Printing apparatus, printing method, and computer program

Abstract

To provide a printing apparatus or the like capable of shortening time required for voltage applied to an actuator to reach desired voltage after a switch is closed.SOLUTION: A printing apparatus includes: a multiplexing unit that generates a time division multiplexed signal that can be transmitted over a single signal line from first data that indicates a first drive waveform and second data that indicates a second drive waveform different from the first drive waveform; and a separation unit that separates a first drive waveform signal that indicates the first drive waveform or a second drive waveform signal that indicates the second drive waveform from the generated time division multiplexed signal, where the first data includes first voltage data that indicates target voltage for each portion of the first drive waveform, and the second data includes second voltage data that indicates target voltage for each portion of the second drive waveform, the multiplexing unit includes a change unit that changes the target voltage of the first voltage data or the second voltage data, and when the target voltage is changed, a time division multiplexed signal based on the first voltage data that indicates the changed target voltage or the second voltage data that indicates the changed target voltage is transmitted to the separation unit.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present technology relates to a printing apparatus, a printing method, and a computer program that perform printing by discharging a liquid from a nozzle.

Background Art

[0002] A printing apparatus has been proposed that includes a control unit that generates a time-division multiplexed signal based on a plurality of data corresponding to a plurality of drive waveforms, an actuator having nozzles, and a switch provided between the control unit and the actuator. The control unit transmits a time-division multiplexed signal and an open / close signal indicating open / close timing to the switch. The switch opens and closes based on the open / close signal, extracts a signal corresponding to a desired drive waveform from the time-division multiplexed signal, and supplies it to the actuator. The actuator is driven by the extracted drive waveform.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The voltage applied to the actuator may take a long time to reach a desired voltage after the switch closes, and the drive waveform of the actuator may deviate significantly from the desired drive waveform.

[0005] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a printing apparatus, a printing method, and a computer program capable of shortening the time from when the switch closes until the voltage applied to the actuator reaches a desired voltage.

Means for Solving the Problems

[0006] A printing apparatus according to an embodiment of the present disclosure includes a nozzle that discharges a liquid by an energy applying element, a storage unit that stores first data indicating at least a first drive waveform and second data indicating a second drive waveform different from the first drive waveform, and at least the first data and the second data are acquired from the storage unit, and a third part that is a part of the second drive waveform is provided between a first part that is a part of the first drive waveform and a second part that is a part of the first drive waveform, and the second part is provided between the third part and a fourth part that is a part of the second drive waveform. A multiplexing unit that generates a time-division multiplexed signal capable of transmitting the first data and the second data on one signal line, and a separation unit that separates 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 generated by the multiplexing unit. The energy applying element is driven by the first drive waveform signal or the second drive waveform signal, the first data includes first voltage data indicating the target voltage of each part of the first drive waveform, the second data includes second voltage data indicating the target voltage of each part of the second drive waveform, the multiplexing unit includes a changing unit that changes the target voltage of the first voltage data or the second voltage data acquired from the storage unit, and when the target voltage is changed by the changing unit, the time-division multiplexed signal based on the first voltage data indicating the changed target voltage or the second voltage data indicating the changed target voltage is transmitted to the separation unit.

[0007] The printing method according to an embodiment of the present disclosure is a printing method of a printing apparatus including a nozzle that discharges a liquid by an energy applying element and a storage unit that stores first data indicating at least a first driving waveform and second data indicating a second driving waveform different from the first driving waveform. The method includes acquiring at least the first data and the second data from the storage unit, arranging such that there is a third portion that is a part of the second driving waveform between a first portion that is a part of the first driving waveform and a second portion that is a part of the first driving waveform, and there is the second portion between the third portion and a fourth portion that is a part of the second driving waveform; generating a time-division multiplexed signal capable of transmitting the first data and the second data on one signal line; separating, from the generated time-division multiplexed signal, a first driving waveform signal indicating the first driving waveform or a second driving waveform signal indicating the second driving waveform; driving the energy applying element with the first driving waveform signal or the second driving waveform signal; the first data including first voltage data indicating target voltages of respective portions of the first driving waveform; the second data including second voltage data indicating target voltages of respective portions of the second driving waveform; changing the target voltage of the first voltage data or the second voltage data acquired from the storage unit; and separating the first driving waveform signal or the second driving waveform signal from the time-division multiplexed signal based on the first voltage data indicating the changed target voltage or the second voltage data indicating the changed target voltage when the target voltage is changed.

[0008] A computer program according to an embodiment of the present disclosure is a computer program executed by a printing apparatus including a nozzle that discharges a liquid by an energy applying element and a storage unit that stores first data indicating at least a first driving waveform and second data indicating a second driving waveform different from the first driving waveform. The printing apparatus acquires at least the first data and the second data from the storage unit, and a third portion that is a part of the second driving waveform is provided between a first portion that is a part of the first driving waveform and a second portion that is a part of the first driving waveform, and the second portion is provided between the third portion and a fourth portion that is a part of the second driving waveform. The first data and the second data are arranged so as to be able to be transmitted on one signal line, and a time-division multiplexed signal is generated. From the generated time-division multiplexed signal, a first driving waveform signal indicating the first driving waveform or a second driving waveform signal indicating the second driving waveform is separated. The energy applying element is driven by the first driving waveform signal or the second driving waveform signal. The first data includes first voltage data indicating a target voltage of each portion of the first driving waveform, the second data includes second voltage data indicating a target voltage of each portion of the second driving waveform, the target voltage of the first voltage data or the second voltage data acquired from the storage unit is changed, and when the target voltage is changed, a process of separating the first driving waveform signal or the second driving waveform signal from the time-division multiplexed signal based on the first voltage data indicating the changed target voltage or the second voltage data indicating the changed target voltage is executed.

Effect of the Invention

[0009] In a printing apparatus, a printing method, and a computer program according to an embodiment of the present disclosure, the multiplexing unit can change the target voltage of each portion of the driving waveform and shorten the time until the voltage applied to the energy applying element reaches a desired voltage.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 8

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Figure 11

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Figure 16

Figure 17

Embodiments for Carrying Out the Invention

[0011] (Embodiment 1) Hereinafter, the present invention will be described based on the drawings showing a printing apparatus according to Embodiment 1. FIG. 1 is a plan view schematically showing the printing apparatus. In the following description, the front, rear, left, and right shown in FIG. 1 are used. The front-rear direction corresponds to the conveyance direction, and the left-right direction corresponds to the scanning direction. Also, the front side of FIG. 1 corresponds to the upper side, the back side corresponds to the lower side, and the up-down direction is also used.

[0012] As shown in FIG. 1, the printing apparatus 1 includes a platen 2, an ink ejection device 3, conveyance rollers 4, 5, etc. On the upper surface of the platen 2, a recording sheet 200, which is a recording medium, is placed. The ink ejection device 3 ejects ink onto the recording sheet 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, and the like.

[0013] On the upper side of the platen 2, two guide rails 11, 12 extending left and right for guiding the carriage 6 are provided. An endless belt 13 extending 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, 12 and reciprocates in the scanning direction in the region facing the platen 2. More specifically, the carriage 6 moves the heads from one position to another from left to right in the scanning direction in a state of supporting the four inkjet heads 8, and performs a first movement of moving the heads from another position to a certain position from right to left in the scanning direction.

[0014] Between the guide rails 11, 12, a cap 20 and a flushing receiver 21 are provided. The cap 20 and the flushing receiver 21 are arranged below the ink ejection device 3. The cap 20 is arranged at the right end of the guide rails 11, 12, and the flushing receiver 21 is arranged at the left end of the guide rails 11, 12. Note that the cap 20 and the flushing receiver 21 may be arranged in reverse left and right.

[0015] The sub-tank 7 and the four inkjet heads 8 are mounted on the carriage 6 and reciprocate in the scanning direction together with the carriage 6. The sub-tank 7 is connected to the cartridge holder 15 via the tube 17. One or more ink cartridges 16 of one or more colors (4 colors in this embodiment) are mounted on the cartridge holder 15. Examples of the four colors include black, yellow, cyan, and magenta.

[0016] Inside the sub-tank 7, four ink chambers (not shown) are formed. The four colors of ink supplied from the four ink cartridges 16 are respectively stored in the four ink chambers.

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

[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 the ink chamber via a tube or the like. A circulation pump is installed between the ink supply port and the ink chamber.

[0019] The ink sent out from the ink chamber by the circulation pump flows into the inkjet head 8 through the ink supply port and is discharged from the nozzles 80. The ink that is not discharged from the nozzles 80 returns to the ink chamber through the ink discharge port. The ink circulates between the ink chamber and the inkjet head 8. While moving in the scanning direction together with the carriage 6, the four inkjet heads 8 discharge the four colors of ink supplied from the sub-tank 7 onto the recording paper 200.

[0020] As shown in FIG. 1, the conveyance roller 4 is disposed on the upstream side (rear side) in the conveyance direction with respect to the platen 2. The conveyance roller 5 is disposed on the downstream side (front side) in the conveyance direction with respect to the platen 2. The two conveyance rollers 4 and 5 are driven synchronously by a motor (not shown). The two conveyance rollers 4 and 5 convey the recording paper 200 placed on the platen 2 in the conveyance direction orthogonal to the scanning direction. The printing apparatus 1 includes a control device 50. The control device 50 includes a CPU or a logic circuit (e.g., FPGA), a memory 55 such as a nonvolatile memory and a RAM. The control device 50 receives a print job and drive waveform data from an external device 100 and stores them in the memory 55. The memory 55 corresponds to a storage unit. The control device 50 controls the driving of the ink ejection device 3, the conveyance roller 4, etc. based on the print job and executes a printing process.

[0021] FIG. 2 is a schematic 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 constitute a plurality of pressure chamber rows. A diaphragm 82 is formed above the pressure chamber 81. A layered piezoelectric body 83 is formed above the diaphragm 82. A first common electrode 84 is formed between the piezoelectric body 83 and the diaphragm 82 above each pressure chamber 81.

[0022] A second common electrode 86 is provided inside the piezoelectric body 83. The second common electrode 86 is disposed above each pressure chamber 81 and above the first common electrode 84. The second common electrode 86 is disposed at a position not facing the first common electrode 84. Individual electrodes 85 are formed on the upper surface of the piezoelectric body 83 above each pressure chamber 81. The individual electrodes 85, the first common electrode 84, and the second common electrode 86 face each other vertically with the piezoelectric body 83 interposed therebetween. The diaphragm 82, the piezoelectric body 83, the first common electrode 84, the individual electrodes 85, and the second common electrode 86 constitute an actuator 88.

[0023] A nozzle plate 87 is provided at the lower part of each pressure chamber 81. A plurality of nozzles 80 penetrating vertically are formed in the nozzle plate 87. Each nozzle 80 is disposed below each pressure chamber 81. The plurality of nozzles 80 constitute a plurality of nozzle rows extending along the pressure chamber row.

[0024] The first common electrode 84 is connected to the COM terminal, which is grounded in this embodiment, and the second common electrode 86 is connected to the VCOM terminal. The VCOM voltage is higher than the COM voltage. The individual electrode 85 is connected to a switch group 54 (see FIG. 3). A High or Low voltage is applied to the individual electrode 85, causing the piezoelectric body 83 to deform and the diaphragm 82 to vibrate. Due to the vibration of the diaphragm 82, ink is ejected from the pressure chamber 81 through the nozzle 80.

[0025] FIG. 3 is a block diagram of the control device 50. The control device 50 includes a control circuit 51, a D / A converter 52, an amplifier 53, a switch group 54, and a memory 55. Drive waveform data is stored in the memory 55. The drive waveform data is digital data indicating the voltage waveform applied to the individual electrode 85, that is, the drive waveform for driving the actuator 88, and is quantized data. In this embodiment, drive waveform data Da, Db, and Dc are stored in the memory 55.

[0026] The D / A converter 52 converts a digital signal into an analog signal. The amplifier 53 is, for example, an analog amplifier that amplifies the analog signal. The switch group 54 includes a plurality of nth switches 54(n) (n = 1, 2,...). The nth switch 54(n) is constituted by, for example, an analog switch IC. One ends of the plurality of nth switches 54(n) are connected to the amplifier 53 via a common bus. The other end of each nth switch 54(n) is connected to each individual electrode 85 corresponding to the plurality of nozzles 80. The control circuit 51 transmits a selection signal S1 for selecting any one of the switches 54(n) and a synchronization signal S2 to the switch group 54. The synchronization signal S2 includes synchronization signals S2a, S2b, and S2c, which will be described later. The control circuit 51 transmits the selection signal S1 in association with any one of the synchronization signals S2a, S2b, or S2c, for example.

[0027] The first capacitor 89a is formed by the individual electrode 85, the first common electrode 84, and the piezoelectric body 83. The second capacitor 89b is formed by the individual electrode 85, the second common electrode 86, and the piezoelectric body 83.

[0028] FIG. 4 is an explanatory diagram for explaining an example of the drive waveforms A, B, and C. The drive waveforms A, B, and C are waveforms for deforming the piezoelectric body 83, vibrating the diaphragm 82, and causing the ink in the pressure chamber 81 to pass through the descender and then be ejected through the nozzle 80 due to the vibration of the diaphragm 82. For example, the drive waveform A is a waveform for ejecting a large droplet, the drive waveform B is a waveform for ejecting a medium droplet, and the drive waveform C is a waveform for ejecting a large droplet, but the ejection timing is different from that of the drive waveform A.

[0029] In FIG. 4, the right side shows a state in the past compared to the left side. The same applies to FIGS. 5 to 11 and FIG. 13. The drive waveform data Da is the quantized data of the drive waveform A, the drive waveform data Db is the quantized data of the drive waveform B, and the drive waveform data Dc is the 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.

[0030] FIG. 5 is an explanatory diagram for explaining an example of time-series data, an analog signal, and a time-division multiplexed signal. In FIG. 5, A, B, and C indicate corresponding to drive waveforms A, B, and C, respectively. When driving the actuator 88, the control circuit 51 accesses the memory 55 to obtain drive waveform data Da, Db, and Dc, and creates time-series data. The time-series data is obtained by arranging data Ak, Bk, and Ck in order with a time interval Δt, and is arranged in the order of A0, B0, C0, A1, B1, C1, ···, Ak, Bk, Ck. The time-series data is a digital signal. Note that the time interval Δt is the reciprocal of a predetermined sampling frequency. The quantized data Ak, Bk, and Ck are arranged in the order of A0, B0, C0, A1, B1, C1, ···, Ak, Bk, Ck at each time corresponding to the reciprocal of the predetermined sampling frequency. In other words, the data length of the quantized data Ak, Bk, and Ck is less than or equal to the length corresponding to the reciprocal of the predetermined sampling frequency.

[0031] Also, the quantized data A0 and the quantized data B0 are continuous, the quantized data B0 and the quantized data C0 are continuous, and the quantized data C0 and the quantized data A1 are continuous. That is, there is no quantized data C0, other quantized data, and data of other waveforms between the quantized data A0 and the quantized data B0. Also, there is no quantized data A0, other quantized data, and data of other waveforms between the quantized data B0 and the quantized data C0. Also, there is no quantized data B0, other quantized data, and data of other waveforms between the quantized data C0 and the quantized data A1. Note that the sampling frequency is 24 MHz, and the data length of the quantized data Ak, Bk, and Ck is approximately 41 nS.

[0032] The control circuit 51 outputs time-series data to the D / A converter 52. As shown in FIG. 5, 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. For example, the switch group 54 is composed of a plurality of semiconductor switches. The plurality of semiconductor switches receive the amplified analog signal. As shown in FIG. 5, the analog signal amplified by the amplifier 53 constitutes a time-division multiplexed signal.

[0033] That is, the time-division multiplexed signal is not an analog signal corresponding only to the data Ak, an analog signal corresponding only to the data Bk, or an analog signal corresponding only to the data Ck. Further, the time-division multiplexed signal is at least an analog signal corresponding to a set of a total of three data, one data Ak, one data Bk, and one data Ck, and an analog signal corresponding to a set of a total of three data, one data Ak+1, one data Bk+1, and one data Ck+1, which are signals continuous in time series.

[0034] For example, in FIG. 5, there is one time-division multiplexed signal. In FIG. 5, although the analog signal corresponding to the data C0 seems to be isolated, it is an analog signal corresponding to a set of a total of three data, data A0, data B0, and data C0, and when data A0 and data B0 are in the zero state, it is a result of being continuous in time series with an analog signal corresponding to a set of a total of three data, data A1, data B1, and data C1, and when data A1 is in the zero state. Also, although the analog signal corresponding to the pair of data Ak and data Bk seems to be isolated, it is an analog signal corresponding to a set of a total of three data, data Ak−1, data Bk−1, and data Ck−1, and when data Ck−1 is in the zero state, it is a result of being continuous in time series with an analog signal corresponding to a set of a total of three data, data Ak, data Bk, and data Ck. The reason why the analog signal corresponding to the pair of data Ak−1 and data Bk−1 also seems to be isolated is the same. Therefore, the analog signal in FIG. 5 can be treated as one time-division multiplexed signal.

[0035] In the time-division multiplexed signal, if the portion corresponding to data Ak-1 is the first portion, the portion corresponding to data Ak is the second portion, the portion corresponding to data Bk-1 is the third portion, and the portion corresponding to data Bk is the fourth portion, there is a third portion between the first portion and the second portion, and there is a second portion between the third portion and the fourth portion. In other words, the first portion and the third portion are continuous, the third portion and the second portion are continuous, and the second portion and the fourth portion are continuous. That is, in the time-division multiplexed signal, there are no second portion, fourth portion, and other waveforms between the first portion and the third portion.

[0036] Also, in the time-division multiplexed signal, there are no first portion, fourth portion, and other waveforms between the third portion and the second portion. Also, in the time-division multiplexed signal, there are no first portion, third portion, and other waveforms between the second portion and the fourth portion. Note that the same relationship holds between data Ak and Ck, and the same relationship holds between data Bk and Ck. The control circuit 51, D / A converter 52, amplifier 53, and memory 55 constitute a multiplexing section. One time-division multiplexed signal fits within one ejection drive cycle. For example, if the ejection drive frequency (injection frequency) is 100 kHz, one ejection drive cycle (injection cycle) is 10 μS, and one time-division multiplexed signal has a length of less than 10 μS. It is preferable that there are three or more of data Ak, data Bk, and data Ck in one time-division multiplexed signal. The reason will be described later.

[0037] As shown in the central figure of FIG. 5, let the analog signal corresponding to data Ck-4 be AS(Ck-4), the analog signal corresponding to data Ak-3 be AS(Ak-3), the analog signal corresponding to data Bk-3 be AS(Bk-3), and the analog signal corresponding to data Ck-3 be AS(Ck-3). The value of data Ak-3 is larger than that of data Ck-4. The value of data Bk-3 is smaller than that of data Ak-3.

[0038] AS(Ak-3) reaches the value of data Ak-3 after a predetermined time has elapsed from the value of AS(Ck-4). AS(Bk-3) reaches the value of data Bk-3 after a predetermined time has elapsed from the value of AS(Ak-3). AS(Ck-3) reaches the value of data Ck-3 after a predetermined time has elapsed from the value of AS(Bk-3). That is, the analog signal reaches the value of the digital signal after a predetermined delay time has elapsed from the start point of the conversion from the digital signal to the analog signal. As shown in the bottom figure of Fig. 5, the same applies to the time-division multiplexed signal obtained by amplifying the analog signal.

[0039] Fig. 6 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. In Fig. 6, t1a indicates the start point of turn-on of the drive waveform signal Pa indicating the drive waveform A, t2a indicates the point in time when the drive waveform signal Pa reaches the target voltage, and t3a indicates the end point of turn-on of the drive waveform signal Pa. t1b indicates the start point of turn-on of the drive waveform signal Pb indicating the drive waveform B, t2b indicates the point in time when the drive waveform signal Pb reaches the target voltage, and t3b indicates the end point of turn-on of the drive waveform signal Pb. t1c indicates the start point of turn-on of the drive waveform signal Pc indicating the drive waveform C, t2c indicates the point in time when the drive waveform signal Pc reaches the target voltage, and t3c indicates the end point of turn-on of the drive waveform signal Pc. In Fig. 6, the drive waveform signals other than the drive waveform signal Pa at the position corresponding to the synchronization signal S2a are drive waveform signals indicating the drive waveform A, similar to the drive waveform signal Pa, and include t1a, t2a, and t3a. Also, the drive waveform signals other than the drive waveform signal Pb at the position corresponding to the synchronization signal S2b are drive waveform signals indicating the drive waveform B, similar to the drive waveform signal Pb, and include t1b, t2b, and t3b. Also, the drive waveform signals other than the drive waveform signal Pc at the position corresponding to the synchronization signal S2c are drive waveform signals indicating the drive waveform C, similar to the drive waveform signal Pc, and include t1c, t2c, and t3c.

[0040] The time between t1a and t2a, the time between t1b and t2b, and the time between t1c and t2c are the so-called transient response times, each becoming a delay time td. The delay time td is stored in advance in the memory 55. t1a is the rising edge (on-time) of the pulse of the synchronization signal S2a. t1b is the rising edge (on-time) of the pulse of the synchronization signal S2b. t1c is the rising edge (on-time) of the pulse of the synchronization signal S2c. t3a is the falling edge of the pulse of the synchronization signal S2a. t3b is the falling edge of the pulse of the synchronization signal S2b. t3c is the falling edge of the pulse of the synchronization signal S2c.

[0041] A time interval Δt is provided between the rising edge of the pulse of the synchronization signal S2a and the rising edge of the pulse of the synchronization signal S2b. Also, a time interval Δt is provided between the rising edge of the pulse of the synchronization signal S2b and the rising edge of the pulse of the synchronization signal S2c, and a time interval Δt is provided between the rising edge of the pulse of the synchronization signal S2c and the rising edge of the pulse of the synchronization signal S2a. The time interval Δt corresponds to the periods of the respective drive waveform signals Pa, Pb, and Pc.

[0042] As described above, the data Ak, Bk, and Ck that constitute the time-series data are arranged in order with a time interval Δt provided. Also, after the elapse of the delay time td, the drive waveform signal Pa reaches the target voltage (a value corresponding to the value of the data Ak). After the elapse of the delay time td, the drive waveform signal Pb reaches the target voltage (a value corresponding to the value of the data Bk). After the elapse of the delay time td, the drive waveform signal Pc reaches the target voltage (a value corresponding to the value of the data Ck).

[0043] Therefore, when accessing the time-division multiplexed signal at the rising edge time t1a of the pulse of the synchronization signal S2a, after the elapse of the delay time td, a drive waveform signal Pa corresponding to the data Ak and indicating the drive waveform A can be obtained. When accessing the time-division multiplexed signal at the rising edge time t1b of the pulse of the synchronization signal S2b, after the elapse of the delay time td, a drive waveform signal Pb corresponding to the data Bk and indicating the drive waveform B can be obtained. When accessing the time-division multiplexed signal at the rising edge time t2c of the pulse of the synchronization signal S1c, after the elapse of the delay time td, a drive waveform signal Pc corresponding to the data Ck and indicating the drive waveform C can be obtained. In other words, one n-th switch 54(n) receives one type of time-division multiplexed signal and separates any one of the drive waveform signal Pa, the drive waveform signal Pb, and the drive waveform signal Pc.

[0044] The switch group 54 selects the n-th switch 54(n) indicated by the selection signal S1 and selects the synchronization signal S2a, S2b, or S2c associated with the selection signal S1. The switch group 54 opens and closes the selected n-th switch 54(n) at the opening and closing timing indicated by the selected synchronization signal S2a to S2c. In other words, the switch group 54 opens and closes the n-th switch 54(n) at a predetermined sampling frequency. Note that the opening of the n-th switch 54(n) indicates the off state of the n-th switch 54(n), and the closing of the n-th switch 54(n) indicates the on state of the n-th switch 54(n).

[0045] FIG. 7 is a schematic diagram of a drive waveform input to the actuator 88 by opening and closing the n-th switch 54(n). When the synchronization signal S2a is selected, the switch group 54 closes the n-th switch 54(n) when the pulse of the synchronization signal S2a is in the high level section, and opens the n-th switch 54(n) when the pulse of the synchronization signal S2a is in the low level section. The first capacitor 89a and the second capacitor 89b hold the charge applied to the individual electrode 85 when the n-th switch 54(n) is closed, and as shown in FIG. 7, 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 at a predetermined sampling frequency, and the actuator 88 is driven by the drive waveform signal Pa. Note that three or more pieces of data Ak are required to represent the unevenness of the drive waveform signal Pa. The drive waveform signal Pa is an analog signal.

[0046] When the synchronization signal S2b is selected, the switch group 54 closes the n-th switch 54(n) when the pulse of the synchronization signal S2b is in the high level section, and opens the n-th switch 54(n) when the pulse of the synchronization signal S2b is in the low level section. The first capacitor 89a and the second capacitor 89b hold the charge applied to the individual electrode 85 when the n-th switch 54(n) is closed, and as shown in FIG. 7, 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 at a predetermined sampling frequency, and the actuator 88 is driven by the drive waveform signal Pb. Note that three or more pieces of data Bk are required to represent the unevenness of the drive waveform signal Pb. The drive waveform signal Pb is an analog signal.

[0047] When the synchronization signal S2c is selected, the switch group 54 closes the n-th switch 54(n) when the pulse of the synchronization signal S2c is in the high level section, and opens the n-th switch 54(n) when the pulse of the synchronization signal S2c is in the low level section. The first capacitor 89a and the second capacitor 89b hold the charge applied to the individual electrode 85 when the n-th switch 54(n) is closed, and as shown in FIG. 7, the drive waveform C1 is input to the actuator 88. In other words, at a predetermined sampling frequency, 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. Note that three or more data Ck are required to represent the unevenness of the drive waveform signal Pc. The drive waveform signal Pc is an analog signal.

[0048] The predetermined sampling frequency is equal to or higher than the resonance frequency of the inkjet head 8. The resonance frequency of the inkjet head 8 is the resonance frequency when the pressure chamber 81 is not filled with ink (liquid), or the resonance frequency when the pressure chamber 81 is filled with ink. For example, when the resonance frequency of the inkjet head 8 when the pressure chamber 81 is not filled with ink is 100 kHz, the resonance frequency of the inkjet head 8 when the pressure chamber 81 is filled with ink is less than 100 kHz. Specifically, the resonance frequency of the inkjet head 8 when the pressure chamber 81 is filled with ink is 90 kHz. That is, the resonance frequency of the inkjet head 8 when the pressure chamber 81 is not filled with ink is higher than the resonance frequency of the inkjet head 8 when the pressure chamber 81 is filled with ink. In the following description, the n-th switch 54(n) is simply referred to as the switch 54(n).

[0049] FIG. 8 is a graph for explaining the relationship between the number of closing switches 54(n) and the delay time. In FIG. 8, graph W1 shows the voltage applied to actuator 88 when the number of closing switches 54(n) is singular, and Wn1 shows the voltage applied to each actuator 88 when the number of closing switches 54(n) is plural. ts indicates the rising points t1a, t1b, t1c of the pulses of the synchronization signal, that is, the turn-on start points t1a, t1b, t1c of the drive waveform signals Pa, Pb, Pc, and te indicates the falling point of the pulse of the synchronization signal, that is, the turn-on end points t3a, t3b, t3c of the drive waveform signals Pa, Pb, Pc (see FIG. 6). V0 indicates the voltage applied to actuator 88 at time ts, and VP1 indicates the target voltage of the drive waveform signals Pa, Pb, Pc. The target voltage VP1 is greater than V0. t1 indicates the time when the voltage applied to actuator 88 reaches the target voltage VP1 when a singular switch 54(n) is closed. t2 indicates the time when the voltage applied to each actuator 88 reaches the target voltage VP1 when a plurality of switches 54(n) are closed.

[0050] As shown in FIG. 8, time points t1 and t2 are between time point ts and time point te, and time point t2 is after time point t1. For example, when a singular switch 54(n) is closed to select drive waveform signal Pa, the delay time td is |t1 - ts|, and when a plurality of switches 54(n) are closed to select drive waveform signal Pa, the delay time td is |t2 - ts|. That is, even when the same drive waveform signal Pa is selected, when the number of closing switches 54(n) is large, the delay time td becomes longer compared to the case when the number of closing switches 54(n) is small. When drive waveform signal Pb or Pc is selected, when the number of closing switches 54(n) is large, the delay time td becomes longer compared to the case when the number of closing switches 54(n) is small.

[0051] When the delay time td becomes long, the drive waveforms A1, B1, and C1 of the actuator 88 (see FIG. 7) may deviate significantly from the desired drive waveforms A, B, and C (see FIG. 4). Therefore, according to the number of closed switches 54(n), the target voltage is changed to suppress the increase in the delay time td even when the number of closed switches 54(n) is large. For example, when the control circuit 51 reads the time-series data Ak, Bk, and Ck from the memory 55 and the number of switches 54(n) that select, for example, the drive waveform signal Pa is equal to or greater than the threshold value, that is, when the number of closed switches 54(n) for selecting the drive waveform signal Pa is equal to or greater than the threshold value, the value of the acquired time-series data Ak, that is, the value corresponding to the target voltage VP1, is changed to the value corresponding to the target voltage VP2. The target voltage VP2 is greater than the target voltage VP1. The magnitude of the changed target voltage VP2 is less than the maximum output voltage of the amplifier 53.

[0052] Note that the threshold value and the target voltage VP2 are stored in the memory 55 in advance, for example. By outputting the value corresponding to the target voltage VP1 from the control circuit 51 to the D / A converter 52, the voltage applied to the actuator 88 becomes the target voltage VP1, and by outputting the value corresponding to the target voltage VP2 from the control circuit 51 to the D / A converter 52, the voltage applied to the actuator 88 becomes the target voltage VP2.

[0053] FIG. 9 is a graph for explaining the relationship between the number of closed switches 54(n), the target voltage, and the delay time. In FIG. 9, Wn2 is a graph showing the voltage applied to each actuator 88 when the target voltage is changed from VP1 to VP2 and the number of closed switches 54(n) is plural. In Wn2, the number of closed switches 54(n) is the same as in the case of Wn1. t3 indicates the time when the voltage applied to each actuator 88 reaches the target voltage VP1 when the target voltage is changed from VP1 to VP2 and a plurality of switches 54(n) are closed. The time point t3 is close to the time point t1. The time point ts constitutes the start time point, the time point te constitutes the end time point, and the time point t3 constitutes the intermediate time point.

[0054] As shown in FIG. 9, when the target voltage is changed from VP1 to VP2 and a plurality of switches 54(n) are closed to select the drive waveform signal Pa, the delay time td is |t3 - ts|. |t3 - ts| is a time close to |t1 - ts|. That is, when a plurality of switches 54(n) are closed, by changing the target voltage from VP1 to VP2, the time until the voltage applied to each actuator 88 becomes VP1, which is the target voltage of the drive waveform signal Pa, is close to the time until the voltage applied to the actuator 88 becomes VP1 when the target voltage is VP1 and a single switch 54(n) is closed. The delay time |t3 - ts| is shorter than the delay time |t2 - ts| when the target voltage is VP1 and a plurality of switches 54(n) are closed to select the drive waveform signal Pa.

[0055] As shown by the dashed line in FIG. 9, even after time point t3, when a plurality of switches 54(n) are closed, the voltage applied to the actuator 88 approaches the target voltage VP2. That is, it becomes larger than the target voltage VP1. It is desirable that the voltage applied to the actuator 88 be VP1, which is the target voltage of the drive waveform signal Pa. Therefore, at time point t3, that is, when the voltage applied to the actuator 88 becomes the target voltage VP1, the plurality of switches 54(n) open, that is, turn off. After the plurality of switches 54(n) open, each actuator 88 maintains the target voltage VP1. Time point t3 is measured in advance and stored in the memory 55. The control circuit 51 outputs an open signal to the plurality of switches 54(n) during the time between time point t3 and time point te. That is, during the time between time point t3 and time point te, the plurality of switches 54(n) turn off.

[0056] The shapes of the graphs Wn2 and W1 between time points ts and te are approximated. That is, in both cases of the graphs Wn2 and W1, the waveforms of the voltage applied to the actuator 88 are approximated.

[0057] Based on the target voltage VP1, when the number of switches 54(n) less than the threshold separates the drive waveform signal Pa from the time-division multiplexed signal, the absolute value of the difference between the first value of the parameters related to the liquid discharged from the nozzle 80, such as the liquid discharge speed, the liquid discharge volume, or the liquid discharge time, and the second value of the parameters when the number of switches 54(n) greater than or equal to the threshold separates the drive waveform signal Pa from the time-division multiplexed signal, is defined as the first absolute value. Based on the first value and the changed target voltage VP2, the absolute value of the difference between the first value and the third value of the parameters when the number of switches 54(n) greater than or equal to the threshold separates the drive waveform signal Pa from the time-division multiplexed signal is defined as the second absolute value. The ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more. In other words, the target voltage VP2 is determined such that the ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more.

[0058] In addition, even when the number of switches 54(n) greater than or equal to the threshold is closed to select the drive waveform signal Pb, the control circuit 51 changes the value of the acquired time-series data Bk, that is, the value corresponding to the target voltage VP1, to the value corresponding to the target voltage VP2, and outputs an open signal to a plurality of switches 54(n) after time point t3.

[0059] Based on the target voltage VP1, when the number of switches 54(n) less than the threshold separates the drive waveform signal Pb from the time-division multiplexed signal, the absolute value of the difference between the fourth value of the parameters related to the liquid discharged from the nozzle 80, such as the liquid discharge speed, the liquid discharge volume, or the liquid discharge time, and the fifth value of the parameters when the number of switches 54(n) greater than or equal to the threshold separates the drive waveform signal Pa from the time-division multiplexed signal, is defined as the third absolute value. Based on the fourth value and the changed target voltage VP2, the absolute value of the difference between the fourth value and the sixth value of the parameters when the number of switches 54(n) greater than or equal to the threshold separates the drive waveform signal Pb from the time-division multiplexed signal is defined as the fourth absolute value. The ratio of the absolute value of the difference between the third absolute value and the fourth absolute value to the third absolute value is 25% or more. In other words, the target voltage VP2 is determined such that the ratio of the absolute value of the difference between the third absolute value and the fourth absolute value to the third absolute value is 25% or more.

[0060] Also, even when selecting the drive waveform signal Pc by closing the switches 54(n) equal to or more than the threshold value, the control circuit 51 changes the value of the acquired time series data Ck, that is, the value corresponding to the target voltage VP1, to the value corresponding to the target voltage VP2, and outputs an open signal to the plurality of switches 54(n) after the time point t3. Also, the ratio of the absolute value of the difference between the third absolute value and the fourth absolute value to the third absolute value is 25% or more. In other words, the target voltage VP2 is determined so that the ratio of the absolute value of the difference between the third absolute value and the fourth absolute value to the third absolute value is 25% or more.

[0061] FIG. 10 is a graph for explaining the relationship between the number of switches 54(n) to be closed and the delay time. In FIG. 10, the graph W1 shows the voltage applied to the actuator 88 when the number of switches 54(n) to be closed is odd, and Wn1 shows the voltage applied to each actuator 88 when the number of switches 54(n) to be closed is plural. ts indicates the rising edge points t1a, t1b, t1c of the pulses of the synchronization signal, that is, the on-start points of the drive waveform signals Pa, Pb, Pc, and te indicates the falling edge points t3a, t3b, t3c of the pulses of the synchronization signal, that is, the on-end points of the drive waveform signals Pa, Pb, Pc. V1 indicates the voltage applied to the actuator 88 at the time point ts, and VP3 indicates the target voltage of the drive waveform signals Pa, Pb, Pc. The target voltage VP3 is smaller than V1. t1 indicates the time point when the voltage applied to the actuator 88 reaches the target voltage VP3 when a single switch 54(n) is closed. t2 indicates the time point when the voltage applied to each actuator 88 reaches the target voltage VP3 when a plurality of switches 54(n) are closed.

[0062] As shown in FIG. 10, time points t1 and t2 are time points between time point ts and time point te, and time point t2 is a time point after time point t1. For example, when a single switch 54(n) is closed to select the drive waveform signal Pa, the delay time td is |t1 - ts|, and when a plurality of switches 54(n) are closed to select the drive waveform signal Pa, the delay time td is |t2 - ts|. That is, even when the same drive waveform signal Pa is selected, when the number of switches 54(n) to be closed is large, the delay time td becomes longer compared to the case where the number of switches 54(n) to be closed is small. When selecting the drive waveform signal Pb or Pc, the delay time td also becomes longer when the number of switches 54(n) to be closed is large compared to the case where the number of switches 54(n) to be closed is small.

[0063] When the delay time td becomes long, there is a possibility that the drive waveforms A1, B1, C1 (see FIG. 7) of the actuator 88 deviate greatly from the desired drive waveforms A, B, C (see FIG. 4). Therefore, according to the number of switches 54(n) to be closed, the target voltage is changed to suppress the increase in the delay time td even when the number of switches 54(n) to be closed is large. For example, the control circuit 51 reads the time-series data Ak, Bk, Ck from the memory 55. For example, when the number of switches 54(n) for selecting the drive waveform signal Pa is equal to or greater than the threshold value, that is, when the number of switches 54(n) to be closed for selecting the drive waveform signal Pa is equal to or greater than the threshold value, the value of the acquired time-series data Ak, that is, the value corresponding to the target voltage VP3, is changed to the value corresponding to the target voltage VP4. The target voltage VP4 is smaller than the target voltage VP3. The magnitude of the changed target voltage VP4 is larger than the minimum output voltage of the amplifier 53.

[0064] The threshold value and the target voltage VP4 are stored in the memory 55 in advance, for example. By outputting the value corresponding to the target voltage VP3 from the control circuit 51 to the D / A converter 52, the voltage applied to the actuator 88 becomes the target voltage VP3, and by outputting the value corresponding to the target voltage VP4 from the control circuit 51 to the D / A converter 52, the voltage applied to the actuator 88 becomes the target voltage VP4.

[0065] FIG. 11 is a graph for explaining the relationship between the number of closed switches 54(n), the target voltage, and the delay time. In FIG. 11, Wn2 is a graph showing the voltage applied to each actuator 88 when the target voltage is changed from VP3 to VP4 and the number of closed switches 54(n) is plural. In Wn2, the number of closed switches 54(n) is the same as in the case of Wn1. t4 indicates the time point when the voltage applied to each actuator 88 reaches the target voltage VP3 when the target voltage is changed from VP3 to VP4 and a plurality of switches 54(n) are closed. The time point t4 is close to the time point t1.

[0066] As shown in FIG. 11, when the target voltage is changed from VP3 to VP4 and a plurality of switches 54(n) are closed to select the drive waveform signal Pa, the delay time td is |t4 - ts|. |t4 - ts| is a time close to |t1 - ts|. That is, when a plurality of switches 54(n) are closed, by changing the target voltage from VP3 to VP4, the time until the voltage applied to each actuator 88 becomes VP3, which is the target voltage of the drive waveform signal Pa, is close to the time until the voltage applied to the actuator 88 becomes VP3, which is the target voltage of the drive waveform signal Pa, when the target voltage is VP3 and a single switch 54(n) is closed. The delay time |t4 - ts| is shorter than the delay time |t2 - ts| when the target voltage is VP3 and a plurality of switches 54(n) are closed to select the drive waveform signal Pa.

[0067] As shown by the dashed line in FIG. 11, even after the time point t4, when a plurality of switches 54(n) are closed, the voltage applied to the actuator 88 approaches the target voltage VP4. That is, it becomes smaller than the target voltage VP3. It is desirable that the voltage applied to the actuator 88 be VP3, which is the target voltage of the drive waveform signal Pa. Therefore, at the time point t4, that is, at the time point when the voltage applied to the actuator 88 becomes the target voltage VP3, the plurality of switches 54(n) open. After the plurality of switches 54(n) open, each actuator 88 maintains the target voltage VP3. The time point t4 is measured in advance and stored in the memory 55. The control circuit 51 outputs an open signal to the plurality of switches 54(n) after the time point t4.

[0068] The shapes of graphs Wn2 and W1 between time point ts and time point te are approximate. That is, in both cases of graphs Wn2 and W1, the waveforms of the voltage applied to actuator 88 are of approximate shapes.

[0069] Based on target voltage VP3, when the number of switches 54(n) below the threshold separates drive waveform signal Pa from the time-division multiplexed signal, the absolute value of the difference between the first value of the parameters regarding the liquid discharged from nozzle 80, such as the liquid discharge speed, the liquid discharge volume, or the liquid discharge time, and the second value of the parameters when the number of switches 54(n) equal to or above the threshold separates drive waveform signal Pa from the time-division multiplexed signal, is defined as the first absolute value. Based on the first value and the changed target voltage VP4, the absolute value of the difference between the first value and the third value of the parameters when the number of switches 54(n) equal to or above the threshold separates drive waveform signal Pa from the time-division multiplexed signal is defined as the second absolute value. The ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more. In other words, target voltage VP4 is determined such that the ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more.

[0070] Even when multiple switches 54(n) are closed to select drive waveform signal Pb, control circuit 51 changes the value of the acquired time-series data Bk, that is, the value corresponding to target voltage VP3, to the value corresponding to target voltage VP4, and outputs an open signal to the multiple switches 54(n) after time point t3. Also, the ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more. In other words, target voltage VP4 is determined such that the ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more.

[0071] Also, even when selecting the drive waveform signal Pc by closing a plurality of switches 54(n), the control circuit 51 changes the value of the acquired time-series data Ck, that is, the value corresponding to the target voltage VP3, to the value corresponding to the target voltage VP4, and outputs an open signal to the plurality of switches 54(n) after time point t3. Also, the ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more. In other words, the target voltage VP4 is determined so that the ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more.

[0072] FIG. 12 is a flowchart for explaining the opening and closing process of the switch 54(n) by the control circuit 51. The control circuit 51 determines whether or not it has received a signal indicating the start of printing from the external device 100 (S1). If it is determined that the signal indicating the start of printing has not been received (S1: NO), the control circuit 51 returns the process to step S1. If it is determined that the signal indicating the start of printing has been received (S1: YES), the control circuit 51 acquires the time-series data Ak, Bk, and Ck (S2).

[0073] The control circuit 51 determines whether or not the number of switches 54(n) that separate the drive waveform signal Pa is equal to or greater than a threshold value in one discharge drive cycle (S3). If it is determined that the number of switches 54(n) that separate the drive waveform signal Pa is equal to or greater than the threshold value (S3: YES), the voltages indicated by the acquired time-series data Ak, that is, the target voltages VP1 and VP3, are changed to the target voltages VP2 and VP4 (S8). By changing the target voltages to VP2 and VP4, the analog signal is amplified as the target voltages VP2 and VP4 by the amplifier 53, and the time-division multiplexed signal amplified as the target voltages VP2 and VP4 is output from the amplifier 53 to the switch 54(n). Then, the time-division multiplexed signal amplified as the target voltages VP2 and VP4 is output to the actuator 88 via the switch 54(n). That is, the amplifier 53 outputs the time-division multiplexed signal amplified as the target voltages VP2 and VP4 to the actuator 88.

[0074] When it is determined that the number of switches 54(n) for separating the drive waveform signal Pa is less than the threshold value (S3: NO), that is, when it is determined that the number of switches 54(n) for separating the drive waveform signal Pa is less than the threshold value, or when the process of step S8 is executed, the control circuit 51 determines whether the number of switches 54(n) for separating the drive waveform signal Pb is greater than or equal to the threshold value in one discharge drive cycle (S4).

[0075] When it is determined that the number of switches 54(n) for separating the drive waveform signal Pb is greater than or equal to the threshold value (S4: YES), the voltages indicated by the acquired time-series data Bk, that is, the target voltages VP1 and VP3, are changed to the target voltages VP2 and VP4 (S9).

[0076] When it is determined that the number of switches 54(n) for separating the drive waveform signal Pb is less than the threshold value (S4: NO), that is, when it is determined that the number of switches 54(n) for separating the drive waveform signal Pb is less than the threshold value, or when the process of step S9 is executed, the control circuit 51 determines whether the number of switches 54(n) for separating the drive waveform signal Pc is greater than or equal to the threshold value in one discharge drive cycle (S5).

[0077] When it is determined that the number of switches 54(n) for separating the drive waveform signal Pc is greater than or equal to the threshold value (S5: YES), the voltages indicated by the acquired time-series data Ck, that is, the target voltages VP1 and VP3, are changed to the target voltages VP2 and VP4 (S10).

[0078] When it is determined that the number of switches 54(n) for separating the drive waveform signal Pc is less than the threshold (S5: NO), that is, when it is determined that the number of switches 54(n) for separating the drive waveform signal Pc is less than the threshold, or when the process of step S10 is executed, the control circuit 51 outputs the time-series data Ak, Bk, and Ck to the D / A converter 52 (S6), and in addition to the selection signal S1 and the synchronization signal S2, transmits the opening / closing signal of the switch 54(n) to the switch group 54 (S7). The transmission of the opening / closing signal of the switch 54(n) means that, for example, the control circuit 51 transmits a closing signal between the time points ts to t3 and t4, and transmits an opening signal between the time points t3, t4 to te (see FIGS. 9 and 11).

[0079] In steps S3, S4, and S5, when it is determined that the number of switches 54(n) for separating the drive waveform signals Pa, Pb, and Pc is less than the threshold (S3: NO, S4: NO, S5: NO), since the target voltages V1 and V3 have not been changed, in step S7, the control circuit 51 does not transmit the opening / closing signal of the switch 54(n), and only transmits the selection signal S1 and the synchronization signal S2.

[0080] In the printing apparatus 1 according to the first embodiment, the control circuit 51 can change the target voltages VP1 and Vp3 of each part of the drive waveforms A, B, and C, that is, the time-series data Ak, Bk, and Ck, to the target voltages VP2 and VP4, and can shorten the time until the voltage applied to the actuator 88 reaches the desired voltage.

[0081] In Embodiment 1, when the number of switches 54(n) that separate the drive waveform signals Pa, Pb, and Pc is equal to or greater than the threshold value, the target voltages VP1 and Vp3 are changed. However, when the number of switches 54(n) that separate the drive waveform signals Pa, Pb, and Pc is less than the threshold value, the target voltages VP1 and Vp3 may be changed. For example, even if the number of switches 54(n) that separate the drive waveform signals Pa, Pb, and Pc is odd, when the time until the voltage applied to the actuator 88 reaches the desired voltage is long, by changing the target voltages VP1 and Vp3 to the target voltages VP2 and VP4, it is possible to shorten the time until the voltage applied to the actuator 88 reaches the desired voltage.

[0082] (Embodiment 2) Hereinafter, the present invention will be described based on the drawings showing the printing apparatus 1 according to Embodiment 2. Among the configurations of the printing apparatus 1 according to Embodiment 2, the same configurations as those in Embodiment 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. FIG. 13 is a graph for explaining the relationship between the number of closed switches 54(n), the target voltage, and the delay time. In FIG. 13, the time point ts1 indicates the time points t2a, t2b, and t2c when the drive waveform signals Pa, Pb, and Pc reach the target voltage (see FIG. 6).

[0083] In Embodiment 1, the switch 54(n) closes from the time point ts, but in Embodiment 2, the switch 54(n) closes from the time point ts1. That is, the switch 54(n) is open during the time between the time point ts and the time point ts1. The time between the time point ts and the time point ts1 is the time between the time point t1a and the time point t2a, the time between the time point t1b and the time point t2b, or the time between the time point t1c and the time point t2c (see FIG. 6), and is the time when the drive waveform signals Pa, Pb, and Pc have not reached the target voltage. By opening the switch 54(n) during the time between the time point ts and the time point ts1, it is possible to avoid acquiring the voltage during the transient response until the target voltage is reached. Also in Embodiment 2, the switch 54(n) is open during the time between the time point t3 and the time point te. The time point ts constitutes the start time point, the time point te constitutes the end time point, the time point ts1 constitutes the first intermediate time point, and the time point t3 constitutes the second intermediate time point.

[0084] On the other hand, since the time for closing the switch 54(n) becomes shorter, for example, when the number of switches 54(n) that close is equal to or greater than the threshold as shown in the graph Wn1 of FIG. 13, there is a possibility that the voltage applied to the actuator 88 does not reach the target voltage VP1 even at the time point te (the falling edge of the pulse of the synchronization signal, that is, the end time of the ON state of the drive waveform signals Pa, Pb, and Pc). As shown in the graph W1 of FIG. 13, when the number of switches 54(n) that close is odd, the voltage applied to the actuator 88 reaches the target voltage VP1 at the time point te.

[0085] In the second embodiment, for example, when the number of switches 54(n) that select the drive waveform signal Pa is equal to or greater than the threshold, that is, when the number of switches 54(n) that close to select the drive waveform signal Pa is equal to or greater than the threshold, the value of the acquired time-series data Ak, that is, the value corresponding to the target voltage VP1, is changed to the value corresponding to the target voltage VP2. By changing the target voltage, the voltage applied to the actuator 88 reaches the target voltage VP1 at the time point te. Also, similar to the first embodiment, the delay time td can be shortened, and the time from when the switch 54(n) closes until the voltage applied to the actuator 88 reaches the desired voltage can be reduced. When the number of switches 54(n) that select the drive waveform signal Pb or Pc is equal to or greater than the threshold, similar effects can be obtained by changing the value corresponding to the target voltage VP1 to the value corresponding to the target voltage VP2.

[0086] In Embodiment 2, the opening / closing process of switch 54(n) by control circuit 51 is the same as that in Embodiment 1, except that in step S7, a process of outputting an open signal to switch 54(n) for the time period between time point ts and time point ts1 is added (see FIG. 13). Specifically, in step S7, an open signal is output from control circuit 51 to switch 54(n) for the time period between time point ts and time point ts1. Subsequently, a close signal is output from control circuit 51 to switch 54(n) for the time period between time point ts1 and time point t3. Then, an open signal is output from control circuit 51 to switch 54(n) for the time period between time point t3 and time point te. That is, switch 54(n) turns off for the time period between time point ts and time point ts1 and for the time period from time point t3 to time point te. Between time point ts and time point te, the closed time of switch 54(n) is sandwiched by the open time of switch 54(n). In Embodiment 2, similar to Embodiment 1, the target voltage VP3 may be changed to target voltage VP4.

[0087] (Embodiment 3) Hereinafter, the present invention will be described based on the drawings showing printing apparatus 1 according to Embodiment 3. Among the configurations of printing apparatus 1 according to Embodiment 3, the same configurations as those in Embodiment 1 or 2 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. FIG. 14 is a block diagram of control device 50 according to Embodiment 3.

[0088] As shown in FIG. 14, a plurality of feedback resistors, for example, first feedback resistor 56a, second feedback resistor 56b, and third feedback resistor 56c, are connected in parallel to amplifier 53. For example, amplifier 53, first feedback resistor 56a, second feedback resistor 56b, and third feedback resistor 56c are included in the configuration of an inverting amplifier circuit. The resistance values of first feedback resistor 56a, second feedback resistor 56b, and third feedback resistor 56c are different. For example, the resistance value of first feedback resistor 56a is larger than that of second feedback resistor 56b, and the resistance value of second feedback resistor 56b is larger than that of third feedback resistor 56c. Note that the plurality of feedback resistors are also part of the multiplexing unit.

[0089] The first feedback resistor 56a, the second feedback resistor 56b, and the third feedback resistor 56c are connected to the input side of the amplifier 53 via the multiplexer 56. A plurality of signals are input to the multiplexer 56 via the first feedback resistor 56a, the second feedback resistor 56b, and the third feedback resistor 56c, that is, via a plurality of feedback resistors. The multiplexer 56 selects one of the plurality of input signals and outputs the selected signal to the input side of the amplifier 53.

[0090] In other words, the multiplexer 56 selects one of the first feedback resistor 56a, the second feedback resistor 56b, and the third feedback resistor 56c. As the resistance value of the feedback resistor increases, the output voltage of the amplifier 53 increases, and the voltage applied to the actuator 88 increases. The control circuit 51 causes the multiplexer 56 to select one of the feedback resistors. That is, the control circuit 51 can change the feedback resistor selected by the multiplexer 56.

[0091] For example, when the multiplexer 56 selects the second feedback resistor 56b, the voltage applied to the actuator 88 becomes a predetermined voltage, that is, the target voltage V1. When the multiplexer 56 selects the first feedback resistor 56a, the voltage applied to the actuator 88 becomes a predetermined voltage, that is, the target voltage V2. The control circuit 51 can change the target voltage V1 to the target voltage V2 by changing the feedback resistor selected by the multiplexer 56 from the second feedback resistor 56b to the first feedback resistor 56a. Specifically, when it is determined that the number of switches 54(n) for separating the drive waveform signal Pa is equal to or greater than the threshold value, when it is determined that the number of switches 54(n) for separating the drive waveform signal Pb is equal to or greater than the threshold value, etc., the control circuit 51 changes the feedback resistor selected by the multiplexer 56 from the second feedback resistor 56b to the first feedback resistor 56a to change the target voltage V1 to the target voltage V2. That is, the control circuit 51 selects the first feedback resistor 56a or the second feedback resistor 56b according to the number of switches 54(n) used when separating the drive waveform signal Pa or the drive waveform signal Pb from the time-division multiplexed signal.

[0092] For example, when the multiplexer 56 selects the second feedback resistor 56b, the voltage applied to the actuator 88 becomes a predetermined voltage, that is, the target voltage V3. When the multiplexer 56 selects the third feedback resistor 56c, the voltage applied to the actuator 88 becomes a predetermined voltage, that is, the target voltage V4. The control circuit 51 can change the target voltage V3 to the target voltage V4 by changing the feedback resistor selected by the multiplexer 56 from the second feedback resistor 56b to the third feedback resistor 56c.

[0093] The opening and closing process of the switch 54(n) by the control circuit 51 in the third embodiment is the same as that in the first embodiment except that the change of the target voltage is executed by changing the feedback resistor selected by the multiplexer 56 in steps S8 to S10 (see FIG. 12), and thus the detailed description thereof is omitted.

[0094] (Embodiment 4) Hereinafter, the present invention will be described based on the drawings showing the printing apparatus 1 according to the fourth embodiment. Among the configurations of the printing apparatus 1 according to the fourth embodiment, the same configurations as those in the first to third embodiments are denoted by the same reference numerals, and the detailed description thereof is omitted. FIG. 15 is a block diagram of the control device 50 according to the fourth embodiment.

[0095] In the first embodiment, the D / A converter 52 and the amplifier 53 were provided, but in the fourth embodiment, a digital amplifier 57 and a low-pass filter (LPF) 58 are provided. As described above, the amplifier 53 is an analog amplifier. The control circuit 51 transmits the time-series data Ak, Bk, Ck, that is, the digital signal, to the digital amplifier 57. The digital signal is, for example, a PWM signal. The digital amplifier 57 changes the duty ratio of the digital signal and outputs the digital signal with the changed duty ratio to the LPF 58. The digital signal is converted into an analog signal by the LPF 58 and transmitted to the switch group 54.

[0096] The control circuit 51 can change the duty ratio of the digital signal in the digital amplifier 57 to change the voltage indicated by the analog signal, that is, the target voltage, from VP1 to VP2 or from VP3 to VP4.

[0097] The opening and closing process of the switch 54(n) by the control circuit 51 in Embodiment 3 is the same as that in Embodiment 1 except that the change of the target voltage is executed by changing the duty ratio in the digital amplifier 57 in Steps S8 to S10 (see FIG. 12), and thus the detailed description thereof is omitted.

[0098] (Embodiment 5) Hereinafter, the present invention will be described based on the drawings showing the printing apparatus 1 according to Embodiment 5. Among the configurations of the printing apparatus 1 according to Embodiment 5, the same configurations as those in Embodiments 1 to 4 are denoted by the same reference numerals, and the detailed description thereof is omitted. FIG. 16 is a block diagram of the control apparatus 50 according to Embodiment 5.

[0099] As shown in FIG. 16, the control apparatus 50 includes an A / D converter 59. A voltage, that is, an analog signal, is transmitted from the amplifier 53 to the A / D converter 59. The A / D converter 59 converts the analog signal into a digital signal and transmits it to the control circuit 51. The control circuit 51 acquires voltages, that is, drive waveform signals Pa, Pb, and Pc, from the amplifier 53. The control circuit 51 changes the values of the time-series data Ak, Bk, and Ck output to the D / A converter 52, that is, the target voltage, based on the difference between the voltage acquired from the amplifier 53 and the target voltage corresponding to the values of the time-series data Ak, Bk, and Ck output to the D / A converter 52. That is, by feedback control, the control circuit 51 changes the target voltage and outputs the changed target voltage to the D / A converter 52.

[0100] FIG. 17 is an example of a conceptual diagram of a table showing the relationship between the target voltage VP1, the number of closed switches, and the coefficient for changing the target voltage VP1. For example, the coefficient is a value for multiplying the target voltage VP1. The table is stored in advance in the memory 55. In the initial state, the coefficient is not stored in the table.

[0101] For example, in the first time, the control circuit 51 outputs the time-series data Ak to the D / A converter 52. When the control circuit 51 acquires the voltage from the amplifier 53 for the first time, it calculates the difference between the voltage (drive waveform signal Pa) acquired from the amplifier 53 for the first time and the target voltage VP1 corresponding to the value of the time-series data Ak output to the D / A converter 52 for the first time. Note that the voltage of the drive waveform signal Pa acquired from the amplifier 53 and the target voltage VP1 are positive voltages, and the difference is the value obtained by subtracting the voltage acquired from the amplifier 53 from the target voltage VP1. Based on the calculated difference, the control circuit 51 stores the coefficient in the table. Note that in the first time, the time-series data Ak is not multiplied by the coefficient stored in the table, and the multiplied value is not output to the D / A converter 52. That is, when the control circuit 51 acquires the voltage from the amplifier 53 for the first time, it maintains the target voltage V1.

[0102] When the control circuit 51 changes the coefficient of the table, it stores the coefficient 1 in each column 76 in the rows where the number of closed switches is 1 to 10. Then, excluding the coefficients in each column 76, it calculates the difference between the coefficients in the left and right columns and the difference between the coefficients in the upper and lower columns according to the magnitude of the calculated difference. Based on these conditions, it changes the coefficient of the table.

[0103] For example, the control circuit 51 sets the difference between the coefficients in the left and right columns to 0.02 based on the magnitude of the calculated difference excluding the coefficients in each column 76. That is, it changes the coefficient so that the coefficient in the right column is 0.02 larger than the coefficient in the left column. The control circuit 51 sets the difference between the coefficients in the upper and lower columns to 0.05 based on the magnitude of the calculated difference excluding the coefficients in each column 76. That is, it changes the coefficient so that the coefficient in the lower column is 0.05 larger than the coefficient in the upper column.

[0104] When the target voltage VP1 output to the D / A converter 52 for the first time is 10 to 11 [V], the number of closed switches is 15, and the difference is larger than the threshold value, the control circuit 51 stores the coefficient 1.05 in the column 70 in the 10 - 11 [V] column of the table and in the rows where the number of closed switches is 11 to 20. Note that 1.05 is determined based on the difference, the target voltage, and the number of closed switches.

[0105] Next, the control circuit 51 stores the coefficient 1.07 in column 71 that is in the column of 11 - 12 [V] of the table and in the row where the number of closed switches is 11 - 20, and stores the coefficient 1.09 in column 72 that is in the column of 12 - 13 [V] of the table and in the row where the number of closed switches is 11 - 20. That is, the control circuit 51 stores the coefficients in each column within the same row of the table such that the coefficient of the right - hand column is 0.02 greater than the coefficient of the left - hand column.

[0106] Next, the control circuit 51 stores the coefficient 1.1 in column 73 that is in the column of 10 - 11 [V] of the table and in the row where the number of closed switches is 21 - 30, stores the coefficient 1.12 in column 74 that is in the column of 11 - 12 [V] of the table and in the row where the number of closed switches is 21 - 30, and stores the coefficient 1.14 in column 75 that is in the column of 12 - 13 [V] of the table and in the row where the number of closed switches is 21 - 30. That is, the control circuit 51 stores the coefficients in each column within the same column of the table such that the coefficient of the lower column is 0.05 greater than the coefficient of the upper column. Note that the difference between the coefficients of the left - and right - hand columns is not limited to 0.02 and is determined according to the magnitude of the obtained difference, and the difference between the coefficients of the upper - and lower - hand columns is not limited to 0.05 and is determined according to the magnitude of the obtained difference.

[0107] Second, the control circuit 51 multiplies the time - series data Bk obtained from the memory 55 by the coefficients stored in the table, and outputs the multiplied value to the D / A converter 52. That is, the target voltage VP1 corresponding to the time - series data Bk is changed to the target voltage VP2. A voltage based on the target voltage VP2 is output to the switch group 54.

[0108] When the control circuit 51 acquires the voltage from the amplifier 53 for the second time, it calculates the difference between the voltage (drive waveform signal Pb) acquired from the amplifier 53 for the second time and the target voltage VP2 corresponding to the time series data Bk output to the D / A converter 52 for the second time. Based on the calculated difference, the control circuit 51 changes the coefficients in the table. The coefficient change is calculated in the same way as the method for calculating the coefficients stored in the table for the first time, and the coefficients stored in the table are changed to the calculated coefficients.

[0109] For the third time, the control circuit 51 multiplies the time series data Ck acquired from the memory 55 by the coefficients stored in the table, and outputs the multiplied value to the D / A converter 52. That is, the target voltage VP1 corresponding to the time series data Ck is changed to the target voltage VP2. A voltage based on the target voltage VP2 is output to the switch group 54.

[0110] When the control circuit 51 acquires the voltage from the amplifier 53 for the third time, it calculates the difference between the voltage (drive waveform signal Pc) acquired from the amplifier 53 for the third time and the target voltage VP2 corresponding to the time series data Ck output to the D / A converter 52 for the third time. Based on the calculated difference, the control circuit 51 changes the coefficients in the table. The coefficient change is calculated in the same way as the method for calculating the coefficients stored in the table for the first time, and the coefficients stored in the table are changed to the calculated coefficients. The control circuit 51 executes the same processing as the second and third times also for the fourth time and after.

[0111] In the initial state, coefficient 1 may be stored in all columns of the table, and the coefficient 1 may be changed to the coefficient calculated after the control circuit 51 outputs the target voltage VP1 to the D / A converter 52 for the first time. That is, the calculated coefficient may be stored in the table.

[0112] The computer program can be deployed to be executed on a single computer, or placed at one site, or distributed over a plurality of sites and executed on a plurality of computers interconnected by a communication network.

[0113] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims. The matters described in each embodiment can be combined with each other. Also, the independent claims and dependent claims described in the claims can be combined with each other in all possible combinations regardless of the citation form. Furthermore, although the claims use a form (multi-claim form) of describing claims that cite two or more other claims, it is not limited to this. It may be described using a form of describing a multi-claim (multi-multi-claim) that cites at least one multi-claim.

Description of Reference Numerals

[0114] 1 Printing device 50 Control device 51 Control circuit 52 D / A converter 53 Amplifier 54 Switch group 55 Memory 56 Multiplexer 57 Digital amplifier 58 LPF 59 A / D converter

Claims

1. A nozzle that discharges a liquid by an energy applying element, a storage unit that stores at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform, at least the first data and the second data are acquired from the storage unit, and there is a third part that is a part of the second drive waveform between a first part that is a part of the first drive waveform and a second part that is a part of the first drive waveform, and the second part is between the third part and a fourth part that is a part of the second drive waveform, and a multiplexing unit that generates a time-division multiplexed signal capable of transmitting the first data and the second data on one signal line, a separation unit that separates 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 generated by the multiplexing unit and comprising, the energy applying element is driven by the first drive waveform signal or the second drive waveform signal, the first data includes first voltage data indicating the target voltage of each part of the first drive waveform, the second data includes second voltage data indicating the target voltage of each part of the second drive waveform, the multiplexing unit includes a changing unit that changes the target voltage of the first voltage data or the second voltage data acquired from the storage unit, when the target voltage is changed by the changing unit, the time-division multiplexed signal based on the first voltage data indicating the changed target voltage or the second voltage data indicating the changed target voltage is transmitted to the separation unit A printing apparatus.

2. The separation unit includes a plurality of separation switches that receive the time-division multiplexed signal from the multiplexing unit, the changing unit, when a predetermined number or more of the separation switches separate the first drive waveform signal from the time-division multiplexed signal within each time corresponding to each part of the first drive waveform, changes the target voltage of the first voltage data acquired from the storage unit, when a predetermined number or more of the separation switches separate the second drive waveform signal from the time-division multiplexed signal within each time corresponding to each part of the second drive waveform, changes the target voltage of the second voltage data acquired from the storage unit The printing apparatus according to Claim 1.

3. The multiplexing unit includes an amplifier that amplifies a signal based on the first voltage data and the second voltage data, the changed target voltage is less than the maximum output voltage of the amplifier The printing apparatus according to Claim 1 or 2.

4. Based on the target voltage of the first voltage data stored in the memory unit, when the separation switches less than the predetermined number separate the first drive waveform signal from the time-division multiplexed signal, the first value of the parameter regarding the liquid ejected from the nozzle, and based on the target voltage of the first voltage data stored in the memory unit, when the separation switches greater than or equal to the predetermined number separate the first drive waveform signal from the time-division multiplexed signal, the absolute value of the difference from the second value of the parameter is the first absolute value, Based on the first value and the target voltage of the changed first voltage data, when the separation switches greater than or equal to the predetermined number separate the first drive waveform signal from the time-division multiplexed signal, the absolute value of the difference from the third value of the parameter is the second absolute value, The ratio of the absolute value of the difference between the first absolute value and the second absolute value to the first absolute value is 25% or more The printing apparatus according to claim 2.

5. Based on the target voltage of the second voltage data stored in the memory unit, when the separation switches less than the predetermined number separate the second drive waveform signal from the time-division multiplexed signal, the fourth value of the parameter regarding the liquid ejected from the nozzle, and based on the target voltage of the second voltage data stored in the memory unit, when the separation switches greater than or equal to the predetermined number separate the second drive waveform signal from the time-division multiplexed signal, the absolute value of the difference from the fifth value of the parameter is the third absolute value, Based on the fourth value and the target voltage of the changed second voltage data, when the separation switches greater than or equal to the predetermined number separate the second drive waveform signal from the time-division multiplexed signal, the absolute value of the difference from the sixth value of the parameter is the fourth absolute value, The ratio of the absolute value of the difference between the third absolute value and the fourth absolute value to the third absolute value is 25% or more The printing apparatus according to claim 2.

6. Each time corresponding to each part of the first drive waveform and the second drive waveform has a start time point, an end time point, and an intermediate time point between the start time point and the end time point, When separating the first drive waveform signal or the second drive waveform signal based on the target voltage of the changed first voltage data or the target voltage of the changed second voltage data by the separation switches greater than or equal to the predetermined number, there is a time off between the intermediate time point and the end time point The printing apparatus according to claim 2.

7. Each of the times corresponding to the respective portions of the first drive waveform and the second drive waveform has a start time, an end time, a first intermediate time between the start time and the end time, and a second intermediate time between the first intermediate time and the end time, When a predetermined number or more of the separation switches separate the first drive waveform signal or the second drive waveform signal based on the target voltage of each of the first voltage data after the change or the target voltage of each of the second voltage data after the change, the time between the start time and the first intermediate time, and the time between the second intermediate time and the end time turn off The printing apparatus according to claim 2.

8. The first voltage data and the second voltage data are digital data, The multiplexing unit includes a DA converter and an analog amplifier, The changing unit transmits a digital signal indicating the first voltage data indicating the target voltage after the change or the second voltage data indicating the target voltage after the change to the DA converter, The DA converter converts the digital signal into an analog signal and transmits it to the analog amplifier, The analog amplifier transmits the analog signal to the energy imparting element, The energy imparting element is driven by the analog signal The printing apparatus according to claim 1 or 2.

9. The first voltage data and the second voltage data are digital data, The multiplexing unit includes a DA converter, an analog amplifier, and a plurality of feedback resistors having different resistance values and connected in parallel to the analog amplifier, The separating unit includes a plurality of separation switches that receive the time-division multiplexed signal from the multiplexing unit, The changing unit transmits a digital signal indicating the first voltage data or the second voltage data to the DA converter, The DA converter converts the digital signal into an analog signal and transmits it to the analog amplifier, The analog amplifier transmits the analog signal to the energy imparting element, The energy imparting element is driven by the analog signal, When separating the first drive waveform signal or the second drive waveform signal from the time-division multiplexed signal, the changing unit changes the target voltage by selecting any one of the feedback resistors according to the number of the separation switches used When the target voltage is changed in the changing unit, the time-division multiplexed signal based on the first voltage data or the second voltage data indicating the changed target voltage is transmitted from the analog amplifier to the separation unit. The printing apparatus according to claim 1 or 2.

10. The first voltage data and the second voltage data are digital data, The multiplexing unit includes a digital amplifier that amplifies a digital signal, The changing unit transmits a digital signal based on the first voltage data or the second voltage data to the digital amplifier, The separation unit includes a plurality of separation switches that receive the time-division multiplexed signal from the multiplexing unit, When separating the first drive waveform signal or the second drive waveform signal from the time-division multiplexed signal, the changing unit changes the duty ratio of the digital signal output to the digital amplifier according to the number of the separation switches used, thereby changing the target voltage. When the target voltage is changed in the changing unit, the time-division multiplexed signal based on the first voltage data or the second voltage data indicating the changed target voltage is transmitted from the digital amplifier to the separation unit. The printing apparatus according to claim 1.

11. The separation unit includes a plurality of separation switches that receive the time-division multiplexed signal from the multiplexing unit, The multiplexing unit includes an amplifier that outputs a voltage corresponding to the target voltage indicated by the first voltage data or the second voltage data, The changing unit acquires a voltage from the amplifier and changes the voltage output to the amplifier based on the difference between the acquired voltage and the target voltage, A change value storage unit that stores a value for changing the target voltage of the first voltage data or the second voltage data acquired from the storage unit according to the number of the separation switches used when separating the first drive waveform signal or the second drive waveform signal from the time-division multiplexed signal and the voltage from the amplifier. When the changing unit acquires a voltage from the amplifier for the second time or later, the changing unit changes the target voltage based on the value stored in the change value storage unit. The printing apparatus according to claim 1.

12. When the changing unit acquires a voltage from the amplifier for the second time or later, the changing unit changes the value stored in the change value storage unit. The printing apparatus according to claim 11.

13. When the voltage is acquired from the amplifier for the first time, the change unit maintains the target voltage and stores the value in the change value storage unit. The printing apparatus according to claim 11 or 12.

14. A printing method of a printing apparatus including a nozzle that discharges a liquid by an energy applying element and a storage unit that stores at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform, acquiring at least the first data and the second data from the storage unit, a third portion that is a part of the second drive waveform is provided 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 provided between the third portion and a fourth portion that is a part of the second drive waveform, and a time-division multiplexed signal capable of transmitting the first data and the second data on one signal line is generated, separating a first drive waveform signal indicating the first drive waveform or a second drive waveform signal indicating the second drive waveform from the generated time-division multiplexed signal, driving the energy applying element with the first drive waveform signal or the second drive waveform signal, the first data includes first voltage data indicating a target voltage of each portion of the first drive waveform, the second data includes second voltage data indicating a target voltage of each portion of the second drive waveform, changing the target voltage of the first voltage data or the second voltage data acquired from the storage unit, when the target voltage is changed, separating the first drive waveform signal or the second drive waveform signal from the time-division multiplexed signal based on the first voltage data indicating the changed target voltage or the second voltage data indicating the changed target voltage, Printing method.

15. A computer program executed by a printing apparatus including a nozzle that discharges a liquid by an energy applying element and a storage unit that stores at least first data indicating a first drive waveform and second data indicating a second drive waveform different from the first drive waveform, in the printing apparatus, acquiring at least the first data and the second data from the storage unit, There is a third portion that is a part of the second drive waveform 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 they are arranged such that the second portion is between the third portion and a fourth portion that is a part of the second drive waveform, and a time-division multiplexed signal capable of transmitting the first data and the second data on one signal line is generated. A first drive waveform signal indicating the first drive waveform or a second drive waveform signal indicating the second drive waveform is separated from the generated time-division multiplexed signal. The energy application element is driven by the first drive waveform signal or the second drive waveform signal. The first data includes first voltage data indicating the target voltage of each portion of the first drive waveform. The second data includes second voltage data indicating the target voltage of each portion of the second drive waveform. The target voltage of the first voltage data or the second voltage data acquired from the storage unit is changed. When the target voltage is changed, the first drive waveform signal or the second drive waveform signal is separated from the time-division multiplexed signal based on the first voltage data indicating the changed target voltage or the second voltage data indicating the changed target voltage. A computer program for executing the process.

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