JP6005674B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a UFP collecting filter that collects UFP, and more particularly, to an image forming apparatus that detects a replacement time of a UFP collecting filter.

  In recent years, some image forming apparatuses include a UFP collection filter that collects UFP (Ultra Fine Particles) that are ultrafine particles. In such an image forming apparatus, UFP generated from the fixing device when toner is fixed on recording paper by heat is collected by a UFP collection filter.

  The UFP collection filter needs to be replaced because the collection ability is reduced when a certain amount or more of UFP is collected. Therefore, the UFP collection filter is bridged between the supply reel and the take-up reel, and when the bridged UFP collection filter is used up, it is taken up by the take-up reel and unused UFP collection from the supply reel. A technique for sending out a filter has been proposed (see, for example, Patent Document 1). Further, since the amount of UFP generated changes according to the in-machine temperature and the image printing rate, a technique for controlling the winding speed of the UFP collecting filter according to the in-machine temperature and the image printing rate has been proposed (for example, Patent Documents). 2).

JP 2012-032663 JP 2011-112708 A

  However, when the UFP collection filter is replaced according to the temperature inside the machine and the image printing rate as in the prior art, the replacement time of the UFP collection filter is too early or too late, and at an appropriate time. The UFP collection filter could not be replaced.

  This invention is made | formed in view of the said subject, and it aims at providing the technique which can solve the said subject.

The image forming apparatus of the present invention is an image forming apparatus including a filter that collects UFP and a fixing unit that fixes a toner image on a recording medium, and detects a fixing temperature and a standby temperature in the fixing unit. Based on the detection means, the number counting means for counting the total number of printed sheets, the fixing temperature, the standby temperature, and the total number of printed sheets, the collected total UFP amount of the filter is calculated, and the calculated collection A fixing temperature coefficient set according to the fixing temperature, and a detecting means for detecting a replacement time of the filter based on a preset total UFP amount and a preset total UFP amount that can be collected by the filter And storage means for storing a standby temperature coefficient set according to the standby temperature and a print number coefficient set according to the cumulative number of printed sheets, and the detection means includes: And calculating serial collection already total UFP weight = reference UFP amount × sigma a (the standby temperature coefficient × the fixing temperature coefficient × the number of printed sheets factor).
The print number coefficient may be set to be lower as the cumulative number of printed sheets increases, and to be a constant value after reaching a predetermined cumulative number of printed sheets.
The fixing temperature coefficient may be set to be higher as the fixing temperature is higher.
The standby temperature coefficient may be set to be higher as the standby temperature is lower.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which can detect the appropriate replacement | exchange time of a UFP collection filter can be provided.

1 is a schematic cross-sectional view of an image forming apparatus according to the present invention. FIG. 2 is a schematic diagram of a fixing unit illustrated in FIG. 1. FIG. 2 is a block diagram illustrating a schematic configuration of the image forming apparatus illustrated in FIG. 1. It is the figure which showed the relationship between the cumulative number of printed sheets and the UFP generation amount. It is the figure which showed the relationship between fixing temperature and the amount of UFP generation. It is the figure which showed the relationship between standby temperature and UFP generation amount. It is the figure which showed the temperature coefficient table. It is the figure which showed the printing number coefficient table. It is the figure which showed the relationship between the performance of a UFP collection filter, and the calculated value of the amount of UFP. It is the flowchart which showed the flow of the process which detects the replacement | exchange time of the UFP collection filter by the control part shown in FIG.

Next, embodiments of the present invention will be specifically described with reference to the drawings.
An image forming apparatus 100 according to an embodiment of the present invention is a multifunction machine having a copying function, a printing function, a scanner function, and the like. Referring to FIG. 1, a document reading unit 120, a document feeding unit 130, and a recording unit 140. The document reading unit 120 is disposed above the recording unit 140, and the document feeding unit 130 is disposed above the document reading unit 120.

  On the front side of the image forming apparatus 100, an operation unit 5 for setting and operating instructions of the image forming apparatus 100 is disposed. The operation unit 5 is provided with an operation panel 51 and operation buttons 52. The user operates the operation unit 5 and inputs an instruction to perform various settings of the image forming apparatus 100 and execute various functions such as image formation. The operation panel 51 is provided on a display unit for displaying various operation keys for accepting operation inputs, and a display surface of the display unit. The operation panel 51 detects an input by pressing an operator's fingertip, a stylus, or the like, and is at a position where the input is detected. A touch panel that receives an operation on the operation key displayed on the display unit by outputting a corresponding signal is provided. The operation button 52 includes a start button that the user instructs to start image formation, a stop / clear button that is used when image formation is stopped, and various settings of the image forming apparatus 100 that are used as default settings. A reset button, a numeric keypad and the like are provided.

  The document reading unit 120 includes a scanner 121, a platen glass 122, and a document reading slit 123. The scanner 121 includes an exposure lamp, a CCD (Charge Coupled Device) sensor, and the like, and is configured to be movable in the conveyance direction of the document MS by the document feeding unit 130. The platen glass 122 is an original table made of a transparent member such as glass. The document reading slit 123 has a slit formed in a direction orthogonal to the direction in which the document MS is conveyed by the document feeding unit 130.

  The document feeding unit 130 is configured to be retractable, and by lifting the document feeding unit 130 upward, the upper surface of the platen glass 122 can be opened and the document MS can be placed on the platen glass 122. When reading the document MS placed on the platen glass 122, the scanner 121 is moved to a position facing the platen glass 122 and reads the document MS while scanning the document MS placed on the platen glass 122. Get image data.

  The document feeding unit 130 includes a document placing unit 131, a document discharge unit 132, and a document transport mechanism 133. The documents MS placed on the document placement unit 131 are sequentially fed out one by one by the document conveyance mechanism 133 and conveyed to a position facing the document reading slit 123 of the document reading unit 120, and then the document discharge unit. It is discharged to 132. When reading the document MS conveyed by the document feeding unit 130, the scanner 121 is moved to a position facing the document reading slit 123, and the document MS is conveyed by the document feeding unit 130 via the document reading slit 123. In synchronization with the operation, the document MS is read to acquire image data.

  The recording unit 140 includes an image forming unit 150, and includes a paper feeding unit 160, a conveyance path 170, a conveyance roller 181, a discharge roller 182, and a cylinder discharge provided in a cylinder discharge space of the image forming apparatus 100. And a tray 190.

  The paper feed unit 160 includes a plurality of paper feed cassettes 161a to 161d that store the recording paper P, and a paper feed roller 162 that feeds the recording paper P from the paper feed cassettes 161a to 161d one by one to the transport path 170. . The paper feed roller 162, the transport roller 181 and the discharge roller 182 function as a transport unit, and the recording paper P is transported. The recording paper P fed to the transport path 170 by the paper feed roller 162 is transported to the image forming unit 150 by the transport roller 181. Then, the recording paper P on which recording is performed by the image forming unit 150 is guided to the discharge roller 182 and output as a printed matter to the in-body discharge tray 190. In the present embodiment, four paper feed cassettes 161a to 161d are provided.

  The image forming unit 150 includes a photosensitive drum 151, a charging unit 152, an exposure unit 153, a developing unit 154, a transfer unit 155, a cleaning unit 156, and a fixing unit 157. The exposure unit 153 is an optical unit including a laser device, a mirror, and the like. The exposure unit 153 outputs laser light based on image data, exposes the photosensitive drum 151 charged by the charging unit 152, and An electrostatic latent image is formed on the surface. The developing unit 154 is a developing unit that develops the electrostatic latent image formed on the photosensitive drum 151 using toner, and forms a toner image based on the electrostatic latent image on the photosensitive drum 151. The transfer unit 155 transfers the toner image formed on the photosensitive drum 151 by the developing unit 154 to the recording paper P. The fixing unit 157 heats the recording paper P on which the toner image is transferred by the transfer unit 155 to fix the toner image on the recording paper P.

  As shown in FIG. 2, the fixing unit 157 includes a heat roller 571 provided with a heater 572 inside, and a press roller 573 that presses against the heat roller 571. While the image forming operation by the image forming unit 150 is not performed, the fixing unit 157 is set in a standby state and the heater 572 is turned off. When the image forming operation is performed by the image forming unit 150, the fixing unit 157 causes the heater 572 to set the heat roller 571 to a temperature (fixing temperature) corresponding to the type of the recording paper P. The fixing unit 157 passes the recording paper P onto which the toner image has been transferred between the heat roller 571 and the press roller 573 heated by the heater 572, and heats the recording paper P to transfer the toner image to the recording paper P. Let it settle. When the image forming operation is completed, the heater 572 is turned off, the fixing unit 157 enters a standby state, and the temperature (standby temperature) of the heat roller 571 gradually decreases.

  Although not shown, the image forming apparatus 100 is provided with a UFP collection filter that collects UFP generated from the fixing unit 157. The UFP collection filter may be provided at the exhaust port of the image forming apparatus 100 or may be provided in the vicinity of the fixing unit 157.

  FIG. 3 is a block diagram illustrating a schematic control configuration of the image forming apparatus 100. The operation unit 5, the document reading unit 120, the document feeding unit 130, the image forming unit 150, and the transport unit (the paper feed roller 162, the transport roller 181, and the discharge roller 182) are connected to the control unit 1 and the control unit 1. The operation is controlled by. In addition, a storage unit 2, an image processing unit 3, a temperature detection unit 4, and a number counting unit 6 are connected to the control unit 1.

  The storage unit 2 is a storage unit such as a semiconductor memory or an HDD (Hard Disk Drive) in which image data acquired by reading a document by the document reading unit 120 is stored. Further, the storage unit 2 stores a UFP generation amount correction coefficient 21 for correcting the UFP amount generated by the image forming operation. The UFP generation amount correction coefficient 21 will be described later.

  The image processing unit 3 is a unit that performs predetermined image processing on the image data. For example, image improvement processing such as enlargement / reduction processing, density adjustment, and gradation adjustment is performed.

  The temperature detection unit 4 has a function of detecting the surface temperature of the heat roller 571. The temperature detection unit 4 detects the fixing temperature of the heat roller 571 when the fixing unit 157 performs the fixing process and the standby temperature of the heat roller 571 when the image forming operation is not performed and the fixing unit 157 is in the standby state.

  The number counting unit 6 has a function of counting the number of printed sheets and calculating the total number of printed sheets.

  The control unit 1 is an information processing unit such as a microcomputer including a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The ROM stores a control program for performing operation control of the image forming apparatus 100. The control unit 1 reads the control program stored in the ROM and develops the control program in the RAM, thereby controlling the entire apparatus according to predetermined instruction information input from the operation unit 5. In addition, the control unit 1 performs UFP capture based on the standby temperature and fixing temperature detected by the temperature detection unit 4 and the cumulative number of printed sheets counted by the number counting unit 6 during the fixing process in the fixing unit 157. It functions as a detection means for detecting the replacement time of the collection filter.

  FIG. 4 is a diagram showing the relationship between the cumulative number of printed sheets and the UFP generation amount. Here, the fixing temperature was fixed at 180 ° C., and the amount of UFP when a 5% print pattern was continuously printed was measured. In the following, the UFP amount generated at that time is measured every predetermined number of sheets. As a result, the amount of UFP generated was the largest at the beginning, and gradually decreased until the cumulative number of printed sheets reached 10,000, and reached a substantially constant value after 10,000 sheets. From this, it was found that the amount of UFP generated increases as the fixing unit 157 becomes newer, and tends to stabilize when the cumulative number of printed sheets exceeds a certain number.

  FIG. 5 is a diagram showing the relationship between the fixing temperature of the heat roller 571 and the amount of UFP generated. Here, the amount of UFP was measured when 1,000 sheets of 5% print patterns were continuously printed with the fixing temperature changed from 170 to 190 ° C. As a result, the higher the fixing temperature, the greater the amount of UFP generated.

  FIG. 6 is a diagram showing the relationship between the standby temperature of the heat roller 571 and the UFP generation amount. Here, when the fixing unit 157 is in a standby state and the standby temperature of the heat roller 571 is 0 to 180 ° C., the heat roller 571 is raised to a predetermined fixing temperature, and a continuous 1,000 sheets of 5% print patterns are respectively obtained. The amount of UFP generated when printing was measured. As a result, the lower the standby temperature, the greater the amount of UFP generated. This is because if the heater 572 is turned on while the standby temperature of the heat roller 571 is low, an overshoot occurs and the fixing temperature of the heat roller 571 rises temporarily. From the experimental results shown in FIG. 5, it is known that the UFP generation amount increases when the fixing temperature is high.

  From the experimental results of FIGS. 4 to 6, it was found that the UFP generation amount affects the cumulative number of printed sheets, the fixing temperature of the heat roller 571, and the standby temperature. Therefore, the UFP generation amount correction coefficient 21 is provided as a correction coefficient for correcting the UFP generation amount based on the cumulative number of printed sheets, the fixing temperature, and the standby temperature. The UFP generation amount correction coefficient 21 includes a fixing temperature coefficient, a standby temperature coefficient, and a print number coefficient, which will be described in detail below.

  FIG. 7 is a temperature coefficient table T1 showing temperature coefficients for correcting the UFP generation amount according to the fixing temperature and standby temperature of the heat roller 571, and FIG. 8 corrects the UFP generation amount according to the cumulative number of printed sheets. It is a print number coefficient table T2 showing the print number coefficient. The temperature coefficient table T1 stores a temperature coefficient obtained by multiplying a fixing temperature coefficient and a standby temperature coefficient in advance. The temperature coefficient table T1 is set so that the reference (coefficient value 1) is when the fixing temperature is 180 ° C. and the standby temperature is 100 ° C. In the print number coefficient table T2, the reference (coefficient value 1) is set when the cumulative print number is 10,000 or more.

  FIG. 9 is a diagram in which the performance of the UFP collection filter provided in the image forming apparatus 100 is examined and associated with the UFP amount calculated based on the temperature coefficient table T1 and the print number coefficient table T2. (1) shown in FIG. 9 is a graph obtained by measuring the actual UFP generation amount when 20,000 sheets are continuously printed without fixing the fixing temperature at 180 ° C. without the UFP collection filter. . (2) shown in FIG. 9 is a graph obtained by measuring the actual UFP generation amount with the UFP collection filter set as the condition (1). (3) shown in FIG. 9 is provided with a waiting time of 10 minutes every time 500 sheets are continuously printed, the temperature coefficient table T1 described above when the standby temperature is 90 to 110 ° C. and the fixing temperature is 175 to 185 ° C. And a UFP amount calculated based on the print sheet number coefficient table T2. (4) shown in FIG. 9 is a graph obtained by measuring the actual UFP generation amount with the UFP collection filter set as the condition of (3).

  As shown in (2), when the UFP collection filter was attached to the image forming apparatus 100, the amount of UFP generated increased from the point a where the cumulative number of printed sheets exceeded 18,000. That is, it was found that the lifetime of the UFP collection filter is at point a. Therefore, the total number of UFPs generated up to point a is the total number of UFPs that can be collected by the UFP collection filter. Here, the point b in (1) corresponds to the point a, and the integrated value of the UFP generation amount measured up to the time point b was 3.1E + 12. In (4), the amount of UFP generated increased from the point c where the cumulative number of printed sheets exceeded 12,000. The point d in (3) corresponds to the point c, and the integrated value of the UFP generation amount calculated up to the point d is 3.1E + 12. From this, it was found that the UFP generation amount was correctly calculated based on the temperature coefficient table T1 and the print number coefficient table T2.

  The standby temperature coefficient, the fixing temperature coefficient, and the print number coefficient may be set as appropriate according to the performance of the UFP collection filter.

  Next, the flow of processing for detecting the replacement time of the UFP collection filter in the image forming apparatus having the above configuration will be described with reference to FIG. It is assumed that the amount of UFP that can be collected by the UFP collection filter (total amount of UFP that can be collected) and the reference UFP amount that is a reference generated by the image forming operation are set in advance.

  The control unit 1 determines whether or not the fixing processing unit 157 is on standby (step s11). If the fixing unit 157 is not on standby (No in step s11), the process proceeds to step s14. When waiting (Yes in step s11), the standby temperature of the heat roller 571 is acquired via the temperature detector 4 (step s12), and the heater 572 controls the heat roller 571 to reach the fixing temperature (step s13). ). Subsequently, the control unit 1 performs fixing processing for fixing the toner image on the recording paper P by the fixing processing unit 157 (step s14), and acquires the fixing temperature of the heat roller 571 via the temperature detection unit 4 (step s14). s15). Subsequently, the control unit 1 causes the number counting unit 6 to count the cumulative number of printed sheets (step s16).

  Subsequently, the control unit 1 refers to the temperature coefficient table T1 to obtain a temperature coefficient corresponding to the standby temperature and the fixing temperature (step s17), and refers to the printed number table to print the number of printed sheets corresponding to the accumulated number of printed sheets. A coefficient is acquired (step s18). If the fixing processing unit 157 is not on standby, the standby temperature coefficient is acquired as standby temperature = fixing temperature. The control unit 1 multiplies the acquired temperature coefficient and print number coefficient to calculate a correction coefficient for the amount of UFP generated in the fixing process (step s19), and calculates the integrated correction coefficient by integration (step s20). The accumulated correction coefficient is accumulated and updated every time the correction coefficient is calculated by the control unit 1 in this process. Subsequently, the control unit 1 multiplies the integrated correction coefficient by the reference UFP amount to calculate the total UFP amount generated until this fixing process (step s21), and the UFP that can be collected by a preset UFP collection filter. The total amount of UFP is subtracted from the amount to calculate the remaining collectable amount of the UFP collection filter (step s22). The control unit 1 detects the replacement time of the UFP collection filter based on the calculated collectable remaining amount (step s23). For example, the control unit 1 may prompt the user to replace the UFP collection filter when the calculated remaining amount that can be collected becomes a predetermined amount or less. In addition, the control unit 1 may prompt the user to replace the UFP collection filter when the total UFP amount falls within a predetermined value up to the collectable UFP amount. Thus, this process ends.

  In the above processing, the replacement time of the UFP collection filter is detected every time one sheet is printed, but the above processing may be performed by obtaining a correction coefficient for every predetermined number of sheets. In this case, the temperature coefficient may be obtained from the average value of the fixing temperature and standby temperature. Further, the fixing temperature coefficient, the standby temperature coefficient, and the print sheet number coefficient are appropriately set according to the timing of performing the above processing.

  According to this, the image forming apparatus 100 calculates the total amount of UFP collected by the UFP collection filter based on the image formation status based on the standby temperature, the fixing temperature, and the cumulative number of printed sheets, and the collected collection Based on the total amount of UFP and the amount of UFP that can be collected by the UFP collection filter set in advance, it is possible to detect an appropriate replacement time of the UFP collection filter.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Control part 2 Memory | storage part 3 Image processing part 4 Temperature detection part 5 Operation part 6 Sheet count part 21 UFP generation amount correction coefficient 51 Operation panel 52 Operation button 100 Image forming apparatus 120 Original reading part 121 Scanner 122 Platen glass 123 Original reading slit DESCRIPTION OF SYMBOLS 130 Document feeding part 131 Document placing part 132 Document discharge part 133 Document conveyance mechanism 140 Recording part 150 Image forming part 151 Photosensitive drum 152 Charging part 153 Exposure part 154 Developing part 155 Transfer part 156 Cleaning part 157 Fixing part 160 Paper feed Section 161a-d Feed cassette 162 Feed roller 170 Transport path 181 Transport roller 182 Discharge roller 190 In-cylinder discharge tray 571 Heat roller 572 Heater 573 Press roller T1 Temperature coefficient table T2 Print sheet coefficient coefficient Bull

Claims (4)

An image forming apparatus comprising a filter for collecting UFP and a fixing unit for fixing a toner image on a recording medium,
Temperature detecting means for detecting a fixing temperature and a standby temperature in the fixing means;
A sheet counting means for counting the total number of printed sheets;
Based on the fixing temperature, the standby temperature, and the accumulated number of printed sheets, the collected total UFP amount of the filter is calculated, and the collected total UFP amount calculated and the preset filter can be collected. Detection means for detecting the replacement time of the filter based on the total amount of UFP ,
Storage means for storing a fixing temperature coefficient set according to the fixing temperature, a standby temperature coefficient set according to the standby temperature, and a print number coefficient set according to the cumulative number of printed sheets,
The detection means includes
The collected total UFP amount = reference UFP amount × Σ (the standby temperature coefficient × the fixing temperature coefficient × the print number coefficient) . The image forming apparatus according to claim 1 , wherein the print number coefficient is set to be lower as the cumulative number of printed sheets increases, and to be a constant value after reaching a predetermined cumulative number of printed sheets. . The fixing temperature coefficient, the image forming apparatus according to claim 1 or 2, characterized in that the fixing temperature is set to be higher the higher. The standby temperature coefficient, the image forming apparatus according to any one of claims 1 to 3, characterized in that said standby temperature is set to be higher as lower.

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