KR20080047888A - Method for compensating display defect of flat display - Google Patents

Abstract

A method for compensating a display defect of a flat panel display device is provided to perfectly compensate a mura defect by adding or subtracting a compensation value optimized according to types of mura defects and gray scales to data to be displayed at the mura defect. An operator inputs model identification information of a display panel as panel information to a computer(S71) and inputs mura defect information to the computer(S72). The inputted panel information and the mura defect information are compared to automatically determine position data of the mura defect corresponding to the panel information and the mura defect information(S73). While increasing or decreasing a compensation value for each gray scale, the compensation value is added to or subtracted from test data, which is then supplied to data lines of the display panel to display the test data, and an inspecting process is performed on a displayed image(S74,S75). Whether or not the display panel has a mura defect is determined, and if a mura defect is shown, the compensation value is adjusted for each gray scale(S76,S77).

Description

Method for Compensating Display Defect of Flat Display

1 is a view showing a correlation between display defects that may occur in a lens assembly and a display panel of an exposure apparatus.

FIG. 2 is a diagram showing a correlation between the lens assembly of FIG. 1 and a line defect. FIG.

3 is a diagram showing luminance patterns and compensation values of line defects.

4 is a view showing a correlation between the lens assembly and the surface defect of FIG.

5 is a diagram showing luminance patterns and compensation values of surface defects.

FIG. 6 is a view illustrating a correlation between a lens assembly of FIG. 1 and a face / line mixed defect. FIG.

Fig. 7 is a graph showing luminance patterns and compensation values of plane / line mixed defects.

8 is a flowchart for explaining step by step a method of manufacturing a flat panel display device according to an embodiment of the present invention;

9 is a flowchart for explaining stepwise determination methods of position data and compensation values of display defects.

FIG. 10 is a diagram showing a system for analyzing display defects and determining a compensation value used in the manufacturing method of FIG. 10; FIG.

11 is a view showing an example of the dither pattern of the FRC applicable in the present invention.

12 is a block diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 13 is a block diagram illustrating in detail the compensation circuit shown in FIG. 12; FIG.

<Description of Major Symbols in Drawing>

101: data driving circuit 102: gate driving circuit

103: liquid crystal display panel 104: timing controller

105: compensation circuit 111: FRC control unit

112: EEPROM 113: Register

114: interface circuit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display device, and more particularly, to a display defect compensation method of a flat panel display device which compensates various types of display stains by an electrical compensation method based on analysis results of a correlation between a lens array of a panel and an exposure machine. It is about.

The flat panel display device includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting diode display (OLED). OLED), and most of them are commercially available and commercially available.

Liquid crystal display devices can meet the trend of light and short and short of electronic products and mass production is improving, and are rapidly replacing cathode ray tubes in many applications.

In particular, an active matrix type liquid crystal display device that drives a liquid crystal cell using a thin film transistor (hereinafter referred to as "TFT") has advantages of high image quality and low power consumption. As a result of research and development, it is rapidly developing into larger size and higher resolution.

The manufacturing process of the liquid crystal display device is to produce a TFT array substrate by a semiconductor process including a photolithography process. The photolithography process will include a series of exposure, development, and etching processes.

In the photolithography process, due to the unevenness of the exposure amount, a display defect in the form of a line (hereinafter referred to as "line defect") in the inspection process for inspecting the display state of the completed substrate, a surface defect in the form of a relatively large surface (Hereinafter referred to as "face defect") and the like can be found. These defects are caused by the difference in the exposure amount in the photolithography process.The overlapping area between the gate and the drain of the TFT, the height of the spacer, the parasitic capacitance between the signal wirings, and the parasitic capacitance between the signal wiring and the pixel electrode are normal. This is due to the difference between the face and the defect face. Since line defects and surface defects look different in luminance and chromaticity than normal display surfaces, the panel showing such display defects loses its basic function as a display device.

To reduce the level of defects in labeling defects, manufacturers are currently mitigating the defects with the repair process alone, but disposing of the panel if the mitigated level does not meet the product standard. In particular, since display defects appear in different forms and display defects differently depending on the display panel, the position, size, and degree of display defects in the inspection process and the repair process should be analyzed for each display panel. Therefore, the display defect is not only solved by a fair solution but also serves as the main cause of the decrease in productivity.

Disclosure of Invention An object of the present invention is to solve the problems caused by the prior art, and is based on a correlation analysis result of a lens array of a display panel and an exposure machine. The present invention provides a method for compensating for display defects of a device.

In order to achieve the above object, the display defect compensation method of the flat panel display device according to an embodiment of the present invention to create a correlation map between the lens and the panel by analyzing the correlation between the lens assembly and the panel with respect to the display panels of different models Doing; Detecting a display defect on the display panel; Comparing the display defect information obtained by analyzing the display defect and the information on the display panel with a correlation map between the lens and the panel and obtaining position information of the display defect from the correlation map between the lens and the panel; Determining compensation values for compensating for the luminance of the display defect; Storing the compensation values and position information of the display defect in a memory; And modulating the digital video data to be displayed on the display defect by using the compensation values and the position information stored in the memory to display an image on the flat panel display panel.

The correlation map between the lens and the panel may include relative position information of the display panel corresponding to overlapping and non-overlapping portions of the lenses of the lens assembly, occurrence position information of line defects that may occur in the display panel obtained from the relative position information, Position information of the display panel to which the compensation values applied to the line defects are added or subtracted, position information on occurrence of surface defects that may occur in the display panel obtained from the relative position information, and display on which the compensation values to the surface defects are added or subtracted. Position information of the panel, position information of surface / line mixed defects that may occur in the display panel obtained from the relative position information, and position information of the display panel to which compensation values given to the surface / line mixed defects are added or subtracted. do.

The position information of the display panel to which the compensation values applied to the line defects are added or subtracted is determined based on the position information of the left progressive compensation region determined based on the start point of the overlapping portion between the lenses and the end point of the overlapping portion between the lenses. Location information of the right progressive compensation area and the central compensation area located between the left progressive compensation area and the right progressive compensation area.

The position information of the display panel to which the compensation values applied to the surface defects are added or subtracted is determined based on the position information of the left progressive compensation region determined based on the start point of the overlapping portion between the lenses and the start point of the overlapping portion between the lenses. Location information of the right progressive compensation area, and location information of the central compensation area neighboring any one of the left progressive compensation area and the right progressive compensation area.

The position information of the display panel to which the compensation values given to the surface / line mixed defects are added or subtracted is position information indicating each of the central compensation region divided by the starting point of the overlapping portion between the lenses and about black lines, and the lenses. And the position information indicating the weak black line and the adjacent weak bright line at the boundary of the end point of the overlapping portion of the liver.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 1 to 13.

Referring to FIG. 1, reference numeral 10 denotes a lens assembly 10 of an exposure apparatus, and reference numeral 11 denotes a substrate of the display panel 11 exposed by the lens assembly.

The lens assembly 10 includes a plurality of lenses, for example seven lenses L1 to L7. The lenses L1 to L7 include electrothermal lenses L1, L3, L5 and L7, and post-heat lenses L2, L4 and L6, and adjacent heat-transfer lenses and the post-heat lenses each have a predetermined width at an edge thereof. Overlap. The lens assembly 10 exposes the substrate of the display panel 11 coated with the photoresist while moving in the direction of the arrow. Following the exposure step, a pattern of desired signal wiring, electrodes, spacers, barrier ribs, etc. is formed on the substrate by the developing step and the etching step. After the various patterns are formed on the substrate, when the display panel is completed by performing a bonding process between the substrate and other substrates, a driving circuit mounting process, and the like, luminance and chromaticity inspections are performed for each gray level of the display panel.

As a result of this inspection process and repeated experiments, the number of line defects or surface defects may be different in the display panel of the same model having the same size, the same resolution, and the same cell pitch. The regularity was found that the position where the defect appeared and the position where the surface defect appeared appeared the same.

According to its regularity, line defects appear in the overlapping portions B1 to B6 of the lenses L1 to L7 in the lens assembly 10 of the exposure apparatus, and surface defects are defined in the lenses (10) in the lens assembly 10 of the exposure apparatus. L1 to L7) in the non-overlapping portions A1 to A7. In the example of FIG. 1, the line defects appearing in the second overlapping part B2, the surface defects appearing in the fourth non-overlapping part A4, the sixth non-overlapping part A6, and the fifth and sixth overlapping parts B5 and B6. ) Shows the face / line mixing defects appearing. Line defects are caused by a change in the exposure amount of the photoresist due to lens aberration compared to other overlapping portions or non-overlapping portions among the overlapping portions B1 to B6 of the lenses L1 to L7. Surface defects are caused by aberration deviations between the lenses L1 to L7, and have more aberration than other lenses among the non-overlapping portions A1 to A7 of the lenses L1 to L7. The exposure amount of the photoresist corresponding to the relative position of the non-overlapping portion of the large or low lens is generated due to the difference of the non-overlapping portion of the other lenses. Face / line mixing defects occur at neighboring non-overlapping and overlapping areas.

In the lens assembly 10 of the exposure apparatus, the overlapping portions B1 to B6 and the non-overlapping portions A1 to A7 of the lenses L1 to L7 are fixed. In contrast, when the display panel exposed by the exposure apparatus has different sizes, resolutions, cell pitches, and the like, the relative positions and the non-overlapping portions A1 to L2 that face the overlapping portions B1 to B6 of the lenses L1 to L7 are different. The relative position opposite to A7) becomes different.

When the model of the display panel is changed, the relative position opposite to the overlapping portions B1 to B6 of the lenses L1 to L7 and the relative position opposite to the non-overlapping portions A1 to A7 are changed. The defect location is different. That is, when the model is changed, since the relative position and the non-overlapping portions A1 to A7 opposite to the overlapping portions B1 to B6 of the lenses L1 to L7 are changed, the starting position P1 of the line defect in FIG. P3, P5, P7, P9, P11) and end positions of line defects (P2, P4, P6, P8, P10, P12), start positions of surface defects (P2, P4, P6, P8, P10, P12) and plane The end positions P1, P3, P5, P7, P9 and P11 of the defects are different. On the other hand, although the position and the number of line defects and surface defects are different even if the model is different, overlapping parts B1 to B6 and non-overlapping parts A1 to A7 of the lenses L1 to L7 are fixed, so that all panels of the model are fixed. The widths of the line defects and the surface defects appearing in the field are the same.

The present invention uses a "correlation map of lenses and panels" in which the relative positions of the overlapping portions B1 to B6 and the non-overlapping portions A1 to A7 of the lenses L1 to L7 are mapped for each model of the display panel. The display panel predicts the shape and position of the display defect. In addition, the present invention determines the position of the display defect using the correlation map between the lens and the panel, and optimizes the compensation value according to the defect degree and the type of the defect found in the inspection process.

2 illustrates an example in which line defects appear on a substrate of a display panel smaller than the length of the lens assembly 10.

Referring to FIG. 2, a photo formed on the substrate of the display panel 11 by the first lens L1 and the seventh lens L7 positioned at both edges of the lenses L1 to L7 of the lens assembly 10. The resist is not exposed. The photoresist formed on the substrate is exposed by the third to fifth lenses L3 to L5 and is exposed by half of the second lens L2 and half of the sixth lens L6.

In the correlation between the lens assembly 10 and the display panel, the position of the display panel 11 where line defects may occur is the second overlapped portion B2 in which the fifth lens L5 and the sixth lens L6 overlap. , A third overlapping portion B1 in which the fourth lens L4 and the fifth lens L5 overlap, and a fourth overlapping portion B4 in which the third lens L3 and the fourth lens L4 overlap, and A fifth overlapping portion B5 in which the two lenses L2 and the third lens L3 overlap.

The reference position to which the compensation value is given at the position where the line defect can occur is P3 and P4 of the second overlapping portion B2, P5 and P6 of the third overlapping portion B1, P7 of the fourth overlapping portion B4, and P8 and P9 and P10 of the fifth overlapping portion B5. These line defects and adjacent normal display surfaces overlap with each other in luminance. Therefore, the luminance pattern of the line defect is the darkest in the central compensation region C1 as shown in FIG. 3, and the luminance gradually increases toward the edge. In order to compensate for the luminance of such line defects, the compensation value applied to the line defects is the highest in the center compensation region C1 and is located in the progressive compensating regions SSG1 and SG2 located at both edges of the center compensation region C1. Progressively lower in each case.

The center compensation area C1 corresponds to a center position in the width direction x of the line defect and is the darkest area in the line defect. Since the center compensation region C1 does not overlap the normal display surface, it appears darkest and the compensation value a1 is applied highest within the line defect. The compensation value a1 of the center compensation area C1 is based on the subjective brightness difference that the luminance measurement device or the naked eye senses the difference between the brightness of the center compensation area C1 and the brightness of the normal display surface. The difference in luminance of the normal display surface is determined by a value which cannot be seen by the naked eye.

The progressive compensation areas SG1 and SG2 are areas in which the luminance of the center compensation area C1 overlaps with the luminance of the normal display surface and is located on the left side SG1 and the right side SG2 of the center compensation area within the line defect. The closer to the compensation area C1, the luminance appears to be closer to the luminance of the central compensation region C1, and the closer to the non-overlapping surface of the normal display surface, the closer to the luminance of the normal display surface. That is, the progressive compensation areas SG1 and SG2 appear darker as they approach the center compensation area C1, and become brighter toward the non-overlapping surfaces of the normal display surface. The progressive compensation areas SG1 and SG2 are divided into a plurality of sections. The width of each of the sections is defined as a width obtained by dividing the width direction length x of the progressive compensation areas SG1 and SG2 by the number of pixels and dividing the conversion length by a multiple of four. In these progressive compensation areas SG1 and SG2, the compensation values b1 to e1 and b1 ′ to e1 ′ are gradually smaller from a section closer to the center compensation region C1 to a section closer to the non-overlapping surface of the normal display surface. The value is automatically determined. In other words, the compensation values b1 to e1, b1 ′ to e1 ′ applied to the respective sections of the progressive compensation areas SG1 and SG2 are determined when the compensation value a1 of the central compensation area C1 is determined. It is automatically determined between the value a1 and '0', which satisfies the perfect symmetry. The number of sections of the progressive compensation areas SG1 and SG2 increases as the compensation value a1 of the central compensation area C1 is higher, and decreases as the compensation value a1 of the central compensation area C1 is lower.

In order to determine the compensation value of the line defect, a criterion for setting the interval between the center compensation region C1 and the progressive compensation regions SG1 and SG2 may be a line defect predicted by the aforementioned "correlation map of lens and panel". Determined based on location. For example, when line defects appear in the second overlapping portion B2 of the lens assembly 10 as shown in FIG. 3, the present invention provides a left progressive compensation area SG1 based on P3 known by the “correlation map between the lens and the panel”. One section to the right and three sections to the left are defined, and one section to the left and three sections to the right are defined symmetrically with respect to P4 based on P4.

In this way, if a line defect appears in the third overlapping portion B3 of the lens assembly 10, the present invention is based on the P5 known by the "correlation map of the lens and the panel" in the left progressive compensation area SG1. In 1, one section to the right and three sections to the left are defined, and symmetrically, one section to the left and three sections to the right are defined in the right gradual compensation region SG1 based on P6.

If line defects appear in the fourth overlapping portion B4 of the lens assembly 10, one section to the right and three sections to the left are defined within the left gradual compensation area SG1 based on P5, and symmetrical thereto. As a result, one section to the left and three sections to the right are determined in the right gradual compensation area SG1 based on P6.

The number of sections divided on the left side in the left progressive compensation area SG1 and the number of sections divided on the right side in the right progressive compensation area SG1 is the compensation value a1 of the central compensation area C1 as described above. The higher the value is, the smaller the compensation value a1 of the central compensation area C1 is.

4 illustrates an example in which surface defects appear on a substrate of a display panel smaller than the length of the lens assembly 10.

Referring to FIG. 4, a photo formed on the substrate of the display panel 11 by the first lens L1 and the seventh lens L7 positioned at both edges of the lenses L1 to L7 of the lens assembly 10. The resist is not exposed. The photoresist formed on the substrate is exposed by the third to fifth lenses L3 to L5 and is exposed by half of the second lens L2 and half of the sixth lens L6.

In the correlation between the lens assembly 10 and the display panel, the position of the display panel 11 where surface defects may occur is the non-overlapping portions A2 to A6 of the lens in the lens assembly 10.

The surface to which the compensation value is given at the position where the surface defect can occur is set larger than the non-overlapping portions A2 to A6 of the lens. This is because the luminance is overlapped between the surface defect and the normal display surface adjacent thereto so that a compensation value is applied to a portion where the luminance of the surface where the surface defect occurs and the luminance of the normal display surface overlap. If a compensation value is assigned only to the plane where the plane defect occurs based on the "correlation map between the lens and the panel", the plane where the plane defect occurs after the compensation is performed through the modulation of data to be displayed on the plane where the plane defect occurs as the compensation value. The luminance difference appears at the boundary between the and the adjacent normal display surface.

As shown in FIG. 5, the luminance pattern of the surface defect is gradually darker in the center compensation region C2 and gradually closer to the normal display surface in the progressive compensation region SG3 corresponding to the boundary with the normal display surface. Since the center compensation region C2 occupies most of the surface defect surface and does not overlap with the normal display surface, it appears darkest in the surface defect and the highest compensation value a2 is applied in the surface defect surface. The compensation value a2 of the central compensation area C2 is based on the subjective luminance difference that the luminance measurement device or the naked eye senses the difference between the brightness of the central compensation area C2 and the brightness of the normal display surface. The difference in luminance of the normal display surface is determined by a value which cannot be seen by the naked eye.

The progressive compensation area SG3 is a surface where the luminance of the central compensation area C2 overlaps with the luminance of the normal display surface, and the closer to the central compensation area C2, the closer the luminance is to the central compensation area C1. In addition, toward the non-overlapping surface of the normal display surface, the luminance appears closer to that of the normal display surface. That is, the progressive compensation area SG3 is darker as it approaches the center compensation area C2, and becomes brighter toward the non-overlapping plane of the normal display surface. The progressive compensation area SG3 is divided into a plurality of sections. The width of each of the sections is defined as a width obtained by dividing the widthwise length x of the progressive compensation area SG3 by the number of pixels and dividing the converted length by a multiple of four. In the gradual compensation area SG3, the compensation values b2 to i2 are automatically determined to be gradually smaller from a section closer to the center compensation area C2 to a section closer to the non-overlapping surface of the normal display surface. In other words, the compensation values b2 ˜ i2 applied to the respective sections of the gradual compensation area SG3 have the compensation values a2 and '0' when the compensation value a2 of the central compensation area C2 is determined. Is automatically determined between. A reference position for dividing the section of the gradual compensation area SG3 is assumed to be a starting point at the second non-overlapping surface A2 of the lens assembly 10 as shown in FIGS. 4 and 5. P3 ', the progressive compensation area SG3 is divided into equal numbers of sections on the left and right sides based on this P3. When the surface defect is generated at the fourth non-overlapping surface A4 of the lens assembly 10, the progressive compensation area SG3 is divided into equal numbers of sections in each of left and right around 'P6' and the surface defect When generated at the sixth non-overlapping surface A6 of the lens assembly 10, the progressive compensation area SG3 is divided into equal numbers of sections at left and right sides, respectively, about 'P10'. The number of sections divided left and right around the reference position in the progressive compensation area SG3 increases as the compensation value a2 of the central compensation area C2 increases, and the compensation value a2 of the central compensation area C2. The lower the), the smaller.

FIG. 6 illustrates an example in which surface / line mixing defects appear on a substrate of a display panel smaller than the length of the lens assembly 10.

Referring to FIG. 6, a photo formed on the substrate of the display panel 11 by the first lens L1 and the seventh lens L7 positioned at both edges of the lenses L1 to L7 of the lens assembly 10. The resist is not exposed. The photoresist formed on the substrate is exposed by the third to fifth lenses L3 to L5 and is exposed by half of the second lens L2 and half of the sixth lens L6.

In the correlation between the lens assembly 10 and the display panel, the position of the display panel 11 where surface / line mixing defects may occur is determined by the non-overlapping portions A2 to A6 of the lens in the lens assembly 10 and neighbors thereof. Are overlapping portions B2 to B5. In FIG. 6, the second non-overlapping portion A2, the second overlapping portion B2 adjacent thereto, the third overlapping portion B3, and the fourth non-overlapping portion A4 adjacent thereto and the fourth overlapping portion B4. 4 illustrates an example in which face / line mixed defects MR1, MR2, and MR3 appear in the fifth overlapping portion B5 and the sixth non-overlapping portion A6 adjacent thereto.

The surface / line mixed defects MR1, MR2, and MR3 are approximately black lines BL as shown in FIG. 7 at the boundary between the non-overlapping portions A1 to A6 and the overlapping portions B1 to B7 of the lenses L1 to L7. About WL appears. The weak black line appears between the end point of the non-overlapping portion and the start point of the about bright line, and the weak black line appears at the end of the overlapping portion and the edge of the normal display surface adjacent thereto. For example, in FIG. 6, about black line BL of the first surface / line mixed defect MR1 is between the starting point P3 of the second overlapping portion B2 and the end point P4 of the second overlapping portion B2 as shown in FIG. 7. About WL appears at the left edge of P4 and the second non-overlapping portion A2 adjacent thereto. In the second face / line mixed defect MR2, about black line BL and about bright line WL appear at both edges. The right weak black line BL of the second face / line mixed defect MR2 appears between the starting point P5 of the third overlapping portion B3 and the end point P6 of the third overlapping portion B3, and the left weak black line BL is It appears between the starting point P7 of the fourth overlapping portion B4 and the end point P8 of the fourth overlapping portion. The left weakened line WL of the second face / line mixed defect MR2 appears at the right edge of the second non-overlapping portion A2 adjacent to P5 and the right side of the second face / line mixed defect MR2. The broken line WL appears at the left edge of P8 and the fifth non-overlapping portion A5 adjacent thereto. About black line BL of 3rd surface / line mixing defect MR3 appears between the starting point P9 of the 5th overlapping part B5, and the end point P10 of the 5th overlapping part B5, and the weakly curved line WL is P9 And the right edge of the neighboring fifth non-overlapping portion A5.

Looking at the luminance patterns in the plane / line mixed defects MR1, MR2, and MR3, the darkest in the central compensation region C3 and the normal in the progressive compensation region SG4 including the weak black line BL and the weak bright line WL are normal. The closer to the display surface, the higher the luminance is. The center compensation area (C3) occupies most of the plane / line mixed defect plane and does not overlap with the brightness of the normal display plane, so it appears darkest within the plane / line mixed defect and has the highest compensation value within the plane / line mixed defect. Apply. The compensation value of the center compensation area C3 is based on the subjective brightness difference between the brightness of the center compensation area and the brightness of the normal display surface and the subjective brightness difference perceived by the naked eye, and the brightness difference between the center compensation area C3 and the normal display surface. Is determined by a value that cannot be felt by the naked eye.

The progressive compensation area SG4 of the plane / line mixed defects MR1, MR2, and MR3 is a plane where the luminance of the center compensation area C3 overlaps with the luminance of the normal display surface, and is closer to the center compensation area C3. The luminance appears to be close to the luminance of the compensation area C3, and the luminance is closer to the non-overlapping surface of the normal display surface. That is, the progressive compensation area SG4 is darker as it approaches the center compensation area C3, and appears brighter toward the non-overlapping plane of the normal display surface. The progressive compensation area SG4 is divided into a plurality of sections. The width of each of the sections is defined as a width obtained by dividing the widthwise length x of the progressive compensation area SG4 by the number of pixels and dividing the converted length by a multiple of four. In this gradual compensation area SG4, the compensation value is automatically determined to be gradually smaller from the section closer to the center compensation area C3 to the section closer to the non-overlapping surface of the normal display surface. In other words, the compensation value applied to each section of the progressive compensation area SG4 is automatically determined between the compensation value and '0' when the compensation value of the central compensation area C3 is determined. The reference position for dividing the section of the progressive compensation area SG4 is a boundary line between the black line BL and the weak line WL, that is, the overlapping portion of the lenses and the non-overlapping portion adjacent thereto. For example, in FIG. 6, the reference position for dividing the sections of the progressive compensation region SG4 in the first surface / line mixed defect MR1 is P4 and the left progressive compensation region SG4 in the second surface / line mixed defect MR2. The reference position for dividing the sections of the frame is P5, the reference position for dividing the sections of the right gradual compensation area SG4 in the second plane / line mixed defect MR2 is P8, the third plane / line mixed defect MR2. ), The reference position for dividing the sections of the progressive compensation area SG4 is P9. Based on this reference position, each of the about black line BL and the about bright line WL is divided into a plurality of sections. The number of sections increases as the compensation value of the central compensation region C3 and the weak black line BL increases, and decreases as the compensation value of the central compensation region C3 and the weak black line BL becomes low.

The compensation values of the above-described line defects, surface defects, and surface / line mixed defects are optimized differently for each gray level in consideration of gamma characteristics of data voltages supplied to the display panel. The compensation values are added to the digital video data to be displayed on the display defects as compensation values for compensating for a display defect appearing at a lower luminance than the luminance of the normal display surface. On the other hand, display defects also include display defects that appear to be brighter than the luminance of the normal display surface. The compensation values for compensating the brightness of the brightly displayed display defects are optimized to compensate for the difference in brightness between the display defects and the normal display surface for each gray level as in the above-described embodiments, and the digital video to be displayed in the brightly displayed display defects. Are subtracted from the data.

These compensation values may be determined by a decimal number less than an integer +1, and the compensation value of the integer value is added to or subtracted from the digital video data using a general bit adder or subtractor, and the compensation value of the decimal value is determined using a dither pattern. Digital video data is added or subtracted by a frame rate control (hereinafter referred to as "FRC") method.

According to the correlation map between the lens and the panel, as described above, the lens arrangements of the lens assembly 10 and the size, resolution, cell pitch, and the like of the display panel are determined according to the type of display defect and According to the model, location information of data lines and pixels of locations at which display defects may occur are classified. In the display defect compensation method of the flat panel display device according to an embodiment of the present invention, the correlation map between the lens and the panel is stored in a memory in the form of a look-up table, and the panel and the display defect information actually found in the inspection process are inputted to the lens and the panel. Automatically select the predicted location of the display defect in the correlation map. The location data of the automatically generated display defects are stored in the memory in the form of a lookup table. The memory in which the position data and the compensation value of the display defect are stored includes a nonvolatile memory, for example, an electrically erasable programmable read only memory (EEPROM) or an extended display identification data ROM (EDID ROM). In addition to the compensation value and position data of the display defect, the EDID ROM basically stores the seller / producer identification information (ID) of the display element and the variables and characteristics of the basic display element. This memory is added to the driving circuit of the calculator and flat panel display device to add or subtract the compensation value of the display defect to the digital video data.

8 and 9 are flowcharts illustrating a method of manufacturing a flat panel display device according to an exemplary embodiment of the present invention step by step. FIG. 10 illustrates a system for analyzing display defects and determining a compensation value used in the inspection process of FIGS. 8 and 9.

8 to 10, in the manufacturing method of the flat panel display device according to the exemplary embodiment of the present invention, after manufacturing the upper and lower plates, respectively, the upper and lower plates are bonded with a sealant or frit glass. (S1, S2, S3) The upper plate and the lower plate may be manufactured in various forms according to the flat panel display panel 40. For example, in the case of a liquid crystal display panel, a color filter, a black matrix, a common electrode, an upper alignment layer, etc. may be formed on an upper plate, and a data line, a gate line, a TFT, a pixel electrode, a lower alignment layer, a column spacer, etc. may be formed on a lower plate. Can be. In the case of a plasma display panel, an address electrode, a lower dielectric, a partition, a phosphor, and the like may be formed on a lower plate, and an upper dielectric, an MgO passivation layer, and a sustain electrode pair may be formed on an upper plate.

Subsequently, in the inspection process of the flat panel display device, test data of each gray level is applied to the flat panel display panel 40 to display test data for each gray level, and the detection device 42 as shown in FIG. The brightness and chromaticity of the entire display surface are measured by electrical inspection and / or visual inspection. (S4) If a display defect is found on the flat panel display in the inspection process (S5), the display defect and normal display surface The luminance difference is analyzed and whether the display defect corresponds to one of line defects, surface defects, and surface / line mixed defects (S6).

Next, the present invention determines position data indicating each pixel in the display defect from the correlation map between the lens and the panel, and determines a compensation value for each gray level to compensate for the luminance of the display defect. The compensation value is artificially determined in the central compensation area of the display defect. When the compensation value of the central compensation area is determined, the compensation values assigned to each section of the progressive compensation area are automatically determined between the compensation value of the central compensation area and '0'. . The gradual compensation area should be optimized for each gray level like the central compensation area (S7).

The present invention stores position data indicating the position of each pixel of the display defect and compensation values of the display defect in a memory through a user connector and a ROM writer (S8).

If no display defects are seen in the entire display surface in step S5, the flat panel display device is determined as good quality and shipped.

As shown in FIG. 9, the operator inputs model identification information including the size, resolution, cell pitch, and the like of the display panel to the computer 44 as panel information. The display defect information including the type of the display defect determined in the process, the display defect and the luminance difference between the normal display surface, is input into the computer 44. (S71, S72)

Subsequently, the method of determining the position data of the display defect and the compensation value executes a program for automatically determining the position data of the display defect using the previously stored "correlation map between the lens and the panel". This program compares the input panel information with the display defect information and automatically determines the position data of the display defect matching the panel information and the display defect information from the "correlation map between the lens and the panel" (S73).

Subsequently, in the method of determining the position data of the display defect and the compensation value, the compensation value is increased or decreased for each gray level, and the test value is supplied to the data lines of the display panel 40 by adding or subtracting the compensation value to the test data. (S74, S75) The position data of the display defect and the method of determining the compensation value determine whether there is a display defect as a result of the inspection process. (S76, S77) If the display defects are not displayed for each gray level in the series of compensation value adjustment and inspection steps S74 to S77, the compensation value at that time is determined as the optimized compensation value. )

The display defect analysis and compensation value determination system supplies data to the sensing device 42 and the flat panel display panel 40 for sensing the luminance and chromaticity of the flat panel 40 as shown in FIG. And a computer 44 for analyzing the luminance and chromaticity of the flat panel display panel 40 from the output signal of &lt; RTI ID = 0.0 &gt;, &lt; / RTI &gt; and a memory 46 for storing the position data of the display defects determined by the computer 44 and the compensation value.

The sensing device 42 detects the brightness and chromaticity of the test image displayed on the flat panel display panel 40 including a camera and / or an optical sensor to generate voltage or current, and then converts the voltage or current into digital sensing data. Supply to computer 44.

The computer 44 supplies the test data for each gray level to the driving circuit of the flat panel display panel, and the test image is applied to the entire display surface of the display panel 40 for each gray level according to the digital sensing data input from the sensing device 42. The luminance and chromaticity of When the display defect is detected by the detection device 42 on the display panel 40 or the panel information and the display defect information are input by the administrator in a subjective evaluation, the computer 44 executes a program to execute the position data of the display defect. Is automatically generated, and the compensation value is added to or subtracted from the test data to be displayed on the display defect while the compensation value is changed, and the test data added to the compensation value is supplied to the display panel 40. The computer 44 observes the change in luminance and chromaticity of the display defect, and as a result, if the luminance of the display defect and the luminance of the normal display surface are determined to be less than or equal to the preset threshold value, the position compensation data as the optimized compensation value is used. To the memory 46 together. Here, the threshold value is an experimentally determined value that does not show a difference in luminance between the line defect and the normal display surface when viewed visually at the same gray level.

The memory 46 stores the position data of the display defect and the compensation value for each gradation under the control of the computer 44, and is added to the driving circuit of the display panel.

FIG. 11 illustrates an example of a dither pattern of an FRC that expresses a fine compensation value of less than '1' among compensation values for compensating for luminance of a line defect described above.

Referring to FIG. 11, the FRC has a size of 8 pixels by 8 pixels, and the number of pixels to which '1' is added is set differently according to the compensation value to express the compensation value corresponding to the fractional gray scale of less than one. Patterns to 8/7 dither patterns are used.

The 1/8 dither pattern sets 8 pixels to which '1' is added among the 64 pixels to express a compensation value corresponding to 1/8 (= 0.125) gray scale, and the 2/8 dither pattern shows 64 pixels. 16 pixels to which '1' is added are set to express a compensation value corresponding to 2/8 (= 0.250) gray scale, and 3/8 dither pattern is 24 pixels to which '1' is added among 64 pixels. Set these to represent the compensation value corresponding to 3/8 (= 0.375) gradation. The 4/8 dither pattern sets 32 pixels to which '1' is added among 64 pixels to express a compensation value corresponding to 4/8 (= 0.500) gray scale, and the 5/8 dither pattern is 64 pixels 40 pixels to which '1' is added are set to express a compensation value corresponding to 5/8 (= 0.625) gray scale, and the 6/8 dither pattern is 48 pixels to which '1' is added among 64 pixels. Set these to represent the compensation value corresponding to 6/8 (= 0.750) gradation. The 7/8 dither pattern expresses a compensation value corresponding to 7/8 (= 0.875) gray level by setting 56 pixels to which '1' is added among 64 pixels. Each of these dither patterns changes the positions of pixels to which '1' is added every frame period.

12 illustrates a flat panel display device according to an exemplary embodiment of the present invention. This flat panel display device will be described by taking a liquid crystal display device as an example.

Referring to FIG. 12, in the flat panel display of the present invention, the display panel 103 in which the data lines 106 and the gate lines 108 cross each other and TFTs for driving the liquid crystal cells Clc are formed at the intersection thereof. ); A compensation circuit 105 for modulating the digital video data Ri / Gi / Bi to be displayed on the line defect using a pre-stored compensation value; A data driving circuit 101 for supplying modulated data Rc / Gc / Bc to the data lines 106; A gate driving circuit 102 for supplying a scan signal to the gate lines 106; And a timing controller 104 for controlling the driving circuits 101 and 102.

Liquid crystal molecules are injected into the liquid crystal display panel 103 between two substrates (a TFT substrate and a color filter substrate). The data lines 106 and the gate lines 108 formed on the TFT substrate are perpendicular to each other. The TFT formed at the intersection of the data lines 106 and the gate lines 108 receives a data voltage supplied via the data line 106 in response to a scan signal from the gate line 108. To the pixel electrode. Black matrices, color filters, and the like, which are not shown, are formed on the color filter substrate. The common electrode supplied with the common voltage Vcom is formed on a TFT substrate in an IPS (In-plain Switching) mode or a FFS (Fringe Field Switching) mode, and is formed in a twisted nematic (TN) mode, an optically compensated bent (OCB) mode, It is formed on the color filter substrate in a VA (Vertically Alignment) mode or the like. Polarizers having light absorption axes perpendicular to each other are attached to the TFT substrate and the color filter substrate.

The compensation circuit 105 receives input data Ri / Gi / Bi from a system interface and compensates for display defects previously stored in digital video data Ri / Gi / Bi to be displayed on each pixel of the display defect. A value is added or subtracted to modulate the digital video data Rc / Gc / Bc to be displayed in the display defect. The compensation circuit 105 outputs modulated digital video data Rc / Gc / Bc to be displayed on the display defect and unmodulated data Ri / Gi / Bi to be displayed on the normal display surface.

The timing controller 104 supplies the digital video data Rc / Gc / Bc, Ri / Gi / Bi from the compensating circuit 105 to the data driving circuit 101 in accordance with the dot clock DCLK and vertical / horizontal. The gate control signal GDC and the data driving circuit 101 for controlling the gate driving circuit 102 are controlled by using the synchronization signals Vsync and Hsync, the data enable signal DE, and the dot clock DCLK. A data control signal DDC is generated. The compensation circuit 105 and the timing controller 104 may be integrated into one chip.

The data driving circuit 101 converts the digital video data Rc / Gc / Bc, Ri / Gi / Bi supplied from the timing controller 104 into an analog gamma compensation voltage and converts the analog gamma compensation voltage into a data line as a data voltage. To the field 106.

The gate driving circuit 102 sequentially supplies a scan signal to the gate lines 108 to select a horizontal line to which a data voltage is supplied.

13 shows the compensation circuit 105 in detail.

Referring to FIG. 13, a compensation circuit 105 according to an exemplary embodiment of the present invention includes an FRC controller 111, an EEPROM 112, a register 113, and an interface circuit 114.

The FRC control unit 111 determines the display position of the digital video data Ri, Bi, and Gi according to the vertical and horizontal synchronization signals Vsync and Hsync, the data enable signal DE, and the dot clock DCLK. The position determination result is compared with the position information PD from the EEPROM 112 to detect digital video data Ri / Bi / Gi to be displayed on the display defect. The FRC control unit 111 supplies the digital video data Ri, Bi, and Gi to be displayed on the display defect as a read address to the EEPROM 112, and the compensation value output from the EEPROM 112 in response to the read address. Field CD is added to and subtracted from the line defect and the digital video data Ri / Bi / Gi to be displayed on the white line. Here, the FRC control unit 111 distributes the compensation value temporally and spatially according to the predetermined dither pattern as shown in FIG. 11 and adds a compensation value of less than 1 gray scale to the digital video data Ri / Bi / Gi in the dither pattern unit. An integer compensation value of one or more gray levels is added to the digital video data in units of pixels.

The EEPROM 112 stores a compensation value CD of display defects and position data PD of display defects in the form of a lookup table. The position data PD and the compensation values CD stored in the EEPROM 112 may be updated by an electrical signal applied from the external computer 44 through the interface circuit 114.

The interface circuit 114 is configured for communication between the compensation circuit 105 and an external system, and the interface circuit 114 is designed in accordance with a communication standard protocol standard such as I ² C. The position data and the compensation value (CD) stored in the EEPROM 112 are required to be updated for reasons such as process change and difference between the applied models, and the user needs to update the user position data (UPD) and the user compensation value (UCD). Is entered via an external system. The computer 44 may read or modify data stored in the EEPROM 112 through the interface circuit 114 when such a request is made.

The register 113 temporarily stores user data UPD and CD transmitted through the interface circuit 114 to update the position data PD and the compensation data CD stored in the EEPROM 112.

Such a liquid crystal display device can be applied to other flat panel display devices without significant change. For example, the liquid crystal display panel 103 may be replaced by a field emission display device, a plasma display panel, an organic light emitting diode display device, or the like.

As described above, the display defect compensation method of the flat panel display device according to the present invention analyzes the correlation between the lens assembly and the panel with respect to the display panels of different models to create a "correlation map between the lens and the panel", The panel information and the display defect information are compared with the "correlation map between the lens and the panel" to automatically determine the position data of the display defect, and optimize the compensation value according to the type and gradation of the display defect. The present invention compensates the luminance of the display defect by adding or subtracting a compensation value to data to be displayed on the display defect. Therefore, the display defect compensation method of the flat panel display device according to the present invention can completely compensate for the luminance of the display defect that is difficult to be compensated only by a fair solution.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (8)

Analyzing the correlation between the lens assembly and the panel with respect to the display panels of various models to create a correlation map between the lens and the panel; Detecting a display defect on the display panel; Comparing display defect information obtained by analyzing the display defect and information on the display panel with a correlation map between the lens and the panel and obtaining position information of the display defect from the correlation map between the lens and the panel; Determining compensation values for compensating for the luminance of the display defect; Storing the compensation values and position information of the display defect in a memory; And And modulating the digital video data to be displayed on the display defect using the compensation values and the position information stored in the memory to display an image on the flat panel display panel. . The method of claim 1, The correlation map of the lens and the panel, Relative position information of the display panel corresponding to overlapping and non-overlapping portions of the lenses of the lens assembly, position information of occurrence of line defects that may occur in the display panel obtained from the relative position information, and compensation values applied to the line defects. The position information of the display panel to which the display panel has been added or subtracted, the position information of occurrence of surface defects that may occur in the display panel obtained from the relative position information, the position information of the display panel to which the compensation values applied to the surface defects are added, and the relative Flat panel display including position information of surface / line mixed defects that can be generated in the display panel obtained from position information, and position information of the display panel to which compensation values given to the surface / line mixed defects are added or subtracted; Method of compensating for display defects on the device. The method of claim 2, Position information of the display panel to which the compensation values applied to the line defects are added or subtracted, Location information of the left progressive compensation region defined based on the start point of the overlapping portion between the lenses, position information of the right progressive compensation region determined based on the end point of the overlapping portion between the lenses, and the left progressive compensation region and the right progressive Including location information of the central compensation area located between the compensation areas, The compensation value of the central compensation area is determined to be the highest value within the line defect, and the compensation value of the progressive compensation areas is determined to be a value between the compensation value of the central compensation area and zero, And the progressive compensation areas are virtually divided into a plurality of sections to which the compensation value is assigned, and the compensation values gradually vary between the sections. The method of claim 3, wherein Position information of the left progressive compensation area, Location information indicating a section disposed on the right side of the left progressive compensation region based on a start point of the overlapping portions between the lenses, and a section disposed on the left side of the left progressive compensation region based on a start point of the overlapping portions between the lenses Including location information indicating a, Position information of the right progressive compensation area, Location information indicating a section disposed on the right side of the right gradual compensation region on the basis of an end point of the overlapping portion between the lenses, and a section disposed on the left side of the right gradual compensation region on the basis of the end point of the overlapping portion between the lenses Display defect compensation method of the flat panel display device comprising the position information indicating. The method of claim 2, Position information of the display panel to which the compensation values applied to the surface defect are added or subtracted, Location information of the left progressive compensation region defined based on the start point of the overlapping portion between the lenses, position information of the right progressive compensation region determined based on the start point of the overlapping portion between the lenses, and the left progressive compensation region and the right progressive Including location information of a central compensation area neighboring any one of the compensation areas; The compensation value of the central compensation area is determined to be the highest value in the plane defect, and the compensation value of the progressive compensation areas is determined to be a value between 0 and the compensation value of the central compensation area. And the progressive compensation areas are virtually divided into a plurality of sections to which the compensation value is assigned, and the compensation values gradually vary between the sections. The method of claim 5, wherein Position information of the progressive compensation region, Position information indicating a section disposed on the right side of the progressive compensation region divided based on one of a start point and an end point of the overlapping portion between the lenses and position information indicating a section disposed on the left side of the progressive compensation region; Display defect compensation method of the flat panel display comprising a. The method of claim 2, Position information of the display panel to which the compensation values given to the surface / line mixed defects are added or subtracted, Position information indicating each of the central compensation region divided by the starting point of the overlapping portion between the lenses and the weak black line, and position indicating the weak bright line adjacent to the weak black line based on the end point of the overlapping portion between the lenses. Contains information, The compensation value of the central compensation area is determined to be the highest value within the plane / line mixing defect, and the compensation values of the weak black line and the weak bright line are determined to be a value between the compensation value of the central compensation area and 0, The weak black line and the weak bright line are virtually divided into a plurality of sections to which the compensation value is respectively provided, and the compensation values gradually vary between the sections. The method of claim 7, wherein The black line and the bright line And position information indicating each of the sections divided based on a start point and an end point of the overlapping portion of the lenses.

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