| dc.description.abstract | This paper is researching about the illumination system in contact capsule endoscope (CCE). It is difficult to obtain the uniform illumination on the observed object because the light intensity of LED will be changed along with its angular displacement and same as luminous intensity distribution curve. As the location of light source (i.e., LED) is approaching imaging lenses which light source incidents into the cone mirror and then the reflected light will be reflected through the lenses to enter CMOS sensor directly. On the other, the strong reflection rays from the transparent view window (TVW) will incident into the cone mirror and then the reflected light will be reflected by cone mirror indirectly and through the lenses to enter CMOS sensor.
The result of above reasons is bound to make over-blooming on the image plane. These over-blooming will cause image to bring up non-uniform, decreasing image quality. Regarding for this problem, I use the optical design software which is Advanced Systems Analysis Program (ASAP) to build a photometric model for the optimal design of LED illumination system in CCE. According to original model of CCE, I set the several key parameters that are LED quantities, location of LED, geometric shape of LED, tilt angle of surface of LED, distance between LED and cone mirror etc. That is why to decrease the stray light and increase the whole illumination uniformity of CCE. It is major goal to raise the efficiency of CCE system in this paper; hereby I design the best case in illumination system of CCE to get it.
The optimal case is designed by the axial displacement of PCB, radial displacement of LED, tilt angle of surface of LED, divergence angle of LED, rotation angle of LED etc. It can improve illumination system and advance the image quality. It can also help doctor to make a diagnosis and treatment by vivo picture more correct. In this paper, the optimal design of illumination uniformity in the CCE is form origin 0.128 up to optimum 0.603 and it would advance the image quality of CCE greatly. Finally, I expect this latest design of the luminous system with very high practicability for examinations, diagnosis or therapies in medical science.
In the future, if the optimal design of CCE will be further using in industrial field or in novel medical detection technology at the same time optical design of CCE will greatly increase its core value.
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