Printing device, control method of printing device, and recording medium

Abstract

The present application provides a printing device, a control method and a recording medium capable of shortening the energization time for each gray scale of a heating element. The printing device includes a thermal head that performs printing on a printed medium; a drive circuit that energizes a plurality of heating elements included in the thermal head based on print data and a selection signal; and a processor that sequentially transmits data of a first gray scale value included in the print data and data of a second gray scale value following the data of the first gray scale value to the drive circuit, turns on the selection signal, and causes the drive circuit to perform first energization of the plurality of heating elements based on the data of the first gray scale value. After the first energization ends, the selection signal is temporarily turned off before the transmission of the data of the second gray scale value is completed, and the drive circuit is caused to perform second energization of the plurality of heating elements based on the data of the second gray scale value.

Description

[0001] Citation of relevant applications

[0002] This application claims priority and interest based on Japanese Patent Application No. 2022-142631, filed on September 8, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This specification discloses information about printing apparatus, methods for controlling printing apparatus, and recording media. Background Technology

[0004] As a type of printing apparatus, thermal printers are known to print desired characters, images, etc., on a printing medium by controlling the energization of multiple heating elements in a thermal head. For example, Patent Document 1 describes the specific structure of such a thermal printer.

[0005] The thermal printer described in Japanese Patent Application Publication No. 2008-279683 transmits grayscale data, including each grayscale value, sequentially from the main controller to the thermal head. The thermal head then energizes each heating element based on the sequentially transmitted grayscale data. This allows, for example, the printing of images with multiple grayscale values.

[0006] Prior art literature

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2008-279683 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] In the aforementioned thermal printers, for example, the more grayscale levels that can be represented, the shorter the power-on time for each grayscale value on the heating element needs to be. Since a shorter power-on time for each grayscale value results in a shorter interval between the corresponding power-on periods, the data for each grayscale value needs to be transmitted from the main controller to the thermal printhead at a higher speed. In other words, the speed of printing data transmission becomes a bottleneck, sometimes making it difficult to shorten the power-on time for each grayscale value on the heating element.

[0011] The present invention was made in view of the above circumstances, and its object is to provide a printing apparatus, a control method for the printing apparatus, and a recording medium capable of shortening the energizing time for each grayscale value of the heating element.

[0012] Problem-solving methods

[0013] A printing apparatus according to one embodiment of the present invention includes: a thermal head for printing on a printable medium; a drive circuit for energizing a plurality of heating elements of the thermal head based on printing data and a gating signal; and a control unit. The control unit sequentially transmits data of a first grayscale value included in the printing data and data of a second grayscale value following the first grayscale value to the drive circuit, thereby activating the gating signal and causing the drive circuit to first energize the plurality of heating elements based on the first grayscale value. After the first energization is completed, the gating signal is temporarily deactivated until the transmission of the second grayscale value is completed, causing the drive circuit to second energize the plurality of heating elements based on the second grayscale value.

[0014] One embodiment of the present invention provides a control method for a printing apparatus, the printing apparatus comprising: a thermal head for printing on a printing medium; and a drive circuit for energizing a plurality of heating elements of the thermal head based on printing data and a gating signal. The control method of the printing apparatus includes: sequentially transmitting data of a first grayscale value included in the printing data and data of a second grayscale value following the first grayscale value to the drive circuit, activating the gating signal, and energizing the drive circuit to first energize the plurality of heating elements based on the first grayscale value; after the first energization is completed, temporarily disconnecting the gating signal before the transmission of the second grayscale value is completed, and energizing the drive circuit to second energize the plurality of heating elements based on the second grayscale value.

[0015] An embodiment of the present invention records a program that enables a computer of a printing apparatus to execute processing. The printing apparatus includes: a thermal head for printing on a printable medium; and a drive circuit for energizing a plurality of heating elements of the thermal head based on print data and a gating signal. The processing includes: sequentially transmitting data of a first grayscale value included in the print data and data of a second grayscale value following the first grayscale value to the drive circuit, activating the gating signal, and energizing the drive circuit to first energize the plurality of heating elements based on the first grayscale value; after the first energization is completed, temporarily disconnecting the gating signal before the transmission of the second grayscale value is completed, and energizing the drive circuit to second energize the plurality of heating elements based on the second grayscale value.

[0016] The effects of the invention

[0017] According to one embodiment of the present invention, a printing apparatus, a control method for the printing apparatus, and a recording medium are provided that can shorten the energizing time for each grayscale value of the heating element. Attached Figure Description

[0018] Figure 1 This is a perspective view of a printing apparatus according to one embodiment of the present invention.

[0019] Figure 2 This is a perspective view of a printing apparatus with a box housed in one embodiment of the present invention.

[0020] Figure 3 This is a perspective view of a box storage section provided in a printing apparatus according to one embodiment of the present invention.

[0021] Figure 4 This is a cross-sectional view of a printing apparatus according to one embodiment of the present invention.

[0022] Figure 5 This is a control block diagram of a printing apparatus according to one embodiment of the present invention.

[0023] Figure 6 This is an example of a timing diagram of a signal processed in one embodiment of the present invention.

[0024] Figure 7 This is a flowchart of a printing process performed by the control unit of a printing apparatus according to one embodiment of the present invention.

[0025] Figure 8 This is an example of a timing diagram of a signal processed in another embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures

[0027] 1: Printing apparatus

[0028] 2: Device frame

[0029] 2a: Discharge outlet

[0030] 3: Input Section

[0031] 4: Display Section

[0032] 5: Control Department

[0033] 5a: Processor

[0034] 6: ROM

[0035] 7: RAM

[0036] 8: Display driving circuit

[0037] 9: Head drive circuit

[0038] 10: Thermal head

[0039] 10a: Heating element

[0040] 11: Conveyor motor drive circuit

[0041] 12: Stepper motor

[0042] 13: Thermistor

[0043] 14: Tool Motor Drive Circuit

[0044] 15: Tool Motor

[0045] 16: Semi-cutting mechanism

[0046] 17: Full cutting mechanism

[0047] 18: Opening and closing the lid

[0048] 18a: Button

[0049] 18b: Window

[0050] 19: Box Storage Department

[0051] 20: Box bearing section

[0052] 21: Paper pressure roller

[0053] 22: Core-type clamping shaft

[0054] 23: Ink ribbon take-up drive shaft

[0055] 24: Bandwidth Detection Switch

[0056] 30: With box

[0057] 31: Box shell

[0058] 32: Core

[0059] 34: Ink ribbon supply core

[0060] 35: Ink ribbon winding core

[0061] 36: Thermal head inserted into the part

[0062] 37: Card-connecting section Detailed Implementation

[0063] Referring to the accompanying drawings, a printing apparatus according to one embodiment of the present invention, a control method for the printing apparatus as an example of a computer, and a recording medium will be described in detail.

[0064] Hereinafter, an embodiment of the present invention will be described using a printing apparatus that prints characters, images, etc. on a tape as the printing medium and is capable of cutting the printed tape (or label) and discharging it outside the apparatus as an example.

[0065] In this specification, "tape" refers to a thin, elongated strip of printed media made of plastic, paper, or any other material. Tape typically has an adhesive layer for bonding. However, tape may also be without an adhesive layer.

[0066] A label is a tag on which certain information is printed, using tape as a printing medium.

[0067] The printing medium is not limited to tapes or labels. Furthermore, the printing device can be a printing device equipped with a thermal head, i.e., a thermal printer, and is not limited to so-called label printers. Additionally, the printing method of a thermal printer is not particularly limited; for example, it can be either thermal transfer or thermal printing.

[0068] Figure 1 This is a perspective view of a printing apparatus 1 according to one embodiment of the present invention. The printing apparatus 1 is a printing apparatus equipped with a thermal head for printing on a printing medium, such as a label printer that prints on a printing medium M in a single pass.

[0069] The following description uses a label printer employing a thermal transfer method with ink ribbon as an example; however, as mentioned above, the printing method of printing device 1 is not particularly limited. For example, the printing method of printing device 1 could also be a thermal method using thermal paper.

[0070] The printing medium M is, for example, a tape. The tape-type printing medium M has a substrate with an adhesive layer and a release paper that can be peeled off and adhered to the substrate in a manner that covers the adhesive layer. The printing medium M can also be a tape without release paper.

[0071] like Figure 1 As shown, the printing apparatus 1 includes an apparatus frame 2, an input section 3, a display section 4, a cover 18, and a box storage section 19. The input section 3, the display section 4, and the cover 18 are arranged on the upper surface of the apparatus frame 2. Although not shown, the apparatus frame 2 is provided with a power cord connection terminal, an external device connection terminal, and a storage medium insertion port.

[0072] The input section 3 is equipped with various keys such as input keys, cross keys, change keys, and confirmation keys.

[0073] Display unit 4 is, for example, a liquid crystal display panel, which displays characters corresponding to input from input unit 3, selection menus for various settings, and messages related to various processes. Alternatively, a touchpad unit may be provided on display unit 4. In this case, display unit 4 can also be considered as part of input unit 3.

[0074] The opening and closing cover 18 is disposed on the upper part of the box storage section 19 and can be opened and closed. The opening and closing cover 18 is opened by pressing the button 18a.

[0075] A window 18b is formed on the opening / closing cover 18. By forming the window 18b on the opening / closing cover 18, the user can visually confirm the cartridge 30 (see reference) even when the opening / closing cover 18 is closed. Figure 2 Whether it is stored in the box storage section 19.

[0076] A discharge port 2a is formed on the side of the device frame 2. The printing medium M that has been printed inside the printing device 1 is discharged from the discharge port 2a to the outside of the device.

[0077] Figure 2 It is a perspective view of the box 30 housed in the printing device 1. Figure 3 This is a perspective view of the box storage section 19 of the printing apparatus 1. The box 30 can be detachably stored in the box storage section 19.

[0078] Figure 4 This is a cross-sectional view of printing apparatus 1. Figure 4 The image shows the state in which the box 30 is stored in the box storage section 19.

[0079] like Figure 2 As shown, the cartridge 30 has a cartridge housing 31. The cartridge housing 31 has a thermal head insertion portion 36 and a locking portion 37, which can accommodate the printing medium M and the ink tape R.

[0080] The cartridge housing 31 is provided with a ribbon core 32, an ink ribbon supply core 34, and an ink ribbon take-up core 35. The printing medium M is wound into a roll on the ribbon core 32 inside the cartridge housing 31. The ink ribbon R for heat transfer is wound into a roll on the ink ribbon supply core 34 inside the cartridge housing 31 with its end wound on the ink ribbon take-up core 35.

[0081] like Figure 3 As shown, the cartridge housing 19 of the device frame 2 is provided with a plurality of cartridge support portions 20 for supporting the cartridge 30 in a predetermined position. A bandwidth detection switch 24 is provided on the cartridge support portion 20, which is used to detect the width of the tape (printing medium M) housed in the cartridge 30. The bandwidth detection switch 24 detects the width of the printing medium M based on the shape of the cartridge.

[0082] The cartridge storage section 19 also includes a thermal head 10, a pressure roller 21, a core engaging shaft 22, and an ink ribbon take-up drive shaft 23. The thermal head 10 has multiple heating elements for printing on the printing medium M. A thermistor 13 is embedded in the thermal head 10. The thermistor 13 measures the temperature of the thermal head 10. The pressure roller 21 conveys the printing medium M downstream.

[0083] With the box 30 stored in the box storage section 19, as follows Figure 4As shown, the engaging portion 37 provided in the cartridge housing 31 is supported by the cartridge receiving portion 20 provided in the cartridge storage portion 19, and the thermal head 10 is inserted into the thermal head insertion portion 36 formed in the cartridge housing 31. The tape core 32 of the tape cartridge 30 engages with the tape core engaging shaft 22, and the tape take-up core 35 engages with the tape take-up drive shaft 23.

[0084] When a printing instruction is input to the printing apparatus 1, the printing medium M is output from the tape core 32 by the rotation of the pressure roller 21. At this time, the tape take-up drive shaft 23 rotates synchronously with the pressure roller 21, so that the tape R and the printing medium M are output together from the tape supply core 34. Thus, the printing medium M and the tape R are conveyed in an overlapping state. Moreover, as the tape R passes between the thermal head 10 and the pressure roller 21, it is heated by the thermal head 10, thereby transferring the ink to the printing medium M for printing.

[0085] The used ink ribbon R, which has passed between the thermal head 10 and the pressure roller 21, is wound up by the ink ribbon winding core 35. On the other hand, the printed medium M, which has passed between the thermal head 10 and the pressure roller 21, is cut by the half-cutting mechanism 16 and the full-cutting mechanism 17 and discharged from the discharge port 2a.

[0086] Figure 5 This is a control block diagram of printing apparatus 1. (Example) Figure 5 As shown, in addition to the aforementioned components (specifically, the input unit 3, display unit 4, thermal head 10, thermistor 13, half-cutting mechanism 16, full-cutting mechanism 17, pressure roller 21, and bandwidth detection switch 24), the printing apparatus 1 also includes a control unit 5, a ROM (Read Only Memory) 6, a RAM (Random Access Memory) 7, a display unit drive circuit 8, a head drive circuit 9, a conveyor motor drive circuit 11, a stepper motor 12, a cutter motor drive circuit 14, and a cutter motor 15.

[0087] The control unit 5, ROM 6, and RAM 7 constitute the computer of the printing apparatus 1. The control unit 5 includes, for example, a processor 5a such as a CPU (Central Processing Unit). The control unit 5 controls each part of the printing apparatus 1, including the thermal head 10, by expanding the program stored in the ROM 6 into the RAM 7 and executing it.

[0088] The control unit 5 is an example of at least one processor, such as a single processor or multiple processors. When adopting a structure including multiple processors, the control unit 5 can be packaged as a single device, or it can be composed of multiple devices physically separated within the printing apparatus 1.

[0089] ROM6 stores the printing control program for printing on the printing medium M, and various data (e.g., fonts) required for the execution of the printing control program.

[0090] RAM7 functions as an input data memory for storing characters, symbols, etc., to be printed. Additionally, RAM7 functions as a printing data memory for storing data (hereinafter referred to as "printing data") representing the printing pattern to be formed on the printing medium, generated based on the information stored in the input data memory. RAM7 also functions as a display data memory for storing display data to be displayed on the display unit 4.

[0091] The display driving circuit 8 controls the display unit 4 based on display data stored in the RAM 7. Under the control of the display driving circuit 8, the display unit 4 displays printed content in a manner that can identify the progress of the printing process.

[0092] In this embodiment, the printing apparatus 1 is capable of 8-grayscale printing. To perform 8-grayscale printing, data for each grayscale value from the first grayscale value to the seventh grayscale value is sequentially transmitted from the control unit 5 to the head drive circuit 9. In this embodiment, grayscale values ​​that are not printed are set to 0 grayscale values, and 7 grayscale values ​​are added to them, thereby enabling the representation of 8 grayscale.

[0093] As an example of a drive circuit, the head drive circuit 9 energizes multiple heating elements 10a based on data of each grayscale value transmitted sequentially and a gating signal. Hereinafter, the period during which the gating signal output from the control unit 5 is turned on will be referred to as the "gating on period".

[0094] During the selection period, the head drive circuit 9 controls the current supply (energization) to the heating element 10a based on the data of each grayscale value. Incidentally, during the selection period and when the grayscale value data represents a printing point, the head drive circuit 9 supplies current to the heating element 10a corresponding to the printing point.

[0095] The denser the print density, the more times the corresponding heating element 10a is energized. For example, at the densest print density, the heating element 10a is energized for all gray values ​​from the 1st to the 7th (i.e., a total of 7 energizations). Thus, in this embodiment, grayscale can be represented by the number of times the heating element 10a is energized.

[0096] The thermal printhead 10 is a printhead having a plurality of heating elements 10a arranged in a row in the main scanning direction. During the selection period, the printhead drive circuit 9 selectively energizes the heating elements 10a according to the printing data. The energized heating elements 10a generate heat and heat the ink ribbon R. Through this thermal transfer, the thermal printhead 10 performs line-by-line printing on the printing medium M.

[0097] The conveyor motor drive circuit 11 drives the stepper motor 12. The stepper motor 12 drives the pressure roller 21. The pressure roller 21 rotates under the power of the stepper motor 12, thereby conveying the conveyor section of the printed medium M along the long side direction (sub-scanning direction) of the printed medium M.

[0098] The tool motor drive circuit 14 drives the tool motor 15. The half-cutting mechanism 16 and the full-cutting mechanism 17 are operated by the power of the tool motor 15 to perform half-cutting or full-cutting on the printing medium M. Full-cutting refers to the action of cutting the substrate of the printing medium M together with the release paper along the width direction. Half-cutting can be an action of cutting only the substrate along the width direction, or it can be an action of cutting the printing medium M in a way that forms a sewing hole.

[0099] Generally, in thermal printers, the higher the printing speed or the more grayscale levels are increased, the shorter the energizing time for each grayscale value on the heating element needs to be. Since a shorter energizing time for each grayscale value results in a shorter interval between energizing periods corresponding to each grayscale value, high-speed transmission of the grayscale data is required. However, increasing the speed of printing data transmission is not easy.

[0100] Therefore, in this embodiment, the control unit 5 sequentially transmits the data of the first gray value contained in the printing data and the data of the second gray value following the data of the first gray value to the head drive circuit 9, turns on the gating signal, and causes the head drive circuit 9 to perform the first power-on of the multiple heating elements 10a based on the data of the first gray value. After the first power-on is completed, the gating signal is temporarily cut off before the data of the second gray value is transmitted, and causes the head drive circuit 9 to perform the second power-on of the multiple heating elements 10a based on the data of the second gray value.

[0101] By disconnecting the strobe signal at the end of each energization corresponding to each grayscale value, the interval of the energization period corresponding to each grayscale value can be fully opened. Therefore, even without increasing the transmission speed of printing data, the energization time for each grayscale value of the heating element 10a can be shortened, for example, increasing the printing speed or increasing the number of grayscale values. The operation of the control unit 5 will be explained in detail below.

[0102] Figure 6 This is an example of a timing diagram of the signals processed in this embodiment. For example... Figure 6 As shown in the timing diagram, printing unit 1 prints and transports one line in 3.12 milliseconds (msec).

[0103] like Figure 6As shown by the symbols TR1 to TR7, the data DT of each gray value from the first gray value to the seventh gray value constituting a line of printed content is transmitted sequentially from the control unit 5 to the head drive circuit 9 in sync with the clock signal CLK.

[0104] Furthermore, the transmission speed (transmission clock) of the printed data from the control unit 5 to the head drive circuit 9 is 20MHz, and the number of dots in one line is 768. The time required to transmit the data DT of each grayscale value of 768 dots to the head drive circuit 9 is 38.4 microseconds (μsec). Hereinafter, this time will be referred to as "transmission time".

[0105] The head drive circuit 9 includes a latch circuit. Whenever the transmission of each grayscale value's data DT is complete, the latch signal LTC becomes active, and the data held by the latch circuit is switched. Specifically, it switches to the grayscale value data DT that was just transmitted.

[0106] The strobe signal STB is also activated along with the latch signal LTC. During the strobe activation period, the head drive circuit 9 selectively energizes the heating element 10a based on the grayscale data DT held by the latch circuit. As a result, the heating element 10a heats up, and the ink tape R is heated, performing thermal transfer printing corresponding to the grayscale data DT.

[0107] More specifically, when the transmission of the first grayscale value data DT is complete (see...) Figure 6 When the symbol TR1 is activated, the latch signal LTC becomes on, the data DT held by the latch circuit is switched to the data DT of the first grayscale value, and the strobe signal STB becomes on. Thus, the printing apparatus 1 switches to the printing period PR1 of the first grayscale value.

[0108] When switching to printing period PR1, the head drive circuit 9 energizes the heating element 10a based on the data DT of the first grayscale value during the strobe-on period. Furthermore, the strobe-on period is set relatively long for the first grayscale value to ensure good coloring. Regarding the first grayscale value, for example, when the heating element 10a is energized at an appropriate time, the strobe signal STB is disconnected, and the energization of the heating element 10a is cut off. Hereinafter, the period during which the strobe signal output from the control unit 5 is disconnected will be referred to as the "strobe-off period".

[0109] During the gating disconnection period, the data DT of the second grayscale value, which is the data of the next grayscale value, is transmitted from the control unit 5 to the head drive circuit 9 (see...). Figure 6 The symbol TR2 in the text.

[0110] When the transmission of the second grayscale value data DT is completed, the latch signal LTC turns on again, the data DT held by the latch circuit switches to the second grayscale value data DT, and the strobe signal STB turns on again. Thus, the printing apparatus 1 switches to the printing period PR2 for the second grayscale value.

[0111] When transitioning to printing period PR2, the head drive circuit 9 energizes the heating element 10a based on the data DT of the second grayscale value during the strobe-on period. Regarding the second grayscale value, when the heating element 10a is energized, for example at an appropriate time, the strobe signal STB is turned off, and the energization of the heating element 10a is cut off.

[0112] Here, we consider the case where there is no gating off period during PR2 in the printing process. In this case, the power-on of the third grayscale value begins at the same time as the power-on of the second grayscale value ends. Therefore, during the gating on period of the second grayscale value, the transmission of the data DT for the third grayscale value must be completed first.

[0113] However, for example, when the power-on time of the second grayscale value is shortened to increase printing speed or increase the number of grayscale values, the transmission of the data DT of the third grayscale value may not be completed before the power-on of the third grayscale value begins. Therefore, in this embodiment, a gating-off period is set after the gating-on period. By setting the gating-off period, even when the power-on time of the second grayscale value is short, the transmission of the data DT of the third grayscale value is completed within the gating-off period (in other words, before the power-on of the third grayscale value begins).

[0114] That is, during the gating and disconnection period of the second grayscale value, the transmission of the third grayscale value data DT, which serves as the data for the next grayscale value, is completed (refer to...). Figure 6 (symbol TR3). When the transmission of the third grayscale value data DT is completed, the latch signal LTC turns on again, the data DT held by the latch circuit switches to the third grayscale value data DT, and the strobe signal STB turns on again. Thus, the printing apparatus 1 switches to the printing period PR3 of the third grayscale value.

[0115] In this way, the control unit 5 sequentially transmits the data of the first gray value (e.g., the data of the second gray value DT) and the data of the second gray value following the first gray value (e.g., the data of the third gray value DT) to the head drive circuit 9, turns on the selection signal, and causes the head drive circuit 9 to perform a first power-on on the multiple heating elements 10a based on the data of the first gray value (e.g., power-on during PR2 in printing), and causes the head drive circuit 9 to perform a second power-on on the multiple heating elements 10a based on the data of the second gray value (e.g., power-on during PR3 in printing). After the first power-on is completed, the selection signal is temporarily turned off so that the second power-on is not performed until the transmission of the data of the second gray value is completed.

[0116] During the printing period after PR3, a gating disconnection period is also set after the gating on period. Therefore, even with a short power-on time, the data DT for the next grayscale value is transmitted within the gating disconnection period.

[0117] Thus, after PR3 during printing, the control unit 5 also sequentially transmits the data of the first gray value (e.g., the data of the third gray value DT) and the data of the second gray value following the first gray value (e.g., the data of the fourth gray value DT) to the head drive circuit 9, turns on the gating signal, and causes the head drive circuit 9 to perform the first power-on of the multiple heating elements 10a based on the data of the first gray value (e.g., power-on during PR3 during printing), and causes the head drive circuit 9 to perform the second power-on of the multiple heating elements 10a based on the data of the second gray value (e.g., power-on during PR4 during printing). After the first power-on is completed, the gating signal is temporarily turned off so that the second power-on is not performed until the transmission of the data of the second gray value is completed.

[0118] The strobe signal STB is turned off for a certain period of time, for example, after the first energization of the multiple heating elements 10a based on the data DT of the first gray value. That is, the strobe-off period is, for example, constant during each printing period.

[0119] After the first power-on ends, during the period when the strobe signal STB is off, the control unit 5 transmits the data DT of the second grayscale value to the head drive circuit 9. That is, during the strobe-off period of a certain time, the transmission of the data DT of the next grayscale value begins and is completed.

[0120] In order to start and complete the transmission of data DT during the gating-off period, the gating-off period is set to a length of, for example, the transmission time required (38.4 microseconds). That is, the disconnection period of the gating signal STB after the first power-on ends is set to a length of, for example, the time required to transmit the data DT of the second grayscale value to the head drive circuit 9.

[0121] Figure 7 This is a flowchart of the printing process.

[0122] When the start instruction for printing processing is input using the input unit 3, the control unit 5 executes the printing program and begins processing. Figure 7 The printing process is shown. When the printing process is performed, the latch signal LTC and the strobe signal STB are initially turned off.

[0123] Specifically, the control unit 5 performs various internal processes (step S101) to transmit the data DT of each grayscale value of the row to be processed to the head drive circuit 9. In addition, when the processing of step S101 is performed for the first time, the first row becomes the row to be processed.

[0124] When the preparation for transmission is completed, the control unit 5 transmits the data DT of the next grayscale value to the head drive circuit 9 (step S102). In addition, when the processing of the row to be processed is performed for the first time in step S102, "data DT of the next grayscale value" is read as "data DT of the first grayscale value of the row to be processed".

[0125] Control unit 5 detects whether a certain time has elapsed since the strobe signal STB was disconnected in step S106 (described later) (e.g., time longer than the transmission time required) (step S103). Furthermore, when processing the row to be processed for the first time in step S103, the phrase "whether a certain time has elapsed since the strobe signal STB was disconnected in step S106 (described later)" is replaced with, for example, "whether the transmission of the first grayscale value of the row to be processed has been detected as complete."

[0126] When the aforementioned time has elapsed, even if the current grayscale value's power-on time is short, since at least the time required for data transmission is ensured during the gating-off period, the transmission of the next grayscale value's data DT (initially the data DT of the first grayscale value) is completed. Therefore, in this case (step S103: Yes), the control unit 5 turns on the gating signal STB (step S104). Thus, during the printing period of the next grayscale value, the head drive circuit 9 powers on the heating element 10a based on the grayscale value's data DT during the gating-on period.

[0127] When, for example, the heating element 10a is energized for an appropriate period of time (step S105: Yes), the control unit 5 disconnects the selection signal STB (step S106). As a result, the energization of the heating element 10a is cut off.

[0128] The control unit 5 determines whether the final grayscale value (here, the 7th grayscale value) of the row to be processed has been energized (step S107). If the final grayscale value has not been energized (step S107: no), the control unit 5 returns to the processing in step S102, takes the next grayscale value as the processing target, and executes the processing in steps S102 to S107.

[0129] With the final grayscale applied (step S107: Yes), the printing process for the current line is completed. Therefore, the control unit 5 determines whether the current line is the final line (step S108).

[0130] If the current processing object's row is not the final row (step S108: No), the control unit 5 updates the processing object's row to the next row (step S109), returns to the processing of step S101, takes the updated row as the processing object, and executes the processing of steps S101 to S108.

[0131] If the line being processed is the final line (step S108: Yes), control unit 5 ends. Figure 7 The printing process shown.

[0132] Thus, according to the printing apparatus 1 of this embodiment, a gating disconnection period is set after the gating on period. Since the transmission of the next grayscale value data DT is completed during the gating disconnection period, the power-on time for each grayscale value can be shortened, for example, the printing speed can be increased or the number of grayscale values ​​can be increased.

[0133] The above is a description of exemplary embodiments of the present invention. The embodiments of the present invention are not limited to the above description, and various modifications can be made within the scope of the technical concept of the present invention. For example, embodiments appropriately combined with those illustratively shown in the specification or obvious embodiments are also included in the embodiments of this application.

[0134] In the above embodiment, the gating disconnection period is fixed. In another embodiment, the gating disconnection period can be of variable length. This other embodiment is described below.

[0135] For example, to shorten the energizing time for each grayscale value of the heating element 10a, the transmission of the data DT for the next grayscale value can be completed before the energizing of the next grayscale value begins. Therefore, the transmission of data DT can begin during the strobe-on period. In this case, the strobe-off period can be set to a length, for example, less than the transmission time required (38.4 microseconds).

[0136] Figure 8 This is an example of a timing diagram showing a scenario where the transmission of the next grayscale value (DT) begins immediately after the transition to printing. Figure 8 For convenience, the diagrams of the clock signal CLK and the latch signal LTC are omitted.

[0137] exist Figure 8 In the example, if the printing period, which is the sum of the gating on period and the gating off period, is longer than the time required for transmission, then the transmission of the data DT of the next grayscale value can be completed before the power-on of the next grayscale value begins.

[0138] As is well known, the power-on time (i.e., the gating period) for each grayscale value varies depending on the operating environment of the thermal head 10. Due to the variation in power-on time, the gating period is sometimes longer than the transmission time required, or sometimes shorter than the transmission time required.

[0139] exist Figure 8In the example, during printing PR1, the strobe-on period is longer than the transmission time required. Therefore, even if no strobe-off period is set after the strobe-on period, the transmission of the second grayscale value data DT is completed before the power-on of the second grayscale value begins.

[0140] During printing PR2, the strobe-on period is shorter than the transmission time. Therefore, at the point when the power-on of the second grayscale value ends, the transmission of the third grayscale value data DT is not completed. Therefore, a strobe-off period is set. The control unit 5 disconnects the strobe signal STB before detecting the completion of the transmission of the third grayscale value data DT.

[0141] Thus, in another implementation, after the first power-on ends, the strobe signal STB is disconnected before the transmission of the data for the second grayscale value is completed.

[0142] During subsequent printing periods, if the strobe-on period is longer than the transmission time required, a strobe-off period will not be set. Conversely, if the strobe-on period is shorter than the transmission time required, a strobe-off period will be set.

[0143] In another implementation, since the gating disconnection period is suppressed for a shorter time, the time spent on printing each grayscale value can be shortened.

Claims

1. A printing apparatus, wherein, have: A thermal print head is used to print on the medium being printed. The driving circuit energizes the multiple heating elements of the thermal head based on the printed data and gating signals. as well as processor, The processor, The driving circuit is sequentially transmitted the data of the first grayscale value contained in the printing data and the data of the second grayscale value following the data of the first grayscale value. The selection signal is turned on, and the driving circuit performs a first energization on the plurality of heating elements based on the data of the first gray value. After the first power-on is completed, the gating signal is temporarily disconnected before the transmission of the second grayscale value data is completed. The driving circuit is then energized a second time on the plurality of heating elements based on the data of the second grayscale value.

2. The printing apparatus according to claim 1, wherein, The strobe signal is disconnected by the processor for a certain period of time after the first power-on ends.

3. The printing apparatus according to claim 1, wherein, The strobe signal is disconnected after the first power-on ends, before the processor detects that the transmission of the second grayscale value data is complete.

4. The printing apparatus according to claim 1, wherein, During the period when the strobe signal is disconnected after the first power-on ends, the processor transmits the data of the second grayscale value to the driving circuit.

5. The printing apparatus according to claim 1, wherein, The disconnection period of the strobe signal after the first power-on ends is set to be longer than the time required for the processor to transmit the data of the second grayscale value to the driving circuit.

6. A control method for a printing apparatus, the printing apparatus comprising: a thermal head for printing on a printable medium; and a drive circuit for energizing a plurality of heating elements of the thermal head based on printing data and a gating signal, wherein... The control method for the printing apparatus includes: The driving circuit is sequentially transmitted the data of the first grayscale value contained in the printing data and the data of the second grayscale value following the data of the first grayscale value. The selection signal is turned on, and the driving circuit performs a first energization on the plurality of heating elements based on the data of the first gray value. After the first power-on is completed, the gating signal is temporarily disconnected before the transmission of the second grayscale value data is completed. The driving circuit is then energized a second time on the plurality of heating elements based on the data of the second grayscale value.

7. A computer-readable non-transitory recording medium recording a program that causes at least one processor of a printing apparatus to execute processing, the printing apparatus comprising: a thermal head for printing on a medium to be printed; and a drive circuit for energizing a plurality of heating elements of the thermal head based on printing data and a gating signal, wherein... The process includes: The driving circuit is sequentially transmitted the data of the first grayscale value contained in the printing data and the data of the second grayscale value following the data of the first grayscale value. The selection signal is turned on, and the driving circuit performs a first energization on the plurality of heating elements based on the data of the first gray value. After the first power-on is completed, the gating signal is temporarily disconnected before the transmission of the second grayscale value data is completed. The driving circuit is then energized a second time on the plurality of heating elements based on the data of the second grayscale value.

8. A computer program product that causes at least one processor of a printing apparatus to perform processing, the printing apparatus comprising: a thermal head for printing on a printable medium; and a drive circuit for energizing a plurality of heating elements of the thermal head based on printing data and a gating signal, wherein... The process includes: The driving circuit is sequentially transmitted the data of the first grayscale value contained in the printing data and the data of the second grayscale value following the data of the first grayscale value. The selection signal is turned on, and the driving circuit performs a first energization on the plurality of heating elements based on the data of the first gray value. After the first power-on is completed, the gating signal is temporarily disconnected before the transmission of the second grayscale value data is completed. The driving circuit is then energized a second time on the plurality of heating elements based on the data of the second grayscale value.

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