is checked whether or not there is a dischargeable residual paper on the transfer material transport path (S1002, S1003).
[0081]
If there is any residual paper, it is determined whether the residual paper has not been transferred (S1004). Further, it is determined whether the paper width of the residual paper is the same as the paper width of the transfer material stopped by being nipped by the nip portion of the fixing device. Alternatively, it is determined whether the width is wider (S1005).
[0082]
If there is residual paper that can be discharged, and if the paper width of the residual paper in the machine is equal to or greater than the paper width of the transfer material stopped while being held After discharging, the automatic discharge is performed assuming that the dirt at the nip portion of the fixing device is cleaned, and then printing is restarted in accordance with an instruction from the controller 212 (S1013, S1014).
[0083]
When the transfer material is held in the nip of the fixing device and there is no untransferred dischargeable residual paper, or the paper width of the untransferred dischargeable residual paper is held in the nip portion of the fixing device. If the paper width is shorter than the paper width of the stopped transfer material, automatic paper ejection is performed as necessary (S1006), and the first sheet after recovery is used as cleaning paper, as described in the first embodiment. I do.
[0084]
Specifically, the following processing is performed.
[0085]
The controller unit 212 transmits a print reservation command and a print command for the page for which printing has been interrupted to the engine control unit (S1007). Upon receiving the print command (S1008), the engine control unit 211 masks the entire image area (without forming an image) and starts the printing operation of the first page resent from the controller unit 212 (S1009). .
[0086]
When the transfer material of the first page is discharged out of the apparatus, the engine control unit 211 notifies the controller unit 212 of a dummy misprint and interrupts the printing operation (S1010). At this time, the engine control unit 211 notifies the controller unit 212 in the misprint detailed status that the first page used as the cleaning paper and the pages reserved thereafter cannot be printed normally. I do.
[0087]
Upon receiving the misprint detail status, the controller unit 212 restarts (recovers) printing from the page notified of the misprint again (S1011).
[0088]
As described above, in order to clean the fixing roller, it is not always necessary to use the first sheet after the recovery, and it is possible to reduce useless transfer material used as cleaning paper.
[0089]
It should be noted that the present embodiment can be variously modified based on the gist of the present invention, and these are not excluded from the scope of the present invention.
[0090]
<Embodiment 3>
Next, a third embodiment of the present invention will be described.
[0091]
In the first and second embodiments, the method of removing the residual toner on the fixing roller without bothering the operator has been described.
[0092]
However, when a medium that is not supported by the image forming apparatus (for example, an OHT coated with a coating agent) is used, and the medium is used as a cleaning paper, the cleaning paper itself is wound around the fixing device. There is a concern that the sheet may stick or jam in the fixing device. In such a case, the methods described in Embodiments 1 and 2 cannot clean the toner stain on the fixing device.
[0093]
Therefore, in the present embodiment, when the cleaning paper is jammed in the fixing device during the passage of the cleaning paper described in the first and second embodiments, the supply of the transfer material suitable for the cleaning paper to the operator is designated by the operator. The user is instructed to set the transfer material in the paper port, and the transfer material is used as cleaning paper.
[0094]
FIG. 11 and FIG. 12 are flowcharts of the present embodiment.
[0095]
When a jam occurs, the engine control unit 211 determines whether the transfer material is held in the nip portion of the fixing device (S1101). If the transfer material is not held in the nip portion of the fixing device, the engine control unit 211 and the controller unit 212 perform the normal recovery process described with reference to FIG. 6 (S1115).
[0096]
If the transfer material is held between the nips of the fixing device, after the jammed paper is removed by the operator, it is checked whether or not there is any residual paper that can be discharged on the transfer material transport path (S1102, S1103).
[0097]
If there is any residual paper, it is determined whether the residual paper has not been transferred (S1104). Further, the paper width of the untransferred residual paper is the same as the paper width of the transfer material stopped by being nipped by the nip portion of the fixing device. It is determined whether the width is wider than that (S1105).
[0098]
If there is residual paper that can be discharged, and if the paper width of the residual paper in the machine is equal to or greater than the paper width of the transfer material stopped while being held Automatic discharge is performed on the assumption that dirt in the nip portion of the fixing device is cleaned by discharging the paper (S1116).
[0099]
During the automatic paper ejection (S1116), it is monitored whether a jam has occurred in the fixing device (S1117). If no jam has occurred in the fixing device, it is determined that dirt on the fixing roller has been cleaned, and the automatic paper ejection is performed. After the end, printing is restarted according to the instruction of the controller unit 212 (S1118, S1119). If a jam occurs in the fixing device during automatic sheet ejection, a forced fixing roller cleaning request is set, and sheet conveyance is interrupted (S1121, S1122).
[0100]
When the transfer material is held in the nip of the fixing device, and there is no untransferred dischargeable residual paper, or the paper width of the untransferred dischargeable residual paper is held in the nip portion of the fixing device. If the transfer material is shorter than the paper width of the stopped transfer material, automatic paper discharge is performed as necessary (S1106). During the automatic paper ejection (S1106), it is monitored whether a jam has occurred in the fixing device (S1107). If a jam has occurred in the fixing device, a forced fixing roller cleaning request is set and the sheet conveyance is interrupted. (S1121, S1122). If no jam has occurred in the fixing device, the first sheet after recovery is used as cleaning paper, as described in the first and second embodiments. However, while the cleaning paper is being fed, it is monitored whether a jam has occurred in the fixing device (SS1112). If a fixing jam has occurred, a forced fixing roller cleaning request is set and the sheet conveyance is interrupted (S1121, S1121). S1122).
[0101]
When the forced fixing roller cleaning request is set, the controller control unit 212 instructs the operator to set the cleaning paper at a predetermined paper feed port (S1201). When the operator instructs execution of forced fixing roller cleaning after the cleaning paper is set, the controller unit instructs the engine control unit 211 to execute forced fixing roller cleaning (S1202, S1203). When the execution of the forced fixing roller cleaning is instructed, the engine control unit 211 starts transporting the cleaning paper from a predetermined paper feed port and clears the forced fixing cleaning request (S1204). After the completion of the forced fixing cleaning, the controller unit 212 and the engine control unit 211 perform recovery processing and restart printing (S1205).
[0102]
As described above, even when a medium that is not supported by the image forming apparatus (for example, an OHT coated with a coating agent) is used, the fixing roller can be cleaned.
[0103]
The embodiments described above can be variously modified based on the gist of the present invention, and these are not excluded from the scope of the invention.
[0104]
【The invention's effect】
As is apparent from the above description, according to the present invention, a fixing unit for performing heat fixing while nipping and transporting at a nip portion between two rotating bodies including a heat source, and masking a laser beam to forcibly form a latent image An image masking means for not carrying the paper, a residual paper detecting means for detecting the residual paper in the image forming apparatus, an automatic paper discharging means for discharging the residual paper in the image forming apparatus to the outside of the image forming apparatus, and a print interruption When the printing operation is interrupted in an image forming apparatus having a misprint notifying unit for notifying that the printing has been interrupted from the engine control unit to the controller unit and a recovery unit for recovering the page where the printing has been interrupted, If there is a possibility that the transfer material is pinched in the nip portion of the fixing unit, the first page recovered by the recovery unit is replaced with the nip of the fixing unit. It is possible to remove toner remaining on the fixing roller by using it as a cleaning paper for cleaning dirt or by using an untransferred transfer material that can be discharged during automatic paper discharge. Thus, at the time of resuming printing, it is possible to prevent the occurrence of image stains, back stains of the transfer material, or jamming around the fixing device due to the stickiness of the residual toner.
[0105]
Further, by having the forced fixing cleaning function, even when a medium not supported by the image forming apparatus is used, the fixing roller can be cleaned.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a laser printer as an image forming apparatus.
FIG. 2 is a schematic system diagram of an engine unit of a laser printer as an image forming apparatus.
FIG. 3 is a diagram of an interface signal between an engine control unit and a controller unit.
FIG. 4 is an explanatory diagram of operations of an engine control unit and a controller unit during printing.
FIG. 5 is an explanatory diagram of jam detection means.
FIG. 6 is a flowchart of a recovery process as a conventional example.
FIG. 7 is an explanatory diagram of operations of an engine control unit and a controller unit of a recovery process as a conventional example.
FIG. 8 is a flowchart of a fixing roller cleaning unit according to the first embodiment of the present invention.
FIG. 9 is an explanatory diagram illustrating operations of an engine control unit and a controller unit of the fixing roller cleaning unit according to the first embodiment of the present invention.
FIG. 10 is a flowchart of a fixing roller cleaning unit according to Embodiment 2 of the present invention.
FIG. 11 is a flowchart 1 of a fixing roller cleaning unit according to Embodiment 3 of the present invention.
FIG. 12 is a flowchart 2 of a fixing roller cleaning unit according to Embodiment 3 of the present invention.
[Explanation of symbols]
2 Density sensor
6 Color shift measurement sensor
18 Drive roller
19 Sensor before cash register
20 fusing paper ejection sensor
23 Lower transport sensor A
24 Upper conveyance sensor A
25 Lower transport sensor B
26 Upper conveyance sensor B
27 Pre-fixing sensor
28 Discharge sensor

Claims (5)

Paper feed means for loading a transfer material, image forming means for carrying a latent image by scanning the modulated laser light on the photoreceptor, developing means for developing the latent image to visualize the image, An image forming apparatus comprising: a transfer unit that transfers a visible image to a transfer material; and a fixing unit that thermally fixes the transfer material onto which the visible image has been transferred while nipping and transporting the transfer material at a nip portion of two rotating bodies including a heat source. In the device,
An engine control unit for controlling the sheet feeding unit, the image forming unit, the developing unit, the transfer unit, and the fixing unit; and an instruction for a printing operation and transmission of image data to the engine control unit, the communication unit being communicably connected to the engine control unit. Has a controller unit that performs
Image mask means for masking the laser light so as not to carry a latent image,
Jam detection means for detecting the jam of the transfer material fed by the paper feeding means,
Residual paper detection means for detecting residual paper in the image forming apparatus;
Automatic paper discharging means for discharging the residual paper in the apparatus to the outside of the apparatus,
When printing is interrupted, the engine control unit notifies the controller unit that the printing has been interrupted.
When the misprint notification unit notifies that the printing has been interrupted, the controller unit has a recovery unit that recovers the interrupted page,
When printing is interrupted, if the residual paper detection unit determines that the transfer material may be held in the nip of the fixing unit, the engine control unit may control the first page recovered by the recovery unit. An image forming apparatus comprising: a fixing roller cleaning unit that uses a fixing roller as cleaning paper for cleaning dirt on a nip portion of the fixing unit. The fixing roller cleaning unit is configured such that the engine control unit masks the entire image area of the first page recovered by the recovery unit with the image mask unit, and an untransferred transfer material removes a nip portion of the fixing unit. And a dummy misprint notifying unit for notifying the controller unit that the printing has been suspended by the misprint notifying unit when the transfer material is discharged outside the apparatus. The image forming apparatus according to claim 1, wherein: The dummy misprint notifying unit, when the engine control unit sets cleaning paper as the first page recovered by the controller unit by the fixing roller cleaning unit, again sends the page used as the cleaning paper to the controller unit. The image forming apparatus according to claim 1, wherein recovery from the image forming apparatus is requested. When printing is interrupted, when it is determined that there is a possibility that the transfer material may be sandwiched in the nip portion of the fixing unit, and the transfer material that stains the nip portion of the fixing unit upstream of the transfer unit. 4. The operation of the fixing roller cleaning unit is not performed when an untransferred transfer material having the same width as that of the untransferred material or the width of the untransferred material is accumulated. Image forming apparatus. If the cleaning paper is wound around the roller of the fixing unit during the operation of the fixing roller cleaning unit or the operation of the automatic sheet discharging unit, the user sets the cleaning paper in a predetermined paper feed port. The image forming apparatus according to any one of claims 1 to 4, further comprising a forced fixing roller cleaning unit that notifies the user that cleaning is to be performed and passes the cleaning paper according to a user's instruction.

Images