JP4904899B2 - Image forming apparatus and image forming apparatus control method - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer having a power saving mode for power saving, and a control method for the image forming apparatus.

  In the conventional image forming apparatus, in order to reduce power consumption in a state where the image forming operation is not performed, an operation in a power saving mode for cutting off the energization of the fixing heater and the drive motor is provided. Time is measured in the normal mode waiting for image formation, and when the measurement time reaches a predetermined time, the operation state of this power saving mode is entered. For example, in the image forming apparatus described in Patent Document 1 below, the presence or absence of a human body around the image forming apparatus is detected when the measurement time in the normal mode reaches a predetermined time. At this time, if a human body is not detected, the mode shifts to an operation state of the power saving mode. However, if a human body is detected, the time for shifting to the power saving mode is extended. Further, in the image forming apparatus described in Patent Document 2 below, when the measurement time in the normal mode reaches a predetermined time, an adjustment process for suppressing the occurrence of density unevenness is executed. In addition, in the conventional image forming apparatus, after the end of the image forming operation, the time measurement is started when the rotational drive of the drive motor is stopped, and the adjustment process of each part of the apparatus is performed during the time measurement. There is one that once clears the measurement time so far and starts time measurement from the beginning after execution of the adjustment process.

JP-A-10-105291 JP 2004-102240 A

  However, in the image forming apparatus described in Patent Document 1 described above, the presence or absence of a human body around the image forming apparatus is one of the conditions for shifting to the power saving mode. There is no description of a case where adjustment processing such as preventing deformation or stirring the toner is executed. In addition, in the image forming apparatus described in Patent Document 2 described above, the time condition for executing the adjustment process in the normal mode is described. However, the transition to the power saving mode as the predetermined time elapses is described. It has not been. Further, in the conventional image forming apparatus that starts the time measurement from the beginning after the adjustment process described above, the time for shifting to the power saving mode is shifted later, and the power saving mode cannot be efficiently shifted. There is.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and an image forming apparatus control method that efficiently shifts from the normal mode to the power saving mode and further reduces power consumption when the adjustment processing of each part of the apparatus is executed in the normal mode operation state Is to provide.

  An image forming apparatus according to the present invention is an image forming apparatus that operates in a normal mode and a power saving mode that consumes less power than the normal mode, and a set time that defines a condition for shifting from the normal mode to the power saving mode An adjustment unit for acquiring adjustment information indicating an operation state of an adjustment process to each unit of the image forming apparatus. An information acquisition unit; and a power saving determination unit that determines whether or not to shift from the normal mode to the power saving mode. The power saving determination unit measures the set time stored in the storage unit and the time measuring unit. Whether to shift from the normal mode to the power saving mode is determined based on the normal mode time and the adjustment information acquired by the adjustment information acquisition unit. And wherein the door.

According to the image forming apparatus of the present invention, in the normal mode operation state, the normal mode time is measured by the timer unit, and the adjustment information indicating the operation state of the adjustment process for each part of the apparatus is acquired by the adjustment information acquisition unit. Then, based on the set time that is a condition for shifting to the power saving mode, the measured normal mode time, and the acquired adjustment information, the power saving determining unit determines whether to shift to the power saving mode.
Since the above adjustment information is used as the determination material related to the transition to the power saving mode, it is possible to determine whether or not to shift to the power saving mode based on the operation state such as whether or not the adjustment process is in operation. it can. Accordingly, the time for shifting to the power saving mode can be flexibly changed in accordance with the operation state of the adjustment process, and the mode can be efficiently shifted to the power saving mode, and the power saving effect of the image forming apparatus can be enhanced.

  In the above-described image forming apparatus according to the present invention, the time measuring unit starts measuring the normal mode time when the final sheet is discharged in association with the image forming operation in the image forming apparatus.

  In the above-described image forming apparatus according to the present invention, the timekeeping unit calculates the normal mode time when the adjustment information acquired by the adjustment information acquisition unit indicates that the adjustment processing is being performed while measuring the normal mode time. Continue to measure.

  In the above-described image forming apparatus according to the present invention, the power saving determination unit determines that the normal mode time during measurement reaches the set time stored in the storage unit and can shift to the power saving mode. To do.

  In the above-described image forming apparatus according to the present invention, the power saving determination unit is configured to receive the adjustment information acquired by the adjustment information acquisition unit when the normal mode time during measurement reaches the set time stored in the storage unit. When the adjustment process is being performed, it is determined that the normal mode can be shifted to the power saving mode after the adjustment process is completed.

  The image forming apparatus control method according to the present invention measures a storage mode for storing a set time for defining a condition for shifting from the normal mode to the power saving mode, and a normal mode time indicating an elapsed time in the normal mode. A time measuring step, an adjustment information obtaining step for obtaining adjustment information indicating an operation state of adjustment processing to each part of the apparatus constituting the image forming apparatus, and power saving for determining whether or not to shift from the normal mode to the power saving mode. A determination step, wherein the power saving determination step is based on the set time stored by the storage step, the normal mode time measured by the time measurement step, and the adjustment information acquired by the adjustment information acquisition step. It is determined whether or not to shift to the power saving mode.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

<Configuration of image forming apparatus>
First, the configuration of an image forming apparatus in which a plurality of toner cartridges are detachably mounted will be described.
FIG. 1 is a diagram showing an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus of FIG. The image forming apparatus 1 forms a full color image by superposing four color toners of yellow (Y), cyan (C), magenta (M), and black (K), or uses only black (K) toner. To form a monochrome image. In the image forming apparatus 1, when an image signal is given from an external device such as a host computer to the main controller 11 shown in FIG. 2, the mechanical controller 12 causes each unit of the engine unit EG to respond to a command from the main controller 11. A predetermined image forming operation is executed by controlling this operation, and an image defined by the image signal is formed on the sheet S.

  In the engine unit EG, as shown in FIG. 1, the photosensitive member 22 is provided to be rotatable in the arrow direction D1. Further, a charging unit 23, a developing unit 4, and a cleaning unit 25 are arranged around the photosensitive member 22 along the rotation direction D1. The charging unit 23 is applied with a predetermined charging bias, and uniformly charges the outer peripheral surface of the photoconductor 22 to a predetermined surface potential. The cleaning unit 25 removes toner remaining on the surface of the photoconductor 22 after the primary transfer, and collects it in a waste toner tank provided inside. The photosensitive member 22, the charging unit 23, and the cleaning unit 25 integrally constitute a photosensitive member cartridge 2, and the photosensitive member cartridge 2 is detachably attached to the main body of the image forming apparatus 1 as a whole. Yes.

  Further, the exposure unit 6 irradiates the light beam L toward the outer peripheral surface of the photosensitive member 22 charged by the charging unit 23. The exposure unit 6 exposes the light beam L onto the photoconductor 22 in accordance with an image signal given from an external device, and forms an electrostatic latent image corresponding to the image signal.

  The electrostatic latent image thus formed is developed with toner by the developing unit 4. The developing unit 4 is configured as a toner cartridge that is detachable with respect to a support frame 40 that is rotatably provided around a rotation axis orthogonal to the paper surface of FIG. 1, and is a yellow toner that contains toner of each color. A cartridge 4Y, a cyan toner cartridge 4C, a magenta toner cartridge 4M, a black toner cartridge 4K, and a rotary drive unit for rotating them integrally are provided. The developing unit 4 is controlled by a mechanical controller 12 shown in FIG. The developing unit 4 is driven to rotate based on a control command from the mechanical controller 12, and the toner cartridges 4Y, 4C, 4M, and 4K are selectively brought into contact with the photosensitive member 22 and face each other with a predetermined gap therebetween. When the toner is positioned at a predetermined developing position, toner is applied to the surface of the photoreceptor 22 from a developing roller 44 provided in the toner cartridge and carrying toner of a selected color. As a result, the electrostatic latent image on the photosensitive member 22 is visualized with the selected toner color.

  The toner image developed by the developing unit 4 as described above is primarily transferred onto the intermediate transfer belt 71 of the transfer unit 7 in the primary transfer region TR1. The transfer unit 7 includes an intermediate transfer belt 71 that is stretched over a plurality of rollers 72 to 75, and a drive unit that rotates the intermediate transfer belt 71 in a predetermined rotation direction D2 by rotationally driving the roller 73. . When transferring a color image onto the sheet S, the color toner images formed on the photosensitive member 22 are superimposed on the intermediate transfer belt 71 to form a color image, and are taken out from the cassette 8 and conveyed one by one. The color image is secondarily transferred onto the sheet S conveyed to the secondary transfer region TR2 along the path F.

  At this time, in order to correctly transfer the image on the intermediate transfer belt 71 to a predetermined position on the sheet S, the timing of feeding the sheet S to the secondary transfer region TR2 is managed. Specifically, a gate roller 81 is provided on the transport path F on the front side of the secondary transfer region TR2, and the gate roller 81 rotates in accordance with the timing of the circumferential movement of the intermediate transfer belt 71. S is sent to the secondary transfer region TR2 at a predetermined timing.

  The sheet S on which the color image is formed in this way is conveyed to the discharge tray unit 89 provided on the upper surface of the main body of the image forming apparatus 1 via the fixing unit 9, the pre-discharge roller 82 and the discharge roller 83.

  Here, the fixing unit 9 is provided with a fixing roller 91 and a pressure roller 92 that rotate while being in pressure contact with each other, and the pressure roller 92 is driven to rotate as the fixing roller 91 is driven to rotate by a driving unit. A fixing heater 9A (see FIG. 2) is inserted inside the fixing roller 91 and the pressure roller 92, and the fixing unit 9 heats and pressurizes the sheet S on which the color image is formed by the toner image, and the toner. The image is fixed by fusing it to the sheet S.

  When images are formed on both sides of the sheet S, the rear end portion of the sheet S on which the image is formed on one side as described above has been conveyed to the reversal position PR via the pre-discharge roller 82. At that time, the rotation direction of the discharge roller 83 is reversed, whereby the sheet S is conveyed in the direction of the arrow D3 along the reverse conveyance path FR. Then, the sheet is again placed on the transport path F before the gate roller 81. At this time, the image is transferred first on the surface of the sheet S on which the image is transferred by contacting the intermediate transfer belt 71 in the secondary transfer region TR2. It is the opposite surface. In this way, images can be formed on both sides of the sheet S.

  Next, as shown in FIG. 2, the main controller 11 includes a CPU 111, an interface 112, a ROM 113, a RAM 114, a memory 115 as a storage unit, and a timer 116 as a timing unit. In addition, an operation unit 119 provided with a display panel 119P is connected to the main controller 11 in order for the user to operate the image forming apparatus 1.

  The interface 112 receives an image signal or the like from an external device. The ROM 113 stores a calculation program executed by the CPU 111, control data for controlling the mechanical controller 12, and the like. The RAM 114 temporarily stores calculation results in the CPU 111 and data such as image signals received via the interface 112. The memory 115 stores, for example, a set time 115A that is input by the user from the operation unit 119 and defines a condition for shifting from the normal mode to the power saving mode. The timer 116 measures the time in the image forming apparatus 1 such as measuring the elapsed time in the normal mode operation state as the normal mode time.

  Here, the memory 115 provided in the main controller 11 uses a non-volatile memory that retains information even in a non-energized state in order to store the set time 115A and the like. As such an element, for example, a flash memory or a ferroelectric memory can be used.

  On the other hand, the mechanical controller 12 includes a CPU 121, a ROM 122, a RAM 123, a motor drive circuit 124, and a heater drive circuit 125. The ROM 122 stores a calculation program executed by the CPU 121, control data for controlling the engine unit EG, and the like. The RAM 123 temporarily stores the calculation result by the CPU 121. The motor drive circuit 124 receives a control signal from the CPU 121 and drives each drive unit for units such as the photosensitive cartridge 2, the developing unit 4, the exposure unit 6, the transfer unit 7, the fixing unit 9, and the cooling fan 10. To control. The heater driving circuit 125 receives a control signal from the CPU 121 and controls the temperature of the fixing heater 9 </ b> A provided in the fixing unit 9. Further, the engine unit EG is provided with various sensors 19 composed of various sensors for purposes such as image density measurement, fixing member temperature / humidity measurement, consumables monitoring, and cover open / close monitoring. Yes.

<Power supply path of image forming apparatus>
Next, the power supply path of the image forming apparatus 1 will be described.
FIG. 3 is a block diagram illustrating a power supply path of the image forming apparatus. As shown in FIG. 3, the image forming apparatus 1 includes a power supply unit 13. The power supply unit 13 converts a DC power supply voltage into DC voltages of 5V, 24V, and 100V, respectively, a DC power supply 131, a DC power supply 132, and a DC power supply. 133 is provided.

  The output voltage of the DC power supply 131 (5 V) is supplied to a control circuit such as a CPU 111 provided in the main controller 11 and a CPU 121 provided in the mechanical controller 12. Further, the output voltage of the DC power supply 132 (24V) is driven by each unit such as the photosensitive cartridge 2, the developing unit 4, the exposure unit 6, the transfer unit 7, the fixing unit 9, and the cooling fan 10 provided in the engine unit EG. Is supplied to a motor or the like for driving the unit and various sensors 19. The output voltage of the DC power supply 133 (100 V) is supplied to a fixing heater 9A provided in the fixing unit 9.

  The image forming apparatus 1 executes an image forming operation when an image signal is received from an external device via an interface 112 (see FIG. 2) provided in the main controller 11. The state in which the image forming operation is being executed or can be executed immediately without taking a preparation time is the normal mode operation state. On the other hand, in order to reduce power consumption, the state of suppressing the supply of the predetermined power described above is the operation state of the power saving mode. In this power saving mode operation state, an output voltage of 5 V is constantly supplied to the main controller 11 and the mechanical controller 12, and therefore communication is possible even during the power saving mode operation.

<Transition from normal mode to power saving mode>
Next, an operation for shifting from the normal mode to the operation state of the power saving mode will be described.
FIG. 4 is a flowchart showing an operation of shifting from the normal mode to the power saving mode and returning to the normal mode again. The operations in each step shown in FIG. 4 are all executed under the control of the CPU 111 provided in the main controller 11.

First, in step S510 shown in FIG. 4, it is determined whether or not a signal indicating that the power is ON or a signal indicating that the discharge of the final sheet has been completed in association with the image forming operation has been received in the operation state of the normal mode. judge. If either signal of power ON or paper discharge completion is received, the process proceeds to the next step S520.
On the other hand, if neither the power-on signal nor the signal indicating completion of paper discharge has been received, that is, if the image forming operation is being performed, the image forming operation ends and the apparatus waits until the final paper discharge is completed.

  In step S520, the timer 116 provided in the main controller 11 starts measuring the normal mode time indicating the elapsed time in the normal mode operation state. Here, the normal mode time to be measured is the elapsed time after the power is turned on in step S510 when a power-on signal is received, and the latest image forming operation is performed when a paper discharge completion signal is received. Along with this, it is an elapsed time after the discharge of the final sheet is completed.

In step S530, it is determined whether or not the normal mode time being measured by the timer 116 has reached a set time that defines a condition for shifting to the power saving mode. If the set time has been reached, the process proceeds to step S550.
On the other hand, if the set time has not been reached, the process advances to step S540 to determine whether an image formation execution signal has been received. This image formation execution signal is a signal for newly executing an image formation operation, and is received from the external device via the interface 112.

Here, the set time is a time set by the user from the operation unit 119 of the image forming apparatus 1, and is stored in the set time 115 </ b> A area of the memory 115 provided in the main controller 11. If the user has not set the set time, the set time stored as an initial value in the set time 115A area is valid.
Note that the storage step of the present invention corresponds to a step of storing the set time set by the user from the operation unit 119 in the set time 115A region.

If an image formation execution signal is received in step S540, the transition process to the power saving mode is terminated while the normal mode operation state is maintained in order to newly execute an image formation operation.
On the other hand, if an image formation execution signal has not been received, the process returns to the determination process of step S530. Until the normal mode time reaches the set time or the image formation execution signal is received, the determination processing in steps S530 and S540 is repeated and waits.

  In step S550, adjustment information indicating the operation state of the adjustment process for each unit is acquired. This adjustment information indicates the presence / absence of an adjustment process in operation, and indicates the type of adjustment process when the adjustment process is in operation. Here, the types of adjustment processing to be performed include, for example, roller position adjustment, toner stirring adjustment, image density adjustment, warm-up adjustment, cool-down adjustment, and the like. Each adjustment process is executed by transmitting a signal instructing execution of the adjustment process from the CPU 111 to the CPU 121 provided in the mechanical controller 12, and the CPU 121 receives this signal and controls the engine unit EG. On the contrary, the adjustment processing end signal is sent from the CPU 121 that controls the engine unit EG to the CPU 111. Based on these signals, the CPU 111 acquires adjustment information indicating the presence or absence of adjustment processing during operation.

In step S560, it is determined whether or not a transition from the current normal mode to the power saving mode is possible. If the transition to the power saving mode is not possible, the adjustment information acquisition process in step S550 and the determination process in step S560 are repeated until standby is possible.
On the other hand, if the transition to the power saving mode is possible, the process proceeds to the next step S570.
Here, whether or not the transition to the power saving mode is possible is determined based on whether or not each unit of the engine unit EG is performing the adjustment processing based on the adjustment information acquired in step S550. In other words, when the normal mode time during measurement reaches the set time and it is possible to shift to the power saving mode, if there is any part of the device that is in the adjustment processing operation, it waits for the end of the adjustment processing to save power. It will shift to the mode.

  In step S570, a transition process from the normal mode to the power saving mode is performed. Here, a signal instructing the shift to the power saving mode is transmitted to the CPU 121. The CPU 121 receives this signal and performs control to cut off the 100V output voltage supplied to the fixing heater 9A and the like. As a result, the image forming apparatus 1 shifts to the operation state of the power saving mode. Here, in addition to the output voltage of 100V supplied to the fixing heater 9A and the like, the output voltage of 24V supplied to a motor or the like for driving each drive unit may be cut off.

In step S580, it is determined whether or not an image formation execution signal has been received in the operation state of the power saving mode. If an image formation execution signal is received, the process proceeds to step S590 in order to shift from the power saving mode to the normal mode operation state in which the image forming operation is possible.
On the other hand, when the image formation execution signal is not received, the operation state of the power saving mode is continued until the image formation execution signal is received.

  In step S590, a signal instructing CPU 121 to shift to the normal mode is transmitted. The CPU 121 receives this signal and performs control to re-energize the output voltage that has been cut off so far. As a result, the image forming apparatus 1 shifts to the original operation mode of the normal mode.

  In addition, the timing process of this invention is corresponded to the process of measuring elapsed time in said step S520-S540. Moreover, the adjustment information acquisition part and adjustment information acquisition process of this invention are corresponded to said step S550. The power saving determination unit and the power saving determination process of the present invention correspond to step S560 described above.

<Example of transition from normal mode to power saving mode>
Next, an example of shifting from the normal mode to the power saving mode will be described using a time chart.
FIG. 5 is a time chart showing an example of transition from the normal mode to the power saving mode, (a) is a time chart showing an example in which the adjustment process is not executed, and (b) is adjusted before reaching the set time. It is a time chart which shows the example which has performed processing, and (c) is a time chart which shows the example under adjustment processing operation, when set time is reached. In FIGS. 3A to 3C, ts indicates the set time stored in the set time 115A area of the memory 115, and the horizontal axis t indicates the passage of time.

  First, in the case of the time chart shown in FIG. 6A, the measurement of the normal mode time is started simultaneously with the completion of the discharge of the final sheet accompanying the image forming operation. Then, when the normal mode time during measurement reaches the set time ts, the operation mode is shifted to the power saving mode.

  Next, in the case of the time chart shown in FIG. 6B, the normal mode time measurement is started at the same time as the paper discharge is completed, and the normal mode time during the measurement is set to the set time ts, as in FIG. When it reaches, it shifts to the power saving mode operation state. Here, in FIG. 5B, the adjustment process has been executed before the normal mode time reaches the set time ts, but this adjustment process operation does not affect the time for shifting to the power saving mode. That is, when the adjustment process is executed, the time is continuously measured without clearing the normal mode time being measured so far.

  Next, in the case of the time chart shown in FIG. 10C, the normal mode time starts to be measured simultaneously with the completion of the paper discharge, as in FIGS. The adjustment process is in operation when the set time ts is reached. For this reason, after the normal mode time reaches the set time ts and the time t1 until the adjustment processing operation ends, the operation mode is shifted to the power saving mode. In other words, after the set time ts + t1 has elapsed from the completion of the discharge of the final sheet, the state shifts to the power saving mode.

Next, a description will be given in comparison with an example of shifting from the normal mode to the power saving mode in the conventional image forming apparatus.
FIG. 6 is a time chart showing an example of transition from the normal mode to the power saving mode in the conventional image forming apparatus, (a) is a time chart showing an example in which adjustment processing is not executed, and (b) is a setting. It is a time chart which shows the example which performed adjustment processing before reaching time. In FIGS. 4A and 4B, ts indicates the set time stored in the set time 115A area of the memory 115, and the horizontal axis t indicates the passage of time.

  First, the time chart shown in FIG. 5A is compared with the time chart shown in FIG. In FIG. 6A, unlike FIG. 5A, the measurement of the normal mode time is started when the discharge of the final sheet is completed and the engine unit EG is stopped. More specifically, the measurement is started when the rotation of the intermediate transfer belt 71 or the like is stopped and the application of the charging bias or the like is stopped. Then, when the normal mode time during measurement reaches the set time ts, the operation mode is shifted to the power saving mode. That is, when the time from the completion of paper discharge to the engine stop is t2, in FIG. 6A, the time from the completion of paper discharge to the transition to the power saving mode is longer by t2 than in FIG. .

  Next, the time chart shown in FIG. 5B and FIG. 6B will be compared. In FIG. 6B, unlike FIG. 5B, the measurement of the normal mode time is started when the discharge of the final sheet is completed and the engine unit EG is stopped. Similarly to FIG. 5B, the adjustment process has been executed before the normal mode time reaches the set time ts. However, in FIG. 6B, the normal mode time is reached when the adjustment process operation ends. Is cleared and re-measured from the beginning. For this reason, when the normal mode time after the end of the adjustment process reaches the set time ts, the operation mode is shifted to the power saving mode. That is, if the time from the engine stop to the execution of the adjustment process is t3 and the adjustment process operation time is t4, the time from the completion of the paper discharge to the transition to the power saving mode is t2 + t3 + t4, as compared with FIG. Only get longer.

  In the time chart examples of FIGS. 5B, 5C, and 6B described above, the adjustment process is executed only once in the normal mode operation state. The type of adjustment processing may be executed a plurality of times, and a plurality of types of adjustment processing may be executed.

  As described above, in the image forming apparatus 1 of the present embodiment, as shown in the time chart examples of FIGS. 5A to 5C, the normal mode is performed simultaneously with the completion of the discharge of the final sheet accompanying the image forming operation. Start measuring time. In the example of the time chart in the conventional image forming apparatus of FIGS. 6A and 6B, the measurement of the normal mode time is started when the engine unit EG is stopped. It can be said that the timing at which the user recognizes that all the image forming operations have been completed is not when the engine unit EG is stopped but when the final paper discharge is completed. Therefore, the user can more accurately grasp the time from the end of the image forming operation to the transition to the power saving mode without feeling uncomfortable.

Further, as shown in the example of the time chart of FIG. 5B, when the adjustment process is executed in the normal mode operation state, the normal mode time is measured without being involved in the adjustment process operation, and the normal mode time is measured. When the set time ts is reached, the operation mode shifts to the power saving mode. In the example of the time chart in the conventional image forming apparatus of FIG. 6B, the normal mode time is once cleared and measured again from the beginning when the adjustment processing operation is completed. For this reason, in the conventional image forming apparatus, it takes a long time to shift to the power saving mode depending on the timing of executing the adjustment process.
In the example of the time chart of FIG. 5B, even when the adjustment process is executed, the time until the transition to the power saving mode is equal to the set time ts as in the example of FIG. The user can easily understand the time until the transition to the power saving mode without being affected by the execution of the adjustment process.

  Further, as shown in the example of the time chart of FIG. 5C, when the adjustment processing operation is being performed when the normal mode time during measurement reaches the set time ts, the power saving mode is performed after the adjustment processing operation is completed. Transition to the operating state. For this reason, the time until the transition to the power saving mode is increased by the waiting time for the end of the adjustment processing operation. However, since the adjustment processing operation is generally completed in a short time, the user may feel uncomfortable with time. Less is. As described above, even when the adjustment process is executed immediately before the transition to the power saving mode, the transition to the power saving mode can be efficiently performed.

1 is a diagram showing an embodiment of an image forming apparatus according to the present invention. 1 is a block diagram illustrating an electrical configuration of an image forming apparatus. FIG. 3 is a block diagram showing a power supply path of the image forming apparatus. The flowchart figure which shows the operation | movement which transfers to power saving mode from normal mode, and returns to normal mode again. It is a time chart figure which shows the example which shifts from normal mode to power saving mode, (a) is a time chart figure which shows the example which does not perform adjustment processing, (b) has already performed adjustment processing before reaching set time The time chart figure which shows the example of (2), (c) is the time chart figure which shows the example during adjustment processing operation when setting time is reached. FIG. 10 is a time chart illustrating an example of transition from a normal mode to a power saving mode in a conventional image forming apparatus, where (a) is a time chart illustrating an example in which adjustment processing is not performed, and (b) is a time before reaching a set time. The time chart figure which shows the example which has already performed adjustment processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 4 ... Developing unit, 6 ... Exposure unit, 7 ... Transfer unit, 8 ... Cassette, 9 ... Fixing unit, 9A ... Fixing heater, 10 ... Cooling fan, 11 ... Main controller, 12 ... Mechanical controller, DESCRIPTION OF SYMBOLS 13 ... Power supply part, 19 ... Various sensors, 111 ... CPU, 112 ... Interface, 113 ... ROM, 114 ... RAM, 115 ... Memory, 116 ... Timer, 119 ... Operation unit, 119P ... Display panel, 121 ... CPU, 122 ... ROM, 123 ... RAM, 124 ... motor drive circuit, 125 ... heater drive circuit, 131-133 ... DC power supply, ts ... set time.

Claims (6)

An image forming apparatus that operates in a normal mode and a power saving mode that consumes less power than the normal mode,
A storage unit that stores a set time that defines a condition for shifting from the normal mode to the power saving mode;
A time measuring unit for measuring a normal mode time indicating an elapsed time in the normal mode;
An adjustment information acquisition unit that acquires adjustment information indicating an operation state of adjustment processing to each unit of the apparatus constituting the image forming apparatus;
A power saving determination unit for determining whether to shift from the normal mode to the power saving mode,
The power saving judgment unit
A set time stored by the storage unit;
Normal mode time measured by the timekeeping unit,
An image forming apparatus that determines whether to shift from the normal mode to the power saving mode based on the adjustment information acquired by the adjustment information acquisition unit.   The image forming apparatus according to claim 1, wherein the time measuring unit starts measuring the normal mode time when a final sheet is discharged in association with an image forming operation in the image forming apparatus.   The time measuring unit continuously measures the normal mode time when the adjustment information acquired by the adjustment information acquisition unit indicates that the adjustment processing is being performed while the normal mode time is being measured. Item 3. The image forming apparatus according to Item 1 or 2.   The power saving determination unit determines that it is possible to shift to the power saving mode when the normal mode time during the measurement reaches a set time stored in the storage unit. The image forming apparatus according to claim 1.   When the adjustment information acquired by the adjustment information acquisition unit indicates that the adjustment processing is being performed when the normal mode time during measurement reaches the set time stored in the storage unit, the power saving determination unit The image forming apparatus according to claim 4, wherein it is determined that the normal mode can be shifted to the power saving mode after the processing operation is completed. A storage step of storing a set time for defining a condition for shifting from the normal mode to the power saving mode;
A time measuring step for measuring a normal mode time indicating an elapsed time in the normal mode;
An adjustment information acquisition step of acquiring adjustment information indicating an operation state of adjustment processing to each part of the apparatus constituting the image forming apparatus;
A power saving determination step of determining whether to shift from the normal mode to the power saving mode,
The power saving judgment step includes:
The set time stored by the storing step;
Normal mode time measured by the time measuring step,
A control method for an image forming apparatus, comprising: determining whether to shift from the normal mode to the power saving mode based on the adjustment information acquired in the adjustment information acquisition step.

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