Abstract: Disclosed is a pattern coil type vertical vibrator including: a housing; a magnetic circuit unit placed in the internal space of the housing, and including a magnet perpendicularly placed and a yoke for fixedly receiving the magnet therein; spring members provided with upper ends fixed to the housing and lower ends fixed to the magnetic circuit unit for vertically and elastically supporting the magnetic circuit unit; a vibrating unit, including a weight assembled with the yoke of the magnetic circuit unit, vertically vibrated together with the magnetic circuit unit through the spring members; and a pattern coil, printed on an upper surface of a base for closing a lower surface of the housing, to which power is supplied, so that the pattern coil is interlinked with a magnetic field generated from the magnet and generates force just upwardly when the power is supplied to the pattern coil.

Abstract: Disclosed is a separator for a fuel cell made of a metal plate coated with TiN, a polymer electrolyte membrane fuel cell comprising the separator and a method for manufacturing the separator. According to the invention, the separator can be made to be thin and it is possible to increase the power density, compared to the prior separator made of graphite. At the same time, a proper level of physical strength can be maintained, so that there is no problem of a breakdown by an external shock. In addition, the flow field can be easily formed and the cost is low. Additionally, the polymer electrolyte membrane fuel cell comprising the separator using a metal plate coated with TiN according to the invention has no problem of corrosion of metal separator due to the electrolyte, compared to the prior metal separator, so that the durability is excellent and the lifetime is long.

Abstract: There is provided a method of recording and reproducing an optical recording medium which performs a tracking servo and a focusing servo by irradiating a laser beam onto determined positions including lands and grooves of a track of the recording medium and detecting a tracking error signal and a focusing error signal using an electric signal from an optical pickup for picking up the laser beam reflected from the recording medium. The method includes the steps of: detecting servo information in a plurality of the determined positions including lands and grooves of the track while rotating the recording medium in a state in which only the focus servo is turned on when the optical recording medium is loaded, storing the servo information of the respective determined positions as a table, and performing the servo of the corresponding positions by applying the servo information in table during an actual data recording/reproduction.