Abstract: Disclosed is a subminiature linear vibrator including a stationary body (100) formed by installing a printed circuit board (10), on which a ring-shaped field coil (12), at least one resonant passive element (14), and a frequency generating control chip (16) are mounted, on a lower case (6) of a main body, the main body including upper and lower cases (4, 6); and a movable body (200) formed by mounting a ring-shaped balance weight (22) and a ring-shaped permanent magnet (24) on the lower surface of a bracket (20) having an air flow hole (21) formed therethrough and connecting an elastic spring (26) to the lower surface of the upper case (4) and an air flow hole peripheral portion (20a) of the bracket (20), wherein the ring-shaped permanent magnet (24), magnetized with two poles vertically located at upper and lower portions thereof, is disposed adjacent to the ring-shaped field coil (12).

Abstract: Disclosed is an improved flat vibration motor to be disposed in a mobile communication terminal, etc. for generating a vibration signal. A brushless-type vibration motor without brushes and a commutator is adopted, instead of a brush-type vibration motor with the brushes and commutator. An eccentric portion is disposed on one side of the peripheral surface of a rotor made of a permanent magnet, and one or more pairs of hall sensors are mounted in the vibration motor so as to start and drive the vibration motor. A motor controller may be used as internally or externally disposed on the vibration motor. The arrangement of a stator coil is improved so as to reduce the loss of magnetic flux as well as remove the non-operation points, thereby preventing the starting and driving disorders of the vibration motor, and improving its performance and efficiency.

Abstract: A filler which imparts heat dissipating and shrinkage reduction characteristics to a mixture of the filler with a synthetic resin. The mixture is useful for providing a layer between gel coat and a layer including glass fiber and resin to prevent the formation of small air voids. The filler imparts structural strength to resin so that a useful product may be made from only a layer of gel coat with a layer of the filler and resin. The filler is preferably a mixture of calcium silicate and mica, and in the preferred embodiment the calcium silicate is wollastonite. An improved apparatus for applying the mixture of synthetic resin and filler comprises a modified prior-art spray gun and a mixer which includes a plurality of augers for thoroughly mixing the filler with the resin. The preferred embodiment of the resin comprises a terpolymer mixed with styrene and having a Brookfield thixatropic index of from 2 to 4.