KR101471356B1 - Method for verifying dropping of a liquid crytal droplet and liquid crystal dispenser implementing the same - Google Patents

Abstract

A method for confirming whether liquid crystal droplets are discharged or not is disclosed. The present invention provides a method for confirming ejection of a liquid crystal droplet, comprising: a first step of providing a liquid crystal droplet ejection signal to a head unit; A second step of storing a current position of a nozzle included in the head unit when the first sensing unit provided in the head unit does not sense a liquid crystal drop; A third step of moving the second sensing unit provided in the head unit to the stored position after completing the liquid crystal droplet ejection operation; A fourth step of, at the stored position, photographing a region within the mother substrate on which the liquid crystal droplet of the second sensing unit provided in the head unit should be ejected; And a fifth step of receiving a photographed image from the second sensing unit and confirming whether a liquid crystal droplet is actually discharged. The method of confirming whether or not the liquid crystal droplet is ejected according to the present invention can automatically confirm whether or not the liquid crystal droplet is actually ejected, and can eject the liquid crystal droplet again when the liquid crystal droplet is not actually ejected.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal dispenser (LCD)

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of confirming whether a liquid crystal droplet is discharged or not, and a liquid crystal dispenser performing the method.

An LCD (Liquid Crystal Display) uses a refractive index anisotropy of a liquid crystal to display a desired image. To this end, the LCD includes a mother substrate having a color filter layer to implement color, a mother substrate having a plurality of pixels, and a liquid crystal layer provided between the mother substrates. Each pixel has a thin film transistor (Thin Film Transistor).

With the above-described configuration, the LCD drives the liquid crystal molecules constituting the liquid crystal layer by the driving element, and controls the amount of light transmitted through the liquid crystal layer to display an image.

The liquid crystal dispenser ejects liquid crystal droplets onto the mother substrate. Here, the liquid crystal droplet is a liquid crystal discharged in a droplet shape through a nozzle.

The liquid crystal dispenser has a head unit.

The head unit includes a nozzle and an optical sensor.

Upon receiving the liquid crystal droplet discharge signal from the control unit, the head unit discharges the liquid crystal droplets D onto the mother substrate MP through the nozzles.

The optical sensor senses a liquid crystal droplet ejected through a nozzle.

When the liquid crystal droplet is sensed, the optical sensor converts the sensed value into a signal and sends the signal to the control unit.

When a signal comes from the optical sensor, the controller counts one liquid crystal drop.

On the other hand, when the optical sensor fails, the optical sensor can not send a signal to the control unit even though the liquid crystal droplet is normally discharged. If the control unit does not receive a signal from the optical sensor even though it has given a signal to eject the liquid crystal droplet to the head unit, the control unit generates an alarm.

The control unit generates an alarm through the speaker by sound or through a display unit to the screen.

Alternatively, the pump (hereinafter referred to as "pump") which provides the pressure for supplying the liquid crystal to the head unit may fail, the nozzle may be clogged, or air bubbles may be generated, and the liquid crystal droplets may not actually be ejected. At this time, the optical sensor can not detect liquid crystal droplets and can not send signals to the control unit. If the control unit does not receive a signal from the optical sensor even though it has given a signal to eject the liquid crystal droplet to the head unit, the control unit generates an alarm.

In either case, when an alarm is generated, the operator must go to the mother substrate and visually confirm whether the liquid crystal droplet has actually been discharged. Particles may fall from the operator onto the mother substrate while the operator visually confirms the mother substrate, thereby contaminating the mother substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to automatically check whether a liquid crystal droplet is actually discharged or not.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a liquid droplet ejection method, A second step of storing a current position of a nozzle included in the head unit when the first sensing unit provided in the head unit does not sense a liquid crystal drop; A third step of moving the second sensing unit provided in the head unit to the stored position after completing the liquid crystal droplet ejection operation; A fourth step of, at the stored position, photographing a region within the mother substrate on which the liquid crystal droplet of the second sensing unit provided in the head unit should be ejected; And a fifth step of receiving a photographed image from the second sensing unit and confirming whether a liquid crystal droplet is actually discharged.

Further, the above object can be achieved by a head supporting apparatus comprising: a head support; A head unit provided on the head support and including a first sensing unit sensing droplets of liquid crystal droplets and a second sensing unit sensing liquid droplets after discharging liquid droplets; And a control unit for receiving an image of a mother substrate area on which a liquid crystal droplet should be ejected from the second sensing unit and confirming whether the liquid crystal droplet is actually ejected when the first sensing unit fails to sense the liquid crystal droplet And a liquid crystal dispenser.

Further, the above object can be achieved by a head supporting apparatus comprising: a head support; A head unit provided on the head support and including a first sensing unit sensing droplets of liquid crystal droplets and a second sensing unit sensing liquid droplets after discharging liquid droplets; And when the first sensing unit fails to sense the liquid crystal droplet, the second sensing unit emits a laser or an ultrasonic wave to the mother substrate area on which the liquid crystal droplet should be discharged to obtain the moving distance of the laser or the ultrasonic wave, And a controller for checking whether the liquid crystal droplet is actually discharged based on the distance.

The method of confirming whether or not the liquid crystal droplet is ejected according to the present invention can automatically check whether the liquid crystal droplet is actually ejected on the mother substrate and can eject the liquid crystal droplet again when the liquid crystal droplet is not actually ejected. Therefore, it is not necessary for the operator to visually confirm whether or not the liquid crystal droplet is actually discharged. Since the operator does not need to go to the mother substrate, a particle from the worker is dropped on the mother substrate and is prevented from contaminating the mother substrate.

Hereinafter, a method of confirming ejection of a liquid crystal droplet according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view illustrating a liquid crystal dispenser according to an embodiment of the present invention.

1, the liquid crystal dispenser includes a frame 11, a stationary table 12, a stage 13, first drive units 14, second drive units 16, a third drive unit (not shown) 17, a head support 15, head units 20, and an electronic balance 30.

The fixing table 12 is fixed to the upper portion of the frame 11.

The stage 13 is installed on the fixed table 12 so as to be movable in the Y-axis direction. A mother substrate (MP) is placed on the stage (13).

The first drive units 14 are installed on both sides of the fixed table 12 one by one.

One end of the first drive unit 14 is coupled to the fixed table 12 and the other end is coupled to the head support 15. The first drive unit 14 moves the head support 15 in the Y-axis direction. As the first drive unit 14, a linear motor is used.

The head support 15 traverses the upper side of the stage 13.

The head units 20 are installed on the head support 15.

The electronic balance (30) is installed in the frame (11). The electronic balance (30) measures the weight of the liquid crystal droplet.

The second drive units 16 are installed on both sides of the fixed table 12 one by one.

One end of the second drive unit 16 is coupled to the stationary table 12 and the other end is coupled to the stage 13. The second drive unit 16 is located between the stationary table 12 and the stage 13. [ The second drive unit 16 moves the stage 13 in the Y-axis direction. As the second drive unit 16, a linear motor is used.

One end of the third drive unit 17 is coupled to the head support 15 and the other end is coupled to the head unit 20. The third drive unit 17 is located between the head support 15 and the head unit 20. The third drive unit 17 moves the head unit 20 in the X-axis direction. As the third drive unit 17, a linear motor is used.

2 is an enlarged view of a portion A in Fig. The dashed arrow indicates a path through which light travels from the light emitting portion to the light receiving portion.

2, the head unit 20 includes a body 21, a nozzle support 22, a sensor support 24, a first sensing unit 25, a second sensing unit 26 ).

The nozzle support 24 is installed at the bottom of the body 21. [

The sensor support 24 is installed at the bottom of the nozzle support 22.

The sensor support 24 comprises a first sensor support 24a and a second sensor support 24b.

The sensor support 24 is provided with a first sensing unit 25.

As the first sensing unit 25, an optical fiber sensor is used.

The first sensing unit 25 includes a light emitting unit 25a emitting light, a light receiving unit 25b receiving light, an amplifier (not shown), an optical cable connecting the light emitting unit 25a and the amplifier, 25b and an optical cable connecting the amplifier.

The amplifier includes a signal processing unit and a power supply unit.

The light emitting portion 25a is installed on the first sensor support 24a.

The light receiving portion 25b is installed on the second sensor support 24b so as to face the light emitting portion 25a.

A nozzle (N) is installed below the nozzle support (22).

The nozzle N is located between the first sensor support 24a and the second sensor support 24b.

And liquid droplets are ejected through the nozzles N.

The second sensing unit 26 is installed in the body 21.

The second sensing unit 26 is a camera that photographs an area on the mother substrate on which the liquid crystal droplet should be discharged, converts the captured image into a signal, and transmits the signal to the control unit.

Alternatively, the second sensing unit 26 is a laser sensor that emits a laser beam onto an area on a mother substrate, converts a moving distance of the laser beam into a signal, and transmits the signal to a controller.

Alternatively, the second sensing unit 26 is an ultrasonic sensor that emits ultrasonic waves to a region on the mother substrate, converts the movement distance of the ultrasonic waves into signals, and transmits the signals to the control unit.

When a liquid crystal droplet is present in the area on the mother substrate, the laser or ultrasonic waves are reflected by colliding with the liquid crystal droplet before being reflected on the mother substrate before being reflected. The controller determines the presence or absence of liquid crystal droplets by the short and long moving distance.

In this embodiment, a camera is used as the second sensing unit 26.

FIG. 3 is a diagram showing a state in which no liquid crystal droplet is present in a region on the mother substrate which the second sensing unit of FIG. 2 photographs. The area A within the mother substrate taken by the second sensing unit 26 is the inside of the rectangular frame shown in FIG.

FIG. 4 is a view showing a state in which a liquid crystal droplet passes between the light receiving unit and the light emitting unit of FIG. 2;

The liquid crystal droplets are ejected through the nozzles N.

The liquid crystal droplets pass between the light emitting portion 25a and the light receiving portion 25b.

The first sensing unit 25 senses the liquid crystal droplet to obtain a sensing value.

Here, the sensing value is a numerical value of the amount of light received by the light receiving portion 25b.

When the liquid crystal droplet passes between the light emitting portion 25a and the light receiving portion 25b, the light emitted to the light emitting portion 25a passes through the liquid crystal droplet and is transmitted to the light receiving portion 25b. Therefore, the amount of light received by the light receiving portion 25b is reduced.

The signal processing unit sends a signal to the control unit (not shown) if the sensing value is less than the reference value.

When a signal comes from the signal processing unit, the control unit counts the number of liquid crystal droplets.

The reference value is calculated in advance before ejecting liquid crystal droplets to the mother substrate MP.

The reference value is calculated as follows.

The operator calculates a middle value between the sensing value when the liquid crystal droplet does not pass through the light emitting portion 25a and the light receiving portion 25b and the sensed value when the liquid crystal droplet passes between the light emitting portion 25a and the light receiving portion 25b. The operator sets the reference value in the signal processing section.

On the other hand, if the control unit does not receive a signal from the signal processing unit even though it sends a signal to eject the liquid crystal droplet to the head unit 20, the control unit generates an alarm.

FIG. 5 is a view showing a state in which liquid crystal droplets are present in a region on the mother substrate which the second sensing unit of FIG. 2 photographs.

The second sensing unit 26 photographs the area on the mother substrate.

The inside of the rounded portion O in which the liquid crystal droplet exists in the region A is dark and the outside of the rounded portion in which the liquid crystal droplet is not present in the region A appears bright.

The second sensing unit 26 converts the photographed image to a control unit.

More specifically, light and dark in the area A are converted into signals and sent to the control unit.

The control unit confirms the presence of liquid crystal droplets in the area A by using the signal received from the second sensing unit 26.

FIG. 6 is a flowchart illustrating a method for confirming ejection of a liquid crystal droplet according to an exemplary embodiment of the present invention.

Referring to FIGS. 1 and 6, a method of confirming ejection of a liquid crystal droplet according to an embodiment of the present invention includes a first step S11 of giving a liquid crystal droplet ejection signal to the head unit 20; A second step (S12) of storing the current position of the nozzle provided in the head unit (20) when the first sensing unit (25) provided in the head unit (20) fails to sense the liquid crystal droplet; A third step (S13) of stopping the operation of ejecting the liquid crystal droplets and generating an alarm when the number of signals that the first sensing unit (25) can not detect because the number of signals that can not be detected by the first sensing unit (25) A fourth step (S14) of moving the second sensing unit (26) provided in the head unit (20) to a stored position after completing the liquid crystal droplet ejection operation; A fifth step (S15) of capturing an area on the mother substrate where the second sensing unit (26) provided in the head unit (20) should eject the liquid crystal droplet at the stored position; A sixth step (S16) of receiving an image photographed by the second sensing unit (16) and confirming whether the liquid crystal droplet is actually discharged; And a seventh step (S17) of performing an operation of ejecting the liquid crystal droplets onto the mother substrate at the stored position when the liquid crystal droplet is not actually ejected and generating an alarm when the liquid crystal droplet is actually ejected do.

In the first step S11, the control unit (not shown) moves the head unit 20 to a predetermined position on the mother substrate MP. The control unit gives a signal to the head unit 20 to eject liquid droplets to the mother substrate through the nozzles N. [

If the first sensing unit 25 fails to sense the liquid crystal droplet even though the control unit gives the signal to the head unit 20 to discharge the liquid crystal droplet in the second step S12, And stores the current position of the nozzle in the controller.

In the third step S13, the set value is the number of signals that the operator determines that there is no need to proceed with ejection of liquid crystal droplets because there is an abnormality in the first sensing unit 25 or the pump.

For example, suppose the set value is 20.

If the number of liquid crystal droplets that the first sensing unit 25 can not detect is 21, the operation of ejecting liquid crystal droplets is interrupted. At this time, the operator checks the first sensing unit 25 and the pump.

In the fourth step S14, the control unit moves the second sensing unit 26 to the position stored in the second step S12. If the stored positions are plural, the second sensing unit 26 moves to each of the stored positions and performs the fifth step (S15) to the seventh step (S17).

In the fifth step S15, the second sensing unit 26 photographs the area A where the liquid crystal droplet should be discharged.

The second sensing unit 26 converts the light and dark in the area A into a signal and sends it to the control unit.

In the sixth step S16, the controller confirms whether the liquid crystal droplet is actually discharged by receiving the signal from the second sensing unit 26. [

As shown in FIG. 3, the controller determines that there is no liquid crystal droplet if there is no dark circle portion O in which the liquid crystal droplet exists in the region A, and there is no difference in light and shade in the region A. Therefore, it is automatically confirmed that the liquid crystal droplet has not actually been ejected by the control unit without depending on the naked eye of the operator.

On the other hand, as shown in FIG. 5, the controller determines that there is a liquid crystal droplet if there is a dark region in the region A where the liquid crystal droplet exists in the region A and the dark circled portion O exists therein. Therefore, it is automatically confirmed that the liquid crystal droplet has actually been discharged by the control unit without depending on the naked eye of the operator.

In the seventh step S17, when it is confirmed that the liquid crystal droplet actually exists, the control unit generates an alarm. The control unit generates an alarm through the speaker by sound or through a display unit to the screen.

When an alarm occurs, the operator checks the first sensing unit 25.

When it is confirmed that the liquid crystal droplet does not actually exist, the control unit gives a signal to the head unit 20 to eject the liquid crystal droplet to the mother substrate at the stored position. Upon receiving the signal, the head unit 20 ejects droplets of liquid crystal onto the mother substrate through the nozzles N.

1 is a perspective view illustrating a liquid crystal dispenser according to an embodiment of the present invention.

2 is an enlarged view of a portion A in Fig.

FIG. 3 is a diagram showing a state in which no liquid crystal droplet is present in a region on the mother substrate which the second sensing unit of FIG. 2 photographs.

FIG. 4 is a view showing a state in which a liquid crystal droplet passes between the light receiving unit and the light emitting unit of FIG. 2;

FIG. 5 is a view showing a state in which liquid crystal droplets are present in a region on the mother substrate which the second sensing unit of FIG. 2 photographs.

FIG. 6 is a flowchart illustrating a method for confirming ejection of a liquid crystal droplet according to an exemplary embodiment of the present invention.

Claims (10)

A method for confirming ejection of a liquid crystal droplet of a liquid crystal dispenser, A first step in which the control unit of the liquid crystal dispenser gives a liquid crystal droplet ejection signal to the head unit; A second step of storing the current position of the nozzle provided in the head unit when the first sensing unit including the light receiving unit and the light emitting unit provided below the nozzle support of the head unit can not sense the liquid crystal droplet; A third step of moving the head unit to move the second sensing unit including the camera provided in the head unit to the stored position in the second step after the liquid crystal droplet discharging operation is completed; A fourth step of, at the stored position, photographing a region within the mother substrate on which the liquid crystal droplet of the second sensing unit provided in the head unit should be ejected; And And checking whether the liquid crystal droplet is actually discharged by receiving the image photographed by the second sensing unit. The method according to claim 1, wherein, in the second step, Wherein the third step to the fifth step are executed in each of the stored positions. The liquid crystal display device according to claim 1, wherein, when the number of signals that can not be sent to the control unit because the first sensing unit does not sense the liquid crystal droplets is greater than the set value, And generating an alarm when the liquid crystal droplet is not ejected. 4. The method according to claim 3, wherein the set value is the number of signals that the operator determines that there is no need to proceed to discharge the liquid crystal droplet due to an error in the first sensing unit or the pump. 4. The method of claim 3, wherein, when the alarm occurs, Wherein the operator checks the first sensing unit and the pump. 2. The liquid crystal display device according to claim 1, wherein when it is confirmed that the liquid crystal droplet is not actually discharged at the stored position in the second step according to the confirmation of the fifth step, And generating an alarm when it is confirmed that the liquid crystal droplet has actually been discharged at the stored position in the second step in accordance with the confirmation of the fifth step, How to check whether the droplet is discharged. The method according to claim 6, wherein, when the alarm occurs, an operator checks the first sensing unit. Head support; A second sensing part provided on the head support and including a first sensing part including a light receiving part for sensing liquid crystal droplets at the time of discharging the liquid crystal droplets and a camera for sensing liquid crystal droplets after discharging the liquid crystal droplets, A head unit provided on the body; And And a control unit for receiving an image of the mother substrate area on which the liquid crystal droplet should be ejected from the second sensing unit to confirm whether the liquid crystal droplet is actually ejected when the first sensing unit does not sense liquid crystal droplets LCD dispenser. Head support; A first sensor part provided on the head supporter and including a light receiving part for sensing a liquid crystal droplet at the time of ejecting the liquid crystal droplet and a light emitting part and a laser sensor or an ultrasonic sensor for sensing the liquid crystal droplet after ejection of the liquid crystal droplet A head unit having one second sensing unit on the body; And When the first sensing unit does not sense the liquid crystal droplet, the second sensing unit senses a reflected signal by emitting a laser or an ultrasonic wave to the mother substrate area where the liquid crystal droplet should be discharged, And a control unit for checking whether the liquid crystal droplet is actually discharged based on the movement distance after the liquid crystal droplet is obtained. The liquid ejecting apparatus according to claim 8 or 9, wherein the controller stores a current position of a nozzle provided in the head unit when the first sensing unit fails to sense the liquid crystal droplet, And moves the head unit to move the second sensing unit to the stored position.

Images