JP2019202268A - Printing device - Google Patents

Abstract

To suppress change in ejection volume and ejection speed of liquid droplets due to oscillation.SOLUTION: The printing device comprises an inkjet head 34 comprising a plurality of nozzles and a control part 9 that performs control by which ejection waveforms, oscillation waveforms or flat waveforms are outputted to the nozzles on the basis of printing data indicating waveforms and read-ahead printing data. The control part 9 performs control by which the flat waveforms are outputted to the nozzles when the printing data indicates the oscillation waveforms and when the read-ahead printing data indicates the ejection waveforms.SELECTED DRAWING: Figure 5

Description

  The present disclosure relates to a printing apparatus.

  Conventionally, as a method for forming an organic light emitting layer of an organic EL (Electro Luminescence) display panel, a method using an ink jet printing apparatus is known. In this method, an organic light emitting layer is formed by discharging ink droplets containing an organic light emitting material and a solvent from a printing apparatus to a pixel region of a substrate.

  The printing apparatus discharges liquid droplets from each nozzle while landing the liquid droplets on the print object while controlling the positional relationship between the nozzles provided in the inkjet head and the print object.

  For example, Patent Document 1 discloses that pixels having a predetermined line width are formed by droplets that have landed on a substrate spreading in a pixel region in the same direction. The diameter of the nozzle currently disclosed by patent document 1 is 20-30 micrometers. The nozzle pitch is 100 to 150 μm, and the number of nozzles is 100 to 300.

  In the method of forming a plurality of pixels having a line width as in the above-mentioned Patent Document 1, when the volume or speed of the droplets discharged from each nozzle varies, the correct amount of droplets does not land in the pixel region. . Therefore, the thickness of the formed light emitting layer may vary.

  1A and 1B are diagrams showing the structure of a thin-film inkjet head. As shown in FIGS. 1A and 1B, the inkjet head includes a nozzle 200, a pressure chamber 210 that communicates with the nozzle 200, a supply pressure chamber 230 that communicates with the pressure chamber 210 and supplies liquid to the pressure chamber 210. And having. A thin film piezoelectric element 220 is provided on the upper part of the diaphragm 212 forming a part of the pressure chamber 210. This ink jet head operates as follows.

  When a voltage is applied to the piezoelectric element 220, the piezoelectric element 220 is deformed from the state shown in FIG. 1A to the state shown in FIG. 1B. Thereby, the capacity | capacitance of the pressure chamber 210 becomes small and a pressure is transmitted to a liquid (for example, refer patent document 2).

  Here, as a drive waveform for driving the piezoelectric element 220, for example, the discharge waveform shown in FIG. 2A is used. As a method for ejecting liquid droplets, it is generally known to resonate and eject vibration waves generated in the pressure chamber 210. By causing the vibration wave to resonate, it is possible to eject a droplet at a low voltage.

  When the ejection waveform shown in FIG. 2A is applied to the piezoelectric element 220, a vibration wave is generated in the pressure chamber 210. The vibration wave strikes a wall in the pressure chamber 210 and vibrates while being attenuated at a specific period (hereinafter referred to as a resonance period T). The resonance period T is a specific value determined by the size and shape of the pressure chamber 210 or the physical properties (for example, viscosity) of the ink.

  Further, as shown in FIG. 2A, the ejection waveform is often used by combining two or more pulses (pulse A and pulse B in the figure). The second pulse B is applied to the vibration wave generated by the first pulse A at the timing of resonance. As a result, the efficiency of ejecting droplets increases, and it becomes possible to eject droplets at a lower voltage. The pulse A plays a role like a run (preparation) until the pulse B is applied. The timing of applying the pulse B is preferably when the time of the resonance period T has elapsed since the application time of the pulse A.

  FIG. 3 shows an example of a conventional printing apparatus.

  The encoder 2 detects the position of a stage (not shown) on which the print object is placed. The adjusting means 121 outputs a waveform generation trigger to the discharge waveform generator 5 and the oscillating waveform generator 6 when detecting the droplet discharge timing based on the detection result of the encoder 2 (not shown). The adjustment unit 121 also outputs a waveform generation trigger to the control unit 122.

  When the discharge waveform generator 5 receives a waveform generation trigger, the discharge waveform generator 5 outputs the discharge waveform shown in FIG. When the waveform generator 6 receives a waveform generation trigger, the waveform generator 6 outputs the waveform shown in FIG. 2B to the switching means 10.

  When receiving the waveform generation trigger, the control unit 122 controls the switching unit 10 based on the print data read out from the storage unit 7 (which may be referred to as image data). The print data is data indicating whether or not to discharge droplets. The print data is 1-bit data for one nozzle and one position (pixel). The print data is updated every time a waveform generation trigger occurs.

  The control unit 122 outputs a control signal instructing to select the ejection waveform output from the ejection waveform generator 5 to the switching unit 10 when the print data indicates ejection of the droplet. In addition, when the print data indicates non-ejection of droplets, the control unit 122 outputs a control signal instructing to select a swing waveform to the switching unit 10. Moreover, the control part 122 outputs the control signal which instruct | indicates to select the flat waveform shown to FIG. 2C to the switching means 10 at the time of the waiting between discharge and rocking | swiveling (non-discharge).

  The ejection waveform is a waveform applied to a nozzle that ejects droplets among a plurality of nozzles.

  The oscillating waveform is a waveform applied to a nozzle that does not discharge droplets among a plurality of nozzles. This swing waveform is applied for the purpose of swinging the ink in the pressure chamber 210 (hereinafter referred to as swing). Therefore, the amplitude level of the oscillating waveform is a level at which ejection is not performed.

  The flat waveform is a waveform at a constant level that does not cause ejection or oscillation. In the conventional printing apparatus shown in FIG. 3, it is used as a connection between the ejection waveform and the oscillation waveform.

  The switching unit 10 selects and outputs any one of a discharge waveform, a swing waveform, and a flat waveform based on a control signal from the control unit 122. Any of the output waveforms is amplified by the amplifier 11 and applied to an inkjet piezoelectric element (for example, the piezoelectric element 220 shown in FIG. 1).

  As described above, in the conventional printing apparatus shown in FIG. 3, based on the position of the stage detected by the encoder 2, whether or not to discharge droplets at each nozzle is controlled, so that the liquid is placed at a desired position. Drops can be ejected.

  In the above-described ejection circuit, there is a possibility that a phenomenon in which ink is clogged in the nozzle (hereinafter referred to as nozzle clogging) occurs when the ejection of the liquid droplet is stopped for a certain period of time. When nozzle clogging occurs, the volume of the ejected droplet changes, and in the worst case, the droplet cannot be ejected.

  The nozzle clogging described above is caused by evaporation of the solvent of the ink exposed to the atmosphere in the vicinity of the nozzle. When the ink solvent evaporates, the ink concentration increases, and as a result, the ink viscosity increases. As a result, the ink hardens and nozzle clogging occurs. Since the viscosity of the ink increases exponentially with respect to the ink density, nozzle clogging occurs due to a slight increase in the ink density.

  Such nozzle clogging can be prevented by applying the oscillation waveform to the nozzle when the nozzle does not discharge and causing the ink in the pressure chamber to oscillate.

JP 2003-266669 A JP 2017-105021 A

  In the droplet discharge method using the resonance period T, it is possible to discharge the droplet by lowering the starting voltage. However, the resonance period T varies between a plurality of ink jet heads or between a plurality of nozzles in the same ink jet head due to manufacturing variations of inkjet heads and variations of constituent members.

  If the drive waveform is adjusted for each nozzle, an optimum drive waveform can be set according to the variation in the resonance period T. However, the number of nozzles in one inkjet head is generally 100 to 1000. Therefore, in order to set a drive waveform for each nozzle, the configuration of the control board and the like becomes complicated, which is not practical.

  In recent years, ink jet heads that can reduce the droplets that can be ejected are often used as the ejection pattern for a printing object becomes more precise. In such an ink jet head, the decay time becomes long, and the influence on the droplet ejection speed becomes large.

  Furthermore, when the discharge pattern is made highly precise, it is necessary to increase the discharge frequency in order to maintain productivity. When the scanning speed is Vmm / second and the maximum frequency for all nozzles is FkHz, the discharge interval is V / F μm. However, when the discharge frequency is increased, the time interval between the discharge waveform and the swing waveform is reduced. Therefore, the oscillation by the oscillation waveform affects the ejection of the droplet using resonance, and the ejection volume and ejection speed of the droplet change.

  An object of one embodiment of the present disclosure is to provide a printing apparatus that can suppress changes in the ejection volume and ejection speed of droplets due to rocking.

  A printing apparatus according to an aspect of the present disclosure includes: an inkjet head including a plurality of nozzles that operate according to a waveform; and waveform data that indicates the waveform to be output to the nozzle in time series. Any one of a discharge waveform that causes ink droplets to be discharged, a swing waveform that causes the nozzle to swing the ink, or a flat waveform that does not cause the nozzle to perform both the discharge and the swing. A control unit that performs control to output to the nozzle, and the control unit outputs the oscillation waveform at a predetermined timing based on the waveform data, and at a timing later than the predetermined timing. When it is determined that the ejection waveform is output, control is performed to output the flat waveform to the nozzle at the predetermined timing.

  According to the present disclosure, it is possible to suppress changes in the discharge volume and discharge speed of droplets due to rocking.

Diagram showing the structure of a thin-film inkjet head Diagram showing the structure of a thin-film inkjet head Diagram showing an example of discharge waveform A figure showing an example of the oscillation waveform Diagram showing flat waveform Diagram showing the configuration of a conventional printing device 2 is a diagram illustrating a main configuration of a printing apparatus according to Embodiment 1 of the present disclosure. FIG. The figure which shows the structural example of the control system which concerns on Embodiment 1 of this indication. The figure which shows the structural example of the control part which concerns on Embodiment 1 of this indication, and the usage example of prefetch print data The figure which shows the structural example of the control part which concerns on Embodiment 2 of this indication, and the usage example of prefetch print data The figure which shows the structural example of the control part which concerns on Embodiment 3 of this indication, and the usage example of prefetch print data The figure which shows the structural example of the control system which concerns on Embodiment 4 of this indication. The figure which shows the usage example of the control part which concerns on Embodiment 4 of this indication, a rocking | fluctuation instruction | indication part, and prefetch print data The figure which shows the structural example of the control system which concerns on Embodiment 5 of this indication. The figure which shows the usage example of the control part which concerns on Embodiment 5 of this indication, a rocking | swiveling instruction | indication part, and prefetch print data

  Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the component which is common in each figure, and those description is abbreviate | omitted suitably.

  In the following, as an example, an ink jet printing apparatus (hereinafter referred to as a printing apparatus) used in a process for applying a light emitting layer of an organic EL panel will be described. However, the printing apparatus of the present disclosure can be widely applied to uses other than the application process of the light emitting layer of the organic EL panel. For example, the printing apparatus of the present disclosure can be applied to a consumer printer or the like.

(Embodiment 1)
A printing apparatus according to the first embodiment of the present disclosure will be described.

<Main configuration of printing device>
The main configuration of the printing apparatus according to the present embodiment will be described with reference to FIG. FIG. 4 is a diagram illustrating a main configuration of the printing apparatus according to the present embodiment.

  As shown in FIG. 4, the printing apparatus includes an X-axis movement stage 32 that moves in the X-axis direction 36 and a Y-axis movement stage 33 that moves in the Y-axis direction 37.

  On the suction stage (not shown) on the Y-axis moving stage 33, the organic EL panel 31 is placed. The organic EL panel 31 is an example of a printing object on which ink droplets are applied by a printing apparatus.

  The X-axis moving stage 32 includes an inkjet head 34 and a microscope camera 35 that confirms the discharge position.

  The inkjet head 34 includes a plurality of nozzles (not shown) arranged along the X-axis direction 36. Each nozzle, for example, ejects ink droplets of different colors. The inkjet head 34 may have the configuration shown in FIGS. 1A and 1B, for example.

  In such a printing apparatus of the present disclosure, when the Y-axis moving stage 33 moves in the Y-axis direction 37, a wide line is printed on the organic EL panel 31 by discharging droplets from a plurality of nozzles. be able to.

  In addition, although the printing apparatus according to the present disclosure has exemplified the configuration in which the discharge position is changed by moving the X-axis movement stage 32 and the Y-axis movement stage 33, the invention is not limited thereto.

  Although not shown in FIG. 4, the printing apparatus according to the present disclosure includes a control system that controls ejection of droplets. This control system will be described later with reference to FIG.

<Waveform>
The waveforms used in the printing apparatus of the present disclosure are the ejection waveform shown in FIG. 2A, the swing waveform shown in FIG. 2B, and the flat waveform shown in FIG. 2C.

  As described above, the ejection waveform is a waveform applied to a nozzle that ejects droplets among a plurality of nozzles. As shown in FIG. 2A, the ejection waveform is configured by combining pulse A and pulse B (see FIG. 2A). Pulse A is a preliminary vibration, and pulse B is a main vibration. Since this vibration causes ink droplets to eject from the nozzle, the voltage value is larger than that of the preliminary vibration. The preliminary vibration plays a role of assisting the main vibration. By assisting this vibration, it is possible to reduce the voltage required for discharging the droplets in the inkjet head 34.

  As described above, the oscillating waveform is a waveform applied to a nozzle that does not discharge droplets among a plurality of nozzles. This swing waveform is applied for the purpose of swinging the ink in the pressure chamber 210. Therefore, the amplitude level of the oscillating waveform is a level at which ejection is not performed.

  As described above, the flat waveform is a waveform of a certain level. In the conventional printing apparatus shown in FIG. 3, the flat waveform is used to connect the ejection waveform and the oscillation waveform. In this embodiment, the flat waveform is applied for the purpose of preventing the nozzle from being ejected or oscillation. The

<Control system configuration>
The configuration of the control system of the printing apparatus according to the present disclosure will be described with reference to FIG. FIG. 5 is a diagram illustrating a configuration example of a control system.

  The motor 1 is a drive source for the Y-axis moving stage 33.

  The encoder 2 detects the position of the Y-axis moving stage 33 and outputs a pulse to the adjusting means 3 at regular intervals.

  The adjusting means 3 outputs a trigger signal to the ejection waveform generator 5 and the oscillating waveform generator 6 based on the pulse from the encoder 2 (not shown). The adjusting unit 3 also outputs a trigger signal to the control unit 9.

  When the discharge waveform generator 5 receives the trigger signal from the adjusting means 3, it generates the discharge waveform shown in FIG. 2A and outputs the discharge waveform to the switching means 10.

  When the oscillating waveform generator 6 receives the trigger signal from the adjusting unit 3, the oscillating waveform generator 6 generates the oscillating waveform shown in FIG. 2B and outputs the oscillating waveform to the switching unit 10.

  When the control unit 9 receives the trigger signal from the adjustment unit 3, the control unit 9 reads out the print data from the storage unit 7 and reads out the pre-read print data from the pre-read storage unit 8. Then, the control unit 9 instructs to select one of the ejection waveform from the ejection waveform generator 5, the oscillation waveform from the oscillation waveform generator 6, and the flat waveform based on the data. A control signal is output to the switching means 10. A specific configuration and operation of the control unit 9 will be described later with reference to FIG.

  The print data and the pre-read print data used in the control unit 9 are data that varies depending on the position of the Y-axis moving stage 33, and the type of waveform (discharge waveform, oscillation waveform, or flat waveform) applied to each nozzle. Indicates. The print data and the pre-read print data correspond to an example of “waveform data”.

  The storage unit 7 holds print data indicating a waveform applied at a predetermined timing.

  The prefetch storage unit 8 holds prefetch print data indicating a waveform applied at a timing later than the predetermined timing.

  Note that a plurality of prefetch storage units 8 can be provided as shown in FIG. As a result, it is possible to change the interval for prohibiting the oscillating waveform before discharging the droplet.

  Based on the control signal from the control unit 9, the switching unit 10 selects any one of a discharge waveform, a swing waveform, and a flat waveform and outputs the selected waveform to the amplifier 11.

  The amplifier 11 amplifies the waveform from the switching means 10 and outputs it to the inkjet head 34. Thereby, any one of the ejection waveform, the swing waveform, and the flat waveform is applied to the piezoelectric element (not shown) of the inkjet head 34.

<Control unit 9>
The configuration of the control unit 9 will be described with reference to FIG. FIG. 6 is a diagram illustrating an example of the control unit 9 and the pre-read print data.

  As shown in FIG. 6, the control unit 9 includes a D flip-flop circuit 101, an inverting circuit 102, a buffer 103, an AND circuit 104, and an OR circuit 105 as digital logic elements.

  The D flip-flop circuit 101 outputs the input signal D at the timing of receiving the trigger signal from the adjusting unit 3.

  The inverting circuit 102 inverts and outputs the input signal D from the D flip-flop circuit 101.

  The buffer 103 outputs the input signal D from the D flip-flop circuit 101 as it is.

  The AND circuit 104 is a logical product, and outputs “1” when all of the plurality of input signals are “1”.

  The OR circuit 105 is a logical sum, and outputs “1” when any of the plurality of input signals is “1”.

  As shown in FIG. 6, the print data, the pre-read print data (1), and the pre-read print data (2) are composed of 2 bits of waveform data bit 0 and waveform data bit 1 for each nozzle.

  The print data, the pre-read print data (1), and the pre-read print data (2) are used for controlling the operation of the nozzle at each time. As described above, the print data indicates the type of waveform at a predetermined timing (hereinafter referred to as the first timing). The pre-read print data (1) indicates a waveform at the second timing next to the first timing. The pre-read print data (2) indicates a waveform at the third timing next to the second timing.

  When the waveform data bit0 is valid (that is, “1”) in the print data, pre-read print data (1), or pre-read print data (2), the control unit 9 displays the waveform indicated by the data as an ejection waveform. It is judged that.

  Further, when the waveform data bit1 is valid (that is, “1”) in the print data, the pre-read print data (1), or the pre-read print data (2), the control unit 9 displays the waveform indicated by the data. Judged to be an oscillating waveform.

  In addition, in the print data, the pre-read print data (1), or the pre-read print data (2), the control unit 9 determines that the waveform data bit0 and the waveform data bit1 are invalid (that is, “0”). It is determined that the waveform shown in the data is a flat waveform.

  In the present embodiment, neither the waveform data bit0 nor the waveform data bit1 is effective at the same time.

<Control processing>
Control processing performed by the control unit 9 will be described with reference to FIG.

  When the control unit 9 determines that the print data indicates the discharge waveform, the control unit 9 selects the discharge waveform regardless of the waveforms indicated by the pre-read print data (1) and the pre-read print data (2). The switching means 10 is instructed (see No. 1 in Table 1 below).

  If the control unit 9 determines that the print data indicates a flat waveform, the control unit 9 selects the flat waveform regardless of the waveforms indicated by the pre-read print data (1) and the pre-read print data (2). Thus, the switching means 10 is instructed (see No. 11 in Table 1 below).

  In addition, when the control unit 9 determines that the print data indicates a swing waveform, the control unit 9 further performs determination based on the pre-read print data (1) and the pre-read print data (2).

  For example, when it is determined that at least one of the pre-read print data (1) and the pre-read print data (2) indicates a discharge waveform, the control unit 9 instructs the switching unit 10 to select a flat waveform. (See Nos. 2-5 and 8 in Table 1 below).

  For example, when the control unit 9 determines that neither the pre-read print data (1) nor the pre-read print data (2) shows the ejection waveform, the control unit 9 instructs the switching unit 10 to select the swing waveform. (See Nos. 6, 7, 9, and 10 in Table 1 below).

A summary of the control processing described above is shown in Table 1 below. In Table 1, “*” means that either “1” or “0” may be used.

  In the above description, the case where the control unit 9 reads the print data and the pre-read print data (1) and (2) has been described as an example, but the present invention is not limited to this. For example, the control unit 9 may read only the prefetch print data (2) and set the print data and the prefetch print data (1) based on the read data. In this case, the control unit 9 may set the pre-read print data (1) by shifting the pre-read print data (2) at the timing of performing control based on the pre-read print data (2). Further, the control unit 9 may set the print data by shifting the prefetch print data (1) at the timing of performing control based on the prefetch print data (1). With such an operation, the control system (printing apparatus) can be configured more simply.

  In addition, when creating print data in advance, it is possible to set so as not to oscillate immediately before ejecting droplets in consideration of the conditions shown in Table 1. However, in that case, the load when creating the print data, the time taken to create the print data, the time taken to transfer the print data, and the like become large. Therefore, the method of the present embodiment described above, that is, the method in which the control unit 9 performs control so as not to swing immediately before ejecting droplets based on the pre-read print data is more excellent.

  As described above, in the present embodiment, even when the rocking is performed at a predetermined timing, the control is performed so that the rocking is not performed when the ejection is scheduled after the timing. . This prevents (prohibits) shaking before ejection, and even when droplets are ejected at a high frequency, changes in the ejection volume and ejection speed of the droplets due to oscillation can be suppressed.

  In the first embodiment, the case of using the pre-read print data (1) and (2) in addition to the print data has been described as an example. However, the present invention is not limited to this. In the following, when only pre-read print data (1) is used in addition to print data (second embodiment), and pre-read print data (1), (2) and (3) are used in addition to print data. The case (Embodiment 3) will be described.

(Embodiment 2)
A printing apparatus according to the second embodiment of the present disclosure will be described.

  The main configuration and control system of the printing apparatus according to the present embodiment are the same as the configurations shown in FIGS. 4 and 5, respectively, and thus the description thereof is omitted here. In the present embodiment, the configuration and operation of the control unit 9 are different from those in the first embodiment.

  The configuration and operation of the control unit 9 according to the present embodiment will be described with reference to FIG. FIG. 7 is a diagram illustrating an example of the control unit 9 and pre-read print data according to the present embodiment.

  As shown in FIG. 7, the control unit 9 of the present embodiment mainly includes the point that the OR circuit 105 is not provided and the pre-read print data (2) as compared with the control unit 9 of the first embodiment. The difference is not used.

  Further, in the present embodiment, the configurations of the print data and the pre-read print data (1) are different from those in the first embodiment. The print data and pre-read print data (1) of the present embodiment are composed of 1 bit of only waveform data bit0 per nozzle.

  The operation of the control unit 9 of the present embodiment is as follows.

  When the control unit 9 determines that the print data indicates the discharge waveform, the control unit 9 instructs the switching unit 10 to select the discharge waveform regardless of the waveform indicated by the pre-read print data (1) (Table 2 below). No. 1 and No. 2).

  On the other hand, when the control unit 9 determines that the print data indicates a swing waveform, the control unit 9 further determines based on the pre-read print data (1).

  For example, when it is determined that the pre-read print data (1) indicates a discharge waveform, the control unit 9 instructs the switching unit 10 to select a flat waveform (see No. 3 in Table 2 below).

  For example, when the control unit 9 determines that the pre-read print data (1) indicates a swing waveform, the control unit 9 instructs the switching unit 10 to select the swing waveform (No. 2 in Table 2 below). 4).

  That is, when the waveform data bit0 of the print data is invalid, if the waveform data bit0 of the prefetch print data (1) is valid, the selection of the flat waveform is instructed, and the waveform data of the prefetch print data (1) is displayed. If bit0 is invalid, selection of the oscillation waveform is instructed.

A summary of the control process described above is shown in Table 2 below.

  In general, when a print object is deformed by expansion or contraction, it is necessary to recreate and transfer print data according to the state of expansion or contraction of the print object in order to eject droplets at the correct position. It becomes. If the print data is recreated, the transfer time increases corresponding to the capacity of the print data, which adversely affects productivity.

  In the present embodiment, the capacity of each of the print data and the pre-read print data (1) is halved compared to the first embodiment. Therefore, it is possible to halve the capacity of the storage units 7 and 8 necessary for holding such data and also to halve the data transfer time. Therefore, the printing apparatus can be reduced in size.

(Embodiment 3)
A printing apparatus according to the third embodiment of the present disclosure will be described.

  The main configuration and control system of the printing apparatus according to the present embodiment are the same as the configurations shown in FIGS. 4 and 5, respectively, and thus the description thereof is omitted here. In the present embodiment, the configuration and operation of the control unit 9 are different from those in the first embodiment.

  The configuration and operation of the control unit 9 of the present embodiment will be described with reference to FIG. FIG. 8 is a diagram illustrating an example of the control unit 9 and pre-read print data according to the present embodiment.

  As shown in FIG. 8, the control unit 9 of the present embodiment mainly includes the point that the OR circuit 105 is not provided and the pre-read print data (3) as compared with the control unit 9 of the first embodiment. The point to use is different. The pre-read print data (3) shows a waveform at the third timing next to the second timing (see the first embodiment).

  Further, in the present embodiment, as in the second embodiment, the print data and the pre-read print data (1) to (3) are configured by 1 bit of only the waveform data bit0 per nozzle.

  The operation of the control unit 9 of the present embodiment is as follows.

  When the waveform data bit0 is valid (that is, “1”) in the print data, prefetch print data (1), prefetch print data (2), or prefetch print data (3), the control unit 9 It is determined that the waveform shown in the data is a discharge waveform.

  Further, the control unit 9 determines that the waveform data bit 0 is invalid (that is, “0”) in the print data, the pre-read print data (1), the pre-read print data (2), or the pre-read print data (3). Then, it is determined that the waveform shown in the data is an oscillating waveform.

  When the control unit 9 determines that the print data indicates the discharge waveform, the control unit 9 instructs the switching unit 10 to select the discharge waveform regardless of the waveforms indicated by the pre-read print data (1) to (3). (Refer to No. 1 in Table 3 below).

  On the other hand, when the control unit 9 determines that the print data indicates a swing waveform, the control unit 9 further determines based on the pre-read print data (1) to (3).

  For example, when it is determined that at least one of the pre-read print data (1) to (3) indicates a discharge waveform, the control unit 9 instructs the switching unit 10 to select a flat waveform (see the following table). 3 No. 2-8).

  Further, for example, when the controller 9 determines that all of the pre-read print data (1) to (3) indicate a swing waveform, the control unit 9 instructs the switching means 10 to select the swing waveform ( (See No. 9 in Table 3 below).

  That is, when the waveform data bit0 of the print data is invalid, if at least one waveform data bit0 is valid among the prefetch print data (1) to (3), the selection of the flat waveform is instructed, and the prefetch is performed. If all the waveform data bit0 of the print data (1) to (3) is invalid, the selection of the swing waveform is instructed.

A summary of the control processing described above is shown in Table 3 below. In Table 3, “*” means that either “1” or “0” may be used.

(Embodiment 4)
A printing apparatus according to the fourth embodiment of the present disclosure will be described.

  The main configuration of the printing apparatus according to the present embodiment is the same as the configuration shown in FIG. Hereinafter, the control system and the like of the present embodiment will be described with reference to FIGS. FIG. 9 is a diagram illustrating a configuration example of the control system of the present embodiment. FIG. 10 is a diagram illustrating a configuration example of the control unit 9 and the swing instruction unit 15 according to the present embodiment and a usage example of prefetch print data.

  In the present embodiment, the print data and the pre-read print data (1) are composed of 1 bit including only waveform data bit0.

  As shown in FIGS. 9 and 10, the control system of the present embodiment includes a swing instruction unit 15 and a swing interval storage unit 16 in addition to the configuration of the first embodiment (see FIG. 5).

  The swing interval storage unit 16 holds data indicating a preset swing interval (hereinafter referred to as swing interval data). The swing interval is an interval from when the swing is performed until the next swing is performed. Here, a case where the swing interval is a printing line (number of droplet discharge timings) will be described as an example. In this embodiment, the swing interval of the swing interval data is set in common for all nozzles.

  As shown in FIG. 10, the swing instruction unit 15 includes a D flip-flop circuit 110, a counter 111, and a comparator 112.

  The counter 111 counts up at every droplet discharge timing (that is, every time a trigger signal is output from the adjusting unit 3).

  The comparator 112 determines whether or not the count value of the counter 111 matches the swing interval data read from the swing interval storage unit 16. When the two match, the comparator 112 outputs a swing instruction signal to the control unit 9.

  When the swing instruction signal is output from the comparator 112, the counter 111 clears the counter value at the timing when the trigger signal is output next from the adjustment unit 3. After clearing, the counter 111 starts counting up.

  When the swing instruction signal received from the swing instruction unit 15 is valid and both the waveform data bit0 of the print data and the waveform data bit0 of the pre-read print data (1) are invalid, the control unit 9 The switching means 10 is instructed to output the oscillation waveform to the nozzles. As a result, all nozzles are swung at the same timing.

  In the present embodiment, since the oscillation waveform is not output for each output (that is, trigger signal) of the adjusting means 3, the frequency of oscillation can be reduced. Therefore, energy consumption can be reduced while preventing the ink from being dried in the inkjet head 34.

  In the above description, the case where the counter 111 counts up every time the trigger signal is output has been described as an example. However, the present invention is not limited to this. For example, the output of the swing instruction signal may be controlled based on the time measured by an internal clock (not shown). In that case, the swing interval shown in the swing interval data is a preset time.

(Embodiment 5)
A printing apparatus according to the fifth embodiment of the present disclosure will be described.

  The main configuration of the printing apparatus according to the present embodiment is the same as the configuration shown in FIG. Hereinafter, the control system and the like of the present embodiment will be described with reference to FIGS. FIG. 11 is a diagram illustrating a configuration example of a control system according to the present embodiment. FIG. 12 is a diagram illustrating a configuration example of the control unit 9 and the swing instruction unit 15 according to the present embodiment and a usage example of prefetch print data.

  As shown in FIGS. 11 and 12, the printing apparatus according to the present embodiment includes a swing instruction unit 15 and a swing interval storage unit 16 as in the fourth embodiment. The difference from the fourth embodiment is that a different rocking interval is set for each nozzle.

  The swing interval storage unit 16 holds swing interval data. In this embodiment, the swing interval of the swing interval data is set for each nozzle, and the swing interval is different for each nozzle.

  The swing instruction unit 15 includes a D flip-flop circuit 110, a counter 111, and a comparator 112.

  The operations of the counter 111 and the comparator 112 are basically the same as those in the first embodiment, but in this embodiment, the timing for clearing the count value is different from that in the first embodiment. In the present embodiment, when the swing instruction signal is output from the comparator 112 or when the discharge waveform is output from the control unit 9, the counter 111 is the timing when the trigger signal is output next from the adjustment unit 3. To clear the counter value.

  When the swing instruction signal received from the swing instruction unit 15 is valid and both the waveform data bit0 of the print data and the waveform data bit0 of the pre-read print data (1) are invalid, the control unit 9 is predetermined. The switching means 10 is instructed to output a swing waveform to one nozzle. This instruction is given to each nozzle. Thereby, each nozzle swings at different timing.

  For example, 100 to 300 nozzles are provided side by side at intervals of 100 to 150 μm. Therefore, a swing waveform is output to all the nozzles, and if all the nozzles swing at a time, the ejection may be affected. In this embodiment, the timing at which the oscillation waveform is output is made different for each nozzle, so that the fluctuations in the droplet discharge volume and the ejection speed due to the oscillation waveform can be reduced.

  Embodiment 4 or 5 described above may be implemented in combination with any of Embodiments 1 to 3.

  The present disclosure is not limited to the description of each of the above embodiments, and various modifications can be made without departing from the spirit of the present disclosure.

  The printing apparatus according to the present disclosure can be widely applied to the formation of a light emitting layer of an organic EL panel whose definition is increasing, and a consumer printing technique that requires high definition.

DESCRIPTION OF SYMBOLS 1 Motor 2 Encoder 3, 121 Adjustment means 5 Discharge waveform generator 6 Oscillation waveform generator 7 Storage part 8 Prefetch storage part 9, 122 Control part 10 Switching means 11 Amplifier 15 Oscillation instruction | indication part 16 Oscillation space | interval memory | storage part 31 Organic EL panel 32 X-axis moving stage 33 Y-axis moving stage 34 Inkjet head 101, 110 D flip-flop circuit 102 Inverting circuit 103 Buffer 104 AND circuit 105 OR circuit 111 Counter 112 Comparator 200 Nozzle 210 Pressure chamber 212 Diaphragm 220 Piezoelectric element

Claims (11)

An inkjet head having a plurality of nozzles that operate according to a waveform;
Based on waveform data indicating the waveform to be output to the nozzle in time series, an ejection waveform for causing the nozzle to eject ink droplets, an oscillation waveform for causing the nozzle to perform oscillation of the ink, Or a control unit that performs control to output to the nozzle either a flat waveform that does not cause the nozzle to perform either the ejection or the oscillation,
The controller is
When it is determined that the oscillation waveform is output at a predetermined timing and the ejection waveform is output at a timing later than the predetermined timing based on the waveform data, the flat waveform is output at the predetermined timing. To output to the nozzle,
Printing device. The controller is
When it is determined that the oscillation waveform is output at a first timing and the ejection waveform is output at a second timing next to the first timing based on the waveform data, the first Control to output the flat waveform to the nozzle at the timing of
The printing apparatus according to claim 1. The controller is
When it is determined that the oscillation waveform is output at the first timing and the oscillation waveform is output at the second timing based on the waveform data, the oscillation waveform is output at the first timing. Control to output a dynamic waveform to the nozzle,
The printing apparatus according to claim 2. The controller is
Based on the waveform data, the oscillation waveform is output at a first timing, and either the second timing following the first timing or the third timing following the second timing If it is determined that the ejection waveform is output at the timing, the control is performed to output the flat waveform to the nozzle at the first timing.
The printing apparatus according to claim 1. The controller is
Based on the waveform data, the swing waveform is output at the first timing, and either the swing waveform or the flat waveform is output at the second timing and the third timing. If it is determined, control to output the oscillation waveform to the nozzle at the first timing,
The printing apparatus according to claim 4. The controller is
When it is determined that the flat waveform is output at the first timing based on the waveform data, control is performed to output the flat waveform to the nozzle at the first timing.
The printing apparatus according to claim 4 or 5. The controller is
Based on the waveform data, the swing waveform is output at a first timing, and the second timing following the first timing, the third timing following the second timing, the second timing, When it is determined that the ejection waveform is output at at least one of the fourth timings after the timing of 3, the control is performed to output the flat waveform to the nozzles at the first timing.
The printing apparatus according to claim 1. The controller is
Based on the waveform data, the swing waveform is output at the first timing, and the swing waveform is output at the second timing, the third timing, and the fourth timing. If it is determined, control to output the oscillation waveform to the nozzle at the first timing,
The printing apparatus according to claim 7. The controller is
When it is determined that the discharge waveform is output at the first timing based on the waveform data, control is performed to output the discharge waveform to the nozzle at the first timing.
The printing apparatus according to any one of claims 2 to 8. A swing instruction unit that outputs a swing instruction signal to the control unit when the swing interval set in common to all of the plurality of nozzles coincides with the actually performed swing interval. Further comprising
The controller is
Based on the waveform data, when it is determined that a waveform other than the discharge waveform is output at the predetermined timing and a timing after the predetermined timing, the swing waveform is determined based on the swing instruction signal. Control to output to all of the plurality of nozzles,
The printing apparatus according to claim 1. When the interval of oscillation set for each of the plurality of nozzles matches the interval of oscillation actually performed, there is further provided an oscillation instruction unit that outputs an oscillation instruction signal to the control unit. And
The controller is
Based on the waveform data, when it is determined that a waveform other than the discharge waveform is output at the predetermined timing and a timing after the predetermined timing, the swing waveform is determined based on the swing instruction signal. Control to output to each of the plurality of nozzles,
The printing apparatus according to claim 1.