JP2013196472A - Information processor and power saving program for information processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve both power consumption reduction and convenience.SOLUTION: The information processor includes: an off-mode 1 for interrupting power supply to its own device; and an off-mode 2 whose power consumption is larger than that of the off-mode 1, and whose time necessary for recovery is shorter than that of the off-mode 1, and a main power source SW12 is controlled by a controller 20 such that the off-mode 1 is shifted to the off-mode 2 after the lapse of a predetermined time without instructing any operation, and that the minimum shift time TA satisfying (power consumption P1 of the off-mode 1×T+power consumption P0 in standby time×recovery time T1 until recovery from the off-mode 1)≤(power consumption P2 of off-mode 2×T+power consumption P0 in standby×recovery time T2 until recovery from the off-mode 2) is preliminarily searched, and that the off-mode 2 is shifted to the off-mode 1 after the lapse of the shift time TA since the off-mode 1 is shifted to the off-mode 2.

Description

  The present invention relates to an information processing apparatus and a power saving program for the information processing apparatus.

  In recent years, there has been an increasing demand for reducing power consumption during standby of image forming apparatuses. For example, in the Erp (Energy-related Products) directive of energy saving regulations in Europe, the mode automatically shifts to an off mode after a predetermined time has elapsed. Therefore, a new regulation is scheduled to reduce power consumption to 0.5 Wac or less. In order to reduce power consumption during standby, it is necessary to reduce the energization area in the apparatus. Therefore, for example, in the technique described in Patent Document 1, the components of the image forming apparatus are divided into a plurality of power supply blocks for controlling or driving, and the power supply line is turned on / off to the power supply block connected to the system control unit. It has been proposed that the switch means control means that is provided with switch means and consumes less power than the system control section turns off the power supply line to the system control section and reduces power consumption.

JP 2006-173695 A

  An object of the present invention is to achieve both power consumption reduction and convenience.

  The information processing device according to claim 1 is a switch means for performing power supply to the own device and shutting off the power supply, a first power saving mode for shutting off power supply to the own device, and the first A second power saving mode that consumes more power than the power saving mode and requires a shorter time than the first power saving mode, and starts the power supply by the switch means. Control is performed so that the second power saving mode is entered when a predetermined time has elapsed without an operation instruction being issued, and the operation instruction has not been issued since the second power saving mode has been entered. The second power saving calculated in advance based on the amount of power required for returning from the first power saving mode and the amount of power required for returning from the second power saving mode. From power mode When the elapsed shift time to transition to the first power-saving mode, so as to shift to the first power saving mode, it is characterized in that and a control means for controlling said switch means.

  The invention according to claim 2 further comprises detection means for detecting attachment of an optional device in which standby power in the second power saving mode changes in the invention according to claim 1, wherein the control means comprises: When the detection unit detects the installation of the optional device, the amount of electric power required for returning from the transition to the first power saving mode when the optional device is mounted, and the optional device The switch means is controlled using the time calculated in advance based on the amount of power required for returning from the transition to the second power saving mode when mounted as the transition time. .

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the control means sets the transition time in a case where a predetermined condition is assumed that the use frequency of the own apparatus is high. It is further characterized by further controlling so as to extend a predetermined time.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the control means is (the amount of power in the first power saving mode at time T) + (the first The minimum amount of time that satisfies (the amount of power required for returning to the power saving mode) ≦ (the amount of power for the second power saving mode at time T) + (the amount of power required for returning to the second power saving mode) The switch means is controlled using T as the transition time.

  According to a fifth aspect of the present invention, there is provided a power saving program for an information processing apparatus that causes a computer to function as a control unit of the information processing apparatus according to any one of the first to fourth aspects.

  According to the information processing apparatus of the first aspect, there is an effect that it is possible to achieve both power consumption reduction and convenience as compared with the case where this configuration is not adopted.

  According to the information processing apparatus of the second aspect, even if the power consumption is changed by the optional device, there is an effect that it is possible to achieve both power consumption reduction and convenience by reflecting the changed power consumption.

  According to the information processing apparatus of the third aspect, there is an effect that priority can be given to convenience when the use frequency of the own apparatus is high.

  According to the information processing apparatus of the fourth aspect, there is an effect that power consumption can be reduced to the maximum while maintaining convenience.

  According to the power saving program of the information processing apparatus according to claim 5, there is an effect that it is possible to achieve both power consumption reduction and convenience as compared with the case where this configuration is not adopted.

1 is a block diagram illustrating a schematic configuration of an image forming apparatus according to a first embodiment of the present invention. It is a block diagram which shows the detailed structure of a controller. (A) is a diagram showing the power in the off mode 1 and the amount of power required for return, and (B) is a diagram showing the power in the off mode 2 and the amount of power required for return. FIG. 3 is a diagram illustrating an example of transition to an off mode and an amount of power in the image forming apparatus according to the first embodiment of the present invention. 3 is a flowchart illustrating an example of a power saving process performed by a controller of the image forming apparatus according to the first embodiment of the present invention. It is a block diagram which shows schematic structure of the image forming apparatus concerning 2nd Embodiment of this invention. 10 is a flowchart illustrating an example of a power saving process performed by a controller 20 of the image forming apparatus according to the second embodiment of the present invention. 10 is a flowchart illustrating an example of a power saving process performed by a controller 20 of an image forming apparatus according to a third embodiment of the present invention.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of an image forming apparatus 10 according to the first embodiment of the present invention.

  The image forming apparatus 10 according to the first embodiment of the present invention includes a main power switch (main power SW) 12 and a sub power switch (sub power SW) 14.

  In the main power supply SW12, the power supplied from the AC outlet 13 to the image forming apparatus 10 via the leakage breaker circuit 16 and the noise filter 18 is turned on / off.

  A power supply circuit A30 to which a controller 20 that controls the entire image forming apparatus 10 is connected is connected to the main power supply SW12. When the main power supply SW12 is turned on, power is supplied from the power supply circuit A30 to the controller 20.

  The main power supply SW12 is connected to a power supply circuit B32 via SW-A22. An operation unit 34, a reading unit 36, and a printing unit 38 are connected to the power supply circuit B32. Further, SW-B 24 is connected between the power supply path B 32 and the operation unit 34, SW-C 26 is connected between the power supply circuit B 32 and the reading unit 36, and SW-D is connected between the power supply circuit B 32 and the printing unit 38. It is connected.

  The SW-A 22, SW-B 24, SW-C 26, and SW-D 28 are controlled to be turned on / off by the controller 20. That is, the controller 20 controls the power supply to each unit (the operation unit 34, the reading unit 36, the printing unit 38, etc.) constituting the image forming apparatus 10.

  In the present embodiment, the main power supply SW12 is connected to the controller 20, and the main power supply SW12 can be turned off by a control signal from the controller 20.

  On the other hand, the sub power SW 14 is connected to the controller 20, and the controller 20 controls the power supply of the entire image forming apparatus 10 according to the status of the sub power switch 14.

  Here, the configuration of the controller 20 will be described. FIG. 2 is a block diagram showing a detailed configuration of the controller 20.

  The controller 20 includes a CPU (Central Processing Unit) 40, and the image forming apparatus 10 is controlled by the CPU 40.

  The CPU 40 is connected to a ROM (Read Only Memory) 42 and a DRAM (Dynamic Random Access Memory) 44 via a memory bus 46, and includes a power supply control circuit 48, an interface circuit 50, an operation control circuit 52, and a video. An interface circuit 54 is connected via I / O (Input / Output) buses 56 and 58.

  For example, as shown in FIG. 2, the interface circuit 50 connects an HDD interface (I / F) 62 for connecting a hard disk (HDD) 60 and a host computer (Host PC) 64 by USB (Universal Serial Bus). USB interface (I / F) 66 and a host interface (I / F) 70 for connecting a host computer 68 to a LAN (Local Area Network).

  An operation panel 72 is connected to the operation control circuit 52, and information operated by the operation panel 72 can be output to the CPU 40.

  The video interface circuit 54 is connected to a print engine 74, a scanner 76, and the like, and performs predetermined image processing on image information obtained by reading the scatter 76, and outputs the image information to the print engine 74. Thus, printing is performed.

  Further, the power supply control circuit 48 is connected to the sub power supply SW14 and to the base of the transistor switch 78.

  The collector of the transistor switch 78 is connected to the CPU 40, and the emitter of the transistor switch 78 is grounded. In the present embodiment, the power supply control circuit 48 controls on / off of the transistor switch 78, so that the CKE signal for entering the self refresh mode of the DRAM 44 can be fixed to the LOW level.

  By the way, the image forming apparatus 10 according to the present embodiment includes an off mode for reducing power consumption, and a predetermined time elapses when no operation instruction or the like is performed on the image forming apparatus 10. Then, it shifts to the off mode. The off mode has two off modes of off mode 1 and off mode 2 in this embodiment.

  The off mode 1 is a state in which the main power source SW12 is turned off, and the power of the image forming apparatus 10 is turned off except for the leakage circuit 16 and the noise filter 18. In other words, the power consumption is reduced (nearly zero), but since the program and data in the DRAM 44 of the controller 20 are not retained, the recovery time becomes longer. As described above, the main power supply SW12 is not only operated by the user, but can be turned off by the control from the controller 20 as described above. Therefore, the main power supply SW12 can be turned off by the control of the controller 20 and can be shifted to the off mode 1. Has been.

  On the other hand, the off mode 2 is the same as the state in which the sub power SW 14 is turned off, and the power control circuit 48 and the DRAM 44 are energized in addition to the leakage breaker circuit 16 and the noise filter 18. That is, since the program and data developed at the time of startup or the like can be held in the DRAM 44, the recovery time is shorter than that in the off mode 1, but the power consumption is larger than that in the off mode 1.

  In the image forming apparatus 10 according to the present embodiment configured as described above, when the main power SW 12 is first turned on, the image forming apparatus 10 starts to be activated. The CPU 40 on the controller 20 reads the program from the ROM 42 after releasing the reset. In addition, the controller 20 turns on SW-A, SW-B, SW-C, and SW-D to energize the operation unit 34, the reading unit 36, and the printing unit 38. The controller 20 reads out the program data in the ROM 42 to the DRAM 44, develops it, and starts various applications while communicating with the operation unit 34, the reading unit 36, and the printing unit 38, thereby shifting the image forming apparatus to a standby state. Let

  Here, when a predetermined time elapses when the operation of the image forming apparatus 10 is not performed, the mode is shifted to the off mode. In this embodiment, first, the mode is shifted to the off mode 2.

  That is, the CPU 40 of the controller 20 holds the developed program and data by putting the program and data in the DRAM 44 into the self-refresh mode. In order to enter the self-refresh mode, the CPU 40 sets the CKE signal output to the DRAM 44 to a low level. The power supply control circuit 48 outputs a signal for fixing the CKE signal input from the CPU 40 to the DRAM 44 to the low level to the transistor switch 78. As a result, the transistor switch 78 is turned on, and the CKE signal is fixed at the low level. Thereafter, the power control circuit 48 shifts to the off mode 2 by turning off the power of the unnecessary circuit.

  Here, when the sub power SW 14 is turned on, the recovery starts from the off mode 2. The power control circuit 48 detects that the sub power SW 14 is turned on, and restarts power supply to the devices in the controller 20. The CPU 40 executes a boot program in the ROM 42 and initializes its own DRAM controller. The power supply control circuit 48 releases the fixed low level of the CKE signal by turning off the transistor switch 78. The CPU 40 changes the CKE signal to the DRAM 44 to a high level and makes a transition from the self-refresh mode to the normal auto-refresh mode. As a result, the program in the DRAM 44 is executed to return to the standby state.

  Further, in the present embodiment, when the state TA in the off mode 2 elapses for a predetermined time TA, the mode shifts to the off mode 1. That is, the controller 20 turns off the main power SW 12 and stops energization of the image forming apparatus 10. As a result, since the program and data in the DRAM 44 of the controller 20 are not held, the recovery time becomes long. However, since power supply other than the leakage breaker circuit 16 and the noise filter 18 is stopped, the power consumption becomes almost zero. Power consumption is reduced.

  Here, a method of calculating the time TA for shifting from the off mode 2 to the off mode 1 will be described in detail.

  The power consumption in the off mode 1 is P1, and the return time from the turn-on of the main power supply SW12 to the return from the off mode 1 is T1.

  Further, the power consumption in the off mode 2 is P2, and the return time from the turn-on of the sub power supply SW14 to the return from the off mode 2 is T2.

  Further, the power consumption during standby is P0. Note that P0, P1, P2, T1, and T2 are determined for each type of image forming apparatus 10.

  As described above, each relationship is P1 <P2 <P0, T1> T2.

  3A and 3B show the power in each off mode and the amount of power required to return. 3A shows the power in the off mode 1 and the amount of power required to return, and FIG. 3B shows the power in the off mode 2 and the amount of power required to return.

  Assuming that the time during the off mode is T, the amount of power required to return from the off mode 1 is (the amount of power in the off mode 1 at the time T) + (the amount of power required for returning from the off mode 1) = P1 × T + P0 × T1, and the amount of power required to return from the off mode 2 is (the amount of power in the off mode 2 at time T) + (the amount of power required for returning from the off mode 2) = P2 × T + P0 × T2. .

  By the way, in the present embodiment, the transition to the off mode 2 which is shorter in the recovery time than the off mode 1 and is convenient is performed first. However, since the power consumption is larger than that in the off mode 1, the transition to the off mode 1 is performed at some point. Is preferable for reducing power consumption.

  Therefore, in the present embodiment, power consumption is reduced and convenience is based on the amount of power required for returning from the transition to the off mode 1 and the amount of power required for returning after the transition to the off mode 2. Therefore, the transition from the off mode 2 to the off mode 1 is controlled in order to obtain a transition time in which compatibility can be achieved.

  Specifically, a time T that satisfies (P1 × T + P0 × T1) ≦ (P2 × T + P0 × T2) is obtained. By obtaining the minimum time among the times T satisfying the above formula as the transition time TA, power consumption can be reduced and convenience can be achieved.

  That is, in the image forming apparatus 10 according to the present embodiment, after a predetermined time elapses from the standby state, the mode shifts to the off mode 2 in which the convenience of short recovery time is emphasized, and then to the off mode 1 after the transition time TA elapses. Control is made so as to shift (FIG. 4).

  Next, a specific process performed by the image forming apparatus 10 according to the first embodiment of the present invention configured as described above will be described. FIG. 5 is a flowchart illustrating an example of the power saving process performed by the controller 20 of the image forming apparatus 10 according to the first embodiment of the present invention.

  First, in step 100, it is determined whether or not a predetermined time has elapsed. If the determination is affirmative, the process proceeds to step 102.

  In step 102, the mode shifts to off mode 2. That is, as described above, the CPU 40 of the controller 20 sets the CKE signal to the low level in order to put the DRAM 44 into the self-refresh mode, and the power supply control circuit 48 outputs a signal for fixing the CKE signal to the low level as a transistor switch. Output to 78. As a result, the transistor switch 78 is turned on, and the CKE signal is fixed at the low level. Thereafter, the power supply control circuit 48 turns off the power supply of the unnecessary circuit, thereby shifting to the off mode 2.

  Next, at step 104, the time T counted in the controller 20 is reset, and the routine proceeds to step 106.

  In step 106, it is determined whether or not the transition time TA has elapsed since the transition to the off mode 2. If the determination is negative, the process proceeds to step 108, and if the determination is affirmative, the process proceeds to step 112.

  In step 108, it is determined whether there is a return factor. In this determination, for example, it is determined whether or not the sub power supply SW14 is turned on. If the determination is negative, the process returns to step 106 and the above-described processing is repeated. If the determination is affirmative, step 110 is performed. Migrate to

  In step 110, a return from the off mode 2 is performed, and the series of processes is terminated. That is, as described above, the power supply control circuit 48 detects that the sub power supply SW14 is turned on, and restarts the power supply to the devices in the controller 20. Then, the CPU 40 executes the boot program in the ROM 42, initializes the controller of the DRAM 44, and the power supply control circuit 48 turns off the transistor switch 78, thereby releasing the CKE signal from being fixed at the low level, and performing self-refresh. Transition from mode to normal auto-refresh mode. As a result, the program in the DRAM 44 is executed to return to the standby state.

  On the other hand, in step 112, the process proceeds to off mode 1 and proceeds to step 114. That is, the controller 20 turns off the main power SW 12 and stops energization of the image forming apparatus 10.

  In step 114, it is determined whether or not there is a return factor. In this determination, for example, it is determined whether or not the main power supply SW 12 is turned on, waits until the determination is affirmed, and the process proceeds to step 116 to return from the off mode 1 and perform a series of processing. finish.

  As described above, in the image forming apparatus 10 according to the present embodiment, when a predetermined time elapses without an operation instruction or the like being performed, the convenient off-state that consumes more power than the off mode 1 but has a short recovery time. Since it shifts to mode 2, it will be in the state which can return immediately, reducing power consumption.

  In addition, the amount of power required for returning from the transition to the off mode 1 after returning to the off mode 1 and the power required for returning from the transition to the off mode 2 without further operation instruction or the like after the transition to the off mode 2 Since the transition to the off mode 1 occurs when the transition time TA calculated in advance based on the amount has elapsed, the power consumption is reduced as compared to continuing the off mode 2.

  Therefore, by controlling to shift from the off mode 2 to the off mode 1 with the calculated time TA as a boundary, both power consumption reduction and convenience can be achieved.

(Second Embodiment)
Next, an image forming apparatus according to the second embodiment of the present invention will be described. FIG. 6 is a block diagram showing a schematic configuration of an image forming apparatus according to the second embodiment of the present invention. In addition, about the same structure as 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  The image forming apparatus may be equipped with an optional device that performs post-processing such as a sort function, a staple function, and a punch function. In this case, since the power consumption at the time of startup increases, the time TA for shifting from the off mode 2 to the off mode 1 calculated in the first embodiment changes.

  Therefore, in the second embodiment, as shown in FIG. 6, the image forming apparatus 10 according to the first embodiment has a detection circuit 80 in the printing unit 38 for detecting the mounting of an optional device that performs post-processing. Furthermore, it is provided.

  That is, the detection circuit 80 detects the installation of the optional device, and changes the time TA for shifting from the off mode 2 to the off mode 1.

  For the time TA when the optional device is mounted, the power amount P0 'at startup is obtained from the type of the mounted optional device.

  Then, a time T satisfying (P1 × T + P0 ′ × T1) ≦ (P2 × T + P0 ′ × T2) is obtained, and a minimum time among the times T satisfying the above formula is obtained as TA. For example, the time TA for each type of option device is calculated and stored in the controller 20 in advance, and the transition time TA for each option device is selected by selecting the time TA to be used based on the detection result of the detection circuit 80. change.

  Next, specific processing performed in the image forming apparatus according to the second embodiment of the present invention will be described. FIG. 7 is a flowchart showing an example of the power saving process performed by the controller 20 of the image forming apparatus according to the second embodiment of the present invention.

  First, in step 200, it is determined whether or not a predetermined time has elapsed. If the determination is affirmative, step 202 is performed.

  In step 202, the process shifts to the off mode 2. That is, as described above, the CPU 40 of the controller 20 sets the CKE signal to the low level in order to put the DRAM 44 into the self-refresh mode, and the power supply control circuit 48 outputs a signal for fixing the CKE signal to the low level as a transistor switch. Output to 78. As a result, the transistor switch 78 is turned on, and the CKE signal is fixed at the low level. Thereafter, the power supply control circuit 48 turns off the power supply of the unnecessary circuit, thereby shifting to the off mode 2.

  Next, at step 204, the time T counted in the controller 20 is reset, and the routine proceeds to step 206.

  In step 206, it is determined whether or not the optional device has been detected by the detection circuit 80. If the determination is affirmative, the process proceeds to step 208, and if the determination is negative, the process proceeds to step 210.

  In step 208, the transition time TA is set to a time corresponding to the type of option device, and the process proceeds to step 210. That is, since the power consumption at the time of activation varies depending on the type of the optional device, the transition time TA is calculated in consideration of the power consumption at the time of activation by the optional device.

  In step 210, it is determined whether or not the transition time TA has elapsed since the transition to the off mode 2. If the determination is negative, the process proceeds to step 212. If the determination is affirmative, the process proceeds to step 216.

  In step 212, it is determined whether there is a return factor. In this determination, for example, it is determined whether or not the sub power supply SW 14 is turned on. If the determination is negative, the process returns to step 210 and the above-described processing is repeated. If the determination is affirmative, step 214 is performed. Migrate to

  In step 214, the return from the off mode 2 is performed, and the series of processing ends. That is, the power control circuit 48 detects that the sub power SW 14 is turned on, and resumes power supply to the devices in the controller 20. Then, the CPU 40 executes the boot program in the ROM 42, initializes the controller of the DRAM 44, and the power supply control circuit 48 turns off the transistor switch 78, thereby releasing the CKE signal from being fixed at the low level, and performing self-refresh. Transition from mode to normal auto-refresh mode. As a result, the program in the DRAM 44 is executed to return to the standby state.

  On the other hand, in step 216, the process shifts to off mode 1 and shifts to step 218. That is, the controller 20 turns off the main power supply SW12 and stops energization of the image forming apparatus.

  In step 218, it is determined whether there is a return factor. In this determination, for example, it is determined whether or not the main power supply SW 12 is turned on, waits until the determination is affirmed, and the process proceeds to step 220 to return from the off mode 1 and perform a series of processing. finish.

  Thus, in this embodiment, even when an optional device whose power consumption changes is attached to the first embodiment, the transition time TA for shifting from the off mode 2 to the off mode 1 considering the optional device is changed. Therefore, even when the optional device is mounted, both power consumption reduction and convenience are compatible, as in the first embodiment.

(Third embodiment)
Next, an image forming apparatus according to the third embodiment will be described.

  In the second embodiment, an example has been described in which the transition time TA for changing from off 2 to off mode 1 is changed depending on whether or not the optional device is attached to the first embodiment, but in the third embodiment, The transition time TA is changed according to the time zone, and the basic configuration is the same as that of the first embodiment.

  That is, in this embodiment, the mode shifts to the off mode 2 and transitions to the off mode 1 after the transition time TA elapses. However, the off mode 1 is preferable from the viewpoint of convenience because the return time is longer than that of the off mode 2. Absent. Therefore, in the third embodiment, in the case where the usage frequency of the image forming apparatus is assumed to be high, the transition time TA is extended to control the convenience.

  Specifically, control is performed so that the transition time TA is extended in a time zone in which use by the user is predicted in advance. For example, a time zone in which use by the user is predicted in advance is determined using calendar information (day of the week) and time information. For example, at night, the transition to the off mode 1 occurs after the transition time TA obtained in the first embodiment has elapsed, and during the daytime on weekdays, the usage frequency is expected to be high, so the transition time TA is extended to give priority to user convenience. Let The extension time may be a predetermined time or may be arbitrarily set by the user.

  Next, specific processing performed in the image forming apparatus according to the third embodiment of the present invention will be described. FIG. 8 is a flowchart showing an example of the power saving process performed by the controller 20 of the image forming apparatus according to the third embodiment of the present invention. Note that the power saving process of the third embodiment is only partially different from the power saving process of the second embodiment. Therefore, the same processes as those of the second embodiment are denoted by the same reference numerals as those of the second embodiment. A description will be given.

  First, in step 200, it is determined whether or not a predetermined time has elapsed. If the determination is affirmative, the process proceeds to step 202.

  In step 202, the process shifts to the off mode 2. That is, as described above, the CPU 40 of the controller 20 sets the CKE signal to the low level in order to put the DRAM 44 into the self-refresh mode, and the power supply control circuit 48 outputs a signal for fixing the CKE signal to the low level as a transistor switch. Output to 78. As a result, the transistor switch 78 is turned on, and the CKE signal is fixed at the low level. Thereafter, the power supply control circuit 48 turns off the power supply of the unnecessary circuit, thereby shifting to the off mode 2.

  Next, at step 204, the time T counted in the controller 20 is reset, and the routine proceeds to step 205.

  In step 205, it is determined whether or not it is a predetermined time zone. The determination is made as to whether or not it is a preset time zone in which use by the user is predicted in advance. If the determination is affirmative, the process proceeds to step 207; Move to 210.

  In step 207, the transition time TA is set to a time extended by a predetermined time, and the process proceeds to step 210. That is, in the time zone in which the use by the user is predicted in advance, the transition time TA is given priority on the return time.

  In step 210, it is determined whether or not the transition time TA has elapsed since the transition to the off mode 2. If the determination is negative, the process proceeds to step 212. If the determination is affirmative, the process proceeds to step 216.

  In step 212, it is determined whether there is a return factor. In this determination, for example, it is determined whether or not the sub power supply SW 14 is turned on. If the determination is negative, the process returns to step 210 and the above-described processing is repeated. If the determination is affirmative, step 214 is performed. Migrate to

  In step 214, the return from the off mode 2 is performed, and the series of processing ends. That is, the power control circuit 48 detects that the sub power SW 14 is turned on, and resumes power supply to the devices in the controller 20. Then, the CPU 40 executes the boot program in the ROM 42, initializes the controller of the DRAM 44, and the power supply control circuit 48 turns off the transistor switch 78, thereby releasing the CKE signal from being fixed at the low level, and performing self-refresh. Transition from mode to normal auto-refresh mode. As a result, the program in the DRAM 44 is executed to return to the standby state.

  On the other hand, in step 216, the process shifts to off mode 1 and shifts to step 218. That is, the controller 20 turns off the main power supply SW12 and stops energization of the image forming apparatus.

  In step 218, it is determined whether there is a return factor. In this determination, for example, it is determined whether or not the main power supply SW 12 is turned on, waits until the determination is affirmed, and the process proceeds to step 220 to return from the off mode 1 and perform a series of processing. finish.

  As described above, in the present embodiment, in the case where the usage frequency is assumed to be high, the transition time TA for shifting from the off mode 2 to the off mode 1 is extended with respect to the first embodiment. When the frequency is high, convenience is given priority. Accordingly, both reduction in power consumption and convenience are achieved in accordance with the frequency of use of the image forming apparatus.

  In the above embodiment, the second embodiment and the third embodiment have been described individually. However, the second embodiment and the third embodiment may be combined. That is, the change of the time TA when the optional device is mounted and the time TA when the frequency of use is assumed to be high may be performed together.

  In each of the above embodiments, the image forming apparatus has been described as an example. However, the present invention is not limited thereto, and various off-modes can be applied as described in the above embodiments by applying various information processing apparatuses. You may make it control so that it may transfer to.

  Each process performed by the controller 20 in each of the above embodiments may be executed by hardware, or may be executed by executing a software program. The program may be stored in various storage media and distributed.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Main power switch 20 Controller 40 CPU
42 ROM
44 DRAM
48 Power control circuit 78 Transistor switch 80 Detection circuit

Claims (5)

Switch means for performing power supply to the device and shutting off the power supply;
A first power saving mode for shutting off power supply to the device; a second power consumption that is higher than that of the first power saving mode and a time required for recovery is shorter than that of the first power saving mode; A power saving mode, and control to shift to the second power saving mode when a predetermined time elapses without an operation instruction being performed after the power supply is started by the switch means. The amount of power required to return from the transition to the first power saving mode after the time that has elapsed since the transition to the second power saving mode has not been issued, and the second power saving mode. When the transition time for shifting from the second power saving mode to the first power saving mode, which has been calculated in advance based on the amount of power required for returning from the transition to the power mode, is passed, First power saving mode To migrate, and control means for controlling said switching means,
An information processing apparatus comprising: A detection means for detecting attachment of an optional device that changes standby power in the second power saving mode;
When the control unit detects that the optional device is installed, the control unit includes an amount of power required for returning from the transition to the first power saving mode when the optional device is installed. The switch means is controlled with the time calculated in advance based on the amount of power required for returning from the transition to the second power saving mode when the optional device is mounted as the transition time. The information processing apparatus according to claim 1.   3. The information according to claim 1, wherein the control unit further controls to extend the transition time for a predetermined time in a case where a predetermined condition is assumed that the use frequency of the own device is high. Processing equipment.   The control means is: (amount of power in the first power saving mode at time T) + (amount of power required for returning from the first power saving mode) ≦ (amount of power in the second power saving mode at time T) 4. The switch unit according to claim 1, wherein the switch unit is controlled by setting a minimum time T satisfying (amount of power) + (amount of power required when returning to the second power saving mode) as the transition time. 5. Information processing device.   A power saving program for an information processing apparatus for causing a computer to function as control means for the information processing apparatus according to any one of claims 1 to 4.

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