Patent Document

CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority from U.S. Provisional Patent Application No. 61/903,875 filed on Nov. 13, 2013, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     Embodiments of the present invention relate to a feeding apparatus and a feeding method. 
     BACKGROUND ART 
     There has been a background that various types (an electromagnetic induction type, an electric-field coupling type, and a resonance type) of noncontact power-feeding modules being inferior to conventional alternating-current (AC) adapters in load response characteristic have been brought into a market. Regarding a technical background, because there is hope that a certain object is achieved, a system design made in consideration of a power supply having a poor load response is needed. 
     Hitherto, there has been a problem that, in the case of driving a system by a noncontact power-feeding module, even when system power would be within a rated electric-power of the noncontact power-feeding module, if the load variation is large, the supply of electric-power to the system is unstable. That is, there is a demand for more stable supply of electric-power in the case of using the noncontact power-feeding module in the supply of electric-power. However, no means for fulfilling the demand is known. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective diagram illustrating an example of the external-appearance of an electronic apparatus according to an embodiment of the invention. 
         FIG. 2  is a block diagram illustrating an example of the system configuration of an electronic apparatus according to an embodiment of the invention. 
         FIG. 3  is a functional block configuration diagram for illustrating a primary part of the embodiment. 
         FIG. 4  is a flowchart illustrating an example of a processing method according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an embodiment of the invention is described with reference to  FIGS. 1 to 4 . 
     Referring first to  FIGS. 1 to 3 , the configuration of an electronic apparatus according to an embodiment is described. This electronic apparatus can be implemented as, e.g., a portable notebook personal computer, a tablet terminal, and other various types of information processing apparatuses. 
       FIG. 1  is a perspective diagram taken from a front side of a notebook computer  10  in a state of opening a display unit thereof. This computer  10  is configured to receive electric-power from a battery  20 . This computer  10  includes a computer main-unit  11  and a display unit  12 . A display device such as a liquid crystal display unit (LCD)  31  is incorporated into the display unit  12 . Moreover, a camera (Web camera)  32  is arranged on a top end portion of the display unit  12 . 
     The display unit  12  is mounted on the computer main-unit turnably between an open position in which the top surface of the computer main-unit  11  is exposed, and a closed position in which the top surface of the computer main-unit  11  is covered by the display unit  12 . The computer main-unit  11  has a thin box-shaped casing on the top surface of which a keyboard  13 , a touch pad  14 , a power-supply switch  16  for power-on/off of this computer  10 , several function buttons  17 , and speakers  18 A and  18 B are arranged. 
     A power-supply connector  21  is also provided on the computer main-unit  11 . The power-supply connector  21  is provided on a side surface, e.g., a left-side surface of the computer main-unit  11 . An external power-supply is detachably connected to the power-supply connector  21 . An alternating-current (AC) adapter can be used as an external power-supply. The AC adapter is a power supply that converts commercial electric-power (AC electric-power) to direct-current (DC) electric-power. 
     The battery  20  is detachably attached to, e.g., a rear-end portion of the computer main-unit  11 . The battery  20  may be a battery built-into this computer  10 . 
     This computer  10  is driven by electric-power from an external power-supply or the battery  20 . If an external power-supply is connected to the power-supply connector  21  of this computer  10 , this computer  10  is driven by electric-power from the external power-supply. Electric-power from the external power-supply is also used to charge the battery  20 . While the external-power supply is not connected to the power-supply connector  21  of this computer  10 , this computer  10  is driven by electric-power from the battery  20 . 
     Moreover, several universal serial bus (USB) ports  22 , high-definition multimedia interfaces (HDMI) output terminals  23 , and a red-green-and-blue (RGB) port  24  are provided in the computer main-unit  11 . 
       FIG. 2  illustrates the system configuration (i.e., the configuration of power-feeding targets) of this computer  10 . This computer  10  includes a central processing unit (CPU)  111 , a system controller  112 , a main memory  113 , a graphic processing unit (GPU)  114 , a sound codec  115 , basic-input-output-system read-only memory (BIOS-ROM)  116 , a hard disk drive (HDD)  117 , an optical disk drive (ODD)  118 , a Bluetooth (BT) module (Bluetooth is a registered trademark)  120 , a wireless local area network (LAN) module  121 , a secure digital (SD) card controller  122 , a peripheral component interconnect (PCI) EXPRESS card controller  123 , an embedded-controller/keyboard-controller integrated circuit (EC/KBC IC)  130 , a keyboard backlight  13 A, a power-supply controller (PSC)  141 , a power-supply circuit  142 , and so on. 
     The CPU  111  is a processor that controls each component of this computer  10 . The CPU  111  executes various software-programs loaded into the main memory  113  from the HDD  117 . The software-programs include an operating system (OS)  201 , a setting application program  202  whose description is omitted, and various application programs  203 . The various applications  203  include the above desktop and full-screen applications. 
     The CPU  111  executes a basic input/output system (BIOS) stored in BIOS-ROM  116  which is a non-volatile memory. The BIOS is a system program for controlling hardware. 
     The GPU  114  is a display controller that controls a liquid crystal display (LCD)  31  used as a display monitor of this computer  10 . The GPU  114  generates, from display data stored in a video memory (video random access memory (VRAM))  114 A, a display signal (low voltage differential signaling (LVDS) signal) to be supplied to the LCD  31 . Moreover, the GPU  114  can also generate, from display data, analog RGB signals and HDMI video signals. Analog RGB signals are supplied to an external display via the RGB ports  24 . The HDMI output terminal  23  can send an HDMI video signal (i.e., a digital uncompressed video signal) and a digital audio signal with one cable. An HDMI control circuit  119  is an interface for sending an HDMI video signal and a digital audio signal via the HDMI output terminal  23  to an external display. 
     The system controller  112  is a bridge device that connects the CPU  111  to each component. The system controller  112  incorporates a serial advanced technology attachment (ATA) controller for controlling the hard disk drive (HDD)  117  and the optical disk drive (ODD)  118 . Moreover, the system controller  112  performs communication with each component on a low PIN count (LPC) bus. 
     The EC/KBC  130  is connected to the LPC bus. The EC/KBC  130 , and the power-supply controller (PSC)  141  and the battery  20  are interconnected to one another via a serial bus such as an inter-integrated circuit (I2C) bus. 
     The EC/KBC  130  is a power management controller for performing the power management of this computer  10  and implemented as a one-chip microcomputer having an embedded keyboard controller that controls, e.g., the keyboard (KB)  13  and the touch pad  14 . The EC/KBC  130  has the function of performing the power-on/off of this computer  10  in response to operations of the power-supply switch  16 , which are performed by users. The control of the power-on/off of this computer  10  is performed by the cooperation of the EC/KBC  130  and the power-supply controller (PSC)  141 . When receiving an ON-signal transmitted from the EC/KBC  130 , the power-supply controller (PSC)  141  controls the power-supply circuit  142  to perform the power-on of this computer  10 . When receiving an OFF-signal transmitted from the EC/KBC  130 , the power-supply controller (PSC)  141  controls the power-supply circuit  142  to perform the power-off of this computer  10 . The EC/KBC  130 , the power-supply controller (PSC)  141  and the power-supply circuit  142  work by electric-power supplied from the battery  20  or an AC adapter  150 , even during the power-off of this computer  10 . 
     Moreover, the EC/KBC  130  can turn on/off the keyboard backlight  13 A arranged on the rear surface of the keyboard  13 . Furthermore, the EC/KBC  130  is connected to a panel opening/closing switch  131  configured to detect the opening/closing of the display unit  12 . Even when the opening of the display unit  12  is detected by the panel opening/closing switch  131 , the EC/KBC  130  can perform the power-on of this computer  10 . 
     The power-supply circuit  142  generates electric-power (operating-power) to be supplied to each component, using electric-power supplied from the battery  20  or from the AC adapter  150  connected as an external power-supply to the computer main-unit  11 . The power-supply circuit  142  also receives electric-power from a noncontact power-feeding module  33  by, e.g., an electromagnetic induction method, and obtains DC-voltage, using a circuit (not shown). This circuit includes, e.g., a pickup coil wound on a pickup core arranged close to a power-feeding line, in which a high-frequency electric-current flows when a constant electric-current is supplied to the power-feeding line connected to the noncontact power-feeding module  33  that is a high-frequency power-supply configured to output a constant alternating electric-current. The circuit also includes a resonance capacitor parallel-connected to this pickup coil, a rectifying portion using a diode bridge parallel connected to this resonance capacitor, and a constant-voltage circuit configured to control electric-current output by this rectifying portion to a predetermined voltage. 
       FIG. 3  is a functional block configuration diagram for illustrating a primary part of the embodiment of the feeding apparatus, which focuses on the power-supply circuit  142 . Reference numeral Sm denotes the above DC-voltage. A higher one of this DC-voltage Sm and a voltage output from the AC adapter  150  through the power-supply connector  21  is selected by diodes D 1  and D 2 , and relates to power-feeding. The EC/KBC  130  receives the DC-voltage Sm as a detection signal that indicates the detection of the noncontact power-feeding module  33 . Thus, the EC/KBC  130  turns on a DC-IN light-emitting diode (LED) LD, and sends out an operating-condition notification signal of the noncontact power-feeding module  33  to an electric-current variation detecting block  142   a  (through the power-supply controller (PSC)  141 ). 
     The electric-current variation detecting block  142   a  is a block that detects the variation of electric-current flowing in a resistor Ri. The voltage drop of the resistor Ri is amplified, e.g., several tens of times by an amplifier O 1 . The AC-component of the amplified voltage-drop is obtained by a capacitor C 0  and compared with a reference voltage Rf 1  by a comparator O 2 . If the AC-component is relatively large, the electric-current variation detecting block  142   a  sends a boost-on signal of several milli-seconds (ms) to a DC/DC converter  142   b.    
     The DC/DC converter integrated circuit (IC)  142   b  includes an input-current limitation control portion  142   b   1 , a pulse-width modulation (PWM) generation portion  142   b   2 , a driver logic portion  142   b   2 , a high-side field-effect transistor (FET) driver block  142   b   4 , and a low-side FET driver block  142   b   5 . 
     The input-current limitation control portion  142   b   1  amplifies the voltage drop of the resistor Ri to, e.g., several tens of times by an amplifier O 3 , and compares the amplified voltage-drop with a reference voltage Rf 2  by a comparator O 4 . If the voltage drop is relatively large, a diode D 0  is conducted. Thus, a control loop, whose input electric-current has a constant value, is effective. 
     The PWM generation portion  142   b   2  compares an output of a saw-tooth wave (triangular wave) transmitter  142   b   2   a  with an input from the input-current limitation control portion  142   b   1  by a comparator O 4 . Thus the PWM generation portion  142   b   2  obtains a PWM signal and sends the PWM signal to the driver logic portion  142   b   3 . 
     The drier logic portion  142   b   3  is configured to control the high-side FET driver block  142   b   4  and the low-side FET driver block  142   b   5  in response to this PWM signal. 
     N-channel metal-oxide semiconductor (MOS) FETs Q 1  and Q 2  are conducted or non-conducted by controlling the high-side FET driver block  142   b   4  and the low-side FET driver block  124   b   5 . Thus, each component is usually supplied with electric-power through a route indicated with dashed lines Rt 1 . However, during the duration of the above boost-on signal, each component is supplied with electric-power through a route indicated with dashed lines Rt 2  in addition to the route indicated with dashed lines Rt 1 . 
     Incidentally, capacitors C 1  and C 2  are used for smoothing. A diode D 3  is used for backflow prevention. A resistor R and an inductor L aim at electric-current stabilization. 
       FIG. 4  is a flowchart illustrating an example of a processing method according to the embodiment. 
     In step S 41 , the electric-current variation detecting block  142   a  monitors an output electric-current of the noncontact power-feeding module  33  while electric-power is supplied by noncontact power-feeding. If the electric-current variation exceeds a threshold (i.e., if the supply capability of the noncontact power-feeding module  33  is exceeded), a boost-on signal is asserted (enabled) against a charger (i.e., the DC/DC converter IC  142   b ). 
     In step S 42 , when the boost-on signal is asserted, the charger performs a boost operation using the battery  20  as a power supply. That is, the charger performs an operation of making an input electric-current constant, using a feedback loop. 
     In step S 43 , then, if the variation of an output electric-current from the noncontact power-feeding module  33  becomes less than a threshold, the electric-current variation detecting block  142   a  de-asserts (disabled) against the charger. 
     In step S 44 , the charger finishes a boost operation when the boost-on signal is de-asserted. Then, electric-power is supplied to the system only from the noncontact power-feeding module  33 . 
     (Regarding DC-IN LED Control in Case of Supplying Electric-power to System by Non-contact Power-feeding) 
     Generally, the EC monitors the voltage of a power-supply line directly or indirectly through an IC, such as the charger, which incorporates a comparator. Then, according to the status of the monitored voltage, the DC-IN LED is turned on or off. Thus, if a power-supply voltage largely varies due to a system load variation, as in the case of performing noncontact power-feeding, the DC-IN LED accordingly repeats turning-on and turning-off. This brings a feeling of anxiety to a user. 
     Then, “providing a blank time (e.g., 100 ms) between the reduction of the power-supply voltage and the turning-off of the DC-IN LED (LD) in the case of supplying electric-power only by contact power-feeding” is added to the controlling of the DC-IN LED (LD) of the EC/KBC  130  according to the embodiment. Consequently, the above problem of anxiety feeling is resolved. 
     As described above, even when the system power is within a rated electric-power, if the electric-current variation of the noncontact power-feeding module exceeds a threshold (i.e., the electric-current variation is at a level that cannot be dealt with by the noncontact power-feeding module), the stable supply of electric-power to the system can be achieved utilizing electric-discharge caused by performing a boost operation using the battery as a power supply. Moreover, providing a blank time in the controlling of the DC-IN LED by the EC has resolved the problem that the DC-IN LED repeats turning-on and turning-off due to the variation of the power-supply voltage in the case of noncontact power-feeding. 
     That is, even when the system power is within the rated electric-power, if the electric-current variation of the noncontact power-feeding module exceeds the threshold (i.e., the electric-current variation is at a level that cannot be dealt with by the noncontact power-feeding module), the stable supply of electric-power to the system is implemented utilizing electric-discharge caused by performing a boost operation using the battery as a power supply. Moreover, providing a blank time in the controlling of the DC-IN LED by the EC resolves the problem that the DC-IN LED repeats turning-on and turning-off due to the variation of the power-supply voltage in the case of noncontact power-feeding. 
     In the future, it is predicted that a power-supply unit, such as a noncontact power-feeding type one, which is inferior to the conventional AC adapters in load response characteristic will be brought into a market. A system design in consideration of a power-supply unit having a poor load response will be needed on a system side in the future. At that time, if designing is performed to suppress system load variation, the problem of the degradation of system performance or the problem of power increase will arise. The presently proposed patent can prevent the problems of the system performance degradation and the power increase, and achieve stable power-feeding. Moreover, it is requested that the problem of the repetition of the turning-on and turning-off of the DC-IN LED due to the variation of the power-supply voltage in the noncontact power-feeding can be resolved by providing a blank time in the controlling of the DC-IN LED by the EC. 
     Even when the system power is within the rated electric-power of the noncontact power-feeding module, if the electric-current variation of the noncontact power-feeding module exceeds the threshold (i.e., the electric-current variation is at a level that cannot be dealt with by the noncontact power-feeding module), the stable supply of electric-power to the system can be achieved utilizing electric-discharge caused by performing a boost operation using the battery as a power supply. 
     To resolve this problem, according to this embodiment, it has been devised that even when the system power is within the rated electric-power of the noncontact power-feeding module, if the electric-current variation of the noncontact power-feeding module exceeds the threshold (i.e., the electric-current variation is at a level that cannot be dealt with by the noncontact power-feeding module), the stable supply of electric-power to the system is implemented utilizing electric-discharge caused by performing a boost operation using the battery as a power supply. 
     According to this embodiment, boosting is performed by detecting the electric-current variation of the system. Thus, the stable supply of electric-power can be implemented without occurrence of variation of the power-supply voltage of the system. This embodiment also can deal with the load variation within the rated electric-power of the noncontact power-feeding module. Even when a power supply such as the noncontact power-feeding module, which is sensitive to the load variation, stable electric-power can be supplied to the system by detecting the variation of the load current of the system and performing an operation of boosting from the battery. 
     Even when the system power is within the rated electric-power of the noncontact power-feeding module, if the electric-current variation of the noncontact power-feeding module exceeds the threshold (i.e., the electric-current variation is at a level that cannot be dealt with by the noncontact power-feeding module), the stable supply of electric-power to the system is impelemented utilizing electric-discharge caused by performing a boost operation using the battery as a power supply. 
     Incidentally, the invention is not limited to the above embodiments themselves. In an implementing stage, the invention may be embodied while variously modifying components without departing from the spirit and scope of the invention. 
     Moreover, various embodiments of the invention can be implemented by appropriately combining plural components disclosed in the above embodiment. For example, some components may be deleted from all components described in the above embodiment. Furthermore, the components in different embodiments may appropriately be combined with one another.

Technology Category: 5