Abstract: A drive motor is premounted on one control substrate disposed only on one side of a body. The control substrate, a mounting plate on which a collet mechanism and others are installed, a head mechanism, a stepping motor, and a front panel are detachably provided on the body at every part. After general assembly of the magnetic disc driving device, parts which constitute the magnetic disc driving device can thus be checked and serviced in a simple manner.

Abstract: A mechanism for supporting magnetic heads has gimbal plates which support both magnetic heads in such a manner than the magnetic heads oppose to each other across a flexible double-sided magnetic disk. The magnetic heads are resiliently pressed onto the magnetic disk through movable members which are resiliently biased.

Abstract: A dark or black print article is ink-jet printed with a white ink composition comprising at least a white pigment having a particle size of less than 3 .mu.m, a solvent and a binder resin with a good print stability. The white ink composition has a good dispersion stability, a good redispersability, and no nozzle clogging.

Abstract: An ink-jet recording head apparatus of charge modulation and continuous jet type comprising an annular ink pump chamber defined by the inner peripheral face of a cylindrical electrostrictive element, the annular side faces of a pair of elastic sealing members and the outer peripheral face of a fluid passage-providing insert, a tortuous inlet path connecting the ink pump chamber to a supply source of ink under pressure, and a tortuous outlet path connecting the ink pump chamber to an ink ejection orifice.

Abstract: In an automatic assembly control system, a flexible coupling mechanism deformable in accordance with the relative positions of an object and a hole to receive the object therein and a detector to detect the displacement or the deformation of the coupling mechanism in the direction of insertion in excess of a certain value are provided so that in the process of inserting the object into the hole the distance between the object and the hole in the direction perpendicular to the direction of insertion is controlled in accordance with the output of the detector.

Abstract: An automatic working machine adapted to carry out works such as cutting, filling, tightening and loosening, which comprises a visual unit for detecting, by means of the image information, a plurality of works and obstacles existing on an object, a working unit which works against a particular work and moves in relation to the object, and a tactile sensor provided in the vicinity of the working unit, the working unit being precisely positioned by the aid of the tactile sensor when the visual unit detects the particular work, the relative position being maintained during the operation, and the working unit along with the tactile sensor being retracted when the visual unit detects an obstacle, to avoid collision thereof with the obstacle.