JP4655857B2 - Image forming apparatus and power saving state transition method - Google Patents

Description

  The present invention relates to an image forming apparatus and a power saving state transition method, and more particularly to an image forming apparatus in which an engine unit and a controller unit can transition to a plurality of power saving states, respectively, and a power saving state transition method of the image forming apparatus. .

  In recent years, controllers of image forming apparatuses such as printing apparatuses have been required to have high performance, and controller power saving has been achieved due to an increase in memory resources such as memory and hard disk necessary for control in the controller and complicated OS control. The recovery time from the state has increased.

  In order to shorten the recovery time according to the usage status and suppress the productivity reduction of the image forming apparatus, it may be possible to transition to a plurality of power saving states. The return time differs depending on the operating state of the image forming apparatus.

Select the appropriate power-saving state according to the operating state of the image forming device, and periodically provide information such as the temperature of the fixing heater of the printing device as a device that achieves both reduction in productivity and power saving. A printing apparatus that acquires and determines an appropriate controller power saving state in accordance with a return time from a power saving state in a printer engine unit is known (Patent Document 1).
JP2001-142588

  However, in the printing apparatus described in Patent Document 1, the most efficient power saving state is determined because the power saving state of the controller is determined without considering the change in the recovery time according to the operation state of the controller. There is a problem that you can not.

  The present invention has been made to solve the above-described problems. By considering the operation state of the controller and shifting to an appropriate power saving state, it is possible to suppress a decrease in productivity and efficiently save. An object of the present invention is to provide an image forming apparatus and a power saving state transition method capable of realizing electric power.

In order to achieve the above object, an image forming apparatus according to a first invention is capable of transitioning to each of a plurality of engine power saving states having different power consumptions and forms an image on a recording medium based on image data. An image forming apparatus comprising: an image forming engine unit; and a controller unit that is capable of transitioning to each of a plurality of controller power saving states having different power consumptions and that controls the image forming engine unit. An engine selection unit that selects one of the plurality of engine power saving states when transitioning to a power saving state, and an engine return time that is determined in advance corresponding to the engine power saving state selected by the engine selection unit And when the controller returns corresponding to each of the plurality of controller power saving states calculated based on the operating state of the controller unit. And controller selection means for selecting a controller power saving state corresponding to the controller returning time that is equal to or shorter than the engine returning time and is closest to the engine returning time from the plurality of controller power saving states, with shifts the image forming engine unit to the selected engine power saving state by means of the controller portion configured to include a transition means for shifting to the controller power saving state selected by the controller selecting means, said controller The unit includes a central processing unit, a volatile memory, and at least one non-volatile memory, and the plurality of controller power saving states includes a first controller power saving state for stopping power supply to the central processing unit, and Central processing unit and non-volatile memory A second controller power saving state in which power supply is stopped, and a third controller power saving state in which power supply to the entire controller unit including the central processing unit, the volatile memory, and the nonvolatile memory is stopped. A first controller recovery time corresponding to the first controller power saving state is calculated based on an operation clock of the central processing unit, and a second controller corresponding to the second controller power saving state The return time is calculated based on the first controller return time and the number of nonvolatile memories, and the third controller return time corresponding to the third controller power saving state is the first controller return time. , Based on the second controller return time and the data capacity stored in the volatile memory Calculated .

The power saving state transition method according to the second aspect of the invention is an image forming engine unit capable of transitioning to each of a plurality of engine power saving states having different power consumptions and forming an image on a recording medium based on image data. When power consumption can transition to each of the different controllers power saving state, and, seen including a controller unit for controlling the image forming engine unit, said controller unit, a central processing unit, volatile memory, and A power saving state transition method for an image forming apparatus including at least one non-volatile memory , wherein when selecting a power saving state, one of the plurality of engine power saving states is selected, and the selected engine saving state is selected. The plurality of controller power saving states calculated on the basis of a predetermined engine return time corresponding to the power state and an operating state of the controller unit Based on the controller return time corresponding to each, a controller power saving state corresponding to the controller return time that is equal to or shorter than the engine return time and closest to the engine return time is selected from the plurality of controller power saving states, Transitioning the image forming engine unit to the selected engine power saving state and transitioning the controller unit to the selected controller power saving state , wherein the plurality of controller power saving states are the central processing A first controller power saving state for stopping power supply to the apparatus; a second controller power saving state for stopping power supply to the central processing unit and the nonvolatile memory; the central processing unit; the volatile memory; And the entire controller unit including the nonvolatile memory A third controller power saving state in which power supply is stopped, and a first controller return time corresponding to the first controller power saving state is calculated based on an operation clock of the central processing unit, and The second controller return time corresponding to the second controller power saving state is calculated based on the first controller return time and the number of the nonvolatile memories, and the third controller return time corresponding to the third controller power saving state is calculated. The controller return time is calculated based on the first controller return time, the second controller return time, and the data capacity stored in the volatile memory .

  According to the first invention and the second invention, when transitioning to the power saving state, any one of the plurality of engine power saving states is selected and predetermined according to the selected engine power saving state. A controller that is shorter than or equal to the engine return time and closest to the engine return time based on the engine return time and the controller return time corresponding to each of the plurality of controller power saving states calculated based on the operation state of the controller unit A controller power saving state corresponding to the return time is selected from a plurality of controller power saving states. Then, the image forming engine unit is shifted to the selected engine power saving state, and the controller unit is shifted to the selected controller power saving state.

  Therefore, the controller recovery time is calculated based on the operation state of the controller unit, and the engine recovery time is changed to the controller power saving state corresponding to the controller recovery time that is not longer than the engine recovery time and is closest to the engine recovery time. Since the transition to the controller power saving state where the power consumption is minimized can be made within a range that does not exceed, it is possible to suppress a reduction in productivity and efficiently achieve power saving.

An image forming apparatus according to a third invention is capable of transitioning to each of a plurality of engine power saving states having different power consumptions, and forms an image on a recording medium based on image data; An image forming apparatus capable of transitioning to each of a plurality of controller power saving states having different power consumptions and including a controller unit that controls the image forming engine unit, wherein the controller unit transitions to a power saving state. Controller selection means for selecting one of the plurality of controller power saving states, and controller return corresponding to the controller power saving state selected by the controller selection means calculated based on the operating state of the controller unit Based on a time and an engine return time predetermined for each of the plurality of engine power saving states. An engine selection unit that selects an engine power saving state corresponding to an engine return time that is equal to or shorter than the controller return time and that is closest to the controller return time, and is selected by the engine selection unit. The image forming engine unit is shifted to the engine power saving state, and the controller unit is configured to transition the controller unit to the controller power saving state selected by the controller selection unit . A central processing unit, a volatile memory, and at least one non-volatile memory, wherein the plurality of controller power saving states include a first controller power saving state in which power supply to the central processing unit is stopped; and the central processing unit And power supply to the nonvolatile memory A second controller power saving state to stop, and a third controller power saving state to stop power supply to the entire controller unit including the central processing unit, the volatile memory, and the nonvolatile memory, The first controller return time corresponding to the first controller power saving state is calculated based on the operation clock of the central processing unit, and the second controller return time corresponding to the second controller power saving state is: The third controller return time calculated based on the first controller return time and the number of the non-volatile memories and corresponding to the third controller power saving state is the first controller return time, the second controller return time, It is calculated on the basis of the controller return time and the data capacity stored in the volatile memory .

The power saving state transition method according to the fourth aspect of the invention is an image forming engine unit capable of transitioning to each of a plurality of engine power saving states having different power consumptions and forming an image on a recording medium based on image data. When power consumption can transition to each of the different controllers power saving state, and, seen including a controller unit for controlling the image forming engine unit, said controller unit, a central processing unit, volatile memory, and A power saving state transition method for an image forming apparatus including at least one non-volatile memory , wherein one of the plurality of controller power saving states is selected when transitioning to a power saving state, and an operation state of the controller unit A controller return time corresponding to the selected controller power-saving state calculated based on each of the plurality of engine power-saving states Correspondingly, an engine power saving state corresponding to an engine return time that is equal to or shorter than the controller return time and closest to the controller return time is determined from the plurality of engine power save states based on a predetermined engine return time. Selecting and transitioning the image forming engine unit to the selected engine power saving state and transitioning the controller unit to the selected controller power saving state , wherein the plurality of controller power saving states include: A first controller power saving state that stops power supply to the central processing unit; a second controller power saving state that stops power supply to the central processing unit and the nonvolatile memory; the central processing unit; And the entire controller unit including the non-volatile memory A third controller power saving state in which power supply is stopped, and a first controller return time corresponding to the first controller power saving state is calculated based on an operation clock of the central processing unit, and The second controller return time corresponding to the second controller power saving state is calculated based on the first controller return time and the number of the nonvolatile memories, and the third controller return time corresponding to the third controller power saving state is calculated. The controller return time is calculated based on the first controller return time, the second controller return time, and the data capacity stored in the volatile memory .

  According to the third and fourth aspects of the invention, the selected controller is selected based on the operating state of the controller unit by selecting one of the plurality of controller power saving states when transitioning to the power saving state. Based on a controller recovery time corresponding to the power saving state and a predetermined engine recovery time corresponding to each of the plurality of engine power saving states, the engine that is equal to or shorter than the controller recovery time and closest to the controller recovery time The engine power saving state corresponding to the return time is selected from a plurality of engine power saving states. Then, the image forming engine unit is shifted to the selected engine power saving state, and the controller unit is shifted to the selected controller power saving state.

  Therefore, the controller recovery time is calculated based on the operation state of the controller unit, and the controller recovery time is changed to the engine power saving state corresponding to the engine recovery time that is not more than the controller recovery time and is closest to the controller recovery time. Since the transition to the engine power saving state where the power consumption is minimized can be made within a range that does not exceed, the productivity reduction can be suppressed and the power saving can be efficiently realized.

  The image forming engine unit includes a fixing heater for fixing an image formed on a recording medium by heating, and a plurality of engine power saving states are set to a plurality of power consumption states of the fixing heater that are limited to different powers during standby. It can be in the state of.

  As described above, according to the image forming apparatus and the power saving state transition method of the present invention, the controller recovery time is calculated based on the operation state of the controller unit, and the power consumption is within a range not exceeding the controller recovery time. It is possible to make a transition to the minimum engine power saving state, or to make a transition to a controller power saving state with low power consumption within a range that does not exceed the engine recovery time. Thus, it is possible to achieve power saving.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the image forming apparatus 10 according to the first embodiment includes an image reading unit 12 that reads a document and generates image data, and an electrostatic latent image on a photoconductor based on the image data. Operation for instructing various processes of the image forming apparatus 10 and the printer engine unit 14 that records, develops the electrostatic latent image using monochrome toner or color toner, transfers the developed image onto a recording sheet, and outputs it. Control of the start and stop of the supply of power supplied from the main power supply 18 to each unit of the image forming apparatus 10 is performed according to the operation panel unit 16 including buttons and an operation panel, the main power supply 18, and the input power control signal. A power supply control unit 20 is provided.

  For example, the printer engine unit 14 is provided with a fixing heater 22 that is heated to a predetermined temperature by lighting a halogen lamp or the like, and fixes an image on which toner has been developed to a recording sheet by heating and pressing.

  In addition, the image forming apparatus 10 is provided with a controller unit 24 for controlling each unit in the image forming apparatus 10 including the printer engine unit 14. The controller unit 24 includes a CPU 26, a DRAM (Dynamic Random Access Memory) 28 as a volatile system memory, a ROM 30 that stores various programs and basic setting data for basic settings for the CPU 26, an OS, and a power saving transition process described later. A hard disk 32A for storing various programs including routines, a hard disk 32B for storing image data and saving data stored in the DRAM 28, and a hard disk controller 34 for controlling the hard disks 32A and 32B are provided. Yes. A bus 36 for connecting the CPU 26, DRAM 28, ROM 30, and hard disk controller 34 to each other is provided.

  In addition, the controller unit 24 is provided with an application specific integrated circuit (ASIC) 38 to which the image reading unit 12, the printer engine unit 14, the operation panel unit 16, and the power supply control unit 20 are connected. Are connected to the bus 36.

  The image forming apparatus 10 is capable of transitioning to a plurality of levels of power saving states with different power consumptions. For example, the image forming apparatus 10 can transition to the engine power saving state of three levels with different power consumptions for the printer engine unit 14. In addition, for example, the controller unit 24 can transition to three levels of controller power saving states with different power consumption.

  The printer engine unit 14 limits the power supplied to the fixing heater 22 and limits the power consumption of the fixing heater 22 during standby, thereby reducing the engine power saving state level 1 (standby power consumption limited to 80%). The engine power saving state level 2 (the standby power consumption is limited to 50%) and the engine power saving state level 3 (the standby power consumption is limited to 20%) are changed.

  In addition, the controller unit 24 stops power supply to the CPU 26 at the controller power saving state level 1 and supplies power to the hard disks 32A and 32B and the hard disk controller 34 in addition to the CPU 26 at the controller power saving state level 2. In the controller power saving state level 3, the power supply to the entire controller unit 24 including the CPU 26, the hard disks 32A and 32B, the hard disk controller 34, and the DRAM 28 is stopped.

  When transitioning to the controller power saving state level 3, the memory data in use existing in the DRAM 28 is saved to the hard disk 32B, and the data saved to the hard disk 32B is restored to the DRAM 28 when returning from the controller power saving state. Thus, the processing operation by the OS or application becomes possible again.

  Note that the image forming apparatus 10 only needs to have a general configuration and functions of a conventionally known image forming apparatus such as a printer or a scanner. The other configurations and general functions of the image forming apparatus 10 are described in detail. Description is omitted.

  Next, the operation of the first embodiment will be described.

  First, when a power saving button (not shown) provided on the operation panel unit 16 is pressed or when the operation panel unit 16 is not operated for a predetermined time or more, or when the power saving state is lower, the power consumption is further reduced. When a change in the power saving state is instructed to make a transition to the power state, the CPU 26 executes the power saving transition processing routine shown in FIG.

  In step 100, the engine power saving state to which the printer engine unit 14 transitions is selected from engine power saving state levels 1 to 3 based on a predetermined condition. For example, when the power saving button is pressed, the engine power saving state level 3 is selected, and when the operation panel unit 16 is not operated, the engine power saving state level 1 is selected and the engine saving state is selected. In the state of the power state level 1, the engine power saving state level 2 is selected when transitioning to the engine power saving state with lower power consumption.

  Then, in step 102, a predicted engine recovery time Tp that is determined in advance corresponding to the engine power saving state selected in step 100 is read. For example, an expected time table that stores each of the engine power saving states at a plurality of levels of the printer engine unit 14 and the estimated engine recovery time is prepared, and the estimated engine recovery time Tp is read from the expected time table. In the predicted time table, the engine return time is obtained in advance based on the temperature change of the fixing heater 22 when returning from each of the engine power saving state levels 1, 2, and 3, and the calculated value is the expected engine return. Stored as time, the expected return time is, for example, 3 seconds for engine power saving state level 1, 15 seconds for engine power saving state level 2, 50 seconds for engine power saving state level 3, and is fixed respectively. It is a value.

In step 104, an estimated controller recovery time when power supply to the CPU 26 is stopped is calculated. The estimated controller recovery time depends on the operation clock setting of the CPU 26. If the operation clock is low, the estimated controller recovery time becomes long, for example, 1 to 5 seconds. Assuming that the frequency is H, the expected controller recovery time is calculated from the following equation.
Expected controller recovery time = a + b / H
Here, a and b are constants, and a and b are obtained in advance by actually measuring the controller return time of the image forming apparatus 10.

In the next step 106, an expected controller recovery time when power supply to the hard disks 32A and 32B and the hard disk controller 34 is stopped is calculated. The estimated controller recovery time depends on the number of drives managed by the hard disk controller 34. As the number of drives increases, the estimated controller recovery time becomes longer, for example, 10 to 20 seconds. Assuming that the number of drives is HD, the expected controller recovery time is calculated from the following equation.
Expected controller recovery time = c + d x HD
Here, c and d are constants, and c and d are obtained in advance by actually measuring the controller return time of the image forming apparatus 10. In the present embodiment, since the hard disk controller 34 manages the hard disks 32A and 32B, the HD is 2.

In step 108, an estimated controller recovery time when power supply to the DRAM 28 is stopped is calculated. The estimated controller recovery time depends on the amount of memory in use in the DRAM 28, and data is saved in the hard disk 32B. Therefore, if the amount of memory in use is large, the estimated controller recovery time becomes longer, for example, 30 to 60 seconds. is there. Assuming that the amount of memory in use is M, the controller recovery expected time is calculated from the following equation.
Expected controller recovery time = e + f x M
Here, e and f are constants, and e and f are obtained in advance by actually measuring the controller return time of the image forming apparatus 10.

  In the next step 110, the controller recovery expected time T3 corresponding to the controller power saving state level 3 of the controller unit 24 is calculated by summing the controller recovery expected time calculated in steps 104 to 108. Here, since the return process for the CPU 26, the return process for the hard disks 32A and 32B, and the return process for the DRAM 28 cannot be executed in parallel, the controller return expected time T3 is the sum of the time required for each return process. Then, in step 112, it is determined whether or not the expected controller recovery time T3 is equal to or shorter than the expected engine recovery time Tp of the printer engine unit. The controller power saving state level 3 is selected as the controller power saving state in which the transition is made, and in step 114, a power control signal is output to the power control unit 20 so as to limit the standby power of the fixing heater 22 of the printer engine unit 14. The printer engine unit 14 is shifted to the engine power saving state selected in step 100. In step 116, after saving data from the DRAM 28 to the hard disk 32B, a power control signal is output to the power control unit 20 so as to stop the power supply to the entire controller unit 24. A transition to state level 3 is made, and the power saving transition processing routine is terminated.

  On the other hand, if the controller return expected time T3 is greater than the engine return expected time Tp in step 112, the controller return expected time calculated in steps 104 and 106 is summed in step 118, whereby the controller of the controller section 24 is summed. An estimated controller recovery time T2 corresponding to the power saving state level 2 is calculated. In step 120, it is determined whether or not the estimated controller recovery time T2 is equal to or less than the expected engine recovery time Tp of the printer engine unit. If T2 is equal to or shorter than the expected engine recovery time Tp, the controller unit 24 selects the controller power saving state level 2 as the controller power saving state to which the transition is made. In step 114, the controller power saving state level selected in step 100 is set. It shifts the pointer engine unit 14. In step 122, a power control signal is output to the power control unit 20 so as to stop power supply to the CPU 26, hard disks 32A, 32B, and hard disk controller 34 of the controller unit, and the controller unit 24 is set to the controller power saving state level. The power saving transition process routine is terminated.

  On the other hand, if it is determined in step 120 that the estimated controller recovery time T2 is greater than the estimated engine recovery time Tp, in step 124, the estimated controller recovery time calculated in step 104 is the controller recovery expected level corresponding to the controller power saving state level 1. As the time T1, it is determined whether or not the expected controller recovery time T1 is less than or equal to the expected engine recovery time Tp of the printer engine unit. If the expected controller recovery time T1 is less than or equal to the expected engine recovery time Tp, the controller unit 24 transitions. Controller power saving state level 1 is selected as the controller power saving state to be executed, and in step 114, the printer engine unit 14 is shifted to the engine power saving state selected in step 100. In step 126, the controller The power supply to the CPU26 outputs a power control signal to stop the power supply control unit 20, by transitioning the controller unit 24 to the controller power conservation state level 1, and ends the power-saving transition processing routine.

  If the controller return expected time T1 is greater than the engine return expected time Tp in step 124, the printer engine unit 14 is shifted to the engine power saving state selected in step 100 in step 124. The controller unit 24 is not shifted to the controller power saving state, but remains in the normal operation state, and the power saving transition processing routine is terminated.

  When returning from the power saving state, power is supplied to the controller unit 24 and the printer engine unit 14 by the power supply control unit 20 and a recovery process is performed. Since the expected recovery time is equal to or shorter than the expected engine recovery time of the printer engine unit 14, when the printer engine unit 14 returns from the engine power saving state, the controller unit 24 returns from the controller power saving state, and immediately. The printer unit 14 is controlled by the controller unit 24, and various processes are performed in the printer engine unit 14.

  As described above, according to the image forming apparatus according to the first embodiment, the controller recovery estimated time is calculated based on the CPU operation clock of the controller unit, the number of hard disk drives, and the data capacity of the DRAM. By shifting to the controller power saving state that corresponds to the expected controller recovery time that is less than the expected engine recovery time and that is closest to the expected engine recovery time, power consumption is minimized within the range that does not exceed the expected engine recovery time. Since the controller can make a transition to the power saving state, productivity reduction can be suppressed and power saving can be realized efficiently.

  Next, an image forming apparatus according to a second embodiment of the present invention will be described. In addition, about the structure and operation | movement fundamentally the same as 1st Embodiment, the same code | symbol as 1st Embodiment is attached | subjected and the description is abbreviate | omitted.

  In the second embodiment, after the controller power saving state in which the controller unit 24 transitions is selected, the engine power saving state in which the printer engine unit 14 transitions is determined so as to be equal to or shorter than the controller return time of the controller unit 24. This is different from the first embodiment.

  The operation of the second embodiment will be described. When a power saving button (not shown) is pressed, when the operation panel unit 16 is not operated for a predetermined time or more, or when a change in the power saving state is instructed, the power saving transition process shown in FIG. A routine is executed by the CPU 26.

  First, in step 200, the controller power saving state to which the controller unit 24 transitions is selected based on a predetermined condition. For example, when the power saving button is pressed, the controller power saving state level 3 is selected, and when the operation panel unit 16 is not operated, the controller power saving state level 1 is selected and the controller power saving state is selected. In the state of the power state level 1, the controller power saving state level 2 is selected when transitioning to the controller power saving state with lower power consumption.

  In step 104, an estimated controller recovery time when the power supply to the CPU 26 is stopped is calculated. In the next step 202, the controller power saving state selected in step 200 is the controller power saving state level 1. If the controller unit 24 is selected to transition to the controller power saving state level 1, the process proceeds to step 206, but the controller power saving state level 2 or the controller power saving state level 3 If the transition to is selected, in step 106, the controller return expected time when the power supply to the hard disks 32A and 32B and the hard disk controller 34 is stopped is calculated.

  In step 204, it is determined whether or not the controller power saving state selected in step 200 is the controller power saving state level 2. It is selected that the controller unit 24 transitions to the controller power saving state level 2. If YES in step 108, the process proceeds to step 206. If transition to the controller power saving state level 3 is selected, in step 108, the controller recovery expected time when the power supply to the DRAM 28 is stopped is determined. Is calculated.

  In step 206, a controller recovery expected time Tc corresponding to the controller power saving state in which the controller unit 24 selected in step 200 is shifted is calculated. In the case of the controller power saving state level 1 of the controller unit 24, the estimated controller recovery time calculated in step 104 is set as the expected controller recovery time Tc. In the case of the controller power saving state level 2 of the controller unit 24, calculated in steps 104 and 106. The estimated controller recovery time Tc is calculated by summing the estimated controller recovery times, and in the case of the controller power saving state level 3 of the controller unit 24, the controller recovery is calculated by adding the estimated controller recovery times calculated in steps 104 to 106. An expected time Tc is calculated.

  In the next step 208, the expected engine recovery time Tp3 corresponding to the engine power saving state level 3 of the printer engine unit 14 is read from the expected time table. In step 210, the estimated engine recovery time Tp3 is calculated in step 206. It is determined whether or not the estimated controller recovery time Tc is equal to or less than 24, and if the estimated engine recovery time Tp3 is equal to or less than the expected controller recovery time Tc, the engine power saving state level is set as the engine power saving state in which the printer engine unit 14 transitions. 3 is selected, and in step 212, a power control signal is output to the power control unit 20 so as to limit the standby power of the fixing heater 22 of the printer engine unit 14 to 20%. Step 14 To migrate to 26.

  In step 214, the expected engine recovery time Tp2 corresponding to the engine power saving state level 2 of the printer engine unit 14 is read from the expected time table. In step 216, the estimated engine recovery time Tp2 is calculated in step 206. It is determined whether or not the estimated controller recovery time Tc is 24 or less, and if the expected engine recovery time Tp2 is less than or equal to the expected controller recovery time Tc, the engine power saving state level is set as the engine power saving state in which the printer engine unit 14 transitions. 2 is selected, and in step 218, a power control signal is output to the power control unit 20 so as to limit the standby power of the fixing heater 22 of the printer engine unit 14 to 50%. Step 14 To migrate to 26.

  In the next step 220, the expected engine recovery time Tp1 corresponding to the engine power saving state level 1 of the printer engine unit 14 is read from the expected time table. In step 222, the estimated engine recovery time Tp1 is calculated in step 206. It is determined whether or not the estimated controller recovery time Tc is 24 or less. If the estimated engine recovery time Tp1 is less than or equal to the expected controller recovery time Tc, the engine power saving state level is set as the engine power saving state in which the printer engine unit 14 transitions. 1 is selected, and in step 224, a power control signal is output to the power control unit 20 so as to limit the standby power of the fixing heater 22 of the printer engine unit 14 to 80%. 14 is changed to step 22 To be migrated.

  In step 226, a process for transitioning the controller unit 24 to the controller power saving state selected in step 200 is performed. In the case of the controller power saving state level 3, after the data is saved from the DRAM 28 to the hard disk 32B, a power control signal is output to the power control unit 20 so as to stop the power supply to the entire controller unit 24. In the case of the power state level 2, a power control signal is output to the power control unit 20 so as to stop power supply to the CPU 26, the hard disks 32A and 32B, and the hard disk controller 34 of the controller unit. Further, in the case of the controller power saving state level 1, a power control signal is output to the power control unit 20 so as to stop the power supply to the CPU 26 of the controller unit. And if it changes to a controller power saving state, a power saving transition process routine will be complete | finished.

  As described above, according to the image forming apparatus according to the second embodiment, the controller recovery estimated time is calculated based on the CPU operation clock of the controller unit, the number of hard disk drives, and the DRAM data capacity. By shifting to the engine power saving state corresponding to the expected engine recovery time that is less than the expected controller recovery time and closest to the expected controller recovery time, power consumption is minimized within the range that does not exceed the expected controller recovery time. Since it is possible to make a transition to the engine power saving state, it is possible to suppress productivity reduction and efficiently achieve power saving.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. 4 is a flowchart showing the contents of a power saving transition processing routine of the image forming apparatus according to the first embodiment of the present invention. 10 is a flowchart showing the contents of a power saving transition processing routine of the image forming apparatus according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 14 Printer engine part 16 Operation panel part 18 Main power supply 20 Power supply control part 22 Fixing heater 24 Controller part 26 CPU
28 DRAM
30 ROM
32A, 32B Hard disk 34 Hard disk controller

Claims (5)

Transition to each of a plurality of engine power saving states with different power consumption, and an image forming engine section that forms an image on a recording medium based on image data, and each of a plurality of controller power saving states with different power consumption An image forming apparatus that includes a controller unit that is capable of transitioning and that controls the image forming engine unit;
The controller unit;
Engine selection means for selecting any of the plurality of engine power saving states when transitioning to a power saving state;
A controller corresponding to each of the plurality of controller power saving states calculated on the basis of a predetermined engine return time corresponding to the engine power saving state selected by the engine selection means and the operating state of the controller unit Controller selection means for selecting a controller power saving state corresponding to a controller returning time that is equal to or shorter than the engine returning time and that is closest to the engine returning time from the plurality of controller power saving states based on the return time;
Transition means for causing the image forming engine section to transition to the engine power saving state selected by the engine selection means, and for causing the controller section to transition to the controller power saving state selected by the controller selection means;
And configured to include,
The controller unit includes a central processing unit, a volatile memory, and at least one nonvolatile memory,
The plurality of controller power saving states include a first controller power saving state in which power supply to the central processing unit is stopped, and a second controller power saving state in which power supply to the central processing unit and the nonvolatile memory is stopped. And a third controller power saving state that stops power supply to the entire controller unit including the central processing unit, the volatile memory, and the nonvolatile memory,
A first controller return time corresponding to the first controller power saving state is calculated based on an operation clock of the central processing unit;
The second controller return time corresponding to the second controller power saving state is calculated based on the first controller return time and the number of nonvolatile memories,
The third controller return time corresponding to the third controller power saving state is based on the first controller return time, the second controller return time, and the data capacity stored in the volatile memory. An image forming apparatus to be calculated . Transition to each of a plurality of engine power saving states with different power consumption, and an image forming engine section that forms an image on a recording medium based on image data, and each of a plurality of controller power saving states with different power consumption An image forming apparatus that includes a controller unit that is capable of transitioning and that controls the image forming engine unit;
The controller unit;
Controller selection means for selecting one of the plurality of controller power saving states when transitioning to a power saving state;
A controller recovery time corresponding to the controller power saving state selected by the controller selection means calculated based on the operating state of the controller unit, and a predetermined engine corresponding to each of the plurality of engine power saving states Engine selection means for selecting, from the plurality of engine power saving states, an engine power saving state corresponding to an engine return time that is equal to or shorter than the controller return time and closest to the controller return time, based on the return time;
Transition means for causing the image forming engine section to transition to the engine power saving state selected by the engine selection means, and for causing the controller section to transition to the controller power saving state selected by the controller selection means;
And configured to include,
The controller unit includes a central processing unit, a volatile memory, and at least one nonvolatile memory,
The plurality of controller power saving states include a first controller power saving state in which power supply to the central processing unit is stopped, and a second controller power saving state in which power supply to the central processing unit and the nonvolatile memory is stopped. And a third controller power saving state in which power supply to the entire controller unit including the central processing unit, the volatile memory, and the nonvolatile memory is stopped.
A first controller return time corresponding to the first controller power saving state is calculated based on an operation clock of the central processing unit;
The second controller return time corresponding to the second controller power saving state is calculated based on the first controller return time and the number of nonvolatile memories,
The third controller recovery time corresponding to the third controller power saving state is based on the first controller recovery time, the second controller recovery time, and the data capacity stored in the volatile memory. An image forming apparatus to be calculated . The image forming engine unit includes a fixing heater for fixing an image formed on a recording medium by heating,
The image forming apparatus according to claim 1, wherein the plurality of engine power saving states are a plurality of states in which power consumption during standby of the fixing heater is limited to different powers. Transition to each of a plurality of engine power saving states with different power consumption, and an image forming engine section that forms an image on a recording medium based on image data, and each of a plurality of controller power saving states with different power consumption transition possible, and, seen including a controller unit for controlling the image forming engine unit, the controller unit, the power saving state of the central processing unit, volatile memory, and an image forming apparatus including at least one non-volatile memory A transition method,
When transitioning to the power saving state, select one of the plurality of engine power saving states,
An engine return time predetermined corresponding to the selected engine power saving state and a controller return time corresponding to each of the plurality of controller power saving states calculated based on the operation state of the controller unit. Based on the controller power saving state, the controller power saving state corresponding to the controller returning time that is equal to or shorter than the engine returning time and closest to the engine returning time is selected,
Transitioning the image forming engine unit to the selected engine power saving state and transitioning the controller unit to the selected controller power saving state ,
The plurality of controller power saving states include a first controller power saving state in which power supply to the central processing unit is stopped, and a second controller power saving state in which power supply to the central processing unit and the nonvolatile memory is stopped. And a third controller power saving state in which power supply to the entire controller unit including the central processing unit, the volatile memory, and the nonvolatile memory is stopped.
A first controller return time corresponding to the first controller power saving state is calculated based on an operation clock of the central processing unit;
The second controller return time corresponding to the second controller power saving state is calculated based on the first controller return time and the number of nonvolatile memories,
The third controller recovery time corresponding to the third controller power saving state is based on the first controller recovery time, the second controller recovery time, and the data capacity stored in the volatile memory. A power saving state transition method characterized by being calculated . Transition to each of a plurality of engine power saving states with different power consumption, and an image forming engine section that forms an image on a recording medium based on image data, and each of a plurality of controller power saving states with different power consumption transition possible, and, seen including a controller unit for controlling the image forming engine unit, the controller unit, the power saving state of the central processing unit, volatile memory, and an image forming apparatus including at least one non-volatile memory A transition method,
When transitioning to the power saving state, select one of the plurality of controller power saving states,
A controller return time corresponding to the selected controller power saving state calculated based on an operating state of the controller unit, and an engine return time predetermined corresponding to each of the plurality of engine power saving states Based on the engine power saving state, the engine power saving state corresponding to the engine return time that is equal to or shorter than the controller return time and closest to the controller return time is selected.
Transitioning the image forming engine unit to the selected engine power saving state and transitioning the controller unit to the selected controller power saving state ,
The plurality of controller power saving states include a first controller power saving state in which power supply to the central processing unit is stopped, and a second controller power saving state in which power supply to the central processing unit and the nonvolatile memory is stopped. And a third controller power saving state in which power supply to the entire controller unit including the central processing unit, the volatile memory, and the nonvolatile memory is stopped.
A first controller return time corresponding to the first controller power saving state is calculated based on an operation clock of the central processing unit;
The second controller return time corresponding to the second controller power saving state is calculated based on the first controller return time and the number of nonvolatile memories,
The third controller recovery time corresponding to the third controller power saving state is based on the first controller recovery time, the second controller recovery time, and the data capacity stored in the volatile memory. A power saving state transition method characterized by being calculated .

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