Image forming apparatus

Abstract

When the fixing temperature correction information cannot be acquired due to a failure or the like of the storage unit or the communication unit, the temperature correction with respect to the fixing target temperature may become excessive, resulting in a fixing failure.SOLUTION: The image forming apparatus includes a developer storage body storing a developer, a developing unit capable of storing the developer supplied from the developer storage body, a fixing unit fixing an image on a recording material by a heating rotator and a pressure rotator, and a temperature control unit controlling a temperature of the heating rotator, wherein the temperature control unit controls a target temperature of the heating rotator from a first temperature to a second temperature based on first information acquired from the developer storage body and second information acquired from the developing unit when the first information and the second information satisfy a predetermined condition. When first information acquired from the developer storage body and second information acquired from the developing means do not satisfy a predetermined condition, the temperature control means controls the target temperature of the heating rotating body to be the first temperature.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electrophotographic image forming apparatus capable of forming an image on a recording material, such as a multifunction machine, a copying machine, a printer, or a facsimile machine. [Background technology]

[0002] In recent years, in image forming apparatuses using electrophotography or the like, efforts have been made to conserve energy by reducing the power consumption of the fixing device, which accounts for a large portion of the power consumption of the image forming apparatus, and shortening the start-up time of the fixing device. To reduce the power consumption of the fixing device, it is necessary to lower the target temperature of the fixing device. The target temperature of the fixing device required to obtain an appropriate image differs depending on the fixing temperature characteristics of the toner, which is an index of the toner's fixing performance on the recording material when the toner is heated and pressurized in the fixing device. Therefore, Patent Document 1 proposes a technology for setting an optimal fixing temperature according to the fixing temperature characteristics of the toner.

[0003] In Patent Document 1, the temperature control temperature of the fixing device is corrected based on correction information for the first fixing temperature of the toner of the developing device stored in a first memory means provided in the main body and correction information for the second fixing temperature stored in a second memory means provided in the toner bottle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-148254 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the fixing temperature correction information is stored in a first storage means provided in the main body or a second storage means provided in the toner bottle as in Patent Document 1, if the information cannot be acquired due to a malfunction of the storage means or communication means, the following problem occurs: If the fixing temperature correction information stored in the storage means changes from a state in which it can be recognized by the control circuit (correct state) to a state in which it cannot be recognized (incorrect state), the temperature correction relative to the fixing target temperature may become excessive, resulting in an abnormal image such as poor fixing. [Means for solving the problem]

[0006] An image forming apparatus according to an embodiment of the present invention is detachably attached to the image forming apparatus and comprises a developer accommodating body containing developer, a developing means capable of accommodating developer supplied from the developer accommodating body, an image forming means for forming an image using the developer, a transfer means for transferring the image formed by the image forming means to a recording material, a rotatable heating rotor having a heating body, and a fixing means for fixing the image transferred by the transfer means to the recording material using a pressure rotor, and a temperature control means for controlling the temperature of the heating rotor.When first information acquired from the developer accommodating body and second information acquired from the developing means satisfy predetermined conditions, the temperature control means controls the target temperature of the heating rotor from a first temperature to a second temperature based on the first information and the second information, and when the first information acquired from the developer accommodating body and the second information acquired from the developing means do not satisfy the predetermined conditions, the temperature control means controls the target temperature of the heating rotor to the first temperature. [Effects of the Invention]

[0007] According to the present invention, an image forming apparatus can be provided that uses a technology for correcting the target fixing temperature using fixing temperature correction information stored in at least one memory means of a developing device or a toner bottle, and that does not produce abnormal images such as poor fixing even when the memory means is abnormal. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention; [Figure 2] Control block diagram of an image forming apparatus according to the present embodiment [Figure 3] 1 is a cross-sectional view of a fixing device 100 according to the present embodiment; [Figure 4] Flowchart explaining the operation of the first embodiment [Figure 5] Flowchart explaining the operation of the second embodiment DETAILED DESCRIPTION OF THE INVENTION

[0009] An image forming apparatus and fixing temperature control according to the present invention will be described below. [Example]

[0010] (Image forming section) 1 is a cross-sectional view of an image forming apparatus. In this embodiment, an image forming apparatus that forms an image using an electrophotographic process will be described as an example.

[0011] The photosensitive drum 101 is an image carrier and is rotated counterclockwise as indicated by the arrow at a predetermined process speed (peripheral speed). During the rotation of the photosensitive drum 101, the photosensitive drum 101 is charged to a predetermined polarity by a charging device 102 such as a charging roller.

[0012] Next, the charged surface of the photosensitive drum 101 is exposed based on the input image information by a laser beam 103 output from a laser optical system 110. The laser optical system 110 outputs the laser beam 103 modulated (on / off) in response to a time-series electric digital pixel signal of the target image information from an image signal generating device such as an image reading device (not shown), and scans and exposes the surface of the photosensitive drum 101. As a result of this scanning and exposure, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 101. Reference numeral 109 denotes a mirror that deflects the laser beam 103 output from the laser optical system 110 to an exposure position on the photosensitive drum 101.

[0013] The electrostatic latent image formed on the photosensitive drum is visualized with yellow toner by a yellow developing device 104y in the developing device 104. This yellow toner image is transferred onto the surface of the intermediate transfer body 105 at a primary transfer portion 111y, which is the contact portion between the photosensitive drum 101y and the intermediate transfer body 105. The toner remaining on the surface of the photosensitive drum 101y is cleaned by a drum cleaner 107y.

[0014] The above-mentioned cycle of charging, exposure, development, primary transfer and drum cleaning is repeated in the same manner to form a magenta toner image, a cyan toner image and a black toner image.

[0015] The multicolor toner images thus formed in succession on the intermediate transfer body 105 are secondarily transferred onto a recording material in a batch in a secondary transfer section 106. Toner remaining on the intermediate transfer body 105 is cleaned by a cleaner 108.

[0016] The recording material that has passed through the secondary transfer unit 106 is introduced into the fixing device 100, which serves as an image heating device, and undergoes a fixing process (image heating process) for the unfixed toner image carried thereon. Then, the recording material that has undergone the fixing process is discharged outside the machine, and a series of image forming operations is completed.

[0017] 2, the image forming apparatus is also provided with a control circuit section 21 represented by a CPU or the like, a third storage means 117 for storing image data and the like, and an operation panel section 112 which serves as an interface for communicating with users and external devices and for accessing the apparatus. The control circuit section 21 monitors and controls the status of various parts of the apparatus, including the image forming section, sheet conveying section, and fixing device 100, and unifies the command system between each device to coordinate the operation of the entire image forming apparatus.

[0018] The third storage means 117 in this embodiment is characterized by storing a video counter value related to the amount of toner consumed from the developing device 104, the amount of toner used calculated from the video counter value, and a correction calculation formula for correcting the fixing temperature control temperature. The video counter value, the amount of toner used, and the correction calculation formula will be described later. In this embodiment, the third storage means 117 is described as being present within the control circuit unit 21, but the third storage means may be a storage means such as an HDD configured to be able to communicate with the control circuit unit 21.

[0019] (developing device) The developing device 104, which serves as a developing means, is detachably connected to a toner bottle 113, which serves as a developer container for storing developer (hereinafter referred to as toner). The developing device 104 can store toner, and the stored toner is consumed each time an electrostatic latent image formed on a photosensitive drum is visualized. A toner usage estimation unit within the image forming apparatus estimates the amount of toner discharged from the developing device 104, and when a predetermined condition is met, toner is replenished from the toner bottle 113 to the developing device 104. As a result, the amount of toner in the developing device 104 is maintained at a substantially constant level. In this embodiment, a video counter system is used as the toner usage estimation unit. A video counter 118 electrically connected to the controller calculates the sum of the densities of each pixel contained in one page of image data (hereinafter referred to as the video counter value) based on the input image data. The video counter value calculated by the video counter 118 is used to calculate the amount of toner used and discharged from the developing device 104.

[0020] Although the video counter method has been described as the means for estimating the amount of consumed toner in this embodiment, a remaining toner amount detection method in which the amount of toner in the developing device 104 is detected by a magnetic permeability sensor or the like may also be adopted.

[0021] Reference numeral 115 denotes a first storage means provided in the developing device 104 for storing information corresponding to correction information for the fixing temperature of the toner in the developing device 104. Reference numeral 116 denotes a second storage means provided in the toner bottle 113 for storing information corresponding to correction information for the fixing temperature of the toner stored in the toner bottle 113. The second storage means in this embodiment employs a nonvolatile memory such as NVRAM, but may also be in the form of an IC tag such as RFID, a QR code (registered trademark), or the like.

[0022] The information corresponding to the toner fixing temperature correction information stored in the first storage means 115 is a correction value for correcting the controlled temperature (hereinafter referred to as fixing temperature correction information 1). The information corresponding to the toner fixing temperature correction information stored in the second storage means 116 is a correction value for correcting the controlled temperature (hereinafter referred to as fixing temperature correction information 2).

[0023] In addition, the fixing temperature correction information 1 stored in the first memory means 115 and the fixing temperature correction information 2 stored in the second memory means 116 are each read on the image forming apparatus side and sent to the control circuit section 21, and are used for controlling this embodiment as described below.

[0024] (fixing device) FIG. 3 is a cross-sectional view of the fixing device 100. As shown in FIG.

[0025] The fixing belt 20 as a heating rotor is a rotatable, endless fixing belt (endless belt) equipped with an elastic layer, and the pressure roller 22 is a pressure roller as a pressure member that forms a fixing nip between itself and the fixing belt. The fixing heater 16 is a fixing heater as a heating element, and the heater holder 17 is a heat-resistant heater holder with a generally trough-shaped cross section. The heater 16 is adhesively fixed to the underside of the heater holder 17 along its length, and is configured to be slidable relative to the fixing belt. The fixing belt 20 is fitted around the heater holder 17.

[0026] The fixing belt 20 has a cylindrical substrate made of cylindrical stainless steel with a thickness of approximately 30 μm, on which a silicone rubber layer (elastic layer) with a thickness of approximately 300 μm is formed, and the surface is covered with a PFA resin tube (outermost layer) with a thickness of approximately 30 μm.

[0027] The pressure roller 22 has a structure in which an approximately 2.5 mm thick silicone rubber layer and an approximately 50 μm thick PFA resin tube are laminated on the surface of an Fe core metal. Both ends of the core metal of the pressure roller 22 are rotatably held between both side plates of the fixing device 100.

[0028] A fixing unit including a fixing heater 16, a heater holder 17, and a fixing belt 20 is installed above the pressure roller 22 as a pressure rotating body. This fixing unit is installed parallel to the pressure roller 22 so that the heater 16 side is in contact with the pressure roller 22.

[0029] The heater holder 17 is made of a highly heat-resistant liquid crystal polymer resin and serves to hold the fixing heater 16 and guide the orbit of the fixing belt 20. Both ends of the heater holder 17 are urged in the axial direction of the pressure roller 22 with a force of 157 N on each side and a total pressure of 314 N by a pressure mechanism (not shown). As a result, the surface of the fixing heater 16 is pressed against the elastic layer of the pressure roller 22 via the fixing belt 20 with a predetermined pressure, forming a fixing nip portion 27 of a predetermined width required for fixing.

[0030] The fixing heater 16 has a resistance heating element B, which is made by applying a conductive paste containing a silver-palladium alloy to a ceramic substrate made of alumina or aluminum nitride in the form of a uniform film about 10 μm thick by screen printing. Furthermore, a glass coating is applied to the heating element to ensure pressure resistance.

[0031] The thermistor 19 and thermistor 18 are a heater back thermistor and a belt back thermistor, respectively, which serve as temperature detection means. The heater back thermistor 19 is installed on the surface opposite the sliding surface of the fixing heater 16 (referred to as the back surface) and serves to detect the back surface temperature of the fixing heater 16. The belt back thermistor 18 is installed above the heater holder 17 so as to elastically contact the inner circumferential surface of the fixing belt 20 and serves to detect the inner surface temperature of the fixing belt 20. Specifically, the temperature detection thermistor is attached to the tip of a stainless steel arm 25 fixedly supported by the heater holder 17. The arm 25 elastically swings, so that the thermistor is always in contact with the inner surface of the fixing belt 20, even when the movement of the inner surface of the fixing belt 20 becomes unstable. The heater back thermistor 19 and the belt back thermistor 18 are each connected to a control circuit unit (CPU) 21, which serves as control means, via A / D converters 64 and 65. The control circuit 21 samples the output from each thermistor at a predetermined interval and reflects the temperature information thus obtained in the temperature control. In other words, the control circuit 21 determines the temperature control content of the fixing heater 16 based on the outputs of the belt-back thermistor 18 and the heater-back thermistor 19, and controls the power supply to the fixing heater 16 using the heater drive control unit 28, which is a power supply unit. The temperature control method of this fixing device mainly determines the power supply value to the heater so that the temperature value detected by the belt-back thermistor 18 can be stably maintained at the desired temperature. Specifically, this is calculated from the target temperature of the belt-back thermistor 18, the detected temperature, the temperature change per unit time, the heater input power value, and PI control parameters. This allows the power to be changed so that the temperature quickly reaches the target temperature (hereinafter referred to as the controlled temperature) and is maintained stably. In this case, since the direct heat source is the fixing heater 16, the temperature detected by the heater backside thermistor 19 and the amount of temperature change are also subjected to auxiliary PI control to prevent the temperature of the fixing belt 20 from fluctuating too suddenly, thereby stabilizing the inner surface temperature of the fixing belt 20 more quickly. This embodiment is characterized in that the temperature control is performed by correcting the temperature control using the fixing temperature correction information 1 stored in the first storage means 115.

[0032] When the image forming operation starts, the pressure roller 22 is driven to rotate at a predetermined peripheral speed in the direction of the arrow. The fixing belt 20, which is in pressure contact with the pressure roller 22, is driven by the pressure roller 22 and rotates at a predetermined speed. At this time, the inner surface of the fixing belt 20 is in a driven rotation state in the direction of the arrow around the outer periphery of the heater holder 17 while sliding in close contact with the sliding surface of the fixing heater 16. Heat-resistant grease is applied to the inner surface of the fixing belt 20 to ensure sliding between the heater holder 17 and the inner surface of the fixing belt 20.

[0033] When the pressure roller 22 is driven to rotate and the cylindrical fixing belt 20 is driven to rotate, power is supplied to the fixing heater 16. When the fixing belt 20 reaches a desired temperature, a recording material (hereinafter referred to as a sheet P) carrying an unfixed toner image t is guided along the entrance guide 23 and introduced into the fixing nip portion 27.

[0034] In the fixing nip portion 27, the toner image bearing surface of the sheet P is in close contact with the outer peripheral surface of the fixing belt 20, and the sheet moves together with the fixing belt 20. During the process of sandwiching and conveying the sheet in the fixing nip, heat from the fixing belt 20 is imparted to the sheet P, and the unfixed toner image is melted and fixed onto the sheet P. After passing through the fixing nip portion 27, the sheet P is separated from the fixing belt 20 by its curvature and is discharged by the fixing discharge rollers 26.

[0035] (Image formation flow) The image forming process according to the present invention will be described with reference to the flowchart of FIG.

[0036] First, a flow in the case where information on the first storage means 115 of the developing device 104 and the second storage means 116 of the toner bottle 113 can be acquired will be described.

[0037] When the control circuit 21 receives an image formation signal for image formation (S001), it sets the print mode (S002). Here, the target base temperature Tb and print speed S for controlling the temperature of the fixing belt 20 using the belt back thermistor 18 are determined from an internal table based on various information used in image formation. The various information includes one or more of sheet information (type, basis weight, size), image information (monochrome mode / color mode), and ambient temperature information. For example, for 64g plain paper, color mode, and a 25°C environment, Tb = 190°C and S = 100% are determined as the print mode. Generally, toner peeling is more likely to occur with sheets of higher basis weight or under conditions with lower boundary temperatures, so the fixing target temperature is set higher. For extra-thick paper or special paper that is still difficult to print even when the temperature is raised to its maximum, the print speed S may be reduced.

[0038] In the following, using this flowchart, a case will be described in which the target fixing temperature can be lowered by 5°C by calculating the correction amount for the target fixing temperature from the correction information for the fixing temperature stored in the first storage unit 115 of the developing device 104 and the second storage unit 116 of the toner bottle 113. For example, in this embodiment, the target basic temperature Tb is set to a high temperature to match toner with poor fixing properties. Depending on the characteristics of the toner, the fixing properties may be good, so it may be possible to set a lower temperature from the perspective of power consumption. Therefore, the actual target fixing temperature is determined by the correction amount for the target fixing temperature stored in the toner bottle 113 and the developing device 104.

[0039] In step S003, the fixing temperature correction information is read from the second storage means 116 of the toner bottle 113, and a determination is made as to whether the fixing temperature correction information is correct. In the determination, it is determined whether the fixing temperature correction information stored in the storage means is within a correct value range. Specifically, it is determined whether the read value is within a predetermined range pre-stored in the image forming apparatus. Here, if the fixing temperature correction information cannot be read from the second storage means 116 of the toner bottle 113, the determination is made as incorrect. Even if the correction information can be read, if the read value is outside the predetermined range, the determination is made as incorrect. If the correction information can be read and the read value is within the predetermined range, the determination is made as correct. If the determination in step S003 is correct, the fixing temperature correction information is read from the first storage means 115 of the developing device 104, and a determination is made as to whether the fixing temperature correction information is correct. If the result of the determination in step (S004) is correct, the process proceeds to step (S005) to determine whether correction of the target fixing temperature is in progress or has been stopped. Specifically, the process checks whether correction has been stopped in step (S011), which will be described later. The state can be determined, for example, by setting a flag in a third storage unit indicating whether correction is in progress and then referencing that flag. If correction is in progress, the temperature correction amount for the target fixing temperature is calculated in step (S006), and the corrected target fixing temperature (in this example, the target temperature can be set 5°C lower, so it is set to 185°C) is determined based on the target base temperature and the temperature correction amount in step (S007). For example, if the toner bottle 113 has just been replaced, the toner in the toner bottle and the toner in the developing device are from different bottles. Therefore, the correction amount read in step S003 and the correction amount read in step S004 are different values. In step S007, the correction amount for the target fixing temperature for the actual image formation is calculated based on the correction amounts read from steps S003 and S004. In step (S008), an image forming operation is performed using the corrected fixing target temperature (185° C.), and in step (S009), the image forming operation is repeated until the final sheet is determined.

[0040] Next, a flow in a state where it is not possible to acquire information from either the first storage means 115 of the developing device 104 or the second storage means 116 of the toner bottle 113 will be described.

[0041] Steps (S001) and (S002) are the same as those described above, so the explanation will be omitted.

[0042] If the fixing temperature correction information cannot be read from the second storage unit 116 of the toner bottle 113 in step S003, the correction of the fixing target temperature (5°C in this example) based on the fixing temperature correction information is stopped in step S011. Then, the fixing target temperature is determined to be the target base temperature (190°C) in step S012, the image forming operation is performed in step S008, and the image forming operation is repeated until the last sheet is determined in step S009. Similarly, if the fixing temperature correction information cannot be read from the first storage unit 115 of the developing device 104 in step S004, the correction of the fixing target temperature (5°C in this example) based on the fixing temperature correction information is stopped in step S011. Then, the fixing target temperature is determined to be the target base temperature (190°C) in step S012, the image forming operation is performed in step S008, and the image forming operation is repeated until the last sheet is determined in step S009.

[0043] Finally, we will explain the flow when the correction of the fixing target temperature is stopped and the image forming operation is performed at the fixing target temperature without correction, and the information from the first storage means 115 of the developing device 104 and the second storage means 116 of the toner bottle 113 can be read.

[0044] Steps (S001) and (S002) are the same as those described above, so the explanation will be omitted.

[0045] In step (S003), the fixing temperature correction information is read from the second storage means 116 of the toner bottle 113, and a determination is made as to whether the fixing temperature correction information is correct. In the determination, it is determined whether the fixing temperature correction information stored in the second storage means 116 is within the correct value range. If the determination in step (S003) determines that the fixing temperature correction information is correct, in step (S004), the fixing temperature correction information is read from the first storage means 115 of the developing device 104, and a determination is made as to whether the fixing temperature correction information is correct. If the determination in step (S004) determines that the fixing temperature correction information is correct, in step (S005), it is determined whether correction of the fixing target temperature is being executed or has been stopped. If correction of the fixing target temperature is stopped, in step (S010), it is determined whether the temperature correction information of the toner in the developing device 104 is in a state where temperature correction can be resumed. Specifically, it is determined whether the correction, which was stopped in S010, can be canceled. Examples of conditions under which it is determined in step (S010) that the toner temperature correction information in the developing device 104 is in a state where temperature correction can be resumed are as follows: when the developing device 104 is replaced with a new one, when an unreadable bottle is replaced with a readable bottle, or when toner is replenished to the developing device 104 from a toner bottle 113 that is recognized by the second storage means 116. Another example is when toner is repeatedly replenished to the developing device 104 from a toner bottle 113 that is recognized by the second storage means 116, and it is determined that the fixing temperature correction information in the first storage means 115 of the developing device 104 has become sufficiently close to the temperature correction information of the toner bottle 113. If it is determined in step (S010) that correction of the fixing target temperature cannot be resumed, correction of the fixing target temperature (5°C in this example) using the fixing temperature correction information obtained from the developing device 104 or toner bottle 113 is stopped in step (S011). Then, in step (S012), the target fixing temperature is determined to be the target basic temperature (190°C), and in step (S008), the image forming operation is performed, and the image forming operation is repeated until the final sheet is determined in step (S009).If, in step (S010), it is determined that the temperature correction information for the toner in the developing device 104 is in a state where correction of the target fixing temperature can be resumed, the temperature correction amount for the target fixing temperature is calculated in step (S006).Then, in step (S007), the corrected target fixing temperature (in this example, it is set to 185°C, assuming that it can be set 5°C lower) is determined from the target basic temperature and the temperature correction amount. In step (S008), the corrected target fixing temperature (185°C) is used to perform image formation, and the image formation is repeated until the final sheet is determined in step (S009).

[0046] As described above, correction of the target fixing temperature is controlled in accordance with the judgment of the correctness of the read state of the storage means storing the correction information for the fixing temperature in at least one of the first storage means 115 of the developing device 104 or the second storage means 116 of the toner bottle 113. This makes it possible to provide an image forming apparatus that does not produce abnormal images such as poor fixing even when an abnormality occurs in the storage means.

[0047] In this embodiment 1, a storage means is provided in both the developing device 104 and the toner bottle 113, but although not shown, the same effect can be obtained by providing the storage means in either the developing device 104 or the toner bottle 113. [Example]

[0048] In the first embodiment, if the information from either the first storage means 115 of the developing device 104 or the second storage means 116 of the toner bottle 113 cannot be read, the correction amount of the fixing target temperature is immediately stopped. However, even if the information from the toner bottle 113 cannot be read, the correction amount of the fixing target temperature may be continued as long as toner is not replenished from the toner bottle 113 to the developing device 104. In the second embodiment, it will be described that even if the information from the toner bottle 113 cannot be read, the correction amount of the fixing target temperature is continued as long as toner is not replenished from the toner bottle 113 to the developing device 104, thereby controlling the correction of the fixing target temperature at the optimal timing.

[0049] The configuration is the same as that of the first embodiment, and therefore a description thereof will be omitted.

[0050] (Image formation flow) The image forming process according to the present invention will be described with reference to the flowchart of FIG.

[0051] First, a flow when information can be read from the first storage means 115 of the developing device 104 and the second storage means 116 of the toner bottle 113 will be described.

[0052] When the control circuit unit 21 receives an image formation signal (S1), it sets the print mode (S2). Here, the control circuit unit 21 determines the target base temperature Tb and print speed S for temperature control of the fixing belt 20 from an internal table using various information used in image formation. Here, the various information refers to one or more types of information including sheet information (type, basis weight, size), image information (monochrome mode / color mode), and outside air temperature information.

[0053] In the example of 64g plain paper, color mode, and a 25°C environment, Tb=190°C and S=100%. Generally, the higher the basis weight and the lower the boundary temperature, the more likely toner peeling occurs, so the target fixing temperature is set higher. For extra-thick paper or special paper that is still difficult to handle even when the temperature is raised to its limit, the print speed may be reduced to address this issue.

[0054] Although not shown, the following flow will be explained using an example in which the correction amount for the target fixing temperature can be calculated from the correction information for the fixing temperature stored in the second storage means 116 of the toner bottle 113 to lower the temperature by 5°C.

[0055] In step (S3), the fixing temperature correction information is read from the second storage means 116 of the toner bottle 113, and a determination is made as to whether the fixing temperature correction information is correct. In the determination, it is determined whether the fixing temperature correction information stored in the second storage means 116 is within the correct value range. If the determination in step (S3) determines that the information is correct, it is determined in step (S4) whether correction of the target fixing temperature is stopped. If temperature correction is being performed, in step (S5), the temperature correction amount for the target fixing temperature is calculated, and the corrected target fixing temperature (in this example, it can be set 5°C lower, so it is set to 185°C) is determined. In step (S6), the corrected target fixing temperature (185°C) is used to perform image formation, and this image formation is repeated until the final sheet is determined in step (S7).

[0056] Next, a flow in a state where information in the second storage means 116 of the toner bottle 113 cannot be read will be described.

[0057] Steps (S1) and (S2) are the same as those described above, so the explanation will be omitted.

[0058] If the fixing temperature correction information cannot be read from the second storage means 116 of the toner bottle 113 in step (S3), it is determined in step (S8) whether toner is being replenished from the toner bottle 113 to the developing device 104 (first predetermined condition). If toner is not being replenished from the toner bottle 113 to the developing device 104 in step (S8), it is determined in step (S4) whether correction of the fixing target temperature is being stopped. If temperature correction is being performed, the temperature correction amount for the fixing target temperature is calculated in step (S5), and the corrected fixing target temperature (set to 185°C in this example, assuming that it can be set 5°C lower) is determined. In step (S6), an image forming operation is performed using the corrected fixing target temperature (185°C), and the image forming operation is continued until the final sheet is determined in step (S7). If toner is replenished from the toner bottle 113 to the developing device 104 in step (S8), the correction of the fixing target temperature (5°C in this example) using the fixing temperature correction information in the second storage means 116 of the toner bottle 113 is stopped in step (S10).Then, the fixing target temperature is determined to be the target basic temperature (190°C).In step (S6), an image forming operation is performed using the target basic temperature (190°C), and the image forming operation is repeated until the final sheet is determined in step (S7).

[0059] Finally, we will explain the flow when the information on the toner bottle 113 cannot be read, the correction of the fixing target temperature using the fixing temperature correction information is stopped, and the image forming operation is performed with the fixing target temperature set to the target basic temperature, and the information on the toner bottle 113 can be read.

[0060] Steps (S1) and (S2) are the same as those described above, so the explanation will be omitted.

[0061] In step (S3), the fixing temperature correction information is read from the second storage means 116 of the toner bottle 113, and a determination is made as to whether the fixing temperature correction information is correct. In the determination, it is determined whether the fixing temperature correction information stored in the second storage means 116 is within the correct value range. If it is determined that the fixing temperature correction information is correct in step (S3), it is determined in step (S4) whether correction of the fixing target temperature is currently stopped. If correction of the fixing target temperature is currently stopped, it is determined in step (S9) whether the temperature correction information for the toner in the developing device 104 is in a state where correction of the fixing target temperature can be resumed (second predetermined condition).

[0062] If it is determined in step (S9) that correction of the target fixing temperature can be resumed, the temperature correction amount for the target fixing temperature is calculated in step (S5) and the corrected target fixing temperature is determined (in this example, it can be set 5°C lower, so it is set to 185°C).In step (S6), the corrected target fixing temperature (185°C) is used to perform image formation, and this is repeated until the final sheet is determined in step (S7).

[0063] If it is determined in step (S9) that the correction of the fixing target temperature cannot be resumed, the correction of the fixing target temperature is stopped in step (S10) and the fixing target temperature is determined to be the target basic temperature (190°C).The image forming operation is performed using the target basic temperature (190°C) in step (S6), and the image forming operation is repeated until the final sheet is determined in step (S7).

[0064] As described above, correction of the target fixing temperature is controlled at the optimum timing by determining whether the read state of the storage means storing the correction information for the fixing temperature in the second storage means 116 of the toner bottle 113 is correct, and by using the first and second predetermined conditions. This makes it possible to provide an image forming apparatus that does not produce abnormal images such as poor fixing even when there is an abnormality in the second storage means 116 of the toner bottle 113.

Claims

1. An image forming apparatus, a developer accommodating body detachably attached to the image forming apparatus and accommodating a developer; a developing means capable of accommodating the developer supplied from the developer accommodating body; an image forming means for forming an image using the developer; a transfer means for transferring the image formed by the image forming means onto a recording material; a fixing unit that fixes the image transferred by the transfer unit onto the recording material by a rotatable heating rotor having a heating element and a pressure rotor; a temperature control means for controlling the temperature of the heating rotor; Equipped with When the first information acquired from the developer accommodating body and the second information acquired from the developing means satisfy a predetermined condition, the temperature control means controls the target temperature of the heating rotator to change from a first temperature to a second temperature based on the first information and the second information, When the first information acquired from the developer accommodating body and the second information acquired from the developing means do not satisfy a predetermined condition, the temperature control means controls the target temperature of the heating rotator to become the first temperature. An image forming apparatus characterized by:

2. When the first information stored in the developer accommodating body cannot be acquired, the temperature control means controls the target temperature of the heating rotator to become the first temperature.

3. When the second information stored in the developing means cannot be acquired, the temperature control means controls the target temperature of the heating rotator to the first temperature.

Images