WO2000019396A1

WO2000019396A1 - Number display system

Info

Publication number: WO2000019396A1
Application number: PCT/HU1999/000066
Authority: WO
Inventors: József JÉGER
Original assignee: Jeger Jozsef
Priority date: 1998-09-30
Filing date: 1999-09-28
Publication date: 2000-04-06
Also published as: HUP9802176A1; AU5991599A; HU9802176D0

Abstract

The invention relates to a display system and method for variable display of characters, in particular Arabic numerals. The system comprises at least one character element (2) representing a digit of a number or a letter, and further comprises a display stand (3) with fixing means for the attachment of at least one character element (2) to the display stand (3). A character element (2) comprises multiple segments (7), and different digits are represented by different combinations of the segments (7). According to the invention, a character element (2) consists of two separate, substantially flat plates (11, 12) having substantially square first and second faces, with segments (7) provided on both faces. The fixing means is adapted for attaching the plates (11, 12) to the display stand (3) adjacent to each other, with one of the two faces facing away from the display stand, in an arbitrary position from the four possible positions where the edges of the square are parallel or perpendicular to the longitudinal axis of the character to be displayed. With the inventive display system, any of the Arabic numerals from 0 to 9 may be displayed using only two plates according to the invention.

Description

NUMBER DISPLAY SYSTEM

Technical Field

The invention relates to a display system and method for the display of characters, in particular Arabic numerals. Such a display system is equipped with multiple character elements, which represent a digit of a number or a letter. The character elements are placed on a display stand, which is provided with fixing means. With the help of the fixing means the character elements may be attached to the display stand, usually in a repeatable manner. In order to simplify the display of the characters, a character element comprises multiple segments, and different digits or letters are represented by different combinations of the segments. In this way there is no need to store an item of each digit or letter for each character to be able to display any desired number or text.

Such display stands are used widespread in the retail business, where especially the actual price of the goods must be displayed to the customers in an aesthetic and easily readable fashion. In certain businesses, like the retail sale of fruits and vegetables, the prices may change daily. Therefore, there is needed a display system which facilitate the frequent change of the displayed price, which latter is mostly displayed with Arabic numerals followed by the sign of the actual currency, e. g. "DM" for German Mark or "$" for US dollars.

Background Art

There are numerous known methods for the display of numbers on a display stand, which allow the changing of the characters for a practically unlimited number of times. One very well known display system, used by schoolchildren, comprises a case to receive character elements printed on a small sheet of paper or other sheet material. In order to be able to display all Arabic numerals, normally ten sheets are used for one character, one for each digit. One sheet is placed in the case, while the other nine must be stored somewhere. Even if the sheets have a digit on both sides, at least five sheets are needed for each character, which means that four sheets still must be stored. In the usual business environment of retail shops, these stored excess characters get lost easily. Beside the easy change of the digits, it would be advantageous if the display system itself could contain all necessary elements to display all possible Arabic numerals, and eventually other letters of the Latin alphabet, or that at least the amount of the necessary elements to display the numbers could be reduced.

A known display for displaying Arabic numerals, especially for price displays, is disclosed in the document WO 98/05020. This price-marking display consists of a case, which may be sub-divided into compartments, and display sheets. The display sheets comprise segments and folding lines, and they are designed to be folded along one of several folding lines, and thereby displaying different Arabic numerals. The folded display sheets are placed in the compartments of the case. In this known system there is no need to store excess characters. However, a disadvantage of this system is that the foldable display sheet is prone to wear, due to the frequent folding, and in the folded state its thickness may appear visually disturbing. The folded nature of the display sheet requires the use of a transparent casing, made of a soft transparent plastic foil, the visual appearance of which is also very quickly affected by the daily wear.

Another known system for the manual change of numbers is disclosed in the Hungarian Patent No. 191 562. This system utilises a display stand with seven or more manually adjustable segments to represent different numerical characters. The segments are positioned in the configuration generally used in digital display systems, and the segments may be either in a contrasting or a non-contrasting state. The main disadvantage of this system that each character element consists of at least seven segments, and the changing of the segments is rather cumbersome. E. g. when changing from "6" to "1", six of the seven segments must be changed. Also, this display system is very inconvenient to handle if the size of the characters is relatively small, e.g. smaller than 10 cm.

Summary of the Invention Accordingly, the object of the present invention is to provide an improved display system and method for the variable display of characters, in particular Arabic numerals. It is sought to provide a system which consists of very few parts, and with which any Arabic numeral from 0 to 9 may be displayed, beside other characters, e. g. some capital Latin letters. It is a particular object of the invention to provide a system and method where the need is largely eliminated to store those characters that are not actually used. A further object of the invention is to provide a system and method providing a quick and convenient change from one character to another. It is also sought to provide a system that is easy to manufacture and generally cost- effective. According to the invention, the above objects are realised with a display system comprising at least one character element representing a digit of a number or a letter, and further comprising a display stand with fixing means for the attachment of at least one character element to the display stand, where a character element comprises multiple segments, and different digits or letters are represented by different combinations of the segments.

According to the invention, a character element consists of two separate, substantially flat plates having substantially square first and second faces, with each face having four edges substantially perpendicular to the adjacent edges, with segments provided on at least one face, preferably on both faces, and the fixing means is adapted for attaching the plates to the display stand a, adjacent to each other, substantially along one of their edges, so that arbitrarily one of the two faces is facing substantially away from the display stand, while the other face is facing the display stand, and further b, in an arbitrary position from the four possible positions where the edges of the square are substantially parallel or substantially perpendicular to the longitudinal axis of the character to be displayed.

Further advantageous embodiments and details of the inventive display system are described in the following specification and claims.

The invention is based on the recognition that with the most widespread digital number display systems, the numbers are displayed with a seven-segment display, which may be regarded as a composition of two squares. The sides or edges of the squares may have one, two, three or four "active" or visible segments. It has been recognised that two square plates with two faces each are sufficient to represent the above four variations of the squares, and it was also recognised that introducing an overlap between the squares, all Arabic numerals may be composed using only two properly designed square plates. Therefore, with the most preferred display system of the invention, there is absolutely no need to store excess or reserve character elements. At the same time a durable, aesthetic display system is created, which also facilitate the quick and convenient change of the displayed numbers, as often as needed. Also, the display system may be realised for a very low cost, with very simple technologies. In the inventive method for displaying of characters, in particular Arabic numerals, a character element representing a digit of a number or a letter is composed of multiple segments, and different digits are displayed by different combinations of the segments. The method according to the invention includes the steps of using two separate, substantially flat plates to compose a character element, where the plates are of having substantially square first and second faces, with each face having four edges substantially perpendicular to the adjacent edges, with segments provided on at least one face, preferably on both faces, and attaching the plates a, adjacent to each other, with one of the two faces facing substantially towards the viewer. b, in an arbitrary position from the four possible positions where the edges of the square are substantially parallel or substantially perpendicular to the longitudinal axis of the character to be displayed.

It has been recognised that the plates of the inventive display system may be used to display characters also without a dedicated display stand. E. g. the plates could be made in the form of adhesive stickers, so that digits or other characters composed of the plates could be attached to any suitable object in a convenient and cost-effective manner.

Brief Description of Drawings

By way of example only, an embodiment of the invention will now be described with reference to the accompanying drawing, in which

Fig. 1 is a schematic perspective of a display board according to the invention,

Figs. 2a and 2b show the most preferred embodiments of the plates used in the display system of the invention, Fig. 3 a and 3b illustrate the composition of the Arabic numerals using the plates shown in Figs. 2a and 2b, according to an especially preferred embodiment of the display system and method,

Fig. 3c is an enlarged part of Fig. 3a, showing the digit "5",

Fig. 4a-c. show further preferred embodiments of the plates used in the display system and method of the invention, Fig. 5. illustrate the composition of the Arabic numerals using the plates shown in Figs. 4a, 4b and 4c,

Fig. 6a show the arrangement of the plates on a display board according to an embodiment of the display stand of the invention, Fig. 6b show the arrangement of the plates on a display board with a similar construction to that of Fig. 1, in cross section, Figs. 7a,7b and 7c illustrate further possible embodiments of the fixing means used in the display system of the invention, Figs. 8 is an exploded, perspective view of a part of a display board similar to that of Fig. 1, Fig. 9 is a top view of the part shown in Fig. 8, and

Fig. 10 in a cross section of the display stand in the plane X-X of Fig. 8, illustrating the method used to remove the plates from the display stand according to Figs. 8, Figs. 1 la and 1 lb illustrate the working principle of a preferred embodiment of the fixing means used in the display system of the invention, in a cross section similar to Fig. 10., and finally Fig. 12 illustrates another possible embodiment of the fixing means.

Best Mode for Carrying out the Invention

The method according to the invention will be obvious to the skilled person based on the following detailed description of the inventive display system. Therefore, the method itself need not be explained separately.

Referring to the figures, in Fig. 1, there is shown a display system 1 comprising character elements 2. The character elements 2 are attached to a display stand, represented by the display board 3. Each character element 2 represents a digit of a number. In the shown embodiment the display board 3 accommodates five digits, i. e. five character elements 2. Obviously, in Fig. 1 the digits of the number "352.72" are displayed on the display board 3. There are also provided means 4 to represent the decimal point between the character elements 2, e. g. a removable or fixed dot 5., and a supporting leg 6 to keep the display board 3 in an erected position. The display board 3 is provided with fixing means, which allow the repeated removable attachment of at least one character element 2 to the display board 3. The functioning of the fixing means will be explained in detail below. By removable attachment it is meant that a character element 2 may be removed from the display board 3 and re-attached or re-fastened again for a practically unlimited number of times.

The character elements 2 comprise multiple segments 7, and different digits are represented by different combinations of the segments 7. According to the invention, a character element 2 consists of two separate, substantially flat plates 11 and 12. (see especially Figs. 2a,2b, 3a,3b and 8). The plates 11 and 12 have substantially square first face 11A,12A and second face 11B, 12B. Each face has four edges 13 substantially perpendicular to the adjacent edges 13, with segments 7 provided on both faces 11A,12A,11B, 12B. As mentioned above, there are also provided fixing means adapted for attaching the plates 11,12 to the display board 3. The plates 11,12 are attached on the display board 3 adjacent to each other, in such a manner that arbitrarily one of the two faces 11A,12A,11B, 12B is facing substantially away from the display board 3, while the other face 11 A,12A,1 IB, 12B is facing the display board 3. The plates 11,12 are in substantially parallel planes, effectively in the plane of the display board 3. Also, the fixing means, which will be described more in detail with reference to Figs. 8, 9, and 1 la, allows the fastening of the plates 11,12 in an arbitrary position from the four possible positions where the edges 13 of the square are substantially parallel or substantially perpendicular to the longitudinal axis of the character to be displayed. Practically this means that the edges 13 of the plates 11,12 appear horizontal and vertical when looking at the display board 3, and one of the plates 11,12 is placed above the other, as shown in the figures.

The segments 7 on the faces 11A,12A,11B, 12B are constituted by substantially straight lines along the edges 13 of the square faces 11A,12A,11B, 12B, the lines extending substantially along the whole edge 13. In a preferred embodiment, as shown best in Fig 2a,2b and 3c, the lines constituting the segments 7 are composed of multiple identical motives arranged in a line, in this case the filled squares 8. In the shown embodiments, three squares 8 constitute a line, i. e. a segment 7. Obviously, the square 8' on the corner of a face 11B,12A,12B belongs to both adjacent segments 7 (see Fig. 3c). It has been found that with this graphical solution the overlap of the plates 11 and 12, which will be explained below, would be less apparent for the person viewing the character 2, and the character 2 would appear to be composed of the pixel-like squares 8. However, it is obvious for the skilled person that while at least three squares 8 are necessary to achieve the desired effect, a line constituting a segment 7 may be composed of more squares, like four, five, six or more. Other motives, like a filled circle, are also applicable. In order to limit the number of the plates to a minimum, and at the same time providing the possibility to represent all the Arabic numerals from 0 to 9, it has been found most practical if the first face 11A of a first plate 11 is provided with one single line along an edge, while the second face 1 IB of the first plate 11 is provided with three lines along three different edges (see Fig. 2a). At the same time, the first face 12A of a second plate 12 is provided with two lines along two adjacent edges, while the second face 12B of the second plate 12 is provided with four lines along the four edges (see Fig. 2b). As it is apparent from the figures, the lines have a substantially equal width.

As it is demonstrated with reference to Figs. 3a and 3b, the two plates 11,12 are themselves sufficient to represent any Arabic numeral from 0 to 9. In order to achieve this, it is foreseen that the fixing means are adapted for attaching the plates 1 1.12 to the display board 3 allowing an overlap 9 of the plates 11,112. The measure of the overlap 9 substantially corresponds to the width d of a line constituting a segment 7 on a plate 11,12 (see Fig. 3c and Fig. 6b) With reference to Figs. 3a and 3b, there is shown how the different Arabic numerals may be composed from the two plates 11 and 12 only. In the upper row the two plates 11,12 are shown with an overlap, as they would appear on the display board 3, while below the relevant numerals the two corresponding plates 11 and 12 are shown separated, so that the relevant one of the faces 11A,11B,12A,12B is facing up, and in the appropriate position to achieve the desired visual effect. It will be appreciated that the faces 11A,11B and 12A may be in four different positions, rotated in 90 degrees relative to each other, which all result in a different image, while the physically different four positions of the face 12B all result in the same visual image. E. g. the four different positions of the face 11B is seen in the upper part of the numbers 0,2,4 and 5 in Fig. 3a. Three different positions of the face 12A is seen e.g. in the lower part of the numbers 1,2 and 3 in Fig. 3a.

It is very easy to learn how a desired number should be displayed. First of all, the two plates 11,12 are easily distinguished, the plate 11 as being the "odd" plate (having one and three segments on the two faces), and the plate 12 as being the "even" plate (having two and four segments). Now the "rule of thumb" dictates that for the digits 0 to 6, it is always the odd plate 11 which is on the top, while for the digits 7 to 9, the even plate 12 must be placed on the top.

It is emphasised that the overlap between the plates 11 and 12 may be done otherwise as well, e. g. all Arabic numerals can be displayed also if the lower plate covers the upper one. But in this case the above "rule of thumb" does not apply. However, other rules may be devised to facilitate the quick composition of a desired digit or letter.

The plates 11,12 themselves may be manufactured of any suitable material, like plastic, metal, paper, wood, etc. It is desirable to make them as thin as possible, so that the overlap would be less apparent. However, practical applications demand that the plates have some rigidity. Plastic sheets or plates with sub-millimetre thickness proved to be a good compromise. The segments may be printed on the plates with conventional printing methods.

It must be noted that an aesthetic and effective representation of the Arabic numerals may be also achieved if the plates of the display system according to the invention do not overlap, but are only positioned adjacent to each other, along one of their edges. In this manner it is possible to represent all digits using only three plates, e.g. the plates 111,112 and 113. Possible embodiments of these are shown in Figs. 4a-c and 5. Figs. 4a-c illustrate the position of the segments 7 on the two faces 111A,111B of the plate 111, on the two faces 112A,112B of the plate 112, and on the two faces 113A,113B of the plate 113, respectively. Fig. 5 demonstrates how all Arabic numerals from 1 to 0 may be composed using only two of the three plates 111,112,113. This embodiment has the disadvantage that one of the plates, which is not actually used, must be stored somewhere, e. g. in a compartment (not shown) on the back side of the display stand. But storing only one excess plate do not pose a serious problem. On the other hand, with this embodiment the plates need not overlap, and therefore the surfaces of the plates may be in the same plane. This may be very advantageous, if for some reason the thickness of the plates 111,1 12, 1 13 may not be neglected, and in an overlapping position the overlap would cause a disturbing visual effect. Turning now to Fig. 6a, it is shown in a vertical cross-section how two of the plates 11 1,1 12 and 113 are positioned on a display stand. The display stand is a substantially plane display board 23, and the fixing means comprises a rectangular depression 24 to receive two of the plates 1 11,112 and 113 in an adjacent position, in Fig. 6a the plates 11 1 and 112 being shown. However, if the plates are positioned on the display stand with an overlap, than two adjacent depressions 34 and 35 are foreseen in the display board 23, as shown in Fig. 6b. In this case the depth Dl of the first depression 34 corresponds substantially to the thickness of a plate 1 1,12, while the depth D2 of the second depression 35 corresponds substantially to the double of the thickness of a plate 11,12. In this manner the plates 11,12 are held in a well-defined position relative to each other and to the display board 23, and their combined visual effect will produce the image of the desired Arabic numeral. An exploded, perspective view of a part of the display board 3 having a similar fixing means as that of the display board 23 is seen in Fig. 8. Here, only the depressions 34 and 35 of one character element are shown, but it is obvious that the depressions for the other character elements are formed in a similar fashion. The plates 11 and 12 in the shown position will produce the image of the Arabic numeral "3". In the embodiment of Fig. 8, the display board 3 is made of a profiled, relatively thin, semi-rigid plastic shell, manufactured with conventional techniques.

In order to allow the stable positioning of the plates 11 ,12 on the display board 3 in an arbitrary position, it is foreseen to use some sort of fastening means to keep the plates 11,12 from falling out of the depressions 34,35. Therefore, it is foreseen that the fixing means also comprise a magnetic or adhesive fixing, as shown more in detail in Figs. 11a and l ib. If adhesive fixing is used, it is best achieved with adhesive foils 36,37. The foils 36,37 may be two-sided, so that there is adhesive material on both sides. The side turning towards the display board 3 provides a strong, permanent fastening of the foils 36,37 to the bottom of the depressions 34,35. The other side turning towards the plates 11,12 provides a relatively weak adhesion, that is sufficient to hold the insignificant weight of the plates 11,12, but allowing the easy removal of the plates, and also allowing the repeated re- attachment and subsequent further removals of the plates 11,12 to and from the display board 3. Of course, a single layer of an appropriate adhesive material may be also applied directly on the outer surface of display board 3, on the bottom of the depressions 34,35. Such adhesive foils and adhesive materials are readily available in commerce.

If the numbers must be changed very often, the adhesive properties of the adhesive foil may deteriorate, due to dirt on the surface and other reasons. Therefore, instead of an adhesive, magnets 38,39 may be used as well to attract the plates 11,12 to the display board 3 with a sufficient force. Obviously, in this case the plates 11,12 must be made of a ferromagnetic material, e. g. a thin steel plate, or at least they may contain a thin steel foil between two plastic sheets. Other magnetic materials may be used as well. Such a magnetic fixing allow a practically unlimited number of removals and re-attachments of the plates 11,12 to the display board 3.

In order to facilitate the removal of the plates 11,12, it is suggested to cover only a part of the bottom of the depression 35 with the adhesive, as shown in Fig. 9. The depression 34 may be covered completely, because the overlapping region between the plates 11,12 will remain without adhesive. This will result in the attachment of the plates 11,12 to the display board 3 only along a part of their surface, and therefore they may be easily removed from the display board 3 by slight bending of the latter, as demonstrated in Fig. 10. Due to the bending, the plates 11,12 will lift off from the display board at the areas without the adhesive, and it is easy to put a fmger 40 under the lifted part 41. The same principle may be utilised with magnetic fixing.

With other possible embodiments, as shown in Figs. 7a and 7b, the fixing means to attach the plates to the display stand may comprise one or two slots 54,55, shown in cross-section in the Figs. 7a-c. In order to provide for the overlap, two parallel slots 54,55 defining two parallel planes may be used. The slots 54,55 may hold the plates along their edges, leaving the faces of the plates 11,12 with the segments visible, or the walls of the slots 54,55 may cover the plates completely. In this case it is foreseen to make the walls 56,57 of the slots 54,55 of a transparent material to make the composed numbers visible. In most cases, the friction between the plates and the walls 56,57 is sufficient to keep the plates from falling out of the slots 54,55. The slots may open to the same direction, as shown in Fig. 7a, or to opposite directions, as shown in Fig. 7b. Only one slot 53 is necessary if the plates do not overlap, as in Fig. 7c. Other possible means to attach the plates to the display board may comprise a pin 64 and an opening 65 receiving the pin 64. Such a system is illustrated in Fig.12. The above embodiments included fixing means that were adapted to attach the plates to the display stand in or removable and re-attachable manner. However, the advantages of the invention may be used also in case of a permanent attachment. E.g. the plates may be of paper, and the fixing means would be constituted by a glue. The alignment of the plates could be made easily with appropriate markings on the plates themselves. In this manner sticker sets with the inventive plates could be made, which could be used in a much more effective manner, than the known number sticker sets containing excess numbers. Compared with traditional number stickers, where at least twenty area units of stickers are necessary to have in reserve to be able to display any Arabic numeral (calculating two area units for a character), or at least eighteen, if the numerals „6" and „9" are identical, with stickers made according to the four faces of the plates 11,12 of the invention, only four area units are necessary to create an arbitrary Arabic numeral. It will be obvious for the skilled person that according to the inventive method, the plates of the invention may be used to display characters on any suitable surface, also without a special display stand.

Although the preferred embodiments of the system according to the invention have been illustrated and described, it is understood by those skilled in the art that various other modifications and embodiments may be made to the invention, without departing from the spirit and intent thereof. The display board 3 may be provided with means to display other information beside the numbers themselves, e. g. the currency unit used, or an indication of the origin of the goods, or any similar information. The fixing means could be also realised in a number of other ways, beside those shown in detail. Therefore, the scope of the invention is to be limited only by the following claims.

Claims

Claims:

1. Display system for the display of characters, in particular Arabic numerals, comprising at least one character element representing a digit of a number or a letter, and further comprising a display stand with fixing means for the attachment of at least one character element to the display stand, where a character element comprises multiple segments, and different digits or letters are represented by different combinations of the segments, wherein a character element consists of two separate, substantially flat plates having substantially square first and second faces, with each face having four edges substantially perpendicular to the adjacent edges, with segments provided on at least one face, preferably on both faces, and the fixing means is adapted for attaching the plates to the display stand a, adjacent to each other, so that arbitrarily one of the two faces is facing substantially away from the display stand, while the other face is facing the display stand, and further b, in an arbitrary position from the four possible positions where the edges of the square are substantially parallel or substantially perpendicular to the longitudinal axis of the character to be displayed.

2. The display system according to claim 1, wherein the segments on the faces are constituted by substantially straight lines along the edges of the square faces, the lines extending substantially along the whole edge.

3. The display system according to claims 1 or 2, wherein a first face of a first plate is provided with one single line along an edge, while the second face of the first plate is provided with three lines along three different edges.

4. The display system according to any one of the claims 1 to 3, wherein a first face of a second plate is provided with two lines along two adjacent edges, while the second face of the second plate is provided with four lines along the four edges.

5. The display system according to any one of the claims 1 to 4, wherein the lines have a substantially equal width.

6. The display system according to any one of the claims 1 to 5, wherein the fixing means are adapted for attaching the plates to the display stand allowing an overlap of the plates, the measure of the overlap substantially corresponding to the width of a line constituting a segment on a plate.

7. The display system according to any one of the claims 1 to 6, wherein the display stand is a substantially plane display board, and the fixing means comprises at least one, preferably two adjacent depressions provided in the display board, the depressions receiving the plates.

8. The display system according to claim 7, wherein the depth of a first depression corresponds substantially to the thickness of a plate, while the depth of the second depression corresponds substantially to the double of the thickness of a plate.

9. The display system according to any one of the claims 1 to 8, wherein the fixing means comprise a magnetic fixing.

10. The display system according to any one of the claims 1 to 8, wherein the fixing means comprise adhesive fixing.

11. The display system according to claim 10, wherein the adhesive fixing comprises an adhesive foil covering at least a part of the surface of a depression receiving a plate.

12. The display system according to any one of the claim 1 to 6, wherein the fixing means comprises at least one slot.

13. The display system according to claim 12, wherein the fixing means comprise two parallel slots defining two parallel planes.

14. The display system according to any one of the claim 1 to 6, wherein the fixing means comprise a pin and an opening receiving the pin.

15. The display system according to any one of the claim 1 to 14, wherein the segments are composed of multiple identical motives arranged in a line.

16. The display system according to any one of the claim 1 to 15, wherein the motives are filled squares or circles.

17. The display system according to any one of the claim 1 to 16, wherein the display stand comprises means to represent a decimal point between the digits.

18. The display system according to any one of the claim 1 to 16, wherein the fixing means is adapted to attach the plates to the display stand in a permanent or removable and re-attachable manner.

19. Method for displaying of characters, in particular Arabic numerals, where a character element representing a digit of a number or a letter is composed of multiple segments, and different digits are displayed by different combinations of the segments, characterised by composing a character element of two separate, substantially flat plates, where the plates are having substantially square first and second faces, with each face having four edges substantially peφendicular to the adjacent edges, with segments provided on at least one face, preferably on both faces, and attaching the plates a, adjacent to each other, with one of the two faces facing substantially towards the viewer, b, in an arbitrary position from the four possible positions where the edges of the squares are substantially parallel or substantially peφendicular to the longitudinal axis of the character to be displayed.

20. The method according to claim 19, wherein a first face of a first plate is provided with one single line along an edge, while the second face of the plate is provided with three lines along three different edges.

21. The method according to claim 19 or 20, wherein a first face of a second plate is provided with two lines along two adjacent edges, while the second face of the plate is provided with four lines along the four edges.

22. The method according to any one of the claims 19 to 21, wherein the plates are attached adjacent to each other with an overlap.

23. The method according to any one of the claims 19 to 22, wherein the plates are attached adjacent to each other in a permanent or removable and re-attachable manner.