JP2010099606A - Method and apparatus for droplet application - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the reliability of inspection of the droplet discharge state of a plurality of nozzles in an application head in a method and an apparatus for droplet application. <P>SOLUTION: In the method for droplet application for applying droplets discharged out of a plurality of linearly arranged nozzles 34 of an application head 22 to a substrate, light radiated from a light source 49 is received by a light receiving part 47 while holding droplets discharged out of the plurality of the nozzles 34 and the discharge states of the droplets discharged simultaneously out of the plurality of the respective nozzles 34 are determined based on the output values of the light receiving part 47. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a droplet coating method and apparatus.

  As a droplet coating method, there is a method in which droplets ejected from a plurality of nozzles arranged in a straight line on a coating head are coated on a substrate. In such a droplet application method, it is necessary to inspect whether or not there is an abnormality in the droplet discharge state such as no droplet discharge, discharge delay, and discharge bending due to the eyes of each nozzle.

In the droplet application method described in Patent Document 1, as a droplet discharge state inspection device, a light source that irradiates light that obliquely intersects the nozzle arrangement direction in the application head, and a plurality of light beams emitted from the light source are used. And a light receiving unit that receives light with a droplet discharged from the nozzle interposed therebetween. Then, when the application head is moved in a direction orthogonal to the nozzle arrangement direction and each of the plurality of nozzles sequentially traverses the light emitted from the light source toward the light receiving portion, a droplet is generated for each nozzle that traverses the light. The coating head is driven so as to discharge the liquid, and it is determined whether the discharge state of the nozzle is normal or abnormal depending on whether or not the light is blocked by the liquid droplets.
Japanese Patent Laid-Open No. 2001-113709

  In the use stage where the droplet applying device applies droplets to the product substrate, droplets are simultaneously ejected from all of the plurality of nozzles of the coating head. At this time, in the droplet applying device, the liquid supply hole is connected to one end side along the nozzle arrangement direction of the plurality of nozzles, and the recovery hole is connected to the other end side, and the liquid is supplied from the liquid supply hole side. The coating liquid is simultaneously supplied to a wide range of nozzles extending from the liquid supply hole side along the nozzle arrangement direction to the recovery hole side. For this reason, the liquid pressure of the coating liquid supplied to each nozzle is relatively low, and depending on the individuality of each nozzle, a droplet discharge bend may occur.

  However, in the inspection apparatus in the droplet discharge state described in Patent Document 1 described above, a droplet is discharged for each nozzle of the coating head, and the droplet discharge state at that time is inspected. Since droplets are ejected for each nozzle of the coating head, the liquid pressure of the coating liquid supplied to the nozzles is relatively high, and the droplets are ejected with momentum, so that ejection bending or the like hardly occurs. That is, since the operating state of the coating head in the inspection stage is different from that in the use stage, the reliability of the inspection is low.

  SUMMARY OF THE INVENTION An object of the present invention is to improve the reliability of inspection of droplet discharge states of a plurality of nozzles in a coating head in a droplet coating method and apparatus.

  According to a first aspect of the present invention, there is provided a droplet coating method in which droplets ejected from a plurality of nozzles arranged in a straight line of a coating head are coated on a substrate, and light irradiated from a light source is transmitted from the plurality of nozzles. Light is received by the light receiving unit with the discharged droplets sandwiched, and the discharge state of the droplets discharged simultaneously from each of the plurality of nozzles is determined based on the output value of the light receiving unit.

  According to a second aspect of the present invention, in the first aspect of the present invention, the light receiving section further includes a plurality of light receiving elements arranged so as to cover the arrangement range of the plurality of nozzles along the arrangement direction of the plurality of nozzles. When a plurality of light receiving elements are provided, a discharge state of droplets from each of the plurality of nozzles is determined based on an output signal of the light receiving element corresponding to each of the plurality of nozzles. .

  According to a third aspect of the present invention, in the second aspect of the invention, droplets are ejected from two different nozzles of the coating head, and the plurality of light receiving elements at this time are output based on output signals from the light receiving elements. Nozzle arrangement intervals are obtained, and light receiving elements corresponding to the plurality of nozzles are determined based on the nozzle arrangement intervals.

  According to a fourth aspect of the present invention, there is provided a droplet coating apparatus for coating droplets ejected from a plurality of nozzles arranged in a straight line on a coating head on a substrate. A light source that emits light, a light receiving unit that receives light emitted from the light source across droplets ejected from the plurality of nozzles, and an output value of the light receiving unit, based on an output value of each of the plurality of nozzles And a control unit for determining the discharge state of the simultaneously discharged droplets.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the light receiving section further includes a plurality of light receiving elements arranged so as to cover the arrangement range of the plurality of nozzles along the arrangement direction of the plurality of nozzles. Is provided.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the control unit further includes the plurality of nozzles individually based on output signals of light receiving elements corresponding to the plurality of nozzles among the plurality of light receiving elements. In this case, the discharge state of the droplets from is determined.

  According to a seventh aspect of the invention, in the sixth aspect of the invention, the control unit causes the droplets to be ejected from two different nozzles of the coating head, and based on output signals from the respective light receiving elements of the light receiving unit at this time. Thus, the arrangement interval of the plurality of nozzles is obtained, and the light receiving element corresponding to each of the plurality of nozzles is determined based on the arrangement interval of the nozzles.

  The reliability of the inspection of the discharge state of the droplets from the plurality of nozzles of the coating head can be improved, and as a result, the droplets can be accurately applied to the substrate.

  1 is a front view showing a schematic configuration of a coating apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the coating apparatus shown in FIG. 1, FIG. 3 is a longitudinal sectional view of a coating head, and FIG. FIG. 5 is a block diagram showing a control system, FIG. 6 is a schematic diagram showing a coating head, a light source, and a light receiving unit, and FIG. 7 is a diagram of a light receiving unit corresponding to the nozzle of the coating head. FIG. 8 is a schematic diagram showing a normal discharge detection state of all nozzles by the light receiving unit, FIG. 9 is a schematic diagram showing a non-discharge detection state of a certain nozzle by the light receiving unit, and FIG. FIG. 11 is a schematic diagram showing a discharge delay detection state of a certain nozzle by the light receiving unit, and FIG. 12 is a schematic diagram showing a mist detection state by the light receiving unit.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The coating apparatus according to the present invention shown in FIGS. 1 and 2 has a rectangular parallelepiped base 1. Legs 2 are provided at predetermined positions on the lower surface of the base 1, and the base 1 is horizontally supported by the legs 2.

  As shown in FIG. 2, attachment plates 3 having a predetermined width dimension are provided along the longitudinal direction at both ends in the width direction of the upper surface of the base 1. Guide members 4 are respectively provided along the longitudinal direction at one end in the width direction of the upper surfaces of the mounting plates 3. On the upper surfaces of these guide members 4, a rectangular plate-shaped X table 5 is slidably engaged with a pair of first receiving members 6 having substantially U-shaped cross sections provided in parallel on both sides of the lower surface in the width direction. It is supported together. On the upper surface of the X table 5, a mounting table 7 smaller than the X table 5 is provided. That is, the mounting table 7 is movable in the X direction along the guide member 4 via the X table 5.

  The guide member 4 is provided with a stator 4a, the first receiving member 6 is provided with a mover 6a, and the stator 4a and the mover 6a form a linear motor 8 serving as a driving means. Yes.

  For example, a glass substrate W used in an active matrix liquid crystal display device is supplied to the mounting table 7. The substrate W is sucked and held on the mounting table 7 by means such as vacuum suction or electrostatic suction. Accordingly, the substrate W held on the mounting table 7 is driven in the X direction by the X table 5.

  A gate-shaped support 11 is erected in the middle of the base 1 in the longitudinal direction so as to straddle the pair of guide members 4. A mounting member 12 made of a prism is horizontally installed on both sides of the support 11.

  A head table 19 is provided on the attachment member 12 so as to be movable along a Y direction (indicated by an arrow in FIG. 2) perpendicular to the X direction which is the driving direction of the X table 5. A first Y drive source 21 composed of a pulse motor is provided on one side of the support 11 in the width direction. The Y drive source 21 drives the head table 19 along the Y direction. The head table 19 may be driven in the Y direction by a linear motor instead of the pulse motor.

  On one side of the head table 19, a plurality of coating heads 22 that are functional thin films by an ink jet method, for example, eject a coating liquid (polyimide coating liquid) for forming an alignment film in a dot shape are arranged along the Y direction. ing. In this embodiment, for example, seven coating heads 22 are arranged in two rows in a staggered manner.

  As shown in FIGS. 3 and 4, each coating head 22 includes a head body 28. The head main body 28 is formed in a cylindrical shape, and its lower surface opening is closed by a flexible plate 29. The flexible plate 29 is covered with a nozzle plate 31, and a plurality of liquid chambers 32 are formed between the nozzle plate 31 and the flexible plate 29.

  Each liquid chamber 32 communicates with a main pipe line 31A formed in the nozzle plate 31 via a branch pipe (not shown), and the coating liquid is supplied from the main pipe line 31A via the branch pipe line to each liquid chamber. 32. One end of the main pipeline 31A is connected to a liquid supply hole 33 described later, and the other end is connected to a recovery hole 37 described later.

  The liquid supply hole 33 communicating with the liquid chamber 32 is formed at one longitudinal end of the head body 28. The coating liquid for forming the functional thin film is supplied to the liquid chambers 32 from the liquid supply holes 33. Thereby, the inside of the liquid chamber 32 is filled with the coating liquid.

  As shown in FIG. 4, the nozzle plate 31 has a plurality of nozzles 34 arranged in a staggered manner (or in a single row) in a straight line along the Y direction, which is a direction orthogonal to the transport direction of the substrate W. Yes. On the upper surface of the flexible plate 29, as shown in FIG. 3, a plurality of piezoelectric elements 35 are provided as driving means so as to face the nozzles 34.

  Each piezoelectric element 35 is supplied with a driving voltage by a driving unit 36 provided in the head main body 28. As a result, the piezoelectric element 35 expands and contracts, and the flexible plate 29 is partially deformed, so that the coating liquid is ejected in the form of dots from the nozzle 34 positioned opposite to the piezoelectric element 35, and the ejected liquid droplets are conveyed. It is applied to the upper surface of the substrate W to be applied. Accordingly, a coating pattern in which dot-shaped coating liquids are arranged in a matrix is formed on the upper surface of the substrate W. And this application | coating pattern adheres and becomes one film | membrane, when each dot-shaped application liquid flows and spreads wet.

  The recovery hole 37 communicating with the liquid chamber 32 is formed at the other longitudinal end of the head body 28. The coating liquid supplied from the liquid supply hole 33 to the liquid chamber 32 can be recovered from the recovery hole 37. That is, each head 22 can not only discharge the coating liquid supplied to the liquid chamber 32 from the nozzle 34, but also collect it from the recovery hole 37 through the liquid chamber 32.

  As shown in FIG. 1, an inspection device 41 for inspecting the discharge state of droplets discharged from the plurality of nozzles 34 of the coating head 22 is provided at one end of the guide member 4. The inspection device 41 has a first movable member 42. The first movable member 42 is provided with a pair of second receiving members 43 (only one is shown) at both ends of the lower surface in the width direction. The receiving members 43 are slidably engaged with the guide member 4. Is provided. When the discharge state of the liquid droplets discharged from the nozzle 34 is not inspected, as shown in FIG. 1, a standby position at one end in the longitudinal direction of the guide member 4, that is, a position that does not interfere with the reciprocating movement of the mounting table 7. Waiting at.

  The first movable member 42 can be driven in the X direction along the guide member 4 by the linear motor 8, and the mounting table 7 provided on the guide member 4 and the first movable member 42 are connected to each other. It can be selectively driven.

  On the upper surface of the first movable member 42, a second movable member 45 movable along the longitudinal direction of the first movable member 42 has a longitudinal direction orthogonal to the first movable member 42. Is provided.

  As shown in FIG. 1, a second Y drive source 46 formed of a pulse motor is provided at one end in the longitudinal direction of the first movable member 42, and the second movable member 46 is provided by the second Y drive source 46. 45 can be driven along the Y direction crossing the X direction, that is, along the direction in which the coating heads 22 are arranged side by side.

  A light receiving portion 47 is provided at one end in the longitudinal direction along the X direction of the second movable member 45, and a light source 49 that emits illumination light toward the light receiving portion 47 is provided at the other end.

  The light source 49 is ejected from a plurality of nozzles 34 in a direction (X direction) perpendicular to the arrangement direction (Y direction) of the nozzles 34 in a direction that intersects the ejection direction of droplets from the nozzles 34 of the coating head 22. Light is irradiated to the droplets to be formed.

  The light receiving unit 47 receives light emitted from the light source 49 with droplets ejected from the plurality of nozzles 34 of each coating head 22 interposed therebetween. The light receiving unit 47 includes, for example, a CCD line sensor, and includes a large number of light receiving elements arranged so as to cover (cover) the arrangement range of the plurality of nozzles 34 in each coating head 22 along the arrangement direction of the nozzles 34. .

  Note that a receiving tray 51 for receiving the coating liquid discharged from the nozzles 34 of the coating heads 22 is provided on the upper surface of the central portion in the longitudinal direction of the second movable member 45 as will be described later.

  FIG. 5 shows a control circuit for inspecting the ejection state of the droplets ejected from the nozzles 34 of the coating head 22 by the inspection device 41. In the figure, reference numeral 52 denotes a control unit. A timing setting device 53 is connected to the control unit 52.

  When the drive signal D1 is input from the control unit 52, the timing setting device 53 applies a discharge signal S1 that applies a voltage to each piezoelectric element 35 via the drive unit 36 provided in the coating head 22. A light emission signal S2 for emitting illumination light from the light source 49 via the light source controller 54 and a light reception signal S3 for operating the light receiving unit 47 are output in synchronization with a predetermined timing. The drive unit 36 that has received the ejection signal S1 supplies the piezoelectric element 35 with a voltage V corresponding to the voltage command signal S11 sent from the control unit 52.

  As a result, the coating liquid is discharged from the nozzle 34 of the predetermined coating head 22, and illumination light is emitted from the light source 49, and the coating liquid before being discharged from the nozzle 34 by the light receiving unit 47 and reaching the substrate W. A droplet is detected. The light emission signal S2 and the light reception signal S3 may be the same signal or different signals.

  The light receiving unit 47 that has detected the droplet of the coating liquid outputs the output value to the control unit 52 as a detection signal K. Based on the output value of the light receiving unit 47, the control unit 52 determines the ejection state of droplets from each of the plurality of nozzles 34 (with ejection, without ejection, ejection delay, ejection bending, etc.).

  The control device 52 outputs a movement signal S6 to the drive controller 55 that controls the driving of the inspection device 41 in the Y direction. Upon receiving the movement signal S6, the drive controller 55 outputs a drive signal D2 to the second Y drive source 46. Accordingly, the second movable member 45 provided with the light receiving unit 47 and the light source 49 is driven by a predetermined distance in the Y direction, and the light receiving unit 47 of the inspection device 41 is ejected from the plurality of nozzles 34 of each coating head 22. The second movable member 45 is positioned with respect to the Y direction so as to be sequentially positioned in the liquid detection range.

  When the liquid droplets ejected from the nozzle 34 with the coating head 22 cause ejection bending, the control unit 52 blocks light from the light source 49 toward another light receiving element 47 that does not correspond to the nozzle 34. The following operation is performed so that the light reception result (light-shielded state) of the other light-receiving element of the light-receiving unit 47 is not erroneously used. That is, as shown in FIG. 6, the control unit 52 determines the discharge state of the liquid droplets from each of the plurality of nozzles 34 based on the output value of the light receiving unit 47 that receives the light emitted from the light source 49. Among the many light receiving elements of the light receiving section 47, each light receiving element (J1, J2,...) Of the light receiving section 47 that has a positional relationship corresponding to each of the plurality of nozzles 34 (N1, N2,. A liquid droplet detection signal of Jn) (an output signal when light traveling from the light source 49 to the light receiving element is blocked by the liquid droplet) (K1, K2,... Kn) and liquid from each of the plurality of nozzles 34 The ejection state of the droplet is determined.

  Specifically, the control operation for determining the droplet discharge state of each of the plurality of nozzles 34 of the coating head 22 by the control unit 52 is performed as follows.

  (A) Procedure for determining the light receiving elements (J1, J2... Jn) of the light receiving section 47 corresponding to each of the plurality of nozzles 34 (N1, N2... Nn) of the coating head 22 (FIG. 7).

  (1) When the number n of nozzles 34 provided in one coating head 22 is known and it is also known that the nozzles 34 are arranged at equal intervals, as shown in FIG. The droplets are ejected from two nozzles as far as possible in the coating head 22, for example, the first and nth N1 and Nn nozzles 34 at both ends of the coating head 22, and the droplets are received by the light receiving unit. 47. At this time, the light receiving elements that output the droplet detection signals K1 and Kn are light receiving elements (J1, Jn) corresponding to the two nozzles 34 (N1, Nn), in other words, N1, Nn nozzles. 34 is a light receiving element (J1, Jn) positioned on the optical axis, and the interval La between these light receiving elements (J1, Jn) is equally divided into n-1 pitches of adjacent nozzles 34 of the coating head 22 ( Arrangement interval) p is obtained. The interval La can be obtained from the arrangement relationship of the light receiving elements obtained from the design data.

  (2) Because of the verification of p obtained in the above (1), as shown in FIG. 7B, from the other two nozzles 34 of the coating head 22, for example, two nozzles 34 of N2 and Nn-1. In the same manner as in the above (1), the application head 22 is discharged from the light receiving elements (K2, Kn-1) of the light receiving portion 47 corresponding to the two nozzles 34 (N2, Nn-1). The pitch p of the adjacent nozzles 34 is obtained. Thereby, the pitch p of the nozzles 34 adjacent to each other in the coating head 22 obtained in the above (1) is calculated.

  (3) The positions of the light receiving elements of the light receiving section 47 corresponding to the plurality of nozzles 34 of the coating head 22 correspond to the first and nth N1 and Nn nozzles 34 at both ends of the coating head 22, respectively. The light receiving elements (J2... Jn-1) at the respective positions through the pitch p of (1) and (2) described above are obtained between the light receiving elements (J1, Jn). As a result, as shown in FIG. 7C, each light receiving element (J1, J2... Jn) of the light receiving portion 47 corresponding to each nozzle 34 (N1, N2... Nn) of the coating head 22 is provided. It is determined. In the light receiving portion 47, each light receiving element that is not in a positional relationship corresponding to each nozzle 34 of the coating head 22 is handled as in a mask range (M1... Mn-1) in which the output signal K is not adopted (FIG. 7). (C)).

  In the coating apparatus, if the relative positional relationship between the plurality of nozzles 34 of the coating head 22 and the light receiving elements of the light receiving unit 47 is known from the beginning, the above (1) to (3) are unnecessary.

(B) Normal ejection detection state of all nozzles 34 of the coating head 22 (FIG. 8)
Drops are simultaneously ejected from all the nozzles 34 (N1, N2,... Nn) of the coating head 22, and each of the light receiving portions 47 corresponding to each of all the nozzles 34 (N1, N2,. When all of the light receiving elements (J1, J2,... Jn) output droplet detection signals (K1, K2,... Kn), it is determined that all the nozzles 34 are in a normal ejection state (FIG. 8). .

(C) No discharge state (FIG. 9) or bent discharge state (FIG. 10) of the nozzle 34 with the coating head 22
Drops are simultaneously ejected from all the nozzles 34 (N1, N2... Nn) of the coating head 22, and the light receiving element (J2) of the light receiving unit 47 corresponding to the nozzle 34 (N2) with the coating head 22 detects the droplets. When the signal (K2) is not output, it is determined that the nozzle 34 is in a no-discharge state (FIG. 9) or a discharge bend state (FIG. 10).

(D) Discharge delay state of the nozzle 34 with the coating head 22 (FIG. 11)
The droplets are simultaneously ejected from all the nozzles 34 (N1, N2,... Nn) of the coating head 22, and light reception corresponding to other nozzles 34 (N1, Nn, etc.) other than the nozzle 34 (N2) with the coating head 22 is performed. After the light receiving element (J1, Jn, etc.) of the unit 47 outputs the droplet detection signal (K1, Kn, etc.), the light receiving element (J2) of the light receiving part 47 corresponding to the certain nozzle 34 (N2) is changed over time. When the droplet detection signal (K2) is output with a delay, it is determined that the certain nozzle 34 is in the discharge delay state (FIG. 11).

(E) Mist detection state by the light receiving unit 47 (FIG. 12)
When the droplets are simultaneously ejected from all the nozzles 34 (N1, N2... Nn) of the coating head 22 a plurality of times (three times in the example of FIG. 12) at the discharge timing of the time interval t, the coating head 22 is present. The light receiving elements (J1, Jn, etc.) of the light receiving section 47 corresponding to the nozzles 34 (N1, Nn, etc.) other than the nozzle 34 (N2) use the droplet detection signals (K1, Kn, etc.) as the droplet ejection timing. On the other hand, the light receiving element (J2) of the light receiving unit 47 corresponding to the nozzle 34 (N2) outputs a droplet detection signal (K2) according to the second ejection timing among the three ejections. However, when the droplet detection signal (K2) is not output in response to the first and third ejection timings, the certain nozzle 34 is in a non-ejection state, and light reception corresponding to the certain nozzle 34 of the light receiving unit 47 is performed. Element (J2) detects mist m (Fig. 12). To determine the one. The mist detection by the light receiving unit 47 is not mistaken for the detection of the droplet discharged from the nozzle 34.

According to the present embodiment, the following operational effects can be obtained.
(a) In the inspection stage of the droplet discharge state from the coating head 22, the light from the light source 49 is emitted from the direction that intersects the discharge direction of the droplet from the nozzle 34 and is orthogonal to the arrangement direction of the nozzle 34. While irradiating the liquid droplets simultaneously ejected from the plurality of nozzles 34, the light irradiated from the light source 49 is received by the light receiving unit 47 with the liquid droplets simultaneously ejected from the plurality of nozzles 34 interposed therebetween. Based on the output value 47, the ejection state of the droplets from each of the plurality of nozzles 34 is determined. That is, as in the use stage for the product substrate W, droplets can be simultaneously ejected from all of the plurality of nozzles 34 of the coating head 22, and the ejection state of the droplets from each nozzle 34 at that time can be inspected. . The operating state of the coating head 22 in the inspection stage is the same as in the use stage, and the reliability of the inspection is improved.

  (b) The light receiving section 47 includes a large number of light receiving elements (J1, J2,... Jn) arranged so as to cover the arrangement range of the plurality of nozzles 34 along the arrangement direction of the nozzles 34. Based on output signals (K1, K2,... Kn) of a number of light receiving elements (J1, J2,... Jn) of the light receiving section 47, the ejection state of droplets from each of the plurality of nozzles 34 is accurately inspected. be able to.

  (c) Out of the many light receiving elements (J1, J2... Jn), the output signals (K1, K2... Kn of the light receiving elements (J1, J2... Jn) corresponding to the nozzles 34 respectively. ) To determine the discharge state of droplets from each of the plurality of nozzles 34. Whether or not the liquid droplets discharged from each of the plurality of nozzles 34 block light from the light source 49 toward the light receiving elements (J1, J2,... Jn) corresponding to the nozzle 34, in other words, the light receiving elements (J1). , J2... Jn) to determine whether the discharge state of the nozzle 34 is normal or abnormal based on the output signals (K1, K2... Kn). When determining the discharge state of droplets from each of the plurality of nozzles 34, the output signals (K1, K2,... Kn) of the light receiving elements (J1, J2... Jn) corresponding to the nozzles 34 are not used. Output signals (K1, K2,... Kn) of other light receiving elements (J1, J2,... Jn) are not used. As a result, even if the liquid droplets discharged from the nozzle 34 cause discharge bends and block light directed from the light source 49 toward other light receiving elements (J1, J2... Jn) not corresponding to the nozzle 34. The output signals (K1, K2... Kn) of the other light receiving elements (J1, J2... Jn) are ignored, and the light reception results (light shielding) of the other light receiving elements (J1, J2... Jn) are ignored. Misuses due to misuse of (status).

  (d) Before using the output signals (K1, K2... Kn) of the light receiving elements (J1, J2... Jn) corresponding to the plurality of nozzles 34 in the above (c), different coating heads 22 are used. A plurality of nozzles 34 (N1) are ejected from two nozzles 34 (for example, N1, Nn) based on output signals (K1, Kn) from the respective light receiving elements (J1, Jn) of the light receiving unit 47 at this time. , N2... Nn), and the light receiving elements (J1, J2... Jn) corresponding to each of the plurality of nozzles 34 are determined based on the arrangement interval p of the nozzles 34. To do. Thereby, even when the relative positional relationship between each nozzle 34 of the coating head 22 and each light receiving element (J1, J2... Jn) of the light receiving portion 47 is not known in advance, the light receiving element (J1) corresponding to each nozzle 34 is obtained. , J2... Jn) can be determined correctly.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

  That is, in the above-described embodiment, when the state of droplet discharge from each of the plurality of nozzles 34 is determined, the droplets are discharged simultaneously from all, but the present invention is not limited to this, and some nozzles 34 The droplets may be discharged simultaneously. In short, it is sufficient that the droplet discharge state can be determined under the same conditions as in the use stage in which droplets are applied to the product substrate. Therefore, the liquid droplets are simultaneously discharged from the nozzles 34 used in the use stage. What is necessary is just to discriminate the discharge state of a droplet.

  Further, the liquid droplets discharged from one nozzle 34 have been described as being received by one light receiving element of the light receiving unit 47. However, the size of the light receiving element is the same as the size of the light receiving element (in the arrangement direction of the nozzles 34). In the case of larger than (dimension), light from the light source is simultaneously blocked by one droplet, for example, two light receiving elements, for example, two droplets, that is, a droplet is detected. In such a case, a set of a plurality of light receiving elements that simultaneously detect one droplet is determined, a set of light receiving elements corresponding to each nozzle 34 is determined, and an output signal from each set of light receiving elements is used as an output signal. Based on this, it is preferable to inspect the discharge state of the droplets from each nozzle 34.

  Further, the light emitted from the light source 49 is applied to the liquid droplets simultaneously ejected from the plurality of nozzles 34 from the direction orthogonal to the arrangement direction of the nozzles 34, and this light is received by the light receiving unit 47. As explained. However, the present invention is not limited to this, and the light irradiated from the oblique direction to the droplets simultaneously ejected from the plurality of nozzles 34 may be received by the light receiving unit 47. It suffices if the droplets simultaneously ejected from the plurality of nozzles 34 can be detected by the light receiving element of the light receiving unit 47.

FIG. 1 is a front view showing a schematic configuration of a coating apparatus according to an embodiment of the present invention. FIG. 2 is a side view of the coating apparatus shown in FIG. FIG. 3 is a longitudinal sectional view of the coating head. FIG. 4 is a bottom view showing the lower surface on which the nozzles of the coating head are formed. FIG. 5 is a block diagram showing a control system. FIG. 6 is a schematic diagram showing a coating head, a light source, and a light receiving unit. FIG. 7 is a schematic diagram showing a procedure for determining the light receiving element of the light receiving unit corresponding to the nozzle of the coating head. FIG. 8 is a schematic diagram showing a normal ejection detection state of all nozzles by the light receiving unit. FIG. 9 is a schematic diagram illustrating a non-ejection detection state of a nozzle by the light receiving unit. FIG. 10 is a schematic diagram illustrating a discharge bending detection state of a certain nozzle by the light receiving unit. FIG. 11 is a schematic diagram illustrating a discharge delay detection state of a certain nozzle by the light receiving unit. FIG. 12 is a schematic diagram showing a mist detection state by the light receiving unit.

Explanation of symbols

22 coating head 34, N1, N2... Nn nozzle 47 light receiving section 49 light source 52 control section J1, J2... Jn light receiving elements K1, K2... Kn droplet detection signal (output signal)

Claims (7)

In a liquid droplet application method for applying liquid droplets discharged from a plurality of nozzles arranged in a straight line on a coating head onto a substrate,
The light emitted from the light source is received by the light receiving unit across the droplets ejected from the plurality of nozzles,
2. A droplet coating method, comprising: determining a discharge state of droplets simultaneously discharged from each of the plurality of nozzles based on an output value of the light receiving unit. When the light receiving unit includes a plurality of light receiving elements arranged so as to cover the arrangement range of the plurality of nozzles along the arrangement direction of the plurality of nozzles,
2. The droplet application method according to claim 1, wherein among the plurality of light receiving elements, a droplet discharge state from each of the plurality of nozzles is determined based on an output signal of a light receiving element corresponding to each of the plurality of nozzles. .   Droplets are ejected from two different nozzles of the coating head, and the arrangement intervals of the plurality of nozzles are obtained based on output signals from the respective light receiving elements of the light receiving unit at this time, and based on the arrangement intervals of the nozzles The droplet coating method according to claim 2, wherein a light receiving element corresponding to each of the plurality of nozzles is determined. In a droplet coating apparatus for coating droplets ejected from a plurality of nozzles arranged in a straight line on a coating head on a substrate,
A light source for irradiating light to droplets ejected from the plurality of nozzles;
A light receiving unit that receives light emitted from the light source with droplets ejected from a plurality of nozzles interposed therebetween;
A droplet applying apparatus comprising: a control unit that determines a discharge state of droplets discharged simultaneously from each of the plurality of nozzles based on an output value of the light receiving unit.   5. The droplet applying device according to claim 4, wherein the light receiving unit includes a plurality of light receiving elements arranged so as to cover an arrangement range of the plurality of nozzles along an arrangement direction of the plurality of nozzles.   The said control part discriminate | determines the discharge state of the droplet from each of these nozzles based on the output signal of the light receiving element corresponding to each of these nozzles among the said many light receiving elements. Droplet coating device.   The control unit discharges droplets from two different nozzles of the coating head, obtains an arrangement interval of the plurality of nozzles based on an output signal from each light receiving element of the light receiving unit at this time, and arranges the nozzles The droplet applying device according to claim 6, wherein a light receiving element corresponding to each of the plurality of nozzles is determined based on the interval.

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