KR20080033731A - Testing apparatus of display panel and testing method thereof - Google Patents

Abstract

An apparatus for testing a display panel and a testing method thereof are provided to photograph pixels and to correct coordinates of the photographed pixels based on a reference coordinate and a rotary angle of the alignment marks for aligning the display panel and detecting the defect pixels. A display panel containing pixels and alignment marks is mounted on a mounting part(S10). A position of the display panel is mechanically corrected(S20). The alignment marks are photographed(S30). A rotary angle of the display panel is calculated from a predetermined reference position based on the coordinate of the photographed alignment mark(S40). The pixels are photographed(S50). The coordinates of the pixels are corrected based on the reference coordinates and the rotary angle of the alignment mark(S60). Thereby, the display panel is aligned and the defect pixels are detected easily.

Description

Display panel inspection device and inspection method {TESTING APPARATUS OF DISPLAY PANEL AND TESTING METHOD THEREOF}

1 is a schematic diagram of a display panel inspecting apparatus according to an exemplary embodiment of the present invention;

2 is a control flowchart illustrating a display panel inspection method according to an exemplary embodiment of the present invention.

3 is a diagram illustrating a method of calculating a rotation angle of a display panel according to an exemplary embodiment of the present invention.

4A and 4B are diagrams for describing coordinate correction of a display panel pixel according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: seating portion 20: light source

30: imaging unit 40: control unit

100: display panel

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display panel inspection apparatus and an inspection method thereof, and more particularly, to a display panel inspection apparatus and an inspection method thereof for detecting light emitted from the display panel.

The liquid crystal display device includes a thin film transistor substrate on which a thin film transistor is formed, a color filter substrate on which a color filter layer is formed, and a liquid crystal panel on which a liquid crystal layer is positioned. Since the liquid crystal panel is a non-light emitting device, a backlight unit for irradiating light may be disposed on the rear surface of the thin film transistor substrate. Light transmitted from the backlight unit is controlled according to the arrangement of the liquid crystal layer.

In the manufacturing process of the thin film transistor substrate, various inspections for detecting whether the product is defective at each step are required. These tests are divided into open short test (O / S) test, array test, visual inspection (VI), and the like. The inspections generally include a process of irradiating light onto the thin film transistor substrate, measuring the amount of light reflected from the substrate, and measuring the amount of light measured to detect defects on the substrate. This process includes the steps of precisely arranging the thin film transistor substrate to a specific seating portion in order to accurately identify the portion where the defect occurs on the substrate.

In general, a separate camera must be provided for alignment of the substrate, and there is a problem in that the substrate must be accurately arranged prior to defect detection. In addition, depending on the characteristics of the process or the environmental conditions of the process it may be necessary to omit the substrate alignment step, in this case there is a problem that can not accurately determine the defect of the substrate.

Accordingly, an object of the present invention is to provide a display panel inspection apparatus and an inspection method thereof, which can easily align display panels and detect defective pixels without additional devices.

According to the present invention, there is provided a display panel including a plurality of pixels and an alignment mark, and a seating unit on which coordinates for identifying the pixels and the alignment mark are formed; An imaging unit which moves relative to the seating unit and picks up pixels and the alignment mark on the display panel; Calculating a rotation angle of the display panel rotated from a predetermined reference position based on the coordinates of the imaged alignment mark, and imaged based on the imaged alignment mark coordinates, the reference coordinates of the alignment mark, and the rotation angle. It is achieved by the inspection apparatus of the display panel including a control unit for correcting the coordinates of the pixel.

The display panel and the seating portion are rectangular, and the display panel includes a plurality of alignment marks to calculate the rotation angle, and at least two alignment marks are formed on a straight line parallel to a predetermined axis. It is preferable.

The display panel includes a first alignment mark and a second alignment mark, wherein the coordinates of the captured first alignment mark are (a1, b1), and the coordinates of the captured second alignment mark are (a2, b2). In this case, the rotation angle θ at which the display panel is rotated from the predetermined reference position is calculated as follows.

[Equation 1]

θ = arctan (H / L) (H = | a2-a1 |, L = | b2-b1 |)

When the reference coordinate of the first alignment mark is (A, B) and the coordinate of the imaged pixel is (x, y), the coordinate of the corrected pixel (x ″, y ″) may be as follows.

[Equation 2]

On the other hand, according to the present invention, the present invention comprises the steps of: seating a display panel including a plurality of pixels and alignment marks on the seating portion, and mechanically correcting the position of the display panel; Imaging the alignment mark and calculating a rotation angle of the display panel rotated from a predetermined reference position based on the coordinates of the captured alignment mark; Imaging the pixel, and correcting the coordinates of the imaged pixel based on the coordinates of the captured alignment mark, the reference coordinate of the alignment mark, and the rotation angle. .

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

In various embodiments, like reference numerals refer to like elements, and like reference numerals refer to like elements in the first embodiment and may be omitted in other embodiments.

1 is a schematic diagram of a display panel inspecting apparatus according to an exemplary embodiment.

As illustrated, the inspection apparatus of the display panel includes a mounting unit 10 on which the display panel 100 is mounted, a light source unit 20, an imaging unit 30, and a control unit 40 that controls the display panel 100.

The display panel 100 according to the present exemplary embodiment is a thin film transistor substrate used in a liquid crystal display device and an OLED panel, and has a substantially rectangular shape. The display panel 100 includes a plurality of pixels including a thin film transistor. In addition, the display panel 100 is marked with an alignment mark for marking this in order to be seated in the correct position of the seating portion 10 in the inspection step. At least two alignment marks may be provided, and when the alignment marks are seated at predetermined coordinates, it may be determined that the display panel 100 is correctly seated on the seating portion.

The mounting portion 10 has a bottom surface having a substantially rectangular shape, and has a mounting area on which the thin film transistor and the display panel 100 on which the plurality of signal lines are formed are mounted. The mounting unit 10 may include fixing means such as a vacuum chuck or an electrostatic chuck for fixing the mounted display panel 100. In addition, the mounting unit 10 is provided with coordinates for identifying pixels and alignment marks when the display panel 100 is seated, and each pixel and alignment mark when the display panel 100 is seated on the mounting unit 10. The position information of the is recognized by the coordinates formed in the seating portion (10).

The light source unit 20 provides light to the display panel 100. The light emitted from the light source 20 is reflected by the optical plate 21 and irradiated to the display panel 100. Light passing through the optical plate 21 and the display panel 100 is reflected again and transmitted through the optical plate 21 to be input to the imaging unit 30. The optical plate 21 may be a polarizing plate that transmits only light in a specific polarization state, and may be provided as a semi-transmissive mirror to partially reflect, partially transmit.

The imaging unit 30 captures an image of the light reflected from the display panel 100 so that the control unit 40 can obtain position information on the pixel and the alignment mark. The imaging unit 30 is provided with a CCD (Charge-coupled device), a micro microscope, etc. In the conventional case, the imaging unit for imaging pixels and the imaging unit for imaging alignment marks are provided with different optical mechanisms, respectively, First, the display panel 100 is aligned with an image pickup unit for capturing the pixels, and the position information of the pixels is obtained using the image pickup unit for imaging the pixels. According to the present exemplary embodiment, the alignment mark and the pixel are captured by one imaging unit 30. The coordinates of the other pixels can be corrected through the coordinates of the alignment marks, that is, the inspection step of the display panel 100 is simplified, and more easily There is an advantage that can get the information.

Although not shown, an image processor may be further provided between the imaging unit 30 and the control unit 40 to convert and process the captured image into an electrical signal.

In addition, the inspection apparatus of the display panel may further include a driving unit (not shown) for relatively moving the seating unit 10 and the imaging unit 30. That is, the mounting unit 10 may move with respect to the imaging unit 30, the mounting unit 10 may be fixed, and the imaging unit 30 may move on the display panel 100. The drive unit includes a motor, a screw, and the like.

The control unit 40 calculates a rotation angle of the display panel 100 rotated from a predetermined reference position based on the coordinates of the imaged alignment mark, and controls the imaged alignment mark coordinates, the reference coordinates and the rotational angle of the alignment mark. The coordinates of the imaged pixel are corrected based on the above. 2 is a control flowchart illustrating a display panel inspection method according to an exemplary embodiment, FIG. 3 is a diagram illustrating a method of calculating a rotation angle of a display panel, and FIGS. 4A and 4B are coordinate corrections of display panel pixels. A diagram for explaining. A method of aligning the display panel 100 to the mounting portion 10 will be described with reference to the drawings.

First, the display panel 100 including a plurality of pixels and alignment marks is seated on the mounting portion 10 (S10), and the position of the display panel 100 is mechanically corrected (S20). Mechanical correction means physically aligning a predetermined reference position of the display panel 100 using a user or a mechanism including a separate driving unit.

Then, the alignment marks 101 and 102 are imaged using the imaging unit 30 (S30), and the field of view angle θ is calculated based on the coordinates of the captured alignment marks 101 and 102 (S40). .

As shown in Fig. 3, the rectangular seating portion 10 is formed with two-dimensional coordinates composed of X and Y axes. The display panel 100 should be aligned at the reference position (I) shown by a dotted line, but is arranged not parallel to both the X and Y axes from the reference position (I) despite the mechanical correction process. . The display panel 100 includes a first alignment mark 101 and a second alignment mark 102 formed on a predetermined axis, in this embodiment, on a straight line parallel to the X axis, and the display panel 100. ) Is aligned at the reference position (I), the coordinates of the first alignment mark 101 are (A, B), and the coordinates of the second alignment mark 102 are (C, B). That is, the alignment marks 101 and 102 have the same Y value B.

However, the coordinates of the first alignment mark 101 picked up substantially are (a1, b1), and the coordinates of the second alignment mark 102 are (a2, b2). The rotation angle θ at which the display panel 100 is rotated from the reference position I may be expressed by Equation 1, where H = | a2-a1 | and L = | b2-b1 |.

[Equation 1]

θ = arctan (H / L)

That is, the rotation angle θ is a degree of inclination of the display panel 100 with respect to the X axis. If the two alignment marks 101 and 102 are parallel to the Y axis rather than the X axis, If is located at, the rotation angle θ will be expressed as arctan (L / H).

After obtaining the rotation angle θ, the pixel is imaged through the imaging unit 30 (S50), and the coordinates ((a1, b1), (a2, b2)) of the alignment marks 101 and 102 captured are aligned. Using the reference coordinates ((A, B) or (C, B)) of the marks 101 and 102 and the rotation angle θ, the coordinates of the pixel to which the defect is detected or to be corrected are corrected (S60).

FIG. 4A illustrates that the sides of the display panel 100 are changed in parallel with the X and Y axes by moving the display panel 100 by the rotation angle θ in the initial arrangement state. Assume that one pixel coordinate on the imaged display panel 100 is (x, y). In the case of a vector whose Z is the origin and has a length up to (x, y), Z, after rotating the display panel 100, the vector Z is the origin and the length up to (x ', y') is determined. Having a vector Z '.

After the vector Z moves by the rotation angle θ, the vector Z 'coordinates (x', y ') are represented by Equation 2.

[Equation 2]

Then, as shown in FIG. 4B, when the display panel 100 is aligned to the reference position I, the vector Z 'is converted to the vector Z ", and the coordinates of the vector Z" are (x ", y"). The captured coordinates (x, y) are finally corrected to (x ", y"). When the display panel 100 is rotated by the rotation angle θ, the coordinates of the corners of the display panel 100, that is, the point corresponding to the origin of the reference position I are (a, b). , y ") is the same as [Equation 3].

[Equation 3]

The coordinates (a, b) are information on the distance from the origin of the display panel 100, and (a, b) can be obtained using the first alignment mark 101.

First, using Equation 2, the coordinates a1 'and b1' after moving the captured first alignment marks a1 and b1 by the rotation angle θ are as follows. Further, (a1 ', b1') is the same as moving (a1, b1) by A on the X axis and by B on the Y axis.

When the above formula is modified, (a, b) is as follows.

Substituting the above equation into [Equation 2], the coordinate of the final vector Z "is (x", y ") as shown in [Equation 4].

[Equation 4]

In summary, the imaging unit 30 captures the coordinates a1 and a2 of the alignment marks and forms them on the substrate using the coordinates A and B of the alignment marks at the rotation angle θ and the reference position I. The coordinates of all the pixels can be corrected. By the above operation, the position information of the pixel can be known easily and accurately without including a separate imaging unit for the alignment of the display panel 100. The corrected coordinate value corresponding to the position information of the pixel is an important data for repairing when a defect occurs in the pixel.

Although some embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that modifications may be made to the embodiment without departing from the spirit or spirit of the invention. . It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described above, according to the present invention, a display panel inspection apparatus and an inspection method thereof capable of easily arranging display panels and detecting defective pixels without additional devices are provided.

Claims (7)

A mounting part on which a display panel including a plurality of pixels and an alignment mark is mounted, and a coordinate for identifying the pixel and the alignment mark is formed; An imaging unit which moves relative to the seating unit and picks up pixels and the alignment mark on the display panel; Calculating a rotation angle of the display panel rotated from a predetermined reference position based on the coordinates of the imaged alignment mark, and imaged based on the imaged alignment mark coordinates, the reference coordinates of the alignment mark, and the rotation angle. And a control unit for correcting the coordinates of the pixels. The method of claim 1, The display panel and the seating portion are rectangular. The display panel includes a plurality of the alignment marks, And at least two of the alignment marks are formed on a straight line parallel to a predetermined axis. The method of claim 2, The display panel includes a first alignment mark and a second alignment mark, When the coordinates of the picked-up first alignment mark are (a1, b1) and the coordinates of the picked-up second alignment mark are (a2, b2), the rotation angle of the display panel rotated from the predetermined reference position ( θ) is the inspection device of the display panel, characterized in that the following equation. [Equation 1] θ = arctan (H / L) (H = | a2-a1 |, L = | b2-b1 |) The method of claim 3, When the reference coordinate of the first alignment mark is (A, B) and the coordinate of the imaged pixel is (x, y), the coordinates (x ", y") of the corrected pixel are as follows. Inspection device of display panel. [Equation 2]

Mounting a display panel including a plurality of pixels and alignment marks in a seating portion, and mechanically correcting a position of the display panel; Imaging the alignment mark and calculating a rotation angle of the display panel rotated from a predetermined reference position based on the coordinates of the captured alignment mark; And imaging the pixel, and correcting the coordinates of the picked-up pixel based on the coordinates of the picked-up alignment mark, the reference coordinate of the alignment mark, and the rotation angle. The method of claim 5, The display panel includes a first alignment mark and a second alignment mark formed on a straight line parallel to a predetermined axis, When the coordinates of the picked-up first alignment mark are (a1, b1) and the coordinates of the picked-up second alignment mark are (a2, b2), the rotation angle of the display panel rotated from the predetermined reference position ( (theta)) is a method of inspecting a display panel characterized by the following equation. [Equation 1] θ = arctan (H / L) (H = | a2-a1 |, L = | b2-b1 |) The method of claim 6, When the reference coordinate of the first alignment mark is (A, B) and the coordinate of the imaged pixel is (x, y), the coordinates (x ", y") of the corrected pixel are as follows. Inspection method of display panel. [Equation 2]

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