IP Library Granted Patent US 7,785,655
Granted Patent B2
US 7,785,655 · App. 11/987,741 · Granted Aug 31, 2010

Liquid crystal dispensing system and method of dispensing liquid crystal material using same

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Quick Facts
Patent No.
US 7,785,655
App. No.
11/987,741
Granted
Aug 31, 2010
Kind
B2
Abstract

A liquid crystal dispensing system includes a container to contain liquid crystal to be dispensed, a discharge pump to receive the liquid crystal from the container and to discharge the liquid crystal, a nozzle to dispense the liquid crystal discharged from the discharge pump onto a substrate, and a control unit to control a dispensing amount of liquid crystal discharged from the discharge pump and to compensate the dispensing amount when the dispensing amount of liquid crystal exceeds a limitation value.

Claims (29)

1. A liquid crystal dispensing method, comprising the steps of:

calculating a dispensing amount and a dispensing position of liquid crystal and setting a liquid crystal dispensing system;

driving a substrate and to position a liquid crystal dispensing system at the dispensing position;

controlling a fixation angle of a discharge pump by driving a second motor in accordance with the calculated dispensing amount;

operating the discharge pump by driving a first motor to dispense liquid crystal onto the substrate;

measuring a dispensing amount of liquid crystal dispensed onto the substrate;

calculating a differential value between the measured dispensing amount and the preset dispensing amount;

comparing the differential value with a second limitation value;

comparing the differential value with a first limitation value;

converting the differential value into a pulse value when the differential value is greater than the first limitation value and less than the second limitation value; and

inputting the converted pulse value to the second motor and controlling a fixation angle of the discharge pump.

2. The method of claim 1 , wherein the first motor and the second motor are servo motors.

3. The method of claim 1 , wherein the second motor is a step motor.

4. The method of claim 1 , wherein the step of calculating a dispensing amount and a dispensing position of liquid crystal, comprises the steps of:

inputting characteristic information of the substrate and the liquid crystal;

calculating a total dispensing amount based on the information; and

calculating a single dispensing amount and a dispensing position of liquid crystal based on the calculated total dispensing amount.

5. The method of claim 1 , wherein the step of controlling a fixation angle of a discharge pump includes the steps of:

converting the calculated dispensing amount into a pulse value;

inputting the converted pulse value to a second motor and driving the second motor; and

operating a controlling member for controlling an angle of a discharge pump by the second motor.

6. The method of claim 1 , wherein the step of measuring a dispensing amount of liquid crystal includes the steps of:

dispensing liquid crystal with a predetermined number of times;

dispensing liquid crystal into a container provided at a gravimeter with a predetermined number of times; and

calculating a single dispensing amount of liquid crystal.

7. The method of claim 1 , wherein the step of controlling a dispensing of liquid crystal further includes the step of stopping the dispensing when the differential value exceeds the second limitation value.

8. The method of claim 1 , wherein the step of controlling a dispensing of liquid crystal further includes the step of performing the current dispensing continuously when the differential value is less than the first limitation value.

9. The method of claim 1 , wherein the first limitation value corresponds to 0.3% of a preset dispensing amount of liquid crystal.

10. The apparatus of claim 1 , wherein the second limitation value corresponds to 0.5% of a preset dispensing amount of liquid crystal.

Assignments (5)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 13, 2013
From: TOP ENGINEERING CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 029982/0647 →
CORRECTIVE ASSIGNMENT TO CORRECT THE THE NAME OF THE SECOND ASSIGNEE TOP ENGINEERING CO., LTD. PREVIOUSLY RECORDED ON REEL 020954 FRAME 0879. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Apr 2, 2012
From: RYU, JOUNG-HO; KWAK, SOO-MIN; SON, HAE-JOON; AN, MAN-HO; KIM, JOON-YOUNG; RYU, DO-HYUN; LEE, SEUNG-SOO
To: LG.PHILIPS LCD CO., LTD.; TOP ENGINEERING CO., LTD.
Reel/Frame 027975/0782 →
CHANGE OF NAME Recorded Oct 17, 2008
From: LG.PHILIPS LCD CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 021754/0045 →
CORRECTED REEL 020247 FRAME 0750 Recorded May 8, 2008
From: RYU, JOUNG HO; KWAK, SOO-MIN; SON, HAE-JOON; AN, MAN-HO; KIM, JOON-YOUNG; RUY, DO-HYUN; LEE, SEUNG-SOO
To: L.G. PHILLIPS LCD CO., LTD.; TOP ENGINEERING CO.
Reel/Frame 020954/0879 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 4, 2007
From: RYU, JOUNG HO; KWAK, SOO-MIN; SON, HAE-JOON; AN, MAN-HO; KIM, JOON-YOUNG; RYU, DO-HYUN; LEE-SEUNG-SOO
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 020247/0750 →