Patent Publication Number: US-2007098191-A1

Title: Audio system of a tablet personal computer and the speaker orientating method thereof

Description:
RELATED APPLICATIONS  
      The present application is based on, and claims priority from, Taiwan Application Serial Number 94137900, filed Oct. 28, 2005, the disclosure of which is hereby incorporated by reference herein in its entirety.  
     FIELD OF THE INVENTION  
      The present invention relates to a tablet personal computer, and particularly relates to an audio system of a tablet personal computer and the orientating method thereof.  
     BACKGROUND OF THE INVENTION  
      Manufacturers have provided tablet personal computers offering several advantages, such as powerful calculation ability, broad screens, and particularly intuitive graphic input devices similar to those found in personal digital assistants, all of which can improve users&#39; operation habits, provide more convenience and make personal computers more available for various circumstances.  
      Generally, an audio system of a conventional portable computer (such as a laptop computer) has several speakers set on predetermined locations to provide stereophony. For example these speakers are fixed adjacent to the screen of the laptop personal computer to provide sound fields directed both from right and left sides of the screen. Since a user should face the screen of the laptop computer while operating, the stereophony generated by the speakers is rather stable. Typically, a tablet personal computer can be operated at every orientation; however each speaker of the tablet personal computer is fixed on predetermined locations. When the relative position of the user to the fixed speakers is changed, the tablet personal computer forms different and perhaps undesirable stereophony.  
       FIGS. 1A  to  1 C illustrate the arrangement of plural speakers fixed on a conventional tablet personal computer.  FIG. 1A  illustrates the initial relative position of the speakers  101  and  102  fixed on the bottom positions of the tablet personal computer adjacent to the screen  100  thereof. The sound fields respectively provided by the two speakers either from the right side or the left side of the screen  100  are mixed to form a predetermined stereophony, wherein the speaker  101  provides the left sound field and the speaker  102  provides the right sound field.  
       FIG. 1B  illustrates the relative position of the speakers  101  and  102  when the tablet personal computer of  FIG. 1A  is rotated 90° clockwise. As the tablet personal computer is rotated, the speakers  101  and  102  are moved to the left side of the screen  100  relatively. The speakers  101  and  102  both provide sound fields from the left side of the screen  100  and provide no sound field from the right side of the screen  100 ; thus the stereophony generated by the speakers  101  and  102  is different from the predetermined stereophony.  
       FIG. 1C  illustrates the relative position of the speakers  101  and  102  when the tablet personal computer of  FIG. 1A  is rotated 180° clockwise. As the tablet personal computer is rotated, the relative position of the speakers  101  and  102  is reversed relative to that of  FIG. 1A . Effectively, the speaker  101  is removed to the right side of the screen  100  to provide a right sound field, and the speaker  102  is removed to the left side of the screen  100  to provide a left sound field.  
      Thus, the predetermined stereophony cannot be duplicated for every setting, the performance of audio systems of tablet personal computers are adversely affected, and tablet personal computers are thereby limited in their operating orientations and convenience.  
     SUMMARY OF THE INVENTION  
      One aspect of present invention is to provide an audio system for a tablet personal computer and the orientating method thereof to overcome the aforementioned problems and to improve the audio performance of the tablet personal computer.  
      In accordance with the objective of the present invention, an audio system is provided to provide the tablet personal computer a predetermined stereophony.  
      In a preferred embodiment of the present invention, the audio system comprises at least two speakers, an audio driver, an angle detector and an audio-adjusting device, wherein each speaker mounted on a frame of the tablet personal computer has a distance apart from another.  
      The audio driver is used for driving the speakers, wherein the audio driver may drive the speakers in accordance with a set of audio parameters to adjust the outputting sound field of each speaker. For example each speaker may be assigned to provide a left sound field, to provide a right sound field, or to mute by the set of audio parameters.  
      The angle detector mounted on the frame of the tablet personal computer is used for generating positional data as the frame is rotated relative to the ground.  
      The audio-adjusting device is used to renew the set of audio parameters in accordance with the positional data.  
      According to the aforementioned embodiment, the orientating method of the audio system comprises the following steps: First, at least two speakers are mounted on the frame of a tablet personal computer, wherein each of the speakers has a distance apart from another. An audio diver is provided to adjust the output of these speakers in accordance with a set of audio parameters, wherein each speaker may be assigned to provide a left sound field, to provide a right sound field, or to mute by the set of audio parameters. An angle detector is mounted on the fame of the tablet personal computer used for generating positional data as the frame is rotated relative to the ground. The audio parameters may be renewed in accordance with the positional data so as to control each of the speakers to form a stereophony substantially equal to a predetermined stereophony. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:  
       FIG. 1A  illustrates the initial relative position of different speakers fixed on the bottom positions of a conventional tablet personal computer adjacent to the screen thereof.  
       FIG. 1B  illustrates the relative position of different speakers when the tablet personal computer of  FIG. 1A  is rotated 90° clockwise.  
       FIG. 1C  illustrates the relative position of different speakers when the tablet personal computer of  FIG. 1A  is rotated 180° clockwise.  
       FIG. 2A  illustrates the initial relative position of the different speakers to the ground, in accordance with the first embodiment of the present invention.  
       FIG. 2B  illustrates the relative position of different speakers when the tablet personal computer of  FIG. 2A  is rotated 90° clockwise.  
       FIG. 2C  illustrates the relative position of different speakers when the tablet personal computer of  FIG. 2A  is rotated 180° clockwise.  
       FIG. 2D  illustrates the relative position of different speakers when the tablet personal computer of  FIG. 2A  is rotated 270° clockwise.  
       FIG. 3A  illustrates the initial relative position of the different speakers to the ground, in accordance with the second embodiment of the present invention.  
       FIG. 3B  illustrates the relative position of different speakers when the tablet personal computer of  FIG. 3A  is rotated 90° anti-clockwise.  
       FIG. 3C  illustrates the relative position of different speakers when the tablet personal computer of  FIG. 3A  is rotated 180° anti-clockwise.  
       FIG. 3D  illustrates the relative position of different speakers when the tablet personal computer of  FIG. 3A  is rotated 270° anti-clockwise.  
       FIG. 4A  is a block diagram illustrating the orientating method of an audio system  400  of a tablet personal computer to duplicate a predetermined stereophony at different rotating angles of the tablet personal computer relative to the ground.  
       FIG. 4B  illustrates the initial relative position of different speakers fixed on a tablet personal computer adjacent to the screen thereof, in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      The features of the present invention are to provide at least two speakers, an audio driver, an angle detector and audio-adjusting device for a tablet personal computer to duplicate a predetermined stereophony. When the tablet personal computer is rotated relative to the ground, the angle detector can detect the relative position of the tablet personal computer to the ground for generating a positional data; the audio-adjusting device can renew a built-in audio parameter/positional data shit in accordance with the positional data, providing the audio driver to control these speakers to output a stereophony substantially equal to a predetermined stereophony.  
      The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following embodiments of an audio system of a tablet personal computer.  
      Embodiment 1  
       FIGS. 2A  to  2 D illustrate the arrangement of plural speakers fixed on a tablet personal computer at different angles relative to the ground, in accordance with the first preferred embodiment of the present invention.  
      In the first embodiment of the present invention, the tablet personal computer  200  comprises three speakers, such as  201   a,    201   b  and  201   c.    
       FIG. 2A  illustrates the initial relative position of the speakers  201   a,    201   b  and  201   c  to the ground, wherein these speakers are respectively fixed on the tablet personal computer  200  adjacent to the screen thereof. The speakers  201   a  and  201   b  are turned on and the speaker  201   c  is turned off, wherein the speaker  201   a  provides a left sound field and the speaker  201   b  provides a right sound field. When the tablet personal computer  200  is rotated clockwise, the positional data, such as rotating angles 0°, 90°, 180° or 270° can be measured by an angle detector to provide the audio system for adjusting these speakers to output sound fields. In the present embodiment, the audio system of the tablet personal computer  200  comprises an application-programming interface (API) system provided by the Microsoft Corporation, wherein the API system includes a built-in audio parameter/positional data shit, shown as Table 1:  
                   TABLE 1                          Positional Data   Speakers Condition                             (Rotating Angle)   Speaker 201a   Speaker 201b   Speaker 201c                0°   L (Left   R (Right   OFF           Sound field)   Sound field)        90°   OFF   L   R       180°   R   L   OFF       270°   OFF   R   L                    
      The audio parameters can be varied by the API system depending on the positional data corresponding to the parameter/positional data shit to control the speakers  201   a,    201   b  and  201   c  condition.  
      When the tablet personal computer  200  is rotated about 90° clockwise (shown as  FIG. 2B ), the speakers&#39; condition is varied by the API system in accordance with the parameter/positional data shit, wherein the speaker  201   a  could be turned off, the speaker  201   b  could be turned on to provide a left sound field, and the speaker  201   c  could be turned on to provide a right sound field.  
      Similarly, when the tablet personal computer  200  is rotated about 180° clockwise (shown as  FIG. 2C ), the speakers&#39; condition is varied by the API system, wherein the speaker  201   c  could be turned off, the speakers  201   b  could be turned on to provide a left sound field, and the speaker  201   a  could be turned on to provide a right sound field. When the tablet personal computer  200  is rotated about 270° clockwise (shown as  FIG. 2D ), the speaker  201   a  could be turned off, the speaker  201   c  could be turned on to provide a left sound field, and the speaker  201   b  could be turned on to provide a right sound field.  
      Embodiment 2  
       FIGS. 3A  to  3 D illustrate the arrangements of plural speakers fixed on a tablet personal computer at different rotating angles relative to the ground, in accordance with the second preferred embodiment of the present invention.  
      In the first present invention, the tablet personal computer  300  comprises four speakers, such as  301   a,    301   b,    301   c,  and  301   d.  Compared to the first embodiment, the four speakers are always turned on, and the outputting sound field of each speaker may be varied depending on different rotating angles of the tablet personal computer relative to the ground.  
       FIG. 3A  illustrates the initial relative position of the speakers  301   a,    301   b,    301   c,  and  301   d  to the ground, wherein these speakers are respectively fixed on the four corners of the tablet personal computer  300 . The speakers  301   a  and  301   d  provide a left sound field and the speakers  301   b  and  301   c  provide a right sound field. When the tablet personal computer  300  is rotated anti-clockwise, the positional data, such as rotating angles 0°, 90°, 180° or 270° can be measured by an angle detector to provide the audio system for adjusting these speakers to output sound fields. In the present embodiment, the audio system of the tablet personal computer  200  comprises an application-programming interface (API) system provided by the Microsoft Corporation, wherein the API system includes a built-in audio parameter/positional data shit, shown as Table 2:  
                       TABLE 2                                      Speaker Condition                                 Positional Data   Speaker   Speaker               (Rotating Angle)   301a   301b   Speaker 301c   Speaker 301d                0°   L   R   R   L        90°   R   R   L   L       180°   R   L   L   R       270°   L   L   R   R                    
      The audio parameters can be varied by the API system depending on the condition of the speakers  301   a,    301   b,    301   c  and  301   d.    
      When the tablet personal computer  300  is rotated about 90° anti-clockwise (shown as  FIG. 3B ), the speakers&#39; condition is varied by the API system in accordance with the parameter/positional data shit, wherein the speakers  301   a  and  301   b  could provide a right sound field, and speakers  301   c  and  301   d  could provide a left sound field.  
      Similarly, when the tablet personal computer  300  is rotated about 180° anti-clockwise (shown as  FIG. 3C ), the speakers&#39; condition is also varied by the API system, wherein the speakers  301   a  and  301   d  could provide a right sound field, and speakers  301   b  and  301   c  could provide a left sound field. When the tablet personal computer  300  is rotated about 270° anti-clockwise (shown as  FIG. 3D ), the speakers  301   c  and  301   d  could provide a right sound field, and speakers  301   a  and  301   b  could provide a left sound field.  
       FIG. 4A  is a block diagram illustrating the orientating method of an audio system  400  of a tablet personal computer to duplicate a predetermined stereophony at different rotating angles of the tablet personal computer relative to the ground. First, an audio system  400  comprising at least two speakers, an audio driver, an angle detector and audio-adjusting device is provided. The audio system  400  of the tablet personal computer comprises four speakers, such as the speakers  401   a,    401   b,    401   c,  and 401 d  mounted adjacent to the screen of the tablet personal computer, wherein each speaker has a distance apart from another. In the preferred embodiment of the present invention, the tablet personal computer is rectangular, the speakers 401 a,    401   b,    401   c,  and  401   d  are mounted on the four corners of the tablet personal computer respectively (shown as  FIG. 4B ).  
      The audio driver  411  electrically connects to each of the speakers  401   a,    401   b,    401   c,  and  401   d . The outputting sound fields of the speakers  401   a,    401   b,    401   c,  and  401   d  are controlled by the audio driver  411  in accordance with a set of audio parameters, wherein the audio parameters are used to determine the outputting volume, frequency, and the on/off condition of each speaker, so as to determine each speaker to provide a left sound field or to provide a right sound field for duplicating a predetermined stereophony. The audio driver may be a chipset, software, a single chip, or the arbitrary combination thereof for audio control.  
      The angle detector  403  electrically connected to the central processing system  405  of the tablet personal computer is used to generate the positional data as the tablet personal computer is rotated relative to the ground. In the preferred embodiment of the present invention, the angle detector  403  is a micro-electrical mechanical device comprising an accelerometer used to measure the rotating angles and the rotating direction of the tablet personal computer&#39;s frame  402  and to provide the central processing system  405  of the tablet personal computer digital signals or analog signals for calculating the relative position of the speakers  401   a,    401   b,    401   c,    401   d  and the frame  402  relative to the ground for providing the positional data. The positional data, such as the relative position about the frame  402  and the speakers  401   a,    401   b,    401   c,  and  401   d  to the ground, can be calculated to determine the rotational displacement of each speaker.  
      In the other preferred embodiment of the present invention, the angle detector  403  further comprises an analog-to-digital converter (ADC) used to transform the analog signals into digital signals measured by the angle detector  403  before the rotational displacement calculation conducted by the central processing system  405 . It must be noted that the central processing system  405  comprises the central processing unit (CPU)  405   a  of the tablet personal computer and other programmable system, such as a chipset  405   b.    
      The audio-adjusting device  409  set in the tablet personal computer and electrically connected to the angle detector  403  and the audio driver  411  is used to renew the set of audio parameters in accordance with the rotational displacement of the speakers to control the audio driver to adjust the sound fields of the speakers to form a stereophony substantially equal to a determined stereophony.  
      The audio-adjusting device  409  may be a single chip, a chipset, software or the arbitrary combination thereof. In some embodiments of the present invention, the audio-adjusting device  409  comprises a built-in parameter/positional data shit used to define the relationships between the audio parameter and the positional data, wherein the positional data is generated by the angle detector  403  as the tablet personal computer is rotated relative to the ground. In some other embodiments of the present invention, the audio-adjusting device  409  further comprises an indicator, such as a screen or indicating lamps used to display the positional data.  
      In some preferred embodiments of the present invention, the audio-adjusting device comprises a register  413  used to store the positional data, such as the rotational displacement of the speakers generated and calculated by the angle detector  403  and the central processing system  405  as the tablet personal computer is rotated relative to the ground. When the positional data is varied, the audio-adjusting device  409  can renew the audio parameters for the audio diver  411  in accordance the built-in audio parameter/positional shift. Meanwhile, the audio diver  411  can monitor the variation of the audio parameters to adjust the outputting sound field of each speaker for forming a stereophony substantially equal to a predetermined stereophony.  
      Of yet another preferred embodiment of the present invention, the audio-adjusting device comprises an application program, such as the application-programming interface (API) system provided by the Microsoft Corporation, by which the user can define predetermined functions to control the audio driver  411 . For example, the audio parameter/positional data shit can be built in the API system used to renew the audio parameters for the audio driver  411  to adjust the outputting sound field of each speaker; thus the outputting volume, frequency and the on/off condition of each speaker are determined to assign each speaker to provide a left sound field, to provide a right sound field or to mute.  
      It must be noted that when the positional data is varied, the audio-adjusting device  409  can automatically renew the audio parameters by the API system or display the positional data on the screen to inform the user optionally calling the API system to renew the audio parameters. Thus, the user has more freedom to adjust the audio system  400 .  
      In addition, the audio-adjusting device may comprise a manual controller, by which the user can renew the audio parameter in accordance with the variation of positional data displayed on the screen to adjust the outputting sound file of each speaker for duplicating the predetermined stereophony.  
      According to the aforementioned embodiments, the features of the present invention are providing at least two speakers to form a predetermined stereophony for a tablet personal computer. When the tablet personal computer is rotated relative to the ground, a angle detector is used for measuring and generating positional data of the rotated tablet personal computer while an audio-adjusting device is used to force the audio driver to adjust the outputting sound field of each speaker in accordance with an audio parameter/positional data shit built in the audio-adjusting device to form a stereophony substantially equal to the predetermined stereophony.  
      As is understood by a person skilled in the art, the foregoing preferred embodiments of the present invention are illustrative of the present invention rather than limiting of the present invention. It is intended that various modifications and similar arrangements included within the spirit and scope of the appended claims are covered, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structure.