LIQUID EJECTION APPARATUS, CONTROL METHOD THEREOF, AND PROGRAM

Abstract

To suppress dot miss even when transfer timing occurs, the transfer timing related to a next discharge cycle, during transfer of a selection signal which relates to a first discharge cycle by a transfer circuit.SOLUTION: A CPU of a printer is configured so that, in occurrence of transfer timing related to a second discharge cycle during transfer of a selection signal SIN related to a first discharge cycle, immediately after latch of the selection signal SIN at a transfer finish time point of the selection signal SIN related to the first discharge cycle, transfer of a signal related to the second discharge cycle is started by a transfer circuit.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a liquid ejection apparatus that ejects liquid such as ink, and a control method and program thereof. [Background technology]

[0002] The inkjet printer (liquid ejection device) described in Patent Document 1 includes a nozzle, an actuator, a signal generation circuit (output circuit), a driver IC (drive circuit), and a signal transmission / reception circuit (transfer circuit). The signal generation circuit generates a waveform signal FIRE, a waveform selection signal SIN, a clock signal (transfer timing signal), etc. for each ejection period, and outputs these to the signal transmission / reception circuit. The signal transmission / reception circuit receives the waveform signal FIRE, the waveform selection signal SIN, the clock signal, etc. from the signal generation circuit, and transfers the waveform signal FIRE and the waveform selection signal SIN to the driver IC at the transfer timing indicated by the clock signal for each ejection period. The driver IC supplies a drive signal indicating a drive mode selected from a plurality of drive modes to the actuator for each ejection period, based on the waveform signal and the selection signal transferred from the transfer circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-167466 A (Fig. 3) Summary of the Invention [Problem to be solved by the invention]

[0004] In one ejection cycle, the transfer of the selection signal ends after the transfer of the waveform signal ends, and the selection signal is latched at the end of the transfer. Usually, after the transfer circuit finishes transferring the waveform signal and selection signal for one ejection cycle, the transfer timing for the next ejection cycle occurs, and the transfer of the waveform signal and selection signal to the drive circuit begins.

[0005] However, for example, when the amount of change in the relative position between the head and the recording medium increases (when the carriage moves at high speed in Patent Document 1), unlike the normal time described above, a transfer timing for the next ejection cycle may occur while the transfer circuit is transferring the waveform signal and selection signal for one ejection cycle. In this case, the transfer circuit cannot properly retrieve the waveform signal and selection signal for the next ejection cycle, and as a result, it cannot transfer the waveform signal and selection signal for the next ejection cycle to the drive circuit. This can result in non-ejection in the next ejection cycle, causing missing dots.

[0006] The object of the present invention is to provide a liquid ejection device, a control method and a program thereof, which can suppress missing dots even when the transfer timing for the next ejection cycle occurs while the transfer circuit is transferring a selection signal for one ejection cycle.

[0007] A liquid ejection device according to the present invention includes a nozzle, an actuator that applies pressure to eject liquid from the nozzle, an output circuit that outputs a waveform signal indicating a plurality of drive modes of the actuator, a selection signal for selecting one of the plurality of drive modes, and a transfer timing signal indicating a transfer timing of the waveform signal and the selection signal for each ejection cycle that is a cycle in which liquid is ejected from the nozzle, a drive circuit that supplies a drive signal indicating a drive mode selected from the plurality of drive modes based on the waveform signal and the selection signal output by the output circuit to the actuator for each ejection cycle, a transfer circuit that receives the waveform signal, the selection signal, and the transfer timing signal from the output circuit, and transfers the waveform signal and the selection signal to the drive circuit at the transfer timing for each ejection cycle, and a control unit, wherein the ejection cycle is a first ejection cycle and an ejection cycle following the first ejection cycle. and a second ejection cycle, wherein in one of the ejection cycles, the transfer of the selection signal ends after the end of the transfer of the waveform signal, and the selection signal is latched at the end of the transfer of the selection signal, and the control unit executes a determination process to determine whether the transfer timing for the second ejection cycle has occurred while the selection signal for the first ejection cycle is being transferred by the transfer circuit, and a transfer process to start the transfer of the waveform signal for the second ejection cycle by the transfer circuit, if it is determined in the determination process that the transfer timing for the second ejection cycle has occurred while the selection signal for the first ejection cycle is being transferred by the transfer circuit, immediately after the selection signal is latched at the end of the transfer of the selection signal for the first ejection cycle, and to start the transfer of the selection signal for the second ejection cycle after the start of the transfer of the waveform signal for the second ejection cycle.

[0008] A control method according to the present invention is a control method for controlling a liquid ejection device including a nozzle, an actuator that applies pressure to eject liquid from the nozzle, an output circuit that outputs a waveform signal indicating a plurality of drive modes of the actuator, a selection signal for selecting one of the plurality of drive modes, and a transfer timing signal indicating a transfer timing of the waveform signal and the selection signal for each ejection cycle that is a cycle for ejecting liquid from the nozzle, a drive circuit that supplies a drive signal indicating a drive mode selected from the plurality of drive modes based on the waveform signal and the selection signal output by the output circuit to the actuator for each ejection cycle, and a transfer circuit that receives the waveform signal, the selection signal, and the transfer timing signal from the output circuit, and transfers the waveform signal and the selection signal to the drive circuit at the transfer timing for each ejection cycle, and a second ejection cycle which is the next ejection cycle of the first ejection cycle, wherein in one of the ejection cycles, the transfer of the selection signal ends after the end of the transfer of the waveform signal, and the selection signal is latched at the end of the transfer of the selection signal, and a determination process is executed to determine whether or not the transfer timing for the second ejection cycle has occurred during the transfer of the selection signal for the first ejection cycle by the transfer circuit, and a transfer process is executed to start the transfer of the waveform signal for the second ejection cycle by the transfer circuit immediately after the selection signal is latched at the end of the transfer of the selection signal for the first ejection cycle, and to start the transfer of the selection signal for the second ejection cycle after the start of the transfer of the waveform signal for the second ejection cycle.

[0009] A program according to the present invention is a liquid ejection device comprising: a nozzle; an actuator that applies pressure to eject liquid from the nozzle; an output circuit that outputs a waveform signal indicating a plurality of drive modes of the actuator, a selection signal for selecting one of the plurality of drive modes, and a transfer timing signal indicating a transfer timing of the waveform signal and the selection signal for each ejection cycle that is a cycle for ejecting liquid from the nozzle; a drive circuit that supplies a drive signal indicating a drive mode selected from the plurality of drive modes based on the waveform signal and the selection signal output by the output circuit to the actuator for each ejection cycle; and a transfer circuit that receives the waveform signal, the selection signal, and the transfer timing signal from the output circuit, and transfers the waveform signal and the selection signal to the drive circuit at the transfer timing for each ejection cycle, and a second ejection cycle, wherein in one of the ejection cycles, the transfer of the selection signal ends after the transfer of the waveform signal ends and the selection signal is latched at the end of the transfer of the selection signal, the liquid ejection device functions as a determination means for determining whether the transfer timing for the second ejection cycle has occurred while the selection signal for the first ejection cycle is being transferred by the transfer circuit, and a transfer means for, when the determination means determines that the transfer timing for the second ejection cycle has occurred while the selection signal for the first ejection cycle is being transferred by the transfer circuit, causing the transfer circuit to start transferring the waveform signal for the second ejection cycle immediately after the selection signal is latched at the end of the transfer of the selection signal for the first ejection cycle, and starting transferring the selection signal for the second ejection cycle after the start of the transfer of the waveform signal for the second ejection cycle. Effect of the Invention

[0010] According to the present invention, by executing the judgment process and the transfer process, even if the transfer timing for the next ejection cycle occurs while the transfer circuit is transferring the selection signal for one ejection cycle, the waveform signal and the selection signal for the next ejection cycle can be transferred to the drive circuit, thereby suppressing missing dots. [Brief description of the drawings]

[0011] [Figure 1] 1 is a plan view showing a printer according to a first embodiment of the present invention. [Diagram 2] 3 is a cross-sectional view of a head included in the printer. [Diagram 3] FIG. 2 is a block diagram showing the electrical configuration of the printer. [Figure 4] 11 is a waveform diagram showing four types of waveform data included in waveform signal FIRE. FIG. [Diagram 5] 10 is an explanatory diagram showing a process in which a waveform signal FIRE and a selection signal SIN are transferred from a transfer circuit to a driver IC. [Figure 6] 4 is a flow chart showing a program executed by the CPU of the printer. [Figure 7] FIG. 11 is a plan view showing a printer according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] As shown in FIG. 1, a printer 100 according to a first embodiment of the present invention comprises a head 10 having a plurality of nozzles N formed on its underside, a carriage 20 that holds the head 10, a moving mechanism 30 that moves the carriage 20 in a scanning direction (a direction perpendicular to the vertical direction), a platen 40 that supports paper P from below, a transport mechanism 50 that transports paper P in a transport direction (a direction perpendicular to the scanning direction and the vertical direction), and a control device 90.

[0013] The movement mechanism 30 includes a pair of guides 31, 32 that support the carriage 20, and a belt 33 connected to the carriage 20. The guides 31, 32 and the belt 33 extend in the scanning direction. When a carriage motor 30m (see FIG. 3) is driven under the control of the control device 90, the belt 33 runs, and the carriage 20 moves along the guides 31, 32 in the scanning direction.

[0014] The platen 40 is disposed below the carriage 20 and the head 10. A paper sheet P is placed on the upper surface of the platen 40.

[0015] The transport mechanism 50 has two roller pairs 51 and 52. The head 10, the carriage 20, and the platen 40 are disposed between the roller pairs 51 and 52 in the transport direction. When the transport motor 50m (see FIG. 3) is driven under the control of the control device 90, the roller pairs 51 and 52 rotate while holding the paper P therebetween, and the paper P is transported in the transport direction.

[0016] As shown in FIG. 2, the head 10 includes a flow passage unit 12 and an actuator unit 13.

[0017] A plurality of nozzles N (see FIG. 1) are formed on the lower surface of the flow path unit 12. A plurality of pressure chambers 12p are formed on the upper surface of the flow path unit 12. A common flow path 12a communicating with an ink tank (not shown) and individual flow paths 12b for each nozzle N are formed inside the flow path unit 12. The individual flow paths 12b are flow paths that extend from the outlet of the common flow path 12a to the nozzles N via the pressure chambers 12p.

[0018] The actuator unit 13 includes a metallic vibration plate 13a arranged on the upper surface of the flow path unit 12 so as to cover the multiple pressure chambers 12p, a piezoelectric layer 13b arranged on the upper surface of the vibration plate 13a, and a plurality of individual electrodes 13c arranged on the upper surface of the piezoelectric layer 13b so as to face each of the multiple pressure chambers 12p.

[0019] The vibration plate 13a and the individual electrodes 13c are electrically connected to a driver IC 14. The driver IC 14 corresponds to the "drive circuit" of the present invention, and maintains the potential of the vibration plate 13a at the ground potential while changing the potential of the individual electrodes 13c. Specifically, the driver IC 14 generates a drive signal based on a control signal (such as a waveform signal FIRE, a selection signal SIN, and a clock signal CLK, which will be described later) from the control device 90, and supplies the drive signal to the individual electrodes 13c via a signal line 14s for each ejection period (the period during which ink is ejected from the nozzle N). As a result, the potential of the individual electrodes 13c changes between a predetermined drive potential and a ground potential. At this time, the portions (actuators 13x) of the vibration plate 13a and the piezoelectric layer 13b sandwiched between each individual electrode 13c and each pressure chamber 12p are deformed, so that the volume of the pressure chamber 12p changes, pressure is applied to the ink in the pressure chamber 12p, and ink is ejected from the nozzle N. The actuator 13x is provided for each individual electrode 13c (that is, for each nozzle N), and is capable of independently deforming in response to the potential supplied to the individual electrode 13c.

[0020] As shown in FIG. 3, the control device 90 includes a CPU (Central Processing Unit) 91, a ROM (Read Only Memory) 92, a RAM (Random Access Memory) 93, and an ASIC (Application Specific Integrated Circuit) 94. Here, the CPU 91 corresponds to the "control unit" of the present invention, and the ROM 92 corresponds to the "storage unit" of the present invention. The ROM 92 stores programs and data for the CPU 91 and the ASIC 94 to perform various controls. The RAM 93 temporarily stores data used when the CPU 91 and the ASIC 94 execute the programs. The control device 90 is connected to an external device (such as a personal computer) so as to be able to communicate with it, and executes recording processing and the like using the CPU 91 and the ASIC 94 based on data input from the external device or an input unit (a switch or button provided on the outer surface of the housing of the printer 100).

[0021] In the recording process, the control device 90 controls the driver IC 14, the carriage motor 30m, and the transport motor 50m based on a recording command received from an external device, and alternates between a transport operation in which the transport mechanism 50 transports the paper P a predetermined distance in the transport direction and a scanning operation in which the carriage 20 moves in the scanning direction and ink is ejected from the nozzles N. In the scanning operation, the control device 90 ejects ink from the nozzles N toward the paper P by supplying a drive signal to the individual electrodes 13c by the driver IC 14 while moving the head 10 and the paper P relatively with the movement mechanism 30. In this way, ink dots are formed on the paper P, and an image is recorded.

[0022] Next, the configuration of the ASIC 94 will be described.

[0023] As shown in FIG. 3, the ASIC 94 includes an output circuit 941 and a transfer circuit 942 .

[0024] The output circuit 941 generates a waveform signal FIRE, a selection signal SIN, a clock signal CLK, and the like, and outputs these signals to a transfer circuit 942 for each ejection period.

[0025] The waveform signal FIRE is a serial signal obtained by serializing four waveform data F0 to F3 (see FIG. 4) that respectively indicate four driving modes of the actuator 13x. The waveform data F0 (see FIG. 4(a)) corresponds to the amount of ink discharged from the nozzle N in one discharge cycle being "zero (no discharge)", and maintains the potential of the individual electrode 13c at the ground potential (0V). The waveform data F1 (see FIG. 4(b)) corresponds to the amount of ink discharged from the nozzle N in one discharge cycle being "small", and includes one pulse that changes the potential of the individual electrode 13c between the ground potential (0V) and the drive potential (VDD), and causes one drop of ink to be discharged. The waveform data F2 (see FIG. 4(c)) corresponds to the amount of ink discharged from the nozzle N in one discharge cycle being "medium", and includes two pulses that change the potential of the individual electrode 13c between the ground potential (0V) and the drive potential (VDD), and causes two drops of ink to be discharged. Waveform data F3 (see Figure 4 (d)) corresponds to a "large" amount of ink ejected from nozzle N within one ejection cycle, and includes four pulses that change the potential of individual electrode 13c between the ground potential (0V) and the drive potential (VDD), ejecting four drops of ink.

[0026] The waveform signal FIRE includes the above four waveform data F0 to F3 (see FIG. 4), and as a whole indicates four drive modes of the actuator 13x.

[0027] The driving mode of the actuator 13x refers to the above-mentioned deformation mode of the actuator 13x in response to the change in the potential of the individual electrode 13c. The driving mode of the actuator 13x differs in response to the change in the potential of the individual electrode 13c (i.e., for each of the waveform data F0 to F3). The change in the volume of the pressure chamber 12p, the state of the meniscus formed in the nozzle N, and the amount of ink ejected from the nozzle N (including zero) differ depending on the driving mode.

[0028] The selection signal SIN is a serial signal including selection data for selecting one of the above four driving modes, and is generated for each actuator 13x and for each ejection period based on image data included in the recording command. The ejection period is determined according to the amount of change in the relative position between the head 10 and the paper P per unit time, and becomes shorter as the amount of change increases (for example, as the scanning speed of the carriage 20 or the transport speed of the paper P increases).

[0029] The clock signal CLK is a signal indicating the transfer timing of various signals from the ASIC 94 to the driver IC 14, and corresponds to the "transfer timing signal" of the present invention. The clock signal CLK is generated and output based on image data included in the recording command, a signal from a rotary encoder 61 provided on the carriage motor 30m, and a signal from a paper sensor 62 provided on the transport path of the paper P. The rotary encoder 61 detects the moving speed of the carriage 20 by the moving mechanism 30 (the relative moving speed between the head 10 and the paper P), and corresponds to the "speed sensor" of the present invention. The transfer timing (first timing) indicated by the clock signal CLK is based on the moving speed detected by the rotary encoder 61.

[0030] The transfer circuit 942 transfers the waveform signal FIRE, the selection signal SIN, the clock signal CLK, and the like received from the output circuit 941 to the driver IC 14 in synchronization with the clock signal CLK (at a first timing indicated by the clock signal CLK) for each ejection period. The transfer circuit 942 has built-in LVDS (Low Voltage Differential Signaling) drivers corresponding to each of the above signals, and transfers each signal to the driver IC 14 as a pulse-shaped differential signal. The LVDS method is a method in which signals of opposite phases (H signal and L signal) are input to two signal lines, and is characterized by being resistant to noise and capable of transmitting at a low voltage by reducing the amplitude of the signal compared to a single-ended method in which a signal is input using only one signal line. The LVDS method can reduce the amplitude of the signal, thereby shortening the time required to switch between the H signal and the L signal, and as a result, the frequency of the signal can be increased and data can be transmitted at a high speed. In particular, the selection signal SIN includes selection data for the number of actuators 13x (the number of nozzles N), and therefore the amount of data can be enormous. By transferring this signal using the LVDS method, high-speed transmission is possible.

[0031] Next, the transfer of waveform signal FIRE and selection signal SIN from transfer circuit 942 to driver IC 14 will be described.

[0032] 5(a) to 5(c), time points t1 to t4 are the times at which the transfer of waveform signal FIRE and selection signal SIN should start. The time between chronologically adjacent time points t1 to t4 corresponds to a discharge period, with the time between time points t1 and Rt being the first discharge period, the time between time points t2 and t3 being the second discharge period, the time between time points t3 and t4 being the third discharge period, and the time between time point t4 and the next time point (not shown) being the fourth discharge period.

[0033] In each ejection cycle, the transfer of the selection signal SIN ends after the transfer of the waveform signal FIRE ends, and the selection signal SIN is latched at the end of the transfer of the selection signal SIN.

[0034] Normally, as shown in FIG. 5(a), after the transfer of the waveform signal FIRE and the selection signal SIN for one ejection cycle is completed, the first timing (the transfer timing indicated by the clock signal CLK) for the next ejection cycle occurs, and the transfer of the waveform signal FIRE and the selection signal SIN begins.

[0035] However, for example, when the amount of change in the relative position between the head 10 and the paper P increases (specifically, when the movement of the carriage 20 increases in speed), unlike the normal state described above, the first timing (time t2) related to the second ejection cycle occurs during the transfer of the waveform signal FIRE and selection signal SIN related to the first ejection cycle, as shown in FIG. 5(b). In this case, the transfer circuit 942 cannot normally receive the waveform signal FIRE and selection signal SIN related to the second ejection cycle, and as a result, cannot transfer the waveform signal FIRE and selection signal SIN related to the second ejection cycle to the driver IC 14. This results in non-ejection in the second ejection cycle, which can cause missing dots.

[0036] Therefore, in this embodiment, in order to suppress the above-mentioned non-ejection (missing dots), the CPU 91 executes a program shown in FIG.

[0037] First, the CPU 91 sets n=1 (S1).

[0038] After S1, the CPU 91 determines whether or not the first timing (transfer timing indicated by the clock signal CLK) for the n-th ejection cycle has occurred (S2). If the first timing for the n-th ejection cycle has not occurred (S2: NO), the CPU 91 repeats the process of S2.

[0039] When the first timing for the nth ejection cycle occurs (S2: YES), the CPU 91 starts transferring signals for the nth ejection cycle (waveform signal FIRE, selection signal SIN, clock signal CLK, etc.) from the transfer circuit 942 to the driver IC 14 (S3).

[0040] After S3, the CPU 91 determines whether n=N (N: the ejection period for the final ejection based on a recording command) (S4).

[0041] If n=N (S4: YES), the CPU 91 ends the program.

[0042] If n≠N (S4: NO), the CPU 91 sets n=n+1 (S5).

[0043] After S5, the CPU 91 determines whether or not the transfer timing for the n-th ejection cycle has occurred (S6). If the transfer timing for the n-th ejection cycle has not occurred (S2: NO), the CPU 91 repeats the process of S6.

[0044] The transfer timing includes a "first timing" indicated by the clock signal CLK and a "second timing" different from the first timing. The second timing is a timing that is not based on the moving speed (the actual moving speed of the carriage 20) detected by the rotary encoder 61. In this embodiment, the second timing is a timing that is generated by a timer built into the control device 90 and is based on a predetermined moving speed (the ideal moving speed of the carriage 20). If the second timing is set as the transfer timing related to the n-th ejection period in S10 described later, it is determined in S6 whether the second timing has occurred, and otherwise it is determined in S6 whether the first timing has occurred. In other words, the "transfer timing" is the "second timing" when S10 is executed, and the "first timing" otherwise.

[0045] When the transfer timing for the nth ejection cycle occurs (S6: YES), the CPU 91 determines whether the transfer timing for the nth ejection cycle has occurred during the transfer of the selection signal SIN for the n-1th ejection cycle (S7: determination process).

[0046] When a transfer timing for the nth discharge cycle occurs during the transfer of the selection signal SIN for the n-1th discharge cycle (S7: YES), the CPU 91 starts the transfer of the signal for the nth discharge cycle by the transfer circuit 942 immediately after the selection signal SIN is latched at the end of the transfer of the selection signal SIN for the n-1th discharge cycle (S8: transfer process). For example, when n=2 and a transfer timing for the second discharge cycle occurs during the transfer of the selection signal SIN for the first discharge cycle (S7: YES), the CPU 91 starts the transfer of the signal for the second discharge cycle by the transfer circuit 942 immediately after the selection signal SIN is latched at the end of the transfer of the selection signal SIN for the first discharge cycle, as shown in FIG.

[0047] In addition, the waveform signal FIRE for the nth ejection cycle transferred in S8 is the same as the waveform signal FIRE for the nth ejection cycle transferred in S3 when the transfer timing for the nth ejection cycle does not occur during the transfer of the selection signal SIN for the n-1th ejection cycle (S7: NO).

[0048] After S8, the CPU 91 determines whether n=N (S9).

[0049] If n=N (S9: YES), the CPU 91 ends the program.

[0050] If n ≠ N (S9: NO), the CPU 91 sets the transfer timing for the (n+1)th ejection cycle as the "second timing" (S10). For example, when n = 2, as shown in FIG. 5(c), the transfer timing for the third ejection cycle is set as the "second timing".

[0051] After S10, the CPU 91 returns the process to S5, sets n=n+1, and then judges whether or not the transfer timing for the n-th ejection cycle has occurred during the transfer of the selection signal SIN for the n-1-th ejection cycle (S7). If the transfer timing for the n-th ejection cycle has not occurred during the transfer of the selection signal SIN for the n-1-th ejection cycle (S7: NO), the CPU 91 sets the transfer timing for the n+1-th ejection cycle to the "first timing" (S11) and returns the process to S3. For example, as shown in FIG. 5(c), the transfer timing for the third ejection cycle is set to the "second timing" (S10), and since the transfer timing for the third ejection cycle has not occurred during the transfer of the selection signal SIN for the second ejection cycle (S7: NO), the transfer timing for the fourth ejection cycle is set to the "first timing".

[0052] 5(c), when a transfer timing for the second ejection cycle occurs during the transfer of the selection signal SIN for the first ejection cycle (S7: YES), the CPU 91 starts the transfer of the signal for the second ejection cycle by the transfer circuit 942 immediately after the selection signal SIN is latched at the end of the transfer of the selection signal SIN for the first ejection cycle (S8: transfer process). As a result, even if a transfer timing for the next ejection cycle occurs during the transfer of the selection signal SIN for one ejection cycle by the transfer circuit 942, the waveform signal FIRE and the selection signal SIN for the next ejection cycle can be transferred to the driver IC 14, and dot dropout can be suppressed.

[0053] The waveform signal FIRE for the nth ejection cycle transferred in the transfer process (S8) is the same as the waveform signal FIRE for the nth ejection cycle transferred in S3 when the transfer timing for the nth ejection cycle does not occur during the transfer of the selection signal SIN for the (n-1)th ejection cycle (S7: NO). In this case, by performing the transfer process (S8) without changing the waveform signal FIRE, the process can be simplified compared to changing the waveform signal FIRE (for example, replacing it with another waveform signal having a shorter transfer time).

[0054] 5(c), if the transfer timing for the second ejection cycle occurs during the transfer of the selection signal SIN for the first ejection cycle (S7: YES), the CPU 91 sets the transfer timing for the third ejection cycle to the "second timing" (a timing not based on the actual moving speed of the carriage 20) (S10). This allows the waveform signal FIRE and the selection signal SIN to be transferred reliably even if the moving speed of the carriage 20 fluctuates.

[0055] As shown in Fig. 5(c), after the CPU 91 sets the transfer timing for the third ejection cycle to the "second timing" (S10), if the transfer timing for the third ejection cycle does not occur during the transfer of the selection signal SIN for the second ejection cycle (S7: NO), the transfer timing for the fourth ejection cycle is set to the "first timing". In other words, after performing the transfer at the "second timing" to ensure the transfer, once the fluctuation in the moving speed of the carriage 20 has settled, the transfer is performed at the "first timing" based on the moving speed of the carriage 20. This makes it possible to maintain the recording quality.

[0056] The second timing is based on a predetermined moving speed (the ideal moving speed of carriage 20). In this case, it is possible to realize both the transfer of waveform signal FIRE and selection signal SIN and the maintenance of recording quality.

[0057] Next, a second embodiment of the present invention will be described with reference to FIG.

[0058] The second embodiment differs from the first embodiment in that the transport mechanism 50 includes a corrugated shape imparting unit 510 and in that the second timing is set in consideration of the corrugated shape imparted by the corrugated shape imparting unit 510.

[0059] The corrugated shape imparting section 510 imparts a corrugated shape along the scanning direction to the paper P, and includes five corrugated plates 511, four ribs 512, and spur rollers 513 and 514.

[0060] The five corrugated plates 511 are disposed at equal intervals in the scanning direction. Each corrugated plate 511 includes a base portion that covers the upper roller of the roller pair 51 on the upstream side in the transport direction relative to the head 10, and a pressing portion that extends from the base portion to the downstream side in the transport direction. A small gap is provided between the pressing portion and the surface of the platen 40.

[0061] The four ribs 512 each extend in the transport direction between two corrugated plates 511 adjacent in the scanning direction. The upper end of each rib 512 is located above the pressing portion of each corrugated plate 511. In this positional relationship, the upper end of each rib 512 supports the paper P from below, and the pressing portions of each corrugated plate 511 press the paper P from above, thereby imparting a corrugated shape along the scanning direction to the paper P.

[0062] The spur rollers 513 and 514 constitute the upper rollers of the roller pair 52 downstream in the transport direction relative to the head 10. The spur roller 513 is positioned so as to overlap with each of the four ribs 512 in the transport direction. The spur roller 514 is positioned so as to overlap with each of the five corrugated plates 511 in the transport direction. The contact point between the spur roller 513 and the lower roller (not shown) of the roller pair 52 is above the lower end of the spur roller 514. In this positional relationship, the lower roller of the roller pair 52 supports the paper P from below, and the spur roller 514 presses the paper P from above, giving the paper P a corrugated shape along the scanning direction.

[0063] The corrugated shape imparting section 510 imparts a corrugated shape to the paper P along the scanning direction, so that the paper P is given stiffness and good transport is achieved.

[0064] However, in order to maintain the recording quality when a corrugated shape is applied to the paper P, it is necessary to change the ink ejection timing (ejection period) from the nozzles N from the ejection timing when a corrugated shape is not applied to the paper P. Therefore, in this embodiment, the second timing is set in consideration of not only the predetermined movement speed (the ideal movement speed of the carriage 20) but also the corrugated shape applied by the corrugated shape applying unit 510.

[0065] According to this embodiment, in addition to the effects of the first embodiment, when a waveform shape is imparted to the paper P, by appropriately setting the second timing, it is possible to more reliably transfer the waveform signal FIRE and the selection signal SIN and maintain the recording quality.

[0066] Next, a third embodiment of the present invention will be described.

[0067] The third embodiment differs from the first embodiment in that the second timing is set based on a time interval stored in a ROM 92 (storage unit).

[0068] In this embodiment, for example, when the printer 100 is manufactured, at regular intervals while the printer 100 is in use, at intervals designated by the user, etc., a time interval from a first timing related to one ejection cycle to a first timing related to the next ejection cycle is stored in the ROM 92. The CPU 91 sets the second timing based on the time interval stored in the ROM 92.

[0069] According to this embodiment, by setting the second timing based on the time interval stored in ROM 92, the second timing does not become inaccurate due to timer failure or the like, compared to setting the second timing by a timer built into the control device 90 as in the first embodiment, and the transfer of the waveform signal FIRE and the selection signal SIN can be more reliably achieved.

[0070] <Modification> Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various design modifications are possible within the scope of the claims.

[0071] In the embodiment described above (see FIG. 5), the waveform signal FIRE and the selection signal SIN start to be transferred at the same timing (the time when the transfer circuit receives a signal from the output circuit) in each ejection cycle, but this is not limited to this. For example, the waveform signal FIRE may start to be transferred first in each ejection cycle, and the selection signal SIN may start to be transferred after a delay time has elapsed since the start of the transfer of the waveform signal FIRE.

[0072] An output circuit and / or a transfer circuit may be provided for each group of actuators.

[0073] The circuit that outputs the waveform signal and the circuit that outputs the selection signal may be provided separately, in which case the two circuits form an output circuit.

[0074] Similarly, the circuit for transferring the waveform signal and the circuit for transferring the selection signal may be provided separately, in which case the two circuits form a transfer circuit.

[0075] In the above embodiment, the transfer circuit transfers the waveform signal and the selection signal to the drive circuit as differential signals, but the present invention is not limited to this.

[0076] The waveform signals and the selection signals are not limited to being serial, but may be parallel.

[0077] In the above embodiment, the actuator is driven by a "push-shooting method (a method in which the actuator 13x is held flat in advance, and the actuator 13x is deformed to a convex shape toward the pressure chamber 12p at a predetermined timing, thereby reducing the volume of the pressure chamber 12p and ejecting ink from the nozzle N)" but is not limited to this. Alternatively, a "pull-shooting method (a method in which the volume of the pressure chamber 12p is temporarily increased and then returned to its original volume after a predetermined time has elapsed, thereby ejecting ink from the nozzle N)" may be employed. In the "pull-shooting method," when the volume of the pressure chamber 12p increases, a negative pressure wave is generated in the pressure chamber 12p, and then the negative pressure wave is inverted and returns to the pressure chamber 12p as a positive pressure wave, at which point the volume of the pressure chamber 12p is returned to its original state, and a positive pressure wave is generated in the pressure chamber 12p, and these pressure waves are superimposed. Such superimposition of pressure waves can apply a large pressure to the ink in the pressure chamber 12p. In the case of the "back-and-forth method," the waveform data F0 (see FIG. 4(a)) maintains the potential of the individual electrode 13c at the drive potential (VDD). The waveform data F1 to F3 (see FIG. 4(b) to (d)) set the potential of the individual electrode 13c to the drive potential (VDD) at the beginning of the ejection cycle, and then change the potential between the drive potential (VDD) and the ground potential (0V).

[0078] The actuator is not limited to a piezoelectric type, and may be of another type (for example, a thermal type using a heating element, an electrostatic type using electrostatic force, etc.).

[0079] In the above embodiment, the head is a serial type, but may be a line type. When the head is a line type, the transport mechanism corresponds to a moving mechanism that moves the head and the recording medium relatively, and the first timing is set based on the moving speed (transport speed) detected by a speed sensor attached to the transport motor.

[0080] The liquid ejected from the nozzles is not limited to ink, and may be a liquid other than ink (for example, a treatment liquid that aggregates or precipitates components in the ink, etc.).

[0081] The present invention is not limited to printers, but can also be applied to facsimiles, copy machines, multifunction machines, etc. The present invention can also be applied to liquid ejection devices used for purposes other than image recording (for example, liquid ejection devices that eject conductive liquid onto a substrate to form a conductive pattern).

[0082] The program according to the present invention can be distributed by recording it on a removable recording medium such as a flexible disk or a fixed recording medium such as a hard disk, or can be distributed via a communication line. [Explanation of symbols]

[0083] 100 Printer (liquid ejection device) 10 Head 13x Actuator 14 Driver IC (drive circuit) 30 Moving mechanism 50 Conveyor mechanism 510 Wave shaping part 61 Rotary encoder (speed sensor) 91 CPU (control unit) 92 ROM (memory section) 941 Output circuit 942 Transfer Circuit N Nozzle FIRE waveform signal SIN Select signal CLK Clock signal (transfer timing signal)

Claims

1. A nozzle; an actuator that applies pressure to eject liquid from the nozzle; an output circuit that outputs a waveform signal indicating a plurality of drive modes of the actuator, a selection signal for selecting one of the plurality of drive modes, and a transfer timing signal indicating a transfer timing of the waveform signal and the selection signal for each ejection period that is a period during which liquid is ejected from the nozzle; a drive circuit that supplies a drive signal indicating a drive mode selected from the plurality of drive modes based on the waveform signal and the selection signal output by the output circuit to the actuator for each ejection period; a transfer circuit that receives the waveform signal, the selection signal, and the transfer timing signal from the output circuit, and transfers the waveform signal and the selection signal to the drive circuit at the transfer timing for each ejection period; A control unit, The ejection period includes a first ejection period and a second ejection period that is a next ejection period to the first ejection period, In one ejection cycle, the transfer of the selection signal is completed after the transfer of the waveform signal is completed, and the selection signal is latched at the end of the transfer of the selection signal, The control unit is a determination process for determining whether or not the transfer timing for the second ejection period has occurred during the transfer of the selection signal for the first ejection period by the transfer circuit; a transfer process in which, when it is determined in the determination process that the transfer timing for the second ejection cycle has occurred during the transfer of the selection signal for the first ejection cycle by the transfer circuit, the transfer circuit starts transferring the waveform signal for the second ejection cycle immediately after the selection signal is latched at the end of the transfer of the selection signal for the first ejection cycle, and starts transferring the selection signal for the second ejection cycle after the start of the transfer of the waveform signal for the second ejection cycle; A liquid ejection apparatus comprising:

2. The liquid ejection device described in claim 1, characterized in that the waveform signal related to the second ejection period transferred in the transfer process is the same as the waveform signal related to the second ejection period transferred when it is determined in the judgment process that the transfer timing related to the second ejection period has not occurred during the transfer of the selection signal related to the first ejection period by the transfer circuit.

3. A head in which the nozzle is formed; a moving mechanism for relatively moving the head and a recording medium; a speed sensor that detects a relative moving speed between the head and the recording medium caused by the moving mechanism; Further equipped with the control unit causes the driving circuit to supply the driving signal to the actuator while causing the moving mechanism to move the head and the recording medium relatively to one another, thereby causing liquid to be ejected from the nozzle toward the recording medium; the transfer timing signal is based on the moving speed detected by the speed sensor; the transfer timing includes a first timing indicated by the transfer timing signal and a second timing not based on the moving speed detected by the speed sensor; The ejection period further includes a third ejection period that is a next ejection period after the second ejection period, The control unit is A liquid ejection device as described in claim 1 or 2, characterized in that when it is determined in the judgment process that the transfer timing related to the second ejection cycle has occurred while the selection signal related to the first ejection cycle is being transferred by the transfer circuit, the transfer timing related to the third ejection cycle is set to the second timing.

4. The ejection period further includes a fourth ejection period that is a next ejection period after the third ejection period, The control unit is A liquid ejection device as described in claim 3, characterized in that after the transfer timing for the third ejection cycle is set to the second timing, if it is determined that the first timing for the fourth ejection cycle has not occurred during the transfer of the selection signal for the third ejection cycle by the transfer circuit, the transfer timing for the fourth ejection cycle is set to the first timing.

5. 5. The liquid ejection apparatus according to claim 3, wherein the second timing is based on a predetermined moving speed.

6. a conveying mechanism that conveys the recording medium in a conveying direction, the conveying mechanism further including a corrugated shape imparting unit that imparts a corrugated shape to the recording medium along a direction perpendicular to the conveying direction; The liquid ejection device according to claim 5 , wherein the second timing is further based on the waveform.

7. A storage unit is further provided to store a time interval from the first timing in one of the ejection cycles to the first timing in the next ejection cycle, 5. The liquid ejection apparatus according to claim 3, wherein the second timing is based on the time interval stored in the storage unit.

8. a control method for controlling a liquid ejection device comprising: a nozzle; an actuator that applies pressure to eject liquid from the nozzle; an output circuit that outputs a waveform signal indicating a plurality of drive modes of the actuator, a selection signal for selecting one of the plurality of drive modes, and a transfer timing signal indicating a transfer timing of the waveform signal and the selection signal for each ejection cycle that is a cycle for ejecting liquid from the nozzle; a drive circuit that supplies a drive signal indicating a drive mode selected from the plurality of drive modes based on the waveform signal and the selection signal output by the output circuit to the actuator for each ejection cycle; and a transfer circuit that receives the waveform signal, the selection signal, and the transfer timing signal from the output circuit, and transfers the waveform signal and the selection signal to the drive circuit at the transfer timing for each ejection cycle, The ejection period includes a first ejection period and a second ejection period that is a next ejection period to the first ejection period, In one ejection cycle, the transfer of the selection signal is completed after the transfer of the waveform signal is completed, and the selection signal is latched at the end of the transfer of the selection signal, a determination process for determining whether or not the transfer timing for the second ejection period has occurred during the transfer of the selection signal for the first ejection period by the transfer circuit; a transfer process in which, when it is determined in the determination process that the transfer timing for the second ejection cycle has occurred during the transfer of the selection signal for the first ejection cycle by the transfer circuit, the transfer circuit starts transferring the waveform signal for the second ejection cycle immediately after the selection signal is latched at the end of the transfer of the selection signal for the first ejection cycle, and starts transferring the selection signal for the second ejection cycle after the start of the transfer of the waveform signal for the second ejection cycle; A control method comprising:

9. a liquid ejection device comprising: a nozzle; an actuator that applies pressure to eject liquid from the nozzle; an output circuit that outputs a waveform signal indicating a plurality of drive modes of the actuator, a selection signal for selecting one of the plurality of drive modes, and a transfer timing signal indicating a transfer timing of the waveform signal and the selection signal for each ejection period that is a period during which liquid is ejected from the nozzle; a drive circuit that supplies a drive signal indicating a drive mode selected from the plurality of drive modes based on the waveform signal and the selection signal output by the output circuit to the actuator for each ejection period; and a transfer circuit that receives the waveform signal, the selection signal, and the transfer timing signal from the output circuit, and transfers the waveform signal and the selection signal to the drive circuit at the transfer timing for each ejection period, wherein the ejection periods include a first ejection period and a second ejection period that is the next ejection period after the first ejection period, and wherein the liquid ejection device is configured such that, in one ejection period, transfer of the selection signal ends after the end of transfer of the waveform signal, and the selection signal is latched at the end of transfer of the selection signal; a determination means for determining whether or not the transfer timing for the second ejection period has occurred during the transfer of the selection signal for the first ejection period by the transfer circuit; and a transfer means for starting transfer of the waveform signal for the second ejection cycle by the transfer circuit immediately after the selection signal is latched at a point in time when the transfer of the waveform signal for the first ejection cycle ends, when the determination means determines that the transfer timing for the second ejection cycle has occurred during the transfer of the selection signal for the first ejection cycle by the transfer circuit; and for starting transfer of the selection signal for the second ejection cycle after a point in time when the transfer of the waveform signal for the second ejection cycle starts; The program is characterized by causing the program to function as follows.

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