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Scrolling of Rotating Scanner LED ROLED Displays

IP.com Disclosure Number: IPCOM000088544D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Fan, GH: AUTHOR [+2]

Abstract

A unique feature of the rotating optical light-emitting diode (ROLED) display is that it is possible to implement a scrolling feature in a particularly simple and effective manner.

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Scrolling of Rotating Scanner LED ROLED Displays

A unique feature of the rotating optical light-emitting diode (ROLED) display is that it is possible to implement a scrolling feature in a particularly simple and effective manner.

Fig. 1 illustrates the essentials of a ROLED system. It consists of a buffer memory and character generator 1 which is used to control the pulsing of a line of light emitting diodes (LEDs) 3 viewed in a rotating mirror 5 or through a refractive scanner. The operation of the memory is synchronized with the mirror by a shaft encoder 7 to provide a stable image.

Two methods of scrolling may be provided. A continuous displacement of the entire image may be obtained by progressively increasing (or decreasing) the time delay 9 between the shaft encoder and memory. This may be done with either analog or digital circuitry. A stepwise displacement may be obtained by digital manipulation of the memory addresses being scanned through. By coordinating both processes in an appropriate way, the contents of an arbitrarily large buffer memory may be scanned through in a manner which will appear perfectly smooth to the eye because of the very short turn-off times of the LEDs.

Fig. 2 shows a particular configuration to clarify the method. Voltage- controlled timing circuit 11 produces a time delay proportional to control voltage V(c), for use in the arrangement described above. The control voltage is provided by integrator 13 which produces a linearly inc...