3 Ways Imaging Colorimetry Can Improve Your FPD Inspection Process Presented By: Hubert Kostal, PhD November 4, 2014
Hubert Kostal, PhD VP of Sales and Marketing As Radiant Vision Systems’ VP of Sales and Marketing, Hubert Kostal has helped global brands implement imaging technology in their production processes to improve display quality and optimize their supply chain. During his 7 years with the company, he has been a key driver in the transition of the technology from the lab to the production floor. Prior to joining Radiant, he held VP roles in both the semiconductor and LCD industries. He holds a PhD in Mathematics from The University of Texas, Austin, and is the owner of 2 patents.
Outline Market drivers • Problem statement • Solution components • Quality inspection • Defect detection • Mura detection • Maximizing ROI • 3 Ways Imaging Colorimetry Improves FPD Inspection 3 4 November 2014
Market forces: keeping up / gaining advantage = [End] Customer experience Display Quality = Return / repair / replacement Cost + Production costs + Lost future business 3 Ways Imaging Colorimetry Improves FPD Inspection 4 4 November 2014
Human inspectors are not all that reliable! Escape (miss) rate Rarity effect Hard to see defects Easy to see defects Human visual inspectors have poor performance on: 0% 50% 100% - Difficult to see defects - Rarely seen defects Occurrence rate 3 Ways Imaging Colorimetry Improves FPD Inspection 5 4 November 2014
Imaging colorimeters …are CCD -based imaging systems (i.e., cameras) that are designed to replicate and quantify human perception of brightness and color 3 Ways Imaging Colorimetry Improves FPD Inspection 6 4 November 2014
Image analysis for FPD inspection Test Library Quality Tests Defect Detection Mura Tests Report Measurement Pass/ Sequence Test Sequence Fail 3 Ways Imaging Colorimetry Improves FPD Inspection 7 4 November 2014
What failure modes to test for? Probability of OPTIONAL* MUST TEST occurrence Individually important Maximum allowed Important in failure rate aggregate A B Ignorable in C aggregate D E F G H I … Z Failure modes * Assuming no “high cost” failure modes exist. 3 Ways Imaging Colorimetry Improves FPD Inspection 8 4 November 2014
Role of test (image analysis) software Test control Test images Test sequence & results Measurement setup Test results 3 Ways Imaging Colorimetry Improves FPD Inspection 9 4 November 2014
Example: Uniformity testing Measurement image Test analysis Color edge mura is a deviation in color at one or more The color edge mura is shown as a deviation from the of the edges. overall color. 3 Ways Imaging Colorimetry Improves FPD Inspection 10 4 November 2014
Example: Pixel-scale defects Measurement image Test analysis Particle defects are very small blemishes on the display. In this particular analysis, the display is segmented into These can be the result of dust or defective pixels regions to allow assessment of clustering. present in the display. 3 Ways Imaging Colorimetry Improves FPD Inspection 11 4 November 2014
Example: Mura detection Measurement image Test analysis Light leakage consists of different size bright areas Individual mura are assigned JND (just noticeable near the edge of the display. difference) or similar values to assess their relative visibility and importance. 3 Ways Imaging Colorimetry Improves FPD Inspection 12 4 November 2014
When does testing pay off? Assessing ROI Value of testing ($) End customer quality Production cost reduction Don’t test. Fix the process instead. Imaging colorimeter based testing 0% ~0.5% ~10 -25% 100% Rate of occurrence of defects 3 Ways Imaging Colorimetry Improves FPD Inspection 13 4 November 2014
Quick summary Market drivers : Quality improvement and cost reduction • Problem : Human inspectors are variable, and less and less capable. • Solution components : Imaging colorimeters and analysis software • Examples: • 1. Quality inspection : Color and luminance uniformity 2. Defect detection : Pixel defects, line defects, and particles 3. Mura detection : General and specific mura Maximizing ROI : When is testing valuable? • 3 Ways Imaging Colorimetry Improves FPD Inspection 14 4 November 2014
Thank You! A recorded version of this presentation will be posted to our website within one week. You will receive a link to it via e-mail. If you have questions regarding this topic or presentation, please contact us at info@RadiantVS.com
Recommend
More recommend
