JP5978641B2 - Printing apparatus and control method thereof - Google Patents

Description

  The present invention relates to a printing apparatus that operates by receiving power from USB bus power and a control method thereof.

  Conventionally, devices that operate only with electric power (USB bus power) from a USB (Universal Serial Bus) interface have been proposed. As such a device, Patent Document 1 describes a digital video camera (imaging device) that operates on USB bus power. This digital video camera detects a terminal for inputting power from a main power supply (AC power supply or battery), a terminal for inputting USB bus power, and whether or not power supplied to each terminal is sufficient. A power detection unit, a main power switch for supplying main power to all blocks of the digital video camera, and a bus power switch for supplying USB bus power to only a part of the blocks of the digital video camera And comprising. In this digital video camera, it is determined whether or not the power from the main power source is sufficient, and when the power from the main power source is sufficient, all the normal operations as a digital video camera are possible. When the main power switch is turned on and the bus power switch is turned off, if the power from the main power supply is not enough, it is further determined whether the power from the USB bus power is sufficient. When the power is sufficient, the main power switch is turned off and the bus power switch is turned on. As a result, even a digital video camera with relatively high power consumption can be operated using USB bus power.

JP 2005-71274 A

  In this way, in devices that operate using USB bus power, the power supply power of USB bus power is limited. Therefore, the power supply power of USB bus power is monitored so as not to cause system down, and appropriate measures are taken. Is required. In particular, since the printing apparatus consumes relatively high power, monitoring the USB bus power and responding appropriately can be considered as an extremely important issue in ensuring the normal operation of the printing apparatus.

  The main purpose of the printing apparatus and the control method thereof according to the present invention is to monitor the power supply state of the USB bus power to the printing apparatus and take appropriate measures.

  The printing apparatus and the control method thereof according to the present invention employ the following means in order to achieve the main object described above.

The printing apparatus of the present invention includes:
A printing device that operates by receiving power from USB bus power,
A feeding power measuring means for measuring the feeding power of the USB bus power;
One operation mode is selected and executed from a plurality of operation modes having different power consumption peaks based on the power supply power measured by the power supply power measuring means so as to operate within the range of the power supply standard value of the USB bus power. An operation mode selection execution means;
It is a summary to provide.

  In the printing apparatus of the present invention, the USB bus power supply power is measured, and a plurality of operation modes having different power consumption peaks based on the supply power measured to operate within the USB bus power supply standard value range. One operation mode is selected and executed. As a result, the power supply state of the USB bus power to the printing apparatus can be monitored and this can be appropriately dealt with.

  In such a printing apparatus of the present invention, the operation mode selection execution means is a means for selecting and executing an operation mode in which the printing speed becomes slower as the measured power supply power is higher among a plurality of modes having different printing speeds. It can also be. In the printing apparatus according to the aspect of the invention in which printing is performed in accordance with operations of a plurality of driving units including the first driving unit and the second driving unit, the operation mode selection execution unit includes the measured power supply power. Is less than a predetermined value, an operation mode in which the operation of the first drive unit and the operation of the second drive unit overlap is selected and executed, and the measured power supply is greater than or equal to the predetermined value It is also possible to select and execute an operation mode in which the operation of the first drive unit and the operation of the second drive unit do not overlap. In this way, the peak of power consumption can be more reliably suppressed, and printing can be executed even when the power supply capability of USB bus power is relatively low.

  Further, in the printing apparatus according to the aspect of the invention in which printing is performed in accordance with the operation of the plurality of driving units, the plurality of driving units include a conveyance unit that conveys a recording medium by driving a conveyance motor, and the recording liquid. An ejection head that ejects the recording medium; and a carriage that moves the ejection head in a direction orthogonal to the conveyance direction of the recording medium by driving a carriage motor, and the operation mode selection execution unit includes the measured power supply When the power is less than the first threshold, an operation mode in which the recording medium conveyance operation and the carriage acceleration operation overlap is selected and executed, and the measured power supply power is greater than or equal to the first threshold Further, it may be a means for selecting and executing an operation mode in which the recording medium conveyance operation and the carriage acceleration operation do not overlap. This makes it possible to execute printing while ensuring print quality even when the power supply capability of the USB bus power is relatively low.

  Furthermore, in the printing apparatus according to the aspect of the invention that performs printing in accordance with the operation of a plurality of drive units, the plurality of drive units include a conveyance unit that conveys a recording medium by driving a conveyance motor, and the recording liquid. An ejection head that ejects the recording medium; and a carriage that moves the ejection head in a direction orthogonal to the conveyance direction of the recording medium by driving a carriage motor, and the operation mode selection execution unit includes the measured power supply When the power is less than the second threshold, the operation mode in which the acceleration operation of the carriage and the ejection operation of the ejection head overlap is selected and executed, and the measured power supply power is greater than or equal to the second threshold Further, it may be a means for selecting and executing an operation mode in which the acceleration operation of the carriage and the discharge operation of the discharge head do not overlap. This makes it possible to execute printing while ensuring print quality even when the power supply capability of the USB bus power is relatively low.

The control method of the printing apparatus of the present invention includes:
A method of controlling a printing apparatus that operates by receiving power from USB bus power,
One operation mode from a plurality of operation modes in which the power consumption of the USB bus power is measured and the peak of power consumption differs based on the measured power supply power so as to operate within the range of the power supply standard value of the USB bus power The main point is to select and execute.

  According to the control method of the printing apparatus of the present invention, the power supply power of the USB bus power is measured, and the peak of the power consumption is based on the power supply power measured to operate within the range of the power supply standard value of the USB bus power. One operation mode is selected from a plurality of different operation modes and executed. As a result, the power supply state of the USB bus power to the printing apparatus can be monitored and this can be appropriately dealt with.

1 is a schematic configuration diagram of a print system. 2 is a functional block diagram of the computer 10 and the printer 20. FIG. 1 is a schematic configuration diagram of a power supply circuit 50. FIG. 6 is a flowchart illustrating an example of a printing process routine when supplying bus power. Explanatory drawing which shows the time change of the power consumption in normal mode printing. Explanatory drawing which shows the time change of the power consumption in 1st low speed mode printing. Explanatory drawing which shows the time change of the power consumption in 2nd low speed mode printing.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an outline of the configuration of a printing system, FIG. 2 is a block diagram showing functional blocks of a computer 10 and a printer 20 that make up the printing system, and FIG. 3 shows a configuration of a power supply circuit 50. It is a block diagram which shows the outline of this. The printing system according to the present embodiment is configured as a computer 10 and a printer 20 connected via a USB cable 60.

  As shown in FIG. 2, the computer 10 includes a CPU 12 as a central processing unit, a hard disk drive (HDD) 13 in which various applications, user files, printer drivers, etc. are stored, and a RAM 14 in which data is temporarily stored. The computer main body 11, a keyboard (and mouse) 16 as an input device, and a display 19 as a display device are configured as a general-purpose computer. In addition to the CPU 12, HDD 13, and RAM 14, the computer main body 11 is connected to a peripheral device (the printer 20 in this embodiment) via the interface 15 for inputting characters from the keyboard 16 and the USB cable 60 connected to the USB port 17 a. A USB host controller 17 compliant with the USB 2.0 standard and a display controller 18 for controlling the display 19 are electrically connected via a bus. Here, the USB controller 17 supports driving by USB bus power (USB bus power). The USB controller 17 monitors the supply current, and when the supply current exceeds the upper limit value, the USB port 17a is shut down to stop power feeding. According to the USB 2.0 standard, the USB bus power has a power supply voltage of 5 V (± 10%) and a maximum current of up to 500 mA. However, the power supply capacity differs depending on the host device.

  The printer 20 of the present embodiment is configured as an ink jet printer that includes a printing mechanism 40. As shown in FIG. 2, the printing mechanism 40 is driven by a carriage belt 43 that is looped in the left-right direction (main scanning direction) and reciprocates left and right along a guide 42. An ink cartridge 44 that supplies ink of each color such as magenta, yellow, and black, and a sheet S from the nozzle by applying pressure to the piezoelectric element to deform each ink supplied from each ink cartridge 44 A print head 45 that ejects ink toward the head, a carriage motor 46 that drives the carriage belt 43 to reciprocate the carriage 41 in the main scanning direction, and transports the paper S in the sub-scanning direction orthogonal to the moving direction of the carriage 41. A paper feed roller 47 for driving, and a paper feed motor 48 for driving the paper feed roller 47. . Here, the print head 45 is driven by a head driver 45a (see FIG. 3), the carriage motor 46 is driven by a motor driver 46a (see FIG. 3), and the paper feed motor 48 is driven by a motor driver 48a (see FIG. 3). Is done. In the present embodiment, the ink cartridge 44 is a so-called off-carriage type that is attached below the printing mechanism 40 and is not mounted on the carriage 41. Of course, an on-carriage type in which the ink cut ridge is mounted on the carriage 41 may be adopted.

  Further, as shown in FIG. 2, the printer 20 of the present embodiment has a main controller 30 that controls the entire printer and a memory card MC inserted into the memory card slot 37 as shown in FIG. A memory card controller 38 for controlling writing and reading, a printer ASIC 49 for controlling the printing mechanism 40, a USB device controller 58 for communicating with the computer 10 as a host device, and a power device (print head 45) of the printer 20. And carriage motor 46, paper feed motor 48, etc.) and logic devices (main controller 30, memory card controller 38, printer ASIC 49, USB device controller 58, etc.) It includes a power supply circuit 50 for supplying a. In the present embodiment, the printer 20 is configured as a system-on-chip (hereinafter referred to as an SOC) 21 in which a main controller 30, a memory card controller 38, a printer ASIC 49, and a USB device controller 58 are integrated on one chip. (See FIG. 3).

  The main controller 30 is configured as a microprocessor centered on a CPU 31, and can be rewritten with a ROM 32 for storing various processing programs, various data, various tables, and a RAM 33 for temporarily storing data. Even with this, a flash memory 34 for holding data and an interface 35 (I / F) for inputting an operation signal from the power button 36 are provided. The main controller 30 inputs image files from the memory card MC inserted in the memory card slot 37 via the memory card controller 38 and detects various sensors (for example, the position of the carriage 41) for detecting the driving state of the printing mechanism 40. Detection signal from a carriage position sensor that detects the rotation angle of the paper feed motor 48 and the rotation angle sensor that detects the rotation angle of the paper feed motor 48 are input via the printer ASIC 49, and received data from the computer 10 is input via the USB device controller 58. doing. Further, the main controller 30 outputs transmission data to be transmitted to the computer 10 side to the USB device controller 58 and outputs a drive command for the printing mechanism 40 to the printer ASIC 48.

  In this embodiment, the USB device controller 58 is configured as a USB controller compliant with the USB 2.0 standard, and exchanges communication data via the USB cable 60. The USB cable 60 has a power system line composed of a VBUS line and a ground (GND) line, and a signal system line composed of a D + line and a D− line, and is connected to the USB port 17a on the computer 10 side at one end. The standard A plug is provided, and the other end is provided with a standard B plug connected to the USB port 58a on the printer 20 side.

  The power supply circuit 50 uses power from the AC adapter 70 for AC-DC conversion of household AC power (such as AC100V and AC200V) to DC power (such as DC20V) and power (USB bus power) from the USB VBUS line. The circuit is configured as a circuit that can be supplied to a power device or a logic device of the printer 20. As shown in FIG. 3, the power supply circuit 50 includes a drive system power line 51 that supplies power to the head driver 45a and the motor drivers 46a and 48a as power devices, and power (USB bus power) from the VBUS line as a diode D1. A power line for bus power 52 supplied to the drive system power line 51 via the power supply line 53, an AC power supply line 53 for supplying power from the AC adapter 70 to the power line 51 via the diode D2, and a drive system power line 51 A DC / DC converter 54 that converts (steps down) the direct current power into the SOC 21 as a logic device, and a power measurement circuit 55 that is connected to the bus power supply line 52 and measures the power supplied from the VBUS line; .

  The power measurement circuit 55 is configured as a circuit for measuring the supply voltage and supply current of the USB bus power. As shown in FIG. 3, the power measurement circuit 55 is used for current detection connected in series to the bus power supply line 52. A resistor R1, an input resistor R2 and a resistor R3 connected to both ends of the resistor R1, an output resistor R4 connected to the ground, a collector terminal connected to the resistor R2, and an emitter terminal connected to the resistor R4 The connected npn-type bipolar transistor 56, the input terminal (+) is connected to the connection point between the resistor R2 and the collector terminal of the bipolar transistor 56, the input terminal (−) is connected to the resistor R3, and the output terminal is the bipolar transistor 56. Operational amplifier 57 connected to the base terminal of the power supply, resistor R5 connected to the ground, resistor R5 and the power line for bus power Comprising a 2 and the connected resistors R6, the. Here, the resistance value of the resistor R1 is set to, for example, 0.1Ω, the resistance value of the resistor R2 is set to, for example, 1 kΩ, the resistance value of the resistor R3 is set to, for example, 1 kΩ, and the resistance value of the resistor R4 is set to, for example, 20 kΩ. Is set. The current detection resistor R1, the input resistors R2 and R3, the output resistor R4, the operational amplifier 57, and the bipolar transistor 56 constitute a high-side current detection circuit that detects the current I1 flowing through the resistor R1. In this current detection circuit, when the input currents of the two input terminals of the operational amplifier 57 are adjusted to be equal, when the current I1 flows through the resistor R1, the current I2 shown in the following equation (1) flows through the resistor R2, and the bipolar A voltage corresponding to the product of the current I2 and the output resistor R4 is output to the emitter terminal of the transistor 56 as the output voltage Vout. The SOC 21 (main controller 30) calculates the current I1 flowing through the resistor R1, that is, the supply current I of the bus power supply line 52 based on the output voltage Vout by the following equation (2) by inputting the output voltage Vout. can do. The resistance value of the resistor R5 is set to, for example, 10 kΩ, and the resistance value of the resistor R6 is set to, for example, 10 kΩ. The resistors R5 and R6 constitute a voltage dividing circuit connected in series with each other. The SOC 21 (main controller 30) inputs the voltage at the connection point between the resistor R5 and the resistor R6, and based on the input voltage and the voltage dividing ratio of the resistors R5 and R6, the supply voltage V of the bus power supply line 52 Can be calculated.

I2 = I1 × R1 / R2 (1)
I1 = R2 / R1 × Vout / R4 (2)

  Next, in the printer 20 of the present embodiment configured as described above, when a print instruction is received from the printer driver of the computer 10 via the USB cable 60, the paper feed roller 47 is first controlled by driving the paper feed motor 48. A paper feeding operation for feeding paper by rotating is performed. When paper is fed, the carriage motor 46 is driven and controlled to move the carriage 41 in the main scanning direction, while discharging the ink from the print head 45 mounted on the carriage 41, and the paper feed motor 48. By performing drive control, the paper feed roller 47 is rotated to repeat the line feed operation for turning the paper. The carriage 41 is moved by driving and controlling the carriage motor 46 so that the moving speed becomes the target speed, and is accompanied by three operations: an acceleration operation, a constant velocity operation, and a deceleration operation. When printing is completed, the paper feed motor 48 is driven and controlled to rotate the paper feed roller 47 to discharge the printed paper.

  Next, an operation when printing is performed in a state where the bus power is supplied from the computer 10 will be described. FIG. 4 is a flowchart illustrating an example of a bus power supply printing process routine executed by the CPU 31 of the main controller 30. This routine is executed when a print instruction is received in a state where power is supplied from the bus power supply line 52.

  When the bus power supply printing process routine is executed, the CPU 31 of the main controller 30 first performs the above-described paper feeding operation (step S100) and inputs the USB bus power supply power Psup (step S110). Here, as the supply power Psup, the value calculated by the product of the supply voltage V and the supply current I measured by the power measurement circuit 55 is input. When the supply power Psup of USB bus power is input, it is determined whether the input supply power Psup is less than the threshold value P1 (step S120) and whether the input supply power Psup is less than the threshold value P2 (step S130). Here, the threshold values P1 and P2 are threshold values for determining step by step until the supplied power Psup reaches the USB power supply standard value (2.5 W in the case of USB 2.0 standard). A value slightly smaller than the USB standard value is set, and the threshold value P1 is set to a value smaller than the threshold value P2.

  If it is determined that the supplied power Psup is less than the threshold value P1, it is determined that there is a margin before the supplied power Psup reaches the supply standard value of the USB bus power, and the print mode is set to the normal mode (step S140). If it is determined that the supplied power Psup is greater than or equal to the threshold value P1 and less than the threshold value P2, it is determined that the supplied power Psup is approaching the supply standard value of the USB bus power, and the print mode is set to be slower than the normal mode. Is set to the first low-speed mode (step S150), and when it is determined that the supply power Psup is equal to or greater than the threshold value P2, it is determined that the supply power Psup has almost no margin to the supply standard value of the USB bus power, and the print mode is printed. The speed is set to the second low speed mode that is slower than the first low speed mode (step S160). Then, the printing process for one scan is executed according to the set printing mode (step S170). Here, the printing process for one scan includes a printing operation in which ink is ejected from the print head 45 while moving the carriage 41 in the main scanning direction, and a line feed operation in which paper is fed by paper feed. When the printing process for one scan is completed, it is determined whether printing is completed (step S180). If it is determined that the printing has not been completed, the process returns to step S110 to repeat the processing of steps S110 to S170. If it is determined that the printing has been completed, a paper discharge operation is performed (step S190), and this routine is executed. finish.

  In this embodiment, the normal mode is a printing mode in which the acceleration operation of the carriage 41 is started during the line feed operation of the paper feed roller 47 and the ink discharge operation of the print head 45 is started during the acceleration operation of the carriage 41. The start of the acceleration operation of the carriage 41 is adjusted so that the ink ejection of the print head 45 is started at the timing when the line feed operation of the paper feed roller 47 is completed. Thereby, part of the time required for the line feed operation can be shortened, and the printing time can be shortened. On the other hand, the ink ejection operation of the print head 45 during the acceleration operation of the carriage 41 is performed in a state where the carriage 41 is in a standby state at a position close to the print area of the paper. Thereby, since the moving distance of the carriage 41 is shortened, the printing time for one scan can be shortened. FIG. 5 shows temporal changes in the power consumption by the paper feeding operation, the power consumption by the carriage operation, the power consumption by the head drive, and the overall power consumption in the normal mode printing. In the normal mode, as shown in FIG. 5, the power consumption due to the line feed operation of the paper feed roller 47 overlaps the power consumption due to the acceleration operation of the carriage 41, and the power consumption due to the acceleration operation of the carriage 41 and the ink ejection operation of the print head 45. Therefore, the overall power consumption peak shows a relatively high value (see “Pmax1” in FIG. 5).

  In the first embodiment, the first low speed mode is a printing mode in which the acceleration operation of the carriage 41 is started after the line feed operation of the paper feed roller 47 is completed, and the ink discharge operation of the print head 45 is started during the acceleration operation of the carriage 41. It is. FIG. 6 shows temporal changes in the power consumption by the paper feed operation, the power consumption by the carriage operation, the power consumption by the head drive, and the overall power consumption in the first low-speed mode printing. In the first low speed mode, as shown in FIG. 6, the power consumption due to the acceleration operation of the carriage 41 and the power consumption due to the ink ejection operation of the print head 45 overlap, but the power consumption due to the line feed operation of the paper feed roller 47 and the carriage 41. Therefore, the peak of the overall power consumption is lower than the value (Pmax1) in the normal mode (see “Pmax2” in FIG. 6).

  In the second low speed mode, in this embodiment, after the line feed operation of the paper feed roller 47 is completed, the acceleration operation of the carriage 41 is started, and the ink of the print head 45 is transferred when the carriage 41 is shifted from the acceleration operation to the constant speed operation. This is a print mode for starting the discharge operation. FIG. 7 shows temporal changes in power consumption by the paper feeding operation, power consumption by the carriage operation, power consumption by the head drive, and overall power consumption in the second low-speed mode printing. In the printing process in the second low-speed mode, as shown in FIG. 7, the power consumption due to the line feed operation of the paper feed roller 47, the power consumption due to the acceleration operation of the carriage 41, and the power consumption due to the ink ejection operation of the print head 45 are all. Since they do not overlap, the peak of the overall power consumption is lower than the value (Pmax2) in the first low speed mode (see “Pmax3” in FIG. 7).

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The power measurement circuit 55 of this embodiment and the main controller 30 for calculating the supplied power Psup correspond to the “feed power measuring means” of the present invention, and the main controller 30 for executing the bus power supply printing process routine of FIG. This corresponds to “operation mode selection execution means”. In this embodiment, an example of the control method of the printing apparatus of the present invention is also clarified by describing the operation of the printer 20 of the present invention.

  According to the printer 20 of the present embodiment described above, the supply power Psup of the bus power supply line 52 is measured using the power measurement circuit 55. If the supply power Psup is less than the threshold value P1, the paper feed roller 47 A normal mode in which an acceleration operation of the carriage 41 is started during the line feed operation and an ink discharge operation of the print head 45 is started during the acceleration operation of the carriage 41 is selected, and the printing process is executed, and the supply power Psup is equal to or higher than the threshold value P1. If it is less than the threshold value P2, the first low-speed mode is selected in which the carriage 41 starts the acceleration operation after the paper feed roller 47 completes the line feed operation and the carriage 41 starts the ink ejection operation during the acceleration operation of the carriage 41. Print processing. When the supplied power Psup is equal to or greater than the threshold value P2, the acceleration operation of the carriage 41 is started after the line feed operation of the paper feed roller 47 is completed, and when the acceleration operation of the carriage 41 is shifted to the constant velocity operation, The second low-speed mode for starting the ink ejection operation is selected and the printing process is executed. As a result, the higher the supply power Psup, the smaller the power consumption peak associated with the execution of printing. As a result, printing processing can be executed while monitoring so that the USB bus power does not exceed the supply standard value.

  In the present embodiment, as a print mode, a normal mode in which the acceleration operation of the carriage 41 is started during the line feed operation of the paper feed roller 47 and the ink discharge operation of the print head 45 is started during the acceleration operation of the carriage 41; The first low-speed mode in which the acceleration operation of the carriage 41 is started after the completion of the line feed operation 47 and the ink discharge operation of the print head 45 is started during the acceleration operation of the carriage 41, and the line feed operation of the paper feed roller 47 is completed. A second low-speed mode for starting the ink discharge operation of the print head 45 when the acceleration operation of the carriage 41 is started and the acceleration operation of the carriage 41 is shifted to the constant speed operation. Some modes may be omitted, or other print modes may be prepared. In the latter case, for example, a plurality of print modes having different line feed speeds (paper feed speeds) of the paper feed roller 47 may be prepared, or a plurality of print modes having different movement speeds of the carriage 41 may be prepared. It is good. In addition, when the moving speed of the carriage 41 becomes slow, the drive interval of the print head 45 also becomes long. In addition, the number of print modes that can be selected may be two or four, as long as the print mode is selected such that the peak of power consumption decreases as the supply power Psup of USB bus power increases. It may be the above. In this case, the selectable print modes may be in any combination.

  In the present embodiment, the printer 20 is configured to operate with power supplied from an AC power source. However, the printer 20 is configured to operate with power supplied from the battery, provided that the printer 20 includes a removable battery. Alternatively, the printer 20 may be provided with a plurality of USB ports, and power from the plurality of USB ports on the host device side may be simultaneously received by the plurality of USB ports on the printer 20 side.

  In the present embodiment, the power measurement circuit 55 detects a current I1 flowing through the resistor R1 by the current detection resistor R1, the input resistors R2 and R3, the output resistor R4, the operational amplifier 57, and the bipolar transistor 56. Although the side current detection circuit is configured, the low side current detection circuit may be configured. Further, any detection circuit may be used as long as it can measure the power supplied from the bus power supply line 52.

  In the present embodiment, the present invention has been described by applying the present invention to an apparatus that operates by receiving the supply of USB bus power from the USB port 17a of the computer 10. However, the present invention is not limited to the case where the supply source of USB bus power is the computer 10. Any host device capable of supplying USB bus power may be used.

  In the present embodiment, the present invention has been described as a form of a printing apparatus, but may be a form of a control method for the printing apparatus.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  10 Computer, 11 Computer body, 12 CPU, 13 Hard disk drive (HDD), 14 RAM, 15 Interface (I / F), 16 Keyboard, 17 USB host controller, 17a USB port, 18 Display controller, 19 Display, 20 Printer , 21 System on chip (SOC), 30 Main controller, 31 CPU, 32 ROM, 33 RAM, 34 Flash memory, 35 Interface (I / F), 36 Power button, 37 Memory card slot, 38 Memory card controller, 40 Printing Mechanism, 41 Carriage, 42 Guide, 43 Carriage belt, 44 Ink cartridge, 45 Print head, 45a Head driver, 46 Carriage motor, 46a motor driver, 47 paper feed roller, 48 paper feed motor, 48a motor driver, 49 printer ASIC, 50 power supply circuit, 51 power supply line, 52 bus power supply line, 53 AC power supply line, 54 DC / DC converter, 55 power measurement circuit, 56 bipolar transistor, 57 operational amplifier, 58 USB device controller, 58a USB port, 60 USB cable, 70 AC adapter, R1-R6 resistors, D1, D2 diodes.

Claims (5)

A printing apparatus having a plurality of drive units including a first drive unit and a second drive unit that operate by receiving power supply by USB bus power,
A feeding power measuring means for measuring the feeding power of the USB bus power;
One operation mode is selected and executed from a plurality of operation modes having different power consumption peaks based on the power supply power measured by the power supply power measuring means so as to operate within the range of the power supply standard value of the USB bus power. An operation mode selection execution means;
Equipped with a,
The operation mode selection execution means selects and executes an operation mode in which the operation of the first drive unit and the operation of the second drive unit overlap when the measured power supply is less than a predetermined value. And means for selecting and executing an operation mode in which the operation of the first drive unit and the operation of the second drive unit do not overlap when the measured power supply is equal to or greater than the predetermined value.
A printing apparatus characterized by that. The printing apparatus according to claim 1,
The operation mode selection execution means is a means for selecting and executing an operation mode in which the print speed becomes slower as the measured power supply power is higher among a plurality of modes having different print speeds. The printing apparatus according to claim 1 , wherein:
As the plurality of drive units, a transport unit that transports a recording medium by driving a transport motor, a discharge head that discharges a recording liquid onto the recording medium, and a transport direction of the recording medium by driving a carriage motor A carriage that moves in a direction orthogonal to the
The operation mode selection execution means selects and executes an operation mode in which a conveyance operation of the recording medium and an acceleration operation of the carriage overlap when the measured power supply power is less than a first threshold, and the measurement The printing apparatus according to claim 1, wherein when the supplied power is equal to or more than the first threshold, an operation mode in which the recording medium conveyance operation and the carriage acceleration operation do not overlap is selected and executed. The printing apparatus according to any one of claims 1 to 3,
As the plurality of drive units, a transport unit that transports a recording medium by driving a transport motor, a discharge head that discharges recording liquid onto the recording medium, and a transport direction of the recording medium by driving a carriage motor A carriage that moves in a direction orthogonal to the
The operation mode selection execution means selects and executes an operation mode in which the acceleration operation of the carriage and the discharge operation of the discharge head overlap when the measured power supply power is less than a second threshold, and the measurement The printing apparatus according to claim 1, wherein when the supplied power is equal to or greater than the second threshold value, the printing apparatus is configured to select and execute an operation mode in which the acceleration operation of the carriage and the discharge operation of the discharge head do not overlap. A method for controlling a printing apparatus having a plurality of drive units including a first drive unit and a second drive unit that operate by receiving power supplied from USB bus power,
One operation mode from a plurality of operation modes in which the power consumption of the USB bus power is measured and the peak of power consumption differs based on the measured power supply power so as to operate within the range of the power supply standard value of the USB bus power Is selected and executed ,
When the measured power supply is less than a predetermined value, an operation mode in which the operation of the first drive unit and the operation of the second drive unit overlap is selected and executed, and the measured power supply is A control method for a printing apparatus, comprising: selecting and executing an operation mode in which the operation of the first drive unit and the operation of the second drive unit do not overlap when the predetermined value is exceeded .