KR101128907B1 - Laser machining apparatus and Method for repairing pixel defect - Google Patents

Abstract

Disclosed are a laser processing apparatus and a method of correcting a defect by irradiating a laser to a defective pixel of a liquid crystal display panel using the same. According to an aspect of the present invention, a laser processing apparatus for correcting pixel defects of a liquid crystal display panel using a laser, comprising: an imaging unit for photographing a liquid crystal display panel mounted on a stage; and an image photographed by the imaging unit To generate a pixel object, select a defective pixel object corresponding to the defective pixel among the pixel objects, and calculate a machining offset with respect to a preset machining reference point; and a laser beam whose irradiation position is adjusted according to the machining offset. A laser processing apparatus including a laser processing unit for irradiating a pixel is provided. According to this, laser processing may be performed with uniform quality regardless of various pixel shapes and sizes of the liquid crystal display panel to correct defects of the liquid crystal display panel.

Laser, imaging, pattern, alignment, defect correction

Description

Laser machining apparatus and method for repairing pixel defects using the same

The present invention relates to a laser processing apparatus and a method of correcting a defect by irradiating a laser to a defective pixel of a liquid crystal display panel using the same.

A liquid crystal display panel is a display that converts various electrical information into visual information by using a change in liquid crystal transmittance according to an applied voltage. Liquid crystal display panels are widely used in terms of low operating voltage and low power consumption and can be used as a portable device.

The liquid crystal display panel is classified into a TN mode, a VA mode, an IPS mode, and the like according to its operation mode. It is classified according to the arrangement method of the liquid crystal molecules and the alignment method of the liquid crystal molecules by voltage, which greatly affects the viewing angle and response speed of each mode.

In TN (Twisted Nematic) mode, when the voltage is OFF, the liquid crystal molecules are stretched horizontally, passing through the light in the backlight, and the screen becomes 'white'. If the voltage is gradually applied in this state, the liquid crystal molecules rise vertically and block the light from the backlight when the maximum voltage is reached, and the screen becomes 'black'. In VA (Vertical Alignment) mode, the liquid crystal molecules are vertical when the voltage is OFF and horizontally when the voltage is maximum. The state of the screen is 'black' when the voltage is off and 'white' when the voltage is full. When the voltage is off, the light of the backlight is almost completely blocked by the polarizing plate without being influenced by the liquid crystal molecules, so that it is possible to express pure black, thereby increasing the contrast ratio. In the In-Plane-Switching (IPS) mode, the amount of backlight light is controlled by rotating horizontally lying liquid crystal molecules in the horizontal direction. Since the vertical inclination of the liquid crystal molecules does not occur, there is a feature that there is little change in luminance and color according to the viewing angle.

Such liquid crystal display panels have various pixel defects such as color defects, pixel defects, dark spots, and short circuits. For example, a bright spot defect is a defect caused by the pixel being always on and always displaying white, and a dark spot defect is a defect caused by the pixel being always turned off and always displaying black.

As such, repair work using a laser has been recently applied to correct pixel defects including bright spot defects.

Repairing may be performed by directly processing a thin film transistor array (TFT) -array portion corresponding to a defective pixel in a liquid crystal display panel or by processing an organic material layer with a laser. Direct processing of the thin film transistor array may be performed by destroying the thin film transistor in the pixel region, shorting the gate and data line lines, or removing the pixel electrode and the common electrode. Processing of the organic material layer may be performed by removing the alignment layer, covering the color filter layer with a black matrix, or blackening the color filter layer directly.

At this time, it is necessary to detect the position of the defective pixel and to irradiate the laser accurately according to the shape and size of the defective pixel to minimize the influence on the surrounding pixels. However, there is a problem that the laser irradiation operation is manually performed by the operator on the liquid crystal display panel including pixels having various shapes and sizes, resulting in inefficiency and low precision in defect correction.

The background art described above is technical information possessed by the inventors for the derivation of the present invention or acquired during the derivation process of the present invention, and is not necessarily a publicly known technique disclosed to the general public before the application of the present invention.

The present invention provides a laser processing apparatus capable of correcting defects in a liquid crystal display panel by performing laser processing with uniform quality regardless of various pixel shapes and sizes of the liquid crystal display panel, and a method for correcting pixel defects using the same.

In addition, an object of the present invention is to provide a laser processing apparatus and a method for correcting pixel defects using the same, which can perform precise laser processing on a pixel at a desired position without a precise pixel alignment operation using an imaging unit in real time.

According to an aspect of the present invention, a laser processing apparatus for correcting pixel defects of a liquid crystal display panel using a laser, comprising: an imaging unit for photographing a liquid crystal display panel mounted on a stage; and an image photographed by the imaging unit To generate a pixel object, select a defective pixel object corresponding to the defective pixel among the pixel objects, and calculate a machining offset with respect to a preset machining reference point; and a laser beam whose irradiation position is adjusted according to the machining offset. A laser processing apparatus including a laser processing unit for irradiating a pixel is provided.

At least one of the imaging unit and the stage may be moved and aligned according to the position of the defective pixel such that the defective pixel is included in the image photographed by the imaging unit.

The light source may further include an illumination light source disposed under the stage to irradiate light passing through the liquid crystal display panel so as to easily distinguish boundaries between pixels constituting the liquid crystal display panel.

The information processing unit may include an image analyzer configured to analyze an image, a pixel object generator configured to generate pixel objects using pattern data corresponding to the liquid crystal display panel according to the analysis result, and a pixel object that is closest to a preset image reference point. A selection unit for selecting a defective pixel object, a machining offset calculator for calculating a machining offset with respect to a machining reference point for the defective pixel object, and a controller for controlling the laser machining unit using pattern data, a machining reference point, and a machining offset can do.

The image analyzer may calculate a difference in brightness values in the image to extract the boundary.

The pixel object generator may generate adjacent pixel pieces of the pixel pieces obtained by image analysis based on the pattern data into one, and extract the outline to generate the pixel object.

The selection unit obtains a pixel reference point with respect to the pixel object, and selects a defective pixel object from a distance between the pixel reference point and the image reference point.

The pattern data may include information regarding the shape and size of pixels constituting the liquid crystal display panel.

The laser processing unit includes a laser oscillation unit for oscillating a laser beam, a scanner for horizontally shifting the focus of the laser beam by a drive signal according to a processing reference point and a processing offset, and an object for condensing a laser beam whose focus is horizontally shifted by the scanner. It may include a lens unit.

At least one of the laser processing unit and the stage may be moved and aligned according to the processing reference point.

According to another aspect of the present invention, a method of correcting a pixel defect of a liquid crystal display panel in a laser processing apparatus, the method comprising: (a) aligning at least one of an imaging unit and a liquid crystal display panel corresponding to a detected defective pixel position; (b) photographing the liquid crystal display panel, (c) analyzing the photographed image to generate a pixel object, (d) selecting a pixel object closest to a preset image reference point as a defective pixel object, ( e) calculating a processing offset for the defective pixel object, (f) aligning at least one of the laser processing unit and the liquid crystal display panel, and (g) using a preset processing reference point and processing offset of the liquid crystal display panel. A pixel defect correction method is provided that includes laser processing a defective pixel.

In step (a), one of the stages on which the imaging unit and the liquid crystal display panel are mounted may be aligned so that the defective pixel is included in the image photographed by the imaging unit.

Step (c) comprises: (c-1) calculating the difference in brightness values in the image to enable boundary extraction; and (c-2) combining adjacent pixel pieces into one based on pattern data corresponding to the liquid crystal display panel. , And (c-3) extracting the outline to generate the pixel object.

The pattern data may include information regarding the shape and size of pixels constituting the liquid crystal display panel.

Step (d) may include (d-1) obtaining a pixel reference point for the pixel object, and (d-2) selecting a defective pixel object from the distance between the pixel reference point and the image reference point.

Prior to step (b), the method may further include irradiating light passing through the liquid crystal display panel from the bottom.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to a preferred embodiment of the present invention, irrespective of various pixel shapes and sizes of the liquid crystal display panel, laser processing may be performed with uniform quality to correct defects of the liquid crystal display panel.

In addition, by using the imaging unit in real time, there is an effect capable of precision laser processing on the pixel of the desired position without precise pixel alignment operation.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

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

1 is a schematic configuration diagram of a laser processing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of an information processing unit according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. The figure which concerns on the image analysis in the information processing unit according to the invention.

1 and 2, the laser processing apparatus 100, the laser processing unit 110, the laser oscillation unit 111, the optical modulator 112, the beam dump 117, the reflection mirror 113, and the beam expander ( 114, scanner 115, objective lens unit 116, laser beam path 118, liquid crystal display panel 150, imaging unit 130, information processing unit 120, illumination light source 140, image The analyzer 121, the pixel object generator 122, the selector 123, the processing offset calculator 124, and the controller 125 are illustrated.

The laser processing apparatus 100 according to the present exemplary embodiment selects a defective pixel object by analyzing a photographed image of the defective pixel and its neighboring pixels present in the provided liquid crystal display panel, and positions the corresponding defective pixel object relative to the processing reference point. By calculating the processing offset based on and using the pattern data for the liquid crystal display panel during laser processing, it is possible to precisely laser process the defective pixels having various shapes and sizes.

The stage is equipped with a liquid crystal display panel 150 which is transferred into the laser processing apparatus 100 by a transfer device of the front end. The conveying device of the front end may be a conveyor or a robot arm or the like.

The liquid crystal display panel 150 mounted on the stage assumes that a defective pixel position is detected primarily. To this end, a defect detection unit may be provided in front of the laser processing apparatus 100 or a defect detection unit may be further included in the laser processing apparatus 100 according to an exemplary embodiment.

The defect detection unit determines the presence or absence of a defective pixel with respect to the liquid crystal display panel 150, and obtains information regarding the position of the defective pixel when there is a defective pixel. To this end, the defect detection unit may be configured to include an imaging camera and a position measuring unit.

The imaging camera photographs a liquid crystal display panel including a defective pixel, and the position measuring unit calculates and outputs position information of the defective pixel using an image signal received from the imaging camera. Since the defective pixel is an abnormally high or low luminance pixel compared to the surrounding pixel, the position measuring unit may determine the position of the defective pixel through the luminance comparison. In addition, various methods for determining the presence or absence of a defect and detecting a position of a defective pixel may be applied in the present embodiment.

The imaging unit 130 photographs a portion of the liquid crystal display panel mounted on the stage, generates an image signal, and outputs the image signal to the information processing unit 120.

The imaging unit 130 has information regarding the position of the defective pixel of the liquid crystal display panel. As described above, the position information can be obtained from the defect detection unit or the position information can be obtained manually from the operator.

Therefore, the defective pixel already detected is included in the portion of the liquid crystal display panel picked up by the imaging unit 130. To this end, the alignment operation is performed by moving the stage on which the imaging unit 130 or the liquid crystal display panel 150 is mounted.

An illumination light source 140 irradiating light passing through the liquid crystal display panel may be disposed under the stage in order to distinguish the boundary of the color filter when the liquid crystal display panel is photographed by the imaging unit 130. The light irradiated from the illumination light source 140 disappears the complex substrate on the TFT surface of the liquid crystal display panel 150, thereby improving the extraction capability of the boundary of the color filter when analyzing the image in the information processing unit 120. Can be.

The information processing unit 120 analyzes the image photographed by the imaging unit 130, generates a pixel object, selects a pixel object corresponding to the defective pixel among the generated pixel objects, and selects the corresponding defective pixel object. With respect to the laser processing unit 110 calculates the processing offset for the processing reference point, which is the data required for laser processing, and based on this to control the driving of the laser processing unit 110 during the subsequent laser processing.

Referring to FIG. 2, the information processing unit 120 includes an image analyzer 121, a pixel object generator 122, a selector 123, a processing offset calculator 124, and a controller 125.

The image analyzer 121 analyzes the photographed image based on the image signal input from the imaging unit 130. In image analysis, image enhancement processing such as image noise removal may be performed together. Here, the image analyzer 121 may effectively remove image noise through bright region dilation and dark region erosion.

The image analyzer 121 may extract a boundary due to a difference in brightness values from the image from which the noise is removed. As described above, the boundary light extraction capability of the color filter may be improved by the illumination light source 140 disposed under the stage.

The pixel object generator 122 generates a pixel object using pattern data of the liquid crystal display panel mounted on the stage according to the image analysis result. The pattern data is information on the shape, size, arrangement pattern, and the like of pixels constituting the liquid crystal display panel corresponding to the liquid crystal display panel that is currently subjected to defect correction. By using the pattern data, it is possible to more accurately determine the boundary of the color filter obtained as a result of image analysis.

The pattern data may be registered with respect to the liquid crystal display panel when the pixels constituting the liquid crystal display panel have a complicated shape or have an irregular pattern, and the pixel data having a more accurate shape may be generated using the pattern data.

Adjacent pixel pieces included in one pixel of the objects obtained by image analysis may be synthesized into one pixel using pattern data. A pixel object may be generated by extracting an outline of a synthesized pixel or a pixel obtained by image analysis.

The selector 123 selects a defective pixel object corresponding to the defective pixel among the pixel objects generated by the pixel object generator 122.

The imaging unit 130 and the liquid crystal display panel 150 may be aligned by the defective pixel position, and an image reference point corresponding to the defective pixel position may be preset for the image photographed after the alignment operation. That is, the pixel object including the image reference point may be selected as the defective pixel object.

Referring to FIG. 3, a method of selecting a defective pixel object is illustrated. Here, although the image reference point i is shown as being the center of the captured image, various points within the image may be set as the image reference point according to an embodiment.

The pixel reference points pc1, pc2, pc3, pc4, and pc5 are obtained for the pixel objects p1, p2, p3, p4, and p5 generated by the pixel object generator 122, and the pixel reference point and the image reference point i The pixel object having the closest pixel reference point may be selected as the defective pixel object by calculating the distance between the?). In FIG. 3, since the pixel reference point closest to the image reference point i is pc3, the pixel object p3 may be selected as the defective pixel object.

The machining offset calculator 124 calculates a machining offset for the selected defective pixel object based on the machining reference point. The processing reference point is a laser irradiation position that becomes a reference when the laser processing unit 110 irradiates a laser to perform a laser processing operation. Therefore, a precise laser irradiation position can be obtained by calculating the machining offset from the machining reference point for the defective pixel object.

Referring to FIG. 3, it is assumed that the image reference point i is the same as the processing reference point, but various processing reference points may be set according to an embodiment.

The processing offsets for finding the starting position of the pixel object with respect to the defective pixel object p3 based on the processing reference point may be offset_x and offset_y. That is, the starting position of the defective pixel object p3 to which the laser beam is to be irradiated may be determined based on the processing offsets of the offset_x and the offset_y and the processing reference point.

Herein, it has been described on the assumption that the starting position is found using the machining offset. However, according to an exemplary embodiment, information on a defective pixel object may be obtained by calculating various machining offsets.

The controller 125 controls the laser processing unit 110 using information such as the pattern data of the liquid crystal display panel 150, the processing reference point of the laser processing unit 110, and the processing offset calculated by the processing offset calculator 124. Control the drive.

The position for laser irradiation can be determined from the processing reference point and the processing offset, and the pattern data can be used to control the direction and time of laser irradiation according to the shape and size of the defective pixel.

Since the shape of the pixel does not need to be limited to a rectangle because the pattern data is used, the present embodiment can be applied to all shapes of pixels that can be expressed in a two-dimensional plane.

The image reference point serves as a reference for the position between the imaging unit 130 and the liquid crystal display panel 150, and the processing reference point serves as a reference for the position between the laser processing unit 110 and the liquid crystal display panel 150. Therefore, the image reference point and the processing reference point may vary according to the alignment operation between the imaging unit 130 and the liquid crystal display panel 150 and the alignment operation between the laser processing unit 110 and the liquid crystal display panel 150, and the information processing unit 120 has data for each alignment to identify the image reference point and the processing reference point.

In addition, the controller 125 may correct the size of the selected defective pixel object by enlarging or reducing it to fit in the processing area. Since the size of the pixel object in the image photographed by the imaging unit 130 and the size of the pixel actually processed by the laser processing unit 110 may be different, a correction operation may be additionally performed.

The laser processing unit 110 irradiates a laser to the defective pixel to directly process the thin film transistor array or to process the organic material layer to correct the corresponding defect. For this purpose, the alignment operation may be performed by moving the stage on which the laser processing unit 110 or the liquid crystal display panel 150 is mounted.

Although FIG. 1 illustrates that the stage on which the liquid crystal display panel 150 is mounted is moved, the stage may be stopped and the laser processing unit 110 may be moved to perform an alignment operation.

The laser beam oscillated by the laser oscillator 111 is modulated by the optical modulator 112 and directed to the beam dump 117 or the reflection mirror 113. The laser beam propagated to the reflecting mirror 113 is enlarged via the beam expander 114 and scanned by the scanner 115 to be the target processing position among the liquid crystal display panels mounted on the stage through the objective lens unit 116 ( Here, the defective pixel is irradiated. This will be described in detail for each component.

The laser oscillator 111 is composed of a laser medium, a pumping unit, a switching unit and the like to output a laser beam. The laser beam oscillated by the laser oscillator 111 may be a pulse laser beam or a continuous wave laser beam.

The optical modulator 112 separates the path of the laser beam to adjust the amount of the laser beam according to the irradiation conditions. The amount of laser beam to be adjusted may be the number of laser pulses in the case of a pulse type, or the irradiation time in the case of a continuous wave type. The number of laser pulses, the irradiation time, and the like may vary depending on the irradiation conditions such as the shape and size of the defective pixel.

A pulse or a time required for correcting a defect of the liquid crystal display panel with respect to the laser beam oscillated from the laser oscillator 111 is a path leading to the objective lens unit 116, and bypasses for the remaining pulse or other time. The amount of laser beam can be adjusted by branching to another path, such as the path (path to beam dump 117 in this embodiment).

The optical modulator 112 calculates the amount of laser beam required to process it according to the size of the defective pixel and directs it to the objective lens unit 116 only for the corresponding number of laser pulses or for a corresponding irradiation time. A modulation control unit (not shown) may be added to control the operation of the optical modulator 112. The modulation control unit may be integrated with the optical modulator 112 or may be connected to a separate device, or may be integrated with the information processing unit 120 that controls the laser processing unit 110.

Such an optical modulator 112 includes an Acoustic Optic Modulator (AOM), but may also include other optical shutters such as an Electro Optical Modulator (EOM), a liquid crystal modulator, a high speed optical switch.

The scanner 115 corresponds to a focus adjusting unit, and finely horizontally shifts the focus of the laser beam in the liquid crystal display panel. The scanner 115 may be a galvano mirror installed so that two mirrors face each other and are positioned two-dimensionally with respect to the laser beam.

The first galvano mirror receives and reflects the laser beam and rotates about the first axis. The second galvano mirror receives and reflects a laser beam reflected from the first galvano mirror while rotating about a second axis different from the first axis. Therefore, by adjusting the angle between the first axis and the second axis, the degree of rotation of the first galvano mirror, and the degree of rotation of the second galvano mirror, the desired point of the liquid crystal display panel on which the laser beam is mounted on the stage (this embodiment In an example, it is possible to irradiate a portion of the defective pixel).

The scanner 115 is driven to position the laser beam to a position for laser irradiation based on the information about the processing reference point and the processing offset, and based on the information about the pattern data (shape, size, etc. of a defective pixel). The laser beam is driven to precisely irradiate the defective pixel.

After the scanner 115 positions the laser beam at a specific point, the objective lens unit 116 collects the laser beam with finely adjusted focus and irradiates a target (defective pixel) to be processed. Here, the objective lens unit 116 may be composed of one objective lens, a plurality of lens groups such as a convex lens, a concave lens may be composed of, or may be composed of a combination of one or more lenses and other optical systems. .

The stage is a part for placing the liquid crystal display panel 150 having the defective pixel, and the distance or / and the position with respect to the objective lens unit 116 may be adjusted to adjust the exact position and the focus. The stage may be added with a mechanical component to enable movement and rotation in conjunction with the transfer device of the front end.

The path of the laser beam can be changed as necessary, and the reflection mirror 113 is used for this purpose.

In this embodiment, driving of the laser oscillator 111, the optical modulator 112, the scanner 115, the stage, and the like may be controlled overall by the information processing unit 120 described above.

In addition, according to the present embodiment, it is preferable to use a laser beam in a wavelength region where absorption is good depending on the material of the liquid crystal display panel 150. To this end, a wavelength converter (not shown) for converting the wavelength of the laser beam before separating the laser beam generated by the laser oscillator 111 by the required amount by the optical modulator 112 may be interposed. In this embodiment, the wavelength converter may include any device for converting the wavelength of the laser beam, and a detailed description thereof will be omitted.

The wavelength converter receives the laser beam generated from the laser oscillation unit 111 and converts the laser beam into a laser beam of an appropriate wavelength, and the optical modulator 112 uses as many lasers as necessary to perform laser processing on the laser beam with the wavelength converted. Only the pulse is sent to the objective lens unit 116 serves to bypass the rest.

In the present embodiment, the laser oscillator 111, the optical modulator 112, the reflection mirror 113, the beam expander 114, the scanner 115, and the objective lens unit 116 are optically connected. Optical phenomena include various phenomena such as reflection, diffraction, and refraction of light. Here, 'optically connected' means that light emitted from one component by various optical phenomena is received by the other component. it means.

Hereinafter, a method of performing laser processing on a defective pixel using a laser in the laser processing apparatus 100 will be described in detail with reference to the drawings of FIG. 4.

4 is a flowchart of a pixel defect correction method using a laser processing apparatus according to an embodiment of the present invention, and FIG. 5 is a flowchart showing some steps of the pixel defect correction method shown in FIG. 4 in more detail.

Laser processing is performed on the liquid crystal display panel in which the defective pixel exists using the laser processing apparatus 100. For this purpose, it is assumed first that the position of a defective pixel present in the liquid crystal display panel is detected.

At least one of the imaging unit 130 and / or the liquid crystal display panel 150 is moved and aligned corresponding to the detected defective pixel position (step S210). The movement of the liquid crystal display panel 150 may be performed by moving the stage on which the liquid crystal display panel 150 is mounted.

The imaging unit 130 photographs the liquid crystal display panel 150 (step S220). The defective pixel is included in the image photographed through the alignment process in step S210.

An illumination light source 140 may be disposed below the stage to irradiate the light passing through the liquid crystal display panel 150 so that the boundary of the color filter is easily distinguished when the liquid crystal display panel is photographed (step S222).

The image analyzer 121 of the information processing unit 120 receives an image signal from the imaging unit 130 and analyzes the captured image (step S230).

Image enhancement processing such as image noise removal (step S232) can be performed with image analysis. Bright noise and dark erosion can effectively remove image noise.

The pixel object generator 122 generates a pixel object according to an image analysis result (step S240). In generating the pixel object, the pattern data of the liquid crystal display panel may be used.

Adjacent pixel pieces included in one pixel may be synthesized into one pixel using pattern data (step S242), and an outline may be extracted to generate pixel objects in pixel units (step S244).

The selector 123 selects a pixel object corresponding to the defective pixel among the generated pixel objects as the defective pixel object (step S250). The pixel object or the nearest pixel object including a preset image reference point therein may be selected as the defective pixel object.

Pixel reference points are obtained for the pixel objects, respectively (step S252). The defective pixel object may be selected by selecting a pixel object having the closest pixel reference point based on the distance from the image reference point (step S254).

The machining offset calculator 124 calculates a machining offset based on a machining reference point preset for the selected defective pixel object (step S260). The machining offset is data related to the position of laser irradiation during subsequent laser machining.

The alignment operation is performed by moving at least one of the laser processing unit 110 and / or the liquid crystal display panel 150 in correspondence with the processing reference point (step S270). The movement of the liquid crystal display panel 150 may be performed by moving the stage on which the liquid crystal display panel 150 is mounted.

The laser processing unit 110 performs laser processing by irradiating a laser beam to the defective pixel under the control of the control unit 125 using the pattern data and the processing offset (step S280).

Through this, it analyzes the image taken in real time with respect to the defective pixel and finely adjusts the irradiation position of the laser beam according to the result, it is possible to precise laser processing for the defective pixel at the desired position without precise pixel alignment work.

Further, by using the pattern data, laser processing can be performed with uniform quality even for pixels having various shapes and sizes.

Steps (steps S230 to S270) performed by the information processing unit 120 among the aforementioned pixel defect correction method may be performed by an automated procedure in a time series order by a software program or the like embedded in the digital processing apparatus. Self-explanatory The codes and code segments that make up the program can be easily deduced by a computer programmer in the field. In addition, the program is stored in a computer readable media, and the steps are implemented by being read and executed by a computer. The information storage medium includes a magnetic recording medium, an optical recording medium, and a carrier wave medium.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

1 is a schematic configuration diagram of a laser processing apparatus according to an embodiment of the present invention.

2 is a block diagram of an information processing unit according to an embodiment of the present invention;

3 is a diagram of image analysis in an information processing unit according to an embodiment of the present invention.

Figure 4 is a flow chart of the pixel defect correction method using a laser processing apparatus according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating some steps of the pixel defect correction method illustrated in FIG. 4 in more detail. FIG.

<Explanation of symbols for the main parts of the drawings>

100: laser processing apparatus 110: laser processing unit

111: laser oscillator 112: optical modulator

113: reflection mirror 114: beam expander

115: scanner 116: objective lens unit

117: beam dump 120: information processing unit

121: image analyzer 122: pixel object generator

123: selection unit 124: machining offset calculation unit

125: control unit 130: imaging unit

140: illumination light source 150: liquid crystal display panel

Claims (16)

A laser processing apparatus for correcting pixel defects in a liquid crystal display panel using a laser, An imaging unit for photographing the liquid crystal display panel mounted on the stage; An information processing unit which generates a pixel object by analyzing the image photographed by the imaging unit, selects a defective pixel object corresponding to a defective pixel among the pixel objects, and calculates a machining offset with respect to a preset machining reference point; A laser processing unit for irradiating the defective pixel with a laser beam whose irradiation position is adjusted according to the processing offset, The information processing unit, An image analyzer for analyzing the image; A pixel object generator for generating the pixel object using pattern data corresponding to the liquid crystal display panel according to an analysis result; A selection unit for selecting a pixel object closest to a preset image reference point as the defective pixel object; A machining offset calculator configured to calculate a machining offset with respect to the machining reference point with respect to the defective pixel object; A control unit for controlling the laser processing unit using the pattern data, the processing reference point, and the processing offset, And the selecting unit obtains a pixel reference point with respect to the pixel object, and selects the defective pixel object from a distance between the pixel reference point and the image reference point. The method of claim 1, And at least one of the imaging unit and the stage is aligned in accordance with the position of the defective pixel such that the defective pixel is included in an image photographed by the imaging unit. The method of claim 1, And an illumination light source disposed under the stage to irradiate light passing through the liquid crystal display panel so as to easily distinguish boundaries between pixels constituting the liquid crystal display panel. delete The method of claim 1, And the image analyzer calculates a difference in brightness values in the image to extract the boundary. The method of claim 1, And the pixel object generating unit combines adjacent pixel pieces of the pixel pieces obtained by image analysis into one based on the pattern data, and extracts an outline to generate the pixel object. delete The method of claim 1, And the pattern data includes information on the shape and size of pixels constituting the liquid crystal display panel. The method of claim 1, The laser processing unit, A laser oscillator for oscillating a laser beam; A scanner for horizontally shifting the focus of the laser beam by a drive signal according to the machining reference point and the machining offset; And an objective lens unit for focusing a laser beam horizontally shifted by the scanner. The method of claim 1, And at least one of the laser processing unit and the stage is aligned according to the processing reference point. In the method of correcting a pixel defect of a liquid crystal display panel in a laser processing apparatus, (a) aligning at least one of the imaging unit and the liquid crystal display panel corresponding to the detected defective pixel position; (b) photographing the liquid crystal display panel; (c) generating a pixel object by analyzing the captured image; (d) selecting a pixel object closest to a preset image reference point as a defective pixel object; (e) calculating a processing offset for the defective pixel object; (f) aligning at least one of the laser processing unit and the liquid crystal display panel; And (g) laser processing a defective pixel of the liquid crystal display panel using a preset machining reference point and the machining offset, Step (d) is, (d-1) obtaining a pixel reference point for the pixel object; And (d-2) selecting the defective pixel object from a distance between the pixel reference point and the image reference point. The method of claim 11, And the step (a) comprises moving and aligning one of the stages on which the imaging unit and the liquid crystal display panel are mounted so that the defective pixel is included in the image photographed by the imaging unit. The method of claim 11, Step (c) is, (c-1) calculating a difference in brightness values in the image to enable boundary extraction; (c-2) combining adjacent pixel pieces into one based on pattern data corresponding to the liquid crystal display panel; And (c-3) extracting an outline to generate the pixel object Pixel defect correction method comprising a. The method of claim 13, And the pattern data includes information about the shape and size of pixels constituting the liquid crystal display panel. delete The method of claim 11, And before step (b), further comprising irradiating light passing through the liquid crystal display panel from below.

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