Image forming device and toner cartridge

Abstract

The present invention discloses an image forming device and a toner cartridge. The image forming device of an embodiment includes: a detection unit that detects temperature information related to the temperature of toner stored in the toner cartridge; an image forming unit that forms a toner image on a sheet using the toner supplied from the toner cartridge; a fixing unit that fixes the toner image formed on the sheet by the image forming unit; and a control unit that controls the fixing temperature in the fixing unit based on the temperature information detected by the detection unit and the accumulated time of the detected temperature information.

Description

Technical Field

[0001] Embodiments of the present invention relate to an image forming apparatus and a toner cartridge. Background Art

[0002] Image forming apparatuses exist that use toners that can be fixed at low temperatures. By using toners that can be fixed at low temperatures, image forming apparatuses can reduce power consumption. Toner is supplied to the image forming apparatus from a toner cartridge installed in the apparatus. The toner in the toner cartridge is exposed to heat generated within the apparatus. Heat generation within the apparatus can be caused by, for example, long-term continuous double-sided copying.

[0003] Toner that can be fixed at low temperatures has a characteristic that its glass transition temperature increases when exposed to high temperatures. If the glass transition temperature of the toner increases, the toner becomes difficult to melt, resulting in a problem of cold offset. Summary of the Invention

[0004] The image forming device of the present invention comprises: a detection unit that detects temperature information related to the temperature of the colorant stored in the colorant box; an image forming unit that forms a colorant image on a sheet using the colorant supplied from the colorant box; a fixing unit that fixes the colorant image formed on the sheet by the image forming unit; and a control unit that controls the fixing temperature in the fixing unit based on the temperature information detected by the detection unit and the accumulated time of detecting the temperature information.

[0005] A toner cartridge according to the present invention stores toner and includes a storage unit that stores characteristic information for correcting a fixing temperature when fixing a toner image formed on a sheet using the toner supplied from the toner cartridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 1 is an external view showing an example of the overall configuration of the image forming apparatus 100 according to the embodiment.

[0007] Figure 2 1 is a diagram showing the configuration of a control system of the image forming apparatus 100 .

[0008] Figure 3 It is a graph showing the change in glass transition temperature.

[0009] Figure 4 1 is a diagram showing changes in temperature within image forming apparatus 100 .

[0010] Figure 5 This is a diagram showing an example of occurrence of cold offset.

[0011] Figure 6 This is a diagram showing an example of occurrence of cold offset.

[0012] Figure 7 It is a block diagram showing a configuration for realizing the first embodiment.

[0013] Figure 8 It is a diagram showing information stored in the storage medium 35 .

[0014] Figure 9 is a diagram showing information stored in the DRAM 310 .

[0015] Figure 10 It is a diagram showing partition identification information.

[0016] Figure 11 is a diagram showing correction information.

[0017] Figure 12 It is a graph showing temperature information.

[0018] Figure 13 4 is a flowchart showing the flow of suppression processing performed by the control unit 400 .

[0019] Figure 14 : is a flowchart showing the flow of temperature information update processing.

[0020] Figure 15 It is a diagram showing whether or not a shift occurs when the first embodiment is applied and when the first embodiment is not applied in several cases.

[0021] Figure 16 It is a block diagram showing a configuration for realizing the second embodiment.

[0022] Figure 17 4 is a flowchart showing the flow of suppression processing performed by the control unit 400 .

[0023] Figure 18 4 is a flowchart showing the flow of suppression processing performed by the control unit 400 .

[0024] Figure 19 It is a diagram showing whether or not a shift occurs when the second embodiment is applied and when the second embodiment is not applied in several cases. DETAILED DESCRIPTION

[0025] An image forming apparatus according to an embodiment includes a detection unit, an image forming unit, a fixing unit, and a control unit. The detection unit detects temperature information related to the temperature of toner stored in a toner cartridge. The image forming unit forms a toner image on a sheet using toner supplied from the toner cartridge. The fixing unit fixes the toner image formed on the sheet by the image forming unit. The control unit controls the fixing temperature in the fixing unit based on the temperature information detected by the detection unit and the accumulated time of the detected temperature information.

[0026] Figure 1 1 is an external view showing an example of the overall structure of an image forming apparatus 100 according to an embodiment. The image forming apparatus 100 is, for example, a multifunction printer. The image forming apparatus 100 includes a display 110, a control panel 120, a printing unit 130, a sheet storage unit 140, and a scanning unit 200. Figure 2 As shown, the image forming apparatus 100 includes a control unit 400 for controlling the entire apparatus.

[0027] Image forming apparatus 100 forms an image on a sheet using a developer. The developer is, for example, a toner. In the following description, the developer is referred to as a toner. The sheet is, for example, paper or label paper. The sheet can be any material as long as the image forming apparatus 100 can form an image on its surface.

[0028] The display 110 is an image display device such as a liquid crystal display, an organic EL (Electro Luminescence) display, etc. The display 110 displays various information related to the image forming apparatus 100 .

[0029] The control panel 120 includes a plurality of buttons. The control panel 120 receives user operations and outputs signals corresponding to the user operations to the control unit 400 of the image forming apparatus 100. Alternatively, the display 110 and the control panel 120 may be formed as an integrated touch panel.

[0030] The printing unit 130 prints images on sheets based on image information generated by the scanning unit 200 or received via a network. The printing unit 130 uses toner to print images. The sheets on which the images are printed can be either stored in the sheet storage unit 140 or manually fed. The sheet storage unit 140 stores sheets used to form images in the printing unit 130.

[0031] The scanner unit 200 reads image information of the object as light and dark. The scanner unit 200 records the read image information. The recorded image information can also be sent to other information processing devices via a network. The recorded image information can also be formed into an image on a sheet by the printer unit 130.

[0032] Figure 2 1 is a diagram showing the configuration of a control system of the image forming apparatus 100 .

[0033] Image forming apparatus 100 includes a printer unit 130, a scanner unit 200, a control panel 120, a controller 400, a hard disk drive (HDD) 300, a DRAM (Dynamic Random Access Memory) 310, and a ROM (Read Only Memory) 320. These units are connected via a system bus.

[0034] The control unit 400 controls the various components connected via the system bus. The ROM 320 stores various control programs required for the operation of the image forming apparatus 100. ROM 320 stores various programs for controlling image forming operations, etc. HDD 300 stores various programs and data. The various programs stored in ROM 320 and HDD 300 are executed under the control of the control unit 400. DRAM 310 is a buffer memory that temporarily stores data generated during the execution of various programs.

[0035] Next, the glass transition temperature of toner will be described. The image forming apparatus 100 forms a toner image on a sheet using toner supplied from a toner cartridge. The toner used in the image forming apparatus 100 is toner that can be fixed at a lower temperature than ordinary toners.

[0036] The toner cartridge is installed in the image forming apparatus 100. Therefore, the toner in the toner cartridge is exposed to heat generated in the image forming apparatus 100. When exposed to heat, the glass transition temperature of the toner increases. Figure 3 It is a graph showing the change in glass transition temperature.

[0037] exist Figure 3 In the figure, the horizontal axis represents the cumulative time (H). The cumulative time is the cumulative time of the exposure time at a certain temperature. The vertical axis represents the change in glass transition temperature. Figure 3 In the embodiment, 30° C., 35° C., 40° C., and 45° C. are listed as the temperatures to which the toner is exposed.

[0038] like Figure 3As shown, at all temperatures, the glass transition temperature rises sharply before the cumulative time reaches 100 hours. Furthermore, if the cumulative time exceeds 200 hours, the glass transition temperature hardly changes. Furthermore, the higher the exposure temperature, the higher the glass transition temperature of the toner. For example, the glass transition temperature is approximately 40°C when exposed to 30°C. On the other hand, the glass transition temperature is approximately 50°C when exposed to 45°C.

[0039] Figure 4 : is a graph showing the change in temperature within the image forming apparatus 100. The horizontal axis represents time. The vertical axis represents the change in temperature. Figure 4 1 shows temperature changes when the image forming apparatus 100 performs intermittent operation and continuous operation. Continuous operation refers to, for example, continuous operation of a large number of double-sided copies. Intermittent operation refers to intermittent operation of a small number of copies.

[0040] like Figure 4 As shown in the figure, the temperature rises sharply during continuous operation compared to intermittent operation. Furthermore, the temperature reached during continuous operation is much higher than during intermittent operation. For example, after two hours, the temperature was approximately 44°C during continuous operation and approximately 33°C during intermittent operation. Therefore, the more continuously an image forming apparatus operates, the higher the glass transition temperature of the toner tends to be.

[0041] If the glass transition temperature of the toner becomes higher, cold offset occurs due to the toner not being melted at the same fixing temperature as before. Figure 5 、 Figure 6 This is a diagram showing an example of occurrence of cold offset. Figure 5 、 Figure 6 Each example shows an occurrence when a black band-like image is formed in the longitudinal direction on a sheet.

[0042] Figure 5 This figure shows an example of what happens when toner forming a band-like image remains unmelted over almost the entire area. The band-like image 501 is an image formed on a sheet by adhering to the fixing portion without melting. Figure 6 This figure shows an example of what happens when a portion of toner forming a band-shaped image remains unmelted. Image 502 is an image formed on a sheet by adhering to the fixing portion without melting.

[0043] If cold offset occurs, unmelted toner adheres to the fixing unit, resulting in the formation of an unintended image on the sheet. Therefore, cold offset is undesirable. Therefore, two embodiments (a first embodiment and a second embodiment) for suppressing cold offset will be described. In the following description, the process for suppressing cold offset will be referred to as "suppression process."

[0044] Figure 7 It is a block diagram showing a configuration for realizing the first embodiment. Figure 7 4 shows the control section 400 , the toner cartridge 30 , the toner replenishing motor 31 , the storage medium 35 , the reading and writing section 36 , and the toner remaining amount detection sensor 37 . Figure 7 1 , the photosensitive drum 11 , the charger 12 , the developing device 14 , the developing drum 14 a , and the cleaner 18 are shown. Figure 7 The temperature sensor 41 and the fixing unit 42 are shown in FIG.

[0045] The photosensitive drum 11 has an organic photoconductor (OPC) on its support surface. The charger 12 uniformly charges the photosensitive drum 11 as it rotates. The cleaner 18 removes residual toner from the photosensitive drum 11. The developing device 14 uses a developing drum 14a to develop the electrostatic latent image formed on the photosensitive drum 11 with toner.

[0046] like Figure 7 As shown in the upper part of the developing device 14, a toner cartridge 30 is provided on the upper part of the developing device 14. The rotation of the toner replenishing motor 31 drives the replenishing mechanism (supply screw) in the toner cartridge 30, causing the toner to fall and be supplied to the developing device 14.

[0047] The developing device 14 is provided with a remaining toner amount detection sensor 37 that measures the magnetic permeability of the developer. The remaining toner amount detection sensor 37 obtains the toner amount representing the amount of toner stored in the developing device 14. A toner shortage can be detected based on the measurement value of the remaining toner amount detection sensor 37.

[0048] The conveyance path 43 is a conveyance path for the sheet. The toner image formed on the developing drum 14a is transferred to the sheet. The toner image transferred to the sheet is fixed by the fixing unit 42. The sheet is then discharged outside the machine.

[0049] In this embodiment, the photosensitive drum 11 , the charger 12 , the developing device 14 , the developing drum 14 a , and the cleaner 18 constitute an image forming unit.

[0050] The toner cartridge 30 includes a storage medium 35. The storage medium 35 stores characteristic information determined by the characteristics of the toner stored in the toner cartridge 30. When the toner cartridge 30 is installed in the image forming apparatus 100, the toner cartridge 30 and the image forming apparatus 100 are electrically connected via a bus. The reader / writer 36 reads and writes information from the storage medium 35.

[0051] Characteristic information includes information stored in storage medium 35 and information stored in the image forming apparatus 100. To distinguish between these two types of information, the information stored in storage medium 35 is referred to as characteristic information A, and the information stored in the image forming apparatus 100 is referred to as characteristic information B. When there is no distinction between characteristic information A and characteristic information B, they are referred to as simply characteristic information.

[0052] When the toner cartridge 30 is installed in the image forming apparatus 100 and the cover housing the toner cartridge 30 is closed, the image forming apparatus 100 can acquire characteristic information A from the toner cartridge 30. The acquired characteristic information A is stored as characteristic information B in the image forming apparatus 100.

[0053] The temperature sensor 41 detects the temperature inside the image forming apparatus 100 in which the toner cartridge 30 is stored. The temperature sensor 41 is disposed near the toner cartridge 30. Therefore, the temperature detected by the temperature sensor 41 is the temperature to which the toner is exposed.

[0054] The toner replenishing motor 31 , the reading and writing unit 36 , the remaining toner amount detection sensor 37 , the temperature sensor 41 , and the fixing unit 42 are controlled by the control unit 400 .

[0055] The information stored in the storage medium 35 will be described. Figure 8 35 is a diagram showing information stored in the storage medium 35. The storage medium 35 stores an identification code and characteristic information A. Figure 8 A1 and A2 shown in the figure indicate the start addresses for storing each information. The identification code is information for determining whether the toner cartridge 30 is a good product.

[0056] The information stored in the DRAM 310 will be described. Figure 9 310 is a diagram showing information stored in the DRAM 310. The DRAM 310 stores an identification code and characteristic information B. Figure 9 B1, B2, and B3 shown in the figure represent the start addresses for storing each information. The identification code is information for identifying the toner cartridge 30 obtained from the storage medium 35. Therefore, the same identification information as that of the storage medium 35 is stored. The temperature information indicates the cumulative time the toner cartridge has been exposed to a certain temperature.

[0057] The characteristic information includes two types of information: one is partition identification information for identifying a partition indicating a correction temperature; and the other is correction information indicating a correction temperature corresponding to the identified partition. The correction temperature indicates the temperature of the correction fixing unit 42.

[0058] Figure 10is a diagram showing partition determination information. The partition determination information is used to determine a partition based on the detected temperature and accumulated time. The detected temperature represents the temperature detected by temperature sensor 41. The accumulated time represents the accumulated time exposed to the detected temperature. The partitions include partition 1, partition 2, and partition 3. Based on the partition determination information, one of partitions 1, 2, and 3 is determined. The correction temperature increases in the order of partition 1, partition 2, and partition 3.

[0059] exist Figure 10 In the partition determination information shown, when the detected temperature is lower than 35°C, it is determined to be partition 1 regardless of the accumulated time. When the detected temperature is 35°C or higher and lower than 40°C, if the accumulated time is less than 25 hours, it is determined to be partition 1. When the detected temperature is 35°C or higher and lower than 40°C, if the accumulated time is more than 25 hours, it is determined to be partition 2. When the detected temperature is 40°C or higher, if the accumulated time is less than 75 hours, it is determined to be partition 2. When the detected temperature is 40°C or higher, if the accumulated time is more than 75 hours, it is determined to be partition 3. In this way, the characteristic information is information used to correct the fixing temperature to be higher when the temperature indicated by the temperature information is higher or the accumulated time is longer. In addition, temperature ranges such as the detected temperature lower than 35°C, the detected temperature higher than 35°C and the detected temperature lower than 40°C are sometimes expressed as "temperature zones".

[0060] Figure 11 : is a diagram showing correction information. The correction information is information indicating a zone and the correction temperature corresponding to the zone. In the case of zone 1, the correction temperature is 0°C. That is, no correction is performed in the case of zone 1. In the case of zone 2, the correction temperature is +5°C. Therefore, in the case of zone 2, the control unit 400 controls so that the temperature of the fixing unit 42 becomes a temperature obtained by adding 5°C to the normal temperature. In the case of zone 3, the correction temperature is +10°C. Therefore, in the case of zone 3, the control unit 400 controls so that the temperature of the fixing unit 42 becomes a temperature obtained by adding 10°C to the normal temperature.

[0061] Figure 12 is a graph showing temperature information. The temperature information indicates exposure to Figure 10 The accumulated time in the same temperature band as the detected temperature in the temperature information is in minutes. Figure 10 When comparing the accumulated time of the partition identification information in the , the comparison is performed after converting from minutes to hours. The temperature information is initialized at a predetermined time (for example, when the toner is replaced).

[0062] Thus, when acquiring the correction temperature, the control unit 400 first acquires the temperature zone with the longest cumulative time from the temperature information. The control unit 400 uses the partition determination information and determines the partition based on the acquired temperature zone and the cumulative time represented by the temperature information. For example, when the temperature zone is lower than 35°C and the cumulative time represented by the temperature information is 720 minutes (12 hours), it is determined to be partition 1. If the partition is determined, the control unit 400 uses the correction information to acquire the correction temperature. For example, in the case of partition 2, +5°C is acquired as the correction temperature. The control unit 400 controls the temperature of the fixing unit 42 so that it reaches the temperature after the correction temperature is added.

[0063] In this way, the characteristic information is information for correcting the fixing temperature based on a combination of the temperature information and the accumulation time.

[0064] Figure 13 This is a flowchart showing the flow of suppression processing performed by the control unit 400 in the first embodiment. The control unit 400 determines whether the cover storing the toner cartridge 30 is closed (ACT 101). If the cover is closed (ACT 101: YES), the identification code is acquired from the storage medium 35 (ACT 102).

[0065] The control unit 400 determines whether the acquired identification code matches the identification code stored in DRAM 310 (ACT 103). If the acquired identification code does not match the identification code stored in DRAM 310 (ACT 103: No), the control unit 400 operates in another mode that does not execute the suppression process (ACT 104) and terminates the process. It should be noted that the case of inconsistency with the identification code refers to, for example, a case where the installed toner cartridge is a counterfeit.

[0066] When the acquired identification code matches the identification code stored in the DRAM 310 (ACT 103 : YES), the control unit 400 copies the characteristic information A to the characteristic information B (ACT 105 ).

[0067] The control unit 400 determines whether image formation is requested based on a user instruction or the like (ACT 106). If image formation is not requested (ACT 106: No), the control unit 400 determines whether the cover is open (ACT 107). If the cover is open (ACT 107: Yes), the process returns to ACT 101. If the cover is not open (ACT 107: No), the process returns to ACT 106.

[0068] When image formation is requested (ACT 106 : YES), the control unit 400 determines the zone (ACT 108 ) and acquires a correction temperature based on the zone (ACT 109 ). The control unit 400 uses the acquired temperature to correct the fixing temperature and controls the fixing unit 42 to adjust the temperature to the corrected temperature (ACT 110 ). The control unit 400 performs image formation (ACT 111 ) and then returns to ACT 106 .

[0069] Figure 14 This is a flow chart showing the flow of temperature information update processing. Figure 12 In addition, the control unit 400 is used to process the accumulated time of the temperature information. Figure 13 The suppression process shown is independent of the temperature information update process performed once per second.

[0070] Each time one minute passes (ACT 201 : YES), the control unit 400 acquires the temperature detected by the temperature sensor 41 (ACT 202). The control unit 400 determines whether the acquired temperature is below 35°C (ACT 203). If the acquired temperature is below 35°C (ACT 203 : YES), the control unit 400 updates the accumulated time below 35°C in the temperature information (ACT 204) and then returns to ACT 201. The accumulated time is updated by one minute.

[0071] If the acquired temperature is not lower than 35°C (ACT 203: No), the control unit 400 determines whether the acquired temperature is lower than 40°C (ACT 205). If the acquired temperature is lower than 40°C (ACT 205: Yes), the control unit 400 updates the accumulated time below 40°C in the temperature information (ACT 206), and then returns to ACT 201. If the acquired temperature is not lower than 40°C (ACT 205: No), the control unit 400 updates the accumulated time above 40°C in the temperature information (ACT 207), and then returns to ACT 201.

[0072] Figure 15 : is a diagram showing whether or not a shift occurs when the first embodiment is applied and when the first embodiment is not applied in several cases. Figure 15 In the example, the "detected temperature", "accumulated time", "division" and the presence or absence of offset are shown for application examples or non-application examples. Figure 10 The "Detection Temperature", "Cumulative Time" and "Partition" described in the same.

[0073] In getting Figure 15 The test conditions for the results shown were 10°C / 20 wt% and a paper weight of 60 g / m 2The test environment is an environment where the rated voltage is set to 90V in an image forming device with a rated voltage of 100V. The method for confirming the offset is as follows: 100 sheets of A4-sized solid tape images with an image density of 1.3 to 1.4 are formed continuously and the presence or absence of offset is determined by visual inspection. Figure 5 、 Figure 6 That kind of cold offset.

[0074] like Figure 15 As shown, in the application example, it is shown whether or not a shift occurs in the partitions 1, 2, and 3. In the non-application example, it is shown whether or not a shift occurs in the partitions 1 and 2.

[0075] like Figure 15 As shown, it can be seen that no offset occurs in any of the application examples. On the other hand, it can be seen that offset occurs in all of the non-application examples. It can be seen that the application of the first embodiment effectively suppresses the occurrence of offset.

[0076] Furthermore, even if the toner thermal characteristics change with time, no deviation occurs in all application examples.

[0077] Next, the second embodiment will be described. The second embodiment will be described using the same configuration as described in the first embodiment. The second embodiment differs significantly from the first embodiment in the function of the toner cartridge 30. The toner cartridge 30 in the first embodiment includes a storage medium 35. On the other hand, the toner cartridge 30 in the second embodiment includes an IC chip. This IC chip is an RFID (Radio Frequency Identifier) with a built-in battery. Furthermore, the IC chip can detect temperature and has memory.

[0078] Figure 16 1 is a block diagram showing a configuration for realizing the second embodiment. The differences from the first embodiment will be described. Figure 16 The composition shown is from Figure 7 The configuration described above is a configuration in which the temperature sensor 41 and the reading / writing unit 36 are removed and an RFID reader 46 is included. In addition, the toner cartridge 30 includes an IC chip 45 instead of the storage medium 35. The RFID reader 46 communicates with the IC chip 45 to acquire various information.

[0079] In addition to the characteristic information A, the IC chip 45 also stores temperature information. In the first embodiment, the temperature information is stored in the DRAM 310. In contrast, in the second embodiment, since the IC chip 45 can detect the temperature, the temperature information is stored in the IC chip 45. The IC chip 45 performs Figure 14The temperature information update process shown is performed to update the temperature information. In the second embodiment, the identification code is not used. Therefore, the identification code is not stored in the IC chip 45 and the DRAM 310.

[0080] As a result, characteristic information A and temperature information are stored in IC chip 45. Characteristic information B is stored in DRAM 310. In the second embodiment, when acquiring the corrected temperature, control unit 400 first acquires characteristic information A and stores it in DRAM 310 as characteristic information B. Control unit 400 acquires temperature information from IC chip 45. Based on the temperature information, control unit 400 acquires the temperature zone with the longest cumulative time. Control unit 400 uses the zone determination information and determines a zone based on the acquired temperature zone and the cumulative time indicated by the temperature information. Once a zone is determined, control unit 400 acquires the corrected temperature using the correction information.

[0081] Figure 17 、 Figure 18 This is a flowchart showing the flow of suppression processing performed by the control unit 400 in the second embodiment. The control unit 400 determines whether the lid housing the toner cartridge 30 is closed (ACT 301). If the lid is closed (ACT 301: YES), the control unit 400 attempts to obtain characteristic information A and temperature information from the IC chip 45 (ACT 302).

[0082] The control unit 400 determines whether the characteristic information A and temperature information have been acquired (ACT 303 ). If the characteristic information A and temperature information have not been acquired (ACT 303 : No), the control unit 400 determines whether acquisition of the characteristic information A and temperature information has failed three times in a row (ACT 307 ).

[0083] If the acquisition of characteristic information A and temperature information fails three times in a row (ACT 307: YES), the control unit 400 operates in another mode that does not execute the suppression process (ACT 308) and ends the process. If the acquisition of characteristic information A and temperature information fails three times in a row (ACT 307: NO), the control unit 400 attempts to acquire characteristic information A and temperature information again (ACT 302).

[0084] If characteristic information A and temperature information have been acquired (ACT 303: YES), control unit 400 copies characteristic information A to characteristic information B and also copies temperature information (ACT 304). Control unit 400 determines whether image formation is requested based on a user instruction or the like (ACT 305). If image formation is not requested (ACT 305: NO), control unit 400 determines whether the lid is open (ACT 306). If the lid is open (ACT 306: YES), the process returns to ACT 301. If the lid is not open (ACT 306: NO), the process returns to ACT 305.

[0085] When the execution of image formation is requested in ACT 305 (ACT 305: YES), the control unit 400 enters Figure 18 In ACT 401, the control unit 400 attempts to obtain temperature information (ACT 401). Since the temperature information is updated every minute, the control unit 400 obtains the latest temperature information when performing image formation.

[0086] The control unit 400 determines whether the temperature information has been acquired (ACT 402 ). If the temperature information has not been acquired (ACT 402 : No), the control unit 400 determines whether the acquisition of the temperature information has failed three times in a row (ACT 408 ).

[0087] If the acquisition of temperature information fails three times in a row (ACT 408 : YES), the control unit 400 determines a partition (ACT 404 ) based on the temperature information stored in the DRAM 310. If the acquisition of temperature information does not fail three times in a row (ACT 408 : NO), the control unit 400 attempts to acquire temperature information again (ACT 401 ).

[0088] If the temperature information has been acquired in ACT 402 (ACT 402 : YES), the control unit 400 copies the temperature information (ACT 403 ). As a result, the temperature information stored in the DRAM 310 is updated to the latest temperature information. The control unit 400 determines the partition based on the temperature information stored in the DRAM 310 (ACT 404 ).

[0089] The control unit 400 acquires the corrected temperature based on the partition (ACT 405 ). The control unit 400 uses the acquired temperature to correct the fixing temperature and controls the fixing unit 42 to adjust the temperature to the corrected temperature (ACT 406 ). The control unit 400 performs image formation (ACT 407 ) and returns to ACT 305 .

[0090] Figure 19 : is a diagram showing whether or not a shift occurs when the second embodiment is applied and when the second embodiment is not applied in several cases. Figure 19 In the example, the "detected temperature", "accumulated time", "division" and the presence or absence of offset are shown for application examples or non-application examples. Figure 10 The "detection temperature", "accumulation time" and "partition" described in the same. The test environment is the same as Figure 15 The contents described in are the same.

[0091] like Figure 19 As shown, in the application example, it is shown whether or not a shift occurs in the partitions 1, 2, and 3. In the non-application example, it is shown whether or not a shift occurs in the partitions 1 and 2.

[0092] like Figure 19 As shown, it can be seen that no offset occurs in any of the application examples. On the other hand, it can be seen that offset occurs in all of the non-application examples. It can be seen that the application of the second embodiment effectively suppresses the occurrence of offset.

[0093] In the embodiment described above, when determining zones, the control unit 400 obtains the temperature zone with the longest cumulative time based on the temperature information and determines the zone based on this temperature zone. In this case, for example, if the cumulative time between 35°C and below 40°C is 60 minutes and the cumulative time between 40°C and above is 59 minutes, the temperature zone between 35°C and below 40°C is determined, even though the difference is only one minute.

[0094] When obtaining the maximum temperature band, all information outside the maximum temperature band is discarded. Therefore, in cases where the accumulated time is similar, the actual state of the exposed toner may differ significantly. Therefore, the following method can also be used.

[0095] First, a value is assigned to each temperature zone. For example, a temperature zone below 35°C is assigned a value of 0, a temperature zone between 35°C and below 40°C is assigned a value of 1, and a temperature zone above 40°C is assigned a value of 2. Furthermore, each time a temperature is detected, the value assigned to the temperature zone to which the detected temperature belongs is accumulated. To determine the zone based on this accumulated value, a threshold value is pre-set and compared with the accumulated value.

[0096] Specifically, suppose that temperatures below 35°C were detected 10 times, temperatures above 35°C and below 40°C were detected 60 times, and temperatures above 40°C were detected 59 times. In this case, the cumulative value is 0 × 10 times + 1 × 60 times + 2 × 59 = 178. Threshold values are set to 50 and 100. Furthermore, values below 50 are assigned to Zone 1, values above 50 and below 100 are assigned to Zone 2, and values above 100 are assigned to Zone 3. In this case, since 178 is above 100, it is assigned to Zone 3. This ensures that information from each temperature zone is not discarded, enabling temperature correction more appropriate for the state of the exposed toner.

[0097] In the embodiment described above, three partitions are used as an example, but two or four or more partitions can also be used. In addition, three temperature zones are used as an example, but two or four or more temperature zones can also be used.

[0098] As described above, characteristic information is determined by the toner's characteristics. Therefore, the partition identification information and correction information are determined by the toner's characteristics. Specifically, the "detected temperature" and "accumulated time" values in the partition identification information are also determined by the toner's characteristics. The "correction temperature" in the correction information is also determined by the toner's characteristics. Therefore, regardless of the toner's properties, since the characteristic information is determined by the toner, it is possible to suppress the occurrence of offset based on the toner.

[0099] In this embodiment, two examples are described, but all examples are common to the following (1) and (2).

[0100] (1) Calibration is performed using the temperature and the cumulative time to which the toner is exposed.

[0101] (2) The higher the temperature to which the toner is exposed, or the longer the accumulated time, the higher the fixing temperature is corrected.

[0102] Therefore, any embodiment is possible as long as the above (1) and (2) are satisfied. For example, regardless of the temperature detection method, the occurrence of offset can be suppressed by satisfying the above (1) and (2).

[0103] In the above-described embodiment, the temperature sensor 41 is preferably positioned near the toner cartridge, where the highest detected temperature is located. Furthermore, the IC chip 45 is also preferably positioned where the highest detected temperature is located. The placement of the temperature sensor 41 and IC chip 45 is not limited as long as they can accurately detect the temperature affecting the toner.

[0104] In the first embodiment, the temperature information stored in the DRAM 310 may also be stored in the toner cartridge 30. By doing so, even when the toner cartridge 30 is set in another image forming apparatus, the image forming apparatus can obtain an appropriate correction temperature.

[0105] Although several embodiments of the present invention have been described, these embodiments are provided for illustrative purposes only and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways and can be omitted, replaced, or modified without departing from the scope of the invention. These embodiments and their variations are included in the scope and spirit of the invention and are also included in the invention described in the claims and their equivalents.

Claims

1. An image forming apparatus, characterized in that: have: a detection unit that detects temperature information related to a temperature of a toner stored in a toner cartridge and exposed to heat generated in the image forming apparatus; an image forming section that forms a toner image on a sheet using toner supplied from the toner cartridge; a fixing section that fixes the toner image formed on the sheet by the image forming section; as well as a control unit that controls the fixing temperature of the fixing unit based on the temperature information detected by the detection unit and an accumulated time indicating an accumulation of times when the temperature information is detected; The control section acquires characteristic information determined by characteristics of the toner, the characteristic information including partition determination information and correction information, The partition determination information is information for determining a partition based on the temperature detected by the detection unit and the accumulated time. The correction information is information indicating the partition and the correction temperature corresponding to the partition. The control unit determines the partition for the toner, acquires a correction temperature based on the determined partition using the corresponding correction information, and controls the fixing temperature in the fixing unit at the corrected temperature.

2. The image forming apparatus according to claim 1, wherein The characteristic information is stored in a storage unit provided in the toner cartridge. The control unit acquires the characteristic information from the storage unit.

3. The image forming apparatus according to claim 2, wherein: The storage unit stores information for determining whether the toner cartridge is a defective product.

4. The image forming apparatus according to claim 1, wherein The characteristic information is information for correcting the fixing temperature to be higher as the temperature indicated by the temperature information is higher or the accumulation time is longer.

5. A toner cartridge containing toner, characterized in that: The toner cartridge is a toner cartridge for an image forming apparatus according to any one of claims 1 to 4, The toner cartridge includes a storage unit that stores characteristic information for correcting a fixing temperature when fixing a toner image formed on a sheet using toner supplied from the toner cartridge.

6. The toner cartridge according to claim 5, wherein: The characteristic information is information for correcting the fixing temperature to be higher as the temperature indicated by the temperature information related to the temperature of the toner stored in the toner cartridge is higher or the accumulated time for which the temperature information is detected is longer.

7. The toner cartridge according to claim 5, wherein The storage unit stores information for determining whether the toner cartridge is a defective product.

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