WO1988005590A1 - Ameliorations apportees a des systemes de rehaussement de caracteres - Google Patents

Ameliorations apportees a des systemes de rehaussement de caracteres Download PDF

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Publication number
WO1988005590A1
WO1988005590A1 PCT/GB1988/000020 GB8800020W WO8805590A1 WO 1988005590 A1 WO1988005590 A1 WO 1988005590A1 GB 8800020 W GB8800020 W GB 8800020W WO 8805590 A1 WO8805590 A1 WO 8805590A1
Authority
WO
WIPO (PCT)
Prior art keywords
dot
character
dots
matrix
extend
Prior art date
Application number
PCT/GB1988/000020
Other languages
English (en)
Inventor
Charles Richard Wadham Lyne
Edmund Howard Spittles
Original Assignee
Plessey Overseas Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Plessey Overseas Limited filed Critical Plessey Overseas Limited
Publication of WO1988005590A1 publication Critical patent/WO1988005590A1/fr

Links

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
    • G09G5/22—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators characterised by the display of characters or indicia using display control signals derived from coded signals representing the characters or indicia, e.g. with a character-code memory
    • G09G5/24—Generation of individual character patterns
    • G09G5/28—Generation of individual character patterns for enhancement of character form, e.g. smoothing

Definitions

  • the present invention relates to character enhancement systems for characters in which the character shape is formed from a matrix of switchable elements. Such characters are often called dot matrix characters and will be referred to hereinafter.
  • Characters displayed on a visual display unit are formed from a matrix of dots and to render them more legible rounding schemes are employed. Such rounding schemes involve additional processing and storage of data to produce the added dots necessary to improve the legibility of each character. The storage of the basic bits necessary to display the character is increased, in known systems by the added bits required for rounding each character.
  • the present invention therefore provides a character display system in which characters are displayed as a matrix of dots including means for determining for each dot displayed whether or not that particular dot should be extended to produce a larger dot.
  • a dot for the purposes of the present invention may be an actual dot or any other switchable element.
  • the extension of the dot is by half a dot width.
  • the extension is preferably towards the edge of the character of which the dot forms a part.
  • the decision to extend a particular dot is made on the basis of a set of logical equations which interpret the presence or absence of dots adjacent to the particular dot and provide an instruction to extend the dot in a particular direction if the logical equations are satisfied.
  • the invention also provides a method of rounding a character for use with visual display systems in which each character comprises a matrix of dots as defined, in which for each particular dot to be displayed a logical decision is taken to extended the length of that particular dot dependent on the presence of the dots adjacent that particular dot.
  • the present invention also provides apparatus for use in character rounding for visual display or other systems in which each character comprises a matrix of dots as hereinbefore defined including logical decision means for deciding, in respect of a particular dot of a character, to extend that dot, the logical decision means including means for determining the presence of the dots adjacent to the particular dot and means for deciding on the result of such determination whether the particular dot is to be extended.
  • Figure 1 shows a typical character with no enhancement
  • Figure 2 shows the character of figure 1 with a known enhancement used in interlaced visual display systems
  • Figure 3 shows the character of figure 1 with enhancement according to the method and apparatus of present invention
  • Figure 4 shows a block schematic diagram of apparatus for implementing the character enhancement method on a master display system with five columns per character.
  • Figure 5 shows a comparison between a selection of basic 5 x 7 characters with no rounding enhancement and the same characters with rounding enhancement according to the present Invention.
  • the character displayed is extremely crude and that in Figure 2 it can be enhanced by a known rounding technique.
  • Such an enhancement however requires additional storage capacity in any system for each character.
  • the character of figure 1 is enhanced in accordance with the present invention by rounding according to a set of logical equations or algorithms.
  • the invention allows a 50% reduction in storage requirements for character generation on a dot matrix, as expressed in dots per bit of stored information, by using a set of logical equations to determine whether or not, a given displayed dot should be extended towards the edge of the character by half a dot.
  • dot matrix is defined for the purposes of the present invention as being any matrix of switchable elements eg. dots lines etc which by virtue of having different patterns of such elements ON or OFF describe typographical characters.
  • Character generators with enhancement (rounding) have as shown in Figure 2 predominantly been used In connection with Teletext and Viewdata display systems to date.
  • the present Invention has applications in computer terminal displays, computer printer design, word processor systems and wherever typographi cal inforaation is stored and presented on a line-by-line basis.
  • the rounding scheme of Figure 2 which Is widely used in Teletext, Viewdata and associated displays of figure 2 is applicable only to interlaced displays.
  • the invention differs from this scheme In the following ways: i) Three stored lines (rather than two) are processed to form one displayed line, ii) The processing differs across the matrix. ill) The form of the equations are different. iv) The invention has. applicability to .both interlaced and non-interlaced displays.
  • a preferred alogrithm for character rounding is as follows: If the character Is composed of a matrix of five or more columns of dots, and three or more rows, then the function of the algorithm is demonstrated by considering any one row of dots in relation to the rows immediately above and below.
  • A2 extends outwards if a) dot B1 is present and A1 is not; or b) dot B3 is present and A3 is not. If there is a single centre column of "A" dots, they extend out in both directions. If there are more than six active columns in the character, inner “A” dots behave as described for "A2" dots, but the dots in the column immediately outside take the place of the "B” dots for the purposes of input to the logical equation.
  • the missing dots may be considered to be either all on or all off.
  • the mechanism for extending the displayed dots by half a dot will depend on the display system to which the algorithm is being applied.
  • the invention can be applied in either a horizontal or a vertical sense to the character matrix as viewed, as appropriate to the mechanism for displaying the characters.
  • FIG 4 A schematic block diagram for the implementation of the above algorithm for a character having five columns as in figure 3 is shown in figure 4.
  • the effect of the rounding method on a set of typical characters is shown by comparison in figure 5 in which the upper set of characters are not rounded and the lower set are rounded according to the present invention to enhance their legibility on a visual display or In printed form.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Controls And Circuits For Display Device (AREA)

Abstract

Le rehaussement de caractères est obtenu par une technique d'arrondissement, dans laquelle la longueur d'un ou de plusieurs point(s) d'un caractère formé par une disposition matricielle de points, telle qu'elle est définie dans la présente invention, est augmentée ou non selon la position dudit ou desdits point(s) par rapport aux points du caractère. La décision d'augmenter cette longueur est prise par référence à des équations logiques qui considèrent la position d'un point dans un caractère donné.
PCT/GB1988/000020 1987-01-13 1988-01-13 Ameliorations apportees a des systemes de rehaussement de caracteres WO1988005590A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8700676 1987-01-13
GB8700676A GB2199967B (en) 1987-01-13 1987-01-13 Improvements in or relating to character enhancement systems

Publications (1)

Publication Number Publication Date
WO1988005590A1 true WO1988005590A1 (fr) 1988-07-28

Family

ID=10610606

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1988/000020 WO1988005590A1 (fr) 1987-01-13 1988-01-13 Ameliorations apportees a des systemes de rehaussement de caracteres

Country Status (3)

Country Link
EP (1) EP0297124A1 (fr)
GB (1) GB2199967B (fr)
WO (1) WO1988005590A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2253452B (en) * 1991-03-05 1994-09-14 Victaulic Plc Pipe couplings

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3878536A (en) * 1971-07-30 1975-04-15 Philips Corp Apparatus for improving the shape of characters formed by a row and column coordinate matrix for display on a cathode-ray tube
GB2055027A (en) * 1979-07-24 1981-02-18 Texas Instruments Ltd Displaying alphanumeric data

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5440176B2 (fr) * 1973-11-05 1979-12-01
JPS52107723A (en) * 1974-12-28 1977-09-09 Seikosha Kk Device for forming picture
JPS526419A (en) * 1975-07-07 1977-01-18 Fuji Xerox Co Ltd Dot matrix convertor
JPS5942309B2 (ja) * 1975-09-12 1984-10-13 株式会社精工舎 画像形成方法
US4107662A (en) * 1976-02-17 1978-08-15 Hitachi, Ltd. Character generator for visual display devices
US4242678A (en) * 1978-07-17 1980-12-30 Dennison Manufacturing Company Variable size character generation using neighborhood-derived shapes
EP0132415B1 (fr) * 1983-07-26 1988-11-02 Oki Electric Industry Company, Limited Système d'impression pour une imprimante de points
US4625222A (en) * 1984-05-17 1986-11-25 International Business Machines Corporation Interacting print enhancement techniques
US4544264A (en) * 1984-05-17 1985-10-01 International Business Machines Corporation Fine line print enhancement

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3878536A (en) * 1971-07-30 1975-04-15 Philips Corp Apparatus for improving the shape of characters formed by a row and column coordinate matrix for display on a cathode-ray tube
GB2055027A (en) * 1979-07-24 1981-02-18 Texas Instruments Ltd Displaying alphanumeric data

Also Published As

Publication number Publication date
GB2199967A (en) 1988-07-20
EP0297124A1 (fr) 1989-01-04
GB8700676D0 (en) 1987-02-18
GB2199967B (en) 1990-12-05

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