WO2010149225A1

WO2010149225A1 - User interface for a device

Info

Publication number: WO2010149225A1
Application number: PCT/EP2009/058064
Authority: WO
Inventors: Tuomo Mikko Huhtanen
Original assignee: Nokia Siemens Networks Oy
Priority date: 2009-06-26
Filing date: 2009-06-26
Publication date: 2010-12-29

Abstract

A mobile terminal device (10) capable of recognising the entry of an alphanumeric character comprises: a keypad (16); detectors associated with the keypad capable of detecting input in the form of a sequence of activations of a plurality of active regions, the active regions being associated with respective key areas (26) for entering numeric characters; and a processor (18) capable of analysing the sequence of activations and comparing them with a predefined sequence of activations corresponding to a path which is representative of the character described on the user input area in order to determine the character to which the input corresponds.

Description

USER INTERFACE FOR A DEVICE

This invention relates to a user interface for a device. It is particularly, but not exclusively, related to a user in- terface in a terminal device, such as a mobile terminal device .

These days, mobile terminals are used for many tasks in addition to traditional ones of making and receiving telephone calls and composing short messages, and this places greater demands on their user interfaces. Simultaneously, there is a demand and trend to decrease the physical size of mobile terminals. The known keypads serve well in the case of numeric input, but when extended to the alpha-numeric domain, there are too few keys. Extended keypads, such QWERTY-based keypads, have been implemented in mobile terminals but the size of a single key becomes so small that an adult user is likely to find it difficult to write with such a miniature keyboard.

Mobile terminal devices typically have a keypad having twelve keys in a 4 by 3 array comprising the ten numeric keys ("0" to "9") and two additional symbol keys, the "*" key and the "#" key. This type of keypad is specified by ITU-T recommendation E.161 and is often referred to as an ITU-T keypad.

Such a keypad is used both for entering alpha-numeric characters into a terminal device comprising the numeric (Arabic) and alphabetic (the 26 Latin letters a to z) characters. The alphabetic characters are often assigned to various of the numeric keys in a way that three or four alphabetic characters are potentially accessible by operation, for example pressing, of each numeric key. This may be done by tapping the numeric key multiple times to cycle through its assigned alphabetic characters. One particular key may, for example, have assigned to it the characters "a", "b", and "c". Press- ing the key once enters the character "a", pressing the key twice within a short period of time enters the character "b", and pressing the key three times within a short period of time enters the character "c". Pressing the button twice over a sufficiently long period enters two instances of the char- acter "a". Terminal devices may be configured to have various context-dependent modes so that pressing numeric keys will enter either numeric or alphabetic input depending on the mode .

It can be slow and cumbersome to use an ITU-T keypad in such a manner and therefore various methods for facilitating text entry have been developed, such as predictive text systems. Touch-sensitive displays which are able to recognise handwriting have also been developed. However, character- recognition applications used in touch-screen text input are complex and, also, error-prone.

Other approaches have been proposed including nScribe, Edge- Writing, Quikwriting, and Xnav. The latter three techniques are described in a thesis document from the Human-Computer

Interaction Institute School of Computer Science at the Carnegie Mellon University entitled "EdgeWrite: A Versatile Design for Text Entry and Control" by Jacob O. Wobbrock dated July 2006 (http: //reporτs- archive.adm.es. emu . edu /anon /hcii /CMU-HCI 1-06 -104 ,ρdf ) . It is desirable to enter alphabetic characters into terminal devices when, for example, composing text and email messages, and adding alphabetic content into contact lists.

According to a first aspect of the invention there is provided a method of recognising the entry of a character into a device comprising the steps of: detecting input in a plurality of distinct regions, the regions being specifically allocated to input areas which are activatable in order to enter numeric characters; and analysing input from at least two of the plurality of distinct regions in order to determine the character to which the input corresponds.

Preferably, the method is capable of detecting alphabetic characters. The method may be capable of detecting a symbol or a command to enter that symbol or to carry out an operation such as an editing operation.

Preferably, each region is specifically allocated to an input area which is activatable in order to enter a specific numeric character. In other words, there is a one-to-one correspondence between a region and its corresponding numeric character .

Preferably, the regions are keypad elements useable to enter numeric characters.

Preferably, the method of recognising the entry of a charac- ter comprises detecting the order in which input is received by the plurality of regions. Alternatively, the method may be order independent and may recognise the entry of a character simply based upon analysing which regions have received input .

Preferably, characters are entered by a user moving an application of pressure, whether it be from a finger or a stylus, across the at least two of the plurality of distinct regions in a way which resembles the graphical form of a character. This may assist the user in being able to enter characters without the need to look at a keypad. Preferably, entering a character involves a movement across at least some of regions during which the application of pressure is maintained and contact is not broken.

Preferably, the device is a terminal device. It may be a mobile terminal device.

According to a second aspect of the invention there is provided a device capable of recognising the entry of a charac- ter comprising: a user input area; detectors associated with the user input area capable of detecting input in a plurality of distinct regions, the regions being specifically allocated to input areas which are acti- vatable in order to enter numeric characters; and a processor capable of analysing input from at least two of the plurality of distinct regions in order to determine the character to which the input corresponds.

Preferably, the user input area is a keypad. Preferably, the plurality of distinct regions has a layout which corresponds to the ITU-T keypad layout. This provides a degree of familiarity to users. Preferably, the device has a user interface comprising the user input area and a display.

According to a third aspect of the invention there is provided a computer program product comprising software code that when executed on a computing system performs a method of recognising the entry of a character into a device comprising the steps of: detecting input in a plurality of distinct regions, the regions being specifically allocated to input areas which are activatable in order to enter numeric characters; and analysing input from at least two of the plurality of distinct regions in order to determine the character to which the input corresponds.

Preferably, the computer program product has executable code portions which are capable of carrying out the steps of the method.

Preferably, the computer program product is stored on a computer-readable medium.

According to a fourth aspect of the invention there is pro- vided a device capable of recognising the entry of a character comprising: a user input area; detectors associated with the user input area capable of detecting input in a plurality of active regions; and a processor capable of analysing input from at least two of the plurality of active regions in order to determine the character to which the input corresponds, the device being configured to receive input from a first of the at least two of the plurality of active regions and then a second of the at least two of the plurality of active regions as an input element traverses the user input area while being in contact with it and being configured not to receive input from any active region as the input element traverses a non-active region in between the first and second active regions .

Preferably, the non-active region is a mask region. The mask region may be provided with apertures through which the ac- tive regions are accessible.

Preferably, as characters are entered on the user input area, by a user moving the input element over the user input area to describe a graphical representation of the character, the user input area is configured so that the input element traverses parts of the non-active region such that it is sufficiently physically separated from active regions and is not able to provide any input to them.

Preferably, the parts of the non-active region traversed are relatively large with respect to the area of the input element. For example, the entire area of the input element in contact with the non-active area may be entirely contained within the non-active region and not overlapping with adja- cent active regions. Preferably, traverses means moving over the user input area in any direction. It is not limited to moving from one side to another but may include moving up and down, moving diagonally, and curved movement.

Preferably, the input element is a finger. The input element may be a stylus.

According to a fifth aspect of the invention there is pro- vided a device capable of recognising the entry of a character comprising: a user input area; detectors associated with the user input area capable of detecting input in the form of a sequence of activations of a plurality of active regions, the active regions being associated with respective key areas for entering numeric characters; and a processor capable of analysing the sequence of activations and comparing them with a predefined sequence of activations corresponding to a path which is representative of the character described on the user input area in order to determine the character to which the input corresponds.

Preferably, the device is configured to receive input from a first active region and then a second active region as an input element traverses the user input area while being in contact with it and being configured not to receive input from any active region as the input element traverses a non-active region in between the first and second active regions. Preferably, the predefined sequence of activations is stored in a lookup table. The lookup table may have a unique sequence of activations assigned to respective ones of a plurality of characters and a processor maps an input sequence to a predefined sequence in order to determine the character.

According to a sixth aspect of the invention there is provided a method of recognising the entry of a character into a device comprising: detecting input in the form of a sequence of activations of a plurality of active regions in a user input area of the device, the active regions being associated with respective key areas for entering numeric characters; analysing the sequence of activations and comparing them with a predefined sequence of activations corresponding to a path which is representative of the character described on the user input area in order to determine the character to which the input corresponds.

According to a seventh aspect of the invention there is provided a computer program product comprising software code that when executed on a computing system performs a method of recognising the entry of a character into a device comprising: detecting input in the form of a sequence of activations of a plurality of active regions in a user input area of the device, the active regions being associated with respective key areas for entering numeric characters; analysing the sequence of activations and comparing them with a predefined sequence of activations corresponding to a path which is representative of the character described on the user input area in order to determine the character to which the input corresponds.

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

Figure 1 shows a mobile terminal device;

Figure 2 shows a user input area of the mobile terminal device of Figure 1 in plan and side views; Figure 3 shows the paths described on the user input area of

Figure 1 to enter alphabetic characters;

Figure 4 shows another embodiment of a user input area of the mobile terminal device of Figure 1 in plan view in combination with the paths taken to enter alphabetic characters; Figure 5 shows the user input area of Figure 4 and the paths described on it to enter other alphabetic characters;

Figure 6 shows the user input area of Figure 4 and the paths described on it to enter numeric characters;

Figure 7 shows another embodiment of a mobile terminal device and its user input area;

Figure 8 shows activations of the user input area of Figure 7 to enter alphabetic characters;

Figure 9 shows activations of the user input area of Figure 7 to enter other alphabetic characters; Figure 10 shows a keypad and activations to enter special characters;

Figure 11 shows the keypad of Figure 10 and activations to enter editing commands; and

Figure 12 shows the keypad of Figure 10 and activations to use it to perform a joystick-like operation. Figure 1 shows a mobile terminal device 10 having a body 12, a display 14, and a user input area 16. The mobile terminal device also has a processor 18 which is capable of receiving input from the user input area 16 and analysing it by refer- ring to a lookup table 19 to determine which character has been entered or which operation has been activated.

Figure 2 shows a user input area 16 of the mobile terminal device of Figure 1 in plan and side views. In plan view, the user input area 16 has a keypad 20 comprising a mask 22 and a number of apertures 24. Accessible through the apertures 24 are touch-sensitive areas 26. When the mobile terminal device is in a mode for receiving input of numeric characters, applying pressure to a particular touch-sensitive area 26 by using, for example, a finger or a stylus, causes selection of the character (that is a number or a symbol) with which the touch-sensitive area is associated.

In order for the mobile terminal device to receive input of alphabetic characters, it needs to be in an appropriate mode. Examples of this are the mobile terminal device being in a short message service composition mode or a contacts editing mode. To enter an alphabetic character into the mobile terminal device 10, a user makes a continuous stroking or gliding movement of a finger 28 over the keypad 20 while the finger

28 is kept in contact with the keypad 20. The movement starts with the user lowering the finger 28 into contact with the keypad 20 (on a part of the mask 22 or on a touch-sensitive area 26 between mask portions) and ends with the user lifting the finger 28 so it is no longer in contact with the keypad 20. This can be seen in the side view of Figure 2 in which the finger 28 is initially not in contact with the keypad 20, is later in contact with a mask 22 portion between the touch- sensitive areas 26 associated with numerals 2 and 5, and is then moving across a touch-sensitive area 26 associated with numeral 8.

Referring back to the plan view of Figure 2, an example is provided of a path that a user' s finger would take over the keypad 20 in order to draw or write the letter "a". In this case, the mobile terminal device 10 determines that the path taken was the sequence of detected inputs into touch- sensitive areas 26 during the writing or drawing of the letter. In this case, describing the letter "a" would produce a sequence of detected inputs of 3, 1, 7, 9, 3, and 9. If the user had instead written the letter "A", the sequence of detected inputs would have been 7, 1, 2, 3, and 9 (assuming, of course, that no cross or lateral movement had been made to form the horizontal bar in the middle of this letter) . From this, it can also be understood that a continuous contact is not require and a user could enter a character simply by making individual touch contacts into the touch-sensitive areas.

The processor 18 compares the sequence of detected inputs with entries from the lookup table 19 in the mobile terminal device 10. The entries of the lookup table 19 are unique sequences of activations corresponding to respective characters and are representative of the sequence of activations which would have taken place had the corresponding character been described by the user on the user input area 16 of the mobile terminal 10. When the sequence of detected inputs is found to match one of the entries in the lookup table 19, the charac- ter to which the sequence of detected inputs corresponds is determined and the character is presented in the display 14 of the mobile terminal device 10.

Figure 3 shows the paths taken to enter other alphabetic characters. As can be seen, they are formed by a user describing a path in a continuous movement during which the finger (or stylus) remains in contact with the keypad 20. It will be clear that in addition to alphabetic characters, any other characters such as numeric characters can be entered.

Figure 4 shows another embodiment of a user input area 16 of the mobile terminal device 10 of Figure 1 in plan view. In this embodiment, the user input area 16 has a plurality of touch-sensitive areas 40 in the form of horizontally 42 and vertically 44 disposed touch-sensitive elements and surrounding non-touch-sensitive areas. In order to enter an alphabetic character into the mobile terminal device 10, a user makes a continuous stroking or gliding movement of a finger over the user input area 16 while the finger is kept in contact with it. It will be understood that as the finger traverses over the user input area 16, at certain points it travels over non-touch-sensitive areas and at other points it travels over touch sensitive areas. Accordingly, the mobile terminal device 10 is able to detect when the finger moves onto and off the horizontally and vertically disposed elements. As can be seen, Figure 4 is presented in combination with the paths taken to enter alphabetic characters. There are 29 alphabetic characters in total, the 26 "a" to "z" characters and three additional alphabetic characters - "a", "δ", and "a" (in the order which is presented in Figure 4) . Figure 5 shows the user input area of Figure 4 and the paths described on it to enter the alphabetic characters of Figure 4 in upper case. There are 29 alphabetic characters in total, the 26 "A" to "Z" characters and three additional alphabetic characters - "A", "Qi", and "A" (in the order which is presented in Figure 5) .

Figure 6 shows the user input area of Figure 4 and the paths described on it to enter numeric characters. In addition, the user input area can be used to enter the characters "?" and "/" which are shown following the numeric characters.

Figure 7 shows another embodiment of a mobile terminal device 70 and its user input area 72. The user input area 72 is itself shown in greater detail. In this embodiment, the user input area 72 has a keypad although rather than being in a conventional ITU-I keypad form, it is in a shape broadly similar to the Greek alphabetic character "Φ" (phi) . The dis- position of the numeric keys "1" to "9" (touch-sensitive areas 74) can clearly be seen.

Figure 8 shows the user input area 72 of Figure 7 and the activations of the touch-sensitive areas 74 required to enter alphabetic characters. These may be activated by the user drawing the shape of the alphabetic character or simply by activating the touch-sensitive areas 74 in turn, whether this is in a predetermined order or in any order chosen by the user. In the case of Figure 8, the touch-sensitive areas 74 of the user input area 72 which are activated to enter particular characters are shaded. Figure 9 shows the user input area 72 of Figure 7 and the activations of touch-sensitive areas 74 required to enter the alphabetic characters of Figure 8 in upper case.

Since only the numeric keys "1" to "9" are needed to enter characters, the remaining three keys, "0", "*", and "#" are available to be used for additional functions like imposing capitalisation and providing control.

Referring to Figures 4, 5, 8, and 9, accessing input of upper case alphabetic characters may be achieved by activating a shift command before character input is begun. This could, for example, be activated by a separate key (not shown) .

As will be understood from the descriptions of Figures 7, 8, and 9, even though the user input area 70 comprises a keypad- type arrangement, it allows a "natural handwriting style" in which a user traces over the keypad a path which has a strong resemblance to the actual physical form of the character being entered.

Figures 10, 11, and 12 show another embodiment of the invention in which a user input area comprises an ITU-T type key- pad. The user input area, in combination with its mobile terminal, is configured to detect sequences of key activations for the input of special characters and particular operations. In this embodiment, when the mobile terminal device is in a relevant input mode, for example as a result of a menu choice during text composition mode, the special character or particular operation will be entered by the mobile terminal recognising sequences of key activations.

Referring to Figure 10, the special character "&" is entered if the mobile terminal recognises the activation of the "1" key followed by activation of the "2" key, the special character "]" is entered if the mobile terminal recognises the activation of the "3" key followed by activation of the "6" key, and the special character "!" is entered if the mobile terminal recognises the activation of the "2" key followed by activation of the "4" key. Reverse key activations cause the entry of other special characters: the special character "%" is entered if the mobile terminal recognises the activation of the "2" key followed by activation of the "1" key, the special character "}" is entered if the mobile terminal recognises the activation of the "6" key followed by activation of the "3" key, and the special character "+" is entered if the mobile terminal recognises the activation of the "4" key followed by activation of the "2" key.

Accordingly, it will be understood that special characters are entered as a result of activating keys which are adjacent to one another in a horizontal, vertical, or diagonal sense.

Referring to Figure 11, the operation "control" is performed if the mobile terminal recognises the activation of the "1" key followed by activation of the "4" key, the operation "page down" is entered if the mobile terminal recognises the activation of the "9" key followed by activation of the "3" key, and the operation "Backspace" is entered if the mobile terminal recognises the activation of the "4" key followed by activation of the "6" key. Reverse key activations cause the entry of other operations; the operation "End" is performed if the mobile terminal recognises the activation of the "4" key followed by activation of the "1" key, the operation "page up" is entered if the mobile terminal recognises the activation of the "3" key followed by activation of the "9" key, and the operation "Delete" is entered if the mobile terminal recognises the activation of the "6" key followed by activation of the "4" key.

The operations of Figure 11 are editing commands and can be used to control a cursor movement on the display of a mobile terminal device, and perform other operations as can be seen from the Figure.

Figure 12 shows the principles of Figures 10 and 11 applied to a joystick function. In this case, when the mobile terminal device is in a relevant input mode for example in a game being played, desired directional movements are achieved by the mobile terminal device detecting sequences of key activations .

Figures 10, 11, and 12 have been described in which entry of characters, operations, and directional commands are possible in a single mobile terminal device which has different modes to receive such entries and a user is able to operate the mobile terminal device to switch between modes. It is envisaged that a mobile terminal device may have the functionality of individuals ones of the Figures or of pairs of the Figures, such as Figures 10 and 11, Figures 10 and 12, or Figures 11 and 12. As will be understood from the preceding embodiments, according to the invention, entry of a character or performing an operation is achievable by activating a sequence of keys or touch-sensitive areas and a small number of such keys or touch-sensitive areas can represent many sequences, and thus many character and operations.

As will be seen from preceding embodiments of the invention, an advantage of the invention is that since sequences of activations to enter characters occur during a path being described which resembles the graphical form of the characters, they are easy to perform and remember. They can also be entered without the need for a user to be closely watching the user input area to make sure that the right key is being activated. However, unlike implementations of character input based on touch sensitive areas and handwriting recognition, in implementing the invention only a relatively small number of distinct active areas need to be provided. This is advan- tageous in terms of the amount of dedicated active touch- sensitive hardware which is required in mobile terminal devices and also the amount of electrical power needed to provide power for their operation.

The invention can be enhanced with other features. Haptic feedback may be provided in two forms, static and dynamic. In the case of static feedback, referring for example to Figure 2, the mask 22 is arranged to project outwardly from the mobile terminal slightly further than the touch-sensitive areas 26. This means that a user is able to get a sense of traversing the keypad area 16 with the finger 28 in terms of feeling a variation of its profile. In the case of dynamic feedback, the mobile terminal device may be provided with a vibration generating element to cause a user detectable vibration effect at the start and at the end of finger contact used to describe a path. In addition, it may activate when the user touches the user input area.

It should be understood that although various embodiments of the invention have been described with reference to a user drawing or writing a character in terms of a finger or stylus movement, it is recognised by the inventor that the different characters can be detected by receiving input from different combinations of touch-sensitive areas and so that in variants of the invention simply activating the appropriate touch- sensitive areas can enter a character. This may be pressing keys or areas in a sequence which puts the user in mind of the graphical form of the letter, pressing keys or areas in a sequence which does not resemble such a form, or pressing a number of keys or areas simultaneously.

Although the Figures have been described with reference to a mobile terminal device, the device does not necessarily have to be a mobile device or indeed a terminal device but may simply be a suitable user device capable of accepting entry of characters or activations of operations.

The invention reduces and simplifies the data to be analysed in character-recognition. Each character is represented by a sequence of activations which, as can be understood from the character systems shown in the Figures and the layout of the keypads, can be quite short. Furthermore, since adjacent keys are actuated consecutively to describe a character, the number of possible combinations is limited.

The character systems shown in the Figures are based on a limited set of strokes (sub-movements to describe a character) combined in a number of different ways to represent each of the characters constituting the system. Therefore, the number of possible strokes is substantially smaller than the number of resulting characters. In some embodiments, the in- vention provides a template, the keypad, for inputting the strokes. The number of required control points, in practice keys, to recognise a stroke is, also, substantially smaller than the number of characters enabled. Accordingly, the area available for the keypad can be populated with fewer, bigger keys, improving the usability of the individual keys.

Since the user uses a text input system similar to handwriting with pen and paper, there is no need for visual assistance to be provided from a keypad, for example characters printed onto keypad keys. The user may even choose the character system quite freely with the terminal device interpreting the input according to the user's language settings. Such character systems include, in addition to Latin characters, Cyrillic, Hebrew, Arabic and Japanese Kanj i and Kana charac- ters . This feature can be further enhanced by allowing users to define their own characters, in the form of a personal shorthand, to represent words and phrases of multiple words.

In some cases, as the path is being described by the user on the user input area it becomes distinguishable from all other potential characters at a point before a complete path for the character has been described. In one embodiment of the invention, this can be interpreted as a shorthand form and the character is entered into the mobile terminal device before the path becomes complete. In this case, the user, see- ing entry of the character into the display of the terminal device can stop continuing to perform its entry. It is also possible for there to be several different paths, at least different in the sense of the sequence of activations required, for the same character, as long as sequences are unique. A further shorthand form can be achieved by imposing a rule that if a path is not yet unique and the path is discontinued then the first match, or the most likely match, in a lookup table is selected. This can encourage users to adopt paths which during their describing soon become unique in or- der to find particularly fast shorthand forms.

While preferred embodiments of the invention have been shown and described, it will be understood that such embodiments are described by way of example only. Numerous variations, changes and substitutions will occur to those skilled in the art without departing from the scope of the present invention. Accordingly, it is intended that the following claims cover all such variations or equivalents as fall within the spirit and the scope of the invention.

Claims

1. A device capable of recognising the entry of a character comprising: a user input area; detectors associated with the user input area capable of detecting input in the form of a sequence of activations of a plurality of active regions, the active regions being associ- ated with respective key areas for entering numeric characters; and a processor capable of analysing the sequence of activations and comparing them with a predefined sequence of activations corresponding to a path which is representative of the char- acter described on the user input area in order to determine the character to which the input corresponds.

2. A device according to claim 1 in which the predefined sequence of activations is stored in a lookup table.

3. A device according to claim 2 in which the lookup table has a unique sequence of activations assigned to respective ones of a plurality of characters and a processor maps an input sequence to a predefined sequence in order to determine the character.

4. A device according to any preceding claim comprising non-active regions between active regions.

5. A device according to claim 4 in which the non-active regions comprise a mask provided with apertures through which the active regions are accessible.

6. A device according to claim 4 or claim 5 in which the user input area is configured so that an input element traverses parts of one of the non-active regions such that it is sufficiently physically separated from active regions and is not able to provide any input to them.

7. A device according to claim 6 in which the relative areas of the non-active region and the input element adapted to be in contact with it are such so that when the input element is in contact with the non-active region, the entire area of the input element is entirely contained within the non-active region and not overlapping with adjacent active regions.

8. A device according to any preceding claim in which each active region is specifically allocated to an input area which is activatable in order to enter a specific numeric character .

9. A device according to any preceding claim which is capable of detecting the entry of alphanumeric characters.

10. A device according to any preceding claim which is capable of detecting the entry of a symbol.

11. A device according to any preceding claim which is capa- ble of detecting the entry of a command to carry out an editing operation.

12. A device according to any preceding claim in which the user input area is a keypad.

13. A device according to any preceding claim which is a mobile terminal device.

14. A device according to any preceding claim in which characters are entered on the user input area by a user moving an input element over the user input area to describe a graphical representation of the character.

15. A device according to any preceding claim in which the predefined sequence of activations represents a complete word or a phrase.

16. A method of recognising the entry of a character into a device comprising: detecting input in the form of a sequence of activations of a plurality of active regions in a user input area of the device, the active regions being associated with respective key areas for entering numeric characters; analysing the sequence of activations and comparing them with a predefined sequence of activations corresponding to a path which is representative of the character described on the user input area in order to determine the character to which the input corresponds.

17. A computer program product comprising software code that when executed on a computing system performs a method of recognising the entry of a character into a device comprising: detecting input in the form of a sequence of activations of a plurality of active regions in a user input area of the device, the active regions being associated with respective key areas for entering numeric characters; analysing the sequence of activations and comparing them with a predefined sequence of activations corresponding to a path which is representative of the character described on the user input area in order to determine the character to which the input corresponds.

18. A computer program product according to claim 17 which has executable code portions which are capable of carrying out the steps of the method.

19. A computer program product according to claim 17 or claim 18 which is stored on a computer-readable medium.