Abstract: A device and method for capacitive measurement and control of the fly height of a recording slider. A recording slider is vertically spaced from a rotating disk surface by an "air bearing". The disk has a first electrically conductive pattern at its surface. The first pattern has an edge with a length extending, for example, radially. The recording slider has one or more electrically conductive rails extending transverse to the radial pattern on the rotating disk. As the disk rotates, the edge of the pattern on the disk scans across the rail of the slider. By measuring the electrical capacitance between the slider and the pattern on the disk, and by processing the electrical capacitance measurement signal, a vertical spacing signal proportional to the vertical spacing between the disk and the slider can be obtained.

Abstract: A magnetographic printing head comprises an array of crossed elongated bar-shaped print elements, each of which is individually magnetizable by electrical conductors wound about respective ones of the print elements. The print elements are arranged in two parallel arrays which are spaced apart from each other to define a passage through which a magnetic medium is to be passed for the imprinting of marks thereon. A mark can be imprinted at each cross point of the crossed arrays upon application of sufficient magnetizing current to each of the print elements at the cross point. The print elements are specifically shaped to provide for concentration of magnetic fields at the cross points in two dimensions to accomplish high resolution printing.

Abstract: An electromagnetic printhead is fabricated with a common flux returning backplate and an array of writing elements extending from the common backplate. The writing elements consist of large pedestals and small pedestals. The placement of the large pedestals provides addressability resolution; the small pedestals provide imaging resolution. The large pedestals accept electromagnetic flux from addressing conductors and transfer the flux through the respectively related small pedestals to an image receptor. There are several fabrication techniques which are eased by the separation of addressability resolution and imaging resolution, primarily because the wide separation of the large pedestals required for the addressing conductors mandate relatively massive removal of material and thus suggest relatively low precision machining techniques. The imaging resolution requires both high spacial precision and accurate dimension control, normally achievable by relatively high precision techniques.

Abstract: Method for controlling plating in an electroless plating process. The plating rate is continuously monitored. The plating rate is compared with a set point plating rate. A control voltage is derived proportional to the difference in plating rate and the desired plating rate, the integral of the difference, and the derivative of the difference. The control voltage is applied to a replenishment control for controlling the replenishment rate of a constituent chemical of the plating process.

Abstract: A magnetic recording head array for printing onto a transfer magnetic recording medium which prints magnetic material onto a medium such as paper includes staggered arrays of magnetic print heads. The heads are in diagonally staggered parallel arrays tilted away from the vertical. Each array in a group of several arrays is also staggered in the vertical direction as well as the longitudinal direction. Preferably, the heads or other bistable elements are wired in clusters with the heads or other elements in the cluster being coupled to the same actuator wires in a half-select type or wiring arrangement. The difference in the wiring of the elements will reside in the sense of the signal as applied to the elements by means such as reversing the helical winding about a core or the like. In the manufacture of the array, the horizontal wiring lines for actuating arrays are in the form of straight lines.

Abstract: A plating rate monitor includes a Wheatstone bridge, one branch of which is a monitoring resistor formed on a printed circuit board located in the same environment as an object being plated. The resistor undergoes plating at the same rate as the object. Each time the bridge becomes balanced, another resistor branch of the bridge, which is variable, is incremented by a preselected value to upset the balance. As the monitoring resistor in the plating environment undergoes plating, a change in its resistance causes the bridge to become balanced once again and the time interval for achieving this balance, for a calculated plating thickness change of the monitoring resistor, determines the plating rate.