The selective frequency analysis method is suggested in the holographic data storage system with the nyquist aperture to reduce the size of hologram. The image filter was designed with many different methods to improve the bit error rate caused by the nyquist aperture. In previous the methods of image restoration for HDS, an iteration time and a highly precise point spread function were necessary. In this paper, we describe the optical system with analytic method. Thereby, we expect our result help the researchers to design the filter.

Optical library system consists of disc magazines, cabinets, transfer robot and drive. Transfer robot delivers desired disc or magazine in cabinet to drive which reads data of disc. Conventional archive system stores discs in a line and transfer robot moves in one dimension. However, to store more discs, new optical archive system, optical library system, is developed which stores discs in two dimension like bookcase. Transfer robot should know the position and stored data of desired magazine to get correct data. In this paper, addressing algorithm using optical character recognition is proposed. Proposed algorithm is evaluated by experiments with implemented system.

In HDD industry, many technologies have been developed and investigated as means to increase the areal density of drives. Thermal flying-height control has been considered and widely applied in current HDD. When contact occur between TFC slider and disk, the slider has a friction heating induced by highly rotated disk. Moreover, because of the friction heating, additional protrusion of slider can occur. The additional protrusion in contact situation can be a severe effect on head part of slider and disk. Therefore, in this paper, we analyze the friction heating and additional protrusion in contact situation.

An archive system is designed to store data for a long time without loss. However, many important factors such as temperature, dust, vibration, and humidity must be considered to design a successful archive system. Read/write devices, for example optical disk drives(ODDs), in an archive system generate heat while they are in operation. Fans are usually used to remove heat but the air flow accompanies dust into the system result in system failure. In this study, an archive system with six ODDs is chosen as an analysis model and flow together with temperature distributions are computed using a CFD simulation package. Flow analysis is focused on four cooling fans at the rear panel and temperature distribution is studied for various cases of fan operation. From the temperature point of view, fans give significant effects on $4^{th}$ to $6^{th}$ ODDs compared to the $1^{st}$ to $3^{rd}$ ODDs. Also, it is noticed which fan is the most important as far as cooling is concerned.