US 4,907,900 A · Auto-realigned print correction

Abstract

A word-processing system or memory typewriter has the usual keyboard, input display and printer, including a correction ribbon for removing erroneous characters from a document held in the printer; together with a spelling dictionary stored within the memory, an error indicator activated upon entry of an incorrect word, and correction information and controls also stored in memory for amending the incorrect word into a trial word which matches one stored in the above-mentioned dictionary. For greater efficiency and ease of use by the operator, if the trial word is satisfactory when displayed, pressing the usual return key on the keyboard signals the system to print that trial word in place of the incorrect word on a printed document, only the erroneous characters being replaced so as to minimize use of the correction ribbon and the print ribbon in unnecessary removal and replacement of valid characters in the incorrect word. If the trial word is longer than the incorrect word, printed text between the incorrect word and the end of the line of text may need removal and replacement. In that case, the above-mentioned pressing of the return key causes an entirely automatic sequence which first removes that printed text, but saves it in storage, then performs correction of just the erroneous characters of the undesired word, followed by printing of the additional characters of the trial word, and finally recalls the saved text and reprints it in proper alignment with the previous automatic entries.

In an electronic typewriter of the kind having operator input of text through a keyboard with a plurality of depressible keys, a memory, a printer for producing an output legible by the operator, the output including thereon a discrete line having an undesired word and one or more characters subsequent thereto;

said memory including a correction buffer register storing in identical order corresponding data for all information appearing on the discrete line, including at least the characters of the undesired word, and the one or more characters subsequent thereto;
a word list stored within the memory, controls in the typewriter for producing from the undesired word a properly-spelled trial word based on the word list, and a display presenting the trial word;
the improvement combining therewith a fully automatic print correction control comprising:
(a) means activating said print correction control in response to said operator's single, momentary pressing of a particular one of the depressible keys, said pressing indicating acceptance of said trial word as replacement for said undesired word,
(b) a further register in said memory storing the characters of said trial word,
(c) means cooperating with characters stored in said registers for developing individual length information for said undesired word and for said trial word in response to activation of said print correction control,
(d) comparison means operating on said individual length information for sensing existence of a length disparity between said undesired word and said trial word,
(e) means for issuing a first electronic signal in response to sensing said existence of a length disparity,
(f) a character position counter associated with said printer, a first count in said counter defining an end-of-word position related to said undesired word, and a second count therein defining an end-of-line position related to a last of said one or more characters,
(g) calculating means generating a difference value between said first and second counts for determining the quantity of characters subsequent to said undesired word, said calculating means operating in response to issuance of said first electronic signal,
(h) means associated with said printer and said buffer register for erasing successively from said legible output said one or more characters subsequent to the undesired word, said means for erasing utilizing said corresponding data in said buffer register for control of said character selection means,
(i) means responsive to said difference value for controlling the number of erasures performed by said means for erasing,
(j) a temporary register in said memory,
(k) means for transferring said corresponding data for each character of said one or more characters from said buffer register into said temporary register simultaneously with erasure of said each character from said legible output by said means for erasing,
(l) means for issuing a second electronic signal in response to performing said number of erasures,
(m) amending means activated automatically in response to said second signal, said amending means changing said undesired word on said legible output into conformity with characters, including blank spaces, at corresponding positions in said further register storing said trial word;
(n) means for detecting the end of the trial word in said further register,
(o) means for issuing a third electronic signal in response to detecting said end of the trial word,
(p) means to recall each of said one or more characters sequentially from said temporary register and print each thereof automatically on said legible output in response to said third signal and in proper alignment with the trial word thereon.

16 more elements

Auto-realigned print correction

Life of this patent

Auto-realigned print correction

Life of this patent

Abstract

Claims12