Dynamic characteristics of lens actuator for digital video disk

This paper deals with the dynamic characteristics of a sliding, rotary type small lens actuator for high recording density disk system such as digital video disc. In particular the influence of the vibration modes of the lens holder on the frequency characteristics in the tracking direction is discussed. In order to understand the vibration mode phenomena, we performed numerical analysis by using the finite element method and observed actual vibration with a scanning type laser doppler velocimeter. As a result, we determined the rotational movement of the lens holder around the jitter axis at a few kHz, which turned out additional phase delay in the tracking servo loop and sometimes appears when the size of the actuator decreases. To suppress this movement, we considered the mechanism of this rotational movement and proposed a method of increasing the moment of inertia around the jitter axis. The effectiveness of this method was also confirmed experimentally.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.