Abstract:
A wireless communication apparatus includes a first connector for detachably connecting a battery charger to the rechargeable battery and a second connector for detachably connecting an AC adapter. A charge detector detects a connection of the battery charger and an AC adapter detector detects a connection of the AC adapter. A charge controller charges the rechargeable battery when the connection of the AC adapter is detected. A light-emitting indicator is controlled such that the light-emitting indicator lights up in a way different from a normal way depending on the charge detector and the AC adapter detector.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a wireless communication apparatus such as mobile telephone equipment, and in particular to a wireless communication apparatus having a rechargeable battery or secondary battery. 
     2. Description of the Related Art 
     Recently, a rechargeable battery has been widely used as a power supply for portable or hand-held wireless telephone equipment in consideration of running costs. Such a rechargeable battery is charged by a battery charger for the wireless telephone equipment. When the wireless telephone equipment is placed on the battery charger, charging power is supplied to the rechargeable battery of the wireless telephone equipment. During battery charging, a light-emitting diode (LED) is turned on or blinking so as to inform a user of charging. The wireless telephone equipment like this has been disclosed in, for example, Japanese Utility-model Unexamined Publication No. 5-76138. 
     Further, an AC-DC converter (hereinafter, called an AC adapter) is frequently used to charge the rechargeable battery. In this case, when the AC adapter is connected to the electronic device, the display of the electronic device or a dedicated LED indicates the charging state. 
     As another conventional example, a rechargeable electronic device such as a household electrical appliance has been disclosed in Japanese Patent Unexamined Publication No. 3-215135. The rechargeable electronic device, for example, a rechargeable shaver or bath bubbling apparatus is provided with a rechargeable battery, a rectifier circuit, and an LED section. The LED section includes three LEDs which are used to indicate charging and operating states. When a battery charger having a transformer therein is connected to the rechargeable electronic device, it is detected and the LED section indicates a charging state. When the rechargeable electronic device is operated, the LED section indicates the operating state. 
     For a wireless communication apparatus such as mobile telephone equipment, it is desirable to reduce in weight and size. According to the above prior-art apparatuses, however, the charge indicator is mounted on the charger or on both the charger and the wireless communication apparatus. Therefore a light source dedicated to charge indication is needed. 
     In the rechargeable electronic device such as a household electrical appliance, no consideration is given to the portability required for mobile telephone equipment. More specifically, a charge indication LED as well as an operation indication LED are mounted on the household electrical appliance. Further, since a photo coupler is used to detect the battery charger, the connection between the battery charger and the household electrical appliance is complicated. 
     Furthermore, according to the above prior-art equipment, only one battery charging connector is provided. Therefore, there may be cases where the rechargeable battery cannot be charged. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a wireless communication apparatus and a charging method which can indicate a charge state with simplified circuit configuration. 
     Another object of the present invention is to provide a wireless communication apparatus and a charging method which can be charged by a plurality of battery charging sources. 
     According to a first aspect of the present invention, a wireless communication apparatus is comprised of a light-emitting indicator and a rechargeable battery as a power supply for the wireless communication apparatus. The wireless communication apparatus is further comprised of a connector for detachably connecting a battery charger to the rechargeable battery, a charge detector for detecting a charge state by monitoring a voltage of the rechargeable battery, and an indicator controller for controlling the light-emitting indicator such that the light-emitting indicator lights up in a way different from a normal way when the charge state is detected by the charge detector. 
     According to a second aspect of the present invention, a wireless communication apparatus is comprised of a rechargeable battery as a power supply for the wireless communication apparatus, a first connector for detachably connecting a first charging source to the rechargeable battery, a first detector for detecting a charge state by monitoring a voltage of the rechargeable battery, a second connector for detachably connecting a second charging source, a second detector for detecting connection of the charging source, and a charge controller connected to the second connector, for charging the rechargeable battery using charge power received from the second charging source when the connection of the second charging source is detected. 
     The wireless communication apparatus may include a light-emitting indicator, and an indicator controller for controlling the light-emitting indicator such that the light-emitting indicator lights up in a way different from a normal way when at least one of the charge state and the connection of the second charging source is detected. 
     According to a third aspect of the present invention, in a method for indicating a charge state in a wireless communication apparatus having a light-emitting indicator and a rechargeable battery as a power supply, a charge state is detected by monitoring a voltage of the rechargeable battery and the light-emitting indicator is controlled such that the light-emitting indicator lights up in a way different from a normal way when the charge state is detected by the charge detector. 
     According to a fourth aspect of the present invention, in a method for charging a rechargeable battery of a wireless communication apparatus, a connection of a battery charger is detected by monitoring a voltage of the rechargeable battery and a connection of an AC-to-DC converter is detected. The rechargeable battery is charged using charge power received from the AC-to-DC converter when the connection of the AC-to-DC converter is detected and the connection of the battery charger is not detected, and is charged using charge power received from the battery charger when the connection of the battery charger is detected. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic block diagram showing mobile telephone equipment according to a first embodiment of the present invention; 
     FIG. 2 is a schematic block diagram showing mobile telephone equipment according to a second embodiment of the present invention; 
     FIG. 3 is a diagram showing charge operation and LED control operation according to the second embodiment; and 
     FIG. 4 is a block diagram showing the detailed circuit configuration of a mobile telephone apparatus according to the second embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a battery charger  10  can be electrically connected to a mobile telephone apparatus  20  through a connector  101 . The mobile telephone apparatus  20  is provided with communication circuits and other necessary circuits which are not shown for simplicity in this figure. The charging power is supplied from the battery charger  10  to a rechargeable battery  102  provided within the mobile telephone apparatus  20 . In addition to the rechargeable battery  102 , a charge indicator of the mobile telephone apparatus  20  is comprised of a charge detector  103 , an LED controller  104  and an LED  105 . 
     The rechargeable battery  102  may be a rechargeable lithium-ion battery. In the case of lithium-ion battery, the battery charger  10  is designed to charge the lithium-ion battery as well known. 
     The charge detector  103  detects the charge state by monitoring a voltage change of a charge power line connecting the connector  101  to the rechargeable battery  102 . More specifically, when the battery charger  10  is connected to the connector  101  of the mobile telephone apparatus  20 , the charge power line increases in voltage. Such a change in voltage is used to detect the connection and the charge state of the battery charger  10 . On the other hand, when the charge detector  103  also detects a predetermined voltage on the charge power line, it is determined that the rechargeable battery  102  is in full charge state. The charge detector  103  outputs a detection signal S DET  to the LED controller  104  which controls the LED  105 . 
     The LED  105  is provided on the housing of the mobile telephone apparatus  20  so as to be easily visible. The LED  105  is normally used to indicate call incoming in an ordinary mobile telephone apparatus. In this embodiment, the LED  105  is also used to indicate the charge state of the rechargeable battery  102 . More specifically, when the charge detector  103  detects the charge state, the LED controller  104  makes the LED  105  blink or simply light up so as to indicate the charge state. When indicating the charge state, it is desirable that the LED  105  lights up in a different way from when normal. It is further desirable that the LED  105  lights up when charging in a different way from when in full charge. 
     Since an ordinary mobile telephone apparatus is usually provided with the LED  105 , it can be used to indicate the charge state. Therefore, this embodiment may be implemented by only adding the charge detector  103  and modifying the LED controller  104  such that it makes the LED  105  blink or simply light up so as to indicate not only the call incoming but also the charge state. 
     FIG. 2 shows a second embodiment of the present invention, where circuit blocks similar to those previously described with reference to FIG. 1 are denoted by the same reference numerals. 
     A battery charger  10  can be electrically connected to a mobile telephone apparatus  30  through a connector  101 . Further, an AC adapter  40  can be electrically connected to the mobile telephone apparatus  30  through a connector  201 . The mobile telephone apparatus  20  is provided with communication circuits and other necessary circuits which are not shown for simplicity in this figure. 
     The connector  201  is connected to a charge controller  202  and an AC adapter detector  203 . The charge controller  202  is further connected to a charge power line which connects the connector  101  to a rechargeable battery  102 . The charging power is supplied from one of the battery charger  10  and the AC adapter  40  to the rechargeable battery  102 . 
     The rechargeable battery  102  may be a rechargeable lithium-ion battery. In the case of lithium-ion battery, the battery charger  10  and the charge controller  202  are designed to charge the lithium-ion battery as well known. 
     A charge detector  103  detects the charge state by monitoring a voltage change of the charge power line connecting the connector  101  to the rechargeable battery  102 . More specifically, when the battery charger  10  is connected to the connector  101  of the mobile telephone apparatus  30 , the charge power line increases in voltage. Such a change in voltage is used to detect the connection and the charge state of the battery charger  10 . On the other hand, when the charge detector  103  also detects a predetermined voltage on the charge power line, it is determined that the rechargeable battery  102  is in full charge state. The charge detector  103  outputs a detection signal S DET1  to an LED controller  204  and the charge controller  202 . 
     The charge controller  202  performs constant current charging of the rechargeable battery  102  when the charge is started by the AC adapter  40 . More specifically, when the AC adapter  40  is connected to the connector  201  of the mobile telephone apparatus  30 , the connector  201  increases in voltage. The AC adapter detector  203  monitors such a change in voltage which is used to detect the connection and the charge state of the AC adapter  40 . When detecting the AC adapter  40 , the AC adapter detector  203  outputs a detection signal S DET2  to the LED controller  204  and the charge controller  202 . When receiving the detection signal S DET2  from the AC adapter detector  203 , the charge controller  202  starts constant current charging while monitoring the detection signal S DET1  received from the charge detector  103 . When the battery voltage reaches the predetermined voltage, the charge detector  103  determines that the rechargeable battery  102  is in full charge state and outputs the detection signal S DET1  indicating the full charge state to the charge controller  202 . When receiving the detection signal S DET1  indicating the full charge state from the charge detector  103 , the charge controller  202  changes from the constant current mode to constant voltage mode. Such a charging way is commonly used in the case of lithium-ion battery and it is the same with the battery charger  10 . 
     The charge controller  202  further performs selection of charge sources. More specifically, when the battery charger  10  and the AC adapter  40  are both connected to the connectors  101  and  201 , respectively, the charge controller  202  receives both the detection signals S DET1  and S DET2  from the charge detector  103  and the AC adapter detector  203 , respectively. In this case, the charge controller  202  stops the charging operation of the AC adapter  40  (see FIG.  3 ). 
     The LED  105  is provided on the housing of the mobile telephone apparatus  30  so as to be easily visible. The LED  105  is normally used to indicate call incoming in an ordinary mobile telephone apparatus. In this embodiment, the LED  105  is also used to indicate the charger type and the charge state of the rechargeable battery  102 . The LED controller  204  performs the control of the LED  105  depending on the detection signals S DET1  and S DET2  as in the case of the charge controller  202 . The details of LED control will be described hereinafter with reference to FIG.  3 . 
     Referring to FIG. 3, when neither the battery charger  10  nor the AC adapter  40  is connected to the mobile telephone apparatus  30 , the detection signals S DET1  and S DET2  are both 0. In this case, the LED controller  204  performs normal control of the LED  105 . That is, when an incoming call occurs, the LED  105  blinks or lights up to inform the user of call incoming. 
     When only the battery charger  10  is connected to the mobile telephone apparatus  30 , the detection signal S DET1  is 1 and the detection signal S DET2  is 0. Since the rechargeable battery  102  is charged by the battery charger  10 , the LED controller  204  makes the LED  105  operate in a charge operation mode different from the normal operation mode to inform the user of charging by the battery charger  10 . For example, the frequency of blinking or the intensity of light may be different between them. 
     When only the AC adapter  40  is connected to the mobile telephone apparatus  30 , the detection signal S DET1  is 0 and the detection signal S DET2  is 1. The rechargeable battery  102  is charged by the charge controller  202  receiving the charge power from the AC adapter  40 . The detection signal S DET1  goes high when the charge is started. Therefore, the LED controller  204  makes the LED  105  operate in the charge operation mode to inform the user of charging by the AC adapter  40 . The LED  105  may blink or light up in different way from the normal operation mode. It is possible that, in the case of the AC adapter  40 , the LED controller  204  makes the LED  105  operate in another charge operation mode different from the charge operation mode. 
     When the battery charger  10  and the AC adapter  40  are both connected to the mobile telephone apparatus  30 , the detection signals S DET1  and S DET2  is both 1. Since the rechargeable battery  102  is charged by the battery charger  10  in this case as described before, the LED controller  204  makes the LED  105  operate in the charge operation mode. The charge operation mode may be different in blinking frequency or light intensity to the normal mode. 
     The LED  105  is not limited to a single LED. The LED  105  may include a plurality of LEDs so that the normal operation mode and the charge operation mode are indicated by changing lighted-up LED or the frequency of blinking. Further, the different charge operation modes may be indicated by different LEDs or different frequencies of blinking. 
     Further, when the battery charger  10  and the AC adapter  40  are both connected to the mobile telephone apparatus  30 , the charge controller  202  and the charge power line can be easily designed to charge the rechargeable battery  102  by the AC adapter  40 . In this case, when the detection signals S DET1  and S DET2  is both 1, the LED controller  204  makes the LED  105  operate in the charge operation mode. 
     Furthermore, when the charge is started, the LED  105  desirably lights up in a different way from when in full charge. 
     FIG. 4 shows the detail circuit configuration of the mobile telephone apparatus  30  of FIG. 2, where circuit blocks similar to those previously described with reference to FIG. 2 are denoted by the same reference numerals and the descriptions are omitted. 
     Referring to FIG. 4, a charge power line  301  connects the connector  101  and the charge controller  202  to the rechargeable battery  102  (here, rechargeable lithium-ion battery). The rechargeable battery  102  is further connected to a power controller  302  which controls power supplying to circuits of the mobile telephone apparatus  30 . 
     The mobile telephone apparatus  30  is further provided with a microprocessor  303  which performs the control of operations including the LED operations as described before. The microprocessor  303  is connected to a speech encoder/decoder (codec)  304  which is further connected to a speaker  305  and a microphone  306 . The microprocessor  303  controls an LED controller  307  so that an LED section  308  is made operate in a selected operation mode as described before. Further, the microprocessor  303  controls an LCD controller  309  which controls a liquid-crystal display (LCD)  310 . The microprocessor  303  controls a telephone channel controller  311  and a radio system  312  which are used to perform telephone communication. 
     As described before, the charge controller  202  operate depending on the detection signals S DET1  and S DET2 . Similarly, the microprocessor  303  controls the operations of the LED section  308  depending on the detection signals S DET1  and S DET2 . It is possible that the LED controller  307  controls the operations of the LED section  308  as in the case of FIG.  2 . It is further possible that the microprocessor  303  controls the selection operation of the charge controller  202  and the operations of the LED section  308 .