JP2012125928A - Recording apparatus and power apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly switch an external power source into a battery and save the battery when the battery is used as a backup of the external power source.SOLUTION: A recording apparatus includes: a drive unit 40 that operates by receiving power from either an AC adaptor 2 or the battery 10; a recording control CPU 41 that controls the drive part 40 and executes recording; and a power unit 3 that supplies power to the drive unit 40 based on the power supplied from either the power supplied from the AC adaptor 2 or the battery 10. The power unit 3 powers the drive unit 40 supplied from the battery 10 and outputs a signal indicating changes of power to the recording control CPU 41 when a voltage supplied from the AC adaptor 2 drops.

Description

  The present invention relates to a recording apparatus that performs recording on a recording medium, and a power supply apparatus that supplies power to the recording apparatus.

  Conventionally, in a recording apparatus such as a printer for recording on a recording medium, it is known that a battery is mounted as a backup power source that normally operates with an external power source such as a commercial power source and this external power source is interrupted. (For example, refer to Patent Document 1). This type of recording apparatus has a configuration in which both the external power supply and the battery are always connected to an operation unit (engine controller in Patent Document 1) that receives power supply in order to quickly switch from the external power supply to the battery. ing.

JP 07-186492 A

By the way, when power is supplied from a battery to a drive unit such as a motor installed in the recording apparatus, it is assumed that the voltage required by the drive unit is higher than the output voltage of the battery. The output voltage is boosted and supplied to the drive unit.
However, when a booster circuit is provided at the output stage of the battery in the conventional recording apparatus, the power from the battery is always supplied to the booster circuit, so that the battery power is not required even when the battery backup is required. There was a problem of consuming. In other words, a general booster circuit consumes power that cannot be ignored even when power is not output to the outside. Therefore, in a configuration in which both an external power supply and a battery are connected to an operating unit that receives power supply, Concern about consumption.
The present invention has been made in view of the above-described circumstances. When a battery is used as a backup for an external power supply, the battery can be quickly switched from the external power supply to the battery when the external power supply is used. An object of the present invention is to provide a recording apparatus and a power supply apparatus that can suppress the above-described problem.

In order to achieve the above object, the present invention includes a transport unit that transports a recording medium and a recording head that performs recording on the recording medium, and operates by receiving power from an external power source or a battery, and the drive Recording control means for controlling the unit to execute recording, voltage boosting means for converting the power supplied from the battery into an operating voltage of the drive unit and outputting the power, and power supplied from the external power source or the battery A power supply device that supplies power to the drive unit based on the power supplied from the power supply, and the power supply device supplies the power supplied from the battery when the voltage supplied from the external power supply decreases. While supplying to the said drive part, the signal which shows the change of a power supply is output with respect to the said recording control means, It is characterized by the above-mentioned.
According to the present invention, when the voltage supplied from the external power supply drops, the power from the battery is supplied to the drive unit instead of the external power supply in response to this voltage drop, and the power of the battery when using the external power supply In addition to reducing consumption, the power supply is quickly switched to the battery when the drive unit cannot be operated with an external power supply. Since the recording control means can be notified to the recording control means that the power source has been changed from the external power supply to the battery, for example, the recording control means is controlled so as to suppress the power consumption amount and current amount of the drive unit, and the operation of the recording apparatus is controlled. It becomes possible to adapt to driving.

Further, the present invention is the recording apparatus, wherein the power supply device converts the power supplied from the battery into an operating voltage of the driving unit and outputs the voltage, and the power output by the boosting unit; And an output circuit that selectively outputs the power supplied from the external power source to the driving unit, and the output circuit converts the power supplied from the external power source and the voltage boosting means and outputs the converted voltage. It is characterized by being configured to output the higher voltage of the power.
According to the present invention, when the voltage supplied from the external power supply is higher, for example, when the boosting means is not performing voltage conversion, the output circuit outputs the power supplied from the external power supply to the drive unit. In addition, for example, when the voltage supplied from the external power supply decreases and the booster performs voltage conversion, if the voltage output from the booster is higher, the power output from the booster is output to the drive unit. To do. As described above, the power supply of the driving unit is appropriately switched depending on the change of the voltage supplied from the external power supply and whether or not the boosting means for converting the voltage of the battery is operated by the output circuit. Without using a simple circuit configuration, power can be stably supplied to the drive unit. Moreover, while the voltage of the power supplied from the external power source is high, the power consumption of the battery can be suppressed, and the battery power can be used efficiently.

Further, the present invention is characterized in that, in the recording apparatus, the power supply device includes power supply control means for performing voltage conversion by the boosting means when the voltage supplied from the external power supply decreases.
According to the present invention, execution and stop of voltage conversion can be accurately controlled by the boosting means.

Further, in the recording apparatus according to the present invention, the boosting unit stores a coil through which the output current of the battery flows, a switch for turning on / off the current flowing through the coil, and a back electromotive force generated in the coil. A capacitor and a boost control means for driving the switch, wherein the power supply control means is connected to the boost control means while the power supplied from the external power supply is below a predetermined voltage. An enable signal is output, and the step-up control unit drives the switch while the enable signal is input from the power supply control unit, and performs voltage conversion by the coil and the capacitor.
According to the present invention, since the boosting unit does not perform switching while the recording apparatus is operated by the external power supply, it is possible to minimize the battery consumption during the operation by the external power supply. When an enable signal is input along with a voltage drop of the external power supply, switching is started and power based on the battery can be output quickly.

The present invention is also characterized in that the recording apparatus further comprises a cut-off switch for cutting off power supply from the external power source and the battery to the output circuit.
According to the present invention, for example, when the recording apparatus is stopped, the power supply from the external power source and the battery is cut off, so that the power consumption of the external power source and the battery while the recording apparatus is not operating can be suppressed.

Further, the present invention is characterized in that in the recording apparatus, the output circuit is configured by diode-ORing a line to which power is supplied from the external power source and a line from which the booster outputs power. To do.
According to the present invention, the power supplied from the external power source and the power from the battery are appropriately selected and supplied without switching the circuit or the like by the diode OR connection, so that the voltage of the external power source is equal to or lower than a predetermined voltage. In this case, the battery power can be quickly supplied to the drive unit by operating the booster circuit.

In the recording apparatus, the recording control unit may drive the driving unit in a power saving mode based on a signal input from the power supply apparatus.
According to the present invention, by driving the drive unit in the power saving mode and suppressing the power consumption of the drive unit, the recording apparatus can be driven for a longer time with the limited power of the battery. In addition, since the load of battery discharge can be reduced, the battery life can be extended.

In order to achieve the above object, the present invention includes a conveyance unit that conveys a recording medium and a recording head that performs recording on the recording medium, and a driving unit that operates by receiving power supply from an external power source or a battery; Connected to a recording apparatus having a recording control means for controlling the driving unit to execute recording, and supplying power to the driving unit based on power supplied from the external power source or power supplied from the battery When the voltage supplied from the external power supply decreases, the power supplied from the battery is supplied to the drive unit, and a signal indicating a change in power supply is output to the recording control means. Features.
According to the power supply device of the present invention, when the voltage supplied from the external power supply drops, the power from the battery is supplied to the drive unit instead of the external power supply in response to this voltage drop, and when the external power supply is used. The power consumption of the battery is reduced, and when the drive unit cannot be operated with an external power supply, the power supply is quickly switched to the battery. Since the recording control means can be notified to the recording control means that the power source has been changed from the external power supply to the battery, for example, the recording control means is controlled so as to suppress the power consumption amount and current amount of the drive unit, and the operation of the recording apparatus is controlled. It becomes possible to adapt to driving.

  According to the present invention, the power consumption of the battery is suppressed when the recording apparatus is driven by an external power source, and recording is performed by quickly switching between the external power source and the battery when the voltage supplied by the external power source drops. Power can be supplied to the drive unit.

1 is a block diagram illustrating a configuration of a printer according to an embodiment of the present invention. It is a circuit diagram which shows the structure of a booster circuit. It is a circuit diagram which shows the structure of a voltage drop detection part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a printer 1 according to an embodiment to which the present invention is applied.
The printer 1 is a recording device that records (prints) characters, images, and the like on a recording medium. In the present embodiment, when the printer 1 is a line thermal printer that heats a thermal roll paper (not shown) accommodated in a main body case (not shown) by a line thermal head and prints characters, images, and the like. Will be described as an example.

The printer 1 includes a power supply device 3 and a recording unit 4 that operates by receiving power supply from the power supply device 3 and performs recording on roll paper.
The recording unit 4 includes a recording control CPU 41 (recording control unit) that controls each part of the printer 1 by executing a control program, a ROM 42 that stores data such as a control program executed by the recording control CPU 41 and setting values, and a recording control CPU 41 A RAM 43 that forms a work area for developing a control program to be executed and data to be processed, and an interface (I / F) unit 47 connected to a host computer 100 outside the printer 1 are provided. The recording unit 4 is transported by a transport motor 44 as a transport unit that transports roll paper according to the control of the recording control CPU 41 and a transport motor 44 as a drive unit 40 controlled by a control system including the recording control CPU 41. And a recording head 45 for recording characters and images by forming colored dots on the roll paper. The units included in the recording unit 4 are connected to each other via a bus 48.
The recording control CPU 41 reads out a control program and data stored in the ROM 42, develops them in the work area of the RAM 43, and executes them to control each part of the printer 1. The recording control CPU 41 transmits / receives various data to / from the host computer 100 via the interface unit 47, and based on the recording execution command and recording data transmitted from the host computer 100, the transport motor 44 of the driving unit 40 and The recording head 45 is controlled to perform recording.

The transport motor 44 is connected to a transport roller that contacts the roll paper. When the transport motor rotates as the transport motor 44 rotates, the roll paper is transported toward the discharge port. The recording unit 4 includes a cutter unit that cuts the roll paper recorded by the recording head 45 in the vicinity of the discharge port, and a cutter drive motor that operates the cutter unit. The recording control CPU 41 controls the cutter unit at a predetermined timing. It is good also as a structure which moves a blade and cuts roll paper. In the configuration provided with this cutter drive motor, the drive unit 40 includes a cutter drive motor.
The printer 1 also includes a sensor 46 for controlling the recording operation. The sensor 46 specifically includes a sensor that detects opening and closing of a cover (not shown) provided in a main body (not shown) that accommodates roll paper, a sensor that detects that the remaining amount of roll paper is exhausted, and the like. It is.

  The printer 1 is connected to an AC adapter 2 (external power source) connected to a commercial AC power source P as a normal power source. The AC adapter 2 rectifies and converts the voltage of, for example, a commercial AC power supply P having an AC voltage of 100 volts, and supplies DC power of 24 volts to the power supply device 3. Based on the power supplied from the AC adapter 2, the power supply device 3 supplies power to each unit of the recording unit 4.

  A system power supply unit 5 is connected to the output stage of the power supply device 3. The system power supply unit 5 supplies, for example, DC 24 volt driving power output from the power supply device 3 to each unit of the driving unit 40. Further, the system power supply unit 5 has a built-in DC / DC converter (not shown) for converting the voltage, and converts the power for driving, for example, 24 VDC supplied from the power supply device 3 to control power. (For example, DC 3.3 volts) is generated and supplied to each part of the control system mounted on the control board such as the recording control CPU 41, the ROM 42, the RAM 43, the sensor 46, and the interface unit 47. The system power supply unit 5 can also be included as a part of the power supply device 3.

  The printer 1 also includes a battery 10. The battery 10 is a secondary battery (lithium ion battery, lithium polymer battery, nickel metal hydride battery, nickel-cadmium battery, etc.) that can be repeatedly charged and discharged. If a power failure or voltage drop occurs in the commercial AC power supply P, the AC adapter When the connector 2 is pulled out or when the AC adapter 2 fails, power is supplied to the recording unit 4 as a backup power source. The battery control CPU 31 of the power supply device 3 functions as a power supply control unit, and when the voltage supplied from the AC adapter 2 decreases, detects the decrease in voltage and executes voltage conversion by the booster circuit 35. Let

The output line of the AC adapter 2 is connected to the node N1 on the output line of the power supply device 3 via the diode D1, and the output stage of the booster circuit 35 is connected via the diode D2. Node N1 is connected to the cathodes of diodes D1 and D2. The diodes D1 and D2 are so-called diode OR circuits. If at least one of the AC adapter 2 and the booster circuit 35 supplies power, the power on the higher voltage side is supplied to the system power supply unit 5. Output circuit. Further, the diodes D1 and D2 prevent current from flowing from the AC adapter 2 to the booster circuit 35, and conversely, current from the booster circuit 35 to the AC adapter 2 is prevented.
In the configuration of the present embodiment, the voltage output from the booster circuit 35 is the same as or slightly lower than the voltage input from the AC adapter 2. For this reason, while the rated voltage power is supplied from the AC adapter 2, the power output from the booster circuit 35 is not consumed, and the power from the AC adapter 2 is supplied to the system power supply unit 5. Further, when the input voltage of the AC adapter 2 falls below a predetermined threshold value, the power output from the booster circuit 35 is supplied to the system power supply unit 5 if the booster circuit 35 outputs power of the predetermined voltage. Is done.
On the output line of the AC adapter 2 connected to the node N1, a switch SW1 that is opened and closed under the control of the battery control CPU 31 is provided. When this switch SW1 is opened, power supply from the AC adapter 2 to the node N1 is cut off. .

The step-up circuit 35 (step-up means) is a circuit for stepping up the output voltage of the battery 10 to a voltage necessary for driving the drive unit 40. When the battery 10 is configured with a secondary battery that is smaller than the main body of the printer 1, it is relatively difficult to increase the discharge voltage. Therefore, the voltage required by the drive unit 40, that is, the voltage supplied by the AC adapter 2 is higher. Discharge at a low voltage (eg, about 7.2V). For this reason, the power supply device 3 converts the discharge voltage of the battery 10 into a voltage by the booster circuit 35.
On the output line of the battery 10, a switch SW2 that is opened and closed under the control of the battery control CPU 31 is provided, and the power supply from the battery 10 to the booster circuit 35 is cut off by the switch SW2.

  Further, the battery control CPU 31 outputs an enable signal S <b> 1 for controlling the operation of the booster circuit 35 to the booster circuit 35. The enable signal S1 may be either active high or active low. When the enable signal S1 is in an inactive state, the booster circuit 35 does not perform voltage conversion, and performs voltage conversion and outputs power while the enable signal S1 is active.

FIG. 2 is a circuit diagram showing the configuration of the booster circuit 35 in detail.
The booster circuit 35 includes a coil L1 and a diode D3 arranged in series between the input side node N2 and the output side node N3, a capacitor C1 connected to one end of the coil L1, and the other end of the coil L1. FET (Field Effect Transistor) as a switch connected to the anode side of the diode D3, a capacitor C2 connected in parallel with the FET on the cathode side of the diode D3, and a control IC 37 (step-up control means) for turning on / off the FET And have. The other ends of the capacitors C1 and C2 are grounded, the drain of the FET is connected to the coil L1, the source is grounded, and the gate is connected to the control IC 37.
Node N2 is connected to switch SW2 (FIG. 1), and node N3 is connected to system power supply unit 5 (FIG. 1). A capacitor C1 that stabilizes the input voltage from the battery 10 is connected in parallel to the FET on the anode side of the diode D3.

  While the enable signal S1 input from the battery control CPU 31 (FIG. 1) is active, the control IC 37 outputs a pulse to the gate of the FET to perform switching at a predetermined cycle. In the booster circuit 35, when the FET is turned on, a current flows through the coil L1 and the capacitor C2 is charged. When the FET is turned off, a high voltage counter electromotive force is generated in the coil L1, and both ends of the capacitor C2 are generated by the counter electromotive force. The voltage increases, and the current boosted by repeating this operation is rectified by the diode D3 and output from the node N4. That is, voltage conversion is performed under the control of the control IC 37 while the enable signal S1 is active, and voltage conversion is not performed when the enable signal S1 is in an inactive state.

  The control IC 37 has a feedback circuit that holds the output voltage of the booster circuit 35 at a predetermined voltage. A voltage obtained by dividing the voltage of the node N4 by the voltage dividing resistors R1 and R2 is input to the feedback terminal 39 of the control IC 37, and the control IC 37 determines the FET based on the voltage value input to the feedback terminal 39. Is adjusted to stabilize the output voltage of the booster circuit 35 at a predetermined voltage (for example, 24 V).

  The battery control CPU 31 (FIG. 1) is connected to a line to which power is supplied from the AC adapter 2 and detects whether or not the output voltage of the AC adapter 2 is within an appropriate range. It has.

FIG. 3 is a circuit diagram showing a configuration of the voltage drop detection unit 32.
The voltage drop detection unit 32 compares the voltage dividing resistors R11 and R12 that divide the output voltage of the AC adapter 2 with the input voltage divided by the resistors R11 and R12 and the reference voltage B1, and the input voltage is the reference voltage. And a comparator 38 that interrupts the battery control CPU 31 when B1 or less. The reference voltage B <b> 1 (predetermined voltage) is configured using, for example, a battery provided in the power supply device 3 separately from the battery 10. The voltage value of the reference voltage B1 is determined in advance based on the voltage required for normal operation of the drive unit 40 or the rated output voltage of the AC adapter 2 and the voltage dividing ratio of the voltage dividing resistors R11 and R12. ing.
The battery control CPU 31 detects a drop in the output voltage of the AC adapter 2 by interruption from the voltage drop detection unit 32.
Also, when the output voltage of the AC adapter 2 rises from a voltage equal to or lower than the reference voltage B1 to a voltage exceeding the reference voltage B1, the output of the comparator 38 is inverted and an interrupt is generated in the battery control CPU 31. For this reason, the battery control CPU 31 can also detect an increase in the output voltage of the AC adapter 2.

The power supply device 3 configured as described above normally outputs power supplied from the AC adapter 2 to the system power supply unit 5 and detects a drop in the output voltage of the AC adapter 2 to supply power to the AC adapter 2. Is switched to the battery 10, and the electric power discharged from the battery 10 is supplied to the system power supply unit 5.
That is, the battery control CPU 31 switches on the switch SW1 and the switch SW2 when the printer 1 is turned on, starts supplying power from the AC adapter 2 to the node N1, and discharges from the battery 10 to the booster circuit 35. To. Further, the battery control CPU 31 sets the enable signal S1 in an inactive state so that the booster circuit 35 does not perform voltage conversion, and supplies power from the AC adapter 2 to the system power supply unit 5.

The battery control CPU 31 monitors the output voltage of the AC adapter 2 by the voltage drop detection unit 32, and activates the enable signal S1 when the output voltage of the AC adapter 2 drops below a predetermined voltage and an interrupt occurs. The voltage conversion by the booster circuit 35 is started by switching. Thereafter, power of a predetermined voltage is output from the booster circuit 35, and this power is supplied from the node N1 to the system power supply unit 5.
Here, the battery control CPU 31 may switch off the switch SW1 when the enable signal S1 is switched to active or after the voltage-converted current is output from the booster circuit 35. In this case, since the power is not supplied from the AC adapter 2 to the node N1 while the output voltage of the AC adapter 2 recovers to a voltage value exceeding the predetermined voltage, the power supply is frequently switched in accordance with the fluctuation of the supply voltage of the AC adapter 2. Undesirable operation can be prevented.

Thereafter, when the battery control CPU 31 detects that the output voltage of the AC adapter 2 has risen to exceed a predetermined voltage by the function of the voltage drop detection unit 32, the battery control CPU 31 is turned on if the switch SW1 is turned off. The signal S1 is switched to the inactive state to stop the voltage conversion of the booster circuit 35. As a result, power is supplied from the AC adapter 2 to the system power supply unit 5 via the node N1.
Here, the battery control CPU 31 has a voltage value higher than the predetermined voltage (reference voltage B1) when the output voltage of the AC adapter 2 exceeds the predetermined voltage (reference voltage B1) for a predetermined time or longer. When the value exceeds the value, the switch SW1 may be turned on to supply the power of the AC adapter 2 to the drive unit 40.

In the above operation, while the power is supplied from the AC adapter 2, if the switch SW2 is on, power is supplied from the battery 10 to the booster circuit 35, but the booster circuit 35 has the enable signal S1 active. Otherwise, since the FET is not switched, only the control IC 37 consumes power. Therefore, the power consumption of the battery 10 during the power supply of the AC adapter 2 can be suppressed to an extremely small level.
On the other hand, when power supply from the battery 10 to the system power supply unit 5 is required due to a drop in the output voltage of the AC adapter 2, the switch SW2 is already on, so the battery control CPU 31 switches the enable signal S1 to active. As soon as the control IC 37 starts switching the FET, a high-voltage current is output from the booster circuit 35. Therefore, the power supply device 3 can quickly switch the power supply from the AC adapter 2 to the battery 10.

  The switches SW1 and SW2 may not be turned on / off independently as described above, but may be turned on / off at the same time. While the switches SW1 and SW2 are on, power is supplied from the AC adapter 2 or the battery 10 to the system power supply unit 5. While the power from the AC adapter 2 is supplied to the system power supply 5, the booster circuit 35 does not perform voltage conversion, so that the power of the battery 10 is not wasted even if the switch SW2 is on. Since the output voltage of the AC adapter 2 is low while the power of the battery 10 is supplied to the system power supply unit 5, even if the switch SW1 is on, the power of the AC adapter 2 is controlled by the function of the output circuit of the diodes D1 and D2. Is not supplied, so there is no problem. Therefore, if the battery control CPU 31 simultaneously turns on and off the switches SW1 and SW2 in conjunction with the power on / off of the printer 1, the power consumption of the printer 1 in the power off state becomes zero. There is. In this case, a common control line may be used to connect the battery control CPU 31 and the switches SW1 and SW2. Alternatively, the switches SW1 and SW2 may be turned on / off mechanically or electrically in conjunction with a power switch (not shown) of the printer 1 without being controlled by the battery control CPU 31.

  The battery control CPU 31 outputs a control signal to the recording control CPU 41 when the enable signal S1 for the booster circuit 35 is switched to active and when the enable signal S1 is switched to the inactive state. Therefore, the recording control CPU 41 can determine whether the recording unit 4 is driven with the power of the AC adapter 2 or with the power of the battery 10.

  For example, the recording control CPU 41 can execute two types of recording operations, that is, a power saving mode and a normal operation mode. The recording control CPU 41 operates in the power saving mode while being driven by the power of the battery 10 and uses the power of the AC adapter 2. While being driven, it operates in the normal operation mode. In the power saving mode, for example, the rotation speed of the transport motor 44 is set lower than that in the normal operation mode. In this case, the peak of power consumption, that is, the current peak of the transport motor 44 is suppressed, and the current supplied to the recording head 45 is also controlled in accordance with the transport speed of the roll paper as the recording medium. Such an operation in the power saving mode is an operation suitable for driving with the battery 10 whose current capacity is limited, and can be driven for a longer time with the limited power of the battery 10. In addition, since the discharge load of the battery 10 can be reduced, the life of the battery 10 can be extended. Furthermore, by reducing the operation of the drive unit 40 in the power saving mode, it is possible to prevent the operation of the drive unit 40 from becoming unstable due to insufficient power, and to operate stably at a low speed. Quality degradation can be prevented.

  As described above, the printer 1 according to the embodiment to which the present invention is applied includes the conveyance motor 44 that conveys roll paper as a recording medium and the recording head 45 that records on the roll paper, and is connected to the commercial AC power supply P. The drive unit 40 that operates by receiving power supply from the AC adapter 2 or the battery 10, the recording control CPU 41 that controls the drive unit 40 to execute recording, and the power supplied from the battery 10 operates the drive unit 40. A booster circuit 35 that converts the voltage into a voltage and outputs the power, and a power supply device 3 that supplies power to the drive unit 40 based on power supplied from the AC adapter 2 based on the commercial AC power supply P or power supplied from the battery 10 When the voltage supplied from the AC adapter 2 drops, the power supply device 3 supplies power supplied from the battery 10. Is supplied to the drive unit 40 and a signal indicating a change in the power supply is output to the recording control CPU 41. Therefore, when the voltage supplied from the AC adapter 2 drops, the battery 10 responds to this voltage drop. Is supplied to the system power supply unit 5 instead of the AC adapter 2 to reduce the power consumption of the battery 10 when the AC adapter 2 is used, and when the drive unit 40 cannot be operated by the AC adapter 2, The power supply is quickly switched to the battery 10. Since the recording control CPU 41 can be notified that the power source has been changed from the AC adapter 2 to the battery 10, for example, the recording control CPU 41 performs control so as to suppress the power consumption amount and current amount of the drive unit 40, and the operation of the printer 1. Can be adapted to battery drive.

  Further, the power supply device 3 of the printer 1 converts the power supplied from the battery 10 into an operating voltage of the drive unit 40 and outputs the voltage, the power output from the booster circuit 35, and the power supplied from the AC adapter 2. And an output circuit that selectively outputs the power to the drive unit 40, and the output circuit outputs the power supplied from the AC adapter 2 to the drive unit 40 unless the booster circuit 35 performs voltage conversion. When the booster circuit 35 outputs the voltage-converted power, the power output by the booster circuit 35 is output to the drive unit 40. That is, the output circuit constituted by the diodes D1 and D2 is supplied from the AC adapter 2 if the voltage supplied from the AC adapter 2 is higher, such as when the booster circuit 35 is not performing voltage conversion. Power to the drive unit 40. In addition, when the voltage supplied from the AC adapter 2 decreases and the booster circuit 35 outputs voltage-converted power, the power output from the booster circuit 35 is higher if the voltage output from the booster circuit 35 is higher. Is output to the drive unit 40. As described above, the power supply of the driving unit 40 is appropriately switched depending on the change of the voltage supplied from the AC adapter 2 by the output circuit and whether or not the booster circuit 35 that converts the voltage of the battery 10 is operated. Therefore, power can be stably supplied to the drive unit 40 without using a complicated circuit configuration. Further, while the voltage supplied from the AC adapter 2 is high, the power consumption of the battery 10 can be suppressed, and the power of the battery 10 can be used efficiently.

Further, since the power supply device 3 includes the battery control CPU 31 that executes voltage conversion by the booster circuit 35 when the voltage supplied from the AC adapter 2 decreases, the booster circuit 35 accurately executes and stops the voltage conversion. Can be controlled.
The booster circuit 35 includes a coil L1 through which the output current of the battery 10 flows, an FET that turns on / off the current flowing through the coil L1, a capacitor C2 that accumulates counter electromotive force generated in the coil L1, and a control IC 37 that drives the FET. The battery control CPU 31 outputs an enable signal to the control IC 37 while the power supplied from the AC adapter 2 is equal to or lower than a predetermined voltage, and the control IC 37 is enabled by the battery control CPU 31. While the signal is input, T is driven, and voltage conversion is executed by the coil L1 and the capacitor C2. For this reason, since the booster circuit 35 does not perform switching while the printer 1 is operated by the AC adapter 2, the consumption of the battery 10 during operation by the AC adapter 2 can be minimized. Then, when an enable signal is input along with a voltage drop of the AC adapter 2, switching is started and power based on the battery 10 can be output quickly.

The printer 1 also includes switches SW1 and SW2 that cut off power supply from the AC adapter 2 and the battery 10 to the output circuit. For example, when the printer 1 is stopped, the power supply from the AC adapter 2 and the battery 10 is cut off. By doing so, power consumption of the AC adapter 2 and the battery 10 while the printer 1 is not operating can be suppressed.
Further, since the output circuit is configured by diode OR-connecting a line to which power is supplied from the AC adapter 2 by the diodes D1 and D2 and a line from which the booster circuit 35 outputs power, the circuit is switched. If the power supplied from the AC adapter 2 and the power from the battery 10 are appropriately selected and supplied, and the voltage of the AC adapter 2 drops below a predetermined voltage, the booster circuit is operated to quickly In addition, the power of the battery 10 can be supplied to the drive unit 40.

  Further, the recording control CPU 41 drives the drive unit 40 in the power saving mode based on the signal input from the battery control CPU 31 to suppress the power consumption of the drive unit 40, thereby limiting the limited power of the battery 10. The printer 1 can be driven for a longer time. In addition, since the discharge load of the battery 10 can be reduced, the life of the battery 10 can be extended.

  The power supply device 3 to which the present invention is applied is connected to a printer 1 having a drive unit 40 and a recording control CPU 41 that controls the drive unit 40 to execute recording. When power is supplied to the drive unit 40 based on the power supplied from the battery 10 and the voltage supplied from the AC adapter 2 is reduced, the power supplied from the battery 10 is supplied to the drive unit 40 and recording is performed. Since a signal indicating the change of the power supply is output to the control CPU 41, when the voltage supplied from the AC adapter 2 drops, the power from the battery 10 is converted into a voltage by the booster circuit in response to the voltage drop, Supply to the drive unit 40. Therefore, it is possible to suppress power consumption of the battery 10 when the AC adapter 2 is used, and to supply power by quickly switching between the AC adapter 2 and the battery 10. Since the recording control CPU 41 can be notified that the battery 10 has been switched to the power supply, for example, the recording control CPU 41 controls the power consumption and current amount of the drive unit 40 to control the operation of the printer 1. Thus, it is possible to adapt the driving to the battery 10.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this. For example, in the above-described embodiment, the configuration in which the diode D1 is provided on the output line of the AC adapter 2 and the diode D2 is provided on the output line of the booster circuit 35 has been described as an example. However, the present invention is not limited thereto. Instead, the output line of the AC adapter 2 and the output line of the booster circuit 35 may be simply connected to the node N1, and a parasitic diode such as an FET is provided as a switch for turning on / off the current flowing through the coil L1. It is effective when not using anything. In the above embodiment, the case where the printer 1 includes the battery 10 has been described as an example. However, a power supply device such as a battery is installed outside the printer 1, and a backup direct current is supplied from the power supply device to the printer 1. A configuration may be employed in which power is supplied. Further, the power supply device 3 may include a charging circuit that charges the battery 10. The circuit configurations shown in FIGS. 2 and 3 are merely examples, and other circuit configurations that can realize the same functions as the circuits of FIGS. 2 and 3 can be used. It is of course possible to replace a part with an equivalent circuit.

  In the above embodiment, a thermal printer that performs recording by applying heat to the thermal roll paper by the recording head 45 has been described as an example, but the present invention is not limited to this, and a thermal sublimation printer, The present invention may be applied to an ink jet printer and a dot impact printer. In this case, the recording head may be mounted on the carriage, and the carriage may be scanned perpendicular to the recording medium conveyance direction. In this case, the carriage driving motor is included in the driving unit 40. Further, a roll paper in which plain paper is wound in a roll shape, various standard size cut papers, and fanfold paper obtained by folding continuous paper may be used as the recording medium. Furthermore, the present invention is also applicable to various printers incorporated in other devices. The program executed by the recording control CPU 41 that performs the above-described operation is not limited to the ROM 42 provided in the printer 1, but is stored in another storage device, a storage medium, or a storage medium of an external device, and is read and executed by the recording control CPU 41. It is good also as a structure.

  DESCRIPTION OF SYMBOLS 1 ... Printer (recording apparatus), 2 ... AC adapter (external power supply), 3 ... Power supply apparatus, 4 ... Recording part, 5 ... System power supply part, 10 ... Battery, 31 ... CPU for battery control (power supply control means), 32 DESCRIPTION OF SYMBOLS ... Voltage drop detection part, 35 ... Boosting circuit (boosting means), 38 ... Comparator, 39 ... Feedback terminal, 40 ... Drive part, 41 ... Recording control CPU (recording control means), 44 ... Conveyance motor (conveyance part) 45, recording head, 100, host computer, B1, reference voltage, D1, D2, diode (output circuit), S1, enable signal, SW1, SW2, switch (cutoff switch).

Claims (8)

A drive unit that includes a conveyance unit that conveys the recording medium and a recording head that performs recording on the recording medium, and operates by receiving power supply from an external power source or a battery;
Recording control means for controlling the driving unit to execute recording;
A power supply device that supplies power to the drive unit based on power supplied from the external power supply or power supplied from the battery, and
When the voltage supplied from the external power supply decreases, the power supply device supplies power supplied from the battery to the drive unit and outputs a signal indicating a change in power supply to the recording control unit To do,
A recording apparatus. The power supply device includes a boosting unit that converts the power supplied from the battery into an operating voltage of the driving unit and outputs the voltage.
An output circuit that selectively outputs the power output from the boosting unit and the power supplied from the external power source to the drive unit;
The output circuit is configured to output the higher one of the electric power supplied from the external power source and the electric power output by the voltage booster by converting the voltage,
The recording apparatus according to claim 1.   The recording apparatus according to claim 2, wherein the power supply device includes a power supply control unit that executes voltage conversion by the boosting unit when a voltage supplied from the external power supply decreases. The boosting means includes a coil through which the output current of the battery flows, a switch for turning on / off the current flowing through the coil, a capacitor for accumulating counter electromotive force generated in the coil, and a boosting control means for driving the switch. And comprising
The power supply control means outputs an enable signal to the boost control means while the voltage supplied from the external power supply is below a predetermined voltage,
4. The recording apparatus according to claim 3, wherein the step-up control unit drives the switch while an enable signal is input from the power source control unit, and performs voltage conversion by the coil and the capacitor. .   5. The recording apparatus according to claim 2, further comprising a cut-off switch that cuts off power supply from the external power source and the battery to the output circuit. 6.   6. The output circuit according to claim 2, wherein a line to which power is supplied from the external power source and a line from which the booster outputs power is diode-ORed. Recording device.   The recording apparatus according to claim 1, wherein the recording control unit drives the driving unit in a power saving mode based on a signal input from the power supply apparatus. A recording unit that includes a conveying unit that conveys the recording medium and a recording head that performs recording on the recording medium, and operates by receiving power from an external power source or a battery; and a recording control unit that controls the driving unit to perform recording Connected to a recording device comprising
Supplying power to the drive unit based on power supplied from the external power supply or power supplied from the battery;
Supplying power supplied from the battery to the drive unit when the voltage supplied from the external power supply decreases, and outputting a signal indicating a change in power supply to the recording control unit;
A power supply characterized by.

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