Abstract: A large-area electroluminescent (EL) faceplate for storage CRT is described. The EL faceplate has a non-planar mesh structure which includes individual current limiting resistance between a power source and an array of small-area active regions for improving the faceplate breakdown characteristics. The mesh, which comprises high conductivity strips and delivers power to the active regions, is substantially reduced in area relative to a simple conventional device, and is disposed on thick dielectric nonactive regions to further reduce the possibility of catastrophic breakdown.
Type:
Grant
Filed:
December 31, 1981
Date of Patent:
May 21, 1985
Assignee:
International Business Machines Corporation
Abstract: Method and apparatus for the constant speed control of a brushless DC motor, whose pole windings receive a pulsed control voltage between their commutation points, control being a function of the speed characteristics of the motor, and the commutation points being synchronized with the drop times of the motor current and the control voltage pulses. In a state in which there are no load changes, the motor current substantially rises or drops between a maximum value I.sub.max and a minimum value I.sub.min according to the pulse mode. In the event of changes in the motor load, a mean motor sum current is retained for maintaining the speed.
Type:
Grant
Filed:
April 26, 1983
Date of Patent:
April 30, 1985
Assignee:
International Business Machines Corporation
Abstract: An electronic component assembly including a printed circuit board unit and a protective cover wherein the cover has flexible flap portions that protect electrical contact pads disposed along at least one edge of the printed circuit board unit. The flap portions can be flexed to expose the electrical contact pads. Removal of the flexing force allows the flaps to return to their relaxed, closed positon by means of the internal resiliency of the cover material. Such flexing of the flap portions can be effected by surfaces of a corresponding mating connector so as to expose the contact pads to the contact pins of the mating connector. When the electronic component assembly is removed from the mating connector, the printed circuit board unit is contained by (i.e., completely surrounded by) the cover thereby protecting the unit from physical impact or dust.
Type:
Grant
Filed:
March 30, 1983
Date of Patent:
February 12, 1985
Assignee:
International Business Machines Corporation
Abstract: Multilayer printed circuit boards are designed and produced using a selective wiring technique which segregates short, medium length and long lines. By placing short medium length and long lines on different layers, line specifications can be relaxed for the layers with shorter lines. This relaxation of specifications allows for the effective use of subtractive, additive and encapsulated wire manufacturing techniques in the production of complex multilayer printed circuit boards. Each layer of segregated line lengths is fabricated in accordance with the appropriate technique for a given line length to obtain a multilayer printed circuit board optimized for cost and/or performance and reliability.
Type:
Grant
Filed:
October 22, 1982
Date of Patent:
January 22, 1985
Assignee:
International Business Machines Corporation
Abstract: A print wire actuator using a telescopic armature pair is presented. The actuator is disposed to propel a print wire through a predetermined distance from a rest position toward a recording medium. The armature pair moves by electromagnetic force over a first portion of the predetermined distance at which point one piece of the armature reaches a mechanical stop. The second piece of the armature continues to move, both ballistically and magnetically, over the remaining portion of the predetermined distance.
Type:
Grant
Filed:
December 20, 1982
Date of Patent:
November 6, 1984
Assignee:
International Business Machines Corporation