JP2008197189A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus having good handleability by appropriately controlling the start-up time of a function available only when printing is stopped. <P>SOLUTION: In the image forming apparatus having the function available only when printing is stopped, when a request to perform the function is made during printing and unprinted data size or the number of unprinted sheets of paper is under a predetermined threshold, the printing is continued, and when the unprinted data size or the number of unprinted sheets of paper is equal to or the predetermined threshold, the printing is interrupted and restarted after the function requested is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus using an electrophotographic system such as a copying machine, a printer, a facsimile machine, and the like.

  In general, in an electrophotographic image forming apparatus, an electrostatic latent image is formed on an image carrier, toner is supplied to the image carrier, and a toner image developed with the toner is transferred and fixed on a sheet or the like. Thus, image formation is performed. Here, the developing device plays a role of supplying toner to the image carrier. In general, a developing device charges a toner to a predetermined potential by a regulating member or the like that is pressed against the developing roller in order to form a thin layer of toner on a developing roller provided to face the image carrier. The toner thus supplied is supplied toward the electrostatic latent image on the image carrier to develop the electrostatic latent image.

  In general, a developing device includes a one-component developing method and a two-component developing method. The one-component development method is a method using a developer mainly composed of toner, and the two-component development method is a method using a developer mainly composed of toner and a carrier (magnetic material).

  In general, in a developing device using a one-component developer, toner is replenished according to the remaining amount of developer (toner) in the developing device. For example, the remaining amount of toner in the developing device is detected by a toner remaining amount detection sensor. When the toner remaining amount reaches a preset residual threshold value, toner is supplied from the toner container to the developing device.

  Printing must be stopped when replenishing toner from the toner container to the developing device, so if the remaining amount of toner in the developing device falls below the residual threshold during printing, printing is interrupted and toner is replenished. Then, printing is resumed.

Therefore, even when printing is completed with several sheets, printing may be interrupted in order to supply toner to the developing device, which is inconvenient. Therefore, in Patent Document 1, when the control unit detects the toner end state, the data type of whether the data to be printed next is character printing or graphics printing is identified. A printing control method has been proposed in which printing is stopped when it is determined that the amount of toner consumption affecting quality exceeds a certain value.
Japanese Patent Laid-Open No. 3-161780

  However, according to Japanese Patent Application Laid-Open No. 2004-260688, control such as means for identifying the type of data to be printed and calculation of toner consumption based on the type of print data is complicated. Moreover, since the operation of the apparatus cannot be set according to the user's preference, it is assumed that there are users who feel that the usability is poor.

  In addition to the above-described toner supply, the operation of the apparatus that can only be performed while printing is stopped includes calibration such as color calibration and density calibration that are performed periodically. The handling of this calibration is not described in Patent Document 1. Therefore, there is a problem of when it is preferable to activate a function that cannot be executed unless printing is stopped, such as toner replenishment and calibration.

  An object of the present invention is to provide an easy-to-use image forming apparatus by appropriately controlling the start time of a function that can be executed only when printing is stopped.

  In order to achieve the above object, according to the present invention, in an image forming apparatus having a function that can only be executed while printing is stopped, if there is a request to execute the function during printing, an unprinted data size or an unprinted A control unit is provided that determines whether to continue printing based on the number of sheets, or to resume printing after interrupting printing and executing the requested function.

  In the above-described image forming apparatus, specifically, when there is a request to execute the function during printing, the control unit continues printing if the unprinted data size or the number of unprinted sheets is less than a predetermined threshold. If the unprinted data size or the number of unprinted sheets is equal to or greater than the predetermined threshold, the printing is interrupted and the function requested to be executed is executed, and then the printing is resumed.

  In the image forming apparatus described above, the control unit stores the information from the sheet number information input unit to which the number of sheets requested to be printed and the number information input unit are stored. A remaining number information management unit for storing the number of printed sheets, a one sheet printing end trigger detecting unit for detecting a trigger indicating that the printing of one sheet has been completed, the remaining number information management unit, and the one sheet printing end trigger detection A calculation unit for calculating the number of unprinted sheets based on information from the set, a function request detecting unit for detecting a function execution request, a threshold information input unit for inputting a predetermined threshold regarding the number of unprinted sheets, When the threshold information management unit that stores information from the threshold information input unit and the function request detection unit detect a function execution request, the remaining number information management unit It comprises a comparison unit for comparing the information from the information and the threshold value information management unit, and a function starting unit that performs the function based on the determination result of the comparison unit.

  The function is specifically developer replenishment, color calibration, or density calibration.

  According to the present invention, in an image forming apparatus having a function that can be executed only when printing is stopped, the function is developer replenishment. When the predicted usage amount of the agent is calculated and there is a request for execution of the developer replenishment during printing, the printing is continued or the printing is interrupted based on the predicted usage amount including the current printing tendency. A control unit is provided for determining whether or not to resume printing after executing the developer replenishment requested.

  In the above-described image forming apparatus, specifically, when there is a request for execution of developer replenishment during printing, the control unit continuously prints up to the predetermined number of sheets to calculate the predicted usage amount, and develops the previous development. If the predicted total developer consumption, which is calculated by adding the estimated usage amount to the developer consumption amount after replenishment of the developer, is less than a predetermined threshold, printing is continued at least until the next predetermined number of sheets, and the predicted total developer consumption If the amount is equal to or greater than the predetermined threshold, the next predetermined number of printings are interrupted and the developer replenishment is executed, and then the printing is resumed.

  In the image forming apparatus, more specifically, the control unit includes a total developer consumption management unit that stores a total developer consumption amount that is a developer consumption amount after the previous developer replenishment, and one sheet. A printing rate input unit for inputting the printing rate for each printing, and a predicted usage amount of the next predetermined number of developers from the latest predetermined printing rate is calculated, and the total developer consumption amount is calculated as the predicted usage amount A calculation unit that calculates a predicted total developer consumption amount, a predicted value management unit that stores the predicted total developer consumption amount, a function request detection unit that detects a function execution request, and a remaining amount of developer A threshold information input unit for inputting a predetermined threshold regarding the lower limit of the threshold, a threshold information management unit for storing information from the threshold information input unit, and the function request detection unit detecting a function execution request. A comparison unit that compares information from the predicted value management unit with information from the threshold value information management unit, and a function activation unit that executes a function based on a determination result in the comparison unit. .

  According to the present invention, there is a case where the start time of the function requested during printing can be turned after the end of the print job. In this case, the printing is not interrupted, so that the user can comfortably use the image forming apparatus. Can be used. Further, since the user can set the threshold value for activating the function, it can be used in a wide range of applications according to the user's preference.

  Hereinafter, an image forming apparatus having a rotary developing unit will be described as an example, but the present invention can also be applied to an image forming apparatus of an ink system or other systems. FIG. 1 is a schematic cross-sectional view for explaining a schematic configuration of an image forming apparatus of the present invention.

  The image forming apparatus 1 includes an image forming unit 10, a replenishing unit 20, an intermediate transfer unit 24, a paper feeding unit 30, a paper transport unit 35, a secondary transfer unit 45, a fixing device 47, and the like.

  The image forming unit 10 includes a rotary developing unit 2, a photosensitive drum 11, a charging roller 12, a drum cleaning device 13, a laser unit 14, and the like.

  The photosensitive drum 11 is an image bearing member on which an electrostatic latent image is formed, and is driven to rotate about the center of the image forming apparatus 1 (the direction of rotation is indicated by an arrow). The rotation shaft (not shown) is provided so as to extend perpendicular to the paper surface of FIG. The photosensitive drum 11 is formed to have a photosensitive layer such as amorphous silicon or an OPC photosensitive member.

  The charging roller 12 is provided on the photosensitive drum 11. Further, the charging roller 12 is in contact with the photosensitive drum 11 in order to uniformly charge the surface of the photosensitive drum 11, and is rotatably supported. Note that a cleaner 12 a for cleaning adhering matter adhering to the charging roller 12 is provided above the charging roller 12.

  The drum cleaning device 13 is provided on the right side of the photosensitive drum 11 in FIG. 1, and is for cleaning toner and deposits remaining on the surface of the photosensitive drum 11.

  The rotary developing unit 2 is for developing the electrostatic latent image formed on the photosensitive drum 11 with toner of each color, and is provided adjacent to the left side of the photosensitive drum 11 in FIG. The rotary developing unit 2 includes a rotating frame 15 and four developing devices 16B (black), 16Y (yellow), 16C (cyan), and 16M (magenta) supported by the rotating frame 15. It is rotated by a drive mechanism that does not include a motor or gear. Accordingly, the rotary developing unit 2 has a cylindrical shape that is rotatable around the rotation shaft 15a. The rotary shaft 15 a of the rotary developing unit 2 passes through the center of the rotary frame 15, and the axial direction thereof is parallel to the axial direction of the rotary shaft of the photosensitive drum 11.

  The rotating frame 15 has four sections that are divided into four equal parts in the circumferential direction by a partition frame 15b extending radially from the center of the rotating shaft 15a. In each section, developing devices 16B, 16Y, 16C, and 16M corresponding to four toner colors of black, yellow, cyan, and magenta are arranged. The developing devices 16B, 16Y, 16C, and 16M have the same configuration. is there. When the rotary developing unit 2 rotates, the developing rollers 53 of the developing devices 16B, 16Y, 16C, and 16M face the photosensitive drum 11 with a predetermined gap.

  The laser unit 14 is for scanning and exposing the photosensitive drum 11 based on image information from an external computer or the like, and is provided above the rotary developing unit 2. Data for causing the laser unit 14 to output the laser light 14L is created by the data processing unit 17 that receives image information. The laser unit 14 emits laser light 14L. A reflection mirror 18 is provided on the optical path of the laser beam 14L, and the laser beam 14L is irradiated onto the surface of the photosensitive drum 11 by the reflection mirror 18 (the laser beam 14L is shown by a two-dot chain line). The laser unit 14 includes a laser light source, a polygon mirror, a polygon mirror driving motor, and the like as an internal configuration (not shown).

  Next, the replenishing unit 20 includes a toner storage container 21 and a toner replenishing device 22. The toner storage containers 21 are provided above the photosensitive drum 11 and the intermediate transfer belt 25, and four toner storage containers 21 are arranged side by side in the direction perpendicular to the paper surface of FIG. Each toner storage container 21 is a portion that stores toner to be replenished to each developing device 16B, 16Y, 16C, 16M of the rotary developing unit 2. That is, each toner storage container 21 stores toner of any one color of black, yellow, cyan, and magenta. In FIG. 1, the toner container 21 is invisible except for one toner container 21.

  The toner replenishing device 22 is disposed above the photosensitive drum 11 and in a space between the laser unit 14 and the toner container 21 and is configured to be movable up and down, and is provided with four corresponding to each color. It is done. Each toner replenishing device 22 is connected to the corresponding toner storage container 21 by a pipe, a hose or the like, and supplies the toner of each color stored in the toner storage container 21 to the corresponding developing device 16B, 16Y, 16C, 16M.

  Specifically, the toner replenishing device 22 has an insertion portion 22a with a thin tip, and when it moves downward, the tip is inserted into the developing devices 16B, 16Y, 16C, and 16M to supply toner. . Further, when the replenishment is completed, it moves upward so that the rotary developing unit 2 can rotate. In FIG. 1, the parts other than one toner supply device 22 are invisible. Further, the moving direction of the toner replenishing device 22 is shown by a broken line.

  The intermediate transfer unit 24 includes an intermediate transfer belt 25 to which toner images of respective colors formed on the photosensitive drum 11 are sequentially transferred, a driving roller 26 for tensioning and rotating the intermediate transfer belt 25, a tension roller 27, and a photosensitive roller. A primary transfer roller 28 adjacent to the body drum 11 via the intermediate transfer belt 25, a driven roller 28a provided between the drive roller 26 and the primary transfer roller 28 in the vicinity of the primary transfer roller 28, and intermediate transfer A belt cleaning device 29 for cleaning the belt 25 is configured. The intermediate transfer belt 25 stretched around each roller rotates and passes through the nip between the photosensitive drum 11 and the primary transfer roller 28, and the toner images of the respective colors are superimposed and primarily transferred, and the superimposed toner images. Is later transferred to the paper P by the secondary transfer unit 45.

  The paper feed unit 30 includes a paper feed cassette 31, a manual feed tray 32, and the like. A paper feed cassette 31 having a placement plate 31 a on which the paper P is placed is provided at the bottom of the image forming apparatus 1. In addition, the paper feeding unit 30 prevents the multi-feeding to the right of the pickup roller 33 and the pickup roller 33 to the right of the pickup roller 31 in order to send the paper P on the loading plate 31 a one by one to the paper conveyance path. A roller pair 34 is provided. Further, a manual feed tray 32 is provided on the right side surface of the apparatus so that paper can be separately fed. The manual feed tray 32 is also provided with a pickup roller 33 for sending the paper P one by one to the paper transport path.

  The paper transport unit 35 is for transporting the paper P in the image forming apparatus 1. The sheet conveying section 35 is a sheet for discharging the image-formed sheet P from the sheet feeding section 30 to a secondary transfer roller 46 described later, and from the secondary transfer roller 46 through the fixing device 47. From the second conveyance path 37 that reaches the discharge port 42, the reverse conveyance path 38 that is provided so as to connect the middle of the first conveyance path 36 to the middle of the second conveyance path 37 on the downstream side of the fixing device 47 in the sheet conveyance direction. Composed. The paper transport direction is indicated by arrows.

  In the upper part of the curved portion 39, the conveyance path from the manual feed tray 32 joins. In front of the secondary transfer roller 46, a registration roller pair 40 for controlling the conveyance timing of the paper P is disposed. A plurality of pairs of conveyance rollers 41 are provided on the conveyance path where these elements are provided, and a guide plate (not shown) for guiding the paper P is also provided as appropriate.

  A plurality of transport roller pairs 41 are provided in the second transport path 37. A guide plate (not shown) for guiding the paper P is also provided as appropriate. A paper discharge port 42 is provided at the end of the second transport path 37, and a discharge tray 43 for receiving the discharged paper P is provided.

  The reverse conveyance path 38 is a conveyance path for duplex printing. The reverse conveyance path 38 is provided so as to join the upstream side of the registration roller pair 40 in the sheet conveyance direction from the branching claw 44 located in the middle of the second conveyance path 37 and downstream of the fixing device 47 in the sheet conveyance direction. The reverse conveyance path 38 is provided so as to pass above the paper feed cassette 31. The reverse conveyance path 38 is also provided with a plurality of conveyance roller pairs 41, and a guide plate (not shown) for guiding the paper P is also provided as appropriate.

  The secondary transfer unit 45 includes a secondary transfer roller 46 and a driving roller 26. The secondary transfer roller 46 is for transferring the toner image transferred to the intermediate transfer belt 25 onto the sheet P conveyed so as to be sandwiched between the secondary transfer roller 46 and the intermediate transfer belt 25. Therefore, the secondary transfer roller 46 is supported so as to be rotatable and in contact with and away from the intermediate transfer belt 25 so as to form a nip via the drive roller 26 and the intermediate transfer belt 25. Further, a voltage is applied to the secondary transfer roller 46 so that the toner is transferred onto the paper P at a predetermined timing by a voltage applying means (not shown).

  The fixing device 47 is for melting and fixing the toner transferred onto the paper P, and is provided in the middle of the second transport path 37 and below the rotary developing unit 2. The fixing device 47 includes a heating roller 48 that incorporates a heater and a pressure roller 49 that presses the heating roller 48. The toner is heated and pressurized and fixed on the paper P.

  Next, an image forming operation will be briefly described. The image forming apparatus 1 executes an image forming operation based on the input image data as follows.

  First, the photosensitive drum 11 is charged by the charging roller 12. The laser unit 14 scans and exposes the surface of the photosensitive drum 11 in accordance with data from the data processing unit 17 to which image data is input, and the electrostatic latent image is formed on the photosensitive drum 11. Is formed. Next, the rotary developing unit 2 is rotated, and any one of the corresponding color developing devices 16 faces the photosensitive drum 11. In this state, the electrostatic latent image on the photosensitive drum 11 is developed by supplying the corresponding color toner. The developed toner image is transferred to the intermediate transfer belt 25. The above operation is sequentially repeated for each color, and a full-color toner image is formed on the intermediate transfer belt 25 (if full color, the intermediate transfer belt 25 rotates four times). Note that when a black single color image is formed, the above operation may be performed once. The toner remaining on the photosensitive drum 11 after the transfer is cleaned by the drum cleaning device 13.

  On the other hand, in the paper feed unit 30, one sheet P is taken out from the paper feed cassette 31 or the manual feed tray 32 by the pickup roller 33 and conveyed to the registration roller pair 40. Thereafter, the sheet P is conveyed from the registration roller pair 40 to the toner image on the intermediate transfer belt 25 in time, and is guided to the secondary transfer unit 45. A predetermined voltage is applied to the secondary transfer roller 46 while being in contact with the intermediate transfer belt 25, and the toner image on the intermediate transfer belt 25 is transferred to the paper P. The sheet P is guided to the fixing device 47 through the second conveyance path 37, and the toner image is fixed on the sheet P by the fixing device 47. In the case of single-sided printing, the paper is sequentially discharged from the paper discharge port 42 via the branching claw 44, and the paper P is received by the discharge tray 43.

  On the other hand, in the case of duplex printing, the paper P that has passed through the fixing device 47 is switched back in the second conveyance path 37 downstream of the branching claw 44 in the paper conveyance direction, and the reverse conveyance path 38 is guided by the branching claw 44. To be introduced. Thereafter, the paper P that is turned upside down is returned to the upstream side of the pair of registration rollers 40 in the first transport path 36 again. Then, the toner image is transferred from the secondary transfer roller 46 in time with the back side of the paper P. After that, it is the same as above.

  Next, features of the image forming apparatus according to the first embodiment of the present invention will be described. This image forming apparatus has a function that can be executed only when printing is stopped, and when the control unit requests execution of the function during printing, it is based on the unprinted data size or the number of unprinted sheets. It is characterized in that it is determined whether to continue printing or to resume printing after interrupting printing and executing a function requested to be executed. Functions that can be executed only when printing is stopped include toner replenishment from the toner storage container 21 to the developing device 16 and calibration such as color calibration and density calibration performed periodically.

  FIG. 2 is a block diagram illustrating a functional configuration of a control unit of the image forming apparatus according to the first embodiment. The control unit 60 stores the information from the number information input unit 61 to which the number of sheets requested to be printed and the number information input unit 61 are stored, and the remaining number information management for storing the calculated unprinted number of sheets. Based on information from the unit 62, a single print end trigger detection unit 63 that detects a trigger indicating the end of printing of one sheet, and the remaining number information management unit 62 and the single print end trigger detection unit 63. A calculation unit 64 that calculates the number of prints, a function request detection unit 65 that detects a function execution request, a threshold information input unit 66 that receives a predetermined threshold regarding the number of unprinted sheets, and a threshold information input unit 66 Information and threshold values from the remaining number information management unit 62 when the function request detection unit 65 detects a function execution request. It comprises a comparator 68 for comparing the information from the broadcast management unit 67, and a function starting unit 69 to perform a function based on the determination result of the comparison unit 68.

  If there is a function execution request during printing by the control unit 60, if the unprinted data size or the number of unprinted sheets is less than a predetermined threshold, printing is continued. If the number of paper sheets to be printed is equal to or greater than a predetermined threshold value, the printing is controlled to be resumed after the printing is interrupted and the function requested to be executed is executed.

  A more specific operation will be described using an example in which the number of unprinted sheets is used. FIG. 3 is a flowchart illustrating the operation of the image forming apparatus according to the first embodiment. First, in step S10, print data is received. At this time, the sheet number information input unit 61 receives information on the number of sheets transmitted together with the print data. In step S 11, information on the number of sheets is stored in the remaining number information management unit 62. In step S12, printing is performed based on the print data.

  Next, the process proceeds to step S13, and if printing is completed for one sheet, the one-sheet printing end trigger detection unit 63 detects a trigger indicating that. In step S14, the trigger is input to the calculation unit 64. The calculation unit 64 reads the number of sheets requested to be printed from the remaining number information management unit 62, subtracts one sheet, and sets the value. The value stored in the remaining number information management unit 62 is updated as the number of unprinted sheets.

  In step S15, the calculation unit 64 determines whether the number of unprinted sheets has become zero. If the number of unprinted sheets is 0 in step S15, it is determined that the print job has been completed, the process is terminated, and the process proceeds to the standby mode. On the other hand, if the number of unprinted sheets is not 0 in step S15, it is determined that the print job has not ended, and the process proceeds to step S16. As will be described later, if there is a function execution request during printing and the print job is completed in step S15 without executing the function, the function may be executed after that.

  In step S16, it is determined whether or not there is a function execution request. A function execution request is detected whenever there is an input to the function request detection unit 65. If there is no function execution request in step S16, the process returns to step S12 to continue printing.

  On the other hand, if there is a function execution request in step S16, the process proceeds to step S17, and the comparison unit 68 determines whether or not the number of unprinted sheets is less than a predetermined threshold. The predetermined threshold is preset by the user, input to the threshold information input unit 66, and stored in the threshold information management unit 67. As the predetermined threshold, the user can set a desired number of sheets up to the number of sheets that can be printed without replenishment when toner replenishment is requested, for example, 10 sheets or 20 sheets. can do.

  If the number of unprinted sheets is less than the predetermined threshold value in step S17, it is determined that printing can be continued, and the process returns to step S12 to continue printing. On the other hand, if the number of unprinted sheets is equal to or greater than the predetermined threshold value in step S17, printing is interrupted, the process proceeds to step S18, and the function requested by the function activation unit 69 is executed. Then, the process returns to step S12 to resume printing.

  As a result, the start time of the function requested during printing may be turned after the end of the print job. In this case, printing is not interrupted, so the user should use the image forming apparatus comfortably. Can do.

  If an unprinted data size is used instead of using the number of unprinted sheets, the unprinted data size is managed instead of managing the number of unprinted sheets. Set the data size.

  FIG. 4 is a state machine diagram of the image forming apparatus according to the first embodiment. The image forming apparatus includes a standby mode in which operations such as printing and functions are not performed, a printing mode in which printing is performed, a state in which printing is performed, a start determination mode for determining whether to execute a function, a function And a function activation mode for executing

  Next, examples of the first embodiment will be described. It is assumed that the user has previously set 10 sheets as a predetermined threshold value. If the current print job is 30 sheets, each time one sheet is printed, 1 is subtracted from the number of unprinted sheets. When a toner replenishment function is requested during printing, the number of unprinted sheets and the threshold of 10 sheets are set. Compare. For example, if there is a function request at the time of printing the 15th sheet, the number of unprinted sheets is 15 and is larger than the threshold value of 10 sheets, so printing is interrupted and the function is executed, and then printing is resumed. If there is a function request at the time of printing the 20th and subsequent sheets, the number of unprinted sheets is less than 10 and less than the threshold of 10 sheets, so printing is continued and the function is executed after the print job is completed.

  Next, features of the image forming apparatus according to the second embodiment of the present invention will be described. This image forming apparatus has toner replenishment that is a function that can be executed only when printing is stopped, and the control unit predicts the next predetermined number of toners for each predetermined number of sheets from the latest predetermined number of printing trends. When the usage amount is calculated and there is a request for toner replenishment during printing, based on the predicted usage amount including the current printing tendency, the printing is continued or the toner for which execution has been requested by interrupting printing It is characterized by determining whether or not printing is resumed after replenishment is executed.

  FIG. 5 is a block diagram illustrating a functional configuration of a control unit of the image forming apparatus according to the second embodiment. The control unit 70 includes a total toner consumption amount management unit 71 that stores a total toner consumption amount that is a toner consumption amount after the previous toner replenishment, and a printing rate input unit that inputs the printing rate for each printing. 72, a calculation unit 73 that calculates a predicted use amount of the next predetermined number of toners from the most recent predetermined number of print rates, and calculates a predicted total toner consumption amount by adding the total toner consumption amount to the predicted use amount; A predicted value management unit 74 for storing a predicted total toner consumption amount, a function request detection unit 75 for detecting a function execution request, a threshold information input unit 76 for inputting a predetermined threshold regarding the lower limit of the remaining amount of toner, When the threshold information management unit 77 that stores information from the threshold information input unit 76 and the function request detection unit 75 detect a function execution request, the predicted value It comprises a comparator 78 for comparing the information from the information and threshold information management unit 76 from the processing section 74, and a function starting unit 79 to perform a function based on the determination result of the comparison unit 78.

  When there is a request for toner replenishment during printing by the control unit 70, printing is continued up to a predetermined number of sheets, and a predicted usage amount of toner required for printing the next predetermined number of sheets is calculated. If the predicted total toner consumption, which includes the toner consumption from the estimated consumption, is less than the predetermined threshold, printing is continued until the next predetermined number of sheets, and if the predicted total toner consumption is greater than the predetermined threshold, the next The printing is controlled to be resumed after the predetermined number of printings are interrupted and the toner supply is executed.

  A more specific operation will be described below. FIG. 6 is a flowchart illustrating the operation of the image forming apparatus according to the second embodiment. First, in step S20, print data is received. In step S21, the number A of printed sheets is set to zero. The number of printed sheets A indicates the number of sheets printed in the current print job.

  Next, the process proceeds to step S22, and printing is performed based on the print data. When one print is completed in step S23, the process proceeds to step S24, where the calculation unit 73 is based on the print rate input to the print rate input unit 72. The toner consumption amount t is roughly estimated, and the process proceeds to step S25 where the toner consumption amount t is added to calculate the toner consumption amount M. The toner consumption amount M is the amount of toner required to print a predetermined number of sheets X. As described above, the toner consumption amount t per sheet is calculated from the printing rate, and this toner consumption amount t is added for X sheets. Can be obtained. The predetermined number X can be set in advance by the user and can be set to 10 or 20 for example.

  In step S26, it is determined whether the print job is completed. If the print job is finished in step S26, the process is finished and the process shifts to the standby mode. As will be described later, if there is a function execution request during printing and if the print job ends in step S26 without executing the function, the function may be executed after that.

  On the other hand, if the print job has not ended in step S26, the process proceeds to step S27 to determine whether or not there has been a function execution request. A function execution request is detected whenever there is an input to the function request detection unit 75. If there is no function execution request in step S27, the process returns to step S22 to continue printing.

  On the other hand, if there is a function execution request in step S27, the process proceeds to step S28 to determine whether or not the predetermined number X has been reached in the current printing. If the predetermined number X has not been reached in step S28, the process returns to step S22 and printing is continued until the predetermined number X is reached. On the other hand, when the predetermined number X is reached in step S28, the process proceeds to step S29, where the calculation unit 73 calculates the predicted usage amount of toner required for printing the next predetermined number X, and the total toner consumption is calculated based on this predicted usage amount. The predicted total toner consumption amount taking the amount into consideration is calculated and stored in the predicted value management unit 74, and the comparison unit 78 compares the predicted total toner consumption amount of the predicted value management unit 74 with the threshold value of the threshold information management unit 77. The predicted use amount is calculated by proportional prediction, that is, the same as the toner consumption amount M. The total toner consumption amount T is the total toner consumption amount from the previous toner supply to the start of the current job. Therefore, the predicted total toner consumption amount is T + 2M, which is obtained by adding the toner consumption amount M and the predicted usage amount M to the total toner consumption amount T. The threshold value Y of the threshold information management unit 77 is the total amount of toner that can be used after one toner supply.

  If the predicted total toner consumption amount is less than the threshold value in step S29, that is, if T + 2M <Y, it is determined that printing can be performed without replenishing toner at least until the next predetermined number X, in order to continue printing. The process returns to step S22. On the other hand, if the predicted total toner consumption amount is greater than or equal to the threshold value in step S29, that is, if T + 2M ≧ Y, it is determined that the toner runs out while the next predetermined number X is being printed, printing is interrupted, and step S30 is performed. Then, after the toner replenishment requested by the function activation unit 79 is executed, the total toner consumption T is set to 0 in step S31, and the process returns to step S22 to resume printing.

  As a result, there is a case where the start time of toner replenishment requested during printing can be turned after the end of the print job. In this case, printing is not interrupted, so the user can comfortably use the image forming apparatus. be able to.

  In the above-described embodiment, the predicted usage amount is calculated by proportional prediction using the toner consumption amount M required to print the predetermined number of sheets X. However, for example, a predetermined time during printing (for example, 1 The predicted usage amount may be calculated by proportional prediction using the toner consumption amount per minute.

  Next, an example of the second embodiment will be described. FIG. 7 is a graph showing the total toner consumption with respect to the number of printed sheets of the image forming apparatus according to the second embodiment. The solid line in the graph is the toner consumption actually required, and the broken line is the predicted consumption.

For example, in the case of graph I, there is a request for toner replenishment before reaching the predetermined number X during printing,
Since the predicted consumption up to 2X sheets predicted when the predetermined number X is reached is less than the threshold Y, printing is continued, and the predicted consumption up to 3X sheets predicted when the number reaches 2X is greater than or equal to the threshold Y. At that time, printing is interrupted and toner is replenished.

In the case of graph II, during printing, there is a request for toner replenishment before reaching the predetermined number X, and the predicted consumption amount up to 2X sheets predicted when the predetermined number X is reached is less than the threshold value Y. Since the predicted consumption amount up to 3X sheets predicted when reaching 2X sheets is less than the threshold value Y, printing is continued.

  The present invention can be used for an image forming apparatus using an electrophotographic system such as a copying machine, a printer, a facsimile machine, and the like, and a composite machine thereof.

1 is a schematic cross-sectional view for explaining a schematic configuration of an image forming apparatus of the present invention. 2 is a block diagram illustrating a functional configuration of a control unit of the image forming apparatus according to the first embodiment. FIG. 3 is a flowchart illustrating an operation of the image forming apparatus according to the first embodiment. 1 is a state machine diagram of an image forming apparatus according to a first embodiment. FIG. 6 is a block diagram illustrating a functional configuration of a control unit of an image forming apparatus according to a second embodiment. 10 is a flowchart illustrating an operation of the image forming apparatus according to the second embodiment. 6 is a graph showing the total toner consumption with respect to the number of printed sheets of the image forming apparatus according to the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 60, 70 Control part 61 Sheet number information input part 62 Remaining sheet number information management part 63 Single sheet printing end trigger detection part 64, 73 Calculation part 65, 75 Function request detection part 66, 76 Threshold information input part 67, 77 Threshold information management unit 68, 78 Comparison unit 69, 79 Function activation unit 71 Total toner consumption management unit 72 Print rate input unit 74 Predicted value management unit

Claims (7)

In an image forming apparatus having a function that cannot be executed unless printing is stopped,
If there is a request to execute the function during printing, either after printing is continued based on the unprinted data size or the number of unprinted sheets, or after the function requested to be executed after printing is interrupted An image forming apparatus comprising a control unit that determines whether to resume printing. The controller is
When there is a request to execute the function during printing, if the unprinted data size or the number of unprinted sheets is less than a predetermined threshold, printing is continued, and the unprinted data size or the number of unprinted sheets is The image forming apparatus according to claim 1, wherein if it is equal to or greater than a predetermined threshold, printing is interrupted and control is performed so that printing is resumed after the requested function is executed. The controller is
A number information input section for inputting the number of sheets requested for printing;
Storing information from the number information input unit, and a remaining number information management unit for storing the calculated unprinted number of sheets;
A one-sheet printing end trigger detection unit for detecting a trigger indicating that one sheet has been printed;
A calculation unit that calculates the number of unprinted sheets based on information from the remaining number information management unit and the one-sheet printing end trigger detection unit;
A function request detection unit for detecting a function execution request;
A threshold information input unit for inputting a predetermined threshold regarding the number of unprinted sheets;
A threshold information management unit for storing information from the threshold information input unit;
A comparison unit that compares information from the remaining number information management unit and information from the threshold information management unit when the function request detection unit detects a function execution request;
The image forming apparatus according to claim 2, further comprising: a function activation unit that executes a function based on a determination result in the comparison unit.   The image forming apparatus according to claim 1, wherein the function is developer replenishment, color calibration, or density calibration. In an image forming apparatus having a function that cannot be executed unless printing is stopped,
The function is developer replenishment,
For each predetermined number of sheets, the predicted usage amount of the next predetermined number of developers is calculated from the most recent predetermined number of printing trends, and if there is a request for execution of developer replenishment during printing, the printing tendency currently being printed is displayed. Including a control unit that determines whether to continue printing based on the predicted usage amount, or to resume printing after interrupting printing and executing the developer supply requested to be executed. Image forming apparatus. The controller is
When there is a request for execution of developer replenishment during printing, printing is continued up to the predetermined number of sheets to calculate the predicted use amount, and the predicted use amount is added to the developer consumption amount after the previous developer replenishment. If the calculated predicted total developer consumption is less than a predetermined threshold, printing is continued for at least the next predetermined number of sheets, and if the predicted total developer consumption is greater than or equal to the predetermined threshold, the next predetermined number of sheets is continued. 6. The image forming apparatus according to claim 5, wherein printing is resumed after the printing is interrupted and the developer replenishment is executed. The controller is
A total developer consumption management section for storing a total developer consumption that is a developer consumption after the last developer replenishment;
A printing rate input section for inputting the printing rate for each printing,
A calculation unit that calculates a predicted usage amount of the next predetermined number of developers from the printing rate of the most recent predetermined number of sheets, and calculates a predicted total developer consumption amount by adding the total developer consumption amount to the predicted usage amount;
A predicted value management unit for storing the predicted total developer consumption amount;
A function request detection unit for detecting a function execution request;
A threshold information input unit for inputting a predetermined threshold regarding the lower limit of the remaining amount of developer;
A threshold information management unit for storing information from the threshold information input unit;
When the function request detection unit detects a function execution request, a comparison unit that compares information from the predicted value management unit and information from the threshold information management unit,
The image forming apparatus according to claim 6, further comprising: a function activation unit that executes a function based on a determination result in the comparison unit.

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