GB2071386A - Multi-segment display - Google Patents

Abstract

A display of the conventional seven-segment form (1-7) has segments (8-28) extending it, allowing improved representation of non numerical symbols. Internal segments, some of which (11-14) are preferably curved, extend the range of symbols easily recognisable. The upper section provides sub- displays (e.g. 1b, 2a, 2b, 7a, 18, 17, 25) for representing superscripts, and a flashing indicator (24) for negative powers. The multi-segment display thus enables the realistic display of numerals, upper and lower case letters of the alphabet, as well as Greek letters, Cyrillic letters, Welsh double consonants, mathematical and other various symbols. <IMAGE>

Description

SPECIFICATION Multi-segment display The present invention relates to a multi-segment display, and especially to an electronic display whose segments can be selectively actuated so as to display any of a multiplicity of symbols.

The most widely used type of electronic multi-segment display is the seven-segment display. This has seven selectively-actuable equal line-segments. Six of them define the perimeter of a parallelogram whpse long and short sides comprise two and one segments respectively, the short sides extending in the lateral direction. The seventh segment bisects the parallelogram parallel to the short sides. Thus actuation of all seven segments displays a stylized figure 8. By activating appropriate combinations of the segments it is possible to display any of the other nine digits or certain other symbols such as some (upper and/or lower case) letters of the alphabet. However, the representations so generated are generally only approximations to the intended symbols, and may not be recognizable by an untrained observer.Many letters are not displayable even approximately.

Several other multi-element displays have been proposed, in an attempt to provide means for representing a wider range of symbols and/or producing better approximations to standard symbols. For example, addition of two centre segments gives a nine-segment display which can represent all digits and most letters -- but with generally poor quality and readability. Display with fourteen (five new ones within the parallelogram) and sixteen (as for fourteen, with top and bottom segments split into two) segments, can give a full alphanumeric display. However, the symbols are still highly stylized.With lower-case letters there is little regard to the conventional positioning and relative sizes of letters: for example 'a', 'b' and 'g' may all be represented as of the same height and extending between the same two limits (the upper and lower sides of the basic parallelogram).

Any of the displays described above may also include a 'decimal point' - i.e. a small segment, usually square or circular, located outside the basic parallelogram, on the right-hand side, close to the base.

A somewhat different form of display is the 'dot matrix'. This uses actuable 'dots' instead of line segments. A relatively iarge number of dots is used -- commonly thirty-five in a seven-by-five matrix.

This allows representation of all the alphanumeric characters, and many more. However, the control of 35 elements requires relatively complex circuitry, but nevertheless the quality of the representations is generally poor. In theory a much larger matrix could be used, giving any desired quality and flexibility of operation. However, for practical purposes having to control even so many as thirty-five elements per character display unit may be unacceptable.

The use of electronic displays is becoming more extensive, both as regards the range of symbols to be displayed and as regards the likely audience. With their increasing use for displaying information in public places and also in the growing field of home computers, there is a growing need for a display which can represent a wide range of symbols in a manner which is clearly readable by a (relatively) untrained operator.

According to the present invention there is provided a multi-segment display which comprises a first plurality of at least seven selectively actuable segments arranged to define a basic parallelogram whose shorter sides are generally horizontal, and a line parallel to said shorter sides which bisects the parallelogram into two lesser parallelograms; and a second plurality of selectively actuable segments located outside the basic parallelogram.

Suitably at least some of said second plurality of segments together with the base of the basic parallelogram define a further parallelogram.

Preferably the display comprises at least one curved and/or tapered segment.

For an electronic display, the segments may be light emitting diodes or liquid crystal elements.

In further aspects the invention provides electronic display apparatus, a calculator or a computer including a display device according to the first aspect.

Two preferred embodiments of the invention will now be described with reference to the accompanying drawings in which: Figure 1 shows a 24-segment (23 plus decimal point) display with independently actuable segments; and Figure 2 shows a 33-segment (32 plus decimal point) display (with 32 independently actuable segments).

In the display of Figure 1, segments 1 a, 1 b and 2 to 7 form a bisected parallelogram like that of a conventional seven segment display, the top short side being 'split' into two separately actuable equal segments 1 a and b. The long sides 2, 3 and 5, 6 are extended downwardly by further segments 8 and 10, each of about half the length of each of segments 2 to 7, and whose lower ends are connected by a segment 9 which is equal and parallel to segments 4 and 7.

The upper parallelogram 1, 2, 7, 6 has an internal curved (concave downwards) segment 11 which extends generally diagonally across the parallelogram from adjacent the top left-hand vertex (1,6) to adjacent an imaginary point P1 in segment 7, a short distance from the bottom right hand vertex (2,7).

Another curved internal segment 12 (concave leftwards) extends from adjacent the other upper vertex (1 ,2) to adjacent point P 1. The lower parallelogram 7, 3, 4, 5 has curved internal segments 13, 14 which are approximate mirror images of segment 11, 12 about the axis of the segment 7: segment 1 3 extends generally diagonally between vertex (4,5) and point P 1 and is concave upwards; segment 14 extends between vertex (3,4) and point P 1 and is concave leftwards. The segments are so shaped and arranged as to give the impression of three lines, 7, 11 + 14, and 12 + 1 3 intersecting at point P 1.

The lower parallelogram 7, 3, 4, 5, has further curved internal segments 1 5 and 1 6 which extend generally along the other diagonal. Segment 1 5 is concave upwards and extends between vertex (5,7) and imaginary point P2, the centre of the parallelogram, whereas segment 1 6 (which is convex downwards) extends between point P2 and vertex (3,4).

Straight segments 1 7 to 20 define a line bisecting the parallelogram 1 to 6 parallel to the long sides thereof. Segments 1 7 and 1 8 are separated by segment 11 at point P3. Segments 1 8 and 1 9 are separated by segment 7 at its midpoint. Segments 19 and 20 are separated by segment 13 and (15+ 16) at point P2.

A 'square' dot-form segment 21 is located outside the parallelogram adjacent vertex (3,4) level with segment 14. Segment 22 provides a comma-form tail beneath the dot segment 21. Tailpiece 23 is a curved (concave upwards) segment which extends upwardly and outwardly from adjacent the dot 21.

This display has, of course, all the capabilities of the conventional seven-segment display, and many more. All digits and upper- and lower-case Roman letters are displayable, and in many cases alternative forms are available -- for example, 'A' may be represented using segments 1 a, 1 b, 2, 3, 5, 6, 7 or 11, 14, 5, 6, 7. In representing lower-case Roman letters, it is possible to achieve normal positioning and correct relative sizes of letters, the four horizontal levels, 1, 7, 4, 9 defining the upper and lower levels of the letters as in conventional lettering. One possible set of representations of the lower case Roman letters is given in the following table.

TABLE: POSSIBLE REPRESENTATIONS OF LOWER-CASE LETTERS ON THE DISPLAY SHOWN IN FIG. 1.

LETTER SEGMENTS ACTUATED LETTER SEGMENTS ACTUATED LETTER a 3,4,5,7,21,23 n 3,5,7 b 3,4,5,6.7 o 3,4,5,7 c 4,5,7 P 3,4,5,7,10 d 2,3,4,5,7 q 3,4,5,7,8,21,23 e 4,5,7,13 r 5,7 f ib, 17-20,7 s 4,7,15,16 9 3.4,5,7,8,9 t 7, 17-20 h 3.5,6,7 u 3,4,5 i 3,21,23 v 5,13 i 3,8,9 w 3,4,5,20 k 5,6,13,16 x 13,15,16 1 2,3,21,23 y 3-5, 8,9 m 3,5,7,19,20 4,7,13 It is also possible to represent all Greek letters (upper and lower case); Cyrillic letters, Welsh double consonants; lower-case Roman letters with accents; punctuation marks; and many mathematical and other symbols. It is believed that the manner in which a particular symbol can be represented is readily deducible from the examples already given, and need not be explained in detail It may be pointed out that, when a plurality of displays is used to express numbers, a segment 21 or 21 and 22 may be used to express a decimal point in British or European notation respectively.

Referring now to the embodiment shown in Figure 2, it can be seen that this includes all of the segments of the Figure 1 embodiment, some of them divided into two separately actuable portions (2a and b, 4a and b; 6a and b; and 7a and b). There are also some new segments: 24 and 25 define a line parallel to the short sides (1, 4, 7) of the basic parallelogram which bisects the upper parallelogram.

Segments 26, 27 and 28 define a line parallel to segments 17 and 18. Segments 26 and 27 are connected for simultaneous actuations, so as to constitute in effect a single segment which is crossed by segment 11 (this is symbolized in the figure by the broken line connecting them. Thus the upper paralleograms include elements forming two adjacent seven-segment displays: (1a, 26 + 27, 28, 7b, 6a, 6b, 24) and (1b, 2a, 2b, 7a, 18, 17, 25). These can be used to represent superscript symbols, e.g.

to represent mathematical indices in the conventional mathematical way (instead of in a way peculiar to calculator readouts and the like).

There may be means for intermittent actuations of segment 24 so that it can flash, suitable at 2-4 Hz, to draw attention to some signigicant feature -- e.g. that the figure displayed is a negative quantity. In this case the segment 24 flashes within any digit formed in the left hand upper parallelogram of which it form part.

The Figure 2 display can reproduce many forms which the Figure 1 display cannot. Somg examples of alternative representations available only to the Figure 2 displays are: '3' (lea, 1b, 12,7a,3,4a,4b); '7' (lea, 1b,2a,2b,3,7a)or(1a, 1b 12, 13,7a) 't' (5, 6a, 6b, tb) ór (18, 19, 16 21 23 7aj; 's' (7b, 1'5, 20, 4v); 'z' (7a, 13, 4b).

Electronic displays are commonly driven by binary logic circuits, each of which can produce 2" 'bits' of information -- e.g. 8, 1 6 and 32. The Figure 1 display, having 24 segments, may be driven by a combination of an 8- and a 1 6-bit logic circuit. The Figure 2 display has thirty-three segments, however since segments 26 and 27 are connected together, there are effectively only thirty-two, so that it can be driven by a single 32-bit circuit. This gives a straight-forward efficient combination, with no 'bits' wasted.

Whereas the illustrated embodiments are preferred, there are many other possible embodiments.

In general, if they are to be driven by binary logic, displays with numbers of controllable segments which are powers of two or simple combinations thereof are preferred. However, in particular cases there may be reasons for using (e.g.) a 27-segment display (which could be driven by a 32-bit circuit, with redundant 'bits'). Of course, these constraints do not apply if binary logic is not used.

j Another modification of the Figure 1 embodiment involves 'splitting' segments 7, 11 and 13 into respective pairs of segments separated by point-form segments. The same modification, although not illustrated, is also applicable to Figure 2. The notional splitting of segment 7 in this way into line segments 7p and 7r and point segment 7q is indicated in broken lines in Figure 1. The segments meeting at a point P 1 could also be split to give point segments lip, 7s and 14p (Figure 1). The provision of such point segments at intersections can give smoother symbols, each such point segment being usable as an extension of any of the adjacent line segments.For example, the lower-case 'e' listed in Table 1 would be improved by the inclusion of 1 4p, and the exclusion of the portions 7t of 7 to the right of 7s. The intersections at the points P2 and P3 could be similarly dealt with. Likewise, in the Figure 2 embodiment a point P4 between the segments 26 and 27 could be similarly treated.

Segment 16 could be concave upwards so that the-line of segments 1 5 and 1 6 would be a simple curve and not sigmoid.

In a modification of the Figure 2 embodiment, instead of using segment 24 as a flashing indicator, a separate segment could be provided. To preserve the efficient 32-segment form, the comma 22 could be emitted, or combined with the point 21.

In the illustrated embodiments, several of the line segments are curved, since this can allow more natural representation of symbols. However it is within the invention to 'replace' all or some of the curved segments by linear ones; the effects of this may be minimized by using some tapered segments.

For example, for notional 'conversion' of the Figure 2 display to a straight-line form, segment 11, 13, 1 5 and 1 6 may be replaced by straight, parallel-sided segments extending between the same points. This will raise point P2 and lower point P3, with corresponding changes in the lengths of segments 1 7 to 20, and 26 and 27. Segments 1 2 and 14 may be replaced with straight segments which taper along their lengths, being narrow adjacent vertices (1,2) and (3,4) and of full width adjacent point P1.

In the detailed description of embodiments it has been assumed that the display includes a basic parallelogram whose sides are in the ratio 2:1, and which is divided into upper and lower parallelograms by segment 7.

Since each of the two parallelograms formed within the basic parallelogram has all four sides of equal length, it is in fact a rhombus.

However, a different shape of basic parallelogram could be used, in which case it would be divided by segment 7 into upper and lower parallelograms which were not (or were not both) rhombuses.

In general, references such as the above to 'a segment 7' are intended to cover the case when the segment so named is a composite of a plurality of segments which may be independently actuable.

Claims (15)

1. Multi-segment display which comprises a first plurality of at least seven selectively actuable segments arranged to define a basic parallelogram whose shorter sides are generally horizontal, and a line parallel to said shorter sides which bisects the parallelogram into two lesser parallelograms: and a second plurality of selectively actuable segments located outside the basic parallelogram

2. A display according to Claim 1, wherein said second plurality comprises continuation segments which continue the long sides of the basic parallelogram in a downward direction, and at least one segment parallel to the short sides of the basic parallelogram extending between said continuation segments.

3. A display according to Claim 1 or Claim 2, wherein said second plurality comprises a point-form and/or a comma-shaped segment adjacent the lower right-hand vertex of the basic parallelogram.

4. A display according to any one of the preceding claims, wherein said second plurality includes segment which extends generally outwardly and upwardly from adjacent the lower right-hand vertex of the basic parallelogram.

5. A display according to any one of the preceding claims, comprising at least one curved and/or tapered elongate segment.

6. A display according to any one of the preceding claims, including segments extending generally along at least some of the diagonals of the upper and lower lesser parallelograms formed within the basic parallelogram.

7. A display according to any one of the preceding claims, including segments extending logitudinally so as to bisect at least one of said lesser parallelograms.

8. A display according to any one of the preceding claims, wherein the upper parallelogram contains: a first internal segment extending from adjacent the upper right hand vertex to adjacent the base of said parallelogram, the spacing of said segment from the right hand side of said parallelogram increasing downwardly; a second internal segment extending from adjacent the upper left hand vertex to adjacent the lower end of said first internal segment; and third and fourth internal segments extending in the longitudinal direction of the basic parallelogram in respective sides of the second internal segment so as substantially to bisect said upper parallelogram.

9. A display according to any one of the preceding claims, including two co-linear segments connected for simultaneous actuation and separated by a third segment extending generally transversely of them, so that the two colinear segments act as a single interrupted segment.

10. A display according to any one of the preceding claims, including an indicator segment and means for its intermittent actuation to provide a flashing display element.

11. A display according to any one of the preceding claims, including a plurality of segments within the basic parallelogram which provide, alone or in combination with some of the elements .defining the basic parallelogram, at least one sub-display in an upper region of the display, by means of which superscript symbols are representable.

12. A display according to Claim 11, wherein said plurality of internal elements comprises two adjacent pairs of co-linear segments parallel to and substantially coextensive with the longitudinal sides of the upper parallelogram; and two laterally extending co-linear segments which bisect the upper parallelogram, each of said laterally extending segments extending substantially between a respective side of the parallelogram and the meeting-point of the two segments of a respective one of said adjacent pairs of segments; the sides of said upper parallelogram each consisting of two equal co-linear segments, whereby said upper parallelogram comprises two adjacent seven-segment displays of conventional form to serve as said sub-displays.

13. A display according to any one of the preceding claims, having 32 independently actuable segments.

14. Multi-segment display which comprises a first plurality of at least seven selectively actuable segments arranged to define a basic parallelogram whose shorter sides are generally horizontal, and a line parallel to said shorter sides which bisects the parallelogram into two lesser parallelograms, said display including at least one curved and/or tapered segment.

15. A display according to any one of the preceding claims, wherein said segments are light emitting diodes or liquid crystal elements.

1 6. A display substantially as described herein with reference to and as shown in Figure 1 or Figure 2 of the accompanying drawings.

1 7. Electronic display equipment including a display according to any one of the precedinng claims.

1 8. An electronic calculator or computer including a display according to any of Claims 1 to 1 5.