Image forming apparatus

Abstract

This will allow for a warning to be issued regarding the potential shortened lifespan of fans installed in image forming machines. [Solution] The image forming apparatus of the present disclosure comprises an image forming unit, a fixing unit, a fan for cooling the inside of the apparatus, a control unit for controlling the image forming operation, and a display unit. In an operating mode in which the operation of the fan is stopped after the transition time has elapsed, the control unit determines whether the operation of the fan will shorten its lifespan based on a comparison of the expected consumption time of the fan and the cumulative consumption time of the fan when setting the transition time. The display unit, on the transition time setting screen, displays the transition times that shorten the lifespan of the fan as not recommended among a plurality of configurable transition times.

Description

Technical Field

[0001] The present disclosure can be applied to, for example, electrophotographic image forming apparatuses such as copiers and printers.

Background Art

[0002] Conventionally, an image forming apparatus includes a fan as a cooling device that exhausts heat generated by a fixing unit to the outside of the apparatus.

[0003] Patent Document 1 describes drive control of a fan, and discloses that after the power of the image forming apparatus is turned off, the control unit variably controls the driving time of the fan according to the temperature of the fixing unit detected by a temperature detection unit such as a thermistor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the life of an image forming apparatus is defined as a predetermined period (for example, a 7-year guarantee) based on the start date of use or the purchase date. However, the cumulative fan rotation time during which a fan defined as the life of the fan can maintain a predetermined capacity is shorter than the life of the image forming apparatus. If a user inadvertently selects a setting in which the rotation of the fan is maintained, a deterioration in the function of the fan may occur during the guarantee period of the image forming apparatus, which may also affect the performance of the image forming apparatus.

[0006] Therefore, in light of the above-mentioned issues, we provide an image forming apparatus that can recommend extending the fan life by displaying an explanatory screen that informs the user of the risk of shortened fan life when setting the transition time for the operating mode that stops the operating fan after the transition time has elapsed, or by guiding the user to change the operating mode setting on the menu setting screen to warn them. [Means for solving the problem]

[0007] To solve the above-mentioned problems, the image forming apparatus of the present disclosure comprises (1) an image forming unit that forms an image on a medium using a developer, (2) a fixing unit that heats and fixes the image formed on the medium using the developer, (3) a fan that cools the inside of the apparatus, (4) a control unit that controls the image forming operation, and (5) a display unit, (6) the control unit, in an operation mode in which the operation of the fan is stopped after the transition time has elapsed, determines whether the operation status of the fan will shorten its lifespan based on the result of comparing the expected consumption time of the fan with the cumulative consumption time of the fan when setting the transition time, and (7) the display unit, on the transition time setting screen, displays the transition time that shortens the lifespan of the fan as a discouraged display among the multiple settable transition times. [Effects of the Invention]

[0008] According to this disclosure, when setting the transition time for the operating mode that stops the operating fan after the transition time has elapsed, it is possible to recommend that the user be informed of the risk of a shortened fan lifespan, or that the user be guided to change the operating mode settings in the menu settings screen to warn them, thereby extending the fan lifespan. [Brief explanation of the drawing]

[0009] [Figure 1] This is a flowchart showing the fan operation management process according to the embodiment. [Figure 2] In this embodiment, the figure shows an estimated value based on the reliability when the fan life is considered to be the life of the bearing. [Figure 3] This is an internal configuration diagram showing the internal configuration of an image forming apparatus according to an embodiment. [Figure 4] This is a block diagram showing the configuration of the control system of the image forming apparatus according to the embodiment. [Figure 5] This flowchart shows the recommended processing for power-saving transition time according to the embodiment. [Figure 6] In this embodiment, the diagram shows the relationship between the number of printable pages, which is the lifespan of the image forming apparatus, and the operating time of the fan. [Figure 7] This is a configuration diagram showing the configuration of the deprecation decision table according to the embodiment. [Figure 8] This embodiment shows a screen diagram illustrating a menu setting screen where the power save transition time can be set. [Figure 9] This is a screen diagram showing the configuration of a warning screen according to the embodiment. [Figure 10] This is a diagram showing a menu setting screen in a modified embodiment where the power saving transition time can be set. [Modes for carrying out the invention]

[0010] (A) Explanation of basic concepts First, we will explain the basic technical concept of the image forming apparatus related to this disclosure.

[0011] In this embodiment, the case in which the image forming apparatus according to the present disclosure is an electrophotographic printer will be used as an example for explanation. The image forming process (or image forming operation) is a concept that includes printing.

[0012] As explained below, in an image forming apparatus, the fan that cools the inside of the enclosure by exhaust operates differently depending on the operating mode set in the image forming apparatus, but the lifespan of the fan is shorter than the lifespan of the image forming apparatus.

[0013] Even if the performance guarantee of the image forming apparatus can be extended, it is generally difficult to perform maintenance and replacement only for the fan. Therefore, if the fan reaches its lifespan, the image forming apparatus may not last until the end of its device lifespan. Thus, it is required to alert the user about how to set the operation mode of the image forming apparatus.

[0014] Therefore, when an operation mode in which the fan operates for a long time is set, a screen can be displayed to warn the user about the risk of shortened fan lifespan. Also, the user can be guided to change the operation mode setting on the menu setting screen. In this way, the user can be alerted to extend the fan lifespan.

[0015] (A-1) Operation Mode of Printer For example, the image forming apparatus forms an image by printing an image with a developer on a sheet of paper as a medium. Assume that the image forming apparatus transitions in the order of print mode, standby mode, power save mode, and energy saving mode as the operation modes during normal printing. Note that the operation modes are not limited to those described above, and a sleep mode etc. can also be considered, but here the sleep mode is regarded as an example of the energy saving mode.

[0016] Here, the transition operation of the operation modes during normal printing will be briefly described.

[0017] [Print Mode] For example, after power-on, the image forming apparatus transitions to the print mode and starts a warm-up operation. After a predetermined time has elapsed, the warm-up operation ends, and the image forming apparatus becomes capable of performing a printing operation. In the print mode, assume that the fixing unit is on and the fan is also on.

[0018] [Transition to Standby Mode] When a predetermined standby transition time has elapsed in the print mode, the image forming apparatus transitions to the standby mode. Even in the standby mode, assume that the fixing unit is on and the fan is also on.

[0019] [Switching to Power Save Mode] After a predetermined power-saving transition time has elapsed since entering standby mode, the image forming apparatus will switch to power-saving mode. In power-saving mode, the fixing unit and the fan will be turned off.

[0020] [Switching to power saving mode] After a predetermined time has elapsed since switching to power-saving mode, the image forming apparatus switches to power-saving mode. In power-saving mode, the fixing unit and the fan are assumed to be off.

[0021] Here, the power-saving transition time refers to the time from the end of printing until the fuser unit heater is controlled to lower the temperature and the printer switches to power-saving mode. The power-saving transition time can be set to various values, such as 1 minute, 2 minutes, 3 minutes, 30 minutes, or 1 hour.

[0022] For example, when image forming machines are shipped from the factory, the power-saving transition time is generally set to a minimum value (e.g., 1 minute) from a power-saving perspective. Furthermore, by minimizing the power-saving transition time, the operating time of the cooling system's fans is also shortened, extending the fans' lifespan.

[0023] On the other hand, some users may set a longer power-saving transition time so that they can print at any time.

[0024] For example, if you want to eliminate waiting time and get printed documents quickly, you can set your printer to stay in standby mode at all times and not switch to power-saving mode. However, if used in this way, the fan will also be running and will wear out.

[0025] (A-2) Printer lifespan and fan lifespan "Lifespan" refers to the period from when a product is shipped to the market until it can no longer perform its expected functions.

[0026] The lifespan of a printer is generally defined by factors such as the number of pages printed, the number of pages printed using standard paper sizes (e.g., the length of A4 paper in the direction of paper transport), and the number of years elapsed since the start of use (or purchase date). For example, some printers are guaranteed to print 600,000 pages or have a 7-year lifespan from the date of manufacture.

[0027] On the other hand, it's not common for fans to be able to operate continuously for the same 7 years as a printer's lifespan. The lifespan of a fan is related to the grease (lubricant) used on the fan's shaft, but generally, the operating time of a fan is specified according to the ambient temperature.

[0028] A common example is the L10 lifespan, which has a reliability of 90% and is defined as 41,000 hours (4.68 years) at 50°C. This means that if the fan is operated for 41,000 hours at an ambient temperature of 50°C, there is a 10% probability that a 30% reduction in fan speed will occur.

[0029] As mentioned above, assuming a fan failure rate of 10%, as in the L10 lifespan, results in low reliability. Therefore, let's consider a case where we can increase the reliability further and reduce the failure rate to 4%.

[0030] Figure 2 shows the estimated value based on the reliability when the fan lifespan is considered to be the same as the bearing lifespan. To keep the failure probability at 4%, the fan lifespan is calculated by multiplying the L10 lifespan by the coefficient α1 = 0.55.

[0031] Therefore, if the failure rate is 4%, the fan's lifespan can be calculated as 41,000 hours × 0.55 = 22,550 hours (equivalent to 2.57 years).

[0032] If the ambient temperature around the fan is 50°C, the fan will reach the end of its lifespan at about half the lifespan of the printer. However, observing the actual operation of the printer reveals that the ambient temperature around the fan differs between printing and standby modes. Therefore, we will consider the fan's lifespan separately for ambient temperatures that correspond to the actual operation of the printer.

[0033] When converting from an L10 lifetime to a temperature Tx lifetime, the lifetime is calculated using the Arrhenius law formula. The Arrhenius law formula is defined as follows: Lx = Lo × 2^{(To-Tx) / 10} …(1) Lx: Lifetime at temperature Tx [h] Lo: Lifetime of L10 [h] Temperature at To:L10 [°C] Tx: Temperature during use Tx [°C]

[0034] The actual operation of the printer will be explained using the following two examples. The first example shows printing one page at a 1-minute interval, and the second example shows printing at a 4-minute interval.

[0035] <Printing conditions> Assuming a 7-year office environment prints 600,000 pages (600,000 sheets), and printing only on weekdays, the weekday printing time and weekday standby time can be divided as follows. Weekends are considered 24-hour standby. In this example, the number of pages printed per day is 600,000 / 7 years / 52 weeks / 5 days = 330 pages.

[0036] We assume the ambient temperature during printing is 41°C and the ambient temperature during standby is 32°C.

[0037] [Example 1: When printing at a rate of 1 page per minute] First, given the printing conditions described above, we determine the daily printing time (weekdays) and standby time (weekdays) based on the number of pages printed per day. In other words, we determine the consumption time during the fan's lifespan.

[0038] The printing time (on weekdays) is 5.5 hours, assuming 1 page per minute to print 330 pages. The waiting time (on weekdays) is (24 hours - 5.5 hours) = 18.5 hours.

[0039] Next, using equation (2), which is a modified version of equation (1), we calculate the consumption time during the fan's lifespan, converted to a 50°C temperature. Lo = Lx / 2^{(To-Tx) × 10} …(2) <Time consumed during printing> Lo = 5.5 / 2^((50 - 41) / 10) = 2.95 hours...(21) <Consumption time during weekdays standby> Lo = 18.5 / 2^((50 - 32) / 10) = 5.312 hours...(22) <Consumption time during holidays standby> Lo = 24 / 2^((50 - 32) / 10) = 6.892... hours...(23) <Consumption time per weekday> Consumption time during printing (21) + Consumption time during standby (22) = 2.95 + 5.31 = 8.26 hours...(24)

[0040] Next, using equations (21) to (24), calculate the consumption time in the fan life when the fan operates for 7 years under the above printing conditions.

[0041] <Consumption time during printing (for 7 years)> Consumption time per weekday × 7 years × 52 weeks × 5 days = 8.26 × 7 × 52 × 5 = 15033 hours...(25) <Consumption time during holidays standby (for 7 years)> Consumption time during holidays standby × 7 years × 52 weeks × 2 days = 6.892 × 7 × 52 × 2 = 5017 hours...(26) <Total consumption time for 7 years> Total consumption time for 7 years = Consumption time during printing (for 7 years) + Consumption time during holidays standby (for 7 years) = 20050 hours...(27)

[0042] Then, since the total consumption time for 7 years is "20050 hours", when the failure probability is 4%, it is less than the fan life of "22550 hours" ("20050 < L4m (= 22550 hours)"), so it is okay with a reliability of 96%. That is, since the printing time < fan life, it can be ensured with a reliability of 96%.

[0043] [Second example: When printing 1 page in 4 minutes] Similar to the above, calculate the printing time (on weekdays) and standby time (on weekdays) per day from the number of printed pages per day.

[0044] The printing time (weekdays) is 22 hours, assuming 330 pages are printed at a rate of 1 page per 4 minutes. The waiting time (weekdays) is (24 hours - 22 hours) = 2 hours.

[0045] The fan lifespan in this case can be calculated by converting it to a 50°C equivalent.

[0046] Lo = Lx / 2^{(To-Tx) × 10} …(2) <Time consumed during printing> Lo = 22 / 2^((50-41) / 10) = 11.79 hours …(31) <Time spent on standby during weekdays> Lo = 2 / 2^((50-32) / 10) = 0.57 hours …(32) <Time spent on standby during holidays> Lo = 24 / 2^((50-32) / 10) = 6.892... hours ... (33) <Average daily consumption time on a weekday> Time consumed during printing (31) + Time consumed while waiting (32) = 11.79 + 0.57 = 12.36 hours …(34)

[0047] Next, using equations (21) to (24), we determine the time consumed during the fan's lifespan when the fan is operated for 7 years under the above printing conditions.

[0048] <Print consumption time (7 years)> Weekday daily consumption time × 7 years × 52 weeks × 5 days = 12.36 × 7 × 52 × 5 = 22,495 hours …(35) <Time spent on standby during holidays (7 years)> Time spent on standby during holidays × 7 years × 52 weeks × 2 days = 6.892 × 7 × 52 × 2 = 5017 hours …(36) <Total consumption time over 7 years> Total time spent over 7 years = Time spent printing (7 years) + Time spent on standby during holidays (7 years) = 27,512 hours ... (37)

[0049] In that case, the total usage time over 7 years is "27,512 hours," which is greater than the fan lifespan of "22,550 hours" if the failure probability is 4% ("27,512 hours > L4m (=22,550 hours)"), so a reliability of 96% cannot be ensured.

[0050] (A-3) Power save transition time and fan life The first example shows concentrated printing throughout the day, while the second example shows spread printing. Comparing these, the fan wear in the first example is shorter than the 22,550-hour lifespan with a 96% reliability rating, which is as expected. However, the second example lasts longer, indicating that the fan wears out unexpectedly.

[0051] In the first example, printing is concentrated, resulting in shorter printing times and shorter exposure times for the fan to high temperatures. On the other hand, in the second example, printing is dispersed, resulting in longer printing times and longer exposure times for the fan to high temperatures.

[0052] As in this second example, if you disable the printer's power-saving transition time (i.e., either not set a power-saving transition time or set it to a long time) and change it to a constant standby state, the fan will wear out faster, and the percentage of printers that don't reach the end of their lifespan will increase.

[0053] To reiterate, the printer normally enters factory-default power-saving mode, and the fan stops. Therefore, even if you print for one minute at four-minute intervals, the fan will remain off for the remaining three minutes, so it will not exceed the fan's lifespan.

[0054] The problem is that users have no way of knowing the relationship between print time and fan life, so they could set a longer power-saving transition time to shorten print time without realizing the drawback of a shorter fan life.

[0055] Therefore, in this embodiment, the user is notified that extending the power-saving transition time will reduce the fan's lifespan to the end of the device's lifespan, and the setting is only enabled if the user is okay with this.

[0056] (B-1) Configuration of the embodiment Figure 3 is an internal configuration diagram showing the internal configuration of an image forming apparatus according to an embodiment.

[0057] In Figure 3, the image forming apparatus 100 according to the embodiment includes a paper feed cassette 102, a hopping roller 103, registration rollers 104 and 105, a transfer roller 114, an image forming unit (hereinafter also referred to as the "ID unit") 111, a fixing unit 116, discharge rollers 119 and 120, a fan 126, a temperature detection unit 127, and an operation display unit 128.

[0058] The image forming apparatus 100 according to this embodiment is an electrophotographic monochrome printer. The image forming apparatus 100 can receive print data via an interface (not shown, such as USB or a local area network (LAN)) and starts printing when print data is received.

[0059] The image forming apparatus 100 may be a color printer or a multifunction device. In any case, any image forming apparatus equipped with a fan 126 as a cooling device to cool the temperature inside the casing can be broadly applied.

[0060] The printing medium 101 is an image-forming medium such as paper, cloth, synthetic resin tape, label, or sticker. Here, we will explain assuming that the printing medium 101 is paper.

[0061] The paper feed cassette 102 contains the printing medium 101. The hopping roller 103 feeds the printing medium 101 contained in the paper feed cassette 102 onto the paper transport path.

[0062] Here, the paper transport path, which serves as the media transport path, is the roughly S-shaped section shown by the dashed line in Figure 3, extending from the paper feed cassette 102 outwards from the device. Although not shown in Figure 3, transport rollers and the like are provided along the paper transport path to transport the printing medium 101.

[0063] The registration rollers 104 and 105 correct the skew of the printing medium 101 fed out by the hopping roller 103 and feed the printing medium 101 to the transfer roller 114 at a predetermined timing.

[0064] The ID unit 111 is positioned opposite the transfer roller 114 and is an image forming unit that forms an image on the first surface (e.g., the top surface) of the conveyed printing medium 101. The ID unit 111 is an electronic LED printing mechanism that performs printing using the K (black) color.

[0065] The ID unit 111 includes a toner cartridge 122, a charging roller 123, a developing roller 124, a toner supply roller 125, an LED head 112, and a photosensitive drum 106.

[0066] The toner cartridge 122 is a developer storage container that holds a K (block) color developer (e.g., toner), and is detachable from the ID unit 111.

[0067] The charging roller 123 charges the surface of the photosensitive drum 106 when a negative high voltage is applied to it.

[0068] The LED head 112 exposes the surface of the photosensitive drum 106, which has been charged by the charging roller 123. This allows an electrostatic latent image to be generated at the exposed location on the surface of the photosensitive drum 106.

[0069] When a negative high voltage is applied, the toner supply roller 125 moves the toner from the toner cartridge 122 to the developing roller 124. This allows the toner from the toner cartridge 122 to be supplied to the developing roller 124.

[0070] The developing roller 124 moves toner onto the electrostatic latent image formed on the surface of the photosensitive drum 106 when a negative high voltage is applied. This allows the toner image to be developed by adhering the toner to the electrostatic latent image.

[0071] The photosensitive drum 106 has its surface charged by the charging roller 123, and an electrostatic latent image is formed on its surface by exposure from the LED head 112. Furthermore, the photosensitive drum 106 develops a toner image by having toner adhere to the electrostatic latent image on its surface from the developing roller 124.

[0072] The ID unit 111, together with the transfer roller 114, moves the toner image generated on the surface of the photosensitive drum 106 onto the first surface of the transported printing medium 101. This allows the toner image to be transferred onto the first surface of the printing medium 101.

[0073] The fixing unit 116 is a fixing means that heats the first surface of the printing medium 101 to fuse the toner of the toner image and fix the toner onto the first surface of the printing medium 101. The fixing unit 116 includes a fixing roller 117 with a halogen heater and a backup roller 118, and the fixing roller 117 is heated to a fixing temperature by the power supplied to the halogen heater.

[0074] The discharge rollers 119 and 120 discharge the printing medium 101, on which the toner has been fixed, to the outside of the device.

[0075] Fan 126 is an example of a cooling device that cools the temperature inside the image forming apparatus 100. Fan 126 exhausts the heat generated by the fuser unit 116 to the outside of the apparatus. For example, when paper containing moisture passes through the fuser unit 116, steam is generated inside the apparatus, and heat is radiated and transferred inside the apparatus, but the fan 126 exhausts the heat, allowing it to be released from inside the apparatus.

[0076] In this embodiment, for the sake of simplicity, we will illustrate a case where one fan 126 is provided in the device, but two or more fans 126 may be provided, for example, as in a color printer.

[0077] The temperature detection unit 127 is a temperature sensor such as a thermistor. The temperature detection unit 127 is positioned, for example, near the axis of the fan 126 and measures the ambient temperature of the fan 126. In this embodiment, the case where the temperature detection unit 127 is a thermistor is illustrated, but it is not limited to this.

[0078] The operation display unit 128 is a liquid crystal display that displays the equipment status, setting information, or warnings of the image forming apparatus 100. The operation display unit 128 can also accept user input. For example, the operation display unit 128 can display a menu setting screen and allow the user to input settings. The operation display unit 128 may be a component in which the operation unit and display unit are physically integrated, such as a touch panel display, or the operation unit and display unit may be separate components.

[0079] Figure 4 is a block diagram showing the configuration of the control system of the image forming apparatus 100 according to this embodiment.

[0080] The printer control unit 201 controls the operation of the image forming apparatus 100. The printer control unit 201 can be implemented using circuit devices such as a CPU, RAM, ROM, or EEPROM. Alternatively, it may be implemented by installing a processing program related to image formation, in which case the processing program causes the computer to function as various processing units of the printer control unit 201.

[0081] The printer control unit 201 is connected to the paper feed motor 202, ID motor 203, LED head 112, high-voltage circuit unit 205, fuser motor 206, toner sensor 210, fuser control unit 204, fan 126, operation display unit 128, and temperature detection unit 127.

[0082] The paper feed motor 202 is a drive unit for feeding and transporting the printing medium 101, and can be a stepping motor, for example. The paper feed motor 202 rotates the hopping roller 103, registration rollers 104 and 105 in response to instructions from the printer control unit 201.

[0083] The ID motor 203 rotates the ID unit 111 and the transfer roller 114, and can be a brushless DC motor, for example.

[0084] The LED head 112 exposes the surface of the charged photosensitive drum 106.

[0085] The fixing motor 206 rotates the fixing roller 117, the discharge rollers 119 and 120, and can be a brushless DC motor, for example.

[0086] The fixing control unit 204 controls the operation of the fixing unit 116. The fixing control unit 204 controls the heating of the halogen heater of the fixing unit 116.

[0087] The high-voltage circuit section 205 is a circuit that generates a high voltage to perform charging, developing, and transfer operations on the ID unit 111.

[0088] The fan 126 is operated under the control of the printer control unit 201. When the image forming apparatus 100 is in print mode or standby mode, it rotates to exhaust air from inside the enclosure, and stops in power save mode or energy saving mode.

[0089] The temperature detection unit 127 is a thermistor or the like, and it provides the detected temperature data to the printer control unit 201.

[0090] The operation display unit 128, under the control of the printer control unit 201, displays various screens, including user-configurable display screens (for example, screens including a menu setting screen). The operation display unit 128 accepts settings for the menu setting screen.

[0091] (B-2) Operation of the embodiment (B-2-1) Fan operation management process Figure 1 is a flowchart showing the fan operation management process according to an embodiment.

[0092] Next, the fan operation management process for managing the operation of the fan 126 in the image forming apparatus 100 according to this embodiment will be described in detail with reference to Figure 1.

[0093] Here, the operating modes of the image forming apparatus 100 are assumed to transition in the following order during normal printing: "print mode," "standby mode," "power save mode," and "power saving mode." The method of transitioning between operating modes is basically the same as described above, so a detailed explanation is omitted here.

[0094] In standby mode, the device switches to power-saving mode after a predetermined power-saving transition time has elapsed. The power-saving transition time refers to the time from the end of printing until the heater control of the fuser unit 116 is performed to lower the temperature and the device switches to power-saving mode. The user can set or change the power-saving transition time, for example, 1 minute, 2 minutes, 3 minutes, 30 minutes, or 1 hour, on the menu setting screen displayed on the operation display unit 128.

[0095] The lifespan of the image forming apparatus 100 shall be, for example, seven years from the date of manufacture, with a guaranteed print run of 600,000 pages.

[0096] The fan's lifespan is considered to be the lifespan of the bearing, and to ensure high reliability, a failure probability of 4% is assumed, resulting in "22,550 hours (= 41,000 hours × 0.55 = 22,550 hours (equivalent to 2.57 years))."

[0097] [Steps S101, S102, S103] The image forming apparatus 100 is in a state of waiting to print a print command (print instruction) from a connected host device (step S101).

[0098] If no print instruction is received (step S102 / NO), the process returns to step S101 and maintains a print-waiting state. On the other hand, if a print instruction is received from a higher-level device (step S102 / YES), the process moves to step S103, and the image forming apparatus 100 starts printing (step S103).

[0099] [Step S104] In the image forming apparatus 100, the printer control unit 201 acquires the cumulative number of printed pages x and the actual printing time Lx during printing, as well as the ambient temperature Tx detected by the temperature detection unit 127 (step S104).

[0100] Here, "cumulative number of printed pages x" is the total number of printed pages sequentially produced by the image forming apparatus 100. For example, the printer control unit 201 updates and stores the cumulative number of printed pages x of the image forming apparatus 100 each time it prints. The printer control unit 201 reads and retrieves the stored cumulative number of printed pages x.

[0101] Furthermore, "print time Lx" is the actual printing time taken during printing. For example, the printer control unit 201 stores the printing time Lx taken during the printing operation after starting the printing operation and retrieves that printing time Lx.

[0102] Furthermore, "ambient temperature Tx" is the temperature detected by the temperature detection unit 127 during printing. For example, the printer control unit 201 uses the temperature detected by the temperature detection unit 127.

[0103] [Step S105] The printer control unit 201 uses the cumulative number of printed pages x to derive the expected operating time of the fan 126 at 50°C (step S105).

[0104] For example, the printer control unit 201 derives the estimated fan consumption time using the following equation (3).

[0105] Estimated fan usage time (A) = (Fan lifespan / Number of prints) × Total number of prints = (22,550 hours / 600,000 pages) × total number of pages printed … (3) "Estimated fan usage time" refers to the estimated fan usage time for the cumulative number of printed pages in this case, based on the relationship between the fan life (considered to be the bearing life) and the printing life of the image forming apparatus 100.

[0106] In this example, the fan life is assumed to be "22,550 hours" with a reliability of 96% (failure probability of 4%) and converted to 50°C. The print life of the image forming apparatus 100 is assumed to be "600,000 sheets". Equation (3) is calculated by multiplying the operating time of fan 126 per sheet by the cumulative number of printed sheets x when printing 600,000 sheets. This derives the expected fan consumption time (A) assumed to be converted to 50°C for the cumulative number of printed sheets.

[0107] [Step S106] The printer control unit 201 derives the cumulative fan consumption time (C) using the actual printing time Lx and the ambient temperature Tx during printing (step S106).

[0108] For example, the printer control unit 201 uses equation (4) to derive the cumulative fan consumption time. Fan cumulative consumption time (C)=Lo=Lx / 2^{(To-Tx)×10}=Lx / 2^{50℃-Tx℃) / 10}…(4)

[0109] Equation (4) is a modified version of the Arrhenius law formula, and the cumulative fan consumption time corresponds to the consumption time relative to the fan's lifespan.

[0110] [Steps S107, S108] The printer control unit 201 compares the estimated fan consumption time (A) with the cumulative fan consumption time (C) (step S107) and stores the comparison result (step S108).

[0111] For example, the printer control unit 201 subtracts the cumulative fan consumption time (C) from the estimated fan consumption time (A) and stores the difference ("estimated fan consumption time (A) - cumulative fan consumption time (C)").

[0112] In this way, the printer control unit 201 can derive the difference obtained by subtracting the cumulative fan consumption time (C) from the estimated fan consumption time (A).

[0113] The difference between the estimated fan usage time (A) and the cumulative fan usage time (C) is calculated each time printing is performed and stored sequentially.

[0114] The storage method should ensure that the most up-to-date information is always stored. For example, the latest information could be updated and older information erased each time it is printed, or, for example, the latest information could be retained along with a history of past information. In any case, the storage should be such that the most up-to-date information can be retrieved.

[0115] To clarify the point in time at which the comparison results are being made, the difference between the estimated fan consumption time (A) and the cumulative fan consumption time (C) may be associated with and stored information such as the date and time of printing. In addition to the date and time of printing, parameters used to derive the difference, such as the cumulative number of pages printed x, printing time Lx, and ambient temperature Tx at the time of printing, may also be associated with and stored.

[0116] (B-1-2) Recommended processing during power save transition time Figure 5 is a flowchart showing the recommended processing for power-saving transition time according to the embodiment.

[0117] When the image forming apparatus 100 is shipped from the factory, the power-saving transition time is generally set to the minimum value (for example, 1 minute) from the perspective of saving power. However, if you want to print faster without waiting, you can set the power-saving transition time to be longer so that the machine does not switch to power-saving mode.

[0118] This section provides examples of how, when a user operates the operation display unit 128 to access the menu settings screen and change the power save transition time setting, the system may recommend an appropriate power save transition time to extend the lifespan of the fan 126, or it may not recommend a power save transition time that could shorten the lifespan of the fan 126.

[0119] [Step S201] To change the power save transition time setting, the user gives a menu setting instruction on the operation display unit 128 (step S201). This allows the user to request the display of a menu setting screen where the power save transition time can be set.

[0120] [Step S202] The printer control unit 201 reads and obtains the latest comparison result between the estimated fan consumption time (A) and the cumulative fan consumption time (C) (step S202).

[0121] [Step S203] The printer control unit 201 uses the difference between the estimated fan usage time (A) and the cumulative fan usage time (C) to determine the current operating time of the fan 126 (step S203).

[0122] Various methods can be applied to determine the current operating time of fan 126 using the difference between the estimated fan usage time (A) and the cumulative fan usage time (C). One example is given below.

[0123] Figure 6 is a diagram showing the relationship between the number of printable pages, which is the lifespan of the image forming apparatus 100, and the operating time of the fan 126 in an embodiment. The horizontal axis represents the number of printable pages, which is the lifespan of the image forming apparatus 100, and the vertical axis represents the operating time of the fan 126 (converted to 50°C).

[0124] In Figure 6, the assumed fan consumption time (A) is shown by a solid line. Here, the assumed fan consumption time (A) can be said to be the time during which fan 126 is operating under the assumed high reliability conditions.

[0125] In contrast, when the cumulative fan consumption time (C) is greater than the expected fan consumption time (A), it can be concluded that the currently operating fan 126 is consuming a lot of power. In other words, because the power-saving transition time from standby mode to power-saving mode is long, the fan 126 is running continuously during that time, and therefore its lifespan will likely be shortened.

[0126] Conversely, when the cumulative fan usage time (C) is less than the expected fan usage time (A), it can be concluded that fan 126 is not being used for long periods. In other words, the power save transition time is set to be short, and fan 126 is not running for a long time, so it can be concluded that fan 126 will have a longer lifespan.

[0127] For example, in Figure 6, the cumulative fan usage time (C1) is greater than the estimated fan usage time (A), and the cumulative fan usage time (C2) is less than the estimated fan usage time (A).

[0128] In this example, the difference between the estimated fan usage time (A) and the cumulative fan usage time (C1) is a negative value, while the difference between the estimated fan lifespan (A) and the cumulative fan usage time (C2) is a positive value. Therefore, based on the difference between the estimated fan usage time (A) and the cumulative fan usage time (C), the current usage time relative to the lifespan of fan 126 can be determined.

[0129] [Step S204] Next, if the cumulative fan usage time (C) is greater than the expected fan usage time (A), the printer control unit 201 determines a power-saving transition time that is not recommended (step S204).

[0130] There are various methods for determining the recommended power-saving transition time, but one example is given below.

[0131] The power save transition time can be set to any of the following: 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 30 minutes, 1 hour, ...

[0132] In this case, as the difference between the cumulative fan consumption time (C) and the expected fan consumption time (A) increases, a shorter power save transition time is recommended, and other power save transition times are not recommended. Conversely, when the difference between the cumulative fan consumption time (C) and the expected fan consumption time (A) is small, a longer power save transition time, including longer times, is recommended, and other power save transition times are not recommended.

[0133] For example, the printer control unit 201 can derive the fan operating time ratio based on equation (5) and apply a method to determine the unrecommended power-saving transition time corresponding to the fan operating time ratio by referring to the unrecommended decision table 600 illustrated in Figure 7. Fan operating time ratio (D) = |Estimated fan consumption time (A) - Cumulative fan consumption time (C)| / Estimated fan consumption time (A) × 100 …(5)

[0134] Equation (5) is an equation that divides the absolute value of the difference between the estimated fan consumption time (A) and the cumulative fan consumption time (C) by the estimated fan consumption time (A). This is intended to represent the ratio of the difference between the estimated fan consumption time (A) and the cumulative fan consumption time (C) to the estimated fan consumption time (A).

[0135] For example, if the fan operating time ratio (D) is 3%, the printer control unit 201 will determine "Not recommended power save transition time: None" by referring to Figure 7. This is because the difference between the expected fan consumption time (A) and the cumulative fan consumption time (C) is small, and considering the lifespan of the fan 126, all power save transition times are recommended.

[0136] For example, if the fan operating time ratio (D) is 30%, the printer control unit 201 will determine the following "unrecommended power-saving transition times: 2 minutes, 3 minutes, 4 minutes, 5 minutes, 30 minutes, 1 hour, ..." by referring to Figure 7. This is because the difference between the expected fan consumption time (A) and the cumulative fan consumption time (C) is large, resulting in increased fan operation of the fan 126. Therefore, to extend its lifespan, the printer control unit 201 does not recommend power-saving transition times of 2 minutes or more.

[0137] [Step S205] The printer control unit 201 displays the power-saving transition times that are not recommended on the menu setting screen (step S205).

[0138] The operating time of fan 126 was measured, and the user was able to select whether it was more or less than the estimated fan consumption time (A) expected from the number of printed pages, on the menu settings screen.

[0139] If the fan operation exceeds the expected fan usage time (A), a discouragement indicator (e.g., "shaded") will be displayed. If the fan operation is less than expected, the discouragement indicator (e.g., "shaded") will be removed.

[0140] Figure 8 is a screen diagram showing a menu setting screen in an embodiment where the power save transition time can be set.

[0141] As illustrated in Figure 8, the menu setting screen 510 has a power save transition time selection list 511 and a setting button 512. The power save transition time selection list 511 is a list in which the user can select a power save transition time from 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 30 minutes, 1 hour, ... After the user makes a selection, the setting of the power save transition time can be changed by selecting the setting button 512. The asterisk in the figure indicates the currently set time.

[0142] If a non-recommended power-saving transition time is determined in step S204, the printer control unit 201 displays these non-recommended power-saving transition times as unrecommended on the menu setting screen 510.

[0143] A deprecation indicator is a display format that informs users that it is not recommended to set a particular setting. Examples of deprecation indicators include shading, color-coded markers, and color-coded text.

[0144] In this embodiment, "shaded area 513" is used as an example, and Figure 8 shows that "3 minutes, 4 minutes, 5 minutes, 30 minutes, 1 hour, ..." are power-saving transition times that are not recommended.

[0145] The "not recommended" indicator simply informs the user that it is not recommended, and the user can still choose whether or not to use it. Even if the power-saving transition time is shaded, it is still possible to select and set it, but in that case, a warning (warning screen 520) will be displayed, as described later.

[0146] A recommended display is a display format that informs the user that it is recommended to set something. In this embodiment, the portion that is not marked as a "not recommended" is referred to as the recommended display. In this embodiment, the case of applying a "not recommended" display such as "shading" is explained as a particular example, but the same effect can be expected when applying a recommended display.

[0147] [Step S206] On the menu settings screen 510, the user selects and sets the power-saving transition time. The printer control unit 201 determines whether the power-saving transition time selected by the user is recommended or not (step S206).

[0148] If no unrecommended power-saving transition time is selected (step S206 / NO), the process proceeds to S207. If an unrecommended power-saving transition time is selected (step S206 / YES), the process proceeds to S208.

[0149] [Step S207] If no unrecommended power-saving transition time is selected (step S206 / NO), the printer control unit 201 sets the selected power-saving transition time (step S207) and terminates the process.

[0150] For example, in Figure 8, if a power-saving transition time of "1 minute" or "2 minutes" is selected, the setting remains as is because the power-saving transition time is short and will not unnecessarily shorten the lifespan of fan 126.

[0151] [Step S208] If a power-saving transition time that is not recommended is selected (step S206 / YES), the printer control unit 201 displays a warning screen 520 on the operation display unit 128 (step S208).

[0152] Figure 9 is a screen diagram showing the configuration of the warning screen 520 according to the embodiment.

[0153] Warning screen 520 is a screen that informs the user that if an unrecommended power-saving transition time is selected, extending the power-saving transition time may shorten the fan's lifespan to the end of the device's lifespan, and asks whether the user still wants to proceed with the setting.

[0154] In Figure 9, the warning screen 520 includes a warning area 521, a selection list 522, and a setting button 523.

[0155] The warning area 521 informs the user that the fan life may be shortened in your environment. This may result in reduced printing speed, unusual noises, etc. Do you want to proceed with the settings? In other words, it informs the user that the fan life may be shortened. Furthermore, it informs the user that a shortened fan life may affect the performance of the device.

[0156] The selection list 522 is a list of items that the user can select. In the example in Figure 9, if the user selects one of the following items: "Revert after specified time," "Keep settings," or "Cancel," and the setting button 510 is selected, the selected item will be set.

[0157] [Steps S209~S212] On the warning screen 520, the user can select any item from the selection list 522 (step S209), and the printer control unit 201 performs the corresponding processing according to the selected item.

[0158] If the option "Revert to original after a predetermined time" is selected (S209), the process proceeds to S210. The printer control unit 201 monitors the time using a timer until a predetermined time has elapsed (S210 / NO). Once the predetermined time has elapsed (S210 / YES), the printer control unit 201 changes the power-saving transition time back to the previous time (S211) and terminates the process.

[0159] Furthermore, if "Maintain settings" is selected as an option (S209), the printer control unit 201 terminates the process without changing the power save transition time. In this case, the user is aware that the fan life may not last until the end of the device's lifespan, but still chooses to set a long power save transition time.

[0160] Furthermore, if "Cancel" is selected as an option (S209), the printer control unit 201 returns to the previous screen and processes according to the user's operation on the previous screen.

[0161] (B-3) Effects of the Embodiment As described above, according to this embodiment, when setting the transition time for an operating mode in which the image forming apparatus is stopped after the transition time has elapsed, the user can be notified if the usage method is such that the fan life will be shortened, based on a comparison between the expected fan consumption time and the cumulative fan consumption time.

[0162] Furthermore, if a usage pattern shortens the fan's lifespan, a "not recommended" indicator can be displayed on the menu settings screen to alert the user.

[0163] Furthermore, by displaying a warning screen informing users that selecting an item marked as "not recommended" may shorten the fan life and potentially affect the overall functionality of the device, it is possible to further raise awareness among users.

[0164] As mentioned above, if the settings may shorten the fan's lifespan, a warning can be issued.

[0165] In a good office environment, such as 25°C, extending the power-saving transition time and shortening the print start time will not trigger unnecessary warnings.

[0166] (C) Other embodiments Although various modified embodiments were mentioned in the embodiments described above, a modified embodiment of the image forming apparatus according to the present invention will now be described.

[0167] (C-1) Figure 10 is a screen diagram showing a menu setting screen in which the power save transition time can be set according to a modified embodiment.

[0168] In the menu setting screen 510A of Figure 10, the menu setting screen 510 has a power save transition time selection list 511 and a setting button 512, and the power save transition time selection list 511 includes an auto setting 514.

[0169] Auto setting 514 is an item in which the image forming apparatus 100 automatically sets the power save transition time.

[0170] For example, the printer control unit 201 selects and sets the shorter of either a predetermined number of minutes or a surplus time.

[0171] For example, the printer control unit 201 calculates the cumulative rotation time (cumulative consumption time) by applying a correction to the fan rotation time based on temperature measurement while the fan is rotating, and transitions to a new mode when it exceeds the expected consumption time.

[0172] (C-2) In the embodiments described above, the cumulative consumption time of the fan was derived using a 50°C conversion as an example, but it is not limited to a 50°C conversion. The cumulative consumption time may also be derived using the actual ambient temperature.

[0173] (C-3) In the embodiment described above, an example was given in which a discouragement indicator, such as shading, is displayed on the menu settings screen for transition times that are likely to shorten the lifespan of the fan.

[0174] Conversely, a recommended transition time could be displayed for periods that are unlikely to shorten the fan's lifespan. This would allow users to easily select a transition time that is visually recommended.

[0175] (C-4) In the embodiments described above, the method for deriving the expected fan consumption time (A) and cumulative consumption time (C) is an example and is not limited thereto. Other methods may be used to derive them. [Explanation of symbols]

[0176] 100: Image forming apparatus, 101: Printing medium, 102: Paper feed cassette, 103: Hopping roller, 104: Register roller, 106: Photosensitive drum, 111: ID unit, 112: LED head, 114: Transfer roller, 116: Fixing unit, 117: Fixing roller, 118: Backup roller, 119: Ejection roller, 122: Toner cartridge, 123: Charging roller, 124: Developing roller, 125: Toner supply roller, 126: Fan, 127: Temperature detection unit, 128: Operation display unit, 201: Printer control unit, 202: Paper feed motor, 203: ID motor, 204: Fusing control unit, 205: High-voltage circuit unit, 206: Fusing motor, 210: Toner sensor 510 and 510A: Menu settings screen, 511: Power save transition time selection list, 512: Settings button, 513: Deprecated display (e.g., shading), 514: Auto settings, 520: Warning screen, 521: Warning area, 522: Selection list, 523: Settings button, 600: Deprecated decision table

Claims

1. An image forming unit that forms an image on a medium using a developer, A fixing unit that heats and fixes the image formed on the medium using the developer, A fan to cool the inside of the device, A control unit that controls the image formation operation, Display unit and Equipped with, The control unit, In an operating mode in which the operation of the fan is stopped after the transition time has elapsed, when setting the transition time, it is determined whether the operating status of the fan will shorten its lifespan based on a comparison of the expected consumption time of the fan and the cumulative consumption time of the fan. The display unit, in the transition time setting screen, displays transition times that shorten the lifespan of the fan as not recommended among the multiple configurable transition times. An image forming apparatus characterized by the following features.

2. The image forming apparatus according to claim 1, characterized in that if any of the transition times that shorten the lifespan of the fan and are not recommended are selected, the display unit displays a warning screen including a statement that the lifespan of the fan may be shortened.

3. The aforementioned transition time is the time from the end of printing until the system switches to power-saving mode. The fan operates during the transition time and stops operating after the transition time has elapsed. The image forming apparatus according to feature 1.

4. It is equipped with a temperature detection unit that detects the temperature inside the device, The control unit derives the estimated consumption time of the fan based on the cumulative number of printed pages. The control unit derives the current lifespan of the fan based on the printing time during printing and the temperature detected by the temperature detection unit, and derives the cumulative lifespan by adding the current lifespan and past lifespans. The image forming apparatus according to feature 1.

Images