Image forming device

Abstract

To solve the problem in which: in an image forming apparatus provided with two acquisition units acquiring the amount of toner remaining in a developer container provided in the image forming apparatus and displaying the remaining amount of toner acquired by the acquisition units on a display unit, when switching display of acquisition values of the two acquisition units on the display unit, a sudden change in the remaining amount of toner should be prevented.SOLUTION: In an image forming apparatus, a control unit controls a display unit to create a first period in which the amount of toner remaining in a toner storage unit acquired by a first acquisition unit is displayed on the display unit and a second period in which the amount of toner remaining in the toner storage unit acquired by a second acquisition unit is displayed on the display unit. The control unit further controls to create, between the first period and the second period, a third period in which a transition in the remaining amount of toner is made so that the remaining amount of toner is reduced with a first gradient, and a fourth period in which a transition in the remaining amount of toner is made so that the remaining amount of toner is reduced with a second gradient. The absolute value of the second gradient is larger than the absolute value of the first gradient.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a process cartridge that is detachably mountable to an image forming apparatus. The image forming apparatus forms an image on a recording material by electrophotography, and includes a copying machine, a laser beam printer, an LED printer, a facsimile machine, a word processor, and a multifunction machine thereof. [Background technology]

[0002] In electrophotographic image forming apparatuses, a process cartridge system is widely adopted in which a photosensitive drum, a developing means, a toner container, etc. are integrated into a cartridge in order to facilitate easy replacement and maintenance of consumables. The image forming apparatus also has a detection unit that detects the amount of toner remaining in the cartridge and a display unit that displays information regarding the amount of toner remaining. Patent Document 1 discloses a configuration in which, as a detection unit that detects the amount of toner remaining, a pixel remaining amount detection unit that uses a pixel remaining amount counting method for the amount of toner remaining and a capacitance remaining amount detection unit that acquires the amount of toner remaining by capacitance are included. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2018-005039 Summary of the Invention [Problem to be solved by the invention]

[0004] When using both the pixel remaining amount detection unit and the capacitance remaining amount detection unit, there may be a large difference between the detection results when switching from the detection result by the pixel remaining amount detection unit to the detection result by the capacitance remaining amount detection unit. At that time, the amount of toner remaining may change significantly, and this may be displayed on the display unit. If the amount of toner remaining on the display unit changes suddenly, the user may mistakenly recognize this as a malfunction of the image forming device.

[0005] Therefore, the object of the present invention is to suppress sudden changes in the remaining toner amount when switching the display of the acquired values ​​of the two acquisition units on the display unit in an image forming device that is provided with two acquisition units that acquire the remaining toner amount in a cartridge and displays the remaining toner amount acquired by the acquisition units on a display unit. [Means for solving the problem]

[0006] A first aspect of the present invention provides an image forming apparatus comprising a developing unit having a toner storage section that stores toner and a developing roller that carries toner in the toner storage section, and a photosensitive drum to which toner is supplied from the developing roller, and which forms an image on a recording material based on image data, the image forming apparatus comprising: a first acquisition section that acquires an amount of toner consumed by the image formation based on the image data, and acquires an amount of toner remaining in the toner storage section based on the amount of toner consumed; a second acquisition section that acquires the amount of toner remaining based on a correlation value that correlates with an amount of toner stored in the toner storage section; a display section that displays the amount of toner remaining acquired by the first acquisition section and the amount of toner remaining acquired by the second acquisition section; and a control section that controls the display section. the control unit controls the display unit so that there is a first period during which the remaining toner amount acquired by the first acquisition unit is displayed on the display unit before the remaining toner amount corresponding to a first threshold is acquired by the second acquisition unit, and there is a second period during which the remaining toner amount acquired by the second acquisition unit is displayed on the display unit after the remaining toner amount corresponding to the first threshold is acquired by the second acquisition unit, and the control unit further controls the display unit so that, in a case where the remaining toner amount corresponding to the first threshold is not acquired by the first acquisition unit by the time the remaining toner amount corresponding to the first threshold is acquired by the second acquisition unit, The display unit is controlled so that during the second period, there is a third period in which the toner remaining amount is displayed according to a first toner remaining amount trend, in which the toner remaining amount is trended so that the toner remaining amount decreases at a first gradient relative to the usage amount of the developing unit, and a fourth period in which the toner remaining amount is displayed according to a second toner remaining amount trend, in which the toner remaining amount is trended so that the toner remaining amount decreases at a second gradient relative to the usage amount of the developing unit after the toner remaining amount trended according to the first toner remaining amount trend reaches the toner remaining amount corresponding to a second threshold value that is smaller than the first threshold value, and the absolute value of the second gradient is greater than the absolute value of the first gradient. Effect of the Invention

[0007] In an image forming device that is provided with two acquisition units for acquiring the remaining toner amount in a cartridge and displays the remaining toner amount acquired by these acquisition units on a display unit, sudden changes in the remaining toner amount can be suppressed when switching the display of the acquired values ​​from the two acquisition units on the display unit. [Brief description of the drawings]

[0008] [Figure 1] Flowchart diagram according to the third embodiment [Diagram 2] 1 is a schematic cross-sectional view of an image forming apparatus according to a first embodiment of the present invention; [Diagram 3] Schematic cross-sectional view of a developing container according to Example 1. [Figure 4]Toner remaining amount detection circuit diagram according to the first embodiment [Diagram 5] Control block diagram according to the first embodiment [Figure 6] FIG. 13 is a graph showing the transition of remaining toner amount in Comparative Example 1. [Figure 7] FIG. 13 is a diagram showing the transition of the remaining toner amount according to the first embodiment; [Figure 8] FIG. 11 is a graph showing the transition of the remaining toner amount according to Comparative Example 2. [Figure 9] FIG. 13 is a graph showing the transition of the remaining toner amount according to the second embodiment. [Figure 10] 1 is a flowchart showing control of an image forming apparatus and a management server according to a first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Example 1 The image forming apparatus and the process cartridge of this embodiment will be described below with reference to the drawings. The image forming apparatus is, for example, an apparatus that forms an image on a recording medium using an electrophotographic image forming process. Examples of the image forming apparatus include electrophotographic copying machines, electrophotographic printers (e.g., LED printers, laser beam printers, etc.), and electrophotographic facsimile machines. The process cartridge refers to one that is detachable from the main body of the image forming apparatus.

[0010] [Image forming equipment] The overall configuration of one embodiment of the image forming apparatus will be described. Fig. 2 is a schematic diagram of the image forming apparatus 200 in which a process cartridge 222 is attached. In Fig. 2, reference numeral 201 denotes a photosensitive drum which is an image carrier, and 204 denotes a laser scanner which scans (exposes) a laser beam on the photosensitive drum 201 using a semiconductor laser 203.

[0011] Reference numeral 222 denotes a process cartridge having the photosensitive drum 201, the charging roller 202, and a developer carrier 224.

[0012] The charging roller 202 is a charging means for uniformly charging the surface of the photosensitive drum 201. The developer carrier 224 is a developing means for developing an electrostatic latent image formed on the photosensitive drum 201 by supplying toner (developer) to the photosensitive drum 201. The process cartridge 222 further has a developing container 207 and a nonvolatile memory 230. The developing container 207 is a toner storage unit for storing toner, and the nonvolatile memory 230 is a storage means for storing information.

[0013] Reference numeral 208 denotes a transfer roller for transferring the toner image developed on the photosensitive drum 201 to a predetermined recording material 216, 219 denotes a fixing device for fusing the toner transferred to the recording material 216 with heat, and 225 denotes a temperature thermistor for controlling the temperature of the fixing device. Reference numeral 210 denotes a paper feed roller for feeding the recording material. Reference numeral 214 denotes a top sensor for synchronizing with the conveyance of the recording material, 211 denotes a paper discharge roller for discharging the recording material 216 after fixing to a paper discharge tray 217, and 215 denotes a paper discharge sensor for detecting the presence or absence of the recording material 216 after fixing. Reference numeral 212 denotes an engine controller including a CPU 213 (control unit) for controlling the above-mentioned components. Reference numeral 226 denotes an environment sensor for detecting the external environment of the image forming apparatus 200.

[0014] [Detection of remaining toner amount by pixel count] A toner remaining amount detection method (acquisition method) by pixel count according to this embodiment will be described. The CPU 213 of the image forming apparatus 200 is provided with a toner remaining amount detection device 240 as a detection unit A (first detection unit, first acquisition unit) that detects (acquires) the remaining amount (toner remaining amount, acquisition value) of the toner T contained in the developing container 207 of the process cartridge 222. The toner remaining amount detection device 240 is provided with a pixel count measurement unit 241 that measures the pixel count (pixel count value) of an output image formed on the recording material 216 by the image forming operation. The toner remaining amount detection device 240 also includes a toner remaining amount calculation unit 242 that calculates the remaining amount of the toner T in the developing container 207 from the measured pixel count value.

[0015] Based on image data during image formation, pixel count measurement unit 241 counts the total number of pixels (number of image pixels) that laser 203 disposed in scanner unit 204 irradiates on photoconductor drum 201. Image forming apparatus 200 described in this embodiment has a resolution of 600 dpi, and the width of one pixel in the main scanning direction is 42.3 μm. Pixel count measurement unit 241 samples one pixel at a sampling period of 80 MHz.

[0016] In this embodiment, when the pixel count value of the laser irradiated onto the photoconductor drum 201 of one sheet of output recording material S is VCn, the printing rate A for printing on one sheet of recording material will be described. The printing rate when printing on A4 paper with a resolution of 600 dpi can be calculated by the formula (1). Printing rate A [%] = “Printed pixel count value VCn” ÷ “Pixel count value VCn printed at 100% on A4 paper” Formula (1) It becomes.

[0017] Next, in the toner remaining amount calculation unit 242, since the pixel count value VCn and the amount of toner actually consumed vary depending on the lifespan of the drum 201 and the developing container 207 and the printing rate A, a correction coefficient γ for unit toner consumption is set, and the toner consumption correction pixel count VCnt is calculated using the following equation (2). VCnt=VCn×γ...Equation (2)

[0018] Then, as shown in the following equation (3), the toner consumption correction pixel count VCnt is added to the cumulative pixel count value VCr from the start of use of the process cartridge 222, which is stored in the non-volatile memory 230 provided in the process cartridge 222, to calculate the total pixel count value VCt. VCt=VCr+VCnt...Equation (3)

[0019] Next, the remaining toner amount calculation unit 242 calculates the remaining toner amount TP in the developing container 207 from the pixel count threshold value VCth and the total pixel count value VCt stored in the non-volatile memory 230, as shown in the following equation (4). TP[%]=(1-VCt / VCth)×100...Equation (4) Then, the remaining toner amount calculation unit 242 writes the total pixel count value VCt into the non-volatile memory 230 as the accumulated pixel count value VCr.

[0020] Here, when detecting remaining toner amount using the pixel count method, the above-mentioned correction coefficient γ changes depending on the printing rate, so there may be an error between the actual amount of toner consumed and the amount of toner consumption calculated by pixel counting.

[0021] [Toner remaining amount method based on electrostatic capacitance] A toner remaining amount detection method (acquisition method) using electrostatic capacitance according to this embodiment will be described. Fig. 3 shows a schematic cross-sectional view of a developer container 207 capable of detecting the amount of toner remaining by the electrostatic capacitance method using a plate antenna. A control block diagram in Fig. 4, which will be described later, shows a plate antenna 302 (electrode) and a toner remaining amount detection circuit 402 as detection unit B (second detection unit, second acquisition unit).

[0022] The plate antenna 302 is installed in the developing container 207 at a position where the toner T is fluid and the reduction degree of the toner T can be directly detected. The plate antenna 302 may be made of any material as long as it is a plate-like material with good conductivity. However, when the plate antenna 302 is installed in the process cartridge 222, it is preferable that the material does not adversely affect the toner particles and is resistant to environmental conditions such as humidity. The plate antenna is provided with a portion that can be electrically connected from the outside. The electrically connectable portion may be directly connected with a conductor or may be pierced with a conductive pin. The toner remaining amount detection by the developing sleeve 224 (developing roller) and the plate antenna 302 measures (obtains) the toner remaining amount using a developing bias applied to the developing sleeve 224. The voltage value induced in the plate antenna 302 by the developing bias applied to the developing sleeve 224 is obtained. If the dielectric constant differs depending on the amount of toner remaining between the developing sleeve 224 and the plate antenna 302, the voltage value induced in the plate antenna 302 also differs. This voltage value is a correlation value that correlates with the amount of toner in the developing container 207, and the remaining amount of toner is detected (acquired) according to this correlation value. The main body of the image forming apparatus 200 and the process cartridge 222 are provided with electrical contacts (not shown). When the process cartridge 222 is mounted in the main body of the image forming apparatus 200, the plate antenna 302 of the process cartridge 222 is electrically connected to a remaining toner amount detection circuit 402 in the main body of the image forming apparatus 200 shown in FIG. 4 through the electrical contacts.

[0023] In FIG. 4, 401 is a developing bias circuit for applying a developing bias, and is connected to a reference capacitor CL1 that serves as a reference capacitance. This reference capacitor CL1 is connected to a toner remaining amount detection circuit 402, and a current I2 flows through it. This I2 is divided into I3 and I4 by R12. The divided current I4 and R11 determine a reference voltage V4. The developing bias 401 is also connected to the developing sleeve 224, and is electrically connected to the toner remaining amount detection circuit 402 via the plate antenna 302. If the electrostatic capacitance between the developing sleeve 224 and the plate antenna 302 is Ccrg, the current flowing from the plate antenna 302 to the toner remaining amount detection circuit 402 is I1. This current I1 is determined by the frequency f [Hz], amplitude voltage Vpp [V], and electrostatic capacitance Ccrg [pF] of the developing bias 401. The current I1 is connected to the input terminal of the OP amplifier in the control circuit 402, and the output voltage value Vout is expressed by the following formula (5). Vout[V]=V4[V]-(f[Hz]×Vpp[V]×Ccrg[pF]×R10[Ω])...Equation (5)

[0024] The voltage value Vout input to the CPU 213 is AD converted to obtain the remaining toner amount value (AD converted value) = Vout [V] ÷ voltage V12 [V]. The CPU 213 detects (obtains) the remaining toner amount using a conversion formula or table based on the remaining toner amount value. The detected remaining toner amount result is written to the non-volatile memory 230.

[0025] Here, in both the toner remaining amount detection method by pixel count (detection unit A) and the toner remaining amount detection method by electrostatic capacitance (detection unit B), when the toner remaining amount is 100%, it indicates that the toner T in the developing container 207 is full and the process cartridge 222 is new. Also, when the toner remaining amount TP=0%, it indicates that the toner T remaining in the developing container 207 is almost gone and the process cartridge 222 is out of toner.

[0026] [Automatic process cartridge shipping] 5 shows a management server S with which a video controller 251 (communication unit) of the image forming apparatus 200 can communicate via an external network N. Note that a host device 252 can also communicate with the management server S via the external network N.

[0027] The image forming device 200 and the host device 252 are installed in a user environment where a user exists. The image forming device 200 and the host device 252 are connected to a local network (not shown), which may be, for example, a LAN (Local Area Network). The management server S is installed in a remote environment away from the user environment. The remote environment is connected to a local network in the user environment via an external network N. The external network N is, for example, the Internet or a VPN (Virtual Private Network). Each of the local network and the external network N may include any number of network devices of any type, such as, for example, routers, switches, gateways, wireless access points, and base stations.

[0028] In the user environment, the user uses the image forming apparatus 200. As described above, the image forming apparatus 200 consumes toner as a consumable material to form an image on a recording medium. When the toner stored in the process cartridge 222 used in the image forming apparatus 200 runs out, the user needs to replace the process cartridge 222 with the depleted toner with a new process cartridge 222. If there is no spare process cartridge 222 in the user environment, the image forming apparatus 200 cannot be used when the toner runs out. In this embodiment, the management server S remotely manages the usage status of the image forming apparatus 200 and the process cartridges to prevent such a situation. The management server S may be implemented as an application server, a database server, or a cloud server using a high-performance general-purpose computer.

[0029] FIG. 10 shows a control flowchart of the image forming apparatus 200 and the management server S regarding the automatic shipment of the process cartridge 222. The image forming apparatus 200 first transmits information on the usage status of the process cartridge 222 to the management server S. The information on the usage status of the process cartridge 222 includes the identification number of the process cartridge 222 in use, the current remaining amount of toner, and the printing rate information. The management server S receives the information on the usage status of the process cartridge 222 transmitted from the image forming apparatus 200 (S201), and calculates the toner-out timing (the timing when the remaining amount of toner becomes 0%) of the process cartridge 222 based on the received information. Next, the management server S acquires cartridge shipment history information (S203). It is determined whether the cartridge shipment conditions are met from the toner-out timing and the cartridge shipment history information (S204). The shipment conditions include, for example, that the user does not have a spare cartridge at hand from the cartridge shipment history information, that the toner-out timing is within a predetermined number of days, and the like. If the result of S204 is Yes, the process cartridge 222 is shipped to the user (S205), and the cartridge shipping history information is updated (S206). If the result of S204 is No, the process waits for the image forming apparatus 200 to send new information.

[0030] Although the toner out timing is calculated by the management server S in S202, it may be obtained from a table or the like. The toner out timing may be calculated by the CPU 213 of the image forming apparatus 200, or may be obtained from a table in the non-volatile memory 230 and sent to the management server S in S200. In S202, the toner near out timing (toner remaining at 5%) may be used as the standard, rather than the toner out timing. In S204, the process cartridge shipping condition may be that the user has a predetermined number of spare cartridges or less.

[0031] [Toner remaining amount calculation method] 5 is a block diagram of a method for calculating the remaining toner amount to be notified in this embodiment. Detection by detection unit A (first detection unit) of the remaining toner amount using pixel counting can be performed from a state in which the remaining toner amount in the developing container 207 of the process cartridge 22 is 100% (when the cartridge is new). On the other hand, detection by detection unit B (second detection unit) of the amount of toner using capacitance can be performed with good accuracy in a range of remaining toner amount of 30% to 0%, assuming that the initial remaining toner amount when the cartridge is unused is 100%.

[0032] Here, in detection unit A, an error may occur between the actual remaining toner amount and the detection value of detection unit A due to the influence of differences in the state of the photosensitive drum 201 and the toner T. On the other hand, detection unit B detects parameters that correlate with the actual amount of toner in the developing container 207, and therefore has higher detection accuracy than detection unit A in the toner amount range of 30% to 0%. A comparative example will be described in which the display of the remaining toner amount on display unit 250 uses the detection value of detection unit A for toner amounts between 100% and 30%, and uses the detection value of detection unit B for toner amounts above 30%.

[0033] (Transition of remaining toner amount in Comparative Example 1) FIG. 6 shows the toner remaining amount transition of Comparative Example 1 in the case where the detection value of the detection unit A is detected to be more than the actual toner remaining amount, and the detection value of the detection unit A is switched to the detection value of the detection unit B. The vertical axis is the toner remaining amount (%) with the unused (new) amount being 100% (toner remaining amount T0). The horizontal axis is the cumulative number of printed sheets (sheets) as the usage amount from when the development unit was unused. Here, if the number of printed sheets when the detection value of the detection unit B reaches the first threshold value Th1 (30%) is P1, the detection value of the detection unit A at the number of printed sheets P1 is T1 (60%). The transition of the actual toner remaining amount is the toner remaining amount transition R, and the transition of the detection value when the detection value of the detection unit A is more than the toner remaining amount transition is A-1. In addition, the toner remaining amount transition based on the detection value of the detection unit B after the usage amount P1 is the toner remaining amount transition B. After the number of printed sheets P1, it is displayed as the toner remaining amount transition B.

[0034] Display unit 250 displays the detection value of detection unit A from the number of printed sheets 0 (P0) to the number of printed sheets P1, and displays the detection value of detection unit B after the number of printed sheets P1. The display is performed on display unit 250. Image forming apparatus 200 transmits the same information as the information regarding the remaining amount of toner used for display on display unit 250 to management server S.

[0035] The toner remaining amount trend when the detection value of detection unit A is detected as more than the actual toner amount is as shown in toner remaining amount trend (A-2). The detection value of detection unit A when detection unit B detects the first threshold value Th1 (30%) is T1 (60%). In order to eliminate the difference between the detection values ​​of detection unit A and detection unit B, the toner remaining amount is displayed according to a toner remaining amount trend (M-1) with a gradient where the toner remaining amount decreases by 1% for every four printed sheets, so as to approach the detection value of detection unit B from point C. Then, from point D1 where the toner remaining amount according to the toner remaining amount trend (M-1) matches the detection value of detection unit B, the toner remaining amount is displayed up to point F where the toner remaining amount is 0% according to the toner remaining amount trend (B-1) of the detection value of detection unit B.

[0036] Here, if the toner remaining amount is changed according to the toner remaining amount transition (M-1) from point C1 to point D, the display unit 250 will show a sudden decrease in toner even though the user's printing rate does not change, which may cause the user to mistakenly believe that image forming device 200 is broken.

[0037] Furthermore, this remaining toner amount information (toner remaining amount transition M-1) is sent from the image forming apparatus 200 to the management server S, and the management server S calculates that the toner will run out at point E (approximately 8,200 sheets).The management server S may then determine that the process cartridge shipping conditions are met because the toner will soon run out. However, in reality, the process cartridge 222 can be used up to point F, which is the number of printed sheets of 12,000, so there is also the problem that the timing of shipping the process cartridge 222 may be too early.

[0038] (Transition of remaining toner amount in this embodiment) The toner remaining amount transition of this embodiment will be described with reference to FIG. 7. FIG. 7 is a graph of the toner remaining amount transition when the detection value of the detection unit A is switched from the detection value of the detection unit A to the detection value of the detection unit B when the detection value of the detection unit A is detected to be more than the actual toner remaining amount. The vertical axis is the toner remaining amount (%) with the unused (new) amount being 100% (toner remaining amount T0, initial toner remaining amount). The horizontal axis is the cumulative number of printed sheets (sheets) as the usage amount from the time when the development unit is unused. The actual toner remaining amount transition is toner remaining amount transition R, and two patterns of the transition of the detection value when the detection value of the detection unit A is more than the toner remaining amount transition R are shown. One is the toner remaining amount transition of the solid line starting from the toner remaining amount transition (A-1), and the other is the toner remaining amount transition of the dashed line starting from the toner remaining amount transition (A-2) whose difference with the toner remaining amount transition R is smaller than the toner remaining amount transition (A-1). The toner remaining amount transition by the detection unit B after the number of printed sheets P1 is toner remaining amount transition B.

[0039] First, the case of toner remaining amount transition (A-1) will be described. The number of printed sheets when the detection value of detection unit B detects the first threshold value Th1 (toner remaining amount 30%) is P1 (first usage amount) (point D). When the number of printed sheets is P1, the detection value of detection unit A is T1 (60%) (point C). Display unit 250 displays a period (first period) in which the detection value of detection unit A is displayed as in toner remaining amount transition (A-1) from the number of printed sheets 0 to point D where the number of printed sheets is P1, and a period (second period) in which the detection value of detection unit B is displayed after the number of printed sheets P1.

[0040] The display unit 250 displays the toner remaining amount according to the first toner remaining amount transition S1, which transitions the toner remaining amount at a gradient (first gradient) where the toner remaining amount decreases by 1% for every 80 printed sheets from point C, which is the number of printed sheets P1. The first gradient has a smaller absolute value than the gradient of the toner remaining amount transition (M-1) in the comparative example. In addition, the first gradient is larger than the ratio ((T0-T1) / P1) of the difference (T0-T1) between T0 and T1 to the number of printed sheets P1. Therefore, even if the display unit 250 displays the toner remaining amount according to the first toner remaining amount transition S1, the user is unlikely to recognize that the image forming device 200 is broken. In addition, even if the first toner remaining amount transition S1 is transmitted from the image forming device 200 to the management server S as information on the toner remaining amount, the management server S calculates that the toner out timing is point I at the number of printed sheets of 12,700 sheets shown in FIG. 7. At the time when the number of printed sheets is P1, the management server S determines that the point I is still a long way off and therefore does not satisfy the cartridge shipping conditions, so that premature dispatch of the process cartridge 222 can be prevented.

[0041] Next, the point G is where the remaining toner amount changing according to the first remaining toner amount change S1 reaches the second threshold value Th2 (15%) before matching the detection value of the detection unit B. The number of printed sheets at point G is P2 (second usage amount). In the period (third period) from point C where the number of printed sheets is P1 to point G where the number of printed sheets is P2, the display unit 250 displays the remaining toner amount changing according to the first remaining toner amount change S1. Then, from point G where the number of printed sheets is P2, the display unit 250 starts displaying according to the second remaining toner amount change S2 where the remaining toner amount changes at a gradient (second gradient) where the remaining toner amount decreases by 1% for every four printed sheets. The second remaining toner amount change S2 continues until point H where the remaining toner amount changes to match the detection value of the detection unit B. Display unit 250 displays a second remaining toner amount transition S2 that transitions the remaining toner amount at a slope (second gradient) where the remaining toner amount decreases by 1% for every 4 printed sheets during the period (fourth period) from point G, which is the number of printed sheets P2, to point H. The second gradient of second remaining toner amount transition S2 has a larger absolute value than the first gradient of first remaining toner amount transition S1.

[0042] The display unit 250 displays the remaining toner amount transition B during the period (second period) from point H to point F where the toner amount becomes 0%.

[0043] Here, the reason for using not only the first toner remaining amount transition S1 but also the second toner remaining amount transition S2 in this embodiment will be explained. If the toner remaining amount transitions from point G, which is the number of printed sheets P2, to point F, where the toner remaining amount becomes 0%, using the first toner remaining amount transition S1, the toner remaining amount will not match the detection value of the detection unit B, and the toner will be out at point I, which is the number of printed sheets 12,700. However, according to the detection value of the detection unit B, the toner remaining amount will be out at point F, which is the number of printed sheets 12,000, so a problem occurs in which the toner remaining amount does not become toner out even though it should be after the number of printed sheets 12,000. Therefore, by using the second toner remaining amount transition S2 as in this embodiment, this problem can be prevented.

[0044] Furthermore, when the display unit 250 displays the remaining toner amount from point G, which is the number of printed sheets P2, using the second remaining toner amount transition S2, the remaining toner amount is closer to toner out than at point C, which is the number of printed sheets P1, so the user is less likely to recognize that this is a malfunction of the image forming device 200. Furthermore, when the second remaining toner amount transition S2 is sent from the image forming device 200 to the management server S as information regarding the remaining toner amount, the management server S may determine that the process cartridge shipping condition is met. However, since the remaining toner amount is closer to toner out than at the number of printed sheets P1, the user is less likely to recognize that the process cartridge was shipped too early.

[0045] Next, the case of remaining toner amount transition (A-2) will be described. When the number of printed sheets is P1, the remaining toner amount detected by detection unit A is T1' (point C'), which has not yet reached the first threshold value Th1. Display unit 250 displays the detection value of detection unit A during the period (first period) from the number of printed sheets 0 (P0) to the number of printed sheets P1, and displays the remaining toner amount so that there is a period (second period) after the number of printed sheets P1 in which the detection value of detection unit B is displayed.

[0046] Display unit 250 changes the remaining toner amount at a first gradient, a first toner remaining amount trend S1, from point C1' where the number of printed pages is P1. The remaining toner amount changing at the first toner remaining amount trend S1 matches the detection value of detection unit B (point H') before it reaches the second threshold value Th2 (15%). The number of printed pages at point H' is set to P3. Display unit 250 displays the remaining toner amount changing at a toner remaining amount trend B from point H' where the number of printed pages is P3 to point F where toner runs out.

[0047] As described above, the feature of this embodiment is that two periods are provided in which the remaining toner amount changes with a first gradient and a second gradient, respectively, when there is a discrepancy between the detection value of detection unit A and the detection value of detection unit B. By displaying the remaining toner amount based on this change in the remaining toner amount on display unit 250, it becomes difficult for a user to recognize that this is a malfunction of image forming apparatus 200, and it is possible to prevent erroneous display of the remaining toner amount.

[0048] Furthermore, by transmitting this remaining toner amount transition as information on the remaining toner amount from the image forming apparatus 200 to the management server S, there is an advantage that the process cartridge can be automatically shipped at an appropriate timing.

[0049] In this embodiment, the toner remaining amount is changed using two thresholds and two gradients. However, the toner remaining amount may be changed gradually closer to the output value of the detection unit B by increasing the number of thresholds and gradients.

[0050] Although detection unit B detects the remaining toner amount by electrostatic capacitance, the present invention is not limited to this. Detection unit B may be an optical sensor having a light-emitting member that emits light into developing container 207 and a light-receiving member that receives the light emitted from the light-emitting member and passed through developing container 207. The correlation value that correlates with the amount of toner in developing container 207 is the intensity of the light received by the light-receiving member or the length of time for which the light is received.

[0051] Example 2 In the first embodiment, a case has been described in which, when there is a difference between the detection value of detection unit A and the detection value of detection unit B, the remaining toner amount changes suddenly when the remaining toner amount is switched from detection unit A to detection unit B. In contrast, in the present embodiment, a method for improving a case in which the change in the remaining toner amount stagnates when the remaining toner amount is switched from detection unit A to detection unit B in display unit 250 will be described.

[0052] We will explain comparison example 2, which is when the detection value of detection part A is used when the toner amount is between 100% and 30%, and when the toner amount is below 30%, the detection value of detection part B is switched to, and the detection value of detection part A is detected as being less than the actual toner amount.

[0053] (Transition of remaining toner amount in Comparative Example 2) FIG. 8 shows the transition of remaining toner when the detection value of detection unit A detects less than the actual amount of remaining toner and is switched from the detection value of detection unit A to the detection value of detection unit B. The vertical axis is the remaining toner (%), with the amount of remaining toner when unused (brand new) being 100% (remaining toner T0). The horizontal axis is the cumulative number of printed pages (sheets) as the amount of usage since the development unit was unused. Remaining toner transition A-3 is the transition of the detection value of detection unit A when it is detected to be less than the actual amount of remaining toner. The transition of the actual remaining toner is referred to as remaining toner transition R. Remaining toner transition B is the transition of the detection value of detection unit B.

[0054] Let P4 be the number of printed sheets at point J where the remaining toner amount in toner remaining amount transition A-3 reaches the first threshold value Th1 (30%). When the number of printed sheets is P4, the detection value of detection unit B has not yet detected the first threshold value Th1. This shows that toner remaining amount transition A-3 is transitioning with less remaining toner than toner remaining amount transition R. Therefore, if the number of printed sheets at point D where the detection value of detection unit B is the first threshold value Th1 is set to P1, toner remaining amount transition M-2 is adopted in which the remaining toner amount is fixed at the first threshold value Th1 from point J where the number of printed sheets is P4 to point D where the number of printed sheets is P1. The remaining toner amount transitions at toner remaining amount transition B from point D where the number of printed sheets is P1 to point F where the remaining toner amount is 0%.

[0055] As in Comparative Example 2, if the toner remaining amount display on display unit 250 remains unchanged from point J to point D, the user may mistakenly recognize this as a malfunction of image forming apparatus 200. Furthermore, if toner remaining amount trend M-2 is sent from image forming apparatus 200 to management server S as toner remaining amount information, the toner remaining amount has not decreased, so the process cartridge shipping condition is not met, and shipping of process cartridge 222 may be delayed.

[0056] (Transition of remaining toner amount in this embodiment) FIG. 9 is a graph showing the transition of the remaining toner amount when the detection value of the detection unit A is switched from the detection value of the detection unit A to the detection value of the detection unit B when the detection value of the detection unit A is detected as less than the actual remaining toner amount. The vertical axis is the remaining toner amount (%), with the unused (brand new) amount being 100% (remaining toner amount T0). The horizontal axis is the cumulative number of printed sheets (sheets) as the usage amount since the development unit was unused. The transition of the actual remaining toner amount is set to the toner remaining amount transition R, and two patterns of transition of the detected value when the detection value of the detection unit A is less than the actual remaining toner amount are shown. One is the solid line toner remaining amount transition starting from the toner remaining amount transition (A-3), and the other is the toner remaining amount transition starting from the toner remaining amount transition (A-4) whose difference with the toner remaining amount transition R is smaller than the toner remaining amount transition (A-3). The transition of the detected value of the detection unit B after the number of printed sheets P1 is set to the toner remaining amount transition B.

[0057] The case where the toner remaining amount transition of detection unit A is toner remaining amount transition (A-3) will be described. At the point (point J) when the number of printed sheets is P4 and detection unit A detects the first threshold value Th1 (30%), detection unit B has not detected the first threshold value Th1. Display unit 250 displays the toner remaining amount so that there is a period (first period) from the number of printed sheets 0 to point J, which is the number of printed sheets P4, in which the detection value of detection unit A is displayed as in toner remaining amount transition (A-3), and a period (second period) after point J in which the detection value of detection unit B is displayed.

[0058] Next, display unit 250 displays the remaining toner amount according to a third remaining toner amount trend S3 that changes the remaining toner amount at a third gradient in which the remaining toner amount decreases by 1% for every 260 printed sheets from point J. The third gradient is a gradient equivalent to a toner consumption printing rate of 1.8%, and is smaller than the ratio ((T0-Th1) / P4) of the difference (T0-Th1) between T0 and the first threshold value Th1 for the number of printed sheets P4.

[0059] It is at point K that the remaining toner amount changing according to the third remaining toner amount change S3 reaches the third threshold value Th3 (5%) before matching the detection value of detection unit B. Here, the number of printed sheets at point K is set to P5. From point K, which is the number of printed sheets P5, the remaining toner amount is displayed according to the fourth remaining toner amount change S4, which changes the remaining toner amount with a zero gradient that fixes the remaining toner amount at the third threshold value Th3. Then, the number of printed sheets at point M1, where the detection value of detection unit B matches the third threshold value Th3, is set to P6. Display unit 250 displays the remaining toner amount changing according to the remaining toner amount change B during the period (second period) from point M1, which is the number of printed sheets P6, to point F, where the remaining toner amount becomes 0%.

[0060] In summary, in the period (fifth period) from point J, which is the number of printed sheets P4, to point K, which is the number of printed sheets P5, display unit 250 displays the remaining toner amount that changes according to the third remaining toner amount trend S3. Then, in the period (sixth period) from point K, which is the number of printed sheets P5, to point M1, which is the number of printed sheets P6, display unit 250 displays the remaining toner amount that changes according to the fourth remaining toner amount trend S4.

[0061] The effect of the third toner remaining amount transition S3 will now be described. On display unit 250, the remaining toner amount is decreasing according to third toner remaining amount transition S3, so that the user is less likely to mistakenly recognize this as a malfunction of image forming device 200. Furthermore, when third toner remaining amount transition S3 is sent from image forming device 200 to management server S as toner remaining amount information, the remaining toner amount is decreasing, so that a toner cartridge is shipped at an appropriate time.

[0062] Next, the effect of the fourth remaining toner amount transition S4 will be described. On the display unit 250, if the third remaining toner amount transition S3 is displayed until the remaining toner amount reaches 0%, the toner out is displayed at point L (10,000 pages printed). However, since the actual toner out occurs at point F (12,000 pages printed), a problem occurs in which the toner out is displayed at an earlier timing than that. By adopting the fourth remaining toner amount transition S4, this problem can be prevented.

[0063] Next, the case where the toner remaining amount transition of detection unit A is toner remaining amount transition (A-4) will be described. Here, the number of printed sheets at point J' where detection unit A detects the first threshold value Th1 (30%) in toner remaining amount transition (A-4) is set to P7. Display unit 250 transitions the toner remaining amount from point J', which is the number of printed sheets P7, through a third toner remaining amount transition S3. The toner remaining amount transitioning through the third toner remaining amount transition S3 matches the detection value of detection unit B at point M2, which is the number of printed sheets P8, before reaching the third threshold value Th3. From point M2, which is the number of printed sheets P8, to point F, where the toner remaining amount becomes 0%, the toner remaining amount transitions through toner remaining amount transition B.

[0064] As described above, by providing two periods in which the remaining toner amount changes with the third gradient and the fourth gradient, respectively, it becomes difficult for a user to mistakenly recognize that the image forming device is broken, and it is possible to prevent an erroneous display of the remaining toner amount. In addition, by transmitting this change in the remaining toner amount as information on the remaining toner amount from the image forming device 200 to the management server S, it is possible to achieve the effect of automatically shipping a process cartridge at an appropriate timing.

[0065] In this embodiment, the toner remaining amount is changed using two thresholds and two gradients, but the thresholds and gradients may be further increased to gradually approach the output value of detection unit B. Detection unit B detects the toner remaining amount by electrostatic capacitance, but this is not limited to this. Detection unit B may be an optical sensor having a light-emitting member that emits light into the developing container 207 and a light-receiving member that receives light that is emitted from the light-emitting member and passes through the developing container 207. The correlation value that correlates with the toner amount in the developing container 207 is the intensity of light received by the light-receiving member or the length of time for which the light is received.

[0066] Example 3 In Examples 1 and 2, the toner transition in the case where a sudden change or stagnation may occur when switching from detection unit A to detection unit B is shown.

[0067] This embodiment shows a control in the case of combining the controls of the embodiments 1 and 2. In the description of this embodiment, the parts that overlap with the embodiments 1 and 2 will be omitted.

[0068] FIG. 1 is a flow chart of the toner remaining amount display according to this embodiment. First, when the toner remaining amount detection is started (S100), it is confirmed whether the detection value of the detection unit A is greater than the first threshold value (S101). If the result is No in S101, it is confirmed whether the detection unit B has detected a detection value equal to or less than the first threshold value Th1 (S102). If the result is Yes in S102, the toner remaining amount is displayed using the detection value of the detection unit B (S105). If the result is No in S102, the toner remaining amount is displayed according to the third toner remaining amount transition S3 (S103). Next, it is confirmed whether the toner remaining amount changed in the third toner remaining amount transition S3 matches the detection value of the detection unit B (S104). If the result is Yes in S104, the toner remaining amount is displayed using the detection value of the detection unit B (S105). If the result in S104 is No, it is checked whether the remaining toner amount shifted in the third remaining toner amount shift S3 is greater than the third threshold value Th3 (S106), and if the result is Yes, the process returns to S103. If the result in S106 is No, the remaining toner amount is fixed to the third threshold value Th3 and displayed (S107). Then, it is checked whether the detection value of detection unit B matches the third threshold value Th3 (S108), and if the result is Yes, the remaining toner amount is displayed using the detection value of detection unit B (S105). If the result in S108 is No, the remaining toner amount is continued to be fixed to the third threshold value Th3 and displayed (S107).

[0069] On the other hand, if the result of S101 is Yes, it is checked whether the detection unit B detects a detection value equal to or less than the first threshold value Th1 (S109). If the result of S101 is No, the detection value of the detection unit A is used to display the remaining toner amount (S110). If the result of S109 is Yes, the remaining toner amount is displayed according to the first remaining toner amount transition S1 (S111). Then, it is checked whether the remaining toner amount changed according to the first remaining toner amount transition S1 is greater than the second threshold value Th2 (S112). If the result of S112 is Yes, it is checked whether the remaining toner amount changed according to the first remaining toner amount transition S1 matches the detection value of the detection unit B (S113). If the result of S113 is No, the process returns to S111. If the result of S113 is Yes, the detection value of the detection unit B is used to display the remaining toner amount (S105). If the result of S112 is No, the remaining toner amount is displayed according to the second remaining toner amount transition S2 (S114). Then, it is confirmed whether the remaining toner amount changed in the second remaining toner amount change coincides with the detection value of detection unit B (S115). If the result in S115 is No, the process returns to S114. If the result in S115 is Yes, the remaining toner amount is displayed using the detection value of detection unit B (S105). [Explanation of symbols]

[0070] 200 Image forming device 201 Photoconductor drum 203 Laser 207 Developer container 213 CPU 222 Process cartridge 224 Developer carrier 230 Non-volatile memory 250 Display section 302 Plate Antenna 401 Developing device circuit 402 Static electricity remaining amount detection control circuit A First detection section B Second detection section

Claims

1. a developing unit including a toner storage section that stores toner and a developing roller that carries the toner in the toner storage section; a photosensitive drum to which toner is supplied from the developing roller; An image forming apparatus for forming an image on a recording material based on image data, comprising: a first acquisition unit that acquires an amount of toner consumed by the image formation based on the image data, and acquires an amount of toner remaining in the toner storage unit based on the amount of toner consumed; a second acquisition unit that acquires the remaining toner amount based on a correlation value that correlates with the amount of toner contained in the toner container; a display unit that displays the remaining toner amount acquired by the first acquisition unit and the remaining toner amount acquired by the second acquisition unit; A control unit that controls the display unit; In an image forming apparatus comprising: The control unit is a first period during which the remaining toner amount acquired by the first acquisition unit is displayed on the display unit before the remaining toner amount corresponding to a first threshold value is acquired by the second acquisition unit, and a second period during which the remaining toner amount acquired by the second acquisition unit is displayed on the display unit after the remaining toner amount corresponding to the first threshold value is acquired by the second acquisition unit. The display unit is controlled so that The control unit further When the amount of remaining toner corresponding to the first threshold value is not acquired by the first acquisition unit until the amount of remaining toner corresponding to the first threshold value is acquired by the second acquisition unit, a third period during which the remaining toner amount is displayed according to a first remaining toner amount transition that transitions the remaining toner amount such that the remaining toner amount decreases at a first gradient with respect to the usage amount of the developing unit between the first period and the second period; a fourth period in which the remaining toner amount is displayed according to a second remaining toner amount transition in which the remaining toner amount is transitioned such that the remaining toner amount decreases at a second gradient with respect to the usage amount of the developing unit after the remaining toner amount transitioned according to the first remaining toner amount transition reaches the remaining toner amount corresponding to a second threshold value that is smaller than the first threshold value; and controlling the display unit so that An image forming apparatus, wherein an absolute value of the second gradient is greater than an absolute value of the first gradient.

2. the remaining toner amount in the toner storage section when the developing unit is unused is defined as an initial remaining toner amount, and the usage amount of the developing unit and the remaining toner amount acquired by the first acquisition unit when the remaining toner amount corresponding to the first threshold value is acquired by the second acquisition unit are defined as a first usage amount and a first remaining toner amount, respectively; When the amount of toner remaining that has been changed in the first change in the amount of toner remaining reaches the amount of toner remaining that corresponds to the second threshold, the amount of toner used by the developing unit is defined as a second amount of toner used. the first period is a period until the usage amount of the developing unit reaches the first usage amount, the third period is a period from when the usage amount of the developing unit reaches the first usage amount to when the remaining toner amount changed according to the first remaining toner amount change reaches the remaining toner amount corresponding to the second threshold value, 2 . The image forming apparatus according to claim 1 , wherein the fourth period is started after the remaining toner amount changed in the first remaining toner amount change reaches the remaining toner amount corresponding to the second threshold value.

3. the fourth period is a period until the remaining toner amount changed according to the second remaining toner amount change coincides with the acquired value of the second acquisition unit, The image forming apparatus according to claim 2, characterized in that the second period is a period from when the remaining toner amount changed in the second remaining toner amount change coincides with the acquired value of the second acquisition unit until when the remaining toner amount acquired by the second acquisition unit becomes zero.

4. 4. The image forming apparatus according to claim 2, wherein an absolute value of the first gradient is greater than a ratio of a difference between the initial remaining amount of toner and the first remaining amount of toner to the first usage amount.

5. A memory for storing information, 5. The image forming apparatus according to claim 1, wherein the memory stores the first threshold value, the second threshold value, the first gradient, and the second gradient.

6. A communication unit capable of communicating with a management server via an external network, 6. The image forming apparatus according to claim 1, wherein the communication unit is configured to transmit information regarding the remaining amount of toner during the third period and the fourth period to the management server.

7. The control unit is When the remaining toner amount corresponding to the first threshold value is acquired by the first acquisition unit before the remaining toner amount corresponding to the first threshold value is acquired by the second acquisition unit, a fifth period during which the remaining toner amount is displayed according to a third remaining toner amount transition in which the remaining toner amount transitions so that the remaining toner amount decreases at a third gradient with respect to the usage amount of the developing unit between the first period and the second period; a sixth period in which the toner remaining amount is fixed to the third threshold value with respect to the usage amount of the developing unit after the toner remaining amount transitioned in the third toner remaining amount transition reaches the toner remaining amount corresponding to a third threshold value smaller than the first threshold value; 7. The image forming apparatus according to claim 1, wherein the display unit is controlled so that the display unit displays a message.

8. the first period is a period until the first acquisition unit acquires the remaining toner amount corresponding to the first threshold value, the fifth period is a period from when the first acquisition unit acquires the remaining toner amount corresponding to the first threshold value until when the remaining toner amount transitioned according to the third remaining toner amount transition reaches the remaining toner amount corresponding to the third threshold value, the sixth period is a period from when the remaining toner amount transitioned in the third remaining toner amount transition reaches the remaining toner amount corresponding to the third threshold value until when the remaining toner amount corresponding to the third threshold value is acquired by the second acquisition unit, the second period is a period from when the second acquisition unit acquires the remaining toner amount corresponding to the third threshold value until when the remaining toner amount acquired by the second acquisition unit becomes zero; 8. The image forming apparatus according to claim 7,

9. an exposure unit for forming an electrostatic latent image on the photosensitive drum; 9. The image forming apparatus according to claim 1, wherein the first acquisition unit acquires the toner consumption amount based on the number of image pixels of an electrostatic latent image formed by the exposure means and a unit toner consumption amount consumed by each of the image pixels.

10. The toner storage unit has an electrode therein, 10. The image forming apparatus according to claim 1, wherein the correlation value is an output value that is output in response to an electrostatic capacitance between the electrode and the developing roller.

11. a light emitting member that emits light into the toner containing section, and a light receiving member that receives the light that is emitted from the light emitting member and passes through the toner containing section, 10. The image forming apparatus according to claim 1, wherein the correlation value is an intensity of the light received by the light receiving member or a length of time during which the light is received.

Images