WO2005026931A2

WO2005026931A2 - Electronic keyboard layout

Info

Publication number: WO2005026931A2
Application number: PCT/GB2004/003862
Authority: WO
Inventors: John Crampton
Original assignee: John Crampton
Priority date: 2003-09-12
Filing date: 2004-09-10
Publication date: 2005-03-24
Also published as: WO2005026931A3

Abstract

This invention relates to an electronic keyboard, and in particular to keyboards in which the organisation of the characters, numerals and functions assigned to each key is optimised. The invention particularly aids text inputting on handheld devices such as PDAs.

Description

ELECTRONIC KEYBOARD LAYOUT

Field of the Invention

This invention relates to an electronic keyboard, and in particular to keyboards in which the organisation of the characters, numerals and functions assigned to each key is optimised.

Background Art

The vast majority of keyboards produced today utilise the "qwerty" layout. The qwerty layout was designed in the 1870s. It is often suggested that the motivation behind this design was to deliberately create an inefficient layout of keys so as to slow down typing speed, preventing early mechanical typewriters from becoming jammed. Regardless of whether or not this was the case, the qwerty design is not an efficient layout, seemingly lacking any intrinsic pattern or order of characters. 'I

Despite this, the qwerty design has become near universal, and those trained in its use are capable of typing at considerable speed. Over the years there have been attempts at replacing the qwerty keyboard. The Dvorak keyboard of the 1930s was claimed to improve typing efficiency, although later studies showed this was at best arguable.

More recently patent CN 1061293 disclosed a keyboard which attempted to speed up typing by assigning 26 common words to a corresponding letter key. US 005584588 disclosed a keyboard which also attempted to improve typing efficiency by re-arranging letters into a recognisably obvious order. Another prior patent, US 005836705, disclosed a modified keyboard which retained much of the qwerty layout.

None of these have been able to successfully replace the qwerty system. Consequently, there is a need for a keyboard whose layout so improves typing efficiency that it is able to overcome resistance generated by the familiarity of the inefficient qwerty keyboard. This is particularly true, given the prevalence of personal computers, as nowadays the majority of those using keyboards are not specifically trained in typing, with many using a limited number of fingers when typing, e.g. one or two per hand. Known keyboard layouts are not therefore well suited to the majority of users.

This is even more particularly true in relation to the problems which arise when utilising conventional keyboard layouts in relation to hand-held electronic devices such as mobile telephones and personal digital assistants ("PDA's").

To date, mobile phones have generally utilised a modified old fashioned telephone fascia "Hard Keyboard" and adopted a multiple button pressing technique to accommodate one number and three letters to each of ten keys plus several, randomly placed, function keys. This results in a number of drawbacks. For example, on average three finger presses are required to input one letter. No preference is given to any of the most frequently used letters (e.g. five of the twelve most frequently used letters O, I, R, L & F require four finger presses to input them), where as many of the least used letters are found in favoured sites (e.g. the letters J, V, Y, P & G only require two presses); There is often no Upper/Lower case facility and there is restricted punctuation and symbols capability. Additionally, looks and style exclude practicality from keyboard development. To try to circumvent these inherent problems of the system users have been forced to virtually invent a new language which is incompatible with normal word processed documents. This problem will inevitably become more acute as device capabilities increase dramatically in the near future.

There therefore exists a need for an efficient keyboard layout which improves typing efficiency, overcoming the problems inherent in the use of keyboards associated with current mobile telephone and other hand held electronic devices.

The use of keyboards associated with PDAs also suffer from a lack of typing efficiency. PDAs have generally favoured the "Soft Keyboard" with the advantage this gives of enabling multiple keyboards on a single screen. For example, one approach is to use a two small screen key format and a three screen larger key format with between forty and fifty keys on each screen, utilising one screen for Upper case, a second for Lower case and a third for Numbers and symbols. However, this approach is also compromised by typing inefficiency. In particular, the use of key sizes of less than one third of a square centimetre means operation is only possible with a stylus, which is particularly inefficient given that a stylus operator is, in effect, a one finger typist. This ineffϊcency is increased as the stylus has to carry out all operations e.g. actuate changes between Upper case, Lower case and Numbers/Symbols screens, operate the Space Key at the end of every word and input the text. Further, the keyboard layout is almost invariably in the traditional Qwerty style, which imports the additional inefficiencies as set out above. Further, the inefficient Qwerty keyboard is at its most inefficient for one finger typists, and those proficient in the use of qwerty keyboards have little advantage as stylus operation reduces even a Qwerty trained user to a one finger typist.

Because of the drawbacks of the inputting means currently used for hand-held electronic devices some users instead operate such hand-held electronic devices utilising full size folding keyboards as a means of inputting text into their hand held devices. However, these keyboards are also set out in the Qwerty format and so still afflicted by the inefficiencies set out above. Further, it is a physical impossibility to hand hold a PDA and a folding Qwerty keyboard and input text. A folding keyboard instead requires a convenient flat surface such as that required by a portable laptop computer. Consequently there may be little advantage in utilising a hand-held electronic device instead of a laptop.

Consequently, there exists a need for an input device capable of overcoming the inherent inefficiencies associated with existing keyboards and input devices currently utilised for a variety of electronic devices.

Summary of the Invention

For the purpose of this specification the term "keyboard" extends to any input device designed to receive inputs invoked by means of an operator's fingers, thumbs, electronic pen, stylus or similar device. Likewise, the term "key" includes conventional keys and touch sensitive keys, portions of a display device or the like. According to one aspect of the present invention there is provided an input device having a plurality of keys, the keys comprising a plurality of letter keys each bearing a letter of an alphabet of a pre-defined language, the input device comprising a group of keys comprising a predetermined number of the most frequently used letters of the alphabet, wherein the predetermined number of keys is grouped such that average separation between any key and remaining keys of the group is limited.

According to another aspect of the present invention there is provided an input device having a plurality of keys, the keys comprising a plurality of letter keys each bearing a letter of an alphabet of a predefined language, the input device comprising a group of keys representing a predetermined number of the most frequently used letters of the alphabet, wherein respective keys of the group commonly used in linking letter combinations are located adjacent or substantially adjacent one another.

According to a further aspect of the present invention there is provided an input device having a plurality of keys, the keys comprising a plurality of letter keys each bearing a letter of an alphabet of a predefined language, the layout of keys being arranged to maximise the number of commonly used linking letter combinations accessible by means of consecutive strokes on adjacent or substantially adjacent keys.

According to a further aspect of the present invention there is provided a hand held electronic device, capable of being held by one hand, comprising a first arrangement of keys for inputting at least text by means of the free hand at least one control key for determining a control function associated with one or more of the keys on the first key arrangement, wherein the at least one control key is located separately from the first arrangement of keys on a part of the device operable by the hand holding the device.

The layout and groupings of keys of the preferred embodiment is designed so as to improve typing efficiency in a variety of different ways. Although the layout is described herein, a man skilled in the appropriate art would possess the necessary technical knowledge to apply this layout to standard keyboard technology so as to be able to produce an operable keyboard with the described layout.

The keyboard layout ensures that a number of the most commonly used letters are positioned proximate to each other, so as to minimise the distance and time taken in moving the fingers between them.

An additional improvement in efficiency may be obtained by also including groups of letters in intuitive and easily recognisable sequences. This facilitates faster location of a desired key.

A further advantage is obtained by combining letters used in common digraphs proximate to each other, digraphs being combinations of two letters commonly used in language in order to form a single phonetic sound.

A still further advantage may be obtained by combining groups of letters commonly used in digrams proximate to each other, digrams being combinations of two letters commonly used in language.

Yet another advantage can be achieved by combining letters commonly used in trigrams proximate to each other, trigrams being combinations of three letters commonly used in language.

Still another advantage may be achieved by combining letters found in commonly used words proximate to each other.

Further advantages may be achieved by combining mathematical device keys proximate to each other. This advantage is enhanced by also including monetary symbols, proximate to mathematical symbols. Yet a further improvement is a combination of these monetary and mathematical symbols as secondary functions of the numerical keys.

Another advantage is the combination of grammatical symbols proximate to each other. A further advantage is the situating of keys commonly used in internet and e-mail software proximate to each other.

A further advantage is the positioning of keys used to modify the onscreen size of text proximate to each other.

Still another advantage is obtained by placing the delete, alt and control keys proximate to each other.

A further advantage in the efficiency of typing may be achieved by assigning word processing techniques as alternative functions of keys. This advantage is further improved if these keys are situated proximate to each other.

Still another advantage is the assigning of a number of commonly used words as alternative representations to the keys.

An additional advantage is the situating of the space, return and cancel keys proximate to each other.

An additional advantage is the use of multi-function keys so as to render a more compact keyboard, further minimising the distance and time taken in moving the fingers between keys.

A further advantage is that by providing a more efficient compact keyboard for handheld devices, larger keys may be utilised, enabling easier and more acceptable finger operation.

A further advantage is that by providing the efficient input device for hand-held- electronic devices, only one key stroke is needed to input any letter or number, making it up to three times faster than mobile phones.

A further advantage is that by using the preferred embodiment of the layout of keys for input devices utilised in relation to hand-held electronic devices, the 12 most used letters comprising 80% of text, are located in primary, priority positions, whilst the 14 least used letters comprising 20% of text are located in secondary positions.

A still further advantage of the present invention is that its advantages can be realised for hand-held electronic devices whilst retaining the popular small mobile phone case size, without the need to resort to full size folding keyboards.

Whilst the specific embodiments depict combinations based on usage within the English language, it will be readily apparent that inventive concepts herein disclosed can be readily adapted for use with other languages.

Brief Description of the Drawings

A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows the layout of a keyboard embodying the invention.

Figure 2 shows a portion of the keyboard of Figure 1 with keys bearing the 12 most commonly used letters in the English language being located proximate to each other.

Figure 3 shows a portion of the keyboard of Figure 1 with keys bearing vowels being located proximate to each other, in an easily recognisable sequence.

Figure 4 shows a portion of the keyboard of Figure 1 with keys bearing letters commonly used in digraphs being located proximate to each other.

Figure 5 shows a portion of the keyboard of Figure 1 with keys bearing the letters of some of the most used digrams being located proximate to each other.

Figure 6 shows a portion of the keyboard of Figure 1 with keys bearing the letters of some of the most used trigrams being located proximate to each other.

Figure 7 shows a portion of the keyboard of Figure 1 with keys bearing letters of the some of the most used words being located proximate to each other. Figure 8 shows a portion of the keyboard of Figure 1 with various function keys located proximate to each other.

Figure 9 shows a portion of the keyboard of Figure 1 with keys bearing some of the most commonly used words in the English language located proximate to each other.

Figure 10 shows a portion of the keyboard of Figure 1 with keys having further predefined functions located proximate to each other.

Figure 11 shows a handheld electronic device incorporating the invention.

Figure 12 shows a lay out for an onscreen key pad in accordance with the present invention.

Figure 13 shows an alternative lay out for an onscreen key pad in accordance with the present invention.

Figure 14 shows an alternative layout for an onscreen key pad in accordance with an embodiment of the present invention.

Figure 15 shows a further layout for an onscreen key pad in accordance with an embodiment of present invention which is the counterpart of Figure 14.

Figure 16 shows an alternative layout for a hard key pad in accordance with an embodiment of the present invention.

Description of Specific Embodiment

Figure 1 depicts a preferred keyboard embodying the invention. It can be seen that it is only twelve keys wide, rather than the 15 key width of the main body of a qwerty keyboard. This reduces the average distance the fingers must travel when typing, increasing the speed and efficiency of typing. This specific design relies on a system of touch sensitivity to access the alternative functions of the keys, so that, for example, a longer depression of the keys will result in the secondary function of the key being accessed instead of the first. However, different systems may be used, either instead of or along side a touch sensitive system, for example including a shift key, which could be incorporated by shortening the space key, by replacing the upper and lower text keys 16 with a caps lock key, or any other form of rearrangement.

The keyboard layout of Figure 1 benefits from the arrangement of a number of commonly used keys proximate to each other, as is shown in subsequent diagrams.

Figure 2 shows the arrangement of keys bearing the 12 most commonly used letters in the English alphabet proximate to each other and in a predefined area on the keyboard. These 12 keys are used in 80% of typing activity. These commonly used keys are located together so that the distance travelled by the fingers is greatly reduced when typing. Additionally, in this design, these letters are located centrally within the keyboard, so that when typing the fingers will most often be located centrally, minimising the distance to any other key.

This layout places the vowels in a central located row, in alphabetical order, thereby providing a readily apparent sequence, facilitating easy identification of the desired key. This layout is enhanced by locating the key representing the letter "U", which is not one of the 12 proximately located most commonly used letters 2, immediately at the end of the row of most commonly used vowels 4, so that all vowels are located in a row, in alphabetical order, as shown in Figure 3. Such a sequence is intuitive and easily recognisable, with the effect typing efficiency is enhanced.

The 8 consonants of the 12 most commonly used letters are arranged in the rows above and below the vowels so as to maximise the number of linking combinations of letters used within the English language, again increasing typing efficiency. Figure 4 shows another arrangement increasing typing efficiency, by locating proximate to each other, and in this case within the same row, seven letters used in the formation of some common digraphs, namely "ph", "wh", "th", "sh", "ch" and "ck". Again, this improves efficiency by providing both a shorter distance for the typing fingers to travel, and also a level of order facilitating location of the desired key.

Similar advantages are derived from the arrangements of highlighted letters in Figures 5 and 6. Figure 5 shows an arrangement in which letters constituting seven of the eight most commonly used digrams, "on", "in", "er", "re", "at", "th", and "he", are proximate one another.

Figure 6 shows that the letters used in nine of the twelve most used trigrams, "con", "ing", "for", "ted", "ers", "ter", "her", "tio" and "the", are proximate one another. Likewise, similar advantages are derived from the fact that the letters comprising nine of the twelve most commonly used words, "that", "the", "he", "it", "is", "of, "in", "a" and "I", are located proximate to each other, as seen in Figure 7.

Figure 8 depicts the position of symbol and function keys, for example the numerical, financial and mathematical keys 8, punctuation keys 9, e-mail and internet keys 10, onscreen text size keys 13, and delete, alt and control keys 14. By locating keys within these groups of keys proximate to each other, and in particular in rows as for key groups 8, 9 and 10, an easily recognisable arrangement is provided, facilitating quick and easy location of the keys. This may be further enhanced by the use of LEDs to indicate which mode of operation is currently selected.

Figure 9 shows further ways in which typing speed and in particular word processing efficiency may be increased. Keys in which a number of word processing operations are included as tertiary functions are included 11. The ready access to these functions, rather than the use of hotkey combinations or on screen, cursor-facilitated access, thus provides further improvements in word processing efficiency. Again, the use of LEDs to indicate which mode of operation is currently selected may further enhance this advantage.

Certain embodiments may provide a text mode function, in which a secondary, tertiary or further functions of letter keys can be accessed by selecting the text mode (as opposed to upper or lower case modes), enabling direct entry of 26 commonly used words. Again this increases the average speed of textual inputting. In certain embodiments, one or more keys has a secondary, tertiary or further functions which permits a commonly used unit object (e.g. by phrase, sentence or paragraph, equation, graphic) to be inserted in a single key stroke. This is useful for example where repeat entries occur, e.g. in e-mail sign off, or for inputting the sender's address in a conventional letter

Figure 10 shows further proximal arrangements of keyboard, in particular groups of keys, designed to improve typing efficiency. Specifically keys of the groups respectively comprising the space, enter and cancel keys 12; cursor control keys 14 and lower case, upper case and text mode keys 16; are located proximate to each other.

Now referring back to Figure 1, it can be seen that in the preferred embodiment all of the individual arrangements described above are combined in a single keyboard, so that all of the above advantages are combined, producing a significant increase in typing efficiency for the majority of users. Additionally, other convenient combinations are provided, so that Q is proximate to U, N is proximate to G, J is proximate to G, C is proximate to K, Y is proximate the vowels, and both B and M are proximate with Y, and so on. It can thus be seen that typing efficiency is increased by arranging the letter keys with regard to their use in the English language, so as to reduce the distance the fingers must travel when typing.

Other embodiments may employ one or more of the advantageous individual groupings, without necessarily including others. For the purpose of this specification, the phrase "located proximate" means as close as possible in distance. In practice, a prominent arrangement of most frequently used keys, and combination of keys, takes priority over a proximal arrangement of less frequently used keys or combination of keys.

From the drawings, it will be apparent that, where possible, keys accessed consecutively on a frequent basis are located adjacent one another (e.g. horizontally or vertically adjacent on drawings) and/or substantially adjacent one another (e.g. diagonally adjacent on drawings).

Typically, two or three letter words, and often larger words can be typed by combinations of letters comprising adjacent or substantially adjacent keys. In other instances, words can be typed in a single stroke, for example where a dedicated key exists. Alternatively, dedicated keys can be assigned to type specific sentences, paragraphs, graphics, etc.

The proximal locations and logically sequenced ordering of keys are particularly advantageous for those who are not trained typists, and those who use a two, three or four finger typing technique, as these are the typists who inevitably spend most time moving fingers between keys as well as searching for the desired key. It will be apparent that similar advantages are also seen for users with stylus, electronic pens and similar devices.

In certain embodiments, one or more of the various groupings of keys is represented by a colour specific to the grouping. For example, letters may be represented by a first shade of grey, numbers by a second shade of grey, cursor control keys by green, and mode/function keys by red. Any suitable means of high-lighting the various groupings may be used. In practice, the choice and configuration of colours may depend on the type of input device, and if appropriate its display type.

It will be obvious to a man skilled in the art that modifications to the example herein described are possible, combining different advantages, or alternative combinations of keys used in digraphs, digrams, trigrams and/or words, possibly also with structured ordering of letter, numerical, mathematical, financial, punctuation, or other functional keys.

Additionally, whilst the embodiment herein described is directed towards a keyboard, the invention could equally be directed towards other control devices, for example handheld electronic devices, and in particular the onscreen key pad of a personal digital assistant/telephone, as shown in Figure 11. This is particularly suited for such devices, for example because they have a restricted key area and mode keys determining which of the multiple functions is accessed via activation of a key (e.g. upper case, lower case and text modes).

With reference to Figure 11, it can be seen that a handheld electronic device is commonly held in one hand, with the thumb balancing it lightly on the opposite side to the fingers (or on top). Certain frequently used keys associated with typing may be placed away from the main arrangement of keys. In this example, "text mode" and "upper case and lower case" (alternatively "capslock") keys 18 are located on a part of the device operable by one of the digits holding the device. The thumb can thus be used to operate these keys. It is possible the keys are located in the alternative, or in addition, on the part of the device operable by one or more of the fingers 20. Such arrangements improve typing efficiency primarily because keys used in conjunction with, or at the same time, as keys in the main arrangement can be accessed without interrupting typing flow.

The advantages of this arrangement apply irrespective of the type of arrangement adopted for the main keys; for example it is useful with qwerty keyboards as well as the preferred keyboards. Alternatively, the advantageous arrangements described above can be incorporated into keyboard layouts appropriate for this type of handheld electronic device. The nature of the device means that there is no need for keys such as cursor control keys nor del, con and alt keys, and the upper case, lower case and text keys are incorporated away from the keyboard. Consequently, layouts such as those seen in Figures 12 and 13 may be used, in which Figure 12 depicts a layout for upper case and lower case modes, and Figure 13 depicts a layout for use in text mode.

Figures, 14, 15 and 16 present particularly preferred embodiments of layouts which may be used in conjunction with the arrangement of Figure 11. These keys would be operated by the right hand of the user and might be touch sensitive so that a "Touch" would input the primary assigned letter (from the most used letters) while "Touch and Hold" would input the secondary assigned letter (from the least used letters). Alternatively, these primary and secondary functions might be accessed by utilising one of the keys operable by one of the digits holding the device. This enables commonly used letters to be grouped together in primary positions, so that the most commonly used letter are most readily accessible, reducing the number of keystrokes and/or number of toggles between different modes. Further functions may also be included, accessed for example via activation of a key operated by a digit holding the device 20, or via the inclusion of or an extension of a pre-existing touch sensitive system. Such further functions might enable the inputting of numbers, symbols and the like.

For example, in Figures 14, 15 and 16, the keyboard has four rows of four keys in which for three of the four rows of keys, the layout of the primary positions is the same 12 key layout highlighted in Figure 2. This enables the 12 most used letters comprising 80% of text to be located in the primary, priority positions, whilst the 14 least used letters comprising 20% of text are located in the secondary positions. Additionally, only one keystroke is needed to input any letter or number, making it up to three times faster than mobile phones. Further, the reduction in the number of keys used in comparison to the input devices currently utilised in relation to PDA's means that larger keys may be utilised, enabling easier and more acceptable finger operation.

In the embodiments of Figures 14, 15 and 16, two of the keys of the bottom row of four keys would be assigned to the two letters of the alphabet not already catered for. The remaining keys might be utilised for symbols andor for cursor movements. The keys operable by the digits holding the device might be assigned to the "space" function, and/or to toggle between modes of operation, such as Upper Case, Lower Case and Numbers, as shown in these particular embodiments. Alternatively, other convenient typing functions might be assigned.

The preferred embodiment of Figure 14 may be used in either "soft" or "hard" formats. Figures 14 and 15 depict the onscreen representations of two alternative, complimentary modes of operation, which may be utilised in relation to an onscreen input device, the modes of Figures 14 and 15 being alternatively selected by the activation of one or more of the keys operated by the digits holding the hand-held device 20. Figure 16 represents a hard key embodiment of the preferred layout in which all functions of the keys are shown at the same time. Note that the embodiment of Figure 16 could also be utilised with an onscreen input device, removing the need to have alternative onscreen representations.

Claims

What is claimed is:

1. An input device having a plurality of keys, the keys comprising a plurality of letter keys each bearing a letter of an alphabet of a pre-defined language, the input device comprising; a group of keys comprising a predetermined number of the most frequently used letters of the alphabet, wherein the predetermined number of keys is grouped such that average separation between any key and remaining keys of the group is limited.

2. An input device as in claim 1 or 2, wherein a plurality of keys of the group commonly used in combination are located proximate one another.

3. An input device according to claim 1, wherein said group of keys comprising the most frequently used letters is arranged so as to maximise the number of commonly used linking letter combinations which may be input by adjacent or substantially adjacent keys.

4. An input device according to any preceding claim, wherein a sub-group of the group of keys comprising frequently used vowels is disposed adjacent a subgroup of the group of keys comprising frequently used consonants.

5. An input device according to claim 4, wherein said sub-group of vowel keys is disposed substantially between said sub-group of consonants and a further sub- group of consonants.

6. An input device according to any preceding claim, wherein said group of keys comprising the most frequently used letters is substantially central having regard to the overall layout of keys.

7. An input device according to any preceding claim, wherein the vowels within said group of keys comprising the most commonly used letters are located adjacent to each other within a row.

8. An input device according to claim 7, wherein said vowels are arranged in alphabetical order.

9. An input device according to any of claims 4 to 8, wherein keys comprising frequently used consonants are arranged in a row below the row comprising vowels.

10. An input device according to any of claims 4 to 9, wherein keys comprising frequently used consonants are arranged in a row above the row comprising the vowels.

11. An input device according to any preceding claims, wherein keys bearing letters used in the formation of a predetermined number of the most commonly used digraphs are located adjacent or substantially adjacent each other.

12. An input device according to any preceding claim, wherein said keys bearing letters used in said digraphs are located in the same row.

13. An input device according to any preceding claim, wherein keys bearing letters used in the formation of a predetermined number of the most commonly used digrams are located adjacent or substantially adjacent each other.

14. An input device according to any proceeding claim, wherein sad keys bearing letters used in said digrams are located in the same row.

15. An input device according to any preceding claim, wherein keys bearing letters used in the formation of the most frequently used three-letter combinations are located proximate to each other.

16. An input device according to claim 15, wherein keys bearing letters used in the formation of the most frequently used three-letter combinations are located such that, in use, respective strokes to type the three-letter combination use adjacent or substantially adjacent keys.

17. An input device according to any preceding claim, wherein keys bearing letters used in the formation of frequently used words within the given language are located proximate to each other.

18. An input device according to any preceding claim, wherein keys bearing the mathematical and financial symbols are located proximate to each other.

19. An input device according to claim 18, wherein said keys bearing mathematical and financial symbols are located adjacent to each other within a row.

20. An input device according to any preceding claim, wherein the mathematical operators and/or financial symbols are accessible by means of an alternative function of numerical keys.

21. An input device according to any preceding claim, wherein keys bearing punctuation symbols are located proximate to each other.

22. An input device according to claim 21, wherein said punctuation keys are located adjacent to each other within a single row.

23. An input device according to any preceding claim, wherein a punctuation symbol is accessible by means of an alternative function of a letter key.

24. An input device according to any preceding claim, wherein keys representing symbols or operations or devices commonly used in internet and/or e-mail software are located proximate to each other.

25. An input device according to claim 24, wherein said keys representing symbols or operations or devices commonly used in internet and/or e-mail software are located adjacent to each other within a single row.

26. An input device according to any preceding claim, wherein a symbol, operation or device commonly used in internet and/or e-mail software is accessible by means of an alternative function of a letter key.

27. An input device according to any preceding claim, in which the "Control", "Alt" and "Delete" keys are located proximate to each other.

28. An input device according to any preceding claim, wherein keys which determine the appearance of text on screen are located proximate to each other.

29. An input device according to any preceding claims, wherein two or more of the "lower case", "upper case", "caps lock" and "text mode" keys are located proximate to each other.

30. An input device according to any preceding claim, wherein cursor control keys are located proximate to each other.

31. An input device according to any preceding claim, wherein the "space", "enter" and "cancel" keys are located proximate to each other.

32. An input device according to any preceding claim, which comprises keys representing word processing operations.

33. An input device according to claim 32, wherein said keys representing word processing operations are located proximate to each other.

34. An input device according to claim 32 or 33, wherein said keys representing word processing operations are located adjacent to each other within a single row.

35. An input device according to any preceding claim, wherein the distance a key probe travels between strokes in use is reduced by reducing the total number of keys relative to a standard qwerty keyboard.

36. An input device according to any preceding claim, wherein the reduction in the number of keys results in a reduction in the number of keys running across the width of the device.

37. An input device according to any preceding claim, wherein the number of keys is reduced by assigning multiple functions to individual keys.

38. An input device according to claim 37, wherein one or more of said functions are accessed via a system of control which utilises touch sensitive keys.

39. An input device according to any preceding claim, wherein a group of characters are also arranged in logical sequence.

40. An input device according to any of claims 33 to 39, wherein said word processing operations are incorporated as alternative functions of keys with other purposes.

41. An input device according to any of claims 32 to 40, wherein one or more commonly used words of the given language are accessible in a single stroke of a key having more than one function.

42. An input device according to claim 41 wherein commonly used words are accessed via use of a text mode function key.

43. An input device according to any preceding claim in which the mode of operation is indicated via an LED.

44. A handheld electronic device comprising an input device according to any preceding claim.

45. A personal digital assistant comprising an input device according to any of claims 1 to 43.

46. A handheld electronic device according to claim 44 or 45, the handheld electronic device being capable of being held by one hand and comprising: a first key arrangement for inputting at least text by use of the free hand; at least one control key located separately from the first key arrangement on a part of the device operable by the hand holding the device.

47. A hand-held electronic device according to claim 46 wherein said first key arrangement comprises a primary and secondary function, wherein said primary function enables the inputting of a predetermined number of the most frequently used letters of the alphabet and said secondary function enables the inputting of a predetermined number of the least frequently used letters of the alphabet.

48. A hand-held device according to claim 47 wherein said first key arrangement comprises one or more further functions enabling the input of numbers and/or symbols.

49. A hand-held device according to claim 47 or claim 48 wherein one or more functions is activated via a touch sensitive method of operation.

50. A hand-held device according to claim 47, claim 48 or claim 49 wherein one or more functions are activated by the operation of said at least one control key.

51. An input device having a plurality of keys, the keys comprising a plurality of letter keys each bearing a letter of an alphabet of a predefined language, the input device comprising: a group of keys representing a predetermined number of the most frequently used letters of the alphabet, wherein respective keys of the group commonly used in linking letter combinations are located adjacent or substantially adjacent one another.

52. An input device having a plurality of keys, the keys comprising a plurality of letter keys each bearing a letter of an alphabet of a predefined language, the layout of keys being arranged to maximise the number of commonly used linking letter combinations accessible by means of consecutive strokes on adjacent or substantially adjacent keys.

53. A hand held electronic device, capable of being held by one hand, comprising: a first arrangement of keys for inputting at least text by means of the free hand; at least one control key for determining a control function associated with one or more of the keys on the first key arrangement, wherein the at least one control key is located separately from the first arrangement of keys on a part of the device operable by the hand holding the device.

54. A hand held electronic device according to claim 48, wherein the at least one control key comprises one or more keys selected from a text mode key, upper case key, lower case key, and capslock key.