Patent Publication Number: US-2007120829-A1

Title: Portable electronic apparatus and power save control method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2005-345908, filed Nov. 30, 2005, the entire contents of which are incorporated herein by reference.  
     BACKGROUND  
      1. Field  
      One embodiment of the invention relates to a power saving technique suitable for, for example, a notebook personal computer that can be powered by a battery.  
      2. Description of the Related Art  
      In accordance with the recent progress of compression/encoding and image processing techniques, recording/reproducing of movies and music video programs as digital data has come to be generally carried out, using, for example, personal computers.  
      Many personal computers of this type are carried by a user and powered by a battery. Battery-powered personal computers enable users to enjoy movies or music video programs anywhere they visit, and anytime even when on the move.  
      For portable electronic apparatuses including such battery-powered personal computers, various methods for reducing power consumption have been proposed to power them as long as possible by batteries (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2005-218006). In the portable digital broadcasting receiver apparatus disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2005-218006, to reduce power consumption, the audio decoding unit is deactivated in the mode of outputting only video data, while the video decoding unit and display device are deactivated in the mode of outputting only audio data.  
      Assume here that music video data recorded on a digital versatile disk (DVD) is reproduced by a battery-powered personal computer. At this time, when the user thinks that they do not need images to enjoy the music, they can enjoy the music for longer by selecting the mode of outputting only audio data.  
      However, with many DVDs, a menu is displayed to enable a user to operate it, and reproduce is performed in accordance with the menu selection. Therefore, even where the user wants to enjoy only music without images, control of simply deactivating the video decoding unit and display device cannot be performed. 
    
    
     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 illustrating a state of a notebook personal computer according to an embodiment of the invention, in which its display unit is open;  
       FIG. 2  is an exemplary block diagram illustrating the configuration of the computer of the embodiment;  
       FIG. 3  is an exemplary block diagram illustrating a content reproducing application program executed in the computer;  
       FIG. 4  is an exemplary flowchart illustrating the procedure of an operation performed by the computer during reproducing recorded data;  
       FIG. 5  is an exemplary flowchart illustrating the procedure of an operation performed, when reproducing recorded data, concerning the opening/closing of the display unit of the computer; and  
       FIG. 6  is an exemplary flowchart illustrating the procedure of another operation (modification) performed by the computer when reproducing recorded data. 
    
    
     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, a portable electronic apparatus permitted to be powered by a battery and including a function for reproducing contents data acquired by multiplexing and encoding video data and audio data, includes a separation unit configured to separate the contents data into the video data and the audio data, a video decoder configured to receive and decode the video data separated by the separation unit, an audio decoder configured to receive and decode the audio data separated by the separation unit, a setting unit configured to set a power saving mode in which only the audio data included in the contents data is reproduced, and a power save control unit configured to stop decoding of part of the video data when the power saving mode is set by the setting unit, the part of the video data being for use other than menu display.  
      Referring first to  FIGS. 1 and 2 , the configuration of a portable electronic apparatus according to the embodiment will be described. The portable electronic apparatus is realized as, for example, a notebook personal computer  10 .  
       FIG. 1  is an exemplary perspective view illustrating a state of the personal computer  10 , in which its display unit is open. As shown, the computer  10  comprises a computer main unit  10   a  and display unit  10   b.  The display unit  10   b  incorporates a thin film transistor liquid crystal display (TFT-LCD)  24 . The display screen of the LCD  24  is located at substantially the center of the display unit  10   b.    
      The display unit  10   b  is angularly movably attached to the computer main unit  10   a  so that it is movable between an open position and closed position. The computer main unit  10   a  has a thin rectangular case, and includes a keyboard  26 , touch pad  27  and speakers  25 A and  25 B, etc., on the upper surface of the case.  
      Referring then to  FIG. 2 , the configuration of the computer  10  will be described.  
      As shown in  FIG. 2 , the computer  10  comprises a CPU  11 , north bridge (NB)  12 , system memory  13 , south bridge (SB)  14 , graphics controller  15 , sound controller  16 , BIOS-ROM  17 , hard disk drive (HDD)  18 , optical disk drive (ODD)  19 , LAN controller  20 , universal serial bus (USB) controller  21 , card controller  22  and embedded controller (EC)  23 .  
      The CPU  11  is a processor for controlling the operation of the computer  10 , and executes various programs, such as an operating system and content reproducing application program  100 , loaded from the HDD  18  to the system memory  13 . The CPU  11  also executes a basic input output system (BIOS) stored in the BIOS-ROM  17 . The BIOS is a program for hardware control.  
      The NB  12  is a bridge device that connects the local bus of the CPU  11  to the SB  14 . The NB  12  contains a memory controller for controlling accesses to the system memory  13 . The NB  12  also has a function for communicating with the graphics controller  15  via an accelerated graphics port (AGP) bus or a serial bus of the PCI express standards.  
      The graphics controller  15  is a display controller for controlling the LCD  24  used as the display monitor of the computer  10 .  
      The SB  14  controls each device on a low pin count (LPC) bus and on a peripheral component interconnect (PCI) bus. Further, the SB  14  contains an integrated drive electronics (IDE) controller for controlling the HDD  18  and ODD  19 , and has a function for communicating with the sound controller  16 .  
      The sound controller  16  is a sound source device, and outputs, to the speakers  25 A and  25 B, audio data corresponding to a sound to be reproduced. A connector (not shown) for a headphone is provided on one side of the computer main unit  10   a  of the computer  10 . When the jack of the headphone is inserted in the connector, the sound controller  16  outputs a music signal to the connector, instead of outputting it to the speakers  25 A and  25 B. Since the connector is provided on one side of the computer main unit  10   a,  the user can enjoy music through the headphone with the display unit  10   b  closed (for example, when the computer  10  is carried, contained in a bag).  
      The LAN controller  20  is a communication device for executing communication of, for example, the Ethernet® standards. The USB controller  21  executes serial communication of, for example, the USB2.0 standards with peripheral devices. The card controller  22  controls a PC card, secure digital (SD) card, etc. The EC  23  is a one-chip microcomputer formed of an embedded controller for power management, and a keyboard controller for controlling the keyboard  26  and touch panel  27 . The EC  23  also has a function for controlling a power supply controller (PSC)  28  for supplying power to each element of the computer  10 . The PSC  28  has a function for supplying power from a battery  29  or AC adaptor  30  to each element of the computer  10 , and a function for charging the battery  29  with the power from the AC adaptor  30 . Whether power is supplied from the AC adaptor  30  (i.e., whether the AC adaptor  30  is connected is always reported from the PSC  28  to the EC  23 .  
      Referring then to  FIG. 3 , a description will be given of the configuration of the content reproducing application program  100  executed in the computer  10  constructed as the above.  FIG. 3  is an exemplary block diagram useful in explaining the function of the content reproducing application program  100 .  
      The content reproducing application program  100  is software for operating the computer  10  as a reproducing apparatus for reproducing the contents data recorded on, for example, a digital versatile disk (DVD) set in the ODD  19 . As shown in  FIG. 3 , the program  100  includes a player manager  101 , navigator  102 , reader  103 , deMUXer  104 , video engine  105  and audio engine  106 .  
      The player manager  101  controls the entire operation of the content reproducing application program  100 , and has a user interface function for receiving instructions from the user. As part of the user interface function, the player manager  101  enables the user to select whether reproducing of recorded data should be executed in a power saving mode (i.e., whether power saving should be ON or OFF), described later, when the computer is powered by the battery. The player manager  101  manages the selected data as setting data.  
      The navigator  102  substantially controls the processing related to the reproducing of recorded data, based on an instruction from the player manager  101 . More specifically, the navigator  102  causes the reader  103  to read, from, for example, a DVD set in the ODD  19 , the data acquired by multiplexing and encoding video data and audio data, and causes the deMUXer  104  to separate the read data into video data and audio data. The navigator  102  further causes the video engine  105  to decode and output the video data acquired by the separation, and causes the audio engine  106  to decode and output the audio data acquired by the separation.  
      The contents data read from, for example, the DVD includes an information section and video object section. The navigator  102  refers to the information contained in the information section to grasp the whole structure of the contents data recorded on the DVD. The video object section contains the video data and audio data multiplexed, encoded and divided into preset units. Each unit holds a header as attribute information. The attribute information includes, for example, information that identifies the video data is for the display of a menu or for the main body.  
      Assume here that the user who carries the computer  10  has performed setting for causing the computer to reproduce contents data in a power saving mode. When the power saving mode is set, the computer  10  reproduces only audio data from the DVD set in the ODD  19 . Namely, the computer  10  executes control for users who do not need display of images and do want to enjoy only the music recorded on the DVD, if the powering period of the battery  29  is elongated (i.e., control for the users who think it sufficient if they can replay the DVD like a CD).  
      As described above, the player manager  101  manages whether the power saving mode is set. If the mode is set, this is reported from the player manager  101  to the navigator  102 . Upon receiving the report, the navigator  102  instructs the video engine  105  to decode only the video data determined to be dedicated to menu display from attribute information held as a header, and not to decode the other video data. Upon receiving the instruction, if the video data from the deMUXer  104  is not for menu display, the video engine  105  stops decoding and supplies the EC  23  an instruction to stop the supply of power to the graphics controller  15  and LCD  24 .  
      Namely, in the computer  10 , when music video data is reproduced from a DVD in the power saving mode, display control to display the menu necessary for each operation and not to display the main body to be displayed after the menu is automatically performed. As a result, reduction of consumption power caused by a reduction in the load of the CPU due to the stop of decoding, and the reduction of consumption power due to the turn off of the graphics controller  15  and LCD  24  are realized, which enables the reproducing of the contents data using the battery  29  to be enjoyed for a longer time.  
       FIG. 4  is an exemplary flowchart illustrating the procedure of an operation performed by the computer when reproducing contents data.  
      When reproducing contents data, the computer  10  determines whether the power saving mode is set (block A 1 ). If it is set (Yes at block A 1 ), the computer  10  determines whether video data as a reproducing target is for menu display (block A 2 ).  
      If the power saving mode is not set (No at block A 1 ), or if the video data is for menu display (Yes at block A 2 ), the computer  10  decodes the video data using the video engine  105  (block A 3 ), and turns on the LCD  24  and graphics controller  15  (block A 4 ).  
      In contrast, if the power saving mode is set, and if the video data is not for menu display (No at block A 2 ), the computer  10  stops the decoding of the video data by the video engine  105  (block A 5 ), and turns off the LCD  24  and graphics controller  15  (block A 6 ).  
      As described above, since a connector for a headphone is provided on a side of the computer main unit  10   a,  music can be enjoyed using the headphone with the display unit  10   b  closed. In this case, the LCD  24  of the display unit  10   b  is not seen. Accordingly, it is preferable to stop decoding to thereby reduce the load of the CPU, and to turn off the graphics controller  15  and LCD  24 , regardless of whether the power saving mode is set, in order to reduce the power consumption.  
      By doing this, after the necessary menu operation, it is possible to shift the computer  10  to the power saving mode simply by closing the display unit  10   b,  without performing the power saving mode-setting process.  
       FIG. 5  is an exemplary flowchart illustrating the procedure of an operation performed, when reproducing contents data, concerning the opening/closing of the display unit of the computer.  
      When reproducing contents data, the computer  10  determines whether the display unit  10   b  is open (block B 1 ). If the display unit  10   b  is open (Yes at block B 1 ), the computer  10  decodes video data using the video engine  105  (block B 2 ), and turns on the LCD  24  and graphics controller  15  (block B 3 ). Blocks B 2  and B 3  are executed not only when the display unit  10   b  is kept open from the beginning of use, but also when the closed display unit  10   b  is opened. Therefore, if the power saving mode is not set, image output is resumed when the display unit  10   b  is opened.  
      On the other hand, if the display unit is closed (No at block B 1 ), the computer  10  stops the decoding of video data by the video engine  105  (block B 4 ) and turns off the LCD  24  and graphics controller  15  (block B 5 ).  
      As described above, the computer  10  performs control for reducing the power consumption during reproducing contents data, in accordance with the opening/closing operation of the display unit  10   b.    
      In the above embodiment, when the power saving mode is set, the decoding of video data by the video engine  105  is stopped to reduce the load of the CPU. However, instead of totally stopping the decoding of video data, video data may be thinned before decoding, and the resultant video data is decoded. Also in this case, the load of the CPU can be reduced to thereby lengthen the duration time of the battery  29 . For instance, when video data is compressed and encoded by MPEG as major standards, the thinning is realized by, for example, decoding only I-picture data.  FIG. 6  is an exemplary flowchart illustrating the procedure of another operation (modification) performed by the computer when reproducing contents data.  
      When reproducing contents data, the computer  10  determines whether the power saving mode is set (block C 1 ). If the mode is not set (No at block C 1 ), the computer  10  performs normal decoding using the video engine  105  (block C 2 ). If the mode is set (Yes at block C 1 ), the computer  10  decodes thinned data using the video engine  105  (block C 3 ).  
      Further, in the above embodiment, the supply of power to the graphics controller  15  and LCD  24  is interrupted when the power saving mode is set or the display unit  10   b  is closed. However, the same advantage (reduction of power consumption) as in the case of turning off the LCD  24  can be acquired also when the brightness of video data to be output to the LCD  24  is set 0.  
      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.