WO2008099153A1

WO2008099153A1 - Segmented display

Info

Publication number: WO2008099153A1
Application number: PCT/GB2008/000471
Authority: WO
Inventors: Eva Rucki; Sebastian Martial Noel; Martina Cornelia Freyer
Original assignee: Troika Design Llp
Priority date: 2007-02-12
Filing date: 2008-02-11
Publication date: 2008-08-21

Abstract

There is provided a segmented display (700) comprising a plurality of activatable display segments arranged so as to define: an outer box of substantially straight lines; a full inner circumference; an upper semi-circumference positioned above the inner circumference; and a lower semi-circumference positioned below the inner circumference.

Description

Segmented Display

Background

Time sequenced display of alphanumeric characters on a display is achieved by one of two alternative means: segmented displays or bitmap displays. For most purposes bitmap displays are preferred since they provide a high degree of versatility and may be used to display images, graphics, etc in addition to alphanumeric characters in various styles or fonts. However, bitmap displays suffer from two disadvantages, and these may become problematic for large scale or very small-scale display purposes.

Occasionally a very large-scale display is required to display only alphanumeric characters, of a known size and in well-defined locations, for example a large-scale clock display at a public location. In such cases a bitmap display with sufficient resolution to display clearly defined characters may be prohibitively expensive, cost in this case being broadly related to size and complexity.

In addition, at very small scales with certain display technologies, pixel density can become a limiting factor in the size of text that can be clearly and economically displayed. At low pixel densities a phenomenon known in typography as Jaggies becomes evident, where a jagged line at the edge of diagonal or curved portions of text causes an ugly appearance and makes the character hard to read clearly and quickly. As a result, very high pixel density is normally required for the clear display of small-scale text and in general, high pixel density means high display cost. Several new technologies such as that provided by E Ink Corporation in the US provide the ability to produce low- cost, relatively low-resolution displays that may be used for example in electronic book applications. However, the problem of pixel density when displaying text means that a simple bitmap display is not ideal. (E Ink Corporation has developed a partial solution to this problem, in the form of a subdivided bitmap display, described later.) Furthermore several such technologies allow the construction of flexible displays, where the provision of large numbers of connections for addressing each pixel causes additional design, production and durability problems, and it is desirable to provide a display requiring minimal address lines, while providing clearly legible displayed characters. An alternative for the display of both large- and small-scale alphanumeric characters is to use a segmented display, having segments with curved or diagonal edges, in an array specifically designed for displaying text and numbers of one size only. However, currently such displays do not provide much versatility in terms of text styles and are hard to read, displayed characters and words being wrongly spaced (in typographical terms), having apparent missing sections, or including otherwise unfamiliar configurations for certain characters (see Figure 5).

Typographic conventions or rules have 'evolved' through centuries of development of printing, establishing the basis for providing clearly legible text and numbers in a wide variety of different typefaces or fonts. When properly applied, typographic rules provide a visually pleasing appearance and measurably improved readability of text. One example of a typographic convention provides a system for the different formatting of heading and body text: body text is normally displayed in large blocks or paragraphs and should ideally use a serif font (with small strokes at the ends of most letterforms), whereas heading text, for short sentences or headings, may advantageously use a sans-serif font.

Fonts are often grouped into font families, each font within a family being suitable for display in conjunction with the others. The optimal display would provide alphanumeric characters similar in appearance to printed characters, providing suitably fine lines with clean, well-defined edges in the diagonal and curved portions as well as the horizontal and vertical portions, and should preferably allow the application of certain typographical conventions.

Brief Summary of the Invention

According to an aspect of the present invention, there is provided a segmented display comprising a plurality of segments each defined by edges, a plurality of said segments having an inner curved edge and a plurality of said segments having an outer curved edge, wherein one of said segments in combination with a first other one of said segments forms part of a substantially curved line and in combination with a second other one of said segments forms part of a substantially straight line.

Brief Description of the Several Views of the Drawings

Figure 1 shows an overview of an embodiment of the invention; Figure 2 shows examples of prior art; Figure 3 shows a further example of prior art; Figure 4 shows a further representation of the art shown in Figure 3; Figure 5 illustrates common typographical terms of reference;

Figure 6 shows a selection of characters in alternative typestyles; Figure 7 shows a first embodiment of the invention;

Figure 8 shows an arrangement of address line connections in an embodiment of the invention;

Figure 9 shows a first set of configurations of active segments; Figure 10 shows a second set of configurations of active segments;

Figure 11 shows a third set of configurations of active segments;

Figure 12 shows a fourth set of configurations of active segments;

Figure 13 shows options for applying additional typographical conventions; Figure 14 shows an alternative embodiment of the invention; and

Figure 15 shows a fifth set of configurations of active segments.

Description

Figure 1 illustrates an overview of a first embodiment of the present invention in use for example in a display 101 , installed at an airport. The display uses multiple segmented displays such as 103 to provide a clear alphanumeric display of the time in different time-zones.

The viewer (in silhouette) 102 reads a very large-scale representation of the time shown in segmented display 103 (only the right-most portion of this section, representing the time in seconds, is included in the figure). In portion

104, two rows of five smaller versions of the segmented display are shown displaying the time in Tokyo. For illustration purposes, the inactive segments of each display unit are shown in outline, and the activated segments are shown in black. In this embodiment, a light-emitting display medium is preferred such as a printed electroluminescent material. It can be appreciated that numbers and characters displayed on 101 are visually more similar to conventional typography than conventional segmented displays would allow. It should also be noted that in this example, the appearance of a cursive script is created in the portions displaying text by the activation of linking segments, which will be described in more detail later.

Figure 2 shows three typical segmented displays, with selected sections active to represent the number 7.

For illustrative purposes active segments such as 202 are represented in black, but an active segment may be in any colour capable of selective activation, for example back-lit or reflective liquid-crystal, illuminated LED, electroluminescent, light emitting organic polymer, etc.

The segmented display 201 is known as a seven segment display showing the 'magic 8^J configuration of segments. Display 201 is useful for displaying only number data, uses the minimum number of segments, and provides a relatively crude display.

Segmented display 203 uses only fourteen segments to display all Latin letter characters, as well as numbers. However, letters may normally only be represented in capitals, and the output remains crude and is not easily readable. Segmented display 204 is a bitmap display, comprising an 8x16 pixel array. In a bitmap display, each pixel is normally either round or square in form, or at least substantially rectilinear. Round pixels typically provide a less coherent image when displaying text and so rectilinear pixels are normally preferred. However, rectilinear pixels in combination are not capable of displaying diagonal or curved edges in a smooth line. The solution is normally to provide a large number of pixels, creating the appearance of a relatively smooth line at high resolutions. Thus, for example, to be easily recognised when reading text at speed, or to provide a visually clean appearance, an alphabetic character must comprise several hundreds or even thousands of individual pixels. To reduce this problem, it is known to provide subdivisions within certain of such pixels to facilitate display of alphanumeric characters, (see E ink Corporation patent application number WO0005704). Such subdivided pixels comprise a substantially rectilinear cell or segment subdivided along either a diagonal line or a curved line, creating at least two pixel segments, such that when only one subsection is activated a region bounded by a diagonal or a curved line is displayed. Such solutions provide for alphabetic characters with some diagonal or curved edges; however, curves defining only outer edges are provided and thus fine lines with both inner and outer curves may not be represented. Furthermore, because the display is essentially pixel based, only limited styles may be displayed with smooth edges, and these tend to appear as relatively thick or 'bold' type, and are thus not ideal for displaying large amounts of body text for example, or for displaying visually attractive and highly readable text styles.

Ease of reading may be represented by a measure of readability. Relative readability may be measured by timing the reading of text in different formats. Readability is of the utmost importance in typography and it has been found that some typestyles or fonts provide better readability, on average, than others. In general, clearly defined characters with smooth and rounded curves are important, as are certain proportions and uniformity of typestyle or font. Text should not be too thick (or bold), too tightly packed, or spread too thinly along a line. In addition it helps if the font has a visually pleasing appearance and is 'well-proportioned'. Good proportions are difficult to define scientifically, but are repeatedly selected in random studies as being preferred by viewers. As a general rule, common fonts used in printing (particularly where used for large bodies of text) can be relied on to have good readability. Figure 3 shows an example of the prior art in segmented displays as described in UK Patent Application No 2 071 386. Display 301 includes a total of 33 segments and includes a number of substantially curvilinear segments such as for example segment 302, each curvilinear segment comprising short sides (for example 3021 , 3022, 3023) and longer sides, and the longer sides comprising an inner arc, for example 3024 and an outer arc, for example 3025. The addition of these curvilinear segments is an improvement over crude segmented displays such as 203 in terms of its ability to display more readable characters as can be seen in Figure 4.

Segmented display 301 also includes a number of segments 303, 304 and 305 positioned outside of the parallelogram containing the remaining segments.

Figure 4 illustrates a series of alphabetic characters as displayed on segmented display 301.

Six rows are shown, each comprising seven copies of segmented display 301 . The upper four rows illustrate how lower-case Latin characters may be displayed; and the lower two rows show capital letters. The letters T, 'q' and T each make use of segments 304 and 305 to provide a tail, to assist in visual recognition of those characters. Numbers may also be displayed using segmented display 301 but these are not illustrated. While display 301 is capable of displaying legible characters in both upper and lower-case configurations as well as numbers, the readability of the characters is limited and the visual representations are crude. Sizeable gaps appear within letters in some places, for example in the lower-case letters 'm' and 'f and character spacing between adjacent letters is markedly uneven, for example, the apparent space between 'k' and T is almost as large as a space that would be represented between words by an inactive segment, for example positioned between say T and 'm\ and this results in poor readability. In short, a reader is required to make too many allowances for the technology (in the form of changes to his normal and automatic reading processes).

Normal reading processes should be interfered with as little as possible for maximum readability. The present invention takes a number of typographical conventions into account and thus provides a set of options for producing substantially more readable text on segmented displays. Figure 5 describes common typographical terms of reference. For Latin characters, all numbers and capital letters and the body portion of lower-case letters normally rest on (or very close to) a nominal baseline 501. Certain lower-case characters have a portion extending below the baseline, to the descender line 502. The region 503 between the baseline and the descender line is known as the descender. For example the portion of the letter y extending below the baseline and terminating at the descender line is known as the descender portion.

The body portion of lower-case letters occupies region 504. Region 504 is known as the x-height (being the height of a lower case 'x') and extends between the baseline and the mean line 505. A third region, known as the ascender 506, extends between the mean line and the ascender line 507. For most fonts, the ascender line defines the upper height limit of tall lower-case characters and the top of all full-sized capital letters. Figure 6 shows a selection of alphanumeric characters in four alternative typestyles.

Set 601 shows a typical sans-serif font. Lines within characters have substantially square ends. Set 602 uses a similar sans-serif font to 601 , except that instead of lower-case characters, small-capitals (small caps) are represented. In addition, numbers in 602 have no descender portions; all rest on the baseline. Characters in set 603 are similar to those in 601 , except for the addition of serifs, or small strokes, typically at the ends of lines within characters. Set 603 can be considered as related to set 601 because of the similarity of form and proportions of characters, particularly within the curvilinear segments of characters. Some characters, such as lower-case letters 'g' and 'e\ are substantially the same in both sets (having no serifs attached in the serif font

603). Set 604 represents an italicised version of set 603, having substantially the same characters but distorted by skewing each character more or less uniformly within a parallelogram.

Each of sets 601 , 602 and 603 includes characters with substantially similar segments. Curvilinear segments in particular use similar rounded geometry; and line widths are narrow and substantially the same from one set to another. Set 604 is an approximately uniformly distorted version of set 603.

Thus sets 601 , 602, 603 and 604 may be considered together as a 'font family'. Font families are commonly used in typography within page layouts for example, to create visually coherent layouts, with different sections of text often demarked by size and or font style. The present invention described below provides a segmented display having less than 100 segments. The display provides means of selectively displaying more than two alternative text styles (i.e. more than simply lowercase or full-sized capitals) in addition to numbers while maintaining the appearance of smooth curves and diagonals, suitably narrow line widths, suitably continuous lines, curved sections with inner and outer radii, and other features that are typographically desirable, thus providing improved readability (per segment) over the prior art.

Figure 7 illustrates a first example embodiment of the present invention. Display 700 includes 81 segments, numbered 701 to 781 . All are shown in black, representing activated segments. Display means may use many alternative display technologies, as described previously, providing black, white, illuminated or coloured output upon activation. This example embodiment uses printed electroluminescent technology, described in more detail later with reference to Figure 8.

With the exception of segments 760, 751 and 761 , whose function will be described later, all segments are contained within a bounding parallelogram having corner segments 701 , 707, 775 and 781 and segments in horizontal and straight lines between said corner segments, together forming a main or bounding parallelogram.

The main parallelogram is subdivided into four internal parallelograms or subsection portions, defined by corner segments as follows: subsection 791 , defined by 701 , 707, 715 and 721 ; subsection 792, defined by 715, 721 , 737 and 741 ; subsection 793, defined by 737, 741 , 762 and 768; and subsection 794: defined by 762, 768, 775 and 781. In this embodiment, each such subsection has substantially the same size and shape. However, some distortion of the described proportions is possible, for example to provide alternative type-styles or font families.

Segments in a line (along the top) between 701 and 707 together correspond to line 507 in Figure 5 and represent the ascender line. Segments in a line between 715 and 721 together correspond to line 505 in Figure 5 and represent the mean line. Thus parallelogram 791 represents the ascender portion (506) of the display

Segments in a line between 762 and 768 together correspond to line 501 in Figure 5 and represent the baseline (segments 761 and 760 are also on the baseline). Thus parallelograms 792 and 793 comprise the upper and lower halves of the x-height (504) of the display.

Segments in a line between 775 and 781 together correspond to line 502 in Figure 5 and represent the descender line. Thus parallelogram 794 comprises the descender portion (503) of the display.

Each of subsection parallelograms 791 , 792, 793 and 794 includes a series of curvilinear segments substantially describing an arc. These arcs may be activated to represent substantially a full semicircle, or (by activating only some of the segments) to represent a smaller arc such as a quadrant. At least one segment within each arc includes curved edges representing both inner and outer radii.

Thus, the ascender portion 791 includes a set of segments 713, 709,

703, 704, 705, 711 and 714, together describing substantially a semi-circle, selectable as two quarter-circles divided by segment 704. Each such quarter- circle includes at least one segment (i.e. 709 and 711 ) having both inner and outer curved edges. Portion 792, representing the upper half of the x-height portion, includes a set of segments 735, 730, 728, 724, 717, 718, 719, 725, 729, 734 and 736 describing a similar arc to that of portion 791. Portion 793, representing the lower half of the x-height portion, includes a set of segments 742, 746, 747, 753, 757, 764, 765, 766, 758, 754, 750 and 744 describing a similar (but inverted) arc to that of portions 791 and 792.

The arcs described within portions 792 and 793 when combined with segments 737 and 741 thus combine to describe substantially a circle, with diameter substantially equal to the x-height and centred on section 739, situated substantially at the centre of the main parallelogram.

Portion 794 includes a series of segments 769, 772, 777, 778, 779, 773 and 770 together describing a semi-circular arc substantially similar to the arc within portion 793.

The x-height portion (portions 792 and 793 combined) includes additionally a set of segments forming a diagonal line between segments 715 and 768, and a second set of segments forming a diagonal line between segments 721 and 762. The x-height portion also includes segments forming bisecting vertical and horizontal lines.

Segment 710 forms a bisecting vertical line through portion 791. Outside the main parallelogram, segments 760, 761 and 751 provide spacing between characters (when inactive) or may be selectively activated to provide underlining or cursive script display options as will be shown later with reference to Figure 10.

Square segments 701 , 704, 707, 715, 718, 721 , 737, 739, 741 , 762, 765, 768, 775, 778 and 781 are regularly spaced across the display and are arranged in a vertically and horizontally uniform grid pattern. As such, when no other segments are used these square segments form a crude bitmap display and may be used to display still or animated pictures and graphics.

A plurality of segments, such as segments 703, 705, 713, 714, 717, 719 in portion 791 (and further segments in portions 792 and 794), are overlap segments. These overlap segments can form part of a substantially curved line in combination with a first other segment, and form part of a substantially straight line in combination with a second other segment. For example, segment 703 can, in combination with segment 709, form a curved line. In combination with segment 702, segment 703 forms a straight line. This overlapping is facilitated by the complementary edges of the overlap segment, in this example an outer arc of segment 703 matching with an inner arc of segment 702, and a straight edge of segment 703 matching with a straight edge of segment 709.

In the preferred embodiment, displays such as 700 are arranged in rows immediately adjacent to each other and in columns with a separating space between adjacent displays corresponding to half of the x-height, thus providing uniform spacing between square segments at the edges of one display and adjacent square segments of the adjacent display, in both vertical and horizontal directions. Thus bitmap displays as described may extend over more than one display unit.

Figure 8 shows a typical arrangement of address line connections suitable for segmented display 700, particularly when using a printed display technology such as printed electroluminescent displays for example available from Pelikon Ltd in the UK. Printed segmented electroluminescent displays are constructed by depositing layers onto a clear substrate as follows. First a clear conductive material is printed across the entire area of the display (for connection to a common ground). Next, electroluminescent (EL) material and backing layers are deposited in a segmented pattern, for example as shown in Figure 7. Next, electrical insulation is selectively applied, usually in several passes, leaving the desired points of connection (to the conductive backing of the EL material) uninsulated. Then conductive ink is printed to form the address lines, making connections (through the holes in insulation) to the segments. Figure 8 is a schematic diagram illustrating the placement of address lines with their connection points. Connection points would not normally be visible from the front view of the display.

In Figure 8, individual address lines are shown for each segment (or combination of segments, where such segments always operate together). Thus, address line 801 connects to segment 760, address line 802 connects to segment 761 and so on for each independent segment. For all alphanumeric characters within a particular character set, certain segments are always activated together and may be connected in parallel. For example, address line 803 connects to both segments 747 and 757, connection 804 connects to segments 773, 779 and 778 through connecting lines 805 and 806, and so on for other selected joined segments. In an alternative embodiment (not shown) the address lines may be illuminated at the same time as the segments they activate. For example, as an alteration to the method described above EL material is deposited at the positions of the address lines in addition to the segmented pattern. Points of connection are left uncovered in order to make connection points, and thus the address-line material is activated at the same time that the addressed segment is activated. Alternatively, depending upon the layout of the segments, it may be possible to connect the EL material of a segment with the EL material of its addressing line, thus only requiring one point of connection. In this embodiment addressing lines are not illuminated at the places where they cross segments, but if a different illumination method were used then the whole of the addressing line could be illuminated.

Figure 8 shows address lines suitable for use in technologies requiring individual addressing of segments or segment groups. Some technologies such as liquid crystal displays allow active matrix or multiplexed activation of segments, for example in rows and columns. Segments of the segmented display of Figure 7 may thus be activated selectively by applying a voltage to address lines as shown in Figure 8. The segmented display provides a highly versatile unit, capable of displaying a variety of visually coherent, easily recognisable and highly readable typestyles.

Figure 9 illustrates a first set of preferred configurations of active segments on segmented display 700, wherein a first combination of segments is activated to provide a first text-style. Figure 9 illustrates the display of a lower-case alphabet on a series of displays such as segmented display 700.

It can be appreciated from Figure 9 that the characters are largely as they would appear in conventional printed form, with few compromises dictated by the arrangement of the segmented display. Some compromises are apparent, for example the character spacing between T and 'g\ and between T and 'j'- However the spacing is not as large as a missing segment would provide and as such does not in practice present serious problems for readability. A marked improvement in terms of readability (measured by sample reading speed) has been achieved relative to the prior art described in relation to Figure 4. Overall the typeface provides a coherent visual impression, having substantially continuous characters and corresponds much more closely to a conventional printed typeface or font.

Figure 10 illustrates a second set of preferred configurations of active segments on a series of segmented displays such as 700, wherein a second combination of segments is activated to provide a second text-style. Figure 10 illustrates the alphabet broadly as shown in Figure 9, having additional segments (namely 760 and 751 ) selectively activated for the majority of characters, thus providing a second combination of segments activated to provide a second text-style (when compared to that of figure 9). In Figure 10, the typeface corresponds substantially to a cursive font.

The letters i, j and s in Figure 10 can also be seen to take different forms to the corresponding letters of Figure 9, this being achieved by selecting a different combination of segments for activation within the main parallelogram in addition to the external linking segments 760 and 751. In addition, some letters such as j, x and z do not show the external linking segments activated. The use of external linking segments is optional (even within a cursive font) and the use or otherwise of these segments depends on design choice. Thus, the term cursive font applies to the character set as a whole and not necessarily to each individual letter. In general it is necessary to modify at least a majority of characters to provide an alternative character set or text-style. Overall the character set can be readily recognised as providing a cursive font.

For a given series of segmented displays, display units within the series or individual segments may be activated according to a time-sequence. Thus in a preferred method of operation a message comprising a series of characters is activated in a sequence from left to right of each line of text, approximating the appearance of the process of writing. In a further enhancement, the activation of individual segments is also time-sequenced such that the appearance of each character corresponds to the normal sequence of manual generation of the corresponding hand-written-character. For example, the cursive lower-case character 'a' shown is preferably generated. by activating segments in turn, with a very short time delay between each activation, in the following sequence (with reference to Figure 7): 760, 751 , 745, 742, 737, 735, 730, 728, 724, 717, 718, 719, 725, 729, 734, 736, 741 , 744, 750, 754, 758, 766, 765, 764, 757, 753, 747, 746, 727, 755. Figure 1 1 illustrates a third set of preferred configurations of active segments on a series of segmented displays such as 700, wherein a third combination of segments is activated to provide a third text-style, in addition to number characters. An alphabet of full-sized capitals together with number characters is shown. The letter 'O' also serves in this example as the number zero. Again, both characters and numbers are readily recognisable and such recognition is further enhanced when characters are seen in context, i.e. in conjunction with other characters from the character set.

Figure 12 illustrates a fourth set of preferred configurations of active segments on a series of segmented displays such as 700, wherein a fourth combination of segments is activated to provide a fourth text-style, in this case small capitals (known in typography as small caps). Again, characters are readily recognisable and appear substantially different from the full-sized capitals shown in Figure 1 1 , particularly when seen in conjunction with each other. Figure 13 illustrates options for applying three additional typographical conventions using segmented display 700. The character set shown corresponds to the cursive font shown in Figure 10. The upper row comprises the letters abcdefg. In addition to segments required for displaying the character, segments in a line from 760 to 768 have all been activated to provide an underlining function, such as may be used to emphasise certain words within text for example.

The central row shows characters jklmnop. In addition, segments in a line between 775 and 781 are activated, to provide a letter underscore' function, which may be used as an alternative method of emphasis within text, or may be used as a graphic device, providing the appearance of a dashed line when used together.

The lower row shows characters uvwxyz. In addition, segments 775, 778 and 781 are activated, providing the appearance of a dotted line.

Figure 14 shows an alternative segmented display 1401 having 107 segments, together forming substantially similar shapes to those of display 700, except for the addition of segments 1402, 1403, 1404, 1405, 1406, 1407, 1408 and 1412. In addition, segments 751 , 760 and 761 of display 700 have effectively been split into smaller segments: segments 1413, and 1414 are positioned to the left of the main body of display 1401 , while segments 1409, 1410 and 1411 are positioned to the right. In addition, certain segments of display 700 are effectively subdivided in display 1401 , into groups of segments occupying substantially the same shape in outline as single segments of display 700, each such subsection being selectable separately, such that only part of a shape may be activated.

Thus, using display 1401 , four text-styles may be displayed, substantially as previously described, by means of combinations of segments substantially similar to those of display 700 and in addition, a fifth text-style may also be displayed as will be described with reference to figure 15.

Figure 15 illustrates a fifth set of preferred configurations of active segments on a series of segmented displays such as 1401 , wherein a fifth combination of segments is activated to provide a fifth text-style, in this case a serif font. As previously described, serif fonts are commonly used in applications requiring the display of larger amounts of text, and generally provide improved readability of smaller-scale text. Again, characters are readily recognisable and appear substantially different from the sans-serif characters of Figure 9, particularly when seen in conjunction with each other.

Similarly, segmented displays such as 1401 may also provide sixth, seventh and eighth text-styles by activating combinations of segments similar to those previously described, thus providing capitals, small-caps and cursive text-styles respectively but with the additional activation of small segments representing serifs in each case.

Claims

1. A segmented display, comprising a plurality of activatable display segments arranged so as to define: an outer box of substantially straight lines; a full inner circumference; an upper semi-circumference positioned above said inner circumference; and a lower semi-circumference positioned below said inner circumference.

2. A segmented display according to claim 1 , wherein activatable display segments define an X-shape within said inner circumference.

3. A segmented display according to claim 1 , further comprising additional segments outside of said outer box.

4. A segmented display comprising a plurality of segments each defined by edges, a plurality of said segments having an inner curved edge and a plurality of said segments having an outer curved edge, wherein one of said segments in combination with a first other one of said segments forms part of a substantially curved line and in combination with a second other one of said segments forms part of a substantially straight line.

5. A segmented display according to claim 4, whereby said display is configurable to display a character having a closed loop having inner and outer curved edges.

6. A segmented display according to claim 4 or claim 5, configurable to display a variety of text-styles.

7. A segmented display according to claim 5, wherein, for an alphabetic character: a first combination of segments is activated to provide a first text-style; a second combination of segments is activated to provide a second text-style; and a third combination of segments is activated to provide a third text-style.

8. A segmented display according to any preceding claim, wherein a plurality of said segments have both an inner curved edge and an outer curved edge.

9. A segmented display according to any preceding claim, wherein a plurality of said segments form a substantially circular portion.

10. A segmented display according to claim 9, wherein a further plurality of said segments form an upper substantially semicircular portion; and a further plurality of said segments form a lower substantially semicircular portion.

11. A segmented display according to claim 10, wherein said substantially circular portion and said upper and lower substantially semicircular portions are located within a bounding parallelogram.

12. A segmented display according to claim 11 , wherein said bounding parallelogram is a rectangle.

13. A segmented display according to claim 11 or claim 12, further comprising additional segments outside of said bounding parallelogram.

14. A segmented display according to claim 13, wherein said additional segments are located to the left of said bounding parallelogram.

15. A segmented display according to any preceding claim, comprising regularly spaced segments arranged in a uniform grid pattern.

16. A segmented display according to any preceding claim, wherein said display is electroluminescent.

17. A segmented display according to any preceding claim, wherein a plurality of segments are connected in parallel such that they activate together.

18. A segmented display according to any preceding claim, configurable to display text in a cursive font.

19. A segmented display according to any preceding claim, configurable to display text with underlining.

20. A segmented display according to any preceding claim, configurable to display text in a serif font.

21. A segmented display according to any previous claim, wherein each of said segments is activated by a conductive addressing line, and at least a portion of the position of each addressing line is illuminated when the corresponding segment is activated.

22. A plurality of segmented displays according to any preceding claim wherein selected segments of each of said displays are activated in sequence.

23. A plurality of segmented displays according to claim 22, wherein said selected segments are activated in a sequence substantially corresponding to the normal sequence of manual generation of the corresponding hand-written character.

24. A segmented display substantially as herein described with reference to Figures 7, 8, 9, 10, 11 and 12.