Multiple LEDs luminous system in capsule endoscope

Yang-Mang Ou*, Shih Wei Huang, Hsin Hung Lee, Yung Lin Chen, Ko Chih Huang, Yi Ting Kuo

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

4 Scopus citations


Developing the luminous system in a capsule endoscope, it is difficult to obtain an uniform illumination[1] on the observed object because of several reasons: the light pattern of LED is sensitively depend on the driving current, location and projective angles; the optical path of LED light source is not parallel to the optical axis of the nearby imaging lenses; the strong reflection from the inner surface of the dome may saturate the CMOS sensors; the object plane of the observed intestine is not flat. Those reasons induce the over-blooming and deep-dark contrast in a picture and distort the original image strongly. The purpose of the article is to construct a photometric model to analyze the LED projection light pattern, and, furthermore, design a novel multiple LEDs luminous system for obtaining an uniform-brightness image. Several key parameters resulting as illumination uniformity has been taken under the model consideration and proven by experimental results. Those parameters include LED light pattern accuracy, choosing LED position relative to the imaging optical axis, LED numbers, arrangement, and the inner curvature of the dome. The novel structure improves the uniformity from 41% to 71% and reduces the light energy loss under 2%. The progress will help medical professionals to diagnose diseases and give treatment precisely based on the vivid image.

Original languageEnglish
Title of host publicationAdvanced Biomedical and Clinical Diagnostic Systems V
StatePublished - 30 Apr 2007
EventAdvanced Biomedical and Clinical Diagnostic Systems V - San Jose, CA, United States
Duration: 21 Jan 200727 Jan 2007

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceAdvanced Biomedical and Clinical Diagnostic Systems V
Country/TerritoryUnited States
CitySan Jose, CA


  • Capsule endoscope
  • Multiple LEDs luminous system
  • Uniformity


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