JP2006340586A - Mobile terminal and method for controlling charging of mobile terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile terminal capable of controlling a charging current by a simple structure, and to provide a method for controlling the charging of the mobile terminal. <P>SOLUTION: When a charger is connected to a charging terminal 1, a signal A is inputted from the charging terminal 1 to a power source IC3. When the signal A is received, the power source IC3 converts it to a signal B and transmits it to a controller 5, and a charging current controller 4 turns an FET 8 on, and starts charging after voltage bucking. Here, when the controller 5 receives the signal B from the power source IC3, it checks if an RF section 7 conducts telecommunication, and if it is not, the controller 5 controls the charging current controller 4 by using a signal C. If the RF section 7 conducts telecommunication, it controls a FET 9, and increases an electric current from the charging terminal 1 so that the current becomes greater than a value of a consumed current. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a portable terminal capable of automatically switching charging control and a charging control method for the portable terminal.

  In recent years, with the improvement in the performance of mobile terminals, the current consumption when using the functions has increased remarkably. For this reason, even if the mobile terminal is set in the charger and charged, the battery is not fully charged, and if the function is used while charging, current is taken out from the battery. Therefore, there is a case where the battery becomes empty even though the portable terminal is connected to the charger, and the power supply is cut off (battery runs out) or reset.

  For example, in 3G communication such as W-CDMA, which consumes a large amount of current, when the RF power received by the base station is small, that is, when the received radio wave is small, the base station moves to the mobile terminal side. A signal that increases power is transmitted. The mobile terminal increases the power by the transmitted signal, but the current consumption increases depending on the power, so both increase.

  In addition, lithium ion batteries generally used for portable terminals have a battery capacity of 600 mA. Therefore, when the mobile terminal transmits at the maximum transmission power, the current consumption may be larger than the charging current from the charger even if charging is performed, and the current from the rechargeable battery may be taken out.

  As conventional techniques for solving such problems, the inventions disclosed in Patent Documents 1 to 3 are known. Patent Document 1 discloses an invention that prevents the charging time from being extended even when a function of consuming current is performed during charging of the mobile phone.

  Patent Document 2 discloses a battery that is being charged regardless of whether or not the mobile communication terminal is operating by supplying a compensation current corresponding to the amount of current input to the mobile communication terminal to the battery. Discloses a charging apparatus and method for a mobile communication terminal that can always supply a predetermined current.

Patent Document 3 discloses an invention that provides a mobile phone charging device capable of maintaining a desired charging current regardless of the operating state of the mobile phone.
JP 2004-032304 A JP 2004-208497 A JP-A-4-183231

  However, the conventional techniques have the following problems.

  The invention described in Patent Document 1 controls the current according to each mode state of the mobile phone, and controls the current by checking the current state for each mode. In the invention described in Patent Document 2, a current sensor is provided in the mobile communication terminal, the current is detected by the current sensor, and the current is controlled so as to supply a compensation current. In the invention described in Patent Document 3, a current detector is provided inside a mobile phone, and the current is controlled by the current detector.

  Although the invention disclosed in any of the documents controls the current, the structure for detecting the current is complicated, and thus the number of steps until the current is controlled is increased.

  Therefore, an object of the present invention is to provide a portable terminal and a charging control method for the portable terminal that can control the charging current with a simple structure.

  In order to achieve the above object, the invention described in claim 1 is a portable terminal that controls a charging current in accordance with a communication state when charging, and the portable terminal performs charging during communication. The charging current is changed according to the radio wave condition during communication of the mobile terminal.

  According to a second aspect of the present invention, in the portable terminal according to the first aspect, the portable terminal further has a threshold value corresponding to the communication state, and the portable terminal has a threshold value corresponding to the threshold value and the communication state. The charging current is controlled based on a result of the comparison by comparing the current value.

  According to a third aspect of the present invention, in the portable terminal according to the first or second aspect, when the portable terminal performs charging during communication, a charging current related to charging is larger than a consumed current related to communication. It is characterized by.

  According to a fourth aspect of the present invention, in the mobile terminal according to any one of the first to third aspects, the mobile terminal further includes a voltage adjusting unit, and the mobile terminal performs charging during communication. The voltage is changed by the voltage adjusting means.

  The invention according to claim 5 is a charging control method for a mobile terminal that controls a charging current according to a communication state when charging, and when the mobile terminal performs charging during communication, The charging current is changed according to the radio wave condition during communication.

  According to a sixth aspect of the present invention, in the portable terminal charging control method according to the fifth aspect, the portable terminal further has a threshold value corresponding to the communication state, and changes according to the threshold value and the communication state. It compares with the electric current value in a portable terminal, and charging current is controlled based on the result of this comparison.

  According to a seventh aspect of the present invention, in the charging control method for the portable terminal according to the fifth or sixth aspect, when the portable terminal performs charging during communication, the charging current related to charging is greater than the consumption current related to communication. Is controlled to be larger.

  The invention described in claim 8 is the portable terminal charging control method according to any one of claims 5 to 7, wherein the portable terminal further includes a voltage adjustment step, and the portable terminal is charged during communication. When performing, the voltage is changed in the voltage adjustment step.

  Thus, according to the portable terminal and the charging control method for the portable terminal of the present invention, it is possible to control the charging current with a simple structure.

Below, the portable terminal of this embodiment and its control method are demonstrated using drawing. In addition, this embodiment is not limited to what is described below, A various change is possible in the range which does not deviate from the meaning.
FIG. 1 is a block diagram illustrating a configuration of the mobile terminal according to the present embodiment.

  The portable terminal of this embodiment includes a charging terminal 1, a battery 2, a power supply IC 3, a charging current control unit 4, a control unit 5, a memory 6, an RF (Radio Frequency) unit 7, an FET (Field- (Effect Transistor) 8 and 9 and a resistor 10.

  The charging terminal 1 connects a charger to the portable terminal of this embodiment. The battery 2 supplies a current for driving each device of the mobile terminal according to the present embodiment. The power supply IC 3 receives a signal A generated when a charger is connected to the charging terminal 1, converts the signal A into a signal B, and notifies the controller 5 of the connection of the charger. The charging current control unit 4 monitors the voltage across the resistor 10 and controls the charging current by the FET 9.

  The control unit 5 identifies that the charger is connected to the charging terminal 1 by the signal B from the power supply IC 3 and controls the charging current control unit 4 by the signal C. By controlling the charging current control unit 4, the FET 9 is also controlled. The memory 6 stores a threshold value used when switching the charging current in various communication modes such as TV viewing and TV phone.

  The RF unit 7 transmits and receives RF signals to and from the outside. The FET 8 turns on / off charging from the charger. The FET 9 performs voltage step-down and charge current control in the entire portable terminal of the present embodiment. The resistor 10 monitors the voltage of the portable terminal of this embodiment.

  In the mobile terminal of the present embodiment, the control unit 5 controls the charging current in each of the communication modes (TV viewing, TV phone etc.). In this case, first, the threshold value of each communication mode stored in the memory 6 is read according to the value of the RF power transmitted from the RF unit 7. Then, the FET 9 is controlled by comparing the read threshold value with the RF power value. In this way, the charging current is controlled.

Note that the RF power value in the present embodiment is, for example, an antenna bar indicating the radio wave condition in a mobile phone, and this RF power value is increased in an environment where the radio wave condition is bad such as underground or in an elevator. To send.
Further, the threshold value stored in the memory 6 stores a threshold value of a radio wave condition in which the consumption current is larger than the charging current in each communication mode.

Next, the operation of the mobile terminal according to the present embodiment will be described with reference to the drawings.
FIG. 3 is a flowchart showing the operation of the mobile terminal according to the present embodiment. When the charger is connected to the charging terminal 1 of the mobile terminal according to the present embodiment, the charging current is controlled depending on whether communication is in progress. Is.

  First, it is confirmed whether or not a charger is connected to the charging terminal 1 of the portable terminal of the present embodiment (step S101). When the charger is not connected to the charging terminal 1 (step S101 / No), it waits until the charger is connected. When a charger is connected to the charging terminal 1 (step S101 / Yes), the signal A is input from the charging terminal 1 to the power supply IC 3 (step S102). Next, upon receiving the signal A from the charging terminal 1, the power supply IC 3 converts the signal A into a signal B and transmits it to the control unit 5 (step S103). At the same time, the charging current control unit 4 turns on the FET 8 to step down and starts charging (step S104).

  Here, when receiving the signal B from the power supply IC 3, the control unit 5 checks whether or not the RF unit 7 is communicating (step S105). When the RF unit 7 is not communicating (step S105 / No), the control unit 5 controls the charging current control unit 4 using the signal C (step S106). The control from the charging current control unit 4 controls the charging current by the FET 9 while monitoring the terminals at both ends of the resistor 10. Then, the charging process is performed as it is without changing the charging current.

  On the other hand, when the RF unit 7 is in communication (step S105 / Yes), since the mobile terminal of the present embodiment is in communication, the current consumption will exceed the charging current as it is. Therefore, by controlling the FET 9 here, the charging current from the charger is controlled to increase the current from the charging terminal 1 (step S107). The value of the charging current to be increased at this time is increased so as to be larger than the value of the consumption current. After the charging current is increased in this way, a process of continuing charging is performed as it is.

  In the conventional charging control, charging is started depending on whether or not a charger is inserted. FIG. 6 is a flowchart showing the operation of the conventional charge control. As shown in FIG. 6, the conventional charging control confirms whether or not a charger is connected (step S301), and starts charging when the charger is connected (Yes in step S301) (step S302). ). Conventionally, charging control is performed in this way, but the present embodiment is characterized in that, as described above, the communication state is monitored and the charging current is controlled according to the communication state.

  Conventionally, for example, a sensor for detecting a voltage has been incorporated for display of a power bar in a mobile communication terminal, but no sensor for detecting a current has been incorporated. However, the mobile terminal according to the present embodiment is characterized in that it does not directly control the charging current based on the current value, but indirectly performs communication by specifying the transmission power, such as performing transmission power control. . Therefore, charging current control can be performed with transmission power that can be indirectly understood without adding a new sensor. Unlike the current value flowing through the portable terminal, the transmission power can be easily known by the function of the existing portable terminal or the like, so there is no need to add a new sensor.

Next, the case where the charging current is controlled using the threshold value in the portable terminal of the present embodiment will be described with reference to the drawings.
FIG. 4 is a flowchart showing the operation when the charging current is controlled by reading out and comparing the threshold values according to the radio wave conditions of each communication mode when the charger is connected to the charging terminal 1.

  First, it is confirmed whether or not a charger is connected to the charging terminal 1 of the portable terminal according to the present embodiment (step S201). When the charger is not connected to the charging terminal 1 (step S201 / No), it waits until the charger is connected. When a charger is connected to the charging terminal 1 (step S201 / Yes), the signal A is input from the charging terminal 1 to the power supply IC 3 (step S202). Next, upon receiving the signal A from the charging terminal 1, the power supply IC 3 converts the signal A into a signal B and transmits it to the control unit 5 (step S203). At the same time, the charging current control unit 4 turns on the FET 8 to step down and starts charging (step S204).

  Here, when receiving the signal B from the power supply IC 3, the control unit 5 checks whether or not the RF unit 7 is communicating (step S205). When the RF unit 7 is not communicating (step S205 / No), the control unit 5 controls the charging current control unit 4 using the signal C (step S206). The control from the charging current control unit 4 controls the charging current by the FET 9 while monitoring the terminals at both ends of the resistor 10. Then, the charging process is performed as it is without changing the charging current.

  On the other hand, when the RF unit 7 is communicating (step S205 / Yes), it is then confirmed whether the RF unit 7 is communicating in each communication mode (TV, 3G call, 2G call, etc.) (step S207). ). Here, when communication is being performed in each communication mode (step S207 / Yes), the threshold corresponding to each communication mode is read from the memory 6 (step S208). As the threshold value in the portable terminal of the present embodiment, data as shown in FIG. 5 is recorded. In FIG. 5, the charging current is set to be controlled at 600 mA or more. If communication in each communication mode is not performed at the time of this confirmation (step S207 / No), the charging process is performed without changing the charging current.

  Once the threshold value is extracted from the memory 6, the RF power value transmitted by the RF unit 7 is compared with the threshold value (step S209). Here, when the RF power value is equal to or smaller than the threshold value (step S209 / No), the charging process is performed without changing the current charging current.

  On the other hand, when the RF power value is larger than the threshold value (step S209 / Yes), first, the signal C is transmitted from the control unit 5 to the charging current control unit 4 in order to increase the charging current from the charger. To do. This signal C is a signal for changing the charging current, and the charging current control unit 4 controls the FET 9 based on the signal C, thereby increasing the charging current from the charger (step S210).

  When changing the charging current, the communication mode is entered in the charging state, but at the time of entering the communication mode, the RF power value does not exceed the threshold value in the memory 6 later (a certain time has passed). If the threshold is exceeded, the charging current may be changed at that point when the threshold is exceeded.

  By performing such processing, even if a charger is connected during communication with the mobile terminal of the present embodiment, the charging current is necessarily greater than the current consumption. Therefore, even if charging is performed during communication, current is not consumed more than the charging current, it is possible to prevent the power from being turned off or reset during charging, and the charging current corresponding to each communication mode. It is also possible to limit / control.

  Moreover, according to the portable terminal of this embodiment, it is also possible to use a DCDC converter as shown in FIG. 2 instead of FET8 which performed ON / OFF control of the charge from a charger. In this case, the DCDC converter 11 performs the step-down control performed by the FET 9.

  The voltage at the charging terminal 1 must be higher than the voltage when the battery 2 is fully charged because of the relationship between the wiring resistance to the battery 2 and the current charged to the battery 2. Therefore, the step-down and the current control are performed by the FET 9, but if the step-down and the current control are performed only by the FET 9, heat generation from the FET 9 is remarkably increased. Therefore, by using the DCDC converter 11 instead of the FET 8, the DCDC converter 11 performs the step-down control performed by the FET 9. Since the DCDC converter 11 can perform voltage conversion with small power loss, it does not lead to significant heat generation. Thereby, heat_generation | fever of FET9 can be suppressed.

  As described above, according to the portable terminal and the control method thereof according to the present embodiment, when the consumption current is larger than the charging current, it is possible to increase the current from the charger and eliminate the current from the battery. Therefore, even when the mobile terminal is connected during charging and communication is performed using a TV viewing function or a TV phone function, the mobile terminal consumes more current than the charging current and draws current from the battery. Can be taken out. Therefore, it is possible to prevent the mobile terminal from being charged and being reset due to power failure.

It is a block diagram which shows the structure of the portable terminal of this embodiment. It is a block diagram which shows the case where a DCDC converter is used in the portable terminal of this embodiment. It is a flowchart which shows operation | movement of the portable terminal of this embodiment. It is a flowchart which shows operation | movement in the case of performing charging control by a threshold value in operation | movement of the portable terminal of this embodiment. FIG. 4 is a diagram illustrating an example of threshold values stored in a memory 6 in the mobile terminal according to the present embodiment. It is a flowchart which shows the operation | movement of the conventional charge control.

Explanation of symbols

1 Charging terminal 2 Battery 3 Power supply IC
4 Charge Current Control Unit 5 Control Unit 6 Memory 7 RF Unit 8, 9 FET
10 Resistance 11 DCDC converter

Claims (8)

A portable terminal that controls a charging current according to a communication state when charging,
When charging the mobile terminal during communication,
A portable terminal, wherein a charging current is changed according to a radio wave condition during the communication of the portable terminal. The mobile terminal further has a threshold value corresponding to the communication state,
2. The mobile phone according to claim 1, wherein the threshold value is compared with a current value in the mobile terminal that changes according to the communication state, and the charging current is controlled based on a result of the comparison. Terminal. When charging the mobile terminal during communication,
The mobile terminal according to claim 1, wherein the charging current related to charging is larger than the current consumption related to communication. The portable terminal further includes a voltage adjustment unit,
The portable terminal according to any one of claims 1 to 3, wherein when the portable terminal performs charging during communication, the voltage adjustment unit changes the voltage. A charging control method for a portable terminal that controls a charging current according to a communication state when charging,
When charging the mobile terminal during communication,
A charging control method for a mobile terminal, wherein a charging current is changed according to a radio wave condition during the communication of the mobile terminal. The mobile terminal further has a threshold value corresponding to the communication state,
The mobile phone according to claim 5, wherein the threshold value is compared with a current value in the mobile terminal that changes according to the communication state, and a charging current is controlled based on a result of the comparison. Charge control method for the terminal. When charging the mobile terminal during communication,
The mobile terminal charging control method according to claim 5 or 6, wherein the charging current related to charging is controlled to be larger than the current consumption related to communication. The portable terminal further includes a voltage adjustment step,
The charging control method for a mobile terminal according to any one of claims 5 to 7, wherein the voltage is changed in the voltage adjustment step when the mobile terminal performs charging during communication.

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