Patent Application
20230288863
This application is based upon, and claims the benefit of priority from, corresponding Japanese Patent Application No. 2022-036975 filed in the Japan Patent Office on Mar. 10, 2022, the entire contents of which are incorporated herein by reference.
The present disclosure relates to an electrophotographic-type image forming apparatus and a determination method.
In the electrophotographic-type image forming apparatus, a rotating member such as a photoreceptive drum used to form a toner image is rotatively driven by rotary driving force supplied by a drive unit such as a motor. In this sort of image forming apparatus, gears used to supply rotational drive power to the rotating member may fail due to aged deterioration. To address the issue, an image forming apparatus, which can determine a timing of gear failure based on drive current supplied to the drive unit, is conventionally known.
According to one aspect of the present disclosure, provided is an image forming apparatus including a gear, a first acquisition processor, a formation processor, a second acquisition processor, and a determination processor. The gear is provided on a transmission path of driving force from a drive unit to a rotating member used for forming a toner image. The first acquisition processor acquires a charged amount of toner used for forming the toner image. The formation processor forms a toner image for detection based on an image for detection with density according to the charged amount of toner acquired by the first acquisition processor among a plurality of images for detection having different color from each other for every time when a specific formation timing arrives using the rotating member. The second acquisition processor acquires a variation width of density in the toner image for detection formed by the formation processor The determination processor determines a failure timing of the gear based on the variation width for each formation timing corresponding to any one of the plurality of images for detection.
According to another aspect of the present disclosure, provided is a determination method executed in an image forming apparatus including a gear provided on a transmission path of driving force from a drive unit to a rotating member used for forming a toner image, which includes a first acquisition step, a formation step, a second acquisition step, and a determination step. In the first acquisition step, a charged amount of toner used for forming the toner image is acquired. In the formation step, a toner image for detection is formed based on an image for detection with density according to the charged amount of toner acquired by the first acquisition step among a plurality of images for detection having different color from each other for every time when a specific formation timing arrives using the rotating member. In the second acquisition step, a variation width of density in the toner image for detection formed by the formation step is acquired. In the determination step, a failure timing of the gear is determined based on the variation width for each formation timing corresponding to any one of the plurality of images for detection.
Now, an embodiment of the present disclosure will be described below with reference to the drawings. It should be noted that the following embodiment is a mere example to carry out the present disclosure and does not intend to limit the technical scope of the present disclosure.
Configuration of Image Forming Apparatus 100
First, described with reference to
For convenience of explanation, in the state where the image forming apparatus 100 is ready to operate (state as shown in
The image forming apparatus 100 is an image processing apparatus having a printing function for forming an image based on image data. Specifically, the image forming apparatus 100 is a multifunctional machine with multiple functions including the printing function. The image forming apparatus of the present disclosure may be a printer, fax machine, or copier capable of forming images by electrophotographic method.
As shown in
The ADF1 feeds a document on which an image to be read out by the image reading unit 2 is drawn. The ADF 1 includes a document placement portion, a plurality of conveying rollers, a document holder, and a paper discharge portion.
The image reading unit 2 realizes a scanning function to read out the image of the document. The image reading unit 2 includes a document table, a light source, plural mirrors, an optical lens, and a CCD (Charge Coupled Device).
The image forming section 3 realizes the printing function. Specifically, the image forming section 3 forms color or monochrome images on a sheet supplied from the paper feeding unit 4 according to the electrophotographic method.
The paper feeding unit 4 supplies a sheet to the image forming section 3. The paper feeding unit 4 is equipped with a sheet cassette, a manual feed tray, and a plurality of conveying rollers.
The operation display unit 5 is a user interface of the image forming apparatus 100. The operation display unit 5 is equipped with a display and a manipulator. The display unit displays various types of information in response to control instructions from the controller 7. For example, the display is a liquid crystal display. The user can input various information to the controller 7 through the manipulator responding to user operations. The manipulator is a touch panel, for example.
The storage unit 6 is a nonvolatile storage device. For example, the storage unit 6 is a nonvolatile memory such as a flash memory.
The controller 7 comprehensively controls the image forming apparatus 100. As shown in
The controller 7 may be a control unit separate from the main control unit which comprehensively controls the image forming apparatus 100. Furthermore, the controller 7 may be an electronic circuit such as an application-specific integrated circuit (ASIC).
Configuration of Image Forming Section 3
Next, a configuration of the image forming section 3 is described below with reference to
As shown in
The image forming unit 21 forms a Y (yellow) color toner image. The image forming unit 22 forms a C (cyan) color toner image. The image forming unit 23 forms a M (magenta) color toner image. The image forming unit 24 forms a K (black) color toner image. As shown in
As shown in
An electrostatic latent image is formed on a surface of the photoreceptive drum 31. For example, the photoreceptive drum 31 has a photosensitive layer formed by an organic photosensitive material. The photoreceptive drum 31 is rotatably supported by a housing of the image forming apparatus 100, which houses the image forming section 3 and the paper feeding unit 4. The photoreceptive drum 31 receives rotary driving force transmitted from the drive unit 37, and rotates in a rotation direction D4 shown in
The photoreceptive drum 31 is used to form a toner image. The photoreceptive drum 31 is an example of an image carrier of the present disclosure as well as an example of a rotating member of the present disclosure.
The charging roller 32, to which a specific charging voltage is applied, electrically charges the surface of the photoreceptive drum 31. For example, the charging roller 32 electrically charges the surface of the photoreceptive drum 31 with positive polarity. As shown in
The developing apparatus 33 develops the electrostatic latent image formed on the surface of the photoreceptive drum 31 using developer including toner and carrier.
As shown in
The housing 41 houses the first conveying member 42, the second conveying member 43, the developing roller 44, and the restrictor 45. The housing 41 also has a circulating-conveying path through which the developer circulates. The circulating-conveying path includes a first conveying path 41A (see
The first conveying member 42 transports the developer contained in the first conveying path 41A in one way of the left-right direction D3. The first conveying member 42 stirs the developer and frictionally charges the toner and carrier. For example, the toner is charged with positive polarity by being frictionally charged with the carrier. For example, the first conveying member 42 is a screw like member rotatable around a rotation axis of the first conveying member 42 along the left-right direction D3 in the first conveying path 41A.
The second conveying member 43 transports the developer contained in the second conveying path 41B in the other way opposite to the way conveyed by the first conveying member 42. The second conveying member 43 stirs the developer to frictionally charge the toner and carrier. For example, the second conveying member 43 is a screw like member rotatable around a rotation axis of the second conveying member 43 along the left-right direction D3 in the second conveying path 41B.
The developing roller 44 is provided to be opposed to the photoreceptive drum 31 and supplies the developer to a facing area R1 (see
As shown in
The restrictor 45 adjusts a thickness of layer of the magnetic brush formed on the outer surface of the developing roller 44. As shown in
The developing apparatus 33 may be equipped with a magnetic roller which pumps up the developer from the second conveying path 41B and supplies the toner contained in the pumped up developer to the developing roller 44. In this example, the developing roller 44 may supply toner to the facing area R1. The developer may be a one-component developer without the carrier.
The primary transfer roller 34 transfers the toner image formed on the surface of the photoreceptive drum 31 by the developing apparatus 33 to the intermediate transfer belt 26 upon a specific primary transfer voltage is applied to the primary transfer roller 34. As shown in
The drum cleaning section 35 cleans the surface of photoreceptive drum 31. As shown in
The toner container 36 contains toner. The toner container 36 supplies toner contained inside the same to developing apparatus 33.
The drive unit 37 generates driving force to rotate the photoreceptive drum 31. Specifically, the drive unit 37 is a motor which generates rotary driving force.
The driving force transmission section 38 transmits driving force generated by the drive unit 37 to the photoreceptive drum 31. The photoreceptive drum 31 is rotated by rotary driving force supplied from the drive unit 37 via the driving force transmission section 38.
As shown in
The first gear 39A may mesh with the second gear 39B. The driving force transmission section 38 may also transmit driving force generated by the drive unit 37 to both the photoreceptive drum 31 and the developing roller 44 (another example of a rotating member of the present disclosure).
The optical scanning device 25 emits light based on image data toward the surface of the photoreceptive drum 31 in each of the image forming units 21-24.
The Intermediate transfer belt 26 is an endless belt to which the toner image formed on the surface of the photoreceptive drum 31 in each of the image forming units 21-24 is transferred. The intermediate transfer belt 26 is tensioned at a specific tension by a drive roller, a tension roller, and four primary transfer rollers 34. The intermediate transfer belt 26 rotates in the rotation direction D5 shown in
The secondary transfer roller 27 transfers the toner image transferred on the surface of the intermediate transfer belt 26 on the sheet supplied from the paper feeding unit 4 upon a specific secondary transfer voltage is applied to the secondary transfer roller 27. As shown in
The fixing device 28 fixes the toner image transferred to the sheet by the secondary transfer roller 27 onto the sheet.
The sheet, on which the toner image is fixed by the fixing device 28, is discharged to the paper discharge tray 29.
A plurality of density sensors 30 detect density of the toner image transferred on the outer surface of the intermediate transfer belt 26. As shown in
Each of the density sensors 30 is a so-called reflective type optical sensor, and is equipped with a light emitting unit to emit light toward the outer surface of the intermediate transfer belt 26 and a light receiving unit to receive light emitted from the light emitting unit and reflected on the outer surface of the intermediate transfer belt 26. An electrical signal according to the amount of light received at the light receiving unit is input to the controller 7 from each of the density sensors 30.
In the image forming apparatus 100, it is often the case that the gears 39 installed in the driving force transmission section 38 fail due to aged deterioration. To address the issue, an image forming apparatus, which can determine a failure timing of the gears 39 based on drive current supplied to the drive unit 37, is conventionally known.
Here, at the timing when increase of load due to aged deterioration of the gears 39 is reflected in the drive current, aged deterioration of the gears 39 may considerably progress. Therefore, in a conventional approach in which the failure timing is determined based on the drive current, preparations for maintenance may not be ready by the time when the failure timing is determined.
In contrast, the image forming apparatus 100 according to the embodiment of the present disclosure can determine the failure timing of the gears 39 earlier as described below.
Configuration of Controller 7
Next, the configuration of the controller 7 will be described with reference to
As shown in
Specifically, the ROM 12 of the controller 7 stores a failure timing determination program to cause the CPU 11 to function as each of parts mentioned above. The CPU 11 functions as each of parts mentioned above by executing the failure timing determination program stored in the ROM 12.
The failure timing determination program is stored in a computer-readable storage medium such as CD, DVD, or flash memory, and may be read from the storage medium and then stored in a storage device such as the storage unit 6. In addition, a part or all of the first acquisition processor 50, formation processor 51, second acquisition processor 52, determination processor 53, and warning processor 54 may be composed of electronic circuits such as application-specific integrated circuit (ASIC).
In the following, exemplary explanations of parts included in and provided corresponding to the image forming unit 24 will be made on behalf of the image forming units 21-24. The following description can be similarly applied to each of the image forming units 21-23.
The first acquisition processor 50 acquires a charged amount of toner used for forming the toner image.
For example, the first acquisition processor 50 calculates the charged amount of toner based on the detection result of current flowing through the developing roller 44 at a timing when a specific electrostatic latent image is developed by the developing apparatus 33 and the density detection result of the toner image based on the specific electrostatic latent image. Specifically, when the formation timing described later arrives, the first acquisition processor 50 controls the image forming section 3 to form the toner image based on the specific electrostatic latent image on the photoreceptive drum 31. The first acquisition processor 50 uses an ammeter (not shown) to detect the current flowing through the developing roller 44 at the timing when the specific electrostatic latent image is developed. The first acquisition processor 50 detects density of the toner image based on the specific electrostatic latent image using the density sensor 30. The first acquisition processor 50 calculates the charged amount of toner by substituting in the specific equation the detection result of the current flowing through the developing roller 44 at the timing when the specific electrostatic latent image is developed and the density detection result of the toner image based on the specific electrostatic latent image. The first acquisition processor 50 may acquire the charged amount of toner at a timing different from the formation timing described below.
The first acquisition processor 50 may estimate the charged amount of toner based on an air temperature and humidity inside the housing of the image forming apparatus 100. Specifically, the first acquisition processor 50 may estimate the charged amount of toner using table data in which a combination of the air temperature and humidity is associated with an estimated value or estimated range of the charged amount of toner. The method of acquiring the charged amount of toner by the first acquisition processor 50 is not limited thereto, and other known method may be used.
For every time when a specific formation timing arrives, using the photoreceptive drum 31, the formation processor 51 forms the toner image for detection 90 (see
Specifically, the formation timing is a timing when a cumulative total value of the number of printed sheets (number of printed sheets) output by the image forming apparatus 100 reaches a multiple of a specific reference number of sheets. The formation timing may be a timing when a cumulative total value of a driving time duration of the drive unit 37 reaches a multiple of a specific reference time.
Each of the images for detection is a monochromatic image expressed only by density of black which is a printing color corresponding to the image forming unit 24 among multiple printing colors (yellow, cyan, magenta, and black). For example, the plurality of images for detection include an image with 12 percent black density, an image with 25 percent black density, an image with 50 percent black density, and an image with 75 percent black density. Namely, each of the images for detection is a halftone image. The plurality of images for detection may include an image with 100 percent black density, i.e., a black image. The number of images for detection may be less than four or more than five.
As shown in
For example, in the image forming apparatus 100, a plurality of image data for detection corresponding to the plurality of images for detection are stored in the ROM 12 of the controller 7 in advance.
For example, the formation processor 51 interrupts an image forming process when the formation timing arrives during execution of the image forming process to form an image based on image data.
The formation processor 51 selects one of the plurality of image data for detection as an image to be formed based on the charged amount of toner acquired by the first acquisition processor 50. For example, if the charged amount of the toner acquired by the first acquisition processor 50 is less than a specific first boundary value, the formation processor 51 selects as the image to be formed image data for detection corresponding to the image for detection with 12 percent black density. Furthermore, if the charged amount of toner acquired by the first acquisition processor 50 is not less than the first boundary value and less than a second boundary value which is higher than the first boundary value, the formation processor 51 selects as the image to be formed the image data for detection corresponding to the image for detection with 25 percent black density. Furthermore, if the charged amount of toner acquired by the first acquisition processor 50 is not less than the second boundary value and less than a third boundary value which is higher than the second boundary value, the formation processor 51 selects as the image to be formed the image data for detection corresponding to the image for detection with 50 percent black density. Furthermore, if the charged amount of toner acquired by the first acquisition processor 50 is not less than the third boundary value, the formation processor 51 selects as the image to be formed the image data for detection corresponding to the image for detection with 75 percent black density. Namely, in the image forming apparatus 100, the greater the charged amount of toner acquired by the first acquisition processor 50 is, the higher density of the image data for detection which is selected as the image to be formed is. The reason is that the higher the charged amount of toner is, the less likely toner in the facing area R1 is transferred to the photoreceptive drum 31, so that a density change due to the failure of the gears 39 less likely appears in the toner image for detection 90 with low density. The reason is also that the smaller the charged amount of toner is, the easier toner in the facing area R1 is transferred to the photoreceptive drum 31, so that the density change due to the failure of the gears 39 less likely appears in the toner image for detection 90 with high density. If the charged amount of toner is acquired at a timing different from the formation timing, the formation processor 51 may select as the image to be formed the image data for detection based on the charged amount of toner acquired last.
The formation processor 51 controls the image forming section 3 to form the toner image for detection 90 based on the image data for detection selected as the image to be formed. Specifically, the formation processor 51 drives each part of the image forming section 3 and the image data for detection as the image to be formed is thereby input to the optical scanning device 25, so that the toner image for detection 90 based on the image data for detection is formed onto the intermediate transfer belt 26. The formation processor 51 separates the secondary transfer roller 27 from the intermediate transfer belt 26 from a timing before the toner image for detection 90 reaches a facing position between the intermediate transfer belt 26 and the secondary transfer roller 27 to a timing after the toner image for detection 90 passes the facing position. Namely, the secondary transfer roller 27 is moved to the separation position.
The formation processor 51 may form the toner image for detection 90 without interrupting the image forming process when the formation timing arrives during executing the image forming process. Specifically, the formation processor 51 may form the toner image for detection 90 in a region of the intermediate transfer belt 26 where the intermediate transfer belt 26 does not contact the sheet supplied from the paper feeding unit 4 (paper absent region).
The second acquisition processor 52 acquires the variation width W1 of density (see
Specifically, the second acquisition processor 52 acquires the variation width W1 based on a detection result of each of the density sensors 30.
Here, the toner image for detection 90 includes a plurality of detectees 91 (portions to be detected) (see
As shown in
For example, the second acquisition processor 52 acquires as the variation width W1 the difference between the highest value and the lowest value among a plurality of density values which corresponds to densities of the plurality of detectees 91 detected by the plurality of density sensors 30 (see
Namely, the second acquisition processor 52 acquires the variation width W1 of density along the left-right direction D3 in the toner image for detection 90 formed by the formation processor 51.
For example, the second acquisition processor 52 stores in the storage unit 6 acquired data including the acquired variation width W1, density of the image for detection corresponding to the formed toner image for detection 90, and information indicating an acquisition date and time of the variation width W1.
As shown in
The second acquisition processor 52 may acquire as the variation width W1 the difference between densities of the toner images for detection 90 at both ends of the toner images for detection 90 in the longitudinal direction of the toner image for detection 90. Namely, the second acquisition processor 52 may acquire as the variation width W1 the difference between the detection result by the density sensor 30A and the detection result by the density sensor 30H. In this example the plurality of density sensors 30 may consist of only two density sensors 30A and 30H.
Instead of the plurality of density sensors 30, a line sensor elongated in the left-right direction D3, which is capable of capturing the toner image transferred to the intermediate transfer belt 26, may be provided. In this example, the second acquisition processor 52 may acquire the variation width W1 using the line sensor. The plurality of density sensors 30 or the line sensor may be installed so as to be opposed to the sheet on which the toner image for detection 90 is transferred by the secondary transfer roller 27. The second acquisition processor 52 may also acquire the variation width W1 based on read image of the sheet on which the toner image for detection 90 is transferred by the image reading unit 2.
The determination processor 53 determines the failure timing of the gears 39 based on the variation width W1 for each of the formation timings corresponding to any one of the plurality of images for detection.
Specifically, the determination processor 53 determines the failure timing based on the variation width W1 for each of the formation timings corresponding to the image for detection in which the toner image for detection 90 is formed last among the plurality of images for detection.
The determination processor 53 determines the failure timing based on the variation width W1 for each of the formation timings on or after an end timing when a decrease trend of the variation width W1 ends among the variation widths W1 for each of the formation timings corresponding to the image for detection in which the toner image for detection 90 is formed last.
Here, it should be noted that the term “failure of the gears 39” in the specification indicates a state where the function of the gears 39 is deteriorated to such an extent that the image quality of the image formed using photoreceptive drum 31 is degraded in excess of a specific acceptable limitation. It should be also noted that the term “failure of the gear 39” in the specification includes a state, in addition to the state in which the function of the gears 39 is deteriorated, a state in which wear of the gears 39 progresses to such an extent that adverse effects mentioned above occur, and a state in which lubricant applied to the gears 39 is decreased to such an extent that the adverse effects mentioned above occur.
Specifically, in the image forming apparatus 100, if the variation width W1 acquired by the second acquisition processor 52 exceeds a specific threshold value TH1 (see
As shown in
As shown in
As shown in
For example, if the acquired data is stored in the storage unit 6 by the second acquisition processor 52, the determination processor 53 determines whether or not the end timing has already arrived, that is, whether or not the initial wear period elapses based on the acquired data and acquired data with the same density of the image for detection as the acquired data.
If the determination processor 53 determines that the end timing has already arrived, the determination processor 53 determines the failure timing based on the acquired data acquired on or after the end timing. For example, if the number of the acquired data acquired on or after the end timing is less than a specific reference number, the determination processor 53 conducts a linear approximation on change with time of the variation width W1 during the normal wear period and determines the failure timing based on the approximation result. If the number of the acquired data acquired on or after the end timing is not less than the reference number, the determination processor 53 conducts a curve approximation on change with time of the variation width W1 during the normal wear period and determines the failure timing based on the approximation result.
On the other hand, if the determination processor 53 determines that the end timing has not yet arrived, the determination processor 53 determines no failure timing.
The determination processor 53 may determine the failure timing based on the variation width W1 for each of formation timings before the end timing. For example, the determination processor 53 may determine the failure timing using artificial intelligence which has learned a relationship between change with time of the variation width W1 obtained during the initial wear period and change with time of the variation width W1 until the gear 39 fails. In this example, the artificial intelligence can learn the relationship by using as teacher data the data, which is obtained through experiments using a plurality of image forming apparatus 100, shows change with time of the variation width W1 from when the image forming apparatus 100 starts until the gear 39 fails for each of the image forming apparatus 100.
The determination processor 53 may also determine the failure timing based on the variation width W1 for each formation timing corresponding to the image for detection in which the number of formation of the toner image for detection 90 is the highest of the plurality of images for detection.
The warning processor 54 warns the failure timing determined by the determination processor 53.
For example, the warning processor 54 causes the operation display unit 5 to display a message including the failure timing determined by the determination processor 53. For example, the failure timing is indicated by the number of possible prints before the failure timing arrives or an operation time of the image forming section 3.
Failure Timing Determination Process Hereinafter, a determination method of the present disclosure is described below with reference to
Step S10
First, in step S10, the controller 7 determines whether or not the formation timing arrives.
Specifically, when the cumulative total value of the number of printed sheets reaches a multiple of the reference number of sheets during execution of the image forming process, the controller 7 determines that the formation timing arrives.
Here, if the controller 7 determines that the formation timing arrives (Yes in S10), the process moves to step S11. If the formation timing does not yet arrive (No in S10), the controller 7 waits for the arrival of the formation timing in step S10.
Step S11
In step S11, the controller 7 interrupts the image forming process to acquire the charged amount of toner. It should be noted that the process of acquiring the charged amount of toner is an example of the first acquisition step of the present disclosure, and it is performed by the first acquisition processor 50 of the controller 7.
The process of acquiring the charged amount of toner may be performed at a time when the image forming apparatus 100 is turned on, when an operation mode of the image forming apparatus 100 is shifted from a power saving mode to a normal mode, or when instructions to execute the image forming process is input. If the process of acquiring the charged amount of toner is executed before execution of the failure timing determination process, the process of acquiring the charged amount of toner in step S11 may be omitted.
Step S12
In step S12, the controller 7 forms the toner image for detection 90 based on the image for detection with density according to the charged amount of toner acquired in step S11 among the plurality of images for detection. It should be noted that the process in step S12 is an example of a forming step of the present disclosure and it is performed by the formation processor 51 of the controller 7.
Specifically, the controller 7 selects as the image to be formed one of the plurality of the image data for detection based on the charged amount of toner acquired in step S11. The controller 7 also controls the image forming section 3 to form the toner image for detection 90 based on the image data for detection selected as the image to be formed. The controller 7 moves the secondary transfer roller 27 to the separation position, from a timing before the toner image for detection 90 reaches the facing position between the intermediate transfer belt 26 and the secondary transfer roller 27 to a timing after the toner image for detection 90 passes the facing position. After the toner image for detection 90 passes the facing position, the controller 7 moves the secondary transfer roller 27 to the contact position to resume the image forming process.
Step S13
In step S13, the controller 7 acquires the variation width W1 of density in the toner image for detection 90 formed in step S12. It should be noted that the process in step S13 is an example of a second acquisition step of the present disclosure, and it is executed by the second acquisition processor 52 of the controller 7.
Specifically, the controller 7 acquires as the variation width W1 the difference between the highest value and the lowest value of the plurality of density values corresponding to densities of the plurality of detectees 91 included in the toner image for detection 90, which are detected by a plurality of density sensors 30. Then, the controller 7 stores in the storage unit 6 the acquired data including the acquired variation width W1, density of the image for detection corresponding to the formed toner image for detection 90, and information indicating the date and time of acquisition of the variation width W1.
Here, the toner image for detection 90 is formed based on the image for detection which is a halftone image. This makes it possible to acquire the variation width W1 larger than a variation width W1 in which the toner image for detection 90 is formed based on an image with 100 percent black density, i.e., a black image for detection.
Step S14
In step S14, the controller 7 determines whether or not the end timing has already arrived.
Specifically, the controller 7 determines whether or not the end timing has already arrived based on the acquired data stored in the storage unit 6 in step S13 and the acquired data with the same density of the image for detection as the acquired data stored.
If the controller 7 determines that the end timing has already arrived (Yes in S14), the process moves to step S15. If the controller 7 determines that the end timing has not yet arrived (No in S14), the process moves to step S10.
If the controller 7 determines that the end timing has already arrived (Yes in S14), the process may move to step S16. Namely, the process in step S15 may be omitted.
Step S15
In step S15, the controller 7 determines whether or not a specific warning timing arrives.
For example, the warning timing includes a timing when the number of acquired data acquired on or after the end timing becomes two among the plurality of acquired data with the same density of the image for detection. The warning timing includes a timing when the number of acquired data acquired on or after the end timing becomes the same as the reference number among the plurality of acquired data with the same of the image for detection.
Here, when the controller 7 determines that the warning timing arrives (Yes in S15), the process moves to step S16. If the controller 7 determines that the warning timing does not arrives (No in S15), the process moves to step S10.
Step S16
In step S16, the controller 7 determines the failure timing of the gear 39. It should be noted that the process of step S16 is an example of a determination step of the present disclosure, and it is executed by the determination processor 53 of the controller 7.
Specifically, if the number of the acquired data acquired on or after the end timing is two among the plurality of acquired data with the same density of the image for detection, the controller 7 conducts a linear approximation on change with time of the variation width W1 during the normal wear period and determines the failure timing based on the approximation result. This makes it possible to determine the failure timing earlier.
If the number of acquired data acquired on or after the end timing is the same as the reference number among the plurality of acquired data with the same density of the image for detection, the controller 7 conducts a curve approximation on change with time of the variation width W1 during the normal wear period and determines the failure timing based on the approximation result. This makes it possible to determine the failure timing with higher accuracy than when conducting the linear approximation on change with time of the variation width W1 during the normal wear period.
Step S17
In step S17, the controller 7 warns the failure timing determined in step S16. Here, the process in step S17 is executed by the warning processor 54 of the controller 7.
Specifically, the controller 7 causes the operation display unit 5 to display a message including the failure timing determined in step S16. This allows the user to prepare for maintenance until the failure timing is warned. For example, the user can prepare gears 39 for replacement and lubricant applied to the gears 39. The user can also make a reservation of a maintenance service by a service person from the manufacturer of the image forming apparatus 100 in advance.
As shown in
On the other hand, as shown in
Thus, in the image forming apparatus 100, the toner image for detection 90 is formed for every time when the formation timing arrives, and the variation width W1 of density in the formed toner image for detection 90 is acquired. The failure timing of the gears 39 is determined based on the variation width W1 for each of the formation timings. This makes it possible to determine the failure timing of the gears 39 earlier than the conventional apparatus configured to determine the failure timing based on the drive current.
Furthermore, in the image forming apparatus 100, the image for detection used for forming the toner image for detection 90 is changed according to the charged amount of toner. The failure timing of the gears 39 is then determined based on the variation width W1 for each of the formation timings corresponding to any one of the plurality of images for detection. Thereby, density of the toner image for detection 90 can be density in which the density change due to the failure of the gear 39 most likely appears at the timing when the toner image for detection 90 is formed. Therefore, it is possible to determine the failure timing more accurately than when only one image for detection is used for forming the toner image for detection 90.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-036975 | Mar 2022 | JP | national |
