Comparison between Photo Interrupter and Giant Magnetoresistive Sensor for Auto Focusing System in the Digital Camera

  • Sakura SikanderEmail author
  • Han Nam Lee
  • Hee-Je Kim
Part of the Studies in Computational Intelligence book series (SCI, volume 466)


Photo interrupter (PI) sensors are used to focus the lens in the optical devices such as digital camera, close circuit camera etc. It is cheap and easy to control. Despite of the advantages it has some limitations such as it is difficult to assemble, needs small tolerance and lacks high speed and accuracy. Magnetoresistive (MR) especially giant magnetoresistive (GMR) sensor provides the solution of PI sensor’s weak points. Furthermore, using GMR sensor shows better performances than PI sensor for the focusing system.


photo interrupter giant magnetoresistive sensor auto focus digital camera 


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  1. 1.
    Smith, C.H., Schneider, R.W.: Low-Field Magnetic Sensing with GMR Sensors. Sensors EXPO (1999)Google Scholar
  2. 2.
    Baibich, M.N., Broto, J.M., Fert, A., Nguyen Van Dau, F., Petroff, F.: Giant Magnetoresistance of (001)Fe/(001)Cr Magnetic Superlattices. Phys. Rev. Lett. 61, 2472–2475 (1988)CrossRefGoogle Scholar
  3. 3.
    Jander, A., Smith, C., Schneider, R.: Magnetoresistive Sensors for Nondestructive Evaluation. In: SPIE International Symposium, vol. 5770, pp. 1–13 (2005)Google Scholar
  4. 4.
    Data Specification from Hitachi Metals (2011)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Dept. of Electrical EngineeringPusan National UniversityBusanRepublic of Korea

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