JP5162187B2 - Mobile terminal and activation method - Google Patents

Description

  The present invention relates to a portable device and a startup method, and more particularly to a portable device using a secondary battery as a power source and a startup method of the portable device.

  A mobile device represented by a mobile phone uses a secondary battery such as a lithium ion battery or a nickel metal hydride battery as a power source. For this reason, it is necessary to charge the secondary battery by receiving power from the outside. In recent years, portable devices equipped with a USB (Universal Serial Bus) connector have become widespread, and can be supplied with power from an external device connected by a USB cable. When receiving power from an external device connected by a USB cable, only a current of 100 mA can be supplied at first according to the standard. In order to increase the current value of the power supplied from the external device, make sure that the external device is a charger, or after communicating with the external device and negotiating The current value of the power supplied from the device cannot be increased. For example, Patent Documents 1 to 3 describe a technique for charging a secondary battery or a technique for driving a portable device with power received from an external device connected by a USB cable.

  However, the conventional technique relates to a technique in the case where the secondary battery stores sufficient power to drive the portable device. If the secondary battery is in an overdischarged state that cannot output the minimum voltage required to drive the portable device, the central processing unit (CPU) of the terminal device cannot be driven and the external device is charged. Neither confirmation of the device nor communication with an external device can be performed. For this reason, there are the following problems.

If power with a current of 100 mA supplied from an external device is supplied, the voltage of the secondary battery rises and the CPU can be driven. However, after starting up, the CPU must execute a boot program before confirming that the external device is a charger or before communicating with the external device, and the power consumption of the CPU during that time Is larger than the 100 mA current power supplied from the external device, the CPU is reset before confirming that the external device is a charger or before communicating with the external device. For this reason, there is a problem that the CPU cannot be activated indefinitely.
JP 2003-28771 A JP 2003-219561 A JP 2005-339184 A

  The present invention has been made to solve the above-described problems, and one of the objects of the present invention is to provide a portable device that can be activated even when the secondary battery is in an overdischarged state. is there.

  Another object of the present invention is to provide a portable device that can be used at an early stage even if the secondary battery is in an overdischarged state.

  Still another object of the present invention is to provide a starting method capable of starting even when the secondary battery is in an overdischarged state.

  Still another object of the present invention is to provide a start-up method capable of making a secondary battery ready for use at an early stage even when the secondary battery is in an overdischarged state.

According to an aspect of the present invention to achieve the above-described object, the portable device includes an input terminal to which an external device can be connected, a secondary battery that receives a supply of current from the external device connected to the input terminal, Current control means for controlling the current flowing from the input terminal to the secondary battery, detection means for detecting whether or not the external device connected to the input terminal is a specific external device, and a voltage higher than the operating voltage from the secondary battery. A control unit that operates when a voltage is supplied, and an activation unit that starts the control unit when the output voltage of the secondary battery is equal to or higher than the operating voltage. The current control unit applies a voltage to the input terminal. In response, the second current flows from the input terminal to the secondary battery on the condition that a first current is passed from the input terminal to the secondary battery, and the external device connected to the input terminal is detected as a specific external device by the detection means. The battery is greater than the first current To flow the second current, activation means, when the output voltage of the secondary battery is lower than the higher starting voltage than the operating voltage, and that a particular external device connected by the detecting means is not detected, the secondary battery The control means is activated on the condition that the output voltage of the output voltage becomes equal to or higher than the activation voltage .

  According to this aspect, in response to the voltage applied to the input terminal, the first current is passed from the input terminal to the secondary battery, and the external device connected to the input terminal is detected as a specific external device. On the condition that the second current larger than the first current flows from the input terminal to the secondary battery. For this reason, if a specific external device is connected, a second current larger than the first current flows through the secondary battery, so that the output voltage of the secondary battery becomes lower than the operating voltage even if the control means operates. There is no. As a result, a portable device that can be activated even when the secondary battery is in an overdischarged state can be provided. In addition, since the control means is activated as soon as the output voltage of the secondary battery becomes the operating voltage, a portable device that can be put into a usable state early even if the secondary battery is in an overdischarged state is provided. be able to.

According to another aspect of the present invention, a portable device includes an input terminal to which an external device can be connected, a secondary battery that receives a current supply from the external device connected to the input terminal, and a secondary battery from the input terminal. Current control means for controlling the flowing current, detection means for detecting whether or not the external device connected to the input terminal is a specific external device, and when a voltage higher than the operating voltage is supplied from the secondary battery A control means that operates, and an activation means that activates the control means when the output voltage of the secondary battery is equal to or higher than the operating voltage. The current control means is supplied with current from an external device connected to the input terminal. In response to this, a first current is passed from the input terminal to the secondary battery, and the secondary battery is connected from the input terminal on the condition that the external device connected to the input terminal is detected as a specific external device by the detecting means. A second greater than the first current To flow the flow, activation means is lower than the higher starting voltage output voltage than the operating voltage of the secondary battery, and, if the detection means that a particular external device connected not detected, the output of the rechargeable battery The control means is started on the condition that the voltage becomes equal to or higher than the starting voltage .

  According to this aspect, in response to the current supplied from the external device connected to the input terminal, the first current is passed from the input terminal to the secondary battery, and the external device connected to the input terminal is specified. A second current larger than the first current flows from the input terminal to the secondary battery on the condition that the external device is detected. For this reason, if a specific external device is connected, a second current larger than the first current flows through the secondary battery, so that the output voltage of the secondary battery becomes lower than the operating voltage even if the control means operates. There is no. As a result, a portable device that can be activated even when the secondary battery is in an overdischarged state can be provided. In addition, since the control means is activated as soon as the output voltage of the secondary battery becomes the operating voltage, a portable device that can be put into a usable state early even if the secondary battery is in an overdischarged state is provided. be able to.

  Preferably, the detection unit detects whether a specific external device is connected to the input terminal before the control unit is activated by the activation unit.

  According to this aspect, since the value of the current flowing through the secondary battery is increased before power is consumed by the control means, it is possible to avoid a decrease in the output voltage of the secondary battery.

Preferably, the start-up voltage is a voltage at which the voltage of the secondary battery becomes equal to or higher than the operating voltage after the execution of the boot program after the control means is started.

  Preferably, storage means for storing a boot program is further provided, and the control means executes the boot program when activated by the activation means, and the activation voltage is from the activation of the control means to the end of execution of the boot program. The power consumed by the control means and the operating voltage are determined.

  According to this aspect, the start-up voltage is determined so that the output voltage of the secondary battery after being consumed by the control means from the start of the control means until the end of execution of the boot program becomes the operating voltage. The control means can surely execute the boot program.

According to still another aspect of the present invention, the portable device has an input terminal to which an external device can be connected, a secondary battery that receives supply of current from the external device connected to the input terminal, and a memory that stores a boot program And a control means that operates when a voltage higher than the operating voltage is supplied and starts the boot program after startup, and starts the control means when the output voltage of the secondary battery is higher than the startup voltage. And a starting voltage for determining whether the external device connected to the input terminal is a specific external device, and starting the control unit until the control unit finishes executing the boot program. It is determined from the power consumed by the control means and the operating voltage.

According to this aspect, the control means is activated when the output voltage of the secondary battery is equal to or higher than the activation voltage higher than the operating voltage, but the external voltage connected to the input terminal is determined by the specific external device. It is determined whether or not the output voltage of the secondary battery after being consumed by the control means from the start of the control means until the end of execution of the boot program becomes the operating voltage. Can be executed reliably. As a result, a portable device that can be activated even when the secondary battery is in an overdischarged state can be provided.

  Preferably, the control means includes switching means for controlling the current control means after activation to switch the current flowing from the input terminal to the secondary battery from the first current to a second current larger than the first current.

  According to this aspect, the control means controls the current switching means after startup, and switches the current flowing from the input terminal to the secondary battery from the first current to the second current. For this reason, even if the control means operates, it can be avoided that the output voltage of the secondary battery becomes lower than the operating voltage.

  Preferably, the control means is a central processing unit (CPU).

According to still another aspect of the present invention, an activation method includes an input terminal to which an external device can be connected, a secondary battery that receives a current from an external device connected to the input terminal, and an operating voltage from the secondary battery. A current switching method executed by a portable device having a control means that operates when the above voltage is supplied, and whether or not the external device connected to the input terminal is a specific external device. A step of detecting, a step of flowing a first current from the input terminal to the secondary battery in response to a voltage being applied to the input terminal, and an external device connected to the input terminal is detected as a specific external device On the condition that the second current larger than the first current is passed from the input terminal to the secondary battery, the step of starting the control means on the condition that the output voltage of the secondary battery is equal to or higher than the operating voltage, only including, to start step If the output voltage of the secondary battery is lower than the starting voltage higher than the operating voltage and it is not detected that a specific external device is connected in the detecting step, the output voltage of the secondary battery becomes equal to or higher than the starting voltage. as a further condition that, including the step of activating the control means.

  According to this aspect, when a specific external device is connected, a second current larger than the first current flows through the secondary battery. Therefore, even if the control means operates, the output voltage of the secondary battery is lower than the operating voltage. Never become. As a result, it is possible to provide an activation method capable of activating a portable device even when the secondary battery is in an overdischarged state. In addition, since the control means is activated as soon as the output voltage of the secondary battery becomes the operating voltage, the activation method can make the portable device ready for use even if the secondary battery is in an overdischarged state. Can be provided.

According to still another aspect of the present invention, an activation method includes an input terminal to which an external device can be connected, a secondary battery that receives supply of current from the external device connected to the input terminal, and a memory that stores a boot program. And a control means that operates when a voltage equal to or higher than the operating voltage is supplied. A current switching method that is executed in a portable device comprising a secondary battery whose output voltage is higher than the operating voltage. And the step of starting the control means and the step of causing the control means after the boot to execute the boot program on the condition that the start-up voltage is the external device connected to the input terminal is a specific external device It is determined from whether or not there is power, the power consumed by the control means from when the control means is activated until the control means finishes executing the boot program, and the operating voltage.

According to this aspect, the startup voltage is consumed by the control unit whether the external device connected to the input terminal is a specific external device and from the start of the control unit to the end of execution of the boot program. After that, the output voltage of the secondary battery is determined to be the operating voltage, so that the boot program can be surely executed by the control means. As a result, it is possible to provide an activation method capable of activating a portable device even when the secondary battery is in an overdischarged state.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  Hereinafter, a mobile phone will be described as an example of the mobile device. FIG. 1 is a perspective view showing an appearance of a mobile phone according to one embodiment of the present invention. Referring to FIG. 1, mobile phone 1 includes an operation side portion 3 and a display side portion 2. An operation key 14 such as a numeric keypad and a call key and the microphone 13 are disposed on the inner side surface of the operation side portion 3, and a USB connector 51 is disposed on the side surface. A liquid crystal display device (LCD) 16 and a first speaker 11 as a receiver are arranged on the inner side surface of the display side portion 2, and a camera 24 (see FIG. 2) is arranged on the outer side surface opposite to the inner side surface. The A second speaker 12 is disposed on the side surface of the display side portion 2. Although an example in which the mobile phone 1 includes the LCD 16 is shown here, an organic EL (ElectroLuminescence) display may be used instead of the LCD 16. The operation side unit 3 and the display side unit 2 are rotatably connected by a hinge mechanism, and the operation side unit 3 and the display side unit 2 can be opened and closed.

  FIG. 2 is a functional block diagram illustrating an example of functions of the mobile phone according to the present embodiment. Referring to FIG. 2, mobile phone 1 includes a CPU 21 for controlling the entire mobile phone 1, a radio circuit 22 connected to an antenna 22A, and a codec unit 28 for processing audio data. Microphone 13, first speaker 11 and second speaker 12 connected to codec unit 28, camera 24, operation unit 25 that accepts user operation input, vibration unit 26, and card interface (I / F) 27 A display control unit 30 for controlling the display of the LCD 16, a non-volatile memory 31 for storing a program executed by the CPU 21, a volatile memory 32 used as a work area of the CPU 21, and an external device. A USB connector 51 which is a connection terminal to be connected, a USB driver circuit 53, a power supply control unit 35, and a secondary battery 71. , Including the.

  The radio circuit 22 is controlled by the CPU 21 and communicates with the radio base station. Specifically, a radio signal received by the antenna 22 </ b> A is input, and an audio signal obtained by demodulating the radio signal is output to the codec unit 28. The radio circuit 22 receives the audio signal from the codec unit 28 and outputs a radio signal obtained by modulating the audio signal to the antenna 22A. The codec unit 28 decodes the audio signal input from the radio circuit 22, converts the decoded digital audio signal into analog, amplifies it, and outputs it to the first speaker 11 or the second speaker 12. The codec unit 28 receives an analog audio signal from the microphone 13, converts the audio signal to digital, encodes it, and outputs the encoded audio signal to the radio circuit 22.

  The non-volatile memory 31 is a NAND flash memory, and stores a program executed by the CPU 21 and variables for executing the program. Specifically, a boot program and an application program are stored.

  The volatile memory 32 is a synchronous DRAM (Dynamic Random Access Memory), and is used as a work area of the CPU 21.

  The CPU 21 is activated when a reset signal is input from the activation unit 61 described later. After startup, the CPU 21 executes a boot program stored in the nonvolatile memory 31, executes initial settings, and then transfers the application program from the nonvolatile memory 31 to the volatile memory 32. The application program is transferred from the nonvolatile memory 31 to the volatile memory 32 because the access speed of the volatile memory 32 is faster than that of the nonvolatile memory 31. The time until the CPU 21 completes the transfer of the application program from the nonvolatile memory 31 to the volatile memory 32 after activation is referred to as activation time T. When the transfer of the application program to the volatile memory 32 is completed, the CPU 21 can execute the application program. The initial setting is, for example, an input / output port setting.

  The display control unit 30 is controlled by the CPU 21 and controls the LCD 16 in accordance with an instruction input from the CPU 21 to display an image on the LCD 16. The image displayed on the LCD 16 includes a moving image and a still image.

A removable flash memory 27A is attached to the card I / F 27. The CPU 21 can access the flash memory 27A via the card I / F 27. Here, an example in which a program to be executed by the CPU 21 is stored in the nonvolatile memory 31 will be described. However, the program is stored in the flash memory 27A, and the program is read from the flash memory 27A and executed by the CPU 21. You may make it do. The recording medium for storing the program is not limited to the flash memory 27A, but a flexible disk, cassette tape, optical disk (CD-ROM (Compact Disc)
-ROM) / MO (Magnetic Optical Disc) / MD (Mini Disc) / DVD (Digital Versatile Disc)), IC card, optical card, mask ROM (Read Only Memory ROM), EPROM (Erasable Programmable ROM), EPROM (Erasable Programmable ROM) and Programmable ROM)).

  Alternatively, the mobile phone 1 may be connected to the Internet via the wireless circuit 22 and a program may be downloaded from a computer connected to the Internet and executed by the CPU 21. The program here includes not only a program directly executable by the CPU 21 but also a source program, a compressed program, an encrypted program, and the like.

  The camera 24 includes a lens and a photoelectric conversion element such as a CMOS (Complementary Metal Oxide Semiconductor) sensor, and focuses light collected by the lens on a CMOS sensor. The CMOS sensor photoelectrically converts the received light to convert image data. It outputs to CPU21. The camera 24 is controlled by the CPU 21, starts imaging in response to an instruction from the CPU 21, and outputs the obtained still image data or moving image data to the CPU 21. The camera 24 includes an image processing circuit that executes image processing for improving the image quality of photoelectrically converted image data, and an A / D conversion circuit that converts image data from analog to digital. The CPU 21 outputs the still image data or moving image data output from the camera 24 to the display control unit 30 and displays it on the LCD 16 or encodes the still image data or moving image data by the compression encoding method, and the EEPROM 34 or card I / F is stored in the flash memory 27A attached to the F27.

  The operation unit 25 includes an operation key 14 and a lamp 25A. The operation key 14 receives an operation input by the user and outputs the received operation to the CPU 21. The lamp 25A emits light under the control of the CPU 21.

  A charger 200 or a USB device 210 is connected to the USB connector 51. The USB device 210 is an electronic device that includes a USB connector and can be connected to the mobile phone 1 with a USB cable. The USB device 210 here is a device that can supply power to the mobile phone 1 via a USB cable.

  The USB driver circuit 53 is controlled by the CPU 21 and communicates with the USB device 210 connected via the USB connector 51.

  The secondary battery 71 is a lithium ion battery, a nickel metal hydride battery, a nickel cadmium battery, or the like, and supplies power to the entire mobile phone 1.

  The power supply control unit 35 is a device for determining the type of device connected to the USB connector 51, an activation unit 61 for activating the CPU 21, a current control unit 65 for controlling the charging current to the secondary battery 71, and the like. A determination unit 67 and a voltage detection unit 63 for detecting the output voltage of the secondary battery 71 are included.

  The voltage detection unit 63 measures the output voltage of the secondary battery 71 and outputs the output voltage of the secondary battery 71 to the device determination unit 67 and the activation unit 61. The device determination unit 67 determines the type of device connected to the USB connector 51 via a USB cable. Here, the USB connector 51 will be described.

  FIG. 3 is a diagram illustrating an example of the USB connector 51. The USB connector 51 includes five terminals of VBUS, D−, D +, NC, and GND. In the charger 200, the D− terminal and the D + terminal are short-circuited, a voltage of, for example, 5V is applied to the VBUS terminal, and the NC terminal is grounded through a resistance of 200 kΩ. On the other hand, in the USB device 210, a predetermined voltage is applied to the VBUS terminal, the D + terminal and the D- terminal are grounded via a 15 kΩ resistor, and the NC terminal becomes an OPEN (open terminal). When the USB device 210 and the mobile phone 1 are connected by a USB cable, communication signals are transmitted / received using the D + terminal and the D− terminal.

  Returning to FIG. 2, when the device determination unit 67 detects that a voltage of 5 V or more at the VBUS terminal of the USB connector 51 is applied, either the charger 200 or the USB device 210 is connected to the USB connector 51. Detect that. When the output voltage of the secondary battery 71 input from the voltage detection unit 63 reaches a predetermined voltage (detection voltage V3), it is detected whether either the charger 200 or the USB device 210 is connected to the USB connector 51. . If the output voltage of the secondary battery 71 input from the voltage detection unit 63 is lower than the predetermined voltage (detection voltage V3), the device determination unit 67 sets the output voltage of the secondary battery 71 to the predetermined voltage (detection voltage V3). Wait until The detection voltage V3 is the lowest voltage at which the voltage detector 63 can operate.

  Then, when a predetermined voltage is applied to the D + terminal of the USB connector 51, the device determination unit 67 determines whether the D− terminal is the same voltage as the D + terminal or the GND voltage. If the D− terminal has the same voltage as the D + terminal, it is determined that the charger 200 is connected. If the D− terminal is the GND voltage, it is determined that the USB device 210 is connected. When the device determination unit 67 determines that the charger 200 is connected to the USB connector 51, the device determination unit 67 outputs a switching signal to the current control unit 65. In addition, the device determination unit 67 outputs a determination signal indicating whether the charger 200 or the USB device 210 is connected to the USB connector 51 to the current control unit 65.

  Note that it may be determined which of the charger 200 and the USB device 210 is connected to the USB connector 51 using the NC terminal. The NC terminal of the charger 200 is grounded through a 200 kΩ resistor, and the NC terminal of the USB device 210 is OPEN (open terminal). Therefore, when the GND voltage is obtained when the voltage is applied to the NC terminal, it is detected that the charger 200 is connected. When the voltage applied to the NC terminal is detected, the USB device is connected. Is detected.

  When the output voltage of the secondary battery 71 input from the voltage detection unit 63 reaches a predetermined voltage (detection voltage V3), the device determination unit 67 connects the charger 200 or the USB device 210 to the USB connector 51. However, since the device discriminating unit 67 is driven, the USB connector 51 can be driven by the power supplied from the charger 200 or the USB device 210 without receiving power from the secondary battery 71. In such a case, when it is detected that a voltage of 5 V or more is applied to the VBUS terminal of the USB connector 51, it may be detected that the charger 200 or the USB device 210 is connected to the USB connector 51. . In this case, the device can be identified immediately after the charger 200 or the USB device 210 is connected to the USB connector 51.

  The current control unit 65 controls the current of power supplied from the charger 200 or the USB device 210 connected via the USB connector 51. The current control unit 65 is controlled by the CPU 21, but is driven even when the CPU 21 is not operating. When power is supplied from the charger 200 or the USB device 210 connected via the USB connector 51, in other words, when the VBUS terminal becomes +5 V or more, the current control unit 65 supplies a current of 100 mA to the secondary battery. Output. In addition, when a switching signal is input from the CPU 21 or the device determination unit 67, the current control unit 65 outputs a current larger than 100 mA, for example, a current of 500 mA or more to the secondary battery 71.

  The activation unit 61 includes a threshold value changing unit 62. If the determination signal input from the device determination unit 67 indicates that the charger 200 is connected, the threshold value changing unit 62 sets the minimum voltage (operating voltage V1) necessary for operating the CPU 21. Set to threshold. If the determination signal input from the device determination unit 67 indicates that the USB device 210 is connected, the threshold value changing unit 62 uses a predetermined voltage (startup voltage V2) for starting the CPU 21. Set to threshold. The startup voltage V2 is determined by the power consumed by the CPU 21 to execute the boot program and transfer the application program stored in the nonvolatile memory 31 to the volatile memory 32, and the operating voltage V1. Specifically, the start-up voltage V2 is the secondary battery even after the CPU 21 executes the boot program and executes the process of transferring the application program stored in the nonvolatile memory 31 to the volatile memory 32. This is a value at which the output voltage 71 is equal to or higher than the operating voltage V1.

  The starting unit 61 is provided on the condition that the voltage value input from the voltage detecting unit 63 (the value of the output voltage of the secondary battery 71) is equal to or greater than the threshold set by the threshold changing unit 62. Start up. If the voltage value input from the voltage detection unit 63 is less than the threshold value, the process waits until a voltage value equal to or higher than the threshold value is input from the voltage detection unit 63. The activation unit 61 outputs a reset signal to the CPU 21 in order to activate the CPU 21.

  That is, when the charger 200 is connected to the USB connector 51, the activation unit 61 determines that the voltage of the voltage input from the voltage detection unit 63 (the value of the output voltage of the secondary battery) is equal to or higher than the operating voltage V1. Start up. In addition, when the USB device 210 is connected to the USB connector 51, the activation unit 61 determines that the voltage value input from the voltage detection unit 63 (the value of the output voltage of the secondary battery) is equal to or greater than the activation voltage V2. Start up.

  When the reset signal is input, the CPU 21 can execute the boot program and thereafter execute the application program stored in the volatile memory 32. The application program includes a program for controlling the USB driver circuit and communicating with the USB device 210 connected to the USB connector 51 and a program for controlling the power supply control unit 55. When a USB device is connected to the USB connector 51, the CPU 21 communicates with the USB device 210 and negotiates, and then outputs a switching signal to the current control unit 65.

  FIG. 4 is a flowchart illustrating an example of a flow of activation processing executed by the CPU. The activation process is a process executed by the CPU 21 in response to a reset signal input from the activation unit 61. Referring to FIG. 4, when a reset signal is input, CPU 21 executes a boot program stored in nonvolatile memory 31 (step S01). The boot program includes a process of transferring an application program stored in the nonvolatile memory 31 to the volatile memory 32 in addition to the process of setting the input / output port.

  Then, the connected device is detected (step S02). It communicates with the power supply control unit 55 and causes the device determination unit 67 of the power supply control unit 55 to detect the connected device. Then, it is determined whether or not the connected device is the charger 200 (step S03). If the charger 200 is connected to the USB connector 51, the process is completed, but if not, the process proceeds to step S04 if the USB device 210 is connected to the USB connector 51.

  In step S04, the USB driver circuit 53 is controlled to communicate with the USB device 210 and negotiate to output a power of 500 mA to the USB device 210. Then, the current value is switched (step S05). Specifically, it communicates with the power supply control unit 55 and outputs a switching signal to the current control unit 65. As a result, a power of 500 mA is supplied to the secondary battery 71.

  FIG. 5 is a first diagram illustrating an example of the transition of the output voltage of the secondary battery. FIG. 5 shows the transition of the output voltage of the secondary battery 71 when the charger 200 is connected to the USB connector 51. At time t0 immediately after the charger 200 is connected to the USB connector 51, the output voltage of the secondary battery 71 is an overdischarged voltage. When the charger 200 is connected to the USB connector 51, power of 100 mA current is supplied from the charger 200 to the secondary battery 71, so that the output voltage gradually increases.

  When the output voltage becomes the detection voltage V3 (time t1), it is detected by the device determination unit 67 that the charger 200 is connected, and the current control unit 65 supplies a power of 500 mA to the secondary battery 71. The For this reason, the output voltage of the secondary battery 71 increases rapidly.

  Then, when the output voltage becomes the operating voltage V1 (time t2), the CPU 21 is activated by the activation unit 61. Since a part of the power supplied from the charger 200 is consumed by the CPU 21, the increasing tendency of the output power of the secondary battery 71 decreases. However, since the power of the current of 500 mA is larger than the power consumed when the CPU 21 operates, the remaining power excluding the power consumed by the CPU 111 is supplied to the secondary battery 71 and the output of the secondary battery 71 The voltage increases. In the CPU 21, the time t3 when the boot time for executing the boot program elapses is defined as time t3.

  FIG. 6 is a second diagram illustrating an example of the transition of the output voltage of the secondary battery. FIG. 6 shows the transition of the output voltage of the secondary battery 71 when the USB device 210 is connected to the USB connector 51. At time t0 immediately after the USB device 210 is connected to the USB connector 51, the output voltage of the secondary battery 71 is an overdischarged voltage. Since electric power with a current of 100 mA is supplied from the charger 200 to the secondary battery 71, the output voltage gradually increases.

  When the output voltage becomes the detection voltage V3 (time t1), the device determination unit 67 detects that the USB 200 is connected, but the current control unit 65 supplies the secondary battery 71 with a power of 100 mA. Will continue.

  When the output voltage becomes the starting voltage V2 higher than the operating voltage V1 (time t4), the starting unit 61 starts the CPU 21. Since the power of 100 mA current supplied from the USB device 210 is smaller than the power consumed when the CPU 21 operates, the secondary battery 71 is discharged, and the output voltage decreases. However, after the CPU 21 executes the boot program (time t5), the output voltage of the secondary battery 71 is higher than the operating voltage V1. Even after the CPU 21 executes the boot program and executes the process of transferring the application program stored in the non-volatile memory 31 to the volatile memory 32, the output voltage of the secondary battery 71 is the starting voltage V2. This is because the value is equal to or higher than the operating voltage V1. Therefore, the CPU 21 can execute the boot program without shutting down while the boot program is being executed (startup time T1).

  After executing the boot program (after time t5), the CPU 21 executes the application program, communicates with the USB device 210, negotiates, and then outputs a switching signal to the current control unit 65. As a result, a current of 500 mA is supplied to the secondary battery 71 in the current control unit 65. Although a part of the power supplied from the USB device 210 is consumed by the CPU 21, the power of the current of 500 mA is larger than the power consumed when the CPU 21 operates, so the output power of the secondary battery 71 is Will increase. In the CPU 21, when the startup time T1 for executing the boot program elapses, it is time t5.

  When the charger 200 is connected, the CPU 21 can execute the application program at a time t3 (see FIG. 5) when the USB device 210 is connected to the USB connector 51. Earlier than time t5 (see FIG. 6). For this reason, it is possible to make the mobile phone 1 usable by connecting the charger 200 earlier than connecting the USB device 210.

  As described above, the mobile phone 1 according to the present embodiment detects whether or not the charger 200 is connected to the USB connector 51 in response to the voltage applied to the USB connector 51, and from the USB connector 51. A second current is passed from the USB connector 51 to the secondary battery 71 on condition that a first current is passed through the secondary battery 71 and it is detected that the charger 200 is connected to the USB connector 51. For this reason, when the charger 200 is connected to the USB connector 51, a second current larger than the first current flows through the secondary battery 71. Therefore, even if the CPU 21 operates, the output voltage of the secondary battery 71 is higher than the operating voltage. It will not be lowered. Therefore, the mobile phone 1 can be activated even when the secondary battery 71 is in an overdischarged state. In addition, since the CPU 21 is activated as soon as the output voltage of the secondary battery 71 becomes the operating voltage, the mobile phone 1 can be brought into a usable state early even if the secondary battery 71 is in an overdischarged state.

  In addition, since the value of the current flowing through the secondary battery 71 is increased before the CPU 21 is activated and power is consumed, it is possible to avoid a decrease in the output voltage of the secondary battery 71.

  Furthermore, when the output voltage of the secondary battery 71 is lower than the starting voltage and it is not detected that the charger 200 is connected to the USB connector 51, the output voltage of the secondary battery 71 is equal to or higher than the starting voltage. Further, the CPU 21 is activated as a condition. Since the starting voltage is determined so that the output voltage of the secondary battery 71 after being consumed by the CPU 21 from the start of the CPU 21 to the end of execution of the boot program becomes the operating voltage, the boot program is stored in the CPU 21. It can be executed reliably.

<Modification>
FIG. 7 is a functional block diagram illustrating an example of functions of the mobile phone according to the modification. Referring to FIG. 7, the difference from the functional block diagram shown in FIG. 2 is that device discriminating unit 67 is deleted and activation unit 61 </ b> A does not have threshold changing unit 62. In the mobile phone 1 according to the modified example, before the CPU 21 becomes operable, the current control unit 65 detects that a voltage of +5 V or more is applied to VBUS of the USB connector 51, so that the charger 200 is connected to the USB connector 51. Alternatively, it can be detected that one of the USB devices 210 is connected. However, it cannot be detected whether the charger 200 or the USB device 210 is connected to the USB connector 51.

  When the current control unit 65 detects that VBUS of the USB connector 51 has become high, it outputs a connection signal to the activation unit 61A. The connection signal is a signal indicating that either the charger 200 or the USB device 210 is connected to the USB connector 51.

  When the connection signal is input, the activation unit 61A activates the CPU 21 on the condition that the voltage value (output voltage value of the secondary battery) input from the voltage detection unit 63 is equal to or higher than the activation voltage V2. . If the voltage value input from the voltage detection unit 63 is less than the startup voltage V2, the process waits until a voltage value equal to or higher than the startup voltage V2 is input from the voltage detection unit 63. The starting unit 61 </ b> A outputs a reset signal to the CPU 21 in order to start the CPU 21.

  Since the mobile phone 1 according to the modification cannot detect which of the charger 200 and the USB device 210 is connected to the USB connector 51, when one of them is connected, the output voltage of the secondary battery 71 is It waits until it becomes more than the starting voltage V2, and when the output voltage of the secondary battery 71 becomes more than the starting voltage V2, CPU21 will be started.

  The activation process executed by the CPU 21 in the modification is the same as that shown in FIG. Further, the transition of the output voltage of the secondary battery 71 in the mobile phone 1 in the modification is the same as that shown in FIG.

  As described above, the mobile phone 1 according to the modification activates the CPU 21 on the condition that the output voltage of the secondary battery 71 is equal to or higher than the activation voltage higher than the operating voltage. For this reason, the activation voltage is determined so that the output voltage of the secondary battery 71 after being consumed by the CPU 21 after the activation of the CPU 21 until the end of execution of the boot program becomes the operating voltage. The boot program can be executed reliably. Therefore, the mobile phone 1 can be activated even when the secondary battery is in an overdischarged state.

  Further, since the CPU 21 controls the current control unit 65 after activation and switches the current flowing from the USB connector 51 to the secondary battery 71 from the first current to the second current, the secondary battery 71 is operated even when the CPU 21 operates. It can be avoided that the output voltage of the output voltage becomes lower than the operating voltage.

  In the present embodiment, the current control unit 65 is configured to output a current of 100 mA to the secondary battery 71 when the VBUS terminal becomes +5 V or more. However, the charger connected via the USB connector 51 When it is detected that a current is supplied from 200 or the USB device 210, a current of 100 mA may be output to the secondary battery.

  In the above-described embodiment, the mobile phone 1 is described as an example of the mobile device. However, as long as the electronic device is driven by the secondary battery 71, for example, a car navigation system, a mobile TV, and a mobile DVD player. Etc. can be applied. Needless to say, the invention can be understood as a startup method for executing the processing executed by the power supply control unit 55 and the CPU 21.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

<Appendix>
(1) The start voltage is a voltage at which the voltage of the secondary battery becomes equal to or higher than the operating voltage after the execution of the boot program is ended after the control unit is started. Mobile devices.

It is a perspective view which shows the external appearance of the mobile telephone in one of embodiment of this invention. It is a functional block diagram which shows an example of the function of the mobile telephone in this Embodiment. It is a figure which shows an example of a USB connector. It is a flowchart which shows an example of the flow of the starting process performed with CPU. It is a 1st figure which shows an example of transition of the output voltage of a secondary battery. It is a 2nd figure which shows an example of transition of the output voltage of a secondary battery. It is a functional block diagram which shows an example of the function of the mobile telephone in a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Mobile phone, 2 Display side part, 3 Operation side part, 11 1st speaker, 12 2nd speaker, 13 Microphone, 14 Operation key, 21 CPU, 22 Wireless circuit, 22A Antenna, 24 Camera, 25 Operation part, 25A Lamp , 26 vibration unit, 27 card I / F, 27A flash memory, 28 codec unit, 30 display control unit, 31 nonvolatile memory, 32 volatile memory, 35 power supply control unit, 51 USB connector, 53 USB driver circuit, 55 power supply Control unit, 61, 61A Start unit, 62 Threshold change unit, 63 Voltage detection unit, 65 Current control unit, 67 Device discrimination unit, 71 Secondary battery, 200 Charger, 210 USB device.

Claims (10)

An input terminal to which an external device can be connected;
A secondary battery that receives a supply of current from an external device connected to the input terminal;
Current control means for controlling current flowing from the input terminal to the secondary battery;
Detecting means for detecting whether or not the external device connected to the input terminal is a specific external device;
Control means that operates when a voltage higher than the operating voltage is supplied from the secondary battery;
Starting means for starting the control means when the output voltage of the secondary battery is equal to or higher than the operating voltage,
The current control means causes a first current to flow from the input terminal to the secondary battery in response to a voltage applied to the input terminal, and an external device connected to the input terminal by the detection means A second current larger than the first current is passed from the input terminal to the secondary battery on the condition that it is detected as a specific external device,
If the output voltage of the secondary battery is lower than the start voltage higher than the operating voltage and the detection means does not detect that the specific external device is connected, the starter means A portable device that activates the control means on the condition that the output voltage becomes equal to or higher than the activation voltage. An input terminal to which an external device can be connected;
A secondary battery that receives a supply of current from an external device connected to the input terminal;
Current control means for controlling current flowing from the input terminal to the secondary battery;
Detecting means for detecting whether or not the external device connected to the input terminal is a specific external device;
Control means that operates when a voltage higher than the operating voltage is supplied from the secondary battery;
Starting means for starting the control means when the output voltage of the secondary battery is equal to or higher than the operating voltage,
The current control means causes a first current to flow from the input terminal to the secondary battery in response to a current supplied from an external device connected to the input terminal, and is connected to the input terminal by the detection means. On the condition that the external device is detected as the specific external device, a second current larger than the first current is passed from the input terminal to the secondary battery,
If the output voltage of the secondary battery is lower than the start voltage higher than the operating voltage and the detection means does not detect that the specific external device is connected, the starter means A portable device that activates the control means on the condition that the output voltage becomes equal to or higher than the activation voltage.   The portable device according to claim 1, wherein the detection unit detects whether the specific external device is connected to the input terminal before the control unit is activated by the activation unit.   The start voltage is a voltage at which the voltage of the secondary battery becomes equal to or higher than the operating voltage after the execution of the boot program is ended after the control means is started. Mobile devices. A storage means for storing a boot program;
The control means executes the boot program when activated by the activation means,
5. The startup voltage is determined from the power consumed by the control unit and the operating voltage from the start of the control unit to the end of execution of the boot program. 6. Mobile devices. An input terminal to which an external device can be connected;
A secondary battery that receives a supply of current from an external device connected to the input terminal;
Storage means for storing a boot program;
Control means that operates when a voltage equal to or higher than the operating voltage is supplied, and executes the boot program after startup,
Starting means for starting the control means when the output voltage of the secondary battery is higher than the starting voltage higher than the operating voltage,
The activation voltage is determined by whether the external device connected to the input terminal is a specific external device, and after the control unit is activated until the control unit finishes executing the boot program. The portable device is determined from the power consumed by and the operating voltage.   The control means includes switching means for controlling the current control means after activation to switch the current flowing from the input terminal to the secondary battery from the first current to a second current larger than the first current. The portable device according to claim 6.   The portable device according to claim 1, wherein the control means is a central processing unit (CPU). An input terminal to which an external device can be connected;
A secondary battery that receives a supply of current from an external device connected to the input terminal;
A control means that operates when a voltage equal to or higher than an operating voltage is supplied from the secondary battery, and a current switching method that is executed in a portable device comprising:
Detecting whether an external device connected to the input terminal is a specific external device; and
Flowing a first current from the input terminal to the secondary battery in response to a voltage being applied to the input terminal;
Passing a second current larger than the first current from the input terminal to the secondary battery on the condition that an external device connected to the input terminal is detected as the specific external device;
Starting the control means on the condition that the output voltage of the secondary battery is equal to or higher than the operating voltage,
In the starting step, when the output voltage of the secondary battery is lower than the starting voltage higher than the operating voltage and it is not detected that the specific external device is connected in the detecting step, the secondary battery An activation method comprising a step of activating the control means on the condition that the output voltage of the battery is equal to or higher than the activation voltage. An input terminal to which an external device can be connected;
A secondary battery that receives a supply of current from an external device connected to the input terminal;
Storage means for storing a boot program;
A control means that operates when a voltage equal to or higher than the operating voltage is supplied, and a current switching method that is executed in a portable device comprising:
Activating the control means on condition that the output voltage of the secondary battery is equal to or higher than the activation voltage higher than the operating voltage;
Including causing the control means after startup to execute the boot program,
The activation voltage is determined by whether the external device connected to the input terminal is a specific external device, and after the control unit is activated until the control unit finishes executing the boot program. The starting method is determined from the power consumed by and the operating voltage.

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