JP5544462B2 - Discharge device - Google Patents

Description

  The present invention relates to an apparatus including a function of discharging a liquid substance.

  Patent Document 1 provides a liquid discharge head, a liquid discharge apparatus, and a liquid discharge method capable of discharging sufficiently small droplets and capable of discharging droplets having a relatively large droplet diameter. It is described. Therefore, in the liquid discharge head of Patent Document 1, a nozzle plate in which a plurality of small nozzles and large nozzles are formed, a cavity that communicates with each of the small nozzles and the large nozzles and stores liquid discharged from the discharge ports, The pressure of the liquid is generated by changing the volume of the cavity, the flow path of the liquid that communicates with the liquid, the electrostatic voltage power source that generates an electrostatic suction force by applying an electrostatic voltage between the liquid and the substrate When the liquid is discharged from the drive voltage power supply and the small nozzle, the liquid is concentrated in the electric field by controlling the electrostatic voltage power supply and the drive voltage power supply. When the liquid is discharged from the large nozzle, the liquid crystal is controlled by the control of the drive voltage power supply. It is described that there is provided a control means for ejecting a piezoelectric liquid.

  Japanese Patent Application Laid-Open No. 2004-228561 describes that gradation recording can be performed at high speed in an ink jet recording apparatus used in an output unit such as a printer or a FAX. Therefore, the pressure chamber for storing ink is provided with an ejection port for ejecting ink, and a counter electrode is disposed at a position facing the ejection port, while pressure applying means for applying pressure to the pressure chamber And electrostatic force generating means for generating an electrostatic force between the counter electrode and the ink, and when ejecting ink onto a recording medium inserted between the ejection port and the counter electrode, the pressure applying means In an ink jet recording apparatus in which pressure is applied to the pressure chamber and electrostatic force is generated by the electrostatic force generating means, ink is applied only by the pressure applied by the pressure applying means, not by the electrostatic force by the electrostatic force generating means. Pressure switching means for switching the pressure between a high pressure range in which discharge is possible and a low pressure range in which ink is discharged by the electrostatic force generated by the electrostatic force generating means in addition to the pressure applied by the pressure applying means is provided. It is has been described.

JP 2007-230179 A Japanese Patent Laid-Open No. 10-315464

  It has been studied to efficiently perform fine drawing and drawing over a wide range by a method of discharging ink by electrostatic force, a method of discharging ink by applying pressure, or a method combining these. For this reason, it has been studied to discharge droplets by changing the size of the droplet diameter according to the drawing pattern. There is a further problem to be solved in order to realize the discharge of droplets by these plural methods with one head.

One aspect of the present invention is a control unit that controls the discharge of the liquid material from the discharge head. The discharge head includes a nozzle, an electrode for obtaining an electrostatic force for discharging the liquid material from the tip of the nozzle, and an actuator for obtaining a change in internal pressure for discharging the liquid material from the tip of the nozzle or another nozzle. Including. The control unit includes a first controller that outputs a voltage signal for forming an electric field by an electrode of the ejection head based on a trigger signal, a second controller that outputs a drive signal for driving an actuator based on the trigger signal, and a voltage signal. And a mode selection unit that selects a first mode in which the liquid material is ejected from the ejection head using a combination of the drive signal and a second mode in which the liquid material is ejected from the ejection head using only the drive signal . The second controller includes a delay control circuit that changes a delay time from detection of the trigger signal to output of the drive signal according to the first mode and the second mode .

  In the method of discharging the liquid material by electrostatic force and the method of discharging the liquid material by fluctuation of internal pressure, the time from the application of the voltage signal to the electrode until the liquid material is discharged, the drive signal to the actuator There is often a difference between the time from application to the time when the liquid substance is discharged. For example, it takes time to form a conical cone (tailor cone) at the tip of the nozzle by an electric field (electrostatic field). Therefore, when the ejection head is moving relative to the target, if the output of the drive signal is not delayed with respect to the trigger signal instructing the ejection of the liquid material, A droplet ejected due to internal pressure fluctuation cannot be deposited at a common position of the target with respect to the trigger signal. Even in a method (mode) in which a liquid material is ejected by combining a voltage signal and a drive signal, the timing at which a droplet is ejected in response to a trigger signal in order to obtain the effect of electrostatic force or the timing at which electrostatic force is applied In many cases, a delay occurs.

  For this reason, this control unit includes a delay control circuit in the second controller that outputs the drive signal so that the delay time from the detection of the trigger signal to the output of the drive signal can be changed (controlled). By controlling in a direction to delay the timing of outputting the drive signal, the difference in the shortest time from the trigger signal until the liquid material is discharged can be compensated, and the time difference during which the liquid material is discharged in each mode can be reduced.

Is set by the mode selection unit, a first mode, in the second mode, the difference between the shortest time from the trigger signal until the liquid material is discharged that Do different. Thus, the delay control circuit is to change the delay time by the first and second modes.

  Another aspect of the present invention is an apparatus having the above-described control unit, the above-described ejection head, and a moving mechanism that relatively moves the target from which the liquid substance is ejected from the ejection head and the ejection head. is there. This apparatus can deposit droplets of different sizes with high accuracy on a predetermined location of the target in different ways. Therefore, it is possible to provide an apparatus suitable for an application for accurately depositing droplets of different sizes in a printing apparatus, a dispensing apparatus, or the like.

  The discharge head may include a nozzle provided with an electrode and a nozzle different from the nozzle and provided with an actuator. The discharge head may have a nozzle including an electrode and an actuator.

  This apparatus preferably further includes a high-speed camera for observing the time from when the liquid material discharged in a different manner reaches the target to the target with the delay time set to a predetermined value. . The delay time in each mode can be set according to the time from the trigger signal to landing on the target.

One of the different aspects of the present invention is a method for controlling the discharge of the liquid material from the discharge head. The discharge head includes a nozzle, an electrode for obtaining an electrostatic force for discharging the liquid material from the tip of the nozzle, and an actuator for obtaining a change in internal pressure for discharging the liquid material from the tip of the nozzle or another nozzle. Including. The method includes the following steps.
1. Output a voltage signal for forming an electric field by the electrode of the ejection head based on the trigger signal.
2. Based on the trigger signal, output a drive signal that drives the actuator after the controlled delay time has elapsed.

It is desirable that the second step of outputting the drive signal further includes the following steps.
A drive signal in the first mode for discharging the liquid material by combining the voltage signal and the drive signal is output after the first delay time has elapsed.
The second mode drive signal for discharging the liquid substance only with the drive signal is output after a second delay time different from the first delay time has elapsed.

  The time difference from the detection of the trigger signal in each mode until the target is deposited (difference in the shortest time) is compensated by controlling the delay time until the drive signal is output, and the accuracy of the position where the droplet is deposited in each mode Can be improved.

1 is a block diagram illustrating a schematic configuration of a discharge device that is an example of an embodiment of the present invention. 2A shows control for ejecting droplets by an electrostatic method, FIG. 2B shows control for ejecting droplets by an electrostatic assist piezo method, and FIG. 2C shows piezo-assist electrostatic. FIG. 2D is a timing chart showing control for ejecting droplets by a piezo method. FIG. The block diagram which shows the control system of a control unit. The block diagram which shows the control system from which a control unit differs. The flowchart which shows the outline | summary of the process of a discharge device.

  FIG. 1 shows an example of a discharge device according to an embodiment of the present invention. The discharge device 1 includes a head block 10 on which a piezo-electrostatic integrated nozzle (integrated nozzle) 50 in which both a piezo method and an electrostatic method are incorporated in the same inkjet head. The integrated nozzle 50 is provided with an electrode 57 for discharging the liquid 55L stored in the tank 55 by an electrostatic method, and a piezo actuator 58 for discharging by pressure fluctuation. The piezoelectric actuator 58 discharges the liquid 55L by pressurizing the cavity 52 of the nozzle 50 in a state where the nozzle 50 is pressurized, and discharges the liquid 55L by a reaction that makes the inside of the cavity 52 negative pressure, so-called strike. It can be used for any of the methods. Accordingly, the head 10 of the ejection device 1 is configured to function as an electrostatic ink jet head (electrostatic head) that ejects femtoliter liquid droplets to a target position of the target 2 by an electrostatic method and picoscopic by a pressure fluctuation method. It has the function of a piezo-type ink jet head (piezo head) that discharges liter-order droplets to the target position of the target 2.

  In the integrated nozzle 50, the liquid 55L can be discharged by combining an electrostatic method and a pressure fluctuation method (piezo method). One of the combined methods is an electrostatic assist piezo method, in which an electric field (electrostatic field) is formed, pressure fluctuation is applied, a part of the liquid is separated to form a droplet, and an electrostatic force is applied to the droplet. This is a method of flying by operating. One of the combined methods is a piezo-assisted electrostatic method, in which a meniscus that does not form droplets is formed by piezo (internal pressure fluctuation), and an electrostatic force due to strong concentrated electric field strength is applied to the meniscus. In this method, a jet flow is generated from the front end of the meniscus so as to land on the target 2.

  The liquid material 55L stored in the tank 55 is supplied to the nozzle 50 through the pipe 54 and guided to the tip 51 of the nozzle. A typical one that forms the body of the nozzle 50 is a glass tube. The main body of the nozzle 50 may be made of resin, ceramic, or the like. Further, the head 10 may be of a type in which the tank 55 is omitted and the liquid material 55L set in advance in the nozzle 50 is discharged.

  The liquid substance 55L is not limited to a liquid but includes a mixture of a liquid and fine particles, an aqueous solution, a solvent, a nanoparticle liquid, a UV curable liquid, an ionic fluid, an oil, a liquid crystal, an adhesive, a reagent, a biological material such as a cell or a gene. It may be a substance. The target 2 is a medium, a container, a tray, or the like for applying, printing, dispensing, mixing, and the like of these liquid substances 55L.

  The ejection device 1 has a gap control mechanism 16 for controlling the distance (interval, gap) between the tip 51 of the nozzle and the target 2 by moving the target 2 and the head block 10 in the first direction (Z direction); A moving mechanism 17 for moving the target 2 with respect to the head block 10 in a direction perpendicular to the Z direction (XY direction) is provided. The target 2 and / or the moving mechanism 17 have a function as a counter electrode that forms a pair with the electrode 57 of the nozzle 50, and by applying a potential (pulsed or constant) to the electrode 57, the electrode 57 and the target 2. An electric field is formed between them and electrostatic discharge (electrostatic attraction droplet formation) is possible.

  An example of the gap control mechanism 16 is a Z stage movable in the Z direction, and can be realized by using a known actuator such as a ball screw. An example of the movement mechanism 17 is an XY movement table. The moving mechanism 17 may be a mechanism for moving the target 2 only in the Y direction or the X direction. It is also possible to realize the gap control mechanism 16 and the XY moving mechanism 17 with one XYZ moving table.

  In the discharge device 1, when discharging the liquid 55 </ b> L by the integral nozzle 50 by the electrostatic method, the head block 10 is brought close to the target 2 by the gap control mechanism 16, and the gap between the nozzle tip 51 and the target 2 is set. A gap G1 suitable for the electrostatic method is set. This ensures that a droplet of about femtoliter can be reliably formed on the target 2 by the electrostatic method. Further, when the liquid 55L is discharged by the integrated nozzle 50 by the pressure fluctuation method, the head block 10 is moved backward from the target 2 by the gap control mechanism 16, and the pressure fluctuation method is applied between the nozzle tip 51 and the target 2. A suitable gap G2 is set. Thus, a droplet of about picoliter can be reliably formed on the target 2 by the pressure fluctuation method. In addition, the ejection device 1 includes a camera 15 for confirming the landing position when ejection is performed by each method. Also in the electrostatic assist piezoelectric method and the piezoelectric assist electrostatic method, the gap control mechanism 16 brings the head block 10 close to the target 2 in order to effectively use the electrostatic force.

  The ejection device 1 moves the target 2 with the moving mechanism 17, determines the ejection position of the target 2 with respect to the head 10, and ejects the liquid material 55 </ b> L to the position to perform the process such as drawing. This is a demand drawing apparatus. The ejection device 1 may determine the position of the target with respect to the head 10 by moving the head 10 by the moving mechanism 17.

  Further, the ejection apparatus 1 uses different ejection methods (modes) of the nozzles 50 depending on the resolution required for the processing on the target 2 or the droplet diameter, and simultaneously moves the ejection head 10 up and down (front and rear) with respect to the target 2. Thus, the gap between the tip 51 of the nozzle head (tip of the nozzle) and the target 2 is controlled.

  The ejection device 1 further includes a control unit 70 that controls the head 10. The control unit 70 applies a pulse-like voltage fluctuation (voltage signal, electrostatic pulse) P1 to the electrode 57 of the head 10 to control the head 10, and the control unit 70 The piezoelectric element 58 includes a piezo controller (second controller) 12 for controlling the head 10 by supplying a driving pulse (in many cases, pulse-like voltage fluctuation, driving signal, piezo pulse) P2 to the piezoelectric element 58. The electrostatic controller 13 includes a driver 31 that generates an electrostatic pulse P1 having a set condition, and a delay control circuit 30 that controls the timing of outputting the electrostatic pulse P1. The piezo controller 12 also includes a driver 21 that generates a piezo pulse P2 having a set condition, and a delay control circuit 20 that controls the timing of outputting the piezo pulse P2.

  The control unit 70 further includes a stage controller 18 that controls the XY movement table 17 and a processor 40 that performs overall control of the ejection device 1. The processor 40 includes an initial setting function 41 and a drawing function 42. The drawing function 42 further includes a mode selection unit 45, a delay setting unit 46, and a gap setting unit 47.

  The mode selection unit 45 selects the controller 12 or 13 according to the size of the droplet to be drawn on the target 2, and controls the controllers 12 and 13 together to combine the electrostatic pulse P1 and the piezo pulse P2 suitable for each mode. Output.

  The delay setting unit 46 sets a delay control circuit 30 of the electrostatic controller 13, a delay control circuit 20 of the piezo controller 12, and delay times Td1 and Td2 for delaying outputs of the electrostatic pulse P1 and the piezo pulse P2. As a result, the electrostatic controller 13 outputs the electrostatic pulse (voltage signal) P1 after the delay time Td1 has elapsed after detecting the trigger signal P0, and the piezo controller 12 delays after detecting the trigger signal P0. After the time Td2 has elapsed, a piezo pulse (drive signal) P2 is output.

  When the electrostatic method is selected, the gap setting unit 47 moves the head block 10 up and down so that a gap suitable for the electrostatic method is obtained by the gap control mechanism 16, and when the piezo method is selected, the gap control mechanism 16, the head block 10 is moved up and down so that a gap suitable for the pressure variation method is obtained.

  When the target 2 is moved to the position where the head 10 is drawn by the stage controller 18, the trigger signal P 0 is output from the trigger selector 14 to the controller 12 or 13, and the liquid material 55 L is discharged from the nozzle 50 to the target 2. The

  The initial setting function 41 includes a function 49 for initial setting of the delay time. Further, the ejection device 1 includes a high-speed camera 11 that is set horizontally with respect to the head 10. The function 49 for initial setting observes, with the high-speed camera 11, the time until the liquid material discharged from the head 10 lands on the target 2 from the trigger signal P 0 in a different method (mode). Specifically, after setting stable discharge conditions for the liquid material 55L on the head 10 in each mode, the high-speed camera 11 is used to capture a droplet landing image in synchronization with the trigger signal P0. Then, how many μs or ms after the input timing of the trigger signal P0 is recorded how the droplets have landed (landed) on the target 2. Further, a delay time Td2 for outputting a piezo pulse P2 for driving the piezo 58 is calculated from the recorded time T.

  Functions for setting a delay time and setting a gap can also be controlled from an application of a personal computer (PC) 5. Furthermore, it is possible to observe the output image of the high-speed camera 11 for obtaining the time until landing and the camera 15 for confirming the landing position with the PC 5, or to set the delay time from the output image. is there.

  FIGS. 2A to 2D show an electrostatic method (mode A), an electrostatic assist piezoelectric method (mode B), a piezoelectric assist electrostatic method (mode C), and a piezoelectric method (mode D). Times T1 to T4 from the trigger signal P0 to ejection (dropping) are shown. The electrostatic method (mode A) shown in FIG. 2A is a method (static) in which liquid is discharged from the tip of a nozzle using an electrostatic force as disclosed in, for example, Japanese Patent Laid-Open No. 2006-58188. When the electrostatic charge is applied, a conical tailor cone is formed at the tip of the nozzle, and when the amount of charge charged to the liquid material 55L exceeds a certain level, the top of the tailor cone is exposed to the target 2 such as the substrate. A jet stream that reaches the surface is created, and a portion of the liquid moves onto the target and becomes droplets. Therefore, when the trigger signal P0 is detected at time t0, the electrostatic pulse P1 is output, and after the formation of the tailor cone and the generation of the jet flow, the liquid droplets land on the target 2 at time t1. Since it takes time to form the tailor cone, the elapsed time T1 from time t0 to time t1 is long, and in some cases, the elapsed time T1 is several tens of ms.

  The electrostatic assist piezo method (mode B) shown in FIG. 2B forms droplets by the operation of the piezo 58 in an environment where an electrostatic field is formed by applying a voltage to the electrode 57 in contact with the liquid material 55L. This is a method of flying by applying an electrostatic force. Accordingly, when the trigger signal P0 is detected at the time t0, the electrostatic pulse P1 is output, and the piezoelectric pulse P2 is output at the time t11, whereby the droplet is deposited on the target 2 at the time t12 after the time T2 ′. This mode B is one of the methods that can discharge droplets smaller than the piezoelectric method (mode D) in a shorter time than the electrostatic method (mode A). The elapsed time T2 from the time t0 to the time t12 at which the electrostatic pulse P1 is output is generally shorter than the elapsed time T1.

  In the piezo-assist electrostatic method (mode C) shown in FIG. 2C, a meniscus similar to a tailor cone is formed at the tip 51 of the nozzle by the operation of the piezo 58, and a voltage is applied to the electrode 57 to apply the meniscus. In this method, a jet flow is formed from the tip to the target 2. Since a voltage may be applied to the electrode 57 in contact with the liquid material 55L when the meniscus protrudes from the tip 51 of the nozzle, the time during which an electric field acts on the liquid material 55L can be shortened. In this mode C, when the trigger signal P0 is detected at time t0, the piezo pulse P2 is output, and the electrostatic pulse P1 is output at time t21 when the meniscus protrudes by the piezo pulse P2, so that time T3 'has elapsed from time t21. At time t22, the droplet reaches the target 2. Since the meniscus protrudes from the tip 51 of the nozzle by the piezo pulse P2, the elapsed time T3 ′ is short and several tens of μs. This mode C is also one of the methods that can discharge droplets smaller than the piezoelectric method (mode D) in a shorter time than the electrostatic method (mode A). Therefore, the elapsed time T3 from time t0 to time t22 is generally shorter than the elapsed time T1. The electrostatic pulse P1 may be output at time t0 together with the piezo pulse P2.

  The piezo method (mode D) shown in FIG. 2D is a method in which droplets are ejected only by fluctuations in the internal pressure of the nozzle 50 obtained by the piezo 58. Therefore, when the trigger signal P0 is detected at time t0, a piezo pulse P2 is output, and the droplet reaches the target 2 at time t31 when the droplet is ejected by the piezo pulse P2. In this mode D, the elapsed time T4 from time t0 to time t31 is the shortest of the above elapsed times T1 to T3, and is often several tens of μs depending on the conditions.

The difference between these elapsed times, that is, the shortest times T1 to T4 from the trigger signal P0 to the time when the droplet is ejected is the landing position in the environment where the target 2 is moving relative to the head 10. It becomes a factor to shift. Therefore, when the mode D is combined with other modes and the liquid material 55L is discharged to the target 2, it is necessary to set an appropriate delay time Td2 in the delay control circuit 20 in order to compensate (absorb) the time difference. . Further, when the liquid material 55L is discharged to the target 2 by combining the mode B or the mode C and the mode D, it is necessary to change the delay time Td2 every time the discharge mode is changed. The setting of the delay time Td2 in the case where the liquid material 55L is discharged to the target 2 by combining all modes A, B, C and D is as follows, for example.
Mode A: Delay time Td2 is not set Mode B: Td2 = T1-T2 ′ (Td1 = T1-T2)
Mode C: Td2 = T1-T3 (Td1 = T1-T3 ′)
Mode D: Td2 = T1-T4

  In each mode, by setting the time from the detection of the trigger signal P0 to the output of the piezo pulse P2 as described above, the time for the droplets discharged in each mode from the trigger signal P0 to reach the target 2 is constant. Can be. That is, by controlling in a direction to delay the timing of outputting the piezo pulse P2 that is a drive signal, the difference in the shortest time from the trigger signal P0 until the liquid material 55L is ejected by each method is compensated, and the liquid material in each mode The timing at which 55L is discharged can be made constant. Therefore, regardless of the ejection mode, it is possible to control the position where droplets are deposited by one trigger signal P0, and the accuracy of the droplet deposition position can be improved. Further, by changing the setting of the delay time depending on the mode, in the discharge device 1 that can discharge the liquid material 55L by a plurality of discharge methods, the discharge method and the landing position can be controlled independently.

  FIG. 3 shows an extracted control system relating to setting of the delay time of the control unit 70. The mode selection unit 45 sets conditions for discharging in that mode to the driver 31 of the electrostatic controller 13 and the driver 21 of the piezo controller 12 by the method (mode) for performing the next discharge. Further, the delay setting unit 46 sets the delay times Td1 and Td2 corresponding to the mode selected by the mode selection unit 45 in the delay control circuit 30 of the electrostatic controller 13 and the delay control circuit 20 of the piezo controller 12, respectively. When the trigger signal P0 is output, the driver 31 of the electrostatic controller 13 and the driver 21 of the piezo controller 12 have predetermined energy (pulse width and pulse height) after the predetermined delay times Td1 and Td2 have elapsed. The electrostatic pulse P1 and the piezo pulse P2 are output, and the nozzle 50 of the head 10 is controlled (driven). A droplet is discharged from the tip 51 of the nozzle 50 to a target (the surface of the target 2) held by the moving mechanism 17 that also functions as a counter electrode.

FIG. 4 shows different examples of systems for controlling the delay time of the control unit 70. For example, when only the combination of modes B, C, and D is to be controlled, the delay in each mode is as follows.
Mode B: Td2 = 0
Mode C: Td2 = T2-T3 (Td1 = T2-T3 ′)
Mode D: Td2 = T2-T4
Therefore, the delay control is required when the electrostatic pulse P1 is output from the electrostatic controller 13 only when the liquid material 55L is ejected by the piezoelectric assist electrostatic method (mode C). Further, in this mode C, the electrostatic pulse P1 is output following the piezo pulse P2. Therefore, in the control system shown in FIG. 4, a selector 32 is provided instead of the delay control circuit 30 on the trigger input side of the driver 31 of the electrostatic controller 13, and the trigger is used as a trigger for outputting the electrostatic pulse P1 depending on the mode. The signal P0 and the piezo pulse P2 can be selected.

  FIG. 5 is a flowchart showing an outline of control related to the change of the discharge mode of the discharge device 1. If it is necessary to change the next discharge method (mode) in step 61, the gap adjustment and the setting of the delay time are changed in step 62. Between the nozzle tip 51 and the target 2 when discharging in the mode (electrostatic discharge (mode A), electrostatic assist piezo discharge (mode B), piezo assist electrostatic discharge (mode C)) using the electrostatic pulse P1. The gap (working distance) G1 is preferably about 15 to 100 μm. On the other hand, in the case of discharging only with the piezo pulse P2 (pressure fluctuation discharge, piezo discharge (mode D)), it is not preferable that the liquid column reaches the target 2, and it reaches the target 2 after the liquid column is changed to a droplet. It is desirable. Therefore, it is desirable that the gap (working distance) G2 between the nozzle tip 51 and the target 2 is about 0.5 mm to 2 mm. Therefore, the gap setting unit 47 controls the gap control mechanism 16 to move the head 10 up and down in the next ejection mode.

  Further, the delay setting unit 46 changes the setting of the delay time Td2 of the delay control circuit 20 of the piezo controller 12 according to the next ejection mode. If necessary, the setting of the delay time Td1 of the delay control circuit 30 of the electrostatic controller 13 is changed.

  Thereafter, the electrostatic controller 13 and the piezo controller 12 detect the trigger signal P0 in step 63. If the ejection mode is the electrostatic system (mode A), the mode is determined in step 64, the electrostatic pulse P1 is output in step 65, and the liquid material 55L is ejected by the electrostatic system.

  If the discharge mode is the electrostatic assist piezo method (mode B), the mode is determined in step 66, and after the delay time Td1 (= T1-T2) has elapsed in step 67, the electrostatic pulse P1 is applied in step 68. Output. Further, after the delay time Td2 (= T1-T2 ′) has elapsed in step 69, a piezo pulse P2 is output in step 70, and the liquid material 55L is discharged by an electrostatic assist piezo method.

  If the ejection mode is the piezo-assist electrostatic method (mode C), the mode is determined in step 71, and after the delay time Td2 (= T1-T3) has elapsed in step 72, a piezo pulse P2 is output in step 73. Thereafter, in step 74, the electrostatic pulse P1 is output to discharge the liquid material 55L by the piezoelectric assist electrostatic method. In step 74, the electrostatic pulse P1 may be output using the output of the piezo pulse P2 as a trigger, and the electrostatic pulse P1 is output after a predetermined delay time Td1 (= T1-T3 ′) has elapsed by the delay circuit. Also good.

  If the ejection mode is the piezo system (mode D), after the delay time Td2 (= T1-T4) has elapsed in step 75, the piezoelectric material P is output in step 76 to eject the liquid material 55L by the piezo system. .

  The discharge device 1 is not limited to one corresponding to these four modes, and may be one corresponding to three or two of these modes. For example, the discharge device 1 is liquid in which the piezo-assisted electrostatic method (mode C) is the first mode, the piezo method (mode D) is the second mode, and the electrostatic method (mode A) is the third mode. The substance 55L may be discharged. In this case, the delay time Td2 until the piezo pulse P2 is output is different between the first mode and the second mode.

  The discharge device 1 may discharge the liquid material 55L using the electrostatic method (mode A) as the first mode and the piezo method (mode D) as the second mode. In this case, since the piezo pulse P2 is not output in the first mode, the delay time Td2 until the piezo pulse P2 is output may be constant.

  The ejection device 1 may eject the liquid material 55L with the piezo-assist electrostatic method (mode C) as the first mode and the piezo method (mode D) as the second mode. In this case, the delay time Td2 can be set based on the mode C. That is, in the piezoelectric assist electrostatic method (mode C), the delay time Td2 can be set to zero, and the delay time Td2 in the piezoelectric method (mode D) can be set to the difference between the time T3 and the time T4. In the piezo-assist electrostatic method (mode C), a small droplet of about femtoliters close to the electrostatic method can be discharged in a short time from the trigger signal P0. Therefore, it is possible to switch between a femtoliter droplet and a picoliter droplet with good response to the trigger signal P0, and to improve the accuracy of the landing position.

  The discharge device 1 is not limited to the above, and a mode (method) suitable for discharging from the above modes is determined depending on the viscosity, specific gravity, particle diameter included in the liquid material, and the like of the liquid material 55L to be discharged. It may be selected and used.

  As described above, in the discharge apparatus 1, the discharge method can be selected in a variable manner, and a droplet of about femtoliter is discharged to the target 2 by the electrostatic method, or about picoliter is used by the pressure fluctuation method. Can be discharged to the target 2, or femtoliters or droplets close to it can be discharged with good response by an electrostatic assist piezo (discharge) method or a piezoelectric assist electrostatic (discharge) method. Furthermore, since droplets of these various sizes can be accurately ejected after a predetermined time has elapsed from the trigger signal P0, droplets of a plurality of methods can be applied or landed at a predetermined position on the target 2 with high accuracy. Can do. Therefore, a plurality of droplets having different sizes can be applied to a predetermined position on the same target 2, drawn, or dispensed by one ejection device 1.

  In the above-described ejection device 1 and ejection head (head block) 10, an example in which only one set of integrated nozzles 50 is mounted is shown, but a plurality of nozzles 50 may be mounted on the head 10. Is possible. Further, the discharge device 1 may include a plurality of heads 10 and can discharge the same or different liquid substances by changing the mode for each head. Furthermore, instead of the nozzle 50 integrated in the head 10, it is also possible to mount one set each of a nozzle dedicated for electrostatic discharge and a nozzle dedicated for piezo discharge. The liquid substance can be discharged by switching between

  In addition, although a piezoelectric method using a piezoelectric element has been described as an example of the pressure fluctuation method, other ink jet heads such as a type in which the inside of a nozzle is pressurized with bubbles can be employed.

1 Discharge device, 10 Discharge head (head block)
12 piezo controller, 13 electrostatic controller 50 integrated nozzle, 57 electrodes, 58 piezo actuator 70 control unit

Claims (6)

A control unit for controlling the discharge of the liquid substance from the discharge head,
The ejection head includes a nozzle,
An electrode for obtaining an electrostatic force for discharging a liquid substance from the tip of the nozzle;
An actuator for obtaining a change in internal pressure for discharging a liquid substance from the tip of the nozzle or another nozzle,
The control unit is
A first controller that outputs a voltage signal for forming an electric field by an electrode of the ejection head based on a trigger signal;
A second controller that outputs a drive signal for driving the actuator based on the trigger signal;
Mode selection for selecting a first mode in which the liquid material is discharged from the discharge head by combining the voltage signal and the drive signal, and a second mode in which the liquid material is discharged from the discharge head only by the drive signal Unit and
The control unit includes a delay control circuit that changes a delay time from detection of the trigger signal to output of the drive signal according to the first mode and the second mode . A control unit according to claim 1 ;
The ejection head;
An apparatus having a target for discharging a liquid substance from the discharge head and a moving mechanism for moving the discharge head relative to each other. The apparatus according to claim 2 , wherein the nozzle of the ejection head includes the electrode and the actuator. In claim 2 or 3 , further
A high speed for observing the time from when the liquid material discharged in the first mode and the second mode reaches the target from the trigger signal with the delay time set to a predetermined value A device having a camera. A method for controlling the discharge of a liquid substance from a discharge head,
The ejection head includes a nozzle,
An electrode for obtaining an electrostatic force for discharging a liquid substance from the tip of the nozzle;
An actuator for obtaining a change in internal pressure for discharging a liquid substance from the tip of the nozzle or another nozzle,
The method is
Outputting a voltage signal for forming an electric field by the electrodes of the ejection head based on a trigger signal;
Outputting a drive signal for driving the actuator after a controlled delay time has elapsed based on the trigger signal. The output of the drive signal according to claim 5 ,
Outputting the drive signal in a first mode for discharging a liquid material by combining the voltage signal and the drive signal after a first delay time has elapsed;
And outputting the drive signal in a second mode in which the liquid substance is ejected only by the drive signal after a second delay time different from the first delay time has elapsed.

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