JP4440203B2 - Mobile terminal device - Google Patents

Description

  The present invention relates to a portable terminal device that can use a secondary battery as a power source.

  A secondary battery is usually used for a portable terminal device in order to secure its power supply. In view of the charging efficiency of the secondary battery, various charging methods for the secondary battery have been proposed.

  For example, Patent Document 1 describes a charging device that can increase the charging efficiency by providing a temperature determination unit in the charging device and correcting the temperature of the duty ratio and current value of pulse charging. Patent Document 2 describes a charging system that performs rapid charging by stopping power supply to a battery and preventing an excessive current from flowing to a charger when a mobile phone enters a call state. Yes.

JP-A-8-182215 JP-A-9-130456

  By the way, it is known that secondary batteries undergo so-called cycle deterioration in which battery characteristics deteriorate depending on the number of charge / discharge cycles. As a result of studies by the inventors of the present invention, it was confirmed that the secondary battery has a characteristic that the cycle life is shortened by charging when the temperature of the secondary battery is high. Moreover, it was confirmed that the secondary battery has a characteristic that the cycle life is shortened even when the charging voltage is high. That is, it has been found that when the battery is charged at a high temperature and a high charging voltage, the deterioration of the secondary battery is accelerated at an accelerated rate.

  This invention is made | formed in view of said situation, Comprising: It aims at providing the portable terminal device which can suppress deterioration of a secondary battery.

  A first aspect of the present invention is a portable terminal device that can use a secondary battery as a power source, and includes a plurality of casings and a casing portion that connects the casings so as to be openable and closable, An open / close state detection unit that detects an open / close state of the housing unit, a charging circuit that supplies power to the secondary battery from an external power source, and a charge control that controls the charging circuit according to a detection result of the open / close state detection unit A portable terminal device including a circuit is provided.

  In a mobile terminal device having an openable / closable casing, it is estimated that the amount of heat generated by processing performed in the mobile terminal device varies depending on the open / close state. Therefore, since the charging circuit is controlled according to the open / closed state of the housing portion with the above configuration, control according to the amount of heat transferred from the mobile terminal device to the secondary battery is possible, and the deterioration of the secondary battery is suppressed. Can do.

  The second aspect of the present invention is the mobile terminal device according to the first aspect, wherein the charge control circuit sets the charge voltage of the secondary battery to the first when the open / closed state detection result is a closed state. When the detection result of the open / closed state is an open state, the charging voltage of the secondary battery is controlled to a second voltage lower than the first voltage.

  With this configuration, for example, in a mobile terminal device, processing with a large amount of heat generation is performed mainly in the open state. Therefore, by controlling the charge voltage high in the closed state and low in the open state, Degradation of the secondary battery can be suppressed.

  Thirdly, the present invention provides a mobile terminal device that can use a secondary battery as a power source, and includes an arithmetic processing unit that controls the operation of the mobile terminal device based on an operation control instruction, and an external power source. A portable terminal device is provided that includes a charging circuit that supplies power to the secondary battery, and a charging control circuit that controls the charging circuit according to a pause state of a predetermined process in the arithmetic processing unit.

  For example, it is presumed that the amount of heat generated in the mobile terminal device is low in the sleep mode when the arithmetic processing unit is not operating. Therefore, since the charging circuit is controlled according to the operation state of the arithmetic processing unit with the above configuration, control according to the amount of heat transferred from the mobile terminal device to the secondary battery is possible, and the deterioration of the secondary battery is suppressed. Can do.

  Fourthly, the present invention provides the portable terminal device according to the third aspect, wherein the charge control circuit performs the second operation when the arithmetic processing unit has not performed the predetermined processing for a first predetermined time or more. The charging voltage of the secondary battery is set to the first voltage while the predetermined processing is being performed or when the second predetermined time has not elapsed since the predetermined processing was performed. Control to a second voltage lower than the first voltage.

  With this configuration, for example, the charging voltage is lowered when the arithmetic processing unit is operating, and the charging voltage is controlled to be high only when the arithmetic processing unit is not operating for a predetermined time or longer, thereby suppressing deterioration of the secondary battery. can do.

  Fifthly, the present invention provides a portable terminal device that can use a secondary battery as a power source, a broadcast wave receiving unit that receives broadcast waves, and a charge that supplies power to the secondary battery from an external power source. A portable terminal device is provided that includes a circuit and a charging control circuit that controls the charging circuit in accordance with an operating state of the broadcast wave receiving unit.

  With this configuration, in a portable terminal device having a broadcast wave receiving unit such as a TV tuner, the amount of heat generated by the operation of the broadcast wave receiving unit is usually relatively large. Therefore, since the charging circuit is controlled according to the operating state of the broadcast wave receiving unit with the above configuration, control according to the amount of heat transmitted from the mobile terminal device to the secondary battery is possible, and the deterioration of the secondary battery is suppressed. be able to.

  Sixthly, the present invention provides the portable terminal device according to the fifth aspect, wherein the charging control circuit sets the charging voltage of the secondary battery to the first when the broadcast wave receiving unit is in a non-operating state. When the broadcast wave receiver is in an operating state, the charging voltage of the secondary battery is controlled to a second voltage lower than the first voltage.

  With this configuration, for example, the deterioration of the secondary battery can be suppressed by controlling the charging voltage to be high when the broadcast wave receiver is not operating and to be low when it is operating.

  Seventhly, the present invention is the portable terminal device according to the second, fourth, or sixth aspect, wherein the second voltage is a condition in which an electric capacity charged in the secondary battery is predetermined. It is the voltage which satisfies.

  With this configuration, even when the charging voltage is lowered, the electric capacity stored in the secondary battery can satisfy a predetermined condition, so that charging that guarantees performance such as standby time of the mobile terminal device can be performed. It can be carried out.

  ADVANTAGE OF THE INVENTION According to this invention, the portable terminal device which can suppress deterioration of a secondary battery can be provided.

  Hereinafter, first to third embodiments of the present invention will be described. First, a schematic configuration of the mobile terminal device according to the first to third embodiments will be described by taking a mobile phone device as an example.

  FIG. 1 is a block diagram showing a schematic configuration of a mobile terminal device according to an embodiment of the present invention. 2 is an external view of the portable terminal device according to the embodiment of the present invention, FIG. 2A is a diagram showing an open state in which the casing is open, and FIG. 2B is a diagram in which the casing is closed. It is a figure which shows the closed state.

  As shown in FIG.1 and FIG.2, the portable terminal device 100 of embodiment of this invention is the 1st housing | casing 1, the 2nd housing | casing 2, and the 1st housing | casing 1 and the 2nd housing | casing. 2 includes a connecting portion 3 that connects the two in an openable / closable manner, a display portion 4, and a speaker 5.

  In addition, the mobile terminal device 100 includes an external power supply connection unit 6, a charging circuit 7, a secondary battery 8, and a charging control circuit 9 that controls the charging circuit 7. Furthermore, the mobile terminal device 100 includes an open / close state detection unit 10, an operation unit 11, a radio unit 12, a television tuner (hereinafter referred to as a TV tuner) 13, and a CPU 14.

  The first housing 1, the second housing 2, and the connecting portion 3 function as an example of the housing portion of the mobile terminal device 100, and the mobile terminal device 100 is open as shown in FIG. An open state that is a state and a closed state that is a closed state as shown in FIG. 2B can be taken. In addition, although the form which folds a housing | casing part was illustrated in FIG. 2, various opening-and-closing systems may be used. For example, there are a slide type and a rotary type other than the folding type of the present embodiment. Moreover, even if it is a housing | casing called what is called a straight type, if this is provided with the opening-and-closing type cover part, this invention is applicable.

  The display unit 4 includes a liquid crystal display device and the like, and performs display according to the operation by the user, the operation state of the mobile terminal device 100, and the like. The speaker 5 outputs sound in accordance with the user's operation, alarm sound, the operating state of the mobile terminal device 100, and the like.

  The external power supply connection unit 6 is configured to have a connection terminal for connecting to, for example, an AC adapter that converts commercial AC power to DC, and receives power from an external power supply. The charging circuit 7 supplies power supplied from the external power supply connection unit 6 to the secondary battery 8. For example, the charging circuit 7 is connected to the drain terminal / source terminal of the external power supply connection unit 6 and the secondary battery 8. It has a channel MOSFET. The secondary battery 8 is a battery that can be repeatedly charged and used. For example, the secondary battery 8 is detachably attached to the first housing 1 and used as a power source for the mobile terminal device 100.

  The charging control circuit 9 controls the charging circuit 7, and includes a charging current detection circuit 9a, a charging voltage detection circuit 9b, and a charging voltage adjustment circuit 9c. The charging current detection circuit 9 a detects the charging current from the potential difference between both ends of the resistor R inserted between the charging circuit 7 and the secondary battery 8. The charging voltage detection circuit 9b detects the voltage of the secondary battery 8. The charging voltage adjustment circuit 9 c controls the charging circuit 7 based on the detection result of the charging current detection circuit 9 a or the charging voltage detection circuit 9 b or an instruction from the CPU 14. For example, the secondary battery 8 is controlled to obtain a desired charging current or charging voltage by controlling the voltage applied to the gate terminal of a P-channel MOSFET provided in the charging circuit 7 described above.

  The open / close state detection unit 10 detects the open / close state of the housing unit. The open / close state detection unit 10 includes, for example, a hall element 10a provided in the first housing 1 and a magnet 10b provided in the second housing 2 as shown in FIG. The hall element 10a converts the magnetic field of the magnet 10b, which changes according to the open / closed state of the casing, into an electrical signal and outputs it to the CPU 14.

  The operation unit 11 receives an operation input from a user, and is a numeric keypad 11 a and navigation key 11 b provided on the main surface of the first housing 1, and a surface perpendicular to the main surface of the first housing 1. And a side key 11c provided on the side surface. The wireless unit 12 performs wireless communication with a wireless base station, for example, and performs voice call, data communication, and the like.

  The TV tuner 13 operates as an example of a broadcast wave receiving unit that receives a broadcast wave. For example, the TV tuner 13 is a digital TV tuner that receives a digital television. The TV tuner 13 receives the broadcast wave from a relay antenna or the like, and receives the broadcast wave from the relay antenna or the like via the CPU 14. The data received from 5 is output.

  The CPU 14 functions as an example of an arithmetic processing unit that controls the operation of the mobile terminal device 100 as a whole, and is configured mainly by a processor that operates according to a predetermined program. Moreover, it has the charge control part 14a which controls the charge voltage adjustment circuit 9c, and the timer 14b which time-measures time.

  Hereinafter, the charge control method according to the first to third embodiments will be described.

(First embodiment)
In a mobile terminal device having an openable / closable casing, it is estimated that the amount of heat generated by processing performed in the mobile terminal varies depending on the open / close state. For example, in processes such as mail transmission / reception, telephone call, and TV reception, the amount of heat generated in the order of mail reception / transmission <call><TV reception is large. Alternatively, it can be said that the amount of heat generated at the time of analog broadcast reception is generally larger in analog broadcast and digital broadcast among TV reception. On the other hand, in relation to the reception of a digital broadcast and a call, the amount of heat generated during a call may exceed the amount of heat generated during reception of the digital broadcast. Therefore, in the charge control method according to the first embodiment, the charge control circuit 9 controls the charging circuit 7 according to the open / closed state of the housing unit, whereby the amount of heat transferred from the mobile terminal device 100 to the secondary battery 8. The charging voltage is controlled according to

  FIG. 3 is a flowchart showing a procedure of the charging control method for the portable terminal device according to the first embodiment of the present invention.

  As shown in FIG. 3, the charging voltage adjusting circuit 9c of the charging control circuit 9 determines whether or not it is necessary to start charging the secondary battery 8 (step S301). For example, it is determined that charging is started when it is detected that an external power source is connected to the external power source connection unit 8 or when the voltage in the attached secondary battery 8 becomes a predetermined threshold value or less. . If it is not necessary to start charging (NO in step S301), the process ends.

  Next, if it is necessary to start charging (YES in step S301), the charging voltage adjustment circuit 9c determines whether or not the mobile terminal device 100 is powered on (step S302). If the mobile terminal device 100 is powered on (YES in step S302), the charging voltage adjustment circuit 9c determines the open / closed state of the casing of the mobile terminal device 100 (step S303). In step S303, the charge control unit 14a of the CPU 14 notifies the charge voltage adjustment circuit 9c of the detection result from the open / close state detection unit 10, whereby the charge voltage adjustment circuit 9c determines the open / close state of the housing unit.

  The closed state means that the surface of the first casing 1 on which the numeric keypad 11a is provided and the display section 4 of the second casing 2 (the largest area when a plurality of display sections are provided). A state in which the surface provided with the display unit is overlapped with each other. And an open state points out the state which is not in a closed state.

  When the casing is not in the closed state, that is, in the open state (NO in step S303), the charging voltage adjustment circuit 9c controls the charging circuit 7 to provide the first charging voltage to the secondary battery 8. The battery is charged with a low charging voltage (for example, 4.2 V), which is an example of a second charging voltage lower than a normal charging voltage (for example, 4.37 V), which is an example (step S304). Processing that increases the amount of heat generated from the mobile terminal device 100, such as wireless communication using the wireless unit 12 and application processing operations, is often performed mainly when the casing is in an open state. Therefore, by charging with a low charging voltage when the casing is in an open state, charging in a situation where the secondary battery 8 is at a high temperature and a high charging voltage is avoided, and deterioration of the secondary battery 8 is suppressed. can do.

  Note that the reason why the normal charging voltage is 4.37 V and the low charging voltage is 4.2 V as described above is as follows. In other words, the power supply capacity at the completion of charging is generally determined by the applied voltage, but if the low charge voltage is lowered as much as possible, sufficient power supply capacity will not be ensured, so it matches the specific required performance. It is necessary to determine the “minimum low charge voltage”. In this embodiment, even after completion of charging with a low charging voltage, in view of the specific required performance that the continuous standby time in the power-on state is required, for example, 500 hours, the minimum is required to exhibit such performance. A low charging voltage such as 4.2 V was determined as a charging voltage that had to be applied for a limited time. Thus, if it is a low charging voltage, it is not necessary to make it low indefinitely, and it is necessary to apply a charging voltage necessary to satisfy the required specifications required for a mobile phone.

  On the other hand, when the mobile terminal device 100 is not turned on (NO in step S302) or when the casing is in a closed state (YES in step S303), the charging voltage adjustment circuit 9c controls the charging circuit 7. The secondary battery 8 is charged with a normal charging voltage.

  After that, the charging voltage adjustment circuit 9c determines the end of charging, such as determining whether or not the secondary battery 8 is fully charged (step S306). If charging is continued (NO in step S306), step S302 is performed. Returning to step S <b> 306, when the charging is finished (YES in step S <b> 306), the process is finished.

  According to the first embodiment of the present invention, since a process with a large amount of heat generation is performed mainly when the casing is open, the charging voltage is high when the casing is closed, and charging is performed when the casing is open. By controlling the voltage to be low, charging in a situation where the secondary battery 8 is at a high temperature and a high charge voltage can be avoided, and deterioration of the secondary battery 8 can be suppressed.

(Second Embodiment)
In the mobile terminal device 100, when the processing of the CPU 14 is paused, it is estimated that the amount of generated heat is low. Therefore, in the charge control method according to the second embodiment, the charge control circuit 9 controls the charging circuit 7 in accordance with the suspension state of the processing in the CPU 14, whereby the amount of heat transferred from the mobile terminal device 100 to the secondary battery 8. The charging voltage is controlled according to

  FIG. 4 is a flowchart showing the procedure of the charging control method for the portable terminal device according to the second embodiment of the present invention. In FIG. 4, the same reference numerals are given to the portions overlapping those in FIG. 3 described in the first embodiment. Here, the operations in steps S301, S302, S305, and S306 are the same as those in the first embodiment, and a description thereof will be omitted.

  As shown in FIG. 4, when the secondary battery 8 needs to be charged (YES in step S301) and the mobile terminal device 100 is turned on (YES in step S302), the CPU 14 counts the timer 14b. Start. The timer 14b is used for determination for setting the mobile terminal device 100 to the sleep mode, and measures a time during which no event occurs for the CPU 14, and a predetermined time limit is set as a timeout time. Note that the sleep mode means that the CPU 14 pauses a predetermined operation such as stopping the lighting of the display unit 4 when the CPU 14 does not perform a predetermined process due to the occurrence of the timeout time and the event, This is an operation mode for reducing power consumption.

  Note that the timer 14b can manage a plurality of times, and the time until the transition to the sleep mode, which is an example of the first predetermined time, and after the occurrence (or termination) of the event, which is an example of the second predetermined time. It is also possible to measure the predetermined time independently. By doing so, switching between the normal charging voltage and the low charging voltage can be performed more finely.

  Next, the CPU 14 determines whether or not there is an event request such as an operation input from the operation unit 11, an incoming call process from the radio unit 12, a received data display process from the TV tuner unit 13 (step S 402). .

  If there is an event request (YES in step S402), the CPU 14 notifies the occurrence of the event to the charging voltage adjusting circuit 9c, and the charging voltage adjusting circuit 9c controls the charging circuit 7 to charge the secondary battery 8 at a low charge. The battery is charged with a voltage (step S403). When the CPU 14 determines that an event is requested, it is necessary to perform application processing according to the event requested by the CPU 14, and thus the portable terminal device 100 generates heat due to the application processing. Therefore, by charging at a low charging voltage, charging in a situation where the secondary battery 8 is at a high temperature and a high charging voltage can be avoided, and deterioration of the secondary battery 8 can be suppressed.

  Then, the CPU 14 resets the timer 14b (step S404), and performs application processing according to the requested event (step S405). If the application has not ended (NO in step S414), the CPU 14 returns to step S405 and continues application processing. When the application ends (YES in step S414), the process returns to step S401 if the charging is continued (NO in step S406), and the process ends if the charging is ended (YES in step S406). If it is determined in step S414 that the application has ended, the elapsed time from the end of the application may be measured using the timer 14b, and the process may proceed to the next step S406 after a predetermined time has elapsed.

  On the other hand, if there is no event request (NO in step S402), the charging voltage adjustment circuit 9c controls the charging circuit 7 to charge the secondary battery 8 with the normal charging voltage (step S407). When the CPU 14 determines that an event is not requested, it is presumed that the process of increasing the amount of heat generated from the mobile terminal device 100 is not performed, so that the secondary battery is charged by charging with the normal charging voltage. 8 can be charged without reducing the electric capacity charged.

  Next, the CPU 14 determines whether or not the timer 14b has timed out (step S408). If the timer 14b has not timed out (NO in step S408), the timer 14b is counted up (step S409), and the process returns to step S402.

  On the other hand, if the timer 14b has timed out (YES in step S408), the CPU 14 performs processing such as turning off the display unit 4 and shifts to the sleep mode 410 (step S410), and ends the charging. If so (YES in step S411), the process ends.

  When charging is continued (NO in step S411), if an event request has not occurred (NO in step S412), the process returns to step S411. If an event request occurs (YES in step S412), the CPU 14 cancels the sleep mode (step S413), proceeds to step S403, and sets the charging voltage to a low charging voltage.

  According to the second embodiment of the present invention, since a process with a large calorific value is performed mainly when an event occurs in the CPU 14, the charging voltage is lowered in the event occurrence state, and no event occurs. By controlling the charging voltage to be high in the state, charging in a situation where the secondary battery 8 is at a high temperature and a high charging voltage can be avoided and deterioration of the secondary battery 8 can be suppressed.

  In addition, you may charge with a normal charge voltage only at the time of sleep mode by performing the procedure (step S407) charged with a normal charge voltage after sleep mode setting (step S410).

(Third embodiment)
In the mobile terminal device 100 equipped with the TV tuner 13, it is estimated that a large amount of heat is generated when the TV tuner 13 is operating. Therefore, in the charge control method according to the third embodiment, the charge control circuit 9 controls the charging circuit 7 in accordance with the operating state of the TV tuner 13, whereby the amount of heat transferred from the mobile terminal device 100 to the secondary battery 8. The charging voltage is controlled according to

  FIG. 5 is a flowchart showing the procedure of the charging control method for the portable terminal device according to the third embodiment of the present invention. In FIG. 5, the same reference numerals are given to the same parts as those in FIG. 3 described in the first embodiment. Here, the operations in steps S301 and S302 are the same as those in the first embodiment, and a description thereof will be omitted.

  As shown in FIG. 5, when the secondary battery 8 needs to be charged (YES in step S <b> 301) and the mobile terminal device 100 is turned on (YES in step S <b> 302), the CPU 14 The operating state is determined (step S501). For example, the CPU 14 determines that the TV tuner 13 is ON after a start instruction for the TV tuner 13 is input by an operation unit 11 or a reservation timer setting until a stop instruction for the TV tuner 13 is input.

  When the TV tuner 13 is in an operating state (YES in step S501), the charging voltage adjustment circuit 9c controls the charging circuit 7 and charges the secondary battery 8 with a low charging voltage (step S502). Since the operation of the TV tuner 13 is a process that increases the amount of heat generated from the mobile terminal device 100, charging at a low charging voltage avoids charging when the secondary battery 8 is at a high temperature and a high charging voltage. Thus, deterioration of the secondary battery 8 can be suppressed.

  On the other hand, when the mobile terminal device 100 is not turned on (NO in step S302) or when the TV tuner 13 is in a non-operating state (NO in step S501), the charging voltage adjustment circuit 9c controls the charging circuit 7. Then, the secondary battery 8 is charged with the normal charging voltage (step S503).

  Thereafter, the charging voltage adjustment circuit 9c returns to step S302 when charging is continued (NO in step S504), and ends processing when charging is terminated (YES in step S504).

  According to the third embodiment of the present invention, the secondary battery 8 is controlled by controlling the charging voltage to be high when the TV tuner 13 is in a non-operating state and to be low when the TV tuner 13 is in an operating state having a large amount of heat generation. Can be prevented from being charged at a high temperature and at a high charging voltage, and the deterioration of the secondary battery 8 can be suppressed.

  In the first to third embodiments described above, the normal charging voltage is desirably a maximum value of the charging voltage guaranteed by the secondary battery 8 attached to the mobile terminal device 100 or a value close to the maximum value. . The low charging voltage is preferably a voltage at which the electric capacity charged in the secondary battery 8 can comply with predetermined conditions such as standby time, call time, and TV viewing time. As a result, it is possible to suppress the deterioration of the secondary battery 8 and to control the charging voltage that guarantees the performance such as the standby time of the mobile terminal device 100.

  The mobile terminal device of the present invention has an effect capable of suppressing the deterioration of the secondary battery, and is useful for a mobile phone device and the like.

The block diagram which shows schematic structure of the portable terminal device which concerns on embodiment of this invention 1 is an external view of a mobile terminal device according to an embodiment of the present invention. The flowchart which shows the procedure of the charge control method of the portable terminal device which concerns on the 1st Embodiment of this invention. The flowchart which shows the procedure of the charge control method of the portable terminal device which concerns on the 2nd Embodiment of this invention. The flowchart which shows the procedure of the charge control method of the portable terminal device which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st housing | casing 2 2nd housing | casing 3 Connection part 4 Display part 5 Speaker 6 External power supply connection part 7 Charging circuit 8 Secondary battery 9 Charging control circuit 9a Charging current detection circuit 9b Charging voltage detection circuit 9c Charging voltage adjustment Circuit 10 Open / Closed State Detection Unit 10a Hall Element 10b Magnet 11 Operation Unit 11a Numeric Keypad 11b Navigation Key 11c Side Key 12 Radio Unit 13 TV Tuner 14 CPU
14a Charge control determination unit 14b Timer 100 Mobile terminal device R Resistance

Claims (1)

A portable terminal device capable of using a secondary battery as a power source,
A housing portion having a plurality of housings and a connecting portion for connecting the housings so as to be opened and closed;
An open / closed state detection unit for detecting an open / closed state of the housing unit;
A charging circuit for supplying power to the secondary battery from an external power source;
E Bei and a charging control circuit for controlling the charging circuit in accordance with a detection result of the open-close state detector,
The charging control circuit charges the secondary battery at a first voltage when the open / closed state detection result is closed, and charges the secondary battery when the open / closed state detection result is open. A portable terminal device that controls a voltage to a second voltage lower than the first voltage .

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