Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority under 35 U.S.C. §119(a) to, and incorporates by reference, the entire contents of Japanese Patent Application No. 2011-254416 filed in Japan on Nov. 21, 2011. 
     BACKGROUND 
     Japanese Patent Application Laid-open No. 2008-278106 describes an image forming apparatus which includes a power control function. 
     In this image forming apparatus, before shifting a power mode of the image forming apparatus from a normal mode to an energy saving mode, the image forming apparatus stores a status of applications installed in the image forming apparatus. 
     Furthermore, when the image forming apparatus shifts the power mode from the energy saving mode to the normal mode, the image forming apparatus controls the power of the image forming apparatus based on the stored status. 
     SUMMARY 
     Aspects of this disclosure relate to image forming apparatuses, device, processes, algorithms and systems. 
     An image forming apparatus includes hardware resources, a processor, application software executed by the processor and configured to perform an image forming process, the application software causing one or more display screens to be displayed, a display processing unit configured to display one of the one or more display screens on a display, a power status storing unit configured to store, in association with each display screen, a power status indicating whether the hardware resource should be provided power during display of the display screen, a power status determining unit configured to determine which hardware resource should be provided power among the hardware resources, based on the display of the display screen and the power status stored by the power status storing unit, and a power control unit configured to provide power to the determined hardware resources. 
     A power control method on an image forming apparatus includes displaying one display screen of one or more display screens on a display of the image forming apparatus, the one or more display screens being displayed by application software installed in the image forming apparatus, determining which hardware resources should be provided power among the hardware resources, based on the displayed display screen and a power status, the power status being stored in association with each display screen and indicating whether the hardware resource should be provided power during display of the display screen, and providing power to the determined hardware resources. 
     According to another embodiment, there is provided a non-transitory computer readable medium having stored thereon a program that, when executed by an image forming apparatus, can cause the image forming apparatus to implement a power control method. The power control method on an image forming apparatus includes displaying one display screen of one or more display screens on a display of the image forming apparatus, the one or more display screens being displayed by application software installed in the image forming apparatus, determining which hardware resources should be provided power among the hardware resources, based on the displayed display screen and a power status, the power status being stored in association with each display screen and indicating whether the hardware resource should be provided power during display of the display screen, and providing power to the determined hardware resource. 
     The foregoing paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the following claims. The described exemplary implementations, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating a functional configuration of the image forming apparatus; 
         FIG. 2  is a table indicating power status information; 
         FIG. 3  is a table indicating operation time; 
         FIG. 4  is a flowchart illustrating a procedure for controlling the power supply of the image forming apparatus; 
         FIG. 5  is a flowchart illustrating a procedure for controlling the power supply of the image forming apparatus; 
         FIG. 6  is a diagram illustrating a functional configuration of the image forming apparatus; 
         FIG. 7  is a table indicating a status of the power supply of the image forming apparatus; 
         FIG. 8  is a table indicating operation time; 
         FIG. 9  is a flowchart illustrating a procedure for controlling power of the image forming apparatus; and 
         FIG. 10  is a block diagram of a hardware configuration of an image forming apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, exemplary implementations will be described with reference to the accompanying drawings. However, variations and modifications may be made without departing from the basic concepts described herein. 
     In an image forming apparatus, the image forming apparatus can control power of the image forming apparatus. 
     In a conventional image forming apparatus, when the image forming apparatus shifts the power mode from the energy saving mode to the normal mode, the image forming apparatus controls power-on and power-off of image forming devices included in the image forming apparatus based on the stored status of an application. 
     However, even if the state of the application is the same, the same devices are not always used. 
     Thus, in the conventional image forming apparatus, if a device that is not used exists, power is wasted. 
     In an image forming apparatus according to aspects of this disclosure, the image forming apparatus is able to reduce power consumption. 
       FIG. 10  is a block diagram of an exemplary hardware configuration of the image forming apparatus  1 . 
     As illustrated in  FIG. 10 , the image forming apparatus  1  includes a controller  10  and an engine  60 , which are mutually connected to each other by a Peripheral Component Interface (PCI) bus. 
     The controller  10  controls a main process of the image forming apparatus  1 , a drawing process, a communication process, and an input process. 
     The engine  60  includes, for example, a printer engine, a plotter, a scanner, and a fax unit. Further, the engine  60  further includes an image processing part which performs error diffusion or gamma conversion. 
     The controller  10  includes a central processing unit (CPU)  11 , a Northbridge (NB)  13 , a system memory (MEM-P)  12 , a Southbridge (SB)  14 , a local memory (MEM-C)  17 , an application specific integrated circuit (ASIC)  16 , and a hard disk drive (HDD)  18 . 
     The NB  13  is connected the ASIC  16  via an accelerated graphics port (AGP) bus  15 . Further, the NB  13  is a bridge to connect the CPU  11 , the MEM-P 12 , the SB  14 , and the AGP  15 . Further, the NB  13  includes a memory controller to control input and output to the MEM-P  12 , and further includes PCI master and an AGP target. 
     The MEM-P  12  includes a read only memory (ROM)  12   a  and a random access memory (RAM)  12   b . The ROM  12   a  is a read only memory to store programs and data. The RAM  12   b  is able to read and write, and is used as an expanding memory to expand the programs and the data, and as a drawing memory. 
     The SB  14  is a bridge to connect the NB  13 , a PCI device, and a peripheral device. The SB  14  is connected to the NB  13  via a PCI bus. The PCI bus is able to connect to a network interface. 
     The ASIC  16  is an integrated circuit that processes an image. The ASIC  16  is a bridge to connect the AGP  15 , the PCI bus, the HDD  18 , and the MEM-C  17 . Further, the ASIC  16  includes a PCI target, an AGP master, an arbiter, a memory controller for controlling the MEM-C  17 , a plurality of direct memory access controllers (DMAC), and a PCI unit for sending data to the engine  60  via the PCI bus. 
     The ASIC  16  is connected to a facsimile control unit (FCU)  30 , an universal serial bus (USB)  40 , and an IEEE 1394 interface  50 . 
     The MEM-C  17  is a local memory to be used as buffer. The HDD  18  is a storage device to store image data, program, font data, and a form. 
     The AGP  15  is a bus interface to speed up a process of graphics. 
       FIG. 1  is a diagram illustrating a functional configuration of the image forming apparatus  1 . 
     As illustrated in  FIG. 1 , the image forming apparatus  1  includes an energy saving processing unit  100 , a display unit  20 , a scanner  31 , a plotter  32 , and a peripheral device  33 . 
     In response to input by a user, the image forming apparatus  1  shifts an operation status from normal status to energy saving status. The normal status is a status in which the image forming apparatus  1  provides power to all hardware units. 
     The energy saving status is a status in which the image forming apparatus  1  stops power to some of the hardware units. Power consumption in the energy saving status is less than power consumption in the normal status. 
     The energy saving processing unit  100  controls the supplying of power to each hardware unit. 
     The energy saving processing unit  100  includes a receiving unit  101 , a display information storing unit  102 , a display processing unit  103 , a power status storing unit  104 , a power status determining unit  105 , a power control unit  106 , a driver control unit  107 , an operating time measuring unit  108 , and an operating time storing unit  109 . 
     The receiving unit  101  receives input of information from a user. The information includes, for example, a display instruction to display on the display unit  20 , a screen to be displayed by an application, or an execution instruction to execute a function. 
     The display information storing unit  102  stores display information to be displayed on the display unit  20  by an application to be executed on the image forming apparatus  1 . 
     The display processing unit  103 , in response to receiving a display instruction by a user, extracts display information corresponding to the display instruction among the display information stored by the display information storing unit  102 . Further, the display processing unit  103  displays a screen on the display unit  20  based on the extracted display information. 
     The power status storing unit  104  stores power status information to determine a power status of each device. The power status information will be described below. 
       FIG. 2  is a table indicating the power status information. 
     As illustrated in  FIG. 2 , the power status storing unit  104  stores a display screen to be displayed on the display unit  20  and a corresponding power status of each device. 
     Herein, the display screen is a display screen displayed on the display unit  20  by an application. When one application displays a plurality of display screens, the power status storing unit  104  stores each of the plurality of display screens. The power status is information indicating power to be supplied to each device. 
     During execution of an application, the display processing unit  103  displays a display screen on the display unit  20  based on the application. Further, the receiving unit  101  is able to receive from a user, on the display screen, an execution instruction to execute a function. That is to say, even while an application is executed, it is possible to execute a different function, and it is possible to use different devices. 
     In this description, the power status storing unit  104  stores display screens and the power status of devices corresponding with them. In detail, the power status storing unit  104  stores, corresponding to every display screen of application, a power-on status of a device or a power-off status of a device. 
     For example, the power status storing unit  104  stores statuses, which are scanner ON, plotter ON, and peripheral device ON, corresponding to screen  1  of a copy application. 
     In another example, the power status storing unit  104  stores statuses, which are scanner ON, plotter ON, and peripheral device OFF, corresponding to screen  2  of the copy application. 
     In this way, the power status storing unit  104  is able to store the power status of devices for every screen of an application. 
     Return to the  FIG. 1 , the power status determining unit  105  determines the power status of a device based on a display screen displayed on the display unit  20  and information stored by the power status storing unit or the operation time storing unit  109 . 
     The power control unit  106  controls, based on the power status determined by the power status determining unit  105 , power supplying to the scanner  31 , the plotter  32 , and the peripheral device  33 . 
     When the receiving unit  101  receives an execution instruction while a display screen is displayed by the display processing unit  103 , the driver control unit  107  determines a driver to execute a function based on the execution instruction. Further, the driver control unit  107  controls the determined driver to execute a process of the function. 
     The operating time measuring unit  108  measures an operating time of the driver. The operation time storing unit  109  stores the measured operation time corresponding to the display screen that is displayed on the display unit  20 . 
       FIG. 3  is a table indicating operation time. 
     As illustrated in  FIG. 3 , the operation time storing unit  109  stores, in association with one another, a display screen displayed on the display unit  20 , operation time of each device, and operation time of all devices. 
     The operation time of each device is the operation time that is measured during display of the display screen on the display unit  20 . 
     The operation time of all devices is the total time of the operation time of each device. 
     A detailed process of controlling of power supply to each device will be described below with reference with a flowchart. 
       FIG. 4  and  FIG. 5  are a flowchart illustrating a procedure for controlling of power supply of the image forming apparatus. 
     As illustrated in  FIG. 4 , the receiving unit  101  receives a display instruction input from a user (step S 100 ). 
     Next, in response to receiving the display instruction, the display processing unit  103  displays a display screen on the display unit  20  based on the display instruction (step S 101 ). 
     Next, in response to displaying the display screen on the display unit  20 , the power status determining unit  105  determines whether the displayed display screen is stored in the power status storing unit  104  or not (step S 102 ). 
     Next, when the power status determining unit  105  determines that the displayed display screen is stored in the power status storing unit  104  (step S 102 : YES), the power status determining unit  105  determines the power status of each device associated with the displayed display screen (step S 103 ). 
     Next, the power control unit  106  controls power supplying to each device based on the determined power status (step S 104 ). 
     As shown in  FIG. 2 , when screen  1  of copy application is displayed, the power control unit  106  supplies power to the scanner  31 , the plotter  32 , and the peripheral  33 . 
     Thus, for the image forming apparatus  1  described herein, even while the same application is executed, the image forming apparatus  1  is able to variably control power supplying to each device. Thus, the image forming apparatus  1  is able to save power by not supplying power to a device that will not be used during display of the display screen. 
     Next, when the power status determining unit  105  determines that the displayed display screen is not stored in the power status storing unit  104  (step S 102 : NO), the power status determining unit  105  determines whether the displayed display screen is stored in the operating time storing unit  109  or not (step S 110 ). 
     Next, when the power status determining unit  105  determines that the displayed display screen is stored in the operation time storing unit  109  (step S 110 : YES), the power status determining unit  105  extracts the operation time of each device and the operation time of all devices, which are associated with the displayed display screen. Further, the power status determining unit  105  calculates an operating rate of the operation time of each device to the operation time of all devices (step S 111 ). 
     Next, the power status determining unit  105  compares the calculated operating time to a predetermined threshold (step S 112 ). 
     Next, the power status determining unit  105  determines the power status of each device based on a result of comparison (step S 113 ). 
     In detail, when the calculated power operating time of a device is more than the predetermined threshold, the power status determining unit  105  determines that power status of the device indicates power on. Further, when the calculated power operating time of a device is less than the predetermined threshold, the power status determining unit  105  determines that power status of the device indicates power off. 
     In  FIG. 3 , for screen  6  of the fax application, the operation rate of the scanner  31  is 20 percent, the operation rate of the plotter  32  is 80 percent, and operation rate of the peripheral device is 0 percent. Further, when the predetermined threshold is 30 percent, power status of the plotter  32  is determined as power on, and power statuses of the scanner  31  and peripheral device  33  are both determined as power off. Thus, the result of the determination is that only the plotter  32  will be provided power. 
     Next, when the power status determining unit  105  determines that the displayed display screen is not stored in the operation time storing unit  109  (step S 110 : NO), the procedure goes to S 120  of  FIG. 5 . 
     As illustrated in  FIG. 5 , when the power status determining unit  105  determines that the displayed display screen is not stored in the operation time storing unit  109  (step S 110 : NO), the driver control unit  107  supplies power to all devices. In detail, the driver control unit  107  supplies power to the scanner  31 , the plotter  32 , and the peripheral device  33 . 
     Next, in response to receiving an execution instruction by the receiving unit  101  (step S 121 : YES), the driver control unit  107  determines a driver to execute function based on the execution instruction, and controls each driver to execute the function. 
     Next, the operation time measuring unit  108  starts measuring an operation time of each device (step S 122 ). 
     Next, when the process of each device is finished (step S 123 : YES), the operation time measuring unit  108  stores the operating time in the operating time storing unit  109  associated with a display screen that is displayed when the execution instruction is received (step S 124 ). Further, when the operating time storing unit  109  has already stored an operation time, the operating time storing unit  109  stores the measured operation time in addition to the stored operation time. 
     In this way, when an application that is not stored in the power status storing unit  104  is executed, the image forming apparatus  1  is able to determine a power status by executing from the process of S 111  to the process of S 104 . 
     For example, an application that is not stored in the power status storing unit  104  includes an added new application like SDK (Software Development Kit) application. 
     Thus, when the new application is added in this image forming apparatus  1 , the image forming apparatus  1  is able to control power without prior information of the new application. 
     Descriptions of configurations below having reference numerals that are the same as those in the above description are omitted unless there is a special necessity. 
     The image forming apparatus  1  is able to control power supplied to each device based on information from a user. 
       FIG. 6  is a diagram illustrating a functional configuration of the image forming apparatus  2 . 
     As illustrated in  FIG. 6 , the image forming apparatus  2  includes the energy saving processing unit  110 , the display unit  20 , the scanner  31 , the plotter  32 , and the peripheral device  33 . 
     The energy saving processing unit  110  includes the input unit  101 , the display information  102 , the display processing unit  103 , the power control unit  106 , the driver control unit  107 , a power state determining unit  112 , a power state storing unit  111 , an operating time measuring unit  113 , an operating time storing unit  114 , and an update unit  115 . 
     The power state storing unit  111  stores power status information of each device corresponding to each user. The power status information will be described below. 
       FIG. 7  is a table indicating the power status information. 
     As illustrated in  FIG. 7 , the power state storing unit  111  stores, associated with each display screen, a user ID for identifying a user, and power status of each device. 
     Further, the user ID includes a shared ID that does not identify a user. 
     Returning to the  FIG. 6 , when the receiving unit  101  receives a display instruction together with a user ID, the power state determining unit  112  determines the power status of each device by referring the power state storing unit  111  or the operating time storing unit  114 . 
     The operating time measuring unit  113  measures an operation time of a device. Further, the operating time measuring unit  113  stores the measured operation time in the operation time storing unit  114  corresponding to a display screen that is displayed on the display unit  20 . 
       FIG. 8  is a table indicating operation time. As illustrated in  FIG. 8 , the operation time storing unit  114  stores an operation time of scanner, an operation time of plotter, an operation time of peripheral device, and an operating time of all devices corresponding to a display screen. 
     In  FIG. 6 , an update unit  115  updates power status stored in the power state storing unit  111  by referring to the operation time storing unit  114 . 
       FIG. 9  is a flowchart illustrating a procedure for the controlling of power supply of the image forming apparatus  2 . 
     As illustrated in  FIG. 9 , the receiving unit  101  receives a display instruction and user ID, which are input from a user (step S 200 ). 
     Next, in response to receiving the display instruction and the user ID, the display processing unit  103  displays a display screen on the display unit  20  based on the display instruction (step S 201 ). 
     Next, in response to displaying the display screen on the display unit  20 , the power status determining unit  112  determines whether the displayed display screen is stored in association with the received user ID in the power state storing unit  111  or not (step S 202 ). 
     Next, when the power status determining unit  112  determines that the displayed display screen is stored in association with the received user ID in the power state storing unit  111  (step S 202 : YES), the power status determining unit  112  determines the power state of each device associated with the displayed display screen and the received user ID (step S 203 ). 
     Next, the power control unit  106  controls power supplying to each device based on the determined power status (step S 204 ). 
     Next, in response to receiving an execution instruction and a user ID by the receiving unit  101  (step S 211 : YES), the driver control unit  107  determines a driver to execute a function based on the execution instruction, and controls each driver to execute the function. 
     Here, when the receiving unit  101  does not receive any execution instruction (step S 211 : NO), the power control process is finished. 
     Next, the operation time measuring unit  113  starts measuring an operation time of each device (step S 212 ). 
     Next, when the process of each driver is finished (step S 213 : YES), the operation time measuring unit  113  stores the operating time in the operating time storing unit  114  in association with user ID and a display screen that is displayed when the execution instruction is received (step S 214 ). Further, when the operating time storing unit  114  has already stored an operation time, the operating time storing unit  114  stores the measured operation time in addition to the stored operation time. 
     Next, the update unit  115  updates the power status stored in the power state storing unit  111  based on the operation time stored in the operation time storing unit  114  (step S 215 ). 
     In detail, the update unit  115  measures an operating rate of each device based on the operation time of each device and the operating time of all devices. 
     Further, when the measured operating rate is more than a predetermined threshold, the update unit  115  updates the power status of a device associated with the user ID and the displayed display screen to the status of power on. 
     Further, when the measured operating rate is less than the predetermined threshold, the update unit  115  updates the power status of a device associated with user ID and the displayed display screen to the status of power off. 
     Here, when the power status determining unit  112  determines that the displayed display screen is not stored in association with the received user ID in the power state storing unit  111  (step S 202 : NO), the power control process goes to step S 110  of  FIG. 4 . 
     The descriptions provided herein are only exemplary, and variations and modifications may be made without departing from the concepts discussed herein.

Technology Category: g