Electronic typographical display device with justification feature
AssigneeRealty & Industrial Corporation
InventorsWilliam R. Grier, Francis H. Shepard, Jr., Arthur L. Arledge
Life of this patent
Estimating the term…
Abstract
An electronic video display of alpha-numeric characters such as words and numbers, in which a justified display is provided on the video screen. The display is generated by sequentially reading characters from a circulating memory corresponding to a display line, in response to stepping pulses. The time delay between each stepping pulse and the one preceding it corresponds to the width of the preceding character, or of the preceding word space. Justification is accomplished by increasing the time interval between stepping pulses corresponding to preceding word spaces, to incrementally increase the width of each word space until the last character on the line is at the right margin.
Claims12
An alpha-numeric display system comprising a display device for displaying a line of characters between left and right margins wherein said display device is periodically scanned at a given rate to display said line, comprising:
- a first repetitively scanned character memory having a plurality of storage locations;
- means for storing in said character memory first and second coded signals corresponding to characters and word spaces respectively;
- means for sequentially reading out successive ones of said first and second coded signals from said character memory in response to stepping pulses;
- means for generating said stepping pulses, with each stepping pulse delayed from the preceding stepping pulse by a time interval corresponding to the width of the preceding character or the desired width of the preceding word space;
- means responsive to the first and second coded signals read out from said character memory for displaying said line of characters and word spaces;
- a second repetitively scanned memory for storing third and fourth coded signals corresponding to stepping pulses for determining the ends of said time intervals corresponding to character widths and desired word space widths respectively;
- means coupled to said second memory for increasing the time intervals defined by said fourth coded signals to increase the widths of the corresponding word spaces to justify said displayed line;
- and
- means for reading out said third and fourth coded signals from said second repetitively scanned memory at said given rate and in synchronism with the scanning of said display device, said means for generating said stepping pulses being responsive to said third and fourth coded signals.
An alpha-numeric display system comprising a display device for displaying a line of characters between left and right margins wherein said display device is periodically scanned at a given rate to display said line, comprising:
- a first repetitively scanned character memory having a plurality of storage locations;
- means for storing in said character memory first and second coded signals corresponding to characters and word spaces respectively;
- means for sequentially reading out successive ones of said first and second coded signals from said character memory in response to stepping pulses;
- means for generating said stepping pulses, with each stepping pulse delayed from the preceding stepping pulse by a time interval corresponding to the width of the preceding character or the desired width of the preceding word space;
- means responsive to the first and second coded signals read out from said character memory for displaying said line of characters and word spaces;
- a second repetitively scanned memory for storing coded end of word space width signals corresponding to stepping pulses for determining the ends of said time intervals corresponding to desired word space widths;
- coupled to said second memory for increasing the time intervals defined by said coded end of word space width signals to increase the widths of the corresponding word spaces to justify said displayed line;
- and
- means for reading out said coded end of word space width signals from said second repetitively scanned memory at said given rate and in synchronism with the scanning of said display device, said means for generating said stepping pulses including means responsive to each of said coded end of word space width signals for generating a stepping pulse corresponding to each character next succeeding a word space.
In a display system for displaying, on a display device, a line of characters in a region between left and right margins, wherein at least one word space occurs between groups of characters in said line, and wherein the system includes a source of coded first signals corresponding to characters in said line and means responsive to said first signals for continuously activating said display device to repetitively display said line in periodic scans;
- the improvement comprising means for justifying said line, said justifying means comprising means for counting the number of word spaces between the groups of characters in said line, means for sequentially adding increments to said word spaces between said groups of characters in said line from the left margin to the last word space in the line, one increment being added during each of a series of successive ones of said scans, means responsive to the number of counted word spaces for repeating the sequence of adding increments to successive ones of said word spaces, and means responsive to the positioning of the last of said characters in the line at said right margin for inhibiting the further addition of increments to said word spaces in said line.
The display system of claim 10 wherein said means for justifying comprises means for storing the number of spaces between said groups of characters.
A justifying typographic apparatus comprising a display device for displaying a line of discrete characters between left and right margins wherein the line of the display device is sequentially scanned at a given rate,
- a memory,
- a source of first coded signals corresponding to characters to be displayed, second coded signals corresponding to word spaces and third coded signals corresponding to fixed spaces,
- means for storing said first, second and third coded signals as they may occur in a text in said memory,
- clock circuit means for producing stepping pulses,
- means for applying said stepping pulses to said memory for sequentially nondestructively reading out coded signals stored in said memory,
- decoding means coupled to said memory and said means for applying said stepping pulses thereto, for sensing the presence of first, second, or third coded signal,
- means responsive to first coded signals read out of said memory for displaying characters corresponding thereto,
- means coupled to said decoding means for inhibiting the application of stepping pulses to said memory at times corresponding to the read out of second coded signals, means for sensing when the termination of each of said word spaces is delayed an extent necessary to delay the last said first coded signal until it appears at the output of said memory at a time corresponding to the position of said right margin,
- means responsive to said sensing means for causing said inhibiting means to maintain said extent of delay of each of said word spaces during successive scans of said line on said display.
Dependencies are inferred from the claim text.