Abstract:
The present invention provides a system for saving power of a portable electronic apparatus, which comprises a central processing unit, a display unit connecting to the central processing unit, an audio processing unit connecting to the central processing unit, and a sensor unit receiving an external signal representing reduced illumination in the environment near the portable electronic apparatus and transmitting a control signal to the audio processing unit, and in response the audio processing unit causes the central processing unit and the display unit to enter into a power-saving mode.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to system improvement and method for saving power, and more particularly to a portable electronic apparatus having a sensor for sensing external conditions (such as changes of light or static electricity) while being in a communication mode, and generating a control signal to activate the portable electronic apparatus to enter into a power-saving mode.  
       BACKGROUND OF THE INVENTION  
       [0002]     Technology has known a rapid, spectacular development in recent several decades. A variety of advanced electronic products are widely used by people, resulting in a significant improvement of living quality. The trend of developing electronic products is slimness, compactness, and lightness. For example, pocket-sized, special-purpose personal computers (e.g., PDAs) are developed as replacement of thick notebooks. Currently, a PDA is capable of not only storing much information but also providing a number of functions including alarm, Walkman, mobile phone, sending and receiving e-mails, and Internet access. However, for such multi-functional electronic product its standby time is limited by the short operating time provided by its battery power supply.  
         [0003]     Referring to  FIG. 1 , a well known portable electronic apparatus is shown in its perspective. The portable electronic apparatus is a typical PDA. Referring to  FIG. 2 , the portable electronic apparatus  11  comprises an audio processing unit  13 , a speaker unit  14 , a CPU (Central Processing Unit)  15 , and a display unit  16 . The portable electronic apparatus  11  not only serves as a personal secretary but also is capable of receiving the external audio via the audio processing unit  13 . The external audio is either an audio signal or a data signal. The audio processing unit  13  is adapted to process the audio or data signal prior to transmitting the same to the CPU  15 . The CPU  15  then further processes the processed audio or data signal in order to either show messages on the display unit  16  or transmit sound waves to the speaker unit  14  for sound amplification.  
         [0004]     Typically, the power supply of the portable electronic apparatus is a battery for maintaining normal operation of the portable electronic apparatus. The portable electronic apparatus is implemented as a PDA. For such a multi-functional PDA, the only way to solve the problem of limited operating time due to short battery life is to find an optimum power saving means. For addressing the above problem, a sensor unit for sensing is incorporated into a PDA as contemplated by the invention. The sensor unit is adapted to sense a using mode (e.g., operation mode or communication mode) of the PDA. In a case of the portable electronic apparatus entered into a communication mode, an external signal (e.g., light or static electricity) received by the sensor unit causes the PDA to enter into a sleeping mode with the display screen being closed. By configuring a method as above, it is also possible to save the power of PDA.  
       SUMMARY OF THE INVENTION  
       [0005]     It is an object of the present invention to provide a system and a method for saving power of a portable electronic apparatus so as to overcome the above drawback of the prior art.  
         [0006]     In one aspect of the present invention, a system is provided in a portable electronic apparatus for saving power, the system comprising a central processing unit; a display unit connecting to the central processing unit; an audio processing unit connecting to the central processing unit; and a sensor unit adapted to function as an ambient sensor for sensing an external condition, such as changes of light or static electricity, while the portable electronic apparatus being in a communication mode where the portable electronic apparatus is in communication with another portable electronic apparatus.  
         [0007]     In another aspect of the present invention, the sensor unit is adapted to generate a control signal in response to the external condition being sensed.  
         [0008]     In yet another aspect of the present invention, the changes of light or static electricity of the external condition being sensed is taken as an external signal which is in turn employed to cause the central processing unit to enter into a power-saving mode such as a standby mode or a sleeping mode.  
         [0009]     In a further aspect of the present invention, in a case of the portable electronic apparatus being in a communication mode, a user of the portable electronic apparatus may put the portable electronic apparatus near the ear to receive a call. Thereby the sensor unit receives an external signal representing reduced illumination in the environment near the portable electronic apparatus and generates a control signal and then transmits the control signal to the central processing unit for causing the central processing unit and the display unit to enter into a power saving mode.  
         [0010]     In yet further aspect of the present invention, a method for saving power is provided for greatly saving power by configuring most components of the portable electronic apparatus into the power-saving mode.  
         [0011]     The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a perspective view of a conventional portable electronic apparatus (e.g., PDA);  
         [0013]      FIG. 2  is a block diagram of the portable electronic apparatus of  FIG. 1 ;  
         [0014]      FIG. 3  is a block diagram of a preferred embodiment of portable electronic apparatus according to the invention;  
         [0015]      FIG. 4  is a detailed block diagram of the portable electronic apparatus of  FIG. 3 ; and  
         [0016]      FIG. 5  is a flowchart depicting a process for saving power in a communication mode of the portable electronic apparatus according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     Referring to  FIG. 3 , a portable electronic apparatus  21  in accordance with a preferred embodiment of the invention is shown. The portable electronic apparatus  21  comprises a control circuit  20  and a sensor unit  22 . Each component is discussed in detailed below.  
         [0018]     The portable electronic apparatus  21  is implemented as a PDA. The PDA not only serves as a pocket-sized, special-purpose personal computer but also has a communication capability. The control circuit  20  comprises an audio processing unit  13  for receiving an external audio signal, a speaker unit  14 , a CPU  15  and a display unit  16 , wherein the display unit  16  and an audio processing unit  13  respectively connect to the CPU  15  and the speaker unit  14  and the sensor unit  22  connect to the audio processing unit  13  respectively. The sensor unit  22  is employed as an ambient sensor by being incorporated into the portable electronic apparatus. The ambient sensor (i.e., the sensor unit  22 ) has the functionality of sensing external conditions of the portable electronic apparatus  21  by receiving an external signal  211 . The external signal  211  in turn is employed to cause the central processing unit  11  and the display unit  16  to enter into a power-saving mode.  
         [0019]     Referring to  FIG. 4 , a detailed block diagram of the portable electronic apparatus  21  is shown, wherein the display unit  16 , speaker unit  14  and audio processing unit  13  respectively connect to the CPU  15 , the sensor unit  22  and speaker unit  14  connect to the audio processing unit  13  respectively. In a case of the portable electronic apparatus  21  is in a communication mode where the portable electronic apparatus is in communication with another portable electronic apparatus, a user of the portable electronic apparatus  21  may put the portable electronic apparatus  21  near the ear to receive a call. Thus, a reduced illumination is sensed by the sensor unit  22 . The reduced illumination represents a positive value of the external signal  211 . Thereafter, the sensor unit  22  generates a control signal  223  and then transmits the control signal  223  to the audio processing unit  13 . Next, the audio processing unit  13  converts the control signal  223  into an interrupt signal  222  which is then transmitted to the CPU  15 . The interrupt signal  222  is adapted to control both the CPU  15  and the display unit  16  to enter into a standby mode or a sleeping mode. Other units of the portable electronic apparatus  21  still work normally. Advantageously, by causing both the CPU  15  and the display unit  16  to enter into the standby mode or the sleeping mode, it is possible to save the power of the portable electronic apparatus.  
         [0020]     Referring to  FIG. 5  in conjunction with  FIGS. 3 and 4 , it is flowchart depicting a process for saving power in a communication mode of the portable electronic apparatus  21  according to the invention, which comprises the steps of:  
         [0021]     In step S 31 , a call is made or received while the portable electronic apparatus being in a communication mode;  
         [0022]     In step S 32 , intercommunication key is pressed such that a user may use the communication functionality of the portable electronic apparatus  21  to communicate with another portable electronic apparatus.  
         [0023]     In step S 33 , the sensor unit is activated to sense the external signal  211  of the portable electronic apparatus  21  and determine whether the external signal  211  is in a positive value, a negative value, or changing from a positive value to a negative value. If it is in a positive value, which means that a reduced illumination is sensed by the sensor unit  22 , the portable electronic apparatus  21  goes to step S 34 . If it is in a negative value, which means that increased illumination is sensed by the sensor unit  22 , the portable electronic apparatus  21  jumps to step S 36 . If it is changing from a positive value to a negative value, the portable electronic apparatus  21  jumps to step S 35 .  
         [0024]     In step S 34 , the positive value of the external signal  211  is sensed by the sensor unit  22  when a user of the portable electronic apparatus  21  puts the portable electronic apparatus  21  near the ear of user to receive a call. Thus, an external signal  211  is sensed by the sensor unit  22  as representing the reduced illumination. A first control signal  223  is generated by the sensor unit  22  and transmitted to the audio processing unit  13 . The audio processing unit  13  then converts the control signal  223  into an interrupt signal  222  which is then transmitted to the CPU  15  to cause both the CPU  15  and the display unit  16  to enter into a power-saving mode. The portable electronic apparatus  21  then jumps to step S 37 .  
         [0025]     In step S 35 , the external signal  211  sensed by the sensor unit  22  is changing from a positive value to a negative value. In this changing mode, the portable electronic apparatus  21  is removed away from the ear of user, which means that the external signal  211  representing increased illumination is sensed by the sensor unit  22 . In this step, a second control signal  223  is generated by the sensor unit  22  and transmitted to the audio processing unit  13 . The audio processing unit  13  then converts the control signal  223  into an interrupt signal  222  which is then transmitted to the CPU  15  to cause both the CPU  15  and the display unit  16  to enter into a normal operating mode.  
         [0026]     In step S 36 , the external signal  211  sensed by the sensor unit  22  is in the negative value, which means that the user of the portable electronic apparatus operates other functions thereof in a normal condition away from the ear thereof. A third control signal  223  is generated by the sensor unit  22  and transmitted to the audio processing unit  13 . The audio processing unit  13  then converts the control signal  223  into an interrupt signal  222  which is then transmitted to the CPU  15  to cause both the CPU  15  and the display unit  16  to enter into a normal operating mode.  
         [0027]     In step S 37 , both the CPU  15  and the display unit  16  enter into a sleeping mode or standby mode, resulting in power saving of the portable electronic apparatus  21 .  
         [0028]     While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.