Browse Prior Art Database

Automatic Inspection Equipment for Thin Film Transistor/Liquid Crystal Display

IP.com Disclosure Number: IPCOM000114985D
Original Publication Date: 1995-Feb-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Gohda, Y: AUTHOR

Abstract

Disclosed is a Automatic Inspection Equipment for Thin Film Transistor - Liquid Crystal Display (TFT-LCD). This equipment takes two stages to detect the defects on a TFT-LCD screen. At the first stage this equipment utilizes the defect emphasis driving mode to search out all potential defects speedily and accurately. At the second stage this equipment uses the normal operation mode to detect all countable defects. This two stage operation improves detectability and operation time of the Automatic Inspection Equipment.

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Automatic Inspection Equipment for Thin Film Transistor/Liquid Crystal
Display

      Disclosed is a Automatic Inspection Equipment for Thin Film
Transistor - Liquid Crystal Display (TFT-LCD).  This equipment takes
two stages to detect the defects on a TFT-LCD screen.  At the first
stage this equipment utilizes the defect emphasis driving mode to
search out all potential defects speedily and accurately.  At the
second stage this equipment uses the normal operation mode to detect
all countable defects.  This two stage operation improves
detectability and operation time of the Automatic Inspection
Equipment.

      The Figure shows the example of this equipment applied to the
TFT-LCD cell inspection system.  This system consists of four main
blocks, TFT-LCD cell driver (1), CCD Camera (2), Image Transaction
Unit (3) and TFT-LCD cell (4).  The TFT-LCD cell driver supports two
complementary driving modes.  One is normal driving mode for
production module level operation, and the other is light defect
emphasis driving mode.  The driver controls write cycle longer and
write pulse width shorter in this emphasis mode.

      In the emphasis driving mode, Image Transaction Unit analyzes
image data from CCD camera and search out all potential light defects
on the LCD screen.  The transaction unit checks up
position,color,spot size and brightness of all potential light
defects.  Then the transaction unit switches driving mode from defect
emphasis driving mode to n...