US 3893715 A
A font of dot-formed numeric fractions for display on a 7 x 9 matrix using a discontinuous fraction bar to obviate a larger matrix size or more than one character space to display a full, numeric fraction.
Description (OCR text may contain errors)
United States Patent 1 [111 3,893,715
Haak July 8, 1975  MATRIX FRACTION FONT 3,l63,949 1/1965 Gley 40/130 D  Inventor: Gary R. Haak, Chicago, Ill.
 Assignee: Teletype Corporation, Skokie, Ill. Primary Examine, Lawrence Ch fl Filed: Dec. 28, 1973 Auomey, Agent, or Firm-W. G. Dosse; J. L. Landis  App1.N0.:429,338
 U.S. Cl 283/] R; 197/! R; 40/130 D;  TR CT 340/1463 A  Int. Cl 842d 15/00 531 Field of Search 197/1 R, 93; 283/1 R; A font of dot-formed numeflc frawons for p y on 40/130 D, 130 E; 340/1463 A 152, 154 a 7 X 9 matrix using a discontinuous fraction bar to obviate a larger matrix size or more than one charac- Reierences Cited ter space to display a full, numeric fraction.
UNITED STATES PATENTS 2,730,040 1/1956 Johnson 197/1 R X 10 Claims, 3 Drawing Figures 14 o Iolbl aoctnnoo ."ooonn 0 none.- ::oououi U'ooooon I.O..I u:...... 000,... u'gouolu 00.00-0 0.00.0 0 0.0.0... 0. 0.0.0 .uiln'o Queen 0 :?::;2:: :"1'" "n 0...000 00...... /'l|:.oao: 25318333 15"?2' #0000... 0.0...Q' 0 Q o u .u g. o I 0 a on. a uooo'no. 0.....
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SHEET HP 2 wrwmm 8 e975 3,893,71 SHEETEUF 2 ."000. .000' 00000. ...000. 0.00.0 .0.00.0 .0000.0 .0.0 .0 0 0 0 000.0 000 0 000 0 0.0000 0.0000 0.0000 0.0000 \000 000 000 0 0 0 000 000 000 0000.0. \00000'0 0000.00 00.0. 00.00'0 00'0..0.00'0... 0.00.0 0.0 .0 0.00.00 0.0000. .000... .000. "000...; .000.'. ww 0% Wm 000 0 000 0 0 k 000 0 0.00.0 0. 0.0 .0000.0 .0.00. "'0'00 ...0'00 '00 ...0.00 000000 0.9000 0.0000 .0'0000 000 0 000 000 0 0 0 000 0 00000. 0000.00 00000.0 00000.0 0'0.00.0 00.0..0 00.00.0 00.00.0 0 000. 0.00.00 0'000'. 0'000'. .00000 000... 0000.0 '0000'0 Gm Z NEHTF JIJL H1975 1 MATRIX FRACTION FONT FIELD OF THE INVENTION The present invention relates to type fonts and more particularly to a font of numeric-fraction-like characters for a character-element printing system.
BACKGROUND OF THE INVENTION Matrix printing of alphanumeric characters is a compromise. If the matrix is small, for example, a 5 X 7 array of dots, the character shape is coarse and distoned. If the matrix size is increased, for example, a 7 X 9 array of dots, the character shape is more refined yet still limited, but the coding complexity is greatly increased. In order to obtain still greater refinement of the type font and in order to print small fractions, a matrix of as much as 8 X l2 has been used. However, a larger matrix size results in undesirable levels of character-font generation complexity and very high cost. Alternatively, fonts are possible having irregular shapes better to accommodate curves, etc. with less than the highest costs of font-generating memory. However, scanning logic then increases in cost and complexity. There was thought to be no convenient way to produce elaborate fonts including fractions, without the high cost of a 8 X l2 matrix or an irregular font.
Fraction fonts have, to be sure, been produced in a 7 X 9 or smaller matrix but only using two or more character spaces to constitute a single numeric fraction or with unacceptably close proximity between the digits of the fraction and the fraction line, slash, or bar.
It is an object of the present invention to produce a readable numeric fraction font on a 7 X 9 dot matrix using only a single character space for a full fraction.
It is another object of the present invention to provide an improved numerical fraction font.
SUMMARY OF THE INVENTION In accordance with the present invention, a font of numeric-fraction-like figures comprises a small matrix of character elements in one corner of a larger matrix, another small matrix of character elements in the opposite corner of the larger matrix, and a discontinuous line extending generally between the remaining two corners of the larger matrix.
BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description will be more readily understood when considered in conjunction with the accompanying drawings wherein:
FIG. 1 shows a straightforward fraction font according to the prior art, using a large (8 X 12) dot matrix;
FIG. 2 shows an example of a fraction using a smaller (5 X 7) dot matrix; and
FIG. 3 shows a fraction font on a 7 X 9 dot matrix, according to the present invention.
DETAILED DESCRIPTION Referring now to FIG. I, a fraction font is shown using a 8 X l2 rectangular matrix of dots in order to generate a more conventional fraction. It is seen that considerable effort has been made to separate the digits l3 and the diagonal lines or bars 14 by means of spaces 16 so that the dots 18 of a digit 13 and the dots 20 of a diagonal line 14 do not intersect or in any way touch one another. This is most essential since any contact between a digit and the diagonal line or bar of a frac tion would tend to make the fraction less readable.
The fraction font shown in FIG. 1 is illustrated in a greatly enlarged size but it will be readily appreciated by one skilled in the art that in normal practice. a printed or displayed character is approximately 0. I00 0.I67 inches high. In the 8 X l2 dot matrix font shown in FIG. 1, each dot l8 and 20 would be on the order of .01 inches in diameter.
With the fractions being formed on this small of a scale, contact between the digits of the fraction and the diagonal fraction bar would result in a tendency of the digit to flow into the bar, at least optically, which would make the fraction appear to be somewhat smeared and sloppy in the area of contact between the digit and the bar. Additionally, the two digits of a fraction cannot be made too small; otherwise, the fraction would be too hard for the normal machine operator to see, whether it is printed on paper or displayed on the screen of a cathode ray tube. It will be appreciated that in the fraction font of FIG. I with the 8 units of width and 12 units of height available in the matrix, each digit was made 5 units or less wide and 5 units high in order to make it large enough for visibility in a normal paper print out or CRT display. This problem can be appreciated more particularly by viewing the fraction (indicated by the reference 22) at a great distance.
It will be apparent to one of ordinary skill in the art that with an 8 X l2 matrix, the formation of a font of typically 60 I00 alphanumeric characters would re quire a rather extensive memory. This comes about because the 8 X l2 matrix comprises no less than 96 individual dot locations or bits of memory that must be used to generate each character in the font. If a font of I00 characters is desired. almost 10,000 memory locations or bits must be provided, simply to generate the font of characters in a printer or display device.
While memory devices have become less expensive with continued advance in electronic technology. 10,000 bits of random access memory are still not cheap. Any changes which modify the font shapes to promote a reduction in the number of dots in the matrix upon which a font of characters is generated is a great improvement since it reduces the amount of memory required to generate a given font and thus results in considerable cost savings.
To this end, in the past, smaller matrices of character fonts have been used, for example, typically, a 5 X 7 matrix as illustrated in FIG. 2. In this matrix, only 35 dots are required to define a character. However, it will be seen from FIG. 2 that there is no way that a legible fraction font can be formed within the confines of a single 5 X 7 matrix. In order to generate numeric fractions in a 5 X 7 matrix, three character spaces were customarily used with the numerator constituting the first character space 30, the diagonal fraction bar or line constituting the second character space 32, and the fraction denominator constituting the third character space 34.
It can be seen that a 5 X 7 matrix serves the purpose of printing legible alphanumeric characters. Fractions can, after a fashion, be printed on a 5 X 7 matrix, as illustrated in FIG. 2. However, many of the character shapes of a 5 X 7 matrix admittedly look crude. Additionally, using three character spaces to produce a single fraction is most objectionable in transmission and displays in which fractions constitute a large proportion of the printed or displayed material. This is most critical in the transmission, display, and printing of stock quotations, etc. Also, the crudeness ofa 5 X 7 alphanumeric font is often objectionable with some characters being often mistaken for others especially at slightly greater-than-normal viewing distances.
In order better to display and print matrix-formed characters, compromises have been made, in that the matrix has been refined somewhat so as to improve the shape of the alphanumeric characters in the font. However, it has not been possible previously to make a readily useable and readable fraction font in the intermediate and very desirable 7 X 9 size matrix. This is because it was considered that the 7 X 9 matrix did not permit sufficient size for a readable digit on each of two opposite corners with a diagonal line separating them. Consequently, if a fraction font were to be used, one had to resort to either the 8 X l2 matrix of FIG. 1 or to the equally undesirable expedient of using more than one character space for a fraction as illustrated in H6. 2.
Referring now to FIG. 3, a fraction font is shown on a 7 X 9 dot matrix in which each digit such as 40 is formed on an adequate 3 X 5 minor matrix at the two, customary, opposite corners 42 and 44 of the font. The two opposite digits of each fraction do not touch one another are separated by a space 46. A fragmentary or hiatal line or bar 48 is formed substantially diagonally from each of the other two corners 50 and 52 but stop ping short of the center of the major matrix at the space 46 and also stopping short of contact with either digit 40. The hiatus is formed in the center of the fraction bar or line in order to preclude the smearing or distortion of the fraction resulting from contact of either digit with the bar. Therefore, as opposed to the continuous but merely foreshortened bar 14 of HO. 1, the bar 48 is formed of two line segments that together form a line that is not smoothly continuous but is discontinuous and even has a gap between the two segments.
A percent sign 54 is shown in FIG. 3 to illustrate that fraction-like figures can also be formed in the same manner and to illustrate the formation of the digit in a 3 X minor matrix.
Although the digits 6" and 9" are not illustrated in FIG. 3, it will be apparent to one of ordinary skill in the art that once the digits 3" and 8" are shown, the digits 6" and 9" can readily be derived therefrom.
Although only one specific embodiment of the invention is shown in the drawing and described in the foregoing specification, it will be understood that invention is not limited to the specific embodiment described, but is capable of modification and rearrangement and substitution of parts and elements such, for example, as line segment character elements without departing from the spirit of the invention.
What is claimed is:
l. A font of numerical fraction-like figures for use with a character element printing system having a parallelogram-shaped major matrix of possible character-element positions, said major matrix having cor- 4 ners, including:
a first minor matrix of possible character-element positions located in a first corner of the major matrix;
a second minor matrix of possible character-element positions located in a second corner of the major matrix diagonally opposite from the first corner; and
a discontinuous line extending generally between a third corner of the major matrix and a fourth corner of the major matrix.
2. A font of numerical-fraction-like figures according to claim 1 wherein the discontinuous line comprises:
a first line segment extending from the third corner of the major matrix in a generally diagonal direction across the major matrix; and
a second line segment extending from the fourth corner of the major matrix in a generally diagonal direction across the major matrix.
3. A font of numerical-fraction-like figures according to claim 2 wherein both the first and second line segments stop short of the center of the major matrix.
4. A font according to claim 2 wherein both line segments stop short of impingement upon either minor matrix.
5. An improved method of printing a double indicium in a character-element matrix embodied in:
a major printing array of generally parallelogram shape in which indicia are formed, wherein the improvement comprises: defining two minor printing arrays of generally parallelogram shape located within the major printing array and at diagonally opposite corners of the major printing array;
forming indicia in both minor printing arrays; and
forming a discontinuous line separating the two minor printing arrays.
6. A method according to claim 5 including positioning the minor printing arrays so as to assure that no character element of one minor printing array will be immediately adjacent to a character element of the other minor printing array.
7. A method according to claim 6 wherein the discontinuous line is placed in a generally diagonal position separating the two minor printing arrays.
8. A method according to claim 7 wherein the discontinuous diagonal line is formed so as to be discontinous in the portion of the major printing array where any element of the diagonal line, if continuous, would lie immediately adjacent to a character element in either of the minor printing arrays.
9. A method according to claim 5 including forming the discontinuous line in the major printing array in a generally diagonal position separating the two minor printing arrays.
10. A method according to claim 9 wherein the discontinuous diagonal line is formed so as to be discontinuous in the portion of the major printing array where any element of the diagonal line, if continuous, would lie immediately adjacent to a character element in either of the minor printing arrays.