Image formation device

Abstract

To provide an image formation device that can automatically clean a fixation unit efficiently even if unframed printing is performed.SOLUTION: An image formation device of the present invention has: a medium accommodation unit that is provided in a device main body, and accommodates a medium; an image formation unit that can form a developer image protruding from an edge of the medium; a fixation unit that fixes the developer image the image formation unit forms to the medium; a data reception unit that receives printing data on unframed image from a host device; and a notification unit that, if a medium larger than a medium size included in the printing data is not accommodated in the medium accommodation unit when the data reception unit receives the printing data, notifies an alarm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an image forming apparatus, and can be applied to, for example, an image forming apparatus such as an electrophotographic printer equipped with a fixing unit. [Background technology]

[0002] Conventionally, an image forming apparatus transfers a toner image formed with toner onto a medium such as printing paper, and then melts and fixes the toner image transferred onto the medium by a fixing unit (fixing roller).

[0003] However, if a printing operation is performed with toner stains on the fixing roller, the stains will be transferred to the transported medium, resulting in deterioration of print quality. Also, if the toner stains are left as they are, the toner may adhere to the fixing roller, causing a similar deterioration of print quality in subsequent operations.

[0004] As a countermeasure to the above, in the past, the possibility that the fixing roller was contaminated with toner was determined by making a prediction based on multiple factors, such as the print settings and whether or not a paper jam occurred during the printing operation, and automatic cleaning was performed at a predetermined timing depending on the result of the judgment (Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-203848 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, unlike general printing, which leaves a certain amount of blank space on all four edges of the medium, there are also image forming devices that are capable of printing all the way to the edges of the medium surface without leaving any margins (hereinafter referred to as "borderless printing").

[0007] Due to the nature of borderless printing as described above, the toner image comes into contact with not only the surface but also the sides of the medium when the image is output, and there is a possibility that the toner will adhere to the medium. Such adhered toner may not be sufficiently fixed to the medium even after the fixing operation is performed. If the medium comes into contact with the fixing roller in this state, the insufficiently fixed toner will be transferred to the fixing roller (Figure 5 shows an example of such toner stains).

[0008] In this way, when performing borderless printing, toner stains may occur regardless of specific factors such as the print settings or whether or not a paper jam occurs during the printing operation, and it can be said that cleaning is required more frequently than when printing with margins.

[0009] Because of the premise that toner stains occur regardless of any specific cause and that cleaning is required more frequently than in bordered printing, problems arise when conventional automatic cleaning control methods (such as those in Patent Document 1) are applied to image forming devices capable of borderless printing. In other words, when there is a shortage of cleaning paper to pass through for the cleaning operation, problems arise such as a lack of consideration for the user, reduced production efficiency, and automatic cleaning not being performed sufficiently at the appropriate time.

[0010] Therefore, there is a demand for an image forming apparatus that is capable of efficiently automatically cleaning the fixing unit even when borderless printing is performed. [Means for solving the problem]

[0011] The image forming device of the present invention is characterized by having (1) a medium storage section provided in the device main body for storing a medium, (2) an image forming section capable of forming a developer image that extends beyond the edge of the medium, (3) a fixing section for fixing the developer image formed by the image forming section to the medium, (4) a data receiving section for receiving print data of a borderless image from a host device, and (5) an alarm section for sounding an alarm when the data receiving section receives the print data and a medium larger than the medium size included in the print data is not stored in the media storage section. Effect of the Invention

[0012] According to the present invention, automatic cleaning of the fixing unit can be carried out efficiently even when borderless printing is performed. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a block diagram showing the configuration of a control system of the printer according to the embodiment. [Diagram 2] 1 is a diagram showing an outline of the overall configuration of a printer according to an embodiment; [Diagram 3] 4 is a flowchart showing a characteristic operation (automatic cleaning process for the fixing unit) of the printer according to the embodiment. [Figure 4] 5A and 5B are explanatory diagrams showing how toner is fixed onto a sheet by a fixing roller according to an embodiment; [Diagram 5] FIG. 4 is an explanatory diagram showing an example of toner staining on a fixing roller. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (A) Main embodiment An embodiment of an image forming apparatus according to the present disclosure will be described in detail below with reference to the drawings. In the following, an example in which the image forming apparatus according to the present disclosure is applied to a printer will be described.

[0015] (A-1) Configuration of the embodiment FIG. 2 is a diagram showing an outline of the overall configuration of the printer according to the embodiment.

[0016] In FIG. 2, printer 1 has paper tray 10 (10-1 to 10-4), paper feed rollers 15 (15-1 to 15-4), entrance sensor 16 (16-1 to 16-4), registration rollers 17 (17-1 to 17-4), entrance sensor 18, write sensor 19, discharge sensor 20, reversal start sensor 21, reversal end sensor 22, reverse paper detection sensor 23, transport rollers 24 (24-1 to 24-4), discharge rollers 25 (25-1 to 25-2), image forming section 30, transfer section 40, fixing section 50, discharge outlet 60, manual paper feed tray 70, and paper feed rollers 71.

[0017] The paper trays 10 (10-1 to 10-4) are arranged in a stack at the bottom of the printer 1, and each of them stores a predetermined size of standard paper P. Note that, although this embodiment shows an example in which four paper trays 10 are provided, the number of paper trays 10 is not particularly limited.

[0018] The paper tray 10 is disposed detachably (openably and closably) with respect to the device body so that the user can set each paper P, and is opened by being pulled out from the device body, and closed by being pushed into the device body. Each paper tray 10 has a placement table 11 on which the paper P is stacked and placed, a pickup roller 12 as a feeding member that feeds out the paper P placed on the placement table 11, a spring 13 as a biasing member that biases the placement table 11 upward and presses the uppermost paper P against the pickup roller 12, a paper detection sensor 14 that detects the presence or absence of paper P stored in the paper tray 10, and the like.

[0019] In this embodiment, the paper P is used as a print medium for forming an image, and is also used as a medium (cleaning paper) for cleaning the fixing rollers 51 and 52 of the fixing unit 50. The cleaning paper is paper that is at least larger than printable paper, and is used to remove pre-fixed toner stains that adhere to the fixing unit 50 by borderless printing by passing the paper through the same transport path as during printing. For example, when borderless printing is performed using B5 (182 mm x 257 mm) paper P, B4 (257 mm x 364 mm) paper P is suitable as cleaning paper.

[0020] The paper P fed from each paper tray 10 is fed to each paper feed path T (T1 to T4) connected to each paper tray 10, and then fed to a paper feed path N common to each paper feed path T, and then fed to paper transport path Rt1 for image formation. Hereinafter, with regard to the transport direction of the paper P, the side from which the paper P is transported is also referred to as the "downstream side", and the side to which the paper P is transported is also referred to as the "upstream side".

[0021] Each paper feed path T is provided with paper feed rollers 15 (15-1 to 15-4) for feeding paper P delivered from each paper tray 10 and sending it upstream within the printer 1 for image formation, and above each paper feed roller 15 is provided an entrance sensor 16 (16-1 to 16-4) for detecting that paper P has been fed.

[0022] Further, in the paper feed path N, registration rollers 17 (17-1 to 17-4) are disposed adjacent to each paper feed path T for feeding the paper P fed through each paper feed path T to the paper transport path Rt1.

[0023] An entrance sensor 18 for detecting that a sheet P has been fed is disposed near the junction of the sheet feed path N and the sheet transport path Rt1.

[0024] The paper transport path Rt1 is a transport path for paper P for image formation, and transports paper P fed from each paper tray 10 to the image forming unit 30, transfer unit 40, and fixing unit 50 on the path, and discharges the paper P to the outside of the printer 1 from a discharge port 60 provided at the top of the printer 1. In addition, a transport roller 24-1 for transporting paper P fed from each paper tray 10 is arranged upstream of the entrance sensor 18 on the paper transport path Rt1, a transport roller 24-2 is arranged upstream of the transport roller 24-1, a writing sensor 19 is arranged upstream of the transport roller 24-2, a discharge sensor 20 is arranged upstream of the fixing unit 50, a transport roller 24-3 is arranged upstream of the discharge sensor 20, and a discharge roller 25-1 is arranged upstream of the transport roller 24-3.

[0025] On the other hand, the paper evacuation path Rt2 and the reversing paper transport path Rt3 are transport paths for the paper P during double-sided printing.

[0026] In the paper evacuation path Rt2, a discharge roller 25-2 is disposed upstream of the transport roller 24-3, and a reverse start sensor 21 is disposed upstream of the discharge roller 25-2.

[0027] In addition, a reversal end sensor 22 is arranged on the reversal paper transport path Rt3, and a transport roller 24-4 is arranged upstream of the reversal end sensor 22 on the reversal paper transport path Rt3, a reversal paper detection sensor 23 is arranged upstream of the transport roller 24-4, and a transport roller 25-5 is arranged upstream of the reversal paper detection sensor 23.

[0028] When single-sided printing is performed, the paper P is conveyed along the paper conveying path Rt1 by conveying rollers 24-3, and is discharged to the discharge port 60 by discharge rollers 25-1.

[0029] On the other hand, when double-sided printing is performed, the paper P with an image formed on one side is sent from the paper transport path Rt1 to the paper evacuation path Rt2, and is transported by the discharge rollers 25-2. When the leading edge of the paper P is detected by the reversal start sensor 21, the discharge rollers 25-2 are rotated in the reverse direction, and the paper P is sent to the reversal paper transport path Rt3 and is reversed. The paper P is then transported by the transport rollers 24-4, fed to the paper transport path Rt1 by the transport rollers 24-5, and transported again along the paper transport path Rt1, where an image is formed on the other side.

[0030] The manual feed tray 70 includes the above-mentioned placement table 11, the above-mentioned pickup roller 12, the above-mentioned spring 13, etc. The paper P fed from the manual feed tray 70 is fed to the paper feed path Q by the paper feed roller 71, and further conveyed along the paper feed path Q to be fed to the paper conveyance path Rt1.

[0031] The image forming section 30 is composed of a toner cartridge that contains toner as a developing agent, a developing unit that forms a toner image as a developing agent image, an LED head (not shown), etc. The photoconductor drum 31 incorporated in the developing unit has a cylindrical shape, and a toner image is formed on its peripheral surface during printing.

[0032] The transfer unit 40 is located below the paper transport path Rt1 and is composed of a cylindrical transfer roller 41 that can rotate in a predetermined direction, a transfer belt (not shown) that serves as a transport means for the paper P, and the like. When the paper P is transported on the paper transport path Rt1 during printing, the transfer unit 40 advances the paper P on the transfer belt and charges the transfer roller 41 to a predetermined potential, thereby transferring the toner image formed on the photoconductor drum 31 of the image forming unit 30 to the upper surface of the paper.

[0033] The fixing unit 50 is located above the paper transport path Rt1 and is composed of rotatable cylindrical fixing rollers 51 and 52 that have the function of applying heat and pressure to the paper P. During a printing operation, the paper P having a toner image transferred thereto by the transfer unit 40 is transported to the fixing unit 50, and the toner image is fixed to the paper P by applying heat and pressure from above and below by the fixing rollers 51 and 52, as illustrated in FIG.

[0034] Next, there will be described the configuration of the control system of the printer 1. Fig. 1 is a block diagram showing the configuration of the control system of the printer according to the embodiment.

[0035] The print control unit 100 as a determination unit is responsible for the main functions of the printer 1 (control of the printing operation and cleaning operation). The print control unit 100 has, for example, a CPU, ROM, RAM, EEPROM, an input / output interface unit, etc., which are not shown, and for example, the CPU executes a program stored in the ROM to realize the functions of the printer 1. The print control unit 100 receives print data and the like from a higher-level device via a communication unit 107 as a data receiving unit. The received print data (including information regarding the size of the print data) is held in the image formation control unit 105.

[0036] The printing control unit 100 has a device setting management unit 101 that manages device settings, a sensor monitoring unit 104 that monitors the detection status of each sensor, an image formation control unit 105 that manages information related to the output image and controls image output operations, and an alarm unit 106.

[0037] The device setting management unit 101 retains a medium setting management unit 103 that manages settings related to the paper P used for printing and settings for cleaning paper, and when a setting operation related to the medium is performed from the operation panel unit 102, a setting value is notified to the medium setting management unit 103. Furthermore, when there is an inquiry about information managed by the medium setting management unit 103, the device setting management unit 101 notifies the medium setting management unit 103 of that fact, obtains the desired information from the medium setting management unit 103, and returns it to the print control unit 100.

[0038] The medium setting management unit 103 manages setting information (medium setting information D) related to the paper P stored in each paper tray 10. The medium setting information D stores information related to the paper P, such as the specifications of the paper P stored in each paper tray 10, length information in the main scanning direction, length information in the sub-scanning direction, and the like.

[0039] Furthermore, the medium setting management unit 103 manages information related to the paper tray 10 designated as the paper tray that stores cleaning paper (cleaning paper storage tray setting information I). In this embodiment, the cleaning paper storage tray setting information I is set by the user via the operation panel unit 102, but in addition to this, the paper tray 10 that stores the maximum size of paper P may be automatically set as the paper tray 10 that stores cleaning paper.

[0040] The sensor monitoring unit 104 monitors the detection state of each sensor, and when a request for notification of the detection state of a specified sensor is made by the print control unit 100, the sensor monitoring unit 104 notifies the detection state of the sensor.

[0041] Based on the output image (print data), the image formation control unit 105 controls the formation of a toner image on the photoconductor drum 31 and the transfer of the toner image onto the paper P by the transfer roller 41, both of which are performed in the image forming unit 30. Furthermore, when a request for notification of length information in the main scanning direction or sub-scanning direction of the output image is made by the print control unit 100, the image formation control unit 105 notifies the requested information.

[0042] When the print control unit 100 determines that paper P is not stored in the paper tray 10 set in the cleaning paper storage tray setting information I, the notification unit 106 performs predetermined processing such as displaying a predetermined warning message (such as a message such as "Cleaning paper is not stored in the specified tray") on the operation panel unit 102 or outputting a warning sound from a speaker (not shown).

[0043] (A-2) Operation of the embodiment Next, the operation of the printer 1 according to the embodiment having the above configuration will be described.

[0044] 3 is a flowchart showing a characteristic operation (automatic cleaning process of the fixing unit) of the printer 1 according to the embodiment. When the printer 1 receives a print request from a host device (not shown), the printer 1 performs control according to the following process sequence.

[0045] <Step S1> The print control unit 100 determines whether cleaning paper is stored in the paper tray 10.

[0046] Specifically, the print control unit 100 requests the medium setting management unit 103 via the device setting management unit 101 to obtain information on the paper tray 10 designated as the cleaning paper (cleaning paper storage tray setting information I). Next, the print control unit 100 requests the sensor monitoring unit 104 to notify the detection state of the paper P by the paper detection sensor 14 present in the corresponding paper tray 10.

[0047] If the acquired detection status is "paper out state", the print control unit 100 determines that cleaning paper (paper P as cleaning paper) is not stored, suspends the ongoing print control, and transitions to the next step S2. On the other hand, if the acquired detection status is "paper present state", the print control unit 100 determines that cleaning paper is stored, and transitions to step S3 described below.

[0048] <Step S2> If it is determined in step S1 above that cleaning paper is not stored in the corresponding paper tray 10, the notification unit 106 uses notification means such as a screen display on the operation panel unit 102 or an alarm sound to prompt the user to store cleaning paper in the paper tray 10. Thereafter, the notification unit 106 displays a screen on the operation panel unit 102 to confirm whether or not cleaning paper has been stored. After the user inputs from the operation panel that cleaning paper has been stored, the print control unit 100 resumes the interrupted print control (restarting the process from step S1).

[0049] <Step S3> The print control unit 100 determines the possibility of toner adhering to the side surface of the paper in the main scanning direction (the vertical side surface PS2 of the paper P in FIG. 5B) when outputting an image.

[0050] First, the print control unit 100 sends a notification request to the image formation control unit 105 to obtain length information in the main scanning direction of the output image. Similarly, the print control unit 100 sends a notification request to the medium setting management unit 103 via the device setting management unit 101 to obtain length information in the main scanning direction of the paper P used for printing.

[0051] Next, the print control unit 100 acquires length information in the main scanning direction of the output image and the paper P used for printing, and then uses each length information to determine the possibility of toner adhesion. For example, if the following formula (1) is established, the print control unit 100 determines that there is a possibility that the toner image will come into contact with the vertical side surface PS2 of the paper P during image output, causing toner to adhere. Lhorizonal+Lhmargin≧Lhmax …(1)

[0052] In the above formula (1), Lhorizonal is the length of the output image in the main scanning direction, and Lhmax is the length of the paper P used for printing in the main scanning direction. In the above formula (1), Lhmargin is a value provided in consideration of the case where, even if it is assumed that Lhorizonal < Lhmax holds and contact between the toner image and the vertical side surface PS2 of the paper P does not occur, contact may occur due to minute displacement that may occur during image output. Note that Lhmargin may be, for example, a set value that can be changed by the user from the operation panel unit 102, or may be a fixed value.

[0053] When the printing control unit 100 determines that there is a possibility that toner may adhere to the vertical side surface PS2 of the paper P according to the result of the establishment of the above formula (1), it transitions to step S4. On the other hand, when it determines that there is no possibility that toner may adhere to the vertical side surface PS2 of the paper P, it transitions to step S5.

[0054] <Step S4> When the printing control unit 100 determines in step S3 described above that there is a possibility that toner may adhere to the vertical side surface PS2 of the paper P, it stores the determination result (the determination result that cleaning is necessary) and transitions to step S7 described later.

[0055] <Step S5> During image output, the printing control unit 100 determines whether toner may adhere to the side surface of the paper in the sub-scanning direction (the horizontal side surface PS1 of the paper P in FIG. 5(B)) in the same manner as in step S3 described above.

[0056] First, the printing control unit 100 issues a notification request to the image forming control unit 105 in order to acquire the length information of the output image in the sub-scanning direction. Similarly, in order to acquire the length information of the paper P used for printing in the sub-scanning direction, a notification request is issued to the medium setting management unit 103 via the device setting management unit 101.

[0057] Next, after the print control unit 100 acquires the length information of the output image and the length of the paper P used for printing in the sub-scanning direction, it uses each length information to determine the possibility of toner adhesion. For example, if the following equation (2) holds, the print control unit 100 determines that the toner image may contact the lateral side PS1 of the paper P during image output, and there is a possibility of toner adhesion. Lvertical + Lvmargin ≧ Lvmax …(2)

[0058] In the above equation (2), Lvertical is the length of the output image in the sub-scanning direction, and Lvmax is the paper length of the paper P used for printing in the sub-scanning direction. In the above equation (2), Lvmargin is a value provided in consideration of the case where, even if Lvertical < Lvmax holds and it is assumed that the toner image does not contact the lateral side PS1 of the paper P, contact may occur due to minute displacement that may occur during image output. Similar to the above Lhmargin, Lvmargin may be a setting value that can be changed by the user from the operation panel unit 102, or may be a fixed value.

[0059] When the print control unit 100 determines that there is a possibility of toner adhering to the lateral side PS1 of the paper P according to the result of the establishment of the above equation (2), it transitions to step S6. On the other hand, when it determines that there is no possibility of toner adhering to the lateral side PS1 of the paper P, it transitions to step S7.

[0060] <Step S6> When the print control unit 100 determines in step S5 described above that there is a possibility of toner adhering to the lateral side PS1 of the paper P, it stores the value of Lvertical and transitions to step S7 described later.

[0061] <Step S7> The print control unit 100 starts executing the printing operation. Since the printing operation of the printer 1 here is the same as the existing process, the description is omitted.

[0062] <Step S8> After starting the printing operation in step S7, the print control unit 100 checks whether there is a next print request. If there is a next print request, the print control unit 100 proceeds to step S9. If there is no next print request, the print control unit 100 proceeds to step S12, which will be described later.

[0063] <Step S9> The print control unit 100 checks whether the value of Lvertical stored when the process of step S6 described above is being performed is being held. The print control unit 100 also sends a notification request to the medium setting management unit 103 via the device setting management unit 101 to obtain length information in the sub-scanning direction of the paper P to be fed in the next print request.

[0064] <Step S10> The print control unit 100 compares the stored value of Lvertical with the length in the sub-scanning direction of the paper P to be fed in response to the acquired next print request.

[0065] The case where the value of Lvertical is retained in the processing of step S6 described above means that there is a possibility that toner has adhered to the lateral side PS1 of the paper P during a previous printing operation, in other words, there is a possibility that toner stains have adhered vertically to the peripheral side of the fixing roller, as illustrated in Figure 5(A).

[0066] If the length of the paper P in the sub-scanning direction to be fed next is equal to or greater than the value of Lvertical held by the print control unit 100, the print control unit 100 determines that there is a possibility that the above-mentioned toner stains will adhere to the next fed paper P, and transitions to step S11. On the other hand, if the value of Lvertical held by the print control unit 100 is greater than the length of the paper P in the sub-scanning direction to be fed next, the print control unit 100 determines that the above-mentioned toner stains will not adhere to the fed paper because the location where the toner stains adhere will not come into contact with the next fed paper P, and transitions to step S12.

[0067] If the print control unit 100 does not hold the value of Lvertical in step S9 and is unable to obtain the value of Lvertical, it skips this process and proceeds to the next step S12. If the print control unit 100 does not hold the value of Lvertical, that is, if there is no possibility that toner stains have adhered to the fixing rollers 51 and 52 during previous printing.

[0068] <Step S11> If the print control unit 100 determines in step S10 described above that there is a possibility that toner may adhere to the lateral side PS1 of the paper P, it stores the determination result (determination that cleaning is necessary) and transitions to step S12 described below.

[0069] <Step S12> If it is determined in step S8 above that there is no next print request (if it is determined in step S10 above that toner stains are not visible or there is no toner stain, or after step S11 above), the print control unit 100 checks whether the next print can be started (whether the process that started the print in step S7 above has ended and the printer 1 is in a state where the next print can be started). If the next print can be started, the print control unit 100 transitions to the next step S13, whereas if the next print cannot be started, the print control unit 100 returns to step S8 above.

[0070] <Step S13> If the print control unit 100 determines in step S12 above that the next print can be started, it then checks whether there is a next print request, and if there is a print request, it transitions to step S14, and if there is no print request, it transitions to step S15, which will be described later.

[0071] <Step S14> If it is determined in step S13 that there is a print request, the print control unit 100 determines whether or not it is necessary to perform a cleaning operation before starting the next print operation.

[0072] The print control unit 100 refers to the judgment result stored in step S4 or step S11 described above, and if a judgment result indicating that there is a possibility of toner contamination occurring (a judgment result indicating that cleaning is necessary) is stored, it transitions to step S15 before starting the next printing operation.

[0073] On the other hand, if no information indicating that cleaning is necessary is stored, the print control unit 100 determines that there is no toner contamination on the fixing rollers 51 and 52. In this case, the print control unit 100 starts the next printing operation without performing a cleaning operation (starting the process from step S1 described above).

[0074] <Step S15> If it is determined in step S13 that there is no next print request (or if it is determined in step S14 that cleaning is necessary), the print control unit 100 executes processing related to the cleaning operation and cleaning control. Note that the processing in step S15 is an example of the cleaning control unit.

[0075] The transition to step S15 occurs when the previous judgments have determined that there is a possibility that toner stains have adhered to the fixing rollers 51 and 52, or when there is no next print request, and this can be said to be an appropriate timing to perform a cleaning operation.

[0076] First, the print control unit 100 checks whether there is a next print request and whether there is paper P being printed on both sides. If there is a next print request, the print control unit 100 puts the execution of the printing operation on hold until cleaning is completed, and similarly, if there is paper P being printed on both sides, the print control unit 100 stops the transport at a predetermined waiting point provided on the reverse paper transport path Rt3. Next, the print control unit 100 requests notification of the setting information of the paper tray designated as the paper tray 10 that contains the cleaning paper to the medium setting management unit 103 via the device setting management unit 101. Based on the acquired information, the print control unit 100 feeds cleaning paper from the corresponding paper tray 10 and performs the cleaning operation of the fixing rollers 51 and 52.

[0077] Furthermore, if there is any information stored in the process of step S4 or step S11, or any value held in the process of step S6, the print control unit 100 deletes all of it since it is no longer necessary.

[0078] After the above-mentioned processing is completed, the print control unit 100 starts the next printing operation or resumes the waiting double-sided printing operation, and if there is no next print request, transitions the printer 1 to a standby state.

[0079] (A-3) Effects of the embodiment As described above, according to this embodiment, the following effects are achieved.

[0080] Printer 1 checks whether cleaning paper is present before performing a printing operation, and notifies the user to insert paper if there is none. This prevents the printing operation from being interrupted due to a lack of cleaning paper when performing borderless printing, which requires frequent cleaning, and prevents the user from having to go through the hassle of resuming printing after an interruption and reduces reduced production efficiency.

[0081] In addition, by controlling the cleaning to be performed appropriately when successive printing requests are completed and when it is determined that there is a possibility that toner stains have adhered to the fixing rollers 51 and 52, cleaning is not performed excessively frequently, which has the effect of suppressing wear of the cleaning paper and the time required for cleaning.

[0082] (B) Other embodiments The present disclosure is not limited to the above-described embodiment, and may include modified embodiments as exemplified below.

[0083] (B-1) As a modified example, when a print job is sent from a higher-level device, the print control unit 100 may determine whether or not the print job contains information indicating that the print is borderless printing. If the print job contains information indicating that the print is borderless printing, the print control unit 100 performs processing according to the flowchart in Fig. 3, but if the print is not borderless printing, the print control unit 100 performs the same processing as in the past.

[0084] (B-2) In the above embodiment, an example was shown in which the paper P stored in the paper tray 10 designated in advance by the user is used as cleaning paper, but the cleaning paper may be dynamically determined at the time of printing by the following method. For example, when the print control unit 100 receives a print job (print data), it may determine whether the paper tray 10 contains paper P larger than the paper size (medium size) contained in the print data, and if the paper tray 10 contains paper P larger than the medium size, that paper P may be used as cleaning paper. The size of the paper P in each paper tray 10 can be confirmed by referring to the medium setting information D of the medium setting management unit 103. Also, whether or not paper P is present in each paper tray 10 can be confirmed by the paper detection sensor 14.

[0085] (B-3) In the above modification of (B-2), the cleaning paper was determined based on the paper size (medium size) included in the print data, but the cleaning paper may be determined according to the size of the print data. The size of the print data is, for example, Lhorizonal (length of the print data in the main scanning direction) and Lvertical (length of the print data in the sub-scanning direction) shown in steps S3 and S5 above. The cleaning paper may be determined based on these values ​​using the method described in (B-2) above.

[0086] (B-4) In the above equations (1) and (2), the margins (Lhmargin, Lvmargin) are taken into account when determining the possibility of toner contacting the side of paper P, but as a variant, the determination may be made without taking these margins into account.

[0087] (B-5) In the above embodiment, in the process of step S5, the lengths in the sub-scanning direction are compared, and if there is a possibility that the toner may come into contact with the side of the paper P, the paper length in the sub-scanning direction is stored in the process of step S6, and the contents of the next print request are taken into account (processes of steps S8 to S10), and finally a determination that cleaning is necessary is stored (process of step S11). As a modified example, if there is a possibility that the toner may come into contact with the side of the paper P based only on the determination result of step S5, a determination that cleaning is necessary may be stored in the process of step S6. In this case, the processes of steps S8 to S11 are omitted.

[0088] (B-6) In the above embodiment, the process of step S13 checks for the next print request, and if there is no next print request, the fixing unit 50 is cleaned in step S15 even if the previous determination that cleaning is necessary has not been stored, but as a modified example, the process of step S13 may be omitted. In this case, the fixing unit 50 is cleaned only based on the previous determination result of step S14 that cleaning is necessary. [Explanation of symbols]

[0089] 1... printer, 10... paper tray, 11... placement table, 12... pickup roller, 13... spring, 14... paper detection sensor, 15... paper feed roller, 16... entrance sensor, 17... registration roller, 18... entrance sensor, 19... writing sensor, 20... discharge sensor, 21... reversal start sensor, 22... reversal end sensor, 23... reversed paper detection sensor, 24... transport roller, 25... discharge roller, 30... image forming section, 31... photosensitive drum, 40... transfer section, 41... transfer roller, 50... fixing section, 51... fixing roller, 52... Fixing roller, 60...ejection outlet, 70...manual feed tray, 71...feed roller, 100...print control unit, 101...device setting management unit, 102...operation panel unit, 103...media setting management unit, 104...sensor monitoring unit, 105...image formation control unit, 106...alarm unit, 107...communication unit, D...media setting information, I...cleaning paper storage tray setting information, N...paper feed path, P...paper, PS1...horizontal side, PS2...vertical side, Q...paper feed path, Rt1...paper transport path, Rt2...paper evacuation path, Rt3...reverse paper transport path, T...paper feed path.

Claims

1. a medium storage section provided in the device body and configured to store a medium; an image forming unit capable of forming a developer image that extends beyond an edge of the medium; a fixing unit that fixes the developer image formed by the image forming unit onto the medium; a data receiving unit that receives print data for a borderless image from a host device; a notification unit that issues an alarm if a medium larger than the medium size included in the print data is not stored in the medium storage unit when the data receiving unit receives the print data; An image forming apparatus comprising:

2. 2. The image forming apparatus according to claim 1, further comprising a determination unit that determines whether or not a cleaning process should be performed to remove dirt from the fixing unit based on a result of comparing the size of the print data with the size of the medium.

3. 3. The image forming apparatus according to claim 2, wherein the determination unit determines whether or not the cleaning process should be performed depending on whether a value obtained by adding a predetermined value to a size of the print data is equal to or larger than a size of the medium.

4. 3. The image forming apparatus according to claim 2, wherein, when the data receiving unit receives print data to be printed next, the determination unit determines whether or not the cleaning process should be executed, taking into account a size of the next print data.

5. An image forming apparatus as described in any one of claims 2 to 4, characterized in that it has a cleaning control unit that, upon receipt of a determination by the determination unit that the cleaning process should be performed, performs the cleaning process using a medium larger than the medium size included in the printing data.

Images