Printing apparatus, method for controlling printing apparatus, and computer program

Abstract

To provide a printing apparatus and the like, capable of maintaining a constant temperature near a switch when a nozzle performs liquid ejection.SOLUTION: A printing apparatus according to one embodiment of the present disclosure is a printing apparatus including a multiplexing circuit and a separation circuit including a switch. Based on a first drive waveform signal separated by the switch, the nozzle is driven in an ejection mode to eject liquid from the nozzle, and based on a second drive waveform signal separated by the switch, the nozzle is driven in a non-ejection mode to increase the temperature of the separation circuit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present technology relates to a printing device, a control method for a printing device, and a computer program. [Background technology]

[0002] Conventionally, devices have been used that form images by ejecting fluid from a head onto a medium. For example, a fluid ejection device described in Patent Document 1 is capable of ejecting fluid (ink) by selecting one drive pulse from a plurality of drive pulses and applying it to a piezoelectric element at an appropriate timing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-142978 A Summary of the Invention [Problem to be solved by the invention]

[0004] The resistance value of the switch for selecting the drive pulse (part of the drive waveform signal) when it is turned on changes depending on the temperature. If the resistance value of the switch when jetting (discharging) fluid (liquid) differs, there will be variation in the quality of the liquid discharged from the nozzle.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a printing device and the like that is capable of maintaining a constant quality of liquid ejection from nozzles. [Means for solving the problem]

[0006] a multiplexing circuit that generates a time division multiplexed signal capable of transmitting the first data and the second data over a single signal line, the time division multiplexed signal being arranged based on at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform, such that a third portion that is part of the second drive waveform is between a first portion that is part of the first drive waveform and a second portion that is part of the first drive waveform, and the second portion is between the third portion and a fourth portion that is part of the second drive waveform, and the first data and the second data are arranged over a single signal line, and a separation circuit that receives the time division multiplexed signal and has a switch that separates from the time division multiplexed signal a first drive waveform signal that indicates the first drive waveform or a second drive waveform signal that indicates the second drive waveform based on a synchronization signal, the printing device causing the nozzle to eject liquid by driving the nozzle to eject based on the first drive waveform signal separated by the switch, and causing the nozzle to not eject based on the second drive waveform signal separated by the switch to increase the temperature of the separation circuit.

[0007] a first portion that is a part of the first drive waveform and a second portion that is a part of the first drive waveform, and a fourth portion that is a part of the second drive waveform, the second portion being between the third portion and a fourth portion that is a part of the second drive waveform, and the first data and the second data being arranged based on at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform, and the first data and the second data being arranged such that the first data and the second data can be transmitted over a single signal line; and a separation circuit to which the time division multiplexed signal is input and which has a switch that separates from the time division multiplexed signal a first drive waveform signal that is indicative of the first drive waveform or a second drive waveform signal that is indicative of the second drive waveform, based on a synchronization signal, the control method for a printing device according to an embodiment of the present disclosure includes: a nozzle capable of ejecting liquid by an energy imparting element;

[0008] a multiplexing circuit that generates a time division multiplexed signal capable of transmitting the first data and the second data over a single signal line, the first data and the second data being arranged based on at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform, the first data and the second data being arranged such that a third portion that is part of the second drive waveform is between a first portion that is part of the first drive waveform and a second portion that is part of the first drive waveform, and the second portion is between the third portion and a fourth portion that is part of the second drive waveform, the first data and the second data being arranged such that the third portion is between the third portion and a fourth portion that is part of the second drive waveform, the first data and the second data being arranged such that the third portion is between the third portion and a fourth portion that is part of the second drive waveform, the second data and the first data being arranged such that the third portion is between the third portion and a fourth portion that is part of the second drive waveform, the second data and the first data being arranged such that the third portion is between the third portion and a fourth portion that is part of the second drive waveform, the second data and the second data being arranged such that the third portion is between the third portion and a fourth portion that is part of the second drive waveform, the second data and the first data being arranged such that the third portion is between the third portion and the fourth portion that is part of the second drive waveform, the second data and the second data being arranged such that the second data and the first data are ... Effect of the Invention

[0009] In a printing device or the like according to an embodiment of the present disclosure, it is possible to maintain constant quality of liquid ejection from nozzles. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a plan view illustrating the printing device. [Diagram 2] FIG. 2 is a simplified partial enlarged cross-sectional view of an inkjet head. [Diagram 3] FIG. 2 is a block diagram of a control device. [Figure 4] 4 is a block diagram showing drive waveform data and a table stored in a memory. FIG. [Diagram 5] 1 is an explanatory diagram illustrating an example of the relationship between the drive waveforms A, B, and C and the drive waveform data Da, Db, and Dc. [Figure 6]FIG. 11 is an explanatory diagram illustrating an example of a mapping information table. [Figure 7] 2A to 2C are explanatory diagrams illustrating an example of time series data, an analog signal, and a time division multiplexed signal. [Figure 8] 4 is an explanatory diagram illustrating the relationship between a time division multiplexed signal and synchronization signals S2a, S2b, and S2c. FIG. [Figure 9] 4 is a schematic diagram of a drive waveform input to an actuator by opening and closing an n-th switch. FIG. [Figure 10] 10 is a flowchart illustrating a printing process performed by the control device. [Figure 11] 4 is a flowchart illustrating a temperature increase process performed by the control device. [Figure 12] 4 is a flowchart illustrating a discharge process performed by a control device. [Figure 13] FIG. 11 is a block diagram of a control device according to a second embodiment. [Figure 14] FIG. 11 is a block diagram showing driving waveform data and a table stored in a memory according to the second embodiment. [Figure 15] FIG. 4 is an explanatory diagram illustrating an example of an ink table. [Figure 16] FIG. 11 is an explanatory diagram illustrating an example of a specific ink condition table. [Figure 17] 10 is a flowchart illustrating a temperature increasing process performed by a control device according to a second embodiment. [Figure 18] 10 is a flowchart illustrating a discharge process performed by a control device according to a second embodiment. [Figure 19] FIG. 11 is a block diagram of a control device according to a third embodiment. [Figure 20] FIG. 11 is a block diagram showing driving waveform data and a table stored in a memory according to a third embodiment. [Figure 21] FIG. 13 is an explanatory diagram showing an example of a temperature rise score table. [Figure 22] FIG. 11 is an explanatory diagram showing an example of a temperature rise degree table. [Figure 23] 11 is a flowchart illustrating a temperature increasing process performed by a control device according to a third embodiment. [Figure 24] FIG. 11 is a block diagram of a control device according to a fourth embodiment. [Diagram 25] FIG. 13 is a block diagram showing driving waveform data and a table stored in a memory according to a fourth embodiment. [Figure 26] 1 is an explanatory diagram illustrating an example of the relationship between drive waveforms A, D, and E and drive waveform data Da, Dd, and De. [Figure 27] FIG. 13 is an explanatory diagram illustrating an example of a mapping information table according to the fourth embodiment. [Figure 28] 2A to 2C are explanatory diagrams illustrating an example of time series data, an analog signal, and a time division multiplexed signal. [Figure 29] 4 is an explanatory diagram illustrating the relationship between a time division multiplexed signal and synchronization signals S2a, S2d, and S2e. FIG. [Diagram 30] FIG. 13 is a schematic diagram of a drive waveform input to an actuator by opening and closing the na-th switch or the nb-th switch. [Diagram 31] FIG. 4 is an explanatory diagram illustrating an example of an ink characteristics table. [Diagram 32] 10 is a flowchart illustrating a temperature increasing process performed by a control device according to a fourth embodiment. [Diagram 33] FIG. 2 is an explanatory diagram showing an example of the arrangement of nozzles in an inkjet head. [Diagram 34] 13 is a flowchart illustrating a temperature increasing process performed by a control device according to a modified example of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Embodiment 1) The present invention will be described below based on the drawings showing a printing device according to a first embodiment. Fig. 1 is a plan view showing a simplified view of a printing device 1. In the following description, the front, back, left and right directions shown in Fig. 1 will be used. The front and back directions correspond to the transport direction, and the left and right directions correspond to the scanning direction. Furthermore, the front side of Fig. 1 corresponds to the top, and the back side corresponds to the bottom, and up and down will also be used.

[0012] 1, the printing device 1 includes a platen 2, an ink ejection device 3, and transport rollers 4 and 5. A recording medium, that is, a recording paper 200, is placed on the upper surface of the platen 2. The ink ejection device 3 ejects ink onto the recording paper 200 placed on the platen 2 to record an image. The ink ejection device 3 includes a carriage 6, a sub-tank 7, four inkjet heads 8, a circulation pump 10, and the like.

[0013] Two guide rails 11 and 12 extending to the left and right are provided above the platen 2 to guide the carriage 6. An endless belt 13 extending to the left and right is connected to the carriage 6. The endless belt 13 is driven by a carriage drive motor 14. By driving the endless belt 13, the carriage 6 is guided by the guide rails 11 and 12 and reciprocates in the scanning direction in an area facing the platen 2. More specifically, while supporting the four inkjet heads 8, the carriage performs a first movement in which the heads are moved from one position to another position from left to right in the scanning direction, and a second movement in which the heads are moved from another position to one position from right to left in the scanning direction.

[0014] A cap 20 and a flushing receiver 21 are provided between the guide rails 11 and 12. The cap 20 and the flushing receiver 21 are disposed below the ink ejection device 3. The cap 20 is disposed at the right end of the guide rails 11 and 12, and the flushing receiver 21 is disposed at the left end of the guide rails 11 and 12. The cap 20 and the flushing receiver 21 may be disposed left and right reversed.

[0015] The sub-tank 7 and the four inkjet heads 8 are mounted on a carriage 6 and move back and forth in the scanning direction together with the carriage 6. The sub-tank 7 is connected to a cartridge holder 15 via a tube 17. Ink cartridges 16 of one or more colors (four colors in this embodiment) are attached to the cartridge holder 15. Examples of the four colors include black, yellow, cyan, and magenta.

[0016] Four ink chambers (liquid chambers) 71 are formed inside the subtank 7. The four ink chambers 71 store the four colors of ink supplied from the four ink cartridges 16, respectively.

[0017] The four inkjet heads 8 are aligned in the scanning direction below the subtank 7. A plurality of nozzles 80 (see FIG. 2) are formed on the bottom surface of each inkjet head 8. One inkjet head 8 corresponds to one color of ink and is connected to one ink chamber 71. That is, the four inkjet heads 8 correspond to four colors of ink, respectively, and are connected to four ink chambers 71, respectively.

[0018] The inkjet head 8 is provided with an ink supply port and an ink discharge port. The ink supply port and the ink discharge port are connected to an ink chamber 71 via a tube or the like to form a circulation path. A circulation pump 10 is interposed between the ink supply port and the ink chamber 71.

[0019] Ink sent from the ink chamber 71 by the circulation pump 10 flows into the inkjet head 8 through an ink supply port and is ejected from the nozzle 80. Ink that is not ejected from the nozzle 80 returns to the ink chamber 71 through an ink outlet port. The ink circulates between the ink chamber 71 and the inkjet head 8. The four inkjet heads 8 eject the four colors of ink supplied from the subtanks 7 onto the recording paper 200 while moving in the scanning direction together with the carriage 6.

[0020] As shown in FIG. 1, the transport roller 4 is disposed upstream (rear) of the platen 2 in the transport direction. The transport roller 5 is disposed downstream (front) of the platen 2 in the transport direction. The two transport rollers 4, 5 are driven synchronously by a motor (not shown). The two transport rollers 4, 5 transport the recording paper 200 placed on the platen 2 in a transport direction perpendicular to the scanning direction. The printing device 1 includes a control device 50. The control device 50 is a CPU or a controller. The device is equipped with a logic circuit (e.g., FPGA), a non-volatile memory, a memory 55 such as RAM, etc. Various control processes are performed by reading and executing a computer program (program product) stored in a portable recording medium 501. The computer program to be read may be pre-installed in the memory 55. Alternatively, the computer program may be downloaded through a network (not shown) connected to a communication network (not shown) and stored in the memory 55. The control device 50 receives a print job and driving waveform data from the external device 100, and stores them in the memory 55. The control device 50 controls the driving of the ink ejection device 3, the transport roller 4, etc., based on the print job, and executes the printing process.

[0021] 2 is a simplified partial enlarged cross-sectional view of the inkjet head 8. The inkjet head 8 includes a plurality of pressure chambers 81. The plurality of pressure chambers 81 form a plurality of pressure chamber rows. A vibration plate 82 is formed above the pressure chambers 81. A layered piezoelectric body 83 is formed above the vibration plate 82. A first common electrode 84 is formed above each pressure chamber 81, between the piezoelectric body 83 and the vibration plate 82.

[0022] A second common electrode 86 is provided inside the piezoelectric body 83. The second common electrode 86 is arranged above each pressure chamber 81 and above the first common electrode 84. The second common electrode 86 is arranged in a position not facing the first common electrode 84. An individual electrode 85 is formed above each pressure chamber 81 on the upper surface of the piezoelectric body 83. The individual electrode 85 faces the first common electrode 84 and the second common electrode 86 vertically with the piezoelectric body 83 in between. The vibration plate 82, the piezoelectric body 83, the first common electrode 84, the individual electrode 85 and the second common electrode 86 constitute an actuator 88.

[0023] A nozzle plate 87 is provided below each pressure chamber 81. A plurality of nozzles 80 are formed in the nozzle plate 87, penetrating vertically. Each nozzle 80 is disposed below each pressure chamber 81. The plurality of nozzles 80 form a plurality of nozzle rows extending along the row of pressure chambers. Each nozzle 80 ejects liquid when an actuator 88 is driven. Note that in the following description, driving the nozzles 80 and driving the actuator are considered to be synonymous.

[0024] The first common electrode 84 is connected to a COM terminal, which in this embodiment is ground, and the second common electrode 86 is connected to a VCOM terminal. The VCOM voltage is higher than the COM voltage. The individual electrodes 85 are connected to a switch group (separation circuit) 54 (see FIG. 3). When a high or low voltage is applied to the individual electrodes 85, the piezoelectric body 83 deforms and the diaphragm 82 vibrates. The vibration of the diaphragm 82 causes ink to be ejected from the pressure chamber 81 through the nozzle 80.

[0025] FIG. 3 is a block diagram of the control device 50, and FIG. 4 is a block diagram showing the driving waveform data and a table stored in the memory 55. The control device 50 includes a control circuit 51, a D / A converter 52, an amplifier 53, a group of switches 54, and a memory 55. The group of switches 54 configures a separation circuit 50b. The memory 55 stores driving waveform data. The driving waveform data is data showing a voltage waveform applied to the individual electrodes 85, that is, a driving waveform for driving the actuator 88, and is quantized data. In this embodiment, the driving waveform data Da to Dc are stored in the memory 55 (see FIG. 4). The memory 55 also stores a mapping information table 551. The mapping information table will be described in detail later.

[0026] The D / A converter 52 converts the digital signal into an analog signal. The amplifier 53 amplifies the analog signal. The amplifier 53 is connected to a switch group 54 via a single signal line L1.

[0027] The switch group 54 includes a plurality of switches 54a. The plurality of switches 54a includes a first switch 54a(1), a second switch 54a(2), . . . , an n-th switch 54a(n).

[0028] One end of each of the first switch 54a(1), the second switch 54a(2), ..., the nth switch 54a(n) is connected to the amplifier 53 via a signal line L1. The other end of each of the first switch 54a(1), the second switch 54a(2), ..., the nth switch 54a(n) is connected to the individual electrodes 85 of the first actuator 88(1), the second actuator 88(2), ..., the nth actuator 88(n), respectively. Driving the nth actuator 88(n) drives the nozzle 80(n).

[0029] The control device 50 transmits (outputs) a switch control signal that controls the opening and closing of the multiple n-th switches 54a(n) to the switch group 54 via a switch control signal line SL1. The control device 50 transmits (outputs) a synchronization signal S2a, a synchronization signal S2b, and a synchronization signal S2c to the switch group 54 via a synchronization signal line SL2. The synchronization signals S2a, S2b, and S2c are also simply referred to as a synchronization signal S2. Details of the synchronization signal S2 will be described later.

[0030] The switch control signal includes first selection information indicating to select one of the multiple n-th switches 54a(n) and second selection information indicating to select one of the three synchronization signals S2a to S2c. The first selection information and the second selection information are linked to each other.

[0031] Fig. 5 is an explanatory diagram illustrating an example of the relationship between the drive waveforms A, B, and C and the drive waveform data Da, Db, and Dc. In the drive waveforms in Fig. 5, the right side shows a state earlier than the left side. The same is true for Figs. 7, 8, 9, 26, 28, 29, and 30. The shapes of the drive waveforms A, B, and C are different from each other.

[0032] The data obtained by converting drive waveform A into a digital signal at a predetermined sampling period is drive waveform data Da. The data obtained by converting drive waveform B into a digital signal at a predetermined sampling period is drive waveform data Db. The data obtained by converting drive waveform C into a digital signal at a predetermined sampling period is drive waveform data Dc.

[0033] The drive waveform data Da is quantized data of the drive waveform A, the drive waveform data Db is quantized data of the drive waveform B, and the drive waveform data Dc is quantized data of the drive waveform C. The drive waveform data Da has quantized data Ak (k=0, 1, 2, ...), the drive waveform data Db has quantized data Bk, and the drive waveform data Dc has quantized data Ck.

[0034] 6 is an explanatory diagram showing an example of the mapping information table 551. The mapping information table 551 is a table showing data to be assigned to a plurality of time slots divided (in terms of time) at time intervals Δt when generating time series data of a time division multiplexed signal.

[0035] The management items (fields) of the mapping information table 551 include a time slot number field and an allocation data field. The time slot number field stores the number assigned to each time slot. The time slots are numbered in ascending chronological order (α1, α2, α3, ...). The allocation data field stores the data name of data Ak, Bk, or Ck (k=0, 1, 2, ...) assigned to each time slot. The data name [Ak] corresponds to the data Ak shown in FIG. 5, the data name [Bk] corresponds to the data Bk shown in FIG. 5, and the data name [Ck] corresponds to the data Ck shown in FIG. 5.

[0036] FIG. 7 is an explanatory diagram for explaining an example of time series data, an analog signal, and a time division multiplexed signal. In FIG. 7, A, B, and C indicate that they correspond to the drive waveforms A, B, and C, respectively. When driving the actuator 88, the control circuit 51 accesses the memory 55, reads the drive waveform data Da, Db, and Dc and the mapping information table 551, and creates time series data. The time series data is obtained by allocating data Ak, Bk, and Ck to each time slot divided for each time interval Δt based on the mapping information table 551. That is, the time series data is obtained by arranging data Ak, Bk, and Ck in order with a time interval Δt provided, and is arranged in the order of A0, B0, C0, A1, B1, C1, . . . , Ak, Bk, and Ck. The time series data is a digital signal. The time interval between Ak-1 and Ak, the time interval between Bk-1 and Bk, and the time interval between Ck-1 and Ck are each 3Δt.

[0037] The control circuit 51 outputs the time series data to the D / A converter 52. As shown in FIG. 7, the D / A converter 52 converts the time series data into an analog signal and outputs it to the amplifier 53. The amplifier 53 amplifies the input analog signal and outputs it to the switch group 54. As shown in FIG. 7, the analog signal amplified by the amplifier 53 constitutes a time division multiplexed signal. In the time division multiplexed signal, if a portion corresponding to data Ak-1 is a first portion, a portion corresponding to data Ak is a second portion, a portion corresponding to data Bk-1 is a third portion, and a portion corresponding to data Bk is a fourth portion, then the third portion is between the first portion and the second portion, and the second portion is between the third portion and the fourth portion. A similar relationship is also established between data Ak and Ck, and a similar relationship is also established between data Bk and Ck. The control circuit 51, the D / A converter 52, the amplifier 53, and the memory 55 constitute a multiplexing circuit 50a.

[0038] FIG. 8 is an explanatory diagram for explaining the relationship between the time division multiplexed signal and the synchronization signals S2a, S2b, and S2c. The synchronization signals S2a, S2b, and S2c are pulse waves. A time interval Δt is provided between the rising point of the pulse of the synchronization signal S2a and the rising point of the pulse of the synchronization signal S2b. A time interval Δt is provided between the rising point of the pulse of the synchronization signal S2b and the rising point of the pulse of the synchronization signal S2c. A time interval Δt is provided between the rising point of the pulse of the synchronization signal S2c and the rising point of the pulse of the synchronization signal S2a. The synchronization signal S2a corresponds to the first synchronization signal, and the synchronization signal S2b corresponds to the second synchronization signal. As shown in FIG. 8, the time width during which the pulses included in the synchronization signals S2a to S2c rise is narrower than the time width (time interval Δt) of the time slot, but may be the same as the time width (time interval Δt) of the time slot. That is, the time width during which the pulses included in the synchronization signals S2a to S2c rise is within the time width (time interval Δt) of the time slot. Furthermore, the synchronization signals S2a to S2c are transmitted by a synchronization signal line SL2.

[0039] As described above, the data Ak, Bk, and Ck constituting the time series data are arranged in order with a time interval Δt provided. Therefore, when the time division multiplexed signal is accessed at the rising edge of the pulse of the synchronization signal S2a, the drive waveform signal Pa corresponding to the data Ak and indicating the drive waveform A can be obtained. When the time division multiplexed signal is accessed at the rising edge of the pulse of the synchronization signal S2b, the drive waveform signal Pb corresponding to the data Bk and indicating the drive waveform B can be obtained. When the time division multiplexed signal is accessed at the rising edge of the pulse of the synchronization signal S2c, the drive waveform signal Pc corresponding to the data Ck and indicating the drive waveform C can be obtained.

[0040] The switch group 54 opens and closes the n-th switch 54a(n) indicated in the first selection information at the opening and closing timings indicated by the synchronization signals S2a to S2c indicated in the second selection information included in the transmitted switch control signal.

[0041] FIG. 9 is a schematic diagram of a drive waveform input to the actuator 88 by opening and closing the n-th switch 54a(n). When the time division multiplexed signal and the synchronization signal S2a are selected, the switch group 54 closes the n-th switch 54a(n) when the pulse of the synchronization signal S2a is in a high level section, and opens the n-th switch 54a(n) when the pulse of the synchronization signal S2a is in a low level section. When the n-th switch 54a(n) is closed, the charge applied to the individual electrode 85 is held, and as shown in FIG. 9, the drive waveform A1 is input to the actuator 88. In other words, the drive waveform signal Pa is separated from the time division multiplexed signal, and the actuator 88 is driven by the drive waveform signal Pa. In this embodiment, the drive waveform A1 corresponds to the first drive waveform, and the drive waveform signal Pa corresponds to the first drive waveform signal. The nozzle 80 is driven based on the drive waveform signal Pa to eject liquid. That is, the nozzle 80 is driven to eject liquid based on the drive waveform signal Pa.

[0042] When the time division multiplexed signal and the synchronization signal S2b are selected, the switch group 54 closes the n-th switch 54a(n) when the pulse of the synchronization signal S2b is in a high level section, and opens the n-th switch 54a(n) when the pulse of the synchronization signal S2b is in a low level section. When the n-th switch 54a(n) is closed, the charge applied to the individual electrode 85 is held, and as shown in FIG. 9, the drive waveform B1 is input to the actuator 88. In other words, the drive waveform signal Pb is separated from the time division multiplexed signal, and the actuator 88 is driven by the drive waveform signal Pb. In this embodiment, the drive waveform B1 corresponds to the first drive waveform, and the drive waveform signal Pb corresponds to the first drive waveform signal. The nozzle 80 is driven based on the drive waveform signal Pb to eject liquid. That is, the nozzle 80 is driven to eject based on the drive waveform signal Pb.

[0043] When the time division multiplexed signal and the synchronization signal S2c are selected, the switch group 54 closes the n-th switch 54a(n) when the pulse of the synchronization signal S2c is in a high level section, and opens the n-th switch 54a(n) when the pulse of the synchronization signal S2c is in a low level section. When the n-th switch 54a(n) is closed, the charge applied to the individual electrode 85 is held, and as shown in FIG. 9, the drive waveform C1 is input to the actuator 88. In other words, the drive waveform signal Pc is separated from the time division multiplexed signal, and the actuator 88 is driven by the drive waveform signal Pc. In this embodiment, the drive waveform C1 corresponds to the second drive waveform, and the drive waveform signal Pc corresponds to the second drive waveform signal. The nozzle 80 is driven based on the drive waveform signal Pc to increase the temperature of the separation circuit 50b (the switch group 54). At this time, the nozzle 80 does not eject liquid. That is, the nozzle 80 is driven to not eject liquid based on the drive waveform signal Pc.

[0044] FIG. 10 is a flow chart for explaining the printing process by the control device 50. The control device 50 judges whether the power of the printing device 1 is turned on (S1). If the power of the printing device 1 is not turned on (S1: NO), the control device 50 returns the process to S1 and waits until the power of the printing device 1 is turned on. If the power of the printing device 1 is turned on (S1: YES), the control device 50 starts the temperature rise process (see FIG. 11) (S2). The temperature rise process is a subroutine executed in parallel with the printing process. The control device 50 judges whether a print job is received from the external device 100 (S3). Note that the control device 50 does not advance the process to S3 after completing the temperature rise process, but executes S3 and subsequent steps simultaneously while executing the temperature rise process as a subroutine. If a print job is not received (S3: NO), the control device 50 returns the process to S3. If a print job is received (S3: YES), the control device 50 judges whether the temperature rise process is completed (S4). If the temperature increase process is complete (S4: YES), the control device 50 executes the discharge process of FIG. 12 (S5), which will be described later, and returns the process to S2. If the temperature increase process is not complete (S4: NO), the control device 50 judges whether the image quality required for the print process specified in the received print job is equal to or higher than a predetermined frequency (S6). If the image quality required is less than the predetermined frequency (S6: NO), the control device 50 advances the process to S5. If the image quality required is equal to or higher than the predetermined frequency (S6: YES), the control device 50 waits until the temperature increase process is complete and the temperature of the separation circuit 50b reaches a predetermined value or higher (S7), and advances the process to S5.

[0045] FIG. 11 is a flow chart for explaining the temperature increase process by the control device 50. The control device 50 judges whether the number of discharge processes (discharge frequency) within a past predetermined time is equal to or greater than a predetermined frequency (S301). If the discharge frequency is equal to or greater than the predetermined frequency (S301: YES), the control device 50 completes the temperature increase process. If the discharge frequency is less than the predetermined frequency (S301: NO), the control device 50 reads out the mapping information table 551 from the memory 55 (S302). The control device 50 generates a time division multiplexed signal based on the mapping information table 551 by the multiplexing circuit 50a (S303). The control device 50 transmits the time division multiplexed signal to the separation circuit 50b (S304). The control device 50 transmits a switch control signal from the control circuit 51 to the separation circuit 50b by the switch control signal line SL1 (S305). The switch control signal in S305 includes second selection information indicating the selection of the synchronization signal S2c. The control device 50 transmits the synchronization signal S2 from the control circuit 51 to the separation circuit 50b via the synchronization signal line SL2 (S306). The control device 50 separates the drive waveform C1 by the switch 54a of the separation circuit 50b (S307). When the drive waveform C1 is separated in S307, the nozzle 80 is driven to not eject, and the temperature of the separation circuit 50b rises. The control device 50 estimates the temperature of the separation circuit 50b (S308). In S308, the control device 50 estimates the temperature of the separation circuit 50b based on the number of drive waveforms C1 separated in S307. The control device 50 may obtain the number of pulses of the synchronization signal S2c output from the control circuit 51 by open loop processing, or may obtain the number of pulses of the synchronization signal S2c input to the separation circuit 50b by feedback processing. The control device 50 may also estimate the temperature based on the outside air temperature (ambient temperature) of the printing device 1. The control device 50 determines whether the temperature estimated in S308 (estimated temperature) is equal to or higher than a predetermined value (S309). If the estimated temperature is equal to or higher than the predetermined value (S309: YES), the control device 50 completes the temperature increase process. If the estimated temperature is lower than the predetermined value (S309: NO), the control device 50 returns the process to S303.

[0046] FIG. 12 is a flow chart for explaining the discharge process by the control device 50. The control device 50 reads out the mapping information table 551 from the memory 55 (S501). The control device 50 generates a time division multiplexed signal based on the mapping information table 551 by the multiplexing circuit 50a (S502). The control device 50 transmits the time division multiplexed signal to the separation circuit 50b (S503). The control device 50 transmits a switch control signal from the control circuit 51 to the separation circuit 50b by the switch control signal line SL1 (S504). The switch control signal in S504 includes second selection information indicating the selection of the synchronization signal S2a or S2b. The control device 50 transmits the synchronization signal S2 from the control circuit 51 to the separation circuit 50b by the synchronization signal line SL2 (S505). The control device 50 separates the drive waveform A1 or B1 by the switch 54a of the separation circuit 50b (S506). The control device 50 determines whether or not to end the discharge process (S507). In S507, if the flushing process or the print task is completed, the control device 50 determines to end the discharge process, and if not completed, determines not to end (continue) the discharge process. If it is determined to end the discharge process (S507: YES), the control device 50 ends the discharge process. If it is determined not to end the discharge process (S507: NO), the control device 50 returns the process to S502.

[0047] In the printing apparatus according to the first embodiment, a time division multiplexed signal including a drive waveform C that increases the temperature of the separation circuit 50b without causing the nozzle 80 to eject liquid is transmitted to the separation circuit 50b. The control device 50 causes the separation circuit 50b to separate the drive waveform C1, thereby energizing the switch 54a of the separation circuit 50b and generating heat by the electrical resistance of the switch 54a. By performing the above-mentioned process when it is estimated that the temperature of the separation circuit 50b is low, it is possible to keep the temperature of the separation circuit 50b (near the switch group 54) constant when the nozzle 80 ejects liquid, and thus it is possible to keep the quality of liquid ejection by the nozzle 80 constant. In this embodiment, a temperature sensor may be provided in the separation circuit 50b or in the vicinity of the separation circuit 50b. In this case, the control device 50 may determine whether or not to increase the temperature of the separation circuit 50b based on the temperature measured by the temperature sensor.

[0048] (Embodiment 2) In the printing device according to the second embodiment, two switches (a switch 54a and b switch 54b) are connected to one actuator. When the drive waveform is separated by the a switch 54a, the nozzle 80 ejects liquid. When the drive waveform is separated by the b switch 54b, the nozzle 80 does not eject liquid, and the temperature of the separation circuit 50b rises. The liquid ejected by the nozzle 80 is a specific ink or a non-specific ink. Since the specific ink is an ink (liquid) whose properties are easily changed by a rise in temperature, it is desirable not to raise the temperature of the separation circuit 50b before the nozzle 80 ejects the specific ink. When the liquid to be ejected by the nozzle 80 specified in the print job is a non-specific ink, the control device 50 causes the b switch 54b to separate the drive waveform signal and raise the temperature of the separation circuit 50b. Hereinafter, the present invention will be described based on the drawings showing the printing device according to the second embodiment. Among the configurations of the second embodiment, the same reference numerals are given to the configurations similar to those of the first embodiment, and detailed description thereof will be omitted. The a switch 54a according to the second embodiment has the same configuration as the switch 54a according to the first embodiment, and is therefore denoted by the same reference numeral.

[0049] 13 is a block diagram of a control device 50 according to embodiment 2. The switch group 54 of the control device 50 according to embodiment 2 includes a plurality of b switches 54b. The plurality of b switches 54b include a first b switch 54b(1), a second b switch 54b(2), ..., an nb switch 54b(n). The a switch 54a and the b switch 54b are configured by, for example, an analog switch IC.

[0050] One end of each of the 1b switch 54b(1), the 2b switch 54b(2), ..., the nb-th switch 54b(n) is connected to the amplifier 53 via a signal line L1. The other end of each of the 1b switch 54b(1), the 2b switch 54b(2), ..., the nb-th switch 54b(n) is connected to the individual electrodes 85 of the first actuator 88(1), the second actuator 88(2), ..., the n-th actuator 88(n), respectively.

[0051] The b switch 54b and the a switch 54a have different resistance values ​​when they are turned on and energized, and the resistance value of the b switch 54b is higher than the resistance value of the a switch 54a. When the drive waveform is separated by the a switch 54a, the nozzle 80 ejects liquid. When the drive waveform is separated by the b switch 54b, the nozzle 80 does not eject liquid, and the temperature of the separation circuit 80b rises. The resistance value of the b switch 54b may be equal to or lower than the resistance value of the a switch 54a.

[0052] The control device 50 according to the second embodiment transmits (outputs) a switch control signal for controlling opening and closing of the multiple na-th switches 54a(n) or the nb-th switch 54b(n) via a switch control signal line SL1 to the switch group 54. The switch control signal includes first selection information indicating to select one of the multiple na-th switches 54a(n) or the nb-th switch 54b(n), and second selection information indicating to select one of the three synchronization signals S2a to S2c.

[0053] 14 is a block diagram showing the driving waveform data and tables stored in the memory 55 according to the second embodiment. The memory 55 according to the second embodiment stores an ink table 552 and a specific ink condition table 553.

[0054] FIG. 15 is an explanatory diagram showing an example of the ink table 552. The ink table 552 stores information about the composition of the ink (liquid) ejected by the nozzle 80. The management items (fields) of the ink table 552 include, for example, an ink name field, a resin fine particle field, an organic solvent field with a saturated vapor pressure of 0.03 hPa or more, a coloring material solid content field, an average pigment particle diameter field, and a water field. The ink name field stores the name of the ink for identifying the ink. The resin fine particle field stores the ratio (mass%) of the resin fine particles contained in the ink. The organic solvent field with a saturated vapor pressure of 0.03 hPa or more stores the ratio (mass%) of the organic solvent contained in the ink with a saturated vapor pressure of 0.03 or more at 20° C. The coloring material solid content field stores the ratio (mass%) of the coloring material solid content contained in the ink. The average pigment particle diameter field stores the average particle diameter (nm) of the pigment particles contained in the ink. The water field stores the ratio (mass%) of the water contained in the ink. In addition to the components shown in FIG. 15, the ink ejected by the nozzle 80 contains components such as a pigment solvent or a surfactant. FIG. 15 shows the composition of the components related to the conditions for determining whether the ink is a specific ink.

[0055] FIG. 16 is an explanatory diagram showing an example of the specific ink condition table 553. The specific ink condition table 553 stores conditions for determining an ink as a specific ink. The management items (fields) of the specific ink condition table 553 include, for example, a condition item field and a condition range field. The condition item field stores items of conditions for determining an ink as a specific ink. The values ​​stored in each record of the condition item field correspond to the management items of the ink table 552. The condition range field stores a numerical range for determining an ink as a specific ink for each condition item. The specific ink in this embodiment is an ink (liquid) that satisfies any one of the following conditions: a resin fine particle ratio of 1 to 10 mass %, an organic solvent ratio of which has a saturated vapor pressure of 0.03 hPa or more at 20° C. of 10 to 30 mass %, a coloring material solid content ratio of 2 to 10 mass %, an average particle diameter of pigment particles of 150 nm or more, or a water ratio of 60 mass % or less. The numerical values ​​of each condition are not limited to those described above.

[0056] Inks that contain 1% or more resin particles, 10% or more organic solvent with a saturated vapor pressure of 0.03 hPa or more at 20°C, or 2% or more colorant solids contain a high proportion of polymers and are highly quick-drying or coagulating when heated. Inks with an average pigment particle diameter of 150 nm or more are prone to particle settling and nozzle clogging when heated. Inks that contain 60% or less water contain a high proportion of solvents and are highly quick-drying when heated. For the reasons described above, inks that meet at least one of the conditions shown in the specific ink condition table 533 are considered to be specific inks that are not suitable for heating.

[0057] The control device 50, which has received a print job from the external device 100, refers to the ink table 552 and the specific ink condition table 553 based on the ink name of the ink specified in the print job, and determines whether the ink ejected by the nozzle 80 is a specific ink. If at least one item of the record in the ink table 552 of the specified ink falls within the numerical range defined in the specific ink condition table 553, the control device 50 determines that the ink is a specific ink. If none of the items of the record in the ink table 552 of the specified ink falls within the numerical range defined in the specific ink condition table 553, the control device 50 determines that the ink is a non-specific ink. In this example, the inks A to G stored in the ink table 552 satisfy at least one of the conditions defined in the specific ink condition table 553, and are therefore determined to be specific inks. Ink H does not satisfy any of the conditions, and is therefore determined to be a non-specific ink.

[0058] The ink table 552 may include an ink type field in which whether the ink is a specific ink or a non-specific ink is stored. In this case, the control device 50 may determine whether the ink is a specific ink or a non-specific ink based on the ink name of the ink specified in the print job and the value stored in the ink type field of the ink table 552. The ink table 552 and the specific ink condition table 553 may be stored in the external device 100. In this case, the print job may include information indicating whether the specified ink is a specific ink or a non-specific ink.

[0059] FIG. 17 is a flowchart for explaining the temperature increase process by the control device 50 according to the second embodiment. The control device 50 refers to the ink table 552 and the specific ink condition table 553 and judges whether the ink specified in the print job is a specific ink (S311). If the ink is a specific ink (S311: YES), the control device 50 completes the temperature increase process. If the ink is a non-specific ink (S311: NO), the control device 50 advances the process to S312. The processes of S312 to S314 are the same as the processes of S302 to S304 shown in FIG. 11. The control device 50 transmits a switch control signal by a switch control signal (S315). Note that the switch control signal in S315 includes first selection information indicating the selection of the b switch 54b and second selection information indicating the selection of the synchronization signal S2c. The control device 50 transmits the synchronization signal S2 from the control circuit 51 to the separation circuit 50b by the synchronization signal line SL2 (S316). The control device 50 separates the driving waveform C1 by the b switch 54b (S317). The processes from S318 to S319 are similar to those from S308 to S309 shown in FIG.

[0060] FIG. 18 is a flow chart for explaining the discharge process by the control device 50 according to the second embodiment. The processes of S511 to S513 are the same as those of S501 to S503 shown in FIG. 12. The control device 50 transmits a switch control signal by a switch control signal (S514). The switch control signal in S514 includes first selection information indicating the selection of the a switch 54a and second selection information indicating the selection of the synchronization signal S2a or S2b. The control device 50 transmits the synchronization signal S2 from the control circuit 51 to the separation circuit 50b by the synchronization signal line SL2 (S515). The control device 50 separates the drive waveform A1 or B1 by the a switch 54a of the separation circuit 50b (S516). The process of S517 is the same as that of S507 shown in FIG. 12.

[0061] In the printing device according to the second embodiment, if the ink (liquid) ejected by the nozzle 80 is a specific ink whose properties are easily changed by an increase in temperature, the temperature of the separation circuit 50b is not increased, and if the ink is a non-specific ink, the temperature of the separation circuit 50b is increased. This makes it possible to maintain a constant quality of liquid ejection by the nozzle 80. Note that the a switch 54a according to this embodiment may separate the drive waveform C1, and the b switch 54b may separate the drive waveform A1 or B1.

[0062] (Embodiment 3) In the printing device according to the third embodiment, three b switches 54b, which increase the temperature of the separation circuit 50b by separating the drive waveform signal, are connected to one actuator 88. The control device 50 of the printing device determines the number of b switches 54b that separate (energize) the drive waveform signal according to the degree of temperature increase required based on the composition of the ink (liquid) ejected by the nozzle 80. The present invention will be described below with reference to the drawings showing the printing device according to the third embodiment. Among the configurations of the third embodiment, the same components as those of the first or second embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0063] 19 is a block diagram of a control device 50 according to embodiment 3. The switch group 54 of the control device 50 according to embodiment 2 includes three b switches 54b (b1 switch 54b1, b2 switch 54b2, and b3 switch 54b3) connected to one actuator 88. The b1 switch 54b1, b2 switch 54b2, and b3 switch 54b3 are connected in parallel, and each has the same configuration as the b switch 54b according to embodiment 2.

[0064] 20 is a block diagram showing drive waveform data and tables stored in the memory 55 according to the third embodiment. The memory 55 according to the third embodiment stores a temperature rise score table 554 and a temperature rise degree table 555. The control device 50 refers to the temperature rise score table 554 and calculates the degree of temperature rise necessity of the separation circuit 50b related to the ejection of ink from the nozzle 80. Thereafter, the control device 50 refers to the temperature rise degree table 555 based on the degree of temperature rise necessity and determines the number of b switches 54b that separate the drive waveform signal.

[0065] FIG. 21 is an explanatory diagram showing an example of the temperature rise score table 554. The temperature rise score table 554 stores a score to be added to the temperature rise necessity degree for the value stored in each management item of the ink table 552. The management items of the temperature rise score table 554 include a score field, a resin fine particle range, a resin fine particle field, an organic solvent field with a saturated vapor pressure of 0.03 hPa or more, a coloring material solid content field, an average pigment particle diameter field, and a water field. The score field stores a score to be added to the temperature rise necessity degree when the ink matches any of the conditions of the record. The resin fine particle range, the resin fine particle field, the organic solvent field with a saturated vapor pressure of 0.03 hPa or more, the coloring material solid content field, the average pigment particle diameter field, and the water field each store a condition (numerical range) for adding a score to the temperature rise necessity degree. The control device 50 reads out the composition of the ink specified in the print job from the ink table 552, and calculates the temperature rise necessity degree by referring to the temperature rise score table 554 based on the condition to which each management item of the read composition applies. That is, the integrated value of the scores of each management item in the temperature rise score table 554 is the degree of necessity for a temperature rise. For example, in the case of ink A shown in the ink table 552 in Fig. 15, a score of 2 is added because the ink contains 1% or more but less than 4% (2%) of resin fine particles, a score of 3 is added because the ink contains less than 10% (7%) of an organic solvent with a saturated vapor pressure of 0.03 hPa or more, a score of 3 is added because the ink contains less than 2% (1%) of colorant solids, a score of 3 is added because the average particle diameter of the pigment particles is less than 80 nm (60 nm), and a score of 3 is added because the ink contains 0% or more (85%) of water. As a result of the above, the degree of necessity for a temperature rise for ink A is 14.

[0066] FIG. 22 is an explanatory diagram showing an example of the temperature rise degree table 555. The temperature rise degree table 555 stores the number of b switches 54b that separate the drive waveform signal with respect to the calculated degree of temperature rise necessity. The management items (fields) of the temperature rise degree table 555 include, for example, a temperature rise necessity field and a switch number field. The temperature rise necessity field stores a numerical range of the temperature rise necessity corresponding to the number of b switches 54b that separate the drive waveform signal. The switch number field stores the number of b switches 54b that separate the drive waveform signal, corresponding to the degree of temperature rise necessity. The control device 50 refers to the temperature rise degree table 555 based on the calculated degree of temperature rise necessity, and determines the number of b switches 54b that separate the drive waveform signal. The greater the number of b switches 54b that separate the drive waveform signal, the higher the temperature rise degree of the separation circuit 50b. In other words, the control device 50 refers to the temperature rise score table 554 and the temperature rise degree table 555, and determines the temperature rise degree of the separation circuit 50b according to the characteristics of the ink (liquid) ejected by the nozzle 80. The temperature rise degree table 555 may include a drive waveform separation switch field instead of or in addition to the switch number field. The drive waveform separation switch field stores information for identifying the b switch 54b that separates the drive waveform signal (identification information of the b1 switch 54b1, identification information of the b2 switch 54b2, or identification information of the b3 switch 54b3), which is set according to the degree of temperature rise necessity or the number of b switches 54b that separate the drive waveform signal. In this case, the control device 50 causes the b switch 54b indicated by the identification information stored in the drive waveform separation switch field corresponding to the degree of temperature rise necessity to separate the drive waveform signal.For example, in the drive waveform separation switch field, identification information of the b1 switch 54b1, identification information of the b2 switch 54b2, and identification information of the b3 switch 54b3 are stored in correspondence with the number of the b switches 54b being 3, any two of identification information of the b1 switch 54b1, identification information of the b2 switch 54b2, and identification information of the b3 switch 54b3 are stored in correspondence with the number of the b switches 54b being 2, and any one of identification information of the b1 switch 54b1, identification information of the b2 switch 54b2, and identification information of the b3 switch 54b3 is stored in correspondence with the number of the b switches 54b being 1. The control device 50 may also store a table in which conditions for each item related to the composition of the ink are stored, and determine the number of b switches 54b that separate the drive waveform signal according to the number of conditions to which the ink ejected by the nozzle 80 falls.

[0067] 23 is a flowchart for explaining the temperature increase process by the control device 50 according to the third embodiment. The control device 50 calculates the degree of necessity of temperature increase for the ink specified in the print job based on the ink table 552 and the temperature increase score table 554 (S321). Based on the degree of necessity of temperature increase, the control device 50 refers to the temperature increase degree table 555 and determines the number of b switches 54b that separate the driving waveform signal (S322). The processes in S323 to S325 are the same as those in S302 to S304 shown in FIG.

[0068] The control device 50 transmits a switch control signal from the control circuit 51 to the separation circuit 50b via the switch control signal line SL1 (S326). The switch control signal in S326 includes first selection information indicating the selection of the b switch 54b and second selection information indicating the selection of the synchronization signal S2c. In this embodiment, when the number of b switches 54b determined in S322 is one, the first selection information indicates the selection of the b1 switch 54b1. When the number of b switches 54b is two, the first selection information indicates the selection of the b1 switch 54b1 and the b2 switch 54b2. When the number of b switches 54b is three, the first selection information indicates the selection of the b1 switch 54b1, the b2 switch 54b2, and the b3 switch 54b3. The b switches 54b indicated by the first selection information may not be fixed with respect to the number of b switches 54b. For example, the b switches 54b indicated by the first selection information may be determined in ascending order of the number of times that the drive waveform signal has been separated in the past, by rotation, or randomly. Moreover, if the number of b switches 54b determined in S322 is 0, the control device 50 does not execute S326 to S330 and completes the temperature increase process.

[0069] The control device 50 transmits the synchronization signal S2 from the control circuit 51 to the separation circuit 50b via the synchronization signal line SL2 (S327). The control device 50 separates the drive waveform C1 by the b switch 54b indicated in the first selection information of the switch control signal (S328). The processes of S329 to S330 are similar to those of S308 to S309 shown in FIG.

[0070] In the printing device according to the third embodiment, the number of b switches 54b that separate the drive waveform signal is determined based on the ink (liquid) discharged by the nozzle 80, thereby controlling the temperature rise of the separation circuit 50b according to the properties of the ink. This makes it possible to maintain the quality of the liquid discharged by the nozzle 80 constant while suppressing the modification of the ink (liquid) due to the temperature rise. The b1 switch 54b1, the b2 switch 54b2, and the b3 switch 54b3 may separate the drive waveform A1 or B1. The temperature rise score table 554 and the temperature rise degree table 555 may be stored in the external device 100, and the print job may include information indicating the number of b switches 54b that separate the drive waveform signal before the nozzle 80 discharges the specified ink.

[0071] (Embodiment 4) In the printing device according to the fourth embodiment, the time division multiplexed signal includes a signal showing a plurality of waveforms that are separated by the switch 54 to raise the temperature of the separation circuit 50b. The control device 50 determines the drive waveform to be separated by the switch 54 according to the characteristics of the ink (liquid) ejected by the nozzle 80. The present invention will be described below with reference to the drawings showing the printing device according to the fourth embodiment. Among the configurations of the fourth embodiment, the same configurations as those of the first, second or third embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0072] 24 is a block diagram of the control device 50 according to the embodiment 4. The configuration of the control device 50 according to the embodiment 4 is similar to the configuration of the control device 50 according to the embodiment 2.

[0073] 25 is a block diagram showing drive waveform data and tables stored in a memory 55 according to the fourth embodiment. In the fourth embodiment, drive waveform data Da, Dd, and De are stored in the memory 55. The memory 55 also stores a mapping information table 551 and an ink characteristics table 556. Details of the mapping information table 551 and the ink characteristics table 556 according to the fourth embodiment will be described later.

[0074] 26 is an explanatory diagram illustrating an example of the relationship between the drive waveforms A, D, E and the drive waveform data Da, Dd, De. Data obtained by converting the drive waveform A into a digital signal at a predetermined sampling period is the drive waveform data Da. Data obtained by converting the drive waveform D into a digital signal at a predetermined sampling period is the drive waveform data Dd. Data obtained by converting the drive waveform E into a digital signal at a predetermined sampling period is the drive waveform data De.

[0075] The drive waveform data Da is quantized data of the drive waveform A, the drive waveform data Dd is quantized data of the drive waveform D, and the drive waveform data De is quantized data of the drive waveform E. The drive waveform data Da has quantized data Ak (k=0, 1, 2, ...), the drive waveform data Dd has quantized data Dk, and the drive waveform data De has quantized data Ek.

[0076] Fig. 27 is an explanatory diagram showing an example of a mapping information table 551 according to the fourth embodiment. In the assigned data field of the mapping information table 551 according to the fourth embodiment, data names of data Ak, Dk, or Ek (k=0, 1, 2, . . .) assigned to each time slot are stored. The data name [Ak] corresponds to the data Ak shown in Fig. 5, the data name [Dk] corresponds to the data Bk shown in Fig. 26, and the data name [Ek] corresponds to the data Ek shown in Fig. 5.

[0077] FIG. 28 is an explanatory diagram for explaining an example of time series data, an analog signal, and a time division multiplexed signal. In FIG. 28, A, D, and E indicate that they correspond to the drive waveforms A, D, and E, respectively. When driving the actuator 88, the control circuit 51 accesses the memory 55, reads the drive waveform data Da, Dd, and De and the mapping information table 551, and creates time series data. The time series data is data Ak, Dk, and Ek that are assigned to each time slot divided for each time interval Δt based on the mapping information table 551. That is, the time series data is data Ak, Dk, and Ek that are arranged in order with a time interval Δt provided, and are arranged in the order of A0, D0, E0, A1, D1, E1, . . . , Ak, Dk, and Ek. The time series data is a digital signal. The time interval between Ak-1 and Ak, the time interval between Dk-1 and Dk, and the time interval between Ek-1 and Ek are each 3Δt.

[0078] The control circuit 51 outputs the time series data to the D / A converter 52. As shown in FIG. 28, the D / A converter 52 converts the time series data into an analog signal and outputs it to the amplifier 53. The amplifier 53 amplifies the input analog signal and outputs it to the switch group 54. As shown in FIG. 28, the analog signal amplified by the amplifier 53 constitutes a time division multiplexed signal. In the time division multiplexed signal, if a portion corresponding to data Ak-1 is a first portion, a portion corresponding to data Ak is a second portion, a portion corresponding to data Dk-1 is a third portion, a portion corresponding to data Dk is a fourth portion, a portion corresponding to data Ek-1 is a fifth portion, and a portion corresponding to data Ek is a sixth portion, then the third portion is between the first portion and the second portion, and the second portion is between the third portion and the fourth portion. Also, the fifth portion is between the third portion and the second portion, and the fourth portion is between the second portion and the sixth portion.

[0079] FIG. 29 is an explanatory diagram for explaining the relationship between the time division multiplexed signal and the synchronization signals S2a, S2d, and S2e. The synchronization signals S2a, S2d, and S2e are pulse waves. A time interval Δt is provided between the rising point of the pulse of the synchronization signal S2a and the rising point of the pulse of the synchronization signal S2d. A time interval Δt is provided between the rising point of the pulse of the synchronization signal S2d and the rising point of the pulse of the synchronization signal S2e. A time interval Δt is provided between the rising point of the pulse of the synchronization signal S2e and the rising point of the pulse of the synchronization signal S2a. The synchronization signal S2a corresponds to the first synchronization signal, and the synchronization signal S2d corresponds to the second synchronization signal. As shown in FIG. 29, the time width at which the pulses included in the synchronization signals S2a, S2d, and S2e rise is narrower than the time width (time interval Δt) of the time slot, but may be the same as the time width (time interval Δt) of the time slot. That is, the time width during which the pulses included in the synchronization signals S2a, S2d, and S2e rise is within the time width (time interval Δt) of the time slot. Furthermore, the synchronization signals S2a, S2d, and S2e are transmitted by the synchronization signal line SL2.

[0080] As described above, the data Ak, Dk, and Ek constituting the time series data are arranged in order with a time interval Δt provided. Therefore, when the time division multiplexed signal is accessed at the rising edge of the pulse of the synchronization signal S2a, the drive waveform signal Pa corresponding to the data Ak and showing the drive waveform A can be obtained. When the time division multiplexed signal is accessed at the rising edge of the pulse of the synchronization signal S2d, the drive waveform signal Pd corresponding to the data Dk and showing the drive waveform D can be obtained. When the time division multiplexed signal is accessed at the rising edge of the pulse of the synchronization signal S2e, the drive waveform signal Pe corresponding to the data Ek and showing the drive waveform E can be obtained.

[0081] The switch group 54 opens and closes the na-th switch 54a(n) or the nb-th switch 54b(n) indicated in the first selection information at the opening and closing timings indicated by the synchronization signals S2a, S2d, S2e indicated in the second selection information included in the transmitted switch control signal.

[0082] FIG. 30 is a schematic diagram of a driving waveform input to the actuator 88 by opening and closing the na-th switch 54a(n) or the nb-th switch 54b(n). When the time division multiplexed signal and the synchronization signal S2a are selected, the switch group 54 closes the na-th switch 54a(n) when the pulse of the synchronization signal S2a is in a high level section, and opens the na-th switch 54a(n) when the pulse of the synchronization signal S2a is in a low level section. When the na-th switch 54a(n) is closed, the charge applied to the individual electrode 85 is held, and as shown in FIG. 30, the driving waveform A1 is input to the actuator 88. In other words, the driving waveform signal Pa is separated from the time division multiplexed signal, and the actuator 88 is driven by the driving waveform signal Pa. In this embodiment, the driving waveform A1 corresponds to the first driving waveform, and the driving waveform signal Pa corresponds to the first driving waveform signal. The nozzle 80 is driven based on the driving waveform signal Pa to eject liquid. That is, the nozzle 80 is driven to eject based on the driving waveform signal Pa.

[0083] When the time division multiplexed signal and the synchronization signal S2d are selected, the switch group 54 closes the nb-th switch 54b(n) when the pulse of the synchronization signal S2d is in a high level section, and opens the nb-th switch 54b(n) when the pulse of the synchronization signal S2d is in a low level section. When the nb-th switch 54b(n) is closed, the charge applied to the individual electrode 85 is held, and as shown in FIG. 30, the drive waveform D1 is input to the actuator 88. In other words, the drive waveform signal Pd is separated from the time division multiplexed signal, and the actuator 88 is driven by the drive waveform signal Pd. In this embodiment, the drive waveform D1 corresponds to the second drive waveform, and the drive waveform signal Pd corresponds to the second drive waveform signal. The nozzle 80 is driven based on the drive waveform signal Pd to increase the temperature of the separation circuit 50b (the switch group 54). At this time, the nozzle 80 does not eject liquid. That is, the nozzle 80 is driven to not eject liquid based on the drive waveform signal Pd.

[0084] When the time division multiplexed signal and the synchronization signal S2e are selected, the switch group 54 closes the nb-th switch 54b(n) when the pulse of the synchronization signal S2e is in a high level section, and opens the nb-th switch 54b(n) when the pulse of the synchronization signal S2e is in a low level section. When the nb-th switch 54b(n) is closed, the charge applied to the individual electrode 85 is held, and as shown in FIG. 30, the drive waveform E1 is input to the actuator 88. In other words, the drive waveform signal Pe is separated from the time division multiplexed signal, and the actuator 88 is driven by the drive waveform signal Pe. In this embodiment, the drive waveform E1 corresponds to the third drive waveform, and the drive waveform signal Pe corresponds to the third drive waveform signal. The nozzle 80 is driven based on the drive waveform signal Pe to increase the temperature of the separation circuit 50b (the switch group 54). At this time, the nozzle 80 does not eject liquid. That is, the nozzle 80 is driven to not eject liquid based on the drive waveform signal Pe.

[0085] In this embodiment, the voltage application time per cycle of the drive waveform D1 is longer than that of the drive waveform E1, and when the b switch 54b separates the drive waveform signal Pd, the degree of heat generation is greater and the temperature rise of the separation circuit 50b is also greater than when the drive waveform signal Pe is separated. The amplitude of the drive waveform D1 may be greater than that of the drive waveform E1, and the frequency of the drive waveform D1 may be higher than that of the drive waveform E1. In any of the above cases, when the b switch 54b separates the drive waveform signal Pd, the degree of heat generation is greater and the temperature rise of the separation circuit 50b is also greater than when the drive waveform signal Pe is separated.

[0086] FIG. 31 is an explanatory diagram showing an example of an ink characteristics table 556. The ink characteristics table 556 stores information related to the classification of the characteristics of the ink ejected by the nozzles 80. The management items of the ink characteristics table 556 include, for example, an ink name field, a specific heat field, and a characteristics field. The ink name field stores the ink name for identifying the ink. The specific heat field stores the specific heat of the ink. The characteristics field stores the type of ink characteristics according to the specific heat of the ink. If the specific heat of the ink is 4.00 J / (g·K) or more, the first characteristics are stored in the characteristics field. If the ink characteristics are less than 4.00 J / (g·K), the second characteristics are stored.

[0087] When the ink specified in the print job has the first characteristic, the control device 50 causes the b switch 54b to separate the drive waveform signal Pd, and when the ink specified in the print job has the second characteristic, the control device 50 causes the b switch 54b to separate the drive waveform signal Pe. The ink characteristic table 556 may have a resin fine particle field, an organic solvent field with a saturated vapor pressure of 0.03 hPa or more, a coloring material solid content field, an average pigment particle diameter field, a water field, or a heat transfer coefficient field, instead of or in addition to the specific heat field. In this case, the characteristic field stores the proportion (mass%) of resin fine particles contained in the ink, the proportion (mass%) of organic solvent contained in the ink with a saturated vapor pressure of 0.03 or more at 20°C, the average particle diameter (nm) of pigment particles contained in the ink, the proportion (mass%) of water contained in the ink, or a type of characteristic corresponding to the heat transfer coefficient. The ink characteristic table 556 may be stored in the external device 100, and the print job may include information indicating the characteristics of the ink ejected by the nozzle 80.

[0088] FIG. 32 is a flowchart for explaining the temperature increase process by the control device 50 according to the fourth embodiment. The control device 50 refers to the ink characteristics table 556 based on the ink name of the ink specified in the print job to identify the characteristics of the ink ejected by the nozzle 80 (S341). The processes of S342 to S344 are similar to the processes of S302 to S304 shown in FIG. 11. The control device 50 transmits a switch control signal from the control circuit 51 to the separation circuit 50b via the switch control signal line SL1 (S345). Note that the switch control signal in S345 includes first selection information indicating the selection of the b switch 54b and second selection information indicating the selection of the synchronization signal S2. In this embodiment, if the ink characteristics are identified as the first characteristics in S341, the second selection information indicates the selection of the synchronization signal S2d. If the ink characteristics are identified as the second characteristics, the second selection information indicates the selection of the synchronization signal S2e. The control device 50 transmits the synchronization signal S2 from the control circuit 51 to the separation circuit 50b via the synchronization signal line SL2 (S346). The control device 50 separates the drive waveform D1 or E1 by the b switch 54b of the separation circuit 50b (S347). The processes of S348 to S349 are similar to those of S308 to S309 shown in FIG.

[0089] (Modification of the fourth embodiment) In a modification of the fourth embodiment, the control device 50 determines the drive waveform signal to be separated by the b switch 54b based on the position of the nozzle 80 that ejects ink.

[0090] Figure 33 is an explanatory diagram showing an example of the arrangement of nozzles 80 in an inkjet head 8. In an inkjet head 8, a plurality of nozzles 80 are arranged at approximately equal intervals in the front-rear and left-right directions (corresponding to the transport direction and scanning direction shown in Figure 1). To avoid complication, only some of the nozzles 80 are labeled with reference numerals in Figure 33.

[0091] In the inkjet head 8, a position far from the center in the front-rear and left-right directions is defined as a first position, and a position close to the center is defined as a second position. In the example shown in FIG. 33, the position of the area (inside) surrounded by the dashed line is the second position, and the periphery (outside) of the area surrounded by the dashed line is the first position. The ratio of the number of nozzles 80 located at the first position to the number of nozzles 80 located at the second position, i.e., the position of the dashed line, can be set arbitrarily. The control device 50 stores whether the position of each nozzle 80 is the first position or the second position, in association with the number n of the nozzle 80 (the number n of the actuator 88 to which the nozzle 80 is provided).

[0092] When the nozzle 80 that ejects ink (liquid) is at the first position, the control device 50 causes the b switch 54b to separate the drive waveform signal Pd, and when the nozzle 80 is at the second position, the control device 50 causes the b switch 54b to separate the drive waveform signal Pe. The drive waveform signal Pd corresponds to the second drive waveform signal, and the drive waveform signal Pe corresponds to the third drive waveform signal. As described above, when the b switch 54b separates the drive waveform signal Pd, the degree of heat generation is higher and the temperature rise of the separation circuit 50b is also higher than when the drive waveform signal Pe is separated. That is, the control device 50 causes the b switch 54b to separate the drive waveform signal Pd so that when the outer nozzle 80 (nozzle 80 at the first position), whose temperature is less likely to rise, ejects ink, the degree of heat generation is higher than when the inner nozzle 80 (nozzle 80 at the second position), whose temperature is more likely to rise, ejects ink.

[0093] FIG. 34 is a flowchart for explaining the temperature increase process by the control device 50 according to a modification of the fourth embodiment. The control device 50 specifies the position of the nozzle based on the number n of the nozzle 80 that ejects the ink specified in the print job (S351). The processes of S352 to S359 are similar to the processes of S342 to S349 shown in FIG. 32. The switch control signal in S355 includes first selection information indicating the selection of the b switch 54b and second selection information indicating the selection of the synchronization signal S2. In this embodiment, if the position of the nozzle 80 is specified to be the first position in S341, the second selection information indicates the selection of the synchronization signal S2d. If the position of the nozzle 80 is specified to be the second position, the second selection information indicates the selection of the synchronization signal S2e.

[0094] In the printing device according to the fourth embodiment, the drive waveform signal to be separated by the b switch 54b is determined based on the characteristics of the ink (liquid) ejected by the nozzle 80 or the position of the nozzle 80 ejecting the ink (liquid), thereby controlling the temperature rise of the separation circuit 50b according to the ink characteristics or the ease of the temperature rise of the separation circuit 50b. This makes it possible to maintain a constant quality of liquid ejection by the nozzle 80.

[0095] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and equivalents to the scope of the claims. In addition, the independent claims and dependent claims described in the claims can be combined with each other in all combinations regardless of the reference format. Furthermore, the claims use a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this. A format in which a multiple claim (multi-multi claim) that references at least one multiple claim may be used. [Explanation of symbols]

[0096] 1 Printing device 2 Platen 3. Ink ejection device 4 Transport roller 5 Transport roller 6 Carriage 7 Subtank 8 Inkjet head 10 Circulation pump 50 Control device 50a multiplex circuit 50b isolation circuit 51 Control circuit 52 D / A Converter 53 Amplifier 54 Switch group (separation circuit) 54a switch (a switch) 54b b switch 55 Memory 71 Ink chamber (liquid chamber) 80 Nozzles 81 Pressure Chamber 82 Diaphragm 83 Piezoelectric 84 1st common electrode 85 Individual electrodes 86 2nd common electrode 87 Nozzle Plate 88 Actuator 100 External device 200 Recording Paper 501 Recording media 551 Mapping Information Table 552 Ink Table 553 Specific Ink Condition Table 554 Temperature Rise Score Table 555 Temperature Rise Table 556 Ink Characteristics Table L1 signal line S2 sync signal SL1 Switch control signal line SL2 Sync signal line

Claims

1. A nozzle capable of ejecting liquid by an energy imparting element; a multiplexing circuit that generates a time division multiplexed signal capable of transmitting the first data and the second data on a single signal line, the first data and the second data being arranged based on at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform such that a third portion that is a part of the second drive waveform is between a first portion that is a part of the first drive waveform and a second portion that is a part of the first drive waveform, and the second portion is between the third portion and a fourth portion that is a part of the second drive waveform; a separation circuit including a switch to which the time division multiplexed signal is input and which separates, based on a synchronization signal, a first drive waveform signal indicating the first drive waveform or a second drive waveform signal indicating the second drive waveform from the time division multiplexed signal; A printing device comprising: driving the nozzle to eject liquid based on the first drive waveform signal separated by the switch; The temperature of the separation circuit is increased by driving the nozzle to a non-ejection state based on the second drive waveform signal separated by the switch. Printing device.

2. The switches include an a switch and a b switch, The a switch separates the first drive waveform signal to eject liquid from the nozzle; By causing the b switch to separate the second driving waveform signal, the temperature of the separation circuit is increased. The printing device of claim 1 .

3. The switch includes a plurality of the b switches. The printing device according to claim 2 .

4. The resistance value of the b switch is different from the resistance value of the a switch. The printing device according to claim 2 .

5. Before liquid is ejected in a printing process, the switch is caused to separate the second driving waveform signal, thereby increasing the temperature of the separation circuit.

3. The printing device according to claim 1 or 2.

6. When the image quality required during printing is equal to or higher than a predetermined frequency, the printing process is started after the temperature of the separation circuit reaches or exceeds a predetermined value.

3. The printing device according to claim 1 or 2.

7. When the frequency of liquid ejection in the printing process is less than a predetermined frequency, the temperature of the separation circuit is increased by causing the switch to separate the second driving waveform signal.

3. The printing device according to claim 1 or 2.

8. the multiplexing circuit generates the time division multiplexed signal in which a fifth portion, which is a part of the third drive waveform, is between the third portion and the second portion, and the fourth portion is arranged between the second portion and a sixth portion, which is a part of the third drive waveform, based on third data indicating a third drive waveform different from the first drive waveform and the second drive waveform; the switch separates a third drive waveform signal indicating the third drive waveform from the time division multiplexed signal based on a synchronization signal; The temperature of the separation circuit is increased by driving the nozzle to a non-ejection state based on the third drive waveform signal separated by the switch.

3. The printing device according to claim 1 or 2.

9. When the liquid ejected from the nozzle has a first characteristic, the switch separates the second driving waveform signal; When the liquid ejected from the nozzle has a second characteristic, the switch separates the third driving waveform signal. The printing device according to claim 8.

10. When the position of the nozzle is in a first position, the switch isolates the second driving waveform signal; When the nozzle is in a second position, the switch separates the third driving waveform signal. The printing device according to claim 8.

11. the liquid is a specific ink or a non-specific ink, When the nozzle ejects the non-specific ink, the switch separates the second driving waveform signal, thereby increasing the temperature of the separation circuit.

3. The printing device according to claim 1 or 2.

12. The specific ink contains 1 to 10% by mass of resin fine particles. The printing device of claim 11.

13. The specific ink contains 10 to 30% by mass of an organic solvent having a saturated vapor pressure of 0.03 hPa or more at 20° C. The printing device of claim 11.

14. The specific ink contains 2 to 10% by mass of a solid coloring material. The printing device of claim 11.

15. The specific ink contains pigment particles having an average particle size of 150 nm or more. The printing device of claim 11.

16. The specific ink contains 60% by mass or less of water. The printing device of claim 11.

17. A control unit that determines the degree of temperature rise of the separation circuit in accordance with the characteristics of the liquid discharged from the nozzle. Equipped 3. The printing device according to claim 1 or 2.

18. a liquid chamber in which the liquid is stored; a circulation pump that pumps the liquid from the liquid chamber to the nozzle; a circulation path for causing ink not ejected from the nozzle to flow into the liquid chamber; Equipped 3. The printing device according to claim 1 or 2.

19. A nozzle capable of ejecting liquid by an energy imparting element; a multiplexing circuit that generates a time division multiplexed signal capable of transmitting the first data and the second data on a single signal line, the first data and the second data being arranged based on at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform such that a third portion that is a part of the second drive waveform is between a first portion that is a part of the first drive waveform and a second portion that is a part of the first drive waveform, and the second portion is between the third portion and a fourth portion that is a part of the second drive waveform; a separation circuit including a switch to which the time division multiplexed signal is input and which separates, based on a synchronization signal, a first drive waveform signal indicating the first drive waveform or a second drive waveform signal indicating the second drive waveform from the time division multiplexed signal; A method for controlling a printing device comprising: driving the nozzle to eject liquid based on the first drive waveform signal separated by the switch; The temperature of the separation circuit is increased by driving the nozzle to a non-ejection state based on the second drive waveform signal separated by the switch. A method for controlling a printing device.

20. A nozzle capable of ejecting liquid by an energy imparting element; a multiplexing circuit that generates a time division multiplexed signal capable of transmitting the first data and the second data on a single signal line, the first data and the second data being arranged based on at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform such that a third portion that is a part of the second drive waveform is between a first portion that is a part of the first drive waveform and a second portion that is a part of the first drive waveform, and the second portion is between the third portion and a fourth portion that is a part of the second drive waveform; a separation circuit including a switch to which the time division multiplexed signal is input and which separates, based on a synchronization signal, a first drive waveform signal indicating the first drive waveform or a second drive waveform signal indicating the second drive waveform from the time division multiplexed signal; A program for controlling a printing device comprising: driving the nozzle to eject liquid based on the first drive waveform signal separated by the switch; The temperature of the separation circuit is increased by driving the nozzle to a non-ejection state based on the second drive waveform signal separated by the switch. A computer program that controls a printing device.

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