Notebook computer

Abstract

To enable a failure of a device to be prevented.SOLUTION: A notebook computer 10 includes a sensor 11, a connector 13, a switching circuit 12, an electric charge removing circuit 16, and a processing unit 17. The sensor 11 senses a human body. A first power supply source is connected to the connector 13. The switching circuit 12 is connected between a power supply path from a second power supply source 14 to a power supply destination 15 and the connector 13, and interrupts a current from the second power supply source 14 to the connector 13 when power is supplied from the second power supply source 14 to the power supply destination 15. The switching circuit 12 feeds a current from the first power supply source to the power supply destination 15 when the first power supply source is connected to the connector 13. The electric charge removing circuit 16 is connected to the switching circuit 12, and when receiving a signal, a current caused by electric charges accumulated in the switching circuit 12 flows therethrough. The processing unit 17 outputs a signal to the electric charge removing circuit 16 when the sensor 11 senses the human body.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a notebook computer. [Background technology]

[0002] Devices such as notebook PCs (Personal Computers) and tablet terminals have multiple power supply sources such as internal batteries, AC (Alternating Current) adapters, etc. When a device has multiple power supply sources, the device performs control to cut off the power supply path so that current does not flow from a power supply source that is supplying power to another power supply source that is not supplying power.

[0003] One technology proposed for notebook PC power is a power management device that determines in advance which conference rooms are likely to be battery-powered and notifies conference participants before the meeting to charge their batteries. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-186738 A Summary of the Invention [Problem to be solved by the invention]

[0005] The power supply path is controlled, for example, by switching a field effect transistor (FET) on and off. In this case, residual charge in the FET may shorten the time it takes for the FET to turn on, causing a large rush current. A large rush current may cause equipment failure.

[0006] In one aspect, the present invention aims to prevent device failure. [Means for solving the problem]

[0007] In one proposal, a notebook computer is provided that has a sensor, a connector, a switch circuit, a charge removal circuit, and a processing unit. The sensor detects a human body. A first power supply source is connected to the connector. The switch circuit is connected between the connector and a power supply path from the second power supply source to the power supply destination, and when power is supplied from the second power supply source to the power supply destination, the switch circuit cuts off a current from the second power supply source to the connector, and when the first power supply source is connected to the connector, the switch circuit passes current from the first power supply source to the power supply destination. The charge removal circuit is connected to the switch circuit, and when a signal is received, a current due to the charge accumulated in the switch circuit flows. When the sensor detects a human body, the processing unit outputs a signal to the charge removal circuit. Effect of the Invention

[0008] According to one aspect, breakdown of the device can be prevented. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an example of a notebook computer according to a first embodiment. [Diagram 2] FIG. 1 is a diagram illustrating an example of a hardware configuration of a notebook PC. [Diagram 3] FIG. 13 illustrates an example of a circuit according to a second embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a control signal in a circuit. [Diagram 5] FIG. 2 is a block diagram showing an example of functions of a notebook PC. [Figure 6] FIG. 1 is a diagram showing an example of the appearance of a notebook PC. [Figure 7] 10 is a flowchart illustrating an example of a procedure for a power supply control process. [Figure 8] FIG. 13 is a diagram showing an example of a timing chart when a charge removing circuit is not applied. [Figure 9] FIG. 13 is a diagram showing an example of a timing chart when a charge removing circuit is applied. [Figure 10]FIG. 13 is a diagram illustrating an example of a circuit according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the present embodiment will be described with reference to the drawings. Note that each embodiment can be implemented in combination with a plurality of other embodiments as long as no contradiction occurs. First Embodiment First, a first embodiment will be described. The first embodiment is for removing electric charge accumulated in a switch circuit that controls a power supply path.

[0011] 1 is a diagram showing an example of a notebook computer according to a first embodiment. The notebook computer 10 is a portable notebook computer. The notebook computer 10 includes a sensor 11, a switch circuit 12, a connector 13, a second power supply source 14, a power supply destination 15, a charge removal circuit 16, and a processing unit 17.

[0012] The sensor 11 is a sensor that detects a human body. For example, the sensor 11 is a SAR (Specific Absorption Rate) sensor. The switch circuit 12 is a circuit that controls a power supply path. For example, the switch circuit 12 is a switching device having two FETs in a back-to-back configuration and a controller that controls the on and off of the two FETs.

[0013] The switch circuit 12 is connected between the connector 13 and a power supply path from the second power supply source 14 to the power supply destination 15. The switch circuit 12 cuts off a current from the second power supply source 14 to the connector 13 when power is supplied from the second power supply source 14 to the power supply destination 15. Furthermore, when the first power supply source is connected to the connector 13, the switch circuit 12 passes current from the first power supply source to the power supply destination 15. For example, the switch circuit 12 cuts off the current from the second power supply source 14 to the connector 13 and passes current from the first power supply source to the power supply destination 15 by switching an FET between on and off.

[0014] The connector 13 is a connector for connecting to a first power supply source. For example, the first power supply source is a commercial power source connected via an AC adapter, and the connector 13 is a connector to which the AC adapter can be connected. Also, for example, the first power supply source is a USB (Universal Serial Bus) Type C device capable of supplying power, and the connector 13 is a USB Type C connector. The second power supply source 14 is a power supply source mounted on the notebook computer 10. For example, the second power supply source 14 is a battery of the notebook computer 10.

[0015] The power supply destination 15 is a device that operates using power provided by the notebook computer 10. The power supply destination 15 is, for example, hardware such as a processor, a memory, a storage device, etc. provided by the notebook computer 10. The power supply destination 15 may also include the sensor 11 and the processing unit 17.

[0016] The charge removal circuit 16 is connected to the switch circuit 12, and upon receiving a signal, a current flows due to the charge accumulated in the switch circuit 12. For example, the charge removal circuit 16 is a circuit including a FET having a source connected to GND, a drain connected to the FET of the switch circuit 12, and a gate connected to the processing unit 17.

[0017] The processing unit 17 is a controller that controls the charge removing circuit 16. The processing unit 17 is, for example, a PMU (Power Management Unit) of the notebook computer 10. When the sensor 11 detects a human body, the processing unit 17 outputs a signal to the charge removing circuit 16. For example, when the processing unit 17 is notified by the sensor 11 that a human body has been detected, the processing unit 17 determines whether or not a first power supply source is connected to the connector 13. Then, when the first power supply source is not connected to the connector 13, the processing unit 17 outputs a one-shot signal.

[0018] According to the first embodiment, the sensor 11 detects a human body. The connector 13 is connected to a first power supply source. The switch circuit 12 is connected between the connector 13 and a power supply path from the second power supply source 14 to the power supply destination 15, and cuts off a current from the second power supply source 14 to the connector 13 when power is supplied from the second power supply source 14 to the power supply destination 15. When the first power supply source is connected to the connector 13, the switch circuit 12 passes current from the first power supply source to the power supply destination 15. The charge removal circuit 16 is connected to the switch circuit 12, and when a signal is received, a current due to the charge accumulated in the switch circuit 12 flows. When the sensor 11 detects a human body, the processing unit 17 outputs a signal to the charge removal circuit 16.

[0019] As a result, when the user attempts to connect the first power supply source, the notebook computer 10 can cause the charge removal circuit 16 to remove the charge accumulated in the switch circuit 12. The notebook computer 10 can prevent a large rush current from occurring by removing the charge remaining in the FET before the first power supply source is connected. Therefore, the notebook computer 10 can prevent the device from breaking down.

[0020] Furthermore, the processor 17 outputs a signal when the first power supply source is not connected to the connector 13. This allows the notebook computer 10 to reduce power consumption by not outputting unnecessary signals.

[0021] When the sensor 11 detects a human body, the processing unit 17 outputs a one-shot signal to the charge removing circuit 16. This allows the notebook computer 10 to reduce power consumption by shortening the signal output time.

[0022] Moreover, the switch circuit 12 switches the FET between on and off to cut off the current from the second power supply source 14 to the connector 13 and to pass current from the first power supply source to the power supply destination 15. This allows the notebook computer 10 to easily control the current path.

[0023] The notebook computer 10 may have a first housing in which a monitor is installed and a second housing in which a keyboard is installed. The connector 13 may be installed on the right or left side of the second housing as viewed from the front of the monitor, and the sensor 11 may be installed on the side opposite to the side on which the connector 13 is installed as viewed from the front of the monitor. This allows the notebook computer 10 to efficiently detect a user who is attempting to connect the first power supply source.

[0024] Second Embodiment Next, a second embodiment will be described below. The second embodiment is for removing electric charge accumulated in a switching device that controls the path of power supplied from an AC adapter and a battery to a notebook PC.

[0025] When an AC adapter is connected to a laptop PC, it receives power from a commercial power source via the AC adapter. The laptop PC also charges its built-in battery with the power supplied via the AC adapter, and receives power from the battery when the AC adapter is not connected. The laptop PC's switching device cuts off the power supply path when power is being supplied from the battery, preventing current from flowing to the connector to which the AC adapter is connected.

[0026] The switching device controls the power supply path by switching the FET on and off. For example, the switching device turns the FET off to cut off the current when the AC adapter is not connected, and turns the FET on to allow current to flow when the AC adapter is connected.

[0027] If charge remains in the FET of the switching device, the time it takes for the FET to turn on when the AC adapter is connected is shortened. This causes the voltage across the FET to rise in a short period of time, resulting in a large rush current. In the second embodiment, the notebook PC uses a SAR sensor to detect when a user attempts to connect an AC adapter, and removes the charge that has accumulated in the switching device before the AC adapter is connected.

[0028] FIG. 2 is a diagram showing an example of the hardware configuration of a notebook PC. Notebook PC 100 is a portable notebook computer. Notebook PC 100 is entirely controlled by processor 101. Memory 102 and multiple peripheral devices are connected to processor 101 via bus 111. Processor 101 may be a multiprocessor. Processor 101 is, for example, a central processing unit (CPU), a micro processing unit (MPU), or a digital signal processor (DSP). At least a part of the functions realized by processor 101 executing a program may be realized by an electronic circuit such as an application specific integrated circuit (ASIC) or a programmable logic device (PLD).

[0029] The memory 102 is used as a main storage device of the notebook PC 100. The memory 102 temporarily stores at least a part of the OS (Operating System) program and application programs to be executed by the processor 101. The memory 102 also stores various data used in the processing by the processor 101. As the memory 102, for example, a volatile semiconductor storage device such as a RAM (Random Access Memory) is used.

[0030] The peripheral devices connected to the bus 111 include a storage device 103, a GPU (Graphics Processing Unit) 104, an input interface 105, an optical drive device 106, and a device connection interface 107. The peripheral devices connected to the bus 111 also include a PMU 108, an SAR sensor 109, and a network interface 110.

[0031] The storage device 103 electrically or magnetically writes and reads data to and from a built-in recording medium. The storage device 103 is used as an auxiliary storage device for a computer. The storage device 103 stores an OS program, application programs, and various data. Note that, for example, a hard disk drive (HDD) or a solid state drive (SSD) can be used as the storage device 103.

[0032] The GPU 104 is connected to a monitor 21. The GPU 104 displays an image on the screen of the monitor 21 in accordance with an instruction from the processor 101. The monitor 21 may be a display device using an organic EL (Electro Luminescence) display device, a liquid crystal display device, or the like.

[0033] The input interface 105 is connected to the keyboard 22 and the touchpad 23. The input interface 105 transmits signals sent from the keyboard 22 and the touchpad 23 to the processor 101. Note that the touchpad 23 is an example of a pointing device, and other pointing devices can also be used. Examples of other pointing devices include a mouse, a touch panel, a tablet, and a trackball.

[0034] The optical drive device 106 uses a laser beam or the like to read data recorded on the optical disc 24. The optical disc 24 is a portable recording medium on which data is recorded so that it can be read by reflection of light. The optical disc 24 includes a DVD (Digital Versatile Disc), a DVD-RAM, a CD-ROM (Compact Disc Read Only Memory), a CD-R (Recordable) / RW (ReWritable), etc.

[0035] The device connection interface 107 is a communication interface for connecting peripheral devices to the notebook PC 100. For example, a memory device 25 or a memory reader / writer 26 can be connected to the device connection interface 107. The memory device 25 is a recording medium equipped with a function for communicating with the device connection interface 107. The memory reader / writer 26 is a device for writing data to the memory card 27 or reading data from the memory card 27. The memory card 27 is a card-type recording medium.

[0036] The PMU 108 includes a processor 108a, a RAM 108b, and a ROM 108c. The processor 108a loads firmware (control software) stored in the ROM 108c into the RAM 108b, and executes processing according to the firmware. The processor 108a is, for example, a CPU, an MPU, or a DSP. At least a part of the functions realized by the processor 108a executing a program may be realized by an electronic circuit such as an ASIC or a PLD.

[0037] The RAM 108b is a volatile semiconductor storage device used as a main storage device of the PMU 108. The RAM 108b temporarily stores at least a part of the program to be executed by the processor 108a. The RAM 108b also stores various data used in the processing by the processor 108a.

[0038] The ROM 108c is a non-volatile semiconductor storage device that stores firmware. As the ROM 108c, an EPROM (Erasable Programmable Read Only Memory) or an EEPROM (Electrically Erasable Programmable Read-Only Memory) can be used.

[0039] The SAR sensor 109 is a sensor that detects a human body by detecting the amount of electromagnetic waves absorbed by the human body. When the SAR sensor 109 detects a human body, it notifies the processor 101 and the PMU 108.

[0040] The network interface 110 is connected to a network 20. The network interface 110 transmits and receives data via the network 20 to and from other computers or communication devices.

[0041] The notebook PC 100 can realize the processing function of the second embodiment by the above hardware configuration. The notebook computer 10 shown in the first embodiment can also be realized by the same hardware as the notebook PC 100 shown in FIG. 2. The PMU 108 is an example of the processing unit 17 shown in the first embodiment. The SAR sensor 109 is an example of the sensor 11 shown in the first embodiment.

[0042] The notebook PC 100 executes a program recorded in, for example, a computer-readable recording medium to realize the processing function of the second embodiment. The program describing the processing contents to be executed by the notebook PC 100 can be recorded in various recording media. For example, the program to be executed by the notebook PC 100 can be stored in the ROM 108c. The processor 108a loads at least a part of the program in the ROM 108c into the RAM 108b and executes the program. The program to be executed by the notebook PC 100 can also be recorded in a portable recording medium such as the optical disk 24, the memory device 25, or the memory card 27. The program stored in the portable recording medium can be installed in the ROM 108c under the control of, for example, the processor 101 and then executed. The processor 108a can also read and execute the program directly from the portable recording medium. Next, a circuit for controlling the power supply path will be described.

[0043] Fig. 3 is a diagram showing an example of a circuit according to the second embodiment. In the second embodiment, a power supply path is controlled by the circuit shown in Fig. 3. The circuit according to the second embodiment includes an AC connector 31, a switching device 32, a charger 33, a switch (SW) 34, a battery 35, a system circuit 36, and a PD (Power Delivery) controller (PD Cont) 37. The circuit according to the second embodiment also includes a charge removing circuit 38, a PMU 108, and a SAR sensor 109.

[0044] The AC connector 31 is an example of the connector 13 shown in the first embodiment. The switching device 32 is an example of the switch circuit 12 shown in the first embodiment. The battery 35 is an example of the second power supply source 14 shown in the first embodiment. The system circuit 36 ​​is an example of the power supply destination 15 shown in the first embodiment.

[0045] The AC connector 31 is a connector to which an AC adapter is connected. The AC connector 31 is connected to the switching device 32 and the PD controller 37. When a commercial power source is connected to the AC connector 31 via the AC adapter, a current from the commercial power source converted to direct current by the AC adapter flows to the switching device 32. Note that, hereinafter, connecting the commercial power source to the AC connector 31 via the AC adapter may be referred to as connecting the AC adapter to the AC connector 31. The commercial power source is an example of the first power supply source described in the first embodiment.

[0046] Furthermore, the PD controller 37 detects whether an AC adapter is connected to the AC connector 31 and whether an AC adapter has been connected to the AC connector 31. A capacitor C100 is connected to a branch between the AC connector 31 and the switching device 32. The capacitor C100 is connected to GND and removes noise from the current flowing from the AC connector 31.

[0047] The switching device 32 controls a path of current from the AC connector 31 and the battery 35. The switching device 32 is connected to the AC connector 31, the charger 33, and the PD controller 37. The switching device 32 includes FETs 32a and 32b and a switch controller (SW Cont) 32c.

[0048] The FETs 32a and 32b are N-channel MOS (Metal Oxide Semiconductor) FETs having a drain (D), a source (S), and a gate (G). In an N-channel MOSFET, a current flows between the drain and the source when a voltage is applied between the gate and the source. In an N-channel MOSFET, a current may flow from the source to the drain due to a body diode even when no voltage is applied between the gate and the source. A P-channel MOSFET may be used as the FETs 32a and 32b.

[0049] The FETs 32a and 32b have a back-to-back configuration in which their sources are connected to each other. The drain of the FET 32a is connected to the AC connector 31. The drain of the FET 32b is connected to the charger 33. The gates of the FETs 32a and 32b are connected to the switch controller 32c.

[0050] When no voltage is applied between the gates and sources of the FETs 32a and 32b, the FETs 32a and 32b are in an OFF state in which a current from the drain to the source of the FETs 32a and 32b is blocked. When the FETs 32a and 32b are in an OFF state, they block the current flowing from the battery 35 via the charger 33 so that it does not flow to the AC connector 31. When a voltage is applied between the gates and sources of the FETs 32a and 32b, the FETs 32a and 32b are in an ON state in which current flows between the drains and sources of the FETs 32a and 32b. When the FETs 32a and 32b are in an ON state, they allow the current from the AC connector 31 to flow to the system circuit 36 ​​via the switching device 32 and the charger 33.

[0051] The switch controller 32c controls the FETs 32a and 32b in accordance with the PD controller 37. The switch controller 32c is connected to the gates of the FETs 32a and 32b and the PD controller 37. When an AC adapter is connected to the AC connector 31, the switch controller 32c outputs a signal to the gates of the FETs 32a and 32b so that a voltage is applied between the gate and source of the FETs 32a and 32b. A capacitor C200 is connected to a branch between the switching device 32 and the charger 33. The capacitor C200 is connected to GND.

[0052] The charger 33 charges the battery 35 with a current flowing from the AC connector 31 via the switching device 32. The charger 33 charges the battery 35 when the charger 33 and the battery 35 are connected by the switch 34. The current flowing from the AC connector 31 via the switching device 32 also flows to the system circuit 36 ​​via the charger 33.

[0053] The switch 34 switches the connection destination of the battery 35 depending on the power supply source to the system circuit 36. When an AC adapter is not connected to the AC connector 31, the switch 34 connects the battery 35 to the system circuit 36. When an AC adapter is not connected to the AC connector 31, the switch 34 connects the charger 33 to the battery 35.

[0054] The battery 35 is charged by a commercial power source via an AC adapter, and supplies power to the system circuit 36 ​​when the AC adapter is not connected to the AC connector 31. The battery 35 is connected to the switch 34 and GND. The battery 35 is charged by the charger 33 when the charger 33 and the battery 35 are connected to each other by the switch 34. Moreover, the battery 35 supplies power to the system circuit 36 ​​when the battery 35 and the system circuit 36 ​​are connected to each other by the switch 34.

[0055] The system circuit 36 ​​is a circuit that operates by power supplied from a commercial power source via an AC adapter or from a battery 35. The system circuit 36 ​​includes hardware of the notebook PC 100, such as a processor 101, a memory 102, and a storage device 103. Note that capacitors C1, C2, ..., Cx in Fig. 3 indicate capacitor components of each piece of hardware included in the system circuit 36, and the parts that use power are connected in parallel to each capacitor.

[0056] The PD controller 37 controls the switching device 32 according to whether or not an AC adapter is connected to the AC connector 31 in accordance with the PMU 108. The PD controller 37 is connected to the AC connector 31, the switch controller 32c, and the PMU 108. The PD controller 37 detects whether or not an AC adapter is connected to the AC connector 31 and whether or not an AC adapter has been connected to the AC connector 31, and notifies the PMU 108 of the detection result. When an AC adapter is connected to the AC connector 31, the PD controller 37 causes the switch controller 32c to output a signal to the gates of the FETs 32a and 32b.

[0057] The charge removal circuit 38 is a circuit that removes the charge accumulated in the switching device 32. The charge removal circuit 38 is connected to the drain of the FET 32a and the PMU 108. The charge removal circuit 38 includes a resistor R1, a FET 38a, and GND. The resistor R1 is a resistor that adjusts the magnitude of the current flowing through the charge removal circuit 38. The resistor R1 is connected to the drain of the FET 32a and the drain of the FET 38a.

[0058] The FET 38a is an N-channel MOSFET. Alternatively, a P-channel MOSFET may be used as the FET 38a. The drain of the FET 38a is connected to the resistor R1. The source of the FET 38a is connected to GND. The gate of the FET 38a is connected to the PMU 108.

[0059] When the SAR sensor 109 detects a human body, the PMU 108 outputs a signal to the gate of the FET 38a so that a voltage is applied between the gate and source of the FET 38a. When a voltage is applied between the gate and source of the FET 38a, a current flows between the drain and source of the FET 38a, and the drain of the FET 32a is connected to GND via the resistor R1 and the FET 38a. When the drain of the FET 32a is connected to GND, a current based on the charge accumulated in the FETs 32a and 32b flows through the charge removal circuit 38. Next, a control signal in the circuit of the second embodiment will be described.

[0060] FIG. 4 is a diagram showing an example of a control signal in the circuit. The circuit shown in FIG. 4 is an enlarged view of the switching device 32, the PD controller 37, the charge removal circuit 38, the PMU 108, and the SAR sensor 109 in the circuit shown in FIG. 3. Note that the capacitor Cdg in FIG. 4 indicates the parasitic capacitance between the drain and gate of the FET 32a. Also, the capacitor Cgs indicates the parasitic capacitance between the gate and source of the FET 32a. Also, V in FIG. SYS indicates a position between the switching device 32 and the charger 33, and V SYS The current and voltage in the figure indicate the current and voltage generated in the system circuit 36 ​​by the power supply via the AC connector 31.

[0061] When an AC adapter is connected to the AC connector 31, the PD controller 37 outputs a signal EN2 to the switch controller 32c. The PD controller 37 continues to output the signal EN2 while the AC adapter is connected to the AC connector 31. While receiving the signal EN2, the switch controller 32c outputs a signal Sw-Gcont to the gates of the FETs 32a and 32b so that a voltage is applied between the gates and sources of the FETs 32a and 32b. When a voltage is applied between the gates and sources of the FETs 32a and 32b by the signal Sw-Gcont, electricity is conducted between the drains and sources of the FETs 32a and 32b. As a result, the supply of power via the AC connector 31 increases V SYSIn this way, the switch controller 32c can easily control the current path by switching the FETs 32a and 32b on and off using the signal Sw-Gcont.

[0062] Here, when a voltage is applied between the gate and source of the FETs 32a and 32b by the signal Sw-Gcont, the resistance of the FETs 32a and 32b gradually decreases, and when the voltage between the gate and source of the FETs 32a and 32b reaches a predetermined value, the FETs 32a and 32b are turned on. SYS The voltage at V gradually rises when a voltage is applied between the gate and source of the FETs 32a and 32b, and rises significantly when the voltage between the gate and source of the FETs 32a and 32b reaches a predetermined value. If charges are stored in the parasitic capacitances represented by the capacitors Cdg and Cgs, a voltage is generated between the gate and source of the FETs 32a and 32b in advance, and V SYS The voltage at V SYS A large rush current occurs in the

[0063] Therefore, when the SAR sensor 109 detects a human body, the PMU 108 outputs a one-shot signal EN1 to the gate of the FET 38a so that a voltage is applied between the gate and source of the FET 38a. As a result, when a user attempts to connect an AC adapter to the AC connector 31, a current flows through the charge removal circuit 38, and the charge accumulated in the parasitic capacitances indicated by the capacitors Cdg and Cgs is removed. Therefore, the charge removal circuit 38 removes the charge accumulated in the FETs 32a and 32b, thereby lengthening the time until the FETs 32a and 32b are turned on when the AC adapter is connected to the AC connector 31, and thus preventing the generation of a large rush current. The signal EN1 is an example of the signal shown in the first embodiment. Next, the functions of the notebook PC 100 will be described.

[0064] 5 is a block diagram showing an example of functions of the notebook PC. The PMU 108 of the notebook PC 100 includes a detection unit 120 and a signal output unit 130. The detection unit 120 and the signal output unit 130 are realized by the processor 108a executing a program stored in the RAM 108b.

[0065] The detection unit 120 determines whether or not the SAR sensor 109 has detected a human body and whether or not an AC adapter has been connected to the AC connector 31. For example, when the detection unit 120 receives a signal indicating that a human body has been detected from the SAR sensor 109, the detection unit 120 determines that the SAR sensor 109 has detected a human body. For example, when the detection unit 120 is notified by the PD controller 37 that an AC adapter is connected to the AC connector 31, the detection unit 120 determines that an AC adapter has been connected to the AC connector 31. Also, for example, when the detection unit 120 is notified by the PD controller 37 that an AC adapter has been connected to the AC connector 31, the detection unit 120 determines that an AC adapter has been connected to the AC connector 31.

[0066] The signal output unit 130 controls the signal according to the detection result of the detection unit 120. When the detection unit 120 determines that the SAR sensor 109 detects a human body and that an AC adapter is not yet connected to the AC connector 31, the signal output unit 130 outputs a one-shot signal EN1 to the charge removal circuit 38. For example, the signal output unit 130 outputs the signal EN1, which is at an H level for a short time, to the gate of the FET 38a. Also, when the detection unit 120 determines that an AC adapter is connected to the AC connector 31, the signal output unit 130 instructs the PD controller 37 to output a signal EN2 to the switching device 32. For example, the signal output unit 130 causes the PD controller 37 to output the signal EN2, which is at an H level, while the AC adapter is connected to the AC connector 31.

[0067] 5 show only a part of the communication paths, and it is possible to set communication paths other than those shown in the figure. Next, the installation location of each piece of hardware in the notebook PC 100 will be described.

[0068] FIG. 6 is a diagram showing an example of the appearance of a notebook PC. The notebook PC 100 has housings 100a and 100b. The housing 100a has a monitor 21 installed therein. The housing 100b has a keyboard 22, a touchpad 23, an AC connector 31, and an SAR sensor 109 installed therein. The notebook PC 100 can be folded so that the surface of the housing 100a on which the monitor 21 is arranged and the surface of the housing 100b on which the keyboard 22 is arranged are on the inside. The housing 100a is an example of the first housing shown in the first embodiment. The housing 100b is an example of the second housing shown in the first embodiment.

[0069] The touch pad 23 is disposed in front of the keyboard 22 of the housing 100b when viewed from the front of the monitor 21. The AC connector 31 is disposed on the left side surface of the housing 100b when viewed from the front of the monitor 21. The SAR sensor 109 is disposed to the right of the touch pad 23 when viewed from the front of the monitor 21.

[0070] Here, when connecting an AC adapter to AC connector 31 installed on the left side surface of housing 100b, there is a high possibility that the user will hold the right side of housing 100b with his / her right hand and connect the AC adapter to AC connector 31 with his / her left hand. By installing SAR sensor 109 on the right side of housing 100b, it is possible to efficiently detect the hand of the user holding housing 100b in an attempt to connect the AC adapter to AC connector 31. The procedure of the process executed by notebook PC 100 will be described in detail below.

[0071] 7 is a flowchart showing an example of a procedure for a power supply control process. The process shown in FIG. 7 will be described below in order of step numbers. [Step S11] The detection unit 120 determines whether or not the SAR sensor 109 has detected a human body. For example, when the detection unit 120 receives a signal indicating that a human body has been detected from the SAR sensor 109, the detection unit 120 determines that the SAR sensor 109 has detected a human body. When the detection unit 120 determines that the SAR sensor 109 has detected a human body, the process proceeds to step S12. When the detection unit 120 determines that the SAR sensor 109 has not detected a human body, the process proceeds to step S14.

[0072] [Step S12] The detection unit 120 determines whether or not an AC adapter is already connected to the AC connector 31. For example, when the detection unit 120 is notified by the PD controller 37 that an AC adapter is already connected to the AC connector 31, the detection unit 120 determines that an AC adapter is already connected to the AC connector 31. When the detection unit 120 determines that an AC adapter is already connected to the AC connector 31, the process proceeds to step S14. When the detection unit 120 determines that an AC adapter is not already connected to the AC connector 31, the process proceeds to step S13.

[0073] [Step S13] The signal output section 130 outputs a one-shot signal EN1 to the charge removing circuit 38. For example, the signal output section 130 outputs the signal EN1, which is at H level for a very short time, to the gate of the FET 38a.

[0074] [Step S14] The detection unit 120 determines whether or not an AC adapter is connected to the AC connector 31. For example, when the detection unit 120 is notified by the PD controller 37 that an AC adapter is connected to the AC connector 31, the detection unit 120 determines that an AC adapter is connected to the AC connector 31. When the detection unit 120 determines that an AC adapter is connected to the AC connector 31, the process proceeds to step S15. When the detection unit 120 determines that an AC adapter is not connected to the AC connector 31, the process proceeds to step S11.

[0075] [Step S15] The signal output unit 130 instructs the PD controller 37 to output a signal EN2 to the switching device 32. For example, the signal output unit 130 causes the PD controller 37 to output a signal EN2 that is at H level while an AC adapter is connected to the AC connector 31. Then, the process proceeds to step S11.

[0076] In this way, the signal output unit 130 outputs a one-shot signal EN1 to the charge removal circuit 38 when the SAR sensor 109 detects a human body and an AC adapter is not yet connected to the AC connector 31. When the SAR sensor 109 detects a human body, the signal output unit 130 outputs the signal EN1 to the charge removal circuit 38, thereby removing the charge accumulated in the FETs 32a and 32b before the AC adapter is connected to the AC connector 31. Furthermore, when an AC adapter is not yet connected to the AC connector 31, the signal output unit 130 outputs the one-shot signal EN1 to the charge removal circuit 38, thereby preventing the signal EN1 from being output when it is not necessary to remove the charge accumulated in the FETs 32a and 32b. This allows the signal output unit 130 to reduce power consumption due to signal output.

[0077] Next, a description will be given, using a timing chart, of the effect of removing the electric charge accumulated in the FETs 32a and 32b before the AC adapter is connected to the AC connector 31. First, a description will be given of a case in which the electric charge removing circuit 38 is not applied.

[0078] FIG. 8 is a diagram showing an example of a timing chart when the charge removal circuit is not applied. The timing chart shown in FIG. SYS and I SYS EN2 indicates the change in the intensity of the signal EN2 output by the PD controller 37 over time. Sw-Gcont indicates the change in the voltage between the gate and source of the FETs 32a and 32b over time. V SYS V SYS The time change of the voltage at I SYS V SYS The time change of the current at

[0079] First, at time T1, when an AC adapter is connected to the AC connector 31, the PD controller 37 outputs an H-level signal EN2. The PD controller 37 maintains the signal EN2 at the H level after time T1. At time T1, a voltage is generated between the gate and source of the FETs 32a and 32b due to the charges accumulated in the FETs 32a and 32b.

[0080] Upon receiving the signal EN2, the switch controller 32c starts outputting the signal Sw-Gcont at time T2. As a result, after time T2, the voltage between the gate and source of the FETs 32a and 32b increases over time. The voltage between the gate and source of the FETs 32a and 32b reduces the resistance of the FETs 32a and 32b, and at time T3, V SYS A current and a voltage are generated at V SYS After time T3, the current and voltage at increase with time.

[0081] Then, at time T4, when the voltage between the gate and source of the FETs 32a and 32b reaches a predetermined value Vth, the FETs 32a and 32b are turned on. SYS The voltage at V increases significantly over time from time T4 to time T5, and then becomes constant after time T5. SYS The voltage at V SYS The current at V increases significantly between time T4 and time T5. SYS The current at decreases and becomes constant after time T5.

[0082] In this way, the charge stored in the FETs 32a and 32b causes V SYS The voltage at V SYS A large rush current flows in the switching device 32. Such a large rush current may cause a breakdown in the switching device 32, etc. Next, a case where the charge removing circuit 38 is applied will be described.

[0083] FIG. 9 is a diagram showing an example of a timing chart when a charge removing circuit is applied. The timing chart shown in FIG. 9 shows EN1, EN2, Sw-Gcont, V SYS and I SYS EN1 indicates the change over time in the intensity of the signal EN1 output by the PMU 108. EN2 indicates the change over time in the intensity of the signal EN2 output by the PD controller 37. Sw-Gcont indicates the change over time in the voltage between the gate and source of the FETs 32a and 32b. V SYS V SYS The time change of the voltage at I SYS V SYS The time change of the current at

[0084] At time t1, a voltage is generated between the gate and source of FETs 32a and 32b due to the charge accumulated in FETs 32a and 32b. First, when the SAR sensor 109 detects a human body, the PMU 108 outputs a signal EN1, which is at H level for a short period of time from time t1 to t2, to the gate of FET 38a. Then, a current due to the charge accumulated in FETs 32a and 32b flows to the charge removal circuit 38, and at time t3, the voltage between the gate and source of FETs 32a and 32b becomes 0V.

[0085] Next, at time t4, when an AC adapter is connected to the AC connector 31, the PD controller 37 outputs the signal EN2 at an H level. After time t4, the PD controller 37 maintains the signal EN2 at an H level.

[0086] Upon receiving the signal EN2, the switch controller 32c starts outputting the signal Sw-Gcont at time t5. As a result, after time t5, the voltage between the gate and source of the FETs 32a and 32b increases over time. The voltage between the gate and source of the FETs 32a and 32b reduces the resistance of the FETs 32a and 32b, and at time t6, V SYS A current and a voltage are generated at V SYSAfter time t6, the current and voltage at increase with time.

[0087] Then, at time t7, when the voltage between the gate and source of the FETs 32a and 32b reaches a predetermined value Vth, the FETs 32a and 32b are turned on. SYS The voltage at V increases significantly over time from time t7 to time t8, and then becomes constant after time t8. SYS Since the time from time t6 to time t8 when the voltage at rises is shorter than the time from time T3 to time T5, V SYS The rise in current in between time t7 and time t8 is smaller than that shown in FIG. SYS The current at decreases and becomes constant after time t8.

[0088] In this way, the PMU 108 outputs the signal EN1, and the charge removal circuit 38 removes the charge accumulated in the FETs 32a and 32b in advance, thereby reducing the V SYS This allows the PMU 108 to increase the time it takes for the voltage at V SYS This can prevent a large rush current from flowing in the power supply, thereby preventing breakdown of the device.

[0089] According to the second embodiment, the SAR sensor 109 detects a human body. The AC connector 31 is connected to a commercial power source. The switching device 32 is connected between the power supply path from the battery 35 to the system circuit 36 ​​and the AC connector 31, and cuts off a current from the battery 35 to the AC connector 31 when power is supplied from the battery 35 to the system circuit 36. When the commercial power source is connected to the AC connector 31, the switching device 32 passes current from the commercial power source to the system circuit 36. The charge removing circuit 38 is connected to the switching device 32, and when the charge removing circuit 38 receives a signal EN1, a current due to the charge accumulated in the switching device 32 flows. When the SAR sensor 109 detects a human body, the PMU 108 outputs a signal EN1 to the charge removing circuit 38. This allows the notebook PC 100 to prevent device failure.

[0090] Furthermore, the PMU 108 outputs a signal EN1 when a commercial power source is not connected to the AC connector 31. This allows the notebook PC 100 to reduce power consumption by not outputting unnecessary signals.

[0091] Furthermore, when the SAR sensor 109 detects a human body, the PMU 108 outputs a one-shot signal EN1 to the charge removing circuit 38. This allows the notebook PC 100 to reduce power consumption by shortening the signal output time.

[0092] Moreover, the switching device 32 switches the FETs 32a and 32b between on and off to cut off the current from the battery 35 to the AC connector 31 and to pass current from the commercial power source to the system circuit 36. This allows the notebook PC 100 to easily control the current path.

[0093] Furthermore, the notebook PC 100 has a housing 100a in which the monitor 21 is installed, and a housing 100b in which the keyboard 22 is installed. The AC connector 31 is installed on the left side surface of the housing 100b when viewed from the front of the monitor 21, and the SAR sensor 109 is installed on the side opposite to the side on which the AC connector 31 is installed when viewed from the front of the monitor 21. This allows the notebook PC 100 to efficiently detect a user attempting to connect an AC adapter to the AC connector 31.

[0094] Other embodiments In the second embodiment, the charge removal circuit 38 removes the charge from the switching device 32 in the power supply path of the commercial power source, but the charge removal circuit 38 may remove the charge from the switching device 32 in the power supply path used when another power supply source is connected. For example, the charge removal circuit 38 may remove the charge from the switching device 32 in the path for supplying power from and charging the USB TypeC device.

[0095] Fig. 10 is a diagram showing an example of a circuit according to another embodiment. The circuit shown in Fig. 10 has a Type C connector 41, a PD controller 37a, and a PMU 108a instead of the AC connector 31, the PD controller 37, and the PMU 108 of the circuit shown in Fig. 3. The circuit shown in Fig. 10 also has a switch 42 and a 5V circuit 43 in addition to the circuit shown in Fig. 3.

[0096] The TypeC connector 41 is a connector to which a USB TypeC device is connected. The TypeC connector 41 is connected to the switching device 32 and the PD controller 37a. When a USB TypeC device (power supply device) that supplies power to another device is connected to the TypeC connector 41, a current flows from the connected device to the switching device 32. When a USB TypeC device (charging device) that is charged by another device is connected to the TypeC connector 41, a current flows from the switching device 32 to the connected device. Whether or not a USB TypeC device is connected to the TypeC connector 41 is detected by the PD controller 37a.

[0097] The PD controller 37a is a PD controller compatible with USB TypeC. The PD controller 37a controls the switching device 32 depending on whether or not a USB TypeC device is connected to the TypeC connector 41. The PD controller 37a is connected to the TypeC connector 41, the switch controller 32c, and the PMU 108a. When a USB TypeC device is connected to the TypeC connector 41, the PD controller 37a causes the switch controller 32c to output a signal Sw-Gcont to the gates of the FETs 32a and 32b.

[0098] When the switching device 32 energizes the FETs 32a and 32b in response to the signal Sw-Gcont, and the power supply device is connected to the Type C connector 41, a power supply path is established from the power supply device to the system circuit 36. When the switching device 32 energizes the FETs 32a and 32b in response to the signal Sw-Gcont, and the charging device is connected to the Type C connector 41, a power supply path is established from the 5V circuit 43 to the charging device.

[0099] The switch 42 switches whether or not to connect the 5V circuit 43 to the switching device 32. When a charging device is connected to the Type-C connector 41, the switch 42 connects the 5V circuit 43 to the switching device 32.

[0100] The 5V circuit 43 is a circuit that supplies power. The 5V circuit 43 receives power from a commercial power source via an AC adapter or from the battery 35. The 5V circuit 43 is connected to the switch 42. When the 5V circuit 43 is connected to the switching device 32 by the switch 42, the 5V circuit 43 supplies power to the charging device via the switching device 32 and the Type C connector 41.

[0101] The PMU 108a is connected to the charge removal circuit 38, the PD controller 37a, the switch 42, and the SAR sensor 109. When the PD controller 37a detects that a charging device is connected to the TypeC connector 41, the PMU 108a connects the switch 42 to the 5V circuit 43 and the switching device 32. When the SAR sensor 109 detects a human body, the PMU 108a outputs a signal EN1 to the gate of the FET 38a so that a voltage is applied between the gate and source of the FET 38a. The signal EN1 connects the drain of the FET 32a to GND via the resistor R1 and the FET 38a. Then, a current based on the charges accumulated in the FETs 32a and 32b flows through the charge removal circuit 38.

[0102] As a result, the PMU 108a can cause the charge removal circuit 38 to remove the charge accumulated in the switching device 32 before the USB TypeC device is connected to the TypeC connector 41. Therefore, the PMU 108a can prevent a large rush current from occurring in the switching device 32 when power is supplied from the power supply device to the system circuit 36 ​​and when charging the charging device from the 5V circuit 43.

[0103] Although the embodiments have been described above, the configurations of the parts shown in the embodiments can be replaced with other parts having similar functions. Any other components or steps may be added. Furthermore, any two or more configurations (features) of the above-mentioned embodiments may be combined. [Explanation of symbols]

[0104] 10. Notebook Computers 11 Sensors 12 Switch Circuit 13 Connectors 14 Second power supply source 15 Power supply destination 16 Charge removal circuit 17 Processing section

Claims

1. A sensor for detecting a human body; a connector to which a first power supply source is connected; a switch circuit connected between a power supply path from a second power supply source to a power supply destination and the connector, the switch circuit cutting off a current from the second power supply source to the connector when power is supplied from the second power supply source to the power supply destination, and allowing a current to flow from the first power supply source to the power supply destination when the first power supply source is connected to the connector; a charge removal circuit connected to the switch circuit, the charge removal circuit receiving a signal and causing a current to flow due to the charge accumulated in the switch circuit; a processing unit that outputs the signal to the charge removing circuit when the sensor detects a human body; A notebook computer having:

2. The processing unit outputs the signal when the first power supply source is not connected to the connector.

2. The notebook computer according to claim 1.

3. When the sensor detects a human body, the processing unit outputs a one-shot signal to the charge removing circuit.

2. The notebook computer according to claim 1.

4. The switch circuit cuts off a current from the second power supply source to the connector and passes current from the first power supply source to the power supply destination by switching a field effect transistor (FET) on and off.

2. The notebook computer according to claim 1.

5. The computer further includes a first housing in which a monitor is installed and a second housing in which a keyboard is installed, the connector is disposed on a right or left side surface of the second housing when viewed from the front of the monitor, The sensor is installed on the opposite side to the side when viewed from the front of the monitor.

2. The notebook computer according to claim 1.

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