High Speed LAPS System for pH Image Using Line Scanning with a Chopping Wheel

Sang-Kon BAE  Il-Yong PARK  Shin-Won KANG  Jin-Ho CHO  

IEICE TRANSACTIONS on Electronics   Vol.E86-C   No.6   pp.1109-1113
Publication Date: 2003/06/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: LETTER
Category: Electronic Circuits
LAPS,  pH image,  line scan,  chopping wheel,  

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We propose a new detection method of a 2-dimensional pH image to measure the pH distribution of test materials by illuminating a frequency modulated light to LAPS using a chopping wheel. It could simultaneously measure signals in one line by applying a modulated light with a different frequency for each pixel, using a chopping wheel for modulating the frequency, and calculating an amplitude with respect to a frequency component by the light source. To test the proposed method, we implement a chopping wheel in consideration of a LAPS's characteristic, and reconstructed an image by frequency analysis using the implemented chopping wheel and 4 mm test pattern image. As a result, we verified that the proposed method using the chopping wheel was able to detect 30 times faster a 3030 pixels pH image having a PSNR more than 22 dB above the conventional method.