Current Optics and Photonics

Optical Society of Korea (한국광학회)
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Design of an Ultrasmall Flexible-endoscope Illumination Optical System with Bat-wing Light Distribution

  • Ju-Yeop Yim (Department of Nano Semiconductor Engineering, Tech University of Korea) ;
  • Chul-Woo Park (Department of Nano Semiconductor Engineering, Tech University of Korea) ;
  • Mee-Suk Jung (Department of Nano Semiconductor Engineering, Tech University of Korea)
  • Received : 2023.08.25
  • Accepted : 2023.10.15
  • Published : 2023.12.25
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Abstract

In this paper, an illumination optical system that can mitigate the saturation phenomenon in the center of an image (caused by the typical flexible-endoscope illumination system using LEDs with Lambertian light distribution) is designed. When an LED with Lambertian light distribution is used as a light source, the amount of light in the center of the endoscopic illumination system is relatively high, compared to the periphery, causing saturation in the image. Since this phenomenon causes difficulty in detecting the patient's lesion, it is necessary to find a lighting-system design that can alleviate the saturation phenomenon. Therefore, in this paper a lighting system with bat-wing light distribution, which can lower the intensity at the center and secure the maximum amount of light at the maximum light distribution angle, is designed. In addition, to check the performance of the designed lighting system, a simulation of illumination and luminance is conducted for a system using a common aspherical lens with otherwise the same components. As a result, it is confirmed that the lighting system designed in this paper effectively reduces the luminance value at the center and secures more luminance values at the periphery than the familiar lighting system.

Keywords

Acknowledgement

This work was supported by a Development of high-performance smart gastroscope system (GK18D0100, Development and commercialization of AI & motorization technology based high-performance smart gastroscope system) grant, funded by the Korea Medical Device Development Fund.

References

  1. Modeling Sources in LightTools, Synopsys Inc., CA, USA, p. 68.
  2. E. Abel, W. Xi, and P. White, "Methods for removing glare in digital endoscope images," Surg. Endosc. 25, 3898-1817 (2011).
  3. P. Han, Y.-C. Tseng, and C.-M. Tsai, "Wide field of view lens design with uniform image illumination in capsule endoscope system," Microsyst. Technol. 27, 1115-1122 (2021). https://doi.org/10.1007/s00542-018-4104-y
  4. A. A. Trofimuk, "Using Bezier curves in the automatic design of nonimaging optical systems," J. Opt. Technol. 80, 259-262 (2013). https://doi.org/10.1364/JOT.80.000259
  5. A. Riskus, "Approximation of a cubic bezier curve by circular arcs and vice versa," Inform. Technol. Contr. 35.6 (2006).
  6. D. E. Lord, G. W. Carter, and R. R. Petrini, "Flow observation by rod lens and low-light video (videotape script: January 4, 1977)," (U. S. Department of Energy Office of Scientific and Technical Information), https://digital.library.unt.edu/ark:/67531/metadc1074549/ (Accessed Date: Aug. 10, 2023).
  7. T. Igarashi, "Illumination optical system for an endoscope," U.S. Patent 4952040A (1990).