Image forming apparatus

Abstract

To provide an image forming apparatus that can appropriately calculate the lifespan of the fixing unit. [Solution] The image forming apparatus 100 includes a fuser unit 106, a display unit 801, and a control unit 300. The control unit 300 calculates print points, detects the print duty cycle, and calculates duty points, which are values ​​corresponding to the print duty cycle. The duty points are either a first value corresponding to a first print duty cycle or a second value corresponding to a second print duty cycle that is greater than the first print duty cycle. The second value is smaller than the first value. A lifespan value calculated based on the print points and duty points is stored in the storage unit 303 so that it can be calculated each time printing based on a print command is performed. When the sum of the duty points and print points accumulated in the storage unit 303 reaches a predetermined threshold value, the control unit 300 displays information on the display unit 801 indicating that the fuser unit 106 has reached the end of its lifespan.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] An image forming apparatus that discards deteriorated toner during non-printing is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technology, the waste toner discharged from the photosensitive drum may adhere to the fixing unit via the printing medium, and there is a problem that the life of the fixing unit considering such a phenomenon cannot be appropriately calculated.

[0005] An object of the present invention is to provide an image forming apparatus capable of appropriately calculating the life of a fixing unit in order to solve the above problems.

Means for Solving the Problems

[0006] An image forming apparatus according to an aspect of the present invention is an image forming apparatus that performs printing by an electrophotographic method using a developer based on print data included in a print command, a fixing unit that fixes the developer transferred to a printing medium to the printing medium, a display unit, a storage unit, a control unit that controls the fixing unit and the display unit, and includes wherein the control unit Based on the print command, the print point is calculated, which is a value based on the area of ​​the printed surface of the printing medium to be printed. The printing duty cycle, which is the ratio of the area on which an image is formed using the developer to the area of ​​the printed surface, is detected. The duty point, which is a value corresponding to the aforementioned printing duty cycle, is calculated. The duty point is a first value corresponding to a first print duty or a second value corresponding to a second print duty that is greater than the first print duty. The second value is smaller than the first value. The life value calculated based on the print point and the duty point is stored in the storage unit so that it can be calculated each time printing based on the print command is performed. When the sum of the duty cycle points and print points accumulated in the storage unit reaches a predetermined threshold value, the control unit displays information on the display unit indicating that the fuser unit has reached the end of its lifespan. It is characterized by the following: An image forming apparatus according to another aspect of the present invention is: An image forming apparatus that performs printing using an electrophotographic method with a developer based on print data included in a print command, A fixing unit for fixing the developer transferred to the printing medium onto the printing medium, Display unit and Memory unit and, A control unit that controls the fixing unit, the display unit and the storage unit, Equipped with, The control unit calculates, based on the print command, the print quantity, which is the area of ​​the printing surface of the printing medium to be printed, and the print amount, which is the ratio of the area on which an image is formed using the developer to the area of ​​the printing surface. The control unit accumulates the lifespan value of the fuser unit, calculated based on the print quantity and the print amount, in the storage unit. When the lifespan value accumulated in the storage unit reaches a predetermined threshold, the control unit displays information indicating that the fuser unit has reached the end of its lifespan on the display unit. It is characterized by the following: [Effects of the Invention]

[0007] According to the present invention, an image forming apparatus capable of appropriately calculating the life of a fixing unit can be provided.

Brief Description of the Drawings

[0008] [Figure 1] FIG. 1 is a cross-sectional view schematically showing the structure of a printer as an image forming apparatus according to Embodiment 1 of the present invention. [Figure 2] FIG. 2 is a block diagram showing the control system of the printer. [Figure 3] FIG. 3 is a flowchart showing an example of the operation of the printer in Embodiment 1. [Figure 4] FIG. 4 is a flowchart showing an example of the operation of the printer in Embodiment 2 of the present invention.

Modes for Carrying Out the Invention

[0009] 《Embodiment 1》 FIG. 1 is a cross-sectional view schematically showing the structure of a printer 100 as an image forming apparatus according to Embodiment 1 of the present invention.

[0010] The printer 100 performs printing by an electrophotographic method using toner based on print data included in a print command. The printer 100 includes, for example, an image forming unit 10 that forms an image on a print medium, a display unit 801, and a control unit 300 that controls the image forming unit 10 and the display unit 801. The printer 100 may further have a configuration shown in FIG. 2 described later.

[0011] The image forming unit 10 includes a paper feeding unit 40, a registration unit 203, a charging unit 226, an LED head 103, a developing unit 104, a photosensitive drum 204 as an image carrier, a transfer unit 105, a fixing unit 106, and a discharge roller 209.

[0012] The paper feeding unit 40 includes a paper feed cassette 101, a paper feed roller 201, and a paper feed sub-roller 202. The paper feed cassette 101 houses the printing medium. The paper feed roller 201 and the paper feed sub-roller 202 separate the printing medium housed in the paper feed cassette 101 and convey it to the registration unit 203.

[0013] The registration unit 203 is, for example, a registration roller that aligns the leading edge of the conveyed printing medium and conveys the printing medium to the transfer unit 105.

[0014] The LED head 103 has LEDs and provides a latent image on the photosensitive drum 204 by laser irradiation.

[0015] The developing unit 104 supplies toner to the photosensitive drum 204.

[0016] The photosensitive drum 204 transfers and conveys the visible image with toner attached to the printing medium.

[0017] The transfer unit 105 includes a transfer roller 205, a charge removal unit 501, and a conveyance unit 502. The transfer roller 205 applies a transfer voltage at a position facing the photosensitive drum 204 in order to transfer the toner image visualized on the photosensitive drum 204 to the printing medium. The transfer roller 205 conveys the printing medium to the fixing unit 106 with a pressing force obtained by a spring.

[0018] The charge removal unit 501 removes the charged electric charges on the non-toner image side of the printing medium that has passed through the transfer roller 205.

[0019] The conveyance unit 502 is a conveyance guide for conveying the printing medium that has passed through the transfer roller 205 to the fixing unit 106.

[0020] The fixing unit 106 fixes the toner transferred to the printing medium onto the printing medium. The fixing unit 106 includes, for example, a fixing roller 206, a pressure roller 207, and a heater 208. The heater 208 is, for example, a halogen lamp and heats the fixing roller 206. The fixing roller 206 is heated by the heater 208 and melts the unfixed toner on the roller surface. The pressure roller 207 pressurizes the fixing roller 206 with pressure obtained by a spring, fixing the molten toner and transporting the printing medium to the discharge roller 209.

[0021] The discharge roller 209 discharges the printing medium conveyed from the fixing unit 106 to the media accumulation section 210. The printing medium discharged from the discharge roller 209 is accumulated in the media accumulation section 210.

[0022] The display unit 801 is, for example, a display that shows information. For example, it may include an LCD unit that displays the printer status in detail to the user.

[0023] When printing is performed based on a print command, the paper feed roller 201 and the paper feed sub-roller 202 feed the printing medium from the paper feed cassette 101. The printing medium is transported to the resist section 203, where the leading edge of the printing medium is aligned by the resist roller. The printing medium is then transported to the nip position between the photosensitive drum 204 and the transfer roller 205.

[0024] When toner is supplied from the developing unit 104 to the photosensitive drum 204, which has been given a latent image by the LED head 103, a visible toner image is transferred onto the photosensitive drum 204. When the printing medium reaches the nip position, a voltage is applied by the transfer roller 205, and the visible image on the photosensitive drum 204 is transferred to the printing medium.

[0025] The static elimination unit 501 removes static charge from the non-toner image plane side of the printing medium after it has passed through the transfer roller 205. The printing medium is then transported through the transport unit 502 to the fixing unit 106. The toner melts and fixes on the printing medium due to the heat from the heater 208 located inside the fixing roller 206. The printing medium is then transported by the pressure roller 207, which moves along with the fixing roller 206, to the discharge roller 209 located downstream, and is deposited in the media accumulation unit 210.

[0026] Figure 2 is a block diagram showing the control system of printer 100. The control unit 300 includes a printing control unit 800, a charging voltage control unit 840, an LED head control unit 850, a developing voltage control unit 860, a transfer voltage control unit 870, a main motor control unit 880, and a fixing control unit 910.

[0027] The control unit 300 can be configured, for example, as a CPU (Central Processing Unit). The control unit 300 may also have circuits other than the CPU. For example, the functions of the control unit 300 are realized by the CPU executing a program stored in the memory unit 303.

[0028] The print control unit 800 includes a counting unit 301, a detection unit 302, a storage unit 303, an arithmetic unit 304, and a discrimination unit 305. The print control unit 800 is composed of, for example, a microprocessor, ROM, RAM, input / output ports, a timer, etc. The print control unit 800 receives a print command including print data and control commands from a higher-level device and performs sequence control for the entire printer 100. The storage unit 303 may be provided outside the control unit 300. In this case, the control unit 300 may control the storage unit 303.

[0029] The counting unit 301 calculates the print point. If the print point is the number of printed pages Ni of the print data based on the print command, the counting unit 301 obtains the number of printed pages Ni. In addition, during printing based on the print command, the counting unit 301 counts the number of pages printed and determines whether the number of printed pages has reached the number of printed pages Ni.

[0030] The detection unit 302 detects the print duty cycle, which will be described later.

[0031] The memory unit 303 stores points (e.g., life points, duty cycle points, print points) for calculating a lifespan value Lf that indicates the fuser unit 106 has reached the end of its lifespan. The memory unit 303 is, for example, a non-volatile memory such as an SSD (Solid State Drive). The memory unit 303 may also store a program for operating the control unit 300 (e.g., a CPU).

[0032] The calculation unit 304 calculates points (e.g., lifetime points, duty cycle points) for calculating the lifetime value Lf.

[0033] The discrimination unit 305 determines whether the lifetime point Cf is equal to or greater than the lifetime value Lf.

[0034] The interface control unit 810 transmits printer information to the host device, analyzes commands input from the host device, and processes the data received from the host device.

[0035] The receiving memory 820 is a memory that stores data received from a higher-level device based on the control of the interface control unit 810.

[0036] The sensor unit 802 includes, for example, multiple sensors for detecting the transport position of the printing medium, and an environmental sensor for detecting the temperature and humidity inside the printer 100. For example, the output of each sensor is input to the print control unit 800 and simultaneously output to the display unit 801.

[0037] The image data editing memory 830 is a memory for editing print data input from a higher-level device via the interface control unit 810 as image data. The image data editing memory 830 receives print data temporarily stored in the receiving memory 820. The image data editing memory 830 is a memory for storing the edited image data for transmission to the LED head 103.

[0038] The charging voltage control unit 840 controls the charging unit 226 (for example, a charging roller) to charge the surface of the photosensitive drum 204 by applying a voltage to it, as instructed by the printing control unit 800.

[0039] The LED head control unit 850 controls the LED head 103 to expose the surface of the photosensitive drum 204 by irradiating it with light, according to the image data stored in the image data editing memory 830. The LED head control unit 850 also controls the transmission of the image data to the LED head 103 at the appropriate timing.

[0040] The developing voltage control unit 860 controls the application of voltage to the developing roller 224 so that toner adheres to the electrostatic latent image formed on the surface of the photosensitive drum 204. As a result, a toner image is formed on the photosensitive drum 204.

[0041] The transfer voltage control unit 870 controls the transfer of the toner image formed on the surface of the photosensitive drum 204 to the printing medium and applies a voltage to the transfer roller 205 according to the instructions of the printing control unit 800. The transfer voltage control unit 870 controls the voltage applied to the transfer roller 205 and sequentially transfers the toner image from the photosensitive drum 204 to the printing medium.

[0042] The main motor control unit 880 drives the main motor 881 for driving each component within the printer 100.

[0043] The fuser control unit 910 fixes the toner image transferred to the printing medium and controls the application of voltage to the heater 208 built into the fuser unit 106 according to the instructions of the print control unit 800. The fuser control unit 910 obtains the temperature detected from the thermistor 912 for measuring the temperature of the fuser unit 106 and controls the heater 208 to turn on or off.

[0044] The print control unit 800 of the control unit 300 calculates print points, detects the print duty cycle, and calculates duty points in a printing operation based on a print command. For example, the counting unit 301 calculates print points, the detection unit 302 detects the print duty cycle, and the calculation unit 304 calculates duty points. The duty points are set to multiple values ​​corresponding to the print duty cycle.

[0045] A print point is a value based on the area of ​​the print surface of the printing medium that is printed based on a print command. For example, a print point can be the number of pages printed. If the printing medium is continuous paper, the print point may also be the area of ​​the print surface.

[0046] The print duty cycle is the ratio of the area on the print surface of the printing medium to the area on which an image is formed using toner. The print duty cycle and duty points may also be calculated as the amount of print.

[0047] Duty points are values ​​corresponding to the print duty cycle. A duty point is either a first value corresponding to the first print duty cycle, or a second value corresponding to a second print duty cycle that is greater than the first. The second value is smaller than the first value. In other words, the larger the print duty cycle, the smaller the value (duty points) corresponding to that print duty cycle is set to.

[0048] The lifetime value calculated based on the print points and duty points is stored in the storage unit 303 so that it can be calculated each time printing based on each print command is performed. The print points and duty points may be accumulated in the storage unit 303 as lifetime points each time printing based on each print command is performed.

[0049] When the sum of duty points and print points accumulated in the memory unit 303 reaches a predetermined threshold value, the print control unit 800 of the control unit 300 displays information on the display unit 801 indicating that the fuser unit 106 has reached the end of its lifespan. This allows the user to know the appropriate time to replace the fuser unit 106.

[0050] As another example, the control unit 300 may calculate, based on a print command, the print amount based on the area of ​​the printing surface of the printing medium to be printed, and the print amount, which is the ratio of the area on which an image is formed using the developer to the area of ​​the printing surface. The control unit may then accumulate the lifespan value of the fuser unit, calculated based on the print amount and the print amount, in a storage unit. When the accumulated lifespan value in the storage unit reaches a predetermined threshold, the control unit 801 may display information indicating that the fuser unit has reached the end of its lifespan. In this case, the print amount is calculated, for example, based on the number of dots in the print command.

[0051] An example of the operation of the printer 100 in Embodiment 1 is described below. Figure 3 is a flowchart showing an example of the operation of the printer 100 in Embodiment 1. In the example shown in Figure 3, the initial value of the life points is set to Cf=0, the print point to Pf, the duty point to Df, and the life value indicating that the fuser unit 106 has reached the end of its life is set to Lf. In the example shown in Figure 3, the first print duty is set to 2%, the duty point as the first value corresponding to the first print duty of 2% is set to Df=5, the second print duty is set to 10%, the duty point as the second value corresponding to the second print duty of 10% is set to Df=4, the duty point as the third value corresponding to a third print duty that is greater than the second print duty is set to Df=3, and the life value Lf=600,000 points.

[0052] Example 1 in Embodiment 1 In step S1, the initial values ​​are set to Cf=Pf=Df=0.

[0053] In step S2, when the printer 100 (for example, the print control unit 800) receives a print command via the interface control unit 810, the counting unit 301 obtains the number of printed pages Ni.

[0054] In step S3, the print control unit 800 sets the print point Pf = Ni. For example, if the number of pages to be printed is 3, then Ni = 3 and Pf = 3 points.

[0055] In step S4, the print control unit 800 (for example, the detection unit 302) determines whether the print duty cycle for the first page is 2% or less. For example, the detection unit 302 determines whether the print duty cycle for the first page is 2% or less based on the image data in the image data editing memory 830.

[0056] If the print duty cycle for the first page is 2% or less, the process proceeds to step S5. If the print duty cycle for the first page is greater than 2%, the process proceeds to step S9.

[0057] In step S5, the duty point Df' is set to 5 points.

[0058] In step S6, duty points are added, so Df = Df' = 5 points.

[0059] In step S7, the print control unit 800 (for example, the counting unit 301) determines whether the number of printed pages has reached the number of printed pages Ni. If the number of printed pages has reached the number of printed pages Ni, the process proceeds to step S50. If the number of printed pages has not reached the number of printed pages Ni, the process returns to step S4 to determine the print duty cycle for the next page (page 2).

[0060] If the print duty cycle for the second page is 2% or less (YES in step S4), Df'=5 points is entered in step S5, Df=5+Df'=10 points in step S6, and it is determined again in step S7 whether the number of printed pages Ni has been completed.

[0061] If the print duty cycle for the third page is 2% or less (YES in step S4), Df'=5 points is entered in step S5, and Df=15 points in step S6.

[0062] In step S7, if it is determined that the number of printed pages has reached Ni, the process proceeds to step S50.

[0063] In step S50, the print control unit 800 of the control unit 300 controls the photosensitive drum 204 or the developing unit 104 to discard toner from the photosensitive drum 204 or the developing unit 104 according to the duty point Df. For example, the photosensitive drum 204 discards toner for the duration of the Df point.

[0064] In step S8, the print control unit 800 (for example, the discrimination unit 305) determines whether the life point (Cf + Pf + Df) is greater than or equal to the life value Lf. That is, the print control unit 800 (for example, the discrimination unit 305) determines whether Cf + Pf + Df ≥ Lf is satisfied. If the life point (Cf + Pf + Df) is greater than or equal to the life value Lf, the print control unit 800 displays information on the display unit 801 indicating that the fuser unit 106 has reached the end of its life. If the life point (Cf + Pf + Df) is less than the life value Lf, the process proceeds to step S12.

[0065] When the third page is printed, the calculation unit 304 calculates the lifetime points (Cf + Pf + Df = 0 + 3 + 15 = 18), and in step S8, the discrimination unit 305 determines that the lifetime points (18 points) are less than the lifetime value Lf (600,000 points).

[0066] In step S12, Cf=18 is stored in the memory unit 303.

[0067] For example, if the print duty cycle for each page is 2% or less, then Cf = 6 points per page. In this case, the number of printable pages is 100,000, and when 100,000 pages are reached in step S8, the process moves to step S51.

[0068] In step S51, the printer 100 notifies the user that the fuser unit 106 has reached the end of its lifespan. For example, the print control unit 800 displays information indicating that the fuser unit 106 has reached the end of its lifespan on the display unit 801.

[0069] Example 2 in Embodiment 1 Next, we will explain the case where the number of printed pages Ni=3, the first page has a print duty cycle of 2% or less (text), the second page has a print duty cycle of approximately 5% (ISO pattern), and the third page has a print duty cycle of more than 10% (image or illustration).

[0070] When the print control unit 800 receives a print command in step S2, the value Pf=3 is stored in the storage unit 303 in step S3.

[0071] In step S4, it is determined that the first page is less than 2%, so in step S5, 5 points are entered into Df', in step S6, Df=Df'=5 points, in step S7, it is determined that the number of printed pages Ni has ended, and the process returns to step S4.

[0072] Since the print duty cycle for the second page is 5%, the determination made in step S4 leads to the process proceeding to step S9.

[0073] Since the print duty cycle for the second page is 5%, the determination in step S9 leads to step S10. In step S10, Df' becomes 4 points, and in step S6, Df = 5 + 4 = 9 points. In step S7, it is determined whether the number of printed pages Ni has been completed, and the process returns to step S4.

[0074] Since the print duty cycle for the third page exceeds 10%, the process proceeds to steps S4, S9, and S11, resulting in Df' = 3 points.

[0075] The process moves from step S11 to step S6, where Df = 9 + 3 = 12 points.

[0076] If all print jobs have a print page count Ni=3 and the print duty cycle is 2% or less, 5%, or greater than 10% using the same pattern combination, then 120,000 pages can be printed before reaching the lifespan value Lf=600,000 points.

[0077] Furthermore, if the print duty cycle for all printed materials is greater than 10%, the lifespan points Cf = 4 points per page printed, allowing for 150,000 pages to be printed up to a lifespan value Lf = 600,000 points.

[0078] Advantages of Embodiment 1 Normally, when the print duty cycle is small, the toner is agitated in the developer unit 104 for a longer time compared to when the print duty cycle is large. As a result, the amount of degraded toner in the developer unit 104 increases, and the amount of waste toner adhering to the fuser unit 106 increases. To account for this phenomenon, the duty point is larger when the print duty cycle is small. This allows the life point Cf to be corrected to take into account the small print duty cycle.

[0079] On the other hand, when the print duty cycle is large, the time spent agitating the toner in the developing unit 104 can be shortened, thereby reducing the amount of waste toner discharged from the developing unit 104 and the photosensitive drum 204. Taking this phenomenon into consideration, the duty point is smaller as the print duty cycle increases. As a result, the life point Cf is corrected to account for the large print duty cycle.

[0080] Therefore, even with the same number of printed pages, the life point Cf is appropriately corrected considering the printing duty cycle, so that the user can be notified of the lifespan of the fuser unit 106 at the appropriate time.

[0081] As described above, this embodiment provides a printer 100 that can appropriately calculate the lifespan of the fuser unit 106.

[0082] Embodiment 2 The configuration of the printer 100 in Embodiment 2 is the same as the configuration of the printer 100 described in Embodiment 1. An example of the operation of the printer 100 in Embodiment 2 is described below.

[0083] Figure 4 is a flowchart showing an example of the operation of the printer 100 in Embodiment 2 of the present invention. The operation for determining the lifespan of the fuser in this invention will be explained using Figures 3 and 5.

[0084] Example 1 in Embodiment 2 In step S1, the initial values ​​are set to Cf=Pf=Df=0.

[0085] In step S2, when the print control unit 800 receives a print command, the counting unit 301 obtains the number of printed pages Ni.

[0086] In step S31, the print control unit 800 sets the print point Pf = Ni. For example, if the number of pages to be printed is 5, then Ni = 5 and Pf = 5 points. The print control unit 800 also sets the duty point Df = 10 points.

[0087] In step S4, the print control unit 800 (for example, the detection unit 302) determines whether the print duty cycle for the first page is 2% or less. For example, the detection unit 302 determines whether the print duty cycle for the first page is 2% or less based on the image data in the image data editing memory 830.

[0088] If the print duty cycle for the first page is 2% or less, the process proceeds to step S33. If the print duty cycle for the first page is greater than 2%, the process proceeds to step S9.

[0089] In step S33, set the duty point Df' to 5 points.

[0090] In step S35, the print control unit 800 (for example, the discrimination unit 305) compares the magnitude relationship between Df' and Df''. If Df' is smaller than Df'', the process proceeds to step S36. If Df' is greater than or equal to Df'', the process proceeds to step S7.

[0091] In step S36, Df' is entered into Df''. On the first page, in step S36, Df'' = 5 points.

[0092] In step S7, the print control unit 800 (for example, the counting unit 301) determines whether the number of printed pages has reached the number of printed pages Ni. If the number of printed pages has reached the number of printed pages Ni, the process proceeds to step S37. If the number of printed pages has not reached the number of printed pages Ni, the process returns to step S4 to determine the print duty cycle for the next page (page 2).

[0093] If the print duty cycle for the second page is 2% or less (YES in step S4), Df'=5 points is entered in step S33, and the relationship between Df' and Df'' is compared in step S35. In step S36, Df''=Df'=5 points, and it is determined again in step S7 whether the number of printed pages Ni has been completed.

[0094] If the print duty cycle for each page from page 3 to page 5 is 2% or less, repeat steps S4, S33, S35, S36, and S7.

[0095] If printing based on the print command is completed (YES in step S7), the process proceeds to step S37.

[0096] In step S37, Df = Ni * Df = 5 * 5 = 25 points.

[0097] In step S50, the print control unit 800 of the control unit 300 controls the photosensitive drum 204 or the developing unit 104 to discard toner from the photosensitive drum 204 or the developing unit 104 according to the duty point Df. For example, the photosensitive drum 204 discards toner for the duration of the Df point.

[0098] In step S8, the print control unit 800 (for example, the discrimination unit 305) determines whether the life point (Cf + Pf + Df) is greater than or equal to the life value Lf. That is, the print control unit 800 (for example, the discrimination unit 305) determines whether Cf + Pf + Df ≥ Lf is satisfied. If the life point (Cf + Pf + Df) is greater than or equal to the life value Lf, the print control unit 800 displays information on the display unit 801 indicating that the fuser unit 106 has reached the end of its life. If the life point (Cf + Pf + Df) is less than the life value Lf, the process proceeds to step S12.

[0099] The calculation unit 304 calculates the lifetime points (Cf + Pf + Df = 0 + 5 + 25 = 30), and in step S8, the discrimination unit 305 determines that the lifetime points (18 points) are less than the lifetime value Lf (600,000 points).

[0100] In step S12, Cf=30 is stored in the memory unit 303.

[0101] For example, if the print duty cycle for each page is 2% or less, then Cf = 6 points per page. In this case, when 100,000 pages are reached in step S8, the print control unit 800 displays information on the display unit 801 indicating that the fuser unit 106 has reached the end of its lifespan. In this case, the number of printable pages becomes 100,000 pages.

[0102] Example 2 in Embodiment 2 Next, we will explain the case where the number of printed pages Ni=5, the print duty cycle of the first page and the fifth page is 2% or less (text), the print duty cycle of the second page is about 5% (ISO pattern), the print duty cycle of the third page is about 15% (image or illustration), and the print duty cycle of the fourth page exceeds 30%.

[0103] When the print control unit 800 receives a print command in step S2, Pf=5 points are stored in the storage unit 303 in step S3.

[0104] In step S4, the first page is determined to be less than 2%, and 5 points are entered into Df' in step S33.

[0105] In step S35, Df' is smaller than Df'', so in step S36 Df'' becomes 5 points, and in step S7 it is determined whether the number of printed pages Ni has ended, and the process returns to step S4.

[0106] Since the print duty cycle for the second page is 5%, the determination made in step S4 leads to the process proceeding to step S9.

[0107] Since the print duty cycle for the second page is 5%, the determination made in step S9 leads to step S10. In step S10, Df' = 4 points.

[0108] Since Df'=4 and Df''=5, the condition in step S35 is met, and in step S36, Df'' is changed to 4 points.

[0109] In other words, in steps S35 and S36, if the print duty detected each time printing based on a print command is executed increases, the print control unit 800 of the control unit 300 updates the duty point Df'' accumulated in the storage unit 303 to a value corresponding to the increased print duty.

[0110] Since the print duty cycle for the third page exceeds 10%, the process proceeds to steps S4, S9, S32, and S11, resulting in Df' = 3 points.

[0111] The process moves from step S11 to steps S35 and S36, where Df” is changed to 3 points.

[0112] Since the print duty cycle for page 4 exceeds 30%, the process proceeds to steps S4, S9, S32, and S34, resulting in Df' = 2 points.

[0113] The process moves from step S34 to steps S35 and S36, where Df” is changed to 2 points.

[0114] In step S4, page 5 is determined to be less than 2%, and 5 points are entered into Df' in step S33.

[0115] In step S35, Df' is greater than Df'', so Df'' = 2 points.

[0116] If printing based on the print command is completed (YES in step S7), the process proceeds to step S37.

[0117] In step S37, Df is the value obtained by multiplying the duty point Df'' updated in step S36 by the print point. If the print point is the number of printed pages Ni, then Df = Ni * Df'' = 5 * 2 = 10 points.

[0118] In step S50, the print control unit 800 of the control unit 300 controls the photosensitive drum 204 or the developing unit 104 to discard toner from the photosensitive drum 204 or the developing unit 104 according to the value (duty point Df) obtained in step S37. For example, the photosensitive drum 204 discards toner equal to Df points.

[0119] If the conditions in step S8 are met, the process proceeds to step S51. In step S51, the printer 100 notifies the user that the fuser unit 106 has reached the end of its lifespan.

[0120] If the conditions in step S8 are not met, the process proceeds to step S12, and the lifetime point is stored in the storage unit 303 as Cf=15.

[0121] For example, if the print duty cycle for each page is greater than 30% in all continuous printing, it will be possible to print 200,000 pages before reaching the lifespan value Lf = 600,000 points.

[0122] Advantages of Embodiment 2 According to Embodiment 2, Df'' is changed in step S36 to account for cases with a high print duty cycle. Therefore, the more pages with a high print duty cycle there are, the less toner can be discarded in step S50. As a result, in addition to the life count of the fuser unit 106 being appropriately corrected considering the print duty cycle, the number of times the developer unit 104, the photosensitive drum 204, or the fuser unit 106 can be replaced can be reduced.

[0123] In the embodiments described above, examples of electrophotographic printers using an LED roller system were explained, but the printer 100 may also be a laser system, an intermediate transfer system, or a tandem system. Furthermore, although a transfer roller 205 is described as an example of a transfer unit 105, any system that forms a latent image using charged toner will not deviate from the present invention. Moreover, as long as there are at least two or more life points where the life count decreases as the print duty cycle increases, the present invention will not deviate from the present invention.

[0124] As described above, this embodiment provides a printer 100 that can appropriately calculate the lifespan of the fuser unit 106.

[0125] The various aspects of this implementation are summarized below as an appendix. (Note 1) An image forming apparatus that performs printing using an electrophotographic method with a developer based on print data included in a print command, A fixing unit for fixing the developer transferred to the printing medium onto the printing medium, Display unit and Memory unit and, The fixing unit and the control unit that controls the display unit, Equipped with, The control unit, Based on the print command, the print point is calculated, which is a value based on the area of ​​the printed surface of the printing medium to be printed. The printing duty cycle, which is the ratio of the area on which an image is formed using the developer to the area of ​​the printed surface, is detected. The duty point, which is a value corresponding to the aforementioned printing duty cycle, is calculated. The duty point is a first value corresponding to a first print duty or a second value corresponding to a second print duty that is greater than the first print duty. The second value is smaller than the first value. The life value calculated based on the print point and the duty point is stored in the storage unit so that it can be calculated each time printing based on the print command is performed. When the sum of the duty cycle points and print points accumulated in the storage unit reaches a predetermined threshold value, the control unit displays information on the display unit indicating that the fuser unit has reached the end of its lifespan. An image forming apparatus characterized by the following features. (Note 2) The duty point is set to a plurality of values, including the first value and the second value. Each value is set to a smaller value as the print duty cycle increases. The image forming apparatus according to Appendix 1, characterized in that it is a picture forming apparatus. (Note 3) Image carrier and, A developing unit that supplies the developer to the image carrier and Furthermore, The control unit controls the image carrier or the developing unit to discard the developer from the image carrier or the developing unit according to the duty cycle. The image forming apparatus according to Appendix 1 or 2, characterized by the features described herein. (Note 4) The image forming apparatus according to any one of appendices 1 to 3, characterized in that, when the print duty detected each time printing based on the print command is performed increases, the control unit updates the duty points accumulated in the storage unit to a value corresponding to the increased print duty. (Note 5) Image carrier and, A developing unit that supplies the developer to the image carrier and Furthermore, When printing based on the print command is completed, the control unit discards the developer from the image carrier or the developing unit according to the value obtained by multiplying the updated value by the print point. An image forming apparatus according to any one of the appendices 1 to 4, characterized in that it is the same as described in appendices 1 to 4. (Note 6) An image forming apparatus that performs printing using an electrophotographic method with a developer based on print data included in a print command, A fixing unit for fixing the developer transferred to the printing medium onto the printing medium, Display unit and Memory unit and, A control unit that controls the fixing unit, the display unit and the storage unit, Equipped with, The control unit calculates, based on the print command, the print quantity, which is the area of ​​the printing surface of the printing medium to be printed, and the print amount, which is the ratio of the area on which an image is formed using the developer to the area of ​​the printing surface. The control unit accumulates the lifespan value of the fuser unit, calculated based on the print quantity and the print amount, in the storage unit. When the lifespan value accumulated in the storage unit reaches a predetermined threshold, the control unit displays information indicating that the fuser unit has reached the end of its lifespan on the display unit. An image forming apparatus characterized by the following features. [Explanation of symbols]

[0126] 10 Image forming unit, 40 Paper feeding unit, 100 Printer (image forming apparatus), 103 LED head, 104 Developing unit, 105 Transfer unit, 106 Fixing unit, 203 Resist unit, 204 Photosensitive drum (image carrier), 209 Discharge roller, 226 Charging unit, 300 Control unit, 303 Storage unit, 501 Static elimination unit, 502 Transport unit 502, 801 Display unit

Claims

1. An image forming apparatus that performs printing using an electrophotographic method with a developer based on print data included in a print command, A fixing unit for fixing the developer transferred to the printing medium onto the printing medium, Display unit and Memory unit and, The fixing unit and the control unit that controls the display unit, Equipped with, The control unit, Based on the print command, the print point is calculated, which is a value based on the area of ​​the printed surface of the printing medium to be printed. The printing duty cycle, which is the ratio of the area on which an image is formed using the developer to the area of ​​the printed surface, is detected. The duty point, which is a value corresponding to the aforementioned printing duty cycle, is calculated. The duty point is a first value corresponding to a first print duty or a second value corresponding to a second print duty that is greater than the first print duty. The second value is smaller than the first value. The life value calculated based on the print point and the duty point is stored in the storage unit so that it can be calculated each time printing based on the print command is performed. When the sum of the duty cycle points and print points accumulated in the storage unit reaches a predetermined threshold value, the control unit displays information on the display unit indicating that the fuser unit has reached the end of its lifespan. An image forming apparatus characterized by the following features.

2. The duty point is set to a plurality of values, including the first value and the second value. Each value is set to a smaller value as the print duty cycle increases. The image forming apparatus according to feature 1.

3. Image carrier and, A developing unit that supplies the developer to the image carrier and Furthermore, The control unit controls the image carrier or the developing unit to discard the developer from the image carrier or the developing unit according to the duty cycle. The image forming apparatus according to claim 1 or 2.

4. The image forming apparatus according to claim 1 or 2, characterized in that, if the print duty detected each time printing based on the print command increases, the control unit updates the duty points accumulated in the storage unit to a value corresponding to the increased print duty.

5. Image carrier and, A developing unit that supplies the developer to the image carrier and Furthermore, When printing based on the print command is completed, the control unit discards the developer from the image carrier or the developing unit according to the value obtained by multiplying the updated value by the print point. The image forming apparatus according to claim 1 or 2.

6. An image forming apparatus that performs printing using an electrophotographic method with a developer based on print data included in a print command, A fixing unit for fixing the developer transferred to the printing medium onto the printing medium, Display unit and Memory unit and, A control unit that controls the fixing unit, the display unit and the storage unit, Equipped with, The control unit calculates, based on the print command, the print quantity, which is the area of ​​the printing surface of the printing medium to be printed, and the print amount, which is the ratio of the area on which an image is formed using the developer to the area of ​​the printing surface. The control unit accumulates the lifespan value of the fuser unit, calculated based on the print quantity and the print amount, in the storage unit. When the lifespan value accumulated in the storage unit reaches a predetermined threshold, the control unit displays information indicating that the fuser unit has reached the end of its lifespan on the display unit. An image forming apparatus characterized by the following features.

Images