Printing device, printing control method, program

Abstract

In a battery-powered printing device, the system performs divided printing with an appropriate number of divisions depending on the situation. [Solution] The printing apparatus includes a thermal head having multiple heating elements, and a control unit that divides the multiple heating elements into two or more groups and controls heating on a group basis based on the measured voltage of a battery supplied to the thermal head and the print density of the print data. The control unit divides the multiple heating elements into more groups than when the voltage is above the first threshold and the print density is above the second threshold, and also than when the voltage is below the first threshold and the print density is below the second threshold.

Description

Technical Field

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[0001] The disclosure of this specification relates to a printing apparatus, a printing control method, and a program.

Background Art

[0002] In a printing apparatus having a thermal head, a split printing technique is known in which a plurality of heating elements of the thermal head are divided into a plurality of blocks and printing is performed in block units. Such a technique is described in, for example, Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a battery-driven printing apparatus, the above-described split printing can suppress battery consumption, but there is a problem that the printing speed decreases as the number of splits increases. Based on the above circumstances, an object according to one aspect of the present invention is to provide a technique for performing split printing with an appropriate number of splits according to the situation in a battery-driven printing apparatus.

Means for Solving the Problems

[0005] A printing apparatus according to one aspect of the present invention includes a thermal head having a plurality of heating elements, and a control unit that divides the plurality of heating elements into two or more groups based on the measured voltage of a battery supplied to the thermal head and the printing rate of print data, and controls heat generation in group units. When the voltage is less than a first threshold value and the printing rate is greater than or equal to a second threshold value, the control unit divides the plurality of heating elements into more groups than when the voltage is greater than or equal to the first threshold value, and also divides the plurality of heating elements into more groups than when the voltage is less than the first threshold value and the printing rate is less than the second threshold value. [Effects of the Invention]

[0006] According to the above embodiment, a battery-powered printing device can perform divided printing with an appropriate number of divisions depending on the situation. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram showing the internal configuration of a printing apparatus according to one embodiment. [Figure 2] Figure 1 is a schematic diagram showing the configuration of the thermal head of the printing apparatus. [Figure 3] Figure 1 is a block diagram of the printing apparatus shown. [Figure 4] Figure 1 is a flowchart showing an example of the printing process performed by the printing device. [Figure 5] This figure shows an example of a division pattern for the heating element in a thermal head. [Figure 6] Figure 1 is a flowchart showing another example of the printing process performed by the printing device. [Figure 7] This figure shows another example of the division pattern of the heating element in a thermal head. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described with reference to the drawings. Below, embodiments of the present invention will be described using a thermal transfer printing apparatus as an example, which can print characters, images, etc., onto a tape, which is the printing medium, using a thermal head, and cut the printed tape (label) to discharge it outside the apparatus. In this specification, tape is a long, thin, strip-shaped printing medium made of plastic, paper, or any other material. Tape typically has an adhesive layer and can be attached. However, tape does not have to have an adhesive layer, and the printing medium is not limited to tape. A label is something on which some information is printed using tape as the printing medium. The printing apparatus may be a thermal printer having a thermal head, and the printing method of the printing apparatus is not limited to the thermal transfer method. For example, it may be a thermal-sensitive type.

[0009] As shown in Figure 1, the device housing 2 of the printing device 1 is provided with a housing section 3 for housing a tape cartridge C. The tape cartridge C housed in the housing section 3 is supported in a predetermined position within the printing device 1 by a plurality of support sections 4. The support sections 4 are provided with a plurality of switches 5. The tape cartridge C has different shapes depending on the width of the tape T housed within it. The plurality of switches 5 provided on the support sections 4 are an example of detection sections for detecting the shape of the tape cartridge C, and are configured such that the combination of switches 5 pressed differs depending on the shape of the tape cartridge C. Therefore, the printing device 1 can detect the width of the tape T housed in the printing device 1 (tape cartridge 20) based on the combination of switches 5 pressed when the tape cartridge C is housed in the housing section 3.

[0010] The printing device 1 comprises a platen roller 6, a thermal head 7, and a cutter 8. The platen roller 6 is an example of a transport unit that transports the tape T supplied from the tape cartridge C. The thermal head 7 is an example of a printing unit that prints on the tape T supplied from the tape cartridge C, and as shown in Figure 2, has a plurality of heating elements 7a aligned in a direction intersecting the transport direction of the tape T. When a print command is input to the printing device 1, the tape T is unwound from the tape cartridge C by the rotation of the platen roller 6. At this time, the ink ribbon R is also unwound from the tape cartridge C along with the tape T. As a result, the tape T and the ink ribbon R are transported in an overlapping state. As the ink ribbon R passes between the platen roller 6 and the thermal head 7, it is heated by the thermal head 7, transferring the ink to the tape T and performing printing. The used ink ribbon R that has passed between the platen roller 6 and the thermal head 7 is wound up inside the tape cartridge C. Meanwhile, the printed tape T that has passed between the platen roller 6 and the thermal head 7 is cut by a cutter 8 located near the discharge port 2a and discharged from the discharge port 2a.

[0011] The printing device 1 further includes a control unit 10, as shown in Figure 3, which includes a power supply circuit 11, a head drive circuit 12, and a control circuit 13. The control unit 10 executes a printing program, and the printing process is performed using electrical energy supplied from the battery 9. Specifically, the power supply circuit 11 converts and stabilizes the voltage generated by the battery 9 and supplies it to each part of the printing device 1. The head drive circuit 12 controls the thermal head 7 with the voltage supplied via the power supply circuit 11. The control circuit 13 includes, for example, a CPU. The control circuit 13 outputs printing data and various control signals (clock signal, latch signal, strobe signal) to the head drive circuit 12, thereby controlling the heat generation of the multiple heating elements 7a of the thermal head 7 via the head drive circuit 12. As a result, the printing device 1 prints the content corresponding to the printing data onto the tape T.

[0012] The printing device 1 configured as described above suppresses peak current by performing segmented printing in order to reduce battery consumption 9. Specifically, the control unit 10 divides the multiple heating elements 7a into two or more groups based on the voltage of the battery 9 and the printing density of the print data, and controls the heat generation on a group basis. This allows the printing device 1 to perform segmented printing while considering the remaining charge of the battery 9 and the magnitude of the load on the battery 9 due to printing (hereinafter referred to as the printing load). In particular, the control unit 10 increases the number of segmented printing divisions when the remaining charge of the battery 9 is low and the printing load is high compared to when the remaining charge of the battery 9 is high. Also, the control unit 10 increases the number of segmented printing divisions when the remaining charge of the battery 9 is low and the printing load is high compared to when the remaining charge of the battery 9 is low and the printing load is low. Specifically, when the voltage of the battery 9 is below a certain threshold (hereinafter referred to as the first threshold) and the print density is above a certain threshold (hereinafter referred to as the second threshold), the control unit 10 divides the multiple heating elements 7a of the thermal head 7 into more groups than when the voltage of the battery 9 is above the first threshold, and also than when the voltage of the battery 9 is below the first threshold and the print density is below the second threshold. As a result, the printing device 1 can avoid generating a high peak current when the battery 9 is low, while also being able to reduce the number of divisions and suppress the decrease in printing speed when a high peak current is not generated even when the battery 9 is low. Therefore, in a battery-powered printing device, divided printing can be performed with an appropriate number of divisions depending on the situation.

[0013] In the printing device 1, the control unit 10 measures the voltage of the battery 9 and calculates the print density of the print data. The method for measuring the voltage of the battery 9 is not particularly limited, but the control unit 10 may, for example, convert the voltage of the battery 9 from the voltage measured using a voltage divider circuit. The print density of the print data only needs to reflect the printing load determined by the print data, and the specific calculation method is not particularly limited. For example, the control unit 10 may calculate the print density of the print data as the number of printed dots (overall average) as a percentage of the total number of dots constituting the print data. For example, the control unit 10 may calculate the print density of each line of print data as the number of printed dots as a percentage of the total number of dots constituting that line, and calculate the maximum value of the line's print density in the entire print data as the print density of the print data, or it may calculate the print density of each line as the print density of the print data.

[0014] The following describes in detail an example of the printing process performed by the printing device 1. When a print command is input and the printing device 1 starts the printing process shown in Figure 4, first the control unit 10 measures the voltage of the battery 9 (step S1) and determines whether the measured voltage is above a threshold (first threshold) (step S2). If it is determined that the measured voltage is above the threshold, the control unit 10 determines the number of divisions for split printing to be 2 (step S3). In other words, if it is determined from the measured voltage that there is a relatively large amount of charge remaining in the battery 9 and there is no need to suppress battery consumption more than usual, the control unit 10 sets the number of divisions to the normal setting. On the other hand, if the control unit 10 determines that the measured voltage is below a threshold (first threshold), the control unit 10 calculates the print rate of the print data, which is an indicator of the printing load. Specifically, it calculates the print rate for each line of print data (step S4) and determines the maximum value of the calculated print rates for each line as the print rate of the print data (step S5). In other words, the control unit calculates the print density corresponding to the maximum number of heating elements that can be simultaneously heated by the thermal head 7 during printing based on the print data. Then, the control unit 10 determines whether the print density of the print data is equal to or greater than a threshold (second threshold) (step S6). If the control unit 10 determines that the calculated print density is less than the threshold, it determines the number of divisions for split printing to be 2 (step S3), and if it determines that the calculated print density is equal to or greater than the threshold, it determines the number of divisions for split printing to be 3 (step S7). In other words, if it is determined from the calculated print density that the peak current will not be high, the control unit 10 sets the number of divisions to the normal setting, and if it is determined that the peak current will be high, it sets the number of divisions to a higher number than normal. Once the number of divisions is determined, the control unit 10 performs printing according to the determined number of divisions (step S8). Specifically, the control unit 10 first identifies the heating elements 7a that may be subject to heat generation during printing on tape T of the width detected using the switch 5, and determines the effective range 70 of the thermal head 7 including the identified heating elements 7a, as shown in Figure 5.Subsequently, if the number of divisions is set to 2 in step S3, the control unit 10 divides the heating elements 7a within the effective range 70 of the thermal head 7 into two groups (group G11 and group G12), as shown in Figure 5, and sequentially performs heating control for group G11 and heating control for group G12 according to the print data. In contrast, if the number of divisions is set to 3 in step S7, the control unit 10 divides the heating elements 7a within the effective range 70 of the thermal head 7 into three groups (group G21, group G22, and group G23), as shown in Figure 5, and sequentially performs heating control for group G21, heating control for group G22, and heating control for group G23 according to the print data. This makes it possible to suppress the peak current by keeping the number of heating elements simultaneously supplying current below a predetermined number.

[0015] As described above, in the printing device 1, the control unit 10 sets a higher number of divisions when the battery 9 is low and the printing load is high compared to when the battery 9 is high, and also compared to when the battery 9 is low and the printing load is low. This allows the printing device 1 to avoid generating high peak currents when the battery 9 is low, while minimizing the reduction in printing speed by keeping the number of divisions to a minimum. In addition, in the printing device 1, the control unit 10 divides the multiple heating elements 7a into the same number of groups (2 in this example) depending on whether the measured voltage is above a first threshold or whether the measured voltage is below the first threshold and the print density is below a second threshold. In other words, the control unit 10 sets the same number of divisions when the battery 9 has a relatively large remaining charge and when the battery 9 has a small remaining charge but the printing load is relatively small. As a result, the printing device 1 can print at the same printing speed as when the battery 9 has a large remaining charge, even when the battery 9 has a small remaining charge, as long as the printing load is small and no large peak currents are generated. Furthermore, in the printing device 1, the control unit 10 determines the number of divisions for the multiple heating elements 7a based on the measured voltage and the maximum value of the print density calculated for each line of print data. By using the maximum value of the print density calculated for each line, the printing device 1 can determine the number of divisions while considering the maximum printing load corresponding to the maximum peak current, thereby reliably avoiding excessive load on the battery 9. Therefore, with the printing device 1, a battery-powered printing device can perform divided printing with an appropriate number of divisions depending on the situation.

[0016] In the printing process shown in Figure 4, the control unit 10 of the printing device 1 identifies the maximum possible printing load on the battery 9 from the entire print data, and determines the number of divisions based on the remaining battery capacity and the maximum printing load, thereby demonstrating an example of executing the entire printing of the print data in a fixed number of divisions. However, the number of divisions may also be determined for each line of print data, as shown in Figure 6. When a print command is input and the printing device 1 starts the printing process shown in Figure 6, first, the control unit 10 acquires data for one line from the print data (step S11). Then, the control unit 10 measures the voltage of the battery 9 (step S12) and determines whether the measured voltage is above a threshold (first threshold) (step S13). If it is determined that the measured voltage is above a threshold, the control unit 10 determines the number of divisions for divided printing to be 2 (step S14). Note that the processing from steps S12 to S14 is the same as the processing from steps S1 to S3 in Figure 4. On the other hand, if the control unit 10 determines that the measured voltage is less than a threshold (first threshold), the control unit 10 calculates the print density of the print data, which is an indicator of the printing load. Specifically, it calculates the print density of a line from the data for one line acquired in step S1 as the print density of the print data (step S15). Then, the control unit 10 determines whether the print density of the print data is equal to or greater than a threshold (second threshold) (step S16). If the control unit 10 determines that the calculated print density is less than the threshold, it determines that the number of divisions for split printing is 2 (step S14), and if it determines that the calculated print density is equal to or greater than the threshold, it determines that the number of divisions for split printing is 3 (step S17). Note that the processing in steps S16 and S17 is the same as the processing in steps S6 and S7 in Figure 4. Once the number of divisions is determined, the control unit 10 prints one line based on the data acquired in step S11 according to the determined number of divisions (step S18). Once printing for one line is complete, the control unit 10 determines whether all lines have been printed (step S19), and repeats the process from step S11 to step S19 until printing for all lines is complete.

[0017] As described above, even when the printing process shown in Figure 6 is performed, the printing device 1 can perform divided printing with an appropriate number of divisions depending on the situation, just as when the printing process shown in Figure 4 is performed. Furthermore, in the printing process shown in Figure 6, the control unit 10 determines the number of divisions to divide the multiple heating elements 7a for each line of print data, based on the measured voltage and the print density calculated for that line. This allows for divided printing to be performed for each line with a number of divisions corresponding to the peak current that may occur during printing on that line, taking into account the printing load which may differ for each line. Therefore, compared to the printing process shown in Figure 6, where the number of divisions is determined based on the maximum peak current that occurs during printing of the entire print data, the number of lines printed with fewer divisions increases, thus improving the overall printing speed while suppressing the consumption of the battery 9.

[0018] The above-described embodiments are presented with specific examples to facilitate understanding of the invention. The present invention is not limited to the above-described embodiments and should be understood to include various modifications and alternative forms of the above-described embodiments. For example, in the above-described embodiments, the printing apparatus 1 that executes printing processing using electrical energy supplied from the battery 9 is exemplified. However, the printing apparatus 1 may be any printing apparatus that can be driven by the battery 9, and further, it may be a printing apparatus that can operate using electrical energy supplied from a commercial power source via an AC adapter. That is, it may be a printing apparatus that switches between the battery 9 and the commercial power source for use. Also, in the above-described embodiments, when dividing a plurality of heating elements 7a into two or more groups, an example of dividing them into the same number of blocks as the number of groups is shown. However, the heating elements 7a of each group may be located at positions separated from each other with the heating elements 7a of other groups interposed therebetween. For example, as shown in FIG. 7, when dividing into two groups, the heating elements 7a belonging to group G1 and the heating elements 7a belonging to group G2 may be arranged alternately. Also, in the above-described embodiments, an example of dividing a plurality of heating elements 7a into either two groups or three groups according to the situation is shown. However, the plurality of heating elements 7a may be divided into two or more groups. For example, they may be divided into either three groups or four groups according to the situation. Also, in the above-described embodiments, examples of the control unit 10 determining one division number for the entire printing data and determining the division number for each line are shown. However, the unit for determining the division number is not limited to these examples. For example, the control unit 10 may determine the division number for every predetermined number of lines. Also, in the above-described embodiments, when determining the division number for each line, an example where the control unit 10 measures the remaining amount of the battery 9 for each line is shown. However, the remaining amount of the battery 9 may be measured only once regardless of the number of lines. Also, in the above-described embodiments, an example of dividing a plurality of heating elements 7a into two or more groups according to the situation and controlling heat generation in group units is shown. However, the control unit 10 may group a plurality of heating elements 7a into one or more groups according to the situation and control heat generation in group units. That is, the control unit 10 may group into either one group or two groups according to the situation and control heat generation in group units.

Explanation of Reference Numerals

[0019] 1: Printing device, 7: Thermal head, 7a: Heating element, 9: Battery, 10: Control unit, G1, G2, G11, G12, G21, G22, G23: Group

Claims

1. A thermal head having multiple heating elements, The system includes a control unit that divides the plurality of heating elements into two or more groups and controls heating on a group basis, based on the measured voltage of the battery supplied to the thermal head and the print density of the print data. The control unit divides the plurality of heating elements into more groups than when the voltage is less than a first threshold and the printing density is greater than or equal to a second threshold, and more than when the voltage is less than a first threshold and the printing density is less than a second threshold. Printing device.

2. In the printing apparatus according to claim 1, The control unit determines the number of divisions for dividing the plurality of heating elements based on the voltage and the maximum value of the print density calculated for each line of the print data. Printing device.

3. In the printing apparatus according to claim 1, The control unit determines, for each line of print data, the number of divisions to divide the plurality of heating elements based on the voltage and the print density calculated for that line. Printing device.

4. In the printing apparatus according to any one of claims 1 to 3, The control unit divides the plurality of heating elements into the same number of groups depending on whether the voltage is equal to or greater than the first threshold, or whether the voltage is less than the first threshold and the printing density is less than the second threshold. Printing device.

5. A printing control method performed by a printing apparatus equipped with a thermal head having multiple heating elements, The plurality of heating elements are divided into two or more groups based on the measured voltage of the battery supplied to the thermal head and the print density of the print data. This includes controlling the heat generation in groups obtained by dividing the plurality of heating elements, Dividing the plurality of heating elements into two or more groups means that when the voltage is less than a first threshold and the printing density is greater than or equal to a second threshold, the plurality of heating elements are divided into more groups than when the voltage is greater than or equal to the first threshold, and more than when the voltage is less than a first threshold and the printing density is less than a second threshold. Print control method.

6. A printing apparatus equipped with a thermal head having multiple heating elements, Based on the measured voltage of the battery supplied to the thermal head and the print density of the print data, the plurality of heating elements are divided into two or more groups. The heat generation is controlled in groups obtained by dividing the plurality of heating elements. By dividing the plurality of heating elements into two or more groups, when the voltage is less than a first threshold and the printing density is greater than or equal to a second threshold, the plurality of heating elements are divided into more groups than when the voltage is greater than or equal to the first threshold, and more than when the voltage is less than a first threshold and the printing density is less than a second threshold. A program that executes a process.

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