JP2011034754A - Coating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably detect bubbles stored between a liquid storage unit to a discharge unit of a tank or the like. <P>SOLUTION: The coating device 100 includes a liquid storage unit 108 with liquid stored, a nozzle head 106 discharging liquid, supply tubes 107a, 107b, 107c piped from the liquid storage unit 108 to the nozzle head 106 through joints 131 to 135, and optical sensors 141 to 145 fitted at or in the vicinity of the joints 131 to 135. The optical sensor 141 consists of a projector 141a projecting light toward inside the joint 131 or the supply tube 107a in its vicinity, and a light receiver 141b receiving light from inside the joint 131 or the supply tube 107a in its vicinity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coating apparatus.

For example, in the manufacturing process of an EL element used for an EL (Electro Luminescence) panel, a liquid EL material liquid is continuously discharged from a nozzle of a coating device toward the substrate, and the nozzle and the substrate are relatively moved. Thus, a carrier transport layer having a predetermined shape is formed on a substrate (see, for example, Patent Document 1).
The EL material liquid is stored in a tank, and a supply pipe is provided from the tank to a nozzle head having a nozzle. The EL material liquid in the tank is supplied to the nozzle head by a pump or the like (see, for example, Patent Document 1). ).

JP 2002-75640 A

  However, in the process of continuously applying a liquid such as an EL material liquid, bubbles in the liquid fed by a pump or the like may stay in the middle of the supply pipe or in the nozzle head. If air bubbles stay in the middle of the supply pipe or in the nozzle head and the size or amount of the air bubbles exceeds an allowable value, liquid may not be discharged from the nozzle. For this reason, it is necessary to detect bubbles remaining in the middle of the supply pipe before the liquid is no longer discharged from the nozzle due to the retention of bubbles. However, it is not certain where the bubbles stay in the supply pipe.

  Therefore, an object of the present invention is to make it possible to reliably detect bubbles accumulated between a liquid storage unit such as a tank and a discharge unit such as a nozzle head.

  In order to solve the above problems, according to the present invention, a coating apparatus includes a liquid storage part in which a liquid is stored, a discharge part that discharges the liquid, and a joint from the liquid storage part to the discharge part via a joint. A piped supply pipe and a bubble detection unit provided in or near the joint and detecting the state of bubbles in the supply pipe in or near the joint are provided.

Preferably, the coating device feeds the liquid in the liquid reservoir to the supply pipe, a moving unit that moves the discharge unit relative to the application target, and a decompression device that sucks gas. A standby position provided in the vicinity of the application target, and a control unit that controls the supply unit, the moving unit, the decompression device, and the bubble detection unit, and the control unit includes the supply unit The bubble detection unit exceeded an allowable value while the discharge unit was moved with respect to the application target by controlling the moving unit while discharging the liquid from the discharge unit. When it is detected that bubbles are present, the discharge unit is moved to the standby position, and the pressure reducing device is connected to the joint to operate the pressure reducing device.
Preferably, the coating device is provided in the joint and is controlled by the control unit to be in a communication state in which the supply pipe communicates with the pressure reduction device, and in a cutoff state in which the supply pipe is blocked from the pressure reduction device. Further comprising a switching unit that can be selectively switched, while the control unit moves the ejection unit relative to the application target by controlling the moving unit while ejecting the liquid from the ejection unit, Switching the switching unit to the blocking state;
When the bubble detection unit detects that bubbles exceeding the allowable value are present and moves the discharge unit to the standby position, the switching unit is switched to the communication state and the decompression device is operated. It was decided.
Preferably, the coating device includes a defoaming unit that is disposed at the standby position, is connected to the decompression device, and performs a suction process on the ejection unit, and the control unit is When it is detected that bubbles exceeding an allowable value are present and the discharge unit is moved to the standby position, the discharge unit is connected to the defoaming unit and the decompression device is operated to perform the suction. It was decided to process.
Preferably, the bubble detecting unit receives light from a projector that projects light into the supply pipe in or near the joint, and light emitted from the projector and from the supply pipe in or near the joint. And a light receiver.

  In order to solve the above-described problem, according to the present invention, a coating apparatus includes a liquid storage part in which a liquid is stored, a discharge part that discharges the liquid, and a joint from the liquid storage part to the discharge part. A projector that includes a supply pipe that is piped through and an optical sensor unit provided in or near the joint, and the optical sensor unit emits light toward the supply pipe in or near the joint. And a light receiver that receives the light emitted from the projector and from the inside of the joint or in the vicinity of the supply pipe.

Preferably, the optical sensor unit further includes a comparator that compares the received light intensity detected by the light receiver with a predetermined allowable value.
More preferably, the coating device is provided in a supply device for sending the liquid in the liquid storage part to the supply pipe, a decompression device for sucking gas, and the joint, and the supply pipe communicates with the decompression device. A switching unit that can be selectively switched between a communication state and a shut-off state in which the supply pipe is disconnected from the decompression device; and a control unit that controls the feeder, the decompression device, and the switching unit, and The control unit switches the switching unit to the communication state and activates the supply unit and the decompression device when the liquid is filled in the supply pipe and the discharge unit, and the supply unit and the decompression device are activated. When the comparator determines that the received light intensity detected by the light receiver is equal to or less than the predetermined allowable value, the switching unit is switched to the cutoff state. It was and.
More preferably, the coating apparatus supplies a liquid in the liquid storage section to the supply pipe, a moving section that moves the discharge section relative to a coating object, and a decompression apparatus that sucks gas. And a control unit that controls the standby position provided in the vicinity of the application target, and the supply unit, the moving unit, the decompression device, and the optical sensor unit, and the control unit includes the supply unit. The light receiving intensity detected by the light receiver while the discharge unit is operated to discharge the liquid from the discharge unit and the moving unit is controlled to move the discharge unit relative to the application target. Moving the discharge part to the standby position, connecting the pressure reducing device to a front joint and operating the pressure reducing device when the comparator determines that the predetermined allowable value is exceeded. did.
More preferably, the application device is provided in the joint and is controlled by the control unit, and a communication state in which the supply pipe communicates with the pressure reduction device, and a shut-off state in which the supply pipe is disconnected from the pressure reduction device. A switching unit that can be selectively switched to when the control unit determines that the received light intensity exceeds the predetermined allowable value and moves the discharge unit to the standby position. The switching unit is switched to the communication state and the decompression device is operated.
More preferably, the coating device includes a defoaming unit that is disposed at the standby position, is connected to the decompression device, and performs a suction process on the discharge unit, and the control unit has the light reception intensity of the light receiving unit. When it is determined by the comparator that the predetermined allowable value is exceeded and the discharge unit is moved to the standby position, the discharge unit is connected to the defoaming unit and the decompression device is operated, The suction process was performed.

  According to the present invention, since the bubble detection unit and the optical sensor unit are provided in the joint where the bubbles are likely to stay between the liquid storage unit and the discharge unit, the bubble detection unit and the optical sensor unit reliably While being able to detect, the bubble can be quantified.

It is drawing which shows a coating device roughly. It is a longitudinal cross-sectional view of a nozzle head and its joint. It is a longitudinal cross-sectional view of a nozzle head, its coupling, a defoaming part, etc. It is a longitudinal cross-sectional view of a nozzle head and its joint. It is a longitudinal cross-sectional view of a nozzle head and its joint. It is a graph which shows an example of the relationship between time and received light intensity. It is a longitudinal cross-sectional view of a nozzle head and its joint. It is a longitudinal cross-sectional view of a nozzle head and its joint. It is a top view which shows the arrangement configuration of the pixel of an EL panel. It is a top view which shows schematic structure of EL panel. It is a circuit diagram showing a circuit corresponding to one pixel of an EL panel. It is the top view which showed 1 pixel of EL panel. It is arrow sectional drawing of the surface along the XIII-XIII line | wire of FIG. It is sectional drawing which shows the pixel electrode exposed between the banks of EL panel. It is explanatory drawing which shows the application pattern of the liquid accompanying the movement of the nozzle head of a coating device. It is a front view of a mobile phone using an EL panel as a display unit. It is a perspective view of a digital camera using an EL panel as a display unit. It is a perspective view of a digital camera using an EL panel as a display unit. It is a perspective view of a personal computer using an EL panel as a display unit.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

[1] Configuration of Coating Device FIG. 1 is a drawing showing a coating device 100. The coating apparatus 100 includes an organic layer of an organic electroluminescence display panel which is a light emitting panel (for example, a hole injection layer, a light emitting layer, and an electron injection layer), an organic layer of an organic transistor, and an organic coloring layer of a color filter of a liquid crystal display ( For example, RGB coloring layers containing organic materials, black matrices containing organic materials), organic conductive layers of various electronic devices (for example, conductive wiring containing organic materials) and other functional layers. is there. In addition, each said layer formed with the coating device 100 is not restricted to what is comprised with an organic material, You may disperse | distribute or melt | dissolve the fine particle of inorganic materials (for example, titanium oxide, silver, etc.) in a solvent.

  The work table 101 is mounted on the moving device 102 and is slidable in a straight line along the horizontal plane with respect to the moving device 102. On this work table 101, a substrate 121 as an application target is placed. The moving direction of the work table 101 is referred to as a sub-scanning direction.

  The moving device 102 moves the work table 101 and the substrate 121 placed thereon in a straight line. For example, the moving device 102 includes a rail that guides the work table 101 and a drive mechanism that drives the work table 101 along the rail. The moving device 102 is controlled by the control unit 119. The control unit 119 drives the moving device 102 intermittently, and the moving device 102 moves the work table 101 and the substrate 121 intermittently. That is, the moving device 102 operates to repeat the movement of the work table 101 and the substrate 121 and the stop of the movement under the control of the control unit 119.

  Above the work table 101, a rail 103 is provided as a guide. The rail 103 is provided so as to be orthogonal to the moving direction of the work table 101 when viewed from above. The rail 103 is attached to the machine casing 104 and supported by the machine casing 104.

A carriage 105 as a nozzle moving mechanism is mounted on the rail 103. The carriage 105 is guided along the rail 103. The carriage 105 is provided so as to be movable along the rail 103. Hereinafter, the moving direction of the carriage 105 is referred to as a main scanning direction.
The carriage 105 incorporates a drive source such as a motor, and the carriage 105 moves along the rail 103 by the drive source. The carriage 105 is controlled by the control unit 119. The control unit 119 drives the carriage 105 in accordance with the intermittent stop of the moving device 102, and the carriage 105 moves in the main scanning direction while the moving device 102 is stopped.

  A nozzle head (ejection unit) 106 is mounted on the carriage 105. The nozzle head 106 is mounted on the carriage 105 with the tip thereof facing downward. FIG. 2 is a cross-sectional view of the nozzle head 106. As shown in FIG. 2, the nozzle head 106 is provided with a main body 161 in a substantially cylindrical shape. A pipe-shaped joint 131 is provided at the upper end of the main body 161, and the hollow of the joint 131 communicates with the hollow 163 of the main body 161. A bottom surface 165 is provided at the lower end of the main body portion 161, and an opening 166 is formed at the center of the bottom surface 165. A nozzle plate 167 is disposed in the lower portion of the hollow portion 163 of the main body portion 161, and the opening 166 is closed by the nozzle plate 167. A minute nozzle hole 168 is formed in the center of the nozzle plate 167. The diameter of the nozzle hole 168 is 10 to 20 μm. The liquid 120 is discharged from the nozzle hole 168. A filter 164 is disposed in the hollow 163 of the main body 161. A hollow 163 of the main body 161 is partitioned by a filter 164 into a region on the joint 131 side and a region on the nozzle hole 168 side.

  As shown in FIG. 1, a supply pipe 107a is piped from the nozzle head 106 to the mass flow controller 109, one end of the supply pipe 107a is connected to the nozzle head 106 by a joint 131, and the other end of the supply pipe 107a is connected by a joint 132. It is connected to the outlet of the mass flow controller 109. The supply pipe 107b is connected from the mass flow controller 109 to the three-way joint 134, one end of the supply pipe 107b is connected to the inlet of the mass flow controller 109 by the joint 133, and the other end of the supply pipe 107b is the nipple 134a of the three-way joint 134. It is connected to the. A supply pipe 107c is piped from the three-way joint 134 to the liquid tank 108, one end of the supply pipe 107c is connected to the nipple 134b of the three-way joint 134, and the other end of the supply pipe 107c is connected to the liquid tank 108 by a joint 135. Yes.

  As the supply pipes 107a, 107b, and 107c, tubes made of a material resistant to the liquid 120 stored in the liquid tank 108 are used. Specifically, the supply pipes 107a, 107b, and 107c are tubes made of silicone resin. Further, the supply pipes 107a, 107b, and 107c have flexibility. The inner diameter of the supply pipes 107a, 107b, and 107c is 1 to 7 mm. The inner diameters of the supply pipes 107a, 107b, and 107c may be equal to each other or different from each other. For example, the inner diameter of the supply pipe 107a is smaller than the inner diameter of the supply pipes 107b and 107c. Specifically, the inner diameter of the supply pipe 107a is 1 mm, and the inner diameter of the supply pipes 107b and 107c is 7 mm.

  A liquid 120 is stored in a liquid tank 108 as a liquid storage unit. The liquid 120 is made of, for example, an organic material. The liquid 120 is appropriately selected according to the application of the coating apparatus 100.

  The liquid tank 108 is provided with a supply device 116. The feeder 116 sends out the liquid 120 in the liquid tank 108 to the supply pipe 107c, and more preferably feeds the liquid 120 to the supply pipe 107c while keeping the pressure of the liquid 120 to be sent out constant. is there. The supply device 116 is a pump, specifically, a piston-type pump or a gas-type pump. The piston-type pressure feed pump has a movable piston housed in a syringe-like liquid tank 108, and the movable piston is pushed by a driving source such as a motor, an air cylinder, or a solenoid, so that the liquid 120 in the liquid tank 108 is discharged. It pushes out to the supply pipe 107c. The gas-type pressure feed pump supplies gas 120 (mainly inert gas (for example, nitrogen gas)) into the sealed liquid tank 108, pressurizes the liquid tank 108, and supplies the liquid 120 in the liquid tank 108. It extrudes to the pipe 107c. Of course, a pump other than the piston-type pump and the gas-type pump may be used for the feeder 116.

  The feeder 116 is controlled by the control unit 119. The control unit 119 drives the supply device 116 in accordance with the movement of the carriage 105, and the supply device 116 performs a supply operation while the carriage 105 is moving.

The mass flow controller 109 measures the flow rate of the liquid 120 flowing through the supply pipes 107a and 107b, and controls the flow rate of the liquid 120 flowing through the supply pipes 107a and 107b. The flow rate measured by the mass flow controller 109 is output to the control unit 119.
Further, the control unit 119 sets a flow rate by the mass flow controller 109 (hereinafter, the set flow rate is referred to as a set flow rate). The mass flow controller 109 performs constant flow control so as to maintain the flow rate of the liquid 120 flowing through the supply pipes 107b and 107c at the set flow rate.

  The joints 131, 132, 133, 134, and 135 are made of a material that is resistant to the liquid 120. The joints 131, 132, 133, 134, and 135 are branched. On the other hand, the exhaust pipe 114 is divided into six sides. The branched nipple 131a of the joint 131 is connected to the first terminal of the exhaust pipe 114 via the valve 110a. A branched nipple 132a of the joint 132 is connected to the second end of the exhaust pipe 114 via a valve 110b. The branched nipple 133a of the joint 133 is connected to the third end of the exhaust pipe 114 through the valve 110c. A nipple 134c of the joint 134 is connected to the fourth end of the exhaust pipe 114 via a valve 110d. A branched nipple 135 a of the joint 135 is connected to the fifth end of the exhaust pipe 114. The sixth terminal of the exhaust pipe 114 is connected to the inlet of the trap 112. An outlet of the trap 112 is connected to one end of the exhaust pipe 115, and the other end of the exhaust pipe 115 is connected to a vacuum pump (decompression device) 113.

  The vacuum pump 113 is, for example, a vacuum pump or a decompression pump, and sucks the gas in the joints 131 to 135 and the supply pipes 107a, 107b, and 107c through the exhaust pipe 115, the trap 112, and the exhaust pipe 114, thereby 135 and the supply pipes 107a, 107b, 107c are decompressed.

  The trap 112 is a cooling trap, for example, and traps moisture and solvent components contained in the gas sucked by the vacuum pump 113. For example, when the volatile component of the liquid 120 in the liquid tank 108 and the supply pipes 107a, 107b, and 107c flows into the trap 112 by suction of the vacuum pump 113, the volatile component is cooled by the trap 112. . Therefore, the volatile component is liquefied and captured by the trap 112.

A sealing cap 150 serving as a defoaming portion is disposed in the standby position of the nozzle head 106 in the vicinity of the work table 101 and below the rail 103.
As shown in FIG. 3, one end of a drain pipe 151 is attached to the sealing cap 150. By closing the lower end of the nozzle head 106 with the sealing cap 150, the nozzle hole 168 of the nozzle head 106 communicates with the drain pipe 151. The other end of the drain pipe 151 is connected to the cooling trap 153.
The cooling trap 153 includes an outer container 154, a refrigerant 155 in the outer container 154, a sealed container 156 that is housed inside the outer container 154 and immersed in the refrigerant 155, and the like. A drain pipe 151 passes through the upper surface of the sealed container 156. Further, the suction tube 152 passes through the upper surface of the sealed container 156. In the sealed container 156, the end of the suction tube 152 is located higher than the end of the drain tube 151. The suction pipe 152 is connected to the vacuum pump 113.
The nozzle head 106 is connected to the sealing cap 150 when the nozzle head 106 is in a standby state where the liquid 120 is not applied to the substrate 121 or when air bubbles staying in the nozzle head 106 and the supply pipes 107a to 107c are removed. Thus, the nozzle head 106 is moved to the sealing cap 150 by the carriage 105.
The vacuum pump 113 is operated and sucked in a state where the sealing cap 150 and the lower end of the nozzle head 106 are in close contact with each other, whereby the liquid 120 in the liquid tank 108 is drawn toward the nozzle head 106 side or dripped from the nozzle head 106. The liquid 120 to be received can be received by the cooling trap 153. Further, when the vacuum pump 113 performs suction, the bubbles remaining in the nozzle head 106 can be sucked out and removed.
In addition, when the trap 112 is a cold trap, the trap 112 is provided in the same manner as the cold trap 112.

  As shown in FIG. 2, a valve 110 a serving as a switching unit is provided on the nipple 131 a branched from the joint 131. The valve 110a communicates / blocks the exhaust pipe 114 and the joint 131. When the valve 110a is open, the exhaust pipe 114 is in communication with the joint 131, and the supply pipes 107a, 107b, 107c are in communication with the vacuum pump 113 through the joint 131, the exhaust pipes 114, 115 and the trap 112. become. When the valve 110 a is closed, the joint 131 is disconnected from the exhaust pipes 114 and 115, the trap 112 and the vacuum pump 113.

  The valve 110a is a solenoid valve. The control unit 119 performs opening / closing control of the valve 110a. Here, the valve 110a includes a valve body 111a and a drive source 111b. A valve body 111 a is disposed in the nipple 131 a of the joint 131. The valve body 111a closes or opens the hollow of the nipple 131a by the drive source 111b.

  As shown in FIG. 1, the valve 110 b is provided in the branched nipple 132 a of the joint 132. A valve 110 c is provided on the branched nipple 133 a of the joint 133. A valve 110 d is provided on the nipple 134 c of the joint 134. A valve 110 e is provided on the branched nipple 135 a of the joint 135. The valves 110b to 110e are provided in the same manner as the valve 110a.

  The joints 131 to 135 are provided with optical sensor units 141 to 145 as bubble detection units, respectively. The optical sensor units 141 to 145 detect the intensity of light from the joints 131 to 135, and detect the light transmittance in the joints 131 to 135 based on the detected light intensity. Thereby, the optical sensor units 141 to 145 detect the liquid 120, detect bubbles existing in the liquid 120 in the respective joints 131 to 135, and quantify the size and amount of the bubbles.

  As shown in FIG. 2, the optical sensor unit 141 includes a projector 141a and a light receiver 141b. The light projector 141 a emits light toward the liquid 120 in the joint 131. The light receiver 141b receives light emitted from the projector 141a and transmitted through the liquid 120.

  For the projector 141a, for example, an incandescent lamp, a fluorescent lamp, a halogen lamp, a tungsten lamp, a semiconductor laser, an LED, or an organic EL can be used. In addition, the light emitted from the projector 141a may be guided by an optical fiber, an optical waveguide, or the like to enter the joint 131. Further, the light emitted from the projector 141a does not always need to be incident on the joint 131, and may be incident intermittently using a shutter or the like. Moreover, although it is preferable to select the wavelength of the light which the light projector 141a outputs according to the absorption area of the liquid 120, it may be versatile white light.

  For the light receiver 141b, for example, a photomultiplier tube, a photodiode, or a phototransistor can be used. In addition, the light that has passed through the joint 131 may be guided by an optical fiber, an optical waveguide, or the like to enter the light receiver 141b. Further, since the illuminance of the projector 141a may fluctuate, it is desirable to monitor the change in the illuminance of the projector 141a itself, and the light receiver 141b detects the intensity of transmitted light in consideration of the illuminance change of the projector 141a.

  In order for the light projected by the projector 141a to pass through the joint 131, the joint 131 is made of a material having optical transparency. For example, the joint 131 is made of glass. It is desirable to provide the joint 131 with a UV cut filter to prevent the liquid 120 from being deteriorated by UV light.

  The entire joint 131 does not have light transmittance, but a part of the joint 131 may have light transmittance. For example, as shown in FIG. 4, two opposing transparent windows 131 b and 131 c may be provided in the joint 131. The light projector 141a is opposed to the transparent window 131b, and the light receiver 141b is opposed to the transparent window 131c. The light projected from the projector 141a passes through the transparent window 131b, the liquid 120 in the joint 131, and the transparent window 131c, and enters the light receiver 141b. It is desirable to provide a UV cut film on the transparent windows 131b and 131c to prevent deterioration of the liquid 120 due to UV light.

  Although the light projector 141 a and the light receiver 141 b are provided outside the joint 131, they may be provided inside the joint 131. Further, instead of the transparent windows 131b and 131c being provided in the joint 131, two opposed insertion ports are provided in the wall surface of the joint 131, the light projector 141a is fitted into one insertion port, and the light receiver 141b is inserted into the other insertion port. May be fitted. A transparent window may be provided over the entire circumference of the joint 131.

  Instead of the projector 141a projecting into the joint 131, the projector 141a may project into the supply pipe 107a near the joint 131 as shown in FIG. In this case, the supply pipe 107a is light transmissive. The entire supply pipe 107a does not have light transmission, but the portion projected by the projector 141a may have light transmission.

  2 to 5, the optical sensor unit 141 is configured to include a transmissive sensor, but may be configured to include a reflective sensor. That is, the light receiver 141b may receive the reflected light reflected by the liquid 120 in the joint 131 instead of receiving the light projected from the projector 141a and transmitted through the transparent windows 131b and 131c.

  The light receiver 141b detects the intensity of the received light. That is, the light receiver 141b photoelectrically converts the intensity of the received light into an electric signal, and outputs a received light intensity signal indicating the intensity of the received light to the control unit 119. The received light intensity detected by the light receiver 141b represents not only the light transmittance of the liquid 120 in the joint 131 but also the reflectance of the liquid 120 in the joint 131. That is, as the light transmittance of the liquid 120 in the joint 131 increases, the received light intensity detected by the light receiver 141b also increases, and thus the received light intensity and the light transmittance have a correlation. On the other hand, as the reflectance of the liquid 120 in the joint 131 increases, the received light intensity detected by the light receiver 141b also decreases, so that the received light intensity and the reflectance have a correlation. Thereby, not only the light receiving intensity but also the light transmittance and reflectance of the liquid 120 in the joint 131 are quantified by the light receiver 141b. When the optical sensor unit 141 is a reflective sensor, the light intensity detected by the light receiver 141b decreases as the light transmittance of the liquid 120 in the joint 131 increases, and the liquid 120 in the joint 131 decreases. As the reflectance increases, the received light intensity detected by the light receiver 141b increases.

The received light intensity detected by the light receiver 141b is obtained by quantifying the state of bubbles contained in the liquid 120 in the joint 131. In other words, if there are no bubbles in the liquid 120 in the joint 131, the received light intensity detected by the light receiver 141b is substantially constant (for example, 40%; initial value) (see line c in the graph of FIG. 6).
On the other hand, as shown in FIG. 7, when fine bubbles are generated in the liquid 120, light is irregularly reflected at the interface between the liquid 120 and the bubbles. For this reason, as the number of fine bubbles generated in the liquid 120 increases, the received light intensity (light transmittance) detected by the light receiver 141b decreases. Thereby, the number of bubbles in the liquid 120 can be quantified. For example, when the number of bubbles in the liquid 120 increases with time as indicated by a line a in the graph shown in FIG. 6, the received light intensity decreases with time.
Also, as shown in FIG. 8, if a large bubble is generated, for example, by combining bubbles generated in the liquid 120, light passes through the cavity of the bubble. Therefore, as the bubble size increases, the received light intensity (light transmittance) detected by the light receiver 141b increases. Thereby, the size of the bubbles in the liquid 120 can be quantified. For example, as shown by the line b in the graph shown in FIG. 6, when the size of the bubbles in the liquid 120 increases with time, the received light intensity increases with time.
The light reception intensity (light transmittance) detected by the light receiver 141b is different between the case where the liquid 120 exists in the joint 131 and the case where the liquid 120 does not exist in the joint 131. Thereby, the presence of the liquid 120 in the joint 131 can be detected.

  The optical sensor units 142 to 145 are provided in the same manner as the optical sensor unit 141. That is, the optical sensor units 142 to 145 include a projector and a light receiver. In addition, the control unit 119 receives the received light intensity signals of the optical sensor units 142 to 145 in parallel with the received light intensity signal of the optical sensor unit 141.

  As described above, the light transmittance of the liquid 120 in or near the joints 131 to 135 is detected by the light receivers of the optical sensor units 141 to 145. The size and number of bubbles generated in the joints 131 to 135 or in the vicinity thereof can be quantified from the detected transmittance. In particular, since bubbles tend to stay in the joints 131 to 135, the size and amount of such bubbles can be easily detected.

  The control unit 119 has a function as a first comparator, and compares the light transmittance based on the level of the received light intensity signal input from the light receiver 141b with a predetermined first allowable value shown in FIG. The first allowable value is a threshold value that partitions whether or not the size of bubbles generated in the liquid 120 existing in the joint 131 is equal to or larger than a predetermined size. For example, the first allowable value is 60%.

  When the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b is equal to or higher than the first allowable value as a result of the comparison, the control unit 119 detects the bubbles generated in the liquid 120 existing in the joint 131. It is determined that the size is greater than or equal to the predetermined size. On the other hand, if the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b is less than the first allowable value as a result of the comparison, the bubble generated in the liquid 120 existing in the joint 131 is determined. Is determined to be less than a predetermined size. Here, the predetermined size is a size that does not hinder the flow of the liquid 120. When the size of the bubbles contained in the liquid 120 in the joint 131 exceeds a size larger than a predetermined size (first threshold shown in FIG. 6), the flow of the liquid 120 is inhibited. The first threshold shown in FIG. 6 is, for example, 80%. The level of the received light intensity signal input from the light receiver 141b being equal to or higher than the first allowable value means that the light sensor 141 has detected a bubble in the joint 131 or the supply pipe 107a in the vicinity thereof.

  When the light transmittance based on the level of the received light intensity signal output from the light receiver 141b is equal to or higher than the first allowable value, the control unit 119 causes the carriage 105 to move the nozzle head 106 to the sealing cap 150 at the standby position. In particular, the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b exceeds the first allowable value (for example, 60%) based on the level of the received light intensity signal input from the light receiver 141b. The nozzle head 106 is moved to the standby position after the first threshold (for example, 80%). Specifically, the control unit 119 predicts the time until the timing T at which the light transmittance based on the level of the received light intensity signal input from the light receiver 141b becomes the first threshold (80%). Then, the control unit 119 moves the carriage 105 and the nozzle head 106 to the standby position by the timing T.

  The control unit 119 has a function as a second comparator, and compares the light transmittance level based on the received light intensity signal input from the light receiver 141b with a predetermined second allowable value shown in FIG. The second allowable value is a threshold value that partitions whether or not the number of bubbles generated in the liquid 120 existing in the joint 131 is less than a predetermined number. This second tolerance value is lower than the first tolerance value. For example, the second tolerance value is 30%.

  When the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b is higher than the second allowable value as a result of the comparison, the number of bubbles generated in the liquid 120 existing in the joint 131. Is determined to be less than the predetermined number. On the other hand, if the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b is equal to or lower than the second allowable value as a result of the comparison, the bubble generated in the liquid 120 existing in the joint 131 is determined. Is determined to be greater than or equal to a predetermined number. Here, the predetermined number is a value that does not hinder the flow of the liquid 120. When the number of bubbles included in the liquid 120 in the joint 131 exceeds the second threshold value shown in FIG. 6, which is larger than the predetermined number, the flow of the liquid 120 is inhibited. The fact that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b is equal to or smaller than the second allowable value means that the air bubbles in the joint 131 or the supply pipe 107a in the vicinity thereof are detected by the optical sensor unit 141. means.

  When the light transmittance based on the level of the received light intensity signal output from the light receiver 141b is equal to or lower than the second allowable value, the control unit 119 causes the carriage 105 to move the nozzle head 106 to the sealing cap 150 at the standby position. . In particular, the control unit 119 determines the second threshold value after the light transmittance based on the level of the received light intensity signal input from the light receiver 141b is less than the second allowable value based on the level of the received light intensity signal input from the light receiver 141b. The nozzle head 106 is moved to the standby position until (for example, 20%). Specifically, the control unit 119 predicts the time until the timing T at which the level of the received light intensity signal input from the light receiver 141b becomes the second threshold (20%). Then, the control unit 119 moves the carriage 105 and the nozzle head 106 to the standby position by the timing T.

  The control unit 119 also has a function as a third comparator, and compares the light transmittance based on the level of the received light intensity signal input from the light receiver 141b with a predetermined third allowable value. The third allowable value is a threshold value for partitioning whether or not the liquid 120 exists in the joint 131. Therefore, if the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b is equal to or lower than the third allowable value as a result of the comparison, it determines that the liquid 120 exists in the joint 131. . On the other hand, when the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b exceeds the third allowable value as a result of the comparison, the control unit 119 determines that the liquid 120 does not exist in the joint 131. . Therefore, the fact that the light transmittance based on the level of the received light intensity signal input from the light receiver 141b is equal to or lower than the third allowable value indicates that the liquid 120 in the joint 131 or the supply pipe 107a in the vicinity thereof is detected by the optical sensor unit 141. Means that.

The functions of the control unit 119 as the first, second, and third comparators may be realized by a logic circuit or may be realized by executing a program.
In parallel with the comparison of the first allowable value, the second allowable value, and the third allowable value of the light transmittance based on the level of the received light intensity signal of the optical sensor unit 141, the control unit 119 includes the optical sensor units 142 to 145. The light transmittance based on the level of the received light intensity signal is compared with the first tolerance value, the second tolerance value, and the third tolerance value.
Note that the first, second, and third comparators may not be built in the control unit 119, but may be provided in each of the optical sensor units 141 to 145 (particularly, at the subsequent stage of the light receiver). In this case, the outputs of the first, second, and third comparators are connected to the control unit 119, and a signal that represents the comparison result by the first, second, and third comparators is input to the control unit 119.

  In FIG. 1, the number of nozzle heads 106 mounted on the carriage 105 is one, but a plurality of nozzle heads 106 may be mounted on the carriage 105. In this case, these nozzle heads 106 are mounted on the carriage 105 in a state of being arranged along the sub-scanning direction. When a plurality of nozzle heads 106 are mounted on the carriage 105, supply pipes 107a to 107c, joints 131 to 135, a liquid tank 108, a mass flow controller 109, valves 110a to 110e, optical sensor units 141 to 145, a trap 112, a vacuum pump 113 and exhaust pipes 114 and 115 are provided for each nozzle head 106.

  Further, although the carriage 105 is moved in the main scanning direction, it may be moved in the main scanning direction and the sub scanning direction. Further, the nozzle head 106 may rotate around its center line. Although the work table 101 is moved in the sub-scanning direction by the moving device 102, it may be moved in the main scanning direction and the sub-scanning direction by the moving device 102. Further, the work table 101 may be rotated around its center by the moving device 102. That is, the nozzle head 106 may be moved relative to the work table 101 by a moving unit including both or one of the moving device 102 and the carriage 105.

  Further, although the valves 110a to 110e are open / close valves, they may be three-way valves. When the valves 110a to 110e are three-way valves, the valves 110a to 110e are connected to the state in which the outlet side of the liquid tank 108 is connected to the vacuum pump 113 side and the outlet side of the liquid tank 108 is connected to the nozzle head 106 side. It is configured to selectively switch to the state.

  In addition, the configuration using the optical sensor units 141 to 145 configured to include the projector and the light receiver as the bubble detection unit has been described as an example. However, the liquid 120 in the joints 131 to 135 may be used by other types of sensors. You may detect, the bubble which exists in the liquid 120 in each coupling 131-135, or may quantify the size and quantity of the bubble which exists in the liquid 120 in each coupling 131-135. For example, a magnetic sensor that detects magnetism as a physical quantity in the joints 131 to 135 or the vicinity thereof, a pressure sensor that detects pressure as a physical quantity in the joints 131 to 135 or the vicinity thereof, and a temperature as a physical quantity in the joints 131 to 135 or the vicinity thereof. You may use the temperature sensor which detects this.

[2] Operation of Coating Apparatus and Coating Method Hereinafter, the operation of the coating apparatus 100 and the coating method using the coating apparatus 100 will be described.

[2-1] Initial operation of coating apparatus, setting process of coating apparatus, and liquid filling process First, the liquid 120 is filled in the liquid tank 108. When the liquid tank 108 is replaceable, the liquid tank 108 filled with the liquid 120 is assembled to the supply pipe 107 c by the joint 135, and the supply device 116 is assembled to the liquid tank 108. At this time, the supply pipes 107a, 107b, and 107c are empty, and the liquid 120 is not filled in the supply pipes 107a, 107b, and 107c.

  Next, the control unit 119 moves the carriage 105 to a predetermined standby position. When the carriage 105 moves to the standby position, the lower end of the nozzle head 106 is blocked by the sealing cap 150.

Next, the control unit 119 controls the valves 110a, 110b, 110c, 110d, and 110e, and the valves 110a, 110b, 110c, 110d, and 110e are opened. In addition, the control unit 119 compares the light transmittance based on the level of the received light intensity signal input from the light receivers of the optical sensor units 141 to 145 with the third allowable value. Thereafter, the control unit 119 continues the comparison process.
Next, the control unit 119 operates the vacuum pump 113 and the feeder 116. By operating the vacuum pump 113, the vacuum in the exhaust pipe 114, the exhaust pipe 115, the drain pipe 151, the suction pipe 152, and the supply pipes 107a, 107b, and 107c is performed by the vacuum 113, and the exhaust pipe 114, the exhaust pipe 115, The drain pipe 151, the suction pipe 152, and the supply pipes 107a, 107b, and 107c have negative pressure.

  Further, since the supply device 116 is operating, the liquid 120 in the liquid tank 108 is sent out to the supply pipes 107c, 107b, 107a. Thereby, the liquid 120 is gradually filled into the supply pipes 107c, 107b, and 107a from the liquid tank 108 side. At this time, since the vacuum in the supply pipes 107c, 107b, and 107a is performed by the vacuum pump 113, the liquid 120 is quickly filled. Further, since the supply pipes 107c, 107b, and 107a are depressurized, it is possible to prevent bubbles from being generated in the liquid 120 filled in the supply pipes 107c, 107b, and 107a. Furthermore, bubbles generated in the liquid 120 filled in the supply pipes 107c, 107b, and 107a can be sucked toward the vacuum pump 113, and the bubbles can be removed. Even if a part of the liquid 120 flows to the exhaust pipe 114 side due to suction, the liquid 120 is captured by the trap 112, so that the vacuum pump 113 can be prevented from being adversely affected.

  The liquid level of the liquid 120 delivered from the liquid tank 108 first reaches the joint 135. Then, the liquid 120 is detected by the light receiver of the optical sensor unit 145. That is, the light transmittance based on the level of the received light intensity signal output from the light receiver of the optical sensor unit 145 to the control unit 119 is equal to or less than the third allowable value. When the light transmittance based on the level of the received light intensity signal output from the light receiver of the optical sensor unit 145 to the control unit 119 becomes equal to or less than the third allowable value, the control unit 119 controls the valve 110e and closes the valve 110e. As a result, the decompression in the supply pipes 107c, 107b, 107a via the valve 110e is stopped.

  Thereafter, the operation of the feeder 116 and the vacuum pump 113 continues. When the liquid level of the liquid 120 in the supply pipe 107c near the nozzle head 106 reaches the joint 134, the light transmittance based on the level of the received light intensity signal output from the light receiver of the optical sensor unit 144 is the third allowable value. Below the value. As a result, the control unit 119 controls the valve 110d, and the valve 110d is closed. When the valve 110d is closed, the pressure reduction in the supply pipes 107b and 107a through the valve 110d is stopped.

  Thereafter, when the liquid level of the liquid 120 near the nozzle head 106 in the supply pipe 107b reaches the joint 133, the light transmittance based on the level of the received light intensity signal output from the light receiver of the optical sensor unit 143 is the third allowable value. The control unit 119 controls the valve 110c, and the valve 110c is closed. Thereby, the decompression in the supply pipe 107a via the valve 110c is stopped.

  Thereafter, when the liquid level of the liquid 120 reaches the joint 132, the light transmittance based on the level of the received light intensity signal output from the light receiver of the optical sensor unit 142 becomes equal to or lower than the third allowable value, and the control unit 119 110b is controlled and the valve 110b is closed. Thereby, the pressure reduction in the supply pipe 107a through the valve 110b is stopped.

Thereafter, when the liquid level of the liquid 120 reaches the joint 131, the level of the received light intensity signal output from the light receiver 141b of the optical sensor unit 141 becomes equal to or lower than the third allowable value, and the control unit 119 controls the valve 110a. The valve 110a is closed. Thereby, pressure reduction in the nozzle head 106 via the valve 110a is stopped.
Thereafter, the operation of the feeder 116 continues. When the liquid 120 is filled into the hollow 163 of the nozzle head 106, the liquid 120 is continuously discharged from the nozzle hole 168 of the nozzle head 106. The liquid 120 discharged from the nozzle hole 168 of the nozzle head 106 is captured by the cooling trap 153.

As described above, the liquid 120 in the liquid tank 108 is sent out to the supply pipes 107c, 107b, and 107a by the supply unit 116 while being decompressed by the vacuum pump 113, so that the supply pipes 107c, 107b, and 107a and the nozzle head are supplied. The time required to fill the liquid 120 in the 106 can be shortened.
In addition, since the supply pipes 107c, 107b, 107a are depressurized when the liquid 120 is filled, bubbles can be prevented from being generated in the liquid 120 filling the supply pipes 107c, 107b, 107a.
Further, even if bubbles are generated in the liquid 120 filled in the supply pipes 107c, 107b, and 107a, the bubbles can be removed because they are sucked to the vacuum pump 113 side.

[2-2] Application Operation and Application Process of Application Apparatus The application operation of the application apparatus 100 set as described above and the organic layer patterning method based on the application operation will be described.
First, the substrate 121 is placed on the work table 101. In addition, the control unit 119 sets the set flow rate of the mass flow controller 109 and adjusts the amount of the liquid 120 ejected from the nozzle head 106.

  Next, the control unit 119 operates the supply device 116 and the carriage 105. The feeder 116 continues to operate from the above setting process.

When the carriage 105 and the nozzle head 106 move, the nozzle head 106 is detached from the sealing cap 150. Then, the nozzle head 106 moves onto the substrate 121. Thereafter, the carriage 105 and the nozzle head 106 continue to move in the main scanning direction. At that time, since the supply device 116 is in operation, the liquid 120 in the liquid tank 108 is sent to the nozzle head 106, and the flow rate of the liquid 120 flowing through the supply pipes 107c, 107b, 107a is set constant by the mass flow controller 109. Controlled by flow rate. Therefore, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106 during the movement of the carriage 105. Therefore, the discharged liquid 120 is applied linearly on the substrate 121, and a linear organic layer pattern along the main scanning direction is formed on the substrate 121. When the carriage 105 moves to the opposite end of the movement range, the control unit 119 stops the carriage 105.
Next, the control unit 119 controls the moving device 102, and the work table 101 and the substrate 121 are moved by a predetermined distance in the sub-scanning direction by the moving device 102. Also at this time, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106. Therefore, a linear organic layer pattern along the sub-scanning direction is formed on the substrate 121. Thereafter, the moving device 102 stops.
Next, the control unit 119 operates the carriage 105, and the nozzle head 106 moves with the carriage 105 in the reverse direction of the main scanning direction. Also at this time, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106. Therefore, a linear organic layer pattern along the main scanning direction is formed on the substrate 121. When the carriage 105 moves to the opposite end of the movement range, the control unit 119 stops the carriage 105.
Next, the control unit 119 controls the moving device 102, and the work table 101 and the substrate 121 are moved by a predetermined distance in the sub-scanning direction by the moving device 102. Also at this time, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106. Therefore, a linear organic layer pattern along the main scanning direction is formed on the substrate 121.

  Thereafter, the control unit 119 repeats intermittent operation control of the carriage 105 and the moving device 102 while continuing the constant flow rate control of the mass flow controller 109 and the operation of the feeder 116. Accordingly, the carriage 105 is repeatedly moved from end to end in the movement range while the liquid 120 is continuously ejected from the nozzle holes 168 of the nozzle head 106, and the moving device 102 is moved when the carriage 105 moves to the end. As a result, the work table 101 and the substrate 121 are moved in the sub-scanning direction by a predetermined distance. As a result, a twisted organic layer pattern is formed on the substrate 121 by the liquid 120 ejected from the nozzle head 106.

  Here, when the control unit 119 performs the above control, the received light intensity signals of the light receivers of the optical sensor units 141 to 145 are output to the control unit 119. The control unit 119 compares the light transmittance based on the level of the received light intensity signal input from the light receivers of the optical sensor units 141 to 145 with the first allowable value and the second allowable value. And if the control part 119 judges that the light transmittance based on the level of the received light intensity signal of the light receiver of the optical sensor parts 141 to 145 exceeds the second allowable value and is lower than the first allowable value as a result of the comparison, Continue the above control. On the other hand, as a result of the comparison, the control unit 119 determines that the light transmittance based on the level of the received light intensity signal of any of the light receivers of the optical sensor units 141 to 145 is greater than or equal to the first tolerance value or less than the second tolerance value. Then, the following processing is performed.

  That is, when the liquid 120 is ejected from the nozzle head 106 and the carriage 105 is moving in the main scanning direction, the light transmittance based on the level of the received light intensity signal of one of the light receivers of the light sensor units 141 to 145 is the first. When the value is greater than or equal to one tolerance value or less than or equal to the second tolerance value, the control unit 119 continues to move the carriage 105 and operate the feeder 116. Therefore, the liquid 120 is continuously discharged to form an organic layer pattern.

  When the carriage 105 moves to the end of the movement range, the control unit 119 moves the carriage 105 to the standby position. When the carriage 105 moves to the standby position, the control unit 119 stops the carriage 105. When the carriage 105 moves to the standby position, the lower end of the nozzle head 106 is closed by the sealing cap 150. Then, the control unit 119 operates the vacuum pump 113. Thereby, the bubble which generate | occur | produced in either of the couplings 131-135 can be removed. That is, while the operation of the feeder 116 continues, the liquid 120 in the nozzle head 106 is sucked into the cooling trap 153, so that bubbles generated in any of the joints 131 to 135 are discharged from the nozzle head 106 together with the liquid 120. Is done. Thereby, a defoaming process is performed. The discharged liquid 120 is captured by the cooling trap 153, and the bubbles contained in the discharged liquid 120 are sucked by the vacuum pump 113.

  In addition, after the carriage 105 moves to the standby position and stops, the control unit 119 opens any of the valves 110a to 110e. Specifically, when the light transmittance based on the level of the received light intensity signal of the light receiver 141b of the optical sensor unit 141 becomes equal to or higher than the first allowable value or equal to or lower than the second allowable value, the control unit 119 switches the valve 110a. open. Similarly, when the light transmittance based on the level of the received light intensity signal of the light receiver of the optical sensor unit 142 becomes equal to or higher than the first allowable value or equal to or lower than the second allowable value, the valve 110b receives the light received by the optical sensor unit 143. When the light transmittance based on the level of the received light intensity signal of the optical device is equal to or higher than the first allowable value or lower than the second allowable value, the valve 110c is based on the level of the received light intensity signal of the optical receiver of the optical sensor unit 144. When the light transmittance is greater than or equal to the first tolerance or less than or equal to the second tolerance, the light transmittance based on the level of the received light intensity signal of the light receiver of the optical sensor unit 145 is greater than or equal to the first tolerance. Or when it becomes below the 2nd tolerance, valve 110e is opened by control part 119. Thereby, bubbles staying in the joints 131 to 135 and the vicinity thereof are sucked together with the liquid 120 by the vacuum pump 113 via the valves 110a to 110e. Thereby, a defoaming process is performed. Further, the liquid 120 sucked together with the bubbles is captured by the trap 112.

  After the defoaming process, the formation of the organic layer pattern resumes. Specifically, the control unit 119 closes one of the valves 110a to 110e that has been opened. Next, the control unit 119 controls the moving device 102 while continuing the operation of the feeder 116, and the work table 101 and the substrate 121 are moved by a predetermined distance in the sub-scanning direction by the moving device 102. Thereby, the position of the nozzle head 106 is positioned on the end of the next row of the row formed last in the organic layer pattern before being interrupted. Then, the control unit 119 sets the set flow rate of the mass flow controller 109 and operates the carriage 105. When the carriage 105 operates, the carriage 105 moves in the main scanning direction. Thereby, the liquid 120 is continuously discharged again from the nozzle head 106, and the formation of the organic layer pattern is resumed.

  As described above, since the optical sensors 141 to 145 are provided in the joints 131 to 135, the bubbles are detected by the joints 131 to 135 in which bubbles are likely to stay, and the size and amount of the bubbles are quantified. Can be. Even if bubbles remain in the joints 131 to 135, the defoaming process is performed before the flow of the liquid 120 in the supply pipes 107a, 107b, and 107c is blocked by the bubbles. Can be prevented from stopping unexpectedly.

  In the above description, both the defoaming process in the nozzle head 106 and the defoaming process in the joints 131 to 135 are performed, but only one of them may be performed.

[3] Configuration of Organic Electroluminescence Display Panel (EL Panel) Manufactured Using Coating Apparatus Regarding EL panel 1 manufactured using coating apparatus 100 shown in FIG. 1, using FIGS. 9 to 13. explain.

  FIG. 9 is a plan view showing an arrangement configuration of a plurality of pixels P in the EL panel 1 which is a light emitting panel. FIG. 10 is a plan view showing a schematic configuration of the EL panel 1. FIG. 11 is a circuit diagram showing a circuit corresponding to one pixel of the EL panel 1 operating in the active matrix driving method. 12 is a plan view corresponding to one pixel P of the EL panel 1, and FIG. 13 is a cross-sectional view taken along the line XIII-XIII in FIG.

As shown in FIGS. 9 and 10, in the EL panel 1, a plurality of pixels P that emit light respectively in R (red), G (green), and B (blue) are arranged in a matrix with a predetermined pattern. .
The EL panel 1 is provided with a plurality of scanning lines 2 and a plurality of signal lines 3. These scanning lines 2 are arranged so as to be substantially parallel to each other along the row direction. These signal lines 3 are arranged so as to be substantially parallel to each other along the column direction. The scanning line 2 and the signal line 3 are substantially orthogonal to the scanning line 2 in plan view. The EL panel 1 is provided with a plurality of voltage supply lines 4. The voltage supply line 4 is provided in parallel to the scanning line 2 in plan view. The voltage supply line 4 is provided along the scanning line 2 between the adjacent scanning lines 2. The pixel P corresponds to a range surrounded by a pair of scanning lines 2 and voltage supply lines 4 and two adjacent signal lines 3. Pixels P are arranged in a matrix. Here, a plurality of pixels P that emit R (red) are arranged along the signal line 3. A plurality of pixels P emitting G (green) are also arranged along the signal line 3. A plurality of pixels P that emit B (blue) are also arranged along the signal line 3. A plurality of columns of pixels P in the direction along the scanning line 2 are arranged in the order of a pixel P that emits light in R (red), a pixel P that emits light in G (green), and a pixel P that emits light in B (blue). ing.

  Further, the EL panel 1 is provided with a bank 13 which is a partition wall. The bank 13 extends in a direction along the signal line 3. Predetermined carrier transport layers (a hole injection layer 8b and a light emitting layer 8c, which will be described later) are provided in a range sandwiched between the banks 13, and the range becomes a light emitting region of the pixel P. That is, the bank 13 partitions the pixel P for each color of R (red), G (green), and B (blue). The carrier transport layer is a layer that transports holes or electrons when a voltage is applied.

  As shown in FIGS. 10 and 11, for each pixel P of the EL panel 1, a switch transistor 5, which is a thin film transistor, a driving transistor 6, which is a thin film transistor, a capacitor 7, and an EL element 8 are provided.

  In each pixel P, the gate of the switch transistor 5 is connected to the scanning line 2. One of the drain and the source of the switch transistor 5 is connected to the signal line 3. The other of the drain and source of the switch transistor 5 is connected to one electrode of the capacitor 7 and the gate of the driving transistor 6. One of the source and drain of the driving transistor 6 is connected to the voltage supply line 4. The other of the source and drain of the driving transistor 6 is connected to the other electrode of the capacitor 7 and the anode of the EL element 8. Note that the cathodes of the EL elements 8 of all the pixels P are maintained at a constant voltage Vcom that is a reference potential (for example, grounded).

  In addition, each scanning line 2 is connected to a scanning driver around the EL panel 1. Each voltage supply line 4 is connected to a constant voltage source or a driver that outputs a voltage signal as appropriate. Each signal line 3 is connected to a data driver. The EL panel 1 is driven by these drivers by an active matrix driving method. The voltage supply line 4 is supplied with predetermined power by a constant voltage source or a driver.

  Next, the circuit structure of the EL panel 1 and the pixel P will be described with reference to FIGS. As shown in FIG. 12, the switch transistor 5 and the drive transistor 6 are arranged along the signal line 3. A capacitor 7 is disposed in the vicinity of the switch transistor 5. An EL element 8 is disposed in the vicinity of the drive transistor 6. Further, the switch transistor 5, the drive transistor 6, the capacitor 7, and the EL element 8 are disposed between the scanning line 2 and the voltage supply line 4.

As shown in FIG. 13, the drive transistor 6 includes a gate electrode 6a, a semiconductor film 6b, a channel protective film 6d, impurity semiconductor films 6f and 6g, a drain electrode 6h, a source electrode 6i, and the like.
The switch transistor 5 is a thin film transistor similar to the drive transistor 6 described in detail below, and includes a gate electrode 5a, a semiconductor film, a channel protective film, an impurity semiconductor film, a drain electrode 5h, a source electrode 5i, and the like. Details are omitted here.
As shown in FIGS. 12 and 13, an interlayer insulating film 11 to be a gate insulating film is formed on one surface of the substrate 10. An interlayer insulating film 12 is formed on the interlayer insulating film 11. The signal line 3 is formed between the interlayer insulating film 11 and the substrate 10. The scanning line 2 and the voltage supply line 4 are formed between the interlayer insulating film 11 and the interlayer insulating film 12.

The gate electrode 6 a is formed between the substrate 10 and the interlayer insulating film 11. The gate electrode 6a is made of, for example, a Cr film, an Al film, a Cr / Al laminated film, an AlTi alloy film, or an AlTiNd alloy film. An insulating interlayer insulating film 11 is formed on the gate electrode 6a. Gate electrode 6 a is covered with interlayer insulating film 11.
The interlayer insulating film 11 is made of, for example, silicon nitride or silicon oxide. An intrinsic semiconductor film 6b is formed on the interlayer insulating film 11 at a position corresponding to the gate electrode 6a. The semiconductor film 6b is opposed to the gate electrode 6a with the interlayer insulating film 11 interposed therebetween.
The semiconductor film 6b is made of, for example, amorphous silicon or polycrystalline silicon. A channel is formed in the semiconductor film 6b. An insulating channel protective film 6d is formed on the central portion of the semiconductor film 6b. The channel protective film 6d is made of, for example, silicon nitride or silicon oxide.
Further, an impurity semiconductor film 6f is formed on one end portion of the semiconductor film 6b so as to partially overlap the channel protective film 6d. Over the other end of the semiconductor film 6b, an impurity semiconductor film 6g is formed so as to partially overlap the channel protective film 6d. The impurity semiconductor films 6f and 6g are formed on both ends of the semiconductor film 6b so as to be separated from each other. The impurity semiconductor films 6f and 6g are n-type semiconductors, but are not limited thereto, and may be p-type semiconductors.
A drain electrode 6h is formed on the impurity semiconductor film 6f. A source electrode 6i is formed on the impurity semiconductor film 6g. The drain electrode 6h and the source electrode 6i are made of, for example, a Cr film, an Al film, a Cr / Al laminated film, an AlTi alloy film, or an AlTiNd alloy film.
An insulating interlayer insulating film 12 serving as a protective film is formed on the channel protective film 6d, the drain electrode 6h, and the source electrode 6i. The channel protective film 6d, the drain electrode 6h, and the source electrode 6i are covered with the interlayer insulating film 12. The drive transistor 6 is covered with an interlayer insulating film 12. The interlayer insulating film 12 is made of, for example, silicon nitride or silicon oxide having a thickness of 100 nm to 200 nm.

  The capacitor 7 is connected between the gate electrode 6 a and the source electrode 6 i of the driving transistor 6. As shown in FIG. 13, one electrode 7 a of the capacitor 7 is formed between the substrate 10 and the interlayer insulating film 11. The other electrode 7 b of the capacitor 7 is formed between the interlayer insulating film 11 and the interlayer insulating film 12. The electrodes 7a and 7b are opposed to each other with the interlayer insulating film 11 that is a dielectric interposed therebetween. Thereby, the capacitor 7 is configured.

The signal line 3, the electrode 7a of the capacitor 7, the gate electrode 5a of the switch transistor 5, and the gate electrode 6a of the driving transistor 6 are formed by processing the conductive film formed on the entire surface of the substrate 10 by a photolithography method, an etching method, or the like. It is formed in a lump.
The scanning line 2, the voltage supply line 4, the electrode 7 b of the capacitor 7, the drain electrode 5 h and source electrode 5 i of the switch transistor 5, and the drain electrode 6 h and source electrode 6 i of the driving transistor 6 are formed on the interlayer insulating film 11. The formed conductive film is formed by shape processing by a photolithography method, an etching method, or the like.

In the interlayer insulating film 11, a contact hole 11a is formed in a region where the gate electrode 5a and the scanning line 2 overlap. A contact hole 11b is formed in a region where the drain electrode 5h and the signal line 3 overlap. A contact hole 11c is formed in a region where the gate electrode 6a and the source electrode 5i overlap. Contact plugs 20a to 20c are embedded in the contact holes 11a to 11c, respectively. The gate electrode 5a of the switch transistor 5 and the scanning line 2 are electrically connected by the contact plug 20a. The contact plug 20b electrically connects the drain electrode 5h of the switch transistor 5 and the signal line 3. The contact plug 20c electrically connects the source electrode 5i of the switch transistor 5 and the electrode 7a of the capacitor 7, and electrically connects the source electrode 5i of the switch transistor 5 and the gate electrode 6a of the drive transistor 6. The scanning line 2 may be in direct contact with the gate electrode 5a, the drain electrode 5h may be in contact with the signal line 3, and the source electrode 5i may be in contact with the gate electrode 6a without using the contact plugs 20a to 20c.
The gate electrode 6 a of the driving transistor 6 is integrally connected to the electrode 7 a of the capacitor 7. A drain electrode 6 h of the drive transistor 6 is integrally connected to the voltage supply line 4. A source electrode 6 i of the driving transistor 6 is integrally connected to an electrode 7 b of the capacitor 7.

The pixel electrode 8 a is provided on the substrate 10 via the interlayer insulating film 11. The pixel electrode 8a is formed independently for each pixel P. The pixel electrode 8a is a transparent electrode, for example, tin-doped indium oxide (ITO), zinc-doped indium oxide, indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), zinc oxide (ZnO), or cadmium − It consists of tin oxide (CTO). The pixel electrode 8a partially overlaps the source electrode 6i of the drive transistor 6, and the pixel electrode 8a and the source electrode 6i are connected.
As shown in FIGS. 12 and 13, the interlayer insulating film 12 includes the scanning line 2, the signal line 3, the voltage supply line 4, the switch transistor 5, the driving transistor 6, the peripheral edge of the pixel electrode 8 a, and the electrode of the capacitor 7. 7b and the interlayer insulating film 11 are formed.
An opening 12a is formed in the interlayer insulating film 12 so that the center of each pixel electrode 8a is exposed. The interlayer insulating film 12 is formed in a lattice shape in plan view.

As shown in FIGS. 12 and 13, the bank 13 extends in the direction along the signal line 3 and is provided in parallel to each other. Therefore, these banks 13 are striped. The bank 13 is formed at a position covering the switch transistor 5 and the drive transistor 6 with the interlayer insulating film 12 interposed therebetween. The side wall 13 a of the bank 13 is located inside the opening 12 a of the interlayer insulating film 12. Further, between the adjacent banks 13, the center side of the pixel electrode 8 a is exposed. A plurality of pixel electrodes 8 a between adjacent banks 13 are arranged along the banks 13.
Then, when the bank 13 forms the hole injection layer 8b or the light emitting layer 8c by a wet method, the pixel P adjacent to the liquid material in which the material to be the hole injection layer 8b or the light emitting layer 8c is dissolved or dispersed in the solvent. It functions as a partition wall that prevents bleeding.

  As shown in FIGS. 12 and 13, the EL element 8 includes a pixel electrode 8a as a first electrode serving as an anode, a hole injection layer 8b that is a compound film formed on the pixel electrode 8a, and a hole. A light emitting layer 8c, which is a compound film formed on the injection layer 8b, and a counter electrode 8d as a second electrode formed on the light emitting layer 8c are provided. The counter electrode 8d is a single electrode common to all the pixels P, and is continuously formed in all the pixels P.

The hole injection layer 8b is a carrier transport layer made of, for example, PEDOT (poly (ethylenedioxy) thiophene) that is a conductive polymer and PSS (polystyrene sulfonate) that is a dopant. The hole injection layer 8b is a layer that injects holes from the pixel electrode 8a toward the light emitting layer 8c.
The light emitting layer 8c includes a material that emits one of R (red), G (green), and B (blue) for each pixel P. The light emitting layer 8c is a carrier transport layer made of, for example, a polyfluorene light emitting material or a polyphenylene vinylene light emitting material. The light emitting layer 8c is a layer that emits light in association with recombination of electrons supplied from the counter electrode 8d and holes injected from the hole injection layer 8b. For this reason, the pixel P that emits R (red), the pixel P that emits G (green), and the pixel P that emits B (blue) have different light emitting materials for the light emitting layer 8c. The R (red), G (green), and B (blue) pattern of the pixel P is a stripe pattern in which the same color pixels are arranged in the vertical direction.

The counter electrode 8d is formed of a material having a work function lower than that of the pixel electrode 8a. The counter electrode 8d is made of, for example, a simple substance or an alloy containing at least one of indium, magnesium, calcium, lithium, barium, and a rare earth metal.
The counter electrode 8d is an electrode common to all the pixels P, and covers the bank 13 together with the compound film such as the light emitting layer 8c.

Further, the hole injection layer 8 b and the light emitting layer 8 c are provided in a band shape in the direction along the bank 13 between the adjacent banks 13, and are provided continuously in the direction along the bank 13. Therefore, the hole injection layer 8 b and the light emitting layer 8 c are not divided for each pixel P in the direction along the bank 13. That is, the hole injection layer 8 b and the light emitting layer 8 c are provided in common to the plurality of pixel electrodes 8 a arranged between the adjacent banks 13. On the other hand, the hole injection layer 8 b and the light emitting layer 8 c are partitioned by the bank 13 in the direction orthogonal to the bank 13.
A hole injection layer 8b and a light emitting layer 8c as a carrier transport layer are stacked on the pixel electrode 8a between the sidewalls 13a of the bank 13 in the opening 12a of the interlayer insulating film 12 (see FIG. 13). . That is, when a voltage is applied between the pixel electrode 8a and the counter electrode 8d, the hole injection layer 8b and the light emitting layer 8c function as a carrier transport layer in a portion overlapping the pixel electrode 8a, and light emission occurs in the light emitting layer 8c in that portion. To do.
Specifically, the sidewall 13 a of the bank 13 provided on the interlayer insulating film 12 is formed inside the opening 12 a of the interlayer insulating film 12.
Then, a liquid material containing a material to be the hole injection layer 8b is applied on the pixel electrode 8a surrounded by the opening 12a and sandwiched between the side walls 13a, and the substrate 10 is heated to dry the liquid material. The compound film thus formed becomes the hole injection layer 8b which is the first carrier transport layer.
Further, a liquid material containing a material to be the light emitting layer 8c is applied on the hole injection layer 8b surrounded by the opening 12a and sandwiched by the side walls 13a, and the substrate 10 is heated to dry the liquid material. The compound film thus formed becomes the light emitting layer 8c which is the second carrier transport layer.
A counter electrode 8d is provided so as to cover the light emitting layer 8c and the bank 13 (see FIG. 13).

In this EL panel 1, the pixel electrode 8a, the substrate 10 and the interlayer insulating film 11 are transparent, and the light emitted from the light emitting layer 8c is transmitted through the pixel electrode 8a, the interlayer insulating film 11 and the substrate 10 and emitted. . Therefore, the back surface of the substrate 10 becomes a display surface.
The display surface may be the opposite side instead of the substrate 10 side. In this case, the counter electrode 8d is a transparent electrode, the pixel electrode 8a is a reflective electrode, and light emitted from the light emitting layer 8c is transmitted through the counter electrode 8d and emitted.

The EL panel 1 is driven as follows to emit light.
In a state where a predetermined level of voltage is applied to all the voltage supply lines 4, the scanning driver sequentially applies voltages to the scanning lines 2, thereby sequentially selecting the scanning lines 2.
When each scanning line 2 is selected, a voltage of a level corresponding to the gradation is applied to all the signal lines 3 by the data driver. Then, since the switch transistor 5 corresponding to the selected scanning line 2 is turned on, a voltage having a level corresponding to the gradation is applied to the gate electrode 6a of the drive transistor 6.
The potential difference between the gate electrode 6a and the source electrode 6i of the drive transistor 6 is determined according to the voltage applied to the gate electrode 6a of the drive transistor 6, and the magnitude of the drain-source current in the drive transistor 6 is determined. The EL element 8 emits light with brightness according to the drain-source current.
Thereafter, when the selection of the scanning line 2 is released, the switch transistor 5 is turned off. Therefore, the electric charge according to the voltage applied to the gate electrode 6a of the drive transistor 6 is stored in the capacitor 7, and the potential difference between the gate electrode 6a and the source electrode 6i of the drive transistor 6 is maintained. For this reason, the drive transistor 6 keeps flowing the drain-source current having the same current value as that at the time of selection, and maintains the luminance of the EL element 8.

[4] Manufacturing Method of Organic Electroluminescence Display Panel Using Coating Device Next, a manufacturing method of the EL panel 1 will be described.

[4-1] Step Before Using the Coating Apparatus A substrate 10 having a size that can take out a plurality of the EL panels 1 shown in FIG. 9 by dicing is prepared.
A gate metal layer is deposited on the substrate 10 by sputtering. Then, the gate metal layer is patterned by photolithography and etching. Thus, the signal line 3, the electrode 7a of the capacitor 7, the gate electrode 5a of the switch transistor 5 and the gate electrode 6a of the drive transistor 6 are formed from the gate metal layer.
Next, an interlayer insulating film 11 to be a gate insulating film such as silicon nitride is deposited by plasma CVD. A contact hole (not shown) opened on the external connection terminal (for example, the end of the scanning line 2) of each scanning line 2 for connecting to a scanning driver located on one side of the EL panel 1 is formed in the interlayer insulating film 11. Form.
Next, a semiconductor layer such as amorphous silicon to be the semiconductor film 6b (5b) and an insulating layer such as silicon nitride to be the channel protective film 6d (5d) are successively deposited. Thereafter, the insulating layer is patterned by photolithography and etching. Thereby, a channel protective film 6d (5d) is formed from the insulating film.
Thereafter, an impurity layer to be the impurity semiconductor films 6f and 6g (5f and 5g) is deposited, and then the impurity layer and the semiconductor layer are successively patterned by photolithography and etching. Thereby, impurity semiconductor films 6f and 6g (5f and 5g) are formed from the impurity layer, and a semiconductor film 6b (5b) is formed from the semiconductor layer.
Then, contact holes 11a to 11c are formed by photolithography and etching. Next, contact plugs 20a to 20c are formed in the contact holes 11a to 11c. This step may be omitted.
A source / drain metal layer to be the drain electrode 5h and source electrode 5i of the switch transistor 5 and the drain electrode 6h and source electrode 6i of the driving transistor 6 is deposited, and the source / drain metal layer is patterned. Thus, the scanning line 2, the voltage supply line 4, the electrode 7b of the capacitor 7, the drain electrode 5h of the switch transistor 5, the source electrode 5i, the drain electrode 6h of the driving transistor 6, and the source electrode 6i are formed from the source / drain metal layer. To do. Thus, the switch transistor 5 and the drive transistor 6 are formed. Then, after depositing an ITO film, the ITO film is patterned to form a pixel electrode 8a from the ITO film.

  Then, an insulating film is formed by vapor deposition so as to cover the switch transistor 5, the drive transistor 6, and the like. Thereafter, the insulating film is patterned by photolithography and etching. Thus, a plurality of openings 12a are formed in the insulating film, and the interlayer insulating film 12 is formed. The opening 12a is formed at the center of each pixel electrode 8a, and the center of the pixel electrode 8a is exposed in each opening 12a. In addition to these openings 12a, the external connection terminals of the scanning lines 2 (not shown) and the external connection terminals of the signal lines 3 for connection to the data driver located on one side of the EL panel 1 (for example, the end portions of the signal lines 3) And a plurality of contact holes opened on the external connection terminals of the voltage supply line 4 (for example, end portions of the voltage supply line 4).

  Next, after depositing a photosensitive resin such as polyimide, the photosensitive resin is exposed to form striped banks 13 parallel to each other. At this time, the bank 13 is formed so that the side wall 13a of the bank 13 is positioned on the pixel electrode 8a. The bank 13 exposes a contact hole (not shown) that opens the external connection terminal.

  Through the above steps, each pixel electrode 8a is exposed in each opening 12a of the interlayer insulating film 12, as shown in FIG. A plurality of pixel electrodes 8 a are exposed in the recesses between the striped banks 13, and the pixel electrodes 8 a are arranged along the banks 13.

[4-2] Coating Step As described in [2-1] above, four coating devices 100 are set. At this time, the material of the hole injection layer 8 b is used for the liquid 120 in the liquid tank 108 of the first coating apparatus 100. The material of the red light emitting layer 8c is used for the liquid 120 in the liquid tank 108 of the second coating apparatus 100. For the liquid 120 in the liquid tank 108 of the third coating apparatus 100, the material of the green light emitting layer 8c is used. For the liquid 120 in the liquid tank 108 of the fourth coating apparatus 100, the material of the blue light emitting layer 8c is used.

  Next, the substrate 10 obtained by the above-described process [4-1] is placed on the work table 101 of the first coating apparatus 100. At this time, the substrate 10 is placed on the work table 101 so that the bank 13 is along the main scanning direction. Here, as shown in FIG. 15, the substrate 10 has unit regions R3 corresponding to one EL panel 1 arranged in a matrix. As shown in FIG. 15, the substrate 10 has a configuration in which a plurality of panel regions R1 arranged in a row in the horizontal direction (main scanning direction) and a margin region R2 between the panel regions R1 are alternately arranged. ing.

  Next, the control unit 119 sets the set flow rate of the mass flow controller 109. Thereby, the flow rate of the liquid 120 flowing through the supply pipes 107c, 107b, and 107a is controlled by the mass flow controller 109 to a constant set flow rate. The operation of the supply device 116 is continued from the setting step, and the liquid 120 discharged from the nozzle hole 168 of the nozzle head 106 is captured by the cooling trap 153.

Next, the control unit 119 operates the carriage 105, and the carriage 105 moves from the standby position onto the substrate 10. As a result, the nozzle head 106 is detached from the sealing cap 150. Then, the carriage 105 moves on the substrate 10 in the main scanning direction. At this time, since the supply device 116 is operating, the liquid 120 in the liquid tank 108 is sent to the nozzle head 106, and the flow rate of the liquid 120 flowing through the supply pipes 107c, 107b, 107a is set to a constant value by the mass flow controller 109. Controlled by flow rate. Therefore, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106 during the movement of the carriage 105. The discharged liquid 120 is applied between the adjacent banks 13. As a result, a band-shaped hole injection layer 8b is formed between the adjacent banks 13, and the pixel electrodes 8a arranged between the adjacent banks 13 are covered with the hole injection layer 8b. When the carriage 105 moves to the opposite end of the movement range, the carriage 105 is stopped by the control unit 119. Then, the control unit 119 controls the moving device 102, the work table 101 and the substrate 10 are moved by one pixel in the sub-scanning direction by the moving device 102, and then the moving device 102 is stopped by the control unit 119.
Next, the control unit 119 operates the carriage 105. As a result, the carriage 105 moves in the reverse direction, and the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106. As a result, a strip-shaped hole injection layer 8b made of the discharged liquid 120 is formed.
When the carriage 105 moves to the opposite end of the movement range, the carriage 105 is stopped by the control unit 119. Then, the control unit 119 controls the moving device 102, the work table 101 and the substrate 10 are moved by one pixel in the sub-scanning direction by the moving device 102, and then the moving device 102 is stopped by the control unit 119.

  Thereafter, by repeating the above operation, as shown in FIG. 15, the strip-shaped hole injection layer 8b made of the discharged liquid 120 is formed in a twisted manner.

When the above operation is performed, the control unit 119 grasps the current position of the moving nozzle head 106. This is because the control unit 119 performs a predetermined calculation process based on the size of the substrate 10, the moving range and moving speed of the carriage 105 and the moving device 102, thereby specifying the current position of the nozzle head 106 with respect to the substrate 10. Is possible.
Further, the control unit 119 can predict the location where the nozzle head 106 is located after a predetermined time from the current position by performing the same calculation process.

When the liquid 120 is applied to the substrate 10 and the hole injection layer 18 b is formed, the received light intensity signals of the light receivers of the optical sensor units 141 to 145 are output to the control unit 119.
The control unit 119 compares the light transmittance based on the level of the received light intensity signal input from the light receivers of the optical sensor units 141 to 145 with the first allowable value, the first threshold value, the second allowable value, and the second threshold value.
As a result of the comparison, if the light transmittance based on the level of the received light intensity signal of any one of the light receivers of the optical sensor units 141 to 145 exceeds the second allowable value and is less than the first allowable value, the control unit 119 continues the control related to the application of the liquid 120 described above.
On the other hand, as a result of the comparison, the control unit 119 determines that the light transmittance based on the level of the received light intensity signal of any of the light receivers of the optical sensor units 141 to 145 is greater than or equal to the first tolerance value or less than the second tolerance value. Then, the following processing is performed.

When the control unit 119 determines that the light transmittance based on the level of any received light intensity signal of the light receivers of the light sensor units 141 to 145 is equal to or greater than the first allowable value, the light receivers of the light sensor units 141 to 145 The timing at which the level of any one of the received light intensity signals becomes the first threshold is predicted. As shown in FIG. 6, the predicted timing at which the light transmittance based on the level of the received light intensity signal becomes the first threshold is the first allowable value from the initial value (for example, 40%) as shown in FIG. The time (T) until the first threshold value (for example, 80%) is reached can be obtained by the arithmetic processing based on the time until the value (for example, 60%) is reached.
Similarly, when the control unit 119 determines that the light transmittance based on the level of the received light intensity signal of any of the light receivers of the optical sensor units 141 to 145 is equal to or less than the second allowable value, the optical sensor units 141 to 145 are used. The timing at which the light transmittance based on the level of the received light intensity signal of any of the receivers becomes the second threshold is predicted. The prediction timing at which the light transmittance based on the level of the received light intensity signal becomes the second threshold, as shown in FIG. 6, the light transmittance based on the level of the received light intensity signal is the second allowable value from the initial value (for example, 40%). The time (T) until the second threshold value (for example, 20%) is reached can be obtained by a calculation process based on the time until the value (for example, 30%) is reached.

Then, the control unit 119 predicts and specifies the position of the nozzle head 106 at a prediction timing at which the light transmittance based on the level of the received light intensity signal becomes the first threshold value or the second threshold value. Hereinafter, the predicted position is referred to as a predicted position.
Further, the control unit 119 determines whether the predicted position of the nozzle head 106 with respect to the substrate 10 is within the panel region R1 or the margin region R2.

When the control unit 119 determines that the predicted position of the nozzle head 106 with respect to the substrate 10 is within the margin region R2, the control unit 119 determines that the control unit 119 has the carriage 105 and the nozzle head when the nozzle head 106 is positioned within the margin region R2 at the prediction timing. 106 is moved to the standby position. When the carriage 105 moves to the standby position, the lower end of the nozzle head 106 is closed by the sealing cap 150. Then, the control unit 119 operates the vacuum pump 113. While the operation of the supply device 116 continues, the liquid 120 in the nozzle head 106 is sucked into the cooling trap 153, so that bubbles staying in any of the couplings 131 to 135 are sucked into the cooling trap 153 together with the liquid 120. . Thereby, a defoaming process is performed.
Here, the timing at which the light transmittance based on the level of the received light intensity signal of any one of the light receivers of the optical sensor units 141 to 145 becomes the first threshold value or the second threshold value is a bubble retained in any of the joints 131 to 135 Is the timing at which the liquid 120 cannot be ejected from the nozzle head 106. If the position of the nozzle head 106 at such timing is within the margin region R2, the liquid 120 may be interrupted in the margin region R2. Accordingly, such timing is predicted, and when the predicted timing is reached, the nozzle head 106 in the margin region R2 is moved to the standby position and the defoaming process is performed, so that the liquid 120 is again discharged from the nozzle head 106. It becomes possible to discharge continuously. Therefore, the application of the liquid 120 can be suitably restarted for the next panel region R1.

On the other hand, when the control unit 119 determines that the predicted position of the nozzle head 106 with respect to the substrate 10 is within the panel region R1, the control unit 119 performs the operation when the nozzle head 106 is positioned within the margin region R2 before the predicted timing. The carriage 105 and the nozzle head 106 are moved up to. When the carriage 105 moves to the standby position, the lower end of the nozzle head 106 is closed by the sealing cap 150. Then, the control unit 119 operates the vacuum pump 113. While the operation of the supply device 116 continues, the liquid 120 in the nozzle head 106 is sucked into the cooling trap 153, so that bubbles staying in any of the couplings 131 to 135 are sucked into the cooling trap 153 together with the liquid 120. . Thereby, a defoaming process is performed.
Here, the timing at which the light transmittance based on the level of the received light intensity signal of any one of the light receivers of the optical sensor units 141 to 145 becomes the first threshold value or the second threshold value is a bubble retained in any of the joints 131 to 135 Is the timing at which the liquid 120 cannot be ejected from the nozzle head 106. If the position of the nozzle head 106 at such timing is within the panel region R1, if the liquid 120 is interrupted in the panel region R1, the productivity of the EL panel decreases. Therefore, such a timing is predicted, and the nozzle head 106 in the margin region R2 is moved to the standby position before the prediction timing (before the liquid 120 is interrupted in the panel region R1), and the defoaming process is performed. As a result, the liquid 120 can be continuously discharged from the nozzle head 106 again. Therefore, the application of the liquid 120 can be suitably restarted for the next panel region R1.

  In addition, after the carriage 105 moves to the standby position and stops, the control unit 119 opens the valves 110a to 110e. Thereby, bubbles staying in the joints 131 to 135 and the vicinity thereof are sucked together with the liquid 120 by the vacuum pump 113 via the valves 110a to 110e. Thereby, a defoaming process is performed.

  When the defoaming process is performed after the nozzle head 106 moves to the standby position, the received light intensity signals of the light receivers of the optical sensor units 141 to 145 are output to the control unit 119. And the control part 119 will stop the vacuum pump 113, if the light transmittance based on the level of the received light intensity signal input from the light receiver of the optical sensor parts 141-145 becomes an initial value (for example, 40%). Thereby, the defoaming process is completed.

  Thereafter, the control unit 119 operates the carriage 105 and the like to move the carriage 105 and the nozzle head 106 to the positions when the application is interrupted for the defoaming process. The control unit 119 restarts the operation of applying the liquid 120 ejected from the nozzle head 106 to the substrate 10 by repeating the control of the carriage 105 and the moving device 102 and the control of the feeder 116 and the mass flow controller 109.

  As described above, when all the pixel electrodes 8 a are covered with the hole injection layer 8 b and the hole injection layer 8 b is dried, the substrate 10 is transferred onto the work table 101 of the second coating apparatus 100. Then, the second coating apparatus 100 operates in the same manner, whereby a strip-shaped red light emitting layer 8c is formed on the hole injection layer 8b. Here, the work table 101 and the substrate 10 are intermittently moved in the sub-scanning direction by the moving device 102, and the moving distance is three pixels.

  Next, the substrate 10 is transferred onto the work table 101 of the third coating apparatus 100. Then, the third coating apparatus 100 operates in the same manner, whereby a strip-shaped green light emitting layer 8c is formed on the hole injection layer 8b. Here, the work table 101 and the substrate 10 are intermittently moved in the sub-scanning direction by the moving device 102, and the moving distance is three pixels.

  Next, the substrate 10 is transferred onto the work table 101 of the fourth coating apparatus 100. Then, the fourth coating apparatus 100 operates in the same manner, whereby a band-like blue light emitting layer 8c is formed on the hole injection layer 8b. Here, the work table 101 and the substrate 10 are intermittently moved in the sub-scanning direction by the moving device 102, and the moving distance is three pixels.

  As described above, the light emitting layer 8c is formed on all the hole injection layers 8b.

  If this coating apparatus 100 is used, after the light transmittance based on the level of the received light intensity signal of the light receivers of the optical sensor units 141 to 145 becomes equal to or higher than the first allowable value or equal to or lower than the second allowable value, the liquid is discharged from the nozzle head 106. The nozzle head 106 is moved to the standby position before 120 becomes unable to discharge, and the defoaming process is performed at the standby position. Therefore, the trouble that the application of the liquid 120 is interrupted due to excessive accumulation of bubbles in the joints 131 to 135 can be reduced.

In particular, the control unit 119 predicts the timing at which the light transmittance based on the level of the received light intensity signal of the light receivers of the optical sensor units 141 to 145 becomes the first threshold value or the second threshold value, and the nozzle head 106 at the predicted timing. Predict the position of. The control unit 119 determines whether the predicted position is inside the panel region R1 or the margin region R2. When it is determined that the predicted position is within the margin region R2, the nozzle head 106 is moved to the standby position when the predicted timing is reached. On the other hand, when it is determined that the predicted position is within the panel region R1, the nozzle head 106 is moved to the standby position when the nozzle head 106 is positioned within the margin region R2 before the predicted timing is reached. Thus, after moving to the standby position, the defoaming process is performed. Therefore, the liquid 120 is not interrupted in the panel region R1 of the substrate 121 without interrupting the application of the liquid 120 in the panel region R1 of the substrate 121.
Therefore, the coating apparatus 100 can satisfactorily apply the liquid 120 to the substrate 121.

[4-3] Step after Using Coating Device After forming the light emitting layer 8c on all the hole injection layers 8b, the counter electrode 8d is formed, and the counter electrode 8d covers the light emitting layer 8c and the bank 13 To do. Thereafter, the EL panel 1 is cut out by dicing.
Thus, the EL panel 1 is completed.

[5] Use of EL panel The EL panel 1 manufactured using the coating apparatus 100 is used as a display panel of various electronic devices.
For example, the EL panel 1 can be applied to the display panel 1a of the mobile phone 200 shown in FIG. Further, the EL panel 1 can be applied to the display panel 1b of the digital camera 300 shown in FIGS. Further, the EL panel 1 can be applied to the display panel 1c of the personal computer 400 shown in FIG.

100 Coating device 102 Moving device (moving unit)
105 Carriage (moving part)
106 Nozzle head (discharge unit)
107a, 107b, 107c Supply pipe 108 Liquid tank (liquid reservoir)
110a, 110b, 110c, 110d, 110e Valve 113 Vacuum pump (pressure reducing device)
116 Feeder 119 Control unit (comparator)
131, 132, 133, 134, 135 Joint 141, 142, 143, 144, 145 Optical sensor unit (bubble detection unit)
141a Emitter 141b Receiver 150 Sealing cap (defoaming part)
151 Drain pipe 152 Suction pipe 153 Cooling trap

Claims (11)

A liquid reservoir in which liquid is stored;
A discharge section for discharging the liquid;
A supply pipe piped through a joint from the liquid storage part to the discharge part;
And a bubble detection unit that is provided in or near the joint and detects a state of bubbles in the supply pipe in or near the joint. A feeder for delivering the liquid in the liquid reservoir to the supply pipe;
A moving unit that moves the discharge unit relative to the application target;
A decompression device for sucking gas;
A standby position provided in the vicinity of the application object;
A control unit for controlling the supply unit, the moving unit, the decompression device, and the bubble detection unit;
While the control unit operates the supply unit to discharge the liquid from the discharge unit and controls the moving unit to move the discharge unit relative to the application target, the bubbles When the detection unit detects that bubbles exceeding an allowable value are present, the discharge unit is moved to the standby position, and the pressure reducing device is connected to the joint to operate the pressure reducing device. The coating apparatus according to claim 1. A switching unit provided in the joint and controlled by the control unit and selectively switched between a communication state in which the supply pipe communicates with the pressure reducing device and a shut-off state in which the supply pipe is disconnected from the pressure reducing device; In addition,
The control unit switches the switching unit to the blocking state while controlling the moving unit while moving the discharge unit relative to the application target while discharging the liquid from the discharge unit,
When the bubble detection unit detects that bubbles exceeding the allowable value are present and moves the discharge unit to the standby position, the switching unit is switched to the communication state and the decompression device is operated. The coating apparatus according to claim 2. The defoaming unit is disposed at the standby position, connected to the decompression device, and performs a suction process on the discharge unit,
The control unit connects the discharge unit to the defoaming unit when the bubble detection unit detects that a bubble exceeding the allowable value exists and moves the discharge unit to the standby position. The coating apparatus according to claim 2 or 3, wherein the suction processing is performed by operating the decompression device.   The bubble detector includes a projector that projects light into the supply pipe in or near the joint, and a light receiver that emits light from the projector and emits light from the supply pipe in or near the joint. The coating apparatus according to claim 1, wherein the coating apparatus includes: A liquid reservoir in which liquid is stored;
A discharge section for discharging the liquid;
A supply pipe piped through a joint from the liquid storage part to the discharge part;
An optical sensor provided in the joint or in the vicinity thereof,
The light sensor unit emits light toward the supply pipe in or near the joint, and a light receiver that emits light from the light projector and receives light from the supply pipe in or near the joint. And a coating apparatus characterized by comprising:   The coating apparatus according to claim 6, wherein the optical sensor unit further includes a comparator that compares the received light intensity detected by the light receiver with a predetermined allowable value. A feeder for delivering the liquid in the liquid reservoir to the supply pipe;
A decompression device for sucking gas;
A switching unit that is provided in the joint and can be selectively switched between a communication state in which the supply pipe communicates with the decompression device and a shut-off state in which the supply pipe is shut off from the decompression device;
A controller that controls the feeder, the pressure reducing device, and the switching unit; and
The control unit switches the switching unit to the communication state and operates the supply unit and the decompression device when the supply pipe and the discharge unit are filled with the liquid, and the supply unit and the decompression device are The switching unit is switched to the cut-off state when the comparator determines that the received light intensity detected by the light receiver is equal to or less than the predetermined allowable value during operation. Item 8. The coating apparatus according to Item 7. A feeder for delivering the liquid in the liquid reservoir to the supply pipe;
A moving unit that moves the discharge unit relative to the application target;
A decompression device for sucking gas;
A standby position provided in the vicinity of the application object;
A controller that controls the feeder, the moving unit, the pressure reducing device, and the optical sensor unit;
The control unit controls the moving unit to move the discharge unit relative to the application target while operating the supply unit to discharge the liquid from the discharge unit. When the comparator determines that the received light intensity detected by the detector exceeds the predetermined allowable value, the discharge unit is moved to the standby position, and the pressure reducing device is connected to a front joint to The coating apparatus according to claim 7, wherein a pressure reducing device is operated. A switching unit provided in the joint and controlled by the control unit and selectively switched between a communication state in which the supply pipe communicates with the pressure reducing device and a shut-off state in which the supply pipe is disconnected from the pressure reducing device; In addition,
The control unit switches the switching unit to the communication state when the comparator determines that the received light intensity exceeds the predetermined allowable value and moves the ejection unit to the standby position. The coating apparatus according to claim 9, wherein the decompression device is operated. The defoaming unit is disposed at the standby position, connected to the decompression device, and performs a suction process on the discharge unit,
The control unit connects the ejection unit to the defoaming unit when the comparator determines that the received light intensity exceeds the predetermined allowable value and moves the ejection unit to the standby position. The coating apparatus according to claim 9 or 10, wherein the suction processing is performed by operating the decompression device.

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