Display devices

• US 4,024,531 A
• Filed: 03/03/1975
• Issued: 05/17/1977
• Est. Priority Date: 03/05/1974
• Status: Expired due to Term

• Current Assignee: National Research Development Corporation
• Original Assignee: National Research Development Corporation
• Inventors: Ashby, Rodney Roberts Rayner
• Primary Examiner(s): Trafton, David L.
• Application Number:
  US05/554,826
• Time in Patent Office: 806 Days
• Field of Search: 340/334, 340/339, 340/324 AD, 340/336, 340/337, 340/324 M
• US Class Current: 345/59
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
• CPC Class Codes: G06F 3/0489 using dedicated keyboard keys or combinations thereof
• CPC Class Codes: G09G 3/004 to give the appearance of moving signs
• CPC Class Codes: G09G 3/29 using self-shift panels with sequential transfer of the discharges from an input position to a further display position

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.

Claims

1. 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.

2. The display of claim 1 wherein said array of light sources is a gas discharge display having an array of cavities, said scan control means being operative to transfer the gas discharge down said gas discharge display at a predetermined rate.