JP2014048317A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To terminate recovery printing earlier.SOLUTION: A controller 221 transmits color information group CL to a CPU 211 together with a print job. When the print job is interrupted, the CPU 211 performs recovery printing in response to a recovery print instruction. The CPU 211 refers to the color information group CL to determine color information of a page on which an image is to be formed first in the recovery printing, and controls drive of a motor M2 for moving an intermediate transfer belt so as to position the intermediate transfer belt 32 in a position according to the color information. The drive control on the motor M2 for moving the intermediate transfer belt is started before receiving the recovery print instruction.

Description

  The present invention relates to an image forming apparatus that performs image formation of a plurality of colors.

  Conventionally, a color image forming apparatus using an electrophotographic process employs a method in which a toner image formed on a photoreceptor is primarily transferred onto an intermediate transfer belt and then secondarily transferred onto a recording sheet. It has been.

  For example, each of the photosensitive members for yellow toner, magenta toner, and cyan toner (hereinafter, these three are collectively referred to as a “color toner photosensitive member”) and a black toner photosensitive member are combined. The body is disposed along the rotational direction of the intermediate transfer belt. As each photoconductor and the intermediate transfer belt rotate while being in contact with each other, the toner images formed on the photoconductor are sequentially superimposed and transferred onto the intermediate transfer belt, and a color image is formed on the intermediate transfer bell. Thereafter, the color image formed on the intermediate transfer belt is transferred to the recording paper downstream in the rotation direction.

  A color image is formed by superimposing toners of four colors of yellow, magenta, cyan, and black, but a black and white image can be formed using only black toner. That is, in forming a black-and-white image, toners of three colors of yellow, magenta, and cyan are not necessary, so that the intermediate transfer belt need not be brought into contact with the color toner photoconductor. On the contrary, when the intermediate transfer belt is brought into contact with the color toner photoconductor, there is a disadvantage that the deterioration of the surface of the photoconductor is promoted and the running cost is increased.

  For the above reasons, in color image formation, the intermediate transfer belt is brought into contact with four photoreceptors for yellow, magenta, cyan, and black. In black-and-white image formation, the intermediate transfer belt is brought into contact with only the black toner photoreceptor. It is a common method to form an image.

  In executing a print job, in continuous printing of a plurality of pages, formation of a color image or formation of a monochrome image may differ from page to page. For example, the first page is a color image, the second page is a color image, and the third page is a black / white image.

  In such a mixed continuous printing example, since the first page is a color image, image formation is performed with the intermediate transfer belt in contact with all four photoconductors. When the image formation for the first page is completed, the process proceeds to the image formation for the second page. However, since the second page is also a color image, the intermediate transfer belt is kept in contact with the color toner photoconductor. When the image formation for the second page is completed, the process proceeds to image formation for the third page (black and white image). At this time, since the image is a black and white image, the intermediate transfer belt is brought into contact with the color toner photoconductor. Change to the separated state. After that, the formation of the black and white image of the third page is started.

  The recording paper on which the toner image is transferred from the intermediate transfer belt is conveyed to the fixing unit, where the toner image is fixed by the action of heat and pressure, and is sequentially discharged. In continuous printing, a series of processes such as image formation, thermal fixing, and discharge are sequentially performed. Therefore, the first page is already being discharged, the second page is being fixed, and the third page is being formed. It can become the state.

  Here, let us consider a case where a paper jam (hereinafter referred to as a jam) occurs during the conveyance of the recording paper. When the jam occurs, the discharge operation is continued for the recording paper that is ready to be discharged, but the recording paper during fixing or image formation is stopped at that location. For example, the first page is discharged, the second page is stopped at the fixing unit, and the third page is stopped at the image forming unit. Thereafter, the user who notices the jam stop performs the jam processing by removing the second and third page recording sheets stopped in the apparatus.

  When the apparatus detects that the recording paper that has been stopped in the apparatus has been removed (jam processing completed), after the initial operation such as the cleaning operation is performed, the page that has not been normally ejected is printed again. Become. This is called recovery printing. In the above example, the first page has been discharged. Accordingly, in this case, since the second page (color image) and the third page (black and white image) in the job are to be printed by the recovery print, the first to be printed in the recovery print is the second page color image. become.

  In this case, as a state before the recovery print is started, how the contact state or separation state between the four photoconductors and the intermediate transfer belt should be considered.

  Conventionally, in Patent Document 1, the contact / separation relationship between the photosensitive member and the intermediate transfer belt is set to a state during image formation when the operation is stopped due to the occurrence of a jam, or an image formation mode that is frequently used. Proposals have been made to achieve this state.

Japanese Patent Laid-Open No. 9-258614

  However, if the contact / separation relationship between the photoconductor immediately before the start of recovery printing and the intermediate transfer belt is uniformly maintained in a state during image formation when the operation is stopped, it is not always efficient. For example, when applied to the above example, since the third page (monochrome image) was being formed, the start of recovery printing is awaited with the intermediate transfer belt in contact with only the black toner photoconductor. .

  However, since the first page of the recovery print is the color image of the second page, an operation of bringing the intermediate transfer belt into contact with the color toner photoconductor is required to start the recovery print. Since the time for this is required at the start of actual recovery printing, the end of recovery printing is also delayed by that amount.

  This is not limited to the above example, and if the contact / separation relationship between the photoconductor and the intermediate transfer belt is different between the state when the operation is stopped and the state when the recovery print should be started, it should match the recovery print. It is necessary to correct the contact / separation relationship.

  As described above, in the related art, after receiving the recovery print start instruction, there is a case where it is necessary to switch the positional relationship between the color toner photoconductor and the intermediate transfer belt from the separated state to the contact state or vice versa. there were. Accordingly, there is a problem that the actual print start in the recovery print is delayed and the end of the recovery print is delayed, resulting in a long overall processing time.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of accelerating the end of recovery printing.

  To achieve the above object, according to the present invention, a toner image is formed on at least one image carrier in accordance with a print job among a plurality of image carriers, and the toner image formed on the image carrier is transferred to a belt member. And an image forming apparatus for performing a series of image forming processes for transferring the toner image transferred to the belt member onto a recording sheet, wherein the belt member is moved with respect to the plurality of image carriers. The print job is interrupted due to an interruption factor, a moving means for switching to a position for forming a color image or a position for forming a monochrome image, an acquisition means for obtaining color information of each page in the print job, A control unit that controls to perform a recovery print in response to a recovery print start instruction, and a color information acquired by the acquisition unit. And determining means for determining whether the color information of the page on which image formation is to be performed first in the recovery print is color or black and white, and the control means is provided when the print job is interrupted. Then, before receiving the recovery print start instruction, control of the moving means for positioning the belt member at a position corresponding to the color information of the page on which image formation is to be performed first determined by the determination means is started. It is characterized by that.

  According to the present invention, the end of recovery printing can be accelerated.

1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a detailed configuration of an image forming unit and a transfer unit, showing a state during color image formation (FIG. (A)) and a state during black-and-white image formation (FIG. (B)). FIG. 6 is a diagram illustrating a state in which a jam occurs in a fixing unit during continuous printing, printing is interrupted, and the apparatus is stopped. 3 is a control block diagram of the image forming apparatus. FIG. 6 is a flowchart of processing during normal printing operation. 6 is a flowchart of a belt position setting operation process executed in step S116 of FIG. 5. It is a flowchart of a controller process. It is the time chart which contrasted the prior art and this invention about the transition of operation | movement from jam generation to recovery printing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention.

  This image forming apparatus is a color image forming apparatus that forms an image of a plurality of colors using an electrophotographic process. First, the configuration and operation of the image forming apparatus will be outlined.

  The recording paper P is fed from the paper feeding units 2a to 2d by the pickup rollers 1a to 1d. In the image forming unit 4, a toner image formed on a photoconductor 31 as an image carrier described later is primarily transferred to an intermediate transfer belt 32 that is a belt member, and the toner image transferred to the intermediate transfer belt 32 is transferred to the transfer unit. 2 is secondarily transferred to the recording paper P. Thereafter, the toner image formed on the recording paper P is thermally fixed in the fixing unit 5, and the recording paper P is discharged by the paper discharge unit 6.

  The image forming apparatus also includes an operation unit 7 as a user IF (interface). In the conveyance path of the recording paper P, in addition to the conveyance rollers 10a to 10p for conveying the recording paper P, a jam detection sensor 9 (9a to 9j) for detecting a jam (hereinafter referred to as jam) of the recording paper P is disposed. The

  When the print job processing is stopped due to an interruption such as the occurrence of a jam (the paper feeding, image formation, fixing, and paper discharge operations of the device are stopped), the user opens a door (not shown) as a jam processing, and enters the inside of the device. The stopped recording sheet P is removed. Thereafter, when the user closes the door, the jam processing is completed and the apparatus returns from the interruption factor.

  FIGS. 2A and 2B are schematic views showing detailed configurations of the image forming unit 4 and the transfer unit 3. In particular, FIG. 2A shows a state when a color image is formed, and FIG. 2B shows a state when a monochrome image is formed.

  The image forming unit 4 includes four photoconductors 31 (31Y, 31M, 31C, and 31Bk) and transfer rollers 34 (34Y, 34M, 34C, and 34Bk) as transfer members corresponding to the photoconductors 31. . Each transfer roller 34 faces the corresponding photoreceptor 31. The photoconductors 31Y, 31M, 31C, and 31Bk are a yellow toner photoconductor, a magenta toner photoconductor, a cyan toner photoconductor, and a black toner photoconductor, respectively. In the image forming unit 4, the electrostatic latent image formed on each photoconductor 31 is developed by a developing device, and a toner image of each color is formed on the surface of each photoconductor 31.

  The intermediate transfer belt 32 is supported by support rollers 33a and 33b and a rotation roller 33c of the transfer unit 3, and the rotation roller 33c is driven by the intermediate transfer belt rotation motor M1 to move the intermediate transfer belt 32 in the direction of arrow 37. Rotate to The intermediate transfer belt 32 rotates and moves between the transfer roller 34 and the photoconductor 31. The yellow, magenta, cyan, and black toner images formed on the respective photoreceptors 31 are sequentially transferred and superimposed on the rotating intermediate transfer belt 32 to form a color toner image on the intermediate transfer belt 32. The The color toner image formed on the intermediate transfer belt 32 is conveyed in the direction of the arrow 37 as the intermediate transfer belt 32 rotates, and the surface of the recording paper P that has been fed and conveyed from the sheet feeding units 2a to 2d. Then, the image is transferred by the transfer roller 35 of the transfer unit 3.

  In this manner, a toner image is formed on at least one photoconductor 31 according to a print job, the toner image formed on the photoconductor 31 is primarily transferred to the intermediate transfer belt 32, and the toner image transferred to the intermediate transfer belt 32 is further transferred. Is secondarily transferred to the recording paper P. These processes are referred to as a series of image forming processes.

  At the time of color image formation (FIG. 2A), not only the black toner photoconductor (31Bk) as a black and white image carrier but also three color toner photoconductors (31Y, M and C) are also in contact with the intermediate transfer belt 32. On the other hand, when forming a black and white image (FIG. 2B), yellow, magenta and cyan toners are not necessary for image formation. Therefore, although the intermediate transfer belt 32 is in contact with the black toner photoconductor (31Bk), the intermediate transfer belt 32 is not in contact with and separated from the color toner photoconductors (31Y, M, and C). ing.

  A configuration and a control mechanism for contacting / separating the intermediate transfer belt 32 to / from the color toner photoreceptors (31Y, M, C) will be described.

  The transfer rollers 34 </ b> Y, 34 </ b> M, and 34 </ b> C are connected to the frame 40, and are provided so as to be rotatable with respect to the frame 40. The frame 40 is connected to the rotation shaft 39 and is rotatable about the rotation shaft 39. The cam 44 is disposed so as to be engageable with the frame 40.

  A gear 43 is coaxially attached to the cam 44, and the gear 43 is engaged with the gear 41. When the gear 41 is driven to rotate by the intermediate transfer belt moving motor M2 as the moving means, the gear 43 rotates, and the cam 44 rotates as the gear 43 rotates. When the frame 40 is driven to be pushed up by the cam 44, the frame 40 rotates in the clockwise direction in FIG. 2, and when the cam 44 is displaced in the retracting direction, the counterclockwise in FIG. Rotate in the direction and descend.

  As the frame 40 is displaced, the transfer rollers 34Y, 34M, and 34C are displaced. That is, as the frame 40 is raised / lowered, the transfer rollers 34Y, 34M, 34C connected to the frame 40 are raised / lowered. A portion of the intermediate transfer belt 32 sandwiched between the transfer rollers 34Y, 34M, and 34C and the photoconductors 31Y, 31M, and 31C is moved up and down by the transfer rollers 34Y, 34M, and 34C. Contact / separate 31C.

  However, the mechanism for bringing the intermediate transfer belt 32 into contact with or separating from the color toner photoreceptors (31Y, M, C) is not limited to the illustrated cam mechanism. By moving the intermediate transfer belt 32, the position of the intermediate transfer belt 32 relative to the color toner photoconductors (31Y, M, C) can be switched between a position for forming a color image and a position for forming a monochrome image. Any mechanism can be used.

  FIGS. 3A and 3B are diagrams illustrating a state in which a jam occurs in the fixing unit 5 during continuous printing, printing is interrupted, and the apparatus is stopped. In particular, FIGS. 3A and 3B show a state where the image forming unit 4 and the transfer unit 3 are forming a monochrome image and a color image when the apparatus is stopped. 3A and 3B show a state in which the image on the recording paper P in which a jam has occurred in the fixing unit 5 was a color image and a monochrome image.

  There are conveyance rollers 10 b and 10 a downstream of the fixing unit 5. Hereinafter, with respect to the recording paper P, a black and white image and a color image may be formed or the recording paper P on which the image is formed may be abbreviated as a black and white paper and a color paper, respectively.

  In the example shown in FIG. 3A, the apparatus is stopped due to the occurrence of a jam during the formation of a monochrome image. Therefore, the intermediate transfer belt 32 is stopped in a state of being separated from the color toner photoconductors (31Y, M, C). Yes. In the example shown in FIG. 3B, since the apparatus is stopped due to the occurrence of a jam during the formation of the color image, the intermediate transfer belt 32 is stopped in contact with the color toner photoconductors (31Y, M, C). ing.

  After the recording paper P stopped in the apparatus is removed by the user (jam processing), the respective photoreceptors 31 and the intermediate transfer belt 32 are cleaned, and the apparatus returns to a printable state again. After the apparatus returns to a printable state, recovery printing is performed.

  In the example shown in FIG. 3A, the image of the recording paper P that has become jammed paper in the fixing unit 5 is a color image. Therefore, when the recovery print is performed, the image of the page on which the image is first formed by the image forming unit 4 and the transfer unit 3 in the recovery print is a color image. On the other hand, in the example shown in FIG. 3B, the image of the page to be imaged first in the recovery print is a monochrome image.

  When the image of the page to be printed first is a color image, it is necessary to start recovery printing in a state where the intermediate transfer belt 32 is in contact with the color toner photoconductors (31Y, M, C). If it is not in such a contact state, a process for making the contact state is required. On the other hand, when the image of the page to be printed first is a black and white image, it is necessary to start recovery printing with the intermediate transfer belt 32 separated from the color toner photoreceptors (31Y, M, C). If it is not in such a separated state, a process for making the separated state is necessary.

  FIG. 4 is a control block diagram of the image forming apparatus.

  The image forming apparatus includes an engine control unit 21 that controls an engine unit of the image forming apparatus and a controller control unit 22 that controls a print job. The engine control unit 21 includes a CPU 211 (acquisition unit, control unit, determination unit) that is a central processing unit, a ROM 212 that stores a program executed by the CPU 211, and a RAM 213 that stores various data associated with the program execution.

  The controller control unit 22 includes an image reading unit 222 that reads an image, a display unit 223 that displays an apparatus state for a user, and a controller 221 that controls these units. A communication path is established between the controller 221 and the CPU 211. A command for instructing a printing operation from the controller 221 to the CPU 211 is transmitted via this communication path. Also, a status notification for notifying the engine state (printable state, unprintable state due to jam, etc.) from the CPU 211 to the controller 221 is also made through this communication path.

  In the engine control unit 21 and the controller control unit 22, illustration and description of other devices not directly related to the present invention are omitted.

  The controller 221 sends various information (including the number of pages) regarding the print job to the CPU 211. The color information of each page in the print job is also transmitted. For example, it is determined whether each image of the original read by the image reading unit 222 is a color image or a monochrome image, and the color information is transmitted to the CPU 211. The color information of each page in the print job is transmitted as a color information group CL for each page, and the CPU 211 acquires the information by receiving the color information group CL (acquisition means). The acquired color information group CL is stored in the RAM 213. In the color information group CL, each page is associated with color information (whether it is a color image or a monochrome image).

  Connected to the CPU 211 are an intermediate transfer belt rotating motor M1 (FIG. 2), an intermediate transfer belt moving motor M2 (FIG. 2), and a jam detection sensor 9 (FIG. 1). Further, the CPU 211 is connected with a recording paper conveying motor 23, a recording paper feeding solenoid 24, an image forming circuit 25, a fixing control circuit 26, and a door open / close detection sensor 30.

  The rotational force of the recording paper transport motor 23 is transmitted to the pickup rollers 1a to 1d by activating the recording paper feed solenoid 24, and the recording paper P is transported into the apparatus from the paper feeding units 2a to 2d.

  The image forming circuit 25 controls the image forming unit 4 and the transfer unit 3. The image forming circuit 25 includes a motor circuit for driving the color toner photoconductors (31Y, M, C) and the black toner photoconductor (31Bk), a charging high-voltage circuit for forming an electrophotographic latent image, and a laser scanner driving circuit. Prepare. The image forming circuit 25 further includes a development high-voltage circuit that forms a toner image from the latent image and a transfer high-voltage circuit that transfers the toner image.

  The fixing control circuit 26 includes an electric circuit that controls a driving voltage of a heating element (not shown) and a thermistor circuit that detects the temperature of the heating element, and controls the fixing unit 5 (FIG. 1). The jam detection sensor 9 (FIG. 1) detects a jam of the recording paper P being conveyed. The door opening / closing detection sensor 30 detects opening / closing of a door (not shown) of the image forming apparatus.

  Next, control processing in the engine control unit 21 and the controller control unit 22 will be described with reference to FIGS.

  FIG. 5 is a flowchart of processing during a normal printing operation. This process is executed in the engine control unit 21 when the image forming apparatus is powered on.

  First, the CPU 211 performs an initial operation when the power is turned on (step S101). The main purpose of this initial operation is to check for equipment failures. Then, the CPU 211 waits for the end of the initial operation (step S102), and when the initial operation ends, waits for a print instruction (print job execution instruction) from the controller 221 (step S103). Here, a color information group CL (FIG. 4) in the print job is also sent from the controller 221 along with the print instruction.

  When the CPU 211 receives the print instruction, the CPU 211 shifts to execution of a print job and starts a print operation (step S104). Next, the CPU 211 refers to the color information group CL attached to the print instruction, and determines whether the color information of the first page in the print job is a color image or a monochrome image (step S105). As a result of the determination, if the color information of the first page is a black and white image, the CPU 211 drives and controls the intermediate transfer belt moving motor M2 from the color toner photoreceptor (31Y, M, C) to the intermediate transfer belt. A control operation for separating 32 is started (step S106). Thereafter, the CPU 211 waits until the separation operation of the intermediate transfer belt 32 is completed (step S107), and when the separation operation is completed, the process proceeds to step S110.

  On the other hand, if the result of determination in step S105 is that the color information of the first page is a color image, the CPU 211 advances the processing to step S108. In step S108, the CPU 211 controls the drive of the intermediate transfer belt moving motor M2, and starts a control operation for bringing the intermediate transfer belt 32 into contact with the color toner photoreceptors (31Y, M, C). Thereafter, the CPU 211 waits until the contact operation of the intermediate transfer belt 32 is completed (step S109), and when the contact operation is completed, the process proceeds to step S110.

  In step S110, the CPU 211 starts pre-rotation. This pre-rotation operation is an operation for starting up each part necessary for the printing operation, such as turning on the main motor, turning on various high voltage voltages of the image forming unit 4 and the transfer unit 3, and turning on the fixing heater. When the start-up is completed, a series of printing operation sequences including feeding of the recording paper P, image formation, fixing, and paper discharge start. The CPU 211 monitors the detection result of the jam detection sensor 9 during execution of this series of printing operation sequences, and continues to determine whether or not a jam has occurred (step S111).

  If the jam has not occurred, the CPU 211 determines whether or not the last page printing operation in the print job has ended (step S112). If the last page printing operation has not ended, the process proceeds to step S111. Return to. Thereby, a series of print sequences is continued. When the printing operation for the last page is completed, the CPU 211 returns the process to step S103.

  If it is determined in step S111 that a jam has occurred, the CPU 211 notifies the occurrence of the jam by transmitting a jam occurrence status to the controller 221 and stops the image forming apparatus (step S113). Due to the stop of the apparatus, the position of the intermediate transfer belt 32 also remains at that time.

  Next, the CPU 211 stands by until the jam processing is completed (step S114). As described above, the jam processing is performed when the user opens the door of the apparatus, removes the paper staying in the apparatus, and closes the door again. The CPU 211 determines whether or not the jam processing has been completed by detecting the door opening / closing operation from the signal output by the door opening / closing detection sensor 30 (FIG. 4).

  If it is determined that the door closing operation has been detected and the jam processing has been completed, the CPU 211 starts the recovery initial operation and executes the belt position setting operation processing of FIG. 6 described later (steps S115 and S116). ). Therefore, the processing of the belt position setting operation is started in response to the cancellation of the interruption factor.

  Here, the recovery initial operation is an operation such as cleaning of the image forming unit 4 necessary for resuming the printing operation. The belt position setting operation is an operation process for positioning the position of the intermediate transfer belt 32 at a position for forming a color image or a position for forming a monochrome image. The recovery initial operation started in step S115 and the belt position setting operation executed in step S116 are actually processed in parallel, and the completion of both operations is determined in step S205 of FIG. . After the process of step S116, the CPU 211 returns the process to step S110.

  FIG. 6 is a flowchart of the belt position setting operation process executed in step S116 of FIG.

  First, the CPU 211 determines whether the color information of the first page in the recovery print is color or monochrome (step S201; determination unit). At that time, the CPU 211 reads the color information group CL acquired and stored from the controller 221 at the start of printing from the RAM 213 (FIG. 4), refers to the color information group CL, and obtains the color information of the first page in the recovery print. Identify. For example, the number of pages being processed at the time of jam occurrence can be counted and stored, and the color information of the first page can be specified from the count value and the color information group CL. For example, the color information of the first page is color in the example of FIG. 3A and black and white in the example of FIG. 3B.

  As a result of the determination, if the first page of the recovery print is a color image, it is determined whether the image of the page that was undergoing the image forming process at the time of jam occurrence is a color image or a black and white image (step S202). ). As a result of the determination, if the image of the page that was being subjected to image formation processing at the time of jam occurrence is a black and white image, this corresponds to the example shown in FIG. Accordingly, the intermediate transfer belt 32 remains in a position for forming a black-and-white image that is separated from the color toner photoconductors (31Y, M, and C). Need to be located).

  In step S203, the CPU 211 starts driving the intermediate transfer belt moving motor M2 so that the intermediate transfer belt 32 is moved and brought into contact with the color toner photoreceptors (31Y, M, C). The CPU 211 waits for the intermediate transfer belt 32 to come into contact with the color toner photoconductor (31Y, M, C) (step S204). When the intermediate transfer belt 32 comes into contact with the color toner photoreceptors (31Y, M, C), the CPU 211 advances the process to step S205.

  On the other hand, if it is determined in step S202 that the image of the page that was being image-formed when the jam occurred is a color image, the intermediate transfer belt 32 is connected to the color toner photoreceptors (31Y, M, C). Is already in contact. That is, the color information of the first page of the recovery print is the same as the color information of the page that was being image-formed when the jam occurred, and there is no need to change the position of the intermediate transfer belt 32. Therefore, the CPU 211 advances the process to step S205 without moving the position of the intermediate transfer belt 32.

  If the image of the first page in the recovery print is a black and white image as a result of the determination in step S201, it is determined whether the image of the page that was undergoing the image forming process when the jam occurred is a color image or a black and white image (Step S209). As a result of the determination, if the image of the page that was being subjected to image formation processing at the time of jam occurrence is a color image, this corresponds to the example shown in FIG. Accordingly, since the intermediate transfer belt 32 remains in contact with the color toner photoreceptors (31Y, M, C), it is necessary to separate the intermediate transfer belt 32 from the position for forming a monochrome image.

  In step S210, the CPU 211 starts driving the intermediate transfer belt moving motor M2 to move the intermediate transfer belt 32 away from the color toner photoreceptors (31Y, M, C). The CPU 211 waits for the intermediate transfer belt 32 to be separated from the color toner photoconductors (31Y, M, C) (step S211). When the intermediate transfer belt 32 is separated from the color toner photoconductors (31Y, M, C) and is positioned at the time for forming a black and white image, the CPU 211 advances the process to step S205.

  On the other hand, as a result of the determination in step S209, if the image of the page that was being image-formed at the time of jam occurrence is a black and white image, the intermediate transfer belt 32 is in contact with the color toner photoconductors (31Y, M, C). Already separated. That is, the color information of the first page of the recovery print is the same as the color information of the page that was being image-formed when the jam occurred, and there is no need to change the position of the intermediate transfer belt 32. Therefore, the CPU 211 advances the process to step S205 without moving the position of the intermediate transfer belt 32.

  In step S205, the CPU 211 determines whether or not the recovery initial operation started in step S115 of FIG. When the initial recovery operation is completed, the CPU 211 notifies the controller 221 that the print operation is possible by transmitting a printable status to the controller 221 (step S206).

  Next, the CPU 211 determines whether or not a recovery print instruction for instructing the start of recovery printing has been received from the controller 221 (step S207). This recovery print instruction is transmitted by the controller 221 in step S304 of FIG. The CPU 211 continues the determination and receives the recovery print instruction, thereby receiving the recovery print start instruction after the interruption due to the jam. When receiving the recovery print instruction, the CPU 211 controls to start the recovery print (step S208; control means). Thereafter, this process ends, and the process returns to step S110 in FIG.

  FIG. 7 is a flowchart of the controller process. This process is periodically executed at regular time intervals by the controller 221 of the controller control unit 22 in parallel with the process of FIG.

  First, the controller 221 determines whether or not a jam occurrence status transmitted from the CPU 211 in step S113 in FIG. 5 has been received (step S301). The controller 221 continues the determination and, when receiving the jam occurrence status, displays that the jam has occurred on the display unit 223 (FIG. 4), thereby prompting the user to perform jam processing (step S302).

  Next, the controller 221 determines whether or not the printable status transmitted from the CPU 211 in step S206 in FIG. 6 has been received (step S303). When the controller 221 continues the determination and receives the printable status, the process proceeds to step S304.

  In step S <b> 304, the controller 221 transmits a recovery print instruction to the CPU 211 of the engine control unit 21. Thereafter, this process ends.

  FIG. 8 is a time chart comparing the prior art and the present invention regarding the transition of the operation from the occurrence of a jam to the recovery print.

  In the prior art shown in the upper side of FIG. 8, after a jam occurrence (81), a jam processing (82) is performed by the user, and then a recovery initial operation (83) such as cleaning is performed by the CPU 211. When the initial recovery operation is completed, the apparatus returns to a printable state, and thus a recovery print instruction (84) is transmitted from the controller 221 and received by the CPU 211.

  In the prior art, from the time when the CPU 211 receives the recovery print instruction (84), the position setting operation (85) for the contact or separation of the intermediate transfer belt 32 with respect to the color toner photoreceptors (31Y, M, C) is performed. Be started. After the position setting operation (85) is completed, the recovery print (86) is started by the CPU 211.

  On the other hand, in the present invention shown in the lower side of FIG. 8, the operations from the jam generation (81) to the jam processing (82) are the same as those in the prior art. However, in the present invention, the CPU 211 performs the position setting operation (85) for the contact or separation of the intermediate transfer belt 32 with respect to the color toner photoconductors (31Y, M, C) during the execution of the recovery initial operation (83). And the position setting operation (85) is completed. That is, before receiving the recovery print instruction (84), the position setting operation (85) is started and completed.

  Thus, when the recovery print instruction (84) is transmitted from the controller 221 and received by the CPU 211 (step S304 in FIG. 7 and step S207 in FIG. 6), the CPU 211 can immediately start the recovery print (86). It becomes.

  According to the present embodiment, when the print job is interrupted, before receiving the recovery print start instruction, the intermediate transfer belt 32 is positioned at a position corresponding to the color information of the page on which an image should be formed first in the recovery print. Control to position is started. As a result, the actual print start in the recovery print is accelerated, and the end of the recovery print can be accelerated. In addition, since the position control of the intermediate transfer belt 32 is completed before receiving the recovery print start instruction, the recovery print can be started as soon as the recovery print is ready.

  Note that, from the viewpoint of accelerating the start and end of recovery printing, even if the position control of the intermediate transfer belt 32 cannot be completed before receiving the recovery print instruction, if the start is started, there are some effects. For this purpose, for example, steps S204 and S211 in FIG. 6 may be abolished, and a determination step corresponding to these may be moved between steps S207 and S208.

  In the present embodiment, the occurrence of a jam is exemplified as a print job interruption factor. However, the present invention is also applicable to other interruption factors (no toner, no recording paper, etc.).

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included.

DESCRIPTION OF SYMBOLS 3 Transfer part 4 Image formation part 31 Photoconductor 32 Intermediate transfer belt 211 CPU
M2 Intermediate transfer belt moving motor CL Color information group

Claims (7)

A toner image is formed on at least one of the plurality of image carriers according to a print job, the toner image formed on the image carrier is transferred to a belt member, and the toner image transferred to the belt member An image forming apparatus for performing a series of image forming processes,
Moving means for moving the belt member to switch the position of the belt member with respect to the plurality of image carriers to be positioned at a position for forming a color image or a position for forming a monochrome image;
Acquisition means for acquiring color information of each page in the print job;
Control means for controlling to perform recovery printing in response to a recovery print start instruction when a print job is interrupted due to an interruption factor;
Determination means for determining whether the color information of the page on which image formation is to be performed first in recovery printing is color or monochrome based on the color information acquired by the acquisition means;
When the print job is interrupted, the control unit is configured to position the belt member at a position corresponding to the color information of the page on which image formation is to be performed first before receiving the recovery print start instruction. An image forming apparatus, wherein control of the moving means for positioning the image is started.   The control means starts control of the moving means for positioning the belt member at a position corresponding to the color information of the page on which image formation is to be performed first in response to elimination of the interruption factor. The image forming apparatus according to claim 1.   The control means completes the control of the moving means for positioning the belt member at a position corresponding to the color information of the page on which image formation is to be performed first before receiving a recovery print start instruction. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The determination unit further determines, based on the color information acquired by the acquisition unit, whether the color information of the page being subjected to the image forming process when the print job is interrupted is color or monochrome. If the color information of the page on which image formation is to be performed first is different from the color information of the page that was being subjected to the image formation processing, the control unit determines that the image formation The moving means is controlled to move the belt member from a position corresponding to the color information of the page being processed to a position corresponding to the color information of the page on which the image should be formed first. The image forming apparatus according to claim 1.   The plurality of image carriers include a plurality of color image carriers on which a color toner image is formed and a black and white image carrier on which a black and white toner image is formed. In the position, the belt member is in contact with all of the plurality of color image carriers and the monochrome image carrier, and in the position for forming the monochrome image, the belt member is the plurality of color members. 5. The image forming apparatus according to claim 1, wherein the image forming apparatus is not in contact with any of the image bearing members and is in contact with the monochrome image bearing member.   The image forming apparatus according to claim 5, wherein the moving unit moves the belt member by displacing a transfer member corresponding to each of the plurality of color image carriers.   The image forming apparatus according to claim 1, wherein the interruption factor is at least one of jamming of recording paper, no toner, and no recording paper.

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