printer

Abstract

To provide a printer capable of maintaining printing operation even when a load to a power source becomes large in a case where the printer has a power feeding function to an external device.SOLUTION: A printer includes a printing part, a power feeding part, and a CPU. The printing part can perform printing operation with respect to a medium on the basis of power of a power source. The power feeding part can feed power to an external device on the basis of the power of the power source. The CPU acquires a parameter indicating a magnitude of a load to the power source at the time of feeding of the power from the power source (S3). When the acquired parameter is equal to or greater than a first predetermined value, the CPU limits power feeding from the power feeding part to the external device (S13).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a printer.

Background Art

[0002] The printer of Patent Document 1 executes operations of main functions such as a printing operation using the power of an AC adapter. The printer includes a temperature detector, a temperature monitoring unit, and a printing condition setting unit. The temperature detector detects the surface temperature of the AC adapter. The temperature monitoring unit monitors the surface temperature detected by the temperature detector. When the surface temperature enters a predetermined warning temperature range, the temperature monitoring unit specifies printing control conditions for reducing the printing load according to the surface temperature. The printing condition setting unit outputs control information corresponding to the specified printing control conditions to a printing control unit and a conveyance control unit. The printing control unit and the conveyance control unit execute printing control based on the output control information.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a function of supplying power to an external device is added to the above printer, the printer executes a printing operation and supplies power to the external device. In this case, since the load on the AC adapter increases, the printer reduces the load of the printing operation of the printer, for example, by reducing the printing speed. Therefore, the printer cannot maintain the planned printing operation.

[0005] An object of the present invention is to provide a printer that can maintain a printing operation even when the load on the power supply increases when it has a function of supplying power to an external device.

Means for Solving the Problems

[0006] The printer according to the present invention is a printer driven by a power source, and includes a printing unit capable of performing a printing operation on a medium based on the power of the power source, a power supply unit capable of supplying power to an external device based on the power of the power source, and a control unit. The control unit executes an acquisition process of acquiring a parameter indicating the magnitude of the load on the power source when power is supplied from the power source, and a first limitation process of limiting the power supply from the power supply unit to the external device when the parameter acquired by the acquisition process becomes equal to or greater than a first predetermined value.

[0007] The above printer ensures the power for executing the printing operation of the printer by limiting the power supply to the external device according to the magnitude of the load on the power source. Therefore, the printer does not need to reduce the load for executing the printing operation. Thus, the printer can maintain the printing operation even when the load on the power source increases when it has a power supply function to the external device.

[0008] In the present invention, the control unit may execute a second limitation process of limiting the power consumed by the printing unit among the power supplied from the power source when the parameter acquired by the acquisition process becomes equal to or greater than a second predetermined value that is equal to or greater than the first predetermined value. When the load on the battery further increases, the printer can maintain the printing operation by limiting the power consumed by the printing unit.

[0009] In the present invention, the second limitation process may limit the power consumed by the printing unit by decelerating to a second printing speed that is slower than a first printing speed in the printing operation being executed by the printing unit. The printer can maintain the printing operation while reducing the load on the power source by simple control.

[0010] In the present invention, when the parameter becomes equal to or greater than a third predetermined value that is equal to or greater than the second predetermined value, the control unit performs a third limiting process of limiting the power consumed by the printing unit by decelerating to a third printing speed that is slower than the second printing speed. When the parameter becomes equal to or greater than the third predetermined value, the control unit may perform at least one of a fourth limiting process of limiting the power consumed by the printing unit by executing the printing operation at a second printing density that is lighter than the first printing density in the printing operation being executed by the printing unit. The printer can maintain the printing operation while reducing the further load on the power supply by decelerating to the third printing speed or making the second printing density lighter.

[0011] In the present invention, after the control unit limits the power consumed by the printing unit by the third limiting process, when the parameter becomes equal to or less than a fourth predetermined value that is equal to or less than the third predetermined value, the control unit performs a first acceleration process of accelerating from the third printing speed to the second printing speed. After the control unit limits the power consumed by the printing unit by the fourth limiting process, when the parameter becomes equal to or less than the fourth predetermined value, the control unit may perform a first density restoration process of restoring from the second printing density to the first printing density. When the load on the power supply becomes lighter, the power that can be consumed by the printing unit increases. In this case, the printer executes the printing operation by accelerating to the second printing speed before the limitation or restoring to the first printing density. Therefore, the printer can efficiently use the power of the power supply.

[0012] In the present invention, the third predetermined value and the fourth predetermined value may be different from each other. The printer can stably perform the printing operation by setting each predetermined value to a different value.

[0013] In the present invention, after the control unit restricts the power consumed by the printing unit by the second restriction process, when the parameter becomes equal to or less than a fifth predetermined value that is equal to or less than the second predetermined value, the control unit may execute a second acceleration process of accelerating from the second printing speed to the first printing speed. When the load on the power supply becomes lighter, the power that can be consumed by the printing unit increases. In this case, the printer accelerates to the first printing speed before the restriction and executes the printing operation. Therefore, the printer can efficiently use the power of the power supply.

[0014] In the present invention, the second predetermined value and the fifth predetermined value may be different from each other. The printer can stably perform the printing operation by setting each predetermined value to a different value.

[0015] In the present invention, the second restriction process may restrict the power consumed by the printing unit by executing the printing operation at a third printing density that is lighter than the first printing density in the printing operation being executed by the printing unit. The printer can maintain the printing operation while reducing the load on the power supply by simple control.

[0016] In the present invention, when the parameter becomes equal to or greater than a third predetermined value that is equal to or greater than the second predetermined value, the control unit executes a third restriction process of restricting the power consumed by the printing unit by executing the printing operation at a fourth printing density that is lighter than the third printing density, and when the parameter becomes equal to or greater than the third predetermined value, the control unit executes a fourth restriction process of restricting the power consumed by the printing unit by decelerating to a fourth printing speed that is slower than the first printing speed in the printing operation being executed by the printing unit. The printer can maintain the printing operation while further reducing the load on the power supply by making the fourth printing density lighter or decelerating to the fourth printing speed.

[0017] In the present invention, after the control unit restricts the power consumed by the printing unit by the third restriction process, when the parameter becomes equal to or less than a fourth predetermined value that is equal to or less than the third predetermined value, a second density restoration process of restoring from the fourth printing density to the third printing density and, after the control unit restricts the power consumed by the printing unit by the fourth restriction process, when the parameter becomes equal to or less than the fourth predetermined value, a third acceleration process of accelerating from the fourth printing speed to the first printing speed may be executed. When the load on the power supply becomes lighter, the power that can be consumed by the printing unit increases. In this case, the printer executes a printing operation such as restoring to the third printing density before the restriction or accelerating to the first printing speed. Therefore, the printer can efficiently use the power of the power supply.

[0018] In the present invention, the third predetermined value and the fourth predetermined value may be different from each other. The printer can stably perform the printing operation by setting each predetermined value to a different value.

[0019] In the present invention, after the control unit restricts the power consumed by the printing unit by the second restriction process, when the parameter becomes equal to or less than a fifth predetermined value that is equal to or less than the second predetermined value, a third density restoration process of restoring from the third printing density to the first printing density may be executed. When the load on the power supply becomes lighter, the power that can be consumed by the printing unit increases. In this case, the printer executes the printing operation by returning to the first printing density before the restriction. Therefore, the printer can efficiently use the power of the power supply.

[0020] In the present invention, the second predetermined value and the fifth predetermined value may be different from each other. The printer can stably perform the printing operation by setting each predetermined value to a different value.

[0021] In the present invention, after the control unit restricts power supply from the power supply unit to the external device by the first restriction process, when the parameter becomes equal to or less than a sixth predetermined value that is equal to or less than the first predetermined value, and the printing operation by the printing unit is completed, the control unit may execute a release process for releasing the restriction on power supply to the external device by the first restriction process. When the load on the power supply becomes lighter, the power that can be consumed by the printer increases. In this case, the printer resumes the restriction on power supply to the external device. Therefore, the printer can efficiently use the power of the power supply. Further, since the printer maintains the restriction on power supply to the external device until the printing operation is completed, it is possible to suppress a change in the driving state of the printer during printing. Therefore, the printer can maintain the print quality.

[0022] In the present invention, the first predetermined value and the sixth predetermined value may be different from each other. The printer can stably perform the printing operation by setting each predetermined value to a different value.

[0023] In the present invention, the power supply may be an AC adapter. The printer can maintain the printing operation even when the load on the AC adapter increases.

[0024] In the present invention, the power supply may be a battery. The printer can maintain the printing operation even when the load on the battery increases.

[0025] In the present invention, the control unit may execute a load estimation process for estimating the parameter based on the image data printed on the medium by the printing unit, and the acquisition process may acquire the parameter estimated by the load estimation process. Since the printer estimates the parameter, there is no need to separately provide a sensor for detecting the load on the power supply, such as a temperature sensor.

[0026] In the present invention, the power supply may be provided with a sensor for measuring the temperature of the power supply. Since the printer directly detects the temperature of the power supply with the sensor and uses the measurement result as a parameter, it can be restricted at a more accurate timing compared to the case of estimating the load.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0028] Embodiments of the present invention will be described with reference to the drawings. The diagonally downward to the right, diagonally upward to the left, diagonally upward to the right, diagonally downward to the left, upward, and downward directions in FIG. 1 are defined as the right side, left side, rear side, front side, upper side, and lower side of the printer 1, respectively.

[0029] As shown in FIG. 1, the printer 1 is configured to be printable on a printing medium. The medium is, for example, a plurality of thermal labels continuously attached to a long cardboard. The printer 1 can be driven by receiving power supply from an external power supply connected to a commercial power outlet (not shown). The external power supply is, for example, an AC adapter 9 (see FIG. 2). The AC adapter 9 is connected to a mounting portion 41 provided at the lower rear of the right side surface of the printer 1. Further, the printer 1 can be driven by receiving power supply from a battery 11 (see FIG. 2). The battery 11 is detachably mounted on a mounting portion 42 (see FIG. 2) provided inside the printer 1. The battery 11 is, for example, a lithium-ion secondary battery.

[0030] On the lower front part of the right side of the printer 1, an interface 43 is provided. The interface 43 is a USB interface (I / F) compliant with the USB Type-C (registered trademark) standard. A cable 3 is connected to the interface 43. The cable 3 is equipped with a connector compliant with the USB Type-C standard and is compatible with USB PD (USB Power Delivery). For example, the cable 3 can transmit power corresponding to a current of up to 5A and transfer various types of information.

[0031] The printer 1 can be connected to, for example, an external device via the interface 43 and the cable 3. The external device is, for example, a tablet PC 5. The tablet PC 5 is equipped with, for example, an LCD touch panel. The user edits image data such as characters and graphics on the touch panel and transmits the image data to the printer 1 via the cable 3. The printer 1 prints characters such as letters and graphics on a medium based on the image data received from the external device.

[0032] Also, the printer 1 can supply power to the tablet PC 5 in accordance with the USB PD (USB Power Delivery) standard. Thus, the printer 1 can charge the tablet PC 5.

[0033] The electrical configuration of the printer 1 will be described with reference to FIG. 2. The printer 1 further includes a charging IC 31, an OR circuit 32, a DCDC power supply 33, a digital circuit unit 6, a printing unit 7, a power supply unit 8, etc. The charging IC 31 executes charging of the battery 11 mounted on the mounting unit 42 based on the power from the AC adapter 9. The battery 11 is equipped with a sensor 11A capable of detecting the battery temperature. The output result from the sensor 11A is transmitted to the CPU 21. The CPU 21 detects the temperature of the battery 11 from the received output result.

[0034] The OR circuit 32 switches the power supply path to the tablet PC 5 according to the presence or absence of the connection between the battery 11 and the AC adapter 9. For example, when only the AC adapter 9 is connected, the OR circuit 32 switches the power supply path to supply power from the power of the AC adapter 9. For example, when only the battery 11 is connected, the OR circuit 32 switches the power supply path to supply power from the power of the battery 11. When the AC adapter 9 and the battery 11 are connected, the OR circuit 32 switches the power supply path so that, for example, while supplying the power of the AC adapter 9 to the battery 11, the power of the AC adapter 9 is supplied to the digital circuit section 6, the printing section 7, the power supply section 8, etc. Note that the switching of the power supply path of the OR circuit 32 is executed automatically, but it may also be settable by the user.

[0035] The DCDC power supply 33 converts the input voltage from the AC adapter 9 or the battery 11 into an output voltage (for example, 3.3 V) for driving the digital circuit section 6. The digital circuit section 6 includes a CPU 21, a RAM 22, a flash memory 23, and an EEPROM 24, etc. The CPU 21 performs overall control of the printer 1. The CPU 21 is electrically connected to the RAM 22, the EEPROM 24, the flash memory 23, the printing section 7, and the power supply section 8.

[0036] The RAM 22 temporarily stores various data such as image data received from the tablet PC 5. Information such as printer settings and printing history is stored in the EEPROM 24. Various programs executed by the CPU 21 for controlling the printer 1 are stored in the flash memory 23.

[0037] The flash memory 23 stores first to sixth predetermined values Th1 to Th6 that are used as threshold values in the main process described later. Each of the predetermined values Th1 to Th6 is a value based on, for example, the rated current of the AC adapter 9 and may be set as appropriate. The first to sixth predetermined values Th1 to Th6 are different from each other. For example, the relationship of the first predetermined value Th1 < the second predetermined value Th2 < the third predetermined value Th3 holds. The relationship of the fourth predetermined value Th4 > the fifth predetermined value Th5 > the sixth predetermined value Th6 holds. Also, the relationship of the third predetermined value Th3 > the fourth predetermined value Th4 holds. The relationship of the second predetermined value Th2 > the fifth predetermined value Th5 holds. The relationship of the first predetermined value Th1 > the sixth predetermined value Th6 holds. Details of each of the predetermined values Th1 to Th6 will be described later.

[0038] The flash memory 23 stores a table showing the driving conditions of the printer 1 shown in FIG. 6. For example, the driving conditions of the printer 1 refer to the driving conditions of the printing unit 7 and the power supply unit 8. The driving conditions of the printer 1 are the printing speed of the printing unit 7 when a printing operation is executed, or the printing density of the image printed on the medium. The driving conditions of the printer 1 are the power supply on / off from the power supply unit 8 to an external device. Based on the relationship between the parameter P described later and each of the predetermined values Th1 to Th6, the driving conditions of the printing unit 7 and the power supply unit 8 are changed. The driving conditions are classified into cases A to D. Which of cases A to D is executed may be automatically set by the printer 1 or set by the user. Details will be described later.

[0039] Power from the AC adapter 9 or the battery 11 is supplied to the printing unit 7. The printing unit 7 can execute printing on the medium based on the power of the AC adapter 9 or the battery 11. The printing unit 7 includes a thermal head 13 and a conveyance motor 15. The thermal head 13 generates heat in response to a signal from the CPU 21 and performs printing on the medium. The conveyance motor 15 drives a feed roller for feeding the medium. The CPU 21 controls the thermal head 13 and the conveyance motor 15 to execute printing on the medium.

[0040] The power supply unit 8 includes a DC-DC power supply 35, a USB PD IC 37, an FET 36, an interface 43, etc. The DC-DC power supply 35 converts the input voltage from the AC adapter 9 or the battery 11 into an output voltage (such as 9V, 5V, etc.) suitable for powering the tablet PC 5. The power from the power supply unit 8 is supplied to the tablet PC 5. The USB PD IC 37 can communicate with the CPU 21 mutually. The USB PD IC 37 can control the value of the output voltage from the DC-DC power supply 35. The USB PD IC 37 executes negotiation conforming to the USB PD (USB Power Delivery) standard with the tablet PC 5 via the interface 43. The USB PD IC 37 controls the power supply from the DC-DC power supply 35 to the tablet PC 5 by turning the FET 36 on and off. For example, when the FET 36 is turned on, power is supplied to the tablet PC 5 via the interface 43 and the cable 3. That is, the power supply unit 8 can supply the power supplied based on the power of the AC adapter 9 or the battery 11 to the tablet PC 5.

[0041] Referring to FIGS. 3 and 4, the main process will be described. In the following description, it is assumed that the printer 1 is driven by the power of the AC adapter 9 as an external power source. The battery 11 may or may not be mounted on the printer 1. It is assumed that a tablet PC 5 is connected to the printer 1 as an external device. When the user presses the power button of the printer 1, the CPU 21 reads and executes a program from the flash memory 23. Thereby, the CPU 21 starts the main process.

[0042] When starting the main process, the CPU 21 determines whether image data has been acquired (S1). If it is determined that the image data has not been acquired (S1: NO), the CPU 21 returns the process and waits. For example, the user operates the tablet PC 5 which is an external device to edit the image data and send it to the printer 1.

[0043] When it is determined that image data has been acquired (S1: YES), the CPU 21 acquires parameter P (S3). Parameter P indicates the magnitude of the load on the AC adapter 9 when power is supplied from the AC adapter 9. The magnitude of the load is, for example, the magnitude of the current required for driving the printing unit 7. Parameter P is calculated by the CPU 21, for example.

[0044] Referring to FIG. 5, the estimation of parameter P will be described in detail. The image data is composed of, for example, N columns. In the calculation of parameter P, the calculation is performed on, for example, the image data of R columns out of N columns. For example, when R = 3, that is, when the number of target lines is 3 lines, the calculation is performed based on the number of on-dots during printing of the 3 target lines. The 3 target lines are, for example, the 1st to 3rd lines.

[0045] For example, assume that the amount of current required for printing each line is 1A, 1.5A, and 0.2A. The total amount of current is 2.7A. When the time required for printing one line is 100 μsec, the average current value per unit time required for printing one line is 2.7 / (100×3) = 0.009 A / μsec.

[0046] Thereafter, based on the number of on-dots of the next 3 lines that were not the target of the calculation, the average current value per unit time is calculated in the same manner. The next 3 target lines are, for example, the 4th to 6th lines. For example, assume that the average current value per unit time is 0.04A. In this case, the integrated average value is (0.009 + 0.04) / 2 = 0.0245. This integrated average value is parameter P. Thereafter, parameter P is updated by calculating the integrated average value based on the average current value of the next 3 target lines. The updated parameter P is temporarily stored in the RAM 22.

[0047] The CPU 21 determines whether to maintain the driving conditions of the printer 1 based on the acquired parameter P (S5). For example, when there are no restrictions on the driving conditions of the printer 1, the driving conditions of the printer 1 are maintained. Also, for example, even when there are restrictions on the driving conditions of the printer 1, it is assumed that the value of the acquired parameter P does not change across each predetermined value Th1 to Th6 that is the target of the next restriction change. In this case, regardless of the upward and downward fluctuations of the parameter P, the driving conditions of the printer 1 are maintained. When it is determined to maintain the driving conditions of the printer 1 (S5: YES), the CPU 21 executes printing for the R line for which the parameter P was acquired while maintaining the driving conditions of the printer 1 (S39).

[0048] For example, the CPU 21 drives the printing unit 7 and the power supply unit 8 under the condition of "no restrictions" among the driving conditions of the printer 1 shown in FIG. 6. The printing speed of the printing unit 7 is set to the first printing speed V1, and the printing density is set to the first printing density D1. The first printing speed V1 is the fastest speed, and the first printing density D1 is the density optimal for printing. The first printing density D1 is set by the user, for example. The optimal density is, for example, the median density between the lightest color and the darkest color. Also, the power supply unit 8 keeps the power supply restriction off. That is, power supply from the power supply unit 8 to the tablet PC 5 is possible.

[0049] As shown in FIG. 7, for example, printing by the printing unit 7 starts from time t0. The parameter P transitions with an upward trend during the interval P1 from time t0 to t1.

[0050] The CPU 21 determines whether printing based on the image data is completed every time the printing of the R line is completed (S41). When printing based on the image data is not completed (S41: NO), the CPU 21 returns the process to S3 and acquires the parameter P for the next R line.

[0051] On the other hand, when it is determined that the driving conditions of the printer 1 are not to be maintained (S5: NO), that is, when there is a possibility that the printer 1 needs to be restricted or the restriction released in relation to each predetermined value Th1 to Th6, the CPU 21 determines whether the parameter P has increased (S7). When it is determined that the parameter P has increased (S7: YES), the CPU 21 determines whether the parameter P is equal to or greater than the first predetermined value Th1 (S9). When it is determined that the parameter P is smaller than the first predetermined value Th1 (S9: NO), since the CPU 21 may exceptionally maintain the driving conditions of the printer 1, printing for the R line is executed without changing the driving conditions of the printer 1 (S39).

[0052] When it is determined that the parameter P is equal to or greater than the first predetermined value Th1 (S9: YES), the CPU 21 determines whether the parameter P is equal to or greater than the second predetermined value Th2 (S11). When it is determined that the parameter P is smaller than the second predetermined value Th2 (S11: NO), that is, when Th1 ≤ P < Th2, the CPU 21 restricts the power supply from the power supply unit 8 to the external device (S13).

[0053] For example, the CPU 21 drives the printing unit 7 and the power supply unit 8 under the condition of "first restriction" among the driving conditions of the printer 1 shown in FIG. 6. The power supply unit 8 restricts the power supply to the external device. Restricting the power supply means stopping the power supply from the power supply unit 8 to the external device. In this case, no restriction is imposed on the printing unit 7. That is, the first printing speed V1 and the first printing density D1 are maintained.

[0054] The CPU 21 drives the printing unit 7 under the "first restriction" driving conditions with the power supply to the external device restricted and executes printing of the R line (S39). The CPU 21 advances the process to S41.

[0055] For example, as shown in FIG. 7, the parameter P once decreases in the section P11 from time t1 to t2, but then changes with an upward trend. At time t2, the parameter P becomes equal to or greater than the second predetermined value Th2.

[0056] When it is determined that the parameter P is equal to or greater than the second predetermined value Th2 (S11: YES), the CPU 21 determines whether the parameter P is equal to or greater than the third predetermined value Th3 (S15). When it is determined that the parameter P is smaller than the third predetermined value Th3 (S15: NO), that is, when Th2 ≤ P < Th3, the CPU 21 restricts the driving conditions of the printing unit 7 (S17). In this case, the CPU 21 restricts the power consumed by the printing unit 7 from the power supplied by the AC adapter 9.

[0057] For example, the CPU 21 drives the printing unit 7 under the condition of "second restriction" among the driving conditions of the printer 1 shown in FIG. 6. For example, in cases A and B, the CPU 21 restricts the power consumed by the printing unit 7 by decelerating to a second printing speed V2 that is slower than the first printing speed V1. On the other hand, in cases C and D, the CPU 21 restricts the power consumed by the printing unit 7 by performing a printing operation at a third printing density D3 that is lighter than the first printing density D1. Note that the third printing density D3 may be the same as or different from the second printing density D2 described later in cases A and B.

[0058] The CPU 21 drives the printing unit 7 under the "second restriction" driving conditions with power supply to external devices restricted, and executes printing on the R line (S39). The CPU 21 proceeds to S41.

[0059] For example, as shown in FIG. 7, although the parameter P once decreases in the section P12 from time t2 to t3, it then changes with an upward trend. The parameter P reaches the third predetermined value Th3 at time t3.

[0060] When it is determined that the parameter P is equal to or greater than the third predetermined value Th3 (S15: YES), the CPU 21 determines whether the parameter P is equal to or greater than the maximum rating Th_max (S19). When it is determined that the parameter P is smaller than the maximum rating Th_max (S19: NO), that is, when Th3 ≤ P < Th_max, the CPU 21 further restricts the driving conditions of the printer 1 (S21).

[0061] For example, the CPU 21 drives the printing unit 7 under the condition of "third restriction" among the driving conditions of the printer 1 shown in FIG. 6. For example, in case A, the CPU 21 restricts the power consumed by the printing unit 7 by decelerating to a third printing speed V3 that is slower than the second printing speed V2. In case B, the CPU 21 restricts the power consumed by the printing unit 7 by executing the printing operation at a second printing density D2 that is lighter than the first printing density D1. In case C, the CPU 21 restricts the power consumed by the printing unit 7 by decelerating to a fourth printing speed V4 that is slower than the first printing speed V1 during the printing operation being executed by the printing unit 7. In this case, the fourth printing speed V4 may be the same as or different from the second printing speed V2 in case A. In case D, the CPU 21 restricts the power consumed by the printing unit 7 by executing the printing operation at a fourth printing density D4 that is lighter than the third printing density D3.

[0062] The CPU 21 drives the printing unit 7 under the "third restricted" driving condition while restricting the power supply to the external device, and executes the printing on the R line (S39). The CPU 21 proceeds to S41 for processing.

[0063] For example, as shown in FIG. 7, the parameter P changes with a downward trend in the section P13 from time t3 to t4. At time t4, the parameter P reaches the fourth predetermined value Th4.

[0064] On the other hand, when it is determined that the parameter P is equal to or greater than the maximum rating Th_max (S19: YES), the CPU 21 further restricts the driving conditions of the printer 1 (S23). The CPU 21 returns the process to S1.

[0065] For example, among the driving conditions of the printer 1 shown in FIG. 6, the driving condition of "fourth restriction" is applied. In this case, in any of cases A to D, assuming that printing cannot be continued, the printing by the printing unit 7 is stopped. In the example shown in FIG. 7, the parameter P does not reach the maximum rating Th_max.

[0066] On the other hand, when it is determined that the acquired parameter P has not increased, i.e., has decreased (S7: NO), the CPU 21 determines whether the parameter P is greater than a fourth predetermined value Th4 (S25). When it is determined that the parameter P is greater than the fourth predetermined value Th4 (S25: YES), since the CPU 21 may exceptionally maintain the driving conditions of the printer 1, printing on the R line is executed under the current driving conditions of the printing unit 7 (S39). The CPU 21 proceeds to S41 with the processing.

[0067] When it is determined that the parameter P is equal to or less than the fourth predetermined value Th4 (S25: NO), the CPU 21 determines whether the parameter P is equal to or less than a fifth predetermined value Th5 (S29). When it is determined that the parameter P is greater than the fifth predetermined value Th5 (S29: YES), i.e., when Th4 ≧ P > Th5, the CPU 21 releases the restriction on the driving conditions (S31).

[0068] For example, the CPU 21 drives the printing unit 7 under the condition of "second restriction" among the driving conditions of the printer 1 shown in FIG. 6. In case A, the CPU 21 accelerates from the third printing speed V3 to the second printing speed V2. In case B, the CPU 21 restores from the second printing density D2 to the first printing density D1. On the other hand, in case C, the CPU 21 accelerates from the fourth printing speed V4 to the first printing speed V1. In case D, the CPU 21 restores from the fourth printing density D4 to the third printing density D3.

[0069] The CPU 21 drives the printing unit 7 under the "second restriction" driving conditions with power supply to the external device restricted to execute printing on the R line (S39). The CPU 21 proceeds to S41 with the processing.

[0070] For example, as shown in FIG. 7, the parameter P transitions with a downward trend while repeating upward and downward movements during the period P14 from time t4 to time t5. The parameter P reaches the fifth predetermined value Th5 at time t5.

[0071] On the other hand, when it is determined that the parameter P is equal to or less than the fifth predetermined value Th5 (S29: NO), the CPU 21 determines whether the parameter P is greater than the sixth predetermined value Th6 (S33). When it is determined that the parameter P is greater than the sixth predetermined value Th6 (S33: YES), that is, when Th5 ≧ P > Th6, the CPU 21 releases the restriction on the driving conditions (S35).

[0072] For example, the CPU 21 drives the printing unit 7 under the condition of "first restriction" among the driving conditions of the printer 1 shown in FIG. 6. In cases A and B, the CPU 21 accelerates from the second printing speed V2 to the first printing speed V1. On the other hand, in cases C and D, the CPU 21 recovers from the third printing density D3 to the first printing density D1.

[0073] The CPU 21 drives the printing unit 7 under the "first restriction" driving condition with power supply to the external device restricted, and executes printing for the R line (S39). The CPU 21 proceeds to the process of S41.

[0074] For example, as shown in FIG. 7, the parameter P once increases during the period P15 from time t5 to t6 and then changes in a downward trend. The parameter P reaches the sixth predetermined value Th6 at time t6.

[0075] On the other hand, when it is determined that the parameter P is equal to or less than the sixth predetermined value Th6 (S33: NO), the CPU 21 performs a release setting for the restriction on power supply from the power supply unit 8 to the external device (S37). In this case, the CPU 21 does not immediately start power supply to the external device by the power supply unit 8. That is, the CPU 21 maintains the "first restriction" on the driving conditions of the printer 1 and executes printing for the R line by the printing unit 7 (S39). The CPU 21 proceeds with the process to S41.

[0076] For example, as shown in FIG. 7, the parameter P once increases during the period P16 from time t6 to t7 and then changes in a downward trend. For example, printing by the printing unit 7 is completed at time t7.

[0077] When it is determined that printing based on image data is completed (S41: YES), CPU 21 determines whether the setting for lifting the limit on power supply from power supply unit 8 to external devices has been set (S43). When it is determined that the setting for lifting the limit on power supply from power supply unit 8 to external devices has not been set (S43: NO), CPU 21 returns the process to S1 and waits without lifting the limit on power supply.

[0078] On the other hand, if it is determined that the setting for lifting the limit on power supply from power supply unit 8 to the external device has been set (S43: YES), i.e., if the process of S37 has been performed, CPU 21 lifts the limit on power supply from power supply unit 8 to the external device (S45). In other words, after restricting power supply from power supply unit 8 to the external device, if parameter P becomes equal to or less than sixth predetermined value Th6 and the printing operation by printing unit 7 is completed, CPU 21 lifts the limit on power supply to the external device by power supply unit 8.

[0079] 7, for example, in section P3 from time t7 onwards, power supply unit 8 supplies power. That is, the restriction on power supply by power supply unit 8 that was imposed in section P2 from time t1 to t7 is lifted when printing is completed.

[0080] The CPU 21 returns the process to S1 and waits.

[0081] As described above, the CPU 21 acquires the parameter P indicating the magnitude of the load on the external power source when power is supplied from the external power source. When the acquired parameter P is equal to or greater than the first predetermined value Th1, the CPU 21 limits the power supply from the power supply unit 8 to the external device.

[0082] The printer 1 ensures power for executing the printing operation of the printer 1 by limiting the power supply to the external device according to the magnitude of the load on the external power source. Therefore, the printer 1 does not need to reduce the load for executing the printing operation. Therefore, when the printer 1 has a power supply function to the external device, it can maintain the printing operation even if the load on the external power source becomes large.

[0083] When the acquired parameter P is equal to or greater than a second predetermined value Th2, the CPU 21 restricts the power consumed by the printing unit 7 out of the power supplied from the external power source. When the load on the battery 11 further increases, the printer 1 can maintain the printing operation by restricting the power consumed by the printing unit 7.

[0084] The CPU 21 restricts the power consumed by the printing unit 7 by decelerating to a second printing speed V2 that is slower than a first printing speed V1 in the printing operation being executed by the printing unit 7. The printer 1 can maintain the printing operation while reducing the load on the external power source through simple control.

[0085] When the parameter P is equal to or greater than a third predetermined value Th3, the CPU 21 restricts the power consumed by the printing unit 7 by decelerating to a third printing speed V3 that is slower than the second printing speed V2. When the parameter P is equal to or greater than a third predetermined value Th3, the CPU 21 restricts the power consumed by the printing unit 7 by executing the printing operation at a second printing density D2 that is lighter than a first printing density D1 in the printing operation being executed by the printing unit 7. The printer 1 can maintain the printing operation while further reducing the load on the external power source by decelerating to the third printing speed V3 or making it lighter to the second printing density D2.

[0086] After restricting the power consumed by the printing unit 7, when the parameter P becomes equal to or less than a fourth predetermined value Th4, the CPU 21 accelerates from the third printing speed V3 to the second printing speed V2. After restricting the power consumed by the printing unit 7, when the parameter P becomes equal to or less than a fourth predetermined value Th4, the CPU 21 restores from the second printing density D2 to the first printing density D1. When the load on the external power source becomes lighter, the power that can be consumed by the printing unit 7 increases. In this case, the printer 1 executes the printing operation by accelerating to the second printing speed V2 before the restriction or restoring to the first printing density D1. Therefore, the printer 1 can efficiently use the power of the external power source.

[0087] After limiting the power consumed by the printing unit 7, when the parameter P becomes equal to or less than the fifth predetermined value Th5, the CPU 21 accelerates from the second printing speed V2 to the first printing speed V1. When the load on the external power supply decreases, the power that can be consumed by the printing unit 7 increases. In this case, the printer 1 accelerates to the first printing speed V1 before the limit and executes the printing operation. Therefore, the printer 1 can efficiently use the power of the external power supply.

[0088] The CPU 21 limits the power consumed by the printing unit 7 by executing the printing operation at a third printing density D3 that is thinner than the first printing density D1 in the printing operation being executed by the printing unit 7. The printer 1 can maintain the printing operation while reducing the load on the external power supply by simple control.

[0089] When the parameter P becomes equal to or greater than the third predetermined value Th3, the CPU 21 limits the power consumed by the printing unit 7 by executing the printing operation at a fourth printing density D4 that is thinner than the third printing density D3. When the parameter P becomes equal to or greater than the third predetermined value Th3, the CPU 21 limits the power consumed by the printing unit 7 by decelerating to a fourth printing speed V4 that is slower than the first printing speed V1 in the printing operation being executed by the printing unit 7. The printer 1 can maintain the printing operation while further reducing the load on the external power supply by making the fourth printing density D4 thinner or decelerating to the fourth printing speed V4.

[0090] After limiting the power consumed by the printing unit 7, when the parameter P becomes equal to or less than the fourth predetermined value Th4, the CPU 21 restores from the fourth printing density D4 to the third printing density D3. After limiting the power consumed by the printing unit 7, when the parameter P becomes equal to or less than the fourth predetermined value Th4, the CPU 21 accelerates from the fourth printing speed V4 to the first printing speed V1. When the load on the external power supply decreases, the power that can be consumed by the printing unit 7 increases. In this case, the printer 1 executes the printing operation by restoring to the third printing density D3 before the limit or accelerating to the first printing speed V1. Therefore, the printer 1 can efficiently use the power of the external power supply.

[0091] After the CPU 21 limits the power consumed by the printing unit 7, when the parameter P becomes equal to or less than the fifth predetermined value Th5, it returns from the third printing density D3 to the first printing density D1. When the load on the power supply becomes lighter, the power that can be consumed by the printing unit 7 increases. In this case, the printer 1 returns to the first printing density D1 before the limitation and executes the printing operation. Therefore, the printer 1 can efficiently use the power of the external power supply.

[0092] After the CPU 21 restricts the power supply from the power supply unit 8 to the external device, when the parameter P becomes equal to or less than the sixth predetermined value Th6 and the printing operation by the printing unit 7 is completed, the CPU 21 releases the restriction on the power supply from the power supply unit 8 to the external device. When the load on the external power supply becomes lighter, the power that can be consumed by the printer 1 increases. In this case, the printer 1 resumes the restriction on the power supply to the external device. Therefore, the printer 1 can efficiently use the power of the external power supply. Further, since the printer 1 maintains the restriction on the power supply to the external device until the printing operation is completed, it is possible to suppress a change in the driving state of the printer 1 during printing. Therefore, the printer 1 can maintain the print quality.

[0093] The first predetermined value Th1 and the sixth predetermined value Th6 are different from each other. The third predetermined value Th3 and the fourth predetermined value Th4 are different from each other. The second predetermined value Th2 and the fifth predetermined value Th5 are different from each other. For example, when each of the predetermined values Th1 to Th6 has the same value, it is also assumed that the parameter P fluctuates in a short time near each of the predetermined values Th1 to Th6. In this case, for example, the limitation and release of the printing speed frequently occur, and the printing operation of the printer 1 becomes unstable. Therefore, the printer 1 can stably perform the printing operation by setting each of the predetermined values Th1 to Th6 to different values.

[0094] The external power supply is the AC adapter 9. The printer 1 can maintain the printing operation even when the load on the AC adapter 9 becomes large.

[0095] The CPU 21 estimates the parameter P based on the image data printed on the medium by the printing unit 7. The CPU 21 acquires the estimated parameter P. Since the printer 1 estimates the parameter P, there is no need to separately provide a sensor for detecting the load on the external power supply, such as a temperature sensor or the like.

[0096] In the above description, the CPU 21 is an example of the "control unit" of the present invention. The AC adapter 9 is an example of the "power supply" of the present invention. The tablet PC 5 is an example of the "external device" of the present invention. The process of S3 executed by the CPU 21 is an example of the "acquisition process" of the present invention. The process of S13 executed by the CPU 21 is an example of the "first restriction process" of the present invention. The process of S17 executed by the CPU 21 is an example of the "second restriction process" of the present invention. The process of S21 executed by the CPU 21 is an example of the "third restriction process" of the present invention. The process of S21 executed by the CPU 21 is an example of the "fourth restriction process" of the present invention. The process of S31 is an example of the "first acceleration process" of the present invention. The process of S31 executed by the CPU 21 is an example of the "first density recovery process" of the present invention. The process of S31 executed by the CPU 21 is an example of the "second density recovery process" of the present invention. The process of S35 is an example of the "second acceleration process" of the present invention. The process of S31 executed by the CPU 21 is an example of the "third acceleration process" of the present invention. The process of S35 executed by the CPU 21 is an example of the "third density recovery process" of the present invention. The process of S45 executed by the CPU 21 is an example of the "release process" of the present invention. The process of S3 executed by the CPU 21 is an example of the "load estimation process" of the present invention.

[0097] The present invention is not limited to the above-described embodiments and the like, and various further modifications are possible. The technologies disclosed in the above embodiments and modifications can be combined within a non-contradictory range. The printer 1 was a thermal type, but it is not limited to this, and an inkjet system may be adopted. The external device was the tablet PC 5, but it is not limited to this. For example, the external device may be a smartphone or a device such as a PC. As the external power supply, the AC adapter 9 was used, but it is not limited to this. For example, the external power supply may be substituted with a battery or the like. The printer 1 may receive power from an external device in accordance with the USB PD (USB Power Delivery) standard.

[0098] In the above embodiment, the first predetermined value Th1 to the sixth predetermined value Th6 were different from each other, but it is not limited to this. At least one of the first predetermined value Th1 to the sixth predetermined value Th6 may be the same value. For example, as shown in FIG. 8, each of the predetermined values Th1 to Th3 may be the same value. In this case, the printer 1 restricts the printer 1 using, for example, only the first predetermined value Th1.

[0099] At time t0, printing based on image data is executed. The estimation of parameter P for the R line is sequentially performed. In the section P101 from time t0 to time t1, parameter P increases. In this case, there is no restriction on the driving conditions of printer 1 ("no restriction"). At time t1, parameter P reaches a predetermined value Th1. In this case, the power supply to external devices by the power supply unit 8 is restricted ("first restriction"). Note that in the section P102 after time t1, the power supply to external devices by the power supply unit 8 remains restricted. In the section P111 from time t1 to t2, parameter P once decreases but then increases. At time t2, parameter P reaches the first predetermined value Th1 again. In this case, for example, the printing speed of the printing unit 7 is restricted from the first printing speed V1 to the second printing speed V2 ("second restriction"). In the section P112 from time t2 to t3, parameter P once decreases but then increases. At time t3, parameter P reaches the predetermined value Th1 again. In the section P113 after time t3, for example, the printing speed by the printing unit 7 is restricted from the second printing speed V2 to the third printing speed V3 ("third restriction").

[0100] Note that in the example of FIG. 8, it is assumed that once a restriction is imposed, there is no release of the restriction until printing is completed. However, printer 1 may sequentially release the restriction by providing predetermined values Th4 to Th6 as in the above embodiment. The predetermined values Th4 to Th6 may be the same or different. Also, it is assumed that parameter P may not decrease even when a restriction is imposed. In such a case, for example, restrictions may be sequentially imposed over a predetermined period of time. Also, a maximum rating Th_max may be provided as in the above embodiment.

[0101] In the above embodiment, the first printing speed V1 was the fastest speed, but it is not limited to this. For example, the first printing speed V1 may be appropriately set to any speed from the fastest speed to the slowest speed. Also, in the above embodiment, the first printing density D1 was the density at the median between the lightest color and the darkest color, but it is not limited to this. For example, the first printing density D1 may be appropriately set to any density from the lightest color to the darkest color. Further, the first printing speed V1 to the fourth printing speed V4, and the first printing density D1 to the fourth printing density D4 may be set on the printer 1 side or may be set by the user.

[0102] In the above embodiment, the power supply from the power supply unit 8 was stopped when the parameter P became equal to or greater than the first predetermined value Th1, but it is not limited to this. For example, the CPU 21 may gradually limit the power that can be supplied from the power supply unit 8.

[0103] In the above embodiment, the integrated average value based on the average current value was used as the parameter P, but it is not limited to this. For example, the parameter P may be a value based on the heat generation temperature of the AC adapter 9. For example, the AC adapter 9 is provided with a sensor for measuring the temperature of the AC adapter 9. The CPU 21 acquires the measurement result of the temperature of the AC adapter 9 by the sensor as the parameter P. In this case, each of the predetermined values Th1 to Th6 may be appropriately set based on the rated temperature of the AC adapter 9. Since the printer 1 directly detects the temperature of the AC adapter 9 with the sensor and uses the measurement result as the parameter P, it can be restricted at a more accurate timing compared to the case of estimating the load.

[0104] In the main process of the above embodiment, the printer 1 was driven by the power of the AC adapter 9, but it is not limited to this. In the main process, for example, the printer 1 may be driven by the battery 11. In this case, each of the predetermined values Th1 to Th6 may be appropriately set based on the rated current of the battery 11. The printer 1 can maintain the printing operation even when the load on the battery 11 increases.

[0105] When the printer 1 is driven by the battery 11, instead of estimating the parameter P, for example, the temperature of the battery 11 detected by the sensor 11A may be used as the parameter P. In this case, each predetermined value Th1 to Th6 may be appropriately set according to the rated temperature of the battery 11.

[0106] In the above embodiment, the parameter P was estimated when R = 3, but it is not limited to this. The target number of lines R may be appropriately set. Also, in the above embodiment, after obtaining the parameter P for the target three lines, the parameter P for the next target three lines was calculated, but it is not limited to this. For example, after calculating the parameter P for lines 1 to 3, the parameter P may be calculated for lines 2 to 4. That is, the lines for which the parameter P is calculated may overlap or may not overlap.

[0107] In the above embodiment, the printer 1 executed printing by the printing unit 7 while estimating the parameter P, but it is not limited to this. For example, the estimation of the parameter P may be performed before printing. After the estimation is completed, printing by the printing unit 7 may be executed.

[0108] In the above embodiment, when the release setting of the power supply restriction was performed in the process of S37 and printing was completed, power supply from the power supply unit 8 to an external device was possible, but it is not limited to this. For example, power supply from the power supply unit 8 to an external device may be resumed when the release setting of S37 is performed.

[0109] Note that instead of the CPU 21, a USB PD IC 37, an ASIC, an FPGA (Field Programmable Gate Array), etc. may be used as a processor. The main process may be distributedly processed by a plurality of processors. The printer 1 may include, for example, another non-temporary storage medium such as an HDD. The non-temporary storage medium may be any storage medium that can retain information regardless of the period for which the information is stored. The non-temporary storage medium may not include a temporary storage medium (for example, a transmitted signal).

[0110] Various programs may be downloaded (i.e., transmitted as transmission signals) from a server connected to a network (not shown in the figure) and stored in a memory such as an HDD. In this case, the various programs only need to be stored in a non-temporary storage medium such as an HDD provided in the server.

Explanation of Reference Numerals

[0111] 1 Printer 5 Tablet PC 7 Printing Unit 8 Power Supply Unit 9 AC Adapter 11 Battery 21 CPU P Parameter V1~V4 Printing Speed D1~D4 Printing Density Th1~Th6 Predetermined Value

Claims

1. A printer driven by a power source, comprising: a printing unit capable of performing a printing operation on a medium based on the power of the power source; a power supply unit capable of supplying power to an external device based on the power of the power source; a control unit and wherein the control unit performs an acquisition process of acquiring a parameter indicating the magnitude of the load on the power source when power is supplied from the power source, and a first limiting process of limiting the power supply from the power supply unit to the external device when the parameter acquired by the acquisition process is equal to or greater than a first predetermined value ; a printer characterized by the above.

2. The control unit performs a second limiting process of limiting the power consumed by the printing unit among the power supplied from the power source when the parameter acquired by the acquisition process is equal to or greater than a second predetermined value that is equal to or greater than the first predetermined value ; a printer according to claim 1, characterized by the above.

3. The second limiting process limits the power consumed by the printing unit by decelerating to a second printing speed that is slower than a first printing speed in the printing operation being performed by the printing unit ; a printer according to claim 2, characterized by the above.

4. The control unit performs a third limiting process of limiting the power consumed by the printing unit by decelerating to a third printing speed that is slower than the second printing speed when the parameter is equal to or greater than a third predetermined value that is equal to or greater than the second predetermined value, and a fourth limiting process of limiting the power consumed by the printing unit by performing the printing operation at a second printing density that is lighter than a first printing density in the printing operation being performed by the printing unit when the parameter is equal to or greater than the third predetermined value and performs at least one of the above ; a printer according to claim 3, characterized by the above.

5. The control unit performs a first acceleration process of accelerating from the third printing speed to the second printing speed when the parameter becomes equal to or less than a fourth predetermined value that is equal to or less than the third predetermined value after limiting the power consumed by the printing unit by the third limiting process, and a first density restoration process of restoring from the second printing density to the first printing density when the parameter becomes equal to or less than the fourth predetermined value after limiting the power consumed by the printing unit by the fourth limiting process ; a printer according to claim 4, characterized by the above.

6. The third predetermined value and the fourth predetermined value are different from each other ; a printer according to claim 5, characterized by the above.

7. The control unit After limiting the power consumed by the printing unit by the second limiting process, when the parameter becomes equal to or less than a fifth predetermined value that is equal to or less than the second predetermined value, a second acceleration process of accelerating from the second printing speed to the first printing speed is executed The printer according to claim 3, characterized in that

8. The second predetermined value and the fifth predetermined value are different from each other The printer according to claim 7, characterized in that

9. The second limiting process limits the power consumed by the printing unit by executing the printing operation at a third printing density that is thinner than the first printing density in the printing operation being executed by the printing unit The printer according to claim 2, characterized in that

10. The control unit when the parameter becomes equal to or greater than a third predetermined value that is equal to or greater than the second predetermined value, limits the power consumed by the printing unit by executing the printing operation at a fourth printing density that is thinner than the third printing density, a third limiting process; and when the parameter becomes equal to or greater than the third predetermined value, limits the power consumed by the printing unit by decelerating to a fourth printing speed that is slower than the first printing speed in the printing operation being executed by the printing unit, a fourth limiting process executes at least one of them The printer according to claim 9, characterized in that

11. The control unit after limiting the power consumed by the printing unit by the third limiting process, when the parameter becomes equal to or less than a fourth predetermined value that is equal to or less than the third predetermined value, a second density recovery process of recovering from the fourth printing density to the third printing density; and after limiting the power consumed by the printing unit by the fourth limiting process, when the parameter becomes equal to or less than the fourth predetermined value, a third acceleration process of accelerating from the fourth printing speed to the first printing speed is executed The printer according to claim 10, characterized in that

12. The third predetermined value and the fourth predetermined value are different from each other The printer according to claim 11, characterized in that

13. The control unit after limiting the power consumed by the printing unit by the second limiting process, when the parameter becomes equal to or less than a fifth predetermined value that is equal to or less than the second predetermined value, a third density recovery process of recovering from the third printing density to the first printing density is executed The printer according to claim 9, characterized in that

14. The second predetermined value and the fifth predetermined value are different from each other The printer according to claim 13, characterized in that

15. The control unit After restricting power supply from the power supply unit to the external device by the first restriction process, when the parameter becomes equal to or less than a sixth predetermined value that is equal to or less than the first predetermined value and the printing operation by the printing unit is completed, a release process for releasing the restriction of power supply to the external device by the first restriction process The printer according to claim 2, characterized in that it executes the above.

16. The first predetermined value and the sixth predetermined value are different from each other The printer according to claim 15, characterized in that it is as described above.

17. The power supply is an AC adapter The printer according to claim 1, characterized in that it is as described above.

18. The power supply is a battery The printer according to claim 1, characterized in that it is as described above.

19. The control unit A load estimation process for estimating the parameter based on the image data printed on the medium by the printing unit Execute In the acquisition process, the parameter estimated by the load estimation process is acquired The printer according to claim 1, characterized in that it is as described above.

20. A sensor for measuring the temperature of the power supply is provided in the power supply In the acquisition process, the measurement result of the temperature of the power supply by the sensor is acquired as the parameter The printer according to claim 1, characterized in that it is as described above.

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