JP4549464B2 - Field discharge head, field discharge control device, and field discharge coating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the field of coating technology. In particular, the present invention relates to an electric field discharge head, an electric field discharge control device, and an electric field discharge coating device that are suitable for forming a stripe-shaped precise coating pattern arranged linearly at a predetermined interval on an object to be coated.
[0002]
[Prior art]
As a method of forming a stripe-shaped coating pattern on an object to be coated, a substance to be ejected (coating material, ink) is ejected from the ejection holes of the ejection head and applied to the object to be coated (web, substrate). The method is known. At this time, a desired coating pattern can be obtained by moving the ejection head or the object to be coated so that the position of the ejection hole coincides with the position to be coated. Moreover, the coating amount to the object to be coated can be controlled by adjusting the discharge amount per unit time and the moving distance.
[0003]
[Problems to be solved by the invention]
However, in such a method using the ejection head, after the material to be ejected is ejected from the ejection hole at a predetermined initial speed, the movement is determined according to the effect of the surface tension and gravity. Therefore, there is a problem that the allowable range of the gap between the discharge hole and the object to be coated is narrow, and the discharge hole has a large spread with respect to the hole diameter.
[0004]
The present invention has been made to solve such a problem, and its purpose is to form a gap between the discharge hole and the coated object when a striped coating pattern is formed on the coated object. An object of the present invention is to provide an electric field discharge head, an electric field discharge control device, and an electric field discharge coating device that have a wide allowable range and can reduce the spread of the discharge holes with respect to the hole diameter.
[0005]
[Means for Solving the Problems]
  The above problems are solved by the present invention described below. That is, the electric field ejection head according to claim 1 of the present invention isLiquid at operating temperature and electrically conductiveAn introduction part for introducing a substance to be discharged, a discharge part in which a plurality of discharge holes arranged linearly at predetermined intervals are formed, and the substance to be discharged introduced from the introduction part is temporarily stored in the discharge part. A manifold serving as a guide passage, and an electrode disposed inside the manifold;, A pressurizing unit that pressurizes the material to be discharged inside the manifoldAnd at least the discharge part is electrically insulated from the electrode,The electrode has a shape extending linearly in the arrangement direction of the discharge portions arranged in a straight line, and the manifold does not reach the pressure for discharging the discharge target material but reaches a pressure close to the pressure to the pressurization portion. The electrode applies an electric field to the material to be ejected under pressure.It is what I did. According to the present invention, after the material to be ejected is ejected from the ejection hole at a predetermined initial velocity, the material to be ejected is subjected not only to the effects of surface tension and gravity but also to the action of an electric field, and performs a predetermined motion determined by the effect. be able to. Therefore, an electric field discharge head is provided in which the allowable range of the gap between the discharge hole and the object to be coated is wide, and the spread of the discharge hole with respect to the hole diameter can be reduced. In addition, since the electrode is disposed inside the manifold, the substance to be discharged is kept in electrical contact with the electrode, and the action of the electric field is stabilized.Furthermore, since the electrode has a shape extending linearly in the arrangement direction of the discharge portions arranged in a straight line, the electrode for a plurality of discharge holes arranged in a straight line at a predetermined interval formed in the discharge portion Can be made uniform.
[0006]
According to a second aspect of the present invention, in the electric field ejection head according to the first aspect, at least the ejection section is made of an electrically insulating material. According to the present invention, electrical insulation with respect to the electrode is ensured by the discharge portion formed of an electrically insulating material.
[0008]
  In addition, the present inventionClaim 3The electric field ejection head according toClaim 1 or 2In the electric field discharge head described above, the electrode is arranged in the vicinity of the inlet of the discharge hole inside the manifold. According to the present invention, the discharge state of the substance to be discharged is stabilized.
[0010]
  In addition, the present inventionClaim 4The electric field discharge control device according toClaims 1-3An electric field ejection control device applied to the electric field ejection head according to any one of the above, an electric field setting means for generating a setting electric field based on an input for setting a form of the generated electric field, an ejection position in the electric field ejection head, A synchronization input means for inputting a synchronization signal including a signal for obtaining synchronization with a coating position in a coating object, a power generation means for generating a predetermined form of power based on the set electric field and the synchronization signal, It is made to have. According to the present invention, the setting electric field is generated based on the input for setting the form of the electric field generated by the electric field setting means, and the synchronization input means synchronizes the discharge position in the electric field discharge head and the coating position in the object to be coated. A synchronization signal including a signal for obtaining the power is input, and a predetermined form of power is generated by the power generation unit based on the set electric field and the synchronization signal. In other words, after the substance to be ejected is ejected from the ejection hole at a predetermined initial velocity, it can be configured to perform not only the effects of surface tension and gravity but also the action of an electric field, and perform a predetermined motion determined thereby. Therefore, an electric field discharge control device is provided in which the allowable range of the gap between the discharge hole and the object to be coated is wide, and the spread of the discharge hole with respect to the hole diameter can be reduced. Further, a predetermined form of electric power determined based on the setting input is supplied to the electric field discharge head while synchronizing the discharge position of the electric field discharge head and the coating position of the object to be coated.
[0011]
  In addition, the present inventionClaim 5The electric field discharge control device according toClaim 4In the electric field discharge control device according to the above, the pressure input unit includes a pressure input unit that inputs a pressure for pressurizing the discharge target substance inside the manifold, and the electric field generation unit generates the electric power based on the pressure. It is what you do. According to the present invention, the pressure in the pressurizing unit is reflected in the electric power generated by the electric field generating means.
[0014]
  In addition, the present inventionClaim 6The electric field discharge control device according toClaim 4 or 5In the electric field ejection control device according to the above, the rectangular wave is a rectangular wave having a voltage amplitude Vp-p of 100 V to 10 kV and a frequency F of 1 Hz to 10 kHz. According to the present invention, the above-described effects are particularly remarkable.
[0016]
An electric field ejection coating apparatus according to a seventh aspect of the present invention includes an electric field ejection head according to any one of the first to third aspects and an electric field ejection control apparatus according to any one of the fourth to sixth aspects. In the discharge coating apparatus, a supply means for supplying the discharge target material to the introduction portion of the electric field discharge head, and the manifold does not reach a pressure for discharging the discharge target material but reaches a pressure close to the pressure. It is assumed that the pressurizing part is pressurizedRukaPressure discharge control means, the electric field discharge control device for controlling the discharge state of the discharge target substance discharged by the electric field discharge head by applying an electric field exceeding the electric field for discharging the discharge target substance, and the electric field discharge head.DomaOr a transport means for transporting the object to be coated and outputting a synchronization signal including a signal for obtaining a synchronization between the ejection position in the electric field ejection head and the coating position in the object to be coated, which indicates a transport state; And a ground-side electrode disposed at a position facing the discharge portion. According to the present invention, the discharge target substance is supplied to the introduction part of the electric field discharge head by the supply means, and the manifold does not reach the pressure for discharging the discharge target substance by the pressure discharge control means but reaches a pressure close thereto. The discharge state of the discharge target substance discharged by the electric field discharge head is controlled by applying an electric field exceeding the electric field for discharging the discharge target substance by the electric field discharge control device with the pressurizing unit being pressurized. The electric field discharge head isDomaAlternatively, the object to be coated is transported and a synchronization signal including a signal for obtaining a synchronization between the ejection position in the electric field ejection head and the coating position in the object to be coated is displayed and the ground electrode is transferred. It arrange | positions in the position facing a discharge part. In other words, after the substance to be ejected is ejected from the ejection hole at a predetermined initial velocity, it can be configured to perform not only the effects of surface tension and gravity but also the action of an electric field, and perform a predetermined motion determined thereby. Therefore, there is provided an electric field discharge coating apparatus in which the allowable range of the gap between the discharge hole and the object to be coated is wide and the spread of the discharge hole with respect to the hole diameter can be reduced.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described. An example of the configuration of the electric field ejection head in the present invention is shown in FIG. 1A is a cross-sectional view of the central portion, and FIG. 1B is a perspective view of the inside. In FIG. 1, 1 is an introduction part, 2 is a discharge part, 3 is a manifold, 4 is an electrode, 5 is a pressurizing part, and 6 is a broken line indicating a boundary. As shown in FIG. 1, the electric field discharge head has a structure in which each element portion is provided mainly on a main body portion constituting the manifold 3. The main body portion is not only a housing (container) but also a support, and is distinguished from the manifold 3 in function. However, in the case of at least the example shown in FIG. 1, the manifold 3 is a main part of the main body portion, and it may not make sense to distinguish them. Therefore, here, the manifold 3 also means a main body portion unless otherwise described. The boundary 6 means a “virtual boundary” when the discharge unit 2 and the manifold 3 are made of the same material and are integrated, and means a “real boundary” when they are combined.
[0018]
The introduction unit 1 is for introducing a substance to be discharged. An introduction port is opened in the introduction unit 1, and piping for feeding the material to be discharged is performed there. By applying pressure to the material to be discharged, the material to be discharged moves in the tube. Then, the substance to be discharged is introduced into the manifold 3 from the introduction port.
[0019]
The discharge part 2 is arrange | positioned at the front-end | tip of a main-body part (in other words, comprises the front-end | tip part of a main-body part). A plurality of discharge holes are formed in the discharge unit 2, and the plurality of discharge holes are linearly arranged at a predetermined interval. Of course, the size and shape of the ejection holes, the number, the arrangement interval, and the like are appropriately determined (designed) according to the purpose, conditions, and the like of coating by the electric field ejection head. The material to be discharged introduced into the manifold 3 is discharged from the plurality of discharge holes when coating is performed.
[0020]
The manifold 3 serves as a passage for temporarily storing the material to be discharged introduced from the introduction unit 1 and leading it to the discharge unit 2. The passage is shown in a simplified manner in FIG. The actual passage has such a shape that a predetermined discharge amount is obtained in all of the plurality of discharge holes formed in the discharge unit 2 and does not become unbalanced.
[0021]
The electrode 4 is disposed inside the manifold 3 and has a shape extending linearly in the arrangement direction of the discharge sections 2 arranged linearly. In the example shown in FIG. 1, the electrode 4 is a rectangular plate electrode, and has a structure in which the lead terminal appears outside the main body portion from near the center of the plate electrode. Power supply for generating an electric field in the electric field discharge head is performed from the lead terminal.
[0022]
Further, the electrode 4 is disposed in the vicinity of the inlet of the discharge hole 2 inside the manifold 3. Compared with the case where it is arranged away from the discharge hole 2, the discharge state of the substance to be discharged is stabilized by arranging it as close to the discharge hole 2 as possible (see FIGS. 3 and 4).
[0023]
The pressurizing unit 5 pressurizes the substance to be discharged introduced into the manifold 3. The upper surface of the material to be discharged introduced from the introduction unit 1 moves up and down inside the manifold 3 in balance between the supply amount and the discharge amount. Usually, the upper and lower movement ranges are controlled so as to be in a range above the upper side portion of the electrode 4 and below the pressure unit 5. In the example shown in FIG. 1, compressed air is introduced into the pressurizing unit 5. The upper surface of the material to be discharged is pressurized by the compressed air. The discharge amount can be controlled by controlling the pressure of the compressed air.
[0024]
In the above-described configuration of the electric field ejection head, at least the ejection section 2 is electrically insulated from the electrode 4. Furthermore, it is preferable that not only the discharge part 2 but also the manifold 3 is electrically insulated from the electrode 4. Here, being electrically insulated means that the definition means that no current (DC current) flows in a static state. Even in a state where a current (displacement current) flows in a dynamic state, if the above definition is satisfied, it is regarded as being electrically insulated here.
[0025]
In order to realize this electrically insulated state, for example, an electrical insulator may be interposed between the electrode 4 and the manifold 3. However, if the discharge section 2 and the manifold 3 are formed of an electrically insulating material, it is more preferable because the generated electric field is almost determined by the characteristics and shape of the electrodes. As the material, for example, plastic or ceramic material can be applied.
[0026]
Although details of the substance to be ejected will be described later, the substance to be ejected is not electrically completely insulating and does not have good electrical conductivity like metal. In the present invention, the electric field discharge head is configured such that current can flow out from the electrode 4 to the discharge target material at a portion where the electrode 4 contacts the discharge target material. On the other hand, it is necessary to prevent current from flowing around and leaking from the material to be discharged. Therefore, in the case where the discharge part 2 and the manifold 3 are made of a conductive material, in order to obtain electrical insulation with respect to the electrode 4, at least the discharge part 2, preferably the inner surface of the discharge part 2 and the manifold 3 is used. On the other hand, it is necessary to provide an insulating coating.
[0027]
Next, the electric field ejection control device will be described. The configuration of the electric field discharge coating apparatus is shown in FIG. 2 as a block diagram, and the configuration of the electric field discharge control apparatus is shown at 20 in FIG. 2, 20 is an electric field discharge device, 21 is an electric field setting means, 22 is a pressure input means, 23 is a synchronous input means, 24 is a power generation means, and 25 is a monitor. The electric field ejection control device 20 is a device that supplies controlled electric power to the electric field ejection head.
[0028]
The electric field setting means 21 generates a setting electric field (data) based on an input for setting the form of the generated electric field. The form of the generated electric field includes direct current and alternating current. The AC waveform includes a sine wave, a triangular wave, a rectangular wave, a pulse, and other waveforms and is not particularly limited. Here, a rectangular wave is a pulse train having a predetermined pulse width and a predetermined period, and a pulse is a waveform whose amplitude changes from a steady state and continues for a finite time and returns to the original state. . The setting items for the form of the electric field to be generated include not only the type of waveform described above, but also the frequency, amplitude value, start condition, end condition, and the like. In addition, the frequency, amplitude value, waveform type, and the like can be set to change in a predetermined pattern as time passes from the start to the end.
[0029]
A plurality of such electric field forms are stored in the storage device as preset data. Then, setting is performed by selecting preset data that matches the coating conditions from among a plurality of preset data. This selection is performed by either a mode performed by an operator's operation or a mode performed by inputting instruction data from the outside. The electric field setting means 21 generates a setting electric field (data) based on the input.
[0030]
The pressure input means 22 inputs the pressure that the pressurizing unit 5 applies to the substance to be discharged introduced into the manifold 3. This pressure is used as data to be referred to when the electric field generating means 24 generates a set electric field in the electric field ejection control device 20.
[0031]
The synchronization input means 23 inputs a synchronization signal including a signal for obtaining synchronization between the ejection position of the electric field ejection head and the coating position of the object to be coated. In the electric field discharge head, the discharge holes are linearly arranged one-dimensionally. When coating is performed on a two-dimensional surface, it is necessary to scan the object to be coated by the electric field discharge head. In the scanning, a relative movement is performed. Of course, either the electric field ejection head or the object to be coated may move, or both of them may move. In this scanning, the synchronization input means 23 inputs a signal of a position at which ejection is started, a signal at a position at which ejection is terminated, a scanning speed signal, and the like as synchronization signals.
[0032]
The power generation unit 24 generates a predetermined form of power based on the set electric field (data) and the synchronization signal. The power generation means 24 basically generates the electric field as it is determined by the set electric field as power, but at that time, it synchronizes based on the synchronization signal. For example, when discharging is started, in the middle of discharging, and when discharging is ended, control of electric power suitable for them is performed.
[0033]
The electric field generating means 24 has a function of changing the form of the electric field generated so as to meet the coating conditions. For example, the discharge amount of the discharge target substance discharged from the electric field discharge head is determined by the pressure inside the manifold 3. However, it is not determined only by that, but the discharge amount is affected by the set electric field, although details will be described later.
Therefore, for example, the amplitude value, which is one of the parameters of the preset data, is changed to match the internal pressure of the manifold 3 which is one of the parameters of the coating condition.
[0034]
The monitor 25 displays the waveform of the power output from the power generation means 24. The electric field setting means 21 displays the set electric field, the pressure input means 22 displays the pressure, the synchronization input means 23 displays the input synchronization signal, and the like. These displays are used by the operator to operate the electric field ejection control device 20 and confirm the state thereof.
[0035]
Next, the operation of the electric field ejection control device 20 in the above configuration will be described.
First, the case of continuous coating will be described as an example (part 1) of the operation of the electric field ejection control device 20. In the electric field setting means 21, the voltage amplitude V_ppIs set to 1 kV and the frequency F is set to 1 kHz, and a set electric field is generated. The power generation means 24 inputs the set electric field. On the other hand, the synchronization input means 22 continues to input a synchronization signal for scanning the object to be coated by the electric field ejection head. The electric field generation means 24 also inputs the synchronization signal.
[0036]
The electric field generation unit 24 generates electric power (voltage waveform) based on the set electric field and supplies it to the electric field discharge head at or slightly before the scanning timing at which the discharge is started. In the middle of discharge, the electric field generating unit 24 maintains the electric power.
Then, the electric field generating unit 24 stops supplying power to the electric field discharge head at or slightly after the scanning timing for ending the discharge.
[0037]
In the continuous coating as described above, a description will be given of conditions in which the allowable range of the gap between the discharge hole and the object to be coated is wide and the spread of the discharge hole with respect to the hole diameter can be reduced. As the form of the electric field, a rectangular wave is more suitable than a sine wave or a triangular wave. The reason for this is not clear, but is presumed to be related to the fact that the rectangle contains many harmonic components.
[0038]
The rectangular wave has a voltage amplitude V_ppIs 100 V to 10 kV and the frequency F is in the range of 1 Hz to 10 kHz. From the viewpoint of ejection stability and ease of voltage control, a range of 1 to 7 kV is more preferable. Moreover, although it depends on the viscosity and material composition of the substance to be discharged, the optimum frequency changes when the electric conductivity is different. In many cases, the optimum frequency increases with increasing electrical conductivity. If the frequency is low, deposition on the electrode is likely to occur, which is not preferable. In addition, when the frequency is high, there is a problem that it is difficult to control power supply performance. A preferable frequency range is 1 Hz to 10 kHz. From the viewpoint of discharge continuity and voltage control, 100 Hz to 4 kHz is more preferable.
[0039]
Moreover, not only alternating current but direct current can be applied. In the case of direct current, it is appropriate to be in the range of 100V to 10kV. In the case of direct current, any polarity is not a problem.
[0040]
Next, the case of intermittent coating will be described as an example (part 2) of the operation of the electric field ejection control device 20. In the electric field setting means 21, a pulse having an absolute voltage Va of 1 kV and an external synchronous oscillation width of 1 msec is set, and the set electric field is generated. The power generation means 24 inputs the set electric field. On the other hand, the synchronization input means 22 inputs a synchronization signal in scanning of an object to be coated by the electric field ejection head, and the pressure input means 22 continues to input the pressure inside the manifold 3 by the pressurizing unit 5. The electric field generating means 24 also inputs the synchronization signal and pressure.
[0041]
The electric field generation unit 24 generates electric power (voltage waveform) based on the above-described set electric field in accordance with the scanning timing at which discharge is started, and supplies the electric power to the electric field discharge head. At that time, 1 kV of the absolute value Va of the voltage is corrected according to the pressure described above. As described above, the discharge amount is affected by the set electric field. The discharge of the discharge target substance in the electric field discharge head is related to the strength of the electric field as well as the pressure applied to the discharge target substance in the manifold 3. In the electric field ejection head, it is necessary to apply a pressure exceeding a predetermined pressure in order to eject the substance to be ejected. When a predetermined electric field is applied at a pressure that does not reach the threshold value but is close to that pressure, the substance to be discharged is discharged.
[0042]
When the application of the electric field is stopped, there are a case where the discharge is continued and a case where the discharge is stopped depending on the condition at that time, but here, the discharge is stopped (in this example).
In that case, since the set electric field is a pulse, the substance to be discharged is discharged intermittently corresponding to the pulse. Thereby, intermittent coating can be performed. The electric field when performing such a discharge operation is the same as the pressure, and it is necessary to apply an electric field that exceeds the threshold electric field. The correction according to the pressure of the absolute value Va of the voltage in the electric field generating unit 24 is performed so as to generate electric power that applies an appropriate electric field exceeding the threshold electric field.
[0043]
During discharge, the electric field generation unit 24 generates electric power based on the set electric field and pressure and supplies the electric power to the electric field discharge head in accordance with the scanning timing for intermittent discharge. Then, the electric field generation unit 24 stops the supply of power to the electric field discharge head in accordance with the scanning timing at which the discharge ends.
[0044]
As described above, the discharge amount can be controlled by the voltage intensity using the fact that discharge occurs when the absolute value Va of the voltage is equal to or higher than the threshold voltage Vt. In this continuous coating, the conditions under which the allowable range of the gap between the discharge hole and the object to be coated is wide and the spread of the discharge hole with respect to the hole diameter can be reduced will be described. The magnitude of the threshold voltage Vt depends on the substance to be ejected and the electrode arrangement, but is appropriate within the range of 100 V to 3 kV. The discharge voltage is appropriate to be 100 to 10 kV as in the case of continuous discharge, and more preferably in the range of 1 to 7 kV.
[0045]
Next, the electric field discharge coating apparatus will be described. The configuration of the electric field ejection coating apparatus is shown in FIG. 2 as a block diagram. In FIG. 2, 20 is an electric field ejection device, 21 is an electric field setting means, 22 is a pressure input means, 23 is a synchronous input means, 24 is a power generation means, 25 is a monitor, 31a, 31b, 31c and 31d are electric field ejection heads, 32 is a linear movement mechanism, 33 is a supply means, and 34 is a pressure discharge control means. Of the parts constituting the electric field ejection coating device, the electric field ejection heads 31a, 31b, 31c, 31d and the electric field ejection control device 20 are the same as those described above, and the description thereof is omitted here.
[0046]
The electric field ejection heads 31 a, 31 b, 31 c, and 31 d are attached to the support body of the linear movement mechanism 32. 2, this portion is a top view, and the electric field discharge heads 31a and 31c are provided on one side surface of the support, and the electric field discharge heads 31b and 31d are provided on the other side surface of the support. It is impossible to form an ejection hole on the side surface of the electric field ejection head. In this manner, by arranging the electric field ejection heads every other, an array of ejection holes having a total length that cannot be realized by a single electric field ejection head is realized.
[0047]
The linear movement mechanism 32 includes a support, a linear guide (not shown) that guides the movement of the support in a direction perpendicular to the longitudinal direction of the support, and a drive unit (not shown) that moves the support. ). The drive unit includes a control device that controls the moving distance from the origin, the moving speed, and the like. The control device of the driving unit controls the movement of the support during coating and outputs a signal related to the position and moving speed of the support. This signal is a synchronization signal input by the above-described synchronization input means 23.
[0048]
Although not shown in FIG. 2, a flat stage on which a plate-shaped object to be coated is placed is provided under the linear movement mechanism 32. The stage has a configuration for positioning and fixing the object to be coated. For the positioning, for example, a contact mechanism is applied in which a plate-shaped object to be coated is brought into contact with the side to determine the position. For fixing, for example, a vacuum suction mechanism is used in which the back surface of the plate-shaped object to be coated is vacuumed and fixed to the stage. A ground-side electrode is disposed at the position of the stage facing the discharge portion of the electric field head or on the entire surface of the stage.
[0049]
The supply means 33 supplies the substance to be discharged to the introduction part of the electric field discharge heads 31a, 31b, 31c, 31d. Normally, fine bubbles remain in the substance to be discharged because air bubbles are embraced in the manufacturing process. The supply means 33 includes a defoaming device that removes bubbles of the air. Further, the supply means 33 includes a pump, and the discharged material to be defoamed is supplied to the introduction part of the electric field discharge heads 31a, 31b, 31c, 31d through the piping by the pump.
[0050]
The pressurization / discharge control means 34 operates the pressurization unit 5 of the electric field discharge heads 31a, 31b, 31c, and 31d to discharge the discharge target substance supplied to the introduction unit from the discharge unit. That is, the compressed air is sent into the manifold 3 to pressurize and discharge the substance to be discharged, and the compressed air is released to release the pressure of the substance to be discharged and stop the discharge. Further, the pressure discharge control means 34 outputs the air pressure inside the manifold 3 as a pressure signal. This pressure signal corresponds to the pressure input by the pressure input means 22 described above.
[0051]
Next, an example of the operation of the electric field discharge coating apparatus in the above-described configuration of the electric field discharge coating apparatus will be described. First, a case where a phosphor is continuously applied to a substrate (object to be coated) of a plasma display panel on which barrier ribs are formed will be described. As the substrate, a glass substrate is usually used. A partition mainly composed of a glass material is formed on the glass substrate. The partition walls have dimensions of, for example, a width of 50 μm, a height of 150 μm, and a pitch of 300 μm, and a plurality (multiple) are formed in parallel on the surface of the glass substrate.
[0052]
The material to be discharged in this coating is an ink (phosphor ink) containing a phosphor in its composition. The phosphor ink is applied between adjacent barrier ribs and dried (fired) to form a phosphor layer between the barrier ribs. Usually, phosphors with three colors of emission colors R, G, and B are used. Here, the phosphor layers of these luminescent colors are formed in order by applying three times. When the partition pitch is 300 μm, the specific color phosphor layer has a pitch of 900 μm. Therefore, the arrangement pitch of the ejection holes of the electric field ejection head is set to 900 μm.
[0053]
In advance, the substrate of the plasma display panel on which the barrier ribs are formed is placed on the stage of the electric field discharge coating apparatus, aligned, vacuum adsorbed and fixed. A predetermined gap is secured between the tip of the discharge portion of the electric field discharge head and its substrate. Further, the phosphor ink is supplied to the introduction unit 1 of the electric field ejection head through the pipe by the supply means 33. The phosphor ink is introduced into the manifold 3, and the supply by the ink supply means is stopped when the upper surface of the phosphor ink reaches between the electrode 4 and the pressure unit 5. Further, the support body of the moving mechanism of the electric field discharge coating apparatus is returned to the origin position. This origin position is slightly ahead of the moving direction of the support with respect to the position to be coated.
[0054]
Next, based on the coating start instruction input, the moving mechanism of the electric field discharge coating apparatus operates to start moving the support attached with the electric field discharge head. When it has moved to just before the position to be coated, the pressurized discharge control means 34 supplies compressed air to the pressurizing unit 5 to pressurize the interior of the manifold 3. At this time, the pressure inside the manifold 3 is a pressure at which the phosphor ink is ejected from the ejection unit 2. Simultaneously with the pressurization, the electric field ejection control device 20 outputs electric power based on a preset electric field (see the description of the electric field ejection control device 20 described above). The electric power is supplied to the electrode 4 of the electric field ejection head.
[0055]
The electric field discharge head discharges the phosphor ink, and the phosphor ink flows down between the partition walls and coating is performed. Since the electric field ejection head and the substrate of the plasma display panel on which the partition walls are formed are moved relative to each other, a stripe-shaped coating film is formed so as to fill between the partition walls and the partition walls. At this time, due to the effect of the electric field, the allowable range of the gap between the discharge hole and the object to be coated is wide, and the spread of the discharge hole with respect to the hole diameter can be reduced. Therefore, highly accurate coating can be performed stably.
[0056]
When it has moved to just before the position where the coating is finished, the pressurized discharge control means 34 stops supplying compressed air to the pressurizing unit 5 and releases the compressed air inside the manifold 3. At this time, the pressure inside the manifold 3 decreases, and becomes a pressure at which the phosphor ink is not discharged from the discharge portion 2. Simultaneously with this pressure reduction, the electric field ejection control device 20 stops outputting power. Accordingly, power is not supplied to the electrode 4 of the electric field ejection head. Next, when the movement stop position is reached, the moving mechanism of the electric field discharge coating apparatus stops moving the support to which the electric field discharge head is attached.
[0057]
With reference to FIG. 3 and FIG. 4, more detailed description will be given of the form of a coating apparatus that is appropriate when performing striped coating accurately in an extremely narrow region of about 300 μm as described above. To do. FIG. 3 shows the arrangement of the object to be coated together with the cross-sectional shape of the electric field discharge head. In FIG. 3, 2 is a discharge part, 3 is a manifold, 4a and 4b are electrodes, 41 is a discharge hole, 42 is a coated object, and 43 is a coated object. G indicates the gap between the discharge unit 2 and the object to be coated 42, and P indicates the position of the electrodes 4a and 4b. The material to be discharged passes through the discharge hole 41 from the inside of the manifold 3 and is discharged into the air to be transferred to the object 42 to be coated.
[0058]
As shown in FIG. 3, the electrode 4 a is an electrode disposed in the vicinity of the inlet of the discharge hole 41 inside the manifold. The electrode 4b is an electrode arranged at a distance. As described above, in the electric field discharge head, the electrode is disposed in the vicinity of the inlet of the discharge hole 41 inside the manifold 3. That is, it arrange | positions in the position of the electrode 4a in FIG. Thereby, the tolerance | permissible_range is wide about the magnitude | size of the clearance gap G between a discharge hole and a to-be-coated object, and the discharge state of a to-be-discharged substance is stabilized. At this time, the size of the gap G is set to 300 μm or more. Thereby, the discharge state of the substance to be discharged is stabilized.
[0059]
The form of the electric field generated in the electric field ejection control device is a rectangular wave. The rectangular wave is an AC waveform that does not include a DC component when integrated. The rectangular wave has a voltage amplitude V_ppIs a rectangular wave having a frequency of 100 kHz to 10 kV and a frequency F of 1 kHz to 10 kHz. Thereby, the stability of the discharge state of the discharge target substance is particularly remarkable.
[0060]
This value is obtained by experience or experiment. An example of the experimental data regarding the form of the electric field coating apparatus and the ejection stability is shown in FIG. In FIG. 4, the horizontal axis represents the value of the gap G between the discharge hole and the object to be coated, and the vertical axis represents the frequency F of the rectangular wave.
For two cases of 0 mm and 7 mm for the position P of the electrode, the boundary value (point) at which the stability of the discharge state of the discharge target substance is obtained and the boundary region (line) connecting the boundary values (points) are shown by curves. The lower side of the frequency F in the boundary region and the larger side of the gap G in the boundary region are regions where the discharge state of the discharged substance is stable.
[0061]
In the example shown in FIG. 4, the electrode position P has a wider region where 0 mm is more stable than 7 mm. The gap G has a maximum value near 300 μm and a minimum value near 400 μm. If the gap G is approximately 300 μm or more, a stable region is wide.
[0062]
Next, the material to be discharged will be described. The material to be discharged is a material that is liquid at the operating temperature and has conductivity. Preferably, the viscosity is in the range of 1000 to 1000000 cps and the electrical conductivity is 10^-Ten-10^-FourΩ^-1cm^-1It is a substance in the range. The composition of the substance to be discharged is basically composed of an organic or inorganic liquid, a binder, and a component (target substance) to be patterned that is determined according to the application. Moreover, various additives, such as a dispersing agent, an antifoamer, and a thixotropic agent, are mixed with the composition as needed.
[0063]
As the liquid that can be used for the material to be discharged, for example, as the inorganic liquid, water, COCl₂, HBr, HNO_Three, H_ThreePO_Four, H₂SO_Four, SOCl₂, SO₂Cl₂, FSO_ThreeH, etc. are mentioned.
[0064]
Examples of the organic liquid include methanol, n-propanol, isopropanol, n-butanol, 2-methyl-1-propanol, tert-butanol, 4-methyl-2-pentanol, benzyl alcohol, α-terpineol, ethylene glycol, glycerin, Alcohols such as diethylene glycol and triethylene glycol; phenols such as phenol, o-cresol, m-cresol, and p-cresol; dioxane, furfural, ethylene glycol dimethyl ether, methyl cellosolve, ethyl cellosolve, butyl cellosolve, Ethers such as ethyl carbitol, butyl carbitol, butyl carbitol acetate, epichlorohydrin; acetone, methyl ethyl ketone, 2-methyl-4-pentanone, acetophen Non, etc. ketones; fatty acids such as formic acid, acetic acid, dichloroacetic acid, trichloroacetic acid; methyl formate, ethyl formate, methyl acetate, ethyl acetate, acetic acid n-butyl, isobutyl acetate, acetic acid-3-methoxybutyl, N-pentyl acetate, ethyl propionate, ethyl lactate, methyl benzoate, diethyl malonate, dimethyl phthalate, diethyl phthalate, diethyl carbonate, ethylene carbonate, propylene carbonate, cellosolve acetate, butyl carbitol acetate, ethyl acetoacetate , Esters such as methyl cyanoacetate and ethyl cyanoacetate; nitromethane, nitrobenzene, acetonitrile, propionitryl, succinonitrile, valeronitrile, benzonitrile, ethylamine, diethylamine, ethylenediamine, aniline, N-methylaniline, N , N-dimethylaniline, o-toluidine, p-toluidine, piperidine, pyridine, α-picoline, 2,6-lutidine, quinoline, propylenediamine, formamide, N-methylformamide, N, N-dimethylformamide, N, N -Nitrogen-containing compounds such as diethylformamide, acetamide, N-methylacetamide, N-methylpropionamide, N, N, N ', N'-tetramethylurea, N-methylpyrrolidone, and the like; dimethylsulfoxide, sulfolane and the like Sulfur compounds; hydrocarbons such as benzene, p-cymene, naphthalene, cyclohexylbenzene, cyclohexane, etc .; 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,1,2 -Tetrachloroethane, 1,1,2,2-tetrachloro Ethane, pentachloroethane, 1,2-dichloroethylene (cis-), tetrachloroethylene, 2-chlorobutane, 1-chloro-2-methylpropane, 2-chloro-2-methylpropane, bromomethane, tribromomethane, 1-bromopropane, And halogenated hydrocarbons.
[0065]
Of the above substances, those which are solid at room temperature may be heated to their melting points or higher to be liquid before being supplied to the head. Such a method is, for example, a common hot-melt type ink jet recording method, but requires quick drying from the point that it is necessary to provide a heater unit in the recording device and it takes time to warm up. It is not used for anything other than special purposes.
[0066]
The boiling point of the liquid is important because it affects the degree of clogging at the opening. The range of a preferable boiling point is 105 ° C to 300 ° C, more preferably 180 ° C to 250 ° C. If it is lower than 150 ° C., clogging due to drying tends to occur, and it is not preferable because it takes longer to dry after recording and other fields than 300 ° C. Such a high boiling point liquid preferably accounts for 50% by mass or more, more preferably 70% by mass or more of the total liquid in the substance to be discharged.
[0067]
The target substance to be dissolved or dispersed in the liquid is not particularly limited, except for coarse particles that cause clogging at the nozzle. For example, conventionally known organic or inorganic coloring pigments, phosphors, dyes, magnetic substances, bright pigments, matte pigments, conductive substances, ceramics and precursors thereof, and the like can be given.
[0068]
Various binders are preferably added in order to firmly adhere the target substance to the recording medium. Examples of the binder to be used include celluloses such as ethyl cellulose and derivatives thereof; alkyd resins; (meth) acrylic resins such as polymethacrylic acid and metal salts thereof; poly (meth) acrylamide resins such as poly N-isopropylacrylamide; Styrene resins such as polystyrene; Saturated and unsaturated polyester resins; Polyolefin resins such as polypropylene; Vinyl resins such as vinyl chloride / vinyl acetate copolymers; Polycarbonate resins; Epoxy resins; Polyurethane resins; Polyacetal resins Amide resin such as benzoguanamine; Urea resin; Melamine resin; Polyvinyl alcohol resin and its anionic cation modification; Polyvinylpyrrolidone and its copolymer; Natural or semi-synthetic trees such as gelatin and soybean protein Or the like can be used. These resins may be used not only alone but also in a blend of two or more as long as they are compatible.
[0069]
【The invention's effect】
  As described above, according to the electric field discharge head according to the first aspect of the present invention, the electric field discharge capable of widening the allowable range of the gap between the discharge hole and the object to be coated and reducing the spread of the discharge hole with respect to the hole diameter. A head is provided. In addition, since the electrode is disposed inside the manifold, the substance to be discharged is kept in electrical contact with the electrode, and the action of the electric field is stabilized. Further, according to the electric field discharge head according to claim 2 of the present invention, electrical insulation with respect to the electrode is ensured by the discharge portion and the manifold formed of the electrically insulating material. Also,Discharge partThe action of the electrodes can be made uniform with respect to the plurality of ejection holes arranged in a straight line at predetermined intervals. In addition, the present inventionClaim 3With the electric field ejection head according to the above, the ejection state of the material to be ejected is stabilized. In addition, the present inventionClaim 1With the electric field ejection head according to the above, the substance to be ejected is pressurized by the pressurizing part of the electric field ejection head. In addition, the present inventionClaim 4According to the electric field discharge control apparatus according to the present invention, there is provided an electric field discharge control apparatus that has a wide allowable range of the gap between the discharge hole and the object to be coated and can reduce the spread of the discharge hole with respect to the hole diameter. Further, it is possible to supply the electric field discharge head with a predetermined form of electric power determined based on the setting input while synchronizing the discharge position in the electric field discharge head and the coating position in the object to be coated. In addition, the present inventionClaim 5According to the electric field discharge control apparatus according to the above, it is possible to reflect the pressure in the pressurizing unit in the electric power generated by the electric field generating means. In addition, the present inventionClaim 6According to the electric field ejection control device according toActionThe effect is particularly remarkable. In addition, the present inventionClaim 7Electric field dischargeCoatingAccording to the apparatus, the allowable range of the gap between the discharge hole and the object to be coated is wide, and the electric field that can reduce the spread of the discharge hole with respect to the hole diameter.vomitA coating apparatus is provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of the configuration of an electric field ejection head in the present invention.
FIG. 2 is a block diagram showing the configuration of the electric field discharge coating apparatus.
FIG. 3 is a diagram showing an arrangement of objects to be coated together with a cross-sectional shape of an electric field ejection head.
FIG. 4 is a diagram showing an example of experimental data relating to the configuration of the electric field coating apparatus and ejection stability.
[Explanation of symbols]
1 Introduction
2 Discharge part
3 Manifold
4 electrodes
5 Pressurizing part
20 Electric field ejection device
21 Electric field setting means
22 Pressure input means
23 Synchronous input means
24 Electric power generation means
25 Monitor
31a, 31b, 31c, 31d Electric field discharge head
32 Linear movement mechanism
33 Supply means
34 Pressure discharge control means

Claims (7)

  An introduction part for introducing a substance to be ejected that is liquid at an operating temperature and has electrical conductivity, an ejection part in which a plurality of ejection holes arranged linearly at a predetermined interval are formed, and the introduction part introduced from the introduction part A manifold serving as a passage for temporarily storing the material to be discharged and leading to the discharge unit; an electrode disposed in the manifold; and a pressure unit for pressurizing the material to be discharged in the manifold; The portion is electrically insulated from the electrode, and the electrode has a shape extending linearly in the arrangement direction of the discharge portions arranged in a straight line, and does not reach a pressure for discharging the discharge target substance. The electric field ejection head, wherein the electrode applies an electric field to the material to be ejected in a state where the manifold is pressurized to the pressure portion to a pressure close to the pressure.   2. The electric field discharge head according to claim 1, wherein at least the discharge portion is formed of an electrically insulating material.   3. The electric field discharge head according to claim 1, wherein the electrode is disposed in the vicinity of the inlet of the discharge hole inside the manifold.   An electric field ejection control device applied to the electric field ejection head according to claim 1, wherein an electric field setting means for generating a setting electric field based on an input for setting a form of an electric field to be generated, and the electric field ejection Synchronous input means for inputting a synchronization signal including a signal for obtaining synchronization between the ejection position on the head and the coating position on the object to be coated, and generating a predetermined form of power based on the set electric field and the synchronization signal And an electric field generation control device.   5. The electric field discharge control apparatus according to claim 4, further comprising pressure input means for inputting a pressure for pressurizing the substance to be discharged inside the manifold in the pressurizing unit, wherein the electric field generating means is based on the pressure. An electric field ejection control device that generates electric power.   6. The electric field ejection control apparatus according to claim 4, wherein the electric field generated is a rectangular wave having a voltage amplitude Vp-p of 100 V to 10 kV and a frequency F of 1 Hz to 10 kHz. apparatus. An electric field discharge coating apparatus comprising: the electric field discharge head according to any one of claims 1 to 3; and the electric field discharge control device according to any one of claims 4 to 6, wherein the discharge target substance is the electric field discharge electric field. said supply means for supplying to the inlet portion, the does not reach the pressure for ejecting the discharged material is pressurized shall be the state that the manifold to a pressure close to it are pressed in the pressing of the discharge head and ejection control means, the electric field discharge control device said electric field discharge head by adding an electric field exceeding the electric field for ejecting the discharged material to control the discharge state of the discharge target substance to be discharged, the electric field discharge heads transfer hand outputs a synchronization signal including a signal for obtaining synchronization with the coating position in the coating object and the ejection position in the field discharge head shows a transport state with or to transfer the object to be coated object When an electric field discharge coating apparatus characterized by having a ground side electrode arranged at a position opposed to the discharge portion.

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