Display devices
AssigneeNational Research Development Corporation
InventorRodney Roberts Rayner Ashby
Life of this patent
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Abstract
A display device using a scanned dot-matrix array produces a running display by shifting the displayed characters by one column at each scan of the array. The characters are fetched from store sequentially and are decoded into dot-matrix form. The dot columns corresponding to each character are then shown sequentially as the display is scanned. The process is repeated at the next scan with a one-column displacement of the characters. In one embodiment the characters are stored in a recycling shift register and the required displacement is achieved by means of a counter incremented at each scan of the array. In another embodiment the characters are stored in a random-access memory and the sequencing and displacement are achieved by means of a preprogrammed micro-computer.
Claims2
A display device including a regular array of light sources, scan control means connected to scan the light sources by sequentially priming the columns of said light souces, a first memory circuit for storing appropriate sets of signals for displaying specified dot columns forming parts of predetermined characters, a second memory circuit for storing character signals representing characters in a sequence corresponding to their receipt at an input of the display device, and a computer programmed to select signals from the second memory circuit in the sequence in which they are stored, to derive the addresses in the first memory circuit from the selected signals of dot column signals specifying columns to be displayed of the characters represented by the selected signals, and to apply the dot column signals to the display in synchronism with the operations of said scan control means in such a way that the displayed dot column signals are shifted by one column in the array on each successive scan of the array.
Dependencies are inferred from the claim text.