JP2008193783A - Charging control method, portable terminal, and charging control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging control method for performing the charging quickly while preventing heat generation, temperature rise or overcharging of a portable terminal surely. <P>SOLUTION: When the temperature of a temperature sensor 113 arranged in the vicinity of a component with high heating value in a portable terminal 10 measured during charging operation of a secondary battery 109 is higher than the temperatures predetermined depending on the state of the portable terminal 10 during waiting and session, a charge control section 110 stops charging operation of the secondary battery 109 temporarily until the measured temperature drops below the predetermined temperature. The temperature sensors 113 are arranged at a plurality of positions in the portable terminal 10 where the heating value is high. When the portable terminal 10 is in session, the charge control section 110 controls the charging current variably depending on the output voltage of the secondary battery 109 and performs charging control while switching the charging current value of the secondary battery 109 to a larger value for the lower output voltage of the secondary battery 109 measured at a voltage measuring section 112. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a charge control method, a portable terminal, and a charge control system, and more particularly, to a charge control method, a portable terminal, and a charge control system for a portable terminal that performs rapid charging in order to shorten a charging time.

  In the conventional technology, a constant charging current flows through the inside of the mobile terminal as long as the mobile terminal is in a charging state connected to the charging device regardless of whether the mobile terminal is on standby or during a call. Yes. During such charging, if communication with large power consumption such as a videophone is performed, the mobile terminal generates more heat than during standby.

  For this reason, conventionally, as a countermeasure against heat generation, the layout of heat generating components (battery, diode, power supply control IC, etc.) on the substrate of the portable terminal is dispersed, or a heat generating sheet such as graphite is pasted on the case of the casing. Has been done. However, as the functionality and size of portable terminals further advance in the future, it will become difficult to cope with these heat generation countermeasures alone.

In order to solve such a problem, for example, in Japanese Patent Application Laid-Open No. 9-130456 “Charging System” of Patent Document 1, it is determined whether or not the mobile phone is in a call when charging. When not in a state, charging is performed with a large charging current in order to perform quick charging, but when in a state of a call, a control technique is proposed in which charging is performed with a small charging current from a trickle power supply. .
JP-A-9-130456 (page 3-4)

  However, in Patent Document 1, when the telephone is in a call state, a constant charging current slightly larger than the current value of the natural discharge of the secondary battery is caused to flow as a trickle charging operation. No matter how low the output voltage is, or whatever state the temperature of the mobile phone is, the charging operation only continues with a small constant charging current, and it is close to a fully charged state In addition, even if the mobile phone generates heat, the charging operation is continued as it is and the temperature continues to rise.

  In other words, in the conventional technology, the charging operation during the call does not control to change the charging current, so that not only the charging becomes insufficient and the call state cannot be continued, but in some cases In some cases, the temperature rise of the mobile phone may reach an abnormal value.

  The present invention has been made in view of such circumstances, and when charging a secondary battery of a mobile terminal, whether the temperature of each part of the mobile terminal, whether during a call or during standby, the output voltage of the secondary battery Depending on how, the charging current can be controlled variably as appropriate, so that charging that can be performed quickly while reliably preventing the heat generation, temperature rise or overcharging of the mobile terminal It is an object to provide a control method, a portable terminal, and a charge control system.

  In order to solve the above-described problems, the charging control method, the portable terminal, and the charging control system according to the present invention employ the following characteristic configuration.

(1) In the charge control method for controlling the charging of the secondary battery of the mobile terminal, the temperature in the mobile terminal, the state of the mobile terminal during a call / standby, the output voltage of the secondary battery, A charge control method for variably controlling a current value of a charge current for charging a secondary battery.
(2) When the portable terminal is in a standby state, the temperature in the portable terminal is a first temperature determined in advance to determine whether or not a charging operation can be performed in the standby state When the temperature is higher than the threshold value, the charging operation is temporarily stopped until the temperature in the mobile terminal falls below the first temperature threshold value. When the mobile terminal is in a call state, the mobile terminal When the temperature inside the portable terminal is higher than a second temperature threshold value that is predetermined for determining whether or not the charging operation can be performed during a call, the temperature inside the portable terminal is set to the second temperature threshold value. The control method according to (1), wherein the charging operation is temporarily stopped until it decreases below.
(3) The charge control method according to (2), wherein the second temperature threshold is set to a value lower than the first temperature threshold.
(4) A plurality of temperature measurement locations in the mobile terminal are set as locations in the vicinity of a part that generates a large amount of heat, and the measurement temperature at any of the measurement locations is in a state where the mobile terminal is in a standby state. When it is detected that it is higher than the first temperature threshold, or when it is detected that the mobile terminal is higher than the second temperature threshold when the mobile terminal is in a call state And (2) or (3) the charging control method for temporarily stopping the charging operation.
(5) When the portable terminal is in a call state, the lower the output voltage of the secondary battery, the higher the charging current value of the secondary battery is switched to a larger value, and the charging operation is performed ( 1) The charge control method.
(6) When the output voltage of the secondary battery is a voltage value equal to or lower than a first voltage threshold predetermined as the highest voltage value that requires rapid charging, the current value of the charging current of the secondary battery is The charging operation is performed by switching to the maximum allowable current value, and the output voltage of the secondary battery is higher than the first voltage threshold value, and the minimum allowable when performing the charging operation during a call. When the voltage value is equal to or lower than a predetermined second voltage threshold as the lowest voltage value to be switched to the charging operation with the limit current value, the current value of the charging current of the secondary battery is changed to a standard charging current during a call. If the output voltage of the secondary battery is higher than the first voltage threshold value, the current value of the charging current of the secondary battery is changed during a call. Charging operation Charging control method of the above (5) to perform a charging operation by switching to the current value of the minimum allowed for making.
(7) A portable terminal in which the charge control method according to any one of (1) to (6) above is mounted.
(8) The mobile terminal according to (7), wherein the mobile terminal is any one of a mobile phone, a PHS phone, a personal digital assistant (PDA), a mobile notebook PC, a mobile game machine, and a mobile music player.
(9) A charge control system comprising the mobile terminal according to (7) or (8) and a charging device that supplies a charging current to the mobile terminal.

  According to the charge control method, the portable terminal, and the charge control system of the present invention, the following effects can be obtained.

  First, when charging during a call, the battery voltage (output voltage) of the secondary battery is measured, and the charging current is appropriately changed according to the output voltage. In addition, it is possible to quickly charge the battery while suppressing temperature rise and overcharge.

  Secondly, when charging, the temperature of each part of the mobile terminal is measured, and when the temperature exceeds a predetermined temperature, the charging operation is stopped and the charging operation is resumed when the temperature falls below the predetermined temperature. The temperature of the mobile terminal can be prevented from rising abnormally, and the mobile terminal can be kept in a safe temperature range.

  Third, when charging the mobile terminal in a standby state, it is possible to perform a quick charge by controlling the maximum allowable charge current to flow, and a short charge equivalent to the conventional quick charge operation. It can be fully charged in time. In addition, even during a call, the lower the battery voltage (output voltage) of the secondary battery, the higher the charging current value is set, and the battery is charged as close to full charge as possible. As a result, a voltage value that can reliably continue the call state can be obtained.

  Hereinafter, preferred embodiments of a charge control method, a portable terminal, and a charge control system according to the present invention will be described with reference to the accompanying drawings.

(Features of the present invention)
Prior to the description of the embodiments of the present invention, the features of the present invention will be described first. The present invention measures the battery voltage (output voltage) and the temperature of the mobile terminal when charging the battery (secondary battery) of the mobile terminal, and variably controls the charging current according to the measurement result. It is characterized by suppressing heat generation and enabling quick charging while preventing overcharging.

(Configuration of Example)
FIG. 1 shows an example of a block configuration of a mobile terminal to which the charge control method of the present invention is applied. In FIG. 1, the mobile terminal 10 includes a wireless processing unit 101 that performs wireless communication with a base station (not shown), a control unit 102 that controls each unit of the mobile terminal 10, and a control for controlling the mobile terminal 10. A storage unit 103 that stores data such as a program, a camera unit 104 used during a videophone call, a display unit 105 that displays various types of information, a speaker 106 that reproduces audio received by the wireless processing unit 101, and the portable terminal It includes at least a microphone 107 to which 10 user's voices are input and an operation unit 108 that includes a numeric keypad, a cursor key, and the like and receives an operation input from the user of the mobile terminal 10.

  Further, as a power supply system of the mobile terminal 10 shown in FIG. 1, a secondary battery 109 that supplies power to each unit of the mobile terminal 10, a charge control unit 110 that controls a charging current of the secondary battery 109, and a charge control unit 110 and at least a charging terminal 111 for connecting the external charging device 20.

  Moreover, the portable terminal 10 of the present embodiment shown in FIG. 1 has a temperature sensor 113 that measures the temperature of each part of the portable terminal 10. In particular, the temperature sensor 113 is disposed in the vicinity of components that generate a relatively large amount of heat, such as the wireless processing unit 101, the control unit 102, the camera unit 104 (heat generated from the built-in DSP), the secondary battery 109, and the charge control unit 110. Has been. The temperature measured by the temperature sensor 113 is monitored by the control unit 102. Furthermore, a voltage measurement unit 112 that measures the output voltage of the secondary battery 109 is included, and the measurement voltage of the voltage measurement unit 112 is also monitored by the control unit 102.

(Description of operation of the embodiment)
Next, an example of a charging control method for the mobile terminal 10 in FIG. 1 will be described with reference to the flowchart in FIG. FIG. 2 is a flowchart showing an example of the charge control method of the present invention. The processing in FIG. 2 is executed by the control unit 102, and the charging current to the secondary battery 109 is controlled by issuing a command to the charging control unit 110.

  First, it is determined whether or not the battery voltage (output voltage) of the secondary battery 109 is in a low state (Low Battery state) (step S1). When the battery voltage of the secondary battery 109 is, for example, a low battery state of 3.45V or less (in the case of (≦ 3.45V) in step S1), the operation of the call function is impossible. It transfers to step S3 and charges by the "standby charge process" which charges rapidly.

  On the other hand, when the battery voltage of the secondary battery 109 is greater than 3.45V, for example, and is not in the low battery state (in the case of step S1 (> 3.45V)), the call function can be operated. Therefore, it is determined whether a voice call (AMR) or a videophone (VP) is currently being performed (step S2). When a call such as a voice call or a videophone call is in progress (Yes in Step S2), the process proceeds to Step S7, and in order to suppress the heat generation of the mobile terminal 10, according to the output voltage level of the secondary battery 109, Charging is performed by a “busy charging process” in which charging is performed by variably controlling the current value so that an excessive charging current does not flow and charging is performed quickly. If the voice call or videophone call is not in progress (No in step S2), the process proceeds to step S3, and charging is performed by a “standby charging process” in which charging is performed rapidly.

<Standby charging process> (Charging current: 600 mA)
In step S3, in order to perform the “standby charging process”, the charging control unit 110 is notified of an instruction to that effect, so that the charging current from the charging device 20 to the secondary battery 109 is set to the maximum allowable level. Is set to, for example, 600 mA, and the charging operation is started (step S3). Thereafter, it is determined whether the remaining battery level of the secondary battery 109 has reached a fully charged state (step S4). When the remaining battery level of the secondary battery 109 reaches a fully charged state (Yes in step S4), the charging operation is terminated.

  If the remaining battery level of the secondary battery 109 has not yet reached the fully charged state (No in Step S4), the result of constantly measuring the temperature of each part of the mobile terminal 10 by the temperature sensor 113 is confirmed (Step S4). S5). When it is higher than a predetermined first temperature threshold, for example, 48 ° C., for example, to determine whether or not the standby charging operation can be performed (in the case of step S5 (> 48 ° C.)), charging is performed. The operation is temporarily stopped (step S6), and the processes of steps S5 and S6 are repeated until the temperature of each part of the portable terminal 10 drops to a predetermined first temperature threshold, for example, 48 ° C. or less, and the charging operation is temporarily performed. Stop.

  When the temperature of each part of the portable terminal 10 becomes a predetermined first temperature threshold value, for example, 48 ° C. or less (in the case of step S5 (≦ 48 ° C.)), the process returns to step S3 and the maximum allowable limit The charging operation with a current value of, for example, 600 mA is resumed, and when the remaining battery level of the secondary battery 109 reaches a fully charged state (Yes in step S4), the charging operation of the “standby charging process” is terminated. .

<In-call charging process> (Charging current: 600 mA, 400 mA, or 200 mA variable)
In step S7, in order to carry out the “busy charging process”, an instruction to that effect is sent to the charging control unit 110, so that the charging current from the charging device 20 to the secondary battery 109 is changed. The standard current value is set to 400 mA, for example, and the charging operation is started (step S7). Thereafter, the result of measuring the output voltage of the secondary battery 109 by the voltage measuring unit 112 is confirmed (step S8).

  When the output voltage of the secondary battery 109 is a first voltage threshold value determined in advance as a maximum voltage value that requires rapid charging, for example, 3.55 V or less (in the case of (≦ 3.55 V) in step S9), rapid In order to perform charging, the charging control unit 110 is instructed to do so, and the charging current from the charging device 20 to the secondary battery 109 is switched to the maximum allowable current value, for example, 600 mA. The operation is continued (step S10). On the other hand, when the output voltage of the secondary battery 109 is higher than a predetermined first voltage threshold, for example, 3.55 V (in the case of (> 3.55 V) in step S9), the output voltage of the secondary battery 109 is Then, it is confirmed whether or not a minimum current value allowed in the charging process during a call, for example, a second voltage threshold value determined in advance as a minimum voltage value to be switched to a charging operation at 200 mA, for example, 3.75 V or less (step S11). ).

  The output voltage of the secondary battery 109 is a second voltage threshold value, for example, 3.75 V or less, which is the lowest voltage value to be switched to a charging operation at a minimum current value, for example, 200 mA, which is allowed in the charging process during a call. When the second voltage threshold value is, for example, 3.75 V or less, which is the maximum voltage value that allows the continuous charging operation at a standard current value of 400 mA, for example, to be continuously performed (in step S11 (≦ 3.75 V )), That is, when the output voltage of the secondary battery 109 is in a voltage range higher than 3.55V and lower than 3.75V, an instruction to that effect is notified to the charging control unit 110. Thus, the charging operation at the standard current value of the charging process during a call, for example, 400 mA is continued (step S12).

  On the other hand, when the output voltage of the secondary battery 109 is higher than a predetermined second voltage threshold, for example, 3.75V (in the case of (> 3.75V) in step S11), an excessive charging current flows, In order to perform a charging operation with a low charging current so that the mobile terminal 10 does not generate heat abnormally, the charging device 20 notifies the charging control unit 110 of an instruction to that effect, thereby charging the secondary battery 109 with a charging current. Is switched to a minimum current value, for example, 200 mA, and the charging operation is continued (step S13).

  Thereafter, in a state where the charging operation with any one of the above-described charging current values is continuously performed, the result of measuring the temperature of each part of the portable terminal 10 by the temperature sensor 113 is confirmed (step S14). As a result of this measurement, when the temperature is higher than a predetermined second temperature threshold, for example, 43 ° C., for determining whether or not the charging operation can be performed during a call (step S14 (> 43 ° C.) In this case, the charging operation is temporarily stopped until the second temperature threshold value is, for example, 43 ° C. or less (step S15), and the temperature of each part of the mobile terminal 10 is set to a predetermined second temperature threshold value, for example, 43 ° C. or less. Until the voltage decreases, the processes in steps S14 and S15 are repeated to temporarily stop the charging operation.

  When the temperature of each part of the portable terminal 10 becomes a predetermined second temperature threshold value, for example, 43 ° C. or less (in the case of step S14 (≦ 43 ° C.)), the charging operation is resumed (step S16). Thereafter, it is determined whether or not the voice call (AMR) or the videophone (VP) is currently being continued (step S17). When a call such as a voice call or a videophone call is in progress (Yes in step S17), the process returns to step S8, and charging is performed by a “busy charging process” in which charging is performed by variably controlling the charging current value. Continue. On the other hand, when the call is not in progress such as a voice call or a videophone (No in step S17), the call is finished and the standby state is entered. The operation is switched to the charging operation by the “standby charging process” to be performed.

  By performing the charging operation as described above, during a call, the current value of the charging current is variably controlled according to the output voltage of the secondary battery 109 and the measured temperature of each part of the mobile terminal 10. The heat generation, temperature rise, and overcharge of the mobile terminal 10 can be suppressed. In addition, the threshold value regarding the measured temperature and the output voltage and the current value of the charging current described above are examples, and in the present invention, it is possible to appropriately tune according to the target mobile terminal 10.

  Further, in the flowchart of FIG. 2, an example of the operation in which the current value of the charging current in the “call charging process” is switched in three stages depending on the output voltage of the secondary voltage 109 is shown. However, the present invention is not limited to this case, and control may be performed so that the current value of the charging current is switched in accordance with the output voltage of the secondary voltage 109 at a plurality of arbitrarily determined stages. In other words, the lower the battery voltage (output voltage) of the secondary battery 109 is, the lower the battery voltage (output voltage) is set in order to control the charging current to be set to a larger value and to perform charging more quickly. Accordingly, the current value of the charging current may be appropriately switched between a plurality of stages.

  Note that the portable terminal 10 applied to the present embodiment may be any portable device, for example, any of a cellular phone, a PHS phone, a personal digital assistant (PDA), a portable notebook PC, and the like. It may be a portable game machine or a portable music player.

(Explanation of effect of embodiment)
As described in detail above, according to the present embodiment, when charging during a call, the battery voltage (output voltage) of the secondary battery 109 is measured by the voltage measuring unit 112 and the output voltage of the secondary battery 109 is measured. Depending on how, the charging current is changed as appropriate, so that it is possible to quickly charge the battery while suppressing heat generation, temperature rise, and overcharging of the mobile terminal 10.

  Further, during charging, the temperature of each part of the mobile terminal 10 is measured by the temperature sensor 113. When the temperature exceeds a predetermined temperature, the charging operation is stopped, and the charging operation is resumed when the temperature is lower than the predetermined temperature. Therefore, it is possible to prevent the temperature of the mobile terminal 10 from rising abnormally and keep the mobile terminal 10 in a safe temperature range.

  In addition, when charging the mobile terminal 10 in the standby state, it is possible to perform rapid charging by controlling the maximum allowable charging current to flow, and the charging time is as short as the conventional rapid charging operation. Can be charged. Even during a call, the lower the battery voltage (output voltage) of the secondary battery 109, the larger the charging current value is set, and the battery is charged as close to full charge as possible. Thus, it is possible to obtain a voltage value that can reliably continue the call state.

  The configuration of the preferred embodiment of the present invention has been described above. However, it should be noted that such examples are merely illustrative of the invention and do not limit the invention in any way. Those skilled in the art will readily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention.

It is a block block diagram which shows an example of the block configuration of the portable terminal to which the charge control method of this invention is applied. It is a flowchart which shows an example of the charge control method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Mobile terminal 20 Charging apparatus 101 Wireless processing part 102 Control part 103 Storage part 104 Camera part 105 Display part 106 Speaker 107 Microphone 108 Operation part 109 Secondary battery 110 Charge control part 111 Charging terminal 112 Voltage measurement part 113 Temperature sensor

Claims (9)

  In the charging control method for controlling the charging of the secondary battery of the mobile terminal, the secondary battery according to the temperature in the mobile terminal, the state of the mobile terminal in a call / standby state, and the output voltage of the secondary battery The charge control method characterized by variably controlling the current value of the charging current for charging the battery.   When the portable terminal is in a standby state, the temperature in the portable terminal is higher than a predetermined first temperature threshold value for determining whether or not the charging operation can be performed in the standby state. When the temperature is high, the charging operation is temporarily stopped until the temperature in the mobile terminal falls below the first temperature threshold, and when the mobile terminal is in a call state, the temperature in the mobile terminal is Is higher than a predetermined second temperature threshold value for determining whether or not a charging operation can be performed during a call, the temperature in the portable terminal decreases below the second temperature threshold value. The charging control method according to claim 1, wherein the charging operation is temporarily stopped until it is performed.   The charge control method according to claim 2, wherein the second temperature threshold is set to a value lower than the first temperature threshold.   When the temperature measurement location in the portable terminal is set as a plurality of locations in the vicinity of a part that generates a large amount of heat, and the measurement temperature at any measurement location is in the standby state of the portable terminal Charging when it is detected that it is higher than the first temperature threshold, or when it is detected that the mobile terminal is higher than the second temperature threshold if it is in a call state 4. The charging control method according to claim 2, wherein the operation is temporarily stopped.   When the mobile terminal is in a call state, the charging operation is performed by switching the current value of the charging current of the secondary battery to a larger value as the output voltage of the secondary battery is lower. The charge control method according to claim 1.   When the output voltage of the secondary battery is a voltage value equal to or lower than a first voltage threshold predetermined as the highest voltage value that requires rapid charging, the current value of the charging current of the secondary battery is allowed. The charging operation is performed by switching to the maximum current value, and the output voltage of the secondary battery is higher than the first voltage threshold, and the minimum current allowed when performing the charging operation during a call. When the voltage value is equal to or lower than a predetermined second voltage threshold value as the lowest voltage value to be switched to the charging operation by value, the current value of the charging current of the secondary battery is set in advance as a standard charging current value during a call. When the charging operation is performed by switching to a predetermined current value, and the output voltage of the secondary battery is higher than the first voltage threshold value, the current value of the charging current of the secondary battery is charged in a busy state. Do the action Charging control method according to claim 5 is switched to the current value of the minimum allowed and performs charging operation.   A portable terminal, comprising the charge control method according to claim 1.   The mobile terminal according to claim 7, wherein the mobile terminal is any one of a mobile phone, a PHS phone, a personal digital assistant (PDA), a mobile notebook PC, a mobile game machine, and a mobile music player. 9. A charging control system comprising: the mobile terminal according to claim 7 or 8; and a charging device that supplies a charging current to the mobile terminal.

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