JP2005185942A - Droplet discharging apparatus and method of driving droplet discharging head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a droplet discharging apparatus and a method of driving a droplet discharging head which reduce the time required to determine conditions of head-driving signals and control the working time and consumption of a functional liquid by decreasing the amount of the liquid discharged in a trial. <P>SOLUTION: A droplet discharging apparatus 1 has a means of detecting residual vibrations, a means of comparing vibrations, a means of controlling the driving waveform and a means of generating driving signals. To generate optimal driving signals, standard information comprising driving signals corresponding to normal discharging conditions for a droplet discharging head 10 and residual vibrations and control information consisting of information on correlation between driving signals and residual vibrations are created. Residual vibrations are then detected and compared with the standard and the control information, and driving signals are adjusted on the basis of the comparison results to create optimal driving signals. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a droplet discharge apparatus including a droplet discharge head that discharges a functional liquid as droplets, and a head driving method of the droplet discharge head.

  2. Description of the Related Art Recently, a droplet discharge device (inkjet device) that discharges a droplet of a functional liquid from a discharge nozzle of a droplet discharge head toward a workpiece (substrate, etc.) and lands the droplet at a predetermined position on the workpiece. It is used to manufacture electro-optical devices and the like.

  In such a droplet discharge head, a voltage is applied to an electrostrictive vibrator provided in the droplet discharge head, and due to the distortion phenomenon, by changing the volume of the functional liquid storage chamber in the droplet discharge head, There is one that applies pressure to the functional liquid in the functional liquid storage chamber and discharges it from the nozzle.

  In such a droplet discharge head, if the nozzle is clogged due to an increase in the viscosity of the functional liquid, bubble bubbles, dust adhesion, etc. In some cases, the ejection direction may vary, and the landing position may not be reached. As a method of monitoring the occurrence of these defects, optical observation of the state of droplets flying in the air, measurement of the weight of the discharged droplets, and optical formation of the point formed by the liquid low landing There are other observations.

  As another method for monitoring the occurrence of the above-mentioned failure and as a method for identifying the cause, a pressure wave (residual vibration) remaining in the flow path of the functional liquid after the functional liquid droplet is discharged is detected. It is considered to observe a change in residual vibration that occurs when it occurs (see Patent Document 1).

Japanese Patent Laid-Open No. 5-24194

  By the way, there are various functional liquids that can be ejected by the liquid droplet ejection apparatus, and the optimum driving conditions of the liquid droplet ejection head, that is, the optimum waveform of the applied head driving signal differs depending on each functional liquid. Further, the optimum drive signal for each nozzle is slightly different due to, for example, a subtle difference in the mounting position of the electrostrictive vibrator or a subtle variation in the nozzle diameter.

  On the other hand, in the electro-optical device substrate, the characteristics of the emitted light vary depending on the thickness of the colored layer. For this reason, if the thickness of the colored layer for each electro-optical device substrate varies, the characteristics vary for each electro-optical device substrate, and the target display characteristics may not be obtained. In addition, if the thickness of each colored layer in the same electro-optical device substrate varies, the uniformity of display characteristics in the same display screen may be impaired. The thickness of the colored layer is determined by the amount of the dye functional liquid discharged onto the substrate. Therefore, the accuracy of the ejection amount of the dye functional liquid that determines the thickness of the colored layer is an important factor that affects the display characteristics of the electro-optical device substrate or the electro-optical device including the electro-optical device substrate.

  Therefore, when a new functional liquid is used, optimum head driving conditions, that is, optimum head driving signal conditions to be applied (driving signal adjustment) are determined for each droplet discharge device and for each nozzle. The condition of the head drive signal is determined. For this reason, the weight of discharged droplets and the optical observation of the state of droplets flying in the air have been performed, which consumes a lot of time and the functional liquid to be tested and discharged. Yes.

  Even when the same functional liquid is ejected by the same liquid droplet ejection device, the characteristics of the functional liquid vary depending on, for example, the production lot of the functional liquid, and the optimum head drive signal conditions described above are often performed. There is a need to. In particular, in the case of using a droplet discharge device for manufacturing a droplet discharge device that requires high accuracy or a product that requires high accuracy, conditions may be determined every time work is started. Therefore, much time is required and the functional liquid is consumed.

  Furthermore, in order to carry out the weight measurement and optical observation of the droplet, a weight measuring machine capable of measuring a highly accurate and minute weight and a high-precision optical detector are necessary. There is a problem that the installation state must be maintained with high accuracy. In addition, a precise measuring instrument is generally expensive, and there is a problem that the manufacturing cost of the apparatus increases. Furthermore, there is a problem that the reliability of the measuring machine may be lowered due to adhesion of mist or the like accompanying discharge of the functional liquid.

  Accordingly, the present invention provides a droplet discharge device and a droplet discharge head drive that can reduce the time required to determine the conditions of the head drive signal and reduce the working liquid and the consumption of the functional liquid by reducing the functional liquid to be tested and discharged. It aims to provide a method.

  The droplet discharge device according to the present invention includes a droplet discharge head having a nozzle that discharges a functional liquid as droplets, a vibration plate corresponding to the nozzle, and a drive element that displaces the vibration plate, and residual vibration of the vibration plate. Residual vibration detection means for detecting, and drive signal control means for generating a drive signal to be applied to the drive element based on the residual vibration information detected by the residual vibration detection means.

  According to the configuration of the present invention, when adjusting the drive signal of the droplet discharge head in the droplet discharge device, the residual vibration of the droplet discharge head after the droplet discharge is detected, and the head drive is performed based on the detected residual vibration state. Since the signal is generated, an appropriate head driving signal can be generated corresponding to the state of each droplet discharge head. Furthermore, the test discharge for determining the condition is sufficient to detect the residual vibration, and the time required for adjusting the drive signal can be shortened, and the amount of the functional liquid to be discharged can be reduced.

  In this case, the drive signal control means adjusts the waveform of the drive signal based on the comparison result of the vibration comparison means for comparing the reference information and the detected vibration information of the residual vibration detected by the residual vibration detection means, and the signal comparison means. It is preferable to include a waveform control unit and a drive signal generation unit that generates a drive signal based on a result adjusted by the waveform control unit.

  According to this configuration, the detected residual vibration is compared with the reference information, and a head drive signal is generated based on the comparison result. Therefore, an appropriate head drive signal is generated corresponding to the state of each droplet discharge head. be able to. In addition, the test discharge for setting the conditions is sufficient for the number of times that the residual vibration can be detected, the time required for adjusting the drive signal can be shortened, and the amount of the functional liquid to be discharged can be reduced. Furthermore, since the reference information can be used repeatedly, if it is created once, the step of creating the reference information can be omitted in the subsequent drive signal adjustment, and the drive signal adjustment can be performed efficiently.

  In this case, the reference information includes standard information composed of standard drive signal information that realizes a normal ejection state, standard residual vibration information that is generated when the standard drive signal is applied to the droplet ejection head, and residual information. It is preferable that each parameter that defines the vibration and reference information that is information on a correlation between each parameter that defines the drive signal.

  According to this configuration, the detected residual vibration is compared with the reference information, and a head drive signal is generated based on the comparison result. Therefore, an appropriate head drive signal is generated corresponding to the state of each droplet discharge head. be able to. Furthermore, in order to compare the detected residual vibration with reference information, which is information on the dependency on each parameter that defines the drive signal of each parameter that defines the residual vibration, the information is compared and calculated. A drive signal can be obtained. Therefore, test ejection other than liquid droplet ejection for obtaining residual vibration information is not required, the time required for drive signal adjustment can be shortened, and the amount of functional liquid to be ejected can be reduced.

  In this case, the information of the standard drive signal is a value of each of a plurality of parameters that defines the standard drive signal, and the information of the standard residual vibration is a value of each of a plurality of parameters that defines the standard residual vibration. Is preferably a value of each parameter that defines the residual vibration detected by the residual vibration detection means.

  According to this configuration, each drive signal and each residual vibration are each represented by a value of a parameter that defines the drive signal or the residual vibration, and thus can be easily compared with each other. Further, the drive signal can be adjusted by calculating and adjusting the parameter value.

  In this case, it is preferable that at least one of the frequency, amplitude, phase, attenuation rate, and bias is a parameter that defines the residual vibration.

  According to this configuration, residual vibration can be accurately and efficiently represented as residual vibration information by appropriately selecting parameters. Further, by appropriately selecting necessary parameters corresponding to the characteristics to be adjusted, unnecessary information can be eliminated and the residual vibration information can be efficiently generated.

  In this case, it is preferable that at least one of the drive voltage, the charge time, the hold time, the discharge time, and the reference potential is a parameter that defines the drive signal.

  According to this configuration, the drive signal can be accurately and efficiently represented as drive signal information by appropriately selecting parameters. Further, by appropriately selecting necessary parameters corresponding to the characteristics to be adjusted, unnecessary information can be eliminated and drive signal information can be created efficiently.

  The droplet ejection head driving method according to the present invention is a droplet ejection head driving method comprising a nozzle that ejects a functional liquid as droplets, a diaphragm corresponding to the nozzle, and a drive element that displaces the diaphragm. A standard having information on a standard drive signal which is a drive signal for realizing a normal discharge state of the droplet discharge head and information on residual vibration generated when the standard drive signal is applied to the droplet discharge head. A first step of creating reference information comprising information and control information which is correlation information between each parameter defining the residual vibration and each parameter defining the drive signal; A second step of detecting a residual vibration at the time of discharging a droplet and creating residual vibration information; a third step of comparing the residual vibration information with the standard information; and control information and residual vibration information. Drive based on Wherein a fourth step of adjusting the, further comprising a fifth step of generating a drive signal based on the result of the fourth step No..

  According to the method of the present invention, the detected residual vibration is compared with the reference information, and a head drive signal is generated based on the comparison result. Therefore, an appropriate head drive signal corresponding to the state of each droplet discharge head is generated. Can be generated. Furthermore, in order to compare the detected residual vibration with reference information, which is information on the dependency on each parameter that defines the drive signal of each parameter that defines the residual vibration, the information is compared and calculated. A drive signal can be obtained. Therefore, there is no need to measure the weight of the droplets or optical observation, and no test ejection other than droplet ejection to obtain residual vibration information is necessary, and the time required for adjusting the drive signal can be shortened and the test ejection is performed. The amount of functional fluid can be reduced.

  In this case, it is preferable that a reference machine is set and the first step is performed using a droplet discharge head that is a standard of the reference machine.

  According to this method, reference information used as a reference in drive signal adjustment can be created using a standard head, and the time required for drive signal adjustment can be shortened, and the amount of functional liquid to be ejected can be reduced. Furthermore, in the droplet discharge device for setting the drive conditions, a weight measuring device for detecting the discharge state, an optical observation device, and the like are not required, and the droplet discharge device can be downsized and manufactured. Cost can be reduced.

  In this case, a sixth step of discharging the droplets from the droplet discharge head and detecting residual vibration at that time to create residual vibration information, and a seventh step of comparing the residual vibration information with the standard information The eighth step of determining the state of the droplet discharge head based on the comparison result of the seventh step, and the ninth step of performing maintenance operation of the droplet discharge head according to the determination result of the eighth step It is preferable to further include an initialization step including: performing the first step, then performing the initialization step, and then sequentially performing the second to fifth steps.

  According to this method, the state of the droplet discharge head can be detected before the head drive signal adjustment step by detecting the residual vibration and comparing it with the standard information. Therefore, when the detected head state cannot be normally ejected due to some abnormality and is not suitable for the head drive signal adjustment process, this can be detected. Further, when it is detected that normal ejection cannot be performed, the state is improved by a maintenance process. Therefore, the head drive signal adjustment can be performed with the droplet discharge head in a normal state.

    In this case, the fourth step preferably includes a determination step for determining whether or not adjustment is possible. If it is determined in the determination step that adjustment is impossible, it is preferable to issue a warning that adjustment is not possible.

  According to this method, a warning is issued when the target result cannot be obtained, such as a state where the adjustment value diverges, so that unnecessary drive signal adjustment can be stopped, and improvement is supported. Can do.

  In this case, it is preferable to issue an abnormality warning when the initialization process is repeated and the determination result of the sixth process is the same over a predetermined number of times.

  According to this method, an abnormality warning can be issued when the state of the droplet discharge head does not improve even after repeated maintenance operations. Therefore, a predetermined number of times of giving an abnormality warning can be set according to the number of maintenance operation repetitions that can be expected to improve the state of the droplet discharge head, and unnecessary maintenance operation repetitions can be stopped, and another improvement countermeasure can be taken. In addition, the state of the droplet discharge head that performs the drive signal adjustment can be surely brought into a normal state.

  A structure and driving method of a droplet discharge head and a droplet discharge device according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
1 and 2 are a plan view and a side view, respectively, showing an embodiment of a droplet discharge device of the present invention. Hereinafter, for convenience of explanation, one direction perpendicular to the direction of the gravitational acceleration of the earth (direction corresponding to the left-right direction in FIGS. 1 and 2) is referred to as “Y-axis direction”, and is perpendicular to the Y-axis direction. The direction perpendicular to the direction of the gravitational acceleration of the earth (the direction corresponding to the vertical direction in FIG. 1) is referred to as the “X-axis direction”.

  The droplet discharge device 1 shown in these drawings includes a droplet discharge head 10 that discharges droplets, and for example, ink such as ink or a functional liquid containing a target material is ink-jetted onto a substrate W as a workpiece. It is an apparatus that forms (draws) a predetermined pattern by discharging in the form of fine droplets by a method (droplet discharge method). The droplet discharge device 1 is an industrial droplet discharge device that can be used for manufacturing, for example, a color filter or an organic EL device in a liquid crystal display device or forming a metal wiring on a substrate.

  The droplet discharge device 1 according to the present embodiment includes, for example, a discharge device main body 1A that is an inkjet discharge device and a control device 1B. The discharge apparatus main body 1A includes an apparatus main body 2, a substrate table (work placement unit) 3, a main scanning drive device 7 that moves the substrate table 3 in the main scanning direction, and a plurality of droplet discharge heads (inkjet heads) 10. And a sub-scanning driving device 8 that moves the head unit 11 in the sub-scanning direction. The discharge device main body 1A includes a maintenance device 12 for maintaining the droplet discharge head 10, a glass scale 15 for measuring the movement distance of the substrate table 3, a main body control device 16, and a dot drop detection unit (dot drop detection device). 19).

  As shown in FIG. 2, the apparatus main body 2 includes a gantry 21 installed on the floor, and a stone surface plate 22 installed on the gantry 21. On the stone surface plate 22, the main scanning drive device 7 is installed. A substrate table 3 is installed on the stone surface plate 22 so as to be movable in the Y-axis direction with respect to the apparatus main body 2. The substrate table 3 moves forward and backward in the Y-axis direction by driving the main scanning drive motor 26. The substrate W is placed on the substrate table 3.

  As shown in FIG. 1, in the vicinity of two sides along the X-axis direction of the substrate table 3, a pre-drawing flushing unit 31 that receives ejected liquid droplets that are discarded and flushed from the liquid droplet ejection head 10, respectively. , 31 are installed. A suction tube (not shown) is connected to the pre-drawing flushing unit, and the discharged and discharged discharge liquid passes through this suction tube and is collected by the drainage device.

  The movement distance of the substrate table 3 in the Y-axis direction is measured by a glass scale 15 installed in parallel with the main scanning drive motor 26 which is a linear motor extending in the Y-axis direction. Based on the signal of the movement distance (current position) of the substrate table 3 detected by the glass scale 15, the discharge timing from the droplet discharge head 10 is generated by the apparatus main body control unit 56 (see FIG. 3) described later.

  A main carriage 42 that supports the head unit 11 is installed in the apparatus main body 2 so as to be movable in the X-axis direction in the space above the substrate table 3. The head unit 11 moves forward or backward in the X-axis direction together with the main carriage 42 by driving a sub-scanning drive motor 43 including a linear motor and a guide.

  In the droplet discharge device 1 of the present embodiment, so-called main scanning of the droplet discharge head 10 is performed by moving the substrate table 3 in the Y-axis direction and using the current position information of the substrate table 3 detected by the glass scale 15. The driving of the droplet discharge head 10 (selective discharge of functional liquid droplets) is performed based on the discharge timing generated by using the above. Correspondingly, so-called sub-scanning is to move the head unit 11 (droplet discharge head 10) in the X-axis direction.

  The maintenance device 12 is installed on the side of the gantry 21 and the stone surface plate 22. The maintenance device 12 includes a capping unit (capping device) 121 for capping the droplet discharge head 10 during standby of the head unit 11, a cleaning unit (cleaning device) 122 for wiping the nozzle formation surface of the droplet discharge head 10, and A regular flushing unit 123 that receives regular flushing of the droplet discharge head 10 and a weight measurement unit (weight measurement device) 125 are provided.

  In addition, the maintenance device 12 includes a moving table 124 that can move in the Y-axis direction. The capping unit 121, the cleaning unit 122, the regular flushing unit 123, and the weight measuring unit 125 are arranged on the moving table 124 in the Y-axis direction. It is installed side by side. When the moving table 124 moves in the Y-axis direction with the head unit 11 moving above the maintenance device 12, any one of the capping unit 121, the cleaning unit 122, the regular flushing unit 123, and the weight measuring unit 125 drops. It can be positioned below the discharge head 10. The head unit 11 moves above the maintenance device 12 during standby, and performs capping, cleaning (wiping), and regular flushing in a predetermined order.

  The capping unit 121 has a plurality of caps arranged so as to correspond to each of the plurality of droplet discharge heads 10 and a lifting mechanism for lifting and lowering these caps. When the head unit 11 is on standby, the nozzle formation surface of the droplet discharge head 10 is covered with this cap. This can prevent the nozzle forming surface from drying during standby. Further, the capping by the capping unit 121 is performed by using a cleaning liquid when the droplet discharge head 10 is initially filled with the discharge liquid or when the discharge liquid is discharged from the droplet discharge head 10 when the discharge liquid is replaced with a different type. It is also performed when cleaning the flow path.

  A suction tube (not shown) leading to each cap is connected to the capping unit 121, and the functional liquid discharged from the droplet discharge head 10 during capping passes through this suction tube, and passes through the capping drainage device ( (Not shown) and is reused as a functional liquid supplied to the droplet discharge head 10. However, the cleaning liquid collected at the time of cleaning the flow path is not reused.

  The cleaning unit 122 operates such that a wiping sheet containing a cleaning liquid (for example, a solvent capable of dissolving a functional liquid) is run by a roller, and the nozzle forming surface of the droplet discharge head 10 is wiped and cleaned by the wiping sheet. To do.

  The regular flushing unit 123 is used for flushing when the head unit 11 is on standby, and receives the ejected liquid droplets discarded and ejected by the liquid droplet ejection head 10. A suction tube (not shown) is connected to the regular flushing unit 123, and the discarded functional liquid passes through the suction tube and is collected by a drainage device (not shown).

  The weight measurement unit 125 is used to measure a single droplet discharge amount (weight) from the droplet discharge head 10 as a preparation stage for the droplet discharge operation on the substrate W. That is, before the droplet discharge operation on the substrate W, the head unit 11 moves above the weight measurement unit 125 and drops droplets from the discharge nozzles of each droplet discharge head 10 one or more times to the weight measurement unit 125. Discharge against. The weight measuring unit 125 includes a liquid receiver that receives the discharged droplets and a weight scale such as an electronic balance, and measures the weight of the discharged droplets. Alternatively, the liquid receiver may be removed and measurement may be performed with a scale outside the apparatus.

  The dot dropout detection unit (dot dropout detection device) 19 is fixedly installed at a place on the stone surface plate 22 that does not overlap the movement area of the substrate table 3 and is located below the movement area of the head unit 11. Has been. The dot dropout detection device 19 is for observing a droplet that is ejected and moving in the air in order to detect dot dropout caused by clogging of the nozzle of the droplet discharge head 10. The missing dot detection device 19 includes, for example, a light projecting unit and a light receiving unit that project and receive laser light. When performing dot missing detection, the head unit 11 discards and discharges droplets from each nozzle while moving in the X-axis direction in the space above the dot missing detection device 19. The projected droplet is projected and received to optically detect the presence and location of a clogged nozzle. At this time, the discharge liquid discharged from the droplet discharge head 10 accumulates in a tray provided in the dot dropout detection device 19, passes through a suction tube (not shown) connected to the bottom of the tray, and discharges ( (Not shown).

  The gantry 21 includes a frame body 44 that is formed by assembling angle members and the like in a square shape, and a plurality of support legs 46 that are dispersedly arranged at the lower part of the frame body 44. The stone surface plate 22 is made of a solid stone material, and the upper surface thereof has high flatness. The stone surface plate 22 prevents the influence of ambient environmental conditions, vibrations, and the like, and the substrate table 3 and the head unit 11 can be moved with high accuracy.

  A main scanning drive device 7 as a Y-axis direction moving mechanism is installed on the stone surface plate 22, and the main scanning drive device 7 includes a main scanning drive motor 26 and an air slider 28. The substrate table 3 is supported by the air slider 28 via a substrate position control device (θ-axis rotation mechanism) 34 having a θ motor. The air slider 28 can move smoothly in the Y-axis direction, and moves in the Y-axis direction by driving the main scanning drive motor 26. As a result, the substrate table 3 moves in the Y-axis direction. In addition, the substrate position control device 34 provided at the lower part of the substrate table 3 allows the substrate table 3 to rotate within a predetermined range about a vertical θ axis passing through the center of the substrate table 3 as a rotation center. The substrate table 3 is formed with a plurality of suction grooves (suction portions) 33 for sucking and fixing the placed substrate W.

  The apparatus main body 2 includes four support columns 23 installed on a stone surface plate 22 and two parallel beams (beams) 24 and 25 extending along the X-axis direction supported by these support columns 23. And further. The substrate table 3 can pass under the girders 24 and 25.

  On the girders 24 and 25, a main carriage 42 and a camera carriage 47 are installed between the girders 24 and 25, respectively. A sub-scanning drive motor 43 is installed in the beam 24 as a common X-axis direction moving mechanism for the main carriage 42 and the camera carriage 47. The main carriage 42 and the camera carriage 47 are installed so as to be able to move smoothly in the X-axis direction by guidance of a sub-scanning drive motor 43 and a linear guide provided on the beam 25, respectively. The main carriage 42 and the camera carriage 47 are independently moved in the X-axis direction by driving of the sub-scanning driving motor 43.

  The head unit 11 is supported on the main carriage 42 via a head height control device 45 (not shown in FIGS. 1 and 2). The head unit 11 can be moved in the vertical direction (Z direction) by a Z motor provided in the head height control device 45. As the head unit 11 moves in the X-axis direction together with the main carriage 42, sub-scanning of the droplet discharge head 10 is performed. The head unit 11 is connected to a pipe (not shown) for supplying the discharge liquid, a wiring cable (not shown), and the like. The head unit 11 is detachable from the main carriage 42.

  The camera carriage 47 is provided with a recognition camera 127 (not shown in FIGS. 1 and 2) for recognizing an image of alignment marks provided at predetermined positions on the substrate W. The recognition camera 127 is supported in a state of being suspended downward from the camera carriage 47. Note that the recognition camera 127 may be used for other purposes.

  The control device 1B includes a host computer 70 that performs arithmetic processing, and a keyboard 71 that can input discharge condition information such as to which position the liquid viscous material is discharged with respect to the target in the discharge device main body 1A. Yes. In addition, the control device 1B includes an external input / output device 73 that inputs / outputs information via a recording medium such as a flexible disk, and a recording unit 72 that stores discharge conditions and the like input via the external input / output device 73. And a CRT 74 which is a monitor device (see FIG. 3).

  Here, the overall operation of the droplet discharge device 1 under the control of the control device 1B will be briefly described. When the substrate W placed (supplied) on the substrate table 3 is positioned (prealigned) at a predetermined position by the operation of the substrate positioning device (not shown) provided in the droplet discharge device 1, the substrate table 3 The substrate W is sucked and fixed to the substrate table 3 by air suction from each suction groove 33. Next, when the substrate table 3 and the camera carriage 47 are moved, the recognition camera is moved above an alignment mark provided at a predetermined position (one or a plurality of positions) of the substrate W, and this alignment mark is recognized. . Based on this recognition result, the θ-axis rotation mechanism operates to correct the angle of the substrate W around the θ-axis, and the position correction of the substrate W in the X-axis direction and the Y-axis direction is performed on the data (this book) alignment).

  When the alignment operation of the substrate W as described above is completed, each droplet discharge head 10 is moved while moving the substrate W in the main scanning direction (Y-axis direction) by moving the substrate table 3 with the head unit 11 stopped. To selectively eject droplets onto the substrate W. At this time, the droplet discharge operation may be performed while the substrate table 3 is moving forward (forward), while it is moving backward (backward), or both forward and backward (reciprocating). Further, the droplet discharge operation may be repeated a plurality of times by reciprocating the substrate table 3 a plurality of times. With the above operation, the discharge of the functional liquid droplets is completed on the substrate W in a region extending along the main scanning direction with a predetermined width (a width that can be discharged by the head unit 11).

  Thereafter, by moving the main carriage 42, the head unit 11 is moved in the sub-scanning direction (X-axis direction) by the predetermined width. In this state, similar to the above-described operation, a selective droplet discharge operation from each droplet discharge head 10 to the substrate W is performed while moving the substrate W in the main scanning direction. When the droplet discharge operation to this region is completed, the head unit 11 is further moved in the sub-scanning direction (X-axis direction) by the predetermined width, and the substrate W is moved in the main scanning direction. However, a similar droplet discharge operation is performed. By repeating this several times, droplet discharge is performed on the entire region of the substrate W. In this manner, the droplet discharge device 1 forms (draws) a predetermined pattern on the substrate W.

  Next, an electrical configuration for driving the droplet discharge device 1 having the above configuration will be described. FIG. 3 is an electrical configuration block diagram showing an electrical configuration of the droplet discharge device. As described above, the control device 1B includes the host computer 70 that performs arithmetic processing, and the keyboard that can input discharge condition information such as to which position the liquid viscous material is discharged with respect to the target in the discharge device main body 1A. 71, an external input / output device 73 for inputting / outputting information via a recording medium such as a flexible disk, a recording unit 72 for storing discharge conditions input via the external input / output device 73, and a monitor device The CRT 74 is provided.

  The main body control device 16 of the discharge device main body 1A includes an interface 53 for receiving discharge conditions and the like from the control device 1B, a RAM 54 for recording various data, a ROM 55 for recording routines for various data processing, and a CPU. The apparatus main body control part 56 which consists of these, etc., the oscillation circuit 57, the drive signal generation part 58 which generates the drive signal COM supplied to the droplet discharge head 10, and the interface 59 are provided.

  The interface 59 outputs the ejection data developed into the dot pattern data to the droplet ejection head 10 and outputs a drive signal to the main scanning driving motor 26 of the main scanning driving device 7 and the sub scanning of the sub scanning driving device 8. Output to the drive motor 43, the head height control device 45, and the substrate position control device 34. The droplet discharge head 10 includes a head drive circuit 140 and a piezoelectric vibrator 17 that is a drive element (head drive element). The discharge data input from the interface 59 to the droplet discharge head 10 is supplied to the head drive circuit 140. Via, it is applied to the piezoelectric vibrator 17. A residual vibration detection circuit 141 can be connected to the piezoelectric vibrator 17 so that the residual vibration of the piezoelectric vibrator 17 can be detected. The output of the residual vibration detection circuit 141 is transmitted to the apparatus main body control unit 56 via the interface 59.

  The weight measurement unit (weight measurement device) 125, the cleaning unit (cleaning device) 122, the capping unit (capping device) 121, the dot dropout detection device 19, and the recognition camera 127 are also provided via the input / output interface 52. It is connected to the main body control unit 56.

  In the droplet discharge device 1 configured as described above, the apparatus main body control unit 56 and the control device 1B function as control means for the entire droplet discharge device 1, as will be described below. In the droplet discharge device 1, the discharge conditions sent from the control device 1B are held in the reception buffer 54A inside the discharge device via the interface 53. The data held in the reception buffer 54A is sent to the intermediate buffer 54B after command analysis is performed. In the intermediate buffer 54B, data in an intermediate format converted into an intermediate code by the apparatus main body control unit 56 is held, and processing for adding information such as the ejection position of the functional liquid droplets is executed by the apparatus main body control unit 56. Is done. Next, the apparatus main body control unit 56 analyzes and decodes the data in the intermediate buffer 54B, and then develops and records the dot pattern data in the output buffer 54C.

  When the dot pattern data corresponding to the amount discharged by the droplet discharge head 10 while scanning once (one scan) from one end of the workpiece W to the other end in the main scanning direction is obtained, the dot pattern data is stored in the interface 59. Is serially transferred to the droplet discharge head 10 via the. When dot pattern data corresponding to one scan is output from the output buffer 54C, the contents of the intermediate buffer 54B are erased, and the next intermediate code conversion is performed.

  The droplet discharge head 10 discharges functional droplets from each nozzle, which will be described later, at a predetermined timing. The drive signal COM generated by the drive signal generation unit 58 is supplied via the interface 59 to the droplet discharge head 10. Is output. Further, the ejection data SI developed into the dot pattern data is serially output to the head drive circuit 140 included in the droplet ejection head 10 via the interface 59 in synchronization with the clock signal CLK from the oscillation circuit 57. . Here, the ejection data SI developed in the dot pattern data includes nozzle selection data that defines from which nozzles formed in the droplet ejection head 10 functional droplets are ejected, Waveform selection data that defines which drive pulse is used to eject functional droplets from each nozzle is also included.

  Next, the configuration of the droplet discharge head 10 and the head unit 11 will be described. The head unit 11 holds a plurality of droplet discharge heads 10 having the same structure as shown in FIG. Here, FIG. 4A is a diagram of the head unit 11 observed from the substrate table 3 side. Two rows of six droplet discharge heads 10 are arranged on the unit plate 61 so that the longitudinal direction of each droplet discharge head 10 forms an angle with respect to the X-axis direction. Further, the droplet discharge head 10 for discharging the functional liquid has a nozzle row extending in the longitudinal direction of the droplet discharge head 10 as shown in FIG. The nozzle row 62 is a row in which 180 nozzles 63 are arranged in a row, and the interval between the nozzles 63 along the direction of the nozzle row 62 is about 140 μm. Each droplet discharge head 10 is arranged such that the nozzles 63 are continuous at a constant pitch in the X-axis direction, and the pitch can be changed by adjusting the angle with respect to the X-axis direction of the droplet discharge head 10. .

  This arrangement pattern is an example. If the droplet discharge head 10 is a dedicated component for various substrates W, the nozzles 63 that match the substrate W may be disposed. Alternatively, the row of six droplet discharge heads 10 may be constituted by one droplet discharge head. That is, the number of droplet discharge heads 10, the number of rows, and the arrangement pattern can be set arbitrarily. In any case, the dots formed by all the discharge nozzles 63 of the twelve droplet discharge heads 10 need only be continuous in the X-axis direction. Further, the head switching valve may be attached to each droplet discharge head 10 or may be attached to a plurality of droplet discharge heads 10.

  FIG. 5 is an exploded perspective view showing the configuration of the head of the droplet discharge device shown in FIGS. 6 is a cross-sectional view of an actuator portion included in the droplet discharge head shown in FIG. 5, and FIG. 7 is a basic waveform diagram of a drive signal applied to a pressure generating element used as the actuator shown in FIG. is there. The droplet discharge head 10 includes, for example, a nozzle plate 64, a pressure generation chamber forming plate 66, and a vibration plate 80 as shown in FIGS. In the pressure generation chamber forming plate 66, a pressure generation chamber 67, a side wall (partition wall) 68, a reservoir 76, and an introduction path 77 are formed. The pressure generation chamber forming plate 66 forms a pressure generation chamber 67 and the like by etching a substrate such as silicon, and the pressure generation chamber 67 is a space for storing a functional liquid immediately before discharge. The side walls 68 are formed so as to partition the pressure generating chambers 67, and the reservoir 76 is a flow path for filling each pressure generating chamber 67 with the functional liquid. Although not shown, the reservoir 76 is provided with an inflow port that communicates with a liquid supply pipe (not shown), and the functional liquid is supplied to the reservoir 76 via the inflow port. The introduction path 77 is formed so that the functional liquid can be introduced from the reservoir 76 to each pressure generating chamber 67.

  The nozzle plate 64 is organic or inorganic on one surface of the pressure generating chamber forming plate 66 so that the nozzle 63 is positioned at a position corresponding to each of the pressure generating chambers 67 formed on the pressure generating chamber forming plate 66. Bonded with an adhesive. The pressure generation chamber forming plate 66 to which the nozzle plate 64 is bonded is further housed in a casing 78 to constitute the droplet discharge head 10. The vibration plate 80 is made of an elastically deformable thin plate, and is bonded to the other surface of the pressure generation chamber forming plate 66 with an organic or inorganic adhesive. A piezoelectric vibrator (PZT) 17 serving as a pressure generating element as a head driving element is provided at a portion corresponding to the position of each pressure generating chamber 67 of the vibration plate 80.

  Here, the pressure generating element is not limited to the longitudinal vibration / lateral effect PZT, but may be a flexural vibration type PZT. Further, the pressure generating element is not limited to the piezoelectric vibrator, and other elements such as a magnetostrictive element may be used. Moreover, the structure which heats a functional liquid with heat sources, such as a heater, and changes a pressure with the bubble which arose by heating may be sufficient. In short, any element that causes pressure fluctuations in a pressure generating chamber, which will be described later, according to a signal given from the outside can be used.

  Next, the basic waveform of the drive pulse constituting the drive signal COM will be described with reference to FIG. In FIG. 7, the drive signal COM for operating the piezoelectric vibrator 17 basically starts from the time T1 to time T2 after the voltage value starts from the intermediate potential Vm (reference voltage) (hold pulse 151). During the (charging time), it rises at a constant slope to the maximum potential VPS (drive voltage) (charging pulse 152), and the maximum potential VPS is maintained from time T2 to time T3 (HOLD time) (hold pulse 153). ). Next, after falling from the time T3 to the time T4 (discharge time) with a certain slope to the lowest potential VLS (discharge pulse 154), the minimum potential VLS is maintained for a predetermined time from the time T4 to the time T5 (hold). Pulse 155). Then, from time T5 to time T6, the voltage value rises at a constant slope to the intermediate potential Vm (charging pulse 156). Then, the intermediate potential Vm is maintained until the next drive pulse (hold pulse 157).

  Therefore, in FIG. 6, when the charging pulse 152 is applied to the piezoelectric vibrator 17, the piezoelectric vibrator 17 bends in the direction of expanding the volume of the pressure generating chamber 67 and generates a negative pressure in the pressure generating chamber 67. As a result, the functional liquid is supplied from the reservoir 76 to the pressure generating chamber 67 through the introduction path 77. Next, when the discharge pulse 154 is applied, the piezoelectric vibrator 17 bends in the direction in which the volume of the pressure generation chamber 67 is contracted, and a positive pressure is generated in the pressure generation chamber 67. As a result, droplets are ejected from the nozzle 63. Then, after the hold pulse 155 is applied, the charging pulse 156 is applied to suppress the vibration of the meniscus (functional liquid surface in the nozzle 63). Therefore, for example, as the maximum potential VPS is higher or the slope of the discharge pulse 154 is steeper, the weight per droplet of functional liquid ejected from the nozzle 63 increases.

  Next, the drive signal generation unit 58 will be described with reference to FIGS. FIG. 8 is a block diagram illustrating a configuration of the drive signal generation unit. FIG. 9 is an explanatory diagram showing a process of generating a drive pulse included in the drive signal COM in the drive signal generation unit 58. FIG. 10 is a timing chart showing the timing of each signal when the drive signal generation unit 58 sets a potential difference (ΔV) in the memory using a data signal.

  As shown in FIG. 8, the drive signal generator 58 includes a memory 81 that receives and records a signal from the apparatus body controller 56, a first latch 82 that reads and temporarily holds the contents of the memory 81, An adder 83 for adding the output of the first latch 82 and the output of another second latch 84 described later, a D / A converter 86 for converting the output of the second latch 84 into analog data, and A voltage amplification unit 88 is provided for amplifying the converted analog signal to the voltage of the drive signal. Furthermore, the drive signal generator 58 includes a current amplifier 89 for the drive signal output from the voltage amplifier 88.

  The memory 81 is a waveform data recording unit that records predetermined parameters that determine the waveform of the drive signal COM. The waveform of the drive signal COM is determined based on predetermined parameters received from the apparatus main body control unit 56 in advance. That is, the drive signal generator 58 receives the clock signals 101, 102, 103, the data signal 108, the address signals 110, 112, 114, 116, the reset signal 107, and the enable signal 109.

  In the drive signal generator 58 configured as described above, as shown in FIG. 9, prior to the generation of the drive signal COM, several data signals indicating the amount of voltage change of the apparatus main body controller 56 and the data signals thereof Are synchronized with the clock signal 101 and output to the memory 81 of the drive signal generator 58. As shown in FIG. 10, the data signal 108 is configured to exchange data by serial transfer using the clock signal 101 as a synchronization signal.

  That is, when transferring a predetermined voltage change amount from the apparatus main body control unit 56, first, a multi-bit data signal is output in synchronization with the clock signal 101, and then the address for storing this data is set to the enable signal 109. Are output as address signals 110, 112, 114, and 116 in synchronization with The memory 81 reads the address signal at the timing when the enable signal 109 is output, and writes the received data to the address. Since the address signals 110, 112, 114 and 116 are 4-bit signals, a maximum of 16 types of voltage change amounts can be recorded in the memory 81. The upper bits of the data are used as codes. The number of bits of the address signals 110, 112, 114, 116 is not limited to 4 bits, and may be set to 5 bits or more. That is, by further increasing the number of bits of the address signals 110, 112, 114, and 116, it is possible to record more than 16 types of voltage change amounts in the memory 81, and thus it is possible to widen the setting range of the voltage change amounts. .

  After the setting of the voltage change amount to each address A, B,... Is completed, for example, when the address B is output to the address signals 110, 112, 114, 116, the first clock signal 102 corresponds to this address B. The voltage change amount ΔV 1 is held by the first latch 82. When the clock signal 103 is next output in this state, a value obtained by adding the output of the first latch 82 to the output of the second latch 84 is held in the second latch 84. That is, as shown in FIG. 9, once the voltage change amount corresponding to the address signal is selected, every time the clock signal 103 is received thereafter, the output of the second latch 84 increases or decreases according to the voltage change amount. To do. The slew rate of the drive waveform is determined by the voltage change amount ΔV 1 stored at the address B of the memory 81 and the unit time ΔT of the clock signal 103. The increase or decrease is determined by the sign of the data stored at each address.

  In the example shown in FIG. 9, the address A stores a value 0 as a voltage change amount, that is, a value when the voltage is maintained. Therefore, when the address A is validated by the clock signal 102, the waveform of the drive signal is kept flat with no increase or decrease. The address C stores a voltage change amount ΔV2 per unit time ΔT in order to determine the slew rate of the drive waveform. Therefore, after the address C is validated by the clock signal 102, the voltage decreases by this voltage ΔV2. In this way, the waveform of the drive signal COM can be freely controlled simply by outputting the address signal and the clock signal from the apparatus main body control unit 56.

  When the drive signal generated by the drive signal generator 58 is applied to the piezoelectric vibrator 17, the piezoelectric vibrator 17 is bent by the applied voltage, and the diaphragm 80 to which one end of the piezoelectric vibrator 17 is fixed is bent. Thus, the volume of the pressure generating chamber 67 is changed. When the charging pulse 152 is applied to the piezoelectric vibrator 17, the piezoelectric vibrator 17 contracts, the vibration plate 80 bends in a direction to expand the pressure generation chamber 67, and a negative pressure is generated in the pressure generation chamber 67. As a result, the functional liquid is supplied from the reservoir 76 to the pressure generating chamber 67 through the introduction path 77. Next, when the discharge pulse 154 is applied, the voltage applied to the piezoelectric vibrator 17 drops to the lowest potential VLS, the piezoelectric vibrator 17 extends to a length corresponding to the lowest potential VLS, and the diaphragm 80 Bends in the direction of contracting the volume of the pressure generating chamber 67, and a positive pressure is generated in the pressure generating chamber 67. As a result, the functional liquid in the pressure generation chamber 67 is discharged as droplets from the nozzle 63.

  The diaphragm 80 of each pressure generation chamber 67 is attenuated by this series of operations (functional droplet discharge operation by the drive signal) until the next drive signal (drive voltage) is input and the droplet is discharged again. It is vibrating. Hereinafter, this damped vibration is also referred to as residual vibration. The residual vibration of the diaphragm 80 is caused by the acoustic resistance r due to the shape of the nozzle 63 and the introduction path 77 or the viscosity of the functional liquid, the inertance m due to the weight of the functional liquid in the flow path, and the compliance Cm of the diaphragm 80. It is assumed to have a natural frequency to be determined.

  A calculation model for residual vibration of the diaphragm 80 based on the above assumption will be described. FIG. 11 is a circuit diagram showing a calculation model of simple vibration assuming residual vibration of the diaphragm 80. Thus, the calculation model of the residual vibration of the diaphragm 80 can be expressed by the sound pressure P, the above-described inertance m, compliance Cm, and acoustic resistance r. When the step response when the sound pressure P is applied to the circuit of FIG. 11 is calculated for the volume velocity u, the following equation is obtained.

  The calculation result obtained from this equation is compared with the experimental result in the residual vibration experiment of the diaphragm 80 after the functional liquid is discharged separately. FIG. 12 is a graph showing the relationship between the experimental value and the calculated value of the residual vibration of the diaphragm 80. As can be seen from the graph shown in FIG. 12, the two waveforms of the experimental value and the calculated value are almost the same.

  FIG. 13 is a block diagram showing an outline of the switching means 143 between the head drive circuit 140 and the residual vibration detection circuit 141 of the head drive element (piezoelectric vibrator 17). With this configuration, the electromotive voltage after the ejection driving operation of the piezoelectric vibrator 17 that is a piezoelectric actuator is input to the waveform shaping circuit 145 via the buffer 144, and the waveform shaping circuit 145 shapes the rectangular wave. be able to. Therefore, the residual vibration waveform detection process can be executed by utilizing the electromotive voltage of the piezoelectric vibrator 17.

  FIG. 14 is a flowchart showing residual vibration detection processing in the present embodiment. When the piezoelectric vibrator 17 is switched from the drive circuit 140 to the residual vibration detection circuit 141 by the switching means 143 and connected, an electromotive voltage is generated from the piezoelectric vibrator 17 after ejection driving (step S61). The capacitor C3 of the waveform shaping circuit 145 removes the DC component (direct current component) of the electromotive voltage (voltage signal) (step S62), and the amplifier 147 removes the DC component from the AC component of the electromotive voltage, ie, The output of the residual vibration waveform of the electromotive voltage is amplified (step S63), and the comparator 148 shapes the waveform from the residual vibration waveform to a residual vibration pulse waveform (step S64).

  In the following description, the drive signal applied to the piezoelectric vibrator 17 is represented by a set of a plurality of drive parameter values. The plurality of drive parameter values in this embodiment are a charge time value, a HOLD time value, a discharge time value, a drive voltage value, and a drive reference voltage value of the drive signal. In the following description, the residual vibration of the piezoelectric vibrator 17 is represented by a set of a plurality of vibration parameter values. The plurality of vibration parameter values in the present embodiment are a frequency value, an amplitude value, a phase value, an attenuation factor value, and a vibration reference voltage value.

  Next, the process of setting the optimum condition of the drive signal by adjusting the value of each drive parameter of the drive signal based on the detected residual vibration will be described. First, standard data is obtained using a standard droplet discharge device (standard machine). As will be described in detail below, the standard data includes a standard drive P value, a standard vibration P value, and an allowable error value.

  Specifically, first, in advance, a drive signal for realizing optimum discharge is obtained in a standard droplet discharge device (standard machine). Then, the residual vibration obtained when the drive signal is given to the droplet discharge head 10 (piezoelectric vibrator 17) of the standard machine is detected.

  In the present embodiment, a drive signal that realizes optimum ejection is referred to as a standard drive signal. Furthermore, the values of a plurality of drive parameters representing the standard drive signal are expressed as standard drive P values. In this embodiment, when a standard drive signal is given to the droplet discharge head 10 (piezoelectric vibrator 17) of the standard machine, the residual vibration obtained from the piezoelectric vibrator 17 is expressed as standard residual vibration. Further, a plurality of residual vibration parameter values representing the standard residual vibration are expressed as a standard vibration P value.

  In addition, a value representing an allowable error corresponding to each residual vibration parameter in the standard vibration P value is referred to as an allowable error value. The standard data is standard information described in the claims.

  Further, residual vibration is detected when a drive signal in which the value of each drive parameter is changed with respect to the standard drive signal is applied to the liquid droplet ejection head 10 (piezoelectric vibrator 17) of the standard machine. The value is obtained and used as control data. FIG. 15 shows an example of the control data table, which is an example in which the drive voltage, which is one of the drive parameters, is changed. Drive parameter values other than the drive voltage are set to the standard drive P value, and the drive voltage is + a volt, + b volt, -b volt, -a volt with respect to the standard drive voltage V that is the drive voltage of the standard drive signal. Is applied to the standard piezoelectric vibrator 17. The residual vibration generated at that time is detected, and the value of each residual vibration parameter is obtained. The term “vibration reference voltage” in the control data indicates an offset amount from the standard vibration reference voltage that is the vibration reference voltage when the standard drive voltage is applied. The values of a and b are set to voltages corresponding to 3% and 1% of the standard drive P value of the drive voltage, for example. As for other driving parameters such as charging time, HOLD time, discharging time, and driving reference voltage, vibration parameters when values are similarly changed are obtained. The control data is the control information described in the claims.

  Data consisting of standard data and control data is denoted as reference data. The reference data is reference information described in the claims. The reference data is input to the host computer 70 via the external input / output device 73 and is recorded and held in the recording unit 72.

  FIG. 16 is a flowchart showing a process for setting the optimum condition of the drive signal in the droplet discharge device 1 (adjuster) that sets the optimum condition of the drive signal. In step S1, a counter for counting the number of repetitions of each process shown below is reset (N = 0). In step S2, 1 is added to the counter (N = N + 1). In step S3, it is determined whether the number N of repetitions exceeds a predetermined number n. If the number of repetitions exceeds n (NO in step S3), the process proceeds from step S3 to step S30.

  In step S30, a warning is issued that the optimum condition of the drive signal cannot be set. In the present embodiment, an optimal condition setting failure message is displayed on the CRT 74. When step S30 ends, the drive signal optimum condition setting step ends. Steps S2 and S3 correspond to a determination step for determining whether or not adjustment is possible, and if the drive signal parameter correction is not repeated n times, the drive signal optimum condition setting step is terminated.

  First, the counter is reset in step S1, and 1 is added to the counter in step S2. At this time, N = 1 (YES in step S3), and the process proceeds from step S3 to step S4. In step S <b> 4, the drive signal having the drive waveform generated by the drive signal generator 58 according to the standard data is applied to the piezoelectric vibrator 17. In step S 5, when the droplet is ejected from the nozzle 63, the switching unit 143 disconnects the head drive circuit 140 from the piezoelectric vibrator 17 and connects the residual vibration detection circuit 141 to the piezoelectric vibrator 17. In step S6, the residual vibration waveform is detected through each step shown in FIG. 14 as described above. In step S7, each value of the vibration parameters (frequency, amplitude, phase, damping rate, vibration reference voltage) (hereinafter referred to as a detected vibration P value of each vibration parameter) from the residual vibration waveform detected in step S6. Ask.

  In step S8, the detected vibration P value obtained in step S7 is compared with the standard vibration P value that is the value of the residual vibration parameter in the standard data and an allowable error value, and the detected vibration P value falls within the allowable range. It is determined whether or not. Specifically, an error value of each detected vibration P value with respect to the corresponding standard vibration P value is obtained, and the obtained error value is compared with the corresponding allowable error value to determine whether the detected vibration P value is within the allowable range. .

  If all the detected vibration P values are within the allowable range (YES in step S8), the process proceeds from step S8 to step S9, and each drive parameter value of the head drive signal is applied to each drive of the head drive signal applied in step S4. Set to the value of the parameter. In this case, the value of each drive parameter of the drive signal is set to the corresponding standard drive P value.

  If any detected vibration P value exceeds the allowable range (NO in step S8), the process proceeds from step S8 to step S10, and the detected vibration P value is the most disparate from the standard vibration P value among the vibration parameters. Select the vibration parameter. More specifically, in each vibration parameter, the difference (deviation value) between the detected vibration P value and the standard vibration P value is obtained, and the ratio of the obtained deviation value to the allowable error value (the deviation value is the multiple of the allowable error value). )) (Here called the divergence ratio). The vibration parameters having the largest value of the deviation ratio are selected by comparing the deviation ratios of the vibration parameters. Hereinafter, the vibration parameter having the largest value of the deviation ratio selected here is referred to as a first vibration parameter.

  Following step S10, in step S11, the value of each drive parameter is determined such that the value of the first vibration parameter becomes the standard vibration P value. Each drive parameter whose value is changed and each vibration parameter value corresponding to each drive parameter are obtained as reference data as shown in FIG. From the correlation between the first drive parameter and each vibration parameter, the value of each drive parameter at which the value of the first vibration parameter becomes the standard vibration P value is obtained. The value of each driving parameter obtained here is called the optimum driving P value of each driving parameter.

  More specifically, for example, a case where the first vibration parameter is amplitude and the detected vibration P value of the amplitude is detection X will be described. FIG. 17 is a graph showing the relationship between the drive voltage and the amplitude of the table shown in FIG. The relationship between the drive voltage and the amplitude of the control data is represented as indicated by a solid line (a line indicated as a standard machine in the figure). The approximate curve representing the relationship between the drive voltage and the amplitude shown in FIG. 15 (in FIG. 17, a straight line is used for simplicity of explanation) is obtained by a processing method such as the least square method. In this figure, a line described as a standard machine indicates the relationship between the drive voltage and the amplitude in the liquid droplet ejection head 10 of the standard liquid droplet ejection apparatus 1 (standard machine). On the other hand, in the present embodiment, in the droplet discharge head 10 of the droplet discharge device 1 (adjuster) that adjusts the drive signal, when the drive voltage of the applied drive waveform is the standard drive P value, the detected vibration P The value was XK. Here, for example, it is assumed that the fluctuation of the amplitude corresponding to the fluctuation of the driving voltage is almost equal between the standard machine and the regulator. Then, the curve representing the relationship between the drive voltage and the amplitude in the adjuster is a parallel translation of the curve representing the relationship between the drive voltage and the amplitude in the standard machine. Accordingly, in the droplet discharge head 10 in the adjuster, the relationship between the drive voltage and the amplitude is expressed as shown by a two-dot chain line in FIG. 17 (a line indicated as an adjuster in the drawing). In the relationship indicated by the two-dot chain line, VS that is the value of the driving voltage corresponding to X0 that is the standard vibration P value of the amplitude that is the first vibration parameter in this case is the optimum driving P value of the driving voltage in this case. is there. For each drive parameter other than the drive voltage, each optimum drive P value is obtained in the same manner.

  Next, the process proceeds from step S11 to step S20, and a first drive signal in which the value of each drive parameter is the optimum drive P value is generated. Next, the process proceeds from step S20 to step S2, and the above steps after step S2 are repeated. In this case, the value of each drive parameter of the drive signal applied in step S4 is the optimum drive P value obtained in step S11. Further, the value of each drive parameter of the head drive signal set in step S9 is also the optimum drive P value obtained in step S11.

  When the above steps are repeated and a residual vibration that falls within the allowable range is obtained, the determination in step S8 is YES, and the process proceeds to step S9. In step S9, the value of each parameter that defines the drive signal is set to the value of each parameter of the drive signal that has generated residual vibration that falls within the allowable range, and the drive signal optimum condition setting step ends.

  In the present embodiment, each of the above functions is realized by software using the apparatus main body control unit 56. However, when each of the above functions can be realized by a single electronic circuit that does not use an arithmetic unit. It is also possible to use such an electronic circuit.

According to the first embodiment, the following effects can be obtained.
(1) When adjusting the drive signal of the droplet discharge head 10 in the droplet discharge apparatus 1, the residual vibration of the droplet discharge head 10 after droplet discharge is detected, and the head drive signal is determined based on the detected residual vibration state. Therefore, an appropriate head driving signal can be generated in accordance with the state of each droplet discharge head 10. Furthermore, the number of test discharges for setting the conditions is sufficient if the residual vibration can be detected (minimum one time), and the time required for adjusting the drive signal can be shortened, and the amount of functional liquid to be tested and discharged can be reduced.

  (2) Since the detected residual vibration is compared with reference data and a head drive signal is generated based on the comparison result, an appropriate head drive signal can be generated corresponding to the state of each droplet discharge head 10. it can. In addition, the test discharge for setting the conditions is sufficient for the number of times that the residual vibration can be detected, the time required for adjusting the drive signal can be shortened, and the amount of the functional liquid to be discharged can be reduced. Furthermore, since the reference data can be used repeatedly, if it is generated once, the step of generating the reference data can be omitted in the subsequent drive signal adjustment, and the drive signal adjustment can be performed efficiently.

  (3) In order to compare the detected residual vibration with the reference data, which is information on the dependency on each parameter that defines the drive signal for each parameter that defines the residual vibration, it is appropriate to compare and calculate the information. A simple driving signal can be obtained. Therefore, test ejection other than liquid droplet ejection for obtaining residual vibration information is not required, the time required for drive signal adjustment can be shortened, and the amount of functional liquid to be ejected can be reduced.

  (4) By using the drive voltage, the charge time, the hold time, the discharge time, and the reference potential as drive parameters that define the drive signal, the drive signal can be accurately and efficiently expressed as drive signal information.

  (5) By using the frequency, amplitude, phase, damping rate, and bias as vibration parameters that define the residual vibration, the residual vibration can be accurately and efficiently expressed as the residual vibration information.

  (6) Since a reference machine is set and the first step is performed using a droplet discharge head as a standard of the reference machine, the reference data can be created using the standard head and is required for drive signal adjustment. The time can be shortened, and the amount of functional liquid discharged from the test can be reduced. Furthermore, in the droplet discharge device for setting the drive conditions, a weight measuring device for detecting the discharge state, an optical observation device, and the like are not required, and the droplet discharge device can be downsized and manufactured. Cost can be reduced.

  (7) To select the first vibration parameter in which the detected vibration P value is most different from the standard vibration P value among the vibration parameters, and to adjust the drive signal condition so as to improve the first vibration parameter value The comparison operation can be simplified, and the drive signal conditions can be adjusted efficiently.

  (8) Each time the adjustment process of the drive signal is performed and the adjustment result is one time, 1 is added to the counter. When the value of the counter exceeds a predetermined number of repetitions, a warning is issued and the drive signal adjustment process Exit. Since a warning is issued in a state where a target result cannot be obtained such as a state in which the adjustment value diverges, wasteful drive signal adjustment can be stopped and improvement measures can be taken.

(Second Embodiment)
Next, a second embodiment relating to a droplet discharge apparatus according to an embodiment of the present invention will be described. The droplet discharge device 1 of the present embodiment is basically the same as the droplet discharge device 1 described in the first embodiment. Only the drive signal optimum condition setting step, which is different from the first embodiment, will be described.

  In the drive signal optimum condition setting process of the present embodiment, an initialization process is performed in addition to the drive signal optimum condition setting process in the first embodiment. The initialization step is a step of detecting a head abnormality occurring in the droplet discharge head 10, recovering the abnormality, and returning the droplet discharge head 10 to a state where normal droplet discharge is possible. Head abnormalities include variations in discharge amount (too little or too much) and inability to discharge. Causes of the head abnormality include generation of bubbles in the functional liquid in the droplet discharge head 10 and clogging of the nozzle 63.

  In the standard droplet discharge device (standard machine), the standard drive signal that realizes optimal discharge is obtained in advance, and the standard residual vibration that is the residual vibration when the droplet discharge head is driven with the standard drive signal is detected. And standard data. The standard data includes standard drive signal data and standard residual vibration data. The standard drive signal is expressed by values of a charge signal, a HOLD time, a discharge time, a drive voltage, and a drive reference voltage, which are drive signal parameters (drive parameters). The standard residual vibration is represented by values of frequency, amplitude, phase, damping factor, and vibration reference voltage, which are parameters of residual vibration (vibration parameters). The value of each drive parameter of the standard drive signal is called a standard drive P value. The value of each residual vibration parameter of the standard residual vibration is referred to as a standard vibration P value. The standard residual vibration data in the standard data includes a standard vibration P value, an allowable error value A, and an allowable error value B.

  The allowable error value A is set to a large value that does not deviate from the allowable value if the droplet discharge head 10 is in a normal state that is not an abnormal head state such as inability to discharge. The allowable error value B is set to a small value that is not allowable when the discharge state varies.

  Further, as in the first embodiment, the residual vibration when a drive signal in which the value of each drive parameter is changed is applied to the droplet discharge head with respect to the standard drive signal is obtained and used as control data.

  FIG. 18 is a flowchart showing an initialization process of the droplet discharge head 10. In step S71, a counter for counting the number of repetitions of each process shown below is reset (N = 0). In step S72, 1 is added to the counter (N = N + 1). In step S73, it is determined whether the number of repetitions N exceeds a predetermined number k.

  First, the counter is reset in step S71, 1 is added to the counter in step S72, and the process proceeds to step S73. At this time, N = 1 (YES in step S73), and the process proceeds to the next step S74. In step S74, the drive signal having the drive waveform generated by the drive signal generator 58 according to the standard data is applied to the piezoelectric vibrator 17. In step S75, when the droplet is ejected from the nozzle 63, the switching unit 143 switches the piezoelectric vibrator 17 from the head drive circuit 140 to the residual vibration detection circuit 141 and connects it. In step S76, the residual vibration waveform is detected through the steps shown in FIG. 14 as described above.

  In step S77, the respective values of the frequency and the damping rate that are residual vibration parameters (hereinafter referred to as detected vibration SP values of the residual vibration parameters) are obtained from the residual vibration waveform detected in step S76. When a head abnormality occurs due to bubbles or the like, the change in residual vibration increases. In the initialization process of the present embodiment, the detected vibration SP value of only the frequency and the damping rate, which are residual vibration parameters in which a change in the residual vibration due to bubble generation is likely to appear, is obtained.

  In step S78, the detected vibration SP value obtained in step S77 is compared with the standard vibration P value which is the value of the residual vibration parameter in the standard data, and it is evaluated whether the residual vibration data value is within the allowable range. Specifically, an error value of each detected vibration SP value with respect to the corresponding standard vibration P value is obtained, and the obtained error value is compared with the corresponding allowable error value A to determine whether the detected vibration P value is within the allowable range. To do.

  If the detected vibration SP value exceeds the allowable range (NO in step S78), the process proceeds to step S79, and head maintenance work such as ink suction and wiping is performed. When step S79 ends, the process proceeds to step S72 again, and the initialization process is repeated. The maintenance work is a maintenance operation described in the claims.

  When the number of repetitions N exceeds the predetermined number k in step S73 (NO in step S73), the process proceeds to step S80. This is a case where the abnormality of the droplet discharge head is not eliminated even if the head maintenance work in step S79 is repeatedly performed. In steps S72 and S73, the maintenance work is repeatedly executed k times in advance, but it can be seen that the determination result in step S78 remains outside the allowable range. That is, it is determined that there is no possibility of abnormal recovery, and the process proceeds to step S80. In step S80, a warning is given that the droplet discharge head 10 is abnormal. In the present embodiment, a message indicating that the droplet discharge head 10 is abnormal is displayed on the CRT 74. When step S80 ends, the initialization process ends. In this case, the process does not shift to the drive signal optimum condition setting step similar to that of the first embodiment.

  If the detected vibration SP value is within the allowable range in step S78 (YES in step S78), the initialization process is terminated. The droplet discharge head 10 is in a state of operating normally. Thereafter, the drive signal optimum condition setting step similar to that of the first embodiment is performed. In this case, in the drive signal optimum condition setting step similar to that of the first embodiment, the allowable error value used as a reference at the time of determination in step S8 is the above-described allowable error value B.

According to the second embodiment, the following effects can be obtained.
(1) Before the head drive signal adjustment step, a head abnormality that has occurred in the droplet discharge head 10 is detected, and if an abnormality is detected, the abnormality is recovered and the droplet discharge head 10 is returned to a normal droplet. An initialization process, which is a process of returning to a state in which ejection can be performed, is performed. Accordingly, it is possible to avoid the abnormal state of the droplet discharge head and perform head drive signal adjustment (setting of drive signal optimum conditions) with a droplet discharge head in a normal state.

  (2) Each time maintenance work is performed, 1 is added to the counter. When the counter value exceeds a predetermined number of repetitions, a warning is issued and the initial setting process is terminated. That is, if the abnormal state of the droplet discharge head is not improved even after repeating the maintenance work a predetermined number of times, a warning can be issued and the initial setting process can be completed. Therefore, useless maintenance work can be stopped and another improvement response can be taken. In addition, the state of the droplet discharge head that performs the drive signal adjustment can be surely brought into a normal state.

(Third embodiment)
Next, a third embodiment relating to a droplet discharge apparatus according to an embodiment of the present invention will be described. The droplet discharge device 1 of the present embodiment is basically the same as the droplet discharge device 1 described in the first embodiment. Only the drive signal optimum condition setting step, which is different from the first embodiment, will be described. In the drive signal optimum condition setting step of the present embodiment, in addition to the drive signal optimum condition setting step in the first embodiment, a step of selecting a drive parameter that most affects the first vibration parameter is performed.

  FIG. 19 is a flowchart showing an optimum condition setting process for drive signals. In FIG. 19, Steps S1 to S10, Step S20, and Step S30 are the same as Steps S1 to S10, Step S20, and Step S30 described in the first embodiment.

  In step S10, the first vibration parameter that is the vibration parameter whose detected vibration P value is most different from the standard vibration P value among the vibration parameters is selected.

  After step S10, in step S12, the drive parameter that most influences the first vibration parameter selected in step S10 is selected from the above-described control data. More specifically, for example, the case where the first vibration parameter is amplitude will be described. FIG. 20 is a graph showing the relationship between the drive voltage and the amplitude of the table shown in FIG. The approximate curve representing the relationship between the drive voltage and the amplitude shown in FIG. 15 (in FIG. 20, a straight line is used for simplicity of explanation) is obtained by a processing method such as a least square method. From the standard vibration P value and the allowable error value, the maximum value XUL and the minimum value XLL of the amplitude falling within the allowable range are obtained. The maximum allowable voltage value VUL and the minimum allowable voltage value VLL, which are drive voltage values corresponding to the maximum allowable amplitude value XUL and the minimum allowable amplitude value XLL, are obtained from the approximate line in FIG. The difference between the allowable maximum voltage value VUL and the allowable minimum voltage value VLL and V that is the standard drive P value of the drive voltage (herein referred to as margin voltage) is obtained, and the ratio of the obtained margin voltage to V that is the standard drive P value ( How many times the marginal voltage is V) (herein referred to as margin ratio) is obtained. Similarly, a margin ratio is obtained for each of the other drive parameters, and a drive parameter having the smallest margin ratio is selected. Hereinafter, the drive signal parameter selected here is referred to as a first drive parameter.

  Following step S12, in step S21, the value of the first drive parameter is determined so that the value of the first vibration parameter becomes the standard vibration P value. The first drive parameters whose values are changed and the values of the vibration parameters corresponding to the respective values are obtained as reference data as shown in FIG. From the correlation between the first drive parameter and the first vibration parameter, the value of the first drive parameter at which the value of the first vibration parameter becomes the standard vibration P value is obtained. The value of the first drive parameter obtained here is called the optimum drive P value of the first drive parameter.

  More specifically, for example, a case where the first vibration parameter is amplitude, the first drive parameter is drive voltage, and the detected vibration P value of amplitude is detection X will be described. As described above, FIG. 17 is a graph showing the relationship between the drive voltage and the amplitude of the table shown in FIG. The relationship between the drive voltage and the amplitude of the control data is represented as indicated by a solid line (a line indicated as a standard machine in the figure). The approximate curve representing the relationship between the drive voltage and the amplitude shown in FIG. 15 (in FIG. 17, a straight line is used for simplicity of explanation) is obtained by a processing method such as the least square method. In this figure, a line described as a standard machine indicates the relationship between the drive voltage and the amplitude in the liquid droplet ejection head 10 of the standard liquid droplet ejection apparatus 1 (standard machine). On the other hand, in the present embodiment, in the droplet discharge head 10 of the droplet discharge apparatus 1 (adjuster) that adjusts the drive signal, the amplitude is detected when the drive voltage of the applied drive waveform is the standard drive P value. The vibration P value was XK. Here, for example, it is assumed that the fluctuation of the amplitude corresponding to the fluctuation of the driving voltage is almost equal between the standard machine and the regulator. Then, the curve representing the relationship between the drive voltage and the amplitude in the adjuster is a parallel translation of the curve representing the relationship between the drive voltage and the amplitude in the standard machine. Accordingly, in the droplet discharge head 10 in the adjuster, the relationship between the drive voltage and the amplitude is expressed as shown by a two-dot chain line in FIG. 17 (a line indicated as an adjuster in the drawing). In the relationship indicated by the two-dot chain line, VS that is the value of the driving voltage corresponding to X0 that is the standard vibration P value of the amplitude that is the first vibration parameter in this case is the driving voltage that is the first driving parameter in this case. Is the optimum drive P value. For drive parameters other than the first drive parameter, the standard drive P value is used as it is as the optimum drive P value.

  After step S21, the process proceeds to step S20 to generate a first drive signal in which each drive parameter value is the optimum drive P value. Next, the process proceeds from step S20 to step S2, and the above steps after step S2 are repeated. In this case, the value of each drive parameter of the drive signal applied in step S4 is the optimum drive P value obtained in step S21. Further, the value of each drive parameter of the head drive signal set in step S9 is also the optimum drive P value obtained in step S21.

  When the above steps are repeated and a residual vibration that falls within the allowable range is obtained, the determination in step S8 is YES, and the process proceeds to step S9. In step S9, the value of each parameter that defines the drive signal is set to the value of each parameter of the drive signal that has generated residual vibration that falls within the allowable range, and the drive signal optimum condition setting step ends.

According to the third embodiment, the following effects can be obtained.
(1) To select the first vibration parameter whose detected vibration P value is most different from the standard vibration P value among the vibration parameters, and to adjust the drive signal condition so as to improve the first vibration parameter value. The comparison operation can be simplified, and the drive signal conditions can be adjusted efficiently.

  (2) Among the vibration parameters, select the first vibration parameter whose detected vibration P value is the most dissimilar from the standard vibration P value, and select the first drive parameter that most affects the first vibration parameter. In one adjustment step, only the value of the first drive parameter was adjusted. For this reason, the interaction of adjustment effects due to simultaneous adjustment of a plurality of drive parameters can be eliminated, adjustment work can be simplified, and drive signal conditions can be adjusted efficiently.

(Fourth embodiment)
Next, a description will be given of a fourth embodiment according to a droplet discharge apparatus which is an embodiment of the present invention. The droplet discharge device 1 of the present embodiment is basically the same as the droplet discharge device 1 described in the first embodiment. Only the drive signal optimum condition setting step, which is different from the first embodiment, will be described. In the drive signal optimum condition setting step of this embodiment, in addition to the drive signal optimum condition setting step in the third embodiment, a step of obtaining an expected value calculated from the obtained optimum drive P value and reference data is performed. ing.

  FIG. 21 and FIG. 22 are flowcharts showing the optimum condition setting process of the drive signal. In FIG. 21, Steps S1 to S10, Step S12, Step S21, Step S20, and Step S30 are the same as Steps S1 to S10, Step S12, Step S21, and Step described in the first and third embodiments. It is the same as S20 and step S30.

  In step S21, the optimum drive P value that is the value of the first drive parameter at which the value of the first vibration parameter becomes the standard vibration P value is obtained. For drive parameters other than the first drive parameter, the standard drive P value is directly used as the optimum drive P value.

  Following step S21, in step S22, the value of each residual vibration parameter (expected vibration P value) when the value of the first drive parameter is set to the optimum drive P value is obtained. Each drive parameter whose value is changed and each vibration parameter value corresponding to each drive parameter are obtained as reference data as shown in FIG. From the correlation between the first drive parameter and each vibration parameter, the value of each residual vibration parameter (expected vibration P value) when the value of the first drive parameter is set to the optimum drive P value is obtained.

  More specifically, for example, a case where the first vibration parameter is amplitude, the first drive parameter is drive voltage, and VS is obtained as the optimum drive P value will be described. FIG. 23 is a graph showing the relationship between the drive voltage and the attenuation rate of the table shown in FIG. The relationship between the drive voltage and the amplitude of the control data is represented as shown by an approximate curve (in FIG. 23, a straight line is used for ease of explanation). The approximate curve representing the relationship between the drive voltage and the amplitude shown in FIG. 15 is obtained by a processing method such as the least square method. Here, in step S21, VS is obtained as the optimum drive P value of the drive voltage that is the first drive parameter. In FIG. 23, σS corresponding to the drive voltage VS is an expected vibration P value of the attenuation rate when the drive voltage that is the first drive parameter becomes VS. For other vibration parameters, the predicted vibration P value is obtained in the same manner.

  Following step S22, in step S23, the predicted vibration P value obtained in step S22 is compared with the standard vibration P value and the allowable error value to determine whether the residual vibration data value is within the allowable range. Specifically, an error value of each predicted vibration P value with respect to the corresponding standard vibration P value is obtained, and the obtained error value is compared with the corresponding allowable error value to determine whether the predicted vibration P value is within the allowable range. . If the predicted vibration P value is within the allowable range (YES in step S23), the process proceeds to step S25, and the value of each drive parameter of the head drive waveform is set to the optimum drive P value.

  Subsequent to step S25, a first drive signal in which the value of each drive parameter is the optimum drive P value is generated (step S20), and the steps after step S2 are repeated. In this case, the drive signal applied in step S4 is the first drive signal. Further, the value of each drive parameter of the head drive signal set in step S9 is the optimum drive P value.

  If the predicted vibration P value exceeds the allowable range (NO in step S23), the process proceeds from step S23 to step S24, and the predicted vibration P value obtained in step S22 and the detected vibration P obtained in step S7. The value is compared with the standard vibration P value, and the error of the predicted vibration P value with respect to the standard vibration P value is compared with the error of the detected vibration P value with respect to the standard vibration P value. That is, it is determined whether the error of the predicted vibration P value with respect to the standard vibration P value is smaller than the error of the detected vibration P value with respect to the standard vibration P value, that is, whether the predicted vibration P value is improved from the detected vibration P value.

  If the error of the predicted vibration P value with respect to the standard vibration P value is smaller than the error of the detected vibration P value with respect to the standard vibration P value, and the predicted vibration P value is improved from the detected vibration P value (YES in step S24), step Proceeding to S25, the value of each drive parameter of the head drive waveform is set to the optimum drive P value.

  After step S25, the process proceeds to step S20, and a first drive signal in which the value of each drive parameter is the optimum drive P value is generated. After step S20, the process proceeds to step S2, and the above steps after step S2 are repeated. In this case, the drive signal applied in step S4 is the first drive signal. Further, the value of each drive parameter of the head drive signal set in step S9 is the optimum drive P value.

  If the error of the predicted vibration P value relative to the standard vibration P value is larger than the error of the detected vibration P value relative to the standard vibration P value, and the predicted vibration P value is not improved from the detected vibration P value (NO in step S24), step Proceed from step S24 to step S31.

  In step S31, the value of the first drive parameter (maximum drive P value) that maximizes the value of the first vibration parameter within the allowable range is obtained. First, an upper vibration P value that is an upper limit value of the allowable range of the first vibration parameter is obtained from the standard vibration P value of the standard data and the allowable error value. Next, the maximum drive P value corresponding to the upper vibration P value is obtained from the upper vibration P value and the reference data. The first drive parameters whose values are changed and the values of the vibration parameters corresponding to the respective values are obtained as reference data as shown in FIG. From the correlation between the first drive parameter and the first vibration parameter, the first drive parameter value at which the first vibration parameter value becomes the upper vibration P value is obtained.

  More specifically, for example, a case where the first vibration parameter is amplitude, the first drive parameter is drive voltage, and the detected vibration P value of amplitude is XK will be described. FIG. 24 is a graph similar to FIG. The relationship between the driving voltage and the amplitude in the droplet discharge head 10 of the standard machine is expressed as shown by a solid line (line indicated as a standard machine in the figure). In this embodiment, the relationship between the drive voltage and the amplitude in the droplet discharge head 10 of the droplet discharge device 1 (adjuster) that adjusts the drive signal is indicated by a two-dot chain line (described as an adjuster in the figure). Line). From the standard vibration P value and the allowable error value, the maximum value XH of the amplitude that falls within the allowable range is obtained. In the relationship indicated by the two-dot chain line in FIG. 24, VH that is the value of the drive voltage corresponding to XH that is the upper vibration P value of the amplitude that is the first vibration parameter in this case is the first drive parameter in this case. It is the maximum drive P value of a certain drive voltage. For drive parameters other than the first drive parameter, the standard drive P value is used as it is as the maximum drive P value.

  After step S31, in step S32, the value of each vibration parameter when the value of each drive parameter is set to the maximum drive P value is calculated. From the correlation between the first drive parameter and each vibration parameter, the value of each residual vibration parameter (upper expected vibration P value) when the value of the first drive parameter is set to the maximum drive P value is obtained.

  More specifically, for example, a case where the first vibration parameter is amplitude, the first drive parameter is drive voltage, and VS is obtained as the optimum drive P value will be described. As described above, FIG. 23 is a graph showing the relationship between the drive voltage and the attenuation rate of the table shown in FIG. The relationship between the drive voltage and the amplitude of the control data is represented as shown by an approximate curve (in FIG. 23, a straight line is used for ease of explanation). Here, in step S31, VH is obtained as the maximum drive P value of the drive voltage that is the first drive parameter. In FIG. 23, σH corresponding to the drive voltage VH is the upper predicted vibration P value of the attenuation rate when the drive voltage that is the first drive parameter becomes VH that is the maximum drive P value. The upper predicted vibration P value is similarly obtained for other vibration parameters.

  After step S32, in step S33, each upper predicted vibration P value obtained in step S32 is compared with each standard vibration P value and an allowable error value, and whether the upper predicted vibration P value is within the allowable range. judge. Specifically, an error value of each upper predicted vibration P value with respect to the corresponding standard vibration P value is obtained, and the obtained error value is compared with the corresponding allowable error value to determine whether the upper predicted vibration P value is within the allowable range. judge. If the upper predicted vibration P value is within the allowable range (YES in step S33), the process proceeds from step S33 to step S35, and the value of each drive parameter of the head drive waveform is set to the maximum drive P value.

  Following step S35, the process proceeds to step S20 to generate a second drive signal in which the value of each drive parameter is the maximum drive P value. After step S20, the process proceeds to step S2, and the above steps after step S2 are repeated. In this case, the drive signal applied in step S4 is the second drive signal. The value of each drive parameter of the head drive waveform set in step S9 is the maximum drive P value.

  If the upper predicted vibration P value exceeds the allowable range (NO in step S33), the process proceeds from step S33 to step S34, and the upper predicted vibration P value obtained in step S32 and the detection obtained in step S7. The vibration P value is compared with the standard vibration P value, and the error of the upper predicted vibration P value with respect to the standard vibration P value is compared with the error of the detected vibration P value with respect to the standard vibration P value. It is determined whether the error of the upper predicted vibration P value with respect to the standard vibration P value is smaller than the error of the detected vibration P value with respect to the standard vibration P value, that is, whether the upper predicted vibration P value is improved from the detected vibration P value.

  The error of the upper predicted vibration P value with respect to the standard vibration P value is smaller than the error of the detected vibration P value with respect to the standard vibration P value, and the upper predicted vibration P value is improved from the detected vibration P value (YES in step S34). The process proceeds from step S34 to step S35, and the value of each drive parameter of the head drive waveform is set to the maximum drive P value.

  Following step S35, the process proceeds to step S20 to generate a second drive signal in which the value of each drive parameter is the maximum drive P value. After step S20, the process proceeds to step S2, and the above steps after step S2 are repeated. In this case, the drive signal applied in step S4 is the second drive signal. The value of each drive parameter of the head drive waveform set in step S9 is the maximum drive P value.

  The error of the upper predicted vibration P value with respect to the standard vibration P value is larger than the error of the detected vibration P value with respect to the standard vibration P value, and the upper predicted vibration P value is not improved from the detected vibration P value (NO in step S34). The process proceeds from step S34 to step S41.

  In step S41, the value of the first drive parameter (minimum drive P value) that minimizes the value of the first vibration parameter within the allowable range is obtained. First, a lower vibration P value that is a lower limit value of the allowable range of the first vibration parameter is obtained from the standard vibration P value of the standard data and the allowable error value. Next, the minimum drive P value corresponding to the lower vibration P value is obtained from the lower vibration P value and the reference data. The first drive parameters whose values are changed and the values of the vibration parameters corresponding to the respective values are obtained as reference data as shown in FIG. From the correlation between the first drive parameter and the first vibration parameter, the first drive parameter value at which the first vibration parameter value becomes the lower vibration P value is obtained.

  More specifically, for example, the case where the first vibration parameter is amplitude, the first drive parameter is drive voltage, and the amplitude detection vibration P value is XK will be described. FIG. 24 is a graph similar to FIG. The relationship between the driving voltage and the amplitude in the droplet discharge head 10 of the standard machine is expressed as shown by a solid line (line indicated as a standard machine in the figure). In this embodiment, the relationship between the drive voltage and the amplitude in the droplet discharge head 10 of the droplet discharge device 1 (adjuster) that adjusts the drive signal is indicated by a two-dot chain line (described as an adjuster in the figure). Line). From the standard vibration P value and the allowable error value, the maximum value XL of the amplitude that falls within the allowable range is obtained. In the relationship indicated by the two-dot chain line in FIG. 24, the driving voltage value VL corresponding to the upper vibration P value XL, which is the first vibration parameter in this case, is the first driving parameter in this case. This is the minimum driving P value of a certain driving voltage. For drive parameters other than the first drive parameter, the standard drive P value is used as the minimum drive P value.

  After step S41, in step S42, the value of each vibration parameter when the value of each drive parameter is set to the minimum drive P value is obtained. From the correlation between the first drive parameter and each vibration parameter, the value of each residual vibration parameter (lower predicted vibration P value) when the value of the first drive parameter is set to the minimum drive P value is obtained.

  More specifically, for example, a case where the first vibration parameter is amplitude, the first drive parameter is drive voltage, and VS is obtained as the optimum drive P value will be described. As described above, FIG. 23 is a graph showing the relationship between the drive voltage and the attenuation rate of the table shown in FIG. The relationship between the drive voltage and the amplitude of the control data is represented as shown by an approximate curve (in FIG. 23, a straight line is used for ease of explanation). Here, in step S41, VL is obtained as the minimum drive P value of the drive voltage that is the first drive parameter. In FIG. 23, σL corresponding to the drive voltage VL is the lower expected vibration P value of the attenuation rate when the drive voltage that is the first drive parameter becomes VL that is the maximum drive P value. The lower predicted vibration P value is similarly obtained for other vibration parameters.

  After step S42, in step S43, the lower predicted vibration P value obtained in step S42 is compared with the standard vibration P value and the allowable error value to determine whether the residual vibration data value is within the allowable range. If the lower predicted vibration P value is within the allowable range (YES in step S43), the process proceeds from step S43 to step S45, and the value of each drive parameter of the head drive waveform is set to the minimum drive P value.

  Next, the process proceeds from step S45 to step S20, and a third drive signal in which the value of each drive parameter is the minimum drive P value is generated. Next, the process proceeds from step S20 to step S2, and the above steps after step S2 are repeated. In this case, the drive signal applied in step S4 is the third drive signal. The value of each drive parameter of the head drive waveform set in step S9 is the minimum drive P value.

  When the lower predicted vibration P value exceeds the allowable range (NO in step S43), the process proceeds from step S43 to step S44, and the lower predicted vibration P value obtained in step S42 and the detection obtained in step S7. The vibration P value is compared with the standard vibration P value, and the error of the lower predicted vibration P value with respect to the standard vibration P value is compared with the error of the detected vibration P value with respect to the standard vibration P value. It is determined whether the error of the lower predicted vibration P value with respect to the standard vibration P value is smaller than the error of the detected vibration P value with respect to the standard vibration P value, that is, whether the lower predicted vibration P value is improved from the detected vibration P value.

  The error of the lower predicted vibration P value with respect to the standard vibration P value is smaller than the error of the detected vibration P value with respect to the standard vibration P value, and the lower predicted vibration P value is improved from the detected vibration P value (YES in step S44). The process proceeds from step S44 to step S45, and the value of each drive parameter of the head drive waveform is set to the minimum drive P value.

  Next, the process proceeds from step S45 to step S20, and a third drive signal in which the value of each drive parameter is the minimum drive P value is generated. Next, the process proceeds from step S20 to step S2, and the above steps after step S2 are repeated. In this case, the drive signal applied in step S4 is the third drive signal. The value of each drive parameter of the head drive waveform set in step S9 is the minimum drive P value.

  In step S44, the error of the lower predicted vibration P value with respect to the standard vibration P value is larger than the error of the detected vibration P value with respect to the standard vibration P value, and the lower predicted vibration P value is not improved from the detected vibration P value (step S44). NO) proceeds from step S44 to step S51. In step S51, the predicted vibration P value obtained in step S22 and the lower predicted vibration P value obtained in step S42 are compared with the standard vibration P value, and an error of the predicted vibration P value with respect to the standard vibration P value, The error of the lower predicted vibration P value with respect to the standard vibration P value is compared. It is determined whether an error of the predicted vibration P value with respect to the standard vibration P value is smaller than an error of the lower predicted vibration P value with respect to the standard vibration P value, that is, whether the expected vibration P value has a greater degree of improvement than the lower predicted vibration P value. .

  In step S51, the error of the predicted vibration P value with respect to the standard vibration P value is smaller than the error of the lower predicted vibration P value with respect to the standard vibration P value, and the expected vibration P value has a greater degree of improvement than the lower predicted vibration P value (step S51). If YES in S51, the process proceeds from step S51 to step S52. In step S52, the predicted vibration P value obtained in step S22 and the upper predicted vibration P value obtained in step S32 are compared with the standard vibration P value, and an error of the predicted vibration P value with respect to the standard vibration P value; An error of the upper predicted vibration P value with respect to the standard vibration P value is compared. It is determined whether an error of the predicted vibration P value with respect to the standard vibration P value is smaller than an error of the lower predicted vibration P value with respect to the standard vibration P value, that is, whether the expected vibration P value has a greater degree of improvement than the lower predicted vibration P value. .

  In step S52, the error of the predicted vibration P value with respect to the standard vibration P value is smaller than the error of the upper predicted vibration P value with respect to the standard vibration P value, and the expected vibration P value has a greater degree of improvement than the upper predicted vibration P value (step S52). If YES in S52, the process proceeds from step S52 to step S25.

  In step S52, the error of the predicted vibration P value with respect to the standard vibration P value is larger than the error of the upper predicted vibration P value with respect to the standard vibration P value, and the degree of improvement of the predicted vibration P value is smaller than the upper predicted vibration P value (step If NO in S52, the process proceeds from step S52 to step S35.

  In step S51, the error of the predicted vibration P value with respect to the standard vibration P value is larger than the error of the lower predicted vibration P value with respect to the standard vibration P value, and the expected vibration P value is less improved than the lower predicted vibration P value (step S51). If NO in S51), the process proceeds from step S51 to step S53. In step S53, the lower expected vibration P value obtained in step S42 and the upper expected vibration P value obtained in step S32 are compared with the standard vibration P value, and the error of the lower expected vibration P value with respect to the standard vibration P value is determined. And the error of the upper predicted vibration P value with respect to the standard vibration P value. Whether the error of the lower predicted vibration P value with respect to the standard vibration P value is smaller than the error of the upper predicted vibration P value with respect to the standard vibration P value, that is, whether the lower predicted vibration P value has a greater degree of improvement than the upper predicted vibration P value. judge.

  In step S53, the error of the lower predicted vibration P value with respect to the standard vibration P value is smaller than the error of the upper predicted vibration P value with respect to the standard vibration P value, and the lower predicted vibration P value has a greater degree of improvement than the upper predicted vibration P value. (YES in step S53), the process proceeds from step S53 to step S45.

  In step S53, the error of the lower predicted vibration P value with respect to the standard vibration P value is larger than the error of the upper predicted vibration P value with respect to the standard vibration P value, and the lower predicted vibration P value is less improved than the upper predicted vibration P value. (NO in step S53), the process proceeds from step S53 to step S35.

  In each step of step S25, step S35, and step S45, as described above, the value of each drive parameter of the head drive waveform is set to the above-described drive P value.

  Next, the process proceeds from step S25, step S35, and step S45 to step S20 to generate the above-described drive signal in which each drive parameter value is the above-described drive P value. Next, the process proceeds from step S20 to step S2, and the above steps after step S2 are repeated.

  When the above steps are repeated and a residual vibration that falls within the allowable range is obtained, the determination in step S8 is YES, and the process proceeds to step S9. In step S9, the value of each parameter that defines the drive signal is set to the value of each parameter of the drive signal that has generated residual vibration that falls within the allowable range, and the drive signal optimum condition setting step ends.

  In the present embodiment, each of the above functions is realized by software using the apparatus main body control unit 56. However, when each of the above functions can be realized by a single electronic circuit that does not use an arithmetic unit. It is also possible to use such an electronic circuit.

According to the fourth embodiment, the following effects can be obtained.
(1) To select the first vibration parameter whose detected vibration P value is most different from the standard vibration P value among the vibration parameters, and to adjust the drive signal condition so as to improve the first vibration parameter value. The comparison operation can be simplified, and the drive signal conditions can be adjusted efficiently.

  (2) Among the vibration parameters, select the first vibration parameter whose detected vibration P value is the most dissimilar from the standard vibration P value, and select the first drive parameter that most affects the first vibration parameter. In one adjustment step, only the value of the first drive parameter was adjusted. For this reason, the interaction of adjustment effects due to simultaneous adjustment of a plurality of drive parameters can be eliminated, adjustment work can be simplified, and drive signal conditions can be adjusted efficiently.

  (3) The predicted vibration P value is calculated and compared with the standard vibration P value and the allowable error value. If it is determined that the predicted vibration P value is within the allowable range, the drive signal at that time is adopted. . If it is determined that the expected vibration P value is not within the allowable range, the adjustment is further continued. By doing so, the probability that the ejection based on the adjusted drive signal condition falls within the allowable range is increased, and the drive signal condition can be adjusted efficiently.

  (4) The predicted vibration P value is calculated and compared with the detected vibration P value and the quasi-vibration P value. When it is determined that the predicted vibration P value is improved from the detected vibration P value, Adopt driving signal. This prevents the adjustment value from diverging by adjusting the drive signal, and increases the probability that the ejection under the adjusted drive signal condition is within the allowable range, thus efficiently adjusting the drive signal condition. can do.

  The embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention, and can be implemented as follows.

  (Modification 1) In the above-described embodiment, the standard machine of the droplet discharge device is set, and the standard data and the reference data are created using the standard machine. Standard data and control data may be created by the discharge device itself.

  (Modification 2) In the above-described embodiment, the drive voltage, the charge time, the hold time, the discharge time, and the reference potential are the drive parameters that define the drive signal, but the influence on the discharge state of the droplet discharge head Only parameters with a large value may be selected as drive parameters. By appropriately selecting necessary parameters corresponding to the characteristics to be adjusted, unnecessary information can be eliminated and drive signal information can be created efficiently.

  (Modification 3) In the above-described embodiment, the frequency, amplitude, phase, attenuation rate, and bias are set as vibration parameters that define the residual vibration. However, parameters that easily vary depending on the state of the droplet discharge head are selected. It may be a vibration parameter. By appropriately selecting parameters with large fluctuations, only effective information can be compared, and residual vibration information can be created efficiently. In addition, drive signal adjustment can be performed efficiently.

  (Modification 4) In the above-described embodiment, the first vibration parameter that is the most deviated vibration parameter is selected, and the drive signal is adjusted to improve the value of the first vibration parameter. You may make it improve a parameter value at once.

  (Modification 5) In the fourth embodiment, in order to obtain the expected vibration P value from the drive P value, the relationship (control data) between the drive voltage and the amplitude in the droplet discharge head 10 of the standard machine is used. The relationship between the drive voltage and the amplitude in the droplet discharge head 10 of the droplet discharge apparatus 1 (adjuster) that adjusts the drive signal is also determined for each drive parameter, and the predicted vibration P value is obtained using the relationship. You may ask.

The technical idea grasped from the above-described embodiments and modifications will be described below.
(Technical Thought 1) Among the parameters that define the residual vibration in the above-described fourth step, the detected parameter value of the residual vibration is the parameter value of the residual vibration when the standard drive signal is applied. And a first vibration parameter, which is the most dissociated vibration parameter, is selected, and the drive signal is adjusted so as to improve the value of the first vibration parameter.

  (Technical idea 2) In the above-described fourth step, among the parameters defining the residual vibration, the detected parameter value of the residual vibration is the parameter value of the residual vibration when the standard drive signal is applied. The first vibration parameter that is the most dissociated vibration parameter is selected, the first drive parameter that is the parameter that defines the drive signal that most affects the first vibration parameter is further selected, and the first vibration parameter A method of driving a droplet discharge head, wherein the value of the first drive parameter is adjusted so as to improve the value.

The top view of a droplet discharge apparatus. The side view of a droplet discharge apparatus. FIG. 3 is an electrical configuration block diagram showing an electrical configuration of the droplet discharge device. (A) is a top view of a head unit, (b) is a top view of a droplet discharge head. The perspective view which shows the structure of a droplet discharge head. FIG. 3 is a cross-sectional view of a droplet discharge head showing a structure of a nozzle portion. The basic waveform figure of the drive signal applied to the piezoelectric vibrator as a drive element. The block diagram which shows the structure of a drive signal production | generation part. Explanatory drawing which shows the process which produces | generates the drive pulse contained in a drive signal in a drive signal generation part. 4 is a timing chart showing the timing of each signal when a potential difference is set in a memory using a data signal in a drive signal generation unit. The circuit diagram which shows the calculation model of the simple vibration which assumed the residual vibration of the diaphragm. The graph which shows the relationship between the experimental value and calculated value of the residual vibration of a diaphragm. The block diagram which shows the outline | summary of the switching means of a head drive circuit and a residual vibration detection circuit. The flowchart which shows a residual vibration detection process. The figure which shows an example of the table of contrast data. The flowchart which shows the drive signal optimal condition setting process in 1st Embodiment. The graph which shows an example of the relationship between a drive voltage and an amplitude. The flowchart which shows the initialization process in 2nd Embodiment. The flowchart which shows the drive signal optimal condition setting process in 3rd Embodiment. The graph which shows an example of the relationship between a drive voltage and an amplitude. The flowchart which shows the drive signal optimal condition setting process in 4th Embodiment. The flowchart which shows the drive signal optimal condition setting process in 4th Embodiment. The graph which shows an example of the relationship between a drive voltage and an attenuation factor. The graph which shows an example of the relationship between a drive voltage and an amplitude.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Droplet discharge apparatus as a droplet discharge apparatus and a workpiece processing apparatus, 3 ... Substrate table, 10 ... Droplet discharge head, 11 ... Head unit, 16 ... Main body control apparatus as drive signal control means, 17 ... Drive element Piezoelectric vibrator, 56... Device main body control section as vibration comparison means and waveform control means, 58... Drive signal generation section as drive signal generation means, 63... Nozzle, 64. Reference numeral 67: Pressure generating chamber, 68: Side wall (partition wall), 76: Reservoir, 77 ... Introduction path, 78 ... Housing, 80 ... Diaphragm, 141 ... Residual vibration detection circuit as residual vibration detection means, W ... Workpiece .

Claims (11)

A droplet discharge head having a nozzle that discharges the functional liquid as droplets, a diaphragm corresponding to the nozzle, and a drive element that displaces the diaphragm;
Residual vibration detecting means for detecting residual vibration of the diaphragm;
A droplet discharge apparatus comprising: drive signal control means for generating a drive signal to be applied to the drive element based on the residual vibration detected by the residual vibration detection means. The drive signal control means includes
Vibration comparison means for comparing reference information and detected vibration information of the residual vibration detected by the residual vibration detection means;
Waveform control means for adjusting the waveform of the drive signal based on the comparison result of the signal comparison means;
The droplet discharge device according to claim 1, further comprising: a drive signal generation unit configured to generate the drive signal based on a result adjusted by the waveform control unit. The reference information is
Standard information comprising standard drive signal information for realizing a normal ejection state and standard residual vibration information generated when the standard drive signal is applied to the droplet ejection head;
3. The droplet discharge device according to claim 1, comprising: each parameter that defines the residual vibration; and reference information that is information on a correlation between each parameter that defines the drive signal. The information of the standard drive signal is a value of each of a plurality of parameters that define the standard drive signal,
The information of the standard residual vibration is a value of each of a plurality of parameters defining the standard residual vibration,
The droplet ejection apparatus according to claim 3, wherein the detected vibration information is a value of each parameter that defines the residual vibration detected by the residual vibration detection unit.   5. The droplet discharge device according to claim 1, wherein at least one of a frequency, an amplitude, a phase, an attenuation rate, and a bias is the parameter that defines the residual vibration.   6. The droplet discharge device according to claim 1, wherein at least one of a drive voltage, a charge time, a hold time, a discharge time, and a reference potential is the parameter that defines the drive signal. A droplet ejection head driving method comprising a nozzle that ejects functional liquid as droplets, a diaphragm corresponding to the nozzle, and a drive element that displaces the diaphragm,
Information on a standard drive signal, which is a drive signal for realizing a normal discharge state of the droplet discharge head or a droplet discharge head equivalent to the droplet discharge head, and the standard drive signal are applied to the droplet discharge head. A standard information having information on a standard residual vibration, which is a residual vibration that occurs when an error occurs, and a correlation information between each parameter that defines the residual vibration and each parameter that defines the drive signal A first step of creating reference information comprising information;
A second step of discharging the droplet from the droplet discharge head, detecting the residual vibration generated at that time, and creating detected residual vibration information;
A third step of comparing the detected residual vibration information with the standard information;
A fourth step of adjusting the drive signal based on the control information and the detected residual vibration information;
And a fifth step of generating a drive signal based on the result of the fourth step. Set the reference machine,
The method for driving a droplet discharge head according to claim 7, wherein the first step is performed using a droplet discharge head that is a standard of the reference machine. A sixth step of discharging droplets from the droplet discharge head, detecting the residual vibration at that time, and creating residual vibration information;
A seventh step of comparing the residual vibration information with the standard information;
An eighth step of determining the state of the droplet discharge head based on the comparison result of the seventh step;
An initialization step including a ninth step of performing maintenance operation of the droplet discharge head according to the determination result of the eighth step,
9. The method of driving a droplet discharge head according to claim 7, wherein the first step is performed, then the initialization step is performed, and then the second to fifth steps are sequentially performed. . The fourth step includes a determination step of determining whether adjustment is possible,
10. The method of driving a droplet discharge head according to claim 7, wherein, when it is determined that the adjustment is impossible in the determination step, a warning that adjustment is not possible is issued. 11. The driving of the droplet discharge head according to claim 7, wherein the initialization process is repeated, and an abnormality warning is issued when the determination result of the sixth process is the same over a predetermined number of times. Method.

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