Return to search

The real-time image focusing technique via DVD pickup head

Due to maturity of experimental technology in recent years, automatic optical inspection (AOI) is used in many industrial applications to replace visual inspection with high-speed and reliable characteristics. Because standard industrial AOI instruments are very expensive, this work introduces a low-cost and high performance AOI instrumentation technique for industrial applications.
In this study, we develop an image auto focusing system based on the pickup head of DVD player. We alter the optical path of pickup head and integrate the CCD camera in this system. The idea is to use focus error signal in the linear focus region to estimate the distance between pickup head and object surface. In addition, a capacitance gauging instrument is used to measure the displacement. A PC based control law is then developed by using the PZT to drive the auto focusing system.
By setting up such a low-cost system, the experimental results show that the time required for focusing performance is within 0.4s in most cases while the longest focusing time is about 1s. It is hoped that the results of this study can be implemented for real industrial AOI applications.

Identiferoai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0716107-163152
Date16 July 2007
CreatorsChiu, Shao-Chun
Contributorsnone, none, CHEN-WEN YEN
PublisherNSYSU
Source SetsNSYSU Electronic Thesis and Dissertation Archive
LanguageCholon
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0716107-163152
Rightswithheld, Copyright information available at source archive

Page generated in 0.002 seconds