Mechanical Filter on Actuator for System Stability of 9.5 mm Drive

Song, Byung Youn; Lee, Dong Ju; Kang, Hyung Joo; Cho, Won Ik; Ryoo, Byung Ryul; Seong, Pyong Yong; Lee, Kyung Ho; Park, No Cheol; Park, Young Pil

doi:10.1143/jjap.43.4786

Cited by 9 publications

(9 citation statements)

References 2 publications

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“…Adding for the comparison, the data transfer rate of BD 1x is defined as 36 Mbps and the one of DVD 1x is defined as 1.38 Mbps. To achieve high rotational speed of disc with maintaining the system stability, pickup actuator should have high resonance frequencies and low resonance peaks of flexible modes (Song et al 2001(Song et al , 2004Lee et al 2002). The frequencies are depend on the structural stiffness of the moving part of the actuator.…”

Section: Introductionmentioning

confidence: 99%

Design of moving magnet type pickup actuator using inserted coil

et al. 2009

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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.

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Section: Introductionmentioning

confidence: 99%

Design of moving magnet type pickup actuator using inserted coil

et al. 2009

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“…An optical pickup actuator is a core component in optical storage devices and used to write the information or read it by positioning precisely an objective lens (OL) on the disk as a track following device. To realize above-mentioned requirements, it is essential for the optical pickup actuator to have wide servo bandwidth and high sensitivity (Lee et al 2002;Song et al 2004;Lee et al 2005b). This servo bandwidth is controlled by flexible mode frequencies and flexible mode peaks which are caused by the flexibility of moving parts in the actuator.…”

Section: Introductionmentioning

confidence: 99%

“…To settle them as the index of the performance of actuators, the gain margin is defined as the absolute value of the difference between the gain at 1 kHz and the gain at the first flexible mode frequency. If an actuator did not have sufficient gain margins, total system becomes unstable for high-speed operations in high density reading and recording (Song et al 2001;Lee et al 2002;Song et al 2004). Therefore, the flexible mode frequencies and peaks of optical pickup actuators are the most important factors for high density reading and recording.…”

Section: Introductionmentioning

confidence: 99%

Design of hybrid type’s optical pickup actuator for system stability in high density reading and recording

et al. 2009

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Recently, there has been a trend to have large capacity and high data transfer rate in optical disk drive. Pickup actuator also should have high performance for satisfying this trend. Since moving magnet type actuator has more simple and robust structure than moving coil type one, we designed moving magnet type to accomplish high flexible mode frequency. However, the driving sensitivity of moving magnet type actuator was low because of its characteristics as following. At first, moving parts including magnets are heavy and electromagnetic (EM) circuits are not closed-loop owing to yoke composed of paramagnetic materials. Therefore, in order to increase the driving sensitivity without the degradation of the other dynamic characteristics, EM circuits were redesigned by adding solenoid coils on existing mechanism. As a result, the hybrid type actuator composed of moving magnet type and moving coil type was suggested to obtain high sensitivities and high flexible mode frequency. Design variables of EM circuits and structure parts were decided through parametric study and design of experiments procedure. Optimization algorithm using variable metric method was used to improve performance. Based on these results, the final model was presented.

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“…It is used to write and read the information by positioning precisely an objective lens (OL) on the disk as a track following device. To realize above-mentioned requirements, it is essential for the optical pickup actuator to have high sensitivity, wide servo bandwidth, and small size (Lee et al 2002(Lee et al , 2005cSong et al 2004). But, to use existing methods to increase the data capacity such as BD and HD-DVD, a very precise focusing servo system and flat disk substrate are needed because the working distance and the defocus margin of OL are relatively small and so a pickup actuator can collide with disk media.…”

Section: Introductionmentioning

confidence: 99%

“…van der Aa et al (2002) reported the realization for a small form factor optical (SFFO) drive, featuring 1 GB on a 30 mm rewritable optical disk, using the linear actuator of rack and pinion type and the four-wire spring type actuator, with dimensions comparable to PCMCIA-like drives. Song et al (2004) introduced a method of improving the gain margin by the redesign of modal parameters for an ultraslim COMBO actuator. Ke and Huang (2004) designed a novel slim tilt-controllable actuator having a printed circuit board as its lens holder for optical pickup heads through DOE procedures.…”

Section: Introductionmentioning

confidence: 99%

Development of symmetric type slim optical pickup actuator for flexible disk system

et al. 2007

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Recently, in information storage devices, several characteristics such as high data transfer rate, large storage capacity and small drive size are required as high-definition television (HDTV) broadcasting, mobile devices, and notebook personal computer (PC) were popularized. In optical disk drive (ODD), several actuators have been developed to satisfy these specifications. In this paper, we presented the symmetric type slim actuator with efficient tracking magnetic circuits for the flexible disk system. At first, electromagnetic (EM) circuits were designed to have big driving force for high sensitivities through design of experiments (DOE). And, in structural parts, we designed the actuator that had proper control bandwidth through several redesigns of moving parts. Consequently, the final model was fabricated and dynamic tests were experimented. And, it was checked that our actuator had a very high tracking sensitivity and could be applied to the flexible disk system.

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Mechanical Filter on Actuator for System Stability of 9.5 mm Drive

Cited by 9 publications

References 2 publications

Design of moving magnet type pickup actuator using inserted coil

Design of moving magnet type pickup actuator using inserted coil

Design of hybrid type’s optical pickup actuator for system stability in high density reading and recording

Development of symmetric type slim optical pickup actuator for flexible disk system

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