KR20070118218A - Sealant dispenser and method for controlling the same - Google Patents

Abstract

A sealant dispenser and a control method thereof are provided to lower a necessary discharge pressure of sealant by making a flow and discharge path of sealant linear, and improve coating precision by exactly sensing an interval between a substrate and a nozzle. A sealant dispenser comprises a measuring unit for measuring a relative distance between a main surface of a substrate(110) mounted in a table and an outlet of a nozzle(130) mounted in an syringe(120), and a coating head unit configured so that the syringe filled with sealant(150) and the nozzle can be disposed on the same axis. The measuring unit is a laser displacement sensor(140) configured by a light emitting unit(142) and a light receiving unit(144). The nozzle of the head unit is interposed between the light emitting unit and the light receiving unit of the laser displacement sensor.

Description

Sealant dispenser and method for controlling the same}

The present invention relates to a sealant dispenser, and more particularly, to a sealant dispenser capable of applying a sealant to a substrate more precisely with a low discharge pressure of the sealant discharged from a nozzle.

In recent years, liquid crystal displays (LCDs) have the advantage that the volume and weight of the liquid crystal display (LCD) can be innovatively reduced, compared to conventional cathode ray tubes (CRT). It is applied to computer monitors or TVs in place of the applied image display apparatuses, and is being widely used.

In the liquid crystal display, a predetermined space is formed between the upper substrate and the lower substrate, and the liquid crystal is filled in the space.

For optimal operation of the liquid crystal display, a cell gap, which is a distance between the lower substrate and the upper substrate, needs to be kept constant. If the cell gap is not constant, the screen uniformity is divided over the entire screen of the liquid crystal display. Appears bad.

This cell gap is maintained by a sealant applied between the lower substrate and the upper substrate. In addition, the sealant plays a very important role such as not only maintaining the cell gap but also bonding the upper and lower substrates together.

Therefore, the pattern, width and height of the sealant are very important in the production process of the liquid crystal display, and are applied onto the substrate by the sealant dispenser.

The sealant dispenser is formed with a nozzle at the end of the injector filled with the sealant therein, and the nozzle is moved to apply a sealant having a predetermined shape to the substrate. That is, the sealant is applied in a desired pattern on the substrate while the nozzle and the substrate move relative to the X and Y axes.

Of course, the nozzle can adjust the thickness and width of the sealant to be applied by movement in the Z-axis to adjust the height with the substrate.

When the sealant of the injector is exhausted, the used injector is removed and a new injector is mounted.

1 is a diagram illustrating a head of a conventional sealant dispenser. The head of the sealant dispenser is a bracket 30 having an injector 20 for storing the sealant and a nozzle 32 coupled to the lower part of the injector 20 to apply the sealant 50. consist of.

In addition, a displacement sensor 40 for measuring the distance between the nozzle 32 and the substrate 10 is provided near the nozzle 32 of the head.

Here, the displacement sensor 40 is generally used an optical laser displacement sensor using a laser.

The laser displacement sensor 40 is inclined in the shape of "∧" the bottom surface of the light emitting portion 42 for emitting the laser 46 on one side of the inclined surface of the bottom surface, and the light emitting portion 42 and the other inclined surface The light receiving unit 44, which receives the laser 46 at predetermined intervals, is formed, and the laser 46 emitted from the light emitting unit 42 is reflected on the substrate 10 to form an image on the light receiving unit 44. ) Outputs an electric signal corresponding to a position where the laser 46 is imaged to a controller (not shown) to determine the distance.

In addition, the injector 20 and the laser displacement sensor 40 are spaced apart a predetermined interval (L), the injector 20 is mounted on the upper surface of one end, the other end is extended to the vicinity of the laser displacement sensor 40 A bracket 30 having a nozzle 32 through which the sealant 50 is discharged is formed at the bottom of the tip.

Accordingly, the laser 46 emitted from the light emitting part 42 of the laser displacement sensor 40 is reflected near the point where the sealant 50 discharged from the nozzle 32 is applied to the substrate, and thus the light receiving part 44 is received. ), The distance between the substrate 10 and the nozzle 32 is measured.

Therefore, when bending exists on the substrate 10 to which the sealant 50 is applied, the position where the laser 46 forms an image on the light receiving unit 44 is changed, so that the laser displacement sensor 40 adjusts the measured value. By transmitting to the control unit, the height of the nozzle 32 is corrected.

However, the conventional sealant dispenser as described above has the following problems.

The nozzle and the injector in which the sealant is stored are not formed on the same axis and are separated from each other. Since the flow path of the sealant is bent in an “L” shape, the pressure required for discharging the sealant is high and the viscosity is high. There is a problem that the use of large sealants is limited.

That is, the long rod-shaped bracket 30 is coupled to the injector 20 in the vertical direction, and the nozzle 32 is installed at the end of the bracket 30 so that the distance between the injectors 20 is far and wide. There was a disadvantage that the pressure required to discharge the runt is increased.

On the other hand, the conventional sealant dispenser cannot accurately detect the gap between the nozzle and the nozzle where the sealant is discharged because the gap between the position where the sealant is discharged on the substrate and the measurement point where the laser is reflected on the substrate is not accurate. The coating precision could not be improved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and improves the structure of the sealant dispenser head to straighten the flow and discharge paths of the sealant, thereby lowering the required discharge pressure of the sealant and the substrate and the nozzle. An object of the present invention is to provide a sealant dispenser capable of accurately detecting gaps and increasing coating accuracy.

In order to achieve the above object, the present invention includes a measuring means for measuring the relative distance between the main surface of the substrate mounted on the table and the discharge port of the nozzle mounted to the injector; In addition, a sealant dispenser is configured to include a sealant-filled injector and an application head portion configured to align on the same axis.

The measuring means may be a laser displacement sensor composed of a light emitting part and a light receiving part, and the nozzle of the head part is positioned between the light emitting part and the light receiving part of the laser displacement sensor.

In addition, the vision camera to check the mounting position of the injector; Adjusting unit for adjusting the coupling position of the injector: characterized in that it is configured to further include.

As described above, according to the sealant dispenser and the control method of the present invention, the following effects can be achieved.

First, the injector and the nozzle are coaxially coupled to each other so that the pressure required for the discharge of the sealant is lowered, which makes it possible to use more viscous sealant. When the sealant having the same viscosity is used, the discharge pressure discharged from the nozzle is lowered, thereby improving the applicability of the sealant.

Second, when replacing the injector, it is possible to correct the position of the nozzle so that the distance between the nozzle and the laser displacement sensor is constant, it is possible to more precisely control the application of the sealant, there is an effect that can reduce the working time.

Third, the sealant is applied more precisely because the gap between the position where the sealant is discharged on the substrate and the measuring point where the laser is reflected on the substrate can be detected more accurately. It can work.

Hereinafter, a preferred embodiment of the sealant dispenser of the present invention will be described in detail with reference to the accompanying drawings.

In addition, in the following description, the same parts as those of the related art of the sealant dispenser of the present invention will be referred to the related art described above with reference to FIG. 1, and the detailed description thereof will be omitted.

Figure 2 is a front view showing the configuration of the sealant dispenser of the present invention, Figure 3 is a side view of the main portion viewed from the direction A of Figure 2, Figure 4 is a vision camera when the nozzle and the substrate in contact with the dispenser head of Figure 2 The measurement point and the position of the nozzle taken in FIG.

The head of the sealant dispenser of the present invention is first provided with an injector (syringe) for storing the sealant.

In addition, a nozzle 130 for discharging the sealant 150 inside the injector 120 to the main surface of the substrate, that is, the surface of the substrate, is mounted at the front end of the injector 120.

In addition, a displacement sensor 140 measuring the relative distance between the discharging end of the nozzle 130 and the substrate 110 is coupled to the distal end of the injector 120.

In addition, a lifting unit (not shown) for adjusting the height of the nozzle 130 with respect to the substrate 110 is provided.

Therefore, the injector 120 is installed to be movable on the X-axis, the Y-axis, and the Z-axis with respect to the substrate 110 seated on a table (not shown), and is applied to the substrate 110. 150 is installed to adjust the pattern and thickness and width.

In addition, a vision camera 170 is provided on a bottom surface of the substrate 110 to measure the distance between the point where the distance is measured by the displacement sensor 140 and the nozzle 130.

In addition, the adjusting unit 160 for adjusting the coupling position of the injector 120 is provided.

In more detail, the injector 120 is generally formed in a cylindrical shape, and the sealant 150 is filled therein.

At this time, the nozzle 130 and the injector 120 are coupled to be positioned coaxially in the vertical direction.

In addition, the injector and the laser displacement sensor of the head portion are collinear with the laser displacement sensor when viewed in a direction (i.e., side view; FIG. 3) in which the light emitting portion and the light receiving portion of the laser displacement sensor are in a straight line. It is installed to be located in.

Therefore, the flow path of the sealant 150 filled in the injector 120 and discharged from the nozzle 130 becomes a straight line.

In addition, the displacement sensor 140 is a light emitting unit 142 for outputting the distance measuring laser toward the substrate 110, and the light receiving unit 144, the laser 146 output from the light emitting unit 142 is received. It is preferable that it is a laser displacement sensor.

Here, the light emitting unit 142 and the light receiving unit 144 of the laser displacement sensor 140 is made of one body, spaced apart from each other by a predetermined distance, the nozzle 130 between the light emitting unit 142 and the light receiving unit 144. The coupling hole 148 is formed.

Therefore, the nozzle 130 coupled to the distal end of the injector 120 is coupled to the coupling hole 148 of the laser displacement sensor 140.

Here, the nozzle 130 and the substrate 110 of the sealant dispenser shown in FIG. 2 are spaced apart by a predetermined interval. Since the spaced interval is very small, about several tens of micrometers, only the end of the nozzle 130 is enlarged. It is shown.

As shown in an enlarged portion of FIG. 2, the position of the measuring point 112 at which the laser 146 output from the light emitting unit 142 of the laser displacement sensor 140 is reflected on the substrate 110 is determined by the sealant. It is preferable that the 150 is installed to be slightly spaced apart from the point discharged from the nozzle 130 is applied to the substrate 110.

At this time, the position of the measurement point 112 is spaced apart from the position where the sealant 150 is applied to the substrate 110 is the minimum distance that the distance measurement is not interfered by the sealant 150 is applied. desirable.

This is because the position of the measuring point 112 where the laser 146 is reflected on the substrate 110 and the position of the point where the sealant 150 is discharged on the substrate 110 are the same. This is to exclude the case where the measurement is interrupted by the sealant 150 applied to the substrate 110.

Therefore, the position where the sealant 150 applied by the nozzle 130 of the height adjusting device of the sealant dispenser head of the present invention is discharged to the substrate 110 and the measuring point 112 and the constant by the laser displacement sensor 140 are constant. Since the distance is very small, the distance between the substrate 110 and the surface of the substrate 110 can be said that there is no difference in the height of the surface of the substrate 110 from the end of the nozzle 130 to the surface of the substrate 110. The actual distance is the same.

In addition, a vision camera 170 is installed below the substrate 110 at the opposite side of the nozzle 130. The vision camera 170 includes a measurement point 112 at which the laser 146 output from the laser displacement sensor 140 is reflected on the substrate 110, and a position at which the sealant 150 is discharged on the substrate 110. It measures the distance.

In addition, the adjusting unit 160 is provided to finely adjust the coupling position of the injector 120, the adjusting unit 160 is composed of a motor or the like to adjust the coupling position and the angle of the injector 120. Preferably, since the configuration of the adjustment unit 160 is obvious to those skilled in the art, a detailed description thereof will be omitted.

On the other hand, in the above embodiment, although the coupling hole is formed between the light receiving unit and the light emitting unit made of a body of the laser displacement sensor, the nozzle is coupled to the coupling hole, the light receiving unit and the light emitting unit of the laser displacement sensor are formed separately, each light receiving unit And the light emitting unit may be mounted to face each other with the nozzle interposed therebetween.

In addition, the above embodiment is a method of adjusting the distance between the nozzle 130 and the substrate 110 by changing the height of the nozzle 130 or the table (not shown) that supports the substrate without moving the nozzle The height may be adjusted to adjust the distance between the nozzle and the substrate.

When the sealant dispenser having the configuration as described above runs out of the sealant 150 inside the injector 120, the injector 120 is replaced. At this time, the nozzle is coupled to the injector 120. The position of 130 is not always constant and some errors may occur.

Accordingly, the present invention provides a control method of a sealant dispenser.

The control method of the sealant dispenser of the present invention includes a contact step of contacting the nozzle and the substrate; A measuring step of measuring the distance between the measuring point and the nozzle by the measuring means measuring the distance to the substrate: a determining step of determining whether the distance measured in the measuring step is within a set value; Correcting step of correcting the position of the nozzle when the distance measured in the measuring step is out of the set value: And, if the distance measured in the measuring step is within the set value, the distance between the nozzle and the substrate at a predetermined interval and the sealant Application step: to start the application is configured to include.

Hereinafter, a preferred embodiment of the control method of the sealant dispenser of the present invention will be described in detail.

In addition, the configuration of the sealant dispenser in the present embodiment will follow the above-described embodiment, and a detailed description thereof will be omitted.

4 is a view showing the position of the measuring point and the nozzle photographed by the vision camera when the nozzle of the sealant dispenser is in contact with the substrate. Here, reference numeral 175 is a screen shot by a vision camera.

When the injector 120 is replaced, a contact step is performed. In the contacting step, the injector 120 is lowered to make contact with the nozzle 130 and the substrate 110 such that the distance between the nozzle 130 and the substrate 110 becomes zero.

At this time, the laser 146 output from the light emitting unit 142 of the laser displacement sensor 140 is reflected on the substrate 110 to be input to the light receiving unit 144, wherein the nozzle 130 and the substrate 110 are used. Since the distance to 0 is zero, the measuring point 112, which is the point at which the laser 146 is reflected, moves to the side at a position when the nozzle 130 and the substrate 110 are spaced apart from each other.

Then, the measuring step is carried out. In the measuring step, the spaced distance d of the position where the sealant 150 is applied to the measuring point 112 and the substrate 110 is measured. This distance measurement is measured by photographing with a vision camera 170 installed in the lower portion of the substrate 110.

Here, since the substrate 110 to which the sealant 150 is applied is transparent glass, the measuring point 112 and the nozzle 130 of the laser displacement sensor 140 are projected onto the substrate 110.

At this time, since the position where the sealant 150 is applied on the substrate 110 is a vertical lower portion of the nozzle 130, and the vision camera 170 is located opposite the nozzle 130, the nozzle The position at which the 130 is projected onto the substrate 110 is regarded as the position where the sealant 150 is applied to the substrate 110, and the distance between the measuring point 112 of the laser displacement sensor 140 and the nozzle 130 ( d) is measured.

After the measuring step, a determination step is performed. In the determining step, it is determined whether the distance d between the measuring point 112 and the nozzle 130 of the laser displacement sensor 140 measured in the measuring step is within a set value. .

At this time, the set value means an appropriate range of the distance (d) between the measuring point 112 and the nozzle 130.

The set value is a value that varies depending on the kind of sealant 150, the coating pressure, the coating speed, or the like, and a detailed description thereof will be omitted since it is apparent to those skilled in the art.

If the distance d between the measuring point 112 and the nozzle 130 determined in the determination step deviates from a set value, it is determined that the injector 120 and the nozzle 130 are not in an appropriate position, and the adjusting unit 160 ) To properly position the injector 120 and the nozzle 130.

After adjusting the positions of the injector 120 and the nozzle 130, it is preferable to return to the measuring step again to measure the distance d between the measuring point 112 and the nozzle 130.

In addition, when the distance (d) between the measuring point 112 and the nozzle 130 determined in the determination step is within the set value, it is determined that the nozzle 130 is in an appropriate position to determine the distance between the nozzle 130 and the substrate 110. In accordance with the application condition of the sealant 150, an appropriate step is spaced apart and the application step of starting the application of the sealant 150 is performed.

When the distance between the nozzle 130 and the substrate 110 in the coating step is separated, the measuring point 112 of the laser displacement sensor 140 is a sealant 150 on the substrate 110, as shown in FIG. ) Is formed in the vicinity of the discharge point.

The laser displacement sensor 140 measures the height of the nozzle 130 with respect to the substrate 110 at the position where the sealant 150 is applied according to the relative movement of the nozzle 130 and the substrate 110.

If the substrate 110 is bent, the height of the point where the laser is reflected at the curved point is changed so that the position where the laser is imaged at the light receiving unit 144 of the laser displacement sensor 140 is changed so that the nozzle 130 is changed. ) Height can be measured.

In addition, the distance between the nozzle 130 and the substrate 110 measured by the laser displacement sensor 140 is sent to a controller (not shown), and in the controller (not shown), the substrate 110 is coated with the sealant 150. The thickness and width of the sealant 150 discharged to the substrate 110 are constant by adjusting the distance between the nozzle 130 and the substrate 110 by operating a lifting unit (not shown) according to the height change of the surface. It can be applied so that it is maintained.

1 is a perspective view showing a conventional sealant dispenser head,

2 is a front view showing the configuration of the sealant dispenser of the present invention;

3 is a side view of the main portion viewed from the direction A of FIG. 2;

FIG. 4 is a diagram illustrating a position of a measuring point and a nozzle photographed by a vision camera when the nozzle of the dispenser head of FIG. 2 contacts the substrate.

* Description of Signs of Major Parts of Drawings *

* 110: substrate 112: measuring point

120: injector 130: nozzle

140: laser displacement sensor 142: light emitting unit

144: light receiving unit 148: coupling hole

150: sealant 160: adjustment unit

170: vision camera

Claims (1)

Measuring means for measuring a relative distance between the main surface of the substrate mounted on the table and the discharge port of the nozzle mounted on the injector; And, A sealant dispenser comprising: an application head portion configured to have a sealant-filled injector and a nozzle positioned on the same axis.

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