JP2015230459A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can suppress a deterioration of a photoreceptor drum.SOLUTION: An image forming apparatus includes a photoreceptor drum, a drum control part that controls the rotation of the photoreceptor drum, a heater that is arranged opposite to a part of the peripheral surface of the photoreceptor drum, and a power source control part. The power source control part returns, during a power-saving mode, the drum control part to a normal mode intermittently for a predetermined period, and the drum control part rotates the photoreceptor drum during the period of the return when the heater is turned on during the period of the return.

Description

  The present invention relates to an image forming apparatus including a photosensitive drum.

  An electrophotographic image forming apparatus is provided with a photosensitive drum. The photosensitive drum carries a toner image and transfers the toner image onto a sheet. Therefore, in order to suppress deterioration in image quality, the surface of the photosensitive drum (the surface carrying the toner image) must be maintained in a good state.

  Here, some image forming apparatuses are equipped with a power saving mode (sleep mode) for suppressing power consumption as a power mode. In such an image forming apparatus, when the mode is shifted to the power saving mode, the inside of the apparatus is gradually cooled, so that condensation is likely to occur on the photosensitive drum. If condensation occurs on the photosensitive drum and the print job is executed as it is, the image quality deteriorates. For this reason, an image forming apparatus equipped with a dew condensation removal mode for removing dew condensation generated on the photosensitive drum has been proposed (see, for example, Patent Document 1).

  In Patent Document 1, when the condensation removal mode is executed, a sheet is conveyed, and the condensation generated on the photosensitive drum is removed by the sheet. At this time, image formation is not performed, and only paper conveyance is performed.

JP-A-8-234649

  In Patent Document 1, even if condensation occurs on the photosensitive drum, the condensation generated on the photosensitive drum can be removed by executing the condensation removal mode. However, when the condensation removal mode is executed, a normal print job cannot be performed during that time, and the convenience for the user is reduced. In order to eliminate such inconvenience, when a heater is installed outside the photoconductor drum and the heater is turned on to warm the photoconductor drum in the power saving mode, it is possible to suppress the occurrence of condensation on the photoconductor drum. There is.

  However, since a transfer roller, a charging device, and the like are disposed in the vicinity of the photosensitive drum, the entire portion around the photosensitive drum cannot be covered with a heater. For this reason, the heater outside the photosensitive drum is in a state of facing only a part of the photosensitive drum. As a result, when the photosensitive drum is warmed by the heater disposed outside the photosensitive drum, a part of the photosensitive drum is heated intensively, and the photosensitive drum is likely to deteriorate.

  The present invention has been made to solve the above-described problems, and has a configuration in which dew condensation is prevented from occurring on the photosensitive drum by heating the photosensitive drum with a heater outside the photosensitive drum. An object of the present invention is to provide an image forming apparatus capable of suppressing deterioration of the image quality.

  In order to achieve the above object, the image forming apparatus of the present invention is equipped with a normal mode and a power saving mode that suppresses power consumption more than the normal mode, and when a predetermined transition condition is satisfied in the normal mode. An image forming apparatus that shifts to a power saving mode and returns to a normal mode when a predetermined return condition is satisfied in the power saving mode. The image forming apparatus is configured to rotate a photosensitive drum supported rotatably and the photosensitive drum. A drum control unit to be controlled, a heater for preventing condensation to warm the photosensitive drum, and a power supply in each mode of the normal mode and the power saving mode. A power control unit for controlling the power supply. The power supply control unit intermittently supplies power to the drum control unit during the power saving mode, thereby intermittently returning the drum control unit to the normal mode for a predetermined period. If the heater is on, the photosensitive drum is rotated during the return period.

  In the configuration of the present invention, if the heater is on during the return period of the drum control unit in the power saving mode, the drum control unit rotates the photosensitive drum. Here, when the photosensitive drum is not rotated, the heat of the heater is intensively applied only to a part of the peripheral surface of the photosensitive drum (a part facing the heater), so that the part of the heater is easily deteriorated. However, when the photosensitive drum is rotated, the portion of the photosensitive drum facing the heater is displaced, so that it is possible to prevent a part of the photosensitive drum from being heated intensively. Thereby, it is possible to suppress deterioration of the photosensitive drum.

  As described above, in the configuration of the present invention, it is possible to suppress deterioration of the photosensitive drum.

Schematic showing an example of a multifunction machine according to an embodiment of the present invention. 1 is a block diagram showing an example of a hardware configuration of a multifunction machine according to an embodiment of the present invention. FIG. 6 is a diagram for explaining the rotation amount of the photosensitive drum when the photosensitive drum is rotated in the power saving mode in the multifunction machine according to the embodiment of the present invention. FIG. 6 is a diagram for explaining the rotation amount of the photosensitive drum when the photosensitive drum is rotated in the power saving mode in the multifunction machine according to the embodiment of the present invention. FIG. 6 is a diagram for explaining the rotation amount of the photosensitive drum when the photosensitive drum is rotated in the power saving mode in the multifunction machine according to the embodiment of the present invention. The flowchart figure for demonstrating the flow of on-off control of the drum heater performed at the time of a power saving mode in the multifunctional device by one Embodiment of this invention. FIG. 7 is a flowchart for explaining the flow of rotation control of the photosensitive drum performed in the power saving mode in the multifunction machine according to the embodiment of the present invention.

  An image forming apparatus according to an embodiment of the present invention will be described by taking as an example a multi-function peripheral equipped with a copy function and a printer function.

<Overall configuration of MFP>
As shown in FIG. 1, the multifunction peripheral 100 (corresponding to the “image forming apparatus” of the present invention) includes an image reading unit 1 and a printing unit 2. The image reading unit 1 reads a document and generates image data. The printing unit 2 transports the paper P along the paper transport path 21 and forms a toner image based on the image data. The image data may be obtained by reading a document by the image reading unit 2 or may be transmitted from a user terminal 200 (see FIG. 2) described later. Then, the printing unit 2 prints the toner image on the paper P being conveyed, and discharges the printed paper P to the discharge tray 22.

  The printing unit 2 includes a paper feeding unit 3, a paper transport unit 4, an image forming unit 5, and a fixing unit 6. The paper feed unit 3 includes a pickup roller 31 and a paper feed roller pair 32, and supplies the paper P stored in the paper cassette 33 to the paper transport path 21. The paper transport unit 4 includes a plurality of transport roller pairs 41 and transports the paper P along the paper transport path 21.

  The image forming unit 5 includes a photosensitive drum 51, a charging device 52, an exposure device 53, a developing device 54, a transfer roller 55, and a cleaning device 56. The photosensitive drum 51 is rotatably supported and is rotated by a driving force transmitted from a drum motor 51M (see FIG. 2) described later. Then, the image forming unit 5 forms a toner image based on the image data on the surface of the photosensitive drum 51, and transfers the toner image from the photosensitive drum 51 to the paper P. The fixing unit 6 includes a heating roller 61 and a pressure roller 62, and fixes the toner image transferred onto the paper P by heating and pressing.

  The multifunction device 100 also includes an operation panel 7. The operation panel 7 includes a liquid crystal display panel 71. The liquid crystal display panel 71 has a touch panel 72 attached to the display surface, and displays soft keys and messages for receiving various settings. Further, the operation panel 7 is also provided with hard keys 73 such as a numeric keypad and a start key.

  In addition, the multifunction peripheral 100 includes a drum heater 8 (corresponding to the “heater” of the present invention) for preventing condensation to warm the photosensitive drum 51. The drum heater 8 is disposed near the outside of the photosensitive drum 51 so as to face a part of the circumferential surface of the photosensitive drum 51.

<Hardware configuration of MFP>
As shown in FIG. 2, the multifunction peripheral 100 includes a main control unit 110 that performs overall control. The main control unit 110 includes a CPU 111, an image processing unit 112, and a storage unit 113. The image processing unit 112 includes an ASIC dedicated to image processing, and performs image processing (enlargement / reduction, density conversion, data format conversion, etc.) on the image data. The storage unit 113 includes a ROM and a RAM, and stores a control program and data.

  The main control unit 110 is connected to the image reading control unit 120, the engine control unit 130, the panel control unit 140, the communication control unit 150, and the power supply control unit 160.

  The image reading control unit 120 receives an instruction from the main control unit 110 and controls the reading operation of the image reading unit 1. The engine control unit 130 receives an instruction from the main control unit 110 and controls the printing operation of the engine unit 2. For example, the engine control unit 130 controls driving of the drum motor 51M for rotating the photosensitive drum 51, and appropriately rotates the photosensitive drum 51.

  The panel control unit 140 receives an instruction from the main control unit 110 and controls the display operation of the operation panel 7. Further, the panel control unit 140 detects an operation performed on the operation panel 7 and transmits a detection result to the main control unit 110.

  For example, the communication control unit 150 is connected to the user terminal 200 via a network so that communication is possible. Accordingly, printing can be performed based on the image data transmitted from the user terminal 200, and image data obtained by reading the document by the image reading unit 1 can be transmitted to the user terminal 200.

  The power supply control unit 160 is connected to a commercial power supply and generates a voltage necessary for operating the multifunction peripheral 100. The power control unit 160 includes the image reading unit 1, the engine unit 2, the operation panel 7, and each control unit (the main control unit 110, the image reading control unit 120, the engine control unit 130, the panel control unit 140, and the communication control unit 150. ) To supply power. Hereinafter, each unit that operates by receiving power supply from the power supply control unit 160 may be collectively referred to as a power-supplied supply unit 170.

  Here, the multifunction peripheral 100 includes a temperature / humidity sensor S1 and a temperature sensor S2. The temperature / humidity sensor S1 is a sensor for detecting the temperature / humidity inside the multifunction peripheral 100, and the temperature sensor S2 is a sensor for detecting the temperature outside the multifunction peripheral 100. Based on the outputs of the temperature / humidity sensor S1 and the temperature sensor S2, the main control unit 110 detects the temperature / humidity (specifically, the ambient temperature and relative humidity of the photosensitive drum 51) in the multifunction peripheral 100. The temperature outside the multifunction device 100 is detected.

  Then, the main control unit 110 performs on / off control of the drum heater 8 based on the detected temperature and humidity. For example, the switch unit 9 is connected to the drum heater 8, and the main control unit 110 performs on / off control of the drum heater 8 by switching on / off of the switch unit 9. The on / off control of the drum heater 8 will be described in detail later.

<Power mode>
The multi-function device 100 includes a normal mode and a power saving mode (sleep mode) as power modes related to power supply to the power supplied unit 170. The normal mode is a mode in which normal power is supplied to the power supplied unit 170. The power saving mode is a mode that suppresses power consumption by restricting power supply to the power-supplied supply unit 170 as compared with the normal mode.

  The power supply control unit 160 supplies power to all parts of the power supplied unit 170 in the normal mode. On the other hand, when the power supply control unit 160 shifts from the normal mode to the power saving mode, the power supply control unit 160 supplies power only to a part of the power supplied unit 170 and stops power supply to other parts.

  Here, the power supply control unit 160 receives power supply even in the power saving mode in order to control power supply in the power saving mode. Moreover, since the panel control part 140 and the communication control part 150 function as a return condition detection part mentioned later, even if it is a power saving mode, it receives electric power supply. As will be described in detail later, the main control unit 110 detects the temperature and humidity inside the multifunction device 100 and the temperature outside the multifunction device 100 based on the outputs of the temperature and humidity sensor S1 and the temperature sensor S2 in the power saving mode. Then, on / off control of the drum heater 8 is performed. Therefore, the part (circuit) necessary for the on / off control of the drum heater 8 in the main controller 110 is supplied with power even in the power saving mode. The power supply control unit 160 may perform on / off control of the drum heater 8 in the power saving mode. In this case, power supply to the main control unit 110 in the power saving mode may be stopped.

  When the condition for shifting from the normal mode to the power saving mode is satisfied, the power supply control unit 160 shifts from the normal mode to the power saving mode. For example, the power supply control unit 160 measures the unused time, which is the time that has passed without the multifunction device 100 being used, and the transition condition is determined when the unused time of the multifunction device 100 exceeds a predetermined threshold time. When satisfied, the normal mode is shifted to the power saving mode. When the unused time is timed by the main control unit 110 and the transition condition is satisfied, the main control unit 110 may notify the power supply control unit 160 to that effect. Alternatively, even when the operation panel 7 receives an instruction to shift from the normal mode to the power saving mode, the power supply control unit 160 shifts from the normal mode to the power saving mode, assuming that the transfer condition is satisfied.

  Then, when the power supply control unit 160 receives a return signal indicating that the return condition from the power saving mode to the normal mode is satisfied from the return condition detection unit, the power supply control unit 160 restarts the power supply to all parts of the power supplied unit 170. (Return from power saving mode to normal power mode).

  A panel control unit 140 is an example of a part corresponding to the return condition detection unit. The panel control unit 140 detects an operation on the touch panel 72 and the hard key 73 even in the power saving mode. When an operation on the touch panel 72 or the hard key 73 is detected, a return signal is output.

  The communication control unit 150 also functions as a return condition detection unit. The communication control unit 150 can communicate with the user terminal 200 even in the power saving mode. When a communication request is received from the user terminal 200, a return signal is output.

<Drum heater on / off control in power saving mode>
The main control unit 110 performs on / off control of the drum heater 8 based on the outputs of the temperature / humidity sensor S1 and the temperature sensor S2. Then, the surrounding environment (temperature and humidity) of the photosensitive drum 51 is maintained such that no condensation occurs on the photosensitive drum 51. In other words, the photosensitive drum 51 is heated so that condensation does not occur on the photosensitive drum 51. This on / off control of the drum heater 8 is performed in the power saving mode in which the multifunction machine 100 is cooled.

  Since the on / off control of the drum heater 8 is performed in the power saving mode, power is supplied to the main controller 110 even in the power saving mode. When the main control unit 110 shifts from the normal mode to the power saving mode, the main control unit 110 detects the ambient temperature and relative humidity of the photosensitive drum 51 based on the output of the temperature and humidity sensor S1. Further, the main control unit 110 detects the temperature outside the multi-function device 100 based on the output of the temperature sensor S2. Hereinafter, the ambient temperature and relative humidity around the photosensitive drum 51 are referred to as internal temperature and internal relative humidity, respectively, and the temperature outside the multifunction peripheral 100 is referred to as external temperature.

  Then, the main controller 110 turns on the drum heater 8 and warms the photosensitive drum 51 when a predetermined heater-on condition is satisfied as a condition for turning on the drum heater 8. Specifically, the main control unit 110 sets a value lower than 100% relative humidity as the reference relative humidity, and turns on the drum heater 51 when the internal relative humidity becomes equal to or higher than the reference relative humidity. That is, the main control unit 110 determines that the heater-on condition is satisfied when the internal relative humidity is equal to or higher than the reference relative humidity. If the reference relative humidity is set too low, the effect of suppressing the occurrence of dew condensation increases, but the power consumption of the drum heater 8 increases accordingly. For this reason, the reference relative humidity is determined in advance in consideration of the effect of suppressing the occurrence of condensation and the power consumption (for example, a value around 90% is set as the reference relative humidity). The reference relative humidity is stored in the storage unit 112.

  When the drum heater 8 is turned on by satisfying the heater-on condition, the photosensitive drum 51 is heated, so that the internal temperature rises and consequently the internal relative humidity falls. That is, an environment in which condensation is unlikely to occur on the photosensitive drum 51 is obtained. As described above, if the drum heater 51 is kept on even in an environment in which condensation is unlikely to occur on the photosensitive drum 51, power is wasted. Therefore, the main controller 110 turns off the drum heater 8 when the internal relative humidity falls below the reference relative humidity, that is, when the heater-on condition is not satisfied. Then, after the drum heater 8 is turned off, when the heater on condition is satisfied again, the drum heater 8 is turned on.

  Here, when the installation environment of the multifunction device 100 is cold, a heater is used, and warmed air may enter the multifunction device 100 (for example, in the morning in winter). In this case, if the temperature difference between the inside and outside of the multifunction peripheral 100 is large, the heated air may touch the photoreceptor drum 51 and condensation may occur on the photoreceptor drum 51. Therefore, main controller 110 determines that the heater-on condition is satisfied and turns on drum heater 8 even when the internal temperature is lower than the external temperature by a predetermined reference temperature difference or more. For example, if the installation environment of the multi-function device 100 is 20 ° C. and the relative humidity is 50% (assuming a heater is used indoors in winter), the dew point is 9 ° C. and the internal temperature is 9 ° C. or less (composite) Condensation occurs when the temperature difference between the inside and outside of the machine 100 is 11 ° C. or more. Accordingly, the reference temperature difference is determined in advance in consideration of what kind of environment the MFP 100 can be installed in. The reference temperature difference is stored in the storage unit 112.

<Rotation control of photoconductor drum in power saving mode>
The power control unit 160 intermittently supplies power to the engine control unit 130 for a predetermined period in the power saving mode. Thereby, the engine control unit 160 is temporarily returned to the normal mode in the power saving mode. For example, the engine control unit 130 temporarily returns to the normal mode at a time interval of 10 minutes to 15 minutes, and the temporary return period is several seconds to several tens of seconds (for example, about 5 seconds). Hereinafter, the temporary return period of the engine control unit 130 in the power saving mode is simply referred to as a temporary return period. Then, the engine control unit 130 performs a predetermined process (hereinafter referred to as a temporary return process) during the temporary return period. For example, the engine control unit 130 detects the apparatus state (such as the remaining amount of paper P stored in the paper cassette 33) of the multifunction device 100 as the temporary return process, and notifies the main control unit 110 of the detection result. Process.

  Here, the drum heater 8 is ON / OFF controlled by the main controller 110 (or the power controller 160) in the power saving mode in order to keep the temperature of the peripheral surface of the photosensitive drum 51 constant. If the drum heater 8 is on during the temporary return period in the power saving mode, the engine control unit 130 rotates the photosensitive drum 51 by a predetermined amount during the temporary return period. For example, the drum motor 51M for rotating the photosensitive drum 51 is a stepping motor, and the engine control unit 130 controls the number of driving pulses of the drum motor 51M (stepping motor) to thereby move the photosensitive drum 51 by a predetermined amount. Rotate.

  Specifically, as shown in FIG. 3, the engine control unit 130 rotates the photosensitive drum 51 by a predetermined amount to face the drum heater 8 in the photosensitive drum 51 at the start of the temporary return period. A portion 51 b different from the portion 51 a that has been disposed is opposed to the drum heater 8. Thereafter, the engine control unit 130 holds the portion 51 b of the photosensitive drum 51 while facing the drum heater 8. As a result, the portion of the photosensitive drum 51 facing the drum heater 8 differs between the start time and end time of the temporary return period of the engine control unit 130. For example, the engine control unit 130 controls the rotation amount of the photoconductive drum 51 so that the portion of the photoconductive drum 51 facing the drum heater 8 does not overlap at the start time and the end time of the temporary return period.

  Then, when the drum heater 8 is turned on when the drum heater 8 is turned on next time, the engine control unit 130 rotates the photoconductor drum 51 by a predetermined amount, so that the photoconductor drum 51 has the previous temporary return period. A portion 51 c different from the portion 51 b facing the drum heater 8 at the end point (the start point of the current temporary return period) is opposed to the drum heater 8. Thereafter, the engine control unit 130 holds the portion 51 c of the photosensitive drum 51 while facing the drum heater 8. Thereafter, if the drum heater 8 is on, the engine control unit 130 rotates the photosensitive drum 51 by a predetermined amount every time the temporary return period starts.

  The rotation amount (predetermined amount) of the photosensitive drum 51 during the temporary return period is not particularly limited. For example, an optimum rotation amount at which the photosensitive drum 51 is easily warmed is experimentally obtained, and the optimum rotation amount is set as the rotation amount of the photosensitive drum 51 during the temporary return period.

  For example, as shown in FIG. 4, by increasing the amount of rotation of the photosensitive drum 51 as compared with the example shown in FIG. 3, the opposite side of the portion 51a facing the drum heater 8 at the start of the temporary return period. The portion 51b may be opposed to the drum heater 8. Alternatively, as shown in FIG. 5, by reducing the rotation amount of the photosensitive drum 51 as compared with the example shown in FIG. 3, the portion 51a facing the drum heater 8 at the start of the temporary return period and the temporary return The portion 51b facing the drum heater 8 may be partially overlapped at the end of the period. In FIG. 5, the overlapping portion is shown in black.

  Further, the rotation amount of the photosensitive drum 51 during the temporary return period may not be constant, and may be controlled based on the internal relative humidity or the temperature difference between the internal temperature and the external temperature. As an example, when the photosensitive drum 51 is likely to be warmed as the amount of rotation of the photosensitive drum 51 during the temporary return period increases, the following control can be considered.

  First, the default value of the rotation amount of the photosensitive drum 51 during the temporary return period is set to a small rotation amount (for example, the rotation amount shown in FIG. 5). In addition, a first reference relative humidity and a second reference phase humidity higher than the first reference relative humidity are set as the reference relative humidity. When the engine control unit 130 is temporarily restored, the internal relative humidity is equal to or higher than the first reference relative humidity, but if the internal relative humidity is lower than the second reference relative humidity, the photoconductor is used to reduce the power consumption of the drum motor 51M. The rotation amount of the drum 51 is set as a default value. On the other hand, if the internal relative humidity is equal to or higher than the second reference relative humidity, the rotation amount of the photosensitive drum 51 is larger than the default value (for example, the rotation shown in FIG. Amount).

  Alternatively, a first reference temperature difference and a second reference temperature difference larger than the first reference temperature difference are set as the reference temperature difference. When the engine control unit 130 temporarily returns, the internal temperature is lower than the first reference temperature difference by more than the first reference temperature difference, but if the difference between the internal temperature and the external temperature does not exceed the second reference temperature difference, the drum motor 51M In order to reduce the power consumption, the rotation amount of the photosensitive drum 51 is set as a default value. On the other hand, if the internal temperature is lower than the external temperature by the second reference temperature difference or more, the rotation amount of the photosensitive drum 51 is larger than the default value (for example, as shown in FIG. Rotation amount).

<Drum heater on / off control flow in power saving mode>
The flow of on / off control of the drum heater 8 in the power saving mode will be described below with reference to the flowchart shown in FIG. It is assumed that the drum heater 8 is off at the start of the flowchart shown in FIG. Then, when the power mode shifts from the normal mode to the power saving mode, the flowchart shown in FIG. 6 starts.

  In step S1, the power supply control unit 160 determines whether or not a return condition is satisfied. As a result, if the return condition is not satisfied, the process proceeds to step S2. In step S2, the main control unit 110 determines whether the heater-on condition is satisfied based on the outputs of the temperature / humidity sensor S1 and the temperature sensor S2. As a result, if the heater-on condition is satisfied, the process proceeds to step S3. If the heater-on condition is not satisfied, the process proceeds to step S4.

  When the process proceeds to step S3, the main control unit 110 switches the drum heater 8 from off to on, while when the process proceeds to step S4, the main control unit 110 maintains the drum heater 8 in an off state. Thereafter, the process proceeds to step S1, and the main control unit 110 determines again whether or not the return condition is satisfied. If the return condition is not satisfied, the main control unit 110 proceeds to step S2. In step S2, main controller 110 determines again whether the heater-on condition is satisfied, and proceeds to step S3 or step S4.

  At this time, the drum heater 8 may be on or the drum heater 8 may be off. When the drum heater 8 is on, the main control unit 110 keeps the drum heater 8 on when the process proceeds to step S3, while the main control unit 110 turns on the drum heater 8 when the process proceeds to step S4. Switch from to off. When the drum heater 8 is off, the main control unit 110 switches the drum heater 8 from off to on when the process proceeds to step S3, and when the process proceeds to step S4, the main control unit 110 turns the drum heater 8 on. Keep off.

  Thus, main controller 110 determines whether or not the heater on condition is satisfied until the return condition is satisfied, and repeats the on / off control of drum heater 8 based on the determination result.

  In step S1, when the power supply control unit 160 determines that the return condition is satisfied, the process proceeds to step S5. In step S5, the power control unit 160 returns from the power saving mode to the normal mode. Thereafter, in step S6, the main controller 110 switches the drum heater 8 from on to off when the drum heater 8 is on, and turns the drum heater 8 on when the drum heater 8 is off. Keep off.

<Flow of photosensitive drum rotation control in power saving mode>
The flow of rotation control of the photosensitive drum 51 in the power saving mode will be described below with reference to the flowchart shown in FIG. It is assumed that the power mode is shifted from the normal mode to the power saving mode at the start of the flowchart shown in FIG. Then, when the engine control unit 130 temporarily returns during the power saving mode, the flowchart shown in FIG. 7 starts.

  In step S11, the engine control unit 130 determines whether the drum heater 8 is on. For example, since the engine control unit 130 communicates with the main control unit 110 during the temporary return period, the data about the on / off of the drum heater 8 is acquired from the main control unit 110 at that time, and the on / off of the drum heater 8 is based on the acquired data. Judging. As a result, if the drum heater 8 is on, the process proceeds to step S12.

  In step S12, the engine control unit 130 determines whether the photosensitive drum 51 has already been rotated during the current temporary return period. As a result, if the photosensitive drum 51 has not yet been rotated, the process proceeds to step S13, and the engine control unit 130 rotates the photosensitive drum 51 by a predetermined amount. Thereafter, the process proceeds to step S14. Note that if the engine control unit 130 determines in step S12 that the photosensitive drum 51 has already been rotated, the process proceeds to step S14.

  In step S14, the engine control unit 130 determines whether or not the temporary return process to be performed in the temporary return period has been completed. As a result, if the temporary return process is completed, the process proceeds to step S15. If the temporary return process is not completed, the process returns to step S11. In step S15, the engine control unit 130 requests the main control unit 110 or the power supply control unit 160 to stop power supply to the engine control unit 130. Thereby, the temporary return of the engine control unit 130 ends.

  As described above, the multifunction peripheral 100 (image forming apparatus) of the present embodiment includes the photosensitive drum 51 that is rotatably supported, and the engine control unit 130 (drum control unit) that controls the rotation of the photosensitive drum 51. A drum heater 8 (heater) for preventing condensation, which is disposed outside the photosensitive drum 51 so as to face a part of the peripheral surface of the photosensitive drum 51, and for heating the photosensitive drum 51, and normal mode and power saving A power control unit 160 that controls power supply in each mode. The power supply control unit 160 intermittently supplies power to the drum control unit during the power saving mode, thereby causing the engine control unit 130 to intermittently return to the normal mode for a predetermined period. If the drum heater 8 is on during the return period, the photosensitive drum 51 is rotated during the return period.

  In this configuration, if the drum heater 8 is on during the return period of the engine control unit 130 in the power saving mode, the engine control unit 130 rotates the photosensitive drum 51. Here, when the photosensitive drum 51 is not rotated, the heat of the drum heater 8 is intensively applied only to a part of the peripheral surface of the photosensitive drum 51 (a portion facing the drum heater 8). A part is likely to deteriorate. However, when the photosensitive drum 51 is rotated, the portion of the photosensitive drum 51 facing the drum heater 8 is shifted, so that it is possible to prevent a part of the photosensitive drum 51 from being heated intensively. it can. Thereby, it is possible to suppress the deterioration of the photosensitive drum 51.

  In the present embodiment, as described above, the engine control unit 130 performs photosensitivity during the return period so that the portion of the photosensitive drum 51 facing the drum heater 8 is different between the start time and the end time of the return period. The body drum 51 is rotated by a predetermined amount. With this configuration, the portion of the photosensitive drum 51 facing the drum heater 51 can be easily made different before and after the temporary return of the engine control unit 130.

  In the present embodiment, as described above, the temperature / humidity sensor S1 for detecting the temperature / humidity in the multifunction peripheral 100, the temperature sensor S2 for detecting the temperature outside the multifunction peripheral 100, and the temperature / humidity sensor S1. And a main control unit 110 (detection unit) that detects an internal temperature and an internal relative humidity in the multi-function device 100 based on the output of the multi-function device 100 and detects an external temperature outside the multi-function device 100 based on the output of the temperature sensor S2. The drum heater 8 is in the power saving mode when the main control unit 110 detects that the internal temperature is lower than the external temperature by a predetermined reference temperature difference or the internal relative humidity is in advance. Turns on when the main control unit 110 detects that the predetermined reference relative humidity is exceeded. That is, the drum heater 8 is turned on when a predetermined heater-on condition is satisfied in the power saving mode, and is not always turned on in the power saving mode. If comprised in this way, the power consumption of the drum heater 8 can be suppressed easily.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the description of the above-described embodiment but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

8 Drum heater (heater)
51 Photosensitive drum 100 MFP (image forming apparatus)
110 Main control unit (detection unit)
130 Engine control unit (drum control unit)
160 Power control unit S1 Temperature / humidity sensor S2 Temperature sensor

Claims (4)

It is equipped with a normal mode and a power saving mode that suppresses power consumption compared to the normal mode, and transitions to the power saving mode when a predetermined transition condition is satisfied in the normal mode, and in advance in the power saving mode. An image forming apparatus that returns to the normal mode when a predetermined return condition is satisfied,
A photoconductor drum supported rotatably;
A drum controller for controlling the rotation of the photosensitive drum;
A heater for preventing condensation that is disposed opposite to a part of the peripheral surface of the photosensitive drum, and that heats the photosensitive drum;
A power control unit that controls power supply in each mode of the normal mode and the power saving mode, and
The power supply control unit intermittently supplies power to the drum control unit during the power saving mode, thereby intermittently returning the drum control unit to the normal mode for a predetermined period of time,
The drum control unit rotates the photosensitive drum during the return period if the heater is turned on during the return period.   The drum controller rotates the photosensitive drum by a predetermined amount during the return period so that a portion of the photosensitive drum facing the heater is different between a start time and an end time of the return period. The image forming apparatus according to claim 1. A temperature and humidity sensor for detecting the temperature and humidity in the image forming apparatus;
A temperature sensor for detecting the temperature outside the image forming apparatus;
A detection unit that detects an internal temperature and an internal relative humidity in the image forming apparatus based on an output of the temperature / humidity sensor and detects an external temperature outside the image forming apparatus based on an output of the temperature sensor;
In the power saving mode, the heater detects when the detection unit detects that the internal temperature is lower than the external temperature by a predetermined reference temperature difference or when the internal relative humidity is in advance. 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is turned on when the detection unit detects that the temperature exceeds a predetermined reference relative humidity. 4.   4. The drum control unit according to claim 3, wherein the drum control unit controls a rotation amount of the photosensitive drum during the return period based on the internal relative humidity or a temperature difference between the internal temperature and the external temperature. The image forming apparatus described.

Images