Abstract: In a circuit board cooling apparatus, inclined rectifier plates 25 are disposed on a plane rectifier plate 21 with an inclination of about 45°, and an air guide plate 26 is disposed toward a distal end of the inclined rectifier plate 25 such that a distal end 26b of the air guide plate 26 is in contact with a soldering face 2 of a circuit board 1. Cooling air from openings 15 is rectified and guided upward due to a plane rectifier plate 21 and the inclined rectifier plates 25, and the cooling air also flows through between the soldering face 2 of the circuit board 1 and the air guide plate 26 so as to be converged on a soldered portion 3 on the circuit board 1. As a result, the soldered portion 3 is pinpointedly cooled and a cooling rate is improved, thereby improving cooling capability. The cooling rate can be set to 50° C./sec or higher, and the use of Pb-free solder is promoted replacing Sn-Pb eutectic solder which has been conventionally employed, thereby enhancing environmental protection.

Abstract: A rolled metal strip which is free of torsion and on which a superior gloss is obtained by a combination of cross rolling and parallel rolling upon cold rolling a metal strip and by rolling the material in a parallel rolling manner in either at least the final stand (in the case of a tandem mill array) or at least the final pass (in the case of a single stand mill such as a reversible mill or the like). If necessary, the metal strip is preliminarily rolled by cross rolling at a rolling reduction rate of over 5% and then cold rolled by either parallel rolling or a combination of cross rolling and parallel rolling.

Abstract: The invention provides a method for improving the luster of a metal sheet surface without deteriorating the productivity and also in reducing the difference in glossiness between the upper and lower surfaces of the metal sheet at the time of cold-rolling. By making the velocity, after rolling of the metal sheet, equal to or larger than the rotational circumferential velocity of the work rolls, and by rolling the metal sheet with upper and lower work rolls crossed with each other in such manner that an angle of slip scratches left on the metal sheet surfaces becomes 5 degrees or larger and shear deformation in the widthwise direction can be effectively given to the metal sheet just before rolling, thereby improving the surface luster of the metal sheet.

Abstract: In a rotor for a printed motor which has an armature, a hub fitted in the center of the armature and a rotating shaft supported by the hub, a cyanate resin is employed to impregnate a glass fabric forming an insulating sheet to which sheet coils are bonded together to form the armature. An insulating sheet of the same material is also interposed between the armature and the hub.

Abstract: A hard disk driving device in which a plurality of hard disks each formed with a magnetic recording layer are secured to the same rotational shaft in a predetermined spaced relation, and a magnetic head mounted on a floating (flying) type head slider is disposed on each surface, characterized in that an area of a portion concerned with flotation of a head slider provided on a head slider assembly sandwiched between adjacent hard disks is made to be smaller than an area of a portion concerned with flotation of a head slider provided on a head slider assembly sandwiched between adjacent hard disks.

Abstract: A servo control apparatus which can accurately control the head with a simplified structure has a voltage controlled oscillator which is controlled in accordance with servo information stored in a servo data region of the disk, and a reversible counter which counts an output signal of the voltage controlled oscillator to convert it to a digital signal corresponding to the amount of deviation of the head from a target track. The digital signal is used for position control for accurate positioning of the head.