Patent Document ID: 5563626
Application ID: 08242903

Base Claim:
1. A text display system including means for receiving and storing an original text, means for receiving and storing an updated text reflecting changes to said original text and means for displaying said updated text using proportionally spaced fonts, said system comprising: means for determining the width of each character used within the system when displaying said characters; means for associating each character of the updated and original texts with a corresponding character width according to said character width determination; means for sequentially accessing each associated character width of the original and updated texts respectively; means for calculating a cumulative character width for each character of both the original and updated texts and comparing said cumulative character widths to identify the lesser; means for interleaving the characters of the original and updated texts and associated cumulative character widths by sequentially storing each said lesser cumulative character width and each associated character in a first and second buffer respectively thereby establishing the order of display of said interleaved characters according to each original and updated cumulative character width; means for calculating the difference between contiguous interleaved cumulative character widths thereby determining ta display position for each interleaved character; and means for sequentially displaying said interleaved characters according to said order at said display positions thereby incrementally displaying and deleting characters of the updated and original texts respectively such that an original character is deleted and replaced by an appropriate number of updated text characters resulting in a smooth text update.

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Claim 5:
5. A text display system as claimed in claim 1 further comprising means responsive to the total width of the updating text for determining whether a single line or a partial or complete screen or display area update is required.