JP4922196B2 - Thermal printer - Google Patents

Description

  The present invention relates to a thermal printer, and in particular, a thermal head that performs printing by heating printing paper, a printing mechanism that includes a paper driving device that drives the printing paper in a sub-scanning direction, and performs printing by controlling the printing mechanism. The present invention relates to a thermal printer that includes a printing control device that performs the above operation, a DC power input unit to which DC power is supplied from the outside, and a rechargeable battery that can be charged with the input DC power.

  As a thermal printer, there is a handy type printer that prints a label or the like attached to a product. Such a thermal printer prints a label on which product information including a product code symbol such as a barcode is printed.

  Such a thermal printer operates using a rechargeable battery mounted therein as a power source. As the rechargeable battery, a lithium ion battery, a nickel-hydrogen battery, or the like is employed. For this reason, in a handy-type thermal printer, it is common to use a thermal head that operates at a low voltage (-10 V).

  Moreover, the thermal printer provided with a rechargeable battery is provided with an external DC input terminal, and takes in DC power from a DC power supply device and charges the rechargeable battery. As the DC power supply device, an AC adapter that supplies DC power from commercial AC power, a car adapter that extracts DC power from a vehicle battery, or the like is used.

  A case where an AC adapter is used will be described. As the AC adapter connected to the thermal printer, there are an AC adapter dedicated to charging and an AC driving adapter that performs charging and driving of the printer.

  FIG. 6 is a schematic block diagram showing a connection state between the thermal printer and the charging AC adapter. In this example, the thermal printer 500 is provided with a thermal head 510 having an allowable voltage of 10V and a rechargeable battery 520 having a charging voltage of 8.4V. This AC adapter 550 is rated for an input AC of 100 V and a DC output of 9 to 9.5 V, and is a charge-only product. The amount of power supplied to the AC adapter 550 is small, and the thermal head 510 and the like cannot be driven. Accordingly, when printing is performed by the thermal printer 500, the thermal head 510 and the like are driven by the charged rechargeable battery 520.

  FIG. 7 is a schematic block diagram showing a thermal printer and an AC adapter for both charging and device driving. In this example, the thermal printer 600 includes a thermal head 610 having an allowable voltage of 10V, a rechargeable battery 620 having a charging voltage of 8.4V, and a charge driving circuit 630. This AC adapter 650 is rated for an input AC of 100V and a DC output of 9 to 9.5V. The AC adapter 650 can supply a large amount of power that can drive the thermal head 610 and the like. The charging drive circuit 630 can drive the thermal head 610 and the like while charging the rechargeable battery 620 with DC power from the AC adapter 650.

  Patent Document 1 describes a portable printer that is driven by power supplied from either a rechargeable battery or an external power source and performs printing with a thermal head. This portable printer measures the drive voltage, determines whether the power is supplied from the rechargeable battery or the external power source based on the measured value, and differentiates the printing operation according to the determination result. The control conditions suitable for each of the rechargeable battery and the external power source having different voltage values are selected so that stable print quality can be obtained.

JP 2000-2111194 A

  As described above, the AC adapter described above has a relatively low voltage (9 V to 9.V) in accordance with the allowable voltage (-10 V) of the thermal head of the thermal printer to be used and the specifications of the rechargeable battery that drives the thermal printer. It is necessary to use a special one that outputs 5V).

  However, general-purpose AC adapters generally have a high output DC voltage (for example, 20V). For this reason, the AC adapter for charging the thermal printer must be a dedicated product for the thermal printer. Similarly, the AC adapter for charging and driving the device is required to have a low voltage and a large amount of power, which must be a dedicated product. In any case, such a dedicated AC adapter is less expensive and more expensive than a general-purpose AC adapter, which increases the cost. In addition, a thermal printer using a rechargeable battery having a different charging voltage or a thermal head having a different allowable voltage has to be provided with a dedicated AC adapter for each, which increases the cost.

  Accordingly, an object of the present invention is to provide a thermal printer that can charge a rechargeable battery with an inexpensive general-purpose DC power supply device.

  In the present invention, means for solving the above-described problems includes a thermal head that performs printing by heating printing paper, a printing mechanism that includes a paper driving device that drives the printing paper in a sub-scanning direction, and the printing mechanism. In a thermal printer comprising a print control device that performs printing by controlling, a DC power input unit that is supplied with DC power from the outside, and a rechargeable battery that can be charged with the input DC power, the input DC A voltage changing device that changes the power to a voltage suitable for charging the rechargeable battery, and in a state where DC power is supplied from the outside to the DC power input portion, the power from the DC power input portion is sent to the print control device. A power supply device that supplies power from the rechargeable battery to the print control device in a state where DC power is not supplied from the outside to the DC power input unit, and the DC power input A power monitoring device that monitors the voltage of the DC power from the power supply unit, and a power cutoff that turns off the DC power from the DC power input unit when the voltage of the DC voltage detected by the power monitoring device is out of a predetermined range And a power source switching device that uses one of the power from the DC power input unit and the power from the rechargeable battery as the driving power of the printing mechanism, and DC power is supplied to the DC power input unit from the outside And a power control device that activates the power supply switching device to use the driving power of the printing mechanism as the power of the rechargeable battery when receiving a print signal from the print control device in a state. It is a printer.

  According to the thermal printer of the present invention, even if high voltage DC power exceeding the allowable charging voltage is input from the DC power input unit, the voltage can be converted into a voltage suitable for charging the rechargeable battery by the voltage changing device. A general-purpose AC adapter that outputs a voltage higher than the allowable voltage can be used, and the cost of the thermal printer can be reduced. In addition, when a printing instruction is input during charging, the power switching device changes the power supply to the printing mechanism to a rechargeable battery according to the instruction from the power control device, so printing is performed even during charging without damaging the thermal head. be able to.

  Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the thermal printer is a thermal portable printer in which a paper roll on which thermal paper is wound is housed and printing is performed by driving a thermal head with a rechargeable battery.

  A schematic structure of the thermal printer 100 will be described. FIG. 1 is a perspective view illustrating an appearance of a printer according to an embodiment.

  The thermal printer 100 has a rectangular parallelepiped appearance, and the printing unit of the thermal printer 100, each functional unit that performs a sheet feeding function, and a rechargeable battery are housed in a housing 101. In this example, a lithium ion rechargeable battery is used as the rechargeable battery. The housing 101 has an internal structure that can store a paper roll on which printing paper made of thermal paper is wound, and an opening 102 is formed on the upper surface so that the paper roll can be introduced inside. A cover 103 is rotatably disposed in the opening 102, and the opening 102 is opened or closed by opening and closing the cover 103.

  The cover 103 is attached to the back side of the housing 101 that forms one side of the opening 102, and the outer side 104 that is the tip side of the cover 103 and the front side that is one side of the opening 102 with the cover 103 closed. A paper discharge port 106 is formed between the side edge 105 and a long and narrow gap for taking out printing paper printed in the width direction of the thermal printer 100.

  Further, a connection connector portion 107 and a battery storage portion 108 are disposed on one side surface of the housing 101.

  Further, the housing 101 is provided with a DC power input unit 210 for supplying DC power from the outside. A plug 404 of the AC adapter 400 is inserted into the DC power input unit 210, and DC power is supplied to the thermal printer 100.

  The AC adapter 400 is formed separately from the thermal printer 100 and is inserted into an external commercial power outlet to output DC power. The AC adapter 400 includes a main body 401 having a DC conversion circuit therein, an outlet plug 402 attached to the main body 401, a DC power output cable 403, and a plug 404. The AC adapter 400 is input from the outlet plug 402. The power of AC 100V is output as DC 20V to the plug 404 at the tip of the cable 403.

  In addition, as a device for supplying DC power from the DC power input unit 210, a car adapter (input / output 12V), a DC-DC converter (input 10 to 60V, output 20V) and the like are used in addition to the general-purpose AC adapter. Can do.

  By connecting the plug 404 to the DC power input unit 210, DC power is supplied to the thermal printer 100, and the rechargeable battery 270 (see FIG. 2) can be charged.

  Next, charging control of the thermal printer 100 will be described. FIG. 2 is a block diagram conceptually showing the control system of the printer according to this example.

  The thermal printer 100 includes a power control circuit 200 inside the housing 101. The power control circuit 200 includes a DC power input unit 210, a voltage changing device 220, a power monitoring device 230, a power control device 240, a power cutoff device 250, a power switching device 260, and a system power supply that is a power supply device. A supply circuit 280 and a print control device 290 are provided. The thermal printer 100 includes a rechargeable battery 270 and a printing mechanism 300.

  The printing control device 290 controls a printing mechanism control circuit 291 that controls the printing mechanism, an interface circuit 292 that exchanges signals with the outside, and calculations necessary to control the entire thermal printer 100. And an arithmetic / control circuit 293.

  The printing mechanism 300 includes a thermal head 301 that heats and prints printing paper based on print data from the printing control device 290, a stepping motor that transmits the printing paper according to the control of the printing mechanism control circuit 291, a transmission, A sheet driving device 302 including a sheet conveying roller and a sensor 303 that detects the position of the printing sheet and the environmental temperature are provided.

  The voltage changing device 220 converts a DC power voltage within a predetermined voltage range (for example, 10 V to 25 V) input from the DC power input unit 210 to a voltage (for example, 8.4 V or 16.5) suitable for charging the rechargeable battery 270. 8V: Varies depending on the specifications of the rechargeable battery). In this example, since the rechargeable battery 270 is a lithium ion rechargeable battery, the CC / CV charging method, that is, the external DC voltage is stepped down to perform constant current voltage charging.

  In addition, the voltage changing device 220 can be set to a long life mode that can extend the life of the battery by making the charging voltage and current variable and adjusting the recharging threshold during charging.

  The power monitoring device 230 monitors the voltage of the DC power from the DC power input unit 210.

  When the voltage of the DC voltage detected by the power monitoring device 230 is out of a predetermined range (10V to 25V), the power cutoff device 250 puts the DC power from the DC power input unit 210 into a cutoff state.

  The power switching device 260 switches the driving power supplied to the printing mechanism 300 to one of the power from the DC power input unit 210 and the power from the rechargeable battery.

  The power control device 240 performs the following control on the power cutoff device 250 and the power supply switching device 260.

  First, based on the detection result of the power monitoring device 230, when the DC power from the DC power input unit 210 is in the predetermined range (10V to 25V), the power supply switching device 260 is operated, DC power is conducted to the voltage changing device 220. Thereby, DC power (8.4 V) for charging is supplied from the voltage changing device 220 to the rechargeable battery 270. In this state, power from the DC power input unit 210 is also supplied to the system power supply circuit 280.

  In addition, when the power control device 240 receives a print signal from the print control device 290 in a state where DC power is supplied from the outside to the DC power input unit, the power control device 240 operates the power supply switching device 260 to operate the print mechanism. The driving power of 300 is the power of the rechargeable battery. Thereby, when there is a print instruction, the power from the DC power input unit 210 to the print mechanism 300 is cut off. However, the power to the print control device 290 is supplied from the DC power input unit 210 when the voltage from the DC power input unit 210 is within a predetermined range.

  Further, even when there is no print instruction, the power control device 240 drives the power supply switching device 260 to drive the system power supply circuit 280 when the voltage of the DC power detected by the power monitoring device 230 is lower than the voltage of the rechargeable battery. Power is supplied from the rechargeable battery.

  The system power supply circuit 280 supplies power to each part of the printing mechanism 300 via the printing control device 290. Electric power is applied to the thermal head 301 of the printing mechanism 300 within the allowable voltage range. That is, when the printer performs printing, the power from the DC power input unit 210 is cut off by the power cut-off device 250, and the power from the rechargeable battery 270 is supplied from the power switching device 260. No voltage exceeding the allowable voltage of 301 is supplied.

  Further, the system power supply circuit 280 supplies power (voltage, 5V, 3.3V, 1.5V, etc.) for driving the print control device 290. As described above, the system power supply circuit 280 is set with an operation input voltage to each unit so that the system power supply circuit 280 can operate properly within the range of the external DC power and the voltage of the rechargeable battery.

  The system power supply circuit 280 controls on / off of each power supply system that is driven by DC power from the rechargeable battery 270 and the DC power input unit 210. That is, the system power supply circuit 280 supplies the DC power from the DC power input unit 210 to the print control device 290 in a state where DC power is supplied to the DC power input unit 210, and the DC power input unit 210. In the state where the DC power is not supplied to the printer, the DC power from the rechargeable battery 270 is supplied to the print control device 290.

  The system power supply circuit 280 supplies the DC power to the printing mechanism 300 via the print control device 290 when the power control device 240 supplies the DC power from the rechargeable battery 270 to the print control device 290. .

  The print control device 290 controls the entire thermal printer 100. That is, the print control device 290 controls the printing mechanism 300 and also acquires information from the voltage change device 220 and the system power supply circuit 280 when supplying power, and the voltage change device 220 and the system power supply circuit 280 When the charging condition is satisfied, an instruction to start charging is sent to the power control device 240.

  The print control device 290 controls the entire thermal printer 100. That is, the thermal printer 100 according to this example is set to various state modes depending on the situation. The modes include a standby mode in which printing by the thermal head 301 is immediately performed, a sleep mode in which the system is in an energy saving state to reduce power consumption, a printing mode in which printing is performed with a thermal head, a charging mode in which a rechargeable battery is charged, a charging mode A long-life charging mode is set in which charging is performed at a low voltage that does not shorten the battery life.

  Transition to each mode is controlled as follows.

  First, at the time of driving with a rechargeable battery, a sleep mode is entered after a predetermined time has elapsed from the standby mode. In the sleep mode, the power supply of unnecessary function units is closed, and only waiting for the interface circuit 292 is performed. When it is necessary to operate the printing mechanism 300 in the sleep mode or when transmission / reception of the interface circuit 292 occurs, the normal standby mode is restored.

  When DC power is supplied from the outside, the sleep mode is not entered, and the normal standby mode is set. As a result, the start to the print mode can be made faster. In the standby mode, charging of the rechargeable battery 270 is controlled by the voltage changing device 220 while waiting for the interface circuit 292.

  With the above-described configuration, the thermal printer 100 is controlled and operated as follows. FIG. 3 is a flowchart showing the operation of the printer.

  First, in the standby mode or the sleep mode, the power monitoring device 230 determines whether the input DC voltage is within a predetermined power range (10V to 25V) (ST1).

  When the input DC power voltage is not within the predetermined range (no of ST1), that is, when DC power is not supplied, or when the DC voltage is less than 5V or exceeds 25V, the power saving mode Depending on the setting state (ST2), the thermal printer 100 enters the sleep mode (ST3) or the standby mode (ST4). When printing is instructed in this state, the thermal printer 100 operates with the rechargeable battery 270.

  When the standby mode is entered, the sleep mode can be entered after a certain period of time to prevent the rechargeable battery from being consumed. Further, when in the sleep mode, it is possible to return to the normal standby mode when the operation of the print driving unit or interface input / output occurs.

  When the voltage is within the predetermined range (YES in ST1), the following processing is performed depending on the presence or absence of a print command from the print control device 290 (ST5).

  That is, when there is no print instruction (no in ST5), the rechargeable battery 270 is charged with DC power from the DC power input unit 210 via the voltage changing device 220. At this time, the thermal printer 100 enters the normal charging mode (ST7) or the long-life charging mode (ST8) depending on the setting state of the long-life charging mode (ST6).

  In each charging mode, the thermal printer 100 is also in a standby mode that allows the system to be activated early. When the external DC power is lower than the set minimum voltage, the thermal printer 100 is set in the sleep mode. can do.

  On the other hand, when there is a print instruction from the print control device 290 in a state where a predetermined voltage is supplied to the DC power input unit 210 (YES in ST5), the power control device 240 causes the DC power input from the DC power input unit 210. The power is supplied to the printing mechanism 300 from the rechargeable battery 270 via the system power supply circuit 280 (ST9), the thermal printer 100 is set to the printing mode (ST10), and the printing mechanism is controlled under the control of the printing control device 290. Printing is performed by driving the thermal head 301 of 300 and the paper driving device 302 by the rechargeable battery 270. At this time, the DC power from the DC power input unit 210 is supplied from the system power supply circuit 280 to the print control device 290.

  The reason for cutting off the DC power from the outside before supplying power from the rechargeable battery 270 to the printing mechanism 300 in Step 9 is as follows. That is, during charging, the voltage on the power supply switching device 260 side in FIG. 2 is higher than the voltage of the rechargeable battery 270, so that no current can flow.

  Next, the types of DC power supply devices that can be used in the thermal printer 100 according to this example will be described.

  FIG. 4 is a block diagram showing an example of a DC power supply device that can be used in the thermal printer according to the embodiment.

  In the example illustrated in FIG. 4, the thermal printer 100 includes a thermal head 301, a rechargeable battery 270, and a power control circuit 200. In this thermal printer 100, the thermal head 301 has an allowable voltage of 10V, the rechargeable battery 270 is of the 2-cell type, and is charged at 8.4V. Then, the voltage changing device 220 of the power control circuit 200 converts the input DC10V to 25V to 8.4V and charges the rechargeable battery 270.

  In this example, an AC adapter 410 that is a general-purpose product can be used. The AC adapter 410 has an input AC of 100 V to 240 V and an output DC of 20 V. The DC 20V power input to the thermal printer 100 is converted to 8.4V by the voltage changing device 220 of the power control circuit 200 and the rechargeable battery 270 is charged.

  In this example, a car adapter 420 that is a general-purpose product can be used. This car adapter 420 outputs the electric power from the battery of the vehicle which is DC12V as it is. The DC 12V power input to the thermal printer 100 is converted to 8.4V by the voltage changing device 220 of the power control circuit 200 and the rechargeable battery 270 is charged.

  Further, in this example, a general-purpose DC-DC converter 430 can be used. This DC converter 430 outputs the electric power from the battery of the vehicle which is DC24V as DC20V. The DC 20V power input to the thermal printer 100 is converted to 8.4V by the voltage changing device 220 of the power control circuit 200 and the rechargeable battery 270 is charged.

  FIG. 5 is a block diagram showing an example of a DC power supply device that can be used in a thermal printer according to another embodiment. In this example, the thermal printer 100A includes a thermal head 301A, a rechargeable battery 270A, and a power control circuit 200A. In this thermal printer 100A, the thermal head 301A has a withstand voltage of 18V, and the rechargeable battery 270A is of a 4-cell type, and is charged at 16.8V. And the voltage change apparatus 220 of 200 A of electric power control circuits converts DC19V-25V input into 16.8V, and charges rechargeable battery 270A.

  In this example, a general-purpose DC-DC converter 440 can be used. The DC converter 440 outputs the electric power from the vehicle battery, which is DC24V, as DC20V. The DC 20V power input to the thermal printer 100A is converted to 16.8V by the voltage changing device of the power control circuit 200A, and the rechargeable battery 270A is charged.

  As described above, according to the thermal printer 100 according to the embodiment, a general-purpose DC power supply device that outputs a voltage higher than the allowable voltage of the thermal head that cannot drive the thermal head can be used. Cost can be reduced. In addition, according to this embodiment, even for a rechargeable battery with a different specification and a thermal printer using a thermal head, the rechargeable battery can be charged with a general-purpose DC power supply device without preparing a dedicated product individually. This eliminates the need to prepare a dedicated DC power supply for charging in many models.

  In the above embodiment, the power monitoring device and the power control device that monitor the input power from the DC power input unit are separated from the power cutoff device that performs power cutoff control and the power switching device that performs switching control. In the example shown in Fig. 2, the power is cut off from the DC power input unit when receiving a print instruction from the power cut-off device. Even if it is configured to provide a function of switching to supply from the same apparatus, the same apparatus as in the above embodiment can be realized.

1 is a perspective view illustrating an appearance of a printer according to an exemplary embodiment. FIG. 2 is a block diagram conceptually showing a control system of a printer according to this example. It is a flowchart which shows the operation | movement of a printer. It is a block diagram which shows the example of the direct-current power supply device which can be used with the thermal printer which concerns on the example of embodiment. It is a block diagram which shows the example of the direct-current power supply device which can be used with the thermal printer which concerns on another example of embodiment. It is a schematic block diagram which shows the connection state of a thermal printer and the AC adapter for charge. FIG. 2 is a schematic block diagram showing an AC adapter for both a thermal printer and charging / device driving.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Thermal printer, 210 DC power input part, 220 Voltage change apparatus, 230 Power monitoring apparatus, 240 Power control apparatus, 250 Power interruption apparatus, 260 Power supply switching apparatus, 270 Rechargeable battery, 280 System power supply circuit (Power supply apparatus), 300 Printing Mechanism, 301 Thermal Head, 302 Paper Drive Device

Claims (3)

A printing mechanism including a thermal head that heats printing paper to perform printing, a paper driving device that drives the printing paper in a sub-scanning direction, a printing control device that controls the printing mechanism to execute printing, and a direct current from the outside In a thermal printer comprising a DC power input unit to which power is supplied and a rechargeable battery that can be charged with the input DC power,
A voltage changing device for changing the input DC power to a voltage suitable for charging the rechargeable battery;
In a state where DC power is supplied from the outside to the DC power input unit, power from the DC power input unit is supplied to the print control device, and DC power is not supplied from the outside to the DC power input unit Then, a power supply device for supplying power from the rechargeable battery to the print control device,
A power monitoring device that monitors the voltage of DC power from the DC power input unit;
A power cut-off device that cuts off DC power from the DC power input unit when the voltage of the DC voltage detected by the power monitoring device is out of a predetermined range;
A power supply switching device that uses one of the power from the DC power input unit and the power from the rechargeable battery as the driving power of the printing mechanism;
When a print signal is received from the print control device in a state where DC power is supplied from the outside to the DC power input unit, the power switching device is operated to change the drive power of the print mechanism to the power of the rechargeable battery. And a power control device
A thermal printer comprising: The thermal printer can be set to a standby mode in which power is supplied to a specific component device so that printing can be performed immediately and a power saving mode in which power is supplied only to a specific component device so that the device does not stop. Yes,
Set the thermal printer to the standby mode when charging the rechargeable battery with the DC power,
The print control device is configured so that a thermal printer can be set to the power saving mode when the DC power is not supplied and when the rechargeable battery cannot be charged by the power control device. The thermal printer according to claim 1. In order to extend the life of the rechargeable battery, the rechargeable battery can be charged in a long life charge mode that is charged over a long period of time at a voltage lower than the charge voltage used regularly,
3. The thermal printer according to claim 1, wherein the power control device is configured so that the input DC power can be set to a voltage suitable for the long-life charging mode.

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