JP2019149929A - Portable terminal - Google Patents

Abstract

To provide a portable terminal that can stop charging when there is a problem with charging a battery in a case in which connection of an external power supply is established, and charge the battery when there is no problem.SOLUTION: A portable terminal 100 includes a battery 5 inside, and drives an electronic circuit 10 with electric power from the battery. This portable terminal is configured such that the battery can be charged by external power from an external power supply device 3. The electronic circuit includes a switching control unit 13 that switches between a charging mode in which the battery is charged with external power and a non-charging mode in which external power is supplied to the electronic circuit without charging the battery. When the temperature of the battery or the temperature around the battery is detected by a temperature detection unit 15, the switching control unit switches between the charging mode and the non-charging mode according to the detected temperature.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for charging a mobile terminal.

  In general, when a mobile terminal such as a smartphone is operated while being powered from the outside, the power supplied from the outside is used for charging the battery of the mobile terminal, and the electronic circuit of the mobile terminal is operated by the power from the battery.

  When the mobile terminal executes a function with a heavy processing load, such as a navigation function, the power consumption increases and the battery temperature rises. In particular, when used in an in-vehicle environment, the battery temperature may easily rise due to the influence of direct sunlight or heating. In such a case, in general, a portable terminal has a function of stopping charging the battery in order to protect the battery. As a result, there is a case where the battery is not charged and the power of the battery is consumed although power is supplied to the mobile terminal.

  Patent Document 1 discloses a portable terminal that can be operated with only an external power source without automatically charging the battery pack when the external power source is connected, and automatically disconnecting the battery pack by switching by a user. doing.

JP 2012-10441 A

  However, the technique of Patent Document 1 has a problem that charging of the battery does not proceed even when the temperature of the battery is not increased.

  Examples of the problem to be solved by the present invention include the above. In the present invention, when an external power supply is connected, if there is a problem in charging the battery, the charging to the battery is stopped, and if there is no problem, the battery can be charged. The purpose is to provide a terminal.

  The invention according to claim 1 is a portable terminal capable of supplying external electric power, a battery for supplying electric power to an electronic circuit of the portable terminal body, and a temperature detection means for detecting the temperature of the battery or the periphery of the battery And a control means for controlling switching between a charging mode for charging the battery with the external power and a non-charging mode for supplying the external power to the electronic circuit without charging the battery. The means controls switching between the charging mode and the non-charging mode in accordance with the temperature detected by the temperature detecting means.

The external appearance of the portable terminal which concerns on an Example is shown. The schematic structure regarding charge of a portable terminal is shown. An example of a battery charging method is shown. The example of the time control of the charge mode by the 3rd Example and the non-charge mode is shown. The example of the cradle for mounting a portable terminal in a vehicle is shown.

  In a preferred embodiment of the present invention, a mobile terminal capable of supplying external power includes a battery that supplies power to an electronic circuit of the mobile terminal body, a temperature detection unit that detects a temperature of the battery or the battery, Control means for controlling switching between a charging mode for charging the battery with the external power and a non-charging mode for supplying the external power to the electronic circuit without charging the battery; The switching between the charging mode and the non-charging mode is controlled according to the temperature detected by the temperature detecting means.

  The portable terminal includes a battery inside and drives an electronic circuit with electric power from the battery. The portable terminal is configured to be able to charge the battery with external power. The control means switches between a charging mode in which the battery is charged with external power and a non-charging mode in which the external power is supplied to the electronic circuit without charging the battery. Specifically, when the temperature of the battery or the temperature around the battery is detected by the temperature detection means, the control means switches between the charging mode and the non-charging mode according to the detected temperature. Thereby, it is possible to determine whether charging is possible in consideration of the temperature of the battery.

  In one aspect of the portable terminal, the control unit sets the charging mode when the detected temperature is lower than a predetermined temperature, and sets the non-charging mode when the detected temperature is equal to or higher than the predetermined temperature. . In this aspect, since the battery is not charged when the detected temperature is high, the battery can be prevented from deteriorating.

  In another aspect of the portable terminal described above, the control means sets the non-charge mode regardless of the detected temperature when the charging rate of the battery is equal to or higher than a predetermined value. In this aspect, when the battery is charged to some extent, it is possible to prevent the battery from deteriorating by avoiding unnecessary repeated charging.

  In another aspect of the portable terminal, the control unit sets the non-charge mode regardless of the detected temperature when the current consumption of the electronic circuit is equal to or higher than a predetermined value. In this aspect, when the power consumption is large, the battery temperature is prevented from increasing as charging is not performed.

  In another aspect of the portable terminal, the control unit calculates a temperature increase rate of the detected temperature, and sets the non-charge mode when the temperature increase rate is equal to or greater than a predetermined value. In this aspect, it is possible to stop the charging of the battery before the temperature of the battery rises to near the limit temperature, thereby reducing damage to the battery.

  In another aspect of the portable terminal, the control unit changes a time ratio between the charging mode and the non-charging mode within a unit time according to the detected temperature. In this aspect, since the time ratio for charging the battery is controlled according to the detected temperature, the charging can be performed with an appropriate time distribution according to the temperature of the battery.

  In another aspect of the portable terminal, the output control means performs the switching when the portable terminal is mounted on a mobile object. Usually, when mounted on a moving body such as a vehicle, the temperature of the battery is particularly likely to rise due to direct sunlight. Therefore, in this aspect, when the portable terminal is mounted on the mobile body, the charging of the battery is controlled based on the temperature of the battery.

  In another preferred embodiment of the present invention, a charge control method that is executed in a portable terminal that includes an electronic circuit and a battery that supplies power to the electronic circuit and that can supply external power is the battery or the battery. Controlling switching between a temperature detection step for detecting ambient temperature, a charging mode for charging the battery with the external power, and a non-charging mode for supplying the external power to the electronic circuit without charging the battery. A control step, wherein the control step controls switching between the charging mode and the non-charging mode in accordance with the temperature detected by the temperature detecting step. Also with this charge control method, it is possible to determine whether charging is possible in consideration of the temperature of the battery.

  In another preferred embodiment of the present invention, a charge control program that is executed in a portable terminal that includes a computer, an electronic circuit, and a battery that supplies power to the electronic circuit and is capable of supplying external power is the battery. Alternatively, a temperature detection step for detecting the temperature around the battery, a charging mode for charging the battery with the external power, and a non-charging mode for supplying the external power to the electronic circuit without charging the battery. Controlling the switching between the charging mode and the non-charging mode in accordance with the temperature detected by the temperature detecting step. To do. By executing this charging control program, it is possible to determine whether or not charging is possible in consideration of the temperature of the battery. This charge control program can be stored and handled in a storage medium.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[First embodiment]
FIG. 1 illustrates an example of a mobile terminal according to the embodiment. The portable terminal 100 can be a smartphone, for example. FIG. 2 shows a configuration related to charging of the mobile terminal 100. In FIG. 2, the power supply line is indicated by a solid line, and the control signal line is indicated by a broken line.

  As illustrated, the mobile terminal 100 is connected to the external power supply device 3. The external power supply device 3 supplies a stabilization voltage such as DC 5 V to the mobile terminal 100 from a power source such as a vehicle battery, a USB terminal of a PC, or a commercial AC power source. The external power supply device 3 includes a connector that can be attached to and detached from the external connector of the mobile terminal 100 at the end of the cable. The connector of the external power supply device 3 is, for example, a cigar charger for supplying power from a vehicle battery, a USB terminal for supplying power from a PC, an AC adapter for supplying power from a commercial AC power source, or the like.

  The mobile terminal 100 includes a battery 5 and an electronic circuit 10. The battery 5 is, for example, a lithium ion battery or a nickel metal hydride battery. The battery 5 is detachable from the mobile terminal 100 and has an electrical contact with the mobile terminal 100.

  The electronic circuit 10 is a circuit provided inside the mobile terminal 100. The electronic circuit 10 includes a charging unit 11, a voltage conversion unit 12, a switching control unit 13, a switch 14, a temperature detection unit 15, and a driven circuit 16. The electronic circuit 10 operates by receiving power supply from the battery 5 when external power is not supplied.

  The driven circuit 16 is a circuit provided for performing the original operation of the mobile terminal 10, and specifically includes a CPU, a memory, a display device, and the like. On the other hand, the parts other than the driven circuit 16, that is, the charging unit 11, the voltage conversion unit 12, the switching control unit 13, the switch 14, and the temperature detection unit 15 are portions that operate for battery charging control according to this embodiment. is there.

  The charging unit 11 outputs the charging current of the battery 5 based on the power supplied from the external power supply device 3. The output terminal of the charging unit 11 is connected to the terminal of the battery 5 and the input terminal T1 of the switch 14.

  An example of a method for charging the battery 5 is shown in FIG. In FIG. 3, a graph 31 shows a change with time of the charging voltage, and a graph 32 shows a change with time of the charging current. When the charging voltage of the battery 5 is less than the predetermined value, the charging unit 11 outputs the charging current while limiting the output so that the charging current to the battery 5 does not exceed the predetermined current value I1. Thereby, the charging voltage of the battery 5 gradually increases as shown in the graph 31. Thus, when the charging voltage of the battery 5 reaches the predetermined voltage value V1 at time t1, the charging unit 11 maintains the predetermined voltage value V1 and continues charging. In the case of a lithium ion battery, the predetermined voltage value V1 is set to 4.0 V, for example. Thereby, as shown in the graph 32, the charging current gradually decreases. Then, the charging unit 11 ends the charging when the charging current becomes equal to or less than the predetermined current value I2. As shown in FIG. 3, constant current charging is performed from time 0 to t1, and constant voltage charging is performed from time t1 to t2.

  The voltage conversion unit 12 converts the voltage supplied from the external power supply device 3 into a voltage near the rated voltage of the battery 5 and outputs the voltage to the input terminal T2 of the switch 14. In addition, the rated voltage in the case of a lithium ion battery is 4.0V, for example.

  The switch 14 is configured by a semiconductor switch or the like, and switches the current supply path to the driven circuit 16 between the battery side and the voltage conversion unit side. Specifically, the switch 14 selects one of the input terminals T <b> 1 and T <b> 2 and supplies power from the output terminal To to the driven circuit 16. Actually, the power supply line is common in the electronic circuit 10, and the power supplied to the driven circuit 16 is the charging unit 11, the power conversion unit 12, the switching control unit 13, the switch 14, the temperature detection. The same is supplied to the unit 15 as well. That is, the entire electronic circuit 10 operates with the power supplied from the switch 14.

  The temperature detector 15 detects the temperature of the battery 5 or the temperature around the battery 5 and supplies the detected temperature to the switching controller 13 as a control signal S15. The temperature detection unit 15 is disposed at a position in contact with or close to the battery 5 in the case of the mobile terminal 100. If the temperature detection means such as a thermistor is built in the battery 5 itself and the detection temperature can be output via the contact of the battery 5, the detection temperature output from the battery 5 is switched. What is necessary is just to supply to the control part 13. In this case, the temperature detection unit 15 becomes unnecessary.

  The switching control unit 13 controls the switch 14 based on the detected temperature of the battery 5 supplied from the temperature detection unit 15 and switches the power supply path to the driven circuit 16. The switching control unit 13 sends a control signal S11 to turn on / off the operation of the charging unit 11, and sends a control signal S12 to turn on / off the operation of the voltage conversion unit 12. Further, the switching control unit 13 controls the switching of the switch 14 by sending a control signal S14.

  Specifically, when the detected temperature of the battery 5 is less than a predetermined value, the switching control unit 13 operates the charging unit 11 to charge the battery 5, stops the voltage conversion unit 12, and connects the switch 14 to the input terminal. Switch to T1 side. Thereby, the battery 5 is charged with the electric power from the external power supply device 3. This mode is called “charging mode”. In the charging mode, the charging power of the battery 5 is supplied to the driven circuit 16 via the switch 14, so that the entire electronic circuit 10 operates with the charging power of the battery 5.

  On the other hand, when the detected temperature of the battery 5 is equal to or higher than a predetermined value, the switching control unit 13 stops the charging unit 11 to stop charging the battery 5, operates the voltage conversion unit 12, and connects the switch 14 to the input terminal. Switch to T2 side. Thereby, the battery 5 is not charged, and the power from the external power supply device 3 is supplied to the driven circuit 16. This mode is called “non-charge mode”. In the non-charge mode, the electric power from the external power supply device 3 is supplied to the driven circuit 16 via the switch 14, so that the entire electronic circuit 10 operates with the power from the external power supply device 3.

  As described above, in this embodiment, when the temperature of the battery 5 is high, the battery 5 is not charged as the non-charge mode, and when the temperature of the battery 5 is low, the battery 5 is charged as the charge mode. Do. Therefore, the battery 5 can be efficiently charged within a range where there is no problem with the battery 5.

(Modification 1)
In addition to the control of the above embodiment, when the charging rate of the battery 5 is equal to or higher than a predetermined value (for example, 80% or higher), the mobile terminal 100 may be set to the non-charging mode regardless of the temperature of the battery 5. Thereby, useless repeated charging of the battery 5 can be prevented, and the life of the battery can be extended. The charging rate of the battery 5 can be determined based on the charging current value of the battery 5. For example, in the example of the graph 32 in FIG. 3, when the charging current of the battery 5 is the predetermined current value I2, the charging rate is 100%. Therefore, the charging current value corresponding to the charging rate of 80% is determined in advance, and the charging current is What is necessary is just to determine with the charging rate having reached 80% when becomes the charging current value.

(Modification 2)
In addition to the control of the above embodiment, when the current consumption of the electronic circuit 10 is equal to or higher than a predetermined value, the mobile terminal 100 may be set to the non-charge mode regardless of the temperature of the battery 5. For example, when the portable terminal 100 is executing an application with high power consumption such as a navigation application, charging may not proceed even if an attempt is made to charge the battery 5 due to high power consumption. In such a case, the temperature of the battery 5 may rise unnecessarily, and the life of the battery 5 may be shortened. Therefore, it is preferable to operate the portable terminal 100 with power from the external power supply device 3 without charging the battery 5.

  As a method for detecting consumption current, the portable terminal 100 may be provided with current measuring means for detecting the current consumed by the electronic circuit 10. Or, if a standard value of current consumption is set for each application, refer to the reference table for the standard value of current consumption and predict the current consumption value corresponding to that application during application startup. It is good.

[Second Embodiment]
In the first embodiment, the charging mode and the non-charging mode are switched based on the temperature of the battery 5. Instead, the charging mode and the non-charging mode may be switched based on the temperature increase rate of the battery 5. By looking at the rate of temperature rise, charging of the battery 5 can be stopped before the temperature of the battery 5 actually rises to near the limit temperature, and damage to the battery 5 can be reduced. Specifically, the temperature increase rate may be calculated as the time change of the detected temperature from the temperature detection unit 15, and when this exceeds a predetermined temperature increase rate, switching from the charging mode to the non-charging mode may be performed.

[Third embodiment]
Instead of the control of the first embodiment, the time ratio between the charging mode and the non-charging mode within the unit time may be changed according to the temperature of the battery 5. For example, the temperature of the battery 5 is classified into several temperature ranges, and the time ratio between the charging mode and the non-charging mode is controlled for each temperature range.

  FIG. 4 shows an example of the time ratio in the third embodiment. In this example, the temperature of the battery 5 is classified into four temperature ranges, and the time ratio between the charging mode and the non-charging mode is set for each temperature range. For example, when the temperature of the battery 5 is lower than 35 ° C., the battery 5 is charged for the entire time, when the temperature is 35 ° C. to 40 ° C., the charging mode time is 70%, and when the temperature is 40 ° C. to 45 ° C. If the temperature is 45 ° C. or higher, the entire time is set to the non-charge mode. Thereby, charge of the battery 5 can be advanced while relieving the temperature rise of the battery 5.

[Fourth embodiment]
In the first embodiment, the control of the first embodiment is performed in all environments. Instead, the control of the first embodiment may be performed only while the mobile terminal 100 is mounted on the vehicle, that is, when the mobile terminal 100 is mounted on the vehicle, as in the first embodiment. In addition, the charging mode and the non-charging mode are switched based on the temperature of the battery 5. On the other hand, when the portable terminal 100 is not mounted on the vehicle, the charging mode is basically set and the battery 5 is charged.

  FIG. 5 shows an example of a cradle used when the mobile terminal 100 is mounted on a vehicle in this embodiment. The cradle 200 is attached to a vehicle dashboard, a front glass, or the like, and holds the mobile terminal 100 by a base portion 214 and a pair of arms 215. An NFC (Near Field Communication) tag 210 is attached to the cradle 200. For example, a unique character string is written in the NFC tag 210. When the portable terminal 100 is attached to the cradle 200, the portable terminal 100 reads the character string from the NFC tag, and determines that the portable terminal 100 is mounted on the vehicle (used in the vehicle). In other cases, it is determined that the mobile terminal 100 is not mounted on the vehicle.

  When the mobile terminal 100 is installed in a vehicle using an in-vehicle cradle, the mobile terminal 100 is usually installed near a dashboard that is exposed to direct sunlight. In such a situation, the temperature of the battery tends to rise. Therefore, by performing the control of the first embodiment, it is possible to charge the battery while preventing the battery temperature from rising.

DESCRIPTION OF SYMBOLS 3 External power supply apparatus 5 Battery 10 Electronic circuit 11 Charging part 12 Voltage conversion part 13 Switching control part 14 Switch 15 Temperature detection part 16 Driven circuit 100 Terminal apparatus 200 Cradle

Claims (1)

A portable terminal capable of supplying external power,
A battery for supplying power to the electronic circuit of the mobile terminal body;
Temperature detecting means for detecting the temperature of the battery or the surroundings of the battery;
Control means for controlling switching between a charging mode for charging the battery with the external power and a non-charging mode for supplying the external power to the electronic circuit without charging the battery;
The mobile terminal according to claim 1, wherein the control unit controls switching between the charging mode and the non-charging mode in accordance with the temperature detected by the temperature detecting unit.

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