IP Library Granted Patent US 7,439,757
Granted Patent B2
US 7,439,757 · App. 11/442,140 · Granted Oct 21, 2008

Apparatus and method for inspecting liquid crystal display

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Quick Facts
Patent No.
US 7,439,757
App. No.
11/442,140
Granted
Oct 21, 2008
Kind
B2
Abstract

A liquid crystal display (LCD) inspection apparatus for inspecting an LCD panel, includes a worktable to support an LCD panel seated on a front side of the worktable, probe units to be electrically connected to the LCD panel, a backlight unit to emit light toward the LCD panel, a first polarizing plate arranged in front of the LCD panel to polarize the light, and a second polarizing plate arranged between the LCD panel and the backlight unit to polarize the light, and a shutter unit to selectively shut off the light emitted from the backlight unit toward the LCD panel.

Claims (23)

1. A liquid crystal display (LCD) inspection apparatus for inspecting an LCD panel, comprising:

a worktable that supports the LCD panel to be seated on the worktable;

probe units that are electrically connected to the LCD panel;

a backlight unit that emits light toward the LCD panel;

a first polarizing plate that is arranged in front of the LCD panel to polarize the light;

a second polarizing plate that is arranged between the LCD panel and the backlight unit to polarize the light; and

a shutter unit that selectively shuts off the light emitted from the backlight unit toward the LCD panel,

wherein the shutter unit is arranged between the second polarizing plate and the backlight unit,

wherein the shutter unit includes at least one shutter that is selectively positioned between the backlight unit and the second polarizing plate; and

a driver that is coupled to the shutter to selectively shut off the backlight unit and the second polarizing plate from each other.

2. The LCD inspection apparatus according to claim 1 , wherein the driver includes a motor that has a shaft extending in a direction perpendicular to an emission direction of the light emitted from the backlight unit, the shaft being coupled to one end of the shutter to hingably rotate the shutter such that the shutter selectively extends in a direction parallel or perpendicular to the emission direction of the light.

3. The LCD inspection apparatus according to claim 1 , wherein the driver includes a motor that has a shaft extending in a direction perpendicular to an extension direction of the shutter, the shaft being coupled to one end of the shutter to hingably rotate the shutter in a direction perpendicular to an emission direction of the light emitted from the backlight unit.

4. The LCD inspection apparatus according to claim 2 , wherein the at least one shutter comprises at least two shutter parts that selectively overlap with one another, thereby shutting off the light emitted from the backlight unit to the second polarizing plate.

5. The LCD inspection apparatus according to claim 3 , wherein the at least one shutter comprises at least two shutters that selectively overlap with one another, thereby shutting off the light emitted from the backlight unit to the second polarizing plate.

6. The LCD inspection apparatus according to claim 1 , further comprising:

an imaging unit that photographs an image of the LCD panel seated on the worktable; and

an image processor that receives an image produced by the imaging unit, and extracts defect information from the received image.

7. The LCD inspection apparatus according to claim 6 , further comprising:

illumination units which emit illumination light to surfaces of the LCD panel seated on the worktable.

8. The LCD inspection apparatus according to claim 7 , wherein the illumination units include:

a first illumination unit that is arranged between the first polarizing plate and the LCD panel, wherein the first illumination unit irradiates a front surface of the LCD panel from a periphery of the LCD panel; and

a second illumination unit that is arranged between the second polarizing plate and the LCD panel, wherein the second illumination unit irradiates a rear surface of the LCD panel from a periphery of the LCD panel.

9. The LCD inspection apparatus according to claim 1 , wherein the shutter unit is arranged between the backlight unit and the second polarizing plate.

Assignments (2)
CHANGE OF NAME Recorded Jun 19, 2008
From: LG.PHILIPS LCD CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 021147/0009 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 30, 2006
From: KANG, DOO WOO; EOM, SOUNG YEOUL; KIM, BONG CHUL; YANG, KI SOUB
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 017943/0912 →