JP2019101336A - Image forming apparatus - Google Patents

Abstract

To solve the problem in which: when a component used in an image forming apparatus is deteriorated, printing cannot be completed until the component is replaced.SOLUTION: A down time calculation unit 33 included in an image forming apparatus 1 calculates the down time until an internal temperature reaching a guarantee temperature is reduced and printing can be resumed, before printing of prints in a number set in a job is completed. A printing time calculation unit 34 performs calculation for adding the down time to a printing time until the internal temperature reaches the guarantee temperature for every printing mode. A printing control unit 35 selects a printing mode in which printing can be completed before a component used in the image forming apparatus reaches the end of its life, on the basis of the printing time calculated by the printing time calculation unit 34 for every printing mode, and controls a conveying unit and a fixing unit according to the selected printing mode to perform printing on a sheet.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus.

  In recent years, a self-diagnosis function has been installed in an image forming apparatus, and it has become possible for the image forming apparatus to notify the user of component replacement when various parts constituting the image forming apparatus deteriorate. With this function, maintenance personnel can predict the replacement time of parts, and can replace parts predicted to be replaced with new parts before the parts are broken. By replacing the parts before the parts fail in this way, it is possible to continue using the image forming apparatus without the downtime period in which the image forming apparatus can not be used.

  As described above, as a result of the self-diagnosis performed by the image forming apparatus, if the replacement time of the parts is approaching, the image forming apparatus notifies the maintenance personnel of the part replacement. Maintenance personnel, after arranging and obtaining new parts, replace parts that are due for replacement. However, it takes some time to replace parts. Therefore, if a part fails unexpectedly, the image forming apparatus can not be used until the part is replaced, resulting in inconvenience for the user. Therefore, it has been required that the image forming apparatus normally continue the printing operation until the parts are replaced.

  However, when the image forming apparatus continues to operate in a high temperature environment, the parts deteriorate due to the temperature, and the parts are prone to failure. When an HDD (Hard Disk Drive) is taken as an example of components, it is known that the longer the time for using the HDD in a high temperature environment, the higher the incidence of failure of the HDD. For example, if the temperature rise in the HDD occurs many times, oil or the like used for the bearing of the disk mounted on the HDD is deteriorated to cause an axial deviation of the disk. For this reason, the head in contact with the disk damages the disk, and the HDD breaks down.

  In the HDD, S. M. A. R. T. There is a self-diagnosis function called (Self-Monitoring Analysis and Reporting Technology). For example, the HDD can predict a failure by self-diagnosis using the printing temperature measured by a temperature sensor incorporated in the image forming apparatus and the number of printed sheets. Therefore, the HDD can provide some information on failure prediction to the outside.

For example, Patent Documents 1 and 2 below disclose techniques for reducing the internal temperature of an image forming apparatus.
Patent Document 1 discloses a technique for prohibiting the formation of an image by the image forming unit and operating a fan when a signal indicating that the temperature is higher than the in-machine limit temperature higher than the in-machine threshold temperature is output. .

  Patent Document 2 discloses a technique for switching the printing speed according to the number of pages of the read image and the temperature of the fixing device.

JP, 2016-173537, A JP, 2017-015814, A

  After detecting that the HDD replacement time is approaching by self-diagnosis of the HDD, in order to prevent the failure of the HDD, it is necessary not to continue operating the image forming apparatus under a high temperature environment. In the image forming apparatus, the fixing device heats the sheet to which the toner has been transferred, whereby the toner is fixed to the sheet. Therefore, as the number of printed sheets increases, the heat generated in the fixing unit continues to flow into the vicinity of the HDD, and the HDD is exposed to high temperatures. Therefore, conventionally, when the temperature in the image forming apparatus reaches a predetermined temperature, printing is temporarily stopped to prevent heat generated mainly in the fixing device from flowing into the HDD. However, if printing of the image forming apparatus is frequently paused, the time taken to complete printing increases, and it takes time for the user to obtain the product.

  In addition, there are normal printing (normal printing mode) in which the fixing device is printed by heating to a normal temperature (normal printing mode), and low temperature printing (low temperature printing mode) in which the fixing device is heated by printing at a lower temperature than normal. By printing while the temperature of the fixing device is low, the temperature rise in the image forming apparatus can be suppressed more than in normal printing. Further, since the fixing device is used at a low temperature, the internal temperature of the image forming apparatus does not easily rise. Therefore, by printing the fixing device at a low temperature, it is possible to increase the number of printable sheets before printing is paused. However, since the temperature of the fixing device is low, the sheet passes through the fixing device in a slower speed than in normal printing in order to apply sufficient heat to the toner transferred to the sheet. In this case, the printing time required for one sheet of paper will be long. As a result, it also took time for the user to obtain the deliverables.

  The present invention has been made in view of such a situation, and has an object of quickly completing printing even in a situation where parts used in an image forming apparatus approach the life.

  The image forming apparatus according to the present invention includes a job receiving unit for receiving a job, an image forming unit for forming an image on a sheet, a conveyance unit for conveying a sheet at a predetermined printing speed, and a sheet conveyed by the conveyance unit. A fixing unit that heats to a predetermined fixing temperature and presses a sheet to fix an image on a sheet, and is provided for each of a plurality of printing modes having different fixing temperature and printing speed, and the internal temperature of the own apparatus for each number of sheets printed Obtain the number of printable sheets from the number of sheets temperature table that is stored in association with the amount of increase in the number of sheets and the printable number of sheets before the internal temperature rises and reaches the guaranteed temperature, and printing of the number of sheets set in the job is completed A pause time is added to the pause time calculator that calculates the pause time until the internal temperature reached the guaranteed temperature falls and becomes printable again, and the print time until the internal temperature reaches the guaranteed temperature. It is possible to complete printing before the parts used in the own device reach the end of life based on the printing time calculation unit which performs calculation for each printing mode and the printing time calculated for each printing mode by the printing time calculation unit And a print control unit which controls the conveyance unit and the fixing unit according to the selected print mode to print on a sheet.

According to the present invention, it is possible to complete printing in the shortest possible time according to the situation while suppressing the internal temperature of the image forming apparatus in use when the life of the part (e.g. HDD) is approaching it can. In addition, since printing is performed in the print mode in which printing can be completed quickly, the time until the user can obtain a product can be shortened.
Problems, configurations, and effects other than those described above will be apparent from the description of the embodiments below.

FIG. 1 is a schematic diagram showing an example of a hardware configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 1 is a hardware configuration diagram showing a configuration example of main parts of an image forming apparatus according to an embodiment of the present invention. It is a functional block diagram showing an example of internal configuration of a control part concerning an example of an embodiment of the present invention. It is an explanatory view showing an example of a parts degradation graph concerning an example of an embodiment of the present invention. It is an explanatory view showing an example of a number-of-sheets temperature graph concerning an example of an embodiment of the present invention. FIG. 6 is an explanatory view showing an example of a graph showing, for each print mode, the relationship between the number of sheets to be printed and the time until the completion of printing according to the embodiment of the present invention. It is a flowchart which shows the example of the process which calculates the printing time until it completes printing which concerns on the example of this invention for every printing mode. It is a flowchart which shows the example of the 1st printing control processing performed by the printing control part which concerns on the example of one embodiment of this invention. It is a flowchart which shows the example of the 2nd print control processing performed by the printing time calculation part which concerns on the example of one embodiment of this invention, and a printing control part. 6 is a flowchart illustrating an example of processing for determining a storage device used in first and second print control processing according to an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In the specification and the drawings, components having substantially the same function or configuration will be assigned the same reference numerals and overlapping descriptions will be omitted.

[One embodiment]
<Hardware Configuration Example of Image Forming Apparatus>
FIG. 1 is a schematic diagram showing an example of the hardware configuration of the image forming apparatus 1.
The image forming apparatus 1 employs an electrophotographic method in which an image is formed using static electricity. For example, toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K) are used. Is a tandem type color image forming apparatus. The image forming apparatus 1 includes a manual feed tray 20, an automatic document feeder 21, an operation display unit 22, a sheet feeding unit 23, an image forming unit 24, an intermediate transfer belt 25 (image carrier), a secondary transfer unit 27, and fixing. And a transport unit 29 and a discharge tray 30.

  The manual feed tray 20 is pulled out from the image forming apparatus main body 2 and used when forming an image on a sheet S of a type not stored in the sheet feeding unit 23. The manual feed tray 20 is inclined upward at a predetermined angle with respect to the horizontal direction, and can load a plurality of sheets S. Then, the sheet S is fed from the manual feed tray 20 to the conveyance path C in the image forming apparatus main body 2.

  The automatic document feeder 21 automatically feeds a document when reading a document. A scanner 21 a provided below the automatic document feeder 21 reads an image of a document placed on a platen glass at the top of the image forming apparatus 1 or a document automatically conveyed by the automatic document feeder 21. Can.

  The operation display unit 22 has a function as an operation unit for instructing start of a job such as an image forming process, for example. The operation display unit 22 is configured by a touch panel including an LCD (Liquid Crystal Display) or the like, and can be operated by the user and can display information. The operation display unit 22 doubles as an operation unit and a display unit. The operation unit may be configured of a mouse, a tablet, or the like, and may be configured separately from the display unit.

  The sheet feeding unit 23 includes a plurality of sheet storage units 23 a capable of storing sheets having different sheet sizes and sheet types. In the sheet feeding unit 23, when the corresponding sheet storage unit 23 a is selected based on an instruction from the image forming apparatus 1, the sheet S is taken out from the sheet storage unit 23 a and the sheet S is sent to the conveyance path C.

  The image forming unit 24 includes four image forming units 26Y, 26M, 26C, and 26K in order to form toner images of yellow, magenta, cyan, and black. The image forming unit 24 controls the operations of the image forming units 26Y, 26M, 26C, and 26K of the image forming unit 24 to form yellow, magenta, cyan, and black toner images. The image forming apparatus 1 also includes a plurality of rollers (conveying rollers) for conveying the sheet S to the conveyance path C as the conveyance unit 29. These rollers are usually constituted by a roller pair.

  The image forming apparatus 1 charges the photosensitive members of the image forming units 26Y, 26M, 26C, and 26K in the image forming mode, and exposes the photosensitive members to erase charges, thereby forming an electrostatic latent image on the photosensitive members. Then, toner is attached to the electrostatic latent images of the yellow, magenta, cyan, and black photosensitive members using a developing unit, and toner images of the respective colors are formed. Next, the toner images formed on the yellow, magenta, cyan, and black photoconductors are sequentially primary-transferred on the surface of the intermediate transfer belt 25 rotating in the direction of the arrow.

  Next, the toner images of the respective colors primarily transferred onto the intermediate transfer belt 25 by the secondary transfer portion 27 (secondary transfer roller) are supplied from the paper feeding portion 23, and the transport portion 29 at a predetermined printing speed. The secondary transfer is performed to the sheet S to be conveyed. A secondary transfer of the toner images of the respective colors on the intermediate transfer belt 25 onto the sheet S forms a color image. The image forming apparatus 1 conveys the sheet S on which the color toner image is formed to the fixing unit 28.

  The fixing unit 28 performs a fixing process on the sheet S on which a color toner image is formed. The fixing unit 28 heats the sheet S conveyed by the conveying unit 29 to a predetermined fixing temperature and pressurizes the sheet S to fix the toner image transferred onto the sheet S to the sheet S. The fixing unit 28 includes, for example, an upper fixing roller and a lower fixing roller, which are fixing members. The upper fixing roller and the lower fixing roller are disposed in pressure contact with each other, and a fixing nip portion is formed as a pressure contact portion between the upper fixing roller and the lower fixing roller.

  A heating unit (not shown) is provided inside the fixing upper roller. The radiant heat from the heating portion heats the roller portion at the outer peripheral portion of the fixing upper roller. The sheet S is conveyed to the fixing nip portion such that the surface on which the toner image has been transferred by the secondary transfer portion 27 (surface to be fixed) faces the fixing upper roller. The sheet S passing through the fixing nip portion is pressurized by the upper fixing roller and the lower fixing roller and heated by the heat of the roller portion of the upper fixing roller. The sheet S on which the fixing process has been performed by the fixing unit 28 is discharged to the sheet discharge tray 30.

<Configuration of Main Part of Image Forming Apparatus>
FIG. 2 is a hardware configuration diagram showing a configuration example of main parts of the image forming apparatus 1.
The image forming apparatus 1 includes a control unit 11, an HDD 12, a communication I / F 13, a temperature sensor 14, and a USB memory 15 in addition to the automatic document feeder 21, the operation display unit 22, and the image forming unit 24 described above. Each unit in the image forming apparatus 1 is connected via a bus.

  The control unit 11 includes a CPU 11a, a ROM 11b, and a RAM 11c. The control unit 11 is used as an example of a computer that controls the operation of each unit in the image forming apparatus 1.

The CPU (Central Processing Unit) 11a controls an image forming process (printing operation) of the image forming unit 24 based on, for example, a print instruction of the user performed through the operation display unit 22 and the contents set in the job.
A ROM (Read Only Memory) 11 b is used as an example of a non-volatile memory, and stores programs, data, and the like necessary for the CPU 11 a to operate.
A random access memory (RAM) 11 c is used as an example of a volatile memory, and temporarily stores information (data) necessary for each process performed by the CPU 11 a.

  The HDD 12 stores programs for the CPU 11 a to control the respective units, programs such as an OS and a controller, and data. Some of the programs and data stored in the HDD 12 are also stored in the ROM 11 b. The HDD 12 is used as an example of a computer-readable non-transitory storage device storing a program executed by the CPU 11 a. The computer-readable non-transitory storage device storing the program executed by the image forming apparatus 1 is not limited to the HDD, and may be, for example, a solid state drive (SSD), a CD-ROM, or a DVD-ROM. Or the like.

  The communication I / F (Interface) 13 is configured by a NIC (Network Interface Card), a modem, or the like, establishes connection with each device such as a print controller (not shown), and performs transmission and reception of various data. It is.

  The temperature sensor 14 is used as an example of a temperature measurement unit that measures the internal temperature of the image forming apparatus 1. The value of the internal temperature detected by the temperature sensor 14 is output to the control unit 11. Before the operation of the image forming apparatus 1, the ambient temperature of the environment (office or the like) where the image forming apparatus 1 is installed is the same as the internal temperature of the image forming apparatus 1. While the image forming apparatus 1 is in operation, for example, heat generated from the fixing unit 28 increases the internal temperature. Then, when the operation of the image forming apparatus 1 is temporarily stopped, the heat generated from the fixing unit 28 disappears, so the internal temperature drops.

  A USB (Universal Serial Bus) memory 15 is used as an example of a diskless storage device that can be attached to and detached from the image forming apparatus 1. For example, when the HDD 12 is degraded and reaches its life, various data are stored in the USB memory 15 used instead of the HDD 12. As described above, in the image forming apparatus 1, in addition to the HDD 12, the USB memory 15 which can be used by being inserted into the memory slot of the image forming apparatus 1 is used as the storage device. The USB memory 15 has a storage capacity equal to that of the HDD 12. The HDD 12 stores various data as the disk rotates as described above. On the other hand, the USB memory 15 does not have a disk. Therefore, the failure rate of the USB memory 15 is lower than that of the HDD 12.

<Example of internal configuration of control unit>
FIG. 3 is a functional block diagram showing an example of the internal configuration of the control unit 11.
The control unit 11 includes a job receiving unit 31, sheet temperature tables 32a and 32b, idle time calculating unit 33, print time calculating unit 34, print control unit 35, storage destination determining unit 36, component life predicting unit 37, and use time storage unit It has 38.

  The job receiving unit 31 receives a job transmitted from a print controller (not shown) connected to the image forming apparatus 1 or a client terminal. In the job, for example, setting of allocation printing, setting of the number of printed sheets, and the like are made.

  The sheet number temperature tables 32a and 32b are provided for each of a plurality of print modes having different fixing temperatures and printing speeds, and the amount of increase in the internal temperature of the own apparatus is stored in association with each sheet of printed sheets. The number-of-sheets temperature table 32a is provided for the normal print mode. The normal printing mode is a printing mode in which the fixing unit 28 fixes an image on the sheet S at a normal fixing temperature and performs printing at a normal printing speed. The number-of-sheets temperature table 32 b is provided for the low temperature printing mode. The low temperature printing mode is a printing mode in which the fixing unit 28 fixes an image on the sheet S at a temperature lower than the normal fixing temperature and performs printing at a printing speed slower than the normal printing speed.

  The pause time calculation unit 33 acquires the printable number of sheets from the number temperature tables 32a and 32b by the time the internal temperature of the image forming apparatus 1 rises and reaches the guaranteed temperature, and the printing of the number of sheets set in the job is completed. Before doing, calculate the rest time until the internal temperature which has reached the guaranteed temperature drops and it is possible to print again.

  The print time calculation unit 34 performs calculation for each print mode by adding the idle time to the print time until the internal temperature reaches the guaranteed temperature.

  Based on the printing time calculated for each printing mode by the printing time calculation unit 34, the printing control unit 35 selects a printing mode in which printing can be completed before the components used in the own apparatus reach the end of life. The transport unit 29 and the fixing unit 28 are controlled according to the selected print mode to print on a sheet. Further, the print control unit 35 selects a print mode in which the time taken to complete printing of the number of print sheets set in the job is shortest, based on the print time. The print control unit 35 can also combine a plurality of print modes based on the print time so that the time taken to complete printing of the number of print sheets set in the job is shortest.

  Further, the print control unit 35 selects the normal print mode when the save destination determination unit 36 selects a diskless storage device other than the HDD 12 as a save destination of various data. Further, the printing control unit 35 selects the low-temperature printing mode when the component life predicting unit 37 requests replacement of the components before the components reach the lifetime and the printing start time is designated in the job. It can also be done.

  The storage destination determination unit 36 preferentially selects the USB memory 15 other than the HDD 12 as a storage destination when the component whose replacement is requested before the component life prediction unit 37 has reached the HDD 12. The storage destination determining unit 36 selects the HDD 12 and the USB memory 15 other than the HDD 12 as the storage destination when the part requested to be replaced before the part reaches the end of life is the HDD 12, and the HDD 12 and the USB memory are selected. 15 can also be used together.

  The part life prediction unit 37 predicts the life of parts used in its own device. At this time, the component life prediction unit 37 predicts the life of the component based on the usage time of each component read from the usage time storage unit 38. The parts for which the usage time is stored are, for example, recording devices such as the HDD 12 built in the image forming apparatus 1.

  The use time storage unit 38 stores the use time of the component. When the part is replaced, the used time of the part is reset when replaced, and the used time is counted again.

<Description of parts deterioration>
As the self-diagnosis function of the image forming apparatus 1 has been enhanced, it has become possible in recent years to quantify the state of quality deterioration of parts.
FIG. 4 is an explanatory view showing an example of a part deterioration graph. In the part deterioration graph, the horizontal axis represents time, and the vertical axis represents the degree of part deterioration. The part deterioration graph indicates that the parts used under the environment where the internal temperature of the image forming apparatus 1 becomes high deteriorate depending on the use time.

  For example, when the image forming apparatus 1 is driven at time t1, the component deterioration becomes the state M1. The state M1 represents that the replacement of the parts is nearing due to the progress of the deterioration of the parts. However, it is possible for the image forming apparatus 1 to continue printing using the part in state M1.

  However, the image forming apparatus 1 continues to be driven without replacing parts, and when the driving time reaches time t2, the part deterioration becomes the state M2. The appearance of the component deterioration in the states M1 and M2 is indicated by a straight line L1 in the drawing. The state M2 represents that the timing for replacing the part has been reached because the deterioration of the part has advanced further than the state M1. For this reason, the image forming apparatus 1 can not print unless the part is replaced with a new one.

  Therefore, it is necessary to replace parts in a period from time t1 to time t2. It is preferable that the parts be replaced immediately, but it is conceivable that the parts can not be replaced before time t2 depending on the stock status of the parts. Even if the time t1 has passed, in order to complete the printing before the component deterioration reaches the state M2, it is necessary to operate the image forming apparatus 1 for a time t3 longer than the time t2. A state in which the component deterioration becomes the state M2 at time t1 and then becomes the state M2 at time t1 is indicated by a broken line L2 in the drawing.

  FIG. 5 is an explanatory view showing an example of a number-of-sheets temperature graph. In the number-of-sheets temperature graph, the horizontal axis represents the number of printed sheets, and the vertical axis represents the internal temperature of the image forming apparatus 1. FIG. 5 shows how the internal temperature reaches the guaranteed temperature Tb in two printing modes (normal printing mode and low-temperature printing mode).

  When the job reception unit 31 receives a job after the component deterioration reaches M1, the pause time calculation unit 33 determines the internal temperature according to the ambient temperature of the image forming apparatus 1 and the guaranteed temperature Tb at which printing pause is required. Calculate the temperature difference. Then, the pause time calculation unit 33 calculates the number of printable sheets and the pause time for each print mode by the print pause, using the sheet number temperature tables 32a and 32b.

  Suppose that the image forming apparatus 1 starts printing when the ambient temperature of the image forming apparatus 1 is Ta. At this time, the internal temperature measured by the temperature sensor 14 of the image forming apparatus 1 is also Ta. In the normal printing mode, when the number of printed sheets reaches a11, the internal temperature of the image forming apparatus 1 reaches the guaranteed temperature Tb. A solid line L11 shows how the internal temperature reaches the guaranteed temperature Tb in the normal printing mode.

  On the other hand, in the low temperature printing mode, the rising speed of the internal temperature becomes slower. For this reason, the internal temperature at the time when the number of printed sheets reaches a11 is lower than the guaranteed temperature Tb. Thereafter, when the number of printed sheets reaches a12, the internal temperature of the image forming apparatus 1 reaches the guaranteed temperature Tb. The manner in which the internal temperature reaches Tb by the low temperature printing mode is indicated by a broken line L12. As described above, in the low-temperature printing mode, it is possible to print more (a12 to a11) sheets than the normal printing mode.

  When the ambient temperature of the image forming apparatus 1 is Taa lower than Ta, the internal temperature is also Taa, so the temperature difference between the internal temperature and the guarantee temperature Tb is large. For this reason, the image forming apparatus 1 can print up to a number greater than a11 sheets and a12 sheets in either the normal printing mode or the low temperature printing mode. The manner in which the internal temperature reaches Taa to the guaranteed temperature Tb in the normal printing mode is indicated by a two-dot chain line L21. The manner in which the internal temperature reaches Taa to the guaranteed temperature Tb in the low-temperature printing mode is indicated by an alternate long and short dash line L22.

  If the number of prints set in the job is greater than the number of prints until the internal temperature reaches the guaranteed temperature Tb (a11 in the normal print mode, a12 in the low-temperature print mode), the print control unit 35 temporarily prints It is considered effective to pause and lower the internal temperature. By lowering the internal temperature, it is possible to extend the time for the component deterioration to reach the state M2.

<Relationship between printing time and pause time>
FIG. 6 is an explanatory view showing an example of a graph showing the relationship between the number of printed sheets and the time until the completion of printing for each print mode. The solid line L31 in the figure is a graph of the normal printing mode, and the broken line L41 is a graph of the low temperature printing mode by low temperature fixing. If the time to reach the state M2 is short after the parts reach the state M1 shown in FIG. 4, the image forming apparatus 1 can not print. For this reason, the printing control unit 35 prints only the pause time calculated by the pause time calculation unit 33 before the internal temperature reaches the guaranteed temperature Tb in the middle of printing regardless of the normal printing mode or the low temperature printing mode. Pause and lower the internal temperature.

  As already shown in FIG. 5, in the normal printing mode, the internal temperature reaches the guaranteed temperature Tb when the number of printed sheets reaches a11. Then, as shown in FIG. 6, when the number of printed sheets becomes a11 in the normal print mode, it becomes time t11. Therefore, in order to prevent the deterioration of the parts, when the time t11 is reached, a fixed time tc for pausing printing is provided to lower the internal temperature.

  Then, after time tc has elapsed, when time t13 is reached, printing in the normal print mode is resumed. When the number of printed sheets after printing restarts is a11 (the accumulated number of printed sheets is represented as a11 × 2 in the drawing), the internal temperature reaches the guaranteed temperature Tb (see FIG. 5) again. Therefore, when the time t14 is reached, the internal temperature is lowered by providing a fixed time tc for stopping the printing again. As described above, the image forming apparatus 1 repeats printing and printing pause according to the number of printable sheets by the time the internal temperature reaches the guaranteed temperature Tb.

  As already shown in FIG. 5, in the low temperature printing mode, the internal temperature reaches the guaranteed temperature Tb when the number of printed sheets becomes a12 more than a11 in the normal printing mode. Then, as shown in FIG. 6, when the number of printed sheets is a12 in the low temperature printing mode, it becomes time t12. The time t12 is later than the time t11 when the internal temperature reaches the guaranteed temperature Tb in the normal print mode. Therefore, the image forming apparatus 1 lowers the internal temperature by providing a predetermined time tc for pausing printing when the time t12 is reached.

  In the low temperature printing mode, the constant time tc in which the internal temperature falls from the guaranteed temperature Tb to a temperature at which printing can be resumed may be the same as the rest time in the normal printing mode. After a predetermined time tc, when time t15 is reached, printing in the low temperature print mode is resumed. After the printing is resumed, when the internal temperature reaches the guaranteed temperature Tb again, the internal temperature is lowered by providing a fixed time tc for stopping the printing again. In this way, printing and printing pause are repeated according to the number of printable sheets until the internal temperature reaches the guaranteed temperature Tb.

In FIG. 6, a section N1 from 0 to a11 printed sheets, a section N2 from a11 printed sheets to a12 printed sheets, and a section N3 from 12 printed sheets a12 to a11 × 2 printed sheets are shown. .
In the section N1, it is shown that the printing in the normal printing mode of the solid line L31 is completed in a shorter time than the low temperature printing mode of the broken line L41.
In the section N2, printing in the normal printing mode is paused for a predetermined time tc, but printing in the low temperature printing mode is performed, so printing in the low temperature printing mode of the broken line L41 is better than the normal printing mode of the solid line L31. It is shown that printing is completed in a short time.
In the section N3, it is shown that the printing in the normal printing mode of the solid line L31 is completed in a shorter time than the low temperature printing mode of the broken line L41.

  Therefore, the print control unit 35 calculates the time from the start of printing to the completion of printing according to the print mode, and presents the user with a print mode capable of completing printing in the shortest time to the user. The mode can be selected. Note that if automatic selection of the print mode is set, the print control unit 35 can automatically select a print mode that can complete printing in a short time and start printing. In addition, the print control unit 35 can also combine a plurality of print modes such that the time until print completion is the shortest.

<Processing example of print control>
Next, processing of print control according to the present embodiment will be described with reference to FIGS.
FIG. 7 is a flowchart showing an example of processing for calculating the printing time required to complete printing for each printing mode.

  First, the pause time calculation unit 33 takes in the number of print sheets set for the job received by the job reception unit 31 (S1). Next, the pause time calculation unit 33 takes in the temperature information measured by the temperature sensor 14 (S2). Then, the pause time calculation unit 33 sets the print mode to the normal print mode (S3), and performs the following determination or calculation.

  Next, the pause time calculation unit 33 refers to the number of sheets temperature table 32a to determine whether the internal temperature exceeds the guaranteed temperature Tb when printing in the normal print mode is completed based on the number of printed sheets taken from the job. It judges (S4). If it is determined that the internal temperature does not exceed the guaranteed temperature Tb (NO in S4), the print time calculation unit 34 calculates the print time taken to complete printing in the normal print mode (S7).

  On the other hand, when it is determined that the internal temperature exceeds the guaranteed temperature Tb (YES in S4), the rest time calculation unit 33 determines whether a rest time is necessary (S5). When it is determined that the pause time is unnecessary (NO in S5), the print time calculation unit 34 calculates the print time taken to complete printing in the normal print mode (S7).

On the other hand, when it is determined that the pause time is necessary (YES in S5), the pause time calculation unit 33 calculates the pause time (S6). Then, the printing time calculation unit 34 takes into consideration the pause time calculated in step S6, the printing time taken to complete the printing in the normal printing mode, and the printing time taken to complete the printing in the low temperature printing mode Is calculated (S7).
After step S7, one of the first print control process shown in FIG. 8 and the second print control process shown in FIG. 9 is performed based on the presetting of the image forming apparatus 1.

<Example of first print control process>
FIG. 8 is a flowchart illustrating an example of the first print control process performed by the print control unit 35. The present process shown in FIG. 8 is performed subsequent to the process of calculating the print time shown in FIG. 7 for each print mode.

  First, the print control unit 35 compares the print time for each print mode calculated in step S7 of FIG. 7 for each print mode (S11), and determines the print mode with the shortest print time (S12). Then, the print control unit 35 performs print control based on the determined print mode (S13). As a result, the print control unit 35 can complete printing in the shortest printing time before the components used in the image forming apparatus 1 reach the end of life.

<Example of Second Print Control Process>
FIG. 9 is a flowchart showing an example of the second print control process performed by the print time calculator 34 and the print controller 35. The main process shown in FIG. 9 is also performed after the process of calculating the print time shown in FIG. 7 for each print mode.

  First, the print time calculation unit 34 combines a plurality of print modes and calculates the time until printing is completed (S21). Then, the printing time is compared for each combination of printing modes (S22), and the combination of printing modes that provides the shortest printing time is determined (S23). Then, the print control unit 35 executes print control based on the determined combination of print modes (S24). Thus, the print control unit 35 can control printing by combining print modes capable of completing printing in the shortest printing time.

<Example of Storage Device Determination Process>
FIG. 10 is a flowchart showing an example of processing for determining a storage device used in the first and second print control processing. In FIG. 10, the storage location determining unit 36 has a small storage capacity but has a small storage capacity such as a large-capacity storage device such as the USB memory 15 as well as the HDD 12 and a non-volatile memory such as the RAM 11c and DRAM (Dynamic RAM). An example of a process of selecting a storage device having a small influence on the life is shown.

  First, the storage destination determination unit 36 starts selecting a storage device to be used as a storage destination of various data (S31). Then, the storage destination determination unit 36 determines the storage device attached to the image forming apparatus 1.

  Next, the save destination determination unit 36 determines whether the storage device is other than the HDD 12 (S32). If there is no storage device other than the HDD 12 (NO in S32), that is, only the HDD 12 is attached to the image forming apparatus 1, the storage destination determination unit 36 determines the storage device to be used as the HDD 12 (S35), This process ends.

  On the other hand, when the storage device is other than the HDD 12 (YES in S32), the save destination determination unit 36 determines whether or not to use the storage device other than the HDD 12 with priority (S33). When using a storage device other than the HDD 12 with priority (YES in S33), the storage location determining unit 36 determines the storage device to be used as a storage device other than the HDD 12 (for example, the USB memory 15) (S35), This process ends.

  On the other hand, when a storage device other than the HDD 12 is not used with priority (NO in S33), the storage location determining unit 36 determines whether the HDD 12 and a storage device other than the HDD 12 are used in combination (S34). When the HDD 12 and a storage device other than the HDD 12 are not used in combination (NO in S34), the storage location determining unit 36 determines the storage device to be used as the HDD 12 (S35), and ends this processing.

  On the other hand, when the HDD 12 and a storage device other than the HDD 12 are used in combination (YES in S34), the storage location determining unit 36 determines the storage device to be used as the HDD 12 and a storage device other than the HDD 12 (USB memory 15) Then (S35), the process ends.

  In the image forming apparatus 1 according to the embodiment described above, when a part replacement is requested by self-diagnosis in a situation where the parts used in the image forming apparatus 1 are approaching the end of life, a new part will arrive. Meanwhile, printing can be continued while preventing the failure of parts. This makes it possible to avoid the situation where the part can not be printed due to the end of its life. Then, the printing control unit 35 selects which printing mode to print out of the normal printing mode in which printing is performed at a normal printing speed and the low temperature printing mode in which printing is performed at low speed by low temperature fixing. It is possible to do. For example, if the internal temperature reaches the guaranteed temperature Tb after reaching the number of print sheets set in the job, the print control unit 35 can select the normal print mode and complete printing quickly. In the normal print mode, if the internal temperature reaches the guaranteed temperature Tb before the number of print sheets set in the job is reached, the print control unit 35 selects the low-temperature print mode to complete printing. Even if it takes time, printing can be completed with as many prints as possible.

  In addition, the printing control unit 35 continues printing while pausing printing before the internal temperature reaches the guaranteed temperature Tb. Since the internal temperature drops due to the printing pause, printing can be resumed again after a certain time tc has passed. This makes it possible to increase the number of printable sheets before replacing a part. Also, by suppressing the rise in the internal temperature, the life of the component can be extended.

  Also, the print control unit 35 can control printing in which the normal print mode and the low temperature print mode are combined. For example, at the start of printing, printing is performed in the normal printing mode, and printing is performed by changing to the low temperature printing mode before the internal temperature reaches the guaranteed temperature Tb. As a result, before the internal temperature reaches the guaranteed temperature Tb, the printing of the number of print sheets set in the job can be completed.

  In addition, even when printing is paused because the internal temperature reaches the guaranteed temperature Tb during printing in the normal printing mode, the printing control unit 35 prints in the low-temperature printing mode before the predetermined time Tc elapses. You may resume This can meet the user's request for printing to be completed as soon as possible.

  When a large capacity USB memory 15 additionally connectable to the image forming apparatus 1 is selected as the data storage destination instead of the HDD 12, even if the internal temperature rises due to the continuous printing being performed. , It is not necessary to consider the lifetime of the USB memory 15. By using a diskless storage device such as the USB memory 15 in combination, the normal printing mode can be continued without executing the low temperature printing mode or pausing during printing.

  In the case of a job for which an execution start time is specified, there are many cases where printing is not required in a short time. For this reason, the print control unit 35 does not have to determine the print mode in which printing can be performed in the shortest time. However, when the print mode which can print in the shortest time is not determined, since the number of printed sheets increases and the use time of the parts also increases, it is necessary to give priority to the service life of the parts.

  In addition, the print control unit 35 calculates the print time including the print pause time based on the number of print sheets set in the job, thereby making it possible to print a plurality of print modes that can be printed in a print time with a small waiting time for the user. It can be selected. In addition, the print control unit 35 may select a print mode including a short pause of printing to complete printing in the shortest time, in order to prevent breakage of the parts when the life of the parts becomes short. it can.

  In addition, after switching between the normal print mode and the low-temperature print mode based on the number of printed sheets set in the job, the print control unit 35 prints on a certain number of sheets S even during printing, Pause printing temporarily. In this way, it is possible to calculate the time until the printing is completed, and to determine the combination of printing modes that complete printing at the shortest from the result of each printing mode.

The present invention is not limited to the above-described embodiment, and it is needless to say that various other application examples and modifications can be taken without departing from the scope of the present invention described in the claims.
For example, the above-described embodiment is a detailed and specific description of the configuration of the device in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to one having all the configurations described. Moreover, it is also possible to add, delete, and replace other configurations for part of the configuration of the present embodiment.
Further, control lines and information lines indicate what is considered to be necessary for the description, and not all control lines and information lines in the product are necessarily shown. In practice, almost all configurations may be considered to be mutually connected.

  DESCRIPTION OF SYMBOLS 1 ... image forming apparatus, 2 ... image forming apparatus main body, 11 ... control part, 11a ... CPU, 12 ... HDD, 14 ... temperature sensor, 15 ... USB memory, 24 ... image forming part, 28 ... fixing part, 29 ... conveyance Part 31 job reception part 32a, 32b number sheet temperature table 33 pause time calculation part 34 print time calculation part 35 print control part 36 storage destination determination part 37 component life prediction part 38 ... Use time storage unit

Claims (9)

A job reception unit that receives a job,
An image forming unit that forms an image on a sheet;
A conveyance unit configured to convey the sheet at a predetermined printing speed;
A fixing unit that heats the sheet conveyed by the conveyance unit to a predetermined fixing temperature and presses the sheet to fix the image on the sheet;
A sheet temperature table which is provided for each of a plurality of printing modes in which the fixing temperature and the printing speed are different, and the increase amount of the internal temperature of the own apparatus is associated with each printing sheet number;
The printable number of sheets is acquired from the number-of-sheets temperature table until the internal temperature rises and reaches the guaranteed temperature, and the internal temperature reaches the guaranteed temperature before the printing of the number of printed sheets set for the job is completed. A pause time calculation unit that calculates a pause time until the temperature drops and printing becomes possible again;
A printing time calculation unit that performs calculation for each printing mode, adding the pause time to the printing time until the internal temperature reaches the guaranteed temperature;
Based on the printing time calculated for each of the printing modes by the printing time calculation unit, the printing mode is selected and selected so that printing can be completed before the parts used in the own apparatus reach the end of life. An image forming apparatus comprising: a print control unit configured to control the conveyance unit and the fixing unit according to the print mode to perform printing on the sheet; Furthermore, a use time storage unit that stores the use time of the part;
A temperature measurement unit that measures an internal temperature in the own device;
A component life prediction unit that predicts the lifetime of the component based on the usage time of the component read from the usage time storage unit and the internal temperature in the own apparatus in which the component is used. The image forming apparatus according to 1. In the printing mode, a normal printing mode in which the fixing unit fixes the image on the sheet at a normal fixing temperature and printing at a normal printing speed, and the fixing unit is lower than the normal fixing temperature The image forming apparatus according to claim 2, further comprising: a low temperature printing mode in which the image is fixed to the sheet at a temperature and printing is performed at a printing speed lower than the normal printing speed. The image forming apparatus according to claim 3, wherein the print control unit selects the print mode in which the time taken to complete printing of the number of print sheets set for the job is shortest based on the print time. The image formation according to claim 3, wherein the print control unit combines a plurality of the print modes based on the print time such that the time taken to complete printing of the number of print sheets set in the job is shortest. apparatus. Furthermore, when the part whose replacement is required before the part reaches the end of life is the disk storage device by the part life prediction unit, a diskless storage device other than the disk storage device is preferentially selected as a save destination The image forming apparatus according to claim 4, further comprising: a storage destination determination unit. The image forming apparatus according to claim 6, wherein the print control unit selects the normal print mode when the storage destination determination unit selects a storage device other than the disk storage device as a storage destination. If the part whose replacement is required before the part reaches its life by the part life prediction unit is a disk storage device, the disk storage device and a diskless storage device other than the disk storage device are saved to The image forming apparatus according to claim 4, further comprising: a storage destination determination unit that selects the disk storage device and the diskless storage device in combination. The print control unit is configured to use the low-temperature print mode when the component life prediction unit requests replacement of the component before the component reaches its life and the print start time is designated in the job. The image forming apparatus according to claim 3 to select.

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