JP2009175708A - Liquid crystal dripping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal dripping device which drips a liquid crystal onto a substrate in order to form a liquid crystal layer. <P>SOLUTION: At least one nozzle is moved relatively to a loaded substrates. A liquid crystal supply part supplies the liquid crystal to the nozzle so that the liquid crystal is dripped onto the substrate from the nozzle. A sensor for fault detection detects whether the liquid crystal is dripped successfully or not on the lower side of the nozzle while the liquid crystal is dripped by the liquid crystal supply part with the nozzle moved. After the end of dripping of the liquid crystal, a sensor for repair is moved to a position where poor dripping of the liquid crystal has been detected by the sensor for fault detection, and determines whether the liquid crystal has been dripped successfully or not and calculates a deficiency of the liquid crystal. A control part controls the liquid crystal supply part so that the liquid crystal is dripped through the nozzle by only the deficient of the liquid crystal calculated by the sensor for repair. Consequently, all steps from a step of detecting whether the liquid crystal is dripped successfully or not to a repair step are automated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal dropping device that drops liquid crystal on a substrate for forming a liquid crystal layer in manufacturing a liquid crystal display device.

  A liquid crystal display (LCD) is superior in visibility to a cathode ray tube (CRT) and has not only lower average power consumption but also less heat generation than a CRT of the same screen size. . As a result, LCDs are attracting attention as next-generation display devices in cell phones, computer monitors, TV fields, etc., together with plasma display panels (PDPs) and field emission displays (FEDs). Yes.

  Generally, a TFT (Thin Film Transister) LCD panel includes a TFT array substrate and a color filter array substrate. The two substrates are separated by about 4 to 5 μm, and a liquid crystal layer is formed between them. The sealant joins the two substrates around the screen display area, while preventing moisture and contaminants from flowing into the liquid crystal layer.

  Meanwhile, there is a liquid crystal dropping method among various methods for forming a liquid crystal layer. The liquid crystal dropping method is a method in which after a liquid crystal is dropped in a space limited by a sealant on a substrate to form a liquid crystal layer, the substrates are bonded together, and then the sealant is cured and bonded. In order to form a liquid crystal layer by a liquid crystal dropping method, a liquid crystal dropping device is used.

  The liquid crystal dropping device operates to drop the liquid crystal from the nozzle on the substrate while moving the nozzle to which the liquid crystal is supplied from a syringe in which the liquid crystal is stored relative to the substrate. At this time, the liquid crystal dropping device drops the liquid crystal with a set dropping amount to form a liquid crystal layer.

  However, in the process of dropping the liquid crystal, a drop drop may occur due to bubbles being mixed into the liquid crystal supplied to the nozzle. The defective dropping causes a liquid crystal dropping defect in which the total dropping amount of the liquid crystal actually dropped after the liquid crystal dropping is less than the set amount.

  According to the prior art, after the operator confirms the dropping failure with the naked eye, the liquid crystal dropping device is manually operated and repaired by the operator's judgment. However, a skilled worker is required when repairing by hand after confirming dripping defects with the naked eye. Further, when the worker is absent, the subsequent process does not proceed until the worker returns to the site and repairs the drip failure, and thus the productivity may decrease.

  In addition, although it is not defective in dropping, when the amount of liquid crystal dropped by one drop is less than the fixed amount, it is difficult for the operator to visually determine how much the amount of liquid crystal dropped is insufficient. Thereby, there may be a problem that it is difficult to accurately repair a liquid crystal dropping defect.

  An object of the present invention is to provide a liquid crystal dropping device that solves the above-described problems and that can automate all processes from the process of detecting the quality of liquid crystal dropping to the repairing process. .

  In order to achieve the above object, a liquid crystal dropping device according to the present invention includes at least one nozzle that moves relative to a loaded substrate, and a liquid crystal applied to the nozzle so that the liquid crystal is dropped from the nozzle onto the substrate. A liquid crystal supply unit for supplying liquid, a defect detection sensor for detecting whether or not the liquid crystal is dropped on the lower side of the nozzle while the liquid crystal is being dropped by the liquid crystal supply unit while the nozzle is moving, and after the liquid crystal is dropped A repair sensor that moves to a position where a liquid crystal dropping defect is detected by the defect detection sensor, determines whether or not the liquid crystal is dropped, and calculates a liquid crystal shortage amount; and a liquid crystal shortage amount calculated by the repair sensor And a control unit that controls the liquid crystal supply unit so that liquid crystal is dropped from the nozzle only.

  According to the present invention, all processes from the process of detecting whether or not the liquid crystal is dropped to the repair process can be automated. This eliminates the need for a skilled worker, and even if the worker is absent, the liquid crystal dropping defect can be automatically repaired. As a result, the subsequent steps can be smoothly performed, and productivity is not reduced.

  In addition, according to the present invention, in the case where the amount of liquid crystal is insufficient, even if it is difficult to visually determine how much the liquid crystal amount is insufficient, the liquid crystal shortage amount can be accurately calculated and the liquid crystal can be dropped by the liquid crystal shortage amount. . Thereby, the liquid crystal dropping defect can be easily repaired.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram illustrating a liquid crystal dropping device according to an embodiment of the present invention.

  Referring to FIG. 1, the liquid crystal dropping device 100 includes at least one nozzle 111, a liquid crystal supply unit 120, a defect detection sensor 130, a repair sensor 140, and a control unit 150.

  The nozzle 111 operates so as to be relatively movable with respect to the loaded substrate 10. The nozzle 111 may form a liquid crystal layer on the substrate 10 by supplying liquid crystal from the liquid crystal supply unit 120 and discharging the liquid crystal onto the substrate 10.

  The liquid crystal supply unit 120 supplies the liquid crystal to the nozzle 111 so that the liquid crystal is dropped onto the substrate 10 from the nozzle 111. The liquid crystal supply unit 120 can be controlled by the control unit 150 so that the liquid crystal is dropped from the nozzle 111 in a set amount.

  The defect detection sensor 130 detects whether or not the liquid crystal is dropped while the liquid crystal supply unit 120 moves the liquid crystal from the nozzle 111 onto the substrate 10 while the nozzle 111 is moving. That is, the defect detection sensor 130 detects whether or not the liquid crystal is accurately dropped from the nozzle 111 by a set amount every time the nozzle 111 moves at a constant interval.

  The liquid crystal dropping failure may occur due to the reason that bubbles are mixed into the liquid crystal supplied to the nozzle 111. For example, there is a dropping failure in which no liquid crystal is dropped at the position where the liquid crystal is dropped, or a non-quantitative drop where the amount of liquid crystal dropped is less than the fixed amount.

  Information about the liquid crystal dropping defect detected from the defect detection sensor 130 can be provided to the controller 150. The control unit 150 recognizes the position of the nozzle 111 corresponding to the time point when the information about the liquid crystal dropping defect is provided from the defect detection sensor 130 as the liquid crystal dropping defect position, and stores the liquid crystal dropping defect position.

  After the liquid crystal dropping is completed, the repair sensor 140 moves to the position where the liquid crystal dropping defect is detected by the defect detection sensor 130 and determines whether the liquid crystal dropping is good or bad. The movement of the repair sensor 140 can be controlled by the control unit 150 that stores a liquid crystal dropping defect position. When the liquid crystal dropping failure is detected, the repair sensor 140 calculates a liquid crystal shortage amount. Information about the liquid crystal deficiency can be provided to the controller 150.

  The control unit 150 controls the liquid crystal supply unit 120 so that liquid crystal is dropped from the nozzle 111 onto the substrate 10 by the liquid crystal deficiency calculated by the repair sensor 140 and repaired. In this process, the control unit 150 can control the nozzle 111 to move to a position where a liquid crystal dropping defect is detected. In addition, the control unit 150 controls the entire liquid crystal dropping apparatus 100 to drop the liquid crystal on the substrate 10 by a set amount.

  The operation example of the liquid crystal dropping apparatus 100 configured as described above will be described as follows.

  If a liquid crystal dropping failure such as a dropping failure or a fixed quantity unreachable dropping occurs while the liquid crystal dropping is progressing from the nozzle 111, the failure detection sensor 130 detects the quality of the liquid crystal dropping and provides it to the control unit 150. The control unit 150 moves the repair sensor 140 to the liquid crystal dropping defect position when the liquid crystal dropping is completed while the liquid crystal dropping defect position is being recognized and stored.

  The repair sensor 140 determines whether the liquid crystal is dropped or not, and if the liquid crystal is dropped, calculates a liquid crystal deficiency amount and provides it to the control unit 150. The control unit 150 controls the liquid crystal supply unit 120 so that liquid crystal is dropped from the nozzle 111 onto the substrate 10 by an amount of liquid crystal deficiency. Thereby, the liquid crystal dropping defect is repaired, and the liquid crystal layer is formed with the dropping amount set on the substrate 10.

  As described above, all processes from the process of detecting whether or not the liquid crystal is dropped to the repair process are automated. Therefore, compared with the process in which the operator confirms whether or not the liquid crystal is dropped with the naked eye and then repairs the liquid crystal dropping device manually operated according to the operator's judgment, a skilled worker is unnecessary. Further, even if the worker is absent, the liquid crystal dropping defect is automatically repaired, so that subsequent processes can proceed smoothly. As a result, productivity does not decrease. If the amount of liquid crystal is insufficient, the liquid crystal deficiency can be accurately calculated and liquid crystal can be dripped only by the amount of liquid crystal deficiency, even though it is difficult to determine with the naked eye how much the amount of liquid crystal is insufficient. Thereby, the liquid crystal dropping defect can be easily repaired.

  Meanwhile, the nozzle 111 can be mounted on the nozzle mounting block 112 of the head unit 110 so that the nozzle 111 can move relative to the substrate 10. Here, the head unit 110 is supported by the head support portion 102, and the head support portion 102 is provided on the frame 101 so as to be horizontally movable in one direction. At the same time, the head unit 110 is provided so as to be horizontally movable in a direction perpendicular to the moving direction of the head support portion 102. Thereby, the nozzle 111 attached to the head unit 110 can move relative to the substrate 10.

  When a large number of unit panels are formed on the lower glass substrate over a large area to increase productivity, a plurality of nozzles 111 may be provided. The unit panel corresponds to an LCD panel adopted for each LCD. The plurality of nozzles 111 are arranged at least one for each unit panel to drop liquid crystal. As a result, the liquid crystal layer is simultaneously formed on a large number of unit panels, thereby improving productivity.

  The liquid crystal supply unit 120 may include a syringe 121 and a pump module 122 in which liquid crystal is stored to supply liquid crystal to the nozzle 111. The pump module 122 is configured to apply a discharge pressure to the liquid crystal when the liquid crystal is supplied from the syringe 121 to the nozzle 111, thereby discharging the liquid crystal from the nozzle 111. The pump module 122 is configured to have a valve function for opening and closing the flow of liquid crystal between the syringe 121 and the nozzle 111, thereby supplying the liquid crystal from the syringe 121 to the nozzle 111 by a set amount.

  As another example, the liquid crystal supply unit 120 may include a pneumatic supply device instead of the pump module 122. The air pressure supply device is configured to supply air or gas having a predetermined pressure into the syringe 121 and apply discharge pressure to the liquid crystal, thereby discharging the liquid crystal from the nozzle 111.

  On the other hand, the defect detection sensor 130 is arranged below the nozzle 111 and can detect a liquid crystal dropping defect while liquid crystal dropping proceeds. The defect detection sensor 130 may be a laser sensor. As shown in FIG. 2, the laser sensor includes a light emitting unit 131 that emits a laser beam and a light receiving unit 132 that receives light emitted from the light emitting unit 131 and processes a light reception signal.

  The light emitting unit 131 and the light receiving unit 132 are arranged separately on both sides of the nozzle 111 below the nozzle 111. The light emitting unit 131 is arranged so that the emitted light passes below the nozzle 111, and the light receiving unit 132 is arranged so that it can receive the emitted light from the light emitting unit 131.

  The light emitting unit 131 can include a large number of light emitting parts to widen the detection area. For this reason, the light emitting portions can be arranged at a predetermined interval along the horizontal direction. A large number of light emitting portions make it possible to detect the drop of the liquid crystal droplets even when the liquid crystal droplets dropped from the nozzle 111 are not vertically dropped but inclined.

  If it is determined that the received light signal obtained during the set time from the time when the nozzle 111 moves to the liquid crystal dropping position to a certain temporary point has a certain value, the light receiving unit 132 determines that the liquid crystal dropping defect such as a dropping defect is present. Can be recognized.

  That is, during the set time, as shown in FIG. 3A, the liquid crystal may drop from the nozzle 111 and may not pass between the light emitting unit 131 and the light receiving unit 132. Then, the light emitted from the light emitting unit 131 travels as it is and enters the light receiving unit 132. Therefore, the received light signal acquired during the set time has a constant value within the allowable error range. In such a case, the light receiving unit 132 determines that the light reception signal acquired during the set time has a constant value, and recognizes that the liquid crystal droplet has not dropped as a drop defect.

  On the other hand, during the set time, as shown in FIG. 3B, the liquid crystal can drop from the nozzle 111 and pass between the light emitting unit 131 and the light receiving unit 132. Then, the light emitted from the light emitting unit 131 is reflected by the liquid crystal droplets while the liquid crystal droplets pass and does not enter the light receiving unit 132. Therefore, the light reception signal values acquired before and after the liquid crystal droplet passes between the light emitting unit 131 and the light receiving unit 132 and the liquid crystal droplet are acquired while passing between the light emitting unit 131 and the light receiving unit 132. The received light signal value is different. In such a case, the light receiving unit 132 recognizes that the liquid crystal droplet has dropped.

  If there is a difference between the received light signal waveform acquired during the set time and the reference signal waveform, the light receiving unit 132 can recognize the liquid crystal dropping failure.

  That is, if the amount of liquid crystal dropped from the nozzle 111 during the set time is less than or greater than the fixed amount, the shape of the liquid crystal droplet that is defective is different from the shape of the liquid crystal droplet that is the fixed amount. As a result, the received light signal waveform obtained from the light receiving unit 132 for the defective liquid crystal droplets is different from the received light signal waveform obtained from the light receiving unit 132 for the fixed liquid crystal droplets.

  The light receiving unit 132 stores the received light signal waveform acquired for the liquid crystal droplet, which is a fixed amount, as a reference signal waveform. The light receiving unit 132 compares the received light signal waveform acquired for the liquid crystal droplet falling from the nozzle 111 with the reference signal waveform, and recognizes that it is a fixed amount of liquid crystal droplet if it is determined to be the same. The light receiving unit 132 determines that the two waveforms are the same if the difference value between the two waveforms satisfies the allowable error range.

  When it is determined that there is a difference between the acquired light reception signal waveform and the reference signal waveform, the light receiving unit 132 recognizes that the liquid crystal droplet is defective. The light receiving unit 132 determines that the two waveforms are different if the difference value between the two waveforms is outside the allowable error range. On the other hand, the light receiving unit 132 may be provided with a signal processing unit that receives light and converts it into an electrical signal, and processes the converted electrical signal.

  As described above, the light emitting unit 131 emits light, and the light receiving unit 132 processes the light reception signal to detect a liquid crystal dropping failure, so that the liquid crystal dropping failure can be detected as a non-contact method. Accordingly, since no influence is exerted on the liquid crystal dropped from the nozzle 111 in the process of detecting the liquid crystal dropping defect, the liquid crystal dropping defect due to the detection process does not occur. As another example, the defect detection sensor 130 may be composed of another non-contact vision sensor.

  On the other hand, the defect detection sensor 130 may further include a liquid crystal scattering prevention cover 136. The liquid crystal scattering prevention cover 136 prevents the liquid crystal dropped from the nozzle 111 from colliding with the substrate 10 and splashing again toward the nozzle 111, thereby preventing inflow between the light emitting unit 131 and the light receiving unit 132. Thereby, the liquid crystal dropping defect can be accurately detected.

  The liquid crystal scattering prevention cover 136 may be disposed on the lower side of the light emitting unit 131 and the light receiving unit 132, and may have a structure in which a hole 136a is formed at a portion corresponding to the lower portion of the nozzle 111.

  On the other hand, the repair sensor 140 is a vision sensor, and as shown in FIG. 4A, an image is acquired at a position (EP) where a liquid crystal dropping defect is detected, and the acquired image is processed to obtain a liquid crystal. The quality of dripping can be determined. Here, if it is determined that the repair sensor 140 is inadequate in dropping, the repairing sensor 140 can output the amount of liquid crystal of one drop to the control unit 150 as the liquid crystal shortage amount. After the liquid crystal dropping is finished, when the controller 150 recognizes that there is only a dropping failure, the nozzle 111 is moved to the position (EP) where the dropping failure has occurred, as shown in FIG. The amount of liquid crystal is discharged.

  If it is determined that the fixed quantity drop has not been achieved or the quantitative quantity drop has been exceeded, the repair sensor 140 measures the volume of the quantitative quantity drop or the quantitative quantity drop from the acquired image. Thereafter, the repair sensor 140 can calculate the liquid crystal deficiency amount or the liquid crystal excess amount by comparing the measured value with the reference value, and output the calculated amount to the control unit 150. Here, the reference value corresponds to the volume value of the quantitative drop.

  There are various methods for measuring the volume of the non-quantitative drop or the volume of the quantitative excess drop from the image acquired by the repair sensor 140. An example of the measurement method will be described as follows. The acquired image may include hue information that varies depending on the height of the surface of the dropped liquid crystal droplet. Using this, the repair sensor 140 can calculate the volume of the dropped liquid crystal droplets after converting into the height data of the surface of the dropped liquid crystal droplets based on the acquired hue data of the image. .

  On the other hand, the liquid crystal may remain at the end portion of the nozzle 111 after the dropping failure or the fixed quantity unsuccessful dropping. In this case, the residual liquid crystal is dropped together in the subsequent dropping process, and there may be a fixed amount dropping excessively. As described above, when there are both inadequate drip or a fixed quantity incomplete quantity drop and a fixed quantity excess drop, after the liquid crystal drop is finished, the control unit 150 is set to a value that reflects the liquid crystal excess quantity in the input liquid crystal deficiency quantity. The liquid crystal deficiency amount is calculated by comparing with the liquid crystal dropping amount value.

  When determining that the liquid crystal is insufficient, the control unit 150 moves the nozzle 111 to a position where the dropping failure or the fixed quantity unsuccessful dropping has occurred, and discharges the liquid crystal from the nozzle 111 by the liquid crystal shortage amount.

  Here, the control unit 150 can cause the liquid crystal to be dropped by moving the nozzle 111 directly above the position where the dropping failure or the fixed quantity unsuccessful dropping has occurred. As another example, the control unit 150 may cause the liquid crystal to be dropped by moving the nozzle 111 to the side where the dropping failure or the fixed quantity unsuccessful dropping has occurred. In this case, even if bubbles remain at the position where the dropping failure or the non-quantitative drop has occurred, the liquid crystal can be dropped onto the remaining bubbles without being immediately dropped onto the remaining bubbles. Therefore, the phenomenon that the remaining bubbles are mixed into the liquid crystal layer can be prevented by dropping the liquid crystal onto the remaining bubbles.

  On the other hand, the repair sensor 140 extracts an image that is determined to be the same as the acquired image and the previously input image, and calculates a liquid crystal deficiency amount or a liquid crystal excess amount corresponding to the extracted image. The data can be output to the control unit 150.

  Here, the pre-input image is an image in which a liquid crystal shortage amount or a liquid crystal excess amount is set based on an image with respect to a predetermined amount of liquid crystal droplets. Then, the repair sensor 140 determines that the two images are the same if the difference between the two images to be compared satisfies the allowable error range. Meanwhile, the repair sensor 140 may include an image processing unit that acquires an image and processes the acquired image in the control unit 150.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. That is, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the claims, and equivalents of all such appropriate changes and modifications are also within the scope of the present invention. It must be regarded as belonging to the scope of the invention.

  The present invention is applicable to a technical field related to a liquid crystal dropping device.

It is a block diagram with respect to the liquid crystal dropping apparatus by one Embodiment of this invention. FIG. 2 is a perspective view illustrating a defect detection sensor and a repair sensor mounted on the head unit in FIG. 1. 3 is a diagram for explaining a process of detecting whether or not a liquid crystal droplet is dropped from a nozzle by the defect detection sensor shown in FIG. 2. 3 is a diagram for explaining a process of detecting whether or not a liquid crystal droplet is dropped from a nozzle by the defect detection sensor shown in FIG. 2. 3 is a diagram for explaining a process of repairing a liquid crystal dropping defect after the liquid crystal dropping defect is determined by the repair sensor illustrated in FIG. 2. 3 is a diagram for explaining a process of repairing a liquid crystal dropping defect after the liquid crystal dropping defect is determined by the repair sensor illustrated in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100: Liquid crystal dropping apparatus 111: Nozzle 120: Liquid crystal supply part 130: Defect detection sensor 140: Repair sensor 150: Control part 10: Board | substrate 110: Head unit 112: Nozzle mounting block 102: Head support part 101: Frame 121: Syringe 122: Pump module 131: Light emitting unit 132: Light receiving unit 136: Liquid crystal scattering prevention cover 136a: Hole

Claims (9)

At least one nozzle that moves relative to the loaded substrate;
A liquid crystal supply unit that supplies liquid crystal to the nozzle so that liquid crystal is dropped from the nozzle onto the substrate;
While the nozzle is moving, during liquid crystal dropping by the liquid crystal supply unit, a defect detection sensor that detects the quality of liquid crystal dropping under the nozzle,
After the liquid crystal dropping is finished, the defect detection sensor moves to a position where the liquid crystal dropping defect is detected, determines whether the liquid crystal dropping is good or not, and calculates a liquid crystal shortage amount,
A control unit that controls the liquid crystal supply unit so that liquid crystal is dropped from the nozzle by the amount of liquid crystal deficiency calculated by the repair sensor;
A liquid crystal dropping device comprising: The repair sensor is
2. The liquid crystal dropping device according to claim 1, comprising a vision sensor, acquiring an image at a position where a liquid crystal dropping defect is detected, and processing the acquired image to determine whether the liquid crystal dropping is good or bad. . The repair sensor is
If it is determined that there is a drip failure, the amount of liquid crystal of one drop is output to the control unit as a liquid crystal shortage amount,
If it is determined that the sensor for repairing is a non-quantitative drop or a quantitative excess drop, after measuring the volume of the non-quantitative drop or the volume of the quantitative excess drop from the acquired image, The liquid crystal dropping device according to claim 2, wherein the liquid crystal deficiency amount or the liquid crystal excess amount is calculated by comparing the two values and output to the control unit. When there are both inadequate drip or fixed quantity drop and overdose drop,
The control unit calculates a liquid crystal shortage amount when it is determined that the liquid crystal shortage is determined by comparing a value reflecting the liquid crystal excess amount with the liquid crystal shortage amount input and a set liquid crystal dropping amount value. The liquid crystal dropping device according to claim 3. The repair sensor is
Comparing the acquired image with a pre-input image and extracting an image determined to be the same, and outputting a liquid crystal deficiency amount or a liquid crystal deficiency amount corresponding to the extracted image to the control unit. The liquid crystal dropping device according to claim 2. When there are both inadequate drip or fixed quantity drop and overdose drop,
The control unit calculates a liquid crystal shortage amount when it is determined that the liquid crystal shortage is determined by comparing a value reflecting the liquid crystal excess amount with the liquid crystal shortage amount input and a set liquid crystal dropping amount value. The liquid crystal dropping device according to claim 5. The controller is
7. The liquid crystal is dropped by moving the nozzle directly above or next to a position where a liquid crystal dropping defect is detected. Liquid crystal dropping device. The defect detection sensor is:
Consisting of a laser sensor,
The laser sensor is
The light emitting unit arranged so that the emitted laser light passes below the nozzle, and a light receiving unit that receives light emitted from the light emitting unit and processes a light reception signal. 2. A liquid crystal dropping device according to 1. The light receiving unit is
From the time when the nozzle moves to the liquid crystal dropping position to a certain temporary point, it is determined that the received light signal has a constant value during the set time, or the acquired received light signal waveform is compared with the reference signal waveform. The liquid crystal dropping device according to claim 8, wherein if it is determined that there is a liquid crystal, it is recognized as a liquid crystal dropping failure.

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