Microsystem Technologies

, Volume 15, Issue 10–11, pp 1719–1728 | Cite as

Design of moving magnet type pickup actuator using inserted coil

  • Myeong-Gyu Song
  • Yoon-Ki Kim
  • No-Cheol Park
  • Jeonghoon Yoo
  • Young-Pil Park
  • Nobuaki Onagi
  • Goichi Akanuma
Technical Paper

Abstract

Recently, the demand of the information storage devices with large storage capacity such as Blu-ray Disc and high-definition television is increased. In keeping with this trend, the optical storage devices are also required to have high data transfer rate and large storage capacity. To satisfy these requirements, the actuator for optical disc drive should have a high servo bandwidth to compensate the vibration of optical disc. The servo bandwidth is limited by some flexible modes of the actuator, thus it is essential to make these frequencies of flexible modes to high frequency region. The frequency of flexible mode depends on materials and shape. Stiff materials and simple shape is useful to increase the frequency of flexible mode. In this paper, we suggested a moving magnet type actuator having flexible modes which are happened at high frequency region. Generally, the moving magnet type actuator has an advantage to increase the frequency of flexible mode because the moving magnet type actuator has simple structure and the Young’s modulus of magnet is high. However, large moving mass and inefficiency of Electromagnetic (EM) circuit cut down driving sensitivities of actuator. To improve driving sensitivities, we designed the model with the closed EM circuit for tracking actuation. The design of experiments (DOE) procedure is applied to get proper design parameters and the variable metric method (VMM) which is a technique of optimization is used to improve driving sensitivity. The lens holder is also improved based on the optimization result of EM circuit. And to make up for the low efficiency of EM circuit, the thermal stability is checked on condition that the input current is very high. At last, the final design of moving magnet type actuator is suggested and it is verified that the driving performance and the structural stiffness of the final design is sufficient.

References

  1. Aman Y, Onagi N, Murata S, Sugimoto Y, Koide D, Tokumaru H (2007) High speed flexible optical disk with cylindrically concaved stabilizer. Jpn J Appl Phys 46(6B):3750–3754. doi:10.1143/JJAP.46.3750 CrossRefGoogle Scholar
  2. Go SS, Ryu JH, Park KH, Jeong HS (1998) Actuating characteristics of an asymetric optical pick-up fine actuator of a high speed CD-ROM. Trans Korean Soc Noise Vibr Eng 8(2):346–352Google Scholar
  3. Jeong HS, Yoon YH (2001) Improvement of magnet circuit characteristics for moving magnet type actuator in high density optical disc. In: Proceedings of the KSNVE Annual Autumn Conference, pp 780–785Google Scholar
  4. Kim DH, Jeong HS, Yoon YH (2004a) Improvement of assembling efficiency for moving magnet type actuator in high density optical disc. Trans Korea Soc Noise Vibr Eng 14(12):1255–1260Google Scholar
  5. Kim H, Cho S, Kim YJ, Kang S (2004b) Effect of thermal deformation of optical pick-up on the optical performance. Jpn J Appl Phys 43(7B):4795–4796. doi:10.1143/JJAP.43.4795 CrossRefGoogle Scholar
  6. Kim H, Cho S, Kang S (2005) Effect of thermal deformations of an optical pick-up base on the optical properties of DVD optical system. Microsyst Technol 11:1065–1070. doi:10.1007/s00542-005-0520-x CrossRefGoogle Scholar
  7. Lee KT, Lee DJ, Park NC, Park YP (2002) Improvement of dynamic characteristics for optical pickup actuator using sensitivity analysis. Microsyst Technol 9:25–30. doi:10.1007/s00542-002-0228-0 CrossRefMathSciNetGoogle Scholar
  8. Matsushita Electric Industrial Co. Ltd (2001) Objective lens driving apparatus (Online) Available at: http://www.freepatentsonline.com/y2001/0021164.html (Accessed 1 April 2009)
  9. Park C, Yoo JH, Park NC, Park YP, Shimano T, Nakamura S (2006) Design of swing arm type actuators considering thermal and dynamic characteristics. Microsyst Technol 13:777–796. doi:10.1007/s00542-006-0280-2 CrossRefGoogle Scholar
  10. Song BY, Shin KS, Kim JG, Nam DS, Sung PY, Lee JH (2001) Development of ferrofluidic damper for optical pick-up actuator. In: Proceeding of the Asia–Pacific vibration conference, Hangzhou, China, Jilin Science and Technology Press, I, pp 259–263Google Scholar
  11. Song BY, Lee DJ, Kang HJ, Cho WI, Ryoo BR, Seong PY, Lee KH, Park NC, Park YP (2004) Mechanical filter on actuator for system stability of 9.5 mm drive. Jpn J Appl Phys 43(7B):4786–4789. doi:10.1143/JJAP.43.4786 CrossRefGoogle Scholar
  12. Song BY, Jang DJ, Lee YB, Lee JH (2007) Improvement of system performance of the optical disc drive adopting ferrofluidic damper for pick-up actuator. Jpn J Appl Phys 46(6B):3741–3746. doi:10.1143/JJAP.46.3741 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Myeong-Gyu Song
    • 1
  • Yoon-Ki Kim
    • 1
  • No-Cheol Park
    • 1
  • Jeonghoon Yoo
    • 1
  • Young-Pil Park
    • 1
  • Nobuaki Onagi
    • 2
  • Goichi Akanuma
    • 3
  1. 1.Center for Information Storage Device (CISD)Yonsei University YERC #332SeoulKorea
  2. 2.Manufacturing Technology R&D CenterRicoh Company Ltd.YokohamaJapan
  3. 3.Advanced Technology R&D CenterRicoh Company Ltd.YokohamaJapan

Personalised recommendations