JP2007183866A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device for completing the image forming processing in a planned required time even when the processing stops on the midway. <P>SOLUTION: The image forming device 1 has: an image forming mechanism 30 that receives control and operates for image formation; and a control section 60 for controlling this operation. The control section 60 comprises: a mechanism control section (Step S14) for making the image forming mechanism 30 form an image; a required time calculation section (Step S12) for calculating the time required for making the image forming mechanism 30 form an image on a specific number of sheets at a predetermined standard speed prior to start of the image formation; and a speed calculation section (Step S13) for calculating the speed at which the image is formed on the remaining number of sheets in the remaining time obtained by subtracting the elapsed time after the start of the image formation in the image forming mechanism from the calculated required time. The mechanism control section makes the image formed at the speed calculated by the speed calculation section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image on a designated number of sheets designated from outside.

  Image forming apparatuses that form images on paper are widely used as printers and copiers, and are not only offices that use image-formed paper, but also printers that provide print and copy services upon request from outside. It is installed and used in other stores. In an image forming apparatus, a time-consuming image forming job is often executed. In this case, usually, a required time corresponding to the number of sheets and the capability of the image forming apparatus is estimated. When the job is completed, the paper on which the image has been formed is delivered to the requester. Since the requester plans the next work based on the estimated required time, the image forming job is completed within the required time. That is important.

Here, Patent Document 1 discloses a technique for changing a driving current of a motor when a load applied to the motor that drives the mechanism of the sheet processing apparatus fluctuates. According to this, when the size or weight of the sheet processed by the mechanism varies, the deceleration of the mechanism can be suppressed.
JP 2003-238209 A

  However, the timing at which the image forming job is completed is greatly delayed not only by deceleration due to load fluctuations but also by stopping the image forming process halfway. For example, the image forming apparatus is stopped by the user for replacement of consumables or confirmation of the processing state, or automatically and temporarily stopped to adjust the mechanism by detecting an abnormality in a sensor inside the image forming apparatus. There are things to do. In such a case, with the technique disclosed in Patent Document 1, the stop of the image forming process directly causes a delay in the job end timing. As a result, the image forming job does not end even if the required time elapses. This means that, for example, in the case of a printer, it is not possible to deliver a paper on which an image is formed as a product to a requester who has received it at a scheduled time.

  In view of the above circumstances, an object of the present invention is to provide an image forming apparatus that finishes an image forming process in a predetermined required time even when the process is stopped midway.

An image forming apparatus of the present invention that achieves the above object is an image forming apparatus that forms an image on a specified number of sheets designated from outside,
An image forming mechanism that operates for image formation under control;
A control unit for controlling the operation of the image mechanism unit,
The control unit is
A mechanism control unit that causes the image forming mechanism unit to form an image;
Prior to the start of image formation of the image forming mechanism section by the mechanism control section, the image forming mechanism section has a predetermined speed slower than an upper limit speed at which the image forming mechanism section can operate for image formation. A required time calculation unit for calculating a required time required to form an image on the specified number of sheets at a standard speed of
The remaining time obtained by subtracting the time elapsed after the start of image formation in the image forming mechanism unit from the required time calculated by the required time calculating unit, and the number of sheets of paper on which the image forming mechanism unit has formed an image from the specified number of sheets. A speed calculating unit that calculates a speed at which the image forming mechanism unit forms an image on the remaining number of sheets excluding the number of sheets;
The mechanism control unit causes the image forming mechanism unit to form an image at a speed calculated by the speed calculation unit.

  According to the image forming apparatus of the present invention, the required time at the standard speed is calculated before the image formation for the designated number of sheets is started. The image forming mechanism that operates for image formation operates at a speed calculated so as to form an image on the remaining number of sheets corresponding to the specified number of sheets in the remaining time with respect to the required time. Accordingly, even when the image forming process is temporarily stopped in the middle, the image forming mechanism unit thereafter forms an image on the remaining number of sheets in the remaining time, and as a result, image formation on the specified number of sheets is performed. However, it ends with the time required previously calculated.

  Here, the image forming apparatus of the present invention causes the image forming mechanism unit to temporarily stop image formation, and causes the image forming mechanism unit to perform an operation for maintaining the function of the image forming mechanism unit. It is preferable to have a maintenance control unit.

  For example, operations for maintaining the functions of the image forming mechanism such as image quality adjustment keep the performance of the image forming apparatus good, but if the image forming apparatus automatically performs such operations, the image forming operation is not performed. In some cases, the user temporarily stops regardless of the user's intention. Even in such a case, according to the image forming apparatus of the present invention, the image forming process for the designated number of sheets is completed in the required time calculated previously.

  In the image forming apparatus according to the present invention, when the speed calculation unit is scheduled to temporarily stop image formation of the image forming mechanism unit by the maintenance control unit, from the remaining time, It is preferable that the image forming speed is calculated based on a time excluding a time when the maintenance control unit is scheduled to stop image formation of the image forming mechanism unit.

  When the image formation is scheduled to be temporarily stopped due to regular maintenance or the like, the image formation speed is calculated based on the time obtained by subtracting the scheduled stop time from the remaining time. Since the image formation is performed at a speed in which the stop is considered in advance before the image formation is stopped, the speed can be kept low.

  As described above, according to the present invention, it is possible to realize an image forming apparatus that finishes an image forming process in a predetermined required time even when the process is stopped midway.

  Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating a printer which is an embodiment of an image forming apparatus according to the present invention.

  The printer 1 shown in the figure forms a color image on a sheet by electrophotography in accordance with image data sent from a computer, and forms an image on the sheet trays 10 and 20 for storing the sheet and the sheet. An image forming mechanism section 30 that operates for the purpose, a stacking section 40 on which sheets on which images are formed are stacked, a user interface section 50 that displays various information, and a control section 60 that controls the operation of the image forming mechanism section 30. ing.

  The paper trays 10 and 20 store the same type of paper, and when one of the paper trays 10 and 20 runs out of paper, the paper is supplied from the other until the paper is replenished. ing. The sheets supplied from the sheet trays 10 and 20 are transported along the transport path R inside the image forming mechanism section 30 and stacked on the stacking section 40.

  The image forming mechanism 30 operates under the control of the control unit 60. The image forming mechanism 30 is provided for each color constituting the color image, and toner image forming portions 33Y, 33M, and 33C that form toner images by charging the surface of the photosensitive drum, irradiating exposure light, and developing the toner. , 33K, the intermediate transfer belt 32 that receives the transfer of the toner image from the toner image forming portions 33Y, 33M, 33C, and 33K and mediates the transfer of the toner image onto the paper, and the toner image transferred to the intermediate transfer belt 32, A transfer unit 36 that transfers to a sheet, a fixing unit 37 that fixes a toner image transferred to the sheet, and a sheet feeding unit 38 that conveys the sheet are provided. The intermediate transfer belt 32 is an endless belt, and the toner images for each color are transferred so as to be sequentially stacked by the toner image forming portions 33Y, 33M, 33C, and 33K as they circulate. The toner image transferred to the intermediate transfer belt 32 is transferred to the paper by the transfer unit 36 and fixed by the fixing unit 37.

  The stacking unit 40 includes trays 41 and 42 for stacking sheets on which images are formed, a sheet feeding unit 43 that transports sheets to these trays 41 and 42, and a stacking control unit 44 that controls the operation of the sheet feeding unit 43. ing. The stacking control unit 44 switches the stacking tray to be switched to the other when one of the trays 41 and 42 provided in the stacking unit 40 is full of paper.

  The control unit 60 controls the overall operation of the printer 1 including the image forming mechanism unit 30. The control unit 60 calculates the image forming speed, which is the number of sheets on which an image is formed per unit time, the intermediate transfer belt 32, the toner image forming units 33Y, 33M, 33C, and 33K, the transfer unit 36, and the sheet feeding unit. 38 by controlling the driving speed of the motor for driving 38 and the exposure speed in the toner image forming sections 33Y, 33M, 33C, and 33K so that the speed at which the image forming mechanism section 30 is formed is the calculated speed. To control. Further, the control unit 60 recognizes that the trays 41 and 42 are switched by communicating with the stacking control unit 44 of the stacking unit 40. Further, the control unit 60 causes the image forming mechanism unit 30 to perform a maintenance operation for maintaining the function. As a maintenance operation, for example, when one of the paper trays 10 and 20 that supplies paper is out of paper, the paper feeding unit 38 switches the paper tray to be switched to the other. There are switching, image quality adjustment for adjusting the color balance of the image formed on the paper by adjusting the density of the toner image formed by the toner image forming units 33Y, 33M, 33C, and 33K. The control unit 60 causes the image forming mechanism unit 30 to temporarily stop image formation while executing these operations. Among the maintenance operations, switching of the paper tray and switching of the stacking tray is an unexpected temporary maintenance because it is executed at the time when a paper out or a full tray is detected. On the other hand, for image quality adjustment, temporary maintenance performed when it is detected that the color balance of the image formed on the intermediate transfer belt 32 or the sheet is abnormal, and, for example, 100 images as a specification of the printer 1 are used. There is regular maintenance scheduled to be executed for each formation.

  The user interface unit 50 includes an LCD panel, and displays information such as a required time under the control of the control unit 60.

  The image forming mechanism unit 30 and the sheet feeding unit 43 correspond to an example of the image forming mechanism unit of the present invention, and the control unit 60 and the stacking control unit 44 correspond to an example of the control unit of the present invention.

  FIG. 2 is a block diagram showing an electrical configuration of the printer shown in FIG.

  The control unit 60 includes a central processing unit 61 (CPU 61) that controls the operation of the entire printer 1 based on a program, a ROM 63 that stores programs and tables, and a RAM 62 that provides the CPU 61 with a temporary storage area. Yes. The operation of the control unit 60 is controlled based on a program executed by the CPU 61. The control unit 60 is connected to the user interface unit 50, the abnormality detection sensor 39, the image forming mechanism unit 30, and the stack control unit 44. The control unit 60 is also connected to an external personal computer 90 that supplies print job data. When the print data including the image data and the information on the designated number of sheets, which is the number of sheets, is transmitted from the personal computer 90 to the printer 1, the printer 1 applies the designated number of sheets to the sheet designated by the personal computer 90. Form an image.

  The abnormality detection sensor 39 includes various sensors such as a position sensor and an optical sensor, and the image forming mechanism 30 such as out of paper in the paper trays 10 and 20 and an abnormality in the color balance of the image formed on the intermediate transfer belt 32. Detects abnormalities that impair the normal functioning of the computer. The control unit 60 causes the image forming mechanism unit 30 to perform a maintenance operation in accordance with the detection result by the abnormality detection sensor 39.

  The stacking control unit 44 includes a CPU 44a, a ROM 44c, and a RAM 44b, and controls the operation of the paper feeding unit 43 based on a program executed by the CPU 44a. When the sheet on which the image is formed is conveyed to the sheet feeding unit 43, the stacking control unit 44 conveys the sheet to one of the trays 41 and 42 to the sheet feeding unit 43. When one of the trays 41 and 42 is full of paper, this is notified to the control unit 60 and switched to the other.

  Here, the operation of the control unit 60 will be described with reference to a flowchart.

  FIG. 3 is a flowchart showing the operation of the control unit shown in FIG.

  When the control unit 60 receives print job data from the externally connected personal computer 90 (Yes in S11), the control unit 60 retrieves the specified number of pieces of information included in the print job data and causes the image forming mechanism unit 30 to form an image. Prior to starting the operation, the time required for forming an image on the designated number of sheets is calculated (step S12). The required time is calculated as the time required to form an image on a specified number of sheets at a predetermined standard speed. Here, a maximum rated speed is defined in the image forming mechanism section 30 as an upper limit speed at which the image forming mechanism section 30 can operate for image formation. However, when the image forming mechanism section 30 operates at the maximum rated speed, the life of the image forming mechanism section 30 is shortened due to wear or the like, and the image quality to be formed tends to become unstable. For this reason, the image forming mechanism 30 is defined with a standard speed that is slower than the maximum rated speed. The standard speed is obtained as a speed at which the print image quality and durability are improved based on the image quality and durability test results at the stage of designing and manufacturing the image forming mechanism 30. That is, in the calculation in step S12, the time required for image formation is calculated based on the standard speed at which the print image quality and durability of the image forming mechanism unit 30 are good. The control unit 60 displays the calculated required time on the user interface unit 50 to notify the user. Thereby, the user can know the required time.

  Next, the control unit 60 calculates the image forming speed (step S13). In this embodiment, every time an image is formed on one sheet, the image forming speed is calculated in step S13. The image forming speed is the number of sheets on which the image forming mechanism unit 30 forms an image per unit time. In calculating the image forming speed, the control unit 60 calculates the remaining number obtained by subtracting the number of sheets on which images have already been formed by the image forming mechanism unit 30 from the designated number. Further, the remaining time is calculated by subtracting the time elapsed after the start of image formation in the image forming mechanism 30 from the required time calculated in step S12. If regular maintenance is scheduled while image formation is performed for the remaining number of sheets, the remaining execution time is calculated by subtracting the time that is scheduled to be stopped for regular maintenance from the calculated remaining time. To do. Then, the image forming speed is calculated as the number of sheets per unit time necessary for image formation on the remaining number of sheets in the calculated remaining execution time. In this way, the speed at which an image can be formed on the remaining number of sheets in the remaining time with respect to the specified time is calculated. Note that the image forming speed may be expressed in the form of time from when an image is formed on one sheet to when an image is formed on the next sheet.

  For example, immediately after the prediction of the required time in step S12, the calculation of the image forming speed in step S13 is performed, and when the regular maintenance is not scheduled, the remaining time is equal to the required time, and the remaining number of sheets Is equal to the specified number. Accordingly, the image forming speed at this time is a speed at which an image is formed on a specified number of sheets in the estimated required time, that is, a standard speed. After the image formation is started, both the remaining time and the remaining number are decreased unless the image formation is stopped. Therefore, the image formation speed calculated when the image formation speed is calculated again in step S13 is The standard speed is maintained. Therefore, the image forming mechanism unit 30 continues image formation at the standard speed. However, when the image formation is stopped by maintenance or user operation, the remaining time is reduced, but the remaining number is not reduced. For this reason, the image forming speed calculated when the image forming speed is calculated again in step S13 is larger than the standard speed.

  Next, the control unit 60 causes the image forming mechanism unit 30 to form an image at the calculated image forming speed (step S14). The control unit 60 includes an intermediate transfer belt 32, toner image forming units 33Y, 33M, 33C, and 33K, a transfer unit 36, a driving speed of a motor that drives the paper feeding unit 38, and toner image forming units 33Y, 33M, 33C, and 33K. The exposure speed is controlled so that the number of sheets on which images are formed per unit time by the image forming mechanism unit 30 is equal to the image forming speed calculated in step S13 described above. In step S <b> 14, the control unit 60 performs operation control corresponding to one process for each of the units constituting the image forming mechanism unit 30.

  In step S15, the control unit 60 determines whether to perform periodic maintenance. For example, when image quality adjustment is scheduled every time an image is formed on 100 sheets of paper, the control unit 60 counts the number of images formed after the previous image quality adjustment, and the counted number is 100 sheets. By determining whether or not the value has been exceeded, it is determined whether or not to perform image quality adjustment as regular maintenance. When it is determined that periodic maintenance is not performed (No in Step S15), the control unit 60 determines whether or not temporary maintenance is performed (Step S16). Specifically, whether or not the abnormality detection sensor 39 has detected an out-of-paper tray out of the paper trays 10 and 20 or an abnormality in the color balance of the image formed on the intermediate transfer belt 32. In addition, it is determined whether or not the control unit 60 has notified the switching of the trays 41 and 42.

  When it is determined in step S15 or step S16 that maintenance is to be performed, the control unit 60 causes the image forming mechanism unit 30 to temporarily stop image formation (step S17) and perform a corresponding maintenance operation. (Step S18), the image forming operation is resumed. While the image formation is stopped, the remaining number does not decrease and the remaining time decreases.

  In step S19, the control unit 60 determines whether or not the image formation on the specified number of sheets is completed. Thus, the process from step S13 is repeated until the image formation on the specified number of sheets is completed, the image forming speed is updated, and the image formation is performed on the specified number of sheets.

  The control unit 60 that executes the process of step S14 described above corresponds to an example of a mechanism control unit according to the present invention, and the control unit 60 that executes the process of step S12 corresponds to an example of a required time calculation unit according to the present invention. The control unit 60 that executes the process of step S13 corresponds to an example of a speed calculation unit according to the present invention. Further, the control unit 60 that executes the processes of steps S15 to S18 and the stacking control unit 44 that switches the trays 41 and 42 correspond to an example of a maintenance control unit according to the present invention.

  FIG. 4 is a timing chart showing the timing at which an image is formed on a sheet under the control of the control unit 60 shown in FIG.

  FIG. 4 shows, as an example, three timings for forming an image on each sheet when an image is formed on a designated number n = 8 sheets. The (a) column of FIG. 4 shows the timing when image formation is not stopped due to maintenance (Set Up), and the (b) column is the case where image formation is stopped due to temporary maintenance. Timing is shown. The column (c) shows the timing when image formation stops due to regular maintenance.

  In step S12 (FIG. 3) prior to the start of image formation, the control unit 60 determines the time required for the image forming mechanism unit 30 to form an image on the designated number of 8 sheets at the standard speed. Calculate as T.

  If image formation does not stop halfway, as shown in the column (a) of FIG. 4, the control unit 60 causes the image forming mechanism unit 30 to set the time interval between one sheet and the next sheet to T / 8. An image is formed at an image forming speed. As a result, images are formed on the eight sheets in the required time T. The image forming speed in this case is a standard speed.

  Here, as shown in the column (b) of FIG. 4, after the image is formed on the third sheet, for example, the abnormality detection sensor 39 determines that the color balance of the image on the intermediate transfer belt 32 is abnormal. When detected, the control unit 60 causes the image forming mechanism unit 30 to temporarily stop image formation and perform image quality adjustment as temporary maintenance (steps S17 and S18 in FIG. 3). As a result of the stop, the remaining time decreases and the remaining number does not decrease. Therefore, the image forming speed calculated when the image forming speed is calculated again (step S13 in FIG. 3) is the same as that for one sheet and the next. The time interval with the other paper is increased to T / 10. As a result, an image is formed in the required time T on the designated number of 8 sheets. As described above, when the image formation is temporarily stopped, the required time is given priority over the life of the image forming mechanism and the stability of the image quality.

  As shown in the column (c) of FIG. 4, for example, the 100th image formation from the previous image quality adjustment corresponds to the third of the designated 8 images, and after the third image formation is completed. When it is known that the image formation will be stopped and the image quality adjustment will be performed, if the image formation is scheduled to be stopped by regular maintenance, the time remaining after the scheduled stop is excluded from the remaining time The image forming speed is calculated based on (Step S13 in FIG. 3). The image forming speed is calculated so that the time between one sheet and the next sheet is T / 9. As a result, even if the image formation is stopped by the regular maintenance, the image formation is performed on the eight sheets in the required time T. In addition, since image formation is performed at a speed considering stopping in advance, the time between one sheet and the next sheet remains T / 9 even after maintenance, and the speed is kept low.

  According to the printer 1 of the present embodiment, the required time T at the standard speed is calculated prior to the start of image formation for a specified number of sheets, for example, eight sheets. On the other hand, the image forming mechanism 30 that operates for image formation operates at a speed calculated so that an image can be formed on the remaining number of sheets for the designated number of 8 sheets in the remaining time with respect to the required time T. Therefore, even when the image forming process is temporarily stopped halfway due to a maintenance operation or a user operation, the image forming mechanism unit 30 operates to form an image on the remaining number of sheets in the remaining time with respect to the required time. Therefore, the image forming process for the designated number of sheets ends at the required time T calculated prior to the start of the process.

  Further, as described above, the stop of image formation is not limited to the user's operation when exchanging consumables or checking the situation, but is automatically performed regardless of the user's intention to maintain the function of the image forming mechanism. It is also generated by the operation. Even in such a case, according to the printer 1 of the present embodiment, the image forming process for the designated number of sheets ends in the required time calculated prior to the start of the process.

  In the present embodiment, the calculation of the image forming speed (step S13 in FIG. 3) has been described as being performed every time an image is formed on one sheet. However, the present invention is not limited to this. Absent. For example, the speed calculation unit of the present invention may calculate the speed every time images are formed on a plurality of sheets or every predetermined time. The image forming speed may be calculated every time the operation stops.

  Moreover, although this embodiment demonstrated as the thing which the required time calculated by the control part 60 was displayed on the user interface part 50 and alert | reported to a user (step S12), this invention is not limited to this. For example, if the user can estimate the required time based on an instruction of the image forming apparatus or original calculation, the required time calculated by the image forming apparatus may not be notified.

  In the present embodiment, the controller 60 controls the intermediate transfer belt 32, the toner image forming units 33Y, 33M, 33C, and 33K, the transfer unit 36, the driving speed of the motor that drives the paper feeding unit 38, the toner image forming unit 33Y, Although it has been described that the image forming speed is controlled by controlling the exposure speed at 33M, 33C, and 33K, the present invention is not limited to this. For example, the control unit of the present invention changes the interval between the sheets when the sheet is transported to the transfer unit by the sheet feeding unit while maintaining the driving speed and exposure speed of each unit described above constant. Thus, the image forming speed may be controlled. In other words, the interval from when one sheet is conveyed to the next sheet may be controlled by the sheet feeding unit.

1 is a diagram illustrating a printer that is an embodiment of an image forming apparatus of the present invention. FIG. 2 is a block diagram illustrating an electrical configuration of the printer illustrated in FIG. 1. It is a flowchart which shows operation | movement of the control part shown in FIG. FIG. 4 is a timing chart showing the timing at which an image is formed on a sheet by the operation control shown in FIG. 3.

Explanation of symbols

1 Printer (image forming device)
DESCRIPTION OF SYMBOLS 10,20 Paper tray 30 Image forming mechanism part 32 Intermediate transfer belts 33Y, 33M, 33C, 33K Toner image forming part 36 Transfer part 37 Fixing part 38 Paper feed part 39 Abnormality detection sensor 40 Stacking part 41, 42 Tray 43 Paper feed part 44 Loading control unit 50 User interface unit 60 Control unit

Claims (3)

An image forming apparatus for forming an image on a specified number of sheets designated from outside,
An image forming mechanism that operates for image formation under control;
A control unit for controlling the operation of the image mechanism unit,
The control unit is
A mechanism control unit that causes the image forming mechanism unit to form an image;
Prior to the start of image formation of the image forming mechanism unit by the mechanism control unit, the image forming mechanism unit has a predetermined speed slower than an upper limit speed at which the image forming mechanism unit can operate for image formation. A required time calculation unit for calculating a required time for forming an image on the specified number of sheets at a standard speed of
The remaining time obtained by subtracting the time elapsed after the start of image formation in the image forming mechanism from the required time calculated by the required time calculating unit, and the number of sheets on which the image is formed by the image forming mechanism from the specified number of sheets. A speed calculating unit that calculates a speed at which the image forming mechanism unit forms an image on the remaining number of sheets excluding the number of sheets;
The image forming apparatus, wherein the mechanism control unit causes the image forming mechanism unit to form an image at a speed calculated by the speed calculating unit.   The image forming apparatus includes a maintenance control unit that causes the image forming mechanism unit to temporarily stop image formation and causes the image forming mechanism unit to perform an operation for maintaining the function of the image forming mechanism unit. The image forming apparatus according to claim 1.   When the speed calculation unit is scheduled to temporarily stop image formation of the image forming mechanism unit by the maintenance control unit, from the remaining time, the maintenance control unit of the image forming mechanism unit 3. The image forming apparatus according to claim 2, wherein the image forming speed is calculated based on a time excluding a time during which image formation is scheduled to be stopped.

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