Abstract: A display device for sequentially displaying multiple sets of image pixels formed on a transparent mosaic through an aperture pattern formed in a substantially opaque mask. An AC gear motor and drive assembly is employed to move the mosaic through a predetermined travel path relative to the mask to sequentially register the image sets with the aperture pattern. A control system is employed to temporarily deactivate the gear motor at predetermined precise positions to display the various images through the aperture pattern.

Abstract: A display apparatus having a transparent image screen which contains a mosaic of four discrete images formed from pixels which are interwoven in a predetermined arrangement such that each of the images are selected by precise positioning of the screen in four different positions relative to a grid mask which masks out all but pixels of a selected image. A platen comprising a platen surface which is supported by a rib structure mounts the image screen and is moveable through a precise pattern for selecting the pixels, and thereby the image, to be projected. A pair of arms are coupled to the platen and an eccentric drive and are driven by the eccentric drive to advance the platen positively through the pattern.

Abstract: A drive control and interface apparatus housed within an advertising display for driving a stepper motor coupled to a display device to sequentially display a plurality of images. The drive control and interface apparatus includes a microprocessor having program memory connected to the motor through a motor driver. A drive control program operates the microprocessor to drive the stepper motor to change the image displayed after a corresponding predetermined period of time. The program includes drive routines for fast and slow image changes that drive the stepper motor to minimize resonance. A control interface connects to the microprocessor. The program is responsive to the control interface to permit manual sequencing of the display and user selection of the corresponding display times for each image.

Abstract: A disc servo pattern and servo detector for use in a system for reading and writing data on a magnetic disc. The magnetic disc has a servo data area formatted with a multiplicity of servo tracks which are formatted with a 1F-2F servo pattern. Each servo frame has a single sync pulse and a single position pulse at predefined positions. The 1F frames are those frames where the sync pulse and position pulse are of opposite polarity. The 2F frames are those where the sync and position pulses are of like polarity. Fill-in pulses separate neighboring sync and position pulses of like polarity.In a preferred embodiment the servo pattern in each servo track is the same as the servo pattern of the neighboring servo track shifted by one frame. Each track has a repeating pattern of two 1F frames followed by two 2F frames, and so on.The system has a servo head for reading a servo pattern on a magnetic disc and producing a servo carrier signal corresponding thereto.