Force characteristics of slim pickup actuator to improve actuating performances

Recently, there has been a trend to lower the tilt margin in multifunctiona l rewritable optical disk drives and many attempts have been made to constr uct a servo system to compensate the tilt in such devices as compact disk-r ewritable (CD-RW) or digital versatile disk-random access memory (DVD-RAM) drives in view of rewritable disks. However, in the slim-type drives for No tebook PCs, it is very difficult to realize mechanisms for tilt servo witho ut accompanying impairment of the gain property, due to spatial constraints . In this paper, we suggest a method of controlling the driving force to di minish the variance of mechanical tilt over the entire movable range of wir e-spring-suspension-type actuators, and propose a process for precise analy sis of driving force. In addition, based on the results of force analysis, we present the conditions that minimize the phase disturbance in subsidiary resonances which have adverse effects on the servo performance of slim-typ e pickup actuators.