JP7047601B2 - Image forming apparatus and control method of image forming apparatus - Google Patents

Description

This disclosure relates to an image forming apparatus and a control method of the image forming apparatus, and in particular, cleaning that removes toner remaining on the image carrier by being pressed against the image carrier after the toner image is transferred to the transferred object. The present invention relates to an image forming apparatus having a portion and a control method of the image forming apparatus.

Conventionally, there has been an image forming apparatus that determines a deterioration state of a cleaning blade that removes toner remaining on an image carrier based on a drive torque of a motor that drives the image carrier (see, for example, Patent Document 1). However, in the case of this image forming apparatus, the influence of the environmental change of the motor current driving the image carrier, the influence of the wear of the bearing, the deterioration of the seal member sliding on the image carrier, and the roller member in contact with the image carrier. Due to the change in the pressure condition, it may not be possible to accurately detect the change in the drive torque due to the deterioration state of the cleaning blade.

In order to solve such a problem, there is an image forming apparatus that determines a cleaning state from a torque difference between the presence and absence of a developer on an image carrier (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 11-352852 Japanese Unexamined Patent Publication No. 2005-202099

However, the formation of the developer band that adheres the developer only to a predetermined position on the image carrier differs depending on the environmental changes at that time (for example, the deterioration state of the developer, the temperature and humidity, the set voltage), and the developer adheres. The amount may vary. Therefore, even if the deterioration state of the cleaning blade is the same, the value of the drive torque of the image carrier may be different. On the other hand, when the developer is not attached to the image carrier, the drive torque value is almost constant because the difference due to the developer does not occur. That is, the difference in driving torque between the presence and absence of the developer may vary due to changes in the environment. Therefore, there is a problem that the deteriorated state of the cleaning unit (for example, the cleaning blade) of the image carrier cannot be accurately identified from the drive torque of the drive unit (for example, the motor).

This disclosure was made in order to solve the above-mentioned problems, and one of the purposes of this disclosure is an image capable of accurately identifying the deteriorated state of the cleaning portion of the image carrier from the drive torque of the drive portion. It is to provide a control method of a forming apparatus and an image forming apparatus.

In order to achieve the above-mentioned object, according to one aspect of this disclosure, the image forming apparatus carries a toner image and transfers the carried toner image to the transferred object, and the image carrier and the image carrier are positive. A drive unit that is rotationally driven in either the direction or the reverse direction, and a cleaning unit that removes the toner remaining on the image carrier after the toner image is transferred to the image carrier by being pressed against the image carrier. It includes a detection unit that detects the drive torque of the image carrier by the drive unit, and a control unit that controls each unit. The control unit acquires drive torques in the forward and reverse directions of the drive unit from the detection unit, and identifies the deteriorated state of the cleaning unit based on the acquired drive torques in the forward and reverse directions.

Preferably, the control unit identifies the deteriorated state by comparing the acquired difference value of the drive torque in the forward direction and the reverse direction with the difference value at the time of the preset life. More preferably, the difference value at the time of life is preset according to the cleaning unit.

More preferably, when the acquired difference value of the drive torque in the forward direction and the reverse direction does not reach the difference value at the time of life, the control unit specifies the deterioration state by calculating the remaining life until it reaches the difference value.

More preferably, the image forming apparatus further includes a storage unit. The control unit stores the acquired values of the drive torque in the forward direction and the reverse direction in the storage unit as a history. More preferably, the control unit calculates the remaining life by adding the history of the drive torque value stored in the storage unit.

More preferably, the image forming apparatus further includes a notification unit for notifying that the cleaning unit is to be replaced, provided that the calculated remaining life is less than a predetermined value.

More preferably, the control unit calculates at least one of the period until the difference value at the time of life is reached and the number of printable sheets until the difference value at the time of life is reached as the remaining life.

Preferably, the image forming apparatus further comprises a notification unit for notifying the identified deterioration state. More preferably, the image forming apparatus further includes a reception unit that accepts a selection of whether or not to notify the deterioration state, and the notification unit is deteriorated on condition that the reception unit accepts the selection of notifying the deterioration state. Notify the status.

Preferably, the image forming apparatus further comprises a transmitter that transmits the identified degradation state to an external device. Preferably, the control unit does not specify the deteriorated state from the time when the cleaning unit is new to a predetermined period.

Preferably, the control unit identifies the deterioration state based on the average driving torque of one or more rotations of the acquired forward and reverse image carriers.

Preferably, the control unit separates the separable parts among the parts that come into contact with the image carrier when the drive torque used to identify the deterioration state is detected by the detection unit.

Preferably, the control unit executes a process for adjusting the detection condition of the drive torque before the drive torque used for identifying the deterioration state is detected by the detection unit.

Preferably, the control unit identifies the deterioration state at the time of initial operation after the power of the image forming apparatus is turned on, at the time of warming up of the image forming apparatus, or at the time of instruction from the user.

Preferably, the drive unit includes a DC motor and a control circuit that keeps the rotational speed of the DC motor constant. The detection unit detects the drive torque by any of the load current, the input voltage, and the power consumption of the DC motor.

Preferably, the image forming apparatus further includes a waste toner container, a transport screw for transporting the waste toner to the waste toner container, and a one-way clutch for transmitting a driving force from the drive unit to the transport screw. In addition to the image carrier, the drive unit rotationally drives the transfer screw via a one-way clutch. The one-way clutch transmits a driving force to the transport screw when the drive unit rotationally drives the image carrier in the forward direction, and drives the drive force to the transport screw when the drive unit rotationally drives the image carrier in the reverse direction. Does not convey. Preferably, the image carrier is a photoconductor or an intermediate transfer belt.

According to another aspect of the invention, the control method is an image carrier that carries a toner image and transfers the carried toner image to a transfer subject, and rotates the image carrier in either the forward or reverse direction. The driving unit to be driven, the cleaning unit to remove the toner remaining on the image carrier after the toner image is transferred to the image carrier by being pressed against the image carrier, and the drive torque of the image carrier by the drive unit. This is a control method for an image forming apparatus including a detection unit for detecting and a control unit for controlling each unit. In the control method, the control unit identifies the deterioration state of the cleaning unit based on the step of acquiring the drive torque in the forward and reverse directions of the drive unit from the detection unit and the acquired drive torque in the forward and reverse directions. Including steps.

According to this disclosure, it is possible to accurately identify the deteriorated state of the cleaning portion of the image carrier from the drive torque of the drive portion.

It is sectional drawing which shows typically the main composition of the part related to image formation in a full-color tandem type image formation apparatus. It is a block diagram which shows the whole structure of an image forming apparatus. It is a graph which shows the outline of the change of the drive torque of the drive motor between the initial use of the cleaning blade and the later. It is a graph which shows the change of the drive torque and torque difference of forward rotation and reverse rotation of a drive motor. It is a graph for demonstrating the remaining life of a cleaning blade. It is a flowchart which shows an example of the flow of a cleaning blade life determination process. It is a functional block diagram which shows the function for determining the life of a cleaning blade in an image forming apparatus.

Hereinafter, each embodiment will be described in detail with reference to the drawings. The same or corresponding parts may be designated with the same reference numerals and the description may not be repeated.

[Structure of image forming unit and transport unit of image forming apparatus]
FIG. 1 is a cross-sectional view schematically showing a main configuration of a part related to image formation in a full-color tandem type image forming apparatus. With reference to FIG. 1, the image forming apparatus 1 is based on an electrophotographic image forming process, transfers a toner image formed on the surface of a photoconductor to a recording medium, and transfers the transferred toner image to a recording medium. Image formation is performed by fixing to. As shown in FIG. 1, the image forming apparatus 1 includes an image forming unit 2 for forming an image and a conveying unit 3 for conveying the paper 31 as a recording medium T.

The image forming unit 2 includes cartridges 10Y, 10M, 10C, 10K, an intermediate transfer belt 20 as an intermediate, support rollers 21 and 22, and a primary transfer roller 15Y, 15M, 15C, 15K as a primary transfer unit. A secondary transfer roller 24 as a secondary transfer unit, a heating roller 25a and a pressure roller 25b as a fixing unit 25, and an intermediate transfer belt cleaning unit 23 are provided.

The cartridges 10Y, 10M, 10C, and 10K are provided corresponding to the toner colors of yellow (Y), magenta (M), cyan (C), and black (K), respectively. When the cartridges 10Y, 10M, 10C, and 10K are generically referred to or when they indicate unspecified ones, they are referred to as cartridge 10. The primary transfer rollers 15Y, 15M, 15C, 15K are arranged so as to face the cartridges 10Y, 10M, 10C, 10K, respectively. When the primary transfer rollers 15Y, 15M, 15C, and 15K are generically referred to or when they indicate unspecified ones, they are referred to as the primary transfer roller 15.

Each cartridge 10 includes a photoconductor drum 11 as an image carrier, a charging unit 12, an exposure unit 13, a developing unit 14, and a photoconductor cleaning unit 16. The photoconductor drum 11 is for supporting an electrostatic latent image formed on the surface of the photosensitive layer on the surface layer thereof. The charging unit 12, the exposure unit 13, the developing unit 14, the primary transfer roller 15, and the photoconductor cleaning unit 16 are provided around the photoconductor drum 11 in this order along the rotation direction of the photoconductor drum 11. .. Therefore, the process proceeds in the order of charging, exposure, development, primary transfer, and photoconductor cleaning.

The charging unit 12 uniformly charges the surface of the photoconductor drum 11. The exposure unit 13 generates an electrostatic latent image on the surface of the photoconductor by exposing a portion corresponding to the image on the surface of the photoconductor drum 11. The developing unit 14 attaches the charged toner to the electrostatic latent image on the surface of the photoconductor by the action of the electric field force generated by the counter electrode. In the case of the present embodiment, it is reverse development in which an image is formed by adhering toner to an exposed portion. The primary transfer roller 15 transfers the toner image formed on the surface of the photoconductor onto the intermediate transfer belt 20 by the action of an electric field force. The photoconductor cleaning unit 16 scrapes the surface of the photoconductor with a cleaning blade to remove the residual transfer toner remaining on the surface of the photoconductor without being transferred to the intermediate transfer belt 20.

In each cartridge 10, a static elimination unit (also referred to as an eraser) (also referred to as an eraser) (not shown) may be provided between the photoconductor cleaning unit 16 and the charging unit 12. The static elimination unit initializes the charged state of the surface of the photoconductor by, for example, irradiating it with light or bringing a member to which a bias voltage is applied into contact with the surface of the photoconductor.

The intermediate transfer belt 20 constitutes an intermediate transfer unit together with the support rollers 21 and 22. The intermediate transfer belt 20 is supported in a state where a constant tension is applied by the support rollers 21 and 22 arranged in parallel. One of the support rollers 21 and 22 (support roller 22 in this embodiment) is connected to the drive motor 26 and is driven by the drive motor 26.

The drive motor 26 is a DC motor. The torque detector 110 detects an index (for example, at least one of rotation speed, load current, input voltage, and power consumption) necessary for controlling the drive motor 26 in a general manner, and these values are detected. The drive torque of the drive motor 26 is specified from the above and transmitted to the control unit 100. The drive control unit 120 includes a control circuit controlled by the control unit 100 and keeping the rotation speed of the drive motor 26 constant by a general method based on the value of the index detected by the torque detection unit 110. The rotation speed of 26 is controlled so that the speed of the intermediate transfer belt 20 is synchronized with the speed of feeding the paper 31.

The intermediate transfer belt 20 is sandwiched between the photoconductor drum 11 of the cartridges 10Y, 10M, 10C, 10K and the corresponding primary transfer rollers 15Y, 15M, 15C, 15K, respectively, and the cartridges 10Y, 10M, 10C, It rotates along the arrangement direction of 10K. The toner images formed on the surface of the photoconductor drum 11 of each cartridge 10Y, 10M, 10C, 10K are transferred onto the intermediate transfer belt 20 in a state of being superimposed on each other.

The secondary transfer roller 24 is arranged at a position downstream of the primary transfer rollers 15Y, 15M, 15C, and 15K in the moving direction of the intermediate transfer belt 20. The secondary transfer roller 24 transfers the toner images of a plurality of colors transferred on the intermediate transfer belt 20 onto the paper 31 as the recording medium T. The fixing unit 25 fixes the toner image transferred on the recording medium T to the recording medium T by heating and pressurizing the toner image.

The intermediate transfer belt cleaning unit 23 includes a cleaning blade 23A and a transfer screw 23B. The cleaning blade 23A cleans the intermediate transfer belt 20 by removing the transfer residual toner remaining on the intermediate transfer belt 20 without being transferred to the recording medium T. The transport screw 23B transports the toner removed by the cleaning blade 23A by the spiral screw to the waste toner container 28 for accumulating the waste toner. The conveyor screw 23B is driven by the drive motor 26 via the one-way clutch 27. In the one-way clutch 27, when the drive motor 26 drives the intermediate transfer belt 20 in the positive direction with respect to the paper 31 feeding direction, the drive motor 26 transmits the driving force to the transfer screw 23B, and the drive motor 26 drives the intermediate transfer belt 20. When the paper 31 is driven in the direction opposite to the feeding direction, it functions so as not to transmit the driving force to the transport screw 23B.

Photoconductor drum 11, charging unit 12, exposure unit 13, developing unit 14, photoconductor cleaning unit 16, primary transfer roller 15, intermediate transfer belt 20, secondary transfer roller 24, fixing unit 25, intermediate transfer belt cleaning. For the unit 23 and the like, a well-known technique of the electrophotographic method may be arbitrarily selected and used.

Next, the transport unit 3 will be described. The transport section 3 includes a recording medium storage section 30, a paper feed roller 32, a timing roller 33, a paper feed sensor 34, a paper discharge roller 36, and double-sided transport rollers 35a and 35b.

The paper feed roller 32 feeds the recording medium T such as the paper 31 from the recording medium storage unit 30 to the transport path 40. The timing roller 33 temporarily stops the recording medium T conveyed on the transfer path 40 in order to adjust the timing at which the toner image is transferred onto the recording medium T by the secondary transfer roller 24. The paper ejection roller 36 ejects the recording medium T after fixing by the fixing portion 25, or conveys the recording medium T to the double-sided conveying path 41. The double-sided transfer rollers 17a and 17b convey the recording medium T to the timing roller 33 via the double-sided transfer path 41.

[Overall configuration of image forming apparatus]
FIG. 2 is a block diagram showing the overall configuration of the image forming apparatus. With reference to FIG. 2, in addition to the image forming unit 2 and the conveying unit 3 already described, the image forming apparatus 1 includes a scanner unit 50, an ADF (Auto Document Feeder) unit 51, a control unit 100, a storage device 105, and an operation. It includes a panel 106, a communication interface (I / F: Interface) 107, and an image processing unit 108. The configuration of the image forming apparatus in FIG. 2 assumes a copying machine, but when the image forming apparatus is a printer-only machine, the scanner unit 50 and the ADF unit 51 in FIG. 2 may not be provided.

The scanner unit 50 reads the document placed on the platen by the image sensor and converts it into image data. The ADF unit 51 conveys a plurality of originals placed on the original tray one by one, and ejects the originals that have been scanned at the reading position of the platen to the output tray.

The control unit 100 includes a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a ROM (Read Only Memory) 103, and an interface (I / F: Interface) 104.

The CPU 101 realizes the processing of the entire image forming apparatus 1 by reading and executing the program stored in the ROM 103.

The RAM 102 is typically a DRAM (Dynamic Random Access Memory) or the like, and temporarily stores data and image data necessary for the CPU 101 to operate a program. Therefore, the RAM 102 functions as a so-called working memory.

The ROM 103 is typically a flash memory or the like, and stores a program executed by the CPU 101, various setting information related to the operation of the image forming apparatus, and the like.

The interface 104 exchanges various signals with an external device. Specifically, the control unit 100 is electrically connected to the storage device 105, the operation panel 106, the communication interface 107, the image processing unit 108, the image processing unit 2, the transport unit 3, the scanner unit 50, and the ADF unit 51 via the interface 104. Is connected.

The storage device 105 stores various control values, data input via the communication interface 107, image data, and the like.

The operation panel 106 is for the user to input various setting values such as the number of copies to be printed, the printing method, the type and size of paper, and the like. The operation panel 106 is further provided with a start button for the image forming apparatus to start reading and printing the original. Further, the operation panel 106 is provided with a display for displaying information.

The communication interface 107 is a device for communicating with an external device. The communication interface 107 is, for example, a wireless LAN (Local Area Network) card. The image forming apparatus 1 is configured to be able to communicate with an external device connected to a LAN or a WAN (Wide Area Network) via the communication interface 107. The communication interface 107 receives data such as image data and various set values from an external device.

The image processing unit 108 is configured by, for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The image processing unit 108 converts the R (red), G (green), and B (blue) image data read by the scanner unit 50 into Y, M, C, and K image data and outputs the data.

[Cleaning blade life judgment process]
FIG. 3 is a graph showing an outline of changes in the drive torque of the drive motor 26 between the initial stage of use and the latter stage of use of the cleaning blade 23A. With reference to FIG. 3, the drive torque of the drive motor 26 for driving the intermediate transfer belt 20 is a load applied to a drive unit such as a gear and a load due to the weight of the intermediate transfer belt 20, in addition to the load due to pressure welding of the cleaning blade 23A. , The load due to the tension of the intermediate transfer belt 20, the load due to the pressure welding of the primary transfer rollers 15Y, 15M, 15C, 15K and the secondary transfer roller 24, and the like. Therefore, it is difficult to know the torque value of the load of the cleaning blade 23A alone.

As the cleaning blade 23A deteriorates, the drive torque of the drive motor 26 that drives the intermediate transfer belt 20 increases in both forward rotation and reverse rotation. The difference in drive torque between forward rotation and reverse rotation also increases. Further, the drive torque required for driving the intermediate transfer belt 20 also varies between the initial stage of use and the latter stage of use due to the influence of deterioration of each bearing and elongation of the intermediate transfer belt 20.

Therefore, even if an attempt is made to determine the deterioration state of the cleaning blade 23A by determining the change in the drive torque only for forward rotation, it is possible to specify how much the influence of the deterioration of each bearing and the elongation of the intermediate transfer belt 20 is. Since it is difficult to do so, the deteriorated state of the cleaning blade 23A cannot be accurately determined.

In the present embodiment, the deterioration state of the cleaning blade 23A is determined by determining the change in the difference in drive torque between the forward rotation and the reverse rotation. The cleaning blade 23A has different drive torques in the case of forward rotation and reverse rotation due to the difference in the contact angle with respect to the intermediate transfer belt 20 and the wear state of the cleaning blade 23A. On the other hand, objects other than the cleaning blade 23A that affect the drive torque (such as bearings and the intermediate transfer belt 20) have substantially the same drive torque regardless of whether the rotation is forward or reverse. Therefore, by determining the change in the difference in the drive torque between the forward rotation and the reverse rotation, factors other than the deterioration of the cleaning blade 23A (factors such as deterioration of each bearing and elongation of the intermediate transfer belt 20) can be eliminated. Therefore, since it is possible to know the change in the drive torque caused only by the cleaning blade 23A, it is possible to more accurately determine the deterioration state of the cleaning blade 23A.

Further, the drive torque T caused only by the cleaning blade 23A ≈ the frictional force F of the cleaning blade = friction coefficient μ × drag force N = shearing force τ × contact area A, and the contact area A1 in the case of normal rotation is reversed. Since the contact area A2 in the case of is usually larger than the contact area A2, the drive torque T1 in the case of forward rotation is larger than the drive torque T2 in the case of reverse rotation.

FIG. 4 is a graph showing changes in drive torque and torque difference between forward and reverse rotation of the drive motor 26. With reference to FIG. 4, the forward and reverse drive torques of the drive motor 26 increase as shown in FIG. 4A as the number of prints or the print time increases. The drive torque for forward rotation temporarily decreases from the new state until the developer is supplied and the cleaning blade 23A and the intermediate transfer belt 20 become familiar with each other. Further, in the case of reverse rotation, the pressure contact angle of the cleaning blade 23A is smaller than that in the case of normal rotation, so that the drive torque of forward rotation has a consistent value as compared with the drive torque of reverse rotation. big.

Further, the torque difference between forward rotation and reverse rotation increases as shown in FIG. 4B as the number of prints or the print time increases. Therefore, the torque difference when the cleaning blade 23A reaches the wear limit can be specified in advance by the durability test as the threshold value of the life of the cleaning blade 23A. As a result, the estimated life of the number of prints or the print time can be set in advance.

FIG. 5 is a graph for explaining the remaining life of the cleaning blade 23A. With reference to FIG. 5A, the number of prints or the print time remaining from the current number of prints or the print time to the estimated number of prints or the print time is the remaining life.

When considering the predicted life in terms of the number of days with reference to FIG. 5B, if the frequency of use is low, the number of prints per number of days is reduced or the print time is shortened, so that the number of remaining life is long. However, when the frequency of use is high, the number of prints per number of days increases, or the print time becomes long, so that the number of remaining life days becomes short.

FIG. 6 is a flowchart showing an example of the flow of the cleaning blade life determination process. With reference to FIG. 6, this cleaning blade life determination process is a process for determining the life of the cleaning blade 23A by using the difference in driving torque between the normal rotation and the reverse rotation of the intermediate transfer belt 20. This process is called from the main process of the image forming apparatus 1 or the like, and is executed by the CPU 101 of the control unit 100.

First, the CPU 101 determines whether or not the start condition of the cleaning blade life determination process is satisfied (step S111). The start condition is, for example, a condition that the image forming apparatus 1 is in the initial operation after the power is turned on, or when some operation is started after the image forming apparatus 1 is not operated for a predetermined time and shifts to the power saving mode. It is a condition that it is a warm-up time for preheating the fixing portion 25, or a condition that an instruction to execute the cleaning blade life determination process is input from the user. The start condition may be a condition that a predetermined cycle (for example, one week, one month, etc.) has been reached.

If it is determined that the start condition is not satisfied (NO in step S111), the CPU 101 returns the process to be executed to the caller of the cleaning blade life determination process. When it is determined that the start condition is satisfied (YES in step S111), the CPU 101 has a threshold value TH_T for determining the torque difference, and the current cumulative number of prints N of the cleaning blade 23A (if the cleaning blade 23A has not been replaced yet). , Cumulative number of prints from a new product. If it has already been replaced, the cumulative number of prints since the replacement.) And the number TH_N for starting the determination of the life are read from the storage device 105 into the RAM 102 (step S112). -Step S114). The determination start number TH_N is, for example, a number less than 1% of the life number, but may be a number exceeding 1%.

Next, the CPU 101 determines whether or not the cumulative number of prints N is equal to or greater than the determination start number TH_N (step S121). When it is determined that the cumulative number of prints N is not equal to or greater than the determination start number TH_N (NO in step S121), the CPU 101 displays on the display of the operation panel 106 that the cumulative print number N has not reached the determination start number TH_N. (Step S122), the process to be executed is returned to the caller of the cleaning blade life determination process.

When it is determined that the cumulative number of prints N is equal to or greater than the determination start number TH_N (YES in step S121), the CPU 101 is a component that is in contact with the intermediate transfer belt 20 and can be separated so as not to be in contact with the intermediate transfer belt 20. (For example, when the secondary transfer roller 24 is configured to be separable, the secondary transfer roller 24) is controlled to be separated (step S123). When the primary transfer rollers 15Y, 15M, 15C, and 15K are configured to be separable, the toner patch is controlled to be separated when the driving torque is detected after the toner patch is created in step S124.

Next, the CPU 101 controls to create a toner patch on the intermediate transfer belt 20 (step S124). The toner patch is one in which toner is transferred to the intermediate transfer belt 20 in a predetermined pattern (for example, a pattern composed of a plurality of lines, a pattern composed of a plurality of points). By transferring a constant toner patch in this way, the drag force due to the cleaning blade 23A or the like is less likely to vary as compared with the case where the transferred toner is not constant. The drive torque of the transfer belt 20 can be detected.

In the present embodiment, after the toner patch is created, the intermediate transfer belt 20 is rotated in the normal direction to detect the drive torque, and then the intermediate transfer belt 20 is rotated in the reverse direction to detect the drive torque. , The toner patch may be created again before the intermediate transfer belt 20 is reversed.

Next, the CPU 101 controls the intermediate transfer belt 20 to rotate in the forward direction, acquires the drive torque detected by the torque detection unit 110, and obtains the average value FT of the drive torque during one rotation of the intermediate transfer belt 20. Calculate (step S125).

Further, the CPU 101 controls the intermediate transfer belt 20 to rotate in the reverse direction, acquires the drive torque detected by the torque detection unit 110, and calculates the average value RT of the drive torque during one rotation of the intermediate transfer belt 20. (Step S126).

Then, the CPU 101 stores the calculated average drive torques FT and RT in the storage device 105 as a history in association with the cumulative number of prints N and the current date and time (step S127).

Next, the CPU 101 determines whether or not the difference FT-RT between the average drive torques FT and RT is less than the threshold value TH_T (step S131). If it is not less than (NO in step S131), that is, if it is determined that the difference FT-RT of the average value is equal to or more than the threshold value TH_T, the CPU 101 has already reached the end of its life and prompts the replacement of the cleaning blade 23A. Is notified by displaying it on the display of the operation panel 106 (step S132), and the process to be executed is returned to the caller of the cleaning blade life determination process.

When it is determined that the difference FT-RT of the average drive torque values is less than the threshold value TH_T (YES in step S131), the CPU 101 determines the cumulative number of prints N, the threshold value TH_T, the average drive torque values FT, RT, and these. The remaining life of the cleaning blade 23A (remaining life number ZN, remaining life days ZT) is calculated based on the history data of (step S133).

Specifically, the slope of the solid line portion of the graph as shown in FIG. 5A is calculated from the historical data, and as shown by the two-dot chain line portion of the graph, the drive torque is reached to the life threshold with the calculated slope. The number of prints with the predicted life when the difference between the two is increased is calculated, and the number of sheets from the current cumulative number of prints N to the calculated number of prints with the predicted life is calculated as the remaining life number ZN.

Further, from the historical data, the slope of the solid line portion of the graph as shown in FIG. 5 (B) is calculated, and as shown by the two-dot chain line portion of the graph, the difference in drive torque reaches the threshold value of the life with the calculated slope. Calculate the predicted lifespan day when the increase occurs, and calculate the number of days from the current day to the calculated predicted lifespan day as the remaining lifespan days ZT.

The remaining lifespan ZN is almost the same regardless of the frequency of use, but the remaining lifespan ZT is shorter when the frequency of use is high than when it is low.

Returning to FIG. 6, the CPU 101 notifies by displaying the calculated remaining life number ZN and remaining life days ZT on the display of the operation panel 106 (step S134), and the remaining life number ZN and the remaining life days ZT and the like are notified. The life determination result is transmitted to an external server together with the identifiable identification information of the image forming apparatus 1 (for example, the serial number of the image forming apparatus 1) (step S135). This external server is installed in the manufacturing company or the sales company of the image forming apparatus 1, collects the life determination results from a plurality of image forming apparatus 1, and uses the collected life determination results as the life of the cleaning blade 23A. It is used for analysis such as verification of the validity of the judgment of.

Next, the CPU 101 determines whether or not the remaining lifespan ZT is less than a predetermined number of days (for example, 30 days, 100 days, etc.) (step S136). If it is determined that the value is less than (YES in step S136), the CPU 101 notifies by displaying on the display of the operation panel 106 that the replacement deadline is near (step S137). If it is determined that the value is not less than (NO in step S136), and after step S137, the CPU 101 returns the process to be executed to the caller of the cleaning blade life determination process.

The replacement deadline approaches each time the remaining lifespan ZT becomes equal to the predetermined number of days (for example, the number of well-separated days relatively short compared to the lifespan, specifically, 30 days, 60 days, 90 days, etc.). Along with that, the remaining life days ZT may be notified.

FIG. 7 is a functional block diagram showing a function for determining the life of the cleaning blade 23A in the image forming apparatus 1. With reference to FIG. 7, the control unit 100 of the image forming apparatus 1 has the motor control unit 111 and the torque acquisition unit by executing the process shown in the flowchart of FIG. 6 described above by the CPU 101 of the control unit 100. The 112, the deterioration state specifying unit 113, and the deterioration state notification unit 114 are configured.

As shown in step S125 and step S126 of FIG. 6, the motor control unit 111 outputs a signal for controlling the drive motor 26 so that the intermediate transfer belt 20 rotates forward or reverse at a predetermined speed. Send to 120.

The drive control unit 120 controls the rotation of the drive motor 26 according to the signal from the motor control unit 111. The drive motor 26 is controlled by the drive control unit 120 and rotates in a predetermined direction at a predetermined speed. The torque detection unit 110 detects at least one of the rotation speed, load current, input voltage, and power consumption of the drive motor 26, feeds it back to the drive control unit 120, and specifies the drive torque of the drive motor 26 from these values. Then, it is transmitted to the torque acquisition unit 112 of the control unit 100. The drive control unit 120 controls the rotation of the drive motor 26 by using the feedback from the torque detection unit 110.

As shown in step S125 and step S126 of FIG. 6, the torque acquisition unit 112 acquires the drive torque from the torque detection unit 110, stores the acquired drive torque for each predetermined cycle in the storage device 105, and stores the intermediate transfer belt. The average values FT and RT of the drive torque during one rotation of 20 are calculated and stored in the storage device 105.

As shown in step S133 of FIG. 6, the deterioration state specifying unit 113 is stored in the storage device 105 in the cumulative number of prints N, the threshold value TH_T, the average drive torque values FT and RT, and their historical data. Based on this, the remaining life of the cleaning blade 23A (remaining life number ZN, remaining life days ZT) is calculated.

The deterioration state notification unit 114 notifies the remaining life number ZN and the remaining life days ZT specified by the deterioration state specifying unit 113 by displaying them on the display of the operation panel 106. Further, when the remaining life days ZT is less than a predetermined number of days, the deterioration state notification unit 114 notifies by displaying on the display of the operation panel 106 that the replacement deadline is near.

[effect]
(1) As described above, the image forming apparatus 1 has the following effects. As shown in FIG. 1, the image forming apparatus 1 carries the toner image and transfers the carried toner image to the paper 31 as the recording medium T, and the intermediate transfer belt 20 in the forward direction and the reverse direction. An intermediate transfer belt cleaning unit that removes the toner remaining on the intermediate transfer belt 20 after the drive motor 26 that is rotationally driven in either direction and the toner image is transferred to the paper 31 by being pressed against the intermediate transfer belt 20. A cleaning blade 23A of 23, a torque detecting unit 110 for detecting the driving torque of the intermediate transfer belt 20 by the driving motor 26, and a control unit 100 for controlling each unit are provided. The control unit 100 acquires drive torques in the forward and reverse directions of the drive motor 26 from the torque detection unit 110, and identifies the deteriorated state of the cleaning blade 23A based on the acquired drive torques in the forward and reverse directions.

Thereby, the deteriorated state of the cleaning blade 23A of the intermediate transfer belt 20 can be accurately specified from the drive torque of the drive motor 26.

(2) As shown in step S131 of FIG. 6, the control unit 100 compares the acquired difference value FT-RT of the drive torque in the forward direction and the reverse direction with the difference value TH_T at the time of the preset life. By doing so, the deterioration state is specified. This makes it possible to accurately identify the deteriorated state of the cleaning blade 23A.

(3) The difference value TH_T at the time of life is set in advance by being stored in the storage device 105 according to the cleaning blade 23A at the time of manufacturing the image forming apparatus 1. Thereby, the difference value TH_T at the time of life can be appropriately set according to the cleaning blade 23A.

(4) As shown in step S131 and step S133 of FIG. 6, the control unit 100 has acquired the difference value FT-RT of the drive torque in the forward direction and the reverse direction, which has not reached the difference value TH_T at the end of the service life. In this case, the deterioration state is specified by calculating the remaining life ZN and ZT until it is reached. Thereby, by accurately calculating the remaining life of the cleaning blade 23A, the deteriorated state of the cleaning blade 23A can be accurately specified.

(5) As shown in FIG. 2, the image forming apparatus 1 further includes a storage device 105. As shown in step S127 of FIG. 6, the control unit 100 stores the acquired values of the drive torques in the forward direction and the reverse direction in the storage device 105 as a history. As a result, the remaining life of the cleaning blade 23A can be calculated accurately.

(6) As shown in step S133 of FIG. 6, the control unit 100 calculates the remaining life by adding the history of the drive torque value stored in the storage device 105. As a result, the remaining life of the cleaning blade 23A can be calculated accurately.

(7) As shown in step S136 and step S137 of FIG. 6, the image forming apparatus 1 prompts the replacement of the cleaning blade 23A on the condition that the calculated remaining life days ZT is less than the predetermined number of days. An operation panel 106 for notifying is further provided. This makes it possible to appropriately notify the user of the replacement time of the cleaning blade 23A.

(8) As shown in step S133 of FIG. 6, the control unit 100 has, as the remaining life, the remaining life days ZT until the difference value TH_T at the time of life is reached, and the difference value TH_T at the time of life. Calculate at least one of the remaining life sheets ZN. Thereby, the remaining life of the cleaning blade 23A can be appropriately calculated.

(9) As shown in step S134 of FIG. 6, the image forming apparatus 1 further includes an operation panel 106 for notifying the specified deterioration state. As a result, the deterioration state of the cleaning blade 23A can be appropriately notified to the user.

(10) As shown in FIG. 2, the image forming apparatus 1 further includes an operation panel 106 that accepts a selection of whether or not to notify the deterioration state. As shown in step S111 and step S134 of FIG. 6, the operation panel 106 notifies the deterioration state on condition that the selection for notifying the deterioration state is accepted. As a result, when the user accepts the selection to notify the deterioration state, the deterioration state can be appropriately notified.

(11) As shown in step S135 of FIG. 6, the image forming apparatus 1 transmits the specified deterioration state to an external server. As a result, the deterioration state of the cleaning blade 23A of each image forming apparatus 1 can be managed by an external server.

(12) As shown in step S121 of FIG. 6, the control unit 100 does not specify the deterioration state from the time when the cleaning blade 23A is new until the cumulative number of prints N reaches the determination start number TH_N. As a result, it is possible to prevent the resource of the control unit 100 from being consumed by executing unnecessary processing such as determining the life at the initial stage of use when the life is not required to be determined.

(13) As shown in steps S125 to S127 and S133 of FIG. 6, the control unit 100 applies the average drive torques FT and RT of one or more rotations of the acquired forward and reverse intermediate transfer belts 20. Based on this, the deterioration state is identified. This makes it possible to accurately identify the deteriorated state of the cleaning blade 23A.

(14) As shown in step S123 of FIG. 6, the control unit 100 is among the parts that come into contact with the intermediate transfer belt 20 when the drive torque used to identify the deteriorated state is detected by the torque detection unit 110. Separateable parts (for example, secondary transfer rollers 24, primary transfer rollers 15Y, 15M, 15C, 15K, etc.) are separated. As a result, the influence of the separated parts on the drive torque can be eliminated, so that the deteriorated state of the cleaning blade 23A can be accurately specified.

(15) As shown in step S124 of FIG. 6, the control unit 100 is a process for adjusting the detection condition of the drive torque before the drive torque used for identifying the deteriorated state is detected by the torque detection unit 110. , Create a toner patch on the intermediate transfer belt 20. As a result, it is possible to unify the detection conditions of the drive torque for each specification of the deteriorated state, so that the deteriorated state of the cleaning blade 23A can be specified with high accuracy.

(16) As shown in step S111 of FIG. 6, the control unit 100 deteriorates at the time of initial operation after the power of the image forming apparatus 1 is turned on, at the time of warming up of the image forming apparatus, or at the time of instruction from the user. Identify the state. As a result, the deteriorated state can be specified at an appropriate frequency, so that the life of the cleaning blade 23A can be appropriately calculated.

(17) As shown in FIG. 1, the drive unit of the intermediate transfer belt 20 includes a drive motor 26 which is a DC motor and a drive control unit 120 which keeps the rotation speed of the drive motor 26 constant. As shown in FIG. 1, the torque detection unit 110 detects the drive torque by any one of the load current, the input voltage, and the power consumption of the drive motor 26.

(18) As shown in FIG. 1, the image forming apparatus 1 transmits a driving force from the waste toner container 28, the transport screw 23B for transporting the waste toner to the waste toner container 28, and the transport screw 23B from the drive motor 26. The one-way clutch 27 is further provided. The drive motor 26 rotationally drives the transfer screw 23B via the one-way clutch 27 in addition to the intermediate transfer belt 20. The one-way clutch 27 transmits a driving force to the transfer screw 23B when the drive motor 26 rotationally drives the intermediate transfer belt 20 in the forward direction, and when the drive motor 26 rotationally drives the intermediate transfer belt 20 in the reverse direction. , The driving force is not transmitted to the transport screw 23B. As a result, even when the drive motor 26 is rotated in the reverse direction, the transport screw 23B can be prevented from reversing, and the waste toner can be prevented from being returned to the intermediate transfer belt cleaning unit 23 side.

[Modification example]
(1) In the above-described embodiment, the deterioration state of the cleaning blade 23A of the intermediate transfer belt cleaning unit 23, which is the cleaning unit for the intermediate transfer belt 20 as the image carrier, is specified. However, the present invention is not limited to this, and the deterioration state of the cleaning blade of the photoconductor cleaning unit 16 which is the cleaning unit for the photoconductor drum 11 as the image carrier may be specified.

(2) In the above-described embodiment, the remaining life number ZN is calculated as the remaining life of the cleaning blade 23A. However, the present invention is not limited to this, and the remaining print area may be calculated or the remaining print length may be calculated.

(3) In the above-described embodiment, as shown in steps S136 and S137 of FIG. 6, when the remaining life days ZT is less than a predetermined number of days, the cleaning blade 23A is notified that the replacement deadline is near. I did it. However, the present invention is not limited to this, and when the remaining life number ZN is less than the predetermined number, it may be notified that the replacement deadline of the cleaning blade 23A is near.

(4) In the above-described embodiment, the function shown in FIG. 7 is configured in the control unit 100 by executing the processing of the software shown in FIG. However, the present invention is not limited to this, and at least a part of the functions shown in FIG. 7 may be realized by the hardware circuit.

(5) In the above-described embodiment, the invention has been described as the image forming apparatus 1. However, the present invention is not limited to this, and the invention may be regarded as a control method as shown in FIG. 6 executed by the image forming apparatus 1, or the image forming apparatus 1 may be made to execute the processing as shown in FIG. The invention may be regarded as a program.

Further, the invention can be regarded as a computer-readable recording medium in which the program is recorded. This recording medium includes magnetic tapes, flexible disks, magnetic disks such as hard disks, CD-ROMs, CD-Rs, CD-RWs, DVD-ROMs, DVD-Rs, DVD-RWs, DVD-RAMs, DVD + Rs, DVDs + RWs, etc. It may be an optical disk, a magneto-optical disk such as MO, a memory card, or a medium such as a USB memory that carries a fixed program, or a program from a server such as an ASP (Application Service Provider) via a communication network. It may be a medium that carries the program fluidly so that it can be downloaded.

(6) The techniques described in embodiments and variants are intended to be implemented, either alone or in combination, wherever possible.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 image forming device, 2 image forming unit, 3 transport unit, 10,10C, 10K, 10M, 10Y cartridge, 11 photoconductor drum, 12 charging unit, 13 exposure unit, 14 developing unit, 15, 15C, 15K, 15M, 15Y primary transfer roller, 16 photoconductor cleaning unit, 17a, 17b, 35a, 35b double-sided transfer roller, 20 intermediate transfer belt, 21.22 support roller, 23 intermediate transfer belt cleaning unit, 23A cleaning blade, 23B transfer screw, 24 Secondary transfer roller, 25 fixing part, 25a heating roller, 25b pressurizing roller, 26 drive motor, 27 one-way clutch, 28 waste toner container, 30 recording medium storage part, 31 paper, 32 paper feed roller, 33 timing roller, 34 Paper passing sensor, 36 paper ejection roller, 40 transport path, 41 double-sided transport path, 50 scanner section, 51 ADF section, 100 control section, 102 RAM, 103 ROM, 104 interface, 105 storage device, 106 operation panel, 107 communication interface , 108 image processing unit, 110 torque detection unit, 111 motor control unit, 112 torque acquisition unit, 113 deterioration state identification unit, 114 deterioration state notification unit, 120 drive control unit.

Claims (20)

An image carrier that carries a toner image and transfers the carried toner image to a transfer target, and an image carrier.
A drive unit that rotationally drives the image carrier in either the forward direction or the reverse direction,
A cleaning unit that removes the toner remaining on the image carrier by being pressed against the image carrier after the toner image is transferred to the image carrier.
A detection unit that detects the drive torque of the image carrier by the drive unit,
Equipped with a control unit that controls each unit
The control unit
The drive torque in the forward direction and the reverse direction of the drive unit is acquired from the detection unit, and the drive torque is obtained from the detection unit.
An image forming apparatus that identifies a deteriorated state of the cleaning portion based on the acquired forward and reverse drive torques. The image according to claim 1, wherein the control unit identifies the deterioration state by comparing the acquired difference values of the drive torques in the forward direction and the reverse direction with the difference values at the time of the preset life. Forming device. The image forming apparatus according to claim 2, wherein the difference value at the time of life is set in advance according to the cleaning unit. When the acquired difference value of the drive torque in the forward direction and the reverse direction does not reach the difference value at the time of the life, the control unit calculates the remaining life until the difference value is reached, thereby specifying the deterioration state. Item 2. The image forming apparatus according to Item 2. With more memory
The image forming apparatus according to claim 4, wherein the control unit stores the acquired forward and reverse drive torque values as a history in the storage unit. The image forming apparatus according to claim 5, wherein the control unit calculates the remaining life by adding a history of drive torque values stored in the storage unit. The image forming apparatus according to claim 4, further comprising a notification unit for notifying that the cleaning unit is to be replaced on condition that the calculated remaining life is less than a predetermined value. The fourth aspect of the present invention, wherein the control unit calculates at least one of the period until the difference value at the time of life is reached and the number of printable sheets until the difference value at the time of life is reached as the remaining life. Image forming device. The image forming apparatus according to claim 1, further comprising a notification unit for notifying the specified deterioration state. Further equipped with a reception unit that accepts the selection of whether or not to notify the deterioration state,
The image forming apparatus according to claim 9, wherein the notification unit notifies the deterioration state on condition that the reception unit has accepted the selection to notify the deterioration state. The image forming apparatus according to claim 1, further comprising a transmission unit that transmits the specified deterioration state to an external device. The image forming apparatus according to claim 1, wherein the control unit does not specify the deteriorated state from the time when the cleaning unit is new to a predetermined period. The image forming apparatus according to claim 1, wherein the control unit identifies the deterioration state based on the average driving torque of one or more rotations of the image carrier in the forward and reverse directions. The first aspect of the present invention, wherein the control unit separates the separable parts among the parts that come into contact with the image carrier when the drive torque used for identifying the deteriorated state is detected by the detection unit. Image forming device. The image according to claim 1, wherein the control unit executes a process (patch control) for adjusting the detection condition of the drive torque before the drive torque used for identifying the deterioration state is detected by the detection unit. Forming device. The image forming apparatus according to claim 1, wherein the control unit identifies the deteriorated state at the time of initial operation after the power of the image forming apparatus is turned on, at the time of warming up of the image forming apparatus, or at the time of an instruction from a user. .. The drive unit
DC motor and
Including a control circuit that keeps the rotation speed of the DC motor constant.
The image forming apparatus according to claim 1, wherein the detection unit detects a drive torque based on any one of the load current, the input voltage, and the power consumption of the DC motor. Waste toner container and
A transport screw that transports waste toner to the waste toner container,
Further equipped with a one-way clutch that transmits a driving force from the driving unit to the transport screw.
In addition to the image carrier, the drive unit rotationally drives the transfer screw via the one-way clutch.
The one-way clutch transmits a driving force to the transport screw when the drive unit rotationally drives the image carrier in the forward direction, and when the drive unit rotationally drives the image carrier in the reverse direction. The image forming apparatus according to claim 1, wherein the driving force is not transmitted to the transport screw. The image forming apparatus according to claim 1, wherein the image carrier is a photoconductor or an intermediate transfer belt. An image carrier that carries a toner image and transfers the carried toner image to a transfer target, and an image carrier.
A drive unit that rotationally drives the image carrier in either the forward direction or the reverse direction,
A cleaning unit that removes the toner remaining on the image carrier by being pressed against the image carrier after the toner image is transferred to the image carrier.
A detection unit that detects the drive torque of the image carrier by the drive unit,
It is a control method of an image forming apparatus including a control unit that controls each unit.
The control unit
A step of acquiring drive torque in the forward direction and the reverse direction of the drive unit from the detection unit, and
A method for controlling an image forming apparatus, which comprises a step of identifying a deteriorated state of the cleaning portion based on acquired forward and reverse drive torques.

Images