Sealant dispenser and control method thereof

Abstract

Disclosed is a sealant dispenser for more precisely dispensing a sealant onto a substrate, and a control method thereof. The sealant dispenser includes a stage on which a substrate is mounted; a nozzle for dispensing a sealant while making a relative motion with the substrate; a syringe coupled to the nozzle, for storing the sealant; and a distance sensor installed on both sides of a lower portion of the syringe, for measuring a vertical distance between a principal plane of the substrate and an outlet of the nozzle. According to the principles of the present invention, because the nozzle and the syringe have substantially the same central axis, the response speed of the sealant to be dispensed is increased and the start point and the end point of paste pattern are more precisely dispensed. Also, by minimizing the distance between the nozzle and a measuring point provided by the distance sensor, it becomes possible to dispense the sealant at higher precision.

1 . A sensor, comprising:
 a light emitting part that emits a beam of light;   a light receiving part that receives a portion of the beam of light after it has been reflected from an interrogated surface, wherein the light receiving part determines a distance from the sensor to the interrogated surface, in part, based on a phase difference of the received light as the sensor is moved relative to the interrogated surface; and   a supporting part that supports the light emitting part and the light receiving part, wherein the light emitting part and the light receiving part are positioned on opposite sides of a syringe mounting portion that receives and mounts a syringe of a sealant on the supporting part.   
   
   
       2 . The sensor according to  claim 1 , wherein the supporting part is arranged above the light receiving part and the light emitting part. 
   
   
       3 . The sensor according to  claim 1 , wherein the supporting part is provided with a coupling hole between the light emitting part and the light receiving part, and wherein the coupling hole is designed to receive a syringe of a sealant. 
   
   
       4 . The sensor according to  claim 1 , wherein the supporting part comprises:
 a first support that supports the light emitting part; and   a second support that supports the light receiving part.   
   
   
       5 . The sensor according to  claim 1 , wherein the light emitting part and the light receiving part are separate elements that are each installed on the supporting part. 
   
   
       6 . The sensor according to  claim 1 , wherein the light emitting part, the light receiving part, and the supporting part are combined as one body. 
   
   
       7 . The sensor according to  claim 1 , wherein the sensor is for use with a sealant dispenser that includes a stage on which a substrate is mounted and a syringe for dispensing a sealant while at least one of the syringe and the stage are moved with respect to each other, wherein the light emitting part and the light receiving part are mounted on opposite sides of a syringe mounting portion of the supporting part, and wherein the sensor measures a vertical distance between the substrate and the syringe. 
   
   
       8 . The sensor according to  claim 7 , wherein the supporting part is arranged above the light emitting part and the light receiving part, and wherein the supporting part comprises a coupling hole that receives and mounts a syringe of a sealant between the between the light emitting part and the light receiving part. 
   
   
       9 . The sensor according to  claim 7 , wherein the coupling hole of the supporting part mounts a syringe of sealant such that a central axis of the syringe, and a central axis of a dispensing nozzle of the syringe, are substantially aligned with the central axis of the opening. 
   
   
       10 . The sensor according to  claim 7 , wherein the light emitting part and light receiving part are mounted on the supporting part such that a central axis of the light beam emitted by the light emitting part and a central axis of a direction of focus of the light receiving part converge at a point adjacent to a location of a nozzle of a syringe mounted in the coupling hole of the support. 
   
   
       11 . The sensor of  claim 10 , further comprising a position adjusting device which operates to adjust a position of the syringe mounting portion relative to the light emitting part and light receiving part. 
   
   
       12 . The sensor of  claim 11 , wherein the position adjusting device maintains a minimum separation distance between a nozzle of a syringe mounted in the syringe mounting portion and a measuring point at which light from the light emitting part is reflected from an interrogated surface located under the sensor. 
   
   
       13 . The sensor according to  claim 7 , wherein a central axis of the light beam emitted by the light emitting part and a central axis of a direction of focus of the light receiving part converge at a position located slightly to one side of a location of a nozzle of a syringe mounted in the coupling hole of the support. 
   
   
       14 . The sensor according to  claim 1 , wherein the light receiving part outputs a signal that is indicative of a distance between the supporting part and a substrate positioned below the sensor.