NO315888B1 - Device and user interface for generating character based text using fingerprint sensor with navigation capability - Google Patents

Description

This invention relates to a character/character generator in the form of a fingerprint sensor with control means, for the input of text/characters in communication and information devices with displays, such as mobile phones, hand-held PCs, PDAs etc.

The compact size of such devices has reduced the dimensions of their keyboards. Such devices are therefore normally equipped with a keyboard as illustrated in Fig. 1 where the number of keys is many fewer than the standard letters that a user needs for the input of meaningful text. The solution for current mobile phones is to let each number key represent 3 or 4 consecutive letters as in Fig. 1. For example, the key that usually gives the number 6 in alphanumeric mode will define one of the letters m, n, or o, depending on the number of times the key is pressed . Thus the word "heilo" can be written by pressing key 4 twice, key 3 twice, key 5 three times, key 5 three times and key 6 three times, thus pressing the keys a total of 13 times. The user needs to remember the positions of these alphanumeric keys, or look up their positions and move the finger position from key to key, as in the example above. This makes inputting text with reduced keyboards a cumbersome and time-consuming task.

There is a strong development trend for such hand-held devices to make them ever smaller, lighter and even cheaper. Even more, their functionality increases continuously as they offer more information and data to the user, and can therefore advantageously have larger displays.

However, such larger displays should not increase the overall dimensions of the already compact information/communication units. Now the two largest elements of the front panel of such information/communication units are the display and the reduced keyboard as in Fig. 1, where usually the reduced keyboard still occupies more space than the display. The only effective way to increase the display size without increasing the overall dimensions of the device is to reduce the keyboard to a minimum size, as indicated in Fig. 2 without losing versatility and user-friendliness in the process of inputting text.

There are several known solutions for performing the process of text input based on current keyboard types, as in Fig. 1. One manufacturer, Ericsson, provides an external QWERTY keyboard as a plug-in device for its mobile phones. However, this solution has the disadvantage of extra size, weight and costs, which is in contrast to user demands for increasingly smaller, lighter, cheaper and more usable mobile phones.

Another known solution is the Nokia Naviroller™ where a mechanical drum in the front panel is rolled around with the finger, thereby producing a vertical column of characters and characters on the display unit. Selection of a special character or character is performed by mechanically depressing the drum. In practice, this is not a faster process than moving your finger from key to key and pressing the selected key one or more times. The Naviroller™ solution also severely limits cursor key movements as it limits cursor movement to one dimension; <up> and <down>, except for pressing the drum when selecting characters.

Tegic Communications has developed a system called T9™ where software logic checks for allowed

combinations of letters in a particular language, thereby minimizing the multiple presses of a key representing multiple characters, as shown in Figure 1. This is an elegant solution as the number of finger presses is expected to be significantly reduced, but the negative aspect is that it requires a translator program for each language, and that these must be stored in the phone's memory. Motorola is said to have developed a similar solution, called iTap™, and thus has the same problems.

Generating text/character input on such reduced keyboards is therefore a slow and cumbersome process, even for alphabetic languages such as the Latin language. However, a large part of the world's population uses character-based languages, such as Chinese, Japanese, Korean, etc. Character-based languages can include hundreds of thousands of characters, thereby greatly exacerbating the problem of inputting text with keyboards.

A known solution for the input of text from ZiCorp, aimed at simplifying the input of characters as shown in Fig. 1. It is based on the fact that Chinese characters are made up of so-called basic strokes, where the sequence defines a certain character . These baselines are assigned to the keys, much in the same way that the letters of the alphabet are assigned to the keys, as shown in Figure 1. This solution enables the input of Chinese characters with a reduced keyboard, as in Figure 1, but does not solve the main problems. A keyboard of considerable size is still required, but due to size limitations it usually contains many fewer keys than the characters needed to form meaningful messages. The finger must therefore be moved around on the keyboard, and each key may have to be mechanically pressed several times to select a message.

The above illustrates the current situation at e.g. mobile phones, where complex input of text is cumbersome as such input must be carried out through the reduced keyboard in Figure 1. The next generation of mobile phones includes so-called WAP phones with Internet access. In general, this development necessitates the need for larger display units, better readability of the much more comprehensive information. Preferably, a larger display unit should not increase the size of the mobile phone. The most appropriate way to increase the size of the display unit without increasing the size of the mobile phone would be to reduce the keyboard size, preferably to a single key, but which still enables the input of complex text to the mobile phone. None of the above solutions will work satisfactorily with such a one-key "keyboard".

It is thus an object of the present invention to provide a system for generating characters for said information and communication units. Such systems should enable the input of complex text in a fast and easy way without the need to download extensive program code into the device's memory, even for devices where the keyboard is replaced by a single key for entering characters/characters. The purpose is achieved by a character generator based on the combination of a sensor for fingerprints which has control means, with analysis/interpretation means and translation means as described in claim 1.

The purpose of the invention is also achieved with a method for using the character generator, where finger movements over the sensor are measured in two dimensions using two orthogonal sensors, where analysis tools are used for categorizing the finger movements over the sensor in relation to predefined sets of finger movement sequences including sequences containing direction and touch /non-touching of the sensor, and where the translation means comprising uniquely defined command tables are used for translating the categorized finger movements into signals for controlling the screen as a result of finger movements over the sensor.

The object of the invention is also achieved by a character generator system for information/communication devices where a combination of a touch-sensitive fingerprint sensor having at least two orthogonal sensors, navigation means coupled to analyzer means containing sequential categories for finger commands and coupled to translation means including a finger command structure, to provide versatility in finger movement-based input of character-based languages by movement-based selection from screen-displayed fields or by drawing the movements or components directly on the sensor.

Further preferred embodiments of the invention appear from the independent patent claims.

The invention will now be described below by means of examples and with reference to the accompanying drawings.

Figure 1 illustrates a traditional keyboard for e.g.

mobile phones, with multi-character keys.

Figure 2 exemplifies the front panel of a new generation of information and communication devices with a large display, brought about by a minimized keyboard.

Figure 3 illustrates the invention schematically.

Figure 4 illustrates categories of finger movements in two

dimensions.

Figure 5 illustrates the input of text for alphabetic languages,

by means of the invention.

Figure 6 illustrates how mathematical operations can be handled on a handheld PC using the invention. Figure 7 schematically illustrates the hierarchy of lines,

components and Chinese characters as in ZiCorps familiar

solution, and how their Zi 8™ reduced strokes can be represented on a reduced keyboard.

Figure 8 tabulates the stroke/character hierarchy in Chinese

sign.

Figure 9 illustrates in tabular form typical finger commands for the analysis/interpreter program, for text input in Morse mode and Display mode on the mobile phone. Figure 10 illustrates typical cooperation of the finger with the mobile phone.

in

The principle of the invention is illustrated schematically in

Fig. 3. A touch-sensitive switch 1, in the form of a fingerprint sensor with control means, is connected to the analysis means 2. The analysis means measure the duration, direction and speed

to the finger movements on the switch, and categorizes the signal from the switch into categories. The classified categories of data are stored in a memory 3 and compared by translation means 4 with predefined tables relating categories of finger movements and sequences thereof to readable characters/signs. The characters corresponding to these categories and sequences are then displayed in the display 5 in a known manner. The form in which this data is presented on the screen and how the input of text is carried out by the user is controlled by the translation means 4.

In its simplest form, the switch 1 can be a single on/off touch-sensitive switch. In this case, the system will record the duration of the finger touches, as well as the interruption periods to distinguish between periods

signals, periods between complete characters/characters and periods between words.

The activation categories can be selected by measuring the activation time tm and the deactivation time tm0ff and comparing them with predefined limits according to defined sets of finger commands. The system includes lower and upper limits for being registered as a signal. Signals shorter than the lower limit defined as tEeg can be ignored to avoid errors caused by accidental touches of switch 1, e.g. due to handling of the information/communication unit. Activation times longer than the predefined limits may also be ignored, or may be classified as a separate code, such as "End Message". In addition, long deactivations may be recorded as periods between characters. Table 1 defines typical time limits.

The time limits in Table 1 above can of course be chosen differently. A particular embodiment of the invention is to set the above areas dynamically to adapt to the user's skills and his learning curve in using the invention. This can be done by registering the e.g. 50 last commands of each type, and calculate the mean and standard deviation. These statistics can be based on any written text or a predefined learning sequence, and can be used to change the category definitions according to the user's speed, and thus also adapt as the user learns the system and increases his input speed.

Although the touch-sensitive switch 1 in its simplest form can be a simple on and off touch-sensitive switch, this will however be insufficient in relation to the purpose of the invention. To produce combined user authentication by fingerprint biometrics, accurate cursor control and fast, versatile and flexible text input, all served by the same single-key sensor, a sensor that can register lateral finger movements is required. The preferred embodiment of the invention must therefore provide a sensor for fingerprints with control means also including the ability to register lateral finger movements on the switch. The patent publication EP 735,502 describes a linear fingerprint sensor. This fingerprint sensor scans the fingerprint, and to be able to analyze the fingerprint, is able to detect finger movements across the sensor in one dimension; <Up> and <Down>. Such one-dimensional detection of finger movement can be extended to two-dimensional finger registration by arranging some of the sensor elements as in Fig. 4. This can be achieved, for example, by using two orthogonal sensors of the type shown in the above-mentioned EP publication. The figure illustrates categories of lateral finger movements that are used to build finger commands, either by basic finger movements, or a combination of these. Fig. 4 defines ten lateral finger movement categories (in addition to vertical depressions); eight directions of movement and two circular movements (clockwise and counter-clockwise). These can also be combined with time measurements to calculate the speed of the movement, thus producing a number of different categories from a single finger movement. All the finger movements (sensor on/off, vertical presses, lateral linear and circular movements), their duration and speed are categorized in the analysis/interpretation means 2.

Such a touch-sensitive switch comprising a fingerprint sensor with control means enables the invention to use a comprehensive and intuitive set of finger commands in the interpreting/translation means 4. Combined finger commands can be made from sequences of basic finger movements.

As the touch sensitive switch serves multiple purposes in a combined function, as in the object of the above invention, a finger command structure applicable to all the functions to be operated is necessary, including the versatility of the input modes. Furthermore, the finger command structure must be intuitive within each mode, to avoid the necessity of memorizing complex finger commands. Such a finger command structure is exemplified in Table 2 below. This finger command structure is a key element of the invention, and represents a basis for the translation means.

The analyzers can be set to alternative modes using finger commands, where the default mode is Display Mode, another can be Character-based input of language (e.g. Chinese characters), etc.

This embodiment of the invention, comprising a single key input device for multiple input modes, uses "universally defined" finger command structures built into the translation means, ensures that the character generator provides the necessary input types in the respective input modes of the information/communication devices. The input modes are arranged in a hierarchy. Level 1 is shown in Table 3a. This is the overall mode level, where the input mode option is set by the information/communication unit. There is a fourth mode in addition to the three modes shown in Table 3a, namely Sleep Mode for minimum power consumption when the sensor does not need to be active.

An important advantage of the invention is that it allows significantly reduced display size {e.g. for WAP applications) as in Fig. 2, as the larger keyboard in Fig. 1 is replaced by a simple character generator key supplemented with e.g. two function keys.

However, the most important advantage of the invention is that it provides full versatility and flexibility for input using a single key unit with multiple functions. This is achieved by supporting a sensor with control means (due to its ability to register lateral finger movements as in Fig. 4) with finger movement categories defined in Table 1 combined with the finger command structure in Table 2 and the input modes and categories as in Tables 3a and 3b.

This versatility and flexibility of input with such a single key will be described by two examples.

The first example includes text input with Latin letters for e.g. a mobile phone with a large display and a minimum keyboard, as shown in Fig. 2. The mobile phone will switch the single key character generator system to text input mode (Level 1 in Table 3a) in response to user selection of e.g. SMS (Short Message System). Thus, the translation means 4 arrange the display 5 typically as shown in Fig. 5a comprising a vertical selection field 8 and a horizontal command field 9. The user can conveniently switch between the vertical and horizontal fields by finger commands

<Slant Down Left> and <Slant Up Right> 10, as with the built-in finger command structure in the translation means 4. In this example, the user uses Latin letters and Arabic numbers for text input. This is the standard text input mode, but he can directly start generating text by finger commands to the vertical selection field 8. Fig. 5b illustrates a number of alternative character sets for the selection field in this mode. When he starts producing text, the default set is uppercase Latin letters, displaying the letter A in the marked center position of the vertical selection field. Let's say the user first wants to enter an E as the first character. He then moves his finger down and rests it on switch 1. This starts scrolling of the vertical selection field. When the letter E is brought to the marked middle position, the user executes

<Double Press> on the switch, selects the desired letter E and shows it in the display 5. This selection automatically changes the character set in the vertical selection field to lowercase letters. The user then swipes their finger up or down on the sensor, according to the position in the alphabet of the next desired character. If he wants to move a single character, or just a few characters, he moves his finger one or more times up or down. If the next character is a greater number of positions away, he moves his finger in the desired direction and then holds his finger still on the switch to start scrolling in the desired direction. The scrolling stops when he lifts his finger from switch 1. If the user needs other character sets, he simply gives the finger command 14 <Finger Left> or <Finger Right>, e.g. to insert numbers, special characters or to use capital letters again (eg for a name). Word separation can be performed with the finger command <Long Press> and periods can be entered as two consecutive <Long Press>, etc. The user can at any time switch (eng.: toggle) to Edit Text Mode with the finger command sequence <Extra Long Press> - <Finger Down> as in Table 2. End of Message can be entered by the finger command sequence comprising two consecutive

<Extra Long Press>.

Before this text input (when the mobile phone is switched ON), the mobile phone automatically sets switch 1 to authentication mode for access control to the mobile phone. The user is then asked by text on the display to swipe their finger down over the sensor. When authentication by fingerprint biometrics is finished, the mobile phone puts the character generator into sleep mode, to save energy. The character generator is then awakened, e.g. up when a request for the character generator is requested, e.g. by SMS input as above. If the user wants to play a game on the mobile phone, its control system sets switch 1 to Marker Control Mode as in Table 3a. Two-dimensional finger movements combined with combined finger command sequences (such as taps, etc.) thereby provide a precise cursor control combined with multiple command functions for quite complex games. This example demonstrates that the invention is capable of rendering full input versatility and flexibility even through a single key character generator, thereby enabling the use of a large display as exemplified in Fig. 2 while still maintaining full functionality.

Another example of the applicability of the invention is illustrated in Fig. 6. This example relates to mathematical calculations on a hand-held PC, but can just as well be built into mobile phones or PDAs. For such calculations, the applicable finger command structure set will be limited to presses on several selection fields as in Table 1, while lateral finger movements are reserved for cursor control. Fig. 6a illustrates a hand-held PC set in Calculation mode (arithmetic), where the display 5 contains another type of vertical selection field 16 and another horizontal selection field 17. The vertical selection field 16 contains all numbers from 0 to 9, and commas (,) which illustrated in Fig 6b. In this mode, the horizontal selection field 17 includes the arithmetic operators (+, -, <*>, /) as well as Clear All (CA11), Clear Memory (MClear), add to memory (M+) , subtract from memory (M-), square root (v) and nth power (n), etc as illustrated in Fig. 6c. In this mode, the lateral finger commands are mainly reserved for cursor control. This means that when the finger is moved laterally over the sensor 1, the cursor moves accordingly on the display 5. An arithmetic formula such as "972 <*> 3 = ?" is formed on the display by moving the cursor to the number "9" in the vertical selection field 16 and <Double Press> to select, then move the cursor to "7" and select, then move the cursor to "2" and select. The cursor is then moved by lateral finger commands to the "<*>" character in the horizontal field and selected by <Double Tap>, then back to the vertical selection field 16 above the number "3" and selected by <Double Tap>. The user then presses <Extra Long Press> which produces "=" on the display, starts the calculation and presents the result "2.916" on the display. Other subsets of characters in the vertical selection field 16 may be included. Control by fingerprint within the selection field can be initiated by the finger command <Short Press> when the cursor is positioned within the vertical selection field to temporarily disconnect the cursor control by finger commands. The user can then change the character set from the vertical selection field 16 by <Finger Left> or <Finger Right> commands (as in Fig. 5b). When the new character set has been activated, the cursor control by lateral finger commands on switch 1 can be switched on by pressing <Short Press> again. Similarly, the horizontal selection field can be changed to other subsets of mathematical operators. This is done by placing the cursor in the horizontal selection field, pressing <Short Press> to disengage the cursor control, using the finger commands <Finger Up> or <Finger Down> to select another subset, and finally to engage the cursor control by pressing <Short Press >. This embodiment of the invention enables a versatile and flexible calculation mode on the display, still operated with a switch 1 in the form of a single key.

While the Latin alphabet contains around 30 standard letters, sign language is composed of hundreds of thousands of characters, even if some of them are rarely used. The large number of such characters compared to the number of standard alphabetic characters represents a serious problem in representing such characters by a multiple of characters per key in a reduced keyboard, in the same way as for alphabetic characters as illustrated in Fig. 1, Key- representation of e.g. Chinese characters are normally resolved by representing so-called base lines on the keys. Chinese characters can then be composed of strictly defined sequences of basic strokes. ZiCorp has taken this a step further by introducing eight reduced lines called Zi 8™ representing the 29 base lines. The hierarchy of reduced Zi 8™ strokes, base strokes, components and Chinese characters is illustrated in Fig. 7a, while Fig. 7b shows how the eight Zi 8™ reduced strokes can be assigned to a reduced keyboard. Fig. 8 shows the relationship between the Zi 8™ reduced strokes, 29 basic strokes and some full Chinese characters. This makes it possible to enter Chinese characters as input with a reduced keyboard. However, this is an even more cumbersome process than writing alphabetic characters, as the Chinese characters are generated through the hierarchy illustrated in Fig. 7a.

The invention, based on a sensor capable of recording lateral finger movements combined with categories of finger movements and their sequences (embedded in the translation/analysis means) and the finger command structure (embedded in the translation means) enables a very efficient method of signs in sign-based languages . This can be achieved in two ways which will be explained below with reference to the figures. The first input method for characters is the selection of characters from selection fields in the display. This is illustrated in Fig. 9. The display is shown with a Chinese text row generated on the display. It has been generated by selecting characters in a hierarchical manner from a vertical selection field 18, supported by an additional horizontal field 19. The vertical selection field 18 comprises several subsets of characters; One set is the Zi 8™ reduced strokes 20, another subset is the 29 basic strokes 21 and a third subset is complete Chinese characters 22. A fourth subset of characters comprises the stroke components 23. Switching between these subsets of characters is done with the finger command

<Finger Left> and <Finger Right>, in the same way as explained in Fig. 5b. These subsets of characters provide the same hierarchy of strokes, components and characters as illustrated in Fig. 7a. The reason for this is that it

the full subset of characters 22 would contain hundreds of thousands of characters, and selecting characters from such a large subset would be totally inefficient. With the illustrated method in Fig. 9, the user can first select a base line from the Zi 8™ subset of reduced lines 20. This then limits the content of the subset of base lines to the relevant ones (as in Fig. 8). Selection of the desired baseline is made from the subset 21. This selection in turn limits the subset of complete characters to those appropriate, so that selection of the final character is appropriate, as it has been limited to only possible characters to a maximum extent. As an intermediate step, line components can be selected from the subset of characters 23. The user can by the finger commands <Left Finger> or <Right Finger> start directly on the subset 21 comprising the basic lines, to eliminate a level of the hierarchy shown in Fig. 7a. Navigation in the vertical selection field 18 and character selection within this field is performed by finger commands exactly as explained in Fig. 5. This is performed by the finger commands <Finger Up> or <Finger Down> followed by <Double Press> when the appropriate character is in the marked position. Scrolling is also carried out in the same way as in Fig; 5 by moving your finger up or down, and then keeping it still on the sensor. The horizontal additional field 19 is used for temporary display when building up complete characters using strokes, and for displaying alternative character candidates as more strokes are entered. This enables rapid selection of the final character even before the full number of baselines or components has been selected from the vertical selection field 18.

This embodiment of the invention is further explained with reference to Fig. 10, which illustrates the introduction of the example text line "Don't forget to transfer at Mong Kok" in Chinese characters. This example is taken from ZiCorp's illustration of its Zi 8™ method. First, SMS mode is activated by the finger command <Circular Finger Movement> 25 on the switch 1. This brings up the input text (e.g. "Message") on the display 5. The intermediate steps are further illustrated in Fig. 11, but Fig. 10 shows that final step where two consecutive <Extra Long Press> have given the command "Message End". This initiates the "Send Message" mode, as illustrated in Fig. 10b. This produces a special horizontal selection field 27 containing the numbers 0 to 9 plus the international remote dialing code prefix "+" (not shown in 27). The user generates numbers for the telephone number with the finger commands <Left Finger> or <Right Finger> 26 in the selection field 27, and <Double Press> on the desired number. This sequence is repeated until the entire number has been generated in the horizontal display field 28. Editing of this number can be performed by finger commands for editing exemplified in Table 2. When the entire number has been generated, the user accepts and thus starts the transmission of the SMS message by pressing function key 7, indicated by "Send" in the display 5. The intermediate steps in generating the text row itself are illustrated in Fig. 11. Fig. 11a illustrates how the text generation mode for Chinese characters brings up the vertical selection field 20 (the subset of Zi 8™ characters) and the horizontal additional field 19 brought up on the display 5. The user selects the appropriate Zi 8™ reduced character by

<Finger Up> or <Finger Down> until the desired reduced character "over" (in Table 8) is highlighted and <Double Press> then. Thus, the reduced line "above" appears in the display 5. In Fig. 11b, the user continues to select the reduced line "left slope" (as in Fig. 8) by finger movement and

<Double Tap>. This brings up the reduced line "left slope" on the display 5. In Fig. 1c, the user has selected the reduced line "down" by similar finger commands. This last choice of reduced stroke has also limited the candidate characters to a small number, and these candidates are displayed in the horizontal additional field 19. The user can now switch from the vertical selection field 20 to the horizontal additional field 19 with the finger command

<Slant down left> and then by finger command place the cursor over the desired character (actually the first character in the horizontal field 19) and then <Double Press> for selection. This selection replaces the three reduced lines from the display with the selected character, as in Fig. Ild. As this action clears the additional horizontal field 19,

the cursor is automatically brought back to the vertical selection field 20, so that the user does not have to give the finger command <Tilt Up Right>. Fig. 11 shows the selection of a component which is brought up in the display 5 by accepting <Double Press> in the horizontal field 19 in Fig. 11f. A similar procedure is repeated until the complete message is generated, as in Fig. llg. Editing of the message can be carried out with finger commands as listed in Table 2. With two consecutive finger commands <Extra Long Press>, the user signals that the message is finished, which automatically generates a display organization as in Fig. 10b. As mentioned above, by finger command <Finger Left> or <Finger Right>, the user can switch from the Zi 8™ character subset of reduced strokes 20 to the subset of basic strokes 21. This allows more scrolling in the vertical selection field 21, but simplifies the procedure as a level in the hierarchy in Fig. 7a is eliminated.

However, the preferred embodiment of the invention is to draw the base lines (or reduced lines) directly on the switch 1, with the possibility of recording lateral finger movements as in Fig. 4. This only requires a dedicated category of finger movements, and their sequences, built-in for a special mode which is direct input of lines on switch 1. The two modes "Draw lines directly on the sensor" and "Generate lines from the selection field" can be operated interactively. The finger movements for drawing the lines directly on the sensor associated with reduced lines and basic lines respectively, are shown in Table 4.

The preferred embodiment of the invention as described above provides the following main advantages compared to other known solutions;

The touch-sensitive switch 1 with control means provides a single-key input device with multiple functions, as it combines fingerprint scanning for user authentication, for access control, with touchpad functionality for controlling a cursor on the display, and with versatile and flexible input capability due to the embedded finger command structure as shown in Table 2.

The touch-sensitive switch 1 with control means and built-in finger command structure enables the input of characters for character-based languages (such as Chinese) either by selecting lines or components from selection fields in the display, or by drawing the lines directly on the sensor. The latter provides a very direct and highly efficient method of inputting text for character-based languages.

The built-in finger command structure enables highly flexible input means, as the user can freely switch between several input modes such as input by Morse code, selection of characters and characters from selection fields on the display, or direct drawing of lines or components on the sensor. This can be achieved by Finger Commands without needing changes to the setup between the different input modes.

Claims (16)

1. Character generator for information/communication devices, characterized in that it comprises a touch- and/or pressure-activated fingerprint sensor and a screen for displaying information, where the sensor is arranged to measure finger movements over the sensor in two dimensions by means of two orthogonal sensors, analyzer means coupled to the sensor for categorizing the two-dimensional movements measured by the sensor in relation to a selected set of categories, translation means including a predetermined table for the categories representing the two-dimensional movements relative to a set of characters indicating selected characters on the screen. 2. Character generator according to claim 1, comprising a timer for measuring the duration of the movements and the time between them, where the categories contain information about duration. 3. Character generator according to claim 2, where the category set comprises the Morse code. 4. Character generator according to claim 1, where the category set comprises linear movements in at least eight directions and two circular movements, clockwise and counter-clockwise. 5. Character generator according to claim 1, where the categories are arranged in a hierarchy so that the first finger movement selects a first set of characters, and the second finger movement selects a character or a subset of characters from the first category. 6. Character generator according to claim 5, wherein the hierarchy has at least three levels. 7. Character generator according to claim 5, wherein the categories define a Chinese character set. 8. Character generator according to claim 1, where at least two of the categorized movements are related to a control signal for the screen, where the screen indicates a list of characters and said control signals indicate scrolling of the list and selection from it. 9. Method for using a character generator according to one of the preceding claims, where finger movements over the sensor are measured in two dimensions using two orthogonal sensors, use of analysis means for categorizing the finger movements over the sensor in relation to predefined sets of finger movement sequences including sequences containing direction and touch/non-touch of the sensor, and using the translation means comprising uniquely defined command tables for translating the categorized finger movements into signals for controlling the display as a result of finger movements over the sensor. 10. Method according to claim 9, where the categories are arranged in a hierarchy, in that a first categorized finger movement selects a first character set, and the second categorized finger movement selects a character or a subgroup of characters from this first character set. 11. Method according to claim 10, where the hierarchy comprises at least three levels. 12. Method according to claim 9, wherein the categories comprise a Chinese character set. 13. Method according to claim 9, where the finger movements control cursor movements in the screen within selected tables of characters, letters or commands. 14. Method according to claim 13, where at least one categorized finger movement controls selection of a desired character, a command or a letter the cursor has been moved to within the selected table. 15. Method according to claim 9, where at least two of the categorized movements are related to a control signal for the screen, where the screen indicates a list of characters and where the control signals indicate scrolling and selection of characters in the list. 16. Character generator system for information/communication devices, characterized in that it comprises a combination of a touch-sensitive fingerprint sensor having at least two orthogonal sensors, navigation means coupled to analyzer means containing sequential categories of finger commands and coupled to translation means including a finger command structure, to provide versatility in finger gesture-based input of character-based languages by gesture-based selection from on-screen displays field or by drawing the movements or components directly on the sensor.