JP2009165268A - Power supply unit and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the power consumption of a charging control circuit for monitoring the state of a battery back and charging the battery pack using an AC power supply. <P>SOLUTION: When a battery pack 18 is attached in a state where an AC adaptor 12 (AC power supply) is connected, a switch SW2 is turned on and a linear regulator 46 is turned on to start up a charging control circuit 44, a switch SW1 is turned on by the started charging control circuit 44, the linear regulator 46 is turned on by a main controller 50 to continue power feed to the charging control circuit 44, the residual capacity of the battery pack 18 is detected by the charging control circuit 44 and the battery pack 18 is charged using the power from the AC power supply. When the residual capacity is input from the charging control circuit 44 to determine the battery pack 18 is fully charged, the main controller 50 turns off the linear regulator 46 and shuts down the charging control circuit 44. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply device that can be mounted on an electric device and to which an external power source and a secondary battery can be attached, and an electric device on which the power supply device is mounted.

Conventionally, electric devices (for example, portable personal computers) that can be operated with electric power from an AC power supply for household use and can be operated with electric power from a built-in secondary battery. And mobile phones, video cameras, portable printers, etc.) have been proposed (see, for example, Patent Document 1). In this electrical device, when both an AC adapter connected to a household AC power source and a secondary battery are mounted, the remaining capacity of the secondary battery is detected to check whether charging is necessary, Is provided with a charge control circuit that supplies power from the AC power source to the secondary battery until it is fully charged.
JP 2003-72057 A

  In recent years, in these types of electrical equipment, reducing standby power by suppressing secondary battery discharge and AC power consumption during power-off seems to be considered as an important issue for energy saving. There is a need for further improvements.

  The main purpose of the power supply device and the electric apparatus of the present invention is to reduce standby power.

  In order to achieve the above-described main object, the power supply device and the electric apparatus of the present invention employ the following means.

The power supply device of the present invention is
A power supply device mounted on an electric device and capable of attaching an external power source and a secondary battery,
A charge control circuit that operates by receiving power from the external power source or the secondary battery, detects the remaining capacity of the secondary battery, and charges the secondary battery with the power from the external power source;
When the external power source and the secondary battery are attached, the power from the external power source or the secondary battery is supplied to the charge control circuit, the power switch of the electrical device is turned off, and the detected remaining power is supplied. Power supply cutoff means for cutting off the supply of power from the external power source or the secondary battery to the charge control circuit when it is determined that the secondary battery is fully charged based on capacity;
It is a summary to provide.

  In the power supply device of the present invention, a charge control circuit that operates by receiving power from an external power source or a secondary battery, detects the remaining capacity of the secondary battery, and charges the secondary battery with the power from the external power source. When the external power source and the secondary battery are installed, the power from the external power source or the secondary battery is supplied to the charging control circuit, the power switch of the electrical device is turned off, and the secondary battery is based on the detected remaining capacity. When it is determined that the battery is fully charged, power supply from the external power source or the secondary battery to the charge control circuit is shut off. Therefore, useless power consumption of the charge control circuit can be suppressed, and standby power at the time of power-off can be further reduced. Here, the “electric device” includes a printing apparatus.

  In such a power supply device of the present invention, the power supply cutoff means is means for cutting off the supply of power to the charge control circuit regardless of whether or not the secondary battery is fully charged when the external power supply is removed. It can also be. In this way, even when the external power source is removed before the secondary battery is fully charged, subsequent useless power consumption of the charge control circuit can be suppressed.

  In the power supply device of the present invention, the charge control circuit is a means for detecting the remaining capacity of the secondary battery based on at least one of the voltage, temperature, and internal impedance of the secondary battery. You can also. In this way, even when the power supply to the charge control circuit is interrupted, the remaining capacity of the secondary battery can be detected properly immediately after the start of power supply.

The electrical equipment of the present invention is
The power supply device of the present invention according to any one of the above-described embodiments, that is, a power supply device that is basically mounted on an electric device and can be attached with an external power supply and a secondary battery, the external power supply or the second power supply Charging that operates by receiving power from the secondary battery, detects the remaining capacity of the secondary battery, and charges the secondary battery with power from the external power source until the detected remaining capacity is fully charged When the control circuit, the external power source and the secondary battery are attached, the power from the external power source or the secondary battery is supplied to the charge control circuit, the power switch of the electrical device is turned off, and the A power supply device comprising: a power supply cutoff unit that cuts off the supply of power from the external power source or the secondary battery to the charge control circuit when full charge of the secondary battery is detected. And

  Since the electric device of the present invention is equipped with the power supply device of the present invention according to any one of the above-described aspects, the same effect as the effect of the power supply device of the present invention, for example, wasteful power consumption of the charging control circuit is achieved. It is possible to reduce the standby power at the time of power-off, and the like can be achieved.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view and a block diagram of a photo printer 10 according to an embodiment of the present invention, and FIG. 2 is a rear perspective view of the photo printer 10.

  As shown in FIG. 1, the photo printer 10 according to the present embodiment includes a printer unit 20 that performs printing by discharging ink onto a sheet P, and an operation panel 30 that is disposed on the upper surface of the printer main body and performs various operations related to printing. And a controller 50 for controlling the entire photo printer 10 and a power supply circuit 40 for supplying power necessary for the operation of the photo printer 10 and charging the battery pack 18 as necessary.

  The printer unit 20 is mounted inside the printer body, and spans a paper feed motor 22 that can drive a paper feed roller 21 that transports the paper P and other transport rollers (not shown), a carriage motor 23a, and a driven roller 23b. A carriage 26 that reciprocates in the main scanning direction along a guide rail 25 arranged in parallel to the paper feed roller 21 by the belt 24, and a dye or pigment as a colorant mounted on water as a solvent mounted on the carriage 26. The ink cartridge 27 that individually contains the contained inks of black (K), cyan (C), magenta (M), and yellow (Y) and the ink supplied from the ink cartridge 27 and pressurizing the ink. And a print head 28 for ejecting ink droplets. Here, the ink card ridge 27 is attached below the printer unit 20, and is configured as a so-called off-carriage type in which the ink card ridge 27 is not mounted on the carriage 26. In the present embodiment, the print head 28 employs a system in which a voltage is applied to the piezoelectric element and the ink is pressurized by deforming the piezoelectric element to eject ink droplets. For example, a method may be adopted in which ink is pressurized by bubbles generated by applying a voltage to a heater or the like to heat the ink and ejecting ink droplets.

  The operation panel 30 includes a liquid crystal display 32 capable of displaying characters, graphics, and symbols, and a button group 34 arranged around the display 32. As shown in FIG. 1, the button group 34 switches the power button 34a for turning on / off the power, and the display size of an image or the like displayed on the display 32 to 6 division display, 15 division display, full screen display, or the like. A display switching button 34b for displaying, a menu button 34c for calling a main menu screen on which a plurality of options related to the printing function are arranged, and a cancel button for canceling the operation in the middle or printing on the paper P in the middle 34d, a print button 34e for instructing execution of printing on the paper P, and up / down / left / right buttons operated when a desired option is selected from among a plurality of options displayed on the display 32 or the cursor is moved. 34f is arranged at the center of the up / down / left / right button 34f and is selected by the up / down / left / right button 34f. Such as is constituted by the OK button 34g for instructing the determined choices.

  As shown in FIG. 2, the photo printer 10 is formed so that the battery pack 18 is detachable on the back side, and can be operated by receiving power from the battery pack 18. The battery pack 18 is configured by connecting a plurality of lithium ion batteries in series, and outputs DC power of about 16.8 V in a fully charged state. In addition, the photo printer 10 can operate by receiving power supply via an AC adapter 12 that performs AC-DC conversion of household AC power (such as AC100V or AC200V) into DC power (such as DC20V). The DC jack 11 into which the DC plug 12a of the AC adapter 12 can be inserted is formed on the back side.

  FIG. 3 is a circuit diagram of the power supply circuit 40. The power circuit 40 includes a forward diode D1 connected to the battery pack 18 in conjunction with the power button 34a, a forward diode D2 connected to the AC adapter 12, and the paper feed motor 22 and print head described above of the printer unit 20. DC-DC conversion of the output voltage of the power line 41 into a control voltage (for example, 3.3 V) is performed. The switch SW1 performs connection and disconnection with the power line 41 for supplying power to an electric drive system such as 28. The DC-DC converter unit 42 that supplies the main controller 50 or converts it to another drive voltage (for example, 42V) and outputs it to another drive system, and the output voltage of the battery pack 18 A voltage sensor to detect and a temperature sensor to detect the battery temperature are built in to monitor the remaining capacity of the battery pack 18 and, if necessary, the battery pack. The battery pack 18 or the AC adapter according to either the charge control circuit 44 for charging the battery 18 and the control signal input from the main controller 50 via the diode D3 or the control signal input from the AC adapter 12 via the transistor T1. The linear regulator 46 that supplies or cuts off the power for operating the circuit from the charge control circuit 44 and the on / off control for controlling the on / off of the transistor T1 when the battery pack 18 is mounted on the photo printer 10. Circuit 48. The transistor T1 has a collector connected to the AC adapter 12, an emitter connected to the main controller 50 via the diode D3 in the reverse direction, and is connected to the linear regulator 46, and is grounded to the ground via the resistor R1, and the base is turned on / off. It is connected to the control circuit 48.

  The on / off control circuit 48 includes a switch SW2 that is connected to the AC adapter 12 via the resistor R2 and that is turned on / off in conjunction with the attachment / detachment of the battery pack 18. The AC adapter 12 is connected in series with a resistor R3, a resistor R4, a capacitor C1, and a diode D4 in the reverse direction. The base of the transistor T1 is connected to the connection point between the resistor R3 and the resistor R4. The node between the capacitor C1 and the diode D4 is connected to the node between the resistor R2 and the switch SW2, and the node between the resistor R4 and the capacitor C1 is connected to the collector of the transistor T2 whose emitter is grounded. ing. Furthermore, the resistor R5, the forward diode D5, and the resistor R6 are connected in series to the AC adapter 12, and the base of the transistor T2 is connected to the connection point between the diode D5 and the resistor R6. And a collector of a transistor T3 whose emitter is grounded is connected to a connection point between the diode D5 and the diode D5. The base of the transistor T3 is connected to the output side of the comparator A1 that compares the output voltage of the AC adapter 12 divided by the voltage dividing resistors R7 and R8 with the output voltage of the power supply V1. In this embodiment, the output voltage of the power source V1 is determined so that the comparator A1 is turned off when the output voltage from the AC adapter 12 side is less than 17.5V, and the comparator A1 is turned on when the output voltage is 17.5V or more. Since the AC adapter 12 is defined as an output of DC 20V, when the AC power is connected through the AC adapter 12, the comparator A1 is turned on, and when the connection of the AC power through the AC adapter 12 is released, The comparator A1 outputs off.

  As shown in FIG. 1, the main controller 50 is configured as a microprocessor centered on the CPU 51. In addition to the CPU 51, a ROM 52 that stores processing programs, a RAM 53 that temporarily stores data, and an input / output A port 55 and a transfer buffer 56 that outputs a print signal to the print head 28 are provided, and these are electrically connected via a bus 57. An operation signal from the buttons of the operation panel 30 is input to the main controller 50 via the input port 55. The main controller 50 receives a control signal for the print head 28 and a drive to the carriage motor 23a. A signal, a drive signal to the paper feed motor 22, a display signal to the display 32, and the like are output via the output port 55.

  Next, the operation of the thus configured photo printer 10 of the present embodiment, in particular, the operation of the power supply circuit 40 will be described. Consider a case where the battery pack 18 is attached while an AC power source is connected via the AC adapter 12. FIG. 4 shows how the output voltage of the AC adapter 12, the potential at point A, the potential at point B, and the potential at point C of the power supply circuit 40 in FIG. When the battery pack 18 is mounted (time t11), the switch SW2 is turned on, current flows from the AC adapter 12 to the resistors R3 and R4 with charging of the capacitor C1, and the transistor T1 is turned on. At this time, when the AC power source is connected via the AC adapter 12, the comparator A1 is turned on to turn on the transistor T3, whereby a current flows from the AC adapter 12 to the resistor R5 and the transistor T3 and the diode D5 Since no current flows through the resistor R6, the transistor T2 is turned off. When the transistor T1 is turned on, the output voltage of the AC adapter 12 acts on the linear regulator 46 (the potential at point C in FIG. 3 rises), so that the linear regulator 46 is turned on, and the AC adapter 12 and the charge control circuit 44 are connected. The battery pack 18 and the charge control circuit 44 are connected via the forward diode D1 while being connected via the forward diode D2. Thereby, the charge control circuit 44 is activated and charging of the battery pack 18 is started. When the charging control circuit 44 is activated, the charging control circuit 44 turns on the switch SW1 (time t12), and a control voltage acts on the main controller 50 from the AC adapter 12 via the DC-DC converter unit 42, thereby causing the main controller to turn on. 50 is started, and the main controller 50 turns on the linear regulator 46. That is, immediately after the switch SW2 is turned on, current flows from the AC adapter 12 in the order of resistor R3, resistor R4, and capacitor C1 to turn on the transistor T1, thereby turning on the linear regulator 46, but the capacitor C1 is fully charged. Then, the transistor T1 is turned off and the potential at the point C in FIG. 3 is reduced to turn off the linear regulator 46. Therefore, the main controller 50 turns on the linear regulator 46 at the previous timing (time t12). It is. When the battery pack 18 is removed (time t13), the main controller 50 detects this, turns off the linear regulator 46, and shuts down the charge control circuit 44.

  When the charging control circuit 44 is activated, the state of the battery pack 18 is monitored as the charging of the battery pack 18 starts. In this embodiment, the state of the battery pack 18 is monitored by detecting the remaining capacity based on the output voltage of the battery pack 18 from the voltage sensor and the battery temperature from the temperature sensor, and using the detected remaining capacity to the main controller 50. This is done by outputting. In the present embodiment, the remaining capacity of the battery pack 18 is detected in advance by storing the relationship between the output voltage of the battery pack 18, the battery temperature, and the remaining capacity as a map. Given that, it was done by deriving the corresponding remaining capacity from the map. The main controller 50 that has input the remaining capacity of the battery pack 18 from the charge control circuit 44 executes a power interruption processing routine shown in FIG. In the power interruption processing routine of FIG. 5, the CPU 51 of the main controller 50 inputs the remaining capacity of the battery pack 18 from the charging control circuit 44 (step S100), and waits until the input remaining capacity becomes fully charged (step S110). ), The linear regulator 46 is turned off (step S120). As a result, the charging of the battery pack 18 is stopped, the charging control circuit 44 is shut down, and the monitoring of the state of the battery pack 18 by the charging control circuit 44 is stopped. Therefore, the power consumption of the charging control circuit 44 can be reduced as compared with the case where the state of the battery pack 18 is constantly monitored.

  Next, consider a case where the AC power supply is connected via the AC adapter 12 and the AC adapter 12 (AC power supply) is removed from the state where the battery pack 18 is attached. FIG. 6 shows how the output voltage of the AC adapter 12, the potential at point A, the potential at point B, and the potential at point C of the power supply circuit 40 in FIG. When the AC adapter 12 is removed (time t21), the output voltage of the AC adapter 12 decreases, and the comparator A1 outputs an off signal to turn off the transistor T3. When the transistor T3 is turned off, the current temporarily flows in the order of the resistor R5, the forward diode D5, and the resistor R6 until the output voltage of the AC adapter 12 becomes completely zero. The charge on the capacitor C1 is rapidly discharged. At this time, the transistor T1 is temporarily turned on by the output voltage of the AC adapter 12, and the linear regulator 46 is turned on by raising the potential at the point C in FIG. Since the potential at the point C decreases as it approaches 0, the linear regulator 46 is turned off. When the power button 34a is turned on with only the battery pack 18 attached (time t22), the switch SW1 is turned on, and the DC-DC converter unit 42 converts the output voltage of the battery pack 18 into a control voltage. Is output to the main controller 50, whereby the main controller 50 is activated and the linear regulator 46 is turned on to supply power to the charging control circuit 44. When the power button 34a is turned off (time t23), the switch SW1 is turned off, the supply of the control voltage to the main controller 50 is shut off, and the linear regulator 46 is turned off. Then, when the AC power supply is connected again via the AC adapter 12 (time t24), the transistor T1 is turned on with the charging of the capacitor C1, the linear regulator 46 is turned on, the charge control circuit 44 is activated, and the battery The charging of the pack 18 is started. When the charging control circuit 44 is activated, the charging control circuit 44 turns on the switch SW1, and a control voltage is applied to the main controller 50 from the AC adapter 12 via the DC-DC converter unit 42, so that the main controller 50 The main controller 50 turns on and turns on the linear regulator 46.

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The photo printer 10 of the present embodiment corresponds to “electric equipment”, the AC adapter 12 and the AC power source correspond to “external power source”, the battery pack 18 corresponds to “secondary battery”, and the charging control circuit 44 includes The main controller 50 and the power supply circuit 40 (excluding the charge control circuit 44) correspond to the “power supply cutoff means”.

  According to the photo printer 10 of this embodiment described in detail above, when the AC adapter 12 (AC power supply) and the battery pack 18 are attached, the charge control circuit 44 is activated and the charge control circuit 44 uses the AC power supply. Is supplied to the battery pack 18 to charge the battery pack 18 and shut down the charge control circuit 44 when the battery pack 18 is fully charged. Power consumption can be minimized. As a result, the standby power of the photo printer 10 can be further reduced.

  Further, according to the photo printer 10 of the present embodiment, when the AC power supply is connected via the AC adapter 12 and the AC adapter 12 (AC power supply) is removed from the state where the battery pack 18 is attached. Similarly, since the charging control circuit 44 is shut down, useless power consumption of the charging control circuit 44 can be suppressed even in this case.

  In the present embodiment, the charge control circuit 46 detects the remaining capacity of the battery pack 18 based on the output voltage of the battery pack 18 and the battery temperature. However, the present invention is not limited to this, and the battery pack 18 is slightly charged / discharged. Any other method may be used such as detecting the remaining capacity by detecting the internal impedance.

  In the present embodiment, the battery pack 18 is constituted by a lithium ion battery, but is not limited to this, and is constituted by any other type of secondary battery such as a nickel cadmium battery or a nickel hydrogen battery. It does n’t matter.

  In the present embodiment, the present invention is applied to the photo printer 10. However, the present invention is not limited to this. The present invention is not limited to this, and may be operated by the power from the secondary battery and the power from the AC power source. For example, the present invention may be applied to any other electric device such as a portable personal computer, a cellular phone, a video camera, a digital still camera, a portable music player, and an information portable terminal. Further, in addition to those in the form of such electric equipment, it may be in the form of a power supply device.

  The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and can of course be implemented in various modes as long as they belong to the technical scope of the present invention.

1 is an external perspective view and a block diagram of a photo printer 10 according to the present embodiment. The perspective view which looked at the photo printer 10 from the back side. The circuit diagram of the power supply circuit 40. FIG. Explanatory drawing which shows the mode of the time change of an AC adapter output voltage and the electric potential of A point, B point, and C point. The flowchart which shows an example of an electric power interruption process routine. Explanatory drawing which shows the mode of the time change of an AC adapter output voltage and the electric potential of A point, B point, and C point.

Explanation of symbols

  10 Photo printer, 11 DC jack, 12 AC adapter, 18 Battery pack, 20 Printer unit, 21 Paper feed roller, 22 Paper feed motor, 23a Carriage motor, 23b Driven roller, 24 Carriage belt, 25 Guide rail, 26 Carriage, 27 Ink cartridge, 28 print head, 30 operation panel, 32 display, 34 buttons, 34a power button, 34b display switching button, 34c menu button, 34d cancel button, 34e print button, 34f up / down / left / right button, 34g OK button, 40 power Circuit, 42 DC-DC converter section, 44 charge control circuit, 46 linear regulator, 48 on / off control circuit, 50 main controller, 51 CPU, 52 ROM, 53 AM, 55 input and output ports, 56 the transfer buffer, 57 bus, R1 to R8 resistors, D1 to D5 diode, T1 to T3 transistors, SW1, SW2 switch, V1 power, A1 comparator.

Claims (5)

A power supply device mounted on an electric device and capable of attaching an external power source and a secondary battery,
A charge control circuit that operates by receiving power from the external power source or the secondary battery, detects the remaining capacity of the secondary battery, and charges the secondary battery with the power from the external power source;
When the external power source and the secondary battery are attached, the power from the external power source or the secondary battery is supplied to the charge control circuit, the power switch of the electrical device is turned off, and the detected remaining power is supplied. Power supply cutoff means for cutting off the supply of power from the external power source or the secondary battery to the charge control circuit when it is determined that the secondary battery is fully charged based on capacity;
A power supply device comprising:   2. The power supply apparatus according to claim 1, wherein the power supply cutoff means is means for cutting off the supply of power to the charge control circuit regardless of whether or not the secondary battery is fully charged when the external power supply is removed. .   The power supply apparatus according to claim 1 or 2, wherein the charge control circuit is means for detecting a remaining capacity of the secondary battery based on at least one of a voltage, a temperature, and an internal impedance of the secondary battery.   The power supply apparatus according to claim 1, wherein the electrical device is a printing apparatus.   An electric device on which the power supply device according to any one of claims 1 to 4 is mounted.

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