Patent Publication Number: US-2007124613-A1

Title: Information processing apparatus and system control method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-340287, filed Nov. 25, 2005, the entire contents of which are incorporated herein by reference.  
     BACKGROUND  
      1. Field  
      One embodiment of the invention relates to an information processing apparatus which can be driven by an AC power supply and also to a system control method.  
      2. Description of the Related Art  
      In general, an information processing apparatus, such as a notebook computer (PC), is configured to be driven by either an AC power supply (commercial AC power supply) or a battery. In an environment where a PC is used by means of an AC power supply, the user can make the best use of the performance of the PC without taking the amount of remaining battery time into consideration. There are a variety of techniques to improve the operability of PCs and safety in using the AC power supply.  
      For example, Jpn. Pat. Appln. KOKAI Publication No. 10-97353 (hereinafter referred to as Document 1) discloses the following matter: When AC power is supplied, even if a power switch is turned off, power supply to a main memory is maintained; then, when the power switch is turned on, the system is restored to an operative condition based on the contents of the main memory.  
      Jpn. Pat. Appln. KOKAI Publication No. 2000-175347 (hereinafter referred to as Document 2) discloses the following matter: If an AC line cord plug is removed from the receptacle without turning off the AC switch, or if the AC switch is not turned off after a power cutoff, power will not be supplied to the apparatus unless the user intentionally turns on the AC switch, so that safety is ensured.  
      In the case where many information processing apparatuses, such as notebook computers (PCs), are used in an educational setting (e.g., a personal computer school) with AC power supply, an environment may be considered, in which all the information processing apparatuses can be easily turned on or off at a time. Generally, such an environment raises drawbacks, for example, decline in safety or operability of each PC.  
      The technique disclosed in Document 1 may be effective, if the user always desires to quickly restore the system to a condition as was immediately before the power off (resume). If not, however, the technique may be inefficient, because the power is wasteful.  
      The technique disclosed in Document 2 is safe but is not considered efficient, because if an AC line cord plug is removed from the receptacle without turning off an AC switch, or if the AC switch is not turned off after a power cutoff, power will not be supplied to the apparatus unless the user intentionally turns on the AC switch. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
      A general architecture that implements the various feature of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention.  
       FIG. 1  is an exemplary perspective view showing a state in which a display unit of a computer according to an embodiment of the present invention is opened;  
       FIG. 2  is an exemplary block diagram showing a system configuration of the computer;  
       FIG. 3  is an exemplary diagram showing an example of a setting screen, which allows setting of an operation mode that should be set when AC power supply is cut off or restarted;  
       FIG. 4  is an exemplary diagram showing a case where a plurality of computers of the same type as the computer shown in  FIG. 1  are used in a personal computer school with AC power supply;  
       FIG. 5  is an exemplary diagram showing operations of each of the computers when a breaker is switched off and on in the structure shown in  FIG. 4 ;  
       FIG. 6  is an exemplary block diagram showing a first configuration example to perform system control in accordance with cutoff/restart of AC power supply;  
       FIG. 7  is an exemplary sequence diagram showing a first operation example based on the configuration example shown in  FIG. 6 ;  
       FIG. 8  is an exemplary block diagram showing a second configuration example to perform system control in accordance with cutoff/restart of AC power supply;  
       FIG. 9  is an exemplary sequence diagram showing a second operation example based on the configuration example shown in  FIG. 8 ; and  
       FIG. 10  is an exemplary flowchart showing an operation flow common to the first operation example ( FIG. 7 ) and the second operation example ( FIG. 9 ). 
    
    
     DETAILED DESCRIPTION  
      Various embodiments according to the invention will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment of the invention, there is provided an information processing apparatus including a detector configured to detect whether a power is supplied and a controller configured to control the apparatus to be in an operable state when the detector detects the power is supplied.  
      First, a configuration of an information processing apparatus according to the embodiment of the present invention will be described with reference to  FIGS. 1 and 2 . The information processing apparatus is implemented as, for example, a notebook computer  10 .  
       FIG. 1  is a perspective view showing a state in which a display unit of the notebook computer  10  is opened. The computer  10  comprises a computer main body  11  and a display unit  12 . The display unit  12  incorporates a display device comprising a TFT-LCD (Thin Film Transistor Liquid Crystal Display)  17 . A display screen of the LCD  17  is located in a substantially central portion of the display unit  12 .  
      The display unit  12  is attached to the computer main body  11  so as to be rotatable between an opened position and a closed position. The computer main body  11  has a thin box-shaped casing. The computer main body  11  comprises a keyboard  13 , a power button  14  to power on/off the computer  10 , an input operation panel  15 , a touch pad  16 , etc., which are arranged on an upper surface of the casing.  
      The input operation panel  15  is an input device, through which an event corresponding to a depressed button is input. It has a plurality of buttons to activate a plurality of functions, respectively. The group of buttons includes a TV activating button  15 A and a DVD/CD activating button  15 B. The TV activating button  15 A is a button to activate TV function in order to play back, view, listen to and record TV broadcast program data. The DVD/CD activating button  15 B is a button to play back video contents recorded in a DVD or CD.  
      A condition display section  30 , which displays conditions inside the computer  10 , is provided in a front surface of the main body  11 . The condition display section  30  contains a plurality of indicators  31 ,  32 , . . . . Operations of turning on and off the indicators are controlled by an embedded controller (EC) to be described later.  
      The indicator  31  indicates whether an AC adapter is connected or not (i.e., whether AC power is supplied or not). For example, green light illuminates when AC power is supplied, and goes out when AC power supply is stopped.  
      The indicator  32  indicates a condition of system power (ON state, OFF state, suspending state (or standby state), hibernation state (or halt state), etc.). For example, the indicator  32  emits green light when power supply is on, and puts it out when power is off. Further, the indicator  32  distinguishes between the suspending state and the hibernation state by a difference in color or a difference in flickering pattern of a predetermined color (e.g., orange).  
      A system configuration of the computer  10  will now be described with reference to  FIG. 2 .  
      As shown in  FIG. 2 , the computer  10  comprises a CPU  111 , a north bridge  112 , a main memory  113 , a graphics controller  114 , a south bridge  119 , a BIOS-ROM  120 , a hard disk drive (HDD)  121 , an optical disk drive (ODD)  122 , a TV tuner  123 , an embedded controller/keyboard controller IC (EC/KBC)  124 , a network controller  125 , a battery  126 , an AC adapter  127 , a power supply controller (PSC)  128 , etc.  
      The CPU  111  is a processor provided to control operations of the computer  10 . It executes an operating system (OS)  200  and various application programs  201  loaded from the hard disk drive (HDD)  121  to a main memory  113 .  
      The CPU  111  also executes a system BIOS stored in the BIOS-ROM  120 . The system BIOS is a program for hardware control.  
      The north bridge  112  is a bridge device which connects the south bridge  119  with a local bus of the CPU  111 . The north bridge  112  incorporates a memory controller which controls access to the main memory  113 . Further, the north bridge  112  has a function for executing communications with the graphics controller  114  via an accelerated graphics port (AGP) bus.  
      The graphics controller  114  is a display controller, which controls an LCD  17  used as a display monitor of the computer  10 . The graphics controller  114  displays video data written in a video memory (VRAM)  114 A on the LCD  17 .  
      The south bridge  119  controls devices on a low pin count (LPC) bus and devices on a peripheral component interconnect (PCI) bus. The south bridge  119  incorporates an integrated drive electronics (IDE) controller to control the HDD  121  and ODD  122 . Further, the south bridge  119  has a function for controlling the TV tuner  123  and a function for controlling access to the BIOS-ROM  120 .  
      The HDD  121  is a storage device which stores various software and data. The optical disk drive (ODD)  123  is a drive unit to drive memory media, such as DVDs and CDs, which store video contents. The TV tuner  123  is a receiver to externally receive broadcast program data, such as TV broadcast program.  
      The network controller  125  is a communication apparatus, which executes communications with an external network, such as the Internet.  
      The embedded controller/keyboard controller IC (EC/KBC)  124  is a one-chip microcomputer, in which an embedded controller to manage power and a keyboard controller to control the keyboard (KB)  13  and the touch pad  16  are integrated.  
      The power supply controller (PSC)  128  generates and supplies power necessary to the respective components of the computer  10  based on power from the battery  126  or external power externally supplied through the AC adapter  127  in accordance with instructions from the embedded controller (EC).  
       FIG. 3  is a diagram showing an example of a setting screen, which allows setting of an operation mode that should be set when AC power supply is cut off (disconnected) or restarted (connected). The setting screen is implemented by a power control setting application to be described later. The following operation modes (shut down modes) can be set in the screen:  
      No AC Power Control  
      Suspending  
      Hibernation  
      Off  
      When the user selects any one of these modes and pushes an OK button, the setting is completed.  
      For example, assume that “Suspending” (storing the system condition in a RAM or the like) is set as the operation mode (shut down mode) to be set when the AC power supply is cut off (disconnected). In this case, when the AC power supply is cut off, instruction information to instruct the system to activate upon restart of the AC power supply is stored in a predetermined memory area. Then, the system is shifted from the ON state to the suspending state (or standby state) and the operation is terminated. When the AC power supply is restarted (reconnected), “Resume” is executed in accordance with the instruction information. As a result, the system is recovered from the suspending state to the ON state.  
      Alternatively, assume that “Hibernation” (storing the system condition in a hard disk or the like) is set as the operation mode (shut down mode) to be set when the AC power supply is cut off (disconnected). In this case, when the AC power supply is cut off, instruction information to instruct the system to activate upon restart of the AC power supply is stored in the predetermined memory area. Then, the system is shifted from the ON state to the hibernation state (or halt state) and the operation is terminated. When the AC power supply is restarted (reconnected), “Recovery from Hibernation” is executed in accordance with the instruction information, with the result that the system is recovered from the hibernation state to the ON state.  
      Further, assume that “Off” (not storing the system condition) is set as the operation mode (shut down mode) to be set when the AC power supply is cut off. In this case, when the AC power supply is cut off (disconnected), instruction information to instruct the system to activate upon restart of the AC power supply is stored in the predetermined memory area. Then, the system is shifted from the ON state to the OFF state, and the system operation is terminated. When the AC power supply is restarted (connected), “Boot” is executed in accordance with the instruction information, with the result that the system is recovered from the OFF state to the ON state.  
      If none of the above three operation modes is set, and “No AC Power Control” is set, when the AC power supply is cut off (disconnected), the AC power-driving is changed to the battery-driving without storing instruction information or shifting the system condition. When the AC power supply is restarted, the battery-driving is changed to the AC power-driving.  
      Through the above process, when the AC adaptor or AC line cord is unexpectedly pulled out from the receptacle, as well as when a breaker  40  is switched off, the system of the computer completes it operation safely. Then, when the AC power supply is restarted, the system is returned to an appropriate condition that the user desires.  
      In the following, explanations will be given on the assumption that any one of the above three operation modes “Suspending”, ”Hibernation” and “Off” is set.  
       FIG. 4  is a diagram showing a case where a plurality of computers of the same type as the computer  10  are used in a personal computer school with AC power supply.  
      Each of the computers in a classroom of a personal computer school receives AC power via the breaker  40 . AC power supply to all computers can be stopped or restarted by turning off or on the switch of the breaker  40 .  
      In each of the computers, when the AC power supply is cut off, if any one of the above three operation modes “Suspending”, “Hibernation” and “Off” is set, instruction information to instruct the system to activate upon restart of the AC power supply is stored in the predetermined memory area. Then, the system is shifted from the ON state to the OFF state, and the operation is terminated. When the AC power supply is restarted, the system is activated in accordance with the instruction information by a process corresponding to “Resume”, “Recovery from hibernation” or “Boot”.  
       FIG. 5  is a diagram showing operations of each of the computers when a breaker is switched off and on in the structure shown in  FIG. 4 .  
      In this description, it is assumed that the breaker  40  in the classroom is turned off at 5:00 p.m. and turned on at 8:30 next morning.  
      Referring to a case A in  FIG. 5 , a computer, which is in the “off” state during the daytime, is continuously off after the breaker is turned off at 5:00 p.m. Even when the switch of the breaker  40  is turned on at 8:30 in the next morning, the system is still in the “off” state.  
      On the other hand, as in a case B in  FIG. 5 , a computer, which is in the “on” state during the daytime, is shifted to any one of the three operation modes “Suspending”, “Hibernation” and “Off” in accordance with the present mode, when the switch of the breaker  40  is turned off at 5:00 p.m. When the switch of the breaker  40  is turned on at 8:30 in the next morning, the system is activated in accordance with the instruction information, and performs a process corresponding to “Resume”, “Recovery from hibernation” or “Boot”. Thus, the computer is shifted to the “on” state.  
       FIG. 6  is a block diagram showing a first configuration example to perform system control in accordance with cutoff/restart of AC power supply. In  FIG. 6 , the same elements as those shown in  FIG. 2  are identified by the same reference numerals as those used in  FIG. 2 .  
      The power supply controller  128  receives AC power via the AC adapter  127  and power from the battery  126 , and supplies necessary power to the components of the computer. When the cutoff/restart of the AC power supply occurs due to the switch on/off of the breaker  40  or inserting/pulling out of the AC adapter  127  (or AC code), the power supply controller  128  transmits the information to an EC  124 A.  
      When the EC  124 A detects the cutoff of the AC power supply through the power supply controller  128 , it notifies the OS  200  of that fact. When the EC  124 A detects the restart of the AC power supply through the power supply controller  128 , it activates the system in accordance with the instruction information set in the internal memory area. The EC  124 A and the power supply controller  128  may be configured to be one unit.  
      The OS  200  transmits notification of cutoff of the AC power supply notified by the EC  124 A to an AC power supply control program  212 . It also performs a mode shift operation required by the AC power supply control program  212 .  
      A power supply control setting application  211  operates under the control of the OS  200 . It sets an operation mode designated by the user through the setting screen described above, and transmits the setting information to the AC power supply control program  212 .  
      When the AC power supply control program  212  receives the notification of cutoff of the AC power transmitted from the OS  200 , if the setting information obtained from the power supply control setting application  211  represents “Suspending”, “Hibernation” or “Off”, the program  212  causes a predetermined memory area (a register or the like) in the EC  124 A to store the instruction information, instructing the system to activate upon restart of the AC power supply. In addition, the program  212  requests the OS  200  to set the operation mode corresponding to the setting information.  
      A first operation example based on the configuration example shown in  FIG. 6  will now be described with reference to  FIG. 7 .  
      In the state where the computer is driven by the AC power supply, the power supply control setting application  211  sets an operation designated by the user through the setting screen (block S 11 ). The set operation mode is transmitted to the AC power supply control program  212 .  
      If the power supply controller  128  detects the cutoff of the AC power supply through the AC adapter  127  (block S 12 ), the power source is changed to the battery  126 . If the EC  124 A is notified of the cutoff of the AC power supply, it notifies the OS  200  of the cutoff of the AC power supply via the BIOS (blocks S 13  and S 14 ). The OS  200 , which has received the notification of the cutoff of the AC power supply, notifies the AC power supply control program  212  of the notification as an event (block S 15 ).  
      Upon receipt of the event of the AC power supply cutoff, the AC power supply control program  212  sends an instruction to activate the system at the restart of the AC power supply to the EC  124 , if the operation mode set by the power supply control setting application  211  in advance is “Suspending”, “Hibernation” or “Off” (block S 16 ). Upon receipt of the instruction from the AC power control program  212 , the EC  124 A stores the instruction information indicative of the instruction in the internal memory (block S 17 ).  
      Then, the AC power control program  212  requests the OS  200  to execute a shifting process corresponding to the operation mode (“Suspending”, “Hibernation” or “Off”) set in advance by the power supply control setting application  211  (block S 18 ).  
      Upon receipt of the request from the AC power control program  212 , the OS  200  executes a shift process corresponding to the operation mode indicated in the request, and notifies the EC of that fact (block S 19 ). Upon receipt of the notification from the OS  200 , the EC  124 A changes the operation mode as requested, and sets the system power supply to a condition corresponding to “Suspending”, “Hibernation” or “Off” (block S 20 ).  
      Thereafter, when the power supply controller  128  detects restart of the AC power supply from the AC adapter  127  (block S 21 ), it uses the AC power supplied from the AC adapter  127 . When the EC  124 A is notified of the restart of the AC power supply, it refers to the instruction information stored in the internal memory. If the instruction information represents instruction to activate the system at the restart of the AC power supply, the EC  124 A causes the system power to be on and the BIOS to be activated (block S 22 ). Upon activation, the BIOS executes the system activation corresponding to the set operation mode (block S 23 ).  
      For example, in the case of “Suspending”, “Resume” is executed; in the case of “Hibernation”, “Recovery from Hibernation” is executed; and in the case of “Off”, “Boot” is executed.  
      As a result, the OS  200  is activated (restored), and turned on (block S 24 ).  
       FIG. 8  is a block diagram showing a second configuration example to perform system control in accordance with cutoff/restart of AC power supply. In  FIG. 8 , the same elements as those shown in  FIG. 2  are identified by the same reference numerals as those used in  FIG. 2 . In the following, explanations will be given mainly for those parts that differ from the first configuration example ( FIG. 6 ) described above.  
      In the first configuration example ( FIG. 6 ), the AC power supply control program  212  instructs the EC  124 A to store the setting information or the OS  200  to perform operation mode shift when the AC power supply is cut off. In the second configuration example, a BIOS performs these processes. More specifically, when a BIOS  120 A shown in  FIG. 8  receives the notification of cutoff of the AC power supply from the EC  124 A, if the setting information obtained from the power supply control setting application  211  represents “Suspending”, “Hibernation” or “Off”, the BIOS  120 A causes a predetermined memory area (register or the like) in the EC  124 A to store instruction information, instructing the system to activate at restart of the AC power supply. In addition, the BIOS  120 A requests the OS  200  to set the operation mode corresponding to the setting information.  
      A second operation example based on the configuration example shown in  FIG. 8  will now be described with reference to  FIG. 9 .  
      In the state where the computer is driven by the AC power supply, the power supply control setting application  211  sets an operation designated by the user through the setting screen. The set operation mode is notified to the BIOS  120 A by the AC power supply control program  212  (block S 31 ).  
      If the power supply controller  128  detects the cutoff of the AC power supply through the AC adapter  127  (block S 32 ), the power source is changed to the battery  126 . If the EC  124 A is notified of the cutoff of the AC power supply, it notifies the BIOS  120 A of the cutoff of the AC power supply (block S 33 ).  
      When the BIOS  120 A receives the notification of the cutoff of the AC power supply, if the operation mode which the Ac power control program  212  has notified of is “Suspending”, “Hibernation” or “Off”, the BIOS  120 A requests the OS  200  to perform a process of shifting to the corresponding operation mode (block S 34 ). Upon receipt of the request from the BIOS  120 A, the OS  200  performs a shifting process corresponding to the operation mode as requested (block S 35 ).  
      Then, the BIOS  120 A sends an instruction that the system should be activated at the restart of the AC power supply to the EC  124 A, and instructs the EC  124 A to shift to the corresponding operation mode (block S 36 ). Upon receipt of the instruction from the BIOS  120 A, the EC  124 A causes the internal memory to store the instruction information representing the instruction (block S 37 ), and executes the shift to the operation mode as instructed (block S 38 ).  
      Thereafter, when the power supply control  128  detects restart of the AC power supply from the AC adapter  127  (block S 39 ), it uses the AC power supplied from the AC adapter  127 . When the EC  124 A is notified of the restart of the AC power supply, it refers to the instruction information stored in the internal memory. If the instruction information represents instruction to activate the system at the restart of the AC power supply, the EC  124 A causes the system power to be on and the BIOS to be activated (block S 40 ). Upon activation, the BIOS executes the system activation corresponding to the set operation mode (block S 41 ).  
      For example, in the case of “Suspending”, “Resume” is executed; in the case of “Hibernation”, “Recovery from Hibernation” is executed; and in the case of “Off”, “Boot” is executed.  
      As a result, the OS  200  is activated (restored), and turned on (block S 42 ).  
      An operation flow common to the first operation example ( FIG. 7 ) and the second operation example ( FIG. 9 ) will now be described with reference to  FIG. 10 .  
      In the state where the computer is driven by the AC power supply (block S 51 ), the power supply controller  128  and the EC  124 A monitor whether the AC power supply is cut off or not (block S 52 ). If the cutoff of the AC power supply is detected, the AC power supply control program  212  or the BIOS  120 A determines whether to execute the AC power supply control based on the type of operation mode set by the power supply control setting application  211  (block S 53 ).  
      If the set operation mode is “Suspending”, instruction information to instruct the system to activate at restart of the AC power supply is stored in a predetermined memory area in the EC  124 A, and the operation mode is shifted to “Suspending” (block S 54 A and S 55 A).  
      If the set operation mode is “Hibernation”, instruction information to instruct the system to activate at restart of the AC power supply is stored in the predetermined memory area in the EC  124 A, and the operation mode is shifted to “Hibernation” (S 54 B and S 55 B).  
      If the set operation mode is “Off”, instruction information to instruct the system to activate at restart of the AC power supply is stored in the predetermined memory area in the EC  124 A, and the operation mode is shifted to “Off” (S 54 C and S 55 C).  
      Thereafter, when restart of the AC power supply is detected (block S 56 ), the EC  124 A refers to the instruction information stored in the internal memory area. If the instruction information represents that the system should be activated at restart of the AC power supply, the system power is turned on and the BIOS is activated. The BIOS, upon activation, executes the system activation corresponding to the set operation mode.  
      For example, in the case of “Suspending”, “Resume” is executed (block S 57 A); in the case of “Hibernation”, “Recovery from Hibernation” is executed (block S 57 B); and in the case of “Off”, “Boot” is executed (block S 57 C). As a result, the OS  200  is activated (restored), and turned on.  
      As described above, according to the embodiment of the present invention, especially in an environment where the AC power supply is used, the operability of the PC is improved while the safety is maintained.  
      In addition, in a personal computer school or the like, a plurality of computers can be turned on or off at a time through one AC path. Further, an AC adapter and AC line cord can be inserted and pulled out safely, and the system recovery as required by the user can be ensured. For example, if a computer is to be moved to another classroom, appropriate control can be carried out only by removing the AC adapter. In this case, therefore, it is unnecessary to operate a power source, such as a power switch. After the computer is moved, the system can be recovered and automatically turned on only by connecting the computer to the power supply via the AC adapter. Thus, the operability is significantly improved.  
      While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.